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Sample records for film inhibits collagen

  1. Properties of Chitosan-Laminated Collagen Film

    Directory of Open Access Journals (Sweden)

    Vera Lazić

    2012-01-01

    Full Text Available The objective of this study is to determine physical, mechanical and barrier properties of chitosan-laminated collagen film. Commercial collagen film, which is used for making collagen casings for dry fermented sausage production, was laminated with chitosan film layer in order to improve the collagen film barrier properties. Different volumes of oregano essential oil per 100 mL of filmogenic solution were added to chitosan film layer: 0, 0.2, 0.4, 0.6 and 0.8 mL to optimize water vapour barrier properties. Chitosan layer with 0.6 or 0.8 % of oregano essential oil lowered the water vapour transmission rate to (1.85±0.10·10–6 and (1.78±0.03·10–6 g/(m2·s·Pa respectively, compared to collagen film ((2.51±0.05·10–6 g/(m2·s·Pa. However, chitosan-laminated collagen film did not show improved mechanical properties compared to the collagen one. Tensile strength decreased from (54.0±3.8 MPa of the uncoated collagen film to (36.3±4.0 MPa when the film was laminated with 0.8 % oregano essential oil chitosan layer. Elongation at break values of laminated films did not differ from those of collagen film ((18.4±2.7 %. Oxygen barrier properties were considerably improved by lamination. Oxygen permeability of collagen film was (1806.8±628.0·10–14 cm3/(m·s·Pa and values of laminated films were below 35·10–14 cm3/(m·s·Pa. Regarding film appearance and colour, lamination with chitosan reduced lightness (L and yellowness (+b of collagen film, while film redness (+a increased. These changes were not visible to the naked eye.

  2. Preparation and characterization of collagen/hydroxypropyl methylcellulose (HPMC) blend film.

    Science.gov (United States)

    Ding, Cuicui; Zhang, Min; Li, Guoying

    2015-03-30

    This study aimed to prepare and characterize the collagen/HPMC blend film (1/1). Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal properties of the film. Both thermal decomposition temperature and denaturation temperature of the blend film were higher than those of the collagen film due to the intermolecular hydrogen bonding interaction between collagen and HPMC, which was demonstrated by Fourier transform infrared spectroscopy. Additionally, the morphologies, mechanical properties and hydrophilicity of films were examined. The blend film exhibited a more homogeneous and compact structure compared with that of the collagen film, as observed from scanning electron microscopy and atomic force microscopy. The tensile strength, ultimate elongation and hydrophilicity of the blend film were superior to those of the pure collagen film. Furthermore, the introduction of polyethylene glycol 1500 had almost no influence on the thermal properties of the blend film but obviously improved its stretch-ability and smoothness. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Collagen films with stabilized liquid crystalline phases and concerns on osteoblast behaviors

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    Tang, Minjian; Ding, Shan; Min, Xiang; Jiao, Yanpeng, E-mail: tjiaoyp@jnu.edu.cn; Li, Lihua; Li, Hong; Zhou, Changren, E-mail: tcrz9@jnu.edu.cn

    2016-01-01

    To duplicate collagen's in vivo liquid crystalline (LC) phase and investigate the relationship between the morphology of LC collagen and osteoblast behavior, a self-assembly method was introduced for preparing collagen films with a stabilized LC phase. The LC texture and topological structure of the films before and after stabilization were observed with polarizing optical microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The relationship between the collagen films and osteoblast behavior was studied with the 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide method, proliferation index detection, alkaline phosphatase measurements, osteocalcin assay, inverted microscopy, SEM observation, AFM observation, and cytoskeleton fluorescence staining. The results showed that the LC collagen film had continuously twisting orientations in the cholesteric phase with a typical series of arced patterns. The collagen fibers assembled in a well-organized orientation in the LC film. Compared to the non-LC film, the LC collagen film can promote cell proliferation, and increase ALP and osteocalcin expression, revealing a contact guide effect on osteoblasts. - Highlights: • Collagen film with liquid crystalline (LC) phase was observed by POM, SEM and AFM. • The effect of LC collagen film on osteoblasts behaviors was studied in detail. • LC collagen film promoted osteoblast proliferation and osteogenesis activity.

  4. A novel combined polyphenol-aldehyde crosslinking of collagen film-Applications in biomedical materials.

    Science.gov (United States)

    Liu, Ting; Shi, Lu; Gu, Zhipeng; Dan, Weihua; Dan, Nianhua

    2017-08-01

    Despite its crucial role in directing cell fate in healthy and diseased tissues, improvements in physical-chemical properties and biocompatibility of type-I collagen are still needed. In this report, we described combined and facile method to modify collagen. The collagen film was first modified by procyanidins solution, in which, then subjected to further crosslinked by dialdehyde alginate, resulting in collagen-procyanidins-dialdehyde alginate film. The properties of the crosslinked collagen films were investigated and the results were discussed. Results from differential scanning calorimetry and thermo gravimetric analysis suggested that the thermal stabilities of the collagen-procyanidins-dialdehyde alginate film were significantly improved. The mechanical properties of collagen-procyanidins-dialdehyde alginate film in terms of elongation at break and tensile strength increased approximately 2-fold and 3-fold, respectively compare to pure collagen film. In addition, the resistance to collagenase degradation of collagen-procyanidins-dialdehyde alginate film was remarkably promoted. The results from methyltetrazolium assay and confocal laser scanning microscopy showed that no cytotoxicity of collagen film was introduced by the combined crosslinking method. Thus, the novel combined by procyanidins-dialdehyde alginate crosslinking method shown in this study provided a non-toxic and efficient crosslinking method that improved various properties of collagen film, which has great potential applications in biomedical materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. A dense and strong bonding collagen film for carbon/carbon composites

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    Cao, Sheng; Li, Hejun, E-mail: lihejun@nwpu.edu.cn; Li, Kezhi; Lu, Jinhua; Zhang, Leilei

    2015-08-30

    Graphical abstract: - Highlights: • Significantly enhancement of biocompatibility on C/C composites by preparing a collagen film. • The dense and continuous collagen film had a strong bonding strength with C/C composites after dehydrathermal treatment (DHT) crosslink. • Numerous oxygen-containing functional groups formed on the surface of C/C composites without matrix damage. - Abstract: A strong bonding collagen film was successfully prepared on carbon/carbon (C/C) composites. The surface conditions of the modified C/C composites were detected by contact angle measurements, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. The roughness, optical morphology, bonding strength and biocompatibility of collagen films at different pH values were detected by confocal laser scanning microscope (CLSM), universal test machine and cytology tests in vitro. After a 4-h modification in 30% H{sub 2}O{sub 2} solution at 100 °C, the contact angle on the surface of C/C composites was decreased from 92.3° to 65.3°. Large quantities of hydroxyl, carboxyl and carbonyl functional groups were formed on the surface of the modified C/C composites. Then a dense and continuous collagen film was prepared on the modified C/C substrate. Bonding strength between collagen film and C/C substrate was reached to 8 MPa level when the pH value of this collagen film was 2.5 after the preparing process. With 2-day dehydrathermal treatment (DHT) crosslinking at 105 °C, the bonding strength was increased to 12 MPa level. At last, the results of in vitro cytological test showed that this collagen film made a great improvement on the biocompatibility on C/C composites.

  6. A dense and strong bonding collagen film for carbon/carbon composites

    International Nuclear Information System (INIS)

    Cao, Sheng; Li, Hejun; Li, Kezhi; Lu, Jinhua; Zhang, Leilei

    2015-01-01

    Graphical abstract: - Highlights: • Significantly enhancement of biocompatibility on C/C composites by preparing a collagen film. • The dense and continuous collagen film had a strong bonding strength with C/C composites after dehydrathermal treatment (DHT) crosslink. • Numerous oxygen-containing functional groups formed on the surface of C/C composites without matrix damage. - Abstract: A strong bonding collagen film was successfully prepared on carbon/carbon (C/C) composites. The surface conditions of the modified C/C composites were detected by contact angle measurements, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. The roughness, optical morphology, bonding strength and biocompatibility of collagen films at different pH values were detected by confocal laser scanning microscope (CLSM), universal test machine and cytology tests in vitro. After a 4-h modification in 30% H 2 O 2 solution at 100 °C, the contact angle on the surface of C/C composites was decreased from 92.3° to 65.3°. Large quantities of hydroxyl, carboxyl and carbonyl functional groups were formed on the surface of the modified C/C composites. Then a dense and continuous collagen film was prepared on the modified C/C substrate. Bonding strength between collagen film and C/C substrate was reached to 8 MPa level when the pH value of this collagen film was 2.5 after the preparing process. With 2-day dehydrathermal treatment (DHT) crosslinking at 105 °C, the bonding strength was increased to 12 MPa level. At last, the results of in vitro cytological test showed that this collagen film made a great improvement on the biocompatibility on C/C composites

  7. Collagen-binding peptidoglycans inhibit MMP mediated collagen degradation and reduce dermal scarring.

    Directory of Open Access Journals (Sweden)

    Kate Stuart

    Full Text Available Scarring of the skin is a large unmet clinical problem that is of high patient concern and impact. Wound healing is complex and involves numerous pathways that are highly orchestrated, leaving the skin sealed, but with abnormal organization and composition of tissue components, namely collagen and proteoglycans, that are then remodeled over time. To improve healing and reduce or eliminate scarring, more rapid restoration of healthy tissue composition and organization offers a unique approach for development of new therapeutics. A synthetic collagen-binding peptidoglycan has been developed that inhibits matrix metalloproteinase-1 and 13 (MMP-1 and MMP-13 mediated collagen degradation. We investigated the synthetic peptidoglycan in a rat incisional model in which a single dose was delivered in a hyaluronic acid (HA vehicle at the time of surgery prior to wound closure. The peptidoglycan treatment resulted in a significant reduction in scar tissue at 21 days as measured by histology and visual analysis. Improved collagen architecture of the treated wounds was demonstrated by increased tensile strength and transmission electron microscopy (TEM analysis of collagen fibril diameters compared to untreated and HA controls. The peptidoglycan's mechanism of action includes masking existing collagen and inhibiting MMP-mediated collagen degradation while modulating collagen organization. The peptidoglycan can be synthesized at low cost with unique design control, and together with demonstrated preclinical efficacy in reducing scarring, warrants further investigation for dermal wound healing.

  8. Investigation of the influence of UV irradiation on collagen thin films by AFM imaging

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    Stylianou, Andreas, E-mail: styliand@mail.ntua.gr; Yova, Dido; Alexandratou, Eleni

    2014-12-01

    Collagen is the major fibrous extracellular matrix protein and due to its unique properties, it has been widely used as biomaterial, scaffold and cell-substrate. The aim of the paper was to use Atomic Force Microscopy (AFM) in order to investigate well-characterized collagen thin films after ultraviolet light (UV) irradiation. The films were also used as in vitro culturing substrates in order to investigate the UV-induced alterations to fibroblasts. A special attention was given in the alteration on collagen D-periodicity. For short irradiation times, spectroscopy (fluorescence/absorption) studies demonstrated that photodegradation took place and AFM imaging showed alterations in surface roughness. Also, it was highlighted that UV-irradiation had different effects when it was applied on collagen solution than on films. Concerning fibroblast culturing, it was shown that fibroblast behavior was affected after UV irradiation of both collagen solution and films. Furthermore, after a long irradiation time, collagen fibrils were deformed revealing that collagen fibrils are consisting of multiple shells and D-periodicity occurred on both outer and inner shells. The clarification of the effects of UV light on collagen and the induced modifications of cell behavior on UV-irradiated collagen-based surfaces will contribute to the better understanding of cell–matrix interactions in the nanoscale and will assist in the appropriate use of UV light for sterilizing and photo-cross-linking applications. - Highlights: • Collagen thin films were formed and exposed in UV irradiation. • Collagen thin films were formed from UV-irradiated collagen solution. • Nanocharacterization of collagen thin films by AFM • Fluorescence and absorption spectroscopy studies on collagen films • Investigation of fibroblast response on collagen films.

  9. Investigation of the influence of UV irradiation on collagen thin films by AFM imaging

    International Nuclear Information System (INIS)

    Stylianou, Andreas; Yova, Dido; Alexandratou, Eleni

    2014-01-01

    Collagen is the major fibrous extracellular matrix protein and due to its unique properties, it has been widely used as biomaterial, scaffold and cell-substrate. The aim of the paper was to use Atomic Force Microscopy (AFM) in order to investigate well-characterized collagen thin films after ultraviolet light (UV) irradiation. The films were also used as in vitro culturing substrates in order to investigate the UV-induced alterations to fibroblasts. A special attention was given in the alteration on collagen D-periodicity. For short irradiation times, spectroscopy (fluorescence/absorption) studies demonstrated that photodegradation took place and AFM imaging showed alterations in surface roughness. Also, it was highlighted that UV-irradiation had different effects when it was applied on collagen solution than on films. Concerning fibroblast culturing, it was shown that fibroblast behavior was affected after UV irradiation of both collagen solution and films. Furthermore, after a long irradiation time, collagen fibrils were deformed revealing that collagen fibrils are consisting of multiple shells and D-periodicity occurred on both outer and inner shells. The clarification of the effects of UV light on collagen and the induced modifications of cell behavior on UV-irradiated collagen-based surfaces will contribute to the better understanding of cell–matrix interactions in the nanoscale and will assist in the appropriate use of UV light for sterilizing and photo-cross-linking applications. - Highlights: • Collagen thin films were formed and exposed in UV irradiation. • Collagen thin films were formed from UV-irradiated collagen solution. • Nanocharacterization of collagen thin films by AFM • Fluorescence and absorption spectroscopy studies on collagen films • Investigation of fibroblast response on collagen films

  10. Ovine tendon collagen: Extraction, characterisation and fabrication of thin films for tissue engineering applications

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    Fauzi, M.B.; Lokanathan, Y. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Aminuddin, B.S. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Ear, Nose & Throat Consultant Clinic, Ampang Puteri Specialist Hospital, Taman Dato Ahmad Razali, 68000 Ampang, Selangor (Malaysia); Ruszymah, B.H.I. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Department of Physiology, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Chowdhury, S.R., E-mail: shiplu@ppukm.ukm.edu.my [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia)

    2016-11-01

    Collagen is the most abundant extracellular matrix (ECM) protein in the human body, thus widely used in tissue engineering and subsequent clinical applications. This study aimed to extract collagen from ovine (Ovis aries) Achilles tendon (OTC), and to evaluate its physicochemical properties and its potential to fabricate thin film with collagen fibrils in a random or aligned orientation. Acid-solubilized protein was extracted from ovine Achilles tendon using 0.35 M acetic acid, and 80% of extracted protein was measured as collagen. SDS-PAGE and mass spectrometry analysis revealed the presence of alpha 1 and alpha 2 chain of collagen type I (col I). Further analysis with Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirms the presence of triple helix structure of col I, similar to commercially available rat tail col I. Drying the OTC solution at 37°C resulted in formation of a thin film with randomly orientated collagen fibrils (random collagen film; RCF). Introduction of unidirectional mechanical intervention using a platform rocker prior to drying facilitated the fabrication of a film with aligned orientation of collagen fibril (aligned collagen film; ACF). It was shown that both RCF and ACF significantly enhanced human dermal fibroblast (HDF) attachment and proliferation than that on plastic surface. Moreover, cells were distributed randomly on RCF, but aligned with the direction of mechanical intervention on ACF. In conclusion, ovine tendon could be an alternative source of col I to fabricate scaffold for tissue engineering applications. - Highlights: • Isolated collagen from ovine tendon was characterized as collagen type I. • Collagen film was fabricated via air drying of ovine tendon collagen. • Collagen fibril alignment was realized via unidirectional platform rocker. • Orientation of cells was attained depending on collagen fibril direction in the film. • Collagen films

  11. Use of collagen film as a dural substitute: preliminary animal studies.

    Science.gov (United States)

    Collins, R L; Christiansen, D; Zazanis, G A; Silver, F H

    1991-02-01

    Cadaver grafts, laminated metallic materials, and synthetic fabrics have been evaluated as dural substitutes. Use of cadaver tissues is limited by fear of transmission of infectious disease while use of synthetic materials is associated with implant encapsulation and foreign body reactions. The purpose of this study is to evaluate the use of collagen film as a dural substitute. Collagen films prepared from bovine skin were used to replace the dura of rabbits and histological observations were made at 16, 28, 42, and 56 days postimplantation. Controls consisted of dura that was removed and then reattached. Control dura showed no signs of inflammation or adhesion to underlying tissue at 16 and 28 days postimplantation. By 56 days postimplantation, extensive connective tissue deposition was observed in close proximity to adjacent bone as well as pia arachnoid adhesions. Implanted collagen film behaved in a similar manner to control dura showing minimal inflammatory response at all time periods. At 56 days postimplantation collagen film appeared strongly infiltrated by connective tissue cells that deposited new collagen. The results of this study suggest that a reconstituted type I collagen film crosslinked with cyanamide acts as a temporary barrier preventing loss of fluid and adhesion formation. It is replaced after approximately 2 months with host collagen with limited inflammatory and fibrotic complications. Further studies are needed to completely characterize the new connective tissue formed as well as long-term biocompatibility and functioning of a reconstituted collagen dural substitute.

  12. Antimicrobial and cell viability measurement of bovine serum albumin capped silver nanoparticles (Ag/BSA) loaded collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film.

    Science.gov (United States)

    Bakare, Rotimi; Hawthrone, Samantha; Vails, Carmen; Gugssa, Ayele; Karim, Alamgir; Stubbs, John; Raghavan, Dharmaraj

    2016-03-01

    Bacterial infection of orthopedic devices has been a major concern in joint replacement procedures. Therefore, this study is aimed at formulating collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film loaded with bovine serum albumin capped silver nanoparticles (Ag/BSA NPs) to inhibit bacterial growth while retaining/promoting osteoblast cells viability. The nanoparticles loaded collagen immobilized PHBV film was characterized for its composition by X-ray Photoelectron Spectroscopy and Anodic Stripping Voltammetry. The extent of loading of Ag/BSA NPs on collagen immobilized PHBV film was found to depend on the chemistry of the functionalized PHBV film and the concentration of Ag/BSA NPs solution used for loading nanoparticles. Our results showed that more Ag/BSA NPs were loaded on higher molecular weight collagen immobilized PHEMA-g-PHBV film. Maximum loading of Ag/BSA NPs on collagen immobilized PHBV film was observed when 16ppm solution was used for adsorption studies. Colony forming unit and optical density measurements showed broad antimicrobial activity towards Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa at significantly lower concentration i.e., 0.19 and 0.31μg/disc, compared to gentamicin and sulfamethoxazole trimethoprim while MTT assay showed that released nanoparticles from Ag/BSA NPs loaded collagen immobilized PHBV film has no impact on MCTC3-E1 cells viability. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Characterization of collagen / chitosan films for skin regenerating scaffold

    International Nuclear Information System (INIS)

    Ismarul, I.N.; Ishak, Y.; Ismail, Z.; Mohd Shalihuddin, W.M.

    2004-01-01

    Various Proportions of chitosan/collagen films (70/30% to 95/05%) w/w were prepared and evaluated for its suitability as skin regenerating scaffold. Interactions between chitosan and collagen were studied using Fourier Transform Infrared spectroscopy (FTIR) and Differential Scanning Colorimetry (DSC). Scanning Electron Microscope (SEM) was used to investigate the morphology of the blend. Mechanical properties were evaluated using a Universal Testing Machine (UTM). The chitosan/collagen films were found to swell proportionally with time until it reaches equilibrium, FTIR spectroscopy indicated no chemical interaction between the components of the blends, DSC data indicated only one peak proving that these two materials are compatible at all proportions investigated. SEM micrographs also indicated good homogeneity between these two materials. (Author)

  14. Studies on collagen-tannic acid-collagenase ternary system: Inhibition of collagenase against collagenolytic degradation of extracellular matrix component of collagen.

    Science.gov (United States)

    Krishnamoorthy, Ganesan; Sehgal, Praveen Kumar; Mandal, Asit Baran; Sadulla, Sayeed

    2012-06-01

    We report the detailed studies on the inhibitory effect of tannic acid (TA) on Clostridium histolyticum collagenase (ChC) activity against degradation of extracellular matrix component of collagen. The TA treated collagen exhibited 64% resistance against collagenolytic hydrolysis by ChC, whereas direct interaction of TA with ChC exhibited 99% inhibition against degradation of collagen and the inhibition was found to be concentration dependant. The kinetic inhibition of ChC has been deduced from the extent of hydrolysis of N-[3-(2-furyl) acryloyl]-Leu-Gly-Pro-Ala (FALGPA). This data provides a selective competitive mode of inhibition on ChC activity seems to be influenced strongly by the nature and structure of TA. TA showed inhibitor activity against the ChC by molecular docking method. This result demonstrated that TA containing digalloyl radical possess the ability to inhibit the ChC. The inhibition of ChC in gaining new insight into the mechanism of stabilization of collagen by TA is discussed.

  15. Cystamine immobilization on TiO2 film surfaces and the influence on inhibition of collagen-induced platelet activation

    International Nuclear Information System (INIS)

    Zhou Yujuan; Weng Yajun; Zhang Liping; Jing Fengjuan; Huang Nan; Chen Junying

    2011-01-01

    Poor haemocompatibility is a main issue of artificial cardiovascular materials in clinical application. Nitric oxide (NO), produced by vascular endothelial cells, is a well known inhibitor of platelet adhesion and activation. Thus, NO-releasing biomaterials are beneficial for improving haemocompatibility of blood-contacting biomedical devices. In this paper, a novel method was developed for enhancement of haemocompatibility by exploiting endogenous NO donors. TiO 2 films were firstly synthesized on Si (1 0 0) wafers via unbalanced magnetron sputtering technology, and then polydopamine was grafted on TiO 2 films and used as a linker for further immobilization of cystamine. The obtained surfaces were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. NO generation is evaluated by saville-griess reagents, and it shows that cystamine immobilized samples are able to catalytically generate NO by decomposing endogenous S-nitrosothiols (RSNO). In vitro platelet adhesion results reveal that cystamine modified surfaces can inhibit collagen-induced platelet activation. ELISA analysis reveals that cGMP in platelets obviously increases on cystamine immobilized surface, which suggests the reducing of platelet activation is through NO/cGMP signal channel. It can be concluded that cystamine immobilized surface shows better blood compatibility by catalyzing NO release from the endogenous NO donor. It may be a promising method for improvement of haemocompatibility of blood-contacting implants.

  16. Improving the cell affinity of a poly(D,L-lactide) film modified by grafting collagen via a plasma technique

    International Nuclear Information System (INIS)

    Zhao Jianhao; Wang Jue; Tu Mei; Luo Binghong; Zhou Changren

    2006-01-01

    Poly(D,L-lactide) films were surface-modified by grafting collagen via NH 3 plasma to improve cell affinity. The modified films were characterized by IR analysis, contact angle measurement, SEM analysis and collagen quantity determination. It was demonstrated that -NH 2 and collagen were incorporated into the surface of PDLLA films. The hydrophilicity of the PDLLA film increased after NH 3 plasma treatment, but decreased with further collagen modification. More collagen was incorporated into the PDLLA films by a grating method as compared to that with an anchorage treatment. L929 fibroblast cells were used to evaluate the cell affinity of the modified films and control. It was shown that PDLLA films surface-modified by grafting collagen via NH 3 plasma more efficiently enhanced the cells attachment and proliferation than those films modified by collagen anchorage or only NH 3 plasma treatment

  17. Mechanical properties and solubility in water of corn starch-collagen composite films: Effect of starch type and concentrations.

    Science.gov (United States)

    Wang, Kun; Wang, Wenhang; Ye, Ran; Liu, Anjun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana

    2017-02-01

    This study investigated the possibility of enhancing the properties of collagen with three different maize starches: waxy maize starch, normal starch, and high amylose starch. Scanning electron microscopy images revealed that starch-collagen films had a rougher surface compared to pure collagen films which became smoother upon heating. Amylose starch and normal starch increased the tensile strength of unheated collagen films in both dry and wet states, while all starches increased tensile strength of collagen film by heating. Depending upon the amylose content and starch concentrations, film solubility in water decreased with the addition of starch. DSC thermograms demonstrated that addition of all starches improved the thermal stability of the collagen film. Moreover, X-ray diffraction results indicated that except for high amylose starch, the crystallinity of both starch and collagen was significantly decreased when subject to heating. FTIR spectra indicated that intermolecular interactions between starch and collagen were enhanced upon heating. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Using carboxylated cellulose nanofibers to enhance mechanical and barrier properties of collagen fiber film by electrostatic interaction.

    Science.gov (United States)

    Wang, Wenhang; Zhang, Xiuling; Li, Cong; Du, Guanhua; Zhang, Hongjie; Ni, Yonghao

    2018-06-01

    Collagen-based films including casings with a promising application in meat industry are still needed to improve its inferior performance. In the present study, the reinforcement of carboxylated cellulose nanofibers (CNF) for collagen film, based on inter-/intra- molecular electrostatic interaction between cationic acid-swollen collagen fiber and anionic carboxylated CNF, was investigated. Adding CNF decreased the zeta-potential but increased particle size of collagen fiber suspension, with little effect on pH. Furthermore, CNF addition led to a higher tensile strength but a lower elongation, and the water vapor and oxygen barrier properties were improved remarkably. Because the CNF content was 50 g kg -1 or lower, the films had a homogeneous interwoven network, and CNF homogeneously embedded into collagen fiber matrix according to the scanning electron microscopy and atomic force microscopy analysis. Additionally, CNF addition increased film thickness and opacity, as well as swelling rate. The incorporation of CNF endows collagen fiber films good mechanical and barrier properties over a proper concentration range (≤ 50 g kg -1 collagen fiber), which is closely associated with electrostatic reaction of collagen fiber and CNF and, subsequently, the form of the homogenous, compatible spatial network, indicating a potential applications of CNF in collagenous protein films, such as edible casings. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. Cystamine immobilization on TiO{sub 2} film surfaces and the influence on inhibition of collagen-induced platelet activation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yujuan [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Weng Yajun, E-mail: wengyj7032@sohu.com [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Zhang Liping; Jing Fengjuan; Huang Nan [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Chen Junying, E-mail: chenjy@263.net [Key Lab. of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2011-12-15

    Poor haemocompatibility is a main issue of artificial cardiovascular materials in clinical application. Nitric oxide (NO), produced by vascular endothelial cells, is a well known inhibitor of platelet adhesion and activation. Thus, NO-releasing biomaterials are beneficial for improving haemocompatibility of blood-contacting biomedical devices. In this paper, a novel method was developed for enhancement of haemocompatibility by exploiting endogenous NO donors. TiO{sub 2} films were firstly synthesized on Si (1 0 0) wafers via unbalanced magnetron sputtering technology, and then polydopamine was grafted on TiO{sub 2} films and used as a linker for further immobilization of cystamine. The obtained surfaces were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis. NO generation is evaluated by saville-griess reagents, and it shows that cystamine immobilized samples are able to catalytically generate NO by decomposing endogenous S-nitrosothiols (RSNO). In vitro platelet adhesion results reveal that cystamine modified surfaces can inhibit collagen-induced platelet activation. ELISA analysis reveals that cGMP in platelets obviously increases on cystamine immobilized surface, which suggests the reducing of platelet activation is through NO/cGMP signal channel. It can be concluded that cystamine immobilized surface shows better blood compatibility by catalyzing NO release from the endogenous NO donor. It may be a promising method for improvement of haemocompatibility of blood-contacting implants.

  20. Inhibition of human arterial smooth muscle (HASM) cell proliferation and collagen synthesis by protamine

    International Nuclear Information System (INIS)

    Drucker, D.E.; Graham, M.F.; Diegelmann, R.F.; Greenfield, L.J.

    1986-01-01

    Atherosclerotic plaques result from vascular smooth muscle cell proliferation and collagen deposition. The authors have been studying factors which modulate HASM cell proliferation and collagen synthesis. HASM cells were isolated from the media of normal human thoracic and infrarenal aortas and grown in vitro. Cell numbers were determined by direct counting and collagen synthesis was measured by incorporation of 3 H-proline into collagenase-digestible protein. In this study, protamine (200 μg/ml) was tested and found to cause a 55% reduction of HASM cell proliferation which was reversible when the cells were returned to control medium or when heparin (100 μg/ml) was added with protamine. Protamine caused a constant 33% decrease in non-collagen protein (NCP) synthesis per cell. In contrast, collagen synthesis was inhibited in dose dependent fashion (88% reduction at 200 μg/ml). Protamine blocks HASM cell proliferation and specifically inhibits collagen production. The exact mechanism of this inhibition is unclear but may be related to a transcriptional event since protamine has a high affinity for DNA

  1. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    International Nuclear Information System (INIS)

    Liu, Yang; Ren, Li; Wang, Yingjun

    2014-01-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair

  2. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China)

    2014-05-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

  3. Interleukin-1 inhibits the synthesis of collagen by fibroblasts.

    Science.gov (United States)

    Bhatnagar, R; Penfornis, H; Mauviel, A; Loyau, G; Saklatvala, J; Pujol, J P

    1986-10-01

    Human dermal fibroblasts, exposed to human or porcine Interleukin-1, responded by an inhibition of collagen synthesis in a dose dependent manner. Incubation with Il-1 for more than 8 h was required to see an appreciable effect. The phenomenon was not dependent on the presence of serum in the culture medium. Since a stimulation of prostaglandin E2 secretion was also observed in presence of Il-1, we investigated the eventual role of arachidonic acid metabolites in the phenomenon. Inhibitors interfering with arachidonate metabolism, namely indomethacin, acetyl salicylic acid, BW 755 C and NDGA had no influence on the inhibition of collagen synthesis caused by Il-1. These data suggest that both cyclooxygenase and lipoxygenase derived metabolites of arachidonic acid are unlikely to play a role in the mechanism.

  4. Low‑dose halofuginone inhibits the synthesis of type I collagen without influencing type II collagen in the extracellular matrix of chondrocytes.

    Science.gov (United States)

    Li, Zeng; Fei, Hao; Wang, Zhen; Zhu, Tianyi

    2017-09-01

    Full‑thickness and large area defects of articular cartilage are unable to completely repair themselves and require surgical intervention, including microfracture, autologous or allogeneic osteochondral grafts, and autologous chondrocyte implantation. A large proportion of regenerative cartilage exists as fibrocartilage, which is unable to withstand impacts in the same way as native hyaline cartilage, owing to excess synthesis of type I collagen in the matrix. The present study demonstrated that low‑dose halofuginone (HF), a plant alkaloid isolated from Dichroa febrifuga, may inhibit the synthesis of type I collagen without influencing type II collagen in the extracellular matrix of chondrocytes. In addition, HF was revealed to inhibit the phosphorylation of mothers against decapentaplegic homolog (Smad)2/3 and promoted Smad7 expression, as well as decrease the synthesis of type I collagen synthesis. Results from the present study indicated that HF treatment suppressed the synthesis of type I collagen by inhibiting the transforming growth factor‑β signaling pathway in chondrocytes. These results may provide an alternative solution to the problems associated with fibrocartilage, and convert fibrocartilage into hyaline cartilage at the mid‑early stages of cartilage regeneration. HF may additionally be used to improve monolayer expansion or 3D cultures of seed cells for the tissue engineering of cartilage.

  5. Modification of fish skin collagen film and absorption property of tannic acid.

    Science.gov (United States)

    Liu, Haiying; Zhao, Lu; Guo, Shidong; Xia, Yu; Zhou, Peng

    2014-06-01

    Fish collagen is a biomacromolecule material and is usually used as a clarifying agent. However, fish collagen is not recyclable, and sedimentation usually occurs in the clarification process using fish collagen so that the filtration process is inevitable. This work aimed to provide a recyclable modified fish skin collagen film (MFCF) for adsorption of tannic acids. The collagen from channel catfish skin was extracted and used for preparation of the fish skin collagen film (FCF) and MFCF. The result indicated that the mechanical properties of MFCF were improved by addition of 2 ml/L glycerol, 6 ml/L polyvinyl alcohol (PVA) and 2 ml/L glutaraldehyde in 15 g/L collagen solution. As the most important property of adsorption material, the hydroscopicity of MFCF was only 54%, significantly lower than that of FCF (295%). Therefore, MFCF would not collapse in water. The infrared and thermal properties of MFCF were also investigated in this work. Results indicated that, in comparison to FCF, the physical and chemical properties of MFCF had been improved significantly. MFCF had higher shrink temperature (79.3 °C) and it did not collapse in distilled water at normal temperature. Furthermore, absorption and desorption properties of tannic acid were studied. MFCF showed good capability of absorption and desorption of tannic acid, which leaded to the suggestion that MFCF could have potential applications in adsorption material.

  6. Inhibition of collagen production in scleroderma fibroblast cultures by a connective tissue glycoprotein extracted from normal dermis

    International Nuclear Information System (INIS)

    Maquart, F.X.; Bellon, G.; Cornillet-Stoupy, J.; Randoux, A.; Triller, R.; Kalis, B.; Borel, J.P.

    1985-01-01

    It was shown in a previous paper that a connective tissue glycoprotein (CTGP) extracted from normal rabbit dermis was able to inhibit total protein and collagen syntheses by normal dermis fibroblast cultures. In the present study, the effects of CTGP on scleroderma fibroblasts were investigated. [ 14 C]Proline incorporation into total proteins of the supernatant was not significantly different from that found in controls. By contrast, the amount of collagen, expressed as percentage of total secreted protein, was far higher in scleroderma cultures than in normal ones (14.4% +/- 6.0% vs 4.6% +/- 0.9%). Addition of CTGP to the medium induced a concentration-dependent inhibition of [ 14 C]proline incorporation into proteins from both control and scleroderma cells. In control cultures, no significant decrease of the percentage of collagen was observed, but over 60 micrograms/ml, both cytotoxic effects and inhibition of protein synthesis occurred. In scleroderma cultures, the inhibition was twice as effective on collagen as on noncollagen protein synthesis. The inhibition of collagen secretion was not related either to changes in collagen hydroxylation or to the intracellular catabolism of newly synthesized procollagen

  7. New ferrimagnetic biocomposite film based in collagen and yttrium iron garnet

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available In recent years a great interest in the study of the association of magnetic with biological material for bioapplications has been observed in the literature. This work analyses the development of new magnetic biocomposite films from a magnetic ferrite and a biopolymer. Magnetic and dielectric properties of Y3Fe5O12 (YIG/collagen composite films were studied as a function of the YIG concentration. This biocomposite was also characterized by Infrared Spectroscopy (IR, Thermal Analysis (DSC and TG and scanning electron microspcopic (SEM methods. The magnetization and dielectric measurements were performed at room temperature. The results demonstrated that ferrimagnetic garnet (YIG and collagen (Col can be used to obtain a homogeneous composite. All the composite films showed a ferromagnetic behavior and they were characterized as a soft magnet material. These results show that Col-YIG biocomposites are biological films with magnetic properties that can be employed as a versatile performance materials, due to their flexible dielectric and magnetic features. They could be used as electronic devices in biological applications.

  8. Atomic force imaging microscopy investigation of the interaction of ultraviolet radiation with collagen thin films

    Science.gov (United States)

    Stylianou, A.; Yova, D.; Alexandratou, E.; Petri, A.

    2013-02-01

    Collagen is the major fibrous protein in the extracellular matrix and consists a significant component of skin, bone, cartilage and tendon. Due to its unique properties, it has been widely used as scaffold or culture substrate for tissue regeneration or/and cell-substrate interaction studies. The ultraviolet light-collagen interaction investigations are crucial for the improvement of many applications such as that of the UV irradiation in the field of biomaterials, as sterilizing and photo-cross-linking method. The aim of this paper was to investigate the mechanisms of UV-collagen interactions by developing a collagen-based, well characterized, surface with controlled topography of collagen thin films in the nanoscale range. The methodology was to quantify the collagen surface modification induced on ultraviolet radiation and correlate it with changes induced in cells. Surface nanoscale characterization was performed by Atomic Force Microscopy (AFM) which is a powerful tool and offers quantitative and qualitative information with a non-destructive manner. In order to investigate cells behavior, the irradiated films were used for in vitro cultivation of human skin fibroblasts and the cells morphology, migration and alignment were assessed with fluorescence microscopy imaging and image processing methods. The clarification of the effects of UV light on collagen thin films and the way of cells behavior to the different modifications that UV induced to the collagen-based surfaces will contribute to the better understanding of cell-matrix interactions in the nanoscale and will assist the appropriate use of UV light for developing biomaterials.

  9. Crosslinked collagen-gelatin-hyaluronic acid biomimetic film for cornea tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang; Ren, Li, E-mail: psliren@scut.edu.cn; Wang, Yingjun, E-mail: imwangyj@163.com

    2013-01-01

    Cornea disease may lead to blindness and keratoplasty is considered as an effective treatment method. However, there is a severe shortage of donor corneas worldwide. This paper presents the crosslinked collagen (Col)-gelatin (Gel)-hyaluronic acid (HA) films developed by making use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as the crosslinker. The test results on the physical and biological properties indicate that the CGH631 film (the mass ratio of Col:Gel:HA = 6:3:1) has appropriate optical performance, hydrophilicity and mechanical properties. The diffusion properties of the CGH631 film to NaCl and tryptophan are also satisfactory and the measured data are 2.43 Multiplication-Sign 10{sup -6} cm{sup 2}/s and 7.97 Multiplication-Sign 10{sup -7} cm{sup 2}/s, respectively. In addition, cell viability studies demonstrate that the CGH631 film has good biocompatibility, on which human corneal epithelial cells attached and proliferated well. This biocompatible film may have potential use in cornea tissue engineering. - Highlights: Black-Right-Pointing-Pointer Crosslinked collagen-gelatin-hyaluronic acid films were fabricated in this study. Black-Right-Pointing-Pointer The film had appropriate physical properties. Black-Right-Pointing-Pointer Diffusion coefficient of the film was comparable with the human cornea. Black-Right-Pointing-Pointer HCEC viability studies confirmed the biocompatibility of the film.

  10. A small-molecule compound inhibits a collagen-specific molecular chaperone and could represent a potential remedy for fibrosis.

    Science.gov (United States)

    Ito, Shinya; Ogawa, Koji; Takeuchi, Koh; Takagi, Motoki; Yoshida, Masahito; Hirokawa, Takatsugu; Hirayama, Shoshiro; Shin-Ya, Kazuo; Shimada, Ichio; Doi, Takayuki; Goshima, Naoki; Natsume, Tohru; Nagata, Kazuhiro

    2017-12-08

    Fibrosis can disrupt tissue structure and integrity and impair organ function. Fibrosis is characterized by abnormal collagen accumulation in the extracellular matrix. Pharmacological inhibition of collagen secretion therefore represents a promising strategy for the management of fibrotic disorders, such as liver and lung fibrosis. Hsp47 is an endoplasmic reticulum (ER)-resident collagen-specific molecular chaperone essential for correct folding of procollagen in the ER. Genetic deletion of Hsp47 or inhibition of its interaction with procollagen interferes with procollagen triple helix production, which vastly reduces procollagen secretion from fibroblasts. Thus, Hsp47 could be a potential and promising target for the management of fibrosis. In this study, we screened small-molecule compounds that inhibit the interaction of Hsp47 with collagen from chemical libraries using surface plasmon resonance (BIAcore), and we found a molecule AK778 and its cleavage product Col003 competitively inhibited the interaction and caused the inhibition of collagen secretion by destabilizing the collagen triple helix. Structural information obtained with NMR analysis revealed that Col003 competitively binds to the collagen-binding site on Hsp47. We propose that these structural insights could provide a basis for designing more effective therapeutic drugs for managing fibrosis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. A novel method to immobilize collagen on polypropylene film as substrate for hepatocyte culture

    International Nuclear Information System (INIS)

    Zhang Yong; Wang Wenjie; Feng Qingling; Cui Fuzhai; Xu Yingxin

    2006-01-01

    To improve the biocompatibility of polypropylene membrane with hepatocytes, film was firstly allowed to generate peroxide groups by ammonium peroxydisulfate (APS) thermal decomposition and was then carboxylated by free radical grafting polymerization using acrylic acid as the monomer and ferrous(II) ions as redox initiator. Collagen was then covalently immobilized through amide bonds between the residue amine groups and carboxylic ones in the presence of water-soluble carbodiimide. The film was characterized by Fourier transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR), X-photoelectron spectroscopy (XPS) and confocal laser scanning microscopy (CLSM), etc. The experimental results show that there exist hydroperoxide groups after APS aqueous thermal decomposition, which are subsequently converted into the polymeric free radicals initiating the vinyl monomers to subject grafting polymerization. The maximum collagen immobilization content is about 10.5 μg/cm 2 by ninhydrin assay. Hepatocytes cultured on collagen immobilized film show stable phenotype and normal liver-specific functions more than 20 days as observed by scanning electronic microscopy (SEM) and biochemical parameters determination

  12. A novel method to immobilize collagen on polypropylene film as substrate for hepatocyte culture

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yong [Biomaterials Laboratory, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang Wenjie [Biomaterials Laboratory, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng Qingling [Biomaterials Laboratory, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)]. E-mail: biomater@mail.tsinghua.edu.cn; Cui Fuzhai [Biomaterials Laboratory, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Xu Yingxin [Institute of General Surgery, Chinese PLA General Hospital, Beijing 100853 (China)

    2006-05-15

    To improve the biocompatibility of polypropylene membrane with hepatocytes, film was firstly allowed to generate peroxide groups by ammonium peroxydisulfate (APS) thermal decomposition and was then carboxylated by free radical grafting polymerization using acrylic acid as the monomer and ferrous(II) ions as redox initiator. Collagen was then covalently immobilized through amide bonds between the residue amine groups and carboxylic ones in the presence of water-soluble carbodiimide. The film was characterized by Fourier transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR), X-photoelectron spectroscopy (XPS) and confocal laser scanning microscopy (CLSM), etc. The experimental results show that there exist hydroperoxide groups after APS aqueous thermal decomposition, which are subsequently converted into the polymeric free radicals initiating the vinyl monomers to subject grafting polymerization. The maximum collagen immobilization content is about 10.5 {mu}g/cm{sup 2} by ninhydrin assay. Hepatocytes cultured on collagen immobilized film show stable phenotype and normal liver-specific functions more than 20 days as observed by scanning electronic microscopy (SEM) and biochemical parameters determination.

  13. Kaempferol suppresses collagen-induced platelet activation by inhibiting NADPH oxidase and protecting SHP-2 from oxidative inactivation.

    Science.gov (United States)

    Wang, Su Bin; Jang, Ji Yong; Chae, Yun Hee; Min, Ji Hyun; Baek, Jin Young; Kim, Myunghee; Park, Yunjeong; Hwang, Gwi Seo; Ryu, Jae-Sang; Chang, Tong-Shin

    2015-06-01

    Reactive oxygen species (ROS) generated upon collagen stimulation act as second messengers to propagate various platelet-activating events. Among the ROS-generating enzymes, NADPH oxidase (NOX) plays a prominent role in platelet activation. Thus, NOX has been suggested as a novel target for anti-platelet drug development. Although kaempferol has been identified as a NOX inhibitor, the influence of kaempferol on the activation of platelets and the underlying mechanism have never been investigated. Here, we studied the effects of kaempferol on NOX activation, ROS-dependent signaling pathways, and functional responses in collagen-stimulated platelets. Superoxide anion generation stimulated by collagen was significantly inhibited by kaempferol in a concentration-dependent manner. More importantly, kaempferol directly bound p47(phox), a major regulatory subunit of NOX, and significantly inhibited collagen-induced phosphorylation of p47(phox) and NOX activation. In accordance with the inhibition of NOX, ROS-dependent inactivation of SH2 domain-containing protein tyrosine phosphatase-2 (SHP-2) was potently protected by kaempferol. Subsequently, the specific tyrosine phosphorylation of key components (Syk, Vav1, Btk, and PLCγ2) of collagen receptor signaling pathways was suppressed by kaempferol. Kaempferol also attenuated downstream responses, including cytosolic calcium elevation, P-selectin surface exposure, and integrin-αIIbβ3 activation. Ultimately, kaempferol inhibited platelet aggregation and adhesion in response to collagen in vitro and prolonged in vivo thrombotic response in carotid arteries of mice. This study shows that kaempferol impairs collagen-induced platelet activation through inhibition of NOX-derived ROS production and subsequent oxidative inactivation of SHP-2. This effect suggests that kaempferol has therapeutic potential for the prevention and treatment of thrombovascular diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Quantitative Raman characterization of cross-linked collagen thin films as a model system for diagnosing early osteoarthritis

    Science.gov (United States)

    Wang, Chao; Durney, Krista M.; Fomovsky, Gregory; Ateshian, Gerard A.; Vukelic, Sinisa

    2016-03-01

    The onset of osteoarthritis (OA)in articular cartilage is characterized by degradation of extracellular matrix (ECM). Specifically, breakage of cross-links between collagen fibrils in the articular cartilage leads to loss of structural integrity of the bulk tissue. Since there are no broadly accepted, non-invasive, label-free tools for diagnosing OA at its early stage, Raman spectroscopyis therefore proposed in this work as a novel, non-destructive diagnostic tool. In this study, collagen thin films were employed to act as a simplified model system of the cartilage collagen extracellular matrix. Cross-link formation was controlled via exposure to glutaraldehyde (GA), by varying exposure time and concentration levels, and Raman spectral information was collected to quantitatively characterize the cross-link assignments imparted to the collagen thin films during treatment. A novel, quantitative method was developed to analyze the Raman signal obtained from collagen thin films. Segments of Raman signal were decomposed and modeled as the sum of individual bands, providing an optimization function for subsequent curve fitting against experimental findings. Relative changes in the concentration of the GA-induced pyridinium cross-links were extracted from the model, as a function of the exposure to GA. Spatially resolved characterization enabled construction of spectral maps of the collagen thin films, which provided detailed information about the variation of cross-link formation at various locations on the specimen. Results showed that Raman spectral data correlate with glutaraldehyde treatment and therefore may be used as a proxy by which to measure loss of collagen cross-links in vivo. This study proposes a promising system of identifying onset of OA and may enable early intervention treatments that may serve to slow or prevent osteoarthritis progression.

  15. Pirfenidone inhibits TGF-β1-induced over-expression of collagen type I and heat shock protein 47 in A549 cells

    Directory of Open Access Journals (Sweden)

    Hisatomi Keiko

    2012-06-01

    Full Text Available Abstract Background Pirfenidone is a novel anti-fibrotic and anti-inflammatory agent that inhibits the progression of fibrosis in animal models and in patients with idiopathic pulmonary fibrosis (IPF. We previously showed that pirfenidone inhibits the over-expression of collagen type I and of heat shock protein (HSP 47, a collagen-specific molecular chaperone, in human lung fibroblasts stimulated with transforming growth factor (TGF-β1 in vitro. The increased numbers of HSP47-positive type II pneumocytes as well as fibroblasts were also diminished by pirfenidone in an animal model of pulmonary fibrosis induced by bleomycin. The present study evaluates the effects of pirfenidone on collagen type I and HSP47 expression in the human alveolar epithelial cell line, A549 cells in vitro. Methods The expression of collagen type I, HSP47 and E-cadherin mRNAs in A549 cells stimulated with TGF-β1 was evaluated by Northern blotting or real-time PCR. The expression of collagen type I, HSP47 and fibronectin proteins was assessed by immunocytochemical staining. Results TGF-β1 stimulated collagen type I and HSP47 mRNA and protein expression in A549 cells, and pirfenidone significantly inhibited this process. Pirfenidone also inhibited over-expression of the fibroblast phenotypic marker fibronectin in A549 cells induced by TGF-β1. Conclusion We concluded that the anti-fibrotic effects of pirfenidone might be mediated not only through the direct inhibition of collagen type I expression but also through the inhibition of HSP47 expression in alveolar epithelial cells, which results in reduced collagen synthesis in lung fibrosis. Furthermore, pirfenidone might partially inhibit the epithelial-mesenchymal transition.

  16. Estradiol inhibits hepatic stellate cell area and collagen synthesis in the chicken liver.

    Science.gov (United States)

    Nishimura, Shotaro; Teshima, Akifumi; Kawabata, Fuminori; Tabata, Shoji

    2017-11-01

    Hepatic stellate cells (HSCs) are the main collagen-producing cells in the liver. The HSC area and amount of collagen fibers are different between male and female chickens. This study was performed to confirm the effect of estradiol on collagen synthesis in the growing chicken liver. Blood estradiol levels in chicks were compared at 4 and 8 weeks of age, and the collagen fibril network in liver tissue was observed at 8 weeks by scanning electron microscopy. Intraperitoneal administrations of estradiol and tamoxifen to male and female chicks, respectively, were performed daily from 5 to 8 weeks of age. The areas of HSCs and collagen contents were measured in the liver tissue. The blood estradiol level was higher in females than in males, and the collagen fibril network was denser in males than in females at 8 weeks of age. Estradiol administration in males induced decreases in the HSC area and collagen content of the liver. Conversely, tamoxifen administration in females induced an increase in the HSC area but did not facilitate collagen synthesis. Based on these results, estradiol inhibits the area and collagen synthesis of HSCs in the growing chicken liver under normal physiological conditions. © 2017 Japanese Society of Animal Science.

  17. Epicutaneous immunization with type II collagen inhibits both onset and progression of chronic collagen-induced arthritis.

    Directory of Open Access Journals (Sweden)

    Jessica Strid

    Full Text Available Epicutaneous immunization is a potential non-invasive technique for antigen-specific immune-modulation. Topical application of protein antigens to barrier-disrupted skin induces potent antigen-specific immunity with a strong Th2-bias. In this study, we investigate whether the autoimmune inflammatory response of chronic collagen-induced arthritis (CCIA in DBA/1-TCR-beta Tg mice can be modified by epicutaneous immunization. We show that epicutaneous immunization with type II collagen (CII inhibited development and progression of CCIA and, importantly, also ameliorated ongoing disease as indicated by clinical scores of disease severity, paw swelling and joints histology. Treated mice show reduced CII-driven T cell proliferation and IFN-gamma production, as well as significantly lower levels of CII-specific IgG2a serum antibodies. In contrast, CII-driven IL-4 production and IgE antibody levels were increased consistent with skewing of the CII response from Th1 to Th2 in treated mice. IL-4 production in treated mice was inversely correlated with disease severity. Moreover, T cells from treated mice inhibited proliferation and IFN-gamma production by T cells from CCIA mice, suggesting induction of regulatory T cells that actively inhibit effector responses in arthritic mice. The levels of CD4(+CD25(+ T cells were however not increased following epicutaneous CII treatment. Together, these results suggest that epicutaneous immunization may be used as an immune-modulating procedure to actively re-programme pathogenic Th1 responses, and could have potential as a novel specific and simple treatment for chronic autoimmune inflammatory diseases such as rheumatoid arthritis.

  18. Physicochemical properties of marine collagen-alginate biomaterial

    Science.gov (United States)

    Soon, K. S.; Hii, S. L.; Wong, C. L.; Leong, L. K.; Woo, K. K.

    2017-12-01

    Collagen base biomaterials are widely applied in the field of tissue engineering. However, these fibrous proteins in animal connective tissues are insufficient to fulfill the mechanical properties for such applications. Therefore, alginate as a natural polysaccharide was incorporated. In this study, Smooth wolf herring skins was collected from the local fish ball processing industry for collagen extraction using acid solubilisation method. On the other hand, alginate from brown seaweed (Sargassum polycystum) was extracted with calcium carbonate at 50 °C. The composite films of different collagen and alginate ratio were prepared by lyophilisation with pure collagen film as control. The effects of alginate on swelling behaviour, porosity, collagenase degradation and tensile strength of the composite films were investigated. Swelling behaviour increased with alginate content, 50 % alginate film achieved 1254.75 % swelling after 24 h. All composite films achieved more than 80 % porosity except the film with 80 % collagen (65.41 %). Porosity was highest in 100 % alginate (94.30 %). Highest tensile strength (1585.87 kPa) and young modulus (27.05 MPa) was found in 50 % alginate film. In addition, resistance to collagenase degradation was improved with alginate content, lowest degradation rate was determined in 80 % alginate film. Results indicated alginate is efficient in improving some mechanical properties of the composite film.

  19. Enhanced stabilization of collagen by furfural.

    Science.gov (United States)

    Lakra, Rachita; Kiran, Manikantan Syamala; Usha, Ramamoorthy; Mohan, Ranganathan; Sundaresan, Raja; Korrapati, Purna Sai

    2014-04-01

    Furfural (2-furancarboxaldehyde), a product derived from plant pentosans, has been investigated for its interaction with collagen. Introduction of furfural during fibril formation enhanced the thermal and mechanical stability of collagen. Collagen films treated with furfural exhibited higher denaturation temperature (Td) (pFurfural and furfural treated collagen films did not have any cytotoxic effect. Rheological characterization showed an increase in shear stress and shear viscosity with increasing shear rate for treated collagen. Circular dichroism (CD) studies indicated that the furfural did not have any impact on triple helical structure of collagen. Scanning electron microscopy (SEM) of furfural treated collagen exhibited small sized porous structure in comparison with untreated collagen. Thus this study provides an alternate ecologically safe crosslinking agent for improving the stability of collagen for biomedical and industrial applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Role of fibronectin in collagen deposition: Fab' to the gelatin-binding domain of fibronectin inhibits both fibronectin and collagen organization in fibroblast extracellular matrix

    OpenAIRE

    1982-01-01

    We report the effect of Fab' (anti-60k) to a 60,000 mol wt gelatin binding domain of fibronectin (1981, J. Biol. Chem. 256:5583) on diploid fibroblast (IMR-90) extracellular fibronectin and collagen organization. Anti-60k Fab' did not inhibit IMR-90 attachment or proliferation in fibronectin-depleted medium. Fibroblasts cultured with preimmune Fab' deposited a dense extracellular network of fibronectin and collagen detectable by immunofluorescence, while anti-60k Fab' prevented extracellular ...

  1. Development and characterization of collagen films with added essential oil of clove india

    Directory of Open Access Journals (Sweden)

    Ailim Yuki Nakashima

    2016-03-01

    Full Text Available This objective of this study was to develop and characterized films based on collagen and analyze the effects of concentrations of clay, plasticizer and essential oil on its characteristics. The solutions were prepared according to an experimental design of 2³ with 3 central points. The films were produced by the "casting" technique, which consists on surface drying, and were characterized by the color, opacity, tensile strength, solubility, water vapor permeability and thickness. Lightness values ranged between 66.76 and 96.03, the brightness decreased with increasing the concentrations of clay, oil and glycerol. The opacity values showed an increase with the addition of glycerol, ranging from 1.96 to 44.24%. The values of tensile strength ranged from 5 to 14 MPa, and the solubility values, from 2.14 to 7.97%. In the 5% level, solubility and tensile strength analyzes were not significant. The water vapor permeability (WVP ranged from 0.77 to 2.51 (g.mm/KPa.m2.d. The most influent factors on the permeability to water vapor in the films are the glycerol and essential oil concentrations, which increases the permeability as these variables increase. In relation to the thickness, the concentration of montmorillonite clay interfered in the range from 0.02 to 0.04mm, and as higher its concentration, greater the thickness. It was concluded that the collagen films obtained good mechanical properties, adequate visual appearance, easy handing and low permeability to water vapor and low water solubility. The essential oil was effective in the structure of the film, since that it improves the look and easier handling.

  2. The synthesis and coupling of photoreactive collagen-based peptides to restore integrin reactivity to an inert substrate, chemically-crosslinked collagen

    Science.gov (United States)

    Malcor, Jean-Daniel; Bax, Daniel; Hamaia, Samir W.; Davidenko, Natalia; Best, Serena M.; Cameron, Ruth E.; Farndale, Richard W.; Bihan, Dominique

    2016-01-01

    Collagen is frequently advocated as a scaffold for use in regenerative medicine. Increasing the mechanical stability of a collagen scaffold is widely achieved by cross-linking using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). However, this treatment consumes the carboxylate-containing amino acid sidechains that are crucial for recognition by the cell-surface integrins, abolishing cell adhesion. Here, we restore cell reactivity to a cross-linked type I collagen film by covalently linking synthetic triple-helical peptides (THPs), mimicking the structure of collagen. These THPs are ligands containing an active cell-recognition motif, GFOGER, a high-affinity binding site for the collagen-binding integrins. We end-stapled peptide strands containing GFOGER by coupling a short diglutamate-containing peptide to their N-terminus, improving the thermal stability of the resulting THP. A photoreactive Diazirine group was grafted onto the end-stapled THP to allow covalent linkage to the collagen film upon UV activation. Such GFOGER-derivatized collagen films showed restored affinity for the ligand-binding I domain of integrin α2β1, and increased integrin-dependent cell attachment and spreading of HT1080 and Rugli cell lines, expressing integrins α2β1 and α1β1, respectively. The method we describe has wide application, beyond collagen films or scaffolds, since the photoreactive diazirine will react with many organic carbon skeletons. PMID:26854392

  3. Efficient inhibition of fibroblast proliferation and collagen expression by ERK2 siRNAs

    International Nuclear Information System (INIS)

    Li, Fengfeng; Fan, Cunyi; Cheng, Tao; Jiang, Chaoyin; Zeng, Bingfang

    2009-01-01

    Transforming growth factor-β1 and fibroblast growth factor-2 play very important roles in fibroblast proliferation and collagen expression. These processes lead to the formation of joint adhesions through the SMAD and MAPK pathways, in which ERK2 is supposed to be crucial. Based on these assumptions, lentivirus (LV)-mediated small interfering RNAs (siRNAs) targeting ERK2 were used to suppress the proliferation and collagen expression of rat joint adhesion tissue fibroblasts (RJATFs). Among four siRNAs examined, siRNA1 caused an 84% reduction in ERK2 expression (p < 0.01) and was selected as the most efficient siRNA for use in this study. In subsequent experiments, significant downregulation of types I and III collagen were observed by quantitative RT-PCR and Western blot analyses. MTT assays and flow cytometry revealed marked inhibition of RJATF proliferation, but no apoptosis. In conclusion, LV-mediated ERK2 siRNAs may represent novel therapies or drug targets for preventing joint adhesion formation.

  4. Ibrutinib Inhibits Platelet Integrin αIIbβ3 Outside-In Signaling and Thrombus Stability But Not Adhesion to Collagen.

    Science.gov (United States)

    Bye, Alexander P; Unsworth, Amanda J; Vaiyapuri, Sakthivel; Stainer, Alexander R; Fry, Michael J; Gibbins, Jonathan M

    2015-11-01

    Ibrutinib is an irreversible Bruton tyrosine kinase inhibitor approved for treatment of Waldenstrom macroglobulinemia, chronic lymphocytic leukemia, and mantle cell lymphoma that increases the risk of bleeding among patients. Platelets from ibrutinib-treated patients exhibit deficiencies in collagen-evoked signaling in suspension; however, the significance of this observation and how it relates to bleeding risk is unclear, as platelets encounter immobile collagen in vivo. We sought to clarify the effects of ibrutinib on platelet function to better understand the mechanism underlying bleeding risk. By comparing signaling in suspension and during adhesion to immobilized ligands, we found that the collagen signaling deficiency caused by ibrutinib is milder during adhesion to immobilized collagen. We also found that platelets in whole blood treated with ibrutinib adhered to collagen under arterial shear but formed unstable thrombi, suggesting that the collagen signaling deficiency caused by ibrutinib may not be the predominant cause of bleeding in vivo. However, clot retraction and signaling evoked by platelet adhesion to immobilized fibrinogen were also inhibited by ibrutinib, indicating that integrin αIIbβ3 outside-in signaling is also effected in addition to GPVI signaling. When ibrutinib was combined with the P2Y12 inhibitor, cangrelor, thrombus formation under arterial shear was inhibited additively. These findings suggest that (1) ibrutinib causes GPVI and integrin αIIbβ3 platelet signaling deficiencies that result in formation of unstable thrombi and may contribute toward bleeding observed in vivo and (2) combining ibrutinib with P2Y12 antagonists, which also inhibit thrombus stability, may have a detrimental effect on hemostasis. © 2015 American Heart Association, Inc.

  5. Thermal helix-coil transition in UV irradiated collagen from rat tail tendon.

    Science.gov (United States)

    Sionkowska, A; Kamińska, A

    1999-05-01

    The thermal helix-coil transition in UV irradiated collagen solution, collagen film and pieces of rat tail tendon (RTT) were compared. Their thermal stability's were determined by differential scanning calorimeter (DSC) and by viscometric measurements. The denaturation temperatures of collagen solution, film and pieces of RTT were different. The helix-coil transition occur near 40 degrees C in collagen solution, near 112 degrees C in collagen film, and near 101 degrees C in pieces of RTT. After UV irradiation the thermal helix-coil transition of collagen samples were changed. These changes depend on the degree of hydratation.

  6. Polyelectrolyte multi-layers assembly of SiCHA nanopowders and collagen type I on aminolysed PLA films to enhance cell-material interactions.

    Science.gov (United States)

    Baba Ismail, Yanny Marliana; Ferreira, Ana Marina; Bretcanu, Oana; Dalgarno, Kenneth; El Haj, Alicia J

    2017-11-01

    This paper presents a new approach in assembling bone extracellular matrix components onto PLA films, and investigates the most favourable environment which can be created using the technique for cell-material interactions. Poly (lactic acid) (PLA) films were chemically modified by covalently binding the poly(ethylene imine) (PEI) as to prepare the substrate for immobilization of polyelectrolyte multilayers (PEMs) coating. Negatively charged polyelectrolyte consists of well-dispersed silicon-carbonated hydroxyapatite (SiCHA) nanopowders in hyaluronic acid (Hya) was deposited onto the modified PLA films followed by SiCHA in collagen type I as the positively charged polyelectrolyte. The outermost layer was finally cross-linked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrocholoride and N-hydroxysulfosuccinimide sodium salt (EDC/NHS) solutions. The physicochemical features of the coated PLA films were monitored via X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscope (AFM). The amounts of calcium and collagen deposited on the surface were qualitatively and quantitatively determined. The surface characterizations suggested that 5-BL has the optimum surface roughness and highest amounts of calcium and collagen depositions among tested films. In vitro human mesenchymal stem cells (hMSCs) cultured on the coated PLA films confirmed that the coating materials greatly improved cell attachment and survival compared to unmodified PLA films. The cell viability, cell proliferation and Alkaline Phosphatase (ALP) expression on 5-BL were found to be the most favourable of the tested films. Hence, this newly developed coating materials assembly could contribute to the improvement of the bioactivity of polymeric materials and structures aimed to bone tissue engineering applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

    Science.gov (United States)

    Wang, Long-Feng; Rhim, Jong-Whan

    2015-09-01

    Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Extracellular Protease Inhibition Alters the Phenotype of Chondrogenically Differentiating Human Mesenchymal Stem Cells (MSCs) in 3D Collagen Microspheres.

    Science.gov (United States)

    Han, Sejin; Li, Yuk Yin; Chan, Barbara Pui

    2016-01-01

    Matrix remodeling of cells is highly regulated by proteases and their inhibitors. Nevertheless, how would the chondrogenesis of mesenchymal stem cells (MSCs) be affected, when the balance of the matrix remodeling is disturbed by inhibiting matrix proteases, is incompletely known. Using a previously developed collagen microencapsulation platform, we investigated whether exposing chondrogenically differentiating MSCs to intracellular and extracellular protease inhibitors will affect the extracellular matrix remodeling and hence the outcomes of chondrogenesis. Results showed that inhibition of matrix proteases particularly the extracellular ones favors the phenotype of fibrocartilage rather than hyaline cartilage in chondrogenically differentiating hMSCs by upregulating type I collagen protein deposition and type II collagen gene expression without significantly altering the hypertrophic markers at gene level. This study suggests the potential of manipulating extracellular proteases to alter the outcomes of hMSC chondrogenesis, contributing to future development of differentiation protocols for fibrocartilage tissues for intervertebral disc and meniscus tissue engineering.

  9. Extracellular Protease Inhibition Alters the Phenotype of Chondrogenically Differentiating Human Mesenchymal Stem Cells (MSCs in 3D Collagen Microspheres.

    Directory of Open Access Journals (Sweden)

    Sejin Han

    Full Text Available Matrix remodeling of cells is highly regulated by proteases and their inhibitors. Nevertheless, how would the chondrogenesis of mesenchymal stem cells (MSCs be affected, when the balance of the matrix remodeling is disturbed by inhibiting matrix proteases, is incompletely known. Using a previously developed collagen microencapsulation platform, we investigated whether exposing chondrogenically differentiating MSCs to intracellular and extracellular protease inhibitors will affect the extracellular matrix remodeling and hence the outcomes of chondrogenesis. Results showed that inhibition of matrix proteases particularly the extracellular ones favors the phenotype of fibrocartilage rather than hyaline cartilage in chondrogenically differentiating hMSCs by upregulating type I collagen protein deposition and type II collagen gene expression without significantly altering the hypertrophic markers at gene level. This study suggests the potential of manipulating extracellular proteases to alter the outcomes of hMSC chondrogenesis, contributing to future development of differentiation protocols for fibrocartilage tissues for intervertebral disc and meniscus tissue engineering.

  10. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study.

    Science.gov (United States)

    Hubbard, Gary P; Wolffram, Siegfried; de Vos, Ric; Bovy, Arnaud; Gibbins, Jonathan M; Lovegrove, Julie A

    2006-09-01

    Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate the possible inhibitory effects of quercetin ingestion from a dietary source on collagen-stimulated platelet aggregation and signalling. A double-blind randomised cross-over pilot study was undertaken. Subjects ingested a soup containing either a high or a low amount of quercetin. Plasma quercetin concentrations and platelet aggregation and signalling were assessed after soup ingestion. The high-quercetin soup contained 69 mg total quercetin compared with the low-quercetin soup containing 5 mg total quercetin. Plasma quercetin concentrations were significantly higher after high-quercetin soup ingestion than after low-quercetin soup ingestion and peaked at 2.59 (sem 0.42) mumol/l. Collagen-stimulated (0.5 mug/ml) platelet aggregation was inhibited after ingestion of the high-quercetin soup in a time-dependent manner. Collagen-stimulated tyrosine phosphorylation of a key component of the collagen-signalling pathway via glycoprotein VI, Syk, was significantly inhibited by ingestion of the high-quercetin soup. The inhibition of Syk tyrosine phosphorylation was correlated with the area under the curve for the high-quercetin plasma profile. In conclusion, the ingestion of quercetin from a dietary source of onion soup could inhibit some aspects of collagen-stimulated platelet aggregation and signalling ex vivo. This further substantiates the epidemiological data suggesting that those who preferentially consume high amounts of quercetin-containing foods have a reduced risk of thrombosis and potential CVD risk.

  11. Lecithin, gelatin and hydrolyzed collagen orally disintegrating films: functional properties.

    Science.gov (United States)

    Borges, J G; Silva, A G; Cervi-Bitencourt, C M; Vanin, F M; Carvalho, R A

    2016-05-01

    Orally disintegrating films (ODFs) can transport natural active compounds such as ethanol extract of propolis (EEP). This paper aimed to investigate the effect of lecithin on different gelatin and hydrolyzed collagen (HC) polymeric matrices with addition of EEP. ODFs were prepared by casting technique and were characterized (color parameters, water content, mechanical properties, microstructure, disintegration time (DT), infrared spectroscopy (FTIR), contact angle (CA), swelling degree and total phenolic content). The mechanical properties were influenced by HC. The microstructure demonstrated increased porosity and roughness in films with EEP, and the addition of lecithin resulted in an increase in the number of pores. Lecithin-gelatin and lecithin-EEP-gelatin interactions were observed by FTIR. The addition of HC and EEP reduced the DT and CA, and HC and lecithin reduced the swelling capacity. However, the swelling capacity was not affected by presence of EEP. The addition of lecithin to gelatin and HC ODFs may improve the incorporation and the oral transport of active compounds such as EEP. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Flavonoids purified from parsley inhibit human blood platelet aggregation and adhesion to collagen under flow.

    Science.gov (United States)

    Gadi, Dounia; Bnouham, Mohamed; Aziz, Mohammed; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Bruel, Arlette; Berrabah, Mohamed; Legrand, Chantal; Fauvel-Lafeve, Françoise; Mekhfi, Hassane

    2012-08-10

    Blood platelets are directly involved in both haemostatic and pathologic thrombotic processes, through their adhesion, secretion and aggregation. In this study, we investigated the effect of genins (aglycone flavonoids without sugar group) isolated from parsley (Petroselinum crispum) leaves in vitro on human platelet aggregation and adhesion to a collagen-coated surface under physiologic flow conditions. The aggregation and adhesion studies were monitored after pre-incubation of platelets with genins. Genins inhibited dose dependently aggregation induced by thrombin, ADP and collagen. The strongest effect was observed in collagen induced aggregation (IC50 = 0.08 ± 0.01 mg/ml). The HPLC identification of genins compounds revealed the presence of keampferol, apigenin and other not identified compounds. The aggregation tests showed that these compounds have anti-aggregating activity. In addition, adhesion of human platelets to collagen was greatly decreased (over 75 %) by genins (0.3 mg/ml). While the mechanism by which genins act is unclear, we suggest that these compounds may interfere with a multiple target step in the haemostasis process. These results show that genins isolated from parsley has a potent antiplatelet activity. It may be an important source of beneficial antiplatelet compounds that decrease thrombosis and cardiovascular diseases.

  13. Type XII and XIV collagens mediate interactions between banded collagen fibers in vitro and may modulate extracellular matrix deformability.

    Science.gov (United States)

    Nishiyama, T; McDonough, A M; Bruns, R R; Burgeson, R E

    1994-11-11

    Type XII and XIV collagens are very large molecules containing three extended globular domains derived from the amino terminus of each alpha chain and an interrupted triple helix. Both collagens are genetically and immunologically unique and have distinct distributions in many tissues. These collagens localize near the surface of banded collagen fibrils. The function of the molecules is unknown. We have prepared a mixture of native type XII and XIV collagens that is free of contaminating proteins by electrophoretic criteria. In addition, we have purified the collagenase-resistant globular domains of type XII or XIV collagens (XII-NC-3 or XIV-NC-3). In this study, we have investigated the effect of intact type XII and XIV and XII-NC-3 or XIV-NC-3 on the interactions between fibroblasts and type I collagen fibrils. We find that both type XII and XIV collagens promote collagen gel contraction mediated by fibroblasts, even in the absence of serum. The activity is present in the NC-3 domains. The effect is dose-dependent and is inhibited by denaturation. The effect of type XII NC-3 is inhibited by the addition of anti-XII antiserum. To elucidate the mechanism underlying this phenomenon, we examined the effect of XII-NC-3 or XIV-NC-3 on deformability of collagen gels by centrifugal force. XII-NC-3 or XIV-NC-3 markedly promotes gel compression after centrifugation. The effect is also inhibited by denaturation, and the activity of type XII-NC3 is inhibited by the addition of anti-XII antiserum. The results indicate that the effect of XII-NC-3 or XIV-NC-3 on collagen gel contraction by fibroblasts is not due to activation of cellular events but rather results from the increase in mobility of hydrated collagen fibrils within the gel. These studies suggest that collagen types XII and XIV may modulate the biomechanical properties of tissues.

  14. Hydroxychloroquine induces inhibition of collagen type II and oligomeric matrix protein COMP expression in chondrocytes

    Directory of Open Access Journals (Sweden)

    Tao Li

    2016-06-01

    Full Text Available The aim of this study was to investigate the effect of hydroxychloroquine on the level of collagen type II and oligomeric matrix protein COMP expression in chondrocytes of knee osteoarthritis. The rate of growth in cartilage cells was analyzed using MTT assay whereas the Col-2 and COMP expression levels were detected by RT-PCR and Western blotting analyses. For the determination of MMP-13 expression, ELISA test was used. The results revealed no significant change in the rate of cartilage cell proliferation in hydroxychloroquine-treated compared to untreated cells. Hydroxychloro-quine treatment exhibited concentration- and time-dependent effect on the inhibition of collagen type II and COMP expression in chondrocytes. However, its treatment caused a significant enhancement in the expression levels of MMP-13 compared to the untreated cells. Therefore, hydroxychloro-quine promotes expression of MMP-13 and reduces collagen type II and COMP expression levels in chondrocytes without any significant change in the growth of cells.

  15. Development of a specific affinity-matured exosite inhibitor to MT1-MMP that efficiently inhibits tumor cell invasion in vitro and metastasis in vivo

    DEFF Research Database (Denmark)

    Botkjaer, Kenneth A; Kwok, Hang Fai; Terp, Mikkel G

    2016-01-01

    therapeutic target. Here, we report the identification of antibody fragments to MT1-MMP that potently and specifically inhibit its cell surface functions. Lead antibody clones displayed inhibitory activity towards pro-MMP-2 activation, collagen-film degradation and gelatin-film degradation, and were shown......The membrane-associated matrix metalloproteinase-14, MT1-MMP, has been implicated in pericellular proteolysis with an important role in cellular invasion of collagenous tissues. It is substantially upregulated in various cancers and rheumatoid arthritis, and has been considered as a potential...... to bind to the MT1-MMP catalytic domain outside the active site cleft, inhibiting binding to triple helical collagen. Affinity maturation using CDR3 randomization created a second generation of antibody fragments with dissociation constants down to 0.11 nM, corresponding to an improved affinity of 332...

  16. Delphinidin prevents high glucose-induced cell proliferation and collagen synthesis by inhibition of NOX-1 and mitochondrial superoxide in mesangial cells

    Directory of Open Access Journals (Sweden)

    Seung Eun Song

    2016-04-01

    Full Text Available This study examined the effect of delphinidin on high glucose-induced cell proliferation and collagen synthesis in mesangial cells. Glucose dose-dependently (5.6–25 mM increased cell proliferation and collagen I and IV mRNA levels, whereas pretreatment with delphinidin (50 μM prevented cell proliferation and the increased collagen mRNA levels induced by high glucose (25 mM. High glucose increased reactive oxygen species (ROS generation, and this was suppressed by pretreating delphinidin or the antioxidant N-acetyl cysteine. NADPH oxidase (NOX 1 was upregulated by high glucose, but pretreatment with delphinidin abrogated this upregulation. Increased mitochondrial superoxide by 25 mM glucose was also suppressed by delphinidin. The NOX inhibitor apocynin and mitochondria-targeted antioxidant Mito TEMPO inhibited ROS generation and cell proliferation induced by high glucose. Phosphorylation of extracellular signal regulated kinase (ERK1/2 was increased by high glucose, which was suppressed by delphinidin, apocynin or Mito TEMPO. Furthermore, PD98059 (an ERK1/2 inhibitor prevented the high glucose-induced cell proliferation and increased collagen mRNA levels. Transforming growth factor (TGF-β protein levels were elevated by high glucose, and pretreatment with delphinidin or PD98059 prevented this augmentation. These results suggest that delphinidin prevents high glucose-induced cell proliferation and collagen synthesis by inhibition of NOX-1 and mitochondrial superoxide in mesangial cells.

  17. Engineering D-Amino Acid Containing Collagen Like Peptide at the Cleavage Site of Clostridium histolyticum Collagenase for Its Inhibition.

    Directory of Open Access Journals (Sweden)

    Punitha Velmurugan

    Full Text Available Collagenase is an important enzyme which plays an important role in degradation of collagen in wound healing, cancer metastasis and even in embryonic development. However, the mechanism of this degradation has not yet been completely understood. In the field of biomedical and protein engineering, the design and development of new peptide based materials is of main concern. In the present work an attempt has been made to study the effect of DAla in collagen like peptide (imino-poor region of type I collagen on the structure and stability of peptide against enzyme hydrolysis. Effect of replacement of DAla in the collagen like peptide has been studied using circular dichroic spectroscopy (CD. Our findings suggest that, DAla substitution leads to conformational changes in the secondary structure and favours the formation of polyproline II conformation than its L-counterpart in the imino-poor region of collagen like peptides. Change in the chirality of alanine at the cleavage site of collagenase in the imino-poor region inhibits collagenolytic activity. This may find application in design of peptides and peptidomimics for enzyme-substrate interaction, specifically with reference to collagen and other extra cellular matrix proteins.

  18. Colloidal Gold--Collagen Protein Core--Shell Nanoconjugate: One-Step Biomimetic Synthesis, Layer-by-Layer Assembled Film, and Controlled Cell Growth.

    Science.gov (United States)

    Xing, Ruirui; Jiao, Tifeng; Yan, Linyin; Ma, Guanghui; Liu, Lei; Dai, Luru; Li, Junbai; Möhwald, Helmuth; Yan, Xuehai

    2015-11-11

    The biogenic synthesis of biomolecule-gold nanoconjugates is of key importance for a broad range of biomedical applications. In this work, a one-step, green, and condition-gentle strategy is presented to synthesize stable colloidal gold-collagen core-shell nanoconjugates in an aqueous solution at room temperature, without use of any reducing agents and stabilizing agents. It is discovered that electrostatic binding between gold ions and collagen proteins and concomitant in situ reduction by hydroxyproline residues are critically responsible for the formation of the core-shell nanoconjugates. The film formed by layer-by-layer assembly of such colloidal gold-collagen nanoconjugates can notably improve the mechanical properties and promote cell adhesion, growth, and differentiation. Thus, the colloidal gold-collagen nanoconjugates synthesized by such a straightforward and clean manner, analogous to a biomineralization pathway, provide new alternatives for developing biologically based hybrid biomaterials toward a range of therapeutic and diagnostic applications.

  19. Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist inhibits collagen synthesis in human hypertrophic scar fibroblasts by targeting Smad3 via miR-145

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hua-Yu; Li, Chao; Zheng, Zhao; Zhou, Qin; Guan, Hao; Su, Lin-Lin; Han, Jun-Tao; Zhu, Xiong-Xiang; Wang, Shu-yue; Li, Jun, E-mail: lijunfmmu@163.com; Hu, Da-Hai, E-mail: hudahaifmmu@aliyun.com

    2015-03-27

    The transcription factor peroxisome proliferator-activated receptor-γ (PPAR-γ) functions to regulate cell differentiation and lipid metabolism. Recently, its agonist has been documented to regulate extracellular matrix production in human dermal fibroblasts. This study explored the underlying molecular mechanisms and gene interactions in hypertrophic scar fibroblasts (HSFBs) in vitro. HSFBs were cultured and treated with or without PPAR-γ agonist or antagonist for gene expression. Bioinformatical analysis predicted that miR-145 could target Smad3 expression. Luciferase assay was used to confirm such an interaction. The data showed that PPAR-γ agonist troglitazone suppressed expression of Smad3 and Col1 in HSFBs. PPAR-γ agonist induced miR-145 at the gene transcriptional level, which in turn inhibited Smad3 expression and Col1 level in HSFBs. Furthermore, ELISA data showed that Col1 level in HSFBs was controlled by a feedback regulation mechanism involved in PPAR-γ agonist and antagonist-regulated expression of miR-145 and Smad3 in HSFBs. These findings indicate that PPAR-γ-miR-145-Smad3 axis plays a role in regulation of collagen synthesis in HSFBs. - Highlights: • PPAR-γ agonist inhibits collagen synthesis in HSFBs. • Smad3 and type I collagen expression are decreased by PPAR-γ agonist. • miR-145 expression is increased by PPAR-γ agonist in HSFBs. • Increased miR-145 inhibits collagen synthesis by targeting Smad3. • miR-145 regulates collagen synthesis.

  20. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    International Nuclear Information System (INIS)

    Skopinska-Wisniewska, J.; Sionkowska, A.; Kaminska, A.; Kaznica, A.; Jachimiak, R.; Drewa, T.

    2009-01-01

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in biomaterial

  1. Surface characterization of collagen/elastin based biomaterials for tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Skopinska-Wisniewska, J., E-mail: joanna@chem.uni.torun.pl [Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun (Poland); Sionkowska, A.; Kaminska, A. [Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Torun (Poland); Kaznica, A.; Jachimiak, R.; Drewa, T. [Collegium Medicum, Nicolaus Copernicus University, Karlowicz 24, 85-092 Bydgoszcz (Poland)

    2009-07-15

    Collagen and elastin are the main proteins of extracellular matrix. Collagen plays a crucial role in tensile strength of tissues, whereas elastin provides resilience to many organs. Both biopolymers are readily available and biocompatible. These properties point out that collagen and elastin are good components of materials for many potential medical applications. The surface properties of biomaterials play an important role in biomedicine as the majority of biological reactions occur on the surface of implanted materials. One of the methods of surface modification is UV-irradiation. The exposition of the biomaterial on ultraviolet light can alterate surface properties of the materials, their chemical stability, swelling properties and mechanical properties as well. The aim of our work was to study the surface properties and biocompatibility of new collagen/elastin based biomaterials and consideration of the influence of ultraviolet light on these properties. The surface properties of collagen/elastin based biomaterials modified by UV-irradiation were studied using the technique of atomic force microscopy (AFM) and contact angle measurements. On the basis of the results the surface free energy and its polar component was calculated using Owens-Wendt method. To assess the biological performance of films based on collagen, elastin and their blends, the response of 3T3 cell was investigated. It was found that the surface of collagen/elastin film is enriched in less polar component - collagen. Exposition on UV light increases polarity of collagen/elastin based films, due to photooxidation process. The AFM images have shown that topography and roughness of the materials had been also affected by UV-irradiation. The changes in surface properties influence on interaction between the material's surface and cells. The investigation of 3T3 cells grown on films based on collagen, elastin and their blends, leads to the conclusion that higher content of elastin in

  2. Triple helix-forming oligonucleotide corresponding to the polypyrimidine sequence in the rat alpha 1(I) collagen promoter specifically inhibits factor binding and transcription.

    Science.gov (United States)

    Kovacs, A; Kandala, J C; Weber, K T; Guntaka, R V

    1996-01-19

    Type I and III fibrillar collagens are the major structural proteins of the extracellular matrix found in various organs including the myocardium. Abnormal and progressive accumulation of fibrillar type I collagen in the interstitial spaces compromises organ function and therefore, the study of transcriptional regulation of this gene and specific targeting of its expression is of major interest. Transient transfection of adult cardiac fibroblasts indicate that the polypurine-polypyrimidine sequence of alpha 1(I) collagen promoter between nucleotides - 200 and -140 represents an overall positive regulatory element. DNase I footprinting and electrophoretic mobility shift assays suggest that multiple factors bind to different elements of this promoter region. We further demonstrate that the unique polypyrimidine sequence between -172 and -138 of the promoter represents a suitable target for a single-stranded polypurine oligonucleotide (TFO) to form a triple helix DNA structure. Modified electrophoretic mobility shift assays show that this TFO specifically inhibits the protein-DNA interaction within the target region. In vitro transcription assays and transient transfection experiments demonstrate that the transcriptional activity of the promoter is inhibited by this oligonucleotide. We propose that TFOs represent a therapeutic potential to specifically influence the expression of alpha 1(I) collagen gene in various disease states where abnormal type I collagen accumulation is known to occur.

  3. Study of HMG-CoA Reductase Inhibition Activity of the Hydrolyzed Product of Snakehead Fish (Channa striata) Skin Collagen with 50 kDa Collagenase from Bacillus licheniformis F11.4.

    Science.gov (United States)

    Virginia, Agnes; Rachmawati, Heni; Riani, Catur; Retnoningrum, Debbie S

    2016-01-01

    Bioactive peptides produced from enzymatic hydrolysis fibrous protein have been proven to have several biological activities. Previous study showed that the hydrolysis product of snakehead fish skin collagen with 26 kDa collagenase from Bacillus licheniformis F11.4 showed HMG-CoA (HMGR) inhibition activity. The aim of this research was to determine the ability of the hydrolysis product produced from snakehead fish skin collagen hydrolysed by 50 kDa collagenase from B. licheniformis F11.4 in inhibiting HMGR activity. Snakehead fish skin collagen was extracted using an acid method and collagenase was produced from B. licheniformis F11.4 using half-strength Luria Bertani (LB) medium containing 5% collagen. Crude collagenase was concentrated and fractionated using the DEAE Sephadex A-25 column eluted with increasing gradient concentrations of NaCl. Collagen, collagenase, and fractions were analyzed using SDS-PAGE and collagenolytic activity was analyzed by the zymography method. Collagenase with 50 kDa molecular weight presented in fraction one was used to hydrolyze the collagen. The reaction was done in 18 hours at 50°C. The hydrolysis product using 3.51 μg collagen and 9 ng collagenase showed 25.8% inhibition activity against pravastatin. This work shows for the first time that the hydrolysis product of snakehead fish skin collagen and 50 kDa collagenase from B. licheniformis F11.4 has potential as an anticholesterol agent.

  4. Fish collagen is an important panallergen in the Japanese population.

    Science.gov (United States)

    Kobayashi, Y; Akiyama, H; Huge, J; Kubota, H; Chikazawa, S; Satoh, T; Miyake, T; Uhara, H; Okuyama, R; Nakagawara, R; Aihara, M; Hamada-Sato, N

    2016-05-01

    Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Comparative Effects of Biodynes, Tocotrienol-Rich Fraction, and Tocopherol in Enhancing Collagen Synthesis and Inhibiting Collagen Degradation in Stress-Induced Premature Senescence Model of Human Diploid Fibroblasts

    Science.gov (United States)

    Jam, Faidruz Azura; Ismail, Zahariah; Wan Ngah, Wan Zurinah

    2013-01-01

    Biodynes, tocotrienol-rich fraction (TRF), and tocopherol have shown antiaging properties. However, the combined effects of these compounds on skin aging are yet to be investigated. This study aimed to elucidate the skin aging effects of biodynes, TRF, and tocopherol on stress-induced premature senescence (SIPS) model of human diploid fibroblasts (HDFs) by determining the expression of collagen and MMPs at gene and protein levels. Primary HDFs were treated with biodynes, TRF, and tocopherol prior to hydrogen peroxide (H2O2) exposure. The expression of COL1A1, COL3A1, MMP1, MMP2, MMP3, and MMP9 genes was determined by qRT-PCR. Type I and type III procollagen proteins were measured by Western blotting while the activities of MMPs were quantified by fluorometric Sensolyte MMP Kit. Our results showed that biodynes, TRF, and tocopherol upregulated collagen genes and downregulated MMP genes (P < 0.05). Type I procollagen and type III procollagen protein levels were significantly increased in response to biodynes, TRF, and tocopherol treatment (P < 0.05) with reduction in MMP-1, MMP-2, MMP-3, and MMP-9 activities (P < 0.05). These findings indicated that biodynes, TRF, and tocopherol effectively enhanced collagen synthesis and inhibited collagen degradation and therefore may protect the skin from aging. PMID:24396567

  6. Comparative Effects of Biodynes, Tocotrienol-Rich Fraction, and Tocopherol in Enhancing Collagen Synthesis and Inhibiting Collagen Degradation in Stress-Induced Premature Senescence Model of Human Diploid Fibroblasts

    Directory of Open Access Journals (Sweden)

    Suzana Makpol

    2013-01-01

    Full Text Available Biodynes, tocotrienol-rich fraction (TRF, and tocopherol have shown antiaging properties. However, the combined effects of these compounds on skin aging are yet to be investigated. This study aimed to elucidate the skin aging effects of biodynes, TRF, and tocopherol on stress-induced premature senescence (SIPS model of human diploid fibroblasts (HDFs by determining the expression of collagen and MMPs at gene and protein levels. Primary HDFs were treated with biodynes, TRF, and tocopherol prior to hydrogen peroxide (H2O2 exposure. The expression of COL1A1, COL3A1, MMP1, MMP2, MMP3, and MMP9 genes was determined by qRT-PCR. Type I and type III procollagen proteins were measured by Western blotting while the activities of MMPs were quantified by fluorometric Sensolyte MMP Kit. Our results showed that biodynes, TRF, and tocopherol upregulated collagen genes and downregulated MMP genes (P<0.05. Type I procollagen and type III procollagen protein levels were significantly increased in response to biodynes, TRF, and tocopherol treatment (P<0.05 with reduction in MMP-1, MMP-2, MMP-3, and MMP-9 activities (P<0.05. These findings indicated that biodynes, TRF, and tocopherol effectively enhanced collagen synthesis and inhibited collagen degradation and therefore may protect the skin from aging.

  7. Inhibiting and healing effects of potassium permanganate for silane films

    Energy Technology Data Exchange (ETDEWEB)

    She, Zuxin; Li, Qing, E-mail: liqingswu@yeah.net; Wang, Shaoyin; Luo, Fei; Chen, Funan; Li, Longqin

    2013-07-31

    In this study, the inhibiting and healing effects of potassium permanganate for silane films were investigated, and the optimal mole ratio of MnO{sub 4}{sup −}/Cl{sup −} was also obtained. The inhibiting process and healing mechanism were studied by electrochemical measurements and scanning electron microcopy coupled with energy dispersive spectroscopy. Results demonstrated that the introduction of potassium permanganate to electrolyte could stop the development of corrosion process and the optimal inhibiting mole ratio of MnO{sub 4}{sup −}/Cl{sup −} is 2 × 10{sup −1} with a protective efficiency about 99.24%. According to its high protective efficiency and the nice results of long-term immersion test, potassium permanganate as an inhibitor could prolong the lifetime of silane films and expand its scope of application. - Highlights: • Healing sol–gel film was obtained by adding KMnO{sub 4} into electrolyte. • An optimal inhibitor mole ratio of MnO{sub 4}{sup −}/Cl{sup −} for Si sol–gel was 2 × 10{sup −1}. • The best protective efficiency was approximately 99.24%. • The inhibiting effect may be due to production of insoluble manganese hydroxide/oxide.

  8. Listeria monocytogenes inhibition by defatted mustard meal-based edible films.

    Science.gov (United States)

    Lee, Hahn-Bit; Noh, Bong Soo; Min, Sea C

    2012-02-01

    An antimicrobial edible film was developed from defatted mustard meal (Sinapis alba) (DMM), a byproduct from the bio-fuel industry, without incorporating external antimicrobials and its antimicrobial activity against Listeria monocytogenes and physical properties were investigated. The DMM colloidal solution consisting of 184 g water, 14 g DMM, and 2g glycerol was homogenized and incubated at 37°C for 0.2, 0.5, 24 or 48 h to prepare a film-forming solution. The pH of a portion of the film-forming solution (pH 5.5) was adjusted to 2.0 or 4.0. Films were formed by drying the film-forming solutions at 23°C for 48 h. The film-forming solution incubated for 48 h inhibited L. monocytogenes in broth and on agar media. Antimicrobial effects of the film prepared from the 48 h-incubated solution increased with decrease in pH of the solution from 5.5 to 2.0. The film from the film forming solution incubated for 48 h (pH 2.0) initially inhibited more than 4.0 log CFU/g of L. monocytogenes inoculated on film-coated salmon. The film-coating retarded the growth of L. monocytogenes in smoked salmon at 5, 10, and 15°C and the antimicrobial effect during storage was more noticeable when the coating was applied before inoculation than when it was applied after inoculation. The tensile strength, percentage elongation, solubility in watercxu, and water vapor permeability of the anti microbial film were 2.44 ± 0.19 MPa, 6.40 ± 1.13%, 3.19 ± 0.90%, and 3.18 ± 0.63 gmm/kPa hm(2), respectively. The antimicrobial DMM films have demonstrated a potential to be applied to foods as wraps or coatings to control the growth of L. monocytogenes. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Synthesis and Characterization of Protein-Conjugated Silver Nanoparticles/Silver Salt Loaded Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) Film for Prevention of Bacterial Infections and Potential Use in Bone Tissue Engineering Applications

    Science.gov (United States)

    Bakare, Rotimi Ayotunde

    Failure of orthopedic implants due to bacterial infection has been a major concern in bone tissue engineering. To this end, we have formulated a potential orthopedic implant made of naturally occurring biodegradable polymer, i.e. poly (3-hydroxylbutyrate-co-3-hydroxylvalerate) (PHBV), modified with BSA conjugated silver nanoparticles and or silver chloride. Upon release of Ag NPs and or Ag+ in the implant region, can promote aseptic environment by inhibition of bacteria growth and also support/maintain bone cell adhesion, growth, and proliferation. For formulating nanoparticles loaded PHBV scaffold, we exploit specific interaction between bovine serum albumin (BSA) of BSA capped silver nanoparticles and collagen of collagen immobilized PHBV scaffold. Therefore, the first part of this study dealt with synthesis and characterization of collagen immobilized PHBV film for loading of BSA stabilized silver (Ag/BSA) nanoparticles. Two different approaches were used to immobilize collagen on macroporous PHBV film. First approach uses thermal radical copolymerization with 2-hydroxyethylmethacrylate (HEMA), while the second approach uses aminolysis to functionalize macroporous PHBV film. Using collagen crosslinker, type I collagen was covalently grafted to formulate collagen immobilized PHEMA-g-PHBV and collagen immobilized NH2-PHBV films, respectively. Spectroscopic (FTIR, XPS), physical (SEM), and thermal (TGA) techniques were used to characterize the functionalized PHBV films. The Ag/BSA nanoparticles were then loaded on collagen immobilized PHBV films and untreated PHBV films. The concentration of nanoparticles loaded on PHBV film was determined by atomic absorption spectrometry and fluorescence spectroscopy. The amount of nanoparticles loaded on collagen immobilized PHBV film was found to be significantly greater than that on untreated PHBV film. The amount of Ag/BSA nanoparticles loaded on collagen immobilized PHBV film was found to depend on the concentration of Ag

  10. Lipo-PGE1 suppresses collagen production in human dermal fibroblasts via the ERK/Ets-1 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yoolhee Yang

    Full Text Available Dysregulation of collagen production contributes to various pathological processes, including tissue fibrosis as well as impaired wound healing. Lipo-prostaglandin E1 (Lipo-PGE1, a lipid microsphere-incorporated prostaglandin E1, is used as a vasodilator for the treatment of peripheral vascular diseases. Lipo-PGE1 was recently shown to enhance human dermal fibroblast (HDF migration and in vivo wound healing. No published study has characterized the role of Lipo-PGE1 in collagen regulation in HDFs. Here, we investigated the cellular signaling mechanism by which Lipo-PGE1 regulates collagen in HDFs. Collagen production was evaluated by the Sircol collagen assay, Western blot analysis of type I collagen and real time PCR. Unexpectedly, Lipo-PGE1 decreased mRNA expression of collagen 1A1, 1A2, and 3A1. Lipo-PGE1 markedly inhibited type I collagen and total soluble collagen production. In addition, Lipo-PGE1 inhibited transforming growth factor-β-induced collagen expression via Smad2 phosphorylation. To further investigate whether extracellular signal-regulated kinase (ERK/Ets-1 signaling, a crucial pathway in collagen regulation, is involved in Lipo-PGE1-inhibited collagen production, cells were pretreated with an ERK-specific inhibitor, PD98059, prior to the addition of Lipo-PGE1. Lipo-PGE1-inhibited collagen mRNA expression and total soluble collagen production were recovered by pretreatment with PD98059. Moreover, Lipo-PGE1 directly induced the phosphorylation of ERK. Furthermore, silencing of Ets-1 recovered Lipo-PGE1-inhibited collagen production and PD98059 blocked Lipo-PGE1-enhanced Ets-1 expression. The present study reveals an important role for Lipo-PGE1 as a negative regulator of collagen gene expression and production via ERK/Ets-1 signaling. These results suggest that Lipo-PGE1 could potentially be a therapeutic target in diseases with deregulated collagen turnover.

  11. Epicutaneous Immunization with Type II Collagen Inhibits both Onset and Progression of Chronic Collagen-Induced Arthritis

    OpenAIRE

    Strid, Jessica; Tan, Lee Aun; Strobel, Stephan; Londei, Marco; Callard, Robin

    2007-01-01

    Epicutaneous immunization is a potential non-invasive technique for antigen-specific immune-modulation. Topical application of protein antigens to barrier-disrupted skin induces potent antigen-specific immunity with a strong Th2-bias. In this study, we investigate whether the autoimmune inflammatory response of chronic collagen-induced arthritis (CCIA) in DBA/1-TCR-beta Tg mice can be modified by epicutaneous immunization. We show that epicutaneous immunization with type II collagen (CII) inh...

  12. Degradation of type IV collagen by neoplastic human skin fibroblasts

    International Nuclear Information System (INIS)

    Sheela, S.; Barrett, J.C.

    1985-01-01

    An assay for the degradation of type IV (basement membrane) collagen was developed as a biochemical marker for neoplastic cells from chemically transformed human skin fibroblasts. Type IV collagen was isolated from basement membrane of Syrian hamster lung and type I collagen was isolated from rat tails; the collagens were radioactively labelled by reductive alkylation. The abilities of normal (KD) and chemically transformed (Hut-11A) human skin fibroblasts to degrade the collagens were studied. A cell-associated assay was performed by growing either normal or transformed cells in the presence of radioactively labelled type IV collagen and measuring the released soluble peptides in the medium. This assay also demonstrated that KD cells failed to synthesize an activity capable of degrading type IV collagen whereas Hut-11A cells degraded type IV collagen in a linear manner for up to 4 h. Human serum at very low concentrations, EDTA and L-cysteine inhibited the enzyme activity, whereas protease inhibitors like phenylmethyl sulfonyl fluoride, N-ethyl maleimide or soybean trypsin inhibitor did not inhibit the enzyme from Hut-11A cells. These results suggest that the ability to degrade specifically type IV collagen may be an important marker for neoplastic human fibroblasts and supports a role for this collagenase in tumor cell invasion

  13. The decorin sequence SYIRIADTNIT binds collagen type I

    DEFF Research Database (Denmark)

    Kalamajski, Sebastian; Aspberg, Anders; Oldberg, Ake

    2007-01-01

    Decorin belongs to the small leucine-rich repeat proteoglycan family, interacts with fibrillar collagens, and regulates the assembly, structure, and biomechanical properties of connective tissues. The decorin-collagen type I-binding region is located in leucine-rich repeats 5-6. Site......-directed mutagenesis of this 54-residue-long collagen-binding sequence identifies Arg-207 and Asp-210 in leucine-rich repeat 6 as crucial for the binding to collagen. The synthetic peptide SYIRIADTNIT, which includes Arg-207 and Asp-210, inhibits the binding of full-length recombinant decorin to collagen in vitro....... These collagen-binding amino acids are exposed on the exterior of the beta-sheet-loop structure of the leucine-rich repeat. This resembles the location of interacting residues in other leucine-rich repeat proteins....

  14. Binding of collagens to an enterotoxigenic strain of Escherichia coli

    International Nuclear Information System (INIS)

    Visai, L.; Speziale, P.; Bozzini, S.

    1990-01-01

    An enterotoxigenic strain of Escherichia coli, B34289c, has been shown to bind the N-terminal region of fibronectin with high affinity. We now report that this strain also binds collagen. The binding of 125I-labeled type II collagen to bacteria was time dependent and reversible. Bacteria expressed a limited number of collagen receptors (2.2 x 10(4) per cell) and bound collagen with a Kd of 20 nM. All collagen types tested (I to V) as well as all tested cyanogen bromide-generated peptides [alpha 1(I)CB2, alpha 1(I)CB3, alpha 1(I)CB7, alpha 1(I)CB8, and alpha 2(I)CB4] were recognized by bacterial receptors, as demonstrated by the ability of these proteins to inhibit the binding of 125I-labeled collagen to bacteria. Of several unlabeled proteins tested in competition experiments, fibronectin and its N-terminal region strongly inhibited binding of the radiolabeled collagen to E. coli cells. Conversely, collagen competed with an 125I-labeled 28-kilodalton fibronectin fragment for bacterial binding. Collagen bound to bacteria could be displaced by excess amounts of either unlabeled fibronectin or its N-terminal fragment. Similarly, collagen could displace 125I-labeled N-terminal peptide of fibronectin bound to the bacterial cell surface. Bacteria grown at 41 degrees C or in the presence of glucose did not express collagen or fibronectin receptors. These results indicate the presence of specific binding sites for collagen on the surface of E. coli cells and furthermore that the collagen and fibronectin binding sites are located in close proximity, possibly on the same structure

  15. Evaluation of human collagen biomaterials in the healing of colonic anastomoses in dogs.

    Science.gov (United States)

    Mutter, D; Aprahamian, M; Tiollier, J; Sonzini, P; Marescaux, J

    1997-04-01

    To investigate the ability of human collagen biomaterials to secure colonic anastomoses in dogs and to evaluate the biocompatibility of anastomotic protection patches (APP). Experimental open study. Experimental research centre, France. 21 mongrel dogs randomised into three groups of 7 each. Standard transverse colonic end-to-end anastomoses were secured with two-layer oxidised collagen I + III sponge covered with thin crosslinked collagen IV film (APP 1) glued around the suture (n = 7); two-layer oxidised collagen I + III sponge covered with thin non-crosslinked collagen I + III film patch (APP 2) (n = 7); or sealed by fibrin sealant (n = 7), which acted as a controls. Gross examination, radiological control (barium enemas), and microscopic examination on day 35 postoperatively. Gross clinical and radiological examinations on day 35 showed normal wound healing in all but one dog in which the anastomoses had occluded by day 16. There was significantly less stricturing with the APP 2 patch (p < 0.05 compared with the controls). Microscopic examination showed complete absorption of the APP 2 patches as well as quicker mucosal and extracellular matrix repair than controls. The APP 1 patch gave the best healing of the muscular layer but did not reduce anastomosis stricturing, and was not totally absorbed. Collagen supporting devices do not alter healing of the large bowel. Encircling patches do not increase the number of adhesions or the rate of anastomotic stricturing and a thin fibrillar collagen I + III dense layer may even improve it. The speed of absorption of the patch depends on the type of dense collagen film. These results argue for a prospective clinical evaluation in humans.

  16. Epac is required for exogenous and endogenous stimulation of adenosine A2B receptor for inhibition of angiotensin II-induced collagen synthesis and myofibroblast differentiation.

    Science.gov (United States)

    Phosri, Sarawuth; Bunrukchai, Kwanchai; Parichatikanond, Warisara; Sato, Vilasinee H; Mangmool, Supachoke

    2018-01-10

    Angiotensin II (Ang II) plays an important role on the pathogenesis of cardiac fibrosis. Prolong and overstimulation of angiotensin II type 1 receptor with Ang II-induced collagen synthesis and myofibroblast differentiation in cardiac fibroblasts, leading to cardiac fibrosis. Although adenosine and its analogues are known to have cardioprotective effects, the mechanistic by which adenosine A 2 receptors (A 2 Rs) inhibit Ang II-induced cardiac fibrosis is not clearly understood. In the present study, we examined the effects of exogenous adenosine and endogenous adenosine on Ang II-induced collagen and myofibroblast differentiation determined by α-smooth muscle action (α-SMA) overexpression and their underlying signal transduction. Elevation of endogenous adenosine levels resulted in the inhibition of Ang II-induced collagen type I and III and α-SMA synthesis in cardiac fibroblasts. Moreover, treatment with exogenous adenosine which selectively stimulated A 2 Rs also suppressed Ang II-induced collagen synthesis and α-SMA production. These antifibrotic effects of both endogenous and exogenous adenosines are mediated through the A 2B receptor (A 2B R) subtype. Stimulation of A 2B R exhibited antifibrotic effects via the cAMP-dependent and Epac-dependent pathways. Our results provide new mechanistic insights regarding the role for cAMP and Epac on A 2B R-mediated antifibrotic effects. Thus, A 2B R is one of the potential therapeutic targets against cardiac fibrosis.

  17. Genetics and biochemistry of collagen binding-triggered glandular differentiation in a human colon carcinoma cell line

    International Nuclear Information System (INIS)

    Pignatelli, M.; Bodmer, W.F.

    1988-01-01

    The authors have examined the interaction between collagen binding and epithelial differentiation by using a human colon carcinoma cell line (SW1222) that can differentiate structurally when grown in a three-dimensional collagen gel to form glandular structures. As much as 66% inhibition of glandular differentiation can be achieved by addition to the culture of a synthetic peptide containing the Arg-Gly-Asp-Thr (RGDT) sequence, which is a cell recognition site found in collagen. Arg-Gly-Asp-Thr also inhibited the cell attachment to collagen-coated plates. Chromosome 15 was found in all human-mouse hybrid clones that could differentiate in the collagen gel and bind collagen. Both binding to collagen and glandular differentiation of the hybrid cells were also inhibited by Arg-Gly-Asp-Thr as for the parent cell line SW1222. The ability of SW1222 cells to express the differentiated phenotype appears, therefore, to be determined by an Arg-Gly-Asp-directed collagen receptor on the cell surface that is controlled by a gene on chromosome 15

  18. Disintegration of collagen fibrils by Glucono-δ-lactone: An implied lead for disintegration of fibrosis.

    Science.gov (United States)

    Jayamani, Jayaraman; Ravikanth Reddy, R; Madhan, Balaraman; Shanmugam, Ganesh

    2018-02-01

    Excess accumulation of collagen (fibrosis) undergoes self-aggregation, which leads to fibrillar collagen, on the extracellular matrix is the hallmark of a number of diseases such as keloids, hypertrophic scars, and systemic scleroderma. Direct inhibition or disintegration of collagen fibrils by small molecules offer a therapeutic approach to prevent or treat the diseases related to fibrosis. Herein, the anti-fibrotic property of Glucono-δ-lactone (GdL), known as acidifier, on the fibrillation and its disintegration of collagen was investigated. As collagen fibrillation is pH dependent, the pH modulation property of GdL is attractive to inhibit self-association of collagen. Optical density and microscopic data indicate that GdL elicits concentration-dependent fibril inhibition and also disintegrates pre-formed collagen fibrils. The simultaneous pH analysis showed that the modulation(lowering) of pH by GdL is the primary cause for its anti-fibrotic activity. The intact triple helical structure of collagen upon treatment of GdL suggests that collagen fibril disintegration can be achieved without affecting the native structure of collagen which is essential for any anti-fibrotic agents. Saturation transfer difference (STD) NMR result reveals that GdL is in proximity to collagen. The present results thus suggest that GdL provides a lead to design novel anti-fibrotic agents for the pathologies related to collagen deposition. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A 48 kDa collagen-binding phosphoprotein isolated from bovine aortic endothelial cells interacts with the collagenous domain, but not the globular domain, of collagen type IV.

    Science.gov (United States)

    Yannariello-Brown, J; Madri, J A

    1990-01-15

    We have identified collagen-binding proteins in detergent extracts of metabolically labelled bovine aortic endothelial cells (BAEC) by collagen type IV-Sepharose affinity chromatography. The major collagen type IV-binding protein identified by SDS/PAGE had a molecular mass of 48 kDa, which we term the 'collagen-binding 48 kDa protein' (CB48). The pI of CB48 was 8.0-8.3 in a two-dimensional gel system, running non-equilibrium pH gel electrophoresis in the first dimension and SDS/PAGE in the second dimension. Under these conditions CB48 separated into two major (a and b) and one minor isoform (c); a was the most basic of the three isoforms. Two-dimensional chymotryptic peptide maps derived from each individual isoform were virtually identical. The charge differences between the isoforms were due in part to differential H3(32)PO4 incorporation by the protein. CB48 bound to intact collagen type IV and the collagenous region of collagen type IV, but not to the globular NC1 domain. Cell-surface labelling and indirect immunofluorescence experiments localized the bulk of CB48 intracellularly in the endoplasmic reticulum Golgi region, with a minor population of molecules on the cell surface. A specific rabbit polyclonal anti-CB48 serum did not inhibit the attachment or spreading of BAEC to collagen type IV in an 'in vitro' adhesion assay, suggesting that the cell-surface population of CB48 is not involved in BAEC adhesion. We conclude that CB48 is a collagen-binding phosphoprotein that interacts with the collagenous domain of collagen type IV and may be involved in intracellular transport of collagen molecules.

  20. Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

    Science.gov (United States)

    Liu, JunLi; Wang, YiHu; Song, ShuJun; Wang, XiJie; Qin, YaYa; Si, ShaoYan; Guo, YanChuan

    2015-01-01

    Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

  1. Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

    Directory of Open Access Journals (Sweden)

    JunLi Liu

    Full Text Available Collagen peptides (CPs and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8 for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg; OVX + calcium citrate (75 mg/kg. After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

  2. Induction and inhibition of film yeast from fermented bamboo shoot by seasoning plants

    Directory of Open Access Journals (Sweden)

    Jaruwan Maneesri

    2007-07-01

    Full Text Available Three samples of fermented bamboo shoot taken from a village in Amphur Kokpho, Pattani Province, were microbiologically examined. Total viable count was between at 104-105 cfu/ml while pH range was between 3.4-4.4. Isolation and identification of film yeast on surface of fermented liquid revealed Saccharomyces cerevisiae J1, Candida krusei J2 and Candida krusei J3. When film yeast was cultivated in liquid culture with different NaCl concentrations (0, 2.5, 5 and 7.5% (w/v, all species tolerated 2.5% NaCl addition. However, growth decreased depending on NaCl concentration. S. cerevisiae J1 grew faster than C. krusei J2 and C. krusei J3. The cultivation of film yeast in medium with different agar concentrations (0.3, 0.5, 1 and 1.5% (w/v within 24 h showed that 0.3% was the optimal agar concentration. Seasoning plants (garlic, ginger, galangal, lemon grass, lesser galangal, clove, kaffir lime, garcinia and shallot were extracted with water (3% (w/v and tested for growth inhibition. Results showed the clove extract inhibited all yeast strains within 12 h and after that the efficiency of inhibition was decreased. At low concentration of 0.75% (w/v clove extract could inhibit film yeast in fermented bamboo shoot.

  3. Chondrogenic properties of collagen type XI, a component of cartilage extracellular matrix.

    Science.gov (United States)

    Li, Ang; Wei, Yiyong; Hung, Clark; Vunjak-Novakovic, Gordana

    2018-08-01

    Cartilage extracellular matrix (ECM) has been used for promoting tissue engineering. However, the exact effects of ECM on chondrogenesis and the acting mechanisms are not well understood. In this study, we investigated the chondrogenic effects of cartilage ECM on human mesenchymal stem cells (MSCs) and identified the contributing molecular components. To this end, a preparation of articular cartilage ECM was supplemented to pellets of chondrogenically differentiating MSCs, pellets of human chondrocytes, and bovine articular cartilage explants to evaluate the effects on cell proliferation and the production of cartilaginous matrix. Selective enzymatic digestion and screening of ECM components were conducted to identify matrix molecules with chondrogenic properties. Cartilage ECM promoted MSC proliferation, production of cartilaginous matrix, and maturity of chondrogenic differentiation, and inhibited the hypertrophic differentiation of MSC-derived chondrocytes. Selective digestion of ECM components revealed a contributory role of collagens in promoting chondrogenesis. The screening of various collagen subtypes revealed strong chondrogenic effect of collagen type XI. Finally, collagen XI was found to promote production and inhibit degradation of cartilage matrix in human articular chondrocyte pellets and bovine articular cartilage explants. Our results indicate that cartilage ECM promotes chondrogenesis and inhibits hypertrophic differentiation in MSCs. Collagen type XI is the ECM component that has the strongest effects on enhancing the production and inhibiting the degradation of cartilage matrix. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Cross-Linking GPVI-Fc by Anti-Fc Antibodies Potentiates Its Inhibition of Atherosclerotic Plaque- and Collagen-Induced Platelet Activation

    Directory of Open Access Journals (Sweden)

    Janina Jamasbi, RPh

    2016-04-01

    Full Text Available To enhance the antithrombotic properties of recombinant glycoprotein VI fragment crystallizable (GPVI-Fc, the authors incubated GPVI-Fc with anti-human Fc antibodies to cross-link the Fc tails of GPVI-Fc. Cross-linking potentiated the inhibition of human plaque- and collagen-induced platelet aggregation by GPVI-Fc under static and flow conditions without increasing bleeding time in vitro. Cross-linking with anti-human-Fc Fab2 was even superior to anti-human-Fc immunoglobulin G (IgG. Advanced optical imaging revealed a continuous sheath-like coverage of collagen fibers by cross-linked GPVI-Fc complexes. Cross-linking of GPVI into oligomeric complexes provides a new, highly effective, and probably safe antithrombotic treatment as it suppresses platelet GPVI-plaque interaction selectively at the site of acute atherothrombosis.

  5. mTOR (Mechanistic Target of Rapamycin) Inhibition Decreases Mechanosignaling, Collagen Accumulation, and Stiffening of the Thoracic Aorta in Elastin-Deficient Mice.

    Science.gov (United States)

    Jiao, Yang; Li, Guangxin; Li, Qingle; Ali, Rahmat; Qin, Lingfeng; Li, Wei; Qyang, Yibing; Greif, Daniel M; Geirsson, Arnar; Humphrey, Jay D; Tellides, George

    2017-09-01

    Elastin deficiency because of heterozygous loss of an ELN allele in Williams syndrome causes obstructive aortopathy characterized by medial thickening and fibrosis and consequent aortic stiffening. Previous work in Eln -null mice with a severe arterial phenotype showed that inhibition of mTOR (mechanistic target of rapamycin), a key regulator of cell growth, lessened the aortic obstruction but did not prevent early postnatal death. We investigated the effects of mTOR inhibition in Eln -null mice partially rescued by human ELN that manifest a less severe arterial phenotype and survive long term. Thoracic aortas of neonatal and juvenile mice with graded elastin deficiency exhibited increased signaling through both mTOR complex 1 and 2. Despite lower predicted wall stress, there was increased phosphorylation of focal adhesion kinase, suggestive of greater integrin activation, and increased transforming growth factor-β-signaling mediators, associated with increased collagen expression. Pharmacological blockade of mTOR by rapalogs did not improve luminal stenosis but reduced mechanosignaling (in delayed fashion after mTOR complex 1 inhibition), medial collagen accumulation, and stiffening of the aorta. Rapalog administration also retarded somatic growth, however, and precipitated neonatal deaths. Complementary, less-toxic strategies to inhibit mTOR via altered growth factor and nutrient responses were not effective. In addition to previously demonstrated therapeutic benefits of rapalogs decreasing smooth muscle cell proliferation in the absence of elastin, we find that rapalogs also prevent aortic fibrosis and stiffening attributable to partial elastin deficiency. Our findings suggest that mTOR-sensitive perturbation of smooth muscle cell mechanosensing contributes to elastin aortopathy. © 2017 American Heart Association, Inc.

  6. Adrenomedullin and adrenotensin regulate collagen synthesis and proliferation in pulmonary arterial smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, W. [School of Control Science and Engineering, Biomedical Engineering Institute, Shandong University, Jinan, Shandong (China); Kong, Q.Y.; Zhao, C.F. [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, Shandong (China); Zhao, F. [Department of Medicine, Weill Medical College of Cornell University, New York, NY (United States); Li, F.H.; Xia, W. [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan, Shandong (China); Wang, R. [Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital, Shandong University, Jinan, Shandong (China); Hu, Y.M. [School of Control Science and Engineering, Biomedical Engineering Institute, Shandong University, Jinan, Shandong (China); Hua, M. [Shandong Institute of Scientific and Technical Information, Jinan, Shandong (China)

    2013-12-10

    To understand the pathophysiological mechanisms of pulmonary arterial smooth muscle cell (PASMC) proliferation and extracellular-matrix accumulation in the development of pulmonary hypertension and remodeling, this study determined the effects of different doses of adrenomedullin (ADM) and adrenotensin (ADT) on PASMC proliferation and collagen synthesis. The objective was to investigate whether extracellular signal-regulated kinase (ERK1/2) signaling was involved in ADM- and ADT-stimulated proliferation of PASMCs in 4-week-old male Wistar rats (body weight: 100-150 g, n=10). The proliferation of PASMCs was examined by 5-bromo-2-deoxyuridine incorporation. A cell growth curve was generated by the Cell Counting Kit-8 method. Expression of collagen I, collagen III, and phosphorylated ERK1/2 (p-ERK1/2) was evaluated by immunofluorescence. The effects of different concentrations of ADM and ADT on collagen I, collagen III, and p-ERK1/2 protein expression were determined by immunoblotting. We also investigated the effect of PD98059 inhibition on the expression of p-ERK1/2 protein by immunoblotting. ADM dose-dependently decreased cell proliferation, whereas ADT dose-dependently increased it; and ADM and ADT inhibited each other with respect to their effects on the proliferation of PASMCs. Consistent with these results, the expression of collagen I, collagen III, and p-ERK1/2 in rat PASMCs decreased after exposure to ADM but was upregulated after exposure to ADT. PD98059 significantly inhibited the downregulation by ADM and the upregulation by ADT of p-ERK1/2 expression. We conclude that ADM inhibited, and ADT stimulated, ERK1/2 signaling in rat PASMCs to regulate cell proliferation and collagen expression.

  7. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    International Nuclear Information System (INIS)

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E.

    1987-01-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of [ 3 H]serotonin, or alter the dose-responsive binding of 125 I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF

  8. SHP-1, a novel peptide isolated from seahorse inhibits collagen release through the suppression of collagenases 1 and 3, nitric oxide products regulated by NF-kappaB/p38 kinase.

    Science.gov (United States)

    Ryu, BoMi; Qian, Zhong-Ji; Kim, Se-Kwon

    2010-01-01

    Considerable efforts have been taken to identify natural peptides as potential bioactive substances. In this study, novel peptide (SHP-1) derived from seahorse (Hippocampus, Syngnathidae) hydrolysate was explored for its inhibitory effects on collagen release in arthritis with the investigation of its underlying mechanism of action. The efficacy of SHP-1 was determined on cartilage protective effects such as inhibition of collagen and GAG release. SHP-1 was able to suppress not only the expression of collagenases 1 and 3, but also the production of NO via down-regulation of iNOS. However, it presented an irrelevant effect on the level of GAG release in chondrocytic and osteoblastic cells. Inhibition of collagen release by SHP-1 is associated with restraining the phosphorylation of NF-kappaB and p38 kinase cascade. Therefore, it could be suggested that SHP-1 has a potential to be used in arthritis treatment.

  9. Changes in type I collagen following laser welding.

    Science.gov (United States)

    Bass, L S; Moazami, N; Pocsidio, J; Oz, M C; LoGerfo, P; Treat, M R

    1992-01-01

    Selection of ideal laser parameters for tissue welding is inhibited by poor understanding of the mechanism. We investigated structural changes in collagen molecules extracted from rat tail tendon (> 90% type I collagen) after tissue welding using an 808 nm diode laser and indocyanine green dye applied to the weld site. Mobility patterns on SDS-PAGE were identical in the lasered and untreated tendon extracts with urea or acetic acid. Pepsin incubation after acetic acid extraction revealed a reduction of collagen alpha and beta bands in lasered compared with untreated specimens. Circular dichroism studies of rat tail tendon showed absence of helical structure in collagen from lasered tendon. No evidence for covalent bonding was present in laser-treated tissues. Collagen molecules are denatured by the laser wavelength and parameters used in this study. No significant amount of helical structure is regenerated on cooling. We conclude that non-covalent interactions between denatured collagen molecules may be responsible for the creation of tissue welding.

  10. Nonlinear optical microscopy reveals invading endothelial cells anisotropically alter three-dimensional collagen matrices

    International Nuclear Information System (INIS)

    Lee, P.-F.; Yeh, Alvin T.; Bayless, Kayla J.

    2009-01-01

    The interactions between endothelial cells (ECs) and the extracellular matrix (ECM) are fundamental in mediating various steps of angiogenesis, including cell adhesion, migration and sprout formation. Here, we used a noninvasive and non-destructive nonlinear optical microscopy (NLOM) technique to optically image endothelial sprouting morphogenesis in three-dimensional (3D) collagen matrices. We simultaneously captured signals from collagen fibers and endothelial cells using second harmonic generation (SHG) and two-photon excited fluorescence (TPF), respectively. Dynamic 3D imaging revealed EC interactions with collagen fibers along with quantifiable alterations in collagen matrix density elicited by EC movement through and morphogenesis within the matrix. Specifically, we observed increased collagen density in the area between bifurcation points of sprouting structures and anisotropic increases in collagen density around the perimeter of lumenal structures, but not advancing sprout tips. Proteinase inhibition studies revealed membrane-associated matrix metalloproteinase were utilized for sprout advancement and lumen expansion. Rho-associated kinase (p160ROCK) inhibition demonstrated that the generation of cell tension increased collagen matrix alterations. This study followed sprouting ECs within a 3D matrix and revealed that the advancing structures recognize and significantly alter their extracellular environment at the periphery of lumens as they progress

  11. Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid

    International Nuclear Information System (INIS)

    Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun; Ren, Li

    2015-01-01

    Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)–citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col–CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS = 60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30 ± 5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin–eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col–CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. - Highlights: • Adding different amounts of citric acid could change the properties of films. • The crosslinked films had better mechanical property than non-modified films. • Crosslinked collagen–citric acid films could tolerate suture during operation. • The films showed good ability of epithelial and stromal repair

  12. Collagen based film with well epithelial and stromal regeneration as corneal repair materials: Improving mechanical property by crosslinking with citric acid

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xuan; Liu, Yang; Li, Weichang; Long, Kai; Wang, Lin; Liu, Sa; Wang, Yingjun [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou (China)

    2015-10-01

    Corneal disease can lead to vision loss. It has become the second greatest cause of blindness in the world, and keratoplasty is considered as an effective treatment method. This paper presents the crosslinked collagen (Col)–citric acid (CA) films developed by making use of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The results showed that the Col–CA films had necessary optical performance, water content. The collagenase resistance of CA crosslinked films was superior to that of EDC crosslinked films. And CA5 film (Col:CA:EDC:NHS = 60:3:10:10) had the best mechanical properties. Cell experiments showed that CA5 film was non-cytotoxic and human corneal epithelial cells could proliferate well on the films. Lamellar keratoplasty showed that the CA5 film could be sutured in the rabbit eyes and was epithelialized completely in about 10 days, and the transparency was restored quickly in 30 ± 5 days. No inflammation and corneal neovascularization were observed at 6 months. Corneal stroma had been repaired; stromal cells and neo-stroma could be seen in the area of operation from the hematoxylin–eosin stained histologic sections and anterior segment optical coherence tomography images. These results indicated that Col–CA films were highly promising biomaterials that could be used in corneal tissue engineering and a variety of other tissue engineering applications. - Highlights: • Adding different amounts of citric acid could change the properties of films. • The crosslinked films had better mechanical property than non-modified films. • Crosslinked collagen–citric acid films could tolerate suture during operation. • The films showed good ability of epithelial and stromal repair.

  13. Histone Deacetylase Inhibition Downregulates Collagen 3A1 in Fibrotic Lung Fibroblasts

    Directory of Open Access Journals (Sweden)

    Victor J. Thannickal

    2013-09-01

    Full Text Available Idiopathic pulmonary fibrosis (IPF is a deadly disease characterized by chronic inflammation and excessive collagen accumulation in the lung. Myofibroblasts are the primary collagen-producing cells in pulmonary fibrosis. Histone deacetylase inhibitor (HDACi can affect gene expression, and some, such as suberoylanilide hydroxamic acid (SAHA, are US FDA approved for cancer treatment. In this study, we investigated SAHA’s effects on the expression of collagen III alpha 1 (COL3A1 in primary human IPF fibroblasts and in a murine model of pulmonary fibrosis. We observed that increased COL3A1 expression in IPF fibroblasts can be substantially reduced by SAHA treatment at the level of transcription as detected by RT-PCR; collagen III protein level was also reduced, as detected by Western blots and immunofluorescence. The deacetylation inhibitor effect of SAHA was verified by observing higher acetylation levels of both histone H3 and H4 in treated IPF cells. Chromatin immunoprecipitation (ChIP experiments demonstrated that the reduced expression of COL3A1 by SAHA is with increased association of the repressive chromatin marker, H3K27Me3, and decreased association of the active chromatin marker, H3K9Ac. In our murine model of bleomycin-induced pulmonary fibrosis, the SAHA treated group demonstrated significantly less collagen III, as detected by immunohistochemistry. Our data indicate that the HDACi SAHA alters the chromatin associated with COL3A1, resulting in its decreased expression.

  14. Collagen V-induced nasal tolerance downregulates pulmonary collagen mRNA gene and TGF-beta expression in experimental systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Parra Edwin R

    2010-01-01

    Full Text Available Abstract Background The purpose of this study was to evaluate collagen deposition, mRNA collagen synthesis and TGF-beta expression in the lung tissue in an experimental model of scleroderma after collagen V-induced nasal tolerance. Methods Female New Zealand rabbits (N = 12 were immunized with 1 mg/ml of collagen V in Freund's adjuvant (IM. After 150 days, six immunized animals were tolerated by nasal administration of collagen V (25 μg/day (IM-TOL daily for 60 days. The collagen content was determined by morphometry, and mRNA expressions of types I, III and V collagen were determined by Real-time PCR. The TGF-beta expression was evaluated by immunostaining and quantified by point counting methods. To statistic analysis ANOVA with Bonferroni test were employed for multiple comparison when appropriate and the level of significance was determined to be p Results IM-TOL, when compared to IM, showed significant reduction in total collagen content around the vessels (0.371 ± 0.118 vs. 0.874 ± 0.282, p p p = 0.026. The lung tissue of IM-TOL, when compared to IM, showed decreased immunostaining of types I, III and V collagen, reduced mRNA expression of types I (0.10 ± 0.07 vs. 1.0 ± 0.528, p = 0.002 and V (1.12 ± 0.42 vs. 4.74 ± 2.25, p = 0.009 collagen, in addition to decreased TGF-beta expression (p Conclusions Collagen V-induced nasal tolerance in the experimental model of SSc regulated the pulmonary remodeling process, inhibiting collagen deposition and collagen I and V mRNA synthesis. Additionally, it decreased TGF-beta expression, suggesting a promising therapeutic option for scleroderma treatment.

  15. Transient inhibition of connective tissue infiltration and collagen deposition into porous poly(lactic-co-glycolic acid) discs.

    Science.gov (United States)

    Love, Ryan J; Jones, Kim S

    2013-12-01

    Connective tissue rapidly proliferates on and around biomaterials implanted in vivo, which impairs the function of the engineered tissues, biosensors, and devices. Glucocorticoids can be utilized to suppress tissue ingrowth, but can only be used for a limited time because they nonselectively arrest cell proliferation in the local environment. The present study examined use of a prolyl-4-hydroxylase inhibitor, 1,4-dihydrophenonthrolin-4-one-3-carboxylic acid (1,4-DPCA), to suppress connective tissue ingrowth in porous PLGA discs implanted in the peritoneal cavity for 28 days. The prolyl-4-hydroxylase inhibitor was found to be effective at inhibiting collagen deposition within and on the outer surface of the disc, and also limited connective tissue ingrowth, but not to the extent of glucocorticoid inhibition. Finally, it was discovered that 1,4-DPCA suppressed Scavenger Receptor A expression on a macrophage-like cell culture, which may account for the drug's ability to limit connective tissue ingrowth in vivo. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

  16. Ingestion of onion soup high in quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in man: a pilot study

    NARCIS (Netherlands)

    Hubbard, G.; Wolffram, S.; Vos, de C.H.; Bovy, A.G.; Gibbins, J.; Lovegrove, J.

    2006-01-01

    Epidemiological data suggest that those who consume a diet rich in quercetin-containing foods may have a reduced risk of CVD. Furthermore, in vitro and ex vivo studies have observed the inhibition of collagen-induced platelet activation by quercetin. The aim of the present study was to investigate

  17. Electrically conducting nanobiocomposites using carbon nanotubes and collagen waste fibers

    International Nuclear Information System (INIS)

    Meiyazhagan, Ashokkumar; Thangavel, Saravanamoorthy; Hashim, Daniel P.; Ajayan, Pulickel M.; Palanisamy, Thanikaivelan

    2015-01-01

    Electrically conducting hybrid biocomposite films were prepared using a simple and cost-effective method by incorporating different types of carbon nanotubes (XCNTs) viz., few walled carbon nanotube (FWCNT) and boron doped carbon nanotube (BCNT) into biopolymers. Collagen extracted from animal skin wastes was blended with guar gum and XCNTs in varying proportions to form flexible and electrically conducting hybrid films. We found that the electrical conductivity of both types of hybrid films increases radically as the XCNT loading increases. BCNT incorporated hybrid films show better electrical conductivity (3.0 × 10 −1 S/cm) than their FWCNT loaded counter parts (4.8 × 10 −4 S/cm) at a dosage of 2 wt.%. On the other hand, mechanical and other physical properties such as transparency, flexibility and surface smoothness of the developed hybrid films were affected as a function of XCNT concentration. We also demonstrated that the developed hybrid films lit up a LED lamp when inserted between batteries and the brightness of the emitted light depended on the XCNT loading. These results suggest a new way to transform an industrial biowaste into innovative advanced materials for applications in fields related to biomedicine, biosensors and electronics. - Highlights: • Hybrid nanobiocomposite films prepared using collagen, guar gum and CNTs. • Examined the effect of CNT doping on the properties of hybrid biocomposite films. • Higher CNT loading improved the conductivity radically, especially for BCNT. • The ability of developed hybrid films to lit up a LED lamp was demonstrated. • The results suggest a new way to transform biowaste into advanced materials

  18. Biodegradable and bioactive CGP/PVA film for fungal growth inhibition.

    Science.gov (United States)

    Silva, Bárbara Dumas S; Ulhoa, Cirano J; Batista, Karla A; Di Medeiros, Maria Carolina; Da Silva Filho, Rômulo Roosevelt; Yamashita, Fabio; Fernandes, Kátia F

    2012-07-01

    In this study, chitinolytic enzymes produced by Trichoderma asperellum were immobilized on a biodegradable film manufactured with a blend of cashew gum polysaccharide (CGP) and polyvinyl alcohol (PVA), and tested as a fungal growth inhibitor. The film was produced by casting a blend of CGP and PVA solution on glass molds. The CGP/PVA film showed 68% water solubility, tensile strength of 23.7 MPa, 187.2% elongation and 52% of mass loss after 90 days in soil. The presence of T-CWD enzymes immobilized by adsorption or covalent attachment resulted in effective inhibition of fungal growth. Sclerotinia sclerotiorum was the most sensitive organism, followed by Aspergillus niger and Penicillium sp. SEM micrograph showed that the presence of immobilized T-CWD enzymes on CGP/PVA film produced morphological modifications on vegetative and germinative structures of the microorganisms, particularly hyphae disruption and changes of spores shape. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. cAMP level modulates scleral collagen remodeling, a critical step in the development of myopia.

    Directory of Open Access Journals (Sweden)

    Yijin Tao

    Full Text Available The development of myopia is associated with decreased ocular scleral collagen synthesis in humans and animal models. Collagen synthesis is, in part, under the influence of cyclic adenosine monophosphate (cAMP. We investigated the associations between cAMP, myopia development in guinea pigs, and collagen synthesis by human scleral fibroblasts (HSFs. Form-deprived myopia (FDM was induced by unilateral masking of guinea pig eyes. Scleral cAMP levels increased selectively in the FDM eyes and returned to normal levels after unmasking and recovery. Unilateral subconjunctival treatment with the adenylyl cyclase (AC activator forskolin resulted in a myopic shift accompanied by reduced collagen mRNA levels, but it did not affect retinal electroretinograms. The AC inhibitor SQ22536 attenuated the progression of FDM. Moreover, forskolin inhibited collagen mRNA levels and collagen secretion by HSFs. The inhibition was reversed by SQ22536. These results demonstrate a critical role of cAMP in control of myopia development. Selective regulation of cAMP to control scleral collagen synthesis may be a novel therapeutic strategy for preventing and treating myopia.

  20. Extracts of Bauhinia championii (Benth.) Benth. inhibit NF-B-signaling in a rat model of collagen-induced arthritis and primary synovial cells.

    Science.gov (United States)

    Xu, Wei; Huang, Mingqing; Zhang, Yuqin; Li, Huang; Zheng, Haiyin; Yu, Lishuang; Chu, Kedan

    2016-06-05

    Bauhinia championii (Benth.) Benth. is used in Chinese traditional medicine to treat arthritis, especially has been used a long time ago on rheumatoid arthritis (RA) in She ethnic minority group. To investigate the anti-RA effect of Bauhinia championii (Benth.) Benth ethyl acetate extract (BCBEE) and the molecular bases of it. BCBEE was studied on a rat model of RA induced by Ⅱcollagen in vivo, as well as on primary synovial cells in vitro. After BCBEE treatment, in vivo, it was showed that paw and joint edema was inhibited, pathological joint changes was ameliorated and the levels of interleukin (IL)-1β and tumor necrosis factor-(TNF-α) was decreased significantly. The protein and mRNA expressions of nuclear factor-B (NF-κB)(p65), IκB, p-IκB and IκB kinase beta (IκKβ) were also down-regulated. Moreover, the in vitro study revealed that BCBEE treatment inhibited primary synovial cells proliferation, and promoted down-regulation of NF-κB(p65), IκB, p-IκB and IκKβ. Taken together, the present study demonstrates that BCBEE produces a protection in a rat model of RA induced by Ⅱcollagen via inhibiting paw and joint edema, ameliorating pathological joint changes and regulating the levels of cytokines and its action mechanism maybe is via down-regulating NF-κB(p65), IκB, p-IκB and IκKβ expression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Fabrication of homobifunctional crosslinker stabilized collagen for biomedical application

    International Nuclear Information System (INIS)

    Lakra, Rachita; Kiran, Manikantan Syamala; Sai, Korrapati Purna

    2015-01-01

    Collagen biopolymer has found widespread application in the field of tissue engineering owing to its excellent tissue compatibility and negligible immunogenicity. Mechanical strength and enzymatic degradation of the collagen necessitates the physical and chemical strength enhancement. One such attempt deals with the understanding of crosslinking behaviour of EGS (ethylene glycol-bis (succinic acid N-hydroxysuccinimide ester)) with collagen to improve the physico-chemical properties. The incorporation of a crosslinker during fibril formation enhanced the thermal and mechanical stability of collagen. EGS crosslinked collagen films exhibited higher denaturation temperature (T d ) and the residue left after thermogravimetric analysis was about 16  ±  5.2%. Mechanical properties determined by uniaxial tensile tests showed a threefold increase in tensile strength and Young’s modulus at higher concentration (100 μM). Water uptake capacity reduced up to a moderate extent upon crosslinking which is essential for the transport of nutrients to the cells. Cell viability was found to be 100% upon treatment with 100 μM EGS whereas only 30% viability could be observed with glutaraldehyde. Rheological studies of crosslinked collagen showed an increase in shear stress and shear viscosity at 37 °C. Crosslinking with EGS resulted in the formation of a uniform fibrillar network. Trinitrobenzene sulfonate (TNBS) assay confirmed that EGS crosslinked collagen by forming a covalent interaction with ε-amino acids of collagen. The homobifunctional crosslinker used in this study enhanced the effectiveness of collagen as a biomaterial for biomedical application. (paper)

  2. Electrophoretic mobility patterns of collagen following laser welding

    Science.gov (United States)

    Bass, Lawrence S.; Moazami, Nader; Pocsidio, Joanne O.; Oz, Mehmet C.; LoGerfo, Paul; Treat, Michael R.

    1991-06-01

    Clinical application of laser vascular anastomosis in inhibited by a lack of understanding of its mechanism. Whether tissue fusion results from covalent or non-covalent bonding of collagen and other structural proteins is unknown. We compared electrophoretic mobility of collagen in laser treated and untreated specimens of rat tail tendon (>90% type I collagen) and rabbit aorta. Welding was performed, using tissue shrinkage as the clinical endpoint, using the 808 nm diode laser (power density 14 watts/cm2) and topical indocyanine green dye (max absorption 805 nm). Collagen was extracted with 8 M urea (denaturing), 0.5 M acetic acid (non-denaturing) and acetic acid/pepsin (cleaves non- helical protein). Mobility patterns on gel electrophoresis (SDS-PAGE) after urea or acetic acid extraction were identical in the lasered and control tendon and vessel (confirmed by optical densitometry), revealing no evidence of formation of novel covalent bonds. Alpha and beta band intensity was diminished in pepsin incubated lasered specimens compared with controls (optical density ratio 0.00 +/- 9 tendon, 0.65 +/- 0.12 aorta), indicating the presence of denatured collagen. With the laser parameters used, collagen is denatured without formation of covalent bonds, suggesting that non-covalent interaction between denatured collagen molecules may be responsible for the weld. Based on this mechanism, welding parameters can be chosen which produce collagen denaturation without cell death.

  3. Inhibiting properties of benzimidazole films for Cu(II)/Cu(I) reduction in chloride media studied by RDE and EQCN techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scendo, M. [Institute of Chemistry, Saint Cross Academy, ul. Checinska 5, 25020 Kielce (Poland)]. E-mail: scendo@pu.kielce.pl; Hepel, M. [Department of Chemistry, State University of New York, Potsdam, NY 13676, USA (United States)

    2007-08-15

    The effects of benzimidazole (BIM) and 2-methylbenzimidazole (MBIM) on the electroreduction of Cu(II) on a rotating Pt disk electrode in chloride media were investigated. These studies were undertaken in conjunction with earlier observation that these imidazole derivatives act as inhibitors of copper corrosion processes and are non-toxic. We have found that BIM and MBIM also form adsorption films on Pt, which are able to inhibit one-electron reduction of Cu(II) to Cu(I) and prevent the development of convective diffusion limiting current wave. The inhibition was found to be controlled by field-assisted mass transfer in the film. The ingress of Cu(II) species into the film was detected using the EQCN technique. The EQCN measurements indicate that small fraction of Cu(I) formed in the film by reduction of Cu(II) is retained in the film, most likely in the form of CuCl. The uptake of CuCl by inhibitor films diminishes in strongly inhibiting films (e.g., in acidic medium). The inhibition effectiveness of Cu(II) reduction process by Pt vertical bar BIM and Pt vertical bar MBIM films increases strongly with increasing acidity of the medium in the pH range from 3.0 to 1.0. The mechanism of this remarkable pH effect has been proposed. It is based on charge and pH-induced film restructuring, including changes in orientation and protonation of BIM molecules in the film.

  4. Immobilisation of hydroxyapatite-collagen on polydopamine grafted stainless steel 316L: Coating adhesion and in vitro cells evaluation.

    Science.gov (United States)

    Tapsir, Zafirah; Jamaludin, Farah H; Pingguan-Murphy, Belinda; Saidin, Syafiqah

    2018-02-01

    The utilisation of hydroxyapatite and collagen as bioactive coating materials could enhance cells attachment, proliferation and osseointegration. However, most methods to form crystal hydroxyapatite coating do not allow the incorporation of polymer/organic compound due to production phase of high sintering temperature. In this study, a polydopamine film was used as an intermediate layer to immobilise hydroxyapatite-collagen without the introduction of high sintering temperature. The surface roughness, coating adhesion, bioactivity and osteoblast attachment on the hydroxyapatite-collagen coating were assessed as these properties remains unknown on the polydopamine grafted film. The coating was developed by grafting stainless steel 316L disks with a polydopamine film. Collagen type I fibres were then immobilised on the grafted film, followed by the biomineralisation of hydroxyapatite. The surface roughness and coating adhesion analyses were later performed by using AFM instrument. An Alamar Blue assay was used to determine the cytotoxicity of the coating, while an alkaline phosphatase activity test was conducted to evaluate the osteogenic differentiation of human fetal osteoblasts on the coating. Finally, the morphology of cells attachment on the coating was visualised under FESEM. The highest RMS roughness and coating adhesion were observed on the hydroxyapatite-collagen coating (hydroxyapatite-coll-dopa). The hydroxyapatite-coll-dopa coating was non-toxic to the osteoblast cells with greater cells proliferation, greater level of alkaline phosphate production and more cells attachment. These results indicate that the immobilisation of hydroxyapatite and collagen using an intermediate polydopamine is identical to enhance coating adhesion, osteoblast cells attachment, proliferation and differentiation, and thus could be implemented as a coating material on orthopaedic and dental implants.

  5. Fibroblast Activation Protein (FAP) Accelerates Collagen Degradation and Clearance from Lungs in Mice

    DEFF Research Database (Denmark)

    Fan, Ming-Hui; Zhu, Qiang; Li, Hui-Hua

    2016-01-01

    , intratracheal bleomycin instillation and thoracic irradiation, we find increased mortality and increased lung fibrosis in FAP-deficient mice compared with wild-type mice. Lung extracellular matrix analysis reveals accumulation of intermediate-sized collagen fragments in FAP-deficient mouse lungs, consistent...... within vitrostudies showing that FAP mediates ordered proteolytic processing of matrix metalloproteinase (MMP)-derived collagen cleavage products. FAP-mediated collagen processing leads to increased collagen internalization without altering expression of the endocytic collagen receptor, Endo180....... Pharmacologic FAP inhibition decreases collagen internalization as expected. Conversely, restoration of FAP expression in the lungs of FAP-deficient mice decreases lung hydroxyproline content after intratracheal bleomycin to levels comparable with that of wild-type controls. Our findings indicate that FAP...

  6. Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

    International Nuclear Information System (INIS)

    Ramp, W.K.; Lenz, L.G.; Galvin, R.J.

    1991-01-01

    Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase were concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of [ 3 H]proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of [ 3 H]hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of [ 3 H]thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone

  7. Softenin, a novel protein that softens the connective tissue of sea cucumbers through inhibiting interaction between collagen fibrils.

    Directory of Open Access Journals (Sweden)

    Yasuhiro Takehana

    Full Text Available The dermis in the holothurian body wall is a typical catch connective tissue or mutable collagenous tissue that shows rapid changes in stiffness. Some chemical factors that change the stiffness of the tissue were found in previous studies, but the molecular mechanisms of the changes are not yet fully understood. Detection of factors that change the stiffness by working directly on the extracellular matrix was vital to clarify the mechanisms of the change. We isolated from the body wall of the sea cucumber Stichopus chloronotus a novel protein, softenin, that softened the body-wall dermis. The apparent molecular mass was 20 kDa. The N-terminal sequence of 17 amino acids had low homology to that of known proteins. We performed sequential chemical and physical dissections of the dermis and tested the effects of softenin on each dissection stage by dynamic mechanical tests. Softenin softened Triton-treated dermis whose cells had been disrupted by detergent. The Triton-treated dermis was subjected to repetitive freeze-and-thawing to make Triton-Freeze-Thaw (TFT dermis that was softer than the Triton-treated dermis, implying that some force-bearing structure had been disrupted by this treatment. TFT dermis was stiffened by tensilin, a stiffening protein of sea cucumbers. Softenin softened the tensilin-stiffened TFT dermis while it had no effect on the TFT dermis without tensilin treatment. We isolated collagen from the dermis. When tensilin was applied to the suspending solution of collagen fibrils, they made a large compact aggregate that was dissolved by the application of softenin or by repetitive freeze-and-thawing. These results strongly suggested that softenin decreased dermal stiffness through inhibiting cross-bridge formation between collagen fibrils; the formation was augmented by tensilin and the bridges were broken by the freeze-thaw treatment. Softenin is thus the first softener of catch connective tissue shown to work on the cross

  8. Kaempferol inhibits fibroblast collagen synthesis, proliferation and activation in hypertrophic scar via targeting TGF-β receptor type I.

    Science.gov (United States)

    Li, Hongwei; Yang, Liu; Zhang, Yuebing; Gao, Zhigang

    2016-10-01

    Hypertrophic scar (HPS) formation is a debilitating condition that results in pain, esthetic symptom and loss of tissue function. So far, no satisfactory therapeutic approach has been available for HPS treatment. In this study, we discovered that a natural small molecule, kaempferol, could significantly inhibit HPS formation in a mechanical load-induced mouse model. Our results also demonstrated that kaempferol remarkably attenuated collagen synthesis, proliferation and activation of fibroblasts in vitro and in vivo. Western blot analysis further revealed that kaempferol significantly down-regulated Smad2 and Smad3 phosphorylation in a dose-dependent manner. At last, we found that such bioactivity of kaempferol which resulted from the inhibition of TGF-β1/Smads signaling was induced by the selective binding of kaempferol to TGF-β receptor type I (TGFβRI). These findings suggest that kaempferol could be developed into a promising agent for the treatment of HPS or other fibroproliferative disorders. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. A microscopic evaluation of collagen-bilirubin interactions: in vitro surface phenomenon.

    Science.gov (United States)

    Usharani, N; Jayakumar, G C; Rao, J R; Chandrasekaran, B; Nair, B U

    2014-02-01

    This study is carried out to understand the morphology variations of collagen I matrices influenced by bilirubin. The characteristics of bilirubin interaction with collagen ascertained using various techniques like XRD, CLSM, fluorescence, SEM and AFM. These techniques are used to understand the distribution, expression and colocalization patterns of collagen-bilirubin complexes. The present investigation mimic the in vivo mechanisms created during the disorder condition like jaundice. Fluorescence technique elucidates the crucial role played by bilirubin deposition and interaction during collagen organization. Influence of bilirubin during collagen fibrillogenesis and banding patterns are clearly visualize using SEM. As a result, collagen-bilirubin complex provides different reconstructed patterns because of the influence of bilirubin concentration. Selectivity, specificity and spatial organization of collagen-bilirubin are determined through AFM imaging. Consequently, it is observed that the morphology and quantity of the bilirubin binding to collagen varied by the concentrations and the adsorption rate in protein solutions. Microscopic studies of collagen-bilirubin interaction confirms that bilirubin influence the fibrillogenesis and alter the rate of collagen organization depending on the bilirubin concentration. This knowledge helps to develop a novel drug to inhibit the interface point of interaction between collagen and bilirubin. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  10. Inhibition of Hb Binding to GP1bα Abrogates Hb-Mediated Thrombus Formation on Immobilized VWF and Collagen under Physiological Shear Stress.

    Science.gov (United States)

    Annarapu, Gowtham K; Singhal, Rashi; Peng, Yuandong; Guchhait, Prasenjit

    2016-01-01

    Reports including our own describe that intravascular hemolysis increases the risk of thrombosis in hemolytic disorders. Our recent study shows that plasma Hb concentrations correlate directly with platelet activation in patients with paroxysmal nocturnal hemoglobinuria (PNH). The binding of Hb to glycoprotein1bα (GP1bα) increases platelet activation. A peptide AA1-50, designed from N-terminal amino acid sequence of GP1bα significantly inhibits the Hb binding to GP1bα as well as Hb-induced platelet activation. This study further examined if the Hb-mediated platelet activation plays any significant role in thrombus formation on subendothelium matrix under physiological flow shear stresses and the inhibition of Hb-platelet interaction can abrogate the above effects of Hb. Study performed thrombus formation assay in vitro by perfusing whole blood over immobilized VWF or collagen type I in presence of Hb under shear stresses simulating arterial or venous flow. The Hb concentrations ranging from 5 to 10 μM, commonly observed level in plasma of the hemolytic patients including PNH, dose-dependently increased thrombus formation on immobilized VWF under higher shear stress of 25 dyne/cm2, but not at 5 dyne/cm2. The above Hb concentrations also increased thrombus formation on immobilized collagen under both shear stresses of 5 and 25 dyne/cm2. The peptide AA1-50 abrogated invariably the above effects of Hb on thrombus formation. This study therefore indicates that the Hb-induced platelet activation plays a crucial role in thrombus formation on immobilized VWF or collagen under physiological flow shear stresses. Thus suggesting a probable role of this mechanism in facilitating thrombosis under hemolytic conditions.

  11. Inhibition of Wnt/β-catenin signaling by a soluble collagen-derived frizzled domain interacting with Wnt3a and the receptors frizzled 1 and 8.

    Directory of Open Access Journals (Sweden)

    Ismaïl Hendaoui

    Full Text Available The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs, which have a cysteine-rich domain (CRD structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18 inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth.

  12. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    International Nuclear Information System (INIS)

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo; Kim, So Young; Jang, Hwan-Hee; Ryu, Sung Ho; Kim, Beom Joon; Lee, Taehoon G.

    2012-01-01

    Highlights: ► We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. ► YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. ► There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. ► The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. ► The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929–933 sequence of the β1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate peptide for the treatment of skin aging and wrinkles.

  13. Aspirin suppresses cardiac fibroblast proliferation and collagen formation through downregulation of angiotensin type 1 receptor transcription

    International Nuclear Information System (INIS)

    Wang, Xianwei; Lu, Jingjun; Khaidakov, Magomed; Mitra, Sona; Ding, Zufeng; Raina, Sameer; Goyal, Tanu; Mehta, Jawahar L.

    2012-01-01

    Aspirin (acetyl salicylic acid, ASA) is a common drug used for its analgesic and antipyretic effects. Recent studies show that ASA not only blocks cyclooxygenase, but also inhibits NADPH oxidase and resultant reactive oxygen species (ROS) generation, a pathway that underlies pathogenesis of several ailments, including hypertension and tissue remodeling after injury. In these disease states, angiotensin II (Ang II) activates NADPH oxidase via its type 1 receptor (AT1R) and leads to fibroblast growth and collagen synthesis. In this study, we examined if ASA would inhibit NADPH oxidase activation, upregulation of AT1R transcription, and subsequent collagen generation in mouse cardiac fibroblasts challenged with Ang II. Mouse heart fibroblasts were isolated and treated with Ang II with or without ASA. As expected, Ang II induced AT1R expression, and stimulated cardiac fibroblast growth and collagen synthesis. The AT1R blocker losartan attenuated these effects of Ang II. Similarly to losartan, ASA, and its SA moiety suppressed Ang II-mediated AT1R transcription and fibroblast proliferation as well as expression of collagens and MMPs. ASA also suppressed the expression of NADPH oxidase subunits (p22 phox , p47 phox , p67 phox , NOX2 and NOX4) and ROS generation. ASA did not affect total NF-κB p65, but inhibited its phosphorylation and activation. These observations suggest that ASA inhibits Ang II-induced NADPH oxidase expression, NF-κB activation and AT1R transcription in cardiac fibroblasts, and fibroblast proliferation and collagen expression. The critical role of NADPH oxidase activity in stimulation of AT1R transcription became apparent in experiments where ASA also inhibited AT1R transcription in cardiac fibroblasts challenged with H 2 O 2 . Since SA had similar effect as ASA on AT1R expression, we suggest that ASA's effect is mediated by its SA moiety. -- Highlights: ► Aspirin in therapeutic concentrations decreases mouse cardiac fibroblast growth and collagen

  14. Aspirin suppresses cardiac fibroblast proliferation and collagen formation through downregulation of angiotensin type 1 receptor transcription

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianwei, E-mail: XWang2@UAMS.edu; Lu, Jingjun; Khaidakov, Magomed; Mitra, Sona; Ding, Zufeng; Raina, Sameer; Goyal, Tanu; Mehta, Jawahar L., E-mail: MehtaJL@UAMS.edu

    2012-03-15

    Aspirin (acetyl salicylic acid, ASA) is a common drug used for its analgesic and antipyretic effects. Recent studies show that ASA not only blocks cyclooxygenase, but also inhibits NADPH oxidase and resultant reactive oxygen species (ROS) generation, a pathway that underlies pathogenesis of several ailments, including hypertension and tissue remodeling after injury. In these disease states, angiotensin II (Ang II) activates NADPH oxidase via its type 1 receptor (AT1R) and leads to fibroblast growth and collagen synthesis. In this study, we examined if ASA would inhibit NADPH oxidase activation, upregulation of AT1R transcription, and subsequent collagen generation in mouse cardiac fibroblasts challenged with Ang II. Mouse heart fibroblasts were isolated and treated with Ang II with or without ASA. As expected, Ang II induced AT1R expression, and stimulated cardiac fibroblast growth and collagen synthesis. The AT1R blocker losartan attenuated these effects of Ang II. Similarly to losartan, ASA, and its SA moiety suppressed Ang II-mediated AT1R transcription and fibroblast proliferation as well as expression of collagens and MMPs. ASA also suppressed the expression of NADPH oxidase subunits (p22{sup phox}, p47{sup phox}, p67{sup phox}, NOX2 and NOX4) and ROS generation. ASA did not affect total NF-κB p65, but inhibited its phosphorylation and activation. These observations suggest that ASA inhibits Ang II-induced NADPH oxidase expression, NF-κB activation and AT1R transcription in cardiac fibroblasts, and fibroblast proliferation and collagen expression. The critical role of NADPH oxidase activity in stimulation of AT1R transcription became apparent in experiments where ASA also inhibited AT1R transcription in cardiac fibroblasts challenged with H{sub 2}O{sub 2}. Since SA had similar effect as ASA on AT1R expression, we suggest that ASA's effect is mediated by its SA moiety. -- Highlights: ► Aspirin in therapeutic concentrations decreases mouse cardiac

  15. Bacterial self-defense antibiotics release from organic-inorganic hybrid multilayer films for long-term anti-adhesion and biofilm inhibition properties.

    Science.gov (United States)

    Xu, Qingwen; Li, Xi; Jin, Yingying; Sun, Lin; Ding, Xiaoxu; Liang, Lin; Wang, Lei; Nan, Kaihui; Ji, Jian; Chen, Hao; Wang, Bailiang

    2017-12-14

    Implant-associated bacterial infections pose serious medical and financial issues due to the colonization and proliferation of pathogens on the surface of the implant. The as-prepared traditional antibacterial surfaces can neither resist bacterial adhesion nor inhibit the development of biofilm over the long term. Herein, novel (montmorillonite/poly-l-lysine-gentamicin sulfate) 8 ((MMT/PLL-GS) 8 ) organic-inorganic hybrid multilayer films were developed to combine enzymatic degradation PLL for on-demand self-defense antibiotics release. Small molecule GS was loaded into the multilayer films during self-assembly and the multilayer films showed pH-dependent and linear growth behavior. The chymotrypsin- (CMS) and bacterial infections-responsive film degradation led to the peeling of the films and GS release. Enzyme-responsive GS release exhibited CMS concentration dependence as measured by the size of the inhibition zone and SEM images. Notably, the obtained antibacterial films showed highly efficient bactericidal activity which killed more than 99.9% of S. aureus in 12 h. Even after 3 d of incubation in S. aureus, E. coli or S. epidermidis solutions, the multilayer films exhibited inhibition zones of more than 1.5 mm in size. Both in vitro and in vivo antibacterial tests indicated good cell compatibility, and anti-inflammatory, and long-term bacterial anti-adhesion and biofilm inhibition properties.

  16. Platelet adhesion and plasma protein adsorption control of collagen surfaces by He+ ion implantation

    International Nuclear Information System (INIS)

    Kurotobi, K.; Suzuki, Y.; Nakajima, H.; Suzuki, H.; Iwaki, M.

    2003-01-01

    He + ion implanted collagen-coated tubes with a fluence of 1 x 10 14 ions/cm 2 were exhibited antithrombogenicity. To investigate the mechanisms of antithrombogenicity of these samples, plasma protein adsorption assay and platelet adhesion experiments were performed. The adsorption of fibrinogen (Fg) and von Willebrand factor (vWf) was minimum on the He + ion implanted collagen with a fluence of 1 x 10 14 ions/cm 2 . Platelet adhesion (using platelet rich plasma) was inhibited on the He + ion implanted collagen with a fluence of 1 x 10 14 ions/cm 2 and was accelerated on the untreated collagen and ion implanted collagen with fluences of 1 x 10 13 , 1 x 10 15 and 1 x 10 16 ions/cm 2 . Platelet activation with washed platelets was observed on untreated collagen and He + ion implanted collagen with a fluence of 1 x 10 14 ions/cm 2 and was inhibited with fluences of 1 x 10 13 , 1 x 10 15 and 1 x 10 16 ions/cm 2 . Generally, platelets can react with a specific ligand inside the collagen (GFOGER sequence). The results of platelets adhesion experiments using washed platelets indicated that there were no ligands such as GFOGER on the He + ion implanted collagen over a fluence of 1 x 10 13 ions/cm 2 . On the 1 x 10 14 ions/cm 2 implanted collagen, no platelet activation was observed due to the influence of plasma proteins. >From the above, it is concluded that the decrease of adsorbed Fg and vWf caused the antithrombogenicity of He + ion implanted collagen with a fluence of 1 x 10 14 ions/cm 2 and that plasma protein adsorption took an important role repairing the graft surface

  17. Increasing extracellular matrix collagen level and MMP activity induces cyst development in polycystic kidney disease.

    Science.gov (United States)

    Liu, Bin; Li, Chenghai; Liu, Zijuan; Dai, Zonghan; Tao, Yunxia

    2012-09-11

    Polycystic Kidney Disease (PKD) kidneys exhibit increased extracellular matrix (ECM) collagen expression and metalloproteinases (MMPs) activity. We investigated the role of these increases on cystic disease progression in PKD kidneys. We examined the role of type I collagen (collagen I) and membrane bound type 1 MMP (MT1-MMP) on cyst development using both in vitro 3 dimensional (3D) collagen gel culture and in vivo PCK rat model of PKD. We found that collagen concentration is critical in controlling the morphogenesis of MDCK cells cultured in 3D gels. MDCK cells did not form 3D structures at collagen I concentrations lower than 1 mg/ml but began forming tubules when the concentration reaches 1 mg/ml. Significantly, these cells began to form cyst when collagen I concentration reached to 1.2 mg/ml, and the ratios of cyst to tubule structures increased as the collagen I concentration increased. These cells exclusively formed cyst structures at a collagen I concentration of 1.8 mg/ml or higher. Overexpression of MT1-MMP in MDCK cells significantly induced cyst growth in 3D collagen gel culture. Conversely, inhibition of MMPs activity with doxycycline, a FDA approved pan-MMPs inhibitor, dramatically slowed cyst growth. More importantly, the treatment of PCK rats with doxycycline significantly decreased renal tubule cell proliferation and markedly inhibited the cystic disease progression. Our data suggest that increased collagen expression and MMP activity in PKD kidneys may induce cyst formation and expansion. Our findings also suggest that MMPs may serve as a therapeutic target for the treatment of human PKD.

  18. Increasing extracellular matrix collagen level and MMP activity induces cyst development in polycystic kidney disease

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2012-09-01

    Full Text Available Abstract Background Polycystic Kidney Disease (PKD kidneys exhibit increased extracellular matrix (ECM collagen expression and metalloproteinases (MMPs activity. We investigated the role of these increases on cystic disease progression in PKD kidneys. Methods We examined the role of type I collagen (collagen I and membrane bound type 1 MMP (MT1-MMP on cyst development using both in vitro 3 dimensional (3D collagen gel culture and in vivo PCK rat model of PKD. Results We found that collagen concentration is critical in controlling the morphogenesis of MDCK cells cultured in 3D gels. MDCK cells did not form 3D structures at collagen I concentrations lower than 1 mg/ml but began forming tubules when the concentration reaches 1 mg/ml. Significantly, these cells began to form cyst when collagen I concentration reached to 1.2 mg/ml, and the ratios of cyst to tubule structures increased as the collagen I concentration increased. These cells exclusively formed cyst structures at a collagen I concentration of 1.8 mg/ml or higher. Overexpression of MT1-MMP in MDCK cells significantly induced cyst growth in 3D collagen gel culture. Conversely, inhibition of MMPs activity with doxycycline, a FDA approved pan-MMPs inhibitor, dramatically slowed cyst growth. More importantly, the treatment of PCK rats with doxycycline significantly decreased renal tubule cell proliferation and markedly inhibited the cystic disease progression. Conclusions Our data suggest that increased collagen expression and MMP activity in PKD kidneys may induce cyst formation and expansion. Our findings also suggest that MMPs may serve as a therapeutic target for the treatment of human PKD.

  19. Differential control of collagen synthesis by the sympathetic and renin-angiotensin systems in the rat left ventricle.

    Science.gov (United States)

    Dab, Houcine; Hachani, Rafik; Hodroj, Wassim; Sakly, Mohsen; Bricca, Giampiero; Kacem, Kamel

    2009-12-03

    In the present study, we tested the hypothesis of the indirect (via the sympathetic nervous system (SNS)) and direct (via AT1 receptors) contributions of Angiotensin II (Ang II) on the synthesis of collagen types I and III in the left ventricle (LV) in vivo. Sympathectomy and blockade of the Ang II receptor AT1 were performed alone or in combination in normotensive rats. The mRNA and protein synthesis of collagen types I and III were examined by Q-RT-PCR and immunoblotting in the LV. Collagen types I and III mRNA were decreased respectively by 53% and 22% after sympathectomy and only collagen type I mRNA was increased by 52% after AT1 receptor blockade. mRNA was not changed for collagen type I but was decreased by 25% for collagen type III after double treatment. Only collagen protein type III was decreased after sympathectomy by 12%, but collagen proteins were increased respectively for types I and III by 145% and 52% after AT1 receptor blockade and by 45% and 60% after double treatment. Deducted interpretations from our experimental approach suggest that Ang II stimulates indirectly (via SNS) and inhibits directly (via AT1 receptors) the collagen type I at transcriptional and protein levels. For collagen type III, it stimulates indirectly the transcription and inhibited directly the protein level. Therefore, the Ang II regulates collagen synthesis differently through indirect and direct pathways.

  20. Effect of nordihydroguaiaretic acid cross-linking on fibrillar collagen: in vitro evaluation of fibroblast adhesion strength and migration

    Directory of Open Access Journals (Sweden)

    Ana Y. Rioja

    2017-04-01

    Full Text Available Fixation is required to reinforce reconstituted collagen for orthopedic bioprostheses such as tendon or ligament replacements. Previous studies have demonstrated that collagen fibers cross-linked by the biocompatible dicatechol nordihydroguaiaretic acid (NDGA have mechanical strength comparable to native tendons. This work focuses on investigating fibroblast behavior on fibrillar and NDGA cross-linked type I collagen to determine if NDGA modulates cell adhesion, morphology, and migration. A spinning disk device that applies a range of hydrodynamic forces under uniform chemical conditions was employed to sensitively quantify cell adhesion strength, and a radial barrier removal assay was used to measure cell migration on films suitable for these quantitative in vitro assays. The compaction of collagen films, mediated by the drying and cross-linking fabrication process, suggests a less open organization compared to native fibrillar collagen that likely allowed the collagen to form more inter-chain bonds and chemical links with NDGA polymers. Fibroblasts strongly adhered to and migrated on native and NDGA cross-linked fibrillar collagen; however, NDGA modestly reduced cell spreading, adhesion strength and migration rate. Thus, it is hypothesized that NDGA cross-linking masked some adhesion receptor binding sites either physically, chemically, or both, thereby modulating adhesion and migration. This alteration in the cell-material interface is considered a minimal trade-off for the superior mechanical and compatibility properties of NDGA cross-linked collagen compared to other fixation approaches.

  1. Collagen gel protects L929 cells from TNFα-induced death by activating NF-κB.

    Science.gov (United States)

    Wang, Hong-Ju; Li, Meng-Qi; Liu, Wei-Wei; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

    2017-09-01

    Type I collagen is one of the most abundant components of extracellular matrix. We previously illustrated that murine fibrosarcoma L929 cells grew well on type I collagen gel and escaped from TNFα-induced cell death. In this study, we investigated the mechanism underlying the protective effect of collagen gel. We used western blot, confocal microscopy, MTT assay and flow cytometry by introducing fluorescence staining to determine the expression levels of nuclear factor kappa B (NF-κB), inhibitory ratio and autophagy. L929 cells on collagen gel showed higher expression of NF-κB in the nucleus. Inhibition of NF-κB with pyrrolidine dithiocarbamate hydrochloride (PDTC) or knockdown by NF-κB-siRNA canceled the protective effect of collagen gel on L929 cells from TNFα-induced death, suggesting for the role of NF-κB in the protection from cell death. We found a new aspect of the effect of PDTC on L929 cells cultured on collagen gel. PDTC alone without TNFα induced apoptosis in the L929 cells cultured on collagen gel but not the cells on plastic dish. The apoptosis induction of the L929 cells cultured on collagen gel with PDTC was repressed by inhibiting autophagy with chloroquine, an autophagy inhibitor, suggesting that autophagy contributes to the death induced by the treatment with PDTC. Possible underlying mechanism of this finding is discussed. NF-κB played an important role in protecting the L929 cells cultured on collagen gel from TNFα-induced death.

  2. The digestion of phagocytosed collagen is inhibited by the proteinase inhibitors leupeptin and E-64

    NARCIS (Netherlands)

    Everts, V.; Beertsen, W.; Tigchelaar-Gutter, W.

    1985-01-01

    Using morphometric methods the effects of the thiol-proteinase inhibitors leupeptin and E-64 on the digestion of intracytoplasmic collagen fibrils were studied in cultured mouse bone explants. Both drugs caused a dose-dependent increase of lysosomal structures containing cross-banded collagen

  3. Early adhesive behavior of bone-marrow-derived mesenchymal stem cells on collagen electrospun fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Casey K; Liao, Susan; Lareu, Ricky R; Raghunath, Michael [Division of Bioengineering, National University of Singapore, 7 Engineering Drive 1, Singapore 117574 (Singapore); Li, Bojun; Ramakrishna, S [Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Larrick, James W, E-mail: doschanc@nus.edu.s [Panorama Research Institute, 2462 Wyandotte Street, Mountain View, CA 94043 (United States)

    2009-06-15

    A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 +- 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

  4. Early adhesive behavior of bone-marrow-derived mesenchymal stem cells on collagen electrospun fibers

    International Nuclear Information System (INIS)

    Chan, Casey K; Liao, Susan; Lareu, Ricky R; Raghunath, Michael; Li, Bojun; Ramakrishna, S; Larrick, James W

    2009-01-01

    A bioabsorbable nanofibrous scaffold was developed for early adhesion of mesenchymal stem cells (MSCs). Collagen nanofibers with diameters of 430 ± 170 nm were fabricated by electrospinning. Over 45% of the MSC population adhered to this collagen nanofiber after 30 min at room temperature. Remarkably, collagen-coated P(LLA-CL) electrospun nanofibers were almost as efficient as collagen nanofibers whereas collagen cast film did not enhance early capture when it was applied on cover slips. The adhesive efficiency could be further increased to over 20% at 20 min and over 55% at 30 min when collagen nanofibers were grafted with monoclonal antibodies recognizing CD29 or CD49a. These data demonstrate that the early adhesive behavior is highly dependent on both the surface texture and the surface chemistry of the substrate. These findings have potential applications for early capture of MSCs in an ex vivo setting under time constraints such as in a surgical setting.

  5. The co-effect of collagen and magnesium ions on calcium carbonate biomineralization

    International Nuclear Information System (INIS)

    Jiao Yunfeng; Feng Qingling; Li Xiaoming

    2006-01-01

    The process of calcium carbonate biomineralization in the solution containing collagen and magnesium ions was studied in this paper. The results were characterized by using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect rules were obtained by the cooperation of collagen and magnesium ions in different concentration. The experiment results showed that in the presence of both collagen and magnesium ions, aragonite and vaterite were precipitated at low Mg/Ca ion concentration ratio, while only aragonite with regular spherical morphology was precipitated at high Mg/Ca ion concentration ratio. It indicated that collagen has a promotional effect on magnesium ions in controlling the polymorph of calcium carbonate crystal. A much wider range of calcium carbonate morphologies was observed in the presence of both collagen and magnesium ions. The experiments suggested that collagen acts in combination with magnesium ions to inhibit calcite crystal growth, while favoring the formation of aragonite crystals

  6. Laminin peptide YIGSR induces collagen synthesis in Hs27 human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jong Hyuk; Kim, Jaeyoon; Lee, Hyeongjoo [NovaCell Technology Inc., Pohang, Kyungbuk 790-784 (Korea, Republic of); Kim, So Young [Department of Dermatology, Chung-Ang University College of Medicine, Seoul 156-756 (Korea, Republic of); Department of Convergence Medicine and Pharmaceutical Biosciences, Graduate School, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Jang, Hwan-Hee [Functional Food and Nutrition Division, Department of Agrofood Resources, Rural Development Administration, Suwon 441-853 (Korea, Republic of); Ryu, Sung Ho [Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Kyungbuk 790-784 (Korea, Republic of); Kim, Beom Joon [Department of Dermatology, Chung-Ang University College of Medicine, Seoul 156-756 (Korea, Republic of); Department of Convergence Medicine and Pharmaceutical Biosciences, Graduate School, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Taehoon G., E-mail: taehoon@novacelltech.com [NovaCell Technology Inc., Pohang, Kyungbuk 790-784 (Korea, Republic of)

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer We identify a function of the YIGSR peptide to enhance collagen synthesis in Hs27. Black-Right-Pointing-Pointer YIGSR peptide enhanced collagen type 1 synthesis both of gene and protein levels. Black-Right-Pointing-Pointer There were no changes in cell proliferation and MMP-1 level in YIGSR treatment. Black-Right-Pointing-Pointer The YIGSR effect on collagen synthesis mediated activation of FAK, pyk2 and ERK. Black-Right-Pointing-Pointer The YIGSR-induced FAK and ERK activation was modulated by FAK and MEK inhibitors. -- Abstract: The dermal ECM is synthesized from fibroblasts and is primarily compromised of fibrillar collagen and elastic fibers, which support the mechanical strength and resiliency of skin, respectively. Laminin, a major glycoprotein located in the basement membrane, promotes cell adhesion, cell growth, differentiation, and migration. The laminin tyrosine-isoleucine-glycine-serine-arginine (YIGSR) peptide, corresponding to the 929-933 sequence of the {beta}1 chain, is known to be a functional motif with effects on the inhibition of tumor metastasis, the regulation of sensory axonal response and the inhibition of angiogenesis through high affinity to the 67 kDa laminin receptor. In this study, we identified a novel function of the YIGSR peptide to enhance collagen synthesis in human dermal fibroblasts. To elucidate this novel function regarding collagen synthesis, we treated human dermal fibroblasts with YIGSR peptide in both a time- and dose-dependent manner. According to subsequent experiments, we found that the YIGSR peptide strongly enhanced collagen type 1 synthesis without changing cell proliferation or cellular MMP-1 level. This YIGSR peptide-mediated collagen type 1 synthesis was modulated by FAK inhibitor and MEK inhibitor. This study clearly reveals that YIGSR peptide plays a novel function on the collagen type 1 synthesis of dermal fibroblasts and also suggests that YIGSR is a strong candidate

  7. Protease inhibitors enhance extracellular collagen fibril deposition in human mesenchymal stem cells.

    Science.gov (United States)

    Han, Sejin; Li, Yuk Yin; Chan, Barbara Pui

    2015-10-15

    Collagen is a widely used naturally occurring biomaterial for scaffolding, whereas mesenchymal stem cells (MSCs) represent a promising cell source in tissue engineering and regenerative medicine. It is generally known that cells are able to remodel their environment by simultaneous degradation of the scaffolds and deposition of newly synthesized extracellular matrix. Nevertheless, the interactions between MSCs and collagen biomaterials are poorly known, and the strategies enhancing the extracellular matrix deposition are yet to be defined. In this study, we aim to investigate the fate of collagen when it is in contact with MSCs and hypothesize that protease inhibition will enhance their extracellular deposition of collagen fibrils. Specifically, human MSCs (hMSCs) were exposed to fluorescence-labeled collagen with and without intracellular or extracellular protease inhibitors (or both) before tracing the collagen at both intracellular and extracellular spaces. Collagen were internalized by hMSCs and degraded intracellularly in lysosomes. In the presence of protease inhibitors, both intracellular collagen fibril growth and extracellular deposition of collagen fibrils were enhanced. Moreover, protease inhibitors work synergistically with ascorbic acid, a well-known matrix deposition-enhancing reagent, in further enhancing collagen fibril deposition at the extracellular space. These findings provide a better understanding of the interactions between hMSCs and collagen biomaterials and suggest a method to manipulate matrix remodeling and deposition of hMSCs, contributing to better scaffolding for tissue engineering and regenerative medicine.

  8. Age-related modifications of type I collagen impair DDR1-induced apoptosis in non-invasive breast carcinoma cells.

    Science.gov (United States)

    Charles, Saby; Hassan, Rammal; Kevin, Magnien; Emilie, Buache; Sylvie, Brassart-Pasco; Laurence, Van-Gulick; Pierre, Jeannesson; Erik, Maquoi; Hamid, Morjani

    2018-05-07

    Type I collagen and DDR1 axis has been described to decrease cell proliferation and to initiate apoptosis in non-invasive breast carcinoma in three-dimensional cell culture matrices. Moreover, MT1-MMP down-regulates these effects. Here, we address the effect of type I collagen aging and MT1-MMP expression on cell proliferation suppression and induced-apoptosis in non-invasive MCF-7 and ZR-75-1 breast carcinoma. We provide evidence for a decrease in cell growth and an increase in apoptosis in the presence of adult collagen when compared to old collagen. This effect involves a differential activation of DDR1, as evidenced by a higher DDR1 phosphorylation level in adult collagen. In adult collagen, inhibition of DDR1 expression and kinase function induced an increase in cell growth to a level similar to that observed in old collagen. The impact of aging on the sensitivity of collagen to MT1-MMP has been reported recently. We used the MT1-MMP expression strategy to verify whether, by degrading adult type I collagen, it could lead to the same phenotype observed in old collagen 3D matrix. MT1-MMP overexpression abrogated the proliferation suppression and induced-apoptosis effects only in the presence of adult collagen. This suggests that differential collagen degradation by MT1-MMP induced a structural disorganization of adult collagen and inhibits DDR1 activation. This could in turn impair DDR1-induced cell growth suppression and apoptosis. Taken together, our data suggest that modifications of collagen structural organization, due to aging, contribute to the loss of the growth suppression and induced apoptosis effect of collagen in luminal breast carcinoma. MT1-MMP-dependent degradation and aging of collagen have no additive effects on these processes.

  9. Calcitonin directly attenuates collagen type II degradation by inhibition of matrix metalloproteinase expression and activity in articular chondrocytes

    DEFF Research Database (Denmark)

    Sondergaard, B C; Wulf, H; Henriksen, K

    2006-01-01

    OBJECTIVE: Calcitonin was recently reported to counter progression of cartilage degradation in an experimental model of osteoarthritis, and the effects were primarily suggested to be mediated by inhibition of subchondral bone resorption. We investigated direct effects of calcitonin on chondrocytes...... by assessing expression of the receptor and pharmacological effects on collagen type II degradation under ex vivo and in vivo conditions. METHODS: Localization of the calcitonin receptor on articular chondrocytes was investigated by immunohistochemistry, and the expression by reverse transcriptase polymerase.......0001-1 microM]. In vivo, cartilage degradation was investigated in ovariectomized (OVX) rats administered with oral calcitonin [2 mg/kg calcitonin] for 9 weeks. RESULTS: The calcitonin receptor was identified in articular chondrocytes by immunohistochemistry and RT-PCR. Calcitonin concentration...

  10. Moisture absorption and retention properties, and activity in alleviating skin photodamage of collagen polypeptide from marine fish skin.

    Science.gov (United States)

    Hou, Hu; Li, Bafang; Zhang, Zhaohui; Xue, Changhu; Yu, Guangli; Wang, Jingfeng; Bao, Yuming; Bu, Lin; Sun, Jiang; Peng, Zhe; Su, Shiwei

    2012-12-01

    Collagen polypeptides were prepared from cod skin. Moisture absorption and retention properties of collagen polypeptides were determined at different relative humidities. In addition, the protective effects of collagen polypeptide against UV-induced damage to mouse skin were evaluated. Collagen polypeptides had good moisture absorption and retention properties and could alleviate the damage induced by UV radiation. The action mechanisms of collagen polypeptide mainly involved enhancing immunity, reducing the loss of moisture and lipid, promoting anti-oxidative properties, inhibiting the increase of glycosaminoglycans, repairing the endogenous collagen and elastin protein fibres, and maintaining the ratio of type III to type I collagen. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Alteration of cellular behavior and response to PI3K pathway inhibition by culture in 3D collagen gels.

    Directory of Open Access Journals (Sweden)

    Brian Fallica

    Full Text Available Most investigations into cancer cell drug response are performed with cells cultured on flat (2D tissue culture plastic. Emerging research has shown that the presence of a three-dimensional (3D extracellular matrix (ECM is critical for normal cell behavior including migration, adhesion, signaling, proliferation and apoptosis. In this study we investigate differences between cancer cell signaling in 2D culture and a 3D ECM, employing real-time, live cell tracking to directly observe U2OS human osteosarcoma and MCF7 human breast cancer cells embedded in type 1 collagen gels. The activation of the important PI3K signaling pathway under these different growth conditions is studied, and the response to inhibition of both PI3K and mTOR with PI103 investigated. Cells grown in 3D gels show reduced proliferation and migration as well as reduced PI3K pathway activation when compared to cells grown in 2D. Our results quantitatively demonstrate that a collagen ECM can protect U2OS cells from PI103. Overall, our data suggests that 3D gels may provide a better medium for investigation of anti-cancer drugs than 2D monolayers, therefore allowing better understanding of cellular response and behavior in native like environments.

  12. Collagen fibrillogenesis: fibronectin, integrins, and minor collagens as organizers and nucleators.

    Science.gov (United States)

    Kadler, Karl E; Hill, Adele; Canty-Laird, Elizabeth G

    2008-10-01

    Collagens are triple helical proteins that occur in the extracellular matrix (ECM) and at the cell-ECM interface. There are more than 30 collagens and collagen-related proteins but the most abundant are collagens I and II that exist as D-periodic (where D = 67 nm) fibrils. The fibrils are of broad biomedical importance and have central roles in embryogenesis, arthritis, tissue repair, fibrosis, tumor invasion, and cardiovascular disease. Collagens I and II spontaneously form fibrils in vitro, which shows that collagen fibrillogenesis is a selfassembly process. However, the situation in vivo is not that simple; collagen I-containing fibrils do not form in the absence of fibronectin, fibronectin-binding and collagen-binding integrins, and collagen V. Likewise, the thin collagen II-containing fibrils in cartilage do not form in the absence of collagen XI. Thus, in vivo, cellular mechanisms are in place to control what is otherwise a protein self-assembly process. This review puts forward a working hypothesis for how fibronectin and integrins (the organizers) determine the site of fibril assembly, and collagens V and XI (the nucleators) initiate collagen fibrillogenesis.

  13. Transformation of amorphous calcium carbonate to rod-like single crystal calcite via "copying" collagen template.

    Science.gov (United States)

    Xue, Zhonghui; Hu, Binbin; Dai, Shuxi; Du, Zuliang

    2015-10-01

    Collagen Langmuir films were prepared by spreading the solution of collagen over deionized water, CaCl2 solution and Ca(HCO3)2 solution. Resultant collagen Langmuir monolayers were then compressed to a lateral pressure of 10 mN/m and held there for different duration, allowing the crystallization of CaCO3. The effect of crystallization time on the phase composition and microstructure of CaCO3 was investigated. It was found that amorphous calcium carbonate (ACC) was obtained at a crystallization time of 6 h. The amorphous CaCO3 was transformed to rod-like single crystal calcite crystals at an extended crystallization time of 12 h and 24 h, via "copying" the symmetry and dimensionalities of collagen fibers. Resultant calcite crystallites were well oriented along the longitudinal axis of collagen fibers. The ordered surface structure of collagen fibers and electrostatic interactions played key roles in tuning the oriented nucleation and growth of the calcite crystallites. The mineralized collagen possessing both desired mechanical properties of collagen fiber and good biocompatibility of calcium carbonate may be assembled into an ideal biomaterial for bone implants. Copyright © 2015. Published by Elsevier B.V.

  14. Effect of indomethacin and lactoferrin on human tenocyte proliferation and collagen formation in vitro

    International Nuclear Information System (INIS)

    Zhang, Yaonan; Wang, Xiao; Qiu, Yiwei; Cornish, Jillian; Carr, Andrew J.; Xia, Zhidao

    2014-01-01

    Highlights: • Indomethacin, a classic NSAID, inhibited human tenocyte proliferation at high concentration (100 µM). • Lactoferrin at 50-100 µg/ml promoted human tenocyte survival, proliferation and collagen synthesis. • Lactoferrin is anabolic to human tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human tenocytes. - Abstract: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with injuries and inflammation of tendon and ligament, and as post-surgical analgesics. The aim of this study is to investigate the effect of indomethacin, a classic NSAID and its combinational effect with an anabolic agent of skeletal tissue, lactoferrin, on the proliferation and collagen formation of human tenocytes in vitro. A factorial experimental design was employed to study the dose-dependent effect of the combination of indomethacin and lactoferrin. The results showed that indomethacin at high concentration (100 μM) inhibited human tenocyte proliferation in culture medium with 1–10% fetal bovine serum (FBS) in vitro. Also, high dose of indomethacin inhibited the collagen formation of human tenocytes in 1% FBS culture medium. Lactoferrin at 50–100 μg/ml promoted human tenocyte survival in serum-free culture medium and enhanced proliferation and collagen synthesis of human tenocytes in 1% FBS culture medium. When 50–100 μg/ml lactoferrin was used in combination with 100–200 μM indomethacin, it partially rescued the inhibitory effects of indomethacin on human tenocyte proliferation, viability and collagen formation. To our knowledge, it is the first evidence that lactoferrin is anabolic to human tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human tenocytes

  15. Effect of indomethacin and lactoferrin on human tenocyte proliferation and collagen formation in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yaonan [Centre for Nanohealth, College of Medicine, Swansea University, Singleton Park, Swansea, UK SA2 8PP (United Kingdom); Department of Orthopaedic, Beijing Hospital of Ministry of Public Health, Beijing, China 100730 (China); Wang, Xiao; Qiu, Yiwei [Centre for Nanohealth, College of Medicine, Swansea University, Singleton Park, Swansea, UK SA2 8PP (United Kingdom); Cornish, Jillian [Department of Medicine, University of Auckland, Private Bag 92019, Auckland (New Zealand); Carr, Andrew J. [Centre for Nanohealth, College of Medicine, Swansea University, Singleton Park, Swansea, UK SA2 8PP (United Kingdom); Xia, Zhidao, E-mail: z.xia@swansea.ac.uk [Centre for Nanohealth, College of Medicine, Swansea University, Singleton Park, Swansea, UK SA2 8PP (United Kingdom)

    2014-11-14

    Highlights: • Indomethacin, a classic NSAID, inhibited human tenocyte proliferation at high concentration (100 µM). • Lactoferrin at 50-100 µg/ml promoted human tenocyte survival, proliferation and collagen synthesis. • Lactoferrin is anabolic to human tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human tenocytes. - Abstract: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in patients with injuries and inflammation of tendon and ligament, and as post-surgical analgesics. The aim of this study is to investigate the effect of indomethacin, a classic NSAID and its combinational effect with an anabolic agent of skeletal tissue, lactoferrin, on the proliferation and collagen formation of human tenocytes in vitro. A factorial experimental design was employed to study the dose-dependent effect of the combination of indomethacin and lactoferrin. The results showed that indomethacin at high concentration (100 μM) inhibited human tenocyte proliferation in culture medium with 1–10% fetal bovine serum (FBS) in vitro. Also, high dose of indomethacin inhibited the collagen formation of human tenocytes in 1% FBS culture medium. Lactoferrin at 50–100 μg/ml promoted human tenocyte survival in serum-free culture medium and enhanced proliferation and collagen synthesis of human tenocytes in 1% FBS culture medium. When 50–100 μg/ml lactoferrin was used in combination with 100–200 μM indomethacin, it partially rescued the inhibitory effects of indomethacin on human tenocyte proliferation, viability and collagen formation. To our knowledge, it is the first evidence that lactoferrin is anabolic to human tenocytes in vitro and reverses potential inhibitory effects of NSAIDs on human tenocytes.

  16. Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Bang, G

    1992-01-01

    fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction....

  17. Collagenous sprue

    DEFF Research Database (Denmark)

    Soendergaard, Christoffer; Riis, Lene Buhl; Nielsen, Ole Haagen

    2014-01-01

    Collagenous sprue is a rare clinicopathological condition of the small bowel. It is characterised by abnormal subepithelial collagen deposition and is typically associated with malabsorption, diarrhoea and weight loss. The clinical features of collagenous sprue often resemble those of coeliac...... disease and together with frequent histological findings like mucosal thinning and intraepithelial lymphocytosis the diagnosis may be hard to reach without awareness of this condition. While coeliac disease is treated using gluten restriction, collagenous sprue is, however, not improved...... by this intervention. In cases of diet-refractory 'coeliac disease' it is therefore essential to consider collagenous sprue to initiate treatment at an early stage to prevent the fibrotic progression. Here, we report a case of a 78-year-old man with collagenous sprue and present the clinical and histological...

  18. Non-enzymatic glycosylation of a type I collagen matrix: effects on osteoblastic development and oxidative stress

    Directory of Open Access Journals (Sweden)

    Barrio Daniel A

    2001-08-01

    Full Text Available Abstract Background The tissue accumulation of protein-bound advanced glycation endproducts (AGE may be involved in the etiology of diabetic chronic complications, including osteopenia. The aim of this study was to investigate the effect of an AGE-modified type I collagen substratum on the adhesion, spreading, proliferation and differentiation of rat osteosarcoma UMR106 and mouse non-transformed MC3T3E1 osteoblastic cells. We also studied the role of reactive oxygen species (ROS and nitric oxide synthase (NOS expression on these AGE-collagen mediated effects. Results AGE-collagen decreased the adhesion of UMR106 cells, but had no effect on the attachment of MC3T3E1 cells. In the UMR106 cell line, AGE-collagen also inhibited cellular proliferation, spreading and alkaline phosphatase (ALP activity. In preosteoblastic MC3T3E1 cells (24-hour culture, proliferation and spreading were significantly increased by AGE-collagen. After one week of culture (differentiated MC3T3E1 osteoblasts AGE-collagen inhibited ALP activity, but had no effect on cell number. In mineralizing MC3T3E1 cells (3-week culture AGE-collagen induced a decrease in the number of surviving cells and of extracellular nodules of mineralization, without modifying their ALP activity. Intracellular ROS production, measured after a 48-hour culture, was decreased by AGE-collagen in MC3T3E1 cells, but was increased by AGE-collagen in UMR106 cells. After a 24-hour culture, AGE-collagen increased the expression of endothelial and inducible NOS, in both osteoblastic cell lines. Conclusions These results suggest that the accumulation of AGE on bone extracellular matrix could regulate the proliferation and differentiation of osteoblastic cells. These effects appear to depend on the stage of osteoblastic development, and possibly involve the modulation of NOS expression and intracellular ROS pathways.

  19. [The effect of calcitonin gene-related peptide on collagen accumulation in pulmonary arteries of rats with hypoxic pulmonary arterial hypertension].

    Science.gov (United States)

    Li, Xian-Wei; Du, Jie; Li, Yuan-Jian

    2013-03-01

    To observe the effect of calcitonin gene-related peptide (CGRP) on pulmonary vascular collagen accumulation in hypoxia rats in order to study the effect of CGRP on hypoxic pulmonary vascular structural remodeling and its possible mechanism. Rats were acclimated for 1 week, and then were randomly divided into three groups: normoxia group, hypoxia group, and hypoxia plus capsaicin group. Pulmonary arterial hypertension was induced by hypoxia in rats. Hypoxia plus capsaicin group, rats were given capsaicin (50 mg/(kg x d), s.c) 4 days before hypoxia to deplete endogenous CGRP. Hypoxia (3% O2) stimulated proliferation of pulmonary arterial smooth muscle cells (PASMCs) and proliferation was measured by BrdU marking. The expression levels of CGRP, phosphorylated ERK1/2 (p-ERK1/ 2), collagen I and collagen III were detected by real-time PCR or Western blot. Right ventricle systolic pressure (RVSP) and mean pulmonary arterial pressure (mPAP) of pulmonary arterial hypertension (PAH) rats induced by hypoxia were higher than those of normoxia rats. By HE and Masson staining, it was demonstrated that hypoxia also significantly induced hypertrophy of pulmonary arteries and increased level of collagen accumulation. Hypoxia dramatically decreased the CGRP level and increased the expression of p-ERK1/2, collagen I, collagen III in pulmonary arteries. All these effects of hypoxia were further aggravated by pre-treatment of rats with capsaicin. CGRP concentration-dependently inhibited hypoxia-induced proliferation of PASMCs, markedly decreased the expression of p-ERK1/2, collagen I and collagen III. All these effects of CGRP were abolished in the presence of CGRP8-37. These results suggest that CGRP might inhibit hypoxia-induced PAH and pulmonary vascular remodeling, through inhibiting phosphorylation of ERK1/2 and alleviating the collagen accumulation of pulmonary arteries.

  20. Collagen-based silver nanoparticles: Study on cell viability, skin permeation, and swelling inhibition

    International Nuclear Information System (INIS)

    Saura Cardoso, Vinicius; Carvalho Filgueiras, Marcelo de; Medeiros Dutra, Yago; Gomes Teles, Ramon Handerson; Rodrigues de Araújo, Alyne; Primo, Fernando Lucas; Mafud, Ana Carolina; Batista, Larissa Fernandes; Mascarenhas, Yvonne Primerano

    2017-01-01

    Collagen is considered the most abundant protein in the animal kingdom, comprising 30% of the total amount of proteins and 6% of the human body by weight. Studies that examine the interaction between silver nanoparticles and proteins have been highlighted in the literature in order to understand the stability of the nanoparticle system, the effects observed in biological systems, and the appearance of new chemical pharmaceutical products. The objective of this study was to analyze the behavior of silver nanoparticles stabilized with collagen (AgNPcol) and to check the skin permeation capacity and action in paw edema induced by carrageenan. AgNPcol synthesis was carried out using solutions of reducing agent sodium borohydride (NaBH 4 ), silver nitrate (AgNO 3 ) and collagen. Characterization was done by using dynamic light scattering (DLS) and X-ray diffraction (XRD) and AFM. Cellular viability testing was performed by using flow cytometry in human melanoma cancer (MV3) and murine fibroblast (L929) cells. The skin permeation study was conducted using a Franz diffusion cell, and the efficiency of AgNPcol against the formation of paw edema in mice was evaluated. The hydrodynamic diameter and zeta potential of AgNPcol were 140.7 ± 7.8 nm and 20.1 ± 0.7 mV, respectively. AgNPcol failed to induce early apoptosis, late apoptosis, and necrosis in L929 cells; however, it exhibited enhanced toxicity in cancer cells (MV3) compared to normal cells (L929). AgNPcol demonstrated increased toxicological effects in cancer MV3 cells, promoting skin permeation, and preventing paw edema. - Highlights: • Silver nanoparticles were synthesized with type I collagen (AgNPcol). • AgNPcol which was characterized by XRD and DLS. • AgNPcol exhibited enhanced toxicity in cancer cells. • The efficiency of the AgNPcol against the paw edema was evaluated.

  1. Collagen-based silver nanoparticles: Study on cell viability, skin permeation, and swelling inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Saura Cardoso, Vinicius, E-mail: vscfisio@ufpi.edu.br [Research Center in Biodiversity and Biotechnology, Biotec, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Physiotherapy Department, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Carvalho Filgueiras, Marcelo de; Medeiros Dutra, Yago; Gomes Teles, Ramon Handerson [Physiotherapy Department, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Morphology and Muscle Physiology Laboratory, LAMFIM, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Rodrigues de Araújo, Alyne [Research Center in Biodiversity and Biotechnology, Biotec, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Primo, Fernando Lucas [Faculdade de Ciências Farmacêuticas, UNESP, Universidade Estadual Paulista, Campus de Araraquara, Departamento de Bioprocessos e Biotecnologia, 14800903 Araraquara, São Paulo (Brazil); Mafud, Ana Carolina; Batista, Larissa Fernandes; Mascarenhas, Yvonne Primerano [Institute of Physics of São Carlos, IFSC, University of São Paulo, USP, 13566590 São Carlos, SP (Brazil); and others

    2017-05-01

    Collagen is considered the most abundant protein in the animal kingdom, comprising 30% of the total amount of proteins and 6% of the human body by weight. Studies that examine the interaction between silver nanoparticles and proteins have been highlighted in the literature in order to understand the stability of the nanoparticle system, the effects observed in biological systems, and the appearance of new chemical pharmaceutical products. The objective of this study was to analyze the behavior of silver nanoparticles stabilized with collagen (AgNPcol) and to check the skin permeation capacity and action in paw edema induced by carrageenan. AgNPcol synthesis was carried out using solutions of reducing agent sodium borohydride (NaBH{sub 4}), silver nitrate (AgNO{sub 3}) and collagen. Characterization was done by using dynamic light scattering (DLS) and X-ray diffraction (XRD) and AFM. Cellular viability testing was performed by using flow cytometry in human melanoma cancer (MV3) and murine fibroblast (L929) cells. The skin permeation study was conducted using a Franz diffusion cell, and the efficiency of AgNPcol against the formation of paw edema in mice was evaluated. The hydrodynamic diameter and zeta potential of AgNPcol were 140.7 ± 7.8 nm and 20.1 ± 0.7 mV, respectively. AgNPcol failed to induce early apoptosis, late apoptosis, and necrosis in L929 cells; however, it exhibited enhanced toxicity in cancer cells (MV3) compared to normal cells (L929). AgNPcol demonstrated increased toxicological effects in cancer MV3 cells, promoting skin permeation, and preventing paw edema. - Highlights: • Silver nanoparticles were synthesized with type I collagen (AgNPcol). • AgNPcol which was characterized by XRD and DLS. • AgNPcol exhibited enhanced toxicity in cancer cells. • The efficiency of the AgNPcol against the paw edema was evaluated.

  2. Effects of the gelatin plasma substitutes Haemaccel, Plasmagel and Plasmion (Geloplasma) on collagen-, ADP- and adrenaline-induced aggregation of human platelets in vitro.

    Science.gov (United States)

    Stibbe, J; van der Plas, P M; Ong, G L; ten Hoor, F; Nauta, J; de Jong, D S; Krenning-Douma, E; Gomes, M

    1981-01-01

    The effect of some gelatin plasma substitutes (Haemaccel, plasmagel and Plasmion (Geloplasma), which are widely used in Europe) on collagen-, ADP- and adrenaline-induced platelet aggregation in human PRP in vitro was studied under controlled conditions (pH, electrolyte composition). Haemaccel inhibited these aggregations, both in citrated as well as in heparinised PRP, whereas they were enhanced by both Plasmagel and Plasmion as compared to the appropriate control. Increasing teh concentration of the inducer overcame the inhibition by Haemaccel. Haemaccel inhibited, while Plasmion enhanced 14C-serotonin release induced by collagen, ADP or adrenaline. Also in the presence of indomethacin (90 muM) Haemaccel inhibited aggregation induced by high concentrations of collagen and the primary aggregation induced by ADP and adrenaline, while Plasmion enhanced these aggregations induced by ADP and adrenaline, while Plasmion enhanced these aggregations. The inhibition by Haemaccel was not caused by binding of Ca2+ to haemaccel.

  3. Methyl salicylate lactoside inhibits inflammatory response of fibroblast-like synoviocytes and joint destruction in collagen-induced arthritis in mice.

    Science.gov (United States)

    Xin, Wenyu; Huang, Chao; Zhang, Xue; Xin, Sheng; Zhou, Yiming; Ma, Xiaowei; Zhang, Dan; Li, Yongjie; Zhou, Sibai; Zhang, Dongming; Zhang, Tiantai; Du, Guanhua

    2014-07-01

    Methyl salicylate 2-O-β-d-lactoside (MSL), whose chemical structure is similar to that of salicylic acid, is a natural product derivative isolated from a traditional Chinese herb. The aim of this study was to investigate the therapeutic effect of MSL in mice with collagen-induced arthritis (CIA) and explore its underlying mechanism. The anti-arthritic effects of MSL were evaluated on human rheumatoid fibroblast-like synoviocytes (FLS) in vitro and CIA in mice in vivo by obtaining clinical scores, measuring hind paw thickness and inflammatory cytokine levels, radiographic evaluations and histopathological assessments. Treatment with MSL after the onset of arthritis significantly prevented the progression and development of rheumatoid arthritis (RA) in CIA mice without megascopic gastric mucosa damage. In addition, MSL inhibited the production of pro-inflammatory mediators, the phosphorylation and translocation of NF-κB, and cell proliferation induced by TNF-α in FLS. MSL non-selectively inhibited the activity of COX in vitro, but was a more potent inhibitor of COX-2 than COX-1. MSL also inhibited the phosphorylation of inhibitor of NF-κB kinase, IκBα and p65, thus blocking the nuclear translocation of NF-κB in TNF-α-stimulated FLS. MSL exerts therapeutic effects on CIA mice, suppressing the inflammatory response and joint destruction by non-selectively inhibiting the activity of COX and suppressing activation of the NF-κB signalling pathway, but without damaging the gastric mucosa. Therefore, MSL has great potential to be developed into a novel therapeutic agent for the treatment of RA. © 2014 The British Pharmacological Society.

  4. Osteogenic cell differentiation on H-terminated and O-terminated nanocrystalline diamond films

    Directory of Open Access Journals (Sweden)

    Liskova J

    2015-01-01

    Full Text Available Jana Liskova,1 Oleg Babchenko,2 Marian Varga,2 Alexander Kromka,2 Daniel Hadraba,1 Zdenek Svindrych,1 Zuzana Burdikova,1 Lucie Bacakova1 1Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; 2Institute of Physics, Academy of Sciences of the Czech Republic, Prague, Czech Republic Abstract: Nanocrystalline diamond (NCD films are promising materials for bone implant coatings because of their biocompatibility, chemical resistance, and mechanical hardness. Moreover, NCD wettability can be tailored by grafting specific atoms. The NCD films used in this study were grown on silicon substrates by microwave plasma-enhanced chemical vapor deposition and grafted by hydrogen atoms (H-termination or oxygen atoms (O-termination. Human osteoblast-like Saos-2 cells were used for biological studies on H-terminated and O-terminated NCD films. The adhesion, growth, and subsequent differentiation of the osteoblasts on NCD films were examined, and the extracellular matrix production and composition were quantified. The osteoblasts that had been cultivated on the O-terminated NCD films exhibited a higher growth rate than those grown on the H-terminated NCD films. The mature collagen fibers were detected in Saos-2 cells on both the H-terminated and O-terminated NCD films; however, the quantity of total collagen in the extracellular matrix was higher on the O-terminated NCD films, as were the amounts of calcium deposition and alkaline phosphatase activity. Nevertheless, the expression of genes for osteogenic markers – type I collagen, alkaline phosphatase, and osteocalcin – was either comparable on the H-terminated and O-terminated films or even lower on the O-terminated films. In conclusion, the higher wettability of the O-terminated NCD films is promising for adhesion and growth of osteoblasts. In addition, the O-terminated surface also seems to support the deposition of extracellular matrix proteins and extracellular matrix

  5. Micro-mechanical model for the tension-stabilized enzymatic degradation of collagen tissues

    Science.gov (United States)

    Nguyen, Thao; Ruberti, Jeffery

    We present a study of how the collagen fiber structure influences the enzymatic degradation of collagen tissues. Experiments of collagen fibrils and tissues show that mechanical tension can slow and halt enzymatic degradation. Tissue-level experiments also show that degradation rate is minimum at a stretch level coincident with the onset of strain-stiffening in the stress response. To understand these phenomena, we developed a micro-mechanical model of a fibrous collagen tissue undergoing enzymatic degradation. Collagen fibers are described as sinusoidal elastica beams, and the tissue is described as a distribution of fibers. We assumed that the degradation reaction is inhibited by the axial strain energy of the crimped collagen fibers. The degradation rate law was calibrated to experiments on isolated single fibrils from bovine sclera. The fiber crimp and properties were fit to uniaxial tension tests of tissue strips. The fibril-level kinetic and tissue-level structural parameters were used to predict tissue-level degradation-induced creep rate under a constant applied force. We showed that we could accurately predict the degradation-induce creep rate of the pericardium and cornea once we accounted for differences in the fiber crimp structure and properties.

  6. Collagen attachment to the substrate controls cell clustering through migration

    International Nuclear Information System (INIS)

    Hou, Yue; Rodriguez, Laura Lara; Wang, Juan; Schneider, Ian C

    2014-01-01

    Cell clustering and scattering play important roles in cancer progression and tissue engineering. While the extracellular matrix (ECM) is known to control cell clustering, much of the quantitative work has focused on the analysis of clustering between cells with strong cell–cell junctions. Much less is known about how the ECM regulates cells with weak cell–cell contact. Clustering characteristics were quantified in rat adenocarcinoma cells, which form clusters on physically adsorbed collagen substrates, but not on covalently attached collagen substrates. Covalently attaching collagen inhibited desorption of collagen from the surface. While changes in proliferation rate could not explain differences seen in the clustering, changes in cell motility could. Cells plated under conditions that resulted in more clustering had a lower persistence time and slower migration rate than those under conditions that resulted in less clustering. Understanding how the ECM regulates clustering will not only impact the fundamental understanding of cancer progression, but also will guide the design of tissue engineered constructs that allow for the clustering or dissemination of cells throughout the construct. (paper)

  7. Effect of Oxytetracycline on In vitro Mineralization and Demineralization Reactions in the Absence and Presence of Collagen

    Directory of Open Access Journals (Sweden)

    Monica Kakkar

    2017-11-01

    Full Text Available Introduction: Oxytetracycline and its derivatives are routinely used to treat various ailments have also been shown to inhibit embryonic bone formation, mineralization in pregnant female rats and parathyroid hormone induced demineralization of bones. Oxytetracycline has also been routinely used as bone fluorochrome to study bone metabolism. However, despite the above observations, its mechanism of action is not clearly understood. Some studies tend to suggest that it acts by inhibiting collagen biosynthesis while others indicate that it acts without influencing collagen metabolism. Aim: To study the mechanism by which oxytetracycline influences the mineralization and demineralization reactions. Materials and Methods: Homogeneous and heterogeneous systems of in vitro mineralization under physiological conditions of temperature, pH and ionic strength were used to investigate the effect of oxytetracycline not only on initial mineral phase formation but also on its subsequent growth or demineralization. In the Homogenous system, supersaturated conditions with respect to calcium and phosphate ions were employed to study their precipitation as mineral phase resembling hydroxyapatite in nature. However, in the heterogeneous system, collagen isolated from sheep tendons was used to induce identical mineral phases under saturated conditions with respect to calcium and phosphate ions prevailing in the body fluids. Results: The study demonstrated that in the homogeneous reaction system (mineralization in the absence of collagen oxytetracycline inhibited both the initial mineral phase formation and its subsequent growth without influencing its demineralization. However, in the heterogeneous system, oxytetracycline was found to inhibit not only the initial mineralization but also its subsequent growth or demineralization. Conclusion: Oxytetracycline acted like crystal poisons to inhibit the mineralization and demineralization reactions by tightly associating

  8. Helminth antigens enable CpG-activated dendritic cells to inhibit the symptoms of collagen-induced arthritis through Foxp3+ regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Franco Carranza

    Full Text Available Dendritic cells (DC have the potential to control the outcome of autoimmunity by modulating the immune response. In this study, we tested the ability of Fasciola hepatica total extract (TE to induce tolerogenic properties in CpG-ODN (CpG maturated DC, to then evaluate the therapeutic potential of these cells to diminish the inflammatory response in collagen induced arthritis (CIA. DBA/1J mice were injected with TE plus CpG treated DC (T/C-DC pulsed with bovine collagen II (CII between two immunizations with CII and clinical scores CIA were determined. The levels of CII-specific IgG2 and IgG1 in sera, the histological analyses in the joints, the cytokine profile in the draining lymph node (DLN cells and in the joints, and the number, and functionality of CD4+CD25+Foxp3+ T cells (Treg were evaluated. Vaccination of mice with CII pulsed T/C-DC diminished the severity and incidence of CIA symptoms and the production of the inflammatory cytokine, while induced the production of anti-inflammatory cytokines. The therapeutic effect was mediated by Treg cells, since the adoptive transfer of CD4+CD25+ T cells, inhibited the inflammatory symptoms in CIA. The in vitro blockage of TGF-β in cultures of DLN cells plus CII pulsed T/C-DC inhibited the expansion of Treg cells. Vaccination with CII pulsed T/C-DC seems to be a very efficient approach to diminish exacerbated immune response in CIA, by inducing the development of Treg cells, and it is therefore an interesting candidate for a cell-based therapy for rheumatoid arthritis (RA.

  9. Endogenous collagen influences differentiation of human multipotent mesenchymal stromal cells.

    Science.gov (United States)

    Fernandes, Hugo; Mentink, Anouk; Bank, Ruud; Stoop, Reinout; van Blitterswijk, Clemens; de Boer, Jan

    2010-05-01

    Human multipotent mesenchymal stromal cells (hMSCs) are multipotent cells that, in the presence of appropriate stimuli, can differentiate into different lineages such as the osteogenic, chondrogenic, and adipogenic lineages. In the presence of ascorbic acid, MSCs secrete an extracellular matrix mainly composed of collagen type I. Here we assessed the potential role of endogenous collagen synthesis in hMSC differentiation and stem cell maintenance. We observed a sharp reduction in proliferation rate of hMSCs in the absence of ascorbic acid, concomitant with a reduction in osteogenesis in vitro and bone formation in vivo. In line with a positive role for collagen type I in osteogenesis, gene expression profiling of hMSCs cultured in the absence of ascorbic acid demonstrated increased expression of genes involved in adipogenesis and chondrogenesis and a reduction in expression of osteogenic genes. We also observed that matrix remodeling and anti-osteoclastogenic signals were high in the presence of ascorbic acid. The presence of collagen type I during the expansion phase of hMSCs did not affect their osteogenic and adipogenic differentiation potential. In conclusion, the collagenous matrix supports both proliferation and differentiation of osteogenic hMSCs but, on the other hand, presents signals stimulating matrix remodeling and inhibiting osteoclastogenesis.

  10. Sustained release of growth hormone and sodium nitrite from biomimetic collagen coating immobilized on silicone tubes improves endothelialization.

    Science.gov (United States)

    Salehi-Nik, Nasim; Malaie-Balasi, Zahra; Amoabediny, Ghassem; Banikarimi, Seyedeh Parnian; Zandieh-Doulabi, Behrouz; Klein-Nulend, Jenneke

    2017-08-01

    Biocompatibility of biomedical devices can be improved by endothelialization of blood-contacting parts mimicking the vascular endothelium's function. Improved endothelialization might be obtained by using biomimetic coatings that allow local sustained release of biologically active molecules, e.g. anti-thrombotic and growth-inducing agents, from nanoliposomes. We aimed to test whether incorporation of growth-inducing nanoliposomal growth hormone (nGH) and anti-thrombotic nanoliposomal sodium nitrite (nNitrite) into collagen coating of silicone tubes enhances endothelialization by stimulating endothelial cell proliferation and inhibiting platelet adhesion. Collagen coating stably immobilized on acrylic acid-grafted silicone tubes decreased the water contact angle from 102° to 56°. Incorporation of 50 or 500nmol/ml nNitrite and 100 or 1000ng/ml nGH into collagen coating decreased the water contact angle further to 48°. After 120h incubation, 58% nitrite and 22% GH of the initial amount of sodium nitrite and GH in nanoliposomes were gradually released from the nNitrite-nGH-collagen coating. Endothelial cell number was increased after surface coating of silicone tubes with collagen by 1.6-fold, and with nNitrite-nGH-collagen conjugate by 1.8-3.9-fold after 2days. After 6days, endothelial cell confluency in the absence of surface coating was 22%, with collagen coating 74%, and with nNitrite-nGH-collagen conjugate coating 83-119%. In the absence of endothelial cells, platelet adhesion was stimulated after collagen coating by 1.3-fold, but inhibited after nNitrite-nGH-collagen conjugate coating by 1.6-3.7-fold. The release of anti-thrombotic prostaglandin I 2 from endothelial cells was stimulated after nNitrite-nGH-collagen conjugate coating by 1.7-2.2-fold compared with collagen coating. Our data shows improved endothelialization and blood compatibility using nNitrite-nGH-collagen conjugate coating on silicone tubes suggesting that these coatings are highly suitable

  11. Cartilage proteoglycans inhibit fibronectin-mediated adhesion

    Science.gov (United States)

    Rich, A. M.; Pearlstein, E.; Weissmann, G.; Hoffstein, S. T.

    1981-09-01

    Normal tissues and organs show, on histological examination, a pattern of cellular and acellular zones that is characteristic and unique for each organ or tissue. This pattern is maintained in health but is sometimes destroyed by disease. For example, in mobile joints, the articular surfaces consist of relatively acellular hyaline cartilage, and the joint space is enclosed by a capsule of loose connective tissue with a lining of fibroblasts and macrophages. In the normal joint these cells are confined to the synovial lining and the articular surface remains acellular. In in vitro culture, macrophages and their precursor monocytes are very adhesive, and fibroblasts can migrate and overgrow surfaces such as collagen or plastic used for tissue culture. The fibroblasts adhere to collagen by means of fibronectin, which they synthesize and secrete1. Because the collagen of cartilage is capable of binding serum fibronectin2 and fibronectin is present in cartilage during its development3, these cells should, in theory, slowly migrate from the synovial lining to the articular surface. It is their absence from the articular cartilage in normal circumstances, and then presence in such pathological states as rheumatoid arthritis, that is striking. We therefore set out to determine whether a component of cartilage could prevent fibroblast adherence in a defined adhesion assay. As normal cartilage is composed of 50% proteoglycans and 50% collagen by dry weight4, we tested the possibility that the proteoglycans in cartilage inhibit fibroblast adhesion to collagen. We present here evidence that fibroblast spreading and adhesion to collagenous substrates is inhibited by cartilage proteoglycans.

  12. Immobilization of Tyrosinase from Avocado Crude Extract in Polypyrrole Films for Inhibitive Detection of Benzoic Acid

    Directory of Open Access Journals (Sweden)

    André Brisolari

    2014-07-01

    Full Text Available Inhibition-based biosensors were developed by immobilizing tyrosinase (Tyr, polyphenol oxidase from the crude extract of avocado fruit on electrochemically prepared polypyrrole (PPy films. The biosensors were prepared during the electropolymerization of pyrrole in a solution containing a fixed volume of the crude extract of avocado. The dependence of the biosensor responses on the volume used from the crude extract, values of pH and temperature was studied, and a substrate, catechol, at different concentrations, was amperometrically detected by these biosensors. Benzoic acid, a competitive inhibitor of Try, was added to the catechol solutions at specific concentrations aimed at obtaining the inhibition constant, K’m, which ranged from 1.7 to 4.6 mmol∙L−1 for 0.0 and 60 µmol∙L−1 of benzoic acid, respectively. Studies on the inhibition caused by benzoic acid by using PPy/Try films, and catechol as a substrate, allowed us propose how to develop, under optimized conditions, simple and low-cost biosensors based on the use of avocado fruit.

  13. Progress towards discovery of antifibrotic drugs targeting synthesis of type I collagen

    KAUST Repository

    Fritz, Dillon Jeffery; Cai, Le; Stefanovic, Lela; Stefanovic, Branko

    2011-01-01

    Type I collagen is the most abundant protein in human body. Fibrosis is characterized by excessive synthesis of type I collagen in parenchymal organs. It is a leading cause of morbidity and mortality worldwide, about 45% of all natural deaths are attributable to some fibroproliferative disease. There is no cure for fibrosis. To find specific antifibrotic therapy targeting type I collagen, critical molecular interactions regulating its synthesis must be elucidated. Type I and type III collagen mRNAs have a unique sequence element at the 5' end, the 5' stem-loop. This stem-loop is not found in any other mRNA. We cloned LARP6 as the protein which binds collagen 5' stem-loop with high affinity and specificity. Mutation of the 5' stem-loop or knock down of LARP6 greatly diminishes collagen expression. Mice with mutation of the 5' stem-loop are resistant to development of liver fibrosis. LARP6 associates collagen mRNAs with filaments composed of nonmuscle myosin; disruption of these filaments abolishes synthesis of type I collagen. Thus, LARP6 dependent collagen synthesis is the specific mechanism of high collagen expression seen in fibrosis. We developed fluorescence polarization (FP) method to screen for drugs that can inhibit binding of LARP6 to 5' stem-loop RNA. FP is high when LARP6 is bound, but decreases to low levels when the binding is competed out. Thus, by measuring decrease in FP it is possible to identify chemical compounds that can dissociate LARP6 from the 5' stem-loop. The method is simple, fast and suitable for high throughput screening. © 2011 Bentham Science Publishers Ltd.

  14. Progress towards discovery of antifibrotic drugs targeting synthesis of type I collagen

    KAUST Repository

    Fritz, Dillon Jeffery

    2011-08-01

    Type I collagen is the most abundant protein in human body. Fibrosis is characterized by excessive synthesis of type I collagen in parenchymal organs. It is a leading cause of morbidity and mortality worldwide, about 45% of all natural deaths are attributable to some fibroproliferative disease. There is no cure for fibrosis. To find specific antifibrotic therapy targeting type I collagen, critical molecular interactions regulating its synthesis must be elucidated. Type I and type III collagen mRNAs have a unique sequence element at the 5\\' end, the 5\\' stem-loop. This stem-loop is not found in any other mRNA. We cloned LARP6 as the protein which binds collagen 5\\' stem-loop with high affinity and specificity. Mutation of the 5\\' stem-loop or knock down of LARP6 greatly diminishes collagen expression. Mice with mutation of the 5\\' stem-loop are resistant to development of liver fibrosis. LARP6 associates collagen mRNAs with filaments composed of nonmuscle myosin; disruption of these filaments abolishes synthesis of type I collagen. Thus, LARP6 dependent collagen synthesis is the specific mechanism of high collagen expression seen in fibrosis. We developed fluorescence polarization (FP) method to screen for drugs that can inhibit binding of LARP6 to 5\\' stem-loop RNA. FP is high when LARP6 is bound, but decreases to low levels when the binding is competed out. Thus, by measuring decrease in FP it is possible to identify chemical compounds that can dissociate LARP6 from the 5\\' stem-loop. The method is simple, fast and suitable for high throughput screening. © 2011 Bentham Science Publishers Ltd.

  15. Mechanical stretching stimulates collagen synthesis via down-regulating SO2/AAT1 pathway

    Science.gov (United States)

    Liu, Jia; Yu, Wen; Liu, Yan; Chen, Selena; Huang, Yaqian; Li, Xiaohui; Liu, Cuiping; Zhang, Yanqiu; Li, Zhenzhen; Du, Jie; Tang, Chaoshu; Du, Junbao; Jin, Hongfang

    2016-01-01

    The aim of the study was to investigate the role of endogenous sulfur dioxide (SO2)/ aspartate aminotransferase 1 (AAT1) pathway in stretch-induced excessive collagen expression and its mechanism. The mechanical stretch downregulated SO2/AAT1 pathway and increased collagen I and III protein expression. Importantly, AAT1 overexpression blocked the increase in collagen I and III expression, transforming growth factor-β1 (TGF- β1) expression and phosphorylation of Smad2/3 induced by stretch, but AAT1 knockdown mimicked the increase in collagen I and III expression, TGF- β1 expression and phosphorylation of Smad2/3 induced by stretch. Mechanistically, SB431542, a TGF-β1/Smad2/3 inhibitor, eliminated excessive collagen I and III accumulation induced by AAT1 knockdown, stretch or stretch plus AAT1 knockdown. In a rat model of high pulmonary blood flow-induced pulmonary vascular collagen accumulation, AAT1 expression and SO2 content in lung tissues of rat were reduced in shunt rats with high pulmonary blood flow. Supplement of SO2 derivatives inhibited activation of TGF- β1/Smad2/3 pathway and alleviated the excessive collagen accumulation in lung tissues of shunt rats. The results suggested that deficiency of endogenous SO2/AAT1 pathway mediated mechanical stretch-stimulated abnormal collagen accumulation via TGF-β1/Smad2/3 pathway. PMID:26880260

  16. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    International Nuclear Information System (INIS)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-ichi; Onodera, Satoshi; Ikejima, Takashi

    2015-01-01

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells

  17. Type I collagen gel protects murine fibrosarcoma L929 cells from TNFα-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong-Ju; He, Wen-Qi; Chen, Ling; Liu, Wei-Wei; Xu, Qian; Xia, Ming-Yu; Hayashi, Toshihiko [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China); Fujisaki, Hitomi; Hattori, Shunji [Nippi Research Institute of Biomatrix, Toride, Ibaraki 302-0017 (Japan); Tashiro, Shin-ichi [Institute for Clinical and Biomedical Sciences, Kyoto 603-8072 (Japan); Onodera, Satoshi [Department of Clinical and Pharmaceutical Sciences, Showa Pharmaceutical University, Tokyo 194-8543 (Japan); Ikejima, Takashi, E-mail: ikejimat@vip.sina.com [China-Japan Research Institute of Medical and Pharmaceutical Sciences, Shenyang Pharmaceutical University, Shenyang 110016 (China)

    2015-02-20

    Murine fibrosarcoma L929 cells have been used to test efficacy of proinflammatory cytokine TNFα. In the present study, we reported on protective effect of type I collagen gel used as L929 cell culture. L929 cell grew and proliferated well on collagen gel. However, the L929 cells exhibited cobblestone-like morphology which was much different from the spread fusiform shape when cultured on conventional cell dishes as well as the cells tended to aggregate. On conventional cell culture dishes, the cells treated with TNFα became round in shape and eventually died in a necroptotic manner. The cells cultured on collagen gel, however, were completely unaffected. TNFα treatment was reported to induce autophagy in L929 cells on the plastic dish, and therefore we investigated the effect of collagen gel on induction of autophagy. The results indicated that autophagy induced by TNFα treatment was much reduced when the cells were cultured on collagen gel. In conclusion, type I collagen gel protected L929 cell from TNFα-induced cell death. - Highlights: • Collagen gel culture changed the morphology of L929 cells. • L929 cell cultured on collagen gel were resistant to TNFα-induced cell death. • Collagen gel culture inhibited TNFα-induced autophagy in L929 cells.

  18. Effect of Postoperative Diclofenac on Anastomotic Healing, Skin Wounds and Subcutaneous Collagen Accumulation

    DEFF Research Database (Denmark)

    Klein, M; Krarup, Peter-Martin; Kongsbak, Mikkel

    2012-01-01

    Background: Retrospective studies have drawn attention to possible detrimental effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the anastomotic leakage rate after colorectal resection. In this study, we examined the effects of the NSAID diclofenac on the breaking strength...... diclofenac treatment significantly inhibited collagen deposition in subcutaneous granulation tissue. Anastomotic strength and skin wound strength were not significantly affected. The ePTFE model is suitable for assessing the effect of various drugs on collagen formation and thus on wound healing....

  19. PVA/Polysaccharides Blended Films: Mechanical Properties

    OpenAIRE

    Silva, Fábio E. F.; Di-Medeiros, Maria Carolina B.; Batista, Karla A.; Fernandes, Kátia F.

    2013-01-01

    Blends of polyvinyl alcohol (PVA) and angico gum (AG) and/or cashew gum (CG) were used to produce films by casting method. Morphological and mechanical properties of these films were studied and compared to the properties of a commercial collagen membrane of bovine origin (MBO). The films presented thickness varying from 70 to 140 μm (PVA/AG) and 140 to 200 μm (PVA/CG). Macroscopic analysis showed that a PVA/CG film was very similar to MBO regarding the color and transparency. The higher valu...

  20. Magnolol inhibits migration of vascular smooth muscle cells via cytoskeletal remodeling pathway to attenuate neointima formation

    International Nuclear Information System (INIS)

    Karki, Rajendra; Kim, Seong-Bin; Kim, Dong-Wook

    2013-01-01

    Background: Increased proliferation and migration of vascular smooth muscle cells (VSMCs) contribute importantly to the formation of both atherosclerotic and restenotic lesions. The objective of this study was to investigate the effect of magnolol on VSMC migration. Methods: The proteolytic activity of matrix metalloproteinases (MMPs) in tumor necrosis factor alpha (TNF-α) stimulated VSMCs was performed by gelatin zymography. VSMC migration was assessed by wound healing and Boyden chamber methods. Collagen induced VSMC adhesion was determined by spectrofluorimeter and stress fibers formation was evaluated by fluorescence microscope. The expression of signaling molecules involved in stress fibers formation was determined by western blot. The phosphorylation of myosin light chain (MLC20) was determined by urea-glycerol polyacrylamide gel electrophoresis. Immunohistochemistry was performed to determine the expression of β1-integrin and collagen type I in the injured carotid arteries of rats on day 35 after vascular injury. Results: VSMC migration was strongly inhibited by magnolol without affecting MMPs expression. Also, magnolol inhibited β1-integrin expression, FAK phosphorylation and RhoA and Cdc42 activation to inhibit the collagen induced stress fibers formation. Moreover, magnolol inhibited the phosphorylation of MLC20. Our in vivo results showed that magnolol inhibited β1-integrin expression, collagen type I deposition and FAK phosphorylation in injured carotid arteries without affecting MMP-2 activity. Conclusions: Magnolol inhibited VSMC migration via inhibition of cytoskeletal remodeling pathway to attenuate neointima formation. General significance: This study provides a rationale for further evaluation of magnolol for the management of atherosclerosis and restenosis. - Highlights: • Magnolol strongly inhibited migration of VSMCs. • Magnolol inhibited stress fibers formation. • MLC20 phosphorylation was also inhibited by magnolol. • Anti

  1. Magnolol inhibits migration of vascular smooth muscle cells via cytoskeletal remodeling pathway to attenuate neointima formation

    Energy Technology Data Exchange (ETDEWEB)

    Karki, Rajendra [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City (United States); Department of Oriental Medicine Resources, Mokpo National University (Korea, Republic of); Kim, Seong-Bin [Jeollanamdo Development Institute for Korean Traditional Medicine, Jangheung gun, Jeollanamdo (Korea, Republic of); Kim, Dong-Wook, E-mail: dbkim@mokpo.ac.kr [Department of Oriental Medicine Resources, Mokpo National University (Korea, Republic of)

    2013-12-10

    Background: Increased proliferation and migration of vascular smooth muscle cells (VSMCs) contribute importantly to the formation of both atherosclerotic and restenotic lesions. The objective of this study was to investigate the effect of magnolol on VSMC migration. Methods: The proteolytic activity of matrix metalloproteinases (MMPs) in tumor necrosis factor alpha (TNF-α) stimulated VSMCs was performed by gelatin zymography. VSMC migration was assessed by wound healing and Boyden chamber methods. Collagen induced VSMC adhesion was determined by spectrofluorimeter and stress fibers formation was evaluated by fluorescence microscope. The expression of signaling molecules involved in stress fibers formation was determined by western blot. The phosphorylation of myosin light chain (MLC20) was determined by urea-glycerol polyacrylamide gel electrophoresis. Immunohistochemistry was performed to determine the expression of β1-integrin and collagen type I in the injured carotid arteries of rats on day 35 after vascular injury. Results: VSMC migration was strongly inhibited by magnolol without affecting MMPs expression. Also, magnolol inhibited β1-integrin expression, FAK phosphorylation and RhoA and Cdc42 activation to inhibit the collagen induced stress fibers formation. Moreover, magnolol inhibited the phosphorylation of MLC20. Our in vivo results showed that magnolol inhibited β1-integrin expression, collagen type I deposition and FAK phosphorylation in injured carotid arteries without affecting MMP-2 activity. Conclusions: Magnolol inhibited VSMC migration via inhibition of cytoskeletal remodeling pathway to attenuate neointima formation. General significance: This study provides a rationale for further evaluation of magnolol for the management of atherosclerosis and restenosis. - Highlights: • Magnolol strongly inhibited migration of VSMCs. • Magnolol inhibited stress fibers formation. • MLC20 phosphorylation was also inhibited by magnolol. • Anti

  2. Fluorescence studies on the aggregation behaviors of collagen modified with NHS-activated poly(γ-glutamic acid).

    Science.gov (United States)

    Zhang, Min; Yang, Junhui; Yang, Qili; Huang, Liulian; Wu, Hui; Chen, Lihui; Ding, Cuicui

    2018-06-01

    The poly(γ-glutamic acid)-NHS (γ-PGA-NHS) esters were used to endow collagen with both of excellent water-solubility and thermal stability via cross-linking reaction between γ-PGA-NHS and collagen. In the present work, the effect of γ-PGA-NHS on the aggregation of collagen molecules was studied by fluorescence techniques. The fluorescence emission spectra of pyrene in collagen solutions and the intrinsic fluorescence emission spectra of collagen suggested different effects of γ-PGA-NHS on collagen molecules: inhibiting aggregation below critical aggregation concentration (CAC) and promoting aggregation above CAC. The two-dimensional (2D) fluorescence correlation spectra indicated that the intermolecular hydrogen bonding and cross-linking between γ-PGA-NHS and collagen would influence the aggregation of collagen molecules. By the ultra-sensitive differential scanning calorimeter (VP-DSC), it was found that the main denaturational transition temperature (T m2 ) of modified collagen increased, while its calorimetric enthalpy changes (ΔH 2 ) decreased compared to those of native collagen, further indicating that the modification of γ-PGA-NHS influenced the aggregation of collagen molecules. The study provide useful information for the utilizing and or the processing of water-soluble collagen in aqueous solution in the fields such as cosmetics, health care products, tissue engineering and biomedical materials, etc. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Ethinyl oestradiol administration in women suppresses synthesis of collagen in tendon in response to exercise

    DEFF Research Database (Denmark)

    Hansen, Mette; Koskinen, Satu O; Petersen, Susanne G

    2008-01-01

    24 h post-exercise through microdialysis catheters placed anterior to the patellar tendon in both legs and subsequently analysed for the amino-terminal propeptide of type I collagen (PINP), a marker of tendon collagen synthesis. To determine the long-term effect of OC usage, patellar tendon cross......-OC 24 h post-exercise is consistent with the hypothesis that oestradiol inhibits exercise-induced collagen synthesis in human tendon. The mechanism behind this is either a direct effect of oestradiol, or an indirect effect via a reduction in levels of free IGF-I. However, the data did not indicate any......Women are at greater risk than men of sustaining certain kinds of injury and diseases of collagen-rich tissues. To determine whether a high level of oestradiol has an acute influence on collagen synthesis in tendons at rest and in response to exercise, one-legged kicking exercise was performed...

  4. Effect of flavones on rat brain and lung matrix metalloproteinase activity measured by film in-situ zymography.

    Science.gov (United States)

    Sasaki, K; Tateoka, N; Ando, H; Yoshizaki, F

    2005-04-01

    We have evaluated the inhibitory activity of flavone, nobiletin, and heptamethoxyflavone on matrix metalloproteinase (MMP) activity in the rat. MMP in 9000-g supernatant fraction of lung homogenate was activated by p-aminophenyl mercuric acetate (APMA), and gelatinolytic activity was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) followed by Coomassie staining. This activity should be related to MMP-2 and/or MMP-9 and was confirmed by gelatin zymography. Fluorescent-conjugated collagen used as a substrate for collagenolytic activity wasinvestigated by SDS-PAGE also. The film in-situ zymography method was applied to rat brain and lung tissue in the same manner. Flavone and nobiletin inhibited the APMA-stimulated gelatinolytic activity and also the collagenolytic activity by more than 75%. The film in-situ zymography method indicated that these compounds might be potent inhibitors of MMP, suggesting the specific inhibition of localized MMP in brain hippocampus and/or lung terminal bronchioles, which may contribute to the prevention of some types of brain disease or cancer invasion and metastasis.

  5. Total glucosides of paeony inhibit the proliferation of fibroblast-like synoviocytes through the regulation of G proteins in rats with collagen-induced arthritis.

    Science.gov (United States)

    Jia, Xiao-Yi; Chang, Yan; Sun, Xiao-Jing; Wu, Hua-Xun; Wang, Chun; Xu, Hong-Mei; Zhang, Lei; Zhang, Ling-Ling; Zheng, Yong-Qiu; Song, Li-Hua; Wei, Wei

    2014-01-01

    The aim of this study was to investigate the expression of G proteins in fibroblast-like synoviocytes (FLSs) from rats with collagen-induced arthritis (CIA) and to determine the effect of total glucosides of paeony (TGP). CIA rats were induced with chicken type II collagen (CCII) in Freund's complete adjuvant. The rats with experimental arthritis were randomly separated into five groups and then treated with TGP (25, 50, and 100mg/kg) from days 14 to 35 after immunization. The secondary inflammatory reactions were evaluated through the polyarthritis index and histopathological changes. The level of cyclic adenosine monophosphate (cAMP) was measured by radioimmunoassay. The FLS proliferation response was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The toxin-catalyzed ADP-ribosylation of G proteins was performed through autoradiography. The results show that TGP (25, 50, and 100mg/kg) significantly decreased the arthritis scores of CIA rats and improved the histopathological changes. TGP inhibited the proliferation of FLSs and increased the level of cAMP. Moreover, the FLS proliferation and the level of Gαi expression were significantly increased, but the level of Gαs expression was decreased after stimulation with IL-1β (10ng/ml) in vitro. TGP (12.5 and 62.5μg/ml) significantly inhibited the FLS proliferation and regulated the balance between Gαi and Gαs. These results demonstrate that TGP may exert its anti-inflammatory effects through the suppression of FLS proliferation, which may be associated with its ability to regulate the balance of G proteins. Thus, TGP may have potential as a therapeutic agent for the treatment of rheumatoid arthritis. © 2013.

  6. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix

    OpenAIRE

    Hui Liang; Xiaoran Li; Bin Wang; Bing Chen; Yannan Zhao; Jie Sun; Yan Zhuang; Jiajia Shi; He Shen; Zhijun Zhang; Jianwu Dai

    2016-01-01

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of ...

  7. A Simple and Efficient Method to Improve Mechanical Properties of Collagen Scaffolds by UV Irradiation

    Directory of Open Access Journals (Sweden)

    F. Khayyatan

    2010-12-01

    Full Text Available Collagen is the major protein component of cartilage, bone, skin and connective tissue and constitutes the major part of the extracellular matrix. Collagen type I has complex structural hierarchy, which consists of treepolypeptide α-chains wound together in a rod-like helical structure. Collagen is an important biomaterial, finding many applications in the field of tissue engineering. It has been processed into various shapes, such as, gel, film, sponge and fiber. It is commonly used as the scaffolding material for tissue engineering due to its many superior properties including low antigenicity and high growth promotion. Unfortunately, poor mechanical properties and rapid degradation rates of collagen scaffolds can cause instability and difficulty in handling. By crosslinking, the structural stability of the collagen and its rate of resorption can be adapted with respect to its demanding requirements. The strength, resorption rate, and biocompatibility of collagenous biomaterials are profoundly influenced by the method and extent of crosslinking. In thisstudy, the effect of UV irradiation on collagen scaffolds has been carried out.Collagen scaffolds were fabricated using freeze drying method with freezing temperature of -80oC, then exposed to UV irradiation. Mean pore size of the scaffolds was obtained as 98.52±14.51 μm using scanning electron microscopy. Collagen scaffolds exposed to UV Irradiation (254 nm for 15 min showed the highest tensile strain (17.37±0.98 %, modulus (1.67±0.15 MPa and maximum load (24.47±2.38 cN values. As partial loss of the native collagen structure may influence attachment, migration, and proliferation of cells on collagen scaffolds, we detected no intact α-chains after SDS-Page chromatography. We demonstrate that UV irradiation is a rapid and easily controlled means of increasing the mechanical strength of collagen scaffolds without any molecular fracture.

  8. Controlling the porosity of collagen, gelatin and elastin biomaterials by ultrashort laser pulses

    International Nuclear Information System (INIS)

    Daskalova, A.; Nathala, Chandra S.R.; Bliznakova, I.; Stoyanova, E.; Zhelyazkova, A.; Ganz, T.; Lueftenegger, S.; Husinsky, W.

    2014-01-01

    We report on the structural investigation of self-organized micropores generated in thin gelatin, collagen, and collagen–elastin films after single and multishot irradiation with pulse durations ranging from 30–100 fs at 800 nm. We systematically studied the effect of laser parameters: laser energy, number of pulses, and pulse duration on the development of the micropores. This work showed that applying laser pulses at different rates significantly modified the thin film surface. The results clearly revealed that femtosecond laser treatment of thin films of biomaterials: gelatin, collagen and collagen–elastin, results in creation of micro/nanopores with different size of cavity formations. Experimentally, it is demonstrated that it is possible to influence the dimensions of the pore sizes, ranging from 100 nm to 2 μm by tuning the laser parameters. We are currently further exploring the possibility of structuring these biomaterials by applying a time delay between separate pulses. First results from cell culture experiments on laser created surface foam of collagen–elastin were successfully obtained, showing the potential of the method to cultivate cells on superficial porous substrates and the preferable selectivity of the cells to proliferate on the laser modified parts of the biopolymer substrate.

  9. Controlling the porosity of collagen, gelatin and elastin biomaterials by ultrashort laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Daskalova, A., E-mail: a_daskalova@code.bg [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee blvd., 1784 Sofia (Bulgaria); Nathala, Chandra S.R. [IAP, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna (Austria); Femtolasers Productions GmbH, Fernkorngasse10, 1100 Vienna (Austria); Bliznakova, I. [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee blvd., 1784 Sofia (Bulgaria); Stoyanova, E. [IBIR, Department of Molecular Immunology, Bulgarian Academy of Sciences, 73, Tzarigradsko Chaussee blvd., 1113 Sofia (Bulgaria); Zhelyazkova, A. [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee blvd., 1784 Sofia (Bulgaria); Ganz, T. [Femtolasers Productions GmbH, Fernkorngasse10, 1100 Vienna (Austria); Lueftenegger, S.; Husinsky, W. [IAP, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Vienna (Austria)

    2014-02-15

    We report on the structural investigation of self-organized micropores generated in thin gelatin, collagen, and collagen–elastin films after single and multishot irradiation with pulse durations ranging from 30–100 fs at 800 nm. We systematically studied the effect of laser parameters: laser energy, number of pulses, and pulse duration on the development of the micropores. This work showed that applying laser pulses at different rates significantly modified the thin film surface. The results clearly revealed that femtosecond laser treatment of thin films of biomaterials: gelatin, collagen and collagen–elastin, results in creation of micro/nanopores with different size of cavity formations. Experimentally, it is demonstrated that it is possible to influence the dimensions of the pore sizes, ranging from 100 nm to 2 μm by tuning the laser parameters. We are currently further exploring the possibility of structuring these biomaterials by applying a time delay between separate pulses. First results from cell culture experiments on laser created surface foam of collagen–elastin were successfully obtained, showing the potential of the method to cultivate cells on superficial porous substrates and the preferable selectivity of the cells to proliferate on the laser modified parts of the biopolymer substrate.

  10. Proximal collagenous gastroenteritides:

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Riis, Lene Buhl; Danese, Silvio

    2014-01-01

    AIM: While collagenous colitis represents the most common form of the collagenous gastroenteritides, the collagenous entities affecting the proximal part of the gastrointestinal tract are much less recognized and possibly overlooked. The aim was to summarize the latest information through a syste...

  11. Endocytic collagen degradation

    DEFF Research Database (Denmark)

    Madsen, Daniel H.; Jürgensen, Henrik J.; Ingvarsen, Signe Ziir

    2012-01-01

    it crucially important to understand both the collagen synthesis and turnover mechanisms in this condition. Here we show that the endocytic collagen receptor, uPARAP/Endo180, is a major determinant in governing the balance between collagen deposition and degradation. Cirrhotic human livers displayed a marked...... up-regulation of uPARAP/Endo180 in activated fibroblasts and hepatic stellate cells located close to the collagen deposits. In a hepatic stellate cell line, uPARAP/Endo180 was shown to be active in, and required for, the uptake and intracellular degradation of collagen. To evaluate the functional...... groups of mice clearly revealed a fibrosis protective role of uPARAP/Endo180. This effect appeared to directly reflect the activity of the collagen receptor, since no compensatory events were noted when comparing the mRNA expression profiles of the two groups of mice in an array system focused on matrix-degrading...

  12. Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation

    OpenAIRE

    Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

    2013-01-01

    The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-depende...

  13. MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Sun, Ming; Stolz, Donna B. [Department of Cell Biology and Physiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261 (United States); He, Fengtian [Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038 (China); Fan, Jie [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Xie, Wen [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Li, Song, E-mail: sol4@pitt.edu [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2014-04-18

    Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl{sub 4}-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.

  14. MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

    International Nuclear Information System (INIS)

    Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang; Sun, Ming; Stolz, Donna B.; He, Fengtian; Fan, Jie; Xie, Wen; Li, Song

    2014-01-01

    Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl 4 -treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation

  15. Collagen Quantification in Tissue Specimens.

    Science.gov (United States)

    Coentro, João Quintas; Capella-Monsonís, Héctor; Graceffa, Valeria; Wu, Zhuning; Mullen, Anne Maria; Raghunath, Michael; Zeugolis, Dimitrios I

    2017-01-01

    Collagen is the major extracellular protein in mammals. Accurate quantification of collagen is essential in the biomaterials (e.g., reproducible collagen scaffold fabrication), drug discovery (e.g., assessment of collagen in pathophysiologies, such as fibrosis), and tissue engineering (e.g., quantification of cell-synthesized collagen) fields. Although measuring hydroxyproline content is the most widely used method to quantify collagen in biological specimens, the process is very laborious. To this end, the Sircol™ Collagen Assay is widely used due to its inherent simplicity and convenience. However, this method leads to overestimation of collagen content due to the interaction of Sirius red with basic amino acids of non-collagenous proteins. Herein, we describe the addition of an ultrafiltration purification step in the process to accurately determine collagen content in tissues.

  16. The influence of specific binding of collagen-silk chimeras to silk biomaterials on hMSC behavior.

    Science.gov (United States)

    An, Bo; DesRochers, Teresa M; Qin, Guokui; Xia, Xiaoxia; Thiagarajan, Geetha; Brodsky, Barbara; Kaplan, David L

    2013-01-01

    Collagen-like proteins in the bacteria Streptococcus pyogenes adopt a triple-helix structure with a thermal stability similar to that of animal collagens, can be expressed in high yield in Escherichia coli and can be easily modified through molecular biology techniques. However, potential applications for such recombinant collagens are limited by their lack of higher order structure to achieve the physical properties needed for most biomaterials. To overcome this problem, the S. pyogenes collagen domain was fused to a repetitive Bombyx mori silk consensus sequence, as a strategy to direct specific non-covalent binding onto solid silk materials whose superior stability, mechanical and material properties have been previously established. This approach resulted in the successful binding of these new collagen-silk chimeric proteins to silk films and porous scaffolds, and the binding affinity could be controlled by varying the number of repeats in the silk sequence. To explore the potential of collagen-silk chimera for regulating biological activity, integrin (Int) and fibronectin (Fn) binding sequences from mammalian collagens were introduced into the bacterial collagen domain. The attachment of bioactive collagen-silk chimeras to solid silk biomaterials promoted hMSC spreading and proliferation substantially in comparison to the controls. The ability to combine the biomaterial features of silk with the biological activities of collagen allowed more rapid cell interactions with silk-based biomaterials, improved regulation of stem cell growth and differentiation, as well as the formation of artificial extracellular matrices useful for tissue engineering applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Collagen Accumulation in Osteosarcoma Cells lacking GLT25D1 Collagen Galactosyltransferase.

    Science.gov (United States)

    Baumann, Stephan; Hennet, Thierry

    2016-08-26

    Collagen is post-translationally modified by prolyl and lysyl hydroxylation and subsequently by glycosylation of hydroxylysine. Despite the widespread occurrence of the glycan structure Glc(α1-2)Gal linked to hydroxylysine in animals, the functional significance of collagen glycosylation remains elusive. To address the role of glycosylation in collagen expression, folding, and secretion, we used the CRISPR/Cas9 system to inactivate the collagen galactosyltransferase GLT25D1 and GLT25D2 genes in osteosarcoma cells. Loss of GLT25D1 led to increased expression and intracellular accumulation of collagen type I, whereas loss of GLT25D2 had no effect on collagen secretion. Inactivation of the GLT25D1 gene resulted in a compensatory induction of GLT25D2 expression. Loss of GLT25D1 decreased collagen glycosylation by up to 60% but did not alter collagen folding and thermal stability. Whereas cells harboring individually inactivated GLT25D1 and GLT25D2 genes could be recovered and maintained in culture, cell clones with simultaneously inactive GLT25D1 and GLT25D2 genes could be not grown and studied, suggesting that a complete loss of collagen glycosylation impairs osteosarcoma cell proliferation and viability. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Inhibition of microRNA-214-5p promotes cell survival and extracellular matrix formation by targeting collagen type IV alpha 1 in osteoblastic MC3T3-E1 cells.

    Science.gov (United States)

    Li, Q S; Meng, F Y; Zhao, Y H; Jin, C L; Tian, J; Yi, X J

    2017-08-01

    This study aimed to investigate the functional effects of microRNA (miR)-214-5p on osteoblastic cells, which might provide a potential role of miR-214-5p in bone fracture healing. Blood samples were obtained from patients with hand fracture or intra-articular calcaneal fracture and from healthy controls (HCs). Expression of miR-214-5p was monitored by qRT-PCR at day 7, 14 and 21 post-surgery. Mouse osteoblastic MC3T3-E1 cells were transfected with antisense oligonucleotides (ASO)-miR-214-5p, collagen type IV alpha 1 (COL4A1) vector or their controls; thereafter, cell viability, apoptotic rate, and the expression of collagen type I alpha 1 (COL1A1), type II collagen (COL-II), and type X collagen (COL-X) were determined. Luciferase reporter assay, qRT-PCR, and Western blot were performed to ascertain whether COL4A1 was a target of miR-214-5p. Plasma miR-214-5p was highly expressed in patients with bone fracture compared with HCs after fracture (p extracellular matrix (ECM) formation of osteoblastic MC3T3-E1 cells by targeting COL4A1. Cite this article: Q. S. Li, F. Y. Meng, Y. H. Zhao, C. L. Jin, J. Tian, X. J. Yi. Inhibition of microRNA-214-5p promotes cell survival and extracellular matrix formation by targeting collagen type IV alpha 1 in osteoblastic MC3T3-E1 cells. Bone Joint Res 2017;6:464-471. DOI: 10.1302/2046-3758.68.BJR-2016-0208.R2. © 2017 Yi et al.

  19. Interleukin-1 alpha modulates collagen gene expression in cultured synovial cells.

    Science.gov (United States)

    Mauviel, A; Teyton, L; Bhatnagar, R; Penfornis, H; Laurent, M; Hartmann, D; Bonaventure, J; Loyau, G; Saklatvala, J; Pujol, J P

    1988-01-01

    The effects of porcine interleukin-1 (IL-1) alpha on collagen production were studied in cultured human rheumatoid synovial cells. Addition of 0.05-5 ng of IL-1/ml into the cultures resulted in a dose-dependent decreased rate of collagen released into the medium over 24 h. To determine whether this inhibition was due to secondary action of prostaglandin E2 (PGE2) secreted in response to IL-1, cultures were incubated in presence of various inhibitors of arachidonate metabolism. Depending on the cell strains, these inhibitors were able to suppress or diminish the effect of IL-1, suggesting that PGE2 is involved in the mechanism. Depression of collagen production caused by IL-1 mainly affected type I collagen and therefore led to a change in the type I/type III collagen ratio in the extracellular medium. Steady-state levels of mRNA for types I and III procollagens were estimated by dot-blot hybridization and compared with the amounts of respective collagens produced in the same cultures. IL-1 generally increased procollagen type I mRNA, but to a variable extent, as did indomethacin (Indo). Depending on the cell strain, the combination of indo and IL-1 could elevate the mRNA level of type I procollagen compared with Indo alone. These results did not correlate with the production rate of collagen in the medium, which was diminished by exposure to IL-1. The level of mRNA for collagen type III was not greatly changed by incubation with IL-1, and a better correlation was generally observed with the amount of type III collagen found in the medium. These data suggest that an additional control mechanism at translational or post-translational level must exist, counterbalancing the stimulatory effect of IL-1 on collagen mRNA transcription. It is likely that IL-1 could modulate the production of collagen in synovial cells by an interplay of different mechanisms, some of them limiting the effect of primary elevation of the steady-state mRNA level. Images Fig. 3. Fig. 4. Fig. 5

  20. The influence of type-I collagen-coated PLLA aligned nanofibers on growth of blood outgrowth endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Feng Zhangqi; Huang Ningping; Wang Yichun; Gu Zhongze [State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096 (China); Lu Huijun [Department of Vascular Surgery, Wuxi People' s Hospital, Wuxi 214023 (China); Leach, Michelle K [Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Liu Changjian, E-mail: gu@seu.edu.c [Department of Vascular Surgery, The Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008 (China)

    2010-12-15

    Nanofibrous scaffolds have been applied widely in tissue engineering to simulate the nanostructure of natural extracellular matrix (ECM) and promote cell bioactivity. The aim of this study was to design a biocompatible nanofibrous scaffold for blood outgrowth endothelial cells (BOECs) and investigate the interaction between the topography of the nanofibrous scaffold and cell growth. Poly(l-lactic acid) (PLLA) random and aligned nanofibers with a uniform diameter distribution were fabricated by electrospinning. NH{sub 3} plasma etching was used to create a hydrophilic surface on the nanofibers to improve type-I collagen adsorption; the conditions of the NH{sub 3} plasma etching were optimized by XPS and water contact angle analysis. Cell attachment, proliferation, viability, phenotype and morphology of BOECs cultured on type-I collagen-coated PLLA film (col-Film), random fibers (col-RFs) and aligned fibers (col-AFs) were detected over a 7 day culture period. The results showed that collagen-coated PLLA nanofibers improved cell attachment and proliferation; col-AFs induced the directional growth of cells along the aligned nanofibers and enhanced endothelialization. We suggest that col-AFs may be a potential implantable scaffold for vascular tissue engineering.

  1. L-arginine mediated renaturation enhances yield of human, α6 Type IV collagen non-collagenous domain from bacterial inclusion bodies.

    Science.gov (United States)

    Gunda, Venugopal; Boosani, Chandra Shekhar; Verma, Raj Kumar; Guda, Chittibabu; Sudhakar, Yakkanti Akul

    2012-10-01

    The anti-angiogenic, carboxy terminal non-collagenous domain (NC1) derived from human Collagen type IV alpha 6 chain, [α6(IV)NC1] or hexastatin, was earlier obtained using different recombinant methods of expression in bacterial systems. However, the effect of L-arginine mediated renaturation in enhancing the relative yields of this protein from bacterial inclusion bodies has not been evaluated. In the present study, direct stirring and on-column renaturation methods using L-arginine and different size exclusion chromatography matrices were applied for enhancing the solubility in purifying the recombinant α6(IV)NC1 from bacterial inclusion bodies. This methodology enabled purification of higher quantities of soluble protein from inclusion bodies, which inhibited endothelial cell proliferation, migration and tube formation. Thus, the scope for L-arginine mediated renaturation in obtaining higher yields of soluble, biologically active NC1 domain from bacterial inclusion bodies was evaluated.

  2. Inhibition of Listeria monocytogenes ATCC 19115 on ham steak by tea bioactive compounds incorporated into chitosan-coated plastic films

    Directory of Open Access Journals (Sweden)

    Vodnar Dan C

    2012-07-01

    Full Text Available Abstract Background The consumer demands for better quality and safety of food products have given rise to the development and implementation of edible films. The use of antimicrobial films can be a promising tool for controlling L. monocytogenes on ready to eat products. The aim of this study was to develop effective antimicrobial films incorporating bioactive compounds from green and black teas into chitosan, for controlling L. monocytogenes ATCC 19115 on vacuum-packaged ham steak. The effectiveness of these antimicrobial films was evaluated at room temperature (20°C for 10 days and at refrigerated temperature (4°C for 8 weeks. Results The HPLC results clearly show that relative concentrations of catechins and caffeine in green tea ranked EGCG>EGC>CAF>ECG>EC>C while in black tea extracts ranked CAF>EGCG>ECG>EGC>EC>C. The chitosan-coated plastic films incorporating green tea and black tea extracts shows specific markers identified by FTIR. Incorporating natural extracts into chitosan showed that the growth of L monocytogenes ATCC 19115 was inhibited. The efficacy of antimicrobial effect of tea extracts incorporated into chitosan-coated plastic film was dose dependent. However, chitosan-coated films without addition of tea extracts did not inhibit the growth of L. monocytogenes ATCC 19115. Chitosan-coated plastic films incorporating 4% Green tea extract was the most effective antimicrobial, reducing the initial counts from 3.2 to 2.65 log CFU/cm2 during room temperature storage and from 3.2 to 1–1.5 log CFU/cm2 during refrigerated storage. Conclusions Incorporation of tea extracts into the chitosan-coated films considerably enhanced their effectiveness against L. monocytogenes ATCC 19115. 4% Green tea incorporated into chitosan-coated plastic film had a better antilisterial effect than 2% green tea or 2% and 4% black tea. Data from this study would provide new formulation options for developing antimicrobial packaging films using tea

  3. Inhibition of Enterococcus faecium adherence to collagen by antibodies against high-affinity binding subdomains of Acm.

    Science.gov (United States)

    Nallapareddy, Sreedhar R; Sillanpää, Jouko; Ganesh, Vannakambadi K; Höök, Magnus; Murray, Barbara E

    2007-06-01

    Strains of Enterococcus faecium express a cell wall-anchored protein, Acm, which mediates adherence to collagen. Here, we (i) identify the minimal and high-affinity binding subsegments of Acm and (ii) show that anti-Acm immunoglobulin Gs (IgGs) purified against these subsegments reduced E. faecium TX2535 strain collagen adherence up to 73 and 50%, respectively, significantly more than the total IgGs against the full-length Acm A domain (28%) (P Acm adherence with functional subsegment-specific antibodies raises the possibility of their use as therapeutic or prophylactic agents.

  4. Neurotrophin 3 upregulates proliferation and collagen production in human aortic valve interstitial cells: a potential role in aortic valve sclerosis.

    Science.gov (United States)

    Yao, Qingzhou; Song, Rui; Ao, Lihua; Cleveland, Joseph C; Fullerton, David A; Meng, Xianzhong

    2017-06-01

    Calcific aortic valve disease (CAVD) is a leading cardiovascular disorder in the elderly. Diseased aortic valves are characterized by sclerosis (fibrosis) and nodular calcification. Sclerosis, an early pathological change, is caused by aortic valve interstitial cell (AVIC) proliferation and overproduction of extracellular matrix (ECM) proteins. However, the mechanism of aortic valve sclerosis remains unclear. Recently, we observed that diseased human aortic valves overexpress growth factor neurotrophin 3 (NT3). In the present study, we tested the hypothesis that NT3 is a profibrogenic factor to human AVICs. AVICs isolated from normal human aortic valves were cultured in M199 growth medium and treated with recombinant human NT3 (0.10 µg/ml). An exposure to NT3 induced AVIC proliferation, upregulated the production of collagen and matrix metalloproteinase (MMP), and augmented collagen deposition. These changes were abolished by inhibition of the Trk receptors. NT3 induced Akt phosphorylation and increased cyclin D1 protein levels in a Trk receptor-dependent fashion. Inhibition of Akt abrogated the effect of NT3 on cyclin D1 production. Furthermore, inhibition of either Akt or cyclin D1 suppressed NT3-induced cellular proliferation and MMP-9 and collagen production, as well as collagen deposition. Thus, NT3 upregulates cellular proliferation, ECM protein production, and collagen deposition in human AVICs. It exerts these effects through the Trk-Akt-cyclin D1 cascade. NT3 is a profibrogenic mediator in human aortic valve, and overproduction of NT3 by aortic valve tissue may contribute to the mechanism of valvular sclerosis. Copyright © 2017 the American Physiological Society.

  5. Collagencin, an antibacterial peptide from fish collagen: Activity, structure and interaction dynamics with membrane

    International Nuclear Information System (INIS)

    Ennaas, Nadia; Hammami, Riadh; Gomaa, Ahmed; Bédard, François; Biron, Éric; Subirade, Muriel; Beaulieu, Lucie; Fliss, Ismail

    2016-01-01

    In this study, we first report characterization of collagencin, an antimicrobial peptide identified from fish collagen hydrolysate. The peptide completely inhibited the growth of Staphylococcus aureus at 1.88 mM. Although non-toxic up to 470 μM, collagencin was hemolytic at higher concentrations. The secondary structure of collagencin was mainly composed by β-sheet and β-turn as determined by CD measurements and molecular dynamics. The peptide is likely to form β-sheet structure under hydrophobic environments and interacts with both anionic (phosphatidylglycerol) and zwitterionic (phosphoethanolamine and phosphatidylcholine) lipids as shown with CD spectroscopy and molecular dynamics. The peptide formed several hydrogen bonds with both POPG and POPE lipids and remained at membrane–water interface, suggesting that collagencin antibacterial action follows a carpet mechanism. Collagenous fish wastes could be processed by enzymatic hydrolysis and transformed into products of high value having functional or biological properties. Marine collagens are a promising source of antimicrobial peptides with new implications in food safety and human health. - Highlights: • Collagencin, an antibacterial (G+ & G-) peptide identified from fish collagen hydrolysate. • The peptide completely inhibited the growth of S. aureus at 1.88 mM and non-toxic at 470 μM. • The secondary structure was mainly composed by β-sheet and turn as determined by CD and MD. • Collagencin interacts with both anionic and zwitterionic lipids as shown with CD and MD. • Collagencin antibacterial action probably follows a carpet mechanism.

  6. Collagencin, an antibacterial peptide from fish collagen: Activity, structure and interaction dynamics with membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ennaas, Nadia [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Hammami, Riadh, E-mail: riadh.hammami@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Gomaa, Ahmed [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Bédard, François; Biron, Éric [Faculty of Pharmacy, Université Laval and Laboratory of Medicinal Chemistry, CHU de Québec Research Centre, G1V 4G2 Québec, QC (Canada); Subirade, Muriel [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Beaulieu, Lucie, E-mail: lucie.beaulieu@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Department of Biology, Chemistry and Geography, Université du Québec à Rimouski (UQAR), 300 Allée des Ursulines, Rimouski, QC G5L 3A1 (Canada); Fliss, Ismail, E-mail: ismail.fliss@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada)

    2016-04-29

    In this study, we first report characterization of collagencin, an antimicrobial peptide identified from fish collagen hydrolysate. The peptide completely inhibited the growth of Staphylococcus aureus at 1.88 mM. Although non-toxic up to 470 μM, collagencin was hemolytic at higher concentrations. The secondary structure of collagencin was mainly composed by β-sheet and β-turn as determined by CD measurements and molecular dynamics. The peptide is likely to form β-sheet structure under hydrophobic environments and interacts with both anionic (phosphatidylglycerol) and zwitterionic (phosphoethanolamine and phosphatidylcholine) lipids as shown with CD spectroscopy and molecular dynamics. The peptide formed several hydrogen bonds with both POPG and POPE lipids and remained at membrane–water interface, suggesting that collagencin antibacterial action follows a carpet mechanism. Collagenous fish wastes could be processed by enzymatic hydrolysis and transformed into products of high value having functional or biological properties. Marine collagens are a promising source of antimicrobial peptides with new implications in food safety and human health. - Highlights: • Collagencin, an antibacterial (G+ & G-) peptide identified from fish collagen hydrolysate. • The peptide completely inhibited the growth of S. aureus at 1.88 mM and non-toxic at 470 μM. • The secondary structure was mainly composed by β-sheet and turn as determined by CD and MD. • Collagencin interacts with both anionic and zwitterionic lipids as shown with CD and MD. • Collagencin antibacterial action probably follows a carpet mechanism.

  7. Next generation bone tissue engineering: non-viral miR-133a inhibition using collagen-nanohydroxyapatite scaffolds rapidly enhances osteogenesis

    Science.gov (United States)

    Mencía Castaño, Irene; Curtin, Caroline M.; Duffy, Garry P.; O'Brien, Fergal J.

    2016-06-01

    Bone grafts are the second most transplanted materials worldwide at a global cost to healthcare systems valued over $30 billion every year. The influence of microRNAs in the regenerative capacity of stem cells offers vast therapeutic potential towards bone grafting; however their efficient delivery to the target site remains a major challenge. This study describes how the functionalisation of porous collagen-nanohydroxyapatite (nHA) scaffolds with miR-133a inhibiting complexes, delivered using non-viral nHA particles, enhanced human mesenchymal stem cell-mediated osteogenesis through the novel focus on a key activator of osteogenesis, Runx2. This study showed enhanced Runx2 and osteocalcin expression, as well as increased alkaline phosphatase activity and calcium deposition, thus demonstrating a further enhanced therapeutic potential of a biomaterial previously optimised for bone repair applications. The promising features of this platform offer potential for a myriad of applications beyond bone repair and tissue engineering, thus presenting a new paradigm for microRNA-based therapeutics.

  8. Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

    International Nuclear Information System (INIS)

    Yano, Hiroyuki; Hamanaka, Ryoji; Nakamura, Miki; Sumiyoshi, Hideaki; Matsuo, Noritaka; Yoshioka, Hidekatsu

    2012-01-01

    Highlights: ► We examine how radiation affects the expression level and signal pathway of collagen. ► TGF-β1 mRNA is elevated earlier than those of collagen genes after irradiation. ► Smad pathway mediates the expression of collagen in radiation induced fibrosis. ► MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both α1and α2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-β1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-β receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of α2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

  9. Smad, but not MAPK, pathway mediates the expression of type I collagen in radiation induced fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Hiroyuki [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Division of Radioisotope Research, Department of Research Support, Research Promotion Project, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Hamanaka, Ryoji; Nakamura, Miki [Cell Biology, Faculty of Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Sumiyoshi, Hideaki; Matsuo, Noritaka [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan); Yoshioka, Hidekatsu, E-mail: hidey@oita-u.ac.jp [Department of Matrix Medicine, Oita University, 1-1 Idaigaoka Hasama-machi, Yufu, Oita 879-5593 (Japan)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer We examine how radiation affects the expression level and signal pathway of collagen. Black-Right-Pointing-Pointer TGF-{beta}1 mRNA is elevated earlier than those of collagen genes after irradiation. Black-Right-Pointing-Pointer Smad pathway mediates the expression of collagen in radiation induced fibrosis. Black-Right-Pointing-Pointer MAPK pathways are not affected in the expression of collagen after irradiation. -- Abstract: Radiation induced fibrosis occurs following a therapeutic or accidental radiation exposure in normal tissues. Tissue fibrosis is the excessive accumulation of collagen and other extracellular matrix components. This study investigated how ionizing radiation affects the expression level and signal pathway of type I collagen. Real time RT-RCR showed that both {alpha}1and {alpha}2 chain of type I collagen mRNA were elevated from 48 h after irradiation with 10 Gy in NIH3T3 cells. The relative luciferase activities of both genes and type I collagen marker were elevated at 72 h. TGF-{beta}1 mRNA was elevated earlier than those of type I collagen genes. A Western blot analysis showed the elevation of Smad phosphorylation at 72 h. Conversely, treatment with TGF-{beta} receptor inhibitor inhibited the mRNA and relative luciferase activity of type I collagen. The phosphorylation of Smad was repressed with the inhibitor, and the luciferase activity was cancelled using a mutant construct of Smad binding site of {alpha}2(I) collagen gene. However, the MAPK pathways, p38, ERK1/2 and JNK, were not affected with specific inhibitors or siRNA. The data showed that the Smad pathway mediated the expression of type I collagen in radiation induced fibrosis.

  10. Morphology and inhibition performance of Ag thin film as antimicrobial coating deposited by RF-PVD on 316 L stainless steel

    Science.gov (United States)

    Purniawan, A.; Khrisna, Y. S. A.; Rasyida, A.; Atmono, T. M.

    2018-04-01

    Foreign body related infection (FBRIs) is caused by forming biofilm of bacterial colony of medical equipment surfaces. In many cases, the FBRIs is still happened on the surface after medical sterilization process has been performed. In order to avoid the case, surface modification by antimicrobial coating was used. In this work, we present silver (Ag) thin film on 316 L stainless steel substrate surface was deposited using Radio Frequency Sputtering PVD (RF-PVD). The morphology of Ag thin film were characterized using SEM-EDX. Surface roughness of the thin film was measured by AFM. In addition, Kirby Bauer Test in Escherichia coli (E. coli) was conducted in order to evaluate the inhibition performance of the Ag thin film antimicrobial coating. Based on SEM and AFM results show that the particle size is increased from 523 nm to 708 nm and surface roughness from 9 to 20 nm for deposition time 10 minutes to 20 minutes, respectively. In addition, the inhibition layer of the coating is about 29 mm.

  11. [Collagen nephritis].

    Science.gov (United States)

    Lago, N R; Bulos, M J; Monserrat, A J

    1997-01-01

    Fibrillar collagen in the glomeruli is considered specific of the nail-patella syndrome. A new nephropathy with diffuse intraglomerular deposition of type III collagen without nail and skeletal abnormalities has been described. We report the case of a 26-year-old woman who presented persistent proteinuria, hematuria, deafness without nail and skeletal abnormalities. The renal biopsy showed focal and segmental glomerulosclerosis by light microscopy. The electron microscopy revealed the presence of massive fibrillar collagen within the mesangial matriz and the basement membrane. This is the first patient reported in our country. We emphasize the usefulness of electron microscopy in the study of glomerular diseases.

  12. A collagen-binding EGFR antibody fragment targeting tumors with a collagen-rich extracellular matrix.

    Science.gov (United States)

    Liang, Hui; Li, Xiaoran; Wang, Bin; Chen, Bing; Zhao, Yannan; Sun, Jie; Zhuang, Yan; Shi, Jiajia; Shen, He; Zhang, Zhijun; Dai, Jianwu

    2016-02-17

    Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn't showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody-drug conjugates (ADC) or immunotoxins.

  13. Fibroblast Activation Protein (FAP) Accelerates Collagen Degradation and Clearance from Lungs in Mice*

    Science.gov (United States)

    Fan, Ming-Hui; Zhu, Qiang; Li, Hui-Hua; Ra, Hyun-Jeong; Majumdar, Sonali; Gulick, Dexter L.; Jerome, Jacob A.; Madsen, Daniel H.; Christofidou-Solomidou, Melpo; Speicher, David W.; Bachovchin, William W.; Feghali-Bostwick, Carol; Puré, Ellen

    2016-01-01

    Idiopathic pulmonary fibrosis is a disease characterized by progressive, unrelenting lung scarring, with death from respiratory failure within 2–4 years unless lung transplantation is performed. New effective therapies are clearly needed. Fibroblast activation protein (FAP) is a cell surface-associated serine protease up-regulated in the lungs of patients with idiopathic pulmonary fibrosis as well as in wound healing and cancer. We postulate that FAP is not only a marker of disease but influences the development of pulmonary fibrosis after lung injury. In two different models of pulmonary fibrosis, intratracheal bleomycin instillation and thoracic irradiation, we find increased mortality and increased lung fibrosis in FAP-deficient mice compared with wild-type mice. Lung extracellular matrix analysis reveals accumulation of intermediate-sized collagen fragments in FAP-deficient mouse lungs, consistent with in vitro studies showing that FAP mediates ordered proteolytic processing of matrix metalloproteinase (MMP)-derived collagen cleavage products. FAP-mediated collagen processing leads to increased collagen internalization without altering expression of the endocytic collagen receptor, Endo180. Pharmacologic FAP inhibition decreases collagen internalization as expected. Conversely, restoration of FAP expression in the lungs of FAP-deficient mice decreases lung hydroxyproline content after intratracheal bleomycin to levels comparable with that of wild-type controls. Our findings indicate that FAP participates directly, in concert with MMPs, in collagen catabolism and clearance and is an important factor in resolving scar after injury and restoring lung homeostasis. Our study identifies FAP as a novel endogenous regulator of fibrosis and is the first to show FAP's protective effects in the lung. PMID:26663085

  14. Hydrolyzed collagen interferes with in vitro photoprotective effectiveness of sunscreens

    Directory of Open Access Journals (Sweden)

    Daniela D'Almeida Peres

    2017-06-01

    Full Text Available ABSTRACT The chronological skin aging is a progressive and natural process with genetic and physiological changes. However, ultraviolet (UV radiation may accelerate the oxidative stress, generating carcinogenesis and photoaging. Natural compounds and their applications are considered a trend in the cosmetic market. The protein-based film-forming compounds play an important role, once it collaborates for the better distribution of sunscreens on the skin. Here we investigated the in vitro photoprotective effectiveness of sunscreens containing the hydrolyzed collagen associated with UVA, UVB and/or inorganic filters. Sunscreens were developed with octocrylene (7.5%, butyl methoxydibenzoylmethane (avobenzone (3.0% and/or titanium dioxide (5.0%, associated or not with the hydrolyzed collagen (3.0%. In vitro photoprotective effectiveness was determined in a Labsphere(r UV2000S by the establishment of the sun protection factor (SPF and critical wavelength (nm values. Physicochemical and organoleptic characteristics were also assayed. The hydrolyzed collagen subjectively improved the formulation sensory characteristics. However, this bioactive compound led to a decrease of the SPF values of the photoprotective formulations containing octocrylene alone and octocrylene + butyl methoxydibenzoylmethane + TiO2. This inadequate interaction may be considered during the development of new sunscreens intended to contain protein-based components.

  15. Human bone marrow mesenchymal stem cells induce collagen production and tongue cancer invasion.

    Directory of Open Access Journals (Sweden)

    Sirpa Salo

    Full Text Available Tumor microenvironment (TME is an active player in carcinogenesis and changes in its composition modify cancer growth. Carcinoma-associated fibroblasts, bone marrow-derived multipotent mesenchymal stem cells (BMMSCs, and inflammatory cells can all affect the composition of TME leading to changes in proliferation, invasion and metastasis formation of carcinoma cells. In this study, we confirmed an interaction between BMMSCs and oral tongue squamous cell carcinoma (OTSCC cells by analyzing the invasion progression and gene expression pattern. In a 3-dimensional myoma organotypic invasion model the presence of BMMSCs inhibited the proliferation but increased the invasion of OTSCC cells. Furthermore, the signals originating from OTSCC cells up-regulated the expression of inflammatory chemokines by BMMSCs, whereas BMMSC products induced the expression of known invasion linked molecules by carcinoma cells. Particularly, after the cell-cell interactions, the chemokine CCL5 was abundantly secreted from BMMSCs and a function blocking antibody against CCL5 inhibited BMMSC enhanced cancer invasion area. However, CCL5 blocking antibody did not inhibit the depth of invasion. Additionally, after exposure to BMMSCs, the expression of type I collagen mRNA in OTSCC cells was markedly up-regulated. Interestingly, also high expression of type I collagen N-terminal propeptide (PINP in vivo correlated with the cancer-specific mortality of OTSCC patients, whereas there was no association between cancer tissue CCL5 levels and the clinical parameters. In conclusion, our results suggest that the interaction between BMMSC and carcinoma cells induce cytokine and matrix molecule expression, of which high level of type I collagen production correlates with the prognosis of OTSCC patients.

  16. Development and characterization of orally-disintegrating films for propolis delivery

    Directory of Open Access Journals (Sweden)

    Josiane Gonçalves Borges

    2013-02-01

    Full Text Available This study aimed at evaluating the effect of different concentrations of hydrolyzed collagen (HC on the properties of an orally disintegrating film containing propolis ethanol extract (PEE as an active component. The films were evaluated in terms of total phenols, mechanical properties, solubility, contact angle, disintegration time, and microstructure. The films were prepared by casting with 2 g of protein mass (gelatin and HC, 30 g of sorbitol/100 g of protein mass, and 100 g of PEE/100 g of protein mass. HC was incorporated at concentrations of 0, 10, 20, and 30 g/100 g of protein mass. It was found that increased concentrations of HC reduced tensile strength and increased elongation; however, all films showed plastic behavior. An increase in solubility at 25 ºC, a reduction in the contact angle, and disintegration time were also observed. Thus, higher concentrations of collagen led to more hydrophilic and more soluble polymeric matrices that showed shorter dissolution time, favoring the use of these materials as carriers for active compounds to be delivered in the oral cavity.

  17. Betanin reduces the accumulation and cross-links of collagen in high-fructose-fed rat heart through inhibiting non-enzymatic glycation.

    Science.gov (United States)

    Han, Junyan; Tan, Chang; Wang, Yiheng; Yang, Shaobin; Tan, Dehong

    2015-02-05

    We attempted to determine whether betanin (from natural pigments) that has antioxidant properties would be protective against fructose-induced diabetic cardiac fibrosis in Sprague-Dawley rats. Fructose water solution (30%) was accessed freely, and betanin (25 and 100 mg/kg/d) was administered by intra-gastric gavage continuously for 60 d. Rats were sacrificed after overnight fast. The rat blood and left ventricle were collected. In vitro antiglycation assay in bovine serum albumin/fructose system was also performed. In rats treated only with fructose, levels of plasma markers: glucose, insulin, HOMA and glycated hemoglobin rised, left ventricle collagen accumulated and cross-linked, profibrotic factor-transforming growth factor (TGF)-β1 and connective tissue growth factor (CTGF) protein expression increased, and soluble collagen decreased, compared with those in normal rats, showing fructose induces diabetic cardiac fibrosis. Treatment with betanin antagonized the changes of these parameters, demonstrating the antifibrotic role of betanin in the selected diabetic models. In further mechanistic study, betanin decreased protein glycation indicated by the decreased levels of protein glycation reactive intermediate (methylglyoxal), advanced glycation end product (N(ε)-(carboxymethyl) lysine) and receptors for advanced glycation end products (AGEs), antagonized oxidative stress and nuclear factor-κB activation elicited by fructose feeding, suggesting inhibition of glycation, oxidative stress and nuclear factor-κB activation may be involved in the antifibrotic mechanisms. Betanin also showed anitglycative effect in BSA/fructose system, which supported that anitglycation was involved in betanin's protective roles in vivo. Taken together, the potential for using betanin as an auxillary therapy for diabetic cardiomyopathy deserves to be explored further. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Glucose oxidase incorporated collagen matrices for dermal wound repair in diabetic rat models: a biochemical study.

    Science.gov (United States)

    Arul, V; Masilamoni, J G; Jesudason, E P; Jaji, P J; Inayathullah, M; Dicky John, D G; Vignesh, S; Jayakumar, R

    2012-05-01

    Impaired wound healing in diabetes is a well-documented phenomenon. Emerging data favor the involvement of free radicals in the pathogenesis of diabetic wound healing. We investigated the beneficial role of the sustained release of reactive oxygen species (ROS) in diabetic dermal wound healing. In order to achieve the sustained delivery of ROS in the wound bed, we have incorporated glucose oxidase in the collagen matrix (GOIC), which is applied to the healing diabetic wound. Our in vitro proteolysis studies on incorporated GOIC show increased stability against the proteases in the collagen matrix. In this study, GOIC film and collagen film (CF) are used as dressing material on the wound of streptozotocin-induced diabetic rats. A significant increase in ROS (p < 0.05) was observed in the fibroblast of GOIC group during the inflammation period compared to the CF and control groups. This elevated level up regulated the antioxidant status in the granulation tissue and improved cellular proliferation in the GOIC group. Interestingly, our biochemical parameters nitric oxide, hydroxyproline, uronic acid, protein, and DNA content in the healing wound showed that there is an increase in proliferation of cells in GOIC when compared to the control and CF groups. In addition, evidence from wound contraction and histology reveals faster healing in the GOIC group. Our observations document that GOIC matrices could be effectively used for diabetic wound healing therapy.

  19. Differential effects of Nd-YAG laser on collagen and elastin production by chick embryo aortae in vitro. Relevance to laser angioplasty for removal of atherosclerotic plaques

    International Nuclear Information System (INIS)

    Abergel, R.P.; Zaragoza, E.J.; Dwyer, R.M.; Uitto, J.

    1985-01-01

    Aortae from 17-day old chick embryos were subjected to irradiation with a Nd:YAG laser at energy densities varying from 1.2 - 4.7 X 10(3) J/cm2. The aortae were pulse-labeled in vitro with [ 3 H]proline or [ 14 C]valine, and the synthesis of collagenous polypeptides and soluble elastin was examined by SDS-polyacrylamide gel electrophoresis, followed by fluorography and quantitative scanning densitometry. Irradiation of the aortae with Nd:YAG laser resulted in inhibition of the synthesis of the extracellular matrix proteins. The production of collagen was inhibited to a considerably larger degree than the production of elastin. Thus, the biosynthetic pathway for collagen production appears to be more susceptible to laser inhibition than the corresponding pathway for elastin production. These observations may have relevance to laser angioplasty which has been proposed to be applicable for removal of atherosclerotic plaques in human vessels. Specifically, the results suggest that inhibition of the extracellular matrix production may result in weakening of the vessel wall with subsequent aneurysm formation and rupture

  20. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  1. Collagens--structure, function, and biosynthesis.

    Science.gov (United States)

    Gelse, K; Pöschl, E; Aigner, T

    2003-11-28

    The extracellular matrix represents a complex alloy of variable members of diverse protein families defining structural integrity and various physiological functions. The most abundant family is the collagens with more than 20 different collagen types identified so far. Collagens are centrally involved in the formation of fibrillar and microfibrillar networks of the extracellular matrix, basement membranes as well as other structures of the extracellular matrix. This review focuses on the distribution and function of various collagen types in different tissues. It introduces their basic structural subunits and points out major steps in the biosynthesis and supramolecular processing of fibrillar collagens as prototypical members of this protein family. A final outlook indicates the importance of different collagen types not only for the understanding of collagen-related diseases, but also as a basis for the therapeutical use of members of this protein family discussed in other chapters of this issue.

  2. Electrospun collagen-based nanofibres: A sustainable material for improved antibiotic utilisation in tissue engineering applications.

    Science.gov (United States)

    Hall Barrientos, Ivan J; Paladino, Eleonora; Szabó, Peter; Brozio, Sarah; Hall, Peter J; Oseghale, Charles I; Passarelli, Melissa K; Moug, Susan J; Black, Richard A; Wilson, Clive G; Zelkó, Romana; Lamprou, Dimitrios A

    2017-10-05

    For the creation of scaffolds in tissue engineering applications, it is essential to control the physical morphology of fibres and to choose compositions which do not disturb normal physiological function. Collagen, the most abundant protein in the human body, is a well-established biopolymer used in electrospinning compositions. It shows high in-vivo stability and is able to maintain a high biomechanical strength over time. In this study, the effects of collagen type I in polylactic acid-drug electrospun scaffolds for tissue engineering applications are examined. The samples produced were subsequently characterised using a range of techniques. Scanning electron microscopy analysis shows that the fibre morphologies varied across PLA-drug and PLA-collagen-drug samples - the addition of collagen caused a decrease in average fibre diameter by nearly half, and produced nanofibres. Atomic force microscopy imaging revealed collagen-banding patterns which show the successful integration of collagen with PLA. Solid-state characterisation suggested a chemical interaction between PLA and drug compounds, irgasan and levofloxacin, and the collagen increased the amorphous regions within the samples. Surface energy analysis of drug powders showed a higher dispersive surface energy of levofloxacin compared with irgasan, and contact angle goniometry showed an increase in hydrophobicity in PLA-collagen-drug samples. The antibacterial studies showed a high efficacy of resistance against the growth of both E. coli and S. Aureus, except with PLA-collagen-LEVO which showed a regrowth of bacteria after 48h. This can be attributed to the low drug release percentage incorporated into the nanofibre during the in vitro release study. However, the studies did show that collagen helped shift both drugs into sustained release behaviour. These ideal modifications to electrospun scaffolds may prove useful in further research regarding the acceptance of human tissue by inhibiting the potential

  3. Sumoylation of the Tumor Suppressor Promyelocytic Leukemia Protein Regulates Arsenic Trioxide-Induced Collagen Synthesis in Osteoblasts.

    Science.gov (United States)

    Xu, Wen-Xiao; Liu, Sheng-Zhi; Wu, Di; Qiao, Guo-Fen; Yan, Jinglong

    2015-01-01

    Promyelocytic leukemia (PML) protein is a tumor suppressor that fuses with retinoic acid receptor-α (PML-RARα) to contribute to the initiation of acute promyelocytic leukemia (APL). Arsenic trioxide (ATO) upregulates expression of TGF-β1, promoting collagen synthesis in osteoblasts, and ATO binds directly to PML to induce oligomerization, sumoylation, and ubiquitination. However, how ATO upregulates TGF-β1 expression is uncertain. Thus, we suggested that PML sumoylation is responsible for regulation of TGF-β1 protein expression. Kunming mice were treated with ATO, and osteoblasts were counted under scanning electron microscopy. Masson's staining was used to quantify collagen content. hFOB1.19 cells were transfected with siRNA against UBC9 or RNF4, and then treated with ATO or FBS. TGF-β1, PML expression, and sumoylation were quantified with Western blot, and collagen quantified via immunocytochemistry. ATO enhanced osteoblast accumulation, collagen synthesis, and PML-NB formation in vivo. Knocking down UBC9 in hFOB1.19 cells inhibited ATO- and FBS-induced PML sumoylation, TGF-β1 expression, and collagen synthesis. Conversely, knocking down RNF4 enhanced ATO- and FBS-induced PML sumoylation, TGF-β1 expression, and collagen synthesis. These data suggest that PML sumoylation is required for ATO-induced collagen synthesis in osteoblasts. © 2015 S. Karger AG, Basel.

  4. Hypoxia-Induced Collagen Synthesis of Human Lung Fibroblasts by Activating the Angiotensin System

    Directory of Open Access Journals (Sweden)

    Shan-Shan Liu

    2013-12-01

    Full Text Available The exact molecular mechanism that mediates hypoxia-induced pulmonary fibrosis needs to be further clarified. The aim of this study was to explore the effect and underlying mechanism of angiotensin II (Ang II on collagen synthesis in hypoxic human lung fibroblast (HLF cells. The HLF-1 cell line was used for in vitro studies. Angiotensinogen (AGT, angiotensin converting enzyme (ACE, angiotensin II type 1 receptor (AT1R and angiotensin II type 2 receptor (AT2R expression levels in human lung fibroblasts were analysed using real-time polymerase chain reaction (RT-PCR after hypoxic treatment. Additionally, the collagen type I (Col-I, AT1R and nuclear factor κappaB (NF-κB protein expression levels were detected using Western blot analysis, and NF-κB nuclear translocation was measured using immunofluorescence localization analysis. Ang II levels in HLF-1 cells were measured with an enzyme-linked immunosorbent assay (ELISA. We found that hypoxia increased Col-I mRNA and protein expression in HLF-1 cells, and this effect could be inhibited by an AT1R or AT2R inhibitor. The levels of NF-κB, RAS components and Ang II production in HLF-1 cells were significantly increased after the hypoxia exposure. Hypoxia or Ang II increased NF-κB-p50 protein expression in HLF-1 cells, and the special effect could be inhibited by telmisartan (TST, an AT1R inhibitor, and partially inhibited by PD123319, an AT2R inhibitor. Importantly, hypoxia-induced NF-κB nuclear translocation could be nearly completely inhibited by an AT1R or AT2R inhibitor. Furthermore pyrrolidine dithiocarbamate (PDTC, a NF-κB blocker, abolished the expression of hypoxia-induced AT1R and Col-I in HLF-1 cells. Our results indicate that Ang II-mediated NF-κB signalling via ATR is involved in hypoxia-induced collagen synthesis in human lung fibroblasts.

  5. The effect of gamma-ray and ethylene oxide sterilization on collagen-based wound-repair materials

    International Nuclear Information System (INIS)

    Gorham, S.D.; Scott, R.

    1993-01-01

    The effects of 2.5, 5.0, 7.5 and 10 Mrad gamma-irradiation and ethylene oxide sterilization on collagen-coated vicryl mesh, on collagen film and vicryl mesh were investigated. No cytotoxic effects were observed towards either L929 cells or human fibroblasts with any of the treatments, even at the highest doses of irradiation. Although the rate of biodegradation and tissue reaction towards the test materials appeared to be relatively unaffected by ethylene oxide, the rate of breakdown in the lumbar muscles of laboratory rats was considerably increased by irradiation. Dose-dependent irradiation damage to the vicryl mesh was confirmed in vitro using viscometry and by an increase in the rate of hydrolysis in phosphate-buffered saline (PBS) at 37 o C. Tensiometric studies on irradiated collagen films showed a dose-dependent reduction in both the break load and elongation before breaking. A small reduction in the break load and stretch to breaking was also observed following treatment with ethylene oxide. The findings presented favour ethylene oxide as a method of sterilization of both the composite membrane and its individual components. However, gamma-irradiation produced no toxic effects or adverse tissue reaction under the conditions described, and is more convenient to use. Hence, provided that the efficacy of the membrane would not be compromised by the higher rate of degradation, it could also be considered for sterilization of the material. (author)

  6. Glaucocalyxin A inhibits platelet activation and thrombus formation preferentially via GPVI signaling pathway.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Platelets play a pivotal role in atherothrombosis and the antiplatelet agents have been proved to be useful in preventing onset of acute clinical events including myocardial infarction and stroke. Increasing number of natural compounds has been identified to be potential antiplatelet agents. Here we report the antiplatelet effect of glaucocalyxin A (GLA, an ent-diterpenoid that we isolated and purified from the aerial parts of Rabdosia japonica (Burm. f. var. glaucocalyx (Maxim. Hara, and investigate the molecular mechanisms by which GLA inhibits platelet activation and thrombus formation. The effect of GLA on platelet activation was measured using platelets freshly isolated from peripheral blood of healthy donors. Results showed that pretreatment of human platelets with lower concentrations of GLA (0.01 μg/ml, 0.1 μg/ml significantly inhibited platelet aggregation induced by collagen (P<0.001 and CRP (P<0.01, a synthetic GPVI ligand, but not by ADP and U46619. Accordingly, GLA inhibited collagen-stimulated tyrosine phosphorylation of Syk, LAT, and phospholipase Cγ2, the signaling events in collagen receptor GPⅥ pathway. GLA also inhibited platelet p-selectin secretion and integrin activation by convulxin, a GPVI selective ligand. Additionally, GLA was found to inhibit low-dose thrombin-induced platelet activation. Using a flow chamber device, GLA was found to attenuate platelet adhesion on collagen surfaces in high shear condition. In vivo studies showed that GLA administration increased the time for complete occlusion upon vascular injury in mice, but did not extend tail-bleeding time when mice were administered with relatively lower doses of GLA. Therefore, the present results provide the molecular basis for the inhibition effect of GLA on platelet activation and its in vivo effect on thrombus formation, suggesting that GLA could potentially be developed as an antiplatelet and antithrombotic agent.

  7. High resolution imaging of collagen organisation and synthesis using a versatile collagen specific probe

    NARCIS (Netherlands)

    Boerboom, R.A.; Krahn - Nash, K.; Megens, R.T.A.; Zandvoort, van M.; Merkx, M.; Bouten, C.V.C.

    2007-01-01

    Collagen is the protein primarily responsible for the load-bearing properties of tissues and collagen architecture is one of the main determinants of the mechanical properties of tissues. Visualisation of changes in collagen three-dimensional structure is essential in order to improve our

  8. Fibronectin- and collagen-mimetic ligands regulate bone marrow stromal cell chondrogenesis in three-dimensional hydrogels

    Directory of Open Access Journals (Sweden)

    JT Connelly

    2011-09-01

    Full Text Available Modification of tissue engineering scaffolds with bioactive molecules is a potential strategy for modulating cell behavior and guiding tissue regeneration. While adhesion to RGD peptides has been shown to inhibit in vitro chondrogenesis, the effects of extracellular matrix (ECM-mimetic ligands with complex secondary and tertiary structures are unknown. This study aimed to determine whether collagen- and fibronectin-mimetic ligands would retain biologic functionality in three-dimensional (3D hydrogels, whether different ECM-mimetic ligands differentially influence in vitro chondrogenesis, and if effects of ligands on differentiation depend on soluble biochemical stimuli. A linear RGD peptide, a recombinant fibronectin fragment containing the seven to ten Type III repeats (FnIII7-10 and a triple helical, collagen mimetic peptide with the GFOGER motif were covalently coupled to agarose gels using the sulfo-SANPAH crosslinker, and bone marrow stromal cells (BMSCs were cultured within the 3D hydrogels. The ligands retained biologic functionality within the agarose gels and promoted density-dependent BMSC spreading. Interactions with all adhesive ligands inhibited stimulation by chondrogenic factors of collagen Type II and aggrecan mRNA levels and deposition of sulfated glycosaminoglycans. In medium containing fetal bovine serum, interactions with the GFOGER peptide enhanced mRNA expression of the osteogenic gene osteocalcin whereas FnIII7-10 inhibited osteocalcin expression. In conclusion, modification of agarose hydrogels with ECM-mimetic ligands can influence the differentiation of BMSCs in a manner that depends strongly on the presence and nature of soluble biochemical stimuli.

  9. Improving the mechanical properties of collagen-based membranes using silk fibroin for corneal tissue engineering.

    Science.gov (United States)

    Long, Kai; Liu, Yang; Li, Weichang; Wang, Lin; Liu, Sa; Wang, Yingjun; Wang, Zhichong; Ren, Li

    2015-03-01

    Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering. © 2014 Wiley Periodicals, Inc.

  10. Collagen macromolecular drug delivery systems

    International Nuclear Information System (INIS)

    Gilbert, D.L.

    1988-01-01

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t 1/2 and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and 14 C-inulin release rates were evaluated subcutaneously in rats

  11. Joint use of developed collagen-containing complexes and cell cultures in creating new tissue equivalents

    Directory of Open Access Journals (Sweden)

    K. V. Kulakova

    2016-01-01

    Full Text Available The purpose of the study is to assess the possibility of applying the integrated module as the basis of a celltissue equivalent for treatment of wounds of skin and soft tissues. In the frame of the set task the following problems were being solved: research of the spatial structure and architectonics of the surface of the developed base collagen-containing materials and their biocompatibility with cell cultures.Materials and methods. The study of a material which is a two-layer complex film, consisting of collagen and polysaccharide components was carried out. The collagen was separated from the dermis and was then impregnated with particulate demineralized bone matrix (DCM according to the original methodology. For the purposes of the study the dehydrated material was created in the form of a film. Electron microscopic examination of surfaces was performed on scanning electron microscope JEOL JSM-IT300LV in high vacuum and at low values of probe current (< 0,1 nА. Studies to assess the viability of the cells cultivated on films of collagen material (tested for cytotoxicity and the adhesive capacity were performed in vitro using strains of diploid human fibroblasts 4–6 passage. The culture condition was visually assessed using an inverted Leica microscope DM IL (Carl Zeiss, Austria, equipped with a computerizes program of control of culture growth (Leica IM 1000.Results. The data obtained in the study of the surface structure of the developed complex module showed that it seems to be promising as a basic component of the cellular-tissue system with its large number of structural formations for fixation of the cells and a well-organized barrier layer capable of vapor - permeability. Experiments in vitro confirmed the absence of toxicity of the material being studied in relation to the culture of dermal human fibroblasts, suggesting the possibility of creation on its basis of cell-tissue complex and further experimental studies in vivo

  12. Murine analogues of etanercept and of F8-IL10 inhibit the progression of collagen-induced arthritis in the mouse.

    Science.gov (United States)

    Doll, Fabia; Schwager, Kathrin; Hemmerle, Teresa; Neri, Dario

    2013-09-27

    Etanercept is a fusion protein consisting of the soluble portion of the p75-tumor necrosis factor receptor (TNFR) and the Fc fragment of human IgG1, which is often used for the treatment of patients with rheumatoid arthritis. F8-IL10 is a human immunocytokine based on the F8 antibody and interleukin-10, which is currently being investigated in rheumatoid arthritis with promising clinical results. We have aimed at expressing murine versions of these two fusion proteins, in order to assess their pharmaceutical performance in the collagen-induced model of rheumatoid arthritis in the mouse. Two fusion proteins (termed muTNFR-Fc and F8-muIL10) were cloned, expressed in chinese hamster ovary (CHO) cells, purified and characterized. Biological activity of muTNFR-Fc was assessed by its ability to inhibit TNF-induced killing of mouse fibroblasts, while F8-muIL10 was characterized in terms of muIL10 activity, of binding affinity to the cognate antigen of F8, the alternatively-spliced EDA domain of fibronectin, by quantitative biodistribution analysis and in vivo imaging. The therapeutic activity of both fusion proteins was investigated in a collagen-induced mouse model of arthritis. Mouse plasma was analyzed for anti-drug antibody formation and cytokine levels were determined by bead-based multiplex technology. The association of F8-IL10 proteins with blood cells was studied in a centrifugation assay with radiolabeled protein. Both fusion proteins exhibited excellent purity and full biological activity in vitro. In addition, F8-muIL10 was able to localize on newly-formed blood vessels in vivo. When used in a murine model of arthritis, the two proteins inhibited arthritis progression. The activity of muTNFR-Fc was tested alone and in combination with F8-huIL10. The chimeric version of F8-IL10 was not better then the fully human fusion protein and showed similar generation of mouse anti-fusion protein antibodies. Incubation studies of F8-muIL10 and F8-huIL10 with blood

  13. Nonlinear optical response of the collagen triple helix and second harmonic microscopy of collagen liquid crystals

    Science.gov (United States)

    Deniset-Besseau, A.; De Sa Peixoto, P.; Duboisset, J.; Loison, C.; Hache, F.; Benichou, E.; Brevet, P.-F.; Mosser, G.; Schanne-Klein, M.-C.

    2010-02-01

    Collagen is characterized by triple helical domains and plays a central role in the formation of fibrillar and microfibrillar networks, basement membranes, as well as other structures of the connective tissue. Remarkably, fibrillar collagen exhibits efficient Second Harmonic Generation (SHG) and SHG microscopy proved to be a sensitive tool to score fibrotic pathologies. However, the nonlinear optical response of fibrillar collagen is not fully characterized yet and quantitative data are required to further process SHG images. We therefore performed Hyper-Rayleigh Scattering (HRS) experiments and measured a second order hyperpolarisability of 1.25 10-27 esu for rat-tail type I collagen. This value is surprisingly large considering that collagen presents no strong harmonophore in its amino-acid sequence. In order to get insight into the physical origin of this nonlinear process, we performed HRS measurements after denaturation of the collagen triple helix and for a collagen-like short model peptide [(Pro-Pro-Gly)10]3. It showed that the collagen large nonlinear response originates in the tight alignment of a large number of weakly efficient harmonophores, presumably the peptide bonds, resulting in a coherent amplification of the nonlinear signal along the triple helix. To illustrate this mechanism, we successfully recorded SHG images in collagen liquid solutions by achieving liquid crystalline ordering of the collagen triple helices.

  14. Oral administration of curcumin suppresses production of matrix metalloproteinase (MMP)-1 and MMP-3 to ameliorate collagen-induced arthritis: inhibition of the PKCdelta/JNK/c-Jun pathway.

    Science.gov (United States)

    Mun, Se Hwan; Kim, Hyuk Soon; Kim, Jie Wan; Ko, Na Young; Kim, Do Kyun; Lee, Beob Yi; Kim, Bokyung; Won, Hyung Sik; Shin, Hwa-Sup; Han, Jeung-Whan; Lee, Hoi Young; Kim, Young Mi; Choi, Wahn Soo

    2009-09-01

    We investigated whether oral administration of curcumin suppressed type II collagen-induced arthritis (CIA) in mice and its effect and mechanism on matrix metalloproteinase (MMP)-1 and MMP-3 production in CIA mice, RA fibroblast-like synoviocytes (FLS), and chondrocytes. CIA in mice was suppressed by oral administration of curcumin in a dose-dependent manner. Macroscopic observations were confirmed by histological examinations. Histological changes including infiltration of immune cells, synovial hyperplasia, cartilage destruction, and bone erosion in the hind paw sections were extensively suppressed by curcumin. The histological scores were consistent with clinical arthritis indexes. Production of MMP-1 and MMP-3 were inhibited by curcumin in CIA hind paw sections and tumor necrosis factor (TNF)-alpha-stimulated FLS and chondrocytes in a dose-dependent manner. As for the mechanism, curcumin inhibited activating phosphorylation of protein kinase Cdelta (PKCdelta) in CIA, FLS, and chondrocytes. Curcumin also suppressed the JNK and c-Jun activation in those cells. This study suggests that the suppression of MMP-1 and MMP-3 production by curcumin in CIA is mediated through the inhibition of PKCdelta and the JNK/c-Jun signaling pathway.

  15. Routes towards Novel Collagen-Like Biomaterials

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    Adrian V. Golser

    2018-04-01

    Full Text Available Collagen plays a major role in providing mechanical support within the extracellular matrix and thus has long been used for various biomedical purposes. Exemplary, it is able to replace damaged tissues without causing adverse reactions in the receiving patient. Today’s collagen grafts mostly are made of decellularized and otherwise processed animal tissue and therefore carry the risk of unwanted side effects and limited mechanical strength, which makes them unsuitable for some applications e.g., within tissue engineering. In order to improve collagen-based biomaterials, recent advances have been made to process soluble collagen through nature-inspired silk-like spinning processes and to overcome the difficulties in providing adequate amounts of source material by manufacturing collagen-like proteins through biotechnological methods and peptide synthesis. Since these methods also open up possibilities to incorporate additional functional domains into the collagen, we discuss one of the best-performing collagen-like type of proteins, which already have additional functional domains in the natural blueprint, the marine mussel byssus collagens, providing inspiration for novel biomaterials based on collagen-silk hybrid proteins.

  16. PHAGOCYTOSIS AND REMODELING OF COLLAGEN MATRICES

    OpenAIRE

    Abraham, Leah C.; Dice, J Fred.; Lee, Kyongbum; Kaplan, David L.

    2007-01-01

    The biodegradation of collagen and the deposition of new collagen-based extracellular matrices are of central importance in tissue remodeling and function. Similarly, for collagen-based biomaterials used in tissue engineering, the degradation of collagen scaffolds with accompanying cellular infiltration and generation of new extracellular matrix is critical for integration of in vitro grown tissues in vivo. In earlier studies we observed significant impact of collagen structure on primary lun...

  17. Collagen XII myopathy with rectus femoris atrophy and collagen XII retention in fibroblasts

    DEFF Research Database (Denmark)

    Witting, Nanna; Krag, Thomas; Werlauff, Ulla

    2018-01-01

    INTRODUCTION: Mutation in the collagen XII gene (COL12A1) was recently reported to induce Bethlem myopathy. We describe a family affected by collagen XII-related myopathy in 3 generations. METHODS: Systematic interview, clinical examination, skin biopsies, and MRI of muscle were used. RESULTS...... affection and abnormal collagen XII retention in fibroblasts. MRI disclosed a selective wasting of the rectus femoris muscle. DISCUSSION: COL12A1 mutations should be considered in patients with a mild Bethlem phenotype who present with selective wasting of the rectus femoris, absence of the outside......-in phenomenon on MRI, and abnormal collagen XII retention in fibroblasts. Muscle Nerve, 2018....

  18. Mechanisms of Nifedipine-Downregulated CD40L/sCD40L Signaling in Collagen Stimulated Human Platelets.

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    Tso-Hsiao Chen

    Full Text Available The platelet-derived soluble CD40L (sCD40L release plays a critical role in the development of atherosclerosis. Nifedipine, a dihydropyridine-based L-type calcium channel blocker (CCB, has been reported to have an anti-atherosclerotic effect beyond its blood pressure-lowering effect, but the molecular mechanisms remain unclear. The present study was designed to investigate whether nifedipine affects sCD40L release from collagen-stimulated human platelets and to determine the potential role of peroxisome proliferator-activated receptor-β/-γ (PPAR-β/-γ. We found that treatment with nifedipine significantly inhibited the platelet surface CD40L expression and sCD40L release in response to collagen, while the inhibition was markedly reversed by blocking PPAR-β/-γ activity with specific antagonist such as GSK0660 and GW9662. Meanwhile, nifedipine also enhanced nitric oxide (NO and cyclic GMP formation in a PPAR-β/-γ-dependent manner. When the NO/cyclic GMP pathway was suppressed, nifedipine-mediated inhibition of sCD40L release was abolished significantly. Collagen-induced phosphorylation of p38MAPK, ERK1/2 and HSP27, matrix metalloproteinase-2 (MMP-2 expression/activity and reactive oxygen species (ROS formation were significantly inhibited by nifedipine, whereas these alterations were all attenuated by co-treatment with PPAR-β/-γ antagonists. Collectively, these results demonstrate that PPAR-β/-γ-dependent pathways contribute to nifedipine-mediated downregulation of CD40L/sCD40L signaling in activated platelets through regulation of NO/ p38MAPK/ERK1/2/HSP27/MMP-2 signalings and provide a novel mechanism regarding the anti-atherosclerotic effect of nifedipine.

  19. Pharmacologic inhibition of lactate production prevents myofibroblast differentiation.

    Science.gov (United States)

    Kottmann, Robert Matthew; Trawick, Emma; Judge, Jennifer L; Wahl, Lindsay A; Epa, Amali P; Owens, Kristina M; Thatcher, Thomas H; Phipps, Richard P; Sime, Patricia J

    2015-12-01

    Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis. Copyright © 2015 the American Physiological Society.

  20. Molecular crowding of collagen: a pathway to produce highly-organized collagenous structures.

    Science.gov (United States)

    Saeidi, Nima; Karmelek, Kathryn P; Paten, Jeffrey A; Zareian, Ramin; DiMasi, Elaine; Ruberti, Jeffrey W

    2012-10-01

    Collagen in vertebrate animals is often arranged in alternating lamellae or in bundles of aligned fibrils which are designed to withstand in vivo mechanical loads. The formation of these organized structures is thought to result from a complex, large-area integration of individual cell motion and locally-controlled synthesis of fibrillar arrays via cell-surface fibripositors (direct matrix printing). The difficulty of reproducing such a process in vitro has prevented tissue engineers from constructing clinically useful load-bearing connective tissue directly from collagen. However, we and others have taken the view that long-range organizational information is potentially encoded into the structure of the collagen molecule itself, allowing the control of fibril organization to extend far from cell (or bounding) surfaces. We here demonstrate a simple, fast, cell-free method capable of producing highly-organized, anistropic collagen fibrillar lamellae de novo which persist over relatively long-distances (tens to hundreds of microns). Our approach to nanoscale organizational control takes advantage of the intrinsic physiochemical properties of collagen molecules by inducing collagen association through molecular crowding and geometric confinement. To mimic biological tissues which comprise planar, aligned collagen lamellae (e.g. cornea, lamellar bone or annulus fibrosus), type I collagen was confined to a thin, planar geometry, concentrated through molecular crowding and polymerized. The resulting fibrillar lamellae show a striking resemblance to native load-bearing lamellae in that the fibrils are small, generally aligned in the plane of the confining space and change direction en masse throughout the thickness of the construct. The process of organizational control is consistent with embryonic development where the bounded planar cell sheets produced by fibroblasts suggest a similar confinement/concentration strategy. Such a simple approach to nanoscale

  1. LARP6 Meets Collagen mRNA: Specific Regulation of Type I Collagen Expression

    Directory of Open Access Journals (Sweden)

    Yujie Zhang

    2016-03-01

    Full Text Available Type I collagen is the most abundant structural protein in all vertebrates, but its constitutive rate of synthesis is low due to long half-life of the protein (60–70 days. However, several hundred fold increased production of type I collagen is often seen in reparative or reactive fibrosis. The mechanism which is responsible for this dramatic upregulation is complex, including multiple levels of regulation. However, posttranscriptional regulation evidently plays a predominant role. Posttranscriptional regulation comprises processing, transport, stabilization and translation of mRNAs and is executed by RNA binding proteins. There are about 800 RNA binding proteins, but only one, La ribonucleoprotein domain family member 6 (LARP6, is specifically involved in type I collagen regulation. In the 5′untranslated region (5’UTR of mRNAs encoding for type I and type III collagens there is an evolutionally conserved stem-loop (SL structure; this structure is not found in any other mRNA, including any other collagen mRNA. LARP6 binds to the 5′SL in sequence specific manner to regulate stability of collagen mRNAs and their translatability. Here, we will review current understanding of how is LARP6 involved in posttranscriptional regulation of collagen mRNAs. We will also discuss how other proteins recruited by LARP6, including nonmuscle myosin, vimentin, serine threonine kinase receptor associated protein (STRAP, 25 kD FK506 binding protein (FKBP25 and RNA helicase A (RHA, contribute to this process.

  2. Collagen Cross-Linking: Current Status and Future Directions

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    Marine Hovakimyan

    2012-01-01

    Full Text Available Collagen cross-linking (CXL using UVA light and riboflavin (vitamin B2 was introduced as a clinical application to stabilize the cornea by inducing cross-links within and between collagen fibers. CXL has been investigated extensively and has been shown clinically to arrest the progression of keratoconic or post-LASIK ectasia. With its minimal cost, simplicity, and proven positive clinical outcome, CXL can be regarded as a useful approach to reduce the number of penetrating keratoplasties performed. Small case series have also indicated that CXL is beneficial in corneal edema by reducing stromal swelling behavior and in keratitis by inhibiting pathogen growth. Despite these encouraging results, CXL remains a relatively new method that is potentially associated with complications. Aspects such as side effects and recurrence rates have still to be elucidated. In light of the growing interest in CXL, our paper summarizes present knowledge about this promising approach. We have intentionally endeavored to include the more relevant studies from the recent literature to provide an overview of the current status of CXL.

  3. Rheology of Heterotypic Collagen Networks

    NARCIS (Netherlands)

    Piechocka, I.K.; van Oosten, A.S.G.; Breuls, R.G.M.; Koenderink, G.H.

    2011-01-01

    Collagen fibrils are the main structural element of connective tissues. In many tissues, these fibrils contain two fibrillar collagens (types I and V) in a ratio that changes during tissue development, regeneration, and various diseases. Here we investigate the influence of collagen composition on

  4. Generation of biologically active endostatin fragments from human collagen XVIII by distinct matrix metalloproteases

    International Nuclear Information System (INIS)

    Heljasvaara, Ritva; Nyberg, Pia; Luostarinen, Jani; Parikka, Mataleena; Heikkilae, Pia; Rehn, Marko; Sorsa, Timo; Salo, Tuula; Pihlajaniemi, Taina

    2005-01-01

    Endostatin, a potent inhibitor of endothelial cell proliferation, migration, angiogenesis and tumor growth, is proteolytically cleaved from the C-terminal noncollagenous NC1 domain of type XVIII collagen. We investigated the endostatin formation from human collagen XVIII by several MMPs in vitro. The generation of endostatin fragments differing in molecular size (24-30 kDa) and in N-terminal sequences was identified in the cases of MMP-3, -7, -9, -13 and -20. The cleavage sites were located in the protease-sensitive hinge region between the trimerization and endostatin domains of NC1. MMP-1, -2, -8 and -12 did not show any significant activity against the C-terminus of collagen XVIII. The anti-proliferative effect of the 20-kDa endostatin, three longer endostatin-containing fragments generated in vitro by distinct MMPs and the entire NC1 domain, on bFGF-stimulated human umbilical vein endothelial cells was established. The anti-migratory potential of some of these fragments was also studied. In addition, production of endostatin fragments between 24-30 kDa by human hepatoblastoma cells was shown to be due to MMP action on type XVIII collagen. Our results indicate that certain, especially cancer-related, MMP family members can generate biologically active endostatin-containing polypeptides from collagen XVIII and thus, by releasing endostatin fragments, may participate in the inhibition of endothelial cell proliferation, migration and angiogenesis

  5. C-peptide prevents SMAD3 binding to alpha promoters to inhibit collagen type IV synthesis.

    Science.gov (United States)

    Li, Yanning; Zhong, Yan; Gong, Wenjian; Gao, Xuehan; Qi, Huanli; Liu, Kun; Qi, Jinsheng

    2018-07-01

    Activation of transforming growth factor β1 (TGFB1)/SMAD3 signaling may lead to additional synthesis of collagen type IV (COL4), which is a major contributor to extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can attenuate fibrosis to have unique beneficial effects in DN. However, whether and how C-peptide affects TGFB1/SMAD3-activated COL4 synthesis is unclear. In this study, pathological changes, expression of COL4 a1-a5 chains ( Col4a1-a5 ), COL4 distribution and protein and TGFB1 and SMAD3 protein were first assessed in a rat model of diabetes. Then, rat mesangial cells were treated with high glucose (HG) and/or C-peptide to investigate the underlying mechanism. Col4a1-a5 expression, COL4 protein and secretion, TGFB1 protein, SMAD3 nuclear translocation and binding of SMAD3 to its cognate sites in the promoters of Col4a1a2 , Col4a3a4 and Col4a5 were measured. It was found that C-peptide attenuated glomerular pathological changes and suppressed renal Col4a1 -a5 mRNA expression, COL4 protein content and TGFB1 protein content. C-peptide had a dose-dependent effect to inhibit Col4a1-a5 mRNA expression, COL4 protein content and secretion, in HG-stimulated mesangial cells. In addition, the HG-induced increase in TGFB1 protein content was significantly reduced by C-peptide. Although not apparently affecting SMAD3 nuclear translocation, C-peptide prevented SMAD3 from binding to its sites in the Col4a1a2 , Col4a3a4 and Col4a5 promoters in HG-stimulated mesangial cells. In conclusion, C-peptide could prevent SMAD3 from binding to its sites in the Col4a1a2 , Col4a3a4 and Col4a5 promoters, to inhibit COL4 generation. These results may provide a mechanism for the alleviation of fibrosis in DN by C-peptide. © 2018 Society for Endocrinology.

  6. Physiological regulation of extracellular matrix collagen and elastin in the arterial wall of rats by noradrenergic tone and angiotensin II.

    Science.gov (United States)

    Dab, Houcine; Kacem, Kamel; Hachani, Rafik; Dhaouadi, Nadra; Hodroj, Wassim; Sakly, Mohsen; Randon, Jacques; Bricca, Giampiero

    2012-03-01

    The interactions between the effects of the sympathetic nervous system (SNS) and angiotensin II (ANG II) on vascular extracellular matrix (ECM) synthesis were determined in rats. The mRNA and protein content of collagen I, collagen III and elastin in the abdominal aorta (AA) and femoral artery (FA) was investigated in Wistar-Kyoto rats treated for 5 weeks with guanethidine, a sympathoplegic, losartan, an ANG II AT1 receptor (AT1R) blocker, or both. The effects of noradrenaline (NE) and ANG II on collagen III and elastin mRNA, and the receptor involved, were tested in cultured vascular smooth muscle cells (VSMCs) in vitro. Guanethidine increased collagen types I and III and decreased elastin, while losartan had an opposite effect, although without effect on collagen III. The combination of treatments abrogated changes induced by simple treatment with collagen I and elastin, but increased collagen III mRNA in AA and not in FA. NE stimulated collagen III mRNA via β receptors and elastin via α1 and α2 receptors. ANG II stimulated collagen III but inhibited elastin mRNA via AT1R. Overall, SNS and ANG II exert opposite and antagonistic effects on major components of ECM in the vascular wall. This may be of relevance for the choice of a therapeutic strategy in vascular diseases.

  7. Distinct characteristics of mandibular bone collagen relative to long bone collagen: relevance to clinical dentistry.

    Science.gov (United States)

    Matsuura, Takashi; Tokutomi, Kentaro; Sasaki, Michiko; Katafuchi, Michitsuna; Mizumachi, Emiri; Sato, Hironobu

    2014-01-01

    Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  8. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

    Directory of Open Access Journals (Sweden)

    Takashi Matsuura

    2014-01-01

    Full Text Available Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  9. Effect of albumin-bound DHA on phosphoinositide phosphorylation in collagen stimulated human platelets

    International Nuclear Information System (INIS)

    Gaudette, D.C.; Holub, B.J.

    1990-01-01

    The effect of exogenous albumin-bound docosahexaenoic acid (22:6n-3) (DHA), arachidonic acid (20:4n-6) (AA), and eicosapendaenoic acid (20:5n-3) (EPA) on phosphoinositide metabolism following collagen stimulation was studied using [3H]inositol prelabelled platelets. Collagen stimulation (3 min, 1.8 micrograms/ml) increased the labelling of both phosphatidylinositol 4-monophosphate (PIP), and phosphatidylinositol 4,5-biphosphate (PIP2). Of the fatty acids tested, only pre-incubation (2 min) with DHA (20 microM) significantly attenuated the collagen-induced increased PIP and PIP2 labelling; EPA was without effect, while AA enhanced PIP labelling. Forty microM DHA was less effective at attenuating the increased PIP and PIP2 labelling even though this concentration of DHA resulted in greater inhibition of platelet aggregation. Neither concentration of DHA attenuated the increased polyphosphoinositide labelling resulting from stimulation by the endoperoxide analogue U46619, or the phorbol ester, PMA. These data suggest that the effect of DHA on attenuating the increased PIP and PIP2 labelling following collagen stimulation likely occurs before thromboxane receptor occupancy, may not occur at the level of protein kinase C activation, and could be mediated in part via a lessened synthesis of thromboxane A2

  10. VEGF-A/Notch-Induced Podosomes Proteolyse Basement Membrane Collagen-IV during Retinal Sprouting Angiogenesis

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    Pirjo Spuul

    2016-10-01

    Full Text Available During angiogenic sprouting, endothelial tip cells emerge from existing vessels in a process that requires vascular basement membrane degradation. Here, we show that F-actin/cortactin/P-Src-based matrix-degrading microdomains called podosomes contribute to this step. In vitro, VEGF-A/Notch signaling regulates the formation of functional podosomes in endothelial cells. Using a retinal neovascularization model, we demonstrate that tip cells assemble podosomes during physiological angiogenesis in vivo. In the retina, podosomes are also part of an interconnected network that surrounds large microvessels and impinges on the underlying basement membrane. Consistently, collagen-IV is scarce in podosome areas. Moreover, Notch inhibition exacerbates podosome formation and collagen-IV loss. We propose that the localized proteolytic action of podosomes on basement membrane collagen-IV facilitates endothelial cell sprouting and anastomosis within the developing vasculature. The identification of podosomes as key components of the sprouting machinery provides another opportunity to target angiogenesis therapeutically.

  11. Kaempferol inhibits thrombosis and platelet activation.

    Science.gov (United States)

    Choi, Jun-Hui; Park, Se-Eun; Kim, Sung-Jun; Kim, Seung

    2015-08-01

    The objectives of the present study were to investigate whether kaempferol affects pro-coagulant proteinase activity, fibrin clot formation, blood clot and thrombin (or collagen/epinephrine)-stimulated platelet activation, thrombosis, and coagulation in ICR (Imprinting Control Region) mice and SD (Sprague-Dawley) rats. Kaempferol significantly inhibited the enzymatic activities of thrombin and FXa by 68 ± 1.6% and 52 ± 2.4%, respectively. Kaempferol also inhibited fibrin polymer formation in turbidity. Microscopic analysis was performed using a fluorescent conjugate. Kaempferol completely attenuated phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and phosphoinositide 3-kinase (PI3K)/PKB (AKT) in thrombin-stimulated platelets and delayed aggregation time (clotting) by 34.6% in an assay of collagen/epinephrine-stimulated platelet activation. Moreover, kaempferol protected against thrombosis development in 3 animal models, including collagen/epinephrine- and thrombin-induced acute thromboembolism models and an FeCl3-induced carotid arterial thrombus model. The ex vivo anticoagulant effect of kaempferol was further confirmed in ICR mice. This study demonstrated that kaempferol may be clinically useful due to its ability to reduce or prevent thrombotic challenge. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. Association of collagen architecture with glioblastoma patient survival.

    Science.gov (United States)

    Pointer, Kelli B; Clark, Paul A; Schroeder, Alexandra B; Salamat, M Shahriar; Eliceiri, Kevin W; Kuo, John S

    2017-06-01

    OBJECTIVE Glioblastoma (GBM) is the most malignant primary brain tumor. Collagen is present in low amounts in normal brain, but in GBMs, collagen gene expression is reportedly upregulated. However, to the authors' knowledge, direct visualization of collagen architecture has not been reported. The authors sought to perform the first direct visualization of GBM collagen architecture, identify clinically relevant collagen signatures, and link them to differential patient survival. METHODS Second-harmonic generation microscopy was used to detect collagen in a GBM patient tissue microarray. Focal and invasive GBM mouse xenografts were stained with Picrosirius red. Quantitation of collagen fibers was performed using custom software. Multivariate survival analysis was done to determine if collagen is a survival marker for patients. RESULTS In focal xenografts, collagen was observed at tumor brain boundaries. For invasive xenografts, collagen was intercalated with tumor cells. Quantitative analysis showed significant differences in collagen fibers for focal and invasive xenografts. The authors also found that GBM patients with more organized collagen had a longer median survival than those with less organized collagen. CONCLUSIONS Collagen architecture can be directly visualized and is different in focal versus invasive GBMs. The authors also demonstrate that collagen signature is associated with patient survival. These findings suggest that there are collagen differences in focal versus invasive GBMs and that collagen is a survival marker for GBM.

  13. Comparison of thermal properties of fish collagen and bovine collagen in the temperature range 298-670K.

    Science.gov (United States)

    Gauza-Włodarczyk, Marlena; Kubisz, Leszek; Mielcarek, Sławomir; Włodarczyk, Dariusz

    2017-11-01

    The increased interest in fish collagen is a consequence of the risk of exposure to Creutzfeld-Jacob disease (CJD) and the bovine spongiform encephalopathy (BSE), whose occurrence is associated with prions carried by bovine collagen. Collagen is the main biopolymer in living organisms and the main component of the skin and bones. Until the discovery of the BSE, bovine collagen had been widely used. The BSE epidemic increased the interest in new sources of collagen such as fish skin collagen (FSC) and its properties. Although the thermal properties of collagen originating from mammals have been well described, less attention has been paid to the thermal properties of FSC. Denaturation temperature is a particularly important parameter, depending on the collagen origin and hydration level. In the reported experiment, the free water and bound water release processes along with thermal denaturation process were studied by means of the differential scanning calorimetry (DSC). Measurements were carried out using a DSC 7 instrument (Elmer-Perkin), in the temperature range 298-670K. The study material was FSC derived by acidic hydration method. The bovine Achilles tendon (BAT) collagen type I was used as the control material. The thermograms recorded revealed both, exothermic and endothermic peaks. For both materials, the peaks in the temperature range of 330-360K were assigned to the release of free water and bound water. The denaturation temperatures of FSC and BAT collagen were determined as 420K and 493K, respectively. Thermal decomposition process was observed at about 500K for FSC and at about 510K for BAT collagen. These results show that FSC is less resistant to high temperature than BAT collagen. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. On the role of type IX collagen in the extracellular matrix of cartilage: type IX collagen is localized to intersections of collagen fibrils

    OpenAIRE

    1986-01-01

    The tissue distribution of type II and type IX collagen in 17-d-old chicken embryo was studied by immunofluorescence using polyclonal antibodies against type II collagen and a peptic fragment of type IX collagen (HMW), respectively. Both proteins were found only in cartilage where they were co-distributed. They occurred uniformly throughout the extracellular matrix, i.e., without distinction between pericellular, territorial, and interterritorial matrices. Tissues that undergo endochondral bo...

  15. ISOCT study of collagen crosslinking of collagen in cancer models (Conference Presentation)

    Science.gov (United States)

    Spicer, Graham; Young, Scott T.; Yi, Ji; Shea, Lonnie D.; Backman, Vadim

    2016-03-01

    The role of extracellular matrix modification and signaling in cancer progression is an increasingly recognized avenue for the progression of the disease. Previous study of field effect carcinogenesis with Inverse Spectroscopic Optical Coherence Tomography (ISOCT) has revealed pronounced changes in the nanoscale-sensitive mass fractal dimension D measured from field effect tissue when compared to healthy tissue. However, the origin of this difference in tissue ultrastructure in field effect carcinogenesis has remained poorly understood. Here, we present findings supporting the idea that enzymatic crosslinking of the extracellular matrix is an effect that presents at the earliest stages of carcinogenesis. We use a model of collagen gel with crosslinking induced by lysyl oxidase (LOXL4) to recapitulate the difference in D previously reported from healthy and cancerous tissue biopsies. Furthermore, STORM imaging of this collagen gel model verifies the morphologic effects of enzymatic crosslinking at length scales as small as 40 nm, close to the previously reported lower length scale sensitivity threshold of 35 nm for ISOCT. Analysis of the autocorrelation function from STORM images of collagen gels and subsequent fitting to the Whittle-Matérn correlation function shows a similar effect of LOXL4 on D from collagen measured with ISOCT and STORM. We extend this to mass spectrometric study of tissue to directly measure concentrations of collagen crosslink residues. The validation of ISOCT as a viable tool for non-invasive rapid quantification of collagen ultrastructure lends it to study other physiological phenomena involving ECM restructuring such as atherosclerotic plaque screening or cervical ripening during pregnancy.

  16. [27- Hydroxycholesterol reverses estradiol induced inhibition of platelet aggregation in postmenopausal women].

    Science.gov (United States)

    Rocha, Gladys; Sierralta, Walter; Valladares, Luis

    2016-11-01

    The decline of estrogen levels increases cardiovascular risk in women. Platelets express estrogen receptors and 17β-estradiol- (E2) can produce a protective effect on thrombus formation. The hydroxylation of cholesterol generates several sterols and 27-hydroxycholesterol (27HC) predominates in circulation. To evaluate the effect of 27HC as an endogenous antagonist of the anti-aggregating properties of E2 in platelets of postmenopausal women. Platelet function of postmenopausal women was evaluated ex-vivo. Platelets pre-incubated with 27HC in the presence or absence of E2, were stimulated with collagen. Aggregation was evaluated using turbidimetry using a Chrono-log aggregometer. Collagen-stimulated platelet aggregation was significantly inhibited by E2. The inhibitory effect of E2 on collagen-stimulated platelet aggregation was significantly reversed in the presence of 27HC. The suppressive effect of E2 on platelet aggregation is inhibited by 27HC, which could contribute to increase cardiovascular risk in postmenopausal women.

  17. uPARAP/Endo180 is essential for cellular uptake of collagen and promotes fibroblast collagen adhesion

    DEFF Research Database (Denmark)

    Engelholm, Lars H; List, Karin; Netzel-Arnett, Sarah

    2003-01-01

    The uptake and lysosomal degradation of collagen by fibroblasts constitute a major pathway in the turnover of connective tissue. However, the molecular mechanisms governing this pathway are poorly understood. Here, we show that the urokinase plasminogen activator receptor-associated protein (u......, these cells had diminished initial adhesion to a range of different collagens, as well as impaired migration on fibrillar collagen. These studies identify a central function of uPARAP/Endo180 in cellular collagen interactions....

  18. Extracellular matrix of smooth muscle cells: interaction of collagen type V with heparan sulfate proteoglycan

    International Nuclear Information System (INIS)

    Gay, S.; Hoeoek, M.; Gay, R.E.; Magargal, W.W.; Reynertson, R.H.

    1986-01-01

    Alteration in the extracellular matrix produced by smooth muscle cells may play a role in the development of atherosclerotic lesions. Consequently the authors have initiated studies on the structural organization of the extracellular matrix produced by cultured smooth muscle cells. Immunohisotological examination of this matrix using well-characterized mono- and polyclonal antibodies showed a partial codistribution of heparan sulfate (HS) proteoglycans with a number of different matrix components including collagen types I, III, IV, V and VI, laminin and fibronectin. Subsequent binding studies between isolated matrix proteins and HS showed that the polysaccharide interacts strongly with type V collagen and to a lesser extent with fibronectin as well as collagen types III and VI. The interaction between type V and HS was readily inhibited by heparin and highly sulfated HS but not be dermatan sulfate, chondroitin sulfate or HS with a low sulfate content. Furthermore, [ 35 S]-HS proteoglycans isolated from cultured smooth muscle cells could be adsorbed on a column of sepharose conjugated with native type V collagen and eluted in a salt gradient. Hence, the interaction between type V and HS may play a major part in stabilizing the extracellular matrix of the vessel wall

  19. Mesenchymal Stem Cells Sense Three Dimensional Type I Collagen through Discoidin Domain Receptor 1.

    Science.gov (United States)

    Lund, A W; Stegemann, J P; Plopper, G E

    2009-01-01

    The extracellular matrix provides structural and organizational cues for tissue development and defines and maintains cellular phenotype during cell fate determination. Multipotent mesenchymal stem cells use this matrix to tightly regulate the balance between their differentiation potential and self-renewal in the native niche. When understood, the mechanisms that govern cell-matrix crosstalk during differentiation will allow for efficient engineering of natural and synthetic matrices to specifically direct and maintain stem cell phenotype. This work identifies the discoidin domain receptor 1 (DDR1), a collagen activated receptor tyrosine kinase, as a potential link through which stem cells sense and respond to the 3D organization of their extracellular matrix microenvironment. DDR1 is dependent upon both the structure and proteolytic state of its collagen ligand and is specifically expressed and localized in three dimensional type I collagen culture. Inhibition of DDR1 expression results in decreased osteogenic potential, increased cell spreading, stress fiber formation and ERK1/2 phosphorylation. Additionally, loss of DDR1 activity alters the cell-mediated organization of the naïve type I collagen matrix. Taken together, these results demonstrate a role for DDR1 in the stem cell response to and interaction with three dimensional type I collagen. Dynamic changes in cell shape in 3D culture and the tuning of the local ECM microstructure, directs crosstalk between DDR1 and two dimensional mechanisms of osteogenesis that can alter their traditional roles.

  20. Characterization of Genipin-Modified Dentin Collagen

    Directory of Open Access Journals (Sweden)

    Hiroko Nagaoka

    2014-01-01

    Full Text Available Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE, on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5% for several treatment times (0–24 h. Changes in biochemical properties of NaB3H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (P< 0.05. The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB3H4.

  1. Membrane-associated 41-kDa GTP-binding protein in collagen-induced platelet activation

    International Nuclear Information System (INIS)

    Walker, G.; Bourguignon, L.Y.

    1990-01-01

    Initially we established that the binding of collagen to human blood platelets stimulates both the rapid loss of PIP2 and the generation of inositol-4,5-bisphosphate (IP2) and inositol-1,4,5-triphosphate (IP3). These results indicate that the binding of collagen stimulates inositol phospholipid-specific phospholipase C during platelet activation. The fact that GTP or GTP-gamma-S augments, and pertussis toxin inhibits, collagen-induced IP3 formation suggests that a GTP-binding protein or (or proteins) may be directly involved in the regulation of phospholipase C-mediated phosphoinositide turnover in human platelets. We have used several complementary techniques to isolate and characterize a platelet 41-kDa polypeptide (or polypeptides) that has a number of structural and functional similarities to the regulatory alpha i subunit of the GTP-binding proteins isolated from bovine brain. This 41-kDa polypeptide (or polypeptides) is found to be closely associated with at least four membrane glycoproteins (e.g., gp180, gp110, gp95, and gp75) in a 330-kDa complex that can be dissociated by treatment with high salt plus urea. Most important, we have demonstrated that antilymphoma 41-kDa (alpha i subunit of GTP-binding proteins) antibody cross-reacts with the platelet 41-kDa protein (or proteins) and the alpha i subunit of bovine brain Gi alpha proteins, and blocks GTP/collagen-induced IP3 formation. These data provide strong evidence that the 41-kDa platelet GTP-binding protein (or proteins) is directly involved in collagen-induced signal transduction during platelet activation

  2. Membrane-associated 41-kDa GTP-binding protein in collagen-induced platelet activation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, G.; Bourguignon, L.Y. (Univ. of Miami Medical School, FL (USA))

    1990-08-01

    Initially we established that the binding of collagen to human blood platelets stimulates both the rapid loss of PIP2 and the generation of inositol-4,5-bisphosphate (IP2) and inositol-1,4,5-triphosphate (IP3). These results indicate that the binding of collagen stimulates inositol phospholipid-specific phospholipase C during platelet activation. The fact that GTP or GTP-gamma-S augments, and pertussis toxin inhibits, collagen-induced IP3 formation suggests that a GTP-binding protein or (or proteins) may be directly involved in the regulation of phospholipase C-mediated phosphoinositide turnover in human platelets. We have used several complementary techniques to isolate and characterize a platelet 41-kDa polypeptide (or polypeptides) that has a number of structural and functional similarities to the regulatory alpha i subunit of the GTP-binding proteins isolated from bovine brain. This 41-kDa polypeptide (or polypeptides) is found to be closely associated with at least four membrane glycoproteins (e.g., gp180, gp110, gp95, and gp75) in a 330-kDa complex that can be dissociated by treatment with high salt plus urea. Most important, we have demonstrated that antilymphoma 41-kDa (alpha i subunit of GTP-binding proteins) antibody cross-reacts with the platelet 41-kDa protein (or proteins) and the alpha i subunit of bovine brain Gi alpha proteins, and blocks GTP/collagen-induced IP3 formation. These data provide strong evidence that the 41-kDa platelet GTP-binding protein (or proteins) is directly involved in collagen-induced signal transduction during platelet activation.

  3. The degree of collagen crosslinks in medical collagen membranes determined by water absorption

    International Nuclear Information System (INIS)

    Braczko, M.; Tederko, A.; Grzybowski, J.

    1994-01-01

    Collagen membranes were crosslinked by using three agents: glutaraldehyde, hexametylenediisocyanate, and UV irradiation. The increasing concentrations of above chemical agents or longer time of UV exposition resulted in the higher cross-links degree and in the decrease of collagen membranes swelling (measured as water absorption), their elasticity and mechanical resistance. According to American standards, the degree of collagen biomaterial cross-links is determined by measuring of the digestion time by pepsin. However, that method is very time-consuming. In our study, we have that a simple, linear regression between logarithm of digestion time by pepsin exists and it was identical for all three cross-linking agents used. We have concluded that determination of water absorption can be an alternative, simple and fast method for examination of collagen membrane cross-links degree. (author). 16 refs, 7 figs, 1 tab

  4. Effect of Topical Probiotic on MMP-13 and Collagen III Expression in the Dermis Layer of Male Rats Irradiated with Ultraviolet-B

    Directory of Open Access Journals (Sweden)

    Vita M. Tawaran

    2016-06-01

    Full Text Available Nowadays, there is a big interest in the use of topical probiotic preparations for skin health. One of the probiotics therurapeutic benefits is used as anti-aging. During aging, there is stimulation of activator protein-1 (AP-1 which is a transcription factor that inhibits the production of collagen and AP-1 supports the breakdown of collagen by enzymes called matrix metalloproteinases (MMPs. As administration of oral Lactobacillus plantarum could inhibit skin aging by lowering the activity of MMP, so the collagen degradation can be derived so probably topical use of Lactobacillus plantarum may give more prominent effects. We used 24 male rats Sprague-Dawley strain as research objects. This study was divided into two groups, the treatment and control groups. The shaved dorsal skin of rats were irradiated with UVB three times a week for 4 weeks with total irradiation dose of 840 mJ/cm2. Skin cream, containing 247.27x107 CFU non-replicating Lactobacillus plantarum FNCC 0020, was smeared on the treatment group, two times daily, whereas the control group did not receive any treatment. Skin biopsies were done at the end of the study for examination of MMP-13 and collagen III expressions. Intensity, distribution, and histoscore of MMP-13 between the treatment and the control group showed no significant difference (p>0.05. The treatment group showed a significant different in the intensity of collagen III with the density distribution of 20–50% and the highest density was 80% (p<0.01. Administration of topical cream L. plantarum FNCC 0020 increased the expression of collagen III density distribution, but not the MMP-13 expression.

  5. Complete Histological Resolution of Collagenous Sprue

    Directory of Open Access Journals (Sweden)

    Hugh J Freeman

    2004-01-01

    Full Text Available A 65-year-old woman developed a watery diarrhea syndrome with collagenous colitis. Later, weight loss and hypoalbuminemia were documented. This prompted small bowel biopsies that showed pathological changes of collagenous sprue. An apparent treatment response to a gluten-free diet and prednisone resulted in reduced diarrhea, weight gain and normalization of serum albumin. Later repeated biopsies from multiple small and large bowel sites over a period of over three years, however, showed reversion to normal small intestinal mucosa but persistent collagenous colitis. These results indicate that collagenous inflammatory disease may be a far more extensive process in the gastrointestinal tract than is currently appreciated. Moreover, collagenous colitis may be a clinical signal that occult small intestinal disease is present. Finally, collagenous sprue may, in some instances, be a completely reversible small intestinal disorder.

  6. Transforming growth factor β1 induces the expression of collagen type I by DNA methylation in cardiac fibroblasts.

    Directory of Open Access Journals (Sweden)

    Xiaodong Pan

    Full Text Available Transforming growth factor-beta (TGF-β, a key mediator of cardiac fibroblast activation, has a major influence on collagen type I production. However, the epigenetic mechanisms by which TGF-β induces collagen type I alpha 1 (COL1A1 expression are not fully understood. This study was designed to examine whether or not DNA methylation is involved in TGF-β-induced COL1A1 expression in cardiac fibroblasts. Cells isolated from neonatal Sprague-Dawley rats were cultured and stimulated with TGF-β1. The mRNA levels of COL1A1 and DNA methyltransferases (DNMTs were determined via quantitative polymerase chain reaction and the protein levels of collagen type I were determined via Western blot as well as enzyme-linked immunosorbent assay. The quantitative methylation of the COL1A1 promoter region was analyzed using the MassARRAY platform of Sequenom. Results showed that TGF-β1 upregulated the mRNA expression of COL1A1 and induced the synthesis of cell-associated and secreted collagen type I in cardiac fibroblasts. DNMT1 and DNMT3a expressions were significantly downregulated and the global DNMT activity was inhibited when treated with 10 ng/mL of TGF-β1 for 48 h. TGF-β1 treatment resulted in a significant reduction of the DNA methylation percentage across multiple CpG sites in the rat COL1A1 promoter. Thus, TGF-β1 can induce collagen type I expression through the inhibition of DNMT1 and DNMT3a expressions as well as global DNMT activity, thereby resulting in DNA demethylation of the COL1A1 promoter. These findings suggested that the DNMT-mediated DNA methylation is an important mechanism in regulating the TGF-β1-induced COL1A1 gene expression.

  7. Rac inhibition reverses the phenotype of fibrotic fibroblasts.

    Directory of Open Access Journals (Sweden)

    Shi-wen Xu

    Full Text Available BACKGROUND: Fibrosis, the excessive deposition of scar tissue by fibroblasts, is one of the largest groups of diseases for which there is no therapy. Fibroblasts from lesional areas of scleroderma patients possess elevated abilities to contract matrix and produce alpha-smooth muscle actin (alpha-SMA, type I collagen and CCN2 (connective tissue growth factor, CTGF. The basis for this phenomenon is poorly understood, and is a necessary prerequisite for developing novel, rational anti-fibrotic strategies. METHODS AND FINDINGS: Compared to healthy skin fibroblasts, dermal fibroblasts cultured from lesional areas of scleroderma (SSc patients possess elevated Rac activity. NSC23766, a Rac inhibitor, suppressed the persistent fibrotic phenotype of lesional SSc fibroblasts. NSC23766 caused a decrease in migration on and contraction of matrix, and alpha-SMA, type I collagen and CCN2 mRNA and protein expression. SSc fibroblasts possessed elevated Akt phosphorylation, which was also blocked by NSC23766. Overexpression of rac1 in normal fibroblasts induced matrix contraction and alpha-SMA, type I collagen and CCN2 mRNA and protein expression. Rac1 activity was blocked by PI3kinase/Akt inhibition. Basal fibroblast activity was not affected by NSC23766. CONCLUSION: Rac inhibition may be considered as a novel treatment for the fibrosis observed in SSc.

  8. Collagen metabolism and basement membrane formation in cultures of mouse mammary epithelial cells: Induction of assembly on fibrillar type I collagen substrata

    International Nuclear Information System (INIS)

    David, G.; van der Schueren, B.; van den Berghe, H.; Nusgens, B.; Van Cauwenberge, D.; Lapiere, C.

    1987-01-01

    Collagen metabolism was compared in cultures of mouse mammary epithelial cells maintained on plastic or fibrillar type I collagen gel substrata. The accumulation of dialysable and non-dialysable [ 3 H]hydroxyproline and the identification of the collagens produced suggest no difference between substrata in the allover rates of collagen synthesis and degradation. The proportion of the [ 3 H]collagen which accumulates in the monolayers of cultures on collagen, however, markedly exceeds that of cultures on plastic. Cultures on collagen deposit a sheet-like layer of extracellular matrix materials on the surface of the collagen fibers. Transformed cells on collagen produce and accumulate more [ 3 H]collage, yet are less effective in basement membrane formation than normal cells, indicting that the accumulation of collagen alone and the effect of interstitial collagen thereupon do not suffice. Thus, exogenous fibrillar collagen appears to enhance, but is not sufficient for proper assembly of collagenous basement membrane components near the basal epithelial cell surface

  9. Introduction of the human proα1(I) collagen gene into proα1(I)-deficient Mov-13 mouse cells leads to formation of functional mouse-human hybrid type I collagen

    International Nuclear Information System (INIS)

    Schnieke, A.; Dziadek, M.; Bateman, J.; Mascara, T.; Harbers, K.; Gelinas, R.; Jaenisch, R.

    1987-01-01

    The Mov-13 mouse strain carries a retroviral insertion in the proα1(I) collagen gene that prevents transcription of the gene. Cell lines derived from homozygous embryos do not express type I collagen although normal amounts of proα2 mRNA are synthesized. The authors have introduced genomic clones of either the human or mouse proα1(I) collagen gene into homozygous cell lines to assess whether the human or mouse proα1(I) chains can associate with the endogenous mouse proα2(I) chain to form stable type I collagen. The human gene under control of the simian virus 40 promoter was efficiently transcribed in the transfected cells. Protein analyses revealed that stable heterotrimers consisting of two human α1 chains and one mouse α2 chain were formed and that type I collagen was secreted by the transfected cells at normal rates. However, the electrophoretic migration of both α1(I) and α2(I) chains in the human-mouse hybrid molecules were retarded, compared to the α(I) chains in control mouse cells. Inhibition of the posttranslational hydroxylation of lysine and proline resulted in comigration of human and mouse α1 and α2 chains, suggesting that increased posttranslational modification caused the altered electrophoretic migration in the human-mouse hybrid molecules. Amino acid sequence differences between the mouse and human α chains may interfere with the normal rate of helix formation and increase the degree of posttranslational modifications similar to those observed in patients with lethal perinatal osteogenesis imperfecta. The Mov-13 mouse system should allow the authors to study the effect specific mutations introduced in transfected proα1(I) genes have on the synthesis, assembly, and function of collagen I

  10. Phase Behaviour and Miscibility Studies of Collagen/Silk Fibroin Macromolecular System in Dilute Solutions and Solid State.

    Science.gov (United States)

    Ghaeli, Ima; de Moraes, Mariana A; Beppu, Marisa M; Lewandowska, Katarzyna; Sionkowska, Alina; Ferreira-da-Silva, Frederico; Ferraz, Maria P; Monteiro, Fernando J

    2017-08-18

    Miscibility is an important issue in biopolymer blends for analysis of the behavior of polymer pairs through the detection of phase separation and improvement of the mechanical and physical properties of the blend. This study presents the formulation of a stable and one-phase mixture of collagen and regenerated silk fibroin (RSF), with the highest miscibility ratio between these two macromolecules, through inducing electrostatic interactions, using salt ions. For this aim, a ternary phase diagram was experimentally built for the mixtures, based on observations of phase behavior of blend solutions with various ratios. The miscibility behavior of the blend solutions in the miscible zones of the phase diagram was confirmed quantitatively by viscosimetric measurements. Assessing the effects of biopolymer mixing ratio and salt ions, before and after dialysis of blend solutions, revealed the importance of ion-specific interactions in the formation of coacervate-based materials containing collagen and RSF blends that can be used in pharmaceutical, drug delivery, and biomedical applications. Moreover, the conformational change of silk fibroin from random coil to beta sheet, in solution and in the final solid films, was detected by circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), respectively. Scanning electron microscopy (SEM) exhibited alterations of surface morphology for the biocomposite films with different ratios. Surface contact angle measurement illustrated different hydrophobic properties for the blended film surfaces. Differential scanning calorimetry (DSC) showed that the formation of the beta sheet structure of silk fibroin enhances the thermal stability of the final blend films. Therefore, the novel method presented in this study resulted in the formation of biocomposite films whose physico-chemical properties can be tuned by silk fibroin conformational changes by applying different component mixing ratios.

  11. Collagen crosslinks in chondromalacia of the patella.

    Science.gov (United States)

    Väätäinen, U; Kiviranta, I; Jaroma, H; Arokosi, J; Tammi, M; Kovanen, V

    1998-02-01

    The aim of the study was to determine collagen concentration and collagen crosslinks in cartilage samples from chondromalacia of the patella. To study the extracellular matrix alterations associated to chondromalacia, we determined the concentration of collagen (hydroxyproline) and its hydroxylysylpyridinoline and lysylpyridinoline crosslinks from chondromalacia foci of the patellae in 12 patients and 7 controls from apparently normal cadavers. The structure of the collagen network in 8 samples of grades II-IV chondromalacia was examined under polarized light microscopy. The full-thickness cartilage samples taken with a surgical knife from chondromalacia lesions did not show changes in collagen, hydroxylysylpyridinoline and lysylpyridinoline concentration as compared with the controls. Polarized light microscopy showed decreased birefringence in the superficial cartilage of chondromalacia lesions, indicating disorganization or disappearance of collagen fibers in this zone. It is concluded that the collagen network shows gradual disorganization with the severity of chondromalacia lesion of the patella without changes in the concentration or crosslinks of collagen.

  12. Influence of hirudin and cobra venom factor on the release of 14C-serotonin and 51chromium from human platelets induced by thrombin, collagen, aggregate gammaglobulin and HLA antibody

    International Nuclear Information System (INIS)

    Hagemeyer, G.M.

    1982-01-01

    The present work investigates the influence of hirudin and cobra venom factor on thrombin, collagen, aggregate gammaglobulin and HLA-antibody-induced release of 14 C-serotonin and 51 chromium from human platelets. Besides the platelet-specific release reaction ( 14 C-serotonin) the extent of platelet lysis was determined by measurement of the loss of 51 chromium from the platelets. The results showed the thrombin, collagen and aggregate-gammaglobulin-induced platelet alteration to be a non-complement-dependent reaction of the platelets with release of 14 C-serotonin. Following long-term incubation small quantities of 51 chromium are also released. As this release of 51 chromium cannot be inhibited using cobra venom factor and does not occur in washed platelets either, it is most probably a non-complement-dependent reaction. The HLA-antibody-induced, specific platelet alteration is both complement-dependent and complement-independent. Differentiation is possible by inhibition of the complement-dependent lysis. On the other hand thrombin is of no relevance to the collagen, aggregate gammaglobulin, and HLA-antibody-induced platelet alteration as the interactions of these substances with platelets are not inhibited by hirudin. The above results are confirmed by investigation of the 51 chromium uptake capacity of washed platelets treated previously with thrombin, collagen and HLA antibody. (orig./MG) [de

  13. Antimicrobial, Rheological, and Thermal Properties of Plasticized Polylactide Films Incorporated with Essential Oils to Inhibit Staphylococcus aureus and Campylobacter jejuni.

    Science.gov (United States)

    Ahmed, Jasim; Hiremath, Nikhil; Jacob, Harsha

    2016-02-01

    Polylactide (PLA) is the most mature biobased and biodegradable polymer. Due to its inherent brittleness, the polymer cannot be used as a packaging material without plasticizer. An attempt was made to develop antimicrobial plasticized PLA film by incorporating polyethylene glycol (PEG) and 3 essential oils (EO), namely cinnamon, garlic, and clove by solvent casting method. Physical, thermal, and rheological properties of those films were evaluated for practical applications whereas the antimicrobial properties were tested against Staphylococcus aureus and Campylobacter jejuni-pathogens related to poultry industry. Both PEG and EOs led to the formation of flexible PLA/PEG/EO films with significant drop in the glass transition temperature (Tg ), and mechanical property. Time-temperature superposition (TTS) principle was employed to melt rheology of EO-based films at selected temperature, and rheological moduli superimposed well in an extended frequency range. Among EOs, cinnamon and clove oil-based films (PLA/PEG/CIN and PLA/PEG/CLO) exhibited a complete zone of inhibition against C. jejuni at the maximum concentration (1.6 mL per 2 g PLA/PEG blend) whereas the garlic oil-based film (PLA/PEG/GAR) had the lowest activity. © 2016 Institute of Food Technologists®

  14. Collagens - structure, function and biosynthesis.

    OpenAIRE

    Gelse, K; Poschl, E; Aigner, T

    2003-01-01

    The extracellular matrix represents a complex alloy of variable members of diverse protein families defining structural integrity and various physiological functions. The most abundant family is the collagens with more than 20 different collagen types identified so far. Collagens are centrally involved in the formation of fibrillar and microfibrillar networks of the extracellular matrix, basement membranes as well as other structures of the extracellular matrix. This review focuses on the dis...

  15. Biomimetic soluble collagen purified from bones.

    Science.gov (United States)

    Ferreira, Ana Marina; Gentile, Piergiorgio; Sartori, Susanna; Pagliano, Cristina; Cabrele, Chiara; Chiono, Valeria; Ciardelli, Gianluca

    2012-11-01

    Type I collagen has been extensively exploited as a biomaterial for biomedical applications and drug delivery; however, small molecular alterations occurring during the isolation procedure and its interaction with residual bone extracellular matrix molecules or proteins might affect the overall material biocompatibility and performance. The aim of the current work is to study the potential alterations in collagen properties and organization associated with the absence of proteoglycans, which mimic pathological conditions associated with age-related diseases. A new approach for evaluating the effect of proteoglycans on the properties of isolated type I collagen from the bone matrix is described. Additional treatment with guanidine hydrochloride was introduced to remove residual proteoglycans from the collagen matrix. The properties of the isolated collagen with/without guanidine hydrochloride treatment were investigated and compared with a commercial rabbit collagen as control. We demonstrate that the absence of proteoglycans in the isolated type I collagen affects its thermal properties, the extraction into its native structure, and its ability to hydrate and self-assemble into fibers. The fine control and tuning of all these features, linked to the absence of non-collagenous proteins as proteoglycans, offer the possibility of designing new strategies and biomaterials with advanced biomimetic properties aimed at regenerating bone tissue in the case of fragility and/or defects. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. FK506-binding protein 10 (FKBP10) regulates lung fibroblast migration via collagen VI synthesis.

    Science.gov (United States)

    Knüppel, Larissa; Heinzelmann, Katharina; Lindner, Michael; Hatz, Rudolf; Behr, Jürgen; Eickelberg, Oliver; Staab-Weijnitz, Claudia A

    2018-04-19

    In idiopathic pulmonary fibrosis (IPF), fibroblasts gain a more migratory phenotype and excessively secrete extracellular matrix (ECM), ultimately leading to alveolar scarring and progressive dyspnea. Here, we analyzed the effects of deficiency of FK506-binding protein 10 (FKBP10), a potential IPF drug target, on primary human lung fibroblast (phLF) adhesion and migration. Using siRNA, FKBP10 expression was inhibited in phLF in absence or presence of 2ng/ml transforming growth factor-β1 (TGF-β1) and 0.1mM 2-phosphoascorbate. Effects on cell adhesion and migration were monitored by an immunofluorescence (IF)-based attachment assay, a conventional scratch assay, and single cell tracking by time-lapse microscopy. Effects on expression of key players in adhesion dynamics and migration were analyzed by qPCR and Western Blot. Colocalization was evaluated by IF microscopy and by proximity ligation assays. FKBP10 knockdown significantly attenuated adhesion and migration of phLF. Expression of collagen VI was decreased, while expression of key components of the focal adhesion complex was mostly upregulated. The effects on migration were 2-phosphoascorbate-dependent, suggesting collagen synthesis as the underlying mechanism. FKBP10 colocalized with collagen VI and coating culture dishes with collagen VI, and to a lesser extent with collagen I, abolished the effect of FKBP10 deficiency on migration. These findings show, to our knowledge for the first time, that FKBP10 interacts with collagen VI and that deficiency of FKBP10 reduces phLF migration mainly by downregulation of collagen VI synthesis. The results strengthen FKBP10 as an important intracellular regulator of ECM remodeling and support the concept of FKBP10 as drug target in IPF.

  17. FcγRIIb on myeloid cells rather than on B cells protects from collagen-induced arthritis.

    Science.gov (United States)

    Yilmaz-Elis, A Seda; Ramirez, Javier Martin; Asmawidjaja, Patrick; van der Kaa, Jos; Mus, Anne-Marie; Brem, Maarten D; Claassens, Jill W C; Breukel, Cor; Brouwers, Conny; Mangsbo, Sara M; Boross, Peter; Lubberts, Erik; Verbeek, J Sjef

    2014-06-15

    Extensive analysis of a variety of arthritis models in germline KO mice has revealed that all four receptors for the Fc part of IgG (FcγR) play a role in the disease process. However, their precise cell type-specific contribution is still unclear. In this study, we analyzed the specific role of the inhibiting FcγRIIb on B lymphocytes (using CD19Cre mice) and in the myeloid cell compartment (using C/EBPαCre mice) in the development of arthritis induced by immunization with either bovine or chicken collagen type II. Despite their comparable anti-mouse collagen autoantibody titers, full FcγRIIb knockout (KO), but not B cell-specific FcγRIIb KO, mice showed a significantly increased incidence and severity of disease compared with wild-type control mice when immunized with bovine collagen. When immunized with chicken collagen, disease incidence was significantly increased in pan-myeloid and full FcγRIIb KO mice, but not in B cell-specific KO mice, whereas disease severity was only significantly increased in full FcγRIIb KO mice compared with incidence and severity in wild-type control mice. We conclude that, although anti-mouse collagen autoantibodies are a prerequisite for the development of collagen-induced arthritis, their presence is insufficient for disease development. FcγRIIb on myeloid effector cells, as a modulator of the threshold for downstream Ab effector pathways, plays a dominant role in the susceptibility to collagen-induced arthritis, whereas FcγRIIb on B cells, as a regulator of Ab production, has a minor effect on disease susceptibility. Copyright © 2014 by The American Association of Immunologists, Inc.

  18. A case report of central toxic keratopathy in a patient post TransPRK (followed by corneal collagen cross-linking).

    Science.gov (United States)

    Davey, Nicholas; Aslanides, Ioannis M; Selimis, Vasilis

    2017-01-01

    The purpose of this article is to report a case of central toxic keratopathy in a patient post transepithelial photorefractive keratectomy (TransPRK), followed immediately by corneal collagen cross-linking. This article describes the case of a 26-year-old male after bilateral aberration-free, TransPRK laser (Schwind Amaris 750S). The procedure was performed for compound myopic astigmatism in November 2015, followed immediately by accelerated corneal collagen cross-linking for early keratoconus. From day 3 post-op, tear film debris underneath both contact lenses with corneal haze and early, progressive central anterior stromal opacity formation only in the left eye were noted. At 2 weeks post-op, the left eye was noted to have a significant hyperopic shift with central corneal thinning in the anterior stroma. A central anterior stromal dense opacity had formed in the left eye with the surrounding superficial stromal haze. As of month 2, the opacity gradually started to improve in size and density. The hyperopic shift peaked at 2 months and continued to improve, largely due to epithelial compensation with a gradual recovery of stromal thickness. The question remains as to what provokes the typical central corneal necrosis/thinning in central toxic keratopathy. We hypothesize that the space between the contact lens and the corneal surface post TransPRK is prone to a "pseudo-interface pathology" that could mimic diffuse lamellar keratitis-like pathology. Suboptimal lid hygiene, resulting in tear film combinations of bacteria, inflammatory cells, matrix metalloproteinases and other proteolytic enzymes, contributes to the degradation of vulnerable, exposed collagen stromal tissue post TransPRK or any surface corneal ablation. Refractive surgeons should maintain a healthy lid margin and tear film, especially in contact lens wearers, to prevent potential complications in refractive surgery procedures.

  19. Alginate-Collagen Fibril Composite Hydrogel

    Directory of Open Access Journals (Sweden)

    Mahmoud Baniasadi

    2015-02-01

    Full Text Available We report on the synthesis and the mechanical characterization of an alginate-collagen fibril composite hydrogel. Native type I collagen fibrils were used to synthesize the fibrous composite hydrogel. We characterized the mechanical properties of the fabricated fibrous hydrogel using tensile testing; rheometry and atomic force microscope (AFM-based nanoindentation experiments. The results show that addition of type I collagen fibrils improves the rheological and indentation properties of the hydrogel.

  20. Preparation and characterization of collagen/PLA, chitosan/PLA, and collagen/chitosan/PLA hybrid scaffolds for cartilage tissue engineering.

    Science.gov (United States)

    Haaparanta, Anne-Marie; Järvinen, Elina; Cengiz, Ibrahim Fatih; Ellä, Ville; Kokkonen, Harri T; Kiviranta, Ilkka; Kellomäki, Minna

    2014-04-01

    In this study, three-dimensional (3D) porous scaffolds were developed for the repair of articular cartilage defects. Novel collagen/polylactide (PLA), chitosan/PLA, and collagen/chitosan/PLA hybrid scaffolds were fabricated by combining freeze-dried natural components and synthetic PLA mesh, where the 3D PLA mesh gives mechanical strength, and the natural polymers, collagen and/or chitosan, mimic the natural cartilage tissue environment of chondrocytes. In total, eight scaffold types were studied: four hybrid structures containing collagen and/or chitosan with PLA, and four parallel plain scaffolds with only collagen and/or chitosan. The potential of these types of scaffolds for cartilage tissue engineering applications were determined by the analysis of the microstructure, water uptake, mechanical strength, and the viability and attachment of adult bovine chondrocytes to the scaffolds. The manufacturing method used was found to be applicable for the manufacturing of hybrid scaffolds with highly porous 3D structures. All the hybrid scaffolds showed a highly porous structure with open pores throughout the scaffold. Collagen was found to bind water inside the structure in all collagen-containing scaffolds better than the chitosan-containing scaffolds, and the plain collagen scaffolds had the highest water absorption. The stiffness of the scaffold was improved by the hybrid structure compared to plain scaffolds. The cell viability and attachment was good in all scaffolds, however, the collagen hybrid scaffolds showed the best penetration of cells into the scaffold. Our results show that from the studied scaffolds the collagen/PLA hybrids are the most promising scaffolds from this group for cartilage tissue engineering.

  1. Effect of radiation on rat skin collagen

    International Nuclear Information System (INIS)

    Nogami, Akira

    1980-01-01

    I. Albino male rats were exposed for 16 weeks to ultraviolet light (UVL) which has principle emission at 305 nm. There were no significant changes between control and UVL-exposed skins in the total hydroxyproline content. However, a little increase of citrate-soluble collagen, a little decrease of insoluble collagen and a decrease of aldehyde content in soluble collagen were observed with UVL exposure. Total acid glycosaminoglycan in skin increased 30% or more from control. These results show that the effect of UVL on rat skin in vivo was merely inflammation phenomenon and that the 'aging' process of skin was not caused in our experimental conditions. II. The effects of radiation on the solubility of rat skin collagen were examined under various conditions. 1) When intact rats were exposed to a single dose of radiation from 43 kVp X-ray source, the solubility in skin collagen did not change at 4,000 R dosage, while in irradiation of 40,000 R a decreased solubility in collagen was observed. When rats were given 400 R a week for 12 weeks, there was no changes in the solubility of collagen during experimental period. 2) In vitro exposure to skins, an irradiation of 40,000 R from 43 kVp X-ray source caused a decrease in the solubility of collagen. While an irradiation of 40,000 R of dosage from 200 kVp X-ray source resulted in the increase in soluble collagen and the decrease in insoluble collagen. 3) When intact rats were given a single dose of 40,000 R from 60 Co- gamma -ray, insoluble collagen decreased in both young and adult rats. Similar changes in collagen solubility were observed in vitro gamma -irradiation. (author)

  2. A 48 kDa collagen-binding phosphoprotein isolated from bovine aortic endothelial cells interacts with the collagenous domain, but not the globular domain, of collagen type IV.

    OpenAIRE

    Yannariello-Brown, J; Madri, J A

    1990-01-01

    We have identified collagen-binding proteins in detergent extracts of metabolically labelled bovine aortic endothelial cells (BAEC) by collagen type IV-Sepharose affinity chromatography. The major collagen type IV-binding protein identified by SDS/PAGE had a molecular mass of 48 kDa, which we term the 'collagen-binding 48 kDa protein' (CB48). The pI of CB48 was 8.0-8.3 in a two-dimensional gel system, running non-equilibrium pH gel electrophoresis in the first dimension and SDS/PAGE in the se...

  3. [Expressiona of c-Jun and collagens I and III in cultured human skin fibroblasts are affected by infrared ray radiation].

    Science.gov (United States)

    Liu, Ping; Yang, Rong-Li; Su, Hui; Li, Lin-Li; Song, Jian-Wen; Lu, Ning; Liu, Yu-Ze

    2016-02-01

    To observe the effect of solar infrared ray (IR) radiation on the expressions of c-Jun and collagens I and III in cultured human skin fibroblasts (HSFs) and explore the molecular mechanism by which IR radiation causes aging of the skin. Primarily cultured HSFs exposed to IR radiation were examined for changes of the cell viability with MTT assay. The mRNA and protein expressions of c-Jun and collagens I and III was detected with real-time quantitative PCR and immunocytochemistry. MTT assay showed that IR irradiation caused inhibition of cell proliferation compared with the control cells. The mRNA and protein expression of collagen I was decreased significantly by IR irradiation with the increase of the irradiation dose (Pradiation to initiate and promote skin photoaging.

  4. Mapuche Herbal Medicine Inhibits Blood Platelet Aggregation

    OpenAIRE

    Falkenberg, Susan Skanderup; Tarnow, Inge; Guzman, Alfonso; Mølgaard, Per; Simonsen, Henrik Toft

    2012-01-01

    12 plant species traditionally used by the Mapuche people in Chile to treat wounds and inflammations have been evaluated for their direct blood platelet inhibition. Seven of the 12 tested plant species showed platelet inhibitory effect in sheep blood, and four of these were also able to inhibit the ADP- (5.0??M) and collagen- (2.0??g/mL) induced aggregations in human blood. These four species in respective extracts (in brackets) were Blechnum chilense (MeOH), Luma apiculata (H2O), Amomyrtus l...

  5. Development of a sensing system to detect C-telopeptide of type-I collagen

    KAUST Repository

    Afsarimanesh, Nasrin

    2016-03-30

    This research work describes a non-invasive and label-free immunosensing technique to detect the C-telopeptide of type-I collagen (CTX-1) by Electrochemical Impedance Spectroscopy (EIS). A planar interdigital capacitive sensor is used to evaluate the properties of the material under test. This sensor was fabricated on the basis of thin film micro-electromechanical system (MEMS) semiconductor device fabrication technology. EIS was used in conjunction with the sensor to detect collagen type-I in blood plasma. At the first stage, the Serum CrossLaps® ELISA was used to measure some known samples in order to obtain a standard curve. Streptavidin agarose was successfully immobilized on the sensing area of the sensor. After that the experiments were done with antibody solution and three known samples of CTX-1, zero concentration which was considered as control, 2.669 ng/ml and 0.798 ng/ml concentration. The results are encouraging for further investigation.

  6. Changes of MMP-1 and collagen type Ialpha1 by UVA, UVB and IRA are differentially regulated by Trx-1.

    Science.gov (United States)

    Buechner, Nicole; Schroeder, Peter; Jakob, Sascha; Kunze, Kerstin; Maresch, Tanja; Calles, Christian; Krutmann, Jean; Haendeler, Judith

    2008-07-01

    Exposure of human skin to solar radiation, which includes ultraviolet (UV) radiation (UVA and UVB) visible light and infrared radiation, induces skin aging. The effects of light have been attributed to irradiation-induced reactive oxygen species (ROS) formation, but the specific signaling pathways are not well understood. Detrimental effects of solar radiation are dermal diseases and photoaging. Exposure of cultured human dermal fibroblasts to UVA, UVB or IRA increased ROS formation in vitro. One important redox regulator is the oxidoreductase thioredoxin-1 (Trx). Trx is ubiquitously expressed and has anti-oxidative and anti-apoptotic properties. Besides its function to reduce H(2)O(2), Trx binds to and regulates transcription factors. The aim of this study was to investigate whether Trx influences the regulation of MMP-1 and collagen Ialpha1 by UVA, UVB and IRA. We irradiated human dermal fibroblasts with UVA, UVB and IRA. UVA, UVB and IRA upregulated MMP-1 expression. Trx inhibited UVA-induced MMP-1 upregulation in a NFkappaB dependent manner. UVA, UVB and IRA reduced collagen Ialpha1 expression. Incubation with Trx inhibited the effects of UVB and IRA on collagen Ialpha1 expression. In conclusion, MMP-1 and collagen Ialpha1, which play important roles in aging processes, seems to be regulated by different transcriptional mechanisms and Trx can only influence distinct signaling pathways induced by UVA, UVB and probably IRA. Thus, Trx may serve as an important contributor to an "anti-aging therapeutic cocktail".

  7. Modern collagen wound dressings: function and purpose.

    Science.gov (United States)

    Fleck, Cynthia Ann; Simman, Richard

    2010-09-01

    Collagen, which is produced by fibroblasts, is the most abundant protein in the human body. A natural structural protein, collagen is involved in all 3 phases of the wound-healing cascade. It stimulates cellular migration and contributes to new tissue development. Because of their chemotactic properties on wound fibroblasts, collagen dressings encourage the deposition and organization of newly formed collagen, creating an environment that fosters healing. Collagen-based biomaterials stimulate and recruit specific cells, such as macrophages and fibroblasts, along the healing cascade to enhance and influence wound healing. These biomaterials can provide moisture or absorption, depending on the delivery system. Collagen dressings are easy to apply and remove and are conformable. Collagen dressings are usually formulated with bovine, avian, or porcine collagen. Oxidized regenerated cellulose, a plant-based material, has been combined with collagen to produce a dressing capable of binding to and protecting growth factors by binding and inactivating matrix metalloproteinases in the wound environment. The increased understanding of the biochemical processes involved in chronic wound healing allows the design of wound care products aimed at correcting imbalances in the wound microenvironment. Traditional advanced wound care products tend to address the wound's macroenvironment, including moist wound environment control, fluid management, and controlled transpiration of wound fluids. The newer class of biomaterials and wound-healing agents, such as collagen and growth factors, targets specific defects in the chronic wound environment. In vitro laboratory data point to the possibility that these agents benefit the wound healing process at a biochemical level. Considerable evidence has indicated that collagen-based dressings may be capable of stimulating healing by manipulating wound biochemistry.

  8. Aryl hydrocarbon receptor suppresses the osteogenesis of mesenchymal stem cells in collagen-induced arthritic mice through the inhibition of β-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Yulong [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Niu, Menglin [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Department of Blood Transfusion, Peking University Cancer Hospital & Institute, No. 52 Fucheng Rd., Beijing 100142 (China); Du, Yuxuan; Mei, Wentong; Cao, Wei; Dou, Yunpeng [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Yu, Haitao [Department of Clinical Laboratory, The First Hospital of Lanzhou University, Lanzhou, Gansu Province 730000 (China); Du, Xiaonan [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Yuan, Huihui, E-mail: huihui_yuan@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China); Zhao, Wenming, E-mail: zhao-wenming@163.com [Department of Immunology, School of Basic Medical Sciences, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069 (China)

    2017-01-15

    The contributions of aryl hydrocarbon receptor (Ahr) to the pathogenesis of rheumatoid arthritis (RA), particularly bone loss, have not been clearly explored. The imbalance between osteoblasts and osteoclasts is a major reason for bone loss. The dysfunction of osteoblasts, which are derived from mesenchymal stem cells (MSCs), induced bone erosion occurs earlier and is characterized as more insidious. Here, we showed that the nuclear expression and translocation of Ahr were both significantly increased in MSCs from collagen-induced arthritis (CIA) mice. The enhanced Ahr suppressed the mRNA levels of osteoblastic markers including Alkaline phosphatase (Alp) and Runt-related transcription factor 2 (Runx2) in the differentiation of MSCs to osteoblasts in CIA. The 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated activation of Ahr dose-dependently suppressed the expression of osteoblastic markers. In addition, the expression of β-catenin was reduced in CIA MSCs compared with control, and the TCDD-mediated activation of the Ahr significantly inhibited β-catenin expression. The Wnt3a-induced the activation of Wnt/β-catenin pathway partly rescued the osteogenesis decline induced by TCDD. Taken together, these results indicate that activated Ahr plays a negative role in CIA MSCs osteogenesis, possibly by suppressing the expression of β-catenin. - Highlights: • The Ahr pathway displays an activated profile in CIA MSCs. • The activation of Ahr suppresses osteogenesis in CIA MSCs. • TCDD suppresses osteogenesis in a dose-dependent manner. • The activation of Ahr inhibits β-catenin expression to exacerbate bone erosion.

  9. Mesenchymal Stem Cells Promote the Osteogenesis in Collagen-Induced Arthritic Mice through the Inhibition of TNF-α

    Science.gov (United States)

    Liu, Chang; Tang, Xiaojun; Feng, Ruihai; Yao, Genhong; Chen, Weiwei; Li, Wenchao; Liang, Jun; Feng, Xuebing

    2018-01-01

    Objective To investigate the effects of umbilical cord mesenchymal stem cell (UC-MSC) transplantation on joint damage and osteoporosis in collagen-induced arthritis (CIA) mice and to explore the mechanisms by which UC-MSCs modulate the osteogenic differentiation. Methods CIA mice were divided into the following treated groups: UC-MSC transplantation group, antitumor necrosis factor- (TNF-) α group, and zoledronic acid (ZA) group. Microcomputed tomography (micro-CT) was used to analyze the bone morphology parameters. Osteogenic differentiation of treated CIA mice was determined. Bone marrow mesenchymal stem cells (BM-MSCs) from CIA mice were treated with TNF-α in vitro to explore their effects on osteogenesis. Results The arthritis score was significantly reduced in the UC-MSC transplantation and anti-TNF-α-treated CIA groups, compared with control mice (P UC-MSC-treated CIA mice. Impaired osteogenic differentiation functions were indicated by decreased ALP activity (P UC-MSC treatment significantly upregulated the impaired osteogenic differentiation ability in CIA mice. Meanwhile, the serum TNF-α level was decreased significantly in the UC-MSC group. The osteogenesis was reduced with the addition of TNF-α in vitro. Conclusion This study demonstrated that UC-MSC transplantation not only significantly improved the joint damage but also played a beneficial role in osteoporosis in CIA mice. Mechanistically, the improved osteogenic differentiation of CIA under UC-MSC treatment may be achieved by inhibition of TNF-α. PMID:29853911

  10. The Mineral–Collagen Interface in Bone

    Science.gov (United States)

    2015-01-01

    The interface between collagen and the mineral reinforcement phase, carbonated hydroxyapatite (cAp), is essential for bone’s remarkable functionality as a biological composite material. The very small dimensions of the cAp phase and the disparate natures of the reinforcement and matrix are essential to the material’s performance but also complicate study of this interface. This article summarizes what is known about the cAp-collagen interface in bone and begins with descriptions of the matrix and reinforcement roles in composites, of the phases bounding the interface, of growth of cAp growing within the collagen matrix, and of the effect of intra- and extrafibrilar mineral on determinations of interfacial properties. Different observed interfacial interactions with cAp (collagen, water, non-collagenous proteins) are reviewed; experimental results on interface interactions during loading are reported as are their influence on macroscopic mechanical properties; conclusions of numerical modeling of interfacial interactions are also presented. The data suggest interfacial interlocking (bending of collagen molecules around cAp nanoplatelets) and water-mediated bonding between collagen and cAp are essential to load transfer. The review concludes with descriptions of areas where new research is needed to improve understanding of how the interface functions. PMID:25824581

  11. Age Increases Monocyte Adhesion on Collagen

    Science.gov (United States)

    Khalaji, Samira; Zondler, Lisa; Kleinjan, Fenneke; Nolte, Ulla; Mulaw, Medhanie A.; Danzer, Karin M.; Weishaupt, Jochen H.; Gottschalk, Kay-E.

    2017-05-01

    Adhesion of monocytes to micro-injuries on arterial walls is an important early step in the occurrence and development of degenerative atherosclerotic lesions. At these injuries, collagen is exposed to the blood stream. We are interested whether age influences monocyte adhesion to collagen under flow, and hence influences the susceptibility to arteriosclerotic lesions. Therefore, we studied adhesion and rolling of human peripheral blood monocytes from old and young individuals on collagen type I coated surface under shear flow. We find that firm adhesion of monocytes to collagen type I is elevated in old individuals. Pre-stimulation by lipopolysaccharide increases the firm adhesion of monocytes homogeneously in older individuals, but heterogeneously in young individuals. Blocking integrin αx showed that adhesion of monocytes to collagen type I is specific to the main collagen binding integrin αxβ2. Surprisingly, we find no significant age-dependent difference in gene expression of integrin αx or integrin β2. However, if all integrins are activated from the outside, no differences exist between the age groups. Altered integrin activation therefore causes the increased adhesion. Our results show that the basal increase in integrin activation in monocytes from old individuals increases monocyte adhesion to collagen and therefore the risk for arteriosclerotic plaques.

  12. Antimicrobial Activity of Nisin and Natamycin Incorporated Sodium Caseinate Extrusion-Blown Films: A Comparative Study with Heat-Pressed/Solution Cast Films.

    Science.gov (United States)

    Colak, Basak Yilin; Peynichou, Pierre; Galland, Sophie; Oulahal, Nadia; Prochazka, Frédéric; Degraeve, Pascal

    2016-05-01

    Antimicrobial edible films based on sodium caseinate, glycerol, and 2 food preservatives (nisin or natamycin) were prepared by classical thermomechanical processes. Food preservatives were compounded (at 65 °C for 2.5 min) with sodium caseinate in a twin-screw extruder. Anti-Listeria activity assays revealed a partial inactivation of nisin following compounding. Thermoplastic pellets containing food preservatives were then used to manufacture films either by blown-film extrusion process or by heat-press. After 24 h of incubation on agar plates, the diameters of K. rhizophila growth inhibition zones around nisin-incorporated films prepared by solution casting (control), extrusion blowing or heat pressing at 80 °C for 7 min of nisin-containing pellets were 15.5 ± 0.9, 9.8 ± 0.2, and 8.6 ± 1.0 mm, respectively. Since heat-pressing for 7 min at 80 °C of nisin-incorporated pellets did not further inactivate nisin, this indicates that nisin inactivation during extrusion-blowing was limited. Moreover, the lower diameter of the K. rhizophila growth inhibition zone around films prepared with nisin-containing pellets compared to that observed around films directly prepared by solution casting confirms that nisin inactivation mainly occurred during the compounding step. Natamycin-containing thermoplastic films inhibited Aspergillus niger growth; however, by contrast with nisin-containing films, heat-pressed films had higher inhibition zone diameters than blown films, therefore suggesting a partial inactivation of natamycin during extrusion-blowing. © 2016 Institute of Food Technologists®

  13. The non-phagocytic route of collagen uptake

    DEFF Research Database (Denmark)

    Madsen, Daniel H; Ingvarsen, Signe; Jürgensen, Henrik J

    2011-01-01

    The degradation of collagens, the most abundant proteins of the extracellular matrix, is involved in numerous physiological and pathological conditions including cancer invasion. An important turnover pathway involves cellular internalization and degradation of large, soluble collagen fragments......, generated by initial cleavage of the insoluble collagen fibers. We have previously observed that in primary mouse fibroblasts, this endocytosis of collagen fragments is dependent on the receptor urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180. Others have identified additional...... mechanisms of collagen uptake, with different associated receptors, in other cell types. These receptors include β1-integrins, being responsible for collagen phagocytosis, and the mannose receptor. We have now utilized a newly developed monoclonal antibody against uPARAP/Endo180, which down...

  14. Sphingosine 1-phosphate (S1P) suppresses the collagen-induced activation of human platelets via S1P4 receptor.

    Science.gov (United States)

    Onuma, Takashi; Tanabe, Kumiko; Kito, Yuko; Tsujimoto, Masanori; Uematsu, Kodai; Enomoto, Yukiko; Matsushima-Nishiwaki, Rie; Doi, Tomoaki; Nagase, Kiyoshi; Akamatsu, Shigeru; Tokuda, Haruhiko; Ogura, Shinji; Iwama, Toru; Kozawa, Osamu; Iida, Hiroki

    2017-08-01

    Sphingosine 1-phosphate (S1P) is as an extracellular factor that acts as a potent lipid mediator by binding to specific receptors, S1P receptors (S1PRs). However, the precise role of S1P in human platelets that express S1PRs has not yet been fully clarified. We previously reported that heat shock protein 27 (HSP27) is released from human platelets accompanied by its phosphorylation stimulated by collagen. In the present study, we investigated the effect of S1P on the collagen-induced platelet activation. S1P pretreatment markedly attenuated the collagen-induced aggregation. Co-stimulation with S1P and collagen suppressed collagen-induced platelet activation, but the effect was weaker than that of S1P-pretreatment. The collagen-stimulated secretion of platelet-derived growth factor (PDGF)-AB and the soluble CD40 ligand (sCD40L) release were significantly reduced by S1P. In addition, S1P suppressed the collagen-induced release of HSP27 as well as the phosphorylation of HSP27. S1P significantly suppressed the collagen-induced phosphorylation of p38 mitogen-activated protein kinase. S1P increased the levels of GTP-bound Gαi and GTP-bound Gα13 coupled to S1PPR1 and/or S1PR4. CYM50260, a selective S1PR4 agonist, but not SEW2871, a selective S1PR1 agonist, suppressed the collagen-stimulated platelet aggregation, PDGF-AB secretion and sCD40L release. In addition, CYM50260 reduced the release of phosphorylated-HSP27 by collagen as well as the phosphorylation of HSP27. The selective S1PR4 antagonist CYM50358, which failed to affect collagen-induced HSP27 phosphorylation, reversed the S1P-induced attenuation of HSP27 phosphorylation by collagen. These results strongly suggest that S1P inhibits the collagen-induced human platelet activation through S1PR4 but not S1PR1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Functional divergence of platelet protein kinase C (PKC) isoforms in thrombus formation on collagen.

    Science.gov (United States)

    Gilio, Karen; Harper, Matthew T; Cosemans, Judith M E M; Konopatskaya, Olga; Munnix, Imke C A; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D; Heemskerk, Johan W M; Poole, Alastair W

    2010-07-23

    Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent alpha-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCalpha and PKCbeta, whereas the novel isoform, PKC, negatively regulates these events. PKCdelta also negatively regulates thrombus formation but not alpha-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCalpha or PKCbeta showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKC. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen.

  16. Functional Divergence of Platelet Protein Kinase C (PKC) Isoforms in Thrombus Formation on Collagen*

    Science.gov (United States)

    Gilio, Karen; Harper, Matthew T.; Cosemans, Judith M. E. M.; Konopatskaya, Olga; Munnix, Imke C. A.; Prinzen, Lenneke; Leitges, Michael; Liu, Qinghang; Molkentin, Jeffery D.; Heemskerk, Johan W. M.; Poole, Alastair W.

    2010-01-01

    Arterial thrombosis, a major cause of myocardial infarction and stroke, is initiated by activation of blood platelets by subendothelial collagen. The protein kinase C (PKC) family centrally regulates platelet activation, and it is becoming clear that the individual PKC isoforms play distinct roles, some of which oppose each other. Here, for the first time, we address all four of the major platelet-expressed PKC isoforms, determining their comparative roles in regulating platelet adhesion to collagen and their subsequent activation under physiological flow conditions. Using mouse gene knock-out and pharmacological approaches in human platelets, we show that collagen-dependent α-granule secretion and thrombus formation are mediated by the conventional PKC isoforms, PKCα and PKCβ, whereas the novel isoform, PKCθ, negatively regulates these events. PKCδ also negatively regulates thrombus formation but not α-granule secretion. In addition, we demonstrate for the first time that individual PKC isoforms differentially regulate platelet calcium signaling and exposure of phosphatidylserine under flow. Although platelet deficient in PKCα or PKCβ showed reduced calcium signaling and phosphatidylserine exposure, these responses were enhanced in the absence of PKCθ. In summary therefore, this direct comparison between individual subtypes of PKC, by standardized methodology under flow conditions, reveals that the four major PKCs expressed in platelets play distinct non-redundant roles, where conventional PKCs promote and novel PKCs inhibit thrombus formation on collagen. PMID:20479008

  17. Nucleation control and inhibition of BaTiO3 films using hydrothermal-electrochemical method

    International Nuclear Information System (INIS)

    Escobar, Ivan; Silva, Carmen; Silva, Eric; Vargas, Tomas; Fuenzalida, Victor

    1999-01-01

    The microstructure of BaTiO 3 films on titanium by the hydrothermal-electrochemical method was investigated using a three electrode high pressure electrochemical cell in a 0.2 M Ba(OH) 2 electrolyte at 150 0 C. The spontaneous initial linked to pure hydrothermal BaTiO 3 formation can be inhibited by cathodically protecting titanium electrode since its immersion in the electrolyte. The application of initial nucleation pulses of varying the cathodic potentials affected the grain size of the deposit. It is suggested that the formation of a titanium oxide layers is a necessary step previous to the nucleation of BaTiO 3

  18. Collagen metabolism in obesity

    DEFF Research Database (Denmark)

    Rasmussen, M H; Jensen, L T; Andersen, T

    1995-01-01

    OBJECTIVE: To investigate the impact of obesity, fat distribution and weight loss on collagen turnover using serum concentrations of the carboxyterminal propeptide of type I procollagen (S-PICP) and the aminoterminal propeptide of type III pro-collagen (S-PIIINP) as markers for collagen turnover...... (r = 0.37; P = 0.004), height (r = 0.27; P = 0.04), waist circumference (r = 0.35; P = 0.007), as well as with WHR (r = 0.33; P = 0.01) and was inversely correlated to age (r = -0.40; P = 0.002). Compared with randomly selected controls from a large pool of healthy volunteers, the obese patients had...... restriction (P obesity and associated with body fat distribution, suggesting...

  19. Collagen as potential cell scaffolds for tissue engineering.

    Science.gov (United States)

    Annuar, N; Spier, R E

    2004-05-01

    Selections of collagen available commercially were tested for their biocompatibility as scaffold to promote cell growth in vitro via simple collagen fast test and cultivation of mammalian cells on the selected type of collagen. It was found that collagen type C9791 promotes the highest degree of aggregation as well as cells growth. This preliminary study also indicated potential use of collagen as scaffold in engineered tissue.

  20. A novel functional role of collagen glycosylation

    DEFF Research Database (Denmark)

    Jürgensen, Henrik J; Madsen, Daniel H; Ingvarsen, Signe

    2011-01-01

    Collagens make up the most abundant component of interstitial extracellular matrices and basement membranes. Collagen remodeling is a crucial process in many normal physiological events and in several pathological conditions. Some collagen subtypes contain specific carbohydrate side chains......, the function of which is poorly known. The endocytic collagen receptor urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180 plays an important role in matrix remodeling through its ability to internalize collagen for lysosomal degradation. uPARAP/Endo180 is a member of the mannose...... receptor protein family. These proteins all include a fibronectin type II domain and a series of C-type lectin-like domains, of which only a minor part possess carbohydrate recognition activity. At least two of the family members, uPARAP/Endo180 and the mannose receptor, interact with collagens...

  1. Enhanced Dupuytren's disease fibroblast populated collagen lattice contraction is independent of endogenous active TGF-β2

    Directory of Open Access Journals (Sweden)

    Howard Jeffrey

    2004-11-01

    Full Text Available Abstract Background Dupuytren's disease (DD is a debilitating fibro-proliferative disorder of the hand characterized by the appearance of fibrotic lesions (nodules and cords leading to flexion contractures of the fingers and loss of hand function. Although the molecular mechanism of DD is unknown, it has been suggested that transforming growth factor-β2 (TGF-β2 may play an important role in the underlying patho-physiology of the disease. The purpose of this study was to further explore this hypothesis by examining the effects of TGF-β2 on primary cell cultures derived from patient-matched disease and normal palmar fascia tissue using a three-dimensional collagen contraction assay. Methods Fibroblast-populated collagen lattice (FPCL contraction assays using primary cell cultures derived from diseased and control fascia of the same DD patients were studied in response to exogenous TGF-β2 and neutralizing anti-TGF-β2 antibodies. Results Contraction of the FPCLs occurred significantly faster and to a greater extent in disease cells compared to control cells. The addition of TGF-β2 enhanced the rate and degree of collagen contraction in a dose-dependent fashion for both control and diseased cells. Neutralizing anti-TGF-β2 antibodies abolished exogenous TGF-β2 stimulated collagen contraction, but did not inhibit the enhanced basal collagen contraction activity of disease FPCL cultures. Conclusions Although exogenous TGF-β2 stimulated both disease and control FPCL contraction, neutralizing anti-TGF-β2 antibodies did not affect the elevated basal collagen contraction activity of disease FPCLs, suggesting that the differences in the collagen contraction activity of control and disease FPCL cultures are not due to differences in the levels of endogenous TGF-β2 activity.

  2. [The genetics of collagen diseases].

    Science.gov (United States)

    Kaplan, J; Maroteaux, P; Frezal, J

    1986-01-01

    Heritable disorders of collagen include Ehler-Danlos syndromes (11 types are actually known), Larsen syndrome and osteogenesis imperfecta. Their clinical, genetic and biochemical features are reviewed. Marfan syndrome is closely related to heritable disorders of collagen.

  3. A detailed examination of platelet function inhibition by nitric oxide in platelet-rich plasma and whole blood.

    Science.gov (United States)

    Zimmermann, Robert; Krueger, Julia; Filipović, Milos R; Ivanović-Burmazović, Ivana; Calatzis, Andreas; Weiss, Dominik R; Eckstein, Reinhold

    2013-01-01

    The question of whether novel instruments such as multiple electrode aggregometry (MEA) can be used for measurement of the effects of nitric oxide (NO) on platelets (PLTs) has not been examined. Therefore, we compared the effects of NO concentrations (1, 10, and 100 microM) on the PLT aggregation response to ADP, arachidonic acid (AA), collagen, ristocetin, and thrombin receptor-activating peptide 6 (TRAP6) using light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA) and examined the effects of NO using the platelet function analyzer (PFA)-100. The response of PLTs to ADP and AA was strongly inhibited by all NO concentrations in LTA and MEA. The inhibition of the responses to ristocetin and collagen was detectable in MEA at lower NO concentrations than in LTA. However, the typically increasing lag phase between collagen addition and the aggregation response in the presence of NO was more obvious in LTA. TRAP caused a reproducible early response in the presence of NO in LTA which was followed by rapid PLT disaggregation, whereas even 100 microM NO did not inhibit the response to TRAP in MEA. Finally, NO prolonged the in-vitro bleeding time remarkably more in the PFA-100 collagen-epinephrin cartridge than in the collagen-ADP cartridge. Whole blood versus PLT rich plasma, citrate versus hirudin, and high versus low shear influenced the effects of NO. This shows that a careful selection of models and potentially a combination of different methods is appropriate for a differentiated evaluation of pharmacological or physiological mechanisms of NO-donors or of NO-inhibitors.

  4. Marine-derived collagen biomaterials from echinoderm connective tissues

    KAUST Repository

    Ferrario, Cinzia; Leggio, Livio; Leone, Roberta; Di Benedetto, Cristiano; Guidetti, Luca; Coccè , Valentina; Ascagni, Miriam; Bonasoro, Francesco; La Porta, Caterina A.M.; Candia Carnevali, M. Daniela; Sugni, Michela

    2016-01-01

    The use of marine collagens is a hot topic in the field of tissue engineering. Echinoderms possess unique connective tissues (Mutable Collagenous Tissues, MCTs) which can represent an innovative source of collagen to develop collagen barrier-membranes for Guided Tissue Regeneration (GTR). In the present work we used MCTs from different echinoderm models (sea urchin, starfish and sea cucumber) to produce echinoderm-derived collagen membranes (EDCMs). Commercial membranes for GTR or soluble/reassembled (fibrillar) bovine collagen substrates were used as controls. The three EDCMs were similar among each other in terms of structure and mechanical performances and were much thinner and mechanically more resistant than the commercial membranes. Number of fibroblasts seeded on sea-urchin membranes were comparable to the bovine collagen substrates. Cell morphology on all EDCMs was similar to that of structurally comparable (reassembled) bovine collagen substrates. Overall, echinoderms, and sea urchins particularly, are alternative collagen sources to produce efficient GTR membranes. Sea urchins display a further advantage in terms of eco-sustainability by recycling tissues from food wastes.

  5. Marine-derived collagen biomaterials from echinoderm connective tissues

    KAUST Repository

    Ferrario, Cinzia

    2016-03-31

    The use of marine collagens is a hot topic in the field of tissue engineering. Echinoderms possess unique connective tissues (Mutable Collagenous Tissues, MCTs) which can represent an innovative source of collagen to develop collagen barrier-membranes for Guided Tissue Regeneration (GTR). In the present work we used MCTs from different echinoderm models (sea urchin, starfish and sea cucumber) to produce echinoderm-derived collagen membranes (EDCMs). Commercial membranes for GTR or soluble/reassembled (fibrillar) bovine collagen substrates were used as controls. The three EDCMs were similar among each other in terms of structure and mechanical performances and were much thinner and mechanically more resistant than the commercial membranes. Number of fibroblasts seeded on sea-urchin membranes were comparable to the bovine collagen substrates. Cell morphology on all EDCMs was similar to that of structurally comparable (reassembled) bovine collagen substrates. Overall, echinoderms, and sea urchins particularly, are alternative collagen sources to produce efficient GTR membranes. Sea urchins display a further advantage in terms of eco-sustainability by recycling tissues from food wastes.

  6. COLOSTRUM-COLLAGEN-HYDROXYAPATITE COMPOSITE, AN EXCELLENT CANDIDATE BIOMATERIAL FOR BONE REPAIR AND BONE INFECTION MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Dio Nurdin Setiawan

    2014-05-01

    Full Text Available In the case ofbone fracture or defect after surgery, which is common in patients with bone cancer (osteosarcoma, it takes a long time for closure and it may cause an infection problem. The use ofcollagen-hydroxyapatite composite with a blend ofcolostrum as a scaffold is aimed to accelerate the process of osteoblast growth, inhibite the emergence of infections, and act as bone tissue repair material. The method used was the hydrogel formation process and freeze dry process to remove the solvent and to form pores. The composition of scaffold composite manufactured was 15% collagen, 75% hydroxyapatite and 10% colostrum. Combination ofscaffold collagen-hydroxyapatite-colostrum has quite reliable properties because SEM test showed that scaffold could bind to both and could bind to both and could form sufficient pores to provide enough place for bone cells (osteoblats to grow. The results of MTT assay revealed percentage of above 60%, which indicates that the material is not toxic. In conclusion, collagen-hydroxyapatite-colostrum combination is an excellent biomaterial candidate for bone repair and bone infection management.

  7. PVA/Polysaccharides Blended Films: Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Fábio E. F. Silva

    2013-01-01

    Full Text Available Blends of polyvinyl alcohol (PVA and angico gum (AG and/or cashew gum (CG were used to produce films by casting method. Morphological and mechanical properties of these films were studied and compared to the properties of a commercial collagen membrane of bovine origin (MBO. The films presented thickness varying from 70 to 140 μm (PVA/AG and 140 to 200 μm (PVA/CG. Macroscopic analysis showed that a PVA/CG film was very similar to MBO regarding the color and transparency. The higher values of tensile strength (TS and elastic modulus (EM were observed in the film. On the other hand, PVA/CG and PVA/CG-AG presented the highest value of percentage of elongation (E%. Pearson’s Correlation Analysis revealed a positive correlation between TS and EM and a negative correlation between E% and EM. The PVA/CG film presented mechanical properties very similar to MBO, with the advantage of a higher E% (11.96 than MBO (2.94. The properties of the PVA blended films depended on the polysaccharide added in the blend, as well as the acid used as a catalyst. However, all produced films presented interesting mechanical characteristics which enables several biotechnological applications.

  8. Determination of osteogenic or adipogenic lineages in muscle-derived stem cells (MDSCs) by a collagen-binding peptide (CBP) derived from bone sialoprotein (BSP)

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yoon Jung [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Lee, Jue Yeon [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Lee, Seung Jin [Department of Industrial Pharmacy, College of Pharmacy, Ewha Womans University, Seoul (Korea, Republic of); Chung, Chong-Pyoung, E-mail: ccpperio@snu.ac.kr [Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Department of Periodontology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul (Korea, Republic of); Park, Yoon Jeong, E-mail: parkyj@snu.ac.kr [Dental Regenerative Biotechnology Major, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Research Institute, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer CBP sequence is identified from BSP and has collagen binding activity. Black-Right-Pointing-Pointer CBP directly activates the MAPK signaling, especially ERK1/2. Black-Right-Pointing-Pointer CBP increase osteoblastic differentiation by the activation of Runx2. Black-Right-Pointing-Pointer CBP decrease adipogenic differentiation by the inhibition of PPAR{gamma}. -- Abstract: Bone sialoprotein (BSP) is a mineralized, tissue-specific, non-collagenous protein that is normally expressed only in mineralized tissues such as bone, dentin, cementum, and calcified cartilage, and at sites of new mineral formation. The binding of BSP to collagen is thought to be important for initiating bone mineralization and bone cell adhesion to the mineralized matrix. Several recent studies have isolated stem cells from muscle tissue, but their functional properties are still unclear. In this study, we examined the effects of a synthetic collagen-binding peptide (CBP) on the differentiation efficiency of muscle-derived stem cells (MDSCs). The CBP sequence (NGVFKYRPRYYLYKHAYFYPHLKRFPVQ) corresponds to residues 35-62 of bone sialoprotein (BSP), which are located within the collagen-binding domain in BSP. Interestingly, this synthetic CBP inhibited adipogenic differentiation but increased osteogenic differentiation in MDSCs. The CBP also induced expression of osteoblastic marker proteins, including alkaline phosphatase (ALP), type I collagen, Runt-related transcription factor 2 (Runx2), and osteocalcin; prevented adipogenic differentiation in MDSCs; and down-regulated adipose-specific mRNAs, such as adipocyte protein 2 (aP2) and peroxisome proliferator-activated receptor {gamma}. The CBP increased Extracellular signal-regulated kinases (ERK) 1/2 protein phosphorylation, which is important in lineage determination. These observations suggest that this CBP determines the osteogenic or adipogenic lineage in MDSCs by activating ERK1/2. Taken together, a

  9. Ductile sliding between mineral crystals followed by rupture of collagen crosslinks: experimentally supported micromechanical explanation of bone strength.

    Science.gov (United States)

    Fritsch, Andreas; Hellmich, Christian; Dormieux, Luc

    2009-09-21

    There is an ongoing discussion on how bone strength could be explained from its internal structure and composition. Reviewing recent experimental and molecular dynamics studies, we here propose a new vision on bone material failure: mutual ductile sliding of hydroxyapatite mineral crystals along layered water films is followed by rupture of collagen crosslinks. In order to cast this vision into a mathematical form, a multiscale continuum micromechanics theory for upscaling of elastoplastic properties is developed, based on the concept of concentration and influence tensors for eigenstressed microheterogeneous materials. The model reflects bone's hierarchical organization, in terms of representative volume elements for cortical bone, for extravascular and extracellular bone material, for mineralized fibrils and the extrafibrillar space, and for wet collagen. In order to get access to the stress states at the interfaces between crystals, the extrafibrillar mineral is resolved into an infinite amount of cylindrical material phases oriented in all directions in space. The multiscale micromechanics model is shown to be able to satisfactorily predict the strength characteristics of different bones from different species, on the basis of their mineral/collagen content, their intercrystalline, intermolecular, lacunar, and vascular porosities, and the elastic and strength properties of hydroxyapatite and (molecular) collagen.

  10. Inhibitory assay for degradation of collagen IV by cathepsin B with a surface plasmon resonance sensor.

    Science.gov (United States)

    Shoji, Atsushi; Suenaga, Yumiko; Hosaka, Atsushi; Ishida, Yuuki; Yanagida, Akio; Sugawara, Masao

    2017-10-25

    We describe a simple method for evaluating the inhibition of collagen IV degradation by cathepsin B with a surface plasmon resonance (SPR) biosensor. The change in the SPR signal decreased with an increase in the concentration of cathepsin B inhibitors. The order of the inhibitory constant (Ki) obtained by the SPR method was CA074Me≈Z-Phe-Phe-FMK < leupeptin. This order was different from that obtained by benzyloxycarbonyl-Phe-Phe-Fluoromethylketone (Z-Phe-Phe-FMK) as a peptide substrate. The comparison of Ki suggested that CA074 and Z-Phe-Phe-FMK inhibited exopeptidase activity, and leupeptin inhibited the endopeptidase activity of cathepsin B more strongly. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation.

    Science.gov (United States)

    Jang, Ja-Young; Kim, Tae-Su; Cai, Jingmei; Kim, Jihyun; Kim, Youngeun; Shin, Kyungha; Kim, Kwang Sei; Park, Sung Kyeong; Lee, Sung-Pyo; Choi, Ehn-Kyoung; Rhee, Man Hee; Kim, Yun-Bae

    2013-12-01

    The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

  12. Thrombin induces epithelial-mesenchymal transition and collagen production by retinal pigment epithelial cells via autocrine PDGF-receptor signaling.

    Science.gov (United States)

    Bastiaans, Jeroen; van Meurs, Jan C; van Holten-Neelen, Conny; Nagtzaam, Nicole M A; van Hagen, P Martin; Chambers, Rachel C; Hooijkaas, Herbert; Dik, Willem A

    2013-12-19

    De-differentiation of RPE cells into mesenchymal cells (epithelial-mesenchymal transition; EMT) and associated collagen production contributes to development of proliferative vitreoretinopathy (PVR). In patients with PVR, intraocular coagulation cascade activation occurs and may play an important initiating role. Therefore, we examined the effect of the coagulation proteins factor Xa and thrombin on EMT and collagen production by RPE cells. Retinal pigment epithelial cells were stimulated with factor Xa or thrombin and the effect on zonula occludens (ZO)-1, α-smooth muscle actin (α-SMA), collagen, and platelet-derived growth factor (PDGF)-B were determined by real-time quantitative-polymerase chain reaction (RQ-PCR), immunofluorescence microscopy, and HPLC and ELISA for collagen and PDGF-BB in culture supernatants, respectively. PDGF-receptor activation was determined by phosphorylation analysis and inhibition studies using the PDGF-receptor tyrosine kinase inhibitor AG1296. Thrombin reduced ZO-1 gene expression (P production of α-SMA and collagen increased. In contrast to thrombin, factor Xa hardly stimulated EMT by RPE. Thrombin clearly induced PDGF-BB production and PDGF-Rβ chain phosphorylation in RPE. Moreover, AG1296 significantly blocked the effect of thrombin on EMT and collagen production. Our findings demonstrate that thrombin is a potent inducer of EMT by RPE via autocrine activation of PDGF-receptor signaling. Coagulation cascade-induced EMT of RPE may thus contribute to the formation of fibrotic retinal membranes in PVR and should be considered as treatment target in PVR.

  13. Protease-activatable collagen targeting based on protein cyclization

    NARCIS (Netherlands)

    Breurken, M.; Lempens, E.H.M.; Merkx, M.

    2010-01-01

    Threading collagen through a protein needle: The collagen-binding protein CNA35 operates by wrapping itself around the collagen triple helix. By connecting the N and C termini through an MMP recognition sequence, a dual-specific MMP-sensitive collagen-targeting ligand is obtained that can be used

  14. Study of collagen metabolism after β radiation injury

    International Nuclear Information System (INIS)

    Zhou Yinghui; Xulan; Wu Shiliang; Zhang Xueguang; Chen Liesong

    2000-01-01

    Objective: To investigate the change of collagen metabolism and it's regulation after β radiation. Method: The animal model of β radiation injury was established by the β radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 was tested. The contents of TGF-β 1 , IL-6 were also detected. Results: After exposure to β radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-β 1 , IL-6 increased. Conclusion: The changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-β 1 and IL-6 may be essential in the regulation of the collagen metabolism

  15. Collagen Conduit Versus Microsurgical Neurorrhaphy

    DEFF Research Database (Denmark)

    Boeckstyns, Michel; Sørensen, Allan Ibsen; Viñeta, Joaquin Fores

    2013-01-01

    To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair.......To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair....

  16. Ionizing radiation modulates the exposure of the HUIV26 cryptic epitope within collagen type IV during angiogenesis

    International Nuclear Information System (INIS)

    Brooks, Peter C.; Roth, Jennifer M.; Lymberis, Stella C.; DeWyngaert, Keith; Broek, Daniel; Formenti, Silvia C.

    2002-01-01

    Purpose: The majority of the research on the biologic effects of ionizing radiation has focused on the impact of radiation on cells in terms of gene expression, DNA damage, and cytotoxicity. In comparison, little information is available concerning the direct effects of radiation on the extracellular microenvironment, specifically the extracellular matrix and its main component, collagen. We have developed a series of monoclonal antibodies that bind to cryptic epitopes of collagen Type IV that are differentially exposed during matrix remodeling and are key mediators of angiogenesis. We have hypothesized that ionizing radiation might affect the process of angiogenesis through a direct effect on the extracellular matrix and specifically on collagen Type IV. Methods and Materials: Angiogenesis was induced in a chick chorioallantoic membrane (CAM) model; 24 h later, a single-dose treatment with ionizing radiation (0.5, 5, and 20 cGy) was administered. Angiogenesis was assessed, and the exposure of two cryptic regulatory epitopes within collagen Type IV (HUI77 and HUIV26) was studied in vitro by solid-phase ELISA and in vivo by immunofluorescence staining. Results: A dose-dependent reduction of angiogenesis with maximum inhibition (85%-90%) occurring at 20 cGy was demonstrated in the CAM model. Exposure of the cryptic HUIV26 site, an angiogenesis control element, was inhibited both in vitro and in vivo by the same radiation dose, whereas little if any change was observed for the HUI77 cryptic epitope. Conclusions: A dose-dependent alteration of the functional exposure of the HUIV26 cryptic epitope is induced by radiation in vitro and in the CAM model in vivo. This radiation-induced change in protein structure and function may contribute to the inhibitory effects of ionizing radiation on new blood vessel growth and warrants further studies in other models

  17. Collagen targeting using multivalent protein-functionalized dendrimers

    NARCIS (Netherlands)

    Breurken, M.; Lempens, E.H.M.; Temming, R.P.; Helms, B.A.; Meijer, E.W.; Merkx, M.

    2011-01-01

    Collagen is an attractive marker for tissue remodeling in a variety of common disease processes. Here we report the preparation of protein dendrimers as multivalent collagen targeting ligands by native chemical ligation of the collagen binding protein CNA35 to cysteine-functionalized dendritic

  18. Building blocks of Collagen based biomaterial devices

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

  19. Polarized Raman anisotropic response of collagen in tendon: towards 3D orientation mapping of collagen in tissues.

    Directory of Open Access Journals (Sweden)

    Leonardo Galvis

    Full Text Available In this study, polarized Raman spectroscopy (PRS was used to characterize the anisotropic response of the amide I band of collagen as a basis for evaluating three-dimensional collagen fibril orientation in tissues. Firstly, the response was investigated theoretically by applying classical Raman theory to collagen-like peptide crystal structures. The theoretical methodology was then tested experimentally, by measuring amide I intensity anisotropy in rat tail as a function of the orientation of the incident laser polarization. For the theoretical study, several collagen-like triple-helical peptide crystal structures obtained from the Protein Data Bank were rotated "in plane" and "out of plane" to evaluate the role of molecular orientation on the intensity of the amide I band. Collagen-like peptides exhibit a sinusoidal anisotropic response when rotated "in plane" with respect to the polarized incident laser. Maximal intensity was obtained when the polarization of the incident light is perpendicular to the molecule and minimal when parallel. In the case of "out of plane" rotation of the molecular structure a decreased anisotropic response was observed, becoming completely isotropic when the structure was perpendicular to the plane of observation. The theoretical Raman response of collagen was compared to that of alpha helical protein fragments. In contrast to collagen, alpha helices have a maximal signal when incident light is parallel to the molecule and minimal when perpendicular. For out-of-plane molecular orientations alpha-helix structures display a decreased average intensity. Results obtained from experiments on rat tail tendon are in excellent agreement with the theoretical predictions, thus demonstrating the high potential of PRS for experimental evaluation of the three-dimensional orientation of collagen fibers in biological tissues.

  20. Changes in guinea-pig dermal collagen during development

    International Nuclear Information System (INIS)

    Shuttleworth, C.A.; Forrest, L.

    1975-01-01

    Guinea-pig dermis was digested with pepsin and the solubilized collagen molecules separated by differential salt precipitation at pH 7.5. Differences in subunit composition and amino acid analysis were noted between type I and type III collagen. Incorporation of radioactive proline into the developing foetus enabled isolation of labelled type I and type III collagens. Comparison of the specific activity of the isolated collagen molecules showed that type III collagen had a high specific activity in the early stages of foetal development, which decreased dramatically during foetal development. The specific activity of pepsin-solubilized type I collagen remained fairly constant during foetal development. (orig.) [de

  1. Targeted inhibition of disheveled PDZ domain via NSC668036 depresses fibrotic process

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cong, E-mail: wangcongweihai@126.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Dai, Jinghong, E-mail: daijinghongnew@163.com [Department of Respiratory Medicine, Nanjing Drum Tower Hospital Affiliated to Medical School of Nanjing University (China); Sun, Zhaorui, E-mail: lanseyunduan@163.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Department of Emergency, Jinling Hospital, Medical School, Nanjing University, Nanjing, Jiangsu 210093 (China); Shi, Chaowen, E-mail: willscw@live.cn [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Cao, Honghui, E-mail: caohonghui92@gmail.com [Immunology and Reproduction Biology Laboratory, Medical School, Nanjing University, Nanjing, Hankou Road 22, Jiangsu 210093 (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093 (China); State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, Jiangsu 210093 (China); and others

    2015-02-01

    In this study, we determined the effects of transforming growth factor-beta (TGF-β) and Wnt/β-catenin signaling on myofibroblast differentiation of NIH/3T3 fibroblasts in vitro and evaluated the therapeutic efficacy of NSC668036 in bleomycin-induced pulmonary fibrosis murine model. In vitro study, NSC668036, a small organic inhibitor of the PDZ domain in Dvl, suppressed β-catenin-driven gene transcription and abolished TGF-β1-induced migration, expression of collagen I and α-smooth muscle actin (α-SMA) in fibroblasts. In vivo study, we found that NSC668036 significantly suppressed accumulation of collagen I, α-SMA, and TGF-β1 but increased the expression of CK19, Occludin and E-cadherin that can inhibit pulmonary fibrogenesis. Because fibrotic lung exhibit aberrant activation of Wnt/β-catenin signaling, these data collectively suggest that inhibition of Wnt/β-catenin signaling at the Dvl level may be an effective approach to the treatment of fibrotic lung diseases. - Highlights: • NSC668036 inhibited the proliferation and migration of NIH/3T3 fibroblasts. • NSC668036 suppressed the Wnt/β-catenin signaling pathway. • TGF-β-induced stimulation of profibrotic responses were inhibited by NSC668036. • NSC668036 can inhibit the development of bleomycin-induced pulmonary fibrosis.

  2. Collagen-based wound dressings for the treatment of diabetes-related foot ulcers: a systematic review

    Directory of Open Access Journals (Sweden)

    Holmes C

    2013-01-01

    Full Text Available Crystal Holmes,1 James S Wrobel,1 Mark P MacEachern,2 Blaise R Boles31Department of Internal Medicine, University of Michigan Medical School, 2A Alfred Taubman Health Sciences Library, University of Michigan, 3Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USABackground: Diabetic foot ulcers are a major source of morbidity, limb loss, and mortality. A prolonged inflammatory response, extracellular matrix degradation irregularities, and increased bacteria presence have all been hypothesized as major contributing factors in the delayed healing of diabetic wounds. Collagen components such as fibroblast and keratinocytes are fundamental to the process of wound healing and skin formation. Wound dressings that contain collagen products create a biological scaffold matrix that supports the regulation of extracellular components and promotes wound healing.Methods: A systematic review of studies reporting collagen wound dressings used in the treatment of Diabetic foot ulcers was conducted. Comprehensive searches were run in Ovid MEDLINE, PubMed, EMBASE, and ISI Web of Science to capture citations pertaining to the use of collagen wound dressings in the treatment of diabetic foot ulcers. The searches were limited to human studies reported in English.Results: Using our search strategy, 26 papers were discussed, and included 13 randomized designs, twelve prospective cohorts, and one retrospective cohort, representing 2386 patients with diabetic foot ulcers. Our design was not a formal meta-analysis. In those studies where complete epithelialization, 58% of collagen-treated wounds completely healed (weighted mean 67%. Only 23% of studies reported control group healing with 29% healing (weighted mean 11% described for controls.Conclusion: Collagen- based wound dressings can be an effective tool in the healing of diabetic foot wounds. The current studies show an overall increase in healing rates despite

  3. Immune responses to implanted human collagen graft in rats

    International Nuclear Information System (INIS)

    Quteish, D.; Dolby, A.E.

    1991-01-01

    Immunity to collagen implants may be mediated by cellular and humoral immune responses. To examine the possibility of such immunological reactivity and crossreactivity to collagen, 39 Sprague-Dawley rats (female, 10 weeks old, approximately 250 g wt) were implanted subcutaneously at thigh sites with crosslinked, freeze-dried human placental type I collagen grafts (4x4x2 mm) which had been irradiated (520 Gray) or left untreated. Blood was obtained by intracardiac sampling prior to implantation or from normal rats, and at various times afterwards when the animals were sacrificed. The sera from these animals were examined for circulating antibodies to human, bovine and rat tail (type I) collagens by enzyme-linked immunosorbent assay (ELISA). Also, the lymphoblastogenic responses of spleen lymphocytes from the irradiated collagen-implanted animals were assessed in culture by measuring thymidine uptake with autologous and normal rat sera in the presence of human bovine type I collagens. Implantation of the irradiated and non-irradiated collagen graft in rats led to a significant increase in the level of circulating antibodies to human collagen. Also antibody to bovine and rat tail collagens was detectable in the animals implanted with irradiated collagen grafts but at a lower level than the human collagen. There was a raised lymphoblastogenic response to both human and bovine collagens. The antibody level and lymphoblastogenesis to the tested collagens gradually decreased towards the end of the post-implantation period. (author)

  4. Uniform spatial distribution of collagen fibril radii within tendon implies local activation of pC-collagen at individual fibrils

    Science.gov (United States)

    Rutenberg, Andrew D.; Brown, Aidan I.; Kreplak, Laurent

    2016-08-01

    Collagen fibril cross-sectional radii show no systematic variation between the interior and the periphery of fibril bundles, indicating an effectively constant rate of collagen incorporation into fibrils throughout the bundle. Such spatially homogeneous incorporation constrains the extracellular diffusion of collagen precursors from sources at the bundle boundary to sinks at the growing fibrils. With a coarse-grained diffusion equation we determine stringent bounds, using parameters extracted from published experimental measurements of tendon development. From the lack of new fibril formation after birth, we further require that the concentration of diffusing precursors stays below the critical concentration for fibril nucleation. We find that the combination of the diffusive bound, which requires larger concentrations to ensure homogeneous fibril radii, and lack of nucleation, which requires lower concentrations, is only marginally consistent with fully processed collagen using conservative bounds. More realistic bounds may leave no consistent concentrations. Therefore, we propose that unprocessed pC-collagen diffuses from the bundle periphery followed by local C-proteinase activity and subsequent collagen incorporation at each fibril. We suggest that C-proteinase is localized within bundles, at fibril surfaces, during radial fibrillar growth. The much greater critical concentration of pC-collagen, as compared to fully processed collagen, then provides broad consistency between homogeneous fibril radii and the lack of fibril nucleation during fibril growth.

  5. [Three-dimensional parallel collagen scaffold promotes tendon extracellular matrix formation].

    Science.gov (United States)

    Zheng, Zefeng; Shen, Weiliang; Le, Huihui; Dai, Xuesong; Ouyang, Hongwei; Chen, Weishan

    2016-03-01

    To investigate the effects of three-dimensional parallel collagen scaffold on the cell shape, arrangement and extracellular matrix formation of tendon stem cells. Parallel collagen scaffold was fabricated by unidirectional freezing technique, while random collagen scaffold was fabricated by freeze-drying technique. The effects of two scaffolds on cell shape and extracellular matrix formation were investigated in vitro by seeding tendon stem/progenitor cells and in vivo by ectopic implantation. Parallel and random collagen scaffolds were produced successfully. Parallel collagen scaffold was more akin to tendon than random collagen scaffold. Tendon stem/progenitor cells were spindle-shaped and unified orientated in parallel collagen scaffold, while cells on random collagen scaffold had disorder orientation. Two weeks after ectopic implantation, cells had nearly the same orientation with the collagen substance. In parallel collagen scaffold, cells had parallel arrangement, and more spindly cells were observed. By contrast, cells in random collagen scaffold were disorder. Parallel collagen scaffold can induce cells to be in spindly and parallel arrangement, and promote parallel extracellular matrix formation; while random collagen scaffold can induce cells in random arrangement. The results indicate that parallel collagen scaffold is an ideal structure to promote tendon repairing.

  6. Imaging collagen type I fibrillogenesis with high spatiotemporal resolution

    International Nuclear Information System (INIS)

    Stamov, Dimitar R; Stock, Erik; Franz, Clemens M; Jähnke, Torsten; Haschke, Heiko

    2015-01-01

    Fibrillar collagens, such as collagen type I, belong to the most abundant extracellular matrix proteins and they have received much attention over the last five decades due to their large interactome, complex hierarchical structure and high mechanical stability. Nevertheless, the collagen self-assembly process is still incompletely understood. Determining the real-time kinetics of collagen type I formation is therefore pivotal for better understanding of collagen type I structure and function, but visualising the dynamic self-assembly process of collagen I on the molecular scale requires imaging techniques offering high spatiotemporal resolution. Fast and high-speed scanning atomic force microscopes (AFM) provide the means to study such processes on the timescale of seconds under near-physiological conditions. In this study we have applied fast AFM tip scanning to study the assembly kinetics of fibrillar collagen type I nanomatrices with a temporal resolution reaching eight seconds for a frame size of 500 nm. By modifying the buffer composition and pH value, the kinetics of collagen fibrillogenesis can be adjusted for optimal analysis by fast AFM scanning. We furthermore show that amplitude-modulation imaging can be successfully applied to extract additional structural information from collagen samples even at high scan rates. Fast AFM scanning with controlled amplitude modulation therefore provides a versatile platform for studying dynamic collagen self-assembly processes at high resolution. - Highlights: • Continuous non-invasive time-lapse investigation of collagen I fibrillogenesis in situ. • Imaging of collagen I self-assembly with high spatiotemporal resolution. • Application of setpoint modulation to study the hierarchical structure of collagen I. • Observing real-time formation of the D-banding pattern in collagen I

  7. Imaging collagen type I fibrillogenesis with high spatiotemporal resolution

    Energy Technology Data Exchange (ETDEWEB)

    Stamov, Dimitar R, E-mail: stamov@jpk.com [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany); Stock, Erik [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany); Franz, Clemens M [DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1a, 76131 Karlsruhe (Germany); Jähnke, Torsten; Haschke, Heiko [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany)

    2015-02-15

    Fibrillar collagens, such as collagen type I, belong to the most abundant extracellular matrix proteins and they have received much attention over the last five decades due to their large interactome, complex hierarchical structure and high mechanical stability. Nevertheless, the collagen self-assembly process is still incompletely understood. Determining the real-time kinetics of collagen type I formation is therefore pivotal for better understanding of collagen type I structure and function, but visualising the dynamic self-assembly process of collagen I on the molecular scale requires imaging techniques offering high spatiotemporal resolution. Fast and high-speed scanning atomic force microscopes (AFM) provide the means to study such processes on the timescale of seconds under near-physiological conditions. In this study we have applied fast AFM tip scanning to study the assembly kinetics of fibrillar collagen type I nanomatrices with a temporal resolution reaching eight seconds for a frame size of 500 nm. By modifying the buffer composition and pH value, the kinetics of collagen fibrillogenesis can be adjusted for optimal analysis by fast AFM scanning. We furthermore show that amplitude-modulation imaging can be successfully applied to extract additional structural information from collagen samples even at high scan rates. Fast AFM scanning with controlled amplitude modulation therefore provides a versatile platform for studying dynamic collagen self-assembly processes at high resolution. - Highlights: • Continuous non-invasive time-lapse investigation of collagen I fibrillogenesis in situ. • Imaging of collagen I self-assembly with high spatiotemporal resolution. • Application of setpoint modulation to study the hierarchical structure of collagen I. • Observing real-time formation of the D-banding pattern in collagen I.

  8. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  9. Adherence, proliferation and collagen turnover by human fibroblasts seeded into different types of collagen sponges

    NARCIS (Netherlands)

    Middelkoop, E.; de Vries, H. J.; Ruuls, L.; Everts, V.; Wildevuur, C. H.; Westerhof, W.

    1995-01-01

    We describe an in vitro model that we have used to evaluate dermal substitutes and to obtain data on cell proliferation, the rate of degradation of the dermal equivalent, contractibility and de novo synthesis of collagen. We tested three classes of collagenous materials: (1) reconstituted

  10. ADHERENCE, PROLIFERATION AND COLLAGEN TURNOVER BY HUMAN FIBROBLASTS SEEDED INTO DIFFERENT TYPES OF COLLAGEN SPONGES

    NARCIS (Netherlands)

    MIDDELKOOP, E; DEVRIES, HJC; RUULS, L; EVERTS, [No Value; WILDEVUUR, CHR; WESTERHOF, W

    We describe an in vitro model that we have used to evaluate dermal substitutes and to obtain data on cell proliferation, the rate of degradation of the dermal equivalent, contractibility and de novo synthesis of collagen. We tested three classes of collagenous materials: (1) reconstituted

  11. Inhibition of chondroitin sulfate glycosaminoglycans incorporation affected odontoblast differentiation in cultured embryonic mouse molars.

    Science.gov (United States)

    Liu, Lipei; Chen, Weiting; Li, Lefeng; Xu, Fangfang; Jiang, Beizhan

    2017-12-01

    Chondroitin sulfate proteoglycan (CSPG) is an important component of extracellular matrix (ECM), it is composed of a core protein and one or more chondroitin sulfate glycosaminoglycan side chains (CS-GAGs). To investigate the roles of its CS-GAGs in dentinogenesis, the mouse mandibular first molar tooth germs at early bell stage were cultivated with or without β-xyloside. As expected, the CS-GAGs were inhibited on their incorporation to CSPGs by β-xyloside, accompanied by the change of morphology of the cultured tooth germs. The histological results and the transmission electron microscopy (TEM) investigation indicated that β-xyloside exhibited obvious inhibiting effects on odontoblasts differentiation compared with the control group. Meanwhile the results of immunohistochemistry, in situ hybridization and quantitative RT-PCR for type I collagen, dentin matrix acidic phosphoprotein 1 and dentin sialophosphoprotein, the products of differentiated odontoblasts, further proved that odontoblasts differentiation was inhibited. Collagen fibers detected in TEM decreased and arranged in disorder as well. Thus we conclude that the inhibition of CS-GAGs incorporation to CSPGs can affect odontoblast differentiation in cultured embryonic mouse molars.

  12. Discoidin Domain Receptor 1 Mediates Myosin-Dependent Collagen Contraction

    Directory of Open Access Journals (Sweden)

    Nuno M. Coelho

    2017-02-01

    Full Text Available Discoidin domain receptor 1 (DDR1 is a tyrosine kinase collagen adhesion receptor that mediates cell migration through association with non-muscle myosin IIA (NMIIA. Because DDR1 is implicated in cancer fibrosis, we hypothesized that DDR1 interacts with NMIIA to enable collagen compaction by traction forces. Mechanical splinting of rat dermal wounds increased DDR1 expression and collagen alignment. In periodontal ligament of DDR1 knockout mice, collagen mechanical reorganization was reduced >30%. Similarly, cultured cells with DDR1 knockdown or expressing kinase-deficient DDR1d showed 50% reduction of aligned collagen. Tractional remodeling of collagen was dependent on DDR1 clustering, activation, and interaction of the DDR1 C-terminal kinase domain with NMIIA filaments. Collagen remodeling by traction forces, DDR1 tyrosine phosphorylation, and myosin light chain phosphorylation were increased on stiff versus soft substrates. Thus, DDR1 clustering, activation, and interaction with NMIIA filaments enhance the collagen tractional remodeling that is important for collagen compaction in fibrosis.

  13. Application of 5-Fluorouracil-Polycaprolactone Sustained-Release Film in Ahmed Glaucoma Valve Implantation Inhibits Postoperative Bleb Scarring in Rabbit Eyes.

    Science.gov (United States)

    Bi, Xiu-Zeng; Pan, Wei-Hua; Yu, Xin-Ping; Song, Zong-Ming; Ren, Zeng-Jin; Sun, Min; Li, Cong-Hui; Nan, Kai-Hui

    2015-01-01

    This study was designed to investigate whether 5-fluorouracil (5-Fu)-polycaprolactone sustained-release film in Ahmed glaucoma valve implantation inhibits postoperative bleb scarring in rabbit eyes. Eighteen New Zealand white rabbits were randomly divided into three groups (A, B and C; n = 6 per group). Group A received combined 5-Fu-polycaprolactone sustained-release film application and Ahmed glaucoma valve implantation, group B received local infiltration of 5-Fu and Ahmed glaucoma valve implantation, and group C received Ahmed glaucoma valve implantation. Postoperative observations were made of the anterior segment, intraocular pressure, central anterior chamber depth, blebs, drainage tube, and accompanying ciliary body detachment. The pathology of the blebs and surrounding tissues were observed at month 3 postoperatively. We revealed that the 5-Fu-polycaprolactone sustained-release film maintained a release concentration range of 13.7 ± 0.12 to 37.41 ± 0.47 μg/ml over three months in vitro. Postoperatively, diffuse blebs with ridges were found in all eyes in group A, two blebs were observed in group B, and no bleb formation was present in group C. The postoperative central anterior chamber depth in group A was significantly less than that of the other two groups. The postoperative intraocular pressure of group A stabilized at 6.33-8.67 mmHg, whereas that of group C gradually remained at 7.55-10.02 mmHg. The histopathology showed that the fibrous tissue thickness of the blebs in group A was significantly thinner than that of the other groups. We conclude that the 5-Fu-polycaprolactone sustained-release film had a sustained drug release effect, which promoted the inhibition of bleb scarring after Ahmed glaucoma valve implantation.

  14. A New Kind of Biomaterials-Bullfrog Skin Collagen

    Institute of Scientific and Technical Information of China (English)

    He LI; Bai Ling LIU; Hua Lin CHEN; Li Zhen GAO

    2003-01-01

    Pepsin-soluble collagen was prepared from bullfrog skin and partially characterized. This study revealed interesting differences, such as molecular weight, amino acid composition, denaturation temperature (Td), in the frog skin collagen when compared to the known vertebrate collagens. This study gives hints that bullfrog skin can be a potential, safe alternative source of collagen from cattle for use in various fields.

  15. Engineering endostatin-producing cartilaginous constructs for cartilage repair using nonviral transfection of chondrocyte-seeded and mesenchymal-stem-cell-seeded collagen scaffolds.

    Science.gov (United States)

    Jeng, Lily; Olsen, Bjorn R; Spector, Myron

    2010-10-01

    Although there is widespread recognition of the importance of angiogenesis in tissue repair, there is little work on the inhibition of angiogenesis in the context of tissue engineering of naturally avascular tissues, like articular cartilage. The objective was to engineer a collagen-scaffold-based cartilaginous construct overexpressing a potent antiangiogenic factor, endostatin, using nonviral transfection. Endostatin-plasmid-supplemented collagen scaffolds were seeded with mesenchymal stem cells and chondrocytes and cultured for 20–22 days. The effects of the following variables on endostatin expression and chondrogenesis were examined: collagen scaffold material, method of nonviral vector incorporation, plasmid load, culture medium, and oxygen tension. An increase and peak of endostatin protein was observed during the first week of culture, followed by a decrease to low levels, suggesting that overexpression of endostatin could be sustained for several days using the nonviral vector. The amount of endostatin produced was tunable with the external factors. Chondrogenesis was observed in the engineered constructs cultured in chondrogenic medium at the 3-week time point, demonstrating that endostatin did not inhibit the chondrogenic potential of mesenchymal stem cells or the general viability of the cells. The ability to engineer endostatin-expressing cartilaginous constructs will be of value for future work exercising regulatory control of angiogenesis in cartilage repair.

  16. Anti-Inflammatory Effects of Licorice and Roasted Licorice Extracts on TPA-Induced Acute Inflammation and Collagen-Induced Arthritis in Mice

    Directory of Open Access Journals (Sweden)

    Ki Rim Kim

    2010-01-01

    Full Text Available The anti-inflammatory activity of licorice (LE and roated licorice (rLE extracts determined in the murine phorbol ester-induced acute inflammation model and collagen-induced arthritis (CIA model of human rheumatoid arthritis. rLE possessed greater activity than LE in inhibiting phorbol ester-induced ear edema. Oral administration of LE or rLE reduced clinical arthritis score, paw swelling, and histopathological changes in a murine CIA. LE and rLE decreased the levels of proinflammatory cytokines in serum and matrix metalloproteinase-3 expression in the joints. Cell proliferation and cytokine secretion in response to type II collagen or lipopolysaccharide stimulation were suppressed in spleen cells from LE or rLE-treated CIA mice. Furthermore, LE and rLE treatment prevented oxidative damages in liver and kidney tissues of CIA mice. Taken together, LE and rLE have benefits in protecting against both acute inflammation and chronic inflammatory conditions including rheumatoid arthritis. rLE may inhibit the acute inflammation more potently than LE.

  17. Measurement of skeletal muscle collagen breakdown by microdialysis

    DEFF Research Database (Denmark)

    Miller, B F; Ellis, D; Robinson, M M

    2011-01-01

    Exercise increases the synthesis of collagen in the extracellular matrix of skeletal muscle. Breakdown of skeletal muscle collagen has not yet been determined because of technical limitations. The purpose of the present study was to use local sampling to determine skeletal muscle collagen breakdown...... collagen breakdown 17–21 h post-exercise, and our measurement of OHP using GC–MS was in agreement with traditional assays....

  18. A case report of central toxic keratopathy in a patient post TransPRK (followed by corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Davey N

    2017-04-01

    Full Text Available Nicholas Davey, Ioannis M Aslanides, Vasilis Selimis Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece Purpose: The purpose of this article is to report a case of central toxic keratopathy in a patient post transepithelial photorefractive keratectomy (TransPRK, followed immediately by corneal collagen cross-linking.Methods: This article describes the case of a 26-year-old male after bilateral aberration-free, TransPRK laser (Schwind Amaris 750S. The procedure was performed for compound myopic astigmatism in November 2015, followed immediately by accelerated corneal collagen cross-linking for early keratoconus.Results: From day 3 post-op, tear film debris underneath both contact lenses with corneal haze and early, progressive central anterior stromal opacity formation only in the left eye were noted. At 2 weeks post-op, the left eye was noted to have a significant hyperopic shift with central corneal thinning in the anterior stroma. A central anterior stromal dense opacity had formed in the left eye with the surrounding superficial stromal haze. As of month 2, the opacity gradually started to improve in size and density. The hyperopic shift peaked at 2 months and continued to improve, largely due to epithelial compensation with a gradual recovery of stromal thickness.Conclusion: The question remains as to what provokes the typical central corneal necrosis/thinning in central toxic keratopathy. We hypothesize that the space between the contact lens and the corneal surface post TransPRK is prone to a “pseudo-interface pathology” that could mimic diffuse lamellar keratitis-like pathology. Suboptimal lid hygiene, resulting in tear film combinations of bacteria, inflammatory cells, matrix metalloproteinases and other proteolytic enzymes, contributes to the degradation of vulnerable, exposed collagen stromal tissue post TransPRK or any surface corneal ablation. Refractive surgeons should maintain a healthy lid margin and tear

  19. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  20. Attachment and growth of human bone marrow derived mesenchymal stem cells on regenerated antheraea pernyi silk fibroin films

    Energy Technology Data Exchange (ETDEWEB)

    Luan Xiying [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Wang Yong [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Duan Xiang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Duan Qiaoyan [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Li Mingzhong [School of Materials Engineering, Suzhou University, Suzhou 215006 (China); Lu Shenzhou [School of Materials Engineering, Suzhou University, Suzhou 215006 (China); Zhang Huanxiang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China); Zhang Xueguang [Institute of Medical Biotechnology, Jiangsu Province Key Laboratory of Stem Cell, Suzhou University, Suzhou 215007 (China)

    2006-12-15

    Silk fibroin of the silkworm Bombyx mori has been studied extensively, while the research on Antheraea pernyi silk fibroin (A. pernyi SF) in biomaterials is only at an early stage. In this study, the attachment, morphology, growth and phenotype of human bone marrow derived mesenchymal stem cells (hBMSCs) cultured on the regenerated A. pernyi SF films were studied in vitro. The results indicated that the attachment of hBMSCs on the regenerated A. pernyi SF films was almost the same as that on the collagen films. MTT and cell counting analyses demonstrated that the growth of hBMSCs on the regenerated A. pernyi SF films was better than that on controls. Moreover, electron scanning microscopy and fluorescence-activated cell sorting assays showed that the regenerated A. pernyi SF supported hBMSCs growth and functional maintenance compared with the controls. These data suggest that the regenerated A. pernyi SF, like Bombyx mori silk fibroin (B. mori SF) and collagen, can support hBMSCs attachment, growth and phenotypic maintenance, and has better biocompatibilities for hBMSCs in vitro culture.

  1. Attachment and growth of human bone marrow derived mesenchymal stem cells on regenerated antheraea pernyi silk fibroin films

    International Nuclear Information System (INIS)

    Luan Xiying; Wang Yong; Duan Xiang; Duan Qiaoyan; Li Mingzhong; Lu Shenzhou; Zhang Huanxiang; Zhang Xueguang

    2006-01-01

    Silk fibroin of the silkworm Bombyx mori has been studied extensively, while the research on Antheraea pernyi silk fibroin (A. pernyi SF) in biomaterials is only at an early stage. In this study, the attachment, morphology, growth and phenotype of human bone marrow derived mesenchymal stem cells (hBMSCs) cultured on the regenerated A. pernyi SF films were studied in vitro. The results indicated that the attachment of hBMSCs on the regenerated A. pernyi SF films was almost the same as that on the collagen films. MTT and cell counting analyses demonstrated that the growth of hBMSCs on the regenerated A. pernyi SF films was better than that on controls. Moreover, electron scanning microscopy and fluorescence-activated cell sorting assays showed that the regenerated A. pernyi SF supported hBMSCs growth and functional maintenance compared with the controls. These data suggest that the regenerated A. pernyi SF, like Bombyx mori silk fibroin (B. mori SF) and collagen, can support hBMSCs attachment, growth and phenotypic maintenance, and has better biocompatibilities for hBMSCs in vitro culture

  2. Fluorescently labaled collagen binding proteins allow specific visualization of collagen in tissues and live cell culture

    NARCIS (Netherlands)

    Krahn, K.B.N.; Bouten, C.V.C.; Tuijl, van S.; Zandvoort, van M.; Merkx, M.

    2006-01-01

    Visualization of the formation and orientation of collagen fibers in tissue engineering experiments is crucial for understanding the factors that determine the mechanical properties of tissues. In this study, collagen-specific fluorescent probes were developed using a new approach that takes

  3. The collagen receptor uPARAP/Endo180

    DEFF Research Database (Denmark)

    Engelholm, Lars H; Ingvarsen, Signe; Jürgensen, Henrik J

    2009-01-01

    The uPAR-associated protein (uPARAP/Endo180), a type-1 membrane protein belonging to the mannose receptor family, is an endocytic receptor for collagen. Through this endocytic function, the protein takes part in a previously unrecognized mechanism of collagen turnover. uPARAP/Endo180 can bind...... and internalize both intact and partially degraded collagens. In some turnover pathways, the function of the receptor probably involves an interplay with certain matrix-degrading proteases whereas, in other physiological processes, redundant mechanisms involving both endocytic and pericellular collagenolysis seem...... in collagen breakdown seems to be involved in invasive tumor growth Udgivelsesdato: 2009...

  4. The minor collagens in articular cartilage

    DEFF Research Database (Denmark)

    Luo, Yunyun; Sinkeviciute, Dovile; He, Yi

    2017-01-01

    Articular cartilage is a connective tissue consisting of a specialized extracellular matrix (ECM) that dominates the bulk of its wet and dry weight. Type II collagen and aggrecan are the main ECM proteins in cartilage. However, little attention has been paid to less abundant molecular components......, especially minor collagens, including type IV, VI, IX, X, XI, XII, XIII, and XIV, etc. Although accounting for only a small fraction of the mature matrix, these minor collagens not only play essential structural roles in the mechanical properties, organization, and shape of articular cartilage, but also...... fulfil specific biological functions. Genetic studies of these minor collagens have revealed that they are associated with multiple connective tissue diseases, especially degenerative joint disease. The progressive destruction of cartilage involves the degradation of matrix constituents including...

  5. Phosphodiesterase inhibition mediates matrix metalloproteinase activity and the level of collagen degradation fragments in a liver fibrosis ex vivo rat model

    Directory of Open Access Journals (Sweden)

    Veidal Sanne Skovgård

    2012-12-01

    Full Text Available Abstract Background Accumulation of extracellular matrix (ECM and increased matrix metalloproteinase (MMP activity are hallmarks of liver fibrosis. The aim of the present study was to develop a model of liver fibrosis combining ex vivo tissue culture of livers from CCl4 treated animals with an ELISA detecting a fragment of type III collagen generated in vitro by MMP-9 (C3M, known to be associated with liver fibrosis and to investigate cAMP modulation of MMP activity and liver tissue turnover in this model. Findings In vivo: Rats were treated for 8 weeks with CCl4/Intralipid. Liver slices were cultured for 48 hours. Levels of C3M were determined in the supernatants of slices cultured without treatment, treated with GM6001 (positive control or treated with IBMX (phosphodiesterase inhibitor. Enzymatic activity of MMP-2 and MMP-9 were studied by gelatin zymography. Ex vivo: The levels of serum C3M increased 77% in the CCl4-treated rats at week 8 (p 4-treated animals had highly increased MMP-9, but not MMP-2 activity, compared to slices derived from control animals. Conclusions We have combined an ex vivo model of liver fibrosis with measurement of a biochemical marker of collagen degradation in the condition medium. This technology may be used to evaluate the molecular process leading to structural fibrotic changes, as collagen species are the predominant structural part of fibrosis. These data suggest that modulation of cAMP may play a role in regulation of collagen degradation associated with liver fibrosis.

  6. Mechanisms of lamellar collagen formation in connective tissues.

    Science.gov (United States)

    Ghazanfari, Samaneh; Khademhosseini, Ali; Smit, Theodoor H

    2016-08-01

    The objective of tissue engineering is to regenerate functional tissues. Engineering functional tissues requires an understanding of the mechanisms that guide the formation and evolution of structure in the extracellular matrix (ECM). In particular, the three-dimensional (3D) collagen fiber arrangement is important as it is the key structural determinant that provides mechanical integrity and biological function. In this review, we survey the current knowledge on collagen organization mechanisms that can be applied to create well-structured functional lamellar tissues and in particular intervertebral disc and cornea. Thus far, the mechanisms behind the formation of cross-aligned collagen fibers in the lamellar structures is not fully understood. We start with cell-induced collagen alignment and strain-stabilization behavior mechanisms which can explain a single anisotropically aligned collagen fiber layer. These mechanisms may explain why there is anisotropy in a single layer in the first place. However, they cannot explain why a consecutive collagen layer is laid down with an alternating alignment. Therefore, we explored another mechanism, called liquid crystal phasing. While dense concentrations of collagen show such behavior, there is little evidence that the conditions for liquid crystal phasing are actually met in vivo. Instead, lysyl aldehyde-derived collagen cross-links have been found essential for correct lamellar matrix deposition. Furthermore, we suggest that supra-cellular (tissue-level) shear stress may be instrumental in the alignment of collagen fibers. Understanding the potential mechanisms behind the lamellar collagen structure in connective tissues will lead to further improvement of the regeneration strategies of functional complex lamellar tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Cosmetic Potential of Marine Fish Skin Collagen

    Directory of Open Access Journals (Sweden)

    Ana L. Alves

    2017-10-01

    Full Text Available Many cosmetic formulations have collagen as a major component because of its significant benefits as a natural humectant and moisturizer. This industry is constantly looking for innovative, sustainable, and truly efficacious products, so marine collagen based formulations are arising as promising alternatives. A solid description and characterization of this protein is fundamental to guarantee the highest quality of each batch. In the present study, we present an extensive characterization of marine-derived collagen extracted from salmon and codfish skins, targeting its inclusion as component in cosmetic formulations. Chemical and physical characterizations were performed using several techniques such as sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE, Fourier Transformation Infrared (FTIR spectroscopy rheology, circular dichroism, X-ray diffraction, humidity uptake, and a biological assessment of the extracts regarding their irritant potential. The results showed an isolation of type I collagen with high purity but with some structural and chemical differences between sources. Collagen demonstrated a good capacity to retain water, thus being suitable for dermal applications as a moisturizer. A topical exposure of collagen in a human reconstructed dermis, as well as the analysis of molecular markers for irritation and inflammation, exhibited no irritant potential. Thus, the isolation of collagen from fish skins for inclusion in dermocosmetic applications may constitute a sustainable and low-cost platform for the biotechnological valorization of fish by-products.

  8. Collagen-Gold Nanoparticle Conjugates for Versatile Biosensing

    Directory of Open Access Journals (Sweden)

    Sarah Unser

    2017-02-01

    Full Text Available Integration of noble metal nanoparticles with proteins offers promising potential to create a wide variety of biosensors that possess both improved selectivity and versatility. The multitude of functionalities that proteins offer coupled with the unique optical properties of noble metal nanoparticles can allow for the realization of simple, colorimetric sensors for a significantly larger range of targets. Herein, we integrate the structural protein collagen with 10 nm gold nanoparticles to develop a protein-nanoparticle conjugate which possess the functionality of the protein with the desired colorimetric properties of the nanoparticles. Applying the many interactions that collagen undergoes in the extracellular matrix, we are able to selectively detect both glucose and heparin with the same collagen-nanoparticle conjugate. Glucose is directly detected through the cross-linking of the collagen fibrils, which brings the attached nanoparticles into closer proximity, leading to a red-shift in the LSPR frequency. Conversely, heparin is detected through a competition assay in which heparin-gold nanoparticles are added to solution and compete with heparin in the solution for the binding sites on the collagen fibrils. The collagen-nanoparticle conjugates are shown to detect both glucose and heparin in the physiological range. Lastly, glucose is selectively detected in 50% mouse serum with the collagen-nanoparticle devices possessing a linear range of 3–25 mM, which is also within the physiologically relevant range.

  9. Collagen synthesis in human musculoskeletal tissues and skin

    DEFF Research Database (Denmark)

    Babraj, J A; Cuthbertson, D J R; Smith, K

    2005-01-01

    We have developed a direct method for the measurement of human musculoskeletal collagen synthesis on the basis of the incorporation of stable isotope-labeled proline or leucine into protein and have used it to measure the rate of synthesis of collagen in tendon, ligament, muscle, and skin....... In postabsorptive, healthy young men (28 +/- 6 yr) synthetic rates for tendon, ligament, muscle, and skin collagen were 0.046 +/- 0.005, 0.040 +/- 0.006, 0.016 +/- 0.002, and 0.037 +/- 0.003%/h, respectively (means +/- SD). In postabsorptive, healthy elderly men (70 +/- 6 yr) the rate of skeletal muscle collagen...... synthesis is greater than in the young (0.023 +/- 0.002%/h, P collagen are similar to those of mixed skeletal muscle protein in the postabsorptive state, whereas the rate for muscle collagen synthesis is much lower in both young and elderly men...

  10. Comparative proteomic analysis of normal and collagen IX null mouse cartilage reveals altered extracellular matrix composition and novel components of the collagen IX interactome.

    Science.gov (United States)

    Brachvogel, Bent; Zaucke, Frank; Dave, Keyur; Norris, Emma L; Stermann, Jacek; Dayakli, Münire; Koch, Manuel; Gorman, Jeffrey J; Bateman, John F; Wilson, Richard

    2013-05-10

    Collagen IX is an integral cartilage extracellular matrix component important in skeletal development and joint function. Proteomic analysis and validation studies revealed novel alterations in collagen IX null cartilage. Matrilin-4, collagen XII, thrombospondin-4, fibronectin, βig-h3, and epiphycan are components of the in vivo collagen IX interactome. We applied a proteomics approach to advance our understanding of collagen IX ablation in cartilage. The cartilage extracellular matrix is essential for endochondral bone development and joint function. In addition to the major aggrecan/collagen II framework, the interacting complex of collagen IX, matrilin-3, and cartilage oligomeric matrix protein (COMP) is essential for cartilage matrix stability, as mutations in Col9a1, Col9a2, Col9a3, Comp, and Matn3 genes cause multiple epiphyseal dysplasia, in which patients develop early onset osteoarthritis. In mice, collagen IX ablation results in severely disturbed growth plate organization, hypocellular regions, and abnormal chondrocyte shape. This abnormal differentiation is likely to involve altered cell-matrix interactions but the mechanism is not known. To investigate the molecular basis of the collagen IX null phenotype we analyzed global differences in protein abundance between wild-type and knock-out femoral head cartilage by capillary HPLC tandem mass spectrometry. We identified 297 proteins in 3-day cartilage and 397 proteins in 21-day cartilage. Components that were differentially abundant between wild-type and collagen IX-deficient cartilage included 15 extracellular matrix proteins. Collagen IX ablation was associated with dramatically reduced COMP and matrilin-3, consistent with known interactions. Matrilin-1, matrilin-4, epiphycan, and thrombospondin-4 levels were reduced in collagen IX null cartilage, providing the first in vivo evidence for these proteins belonging to the collagen IX interactome. Thrombospondin-4 expression was reduced at the mRNA level

  11. Postnatal development of collagen structure in ovine articular cartilage

    Directory of Open Access Journals (Sweden)

    Kranenbarg Sander

    2010-06-01

    Full Text Available Abstract Background Articular cartilage (AC is the layer of tissue that covers the articulating ends of the bones in diarthrodial joints. Across species, adult AC shows an arcade-like structure with collagen predominantly perpendicular to the subchondral bone near the bone, and collagen predominantly parallel to the articular surface near the articular surface. Recent studies into collagen fibre orientation in stillborn and juvenile animals showed that this structure is absent at birth. Since the collagen structure is an important factor for AC mechanics, the absence of the adult Benninghoff structure has implications for perinatal AC mechanobiology. The current objective is to quantify the dynamics of collagen network development in a model animal from birth to maturity. We further aim to show the presence or absence of zonal differentiation at birth, and to assess differences in collagen network development between different anatomical sites of a single joint surface. We use quantitative polarised light microscopy to investigate properties of the collagen network and we use the sheep (Ovis aries as our model animal. Results Predominant collagen orientation is parallel to the articular surface throughout the tissue depth for perinatal cartilage. This remodels to the Benninghoff structure before the sheep reach sexual maturity. Remodelling of predominant collagen orientation starts at a depth just below the future transitional zone. Tissue retardance shows a minimum near the articular surface at all ages, which indicates the presence of zonal differentiation at all ages. The absolute position of this minimum does change between birth and maturity. Between different anatomical sites, we find differences in the dynamics of collagen remodelling, but no differences in adult collagen structure. Conclusions The collagen network in articular cartilage remodels between birth and sexual maturity from a network with predominant orientation parallel to the

  12. Chitosan: collagen sponges. In vitro mineralization

    International Nuclear Information System (INIS)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G.

    2011-01-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca 2+ and PO 4 3- . The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  13. Mineralized Collagen: Rationale, Current Status, and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Zhi-Ye Qiu

    2015-07-01

    Full Text Available This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.

  14. Mechanical response of collagen molecule under hydrostatic compression

    International Nuclear Information System (INIS)

    Saini, Karanvir; Kumar, Navin

    2015-01-01

    Proteins like collagen are the basic building blocks of various body tissues (soft and hard). Collagen molecules find their presence in the skeletal system of the body where they bear mechanical loads from different directions, either individually or along with hydroxy-apatite crystals. Therefore, it is very important to understand the mechanical behavior of the collagen molecule which is subjected to multi-axial state of loading. The estimation of strains of collagen molecule along different directions resulting from the changes in hydrostatic pressure magnitude, can provide us new insights into its mechanical behavior. In the present work, full atomistic simulations have been used to study global (volumetric) as well as local (along different directions) mechanical properties of the hydrated collagen molecule which is subjected to different hydrostatic pressure magnitudes. To estimate the local mechanical properties, the strains of collagen molecule along its longitudinal and transverse directions have been acquired at different hydrostatic pressure magnitudes. In spite of non-homogeneous distribution of atoms within the collagen molecule, the calculated values of local mechanical properties have been found to carry the same order of magnitude along the longitudinal and transverse directions. It has been demonstrated that the values of global mechanical properties like compressibility, bulk modulus, etc. as well as local mechanical properties like linear compressibility, linear elastic modulus, etc. are functions of magnitudes of applied hydrostatic pressures. The mechanical characteristics of collagen molecule based on the atomistic model have also been compared with that of the continuum model in the present work. The comparison showed up orthotropic material behavior for the collagen molecule. The information on collagen molecule provided in the present study can be very helpful in designing the future bio-materials.

  15. Mechanical response of collagen molecule under hydrostatic compression.

    Science.gov (United States)

    Saini, Karanvir; Kumar, Navin

    2015-04-01

    Proteins like collagen are the basic building blocks of various body tissues (soft and hard). Collagen molecules find their presence in the skeletal system of the body where they bear mechanical loads from different directions, either individually or along with hydroxy-apatite crystals. Therefore, it is very important to understand the mechanical behavior of the collagen molecule which is subjected to multi-axial state of loading. The estimation of strains of collagen molecule along different directions resulting from the changes in hydrostatic pressure magnitude, can provide us new insights into its mechanical behavior. In the present work, full atomistic simulations have been used to study global (volumetric) as well as local (along different directions) mechanical properties of the hydrated collagen molecule which is subjected to different hydrostatic pressure magnitudes. To estimate the local mechanical properties, the strains of collagen molecule along its longitudinal and transverse directions have been acquired at different hydrostatic pressure magnitudes. In spite of non-homogeneous distribution of atoms within the collagen molecule, the calculated values of local mechanical properties have been found to carry the same order of magnitude along the longitudinal and transverse directions. It has been demonstrated that the values of global mechanical properties like compressibility, bulk modulus, etc. as well as local mechanical properties like linear compressibility, linear elastic modulus, etc. are functions of magnitudes of applied hydrostatic pressures. The mechanical characteristics of collagen molecule based on the atomistic model have also been compared with that of the continuum model in the present work. The comparison showed up orthotropic material behavior for the collagen molecule. The information on collagen molecule provided in the present study can be very helpful in designing the future bio-materials. Copyright © 2015 Elsevier B.V. All rights

  16. Mechanical response of collagen molecule under hydrostatic compression

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Karanvir, E-mail: karans@iitrpr.ac.in; Kumar, Navin

    2015-04-01

    Proteins like collagen are the basic building blocks of various body tissues (soft and hard). Collagen molecules find their presence in the skeletal system of the body where they bear mechanical loads from different directions, either individually or along with hydroxy-apatite crystals. Therefore, it is very important to understand the mechanical behavior of the collagen molecule which is subjected to multi-axial state of loading. The estimation of strains of collagen molecule along different directions resulting from the changes in hydrostatic pressure magnitude, can provide us new insights into its mechanical behavior. In the present work, full atomistic simulations have been used to study global (volumetric) as well as local (along different directions) mechanical properties of the hydrated collagen molecule which is subjected to different hydrostatic pressure magnitudes. To estimate the local mechanical properties, the strains of collagen molecule along its longitudinal and transverse directions have been acquired at different hydrostatic pressure magnitudes. In spite of non-homogeneous distribution of atoms within the collagen molecule, the calculated values of local mechanical properties have been found to carry the same order of magnitude along the longitudinal and transverse directions. It has been demonstrated that the values of global mechanical properties like compressibility, bulk modulus, etc. as well as local mechanical properties like linear compressibility, linear elastic modulus, etc. are functions of magnitudes of applied hydrostatic pressures. The mechanical characteristics of collagen molecule based on the atomistic model have also been compared with that of the continuum model in the present work. The comparison showed up orthotropic material behavior for the collagen molecule. The information on collagen molecule provided in the present study can be very helpful in designing the future bio-materials.

  17. Collagen based Biomaterials from CLRI: An Inspiration from the ...

    Indian Academy of Sciences (India)

    Collagen-based Smart Biomaterials · Smart materials: As smart people see them · Some Biomaterials based on Collagen in Human Health care · Questions of Value to this presentation ... Collagen based biomaterials · COLLAGEN IN VISION CARE · Slide 57 · Bandage lens: A smart device · Work at CLRI: In summary.

  18. Didymin Alleviates Hepatic Fibrosis Through Inhibiting ERK and PI3K/Akt Pathways via Regulation of Raf Kinase Inhibitor Protein

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    Xing Lin

    2016-12-01

    Full Text Available Background: Didymin has been reported to have anti-cancer potential. However, the effect of didymin on liver fibrosis remains illdefined. Methods: Hepatic fibrosis was induced by CCl4 in rats. The effects of didymin on liver pathology and collagen accumulation were observed by hematoxylin-eosin and Masson's trichrome staining, respectively. Serum transaminases activities and collagen-related indicators levels were determined by commercially available kits. Moreover, the effects of didymin on hepatic stellate cell apoptosis and cell cycle were analyzed by flow cytometry. Mitochondrial membrane potential was detected by using rhodamine-123 dye. The expression of Raf kinase inhibitor protein (RKIP and the phosphorylation of the ERK/MAPK and PI3K/Akt pathways were assessed by Western blot. Results: Didymin significantly ameliorated chronic liver injury and collagen deposition. It strongly inhibited hepatic stellate cells proliferation, induced apoptosis and caused cell cycle arrest in G2/M phase. Moreover, didymin notably attenuated mitochondrial membrane potential, accompanied by release of cytochrome C. Didymin significantly inhibited the ERK/MAPK and PI3K/Akt pathways. The effects of didymin on the collagen accumulation in rats and on the biological behaviors of hepatic stellate cells were largely abolished by the specific RKIP inhibitor locostatin. Conclusion: Didymin alleviates hepatic fibrosis by inhibiting ERK/MAPK and PI3K/Akt pathways via regulation of RKIP expression.

  19. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    Energy Technology Data Exchange (ETDEWEB)

    Yunoki, Shunji [Life Science Group, Tokyo Metropolitan Industrial Technology Research Institute, 2-11-1 Fukasawa, Setagaya-ku, Tokyo 158-0081 (Japan); Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori [Department of Sports Medicine and Joint Surgery, Graduate School of Medicine, Hokkaido University, Kita-15 Nishi-7, Sapporo, Hokkaido 060-8638 Japan (Japan); Ikoma, Toshiyuki; Tanaka, Junzo, E-mail: yunoki.shunji@iri-tokyo.jp [Department of Metallurgy and Ceramics Science, 2-12-1-S7-1, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2011-02-15

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm{sup -3} and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 {+-} 0.48 and 0.651 {+-} 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  20. Effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of hydroxyapatite-collagen composites as artificial bone materials

    International Nuclear Information System (INIS)

    Yunoki, Shunji; Sugiura, Hiroaki; Kondo, Eiji; Yasuda, Kazunori; Ikoma, Toshiyuki; Tanaka, Junzo

    2011-01-01

    The aim of this study was to evaluate the effects of increased collagen-matrix density on the mechanical properties and in vivo absorbability of porous hydroxyapatite (HAp)-collagen composites as artificial bone materials. Seven types of porous HAp-collagen composites were prepared from HAp nanocrystals and dense collagen fibrils. Their densities and HAp/collagen weight ratios ranged from 122 to 331 mg cm -3 and from 20/80 to 80/20, respectively. The flexural modulus and strength increased with an increase in density, reaching 2.46 ± 0.48 and 0.651 ± 0.103 MPa, respectively. The porous composites with a higher collagen-matrix density exhibited much higher mechanical properties at the same densities, suggesting that increasing the collagen-matrix density is an effective way of improving the mechanical properties. It was also suggested that other structural factors in addition to collagen-matrix density are required to achieve bone-like mechanical properties. The in vivo absorbability of the composites was investigated in bone defects of rabbit femurs, demonstrating that the absorption rate decreased with increases in the composite density. An exhaustive increase in density is probably limited by decreases in absorbability as artificial bones.

  1. Collagen Type I as a Ligand for Receptor-Mediated Signaling

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    Iris Boraschi-Diaz

    2017-05-01

    Full Text Available Collagens form the fibrous component of the extracellular matrix in all multi-cellular animals. Collagen type I is the most abundant collagen present in skin, tendons, vasculature, as well as the organic portion of the calcified tissue of bone and teeth. This review focuses on numerous receptors for which collagen acts as a ligand, including integrins, discoidin domain receptors DDR1 and 2, OSCAR, GPVI, G6b-B, and LAIR-1 of the leukocyte receptor complex (LRC and mannose family receptor uPARAP/Endo180. We explore the process of collagen production and self-assembly, as well as its degradation by collagenases and gelatinases in order to predict potential temporal and spatial sites of action of different collagen receptors. While the interactions of the mature collagen matrix with integrins and DDR are well-appreciated, potential signals from immature matrix as well as collagen degradation products are possible but not yet described. The role of multiple collagen receptors in physiological processes and their contribution to pathophysiology of diseases affecting collagen homeostasis require further studies.

  2. Measurement of the quadratic hyperpolarizability of the collagen triple helix and application to second harmonic imaging of natural and biomimetic collagenous tissues

    Science.gov (United States)

    Deniset-Besseau, A.; Strupler, M.; Duboisset, J.; De Sa Peixoto, P.; Benichou, E.; Fligny, C.; Tharaux, P.-L.; Mosser, G.; Brevet, P.-F.; Schanne-Klein, M.-C.

    2009-09-01

    Collagen is a major protein of the extracellular matrix that is characterized by triple helical domains. It plays a central role in the formation of fibrillar and microfibrillar networks, basement membranes, as well as other structures of the connective tissue. Remarkably, fibrillar collagen exhibits efficient Second Harmonic Generation (SHG) so that SHG microscopy proved to be a sensitive tool to probe the three-dimensional architecture of fibrillar collagen and to assess the progression of fibrotic pathologies. We obtained sensitive and reproducible measurements of the fibrosis extent, but we needed quantitative data at the molecular level to further process SHG images. We therefore performed Hyper- Rayleigh Scattering (HRS) experiments and measured a second order hyperpolarisability of 1.25 10-27 esu for rat-tail type I collagen. This value is surprisingly large considering that collagen presents no strong harmonophore in its aminoacid sequence. In order to get insight into the physical origin of this nonlinear process, we performed HRS measurements after denaturation of the collagen triple helix and for a collagen-like short model peptide [(Pro-Pro- Gly)10]3. It showed that the collagen large nonlinear response originates in the tight alignment of a large number of weakly efficient harmonophores, presumably the peptide bonds, resulting in a coherent amplification of the nonlinear signal along the triple helix. To illustrate this mechanism, we successfully recorded SHG images in collagenous biomimetic matrices.

  3. Relative orientation of collagen molecules within a fibril: a homology model for homo sapiens type I collagen.

    Science.gov (United States)

    Collier, Thomas A; Nash, Anthony; Birch, Helen L; de Leeuw, Nora H

    2018-02-15

    Type I collagen is an essential extracellular protein that plays an important structural role in tissues that require high tensile strength. However, owing to the molecule's size, to date no experimental structural data are available for the Homo sapiens species. Therefore, there is a real need to develop a reliable homology model and a method to study the packing of the collagen molecules within the fibril. Through the use of the homology model and implementation of a novel simulation technique, we have ascertained the orientations of the collagen molecules within a fibril, which is currently below the resolution limit of experimental techniques. The longitudinal orientation of collagen molecules within a fibril has a significant effect on the mechanical and biological properties of the fibril, owing to the different amino acid side chains available at the interface between the molecules.

  4. Lack of collagen XVIII/endostatin exacerbates immune-mediated glomerulonephritis.

    Science.gov (United States)

    Hamano, Yuki; Okude, Takashi; Shirai, Ryota; Sato, Ikumi; Kimura, Ryota; Ogawa, Makoto; Ueda, Yoshihiko; Yokosuka, Osamu; Kalluri, Raghu; Ueda, Shiro

    2010-09-01

    Collagen XVIII is a component of the highly specialized extracellular matrix associated with basement membranes of epithelia and endothelia. In the normal kidney, collagen XVIII is distributed throughout glomerular and tubular basement membranes, mesangial matrix, and Bowman's capsule. Proteolytic cleavage within its C-terminal domain releases the fragment endostatin, which has antiangiogenic properties. Because damage to the glomerular basement membrane (GBM) accompanies immune-mediated renal injury, we investigated the role of collagen XVIII/endostatin in this disorder. We induced anti-GBM glomerulonephritis in collagen XVIII alpha1-null and wild-type mice and compared the resulting matrix accumulation, inflammation, and capillary rarefaction. Anti-GBM disease upregulated collagen XVIII/endostatin expression within the GBM and Bowman's capsule of wild-type mice. Collagen XVIII/endostatin-deficient mice developed more severe glomerular and tubulointerstitial injury than wild-type mice. Collagen XVIII/endostatin deficiency altered matrix remodeling, enhanced the inflammatory response, and promoted capillary rarefaction and vascular endothelial cell damage, but did not affect endothelial proliferation. Supplementing collagen XVIII-deficient mice with exogenous endostatin did not affect the progression of anti-GBM disease. Taken together, these results suggest that collagen XVIII/endostatin preserves the integrity of the extracellular matrix and capillaries in the kidney, protecting against progressive glomerulonephritis.

  5. ELECTRICAL AND THERMODYNAMIC PROPERTIES OF A COLLAGEN SOLUTION

    Directory of Open Access Journals (Sweden)

    Jaromír Štancl

    2017-06-01

    Full Text Available This paper focuses on measurements of the electrical properties, the specific heat capacity and the thermal conductivity of a collagen solution (7.19% mass fraction of native bovine collagen in water. The results of our experiments show that specific electrical conductivity of collagen solution is strongly dependent on temperature. The transition region of collagen to gelatin has been observed from the measured temperature dependence of specific electrical conductivity, and has been confirmed by specific heat capacity measurements by a differential scanning calorimetry.

  6. Collagen Fibrils: Nature's Highly Tunable Nonlinear Springs.

    Science.gov (United States)

    Andriotis, Orestis G; Desissaire, Sylvia; Thurner, Philipp J

    2018-03-21

    Tissue hydration is well known to influence tissue mechanics and can be tuned via osmotic pressure. Collagen fibrils are nature's nanoscale building blocks to achieve biomechanical function in a broad range of biological tissues and across many species. Intrafibrillar covalent cross-links have long been thought to play a pivotal role in collagen fibril elasticity, but predominantly at large, far from physiological, strains. Performing nanotensile experiments of collagen fibrils at varying hydration levels by adjusting osmotic pressure in situ during atomic force microscopy experiments, we show the power the intrafibrillar noncovalent interactions have for defining collagen fibril tensile elasticity at low fibril strains. Nanomechanical tensile tests reveal that osmotic pressure increases collagen fibril stiffness up to 24-fold in transverse (nanoindentation) and up to 6-fold in the longitudinal direction (tension), compared to physiological saline in a reversible fashion. We attribute the stiffening to the density and strength of weak intermolecular forces tuned by hydration and hence collagen packing density. This reversible mechanism may be employed by cells to alter their mechanical microenvironment in a reversible manner. The mechanism could also be translated to tissue engineering approaches for customizing scaffold mechanics in spatially resolved fashion, and it may help explain local mechanical changes during development of diseases and inflammation.

  7. Circular RNA profiling reveals that circCOL3A1-859267 regulate type I collagen expression in photoaged human dermal fibroblasts

    International Nuclear Information System (INIS)

    Peng, Yating; Song, Xiaojing; Zheng, Yue; Wang, Xinyi; Lai, Wei

    2017-01-01

    Production of type I collagen declines is a main characteristic during photoaging, but the mechanism is still not fully understood. Circular RNAs (circRNAs) are a class of newly identified non-coding RNAs with regulatory potency by sequestering miRNAs like a sponge. It's more stable than linear RNAs, and would be a useful tool for regulation of gene expression. However, the role of circRNAs in collagen expression during photoaging is still unclear. Here we performed deep sequencing of RNA generated from UVA irradiated and no irradiated human dermal fibroblasts (HDFs) and identified 29 significantly differentially expressed circRNAs (fold change ≥ 1.5, P < 0.05), 12 circRNAs were up-regulated and 17 circRNAs were down-regulated.3 most differentially expressed circRNAs were verified by qRT-PCR and the down-regulated circCOL3A1-859267 exhibited the most significantly altered in photoaged HDFs. Overexpression of circCOL3A1-859267 inhibited UVA-induced decrease of type I collagen expression and silencing of it reduced type I collagen intensity. Via a bioinformatic method, 44 miRNAs were predicted to binding with circCOL3A1-859267, 5 of them have been confirmed or predicted to interact with type I collagen. This study show that circCOL3A1-859267 regulate type I collagen expression in photoaged HDFs, suggesting it may be a novel target for interfering photoaging.

  8. Collagen like peptide bioconjugates for targeted drug delivery applications

    Science.gov (United States)

    Luo, Tianzhi

    Collagen is the most abundant protein in mammals, and there has been long-standing interest in understanding and controlling collagen assembly in the design of new materials. Collagen-like peptides (CLP), also known as collagen-mimetic peptides (CMP), are short synthetic peptides which mimic the triple helical conformation of native collagens. In the past few decades, collagen like peptides and their conjugated hybrids have become a new class of biomaterials that possesses unique structures and properties. In addition to traditional applications of using CLPs to decipher the role of different amino acid residues and tripeptide motifs in stabilizing the collagen triple helix and mimicking collagen fibril formation, with the introduction of specific interactions including electrostatic interactions, pi-pi stacking interaction and metal-ligand coordination, a variety of artificial collagen-like peptides with well-defined sequences have been designed to create higher order assemblies with specific biological functions. The CLPs have also been widely used as bioactive domains or physical cross-linkers to fabricate hydrogels, which have shown potential to improve cell adhesion, proliferation and ECM macromolecule production. Despite this widespread use, the utilization of CLPs as domains in stimuli responsive bioconjugates represents a relatively new area for the development of functional polymeric materials. In this work, a new class of thermoresponsive diblock conjugates, containing collagen-like peptides and a thermoresponsive polymer, namely poly(diethylene glycol methyl ether methacrylate) (PDEGMEMA), is introduced. The CLP domain maintains its triple helix conformation after conjugation with the polymer. The engineered LCST of these conjugates has enabled temperature-induced assembly under aqueous conditions, at physiologically relevant temperatures, into well-defined vesicles with diameters of approximately 50-200 nm. The formation of nanostructures was driven by

  9. Myocardial repair with long-term and low-dose administration of a nitric oxide synthesis inhibitor. Myofibroblasts, type III collagen and fibronectin

    Directory of Open Access Journals (Sweden)

    Pessanha Mônica Gomes

    1999-01-01

    Full Text Available OBJECTIVE: To study the healing process of the myocardium in hypertensive rats undergoing inhibition of nitric oxide synthesis. METHODS: Two groups of animals were studied: one received L-NAME, 12mg/kg/day, and the other was a control group. The presence of type III collagen, fibronectin, and alpha-smooth muscle actin-positive cells was assessed by immunohistochemistry. RESULTS: Fibronectin was seen in both early and late lesions, while type III collagen was seen mainly in areas of incomplete healing, situated among myocytes and around the intramyocardial branches of the coronary arteries. Areas representing early and late lesions showed a population of spindle-shaped cells. Immunohistochemistry showed that these cells were positive for alpha-smooth muscle actin. CONCLUSION: In the myocardium of hypertensive rats, the alpha-smooth muscle actin-positive cells are related to the accumulation of type III collagen and fibronectin in the areas of myocardial damage.

  10. Evaporation and Hydrocarbon Chain Conformation of Surface Lipid Films

    Science.gov (United States)

    Sledge, Samiyyah M.; Khimji, Hussain; Borchman, Douglas; Oliver, Alexandria; Michael, Heidi; Dennis, Emily K.; Gerlach, Dylan; Bhola, Rahul; Stephen, Elsa

    2016-01-01

    Purpose The inhibition of the rate of evaporation (Revap) by surface lipids is relevant to reservoirs and dry eye. Our aim was to test the idea that lipid surface films inhibit Revap. Methods Revap were determined gravimetrically. Hydrocarbon chain conformation and structure were measured using a Raman microscope. Six 1-hydroxyl hydrocarbons (11–24 carbons in length) and human meibum were studied. Reflex tears were obtained from a 62-year-old male. Results The Raman scattering intensity of the lipid film deviated by about 7 % for hydroxyl lipids and varied by 21 % for meibum films across the entire film at a resolution of 5 µm2. All of the surface lipids were ordered. Revap of the shorter chain hydroxyl lipids were slightly (7%) but significantly lower compared with the longer chain hydroxyl lipids. Revap of both groups was essentially similar to that of buffer. A hydroxyl lipid film did not influence Revap over an estimated average thickness range of 0.69 to >6.9 µm. Revap of human tears and buffer with and without human meibum (34.4 µm thick) was not significantly different. Revap of human tears was not significantly different from buffer. Conclusions Human meibum and hydroxyl lipids, regardless of their fluidity, chain length, or thickness did not inhibit Revap of buffer or tears even though they completely covered the surface. It is unlikely that hydroxyl lipids can be used to inhibit Revap of reservoirs. Our data do not support the widely accepted (yet unconfirmed) idea that the tear film lipid layer inhibits Revap of tears. PMID:27395776

  11. Extraction and Characterization of Collagen from Sea Cucumber Flesh

    Directory of Open Access Journals (Sweden)

    Alhana

    2015-11-01

    Full Text Available Sea cucumber (Stichopus variegatus is one of the Echinodermata phylum that grows along Indonesian coastal. Sea cucumber is potential source of collagen. The purposes of this research were to determine the optimal concentration of NaOH and CH3COOH solution in collagen production and analyze the physicochemical characteristics of collagen from S. variegatus. Yield of the collagen was 1.5% (based on wet weight basis, produced by pretreatment with NaOH 0,30%, hydrolysis with CH3COOH 0.10% and extracted using distilled water. Protein, moisture, and ash content of the collagen was 67.68%, 13.64%, and 4.15%, respectively. Collagen was extracted using distilled water at 45°C during 2h and still had triple helix structure ; pH 7.37 ; melting temperature 163.67°C and whiteness 69.25%. The major amino acid content of collagen were glycine, alanine, proline and glutamic acid.

  12. New infrared-assisted method for sol-gel derived ZnO:Ag thin films: Structural and bacterial inhibition properties.

    Science.gov (United States)

    González-Penguelly, Brenely; Morales-Ramírez, Ángel de Jesús; Rodríguez-Rosales, Miriam Guadalupe; Rodríguez-Nava, Celestino Odín; Carrera-Jota, María Luz

    2017-09-01

    A new sol-gel method, based on crystallization with Infrared heating, was developed to obtain ZnO:Ag thin films. The common sol, with zinc acetate as precursor and silver nitrate as doping source (1, 3 and 5 % molar), isopropanol and distilled water as solvents and monoethanolamine as stabilizer agent; was modified with Pluronic F127 and diethylene glycol as rheological agents, and with urea as fuel to produce enough energy to the combustion and to promote the crystallization process. Later, Corning glass-substrates were dipped into the sol at a constant speed of 3mms -1 . To provide the necessary energy for obtaining the hexagonal ZnO structure of the coatings during the drying and consolidation process, instead of using the common furnace heat-treatment, the films were heated by means of an infrared (IR) ceramic lamp (800W) for 15, 30, 45, 60 and 180 minutes, and the effect of this annealing method was analyzed. The structural properties were examined by means of X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), whereas morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The examination revealed a homogeneous distribution of particles with the characteristic pores of pluronic F127, and the coating roughness had an average value of 100nm by AFM. To evaluate the effect on the number of dipping cycles and the IR-treatment on the thickness, ellipsometry results for 1, 3 and 5 deposits were analyzed and showed increments of 780, 945 and 1082nm, respectively. Finally, to test of the antibacterial activity, instead of the common one-microorganism approach, environmental microorganisms that grow with expose of the broth to the ambient conditions were employed (microbial consortium), which is a real environmental condition. The biological test was carried out by kinetic growth inhibition (optical density) of heterotrophic bacteria in culture liquid media under conditions of light, light-dark and

  13. Collagen Structural Hierarchy and Susceptibility to Degradation by Ultraviolet Radiation.

    Science.gov (United States)

    Rabotyagova, Olena S; Cebe, Peggy; Kaplan, David L

    2008-12-01

    Collagen type I is the most abundant extracellular matrix protein in the human body, providing the basis for tissue structure and directing cellular functions. Collagen has complex structural hierarchy, organized at different length scales, including the characteristic triple helical feature. In the present study, the relationship between collagen structure (native vs. denatured) and sensitivity to UV radiation was assessed, with a focus on changes in primary structure, changes in conformation, microstructure and material properties. A brief review of free radical reactions involved in collagen degradation is also provided as a mechanistic basis for the changes observed in the study. Structural and functional changes in the collagens were related to the initial conformation (native vs. denatured) and the energy of irradiation. These changes were tracked using SDS-PAGE to assess molecular weight, Fourier transform infrared (FTIR) spectroscopy to study changes in the secondary structure, and atomic force microscopy (AFM) to characterize changes in mechanical properties. The results correlate differences in sensitivity to irradiation with initial collagen structural state: collagen in native conformation vs. heat-treated (denatured) collagen. Changes in collagen were found at all levels of the hierarchical structural organization. In general, the native collagen triple helix is most sensitive to UV-254nm radiation. The triple helix delays single chain degradation. The loss of the triple helix in collagen is accompanied by hydrogen abstraction through free radical mechanisms. The results received suggest that the effects of electromagnetic radiation on biologically relevant extracellular matrices (collagen in the present study) are important to assess in the context of the state of collagen structure. The results have implications in tissue remodeling, wound repair and disease progression.

  14. Collagen Homeostasis and Metabolism

    DEFF Research Database (Denmark)

    Magnusson, S Peter; Heinemeier, Katja M; Kjaer, Michael

    2016-01-01

    The musculoskeletal system and its collagen rich tissue is important for ensuring architecture of skeletal muscle, energy storage in tendon and ligaments, joint surface protection, and for ensuring the transfer of muscular forces into resulting limb movement. Structure of tendon is stable...... inactivity or immobilization of the human body will conversely result in a dramatic loss in tendon stiffness and collagen synthesis. This illustrates the importance of regular mechanical load in order to preserve the stabilizing role of the connective tissue for the overall function of the musculoskeletal...

  15. Anti-Inflammatory Inhibitors Targeting Jak and Ikk Have An Anabolic Effect on Type II Collagen Turnover ex Vivo

    DEFF Research Database (Denmark)

    Kjelgaard-Petersen, Cecilie Freja; Bay-Jensen, Anne-Christine; Karsdal, M.A.

    2016-01-01

    be beneficial for the selection of novel anti-inflammatory treatments for RA and iOA. Objectives The aim of this study was to investigate the direct effect of the anti-inflammatory inhibitors R406 (the active metabolite of Fostamatinib), Tofacitinib, TPCA-1 and SB203580 on the cartilage ECM turnover. Methods...... Full depth bovine cartilage ex vivo cultures were cultured for 3 weeks with OSM [10 ng/mL] and TNFα [2 ng/mL] (O+T) or together with R406, Tofacitinib or TPCA-1 at 10 μM and a two-fold dilution to 0.16 μM. SB203580 was tested at 3 μM, 1 μM and 0.3 μM. As negative control, untreated explants were...... R406, the Jak inhibitor Tofacitinib, and the IKK inhibitor TPCA-1 inhibited the release of ARGS or AGNx1, while the p38 inhibitor, SB203580, had no effect. The turnover of type II collagen was measured by the formation of type II collagen (ProC2) and MMP-mediated degradation of type II collagen (C2M...

  16. Cervical Collagen Concentration within Fifteen Months after Delivery

    DEFF Research Database (Denmark)

    Sundtoft, Iben; Uldbjerg, Niels; Sommer, Steffe

    2011-01-01

    OBJECTIVE: Cervical collagen concentration decreases during pregnancy. The increased risk of preterm birth following a short interpregnancy interval may be explained by an incomplete remodeling of the cervix. The objective of this study was to describe the changes in cervical collagen concentration...... over 15 months following delivery. METHODS: The collagen concentrations were determined in cervical biopsies obtained from 15 women at 3, 6, 9, 12, and 15 months after delivery. RESULTS: The mean cervical collagen concentrations were 50, 59, 63, 65, and 65 % of dry weight (SD 4.2 – 6.5). This increase...... was statistically significant until month 9, but not between months 9 and 12. CONCLUSIONS: Low collagen concentrations in the uterine cervix may contribute to the association between a short interpregnancy interval and preterm birth....

  17. Collagen-like proteins in pathogenic E. coli strains.

    Directory of Open Access Journals (Sweden)

    Neelanjana Ghosh

    Full Text Available The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages.

  18. Absence of FKBP10 in recessive type XI osteogenesis imperfecta leads to diminished collagen cross-linking and reduced collagen deposition in extracellular matrix.

    Science.gov (United States)

    Barnes, Aileen M; Cabral, Wayne A; Weis, MaryAnn; Makareeva, Elena; Mertz, Edward L; Leikin, Sergey; Eyre, David; Trujillo, Carlos; Marini, Joan C

    2012-11-01

    Recessive osteogenesis imperfecta (OI) is caused by defects in genes whose products interact with type I collagen for modification and/or folding. We identified a Palestinian pedigree with moderate and lethal forms of recessive OI caused by mutations in FKBP10 or PPIB, which encode endoplasmic reticulum resident chaperone/isomerases FKBP65 and CyPB, respectively. In one pedigree branch, both parents carry a deletion in PPIB (c.563_566delACAG), causing lethal type IX OI in their two children. In another branch, a child with moderate type XI OI has a homozygous FKBP10 mutation (c.1271_1272delCCinsA). Proband FKBP10 transcripts are 4% of control and FKBP65 protein is absent from proband cells. Proband collagen electrophoresis reveals slight band broadening, compatible with ≈10% over-modification. Normal chain incorporation, helix folding, and collagen T(m) support a minimal general collagen chaperone role for FKBP65. However, there is a dramatic decrease in collagen deposited in culture despite normal collagen secretion. Mass spectrometry reveals absence of hydroxylation of the collagen telopeptide lysine involved in cross-linking, suggesting that FKBP65 is required for lysyl hydroxylase activity or access to type I collagen telopeptide lysines, perhaps through its function as a peptidylprolyl isomerase. Proband collagen to organics ratio in matrix is approximately 30% of normal in Raman spectra. Immunofluorescence shows sparse, disorganized collagen fibrils in proband matrix. Published 2012 Wiley Periodicals, Inc.*This article is a US Government work and, as such, is in the public domain of the United States of America.

  19. Hyaluronan in aged collagen matrix increases prostate epithelial cell proliferation

    Science.gov (United States)

    Damodarasamy, Mamatha; Vernon, Robert B.; Chan, Christina K.; Plymate, Stephen R.; Wight, Thomas N.

    2015-01-01

    The extracellular matrix (ECM) of the prostate, which is comprised primarily of collagen, becomes increasingly disorganized with age, a property that may influence the development of hyperplasia and cancer. Collageous ECM extracted from the tails of aged mice exhibits many characteristics of collagen in aged tissues, including the prostate. When polymerized into a 3-dimensional (3D) gel, these collagen extracts can serve as models for the study of specific cell-ECM interactions. In the present study, we examined the behaviors of human prostatic epithelial cell lines representing normal prostate epithelial cells (PEC), benign prostatic hyperplasia (BPH-1), and adenocarcinoma (LNCaP) cultured in contact with 3D gels made from collagen extracts of young and aged mice. We found that proliferation of PEC, BPH-1, and LNCaP cells were all increased by culture on aged collagen gels relative to young collagen gels. In examining age-associated differences in the composition of the collagen extracts, we found that aged and young collagen had a similar amount of several collagen-associated ECM components, but aged collagen had a much greater content of the glycosaminoglycan hyaluronan (HA) than young collagen. The addition of HA (of similar size and concentration to that found in aged collagen extracts) to cells placed in young collagen elicited significantly increased proliferation in BPH-1 cells, but not in PEC or LNCaP cells, relative to controls not exposed to HA. Of note, histochemical analyses of human prostatic tissues showed significantly higher expression of HA in BPH and prostate cancer stroma relative to stroma of normal prostate. Collectively, these results suggest that changes in ECM involving increased levels of HA contribute to the growth of prostatic epithelium with aging. PMID:25124870

  20. Fibrous mini-collagens in hydra nematocysts.

    Science.gov (United States)

    Holstein, T W; Benoit, M; Herder, G V; David, C N; Wanner, G; Gaub, H E

    1994-07-15

    Nematocysts (cnidocysts) are exocytotic organelles found in all cnidarians. Here, atomic force microscopy and field emission scanning electron microscopy reveal the structure of the nematocyst capsule wall. The outer wall consists of globular proteins of unknown function. The inner wall consists of bundles of collagen-like fibrils having a spacing of 50 to 100 nanometers and cross-striations at intervals of 32 nanometers. The fibrils consist of polymers of "mini-collagens," which are abundant in the nematocysts of Hydra. The distinct pattern of mini-collagen fibers in the inner wall can provide the tensile strength necessary to withstand the high osmotic pressure (15 megapascals) in the capsules.

  1. Stabilization and anomalous hydration of collagen fibril under heating.

    Directory of Open Access Journals (Sweden)

    Sasun G Gevorkian

    Full Text Available BACKGROUND: Type I collagen is the most common protein among higher vertebrates. It forms the basis of fibrous connective tissues (tendon, chord, skin, bones and ensures mechanical stability and strength of these tissues. It is known, however, that separate triple-helical collagen macromolecules are unstable at physiological temperatures. We want to understand the mechanism of collagen stability at the intermolecular level. To this end, we study the collagen fibril, an intermediate level in the collagen hierarchy between triple-helical macromolecule and tendon. METHODOLOGY/PRINCIPAL FINDING: When heating a native fibril sample, its Young's modulus decreases in temperature range 20-58°C due to partial denaturation of triple-helices, but it is approximately constant at 58-75°C, because of stabilization by inter-molecular interactions. The stabilization temperature range 58-75°C has two further important features: here the fibril absorbs water under heating and the internal friction displays a peak. We relate these experimental findings to restructuring of collagen triple-helices in fibril. A theoretical description of the experimental results is provided via a generalization of the standard Zimm-Bragg model for the helix-coil transition. It takes into account intermolecular interactions of collagen triple-helices in fibril and describes water adsorption via the Langmuir mechanism. CONCLUSION/SIGNIFICANCE: We uncovered an inter-molecular mechanism that stabilizes the fibril made of unstable collagen macromolecules. This mechanism can be relevant for explaining stability of collagen.

  2. Collagen-Induced Arthritis: A model for Murine Autoimmune Arthritis.

    Science.gov (United States)

    Pietrosimone, K M; Jin, M; Poston, B; Liu, P

    2015-10-20

    Collagen-induced arthritis (CIA) is a common autoimmune animal model used to study rheumatoid arthritis (RA). The development of CIA involves infiltration of macrophages and neutrophils into the joint, as well as T and B cell responses to type II collagen. In murine CIA, genetically susceptible mice (DBA/1J) are immunized with a type II bovine collagen emulsion in complete Freund's adjuvant (CFA), and receive a boost of type II bovine collagen in incomplete Freund's adjuvant (IFA) 21 days after the first injection. These mice typically develop disease 26 to 35 days after the initial injection. C57BL/6J mice are resistant to arthritis induced by type II bovine collagen, but can develop arthritis when immunized with type II chicken collagen in CFA, and receive a boost of type II chicken collagen in IFA 21 days after the first injection. The concentration of heat-killed Mycobacterium tuberculosis H37RA (MT) in CFA also differs for each strain. DBA/1J mice develop arthritis with 1 mg/ml MT, while C57BL/6J mice require and 3-4 mg/ml MT in order to develop arthritis. CIA develops slowly in C57BL/6J mice and cases of arthritis are mild when compared to DBA/1J mice. This protocol describes immunization of DBA/1J mice with type II bovine collagen and the immunization of C57BL/6J mice with type II chicken collagen.

  3. Mesenchymal Stem Cells Promote the Osteogenesis in Collagen-Induced Arthritic Mice through the Inhibition of TNF-α

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2018-01-01

    Full Text Available Objective. To investigate the effects of umbilical cord mesenchymal stem cell (UC-MSC transplantation on joint damage and osteoporosis in collagen-induced arthritis (CIA mice and to explore the mechanisms by which UC-MSCs modulate the osteogenic differentiation. Methods. CIA mice were divided into the following treated groups: UC-MSC transplantation group, antitumor necrosis factor- (TNF- α group, and zoledronic acid (ZA group. Microcomputed tomography (micro-CT was used to analyze the bone morphology parameters. Osteogenic differentiation of treated CIA mice was determined. Bone marrow mesenchymal stem cells (BM-MSCs from CIA mice were treated with TNF-α in vitro to explore their effects on osteogenesis. Results. The arthritis score was significantly reduced in the UC-MSC transplantation and anti-TNF-α-treated CIA groups, compared with control mice (P<0.001. Micro-CT showed that CIA mice developed osteoporosis at 12 weeks after immunization. The bone morphology parameters were partially improved in UC-MSC-treated CIA mice. Impaired osteogenic differentiation functions were indicated by decreased ALP activity (P<0.001 and reduced mRNA and protein levels of osteogenic marker genes (P<0.05 in CIA mice compared with DBA/1 mice. UC-MSC treatment significantly upregulated the impaired osteogenic differentiation ability in CIA mice. Meanwhile, the serum TNF-α level was decreased significantly in the UC-MSC group. The osteogenesis was reduced with the addition of TNF-α in vitro. Conclusion. This study demonstrated that UC-MSC transplantation not only significantly improved the joint damage but also played a beneficial role in osteoporosis in CIA mice. Mechanistically, the improved osteogenic differentiation of CIA under UC-MSC treatment may be achieved by inhibition of TNF-α.

  4. Differential regulation of collagen secretion by kinin receptors in cardiac fibroblast and myofibroblast

    Energy Technology Data Exchange (ETDEWEB)

    Catalán, Mabel; Smolic, Christian [Centro de estudios moleculares de la célula, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile); Contreras, Ariel [Instituto Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile (Chile); Ayala, Pedro; Olmedo, Ivonne; Copaja, Miguel; Boza, Pía; Vivar, Raúl; Avalos, Yennifer [Centro de estudios moleculares de la célula, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile); Lavandero, Sergio [Centro de estudios moleculares de la célula, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile); Instituto Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile (Chile); Department of Internal Medicine (Cardiology Division), University of Texas Southwestern Medical Center, Dallas, TX (United States); Velarde, Victoria [Departamento de Ciencias Fisiológicas, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago (Chile); Díaz-Araya, Guillermo, E-mail: gadiaz@ciq.uchile.cl [Centro de estudios moleculares de la célula, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile (Chile)

    2012-06-15

    Kinins mediate their cellular effects through B1 (B1R) and B2 (B2R) receptors, and the activation of B2R reduces collagen synthesis in cardiac fibroblasts (CF). However, the question of whether B1R and/or B2R have a role in cardiac myofibroblasts remains unanswered. Methods: CF were isolated from neonate rats and myofibroblasts were generated by an 84 h treatment with TGF-β1 (CMF). B1R was evaluated by western blot, immunocytochemistry and radioligand assay; B2R, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and cyclooxygenases 1and 2 (COX-1, and COX-2) were evaluated by western blot; intracellular Ca{sup +2} levels were evaluated with Fluo-4AM; collagen secretion was measured in the culture media using the picrosirius red assay kit. Results: B2R, iNOS, COX-1 and low levels of B1R but not eNOS, were detected by western blot in CF. Also, B1R, B2R, and COX-2 but not iNOS, eNOS or COX-1, were detected by western blot in CMF. By immunocytochemistry, our results showed lower intracellular B1R levels in CF and higher B1R levels in CMF, mainly localized on the cell membrane. Additionally, we found B1R only in CMF cellular membrane through radioligand displacement assay. Bradykinin (BK) B2R agonist increased intracellular Ca{sup 2+} levels and reduced collagen secretion both in CF and CMF. These effects were blocked by HOE-140, and inhibited by L-NAME, 1400W and indomethacin. Des-Arg-kallidin (DAKD) B1R agonist did not increase intracellular Ca{sup 2+} levels in CF; however, after preincubation for 1 h with DAKD and re-stimulation with the same agonist, we found a low increase in intracellular Ca{sup 2+} levels. Finally, DAKD increased intracellular Ca{sup 2+} levels and decreased collagen secretion in CMF, being this effect blocked by the B1R antagonist des-Arg9-Leu8-kallidin and indomethacin, but not by L-NAME or 1400 W. Conclusion: B1R, B2R, iNOS and COX-1 were expressed differently between CF and CMF, and collagen secretion was

  5. Differential regulation of collagen secretion by kinin receptors in cardiac fibroblast and myofibroblast

    International Nuclear Information System (INIS)

    Catalán, Mabel; Smolic, Christian; Contreras, Ariel; Ayala, Pedro; Olmedo, Ivonne; Copaja, Miguel; Boza, Pía; Vivar, Raúl; Avalos, Yennifer; Lavandero, Sergio; Velarde, Victoria; Díaz-Araya, Guillermo

    2012-01-01

    Kinins mediate their cellular effects through B1 (B1R) and B2 (B2R) receptors, and the activation of B2R reduces collagen synthesis in cardiac fibroblasts (CF). However, the question of whether B1R and/or B2R have a role in cardiac myofibroblasts remains unanswered. Methods: CF were isolated from neonate rats and myofibroblasts were generated by an 84 h treatment with TGF-β1 (CMF). B1R was evaluated by western blot, immunocytochemistry and radioligand assay; B2R, inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and cyclooxygenases 1and 2 (COX-1, and COX-2) were evaluated by western blot; intracellular Ca +2 levels were evaluated with Fluo-4AM; collagen secretion was measured in the culture media using the picrosirius red assay kit. Results: B2R, iNOS, COX-1 and low levels of B1R but not eNOS, were detected by western blot in CF. Also, B1R, B2R, and COX-2 but not iNOS, eNOS or COX-1, were detected by western blot in CMF. By immunocytochemistry, our results showed lower intracellular B1R levels in CF and higher B1R levels in CMF, mainly localized on the cell membrane. Additionally, we found B1R only in CMF cellular membrane through radioligand displacement assay. Bradykinin (BK) B2R agonist increased intracellular Ca 2+ levels and reduced collagen secretion both in CF and CMF. These effects were blocked by HOE-140, and inhibited by L-NAME, 1400W and indomethacin. Des-Arg-kallidin (DAKD) B1R agonist did not increase intracellular Ca 2+ levels in CF; however, after preincubation for 1 h with DAKD and re-stimulation with the same agonist, we found a low increase in intracellular Ca 2+ levels. Finally, DAKD increased intracellular Ca 2+ levels and decreased collagen secretion in CMF, being this effect blocked by the B1R antagonist des-Arg9-Leu8-kallidin and indomethacin, but not by L-NAME or 1400 W. Conclusion: B1R, B2R, iNOS and COX-1 were expressed differently between CF and CMF, and collagen secretion was regulated differentially by

  6. Fracture mechanics of collagen fibrils

    DEFF Research Database (Denmark)

    Svensson, Rene B; Mulder, Hindrik; Kovanen, Vuokko

    2013-01-01

    Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within...... fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy...... technique to measure the mechanical behavior of individual collagen fibrils loaded to failure. Fibrils from human patellar tendons, rat-tail tendons (RTTs), NaBH₄ reduced RTTs, and tail tendons of Zucker diabetic fat rats were tested. We found a characteristic three-phase stress-strain behavior in the human...

  7. Preparation, Cell Compatibility and Degradability of Collagen-Modified Poly(lactic acid

    Directory of Open Access Journals (Sweden)

    Miaomiao Cui

    2015-01-01

    Full Text Available Poly(lactic acid (PLA was modified using collagen through a grafting method to improve its biocompatibility and degradability. The carboxylic group at the open end of PLA was transferred into the reactive acylchlorided group by a reaction with phosphorus pentachloride. Then, collagen-modified PLA (collagen-PLA was prepared by the reaction between the reactive acylchlorided group and amino/hydroxyl groups on collagen. Subsequently, the structure of collagen-PLA was confirmed by Fourier transform infrared spectroscopy, fluorescein isothiocyanate-labeled fluorescence spectroscopy, X-ray photoelectron spectroscopy, and DSC analyses. Finally, some properties of collagen-PLA, such as hydrophilicity, cell compatibility and degradability were characterized. Results showed that collagen had been grafted onto the PLA with 5% graft ratio. Water contact angle and water absorption behavior tests indicated that the hydrophilicity of collagen-PLA was significantly higher than that of PLA. The cell compatibility of collagen-PLA with mouse embryonic fibroblasts (3T3 was also significantly better than PLA in terms of cell morphology and cell proliferation, and the degradability of PLA was also improved after introducing collagen. Results suggested that collagen-PLA was a promising candidate for biomedical applications.

  8. Mapuche herbal medicine inhibits blood platelet aggregation.

    Science.gov (United States)

    Falkenberg, Susan Skanderup; Tarnow, Inge; Guzman, Alfonso; Mølgaard, Per; Simonsen, Henrik Toft

    2012-01-01

    12 plant species traditionally used by the Mapuche people in Chile to treat wounds and inflammations have been evaluated for their direct blood platelet inhibition. Seven of the 12 tested plant species showed platelet inhibitory effect in sheep blood, and four of these were also able to inhibit the ADP- (5.0 μM) and collagen- (2.0 μg/mL) induced aggregations in human blood. These four species in respective extracts (in brackets) were Blechnum chilense (MeOH), Luma apiculata (H(2)O), Amomyrtus luma (DCM : MeOH 1 : 1) and Cestrum parqui (DCM : MeOH 1 : 1). The platelet aggregating inhibitory effects of A. luma (DCM : MeOH 1 : 1), and L. apiculata (H(2)O) were substantial and confirmed by inhibition of platelet surface activation markers.

  9. The response to estrogen deprivation on cartilage collagen degradation markers; CTX-II is unique compared to other markers of collagen turnover

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Tabassi, Nadine; Sondergaard, Lene

    2009-01-01

    ABSTRACT: INTRODUCTION: The urinary level of type II collagen degradation marker CTX-II is increased in postmenopausal women and in ovariectomized rats, suggesting that estrogen deprivation induces cartilage breakdown. Here we investigate whether this response to estrogen holds true for other type...... II collagen turnover markers known to be affected in osteoarthritis, and whether it relates to its presence in specific areas of cartilage tissue. METHODS: The type II collagen degradation markers CTX-II and Helix-II were measured in body fluids of pre- and postmenopausal women and of ovariectomized...... rats receiving estrogen or not. Levels of PIIANP, a marker of type II collagen synthesis, were also measured in rats. Rat knee cartilage was analyzed for immunoreactivity of CTX-II and PIIANP and for type II collagen expression. RESULTS: As expected, urinary levels of CTX-II are significantly increased...

  10. Collagen Induced Arthritis in DBA/1J Mice Associates with Oxylipin Changes in Plasma

    Directory of Open Access Journals (Sweden)

    Min He

    2015-01-01

    Full Text Available Oxylipins play important roles in various biological processes and are considered as mediators of inflammation for a wide range of diseases such as rheumatoid arthritis (RA. The purpose of this research was to study differences in oxylipin levels between a widely used collagen induced arthritis (CIA mice model and healthy control (Ctrl mice. DBA/1J male mice (age: 6-7 weeks were selected and randomly divided into two groups, namely, a CIA and a Ctrl group. The CIA mice were injected intraperitoneally (i.p. with the joint cartilage component collagen type II (CII and an adjuvant injection of lipopolysaccharide (LPS. Oxylipin metabolites were extracted from plasma for each individual sample using solid phase extraction (SPE and were detected with high performance liquid chromatography/tandem mass spectrometry (HPLC-ESI-MS/MS, using dynamic multiple reaction monitoring (dMRM. Both univariate and multivariate statistical analyses were applied. The results in univariate Student’s t-test revealed 10 significantly up- or downregulated oxylipins in CIA mice, which were supplemented by another 6 additional oxylipins, contributing to group clustering upon multivariate analysis. The dysregulation of these oxylipins revealed the presence of ROS-generated oxylipins and an increase of inflammation in CIA mice. The results also suggested that the collagen induced arthritis might associate with dysregulation of apoptosis, possibly inhibited by activated NF-κB because of insufficient PPAR-γ ligands.

  11. Factors regulating collagen synthesis and degradation during second-intention healing of wounds in the thoracic region and the distal aspect of the forelimb of horses.

    Science.gov (United States)

    Schwartz, Anne J; Wilson, David A; Keegan, Kevin G; Ganjam, Venkataseshu K; Sun, Yao; Weber, Karl T; Zhang, Jiakun

    2002-11-01

    To determine significant molecular and cellular factors responsible for differences in second-intention healing in thoracic and metacarpal wounds of horses. 6 adult mixed-breed horses. A full-thickness skin wound on the metacarpus and another such wound on the pectoral region were created, photographed, and measured, and tissue was harvested from these sites weekly for 4 weeks. Gene expression of type-I collagen, transforming growth factor (TGF)-beta1, matrix metalloproteinase (MMP)-1, and tissue inhibitor of metalloproteinase (TIMP)-1 were determined by quantitative in situ hybridization. Myofibroblasts were detected by immunohistochemical labeling with alpha-smooth muscle actin (alpha-SMA). Collagen accumulation was detected by use of picrosirius red staining. Tissue morphology was examined by use of H&E staining. Unlike thoracic wounds, forelimb wounds enlarged during the first 2 weeks. Myofibroblasts, detected by week 1, remained abundant with superior organization in thoracic wounds. Type-I collagen mRNA accumulated progressively in both wounds. More type-I collagen and TGF-beta1 mRNA were seen in forelimb wounds. Volume of MMP-1 mRNA decreased from day 0 in both wounds. By week 3, TIMP-1 mRNA concentration was greater in thoracic wounds. Greater collagen synthesis in metacarpal than thoracic wounds was documented by increased concentrations of myofibroblasts, type-I collagen mRNA,TGF-beta1 mRNA, and decreased collagen degradation (ie, MMP-1). Imbalanced collagen synthesis and degradation likely correlate with development of exuberant granulation tissue, delaying healing in wounds of the distal portions of the limbs. Factors that inhibit collagen synthesis or stimulate collagenase may provide treatment options for horses with exuberant granulation tissue.

  12. Mesenchymal Stem Cells Promote the Osteogenesis in Collagen-Induced Arthritic Mice through the Inhibition of TNF-α

    OpenAIRE

    Liu, Chang; Zhang, Huayong; Tang, Xiaojun; Feng, Ruihai; Yao, Genhong; Chen, Weiwei; Li, Wenchao; Liang, Jun; Feng, Xuebing; Sun, Lingyun

    2018-01-01

    Objective. To investigate the effects of umbilical cord mesenchymal stem cell (UC-MSC) transplantation on joint damage and osteoporosis in collagen-induced arthritis (CIA) mice and to explore the mechanisms by which UC-MSCs modulate the osteogenic differentiation. Methods. CIA mice were divided into the following treated groups: UC-MSC transplantation group, antitumor necrosis factor- (TNF-) α group, and zoledronic acid (ZA) group. Microcomputed tomography (micro-CT) was used to analyze the b...

  13. Study of collagen metabolism and regulation after β radiation injury

    International Nuclear Information System (INIS)

    Zhou Yinghui; Xu Lan; Wu Shiliang; Qiu Hao; Jiang Zhi; Tu Youbin; Zhang Xueguang

    2001-01-01

    The animal model of β radiation injury was established by the β radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 were tested. The contents of TGF-β 1 , IL-6 were also detected. The results showed that after exposure to β radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-β 1 , IL-6 increased. The results suggest that changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-β 1 , IL-6 may be essential in the regulation of the collagen metabolism

  14. Collagen derived serum markers in carcinoma of the prostate

    DEFF Research Database (Denmark)

    Rudnicki, M; Jensen, L T; Iversen, P

    1995-01-01

    Three new collagen markers deriving from the collagenous matrix, e.g. carboxyterminal propeptide of type I procollagen (PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP), and aminoterminal propeptide of type III procollagen (PIIINP) were used for the diagnose...

  15. Immunosuppression by fractionated total lymphoid irradiation in collagen arthritis

    International Nuclear Information System (INIS)

    McCune, W.J.; Buckley, J.A.; Belli, J.A.; Trentham, D.E.

    1982-01-01

    Treatments with fractionated total lymphoid irradiation (TLI) and cyclophosphamide were evaluated for rats injected with type II collagen. Preadministration of TLI and repeated injections of cyclophosphamide suppressed the severity of arthritis and lowered antibody titers to collagen significantly. TLI initiated at the onset of collagen arthritis decreased humoral and cellular responses to collagen but did not affect the severity of arthritis. These data demonstrate that both TLi and cyclophosphamide are immunosuppressive in an experimentally inducible autoimmune disease

  16. Effect of wettability and surface roughness on the adhesion properties of collagen on PDMS films treated by capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Juárez-Moreno, J.A. [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico); Ávila-Ortega, A. [Facultad de Ingeniería Química—UADY, Periférico Norte Kilómetro 33.5, Col. Chuburna de Hidalgo Inn, C.P. , 97203 Mérida, Yucatán (Mexico); Oliva, A.I. [Centro de Investigación y de Estudios Avanzados del IPN–Unidad Mérida, Km. 6 Antigua carretera a Progreso Apdo. Postal 73, Cordemex, 97310 Mérida, Yucatán (Mexico); Avilés, F. [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico); Cauich-Rodríguez, J.V., E-mail: jvcr@cicy.mx [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico)

    2015-09-15

    Highlights: • Plasma treatment was used as an adhesive tool for PDMS/collagen composite preparation. • Response surface methodology was used for statistical optimization. • A microscopic roughness can also lead to a mechanical interlocking between materials. • Hydroxyl groups on the PDMS surface contribute to the enhanced chemical interactions. • PDMS/collagen composite obtained by plasma treatment exhibited higher peel strength. - Abstract: Direct chemical bonding of biomolecules to the surface of chemically inert polymers such as polydimethylsiloxane (PDMS) is not easily achieved. Therefore, pre-activation of such materials, followed by attachment of the biomolecule is necessary. This paper describes a procedure to functionalize a PDMS surface by oxygen-based plasma followed by the adhesion of collagen type I for the preparation of adhesive-free bilayer composite intended as skin substitute. Plasma treatments between 40 and 120 W for 5 to 15 min were used and the extent of surface modification was followed by contact angle, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and adhesion test. It was found that as the plasma power and time were increased, PDMS contact angle decreased while surface roughness increased as revealed by SEM and AFM. The formation of oxygen-containing functional groups at the surface was detected by FTIR. T-peel tests, performed on PDMS treated at 80 W/13 min and covered with collagen showed maximum peel strength of 0.1 N/mm which was 3 times higher than that measured for the untreated bilayer composite. The observed enhancement in the adhesion strength was attributed to the increased mechanical interlocking driven by the increased roughness and the formation of hydrophilic functional groups.

  17. Effect of wettability and surface roughness on the adhesion properties of collagen on PDMS films treated by capacitively coupled oxygen plasma

    International Nuclear Information System (INIS)

    Juárez-Moreno, J.A.; Ávila-Ortega, A.; Oliva, A.I.; Avilés, F.; Cauich-Rodríguez, J.V.

    2015-01-01

    Highlights: • Plasma treatment was used as an adhesive tool for PDMS/collagen composite preparation. • Response surface methodology was used for statistical optimization. • A microscopic roughness can also lead to a mechanical interlocking between materials. • Hydroxyl groups on the PDMS surface contribute to the enhanced chemical interactions. • PDMS/collagen composite obtained by plasma treatment exhibited higher peel strength. - Abstract: Direct chemical bonding of biomolecules to the surface of chemically inert polymers such as polydimethylsiloxane (PDMS) is not easily achieved. Therefore, pre-activation of such materials, followed by attachment of the biomolecule is necessary. This paper describes a procedure to functionalize a PDMS surface by oxygen-based plasma followed by the adhesion of collagen type I for the preparation of adhesive-free bilayer composite intended as skin substitute. Plasma treatments between 40 and 120 W for 5 to 15 min were used and the extent of surface modification was followed by contact angle, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and adhesion test. It was found that as the plasma power and time were increased, PDMS contact angle decreased while surface roughness increased as revealed by SEM and AFM. The formation of oxygen-containing functional groups at the surface was detected by FTIR. T-peel tests, performed on PDMS treated at 80 W/13 min and covered with collagen showed maximum peel strength of 0.1 N/mm which was 3 times higher than that measured for the untreated bilayer composite. The observed enhancement in the adhesion strength was attributed to the increased mechanical interlocking driven by the increased roughness and the formation of hydrophilic functional groups

  18. Stability and cellular responses to fluorapatite-collagen composites.

    Science.gov (United States)

    Yoon, Byung-Ho; Kim, Hae-Won; Lee, Su-Hee; Bae, Chang-Jun; Koh, Young-Hag; Kong, Young-Min; Kim, Hyoun-Ee

    2005-06-01

    Fluorapatite (FA)-collagen composites were synthesized via a biomimetic coprecipitation method in order to improve the structural stability and cellular responses. Different amounts of ammonium fluoride (NH4F), acting as a fluorine source for FA, were added to the precipitation of the composites. The precipitated composites were freeze-dried and isostatically pressed in a dense body. The added fluorine was incorporated nearly fully into the apatite structure (fluoridation), and a near stoichiometric FA-collagen composite was obtained with complete fluoridation. The freeze-dried composites had a typical biomimetic network, consisting of collagen fibers and precipitates of nano-sized apatite crystals. The human osteoblast-like cells on the FA-collagen composites exhibited significantly higher proliferation and differentiation (according to alkaline phosphatase activity) than those on the hydroxyapatite-collagen composite. These enhanced osteoblastic cell responses were attributed to the fluorine release and the reduced dissolution rate.

  19. Controlled self assembly of collagen nanoparticle

    Science.gov (United States)

    Papi, Massimiliano; Palmieri, Valentina; Maulucci, Giuseppe; Arcovito, Giuseppe; Greco, Emanuela; Quintiliani, Gianluca; Fraziano, Maurizio; De Spirito, Marco

    2011-11-01

    In recent years carrier-mediated drug delivery has emerged as a powerful methodology for the treatment of various pathologies. The therapeutic index of traditional and novel drugs is enhanced via the increase of specificity due to targeting of drugs to a particular tissue, cell or intracellular compartment, the control over release kinetics, the protection of the active agent, or a combination of the above. Collagen is an important biomaterial in medical applications and ideal as protein-based drug delivery platform due to its special characteristics, such as biocompatibility, low toxicity, biodegradability, and weak antigenicity. While some many attempts have been made, further work is needed to produce fully biocompatible collagen hydrogels of desired size and able to release drugs on a specific target. In this article we propose a novel method to obtain spherical particles made of polymerized collagen surrounded by DMPC liposomes. The liposomes allow to control both the particles dimension and the gelling environment during the collagen polymerization. Furthermore, an optical based method to visualize and quantify each step of the proposed protocol is detailed and discussed.

  20. Collagenous gastritis: a morphologic and immunohistochemical study of 40 patients.

    Science.gov (United States)

    Arnason, Thomas; Brown, Ian S; Goldsmith, Jeffrey D; Anderson, William; O'Brien, Blake H; Wilson, Claire; Winter, Harland; Lauwers, Gregory Y

    2015-04-01

    Collagenous gastritis is a rare condition defined histologically by a superficial subepithelial collagen layer. This study further characterizes the morphologic spectrum of collagenous gastritis by evaluating a multi-institutional series of 40 patients (26 female and 14 male). The median age at onset was 16 years (range 3-89 years), including 24 patients (60%) under age 18. Twelve patients (30%) had associated celiac disease, collagenous sprue, or collagenous colitis. Hematoxylin and eosin slides were reviewed in biopsies from all patients and tenascin, gastrin, eotaxin, and IgG4/IgG immunohistochemical stains were applied to a subset. The distribution of subepithelial collagen favored the body/fundus in pediatric patients and the antrum in adults. There were increased surface intraepithelial lymphocytes (>25 lymphocytes/100 epithelial cells) in five patients. Three of these patients had associated celiac and/or collagenous sprue/colitis, while the remaining two had increased duodenal lymphocytosis without specific etiology. An eosinophil-rich pattern (>30 eosinophils/high power field) was seen in 21/40 (52%) patients. Seven patients' biopsies demonstrated atrophy of the gastric corpus mucosa. Tenascin immunohistochemistry highlighted the subepithelial collagen in all 21 specimens evaluated and was a more sensitive method of collagen detection in biopsies from two patients with subtle subepithelial collagen. No increased eotaxin expression was identified in 16 specimens evaluated. One of the twenty-three biopsies tested had increased IgG4-positive cells (100/high power field) with an IgG4/IgG ratio of 55%. In summary, collagenous gastritis presents three distinct histologic patterns including a lymphocytic gastritis-like pattern, an eosinophil-rich pattern, and an atrophic pattern. Eotaxin and IgG4 were not elevated enough to implicate these pathways in the pathogenesis. Tenascin immunohistochemistry can be used as a sensitive method of collagen detection.

  1. Development of a novel collagen-GAG nanofibrous scaffold via electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Shaoping [Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent 119260 (Singapore); Teo, Wee Eong [Division of Bioengineering, National University of Singapore, 10 Kent Ridge Crescent 119260 (Singapore); Zhu Xiao [Singapore Eye Research Institute, Singapore National Eye Center, 11 Third Hospital Avenue, Singapore 168751 (Singapore); Beuerman, Roger [Singapore Eye Research Institute, Singapore National Eye Center, 11 Third Hospital Avenue, Singapore 168751 (Singapore); Ramakrishna, Seeram [Division of Bioengineering, National University of Singapore, 10 Kent Ridge Crescent 119260 (Singapore); Yung, Lin Yue Lanry [Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent 119260 (Singapore)]. E-mail: cheyly@nus.edu.sg

    2007-03-15

    Collagen and glycosaminoglycan (GAG) are native constituents of human tissues and are widely utilized to fabricate scaffolds serving as an analog of native extracellular matrix (ECM).The development of blended collagen and GAG scaffolds may potentially be used in many soft tissue engineering applications since the scaffolds mimic the structure and biological function of native ECM. In this study, we were able to obtain a novel nanofibrous collagen-GAG scaffold by electrospinning with collagen and chondroitin sulfate (CS), a widely used GAG. The electrospun collagen-GAG scaffold exhibited a uniform fiber structure in nano-scale diameter. By crosslinking with glutaraldehyde vapor, the collagen-GAG scaffolds could resist from collagenase degradation and enhance the biostability of the scaffolds. This led to the increased proliferation of rabbit conjunctiva fibroblast on the scaffolds. Incorporation of CS into collagen nanofibers without crosslinking did not increase the biostability but still promoted cell growth. In conclusion, the electrospun collagen-GAG scaffolds, with high surface-to-volume ratio, may potentially provide a better environment for tissue formation/biosynthesis compared with the traditional scaffolds.

  2. Development of a novel collagen-GAG nanofibrous scaffold via electrospinning

    International Nuclear Information System (INIS)

    Zhong Shaoping; Teo, Wee Eong; Zhu Xiao; Beuerman, Roger; Ramakrishna, Seeram; Yung, Lin Yue Lanry

    2007-01-01

    Collagen and glycosaminoglycan (GAG) are native constituents of human tissues and are widely utilized to fabricate scaffolds serving as an analog of native extracellular matrix (ECM).The development of blended collagen and GAG scaffolds may potentially be used in many soft tissue engineering applications since the scaffolds mimic the structure and biological function of native ECM. In this study, we were able to obtain a novel nanofibrous collagen-GAG scaffold by electrospinning with collagen and chondroitin sulfate (CS), a widely used GAG. The electrospun collagen-GAG scaffold exhibited a uniform fiber structure in nano-scale diameter. By crosslinking with glutaraldehyde vapor, the collagen-GAG scaffolds could resist from collagenase degradation and enhance the biostability of the scaffolds. This led to the increased proliferation of rabbit conjunctiva fibroblast on the scaffolds. Incorporation of CS into collagen nanofibers without crosslinking did not increase the biostability but still promoted cell growth. In conclusion, the electrospun collagen-GAG scaffolds, with high surface-to-volume ratio, may potentially provide a better environment for tissue formation/biosynthesis compared with the traditional scaffolds

  3. Impaired epidermal wound healing in vivo upon inhibition or deletion of Rac1

    DEFF Research Database (Denmark)

    Tscharntke, Michael; Pofahl, Ruth; Chrostek-Grashoff, Anna

    2007-01-01

    inhibited on collagen I and, to a lesser extent, on fibronectin. Stroboscopic analysis of cell dynamics (SACED) of N17Rac1 transgenic and control keratinocytes identified decreased lamella-protrusion persistence in connection with increased ruffle frequency as a probable mechanism for the observed...

  4. Asporin competes with decorin for collagen binding, binds calcium and promotes osteoblast collagen mineralization

    DEFF Research Database (Denmark)

    Kalamajski, Sebastian; Aspberg, Anders; Lindblom, Karin

    2009-01-01

    , but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyapatite formation in vitro. In the presence of asporin, the number of collagen nodules, and mRNA of osteoblastic markers Osterix and Runx2, were increased. Moreover, decorin or the collagen-binding asporin fragment...... biomineralization activity. We also show that asporin can be expressed in Escherichia coli (Rosetta-gami) with correctly positioned cysteine bridges, and a similar system can possibly be used for the expression of other SLRPs (small LRR proteoglycans/proteins)....

  5. Mycobacterial laminin-binding histone-like protein mediates collagen-dependent cytoadherence

    Directory of Open Access Journals (Sweden)

    André Alves Dias

    2012-12-01

    Full Text Available When grown in the presence of exogenous collagen I, Mycobacterium bovis BCG was shown to form clumps. Scanning electron microscopy examination of these clumps revealed the presence of collagen fibres cross-linking the bacilli. Since collagen is a major constituent of the eukaryotic extracellular matrices, we assayed BCG cytoadherence in the presence of exogenous collagen I. Collagen increased the interaction of the bacilli with A549 type II pneumocytes or U937 macrophages, suggesting that BCG is able to recruit collagen to facilitate its attachment to host cells. Using an affinity chromatography approach, we have isolated a BCG collagen-binding protein corresponding to the previously described mycobacterial laminin-binding histone-like protein (LBP/Hlp, a highly conserved protein associated with the mycobacterial cell wall. Moreover, Mycobacterium leprae LBP/Hlp, a well-characterized adhesin, was also able to bind collagen I. Finally, using recombinant fragments of M. leprae LBP/Hlp, we mapped the collagen-binding activity within the C-terminal domain of the adhesin. Since this protein was already shown to be involved in the recognition of laminin and heparan sulphate-containing proteoglycans, the present observations reinforce the adhesive activities of LBP/Hlp, which can be therefore considered as a multifaceted mycobacterial adhesin, playing an important role in both leprosy and tuberculosis pathogenesis.

  6. Collagen-Induced Arthritis: A model for Murine Autoimmune Arthritis

    OpenAIRE

    Pietrosimone, K. M.; Jin, M.; Poston, B.; Liu, P.

    2015-01-01

    Collagen-induced arthritis (CIA) is a common autoimmune animal model used to study rheumatoid arthritis (RA). The development of CIA involves infiltration of macrophages and neutrophils into the joint, as well as T and B cell responses to type II collagen. In murine CIA, genetically susceptible mice (DBA/1J) are immunized with a type II bovine collagen emulsion in complete Freund’s adjuvant (CFA), and receive a boost of type II bovine collagen in incomplete Freund’s adjuvant (IFA) 21 days aft...

  7. Study of collagen metabolism and regulation after {beta} radiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Yinghui, Zhou; Lan, Xu; Shiliang, Wu; Hao, Qiu; Zhi, Jiang; Youbin, Tu; Xueguang, Zhang [Suzhou Medical College (China)

    2001-04-01

    The animal model of {beta} radiation injury was established by the {beta} radiation produced by the linear accelerator; and irradiated NIH 3T3 cells were studied. In the experiment the contents of total collagen, collagen type I and type III were measured. The activity of MMPs-1 were tested. The contents of TGF-{beta}{sub 1}, IL-6 were also detected. The results showed that after exposure to {beta} radiation, little change was found in the content of total collagen, but the content of collagen I decreased and the content of collagen III, MMPs-1 activity increased; the expression of TGF-{beta}{sub 1}, IL-6 increased. The results suggest that changes in the metabolism of collagen play an important role in the irradiated injury of the skin; TGF-{beta}{sub 1}, IL-6 may be essential in the regulation of the collagen metabolism.

  8. Type V Collagen is Persistently Altered after Inguinal Hernia Repair

    DEFF Research Database (Denmark)

    Lorentzen, L; Henriksen, N A; Juhl, P

    2018-01-01

    BACKGROUND AND AIMS: Hernia formation is associated with alterations of collagen metabolism. Collagen synthesis and degradation cause a systemic release of products, which are measurable in serum. Recently, we reported changes in type V and IV collagen metabolisms in patients with inguinal...... elective cholecystectomy served as controls (n = 10). Whole venous blood was collected 35-55 months after operation. Biomarkers for type V collagen synthesis (Pro-C5) and degradation (C5M) and those for type IV collagen synthesis (P4NP) and degradation (C4M2) were measured by a solid-phase competitive...... assay. RESULTS: The turnover of type V collagen (Pro-C5/C5M) was slightly higher postoperatively when compared to preoperatively in the inguinal hernia group (P = 0.034). In addition, the results revealed a postoperatively lower type V collagen turnover level in the inguinal hernia group compared...

  9. In vivo determination of arterial collagen synthesis in atherosclerotic rabbits

    International Nuclear Information System (INIS)

    Opsahl, W.P.; DeLuca, D.J.; Ehrhart, L.A.

    1986-01-01

    Collagen and non-collagen protein synthesis rates were determined in vivo in tissues from rabbits fed a control or atherogenic diet supplemented with 2% peanut oil and 0.25% cholesterol for 4 months. Rabbits received a bolus intravenous injection of L-[ 3 H]-proline (1.0 mCi/kg) and unlabeled L-proline (7 mmoles/kg) in 0.9% NaCl. Plasma proline specific activity decreased only 20% over 5 hr and was similar to the specific activity of free proline in tissues. Thoracic aortas from atherosclerotic rabbits exhibited raised plaques covering at least 75% of the surface. Thoracic intima plus a portion of the media (TIM) was separated from the remaining media plus adventitia (TMA). Dry delipidated weight, total collagen content, and collagen as a percent of dry weight were increased significantly in the TIM of atherosclerotic rabbits. Collagen synthesis rates and collagen synthesis as a percent of total protein synthesis were likewise increased both in the TIM and in the abdominal aortas. No differences from controls either in collagen content or collagen synthesis rates were observed in the TMA, lung or skin. These results demonstrate for the first time in vivo that formation of atherosclerotic plaques is associated with increased rates of collagen synthesis. Furthermore, as previously observed with incubations in vitro, collagen synthesis was elevated to a greater extent than noncollagen protein synthesis in atherosclerotic aortas from rabbits fed cholesterol plus peanut oil

  10. Protective effects of a blueberry extract in acute inflammation and collagen-induced arthritis in the rat.

    Science.gov (United States)

    Figueira, Maria-Eduardo; Oliveira, Mónica; Direito, Rosa; Rocha, João; Alves, Paula; Serra, Ana-Teresa; Duarte, Catarina; Bronze, Rosário; Fernandes, Adelaide; Brites, Dora; Freitas, Marisa; Fernandes, Eduarda; Sepodes, Bruno

    2016-10-01

    Here we investigated the anti-inflammatory effect of a blueberry extract in the carrageenan-induced paw edema model and collagen-induced arthritis model, both in rats. Along with the chemical characterization of the phenolic content of the fruits and extract, the antioxidant potential of the extract, the cellular antioxidant activity and the effects over neutrophils' oxidative burst, were studied in order to provide a mechanistic insight for the anti-inflammatory effects observed. The extract significantly inhibited paw edema formation in an acute model the rat. Our results also demonstrate that the standardized extract had pharmacological activity when administered orally in the collagen-induced arthritis model in the rat and was able to significantly reduce the development of clinical signs of arthritis and the degree of bone resorption, soft tissue swelling and osteophyte formation, consequently improving articular function in treated animals. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Activation of PPARs α, β/δ, and γ Impairs TGF-β1-Induced Collagens' Production and Modulates the TIMP-1/MMPs Balance in Three-Dimensional Cultured Chondrocytes

    Directory of Open Access Journals (Sweden)

    Paul-Emile Poleni

    2010-01-01

    Full Text Available Background and Purpose. We investigated the potency of Peroxisome Proliferators-Activated Receptors (PPARs α, β/δ, and γ agonists to modulate Transforming Growth Factor-β1 (TGF-β1- induced collagen production or changes in Tissue Inhibitor of Matrix Metalloproteinase- (TIMP- 1/Matrix Metalloproteinase (MMP balance in rat chondrocytes embedded in alginate beads. Experimental Approach. Collagen production was evaluated by quantitative Sirius red staining, while TIMP-1 protein levels and global MMP (-1, -2, -3, -7, and -9 or specific MMP-13 activities were measured by ELISA and fluorigenic assays in culture media, respectively. Levels of mRNA for type II collagen, TIMP-1, and MMP-3 & 13 were quantified by real-time PCR. Key Results. TGF-β1 increased collagen deposition and type II collagen mRNA levels, while inducing TIMP-1 mRNA and protein expression. In contrast, it decreased global MMP or specific MMP-13 activities, while decreasing MMP-3 or MMP-13 mRNA levels. PPAR agonists reduced most of the effects of TGF-β1 on changes in collagen metabolism and TIMP-1/MMP balance in rat in a PPAR-dependent manner, excepted for Wy14643 on MMP activities. Conclusions and Implications. PPAR agonists reduce TGF-β1-modulated ECM turnover and inhibit chondrocyte activities crucial for collagen biosynthesis, and display a different inhibitory profile depending on selectivity for PPAR isotypes.

  12. A urokinase receptor-associated protein with specific collagen binding properties

    DEFF Research Database (Denmark)

    Behrendt, N; Jensen, O N; Engelholm, L H

    2000-01-01

    membrane-bound lectin with hitherto unknown function. The human cDNA was cloned and sequenced. The protein, designated uPARAP, is a member of the macrophage mannose receptor protein family and contains a putative collagen-binding (fibronectin type II) domain in addition to 8 C-type carbohydrate recognition...... domains. It proved capable of binding strongly to a single type of collagen, collagen V. This collagen binding reaction at the exact site of plasminogen activation on the cell may lead to adhesive functions as well as a contribution to cellular degradation of collagen matrices....

  13. Decorin alleviated chronic hydrocephalus via inhibiting TGF-β1/Smad/CTGF pathway after subarachnoid hemorrhage in rats.

    Science.gov (United States)

    Yan, Hui; Chen, Yujie; Li, Lingyong; Jiang, Jiaode; Wu, Guangyong; Zuo, Yuchun; Zhang, John H; Feng, Hua; Yan, Xiaoxin; Liu, Fei

    2016-01-01

    Chronic hydrocephalus is one of the severe complications after subarachnoid hemorrhage (SAH). However, there is no efficient treatment for the prevention of chronic hydrocephalus, partially due to poor understanding of underlying pathogenesis, subarachnoid fibrosis. Transforming growth factor-β1(TGF-β1) is a potent fibrogenic factor implicated in wide range of fibrotic diseases. To investigate whether decorin, a natural antagonist for TGF-β1, protects against subarachnoid fibrosis and chronic hydrocephalus after SAH, two-hemorrhage-injection SAH model was conducted in 6-week-old rats. Recombinant human decorin(rhDecorin) (30ug/2ul) was administered before blood injection and on the 10th day after SAH. TGF-β1, p-Smad2/3, connective tissue growth factor (CTGF), collagen I and pro-collagen I c-terminal propeptide were assessed via western blotting, enzyme-linked immunosorbent assay, radioimmunoassay and immunofluorescence. And neurobehavioral tests and Morris water maze were employed to evaluate long-term neurological functions after SAH. We found that SAH induced heightened activation of TGF-β1/Smad/CTGF axis, presenting as a two peak response of TGF-β1 in cerebrospinal fluid, elevation of TGF-β1, p-Smad2/3, CTGF, collagen I in brain parenchyma and pro-collagen I c-terminal propeptide in cerebrospinal fluid, and increased lateral ventricle index. rhDecorin treatment effectively inhibited up-regulation of TGF-β1, p-Smad2/3, CTGF, collagen I and pro-collagen I c-terminal propeptide after SAH. Moreover, rhDecorin treatment significantly reduced lateral ventricular index and incidence of chronic hydrocephalus after SAH. Importantly, rhDecorin improved neurocognitive deficits after SAH. In conclusion, rhDecorin suppresses extracellular matrix accumulation and following subarachnoid fibrosis via inhibiting TGF-β1/Smad/CTGF pathway, preventing development of hydrocephalus and attenuating long-term neurocognitive defects after SAH. Copyright © 2015 Elsevier B

  14. Collagen metabolism in obesity: the effect of weight loss

    DEFF Research Database (Denmark)

    Rasmussen, M H; Jensen, L T; Andersen, T

    1995-01-01

    OBJECTIVE: To investigate the impact of obesity, fat distribution and weight loss on collagen turnover using serum concentrations of the carboxyterminal propeptide of type I procollagen (S-PICP) and the aminoterminal propeptide of type III pro-collagen (S-PIIINP) as markers for collagen turnover...... an increased turnover of type III collagen related to obesity in general and to abdominal obesity in particular. S-PIIINP levels decreases during weight loss in obese subjects, whereas S-PICP levels seems un-related to obesity and weight loss....

  15. Location of 3-hydroxyproline residues in collagen types I, II, III, and V/XI implies a role in fibril supramolecular assembly.

    Science.gov (United States)

    Weis, Mary Ann; Hudson, David M; Kim, Lammy; Scott, Melissa; Wu, Jiann-Jiu; Eyre, David R

    2010-01-22

    Collagen triple helices are stabilized by 4-hydroxyproline residues. No function is known for the much less common 3-hydroxyproline (3Hyp), although genetic defects inhibiting its formation cause recessive osteogenesis imperfecta. To help understand the pathogenesis, we used mass spectrometry to identify the sites and local sequence motifs of 3Hyp residues in fibril-forming collagens from normal human and bovine tissues. The results confirm a single, essentially fully occupied 3Hyp site (A1) at Pro(986) in A-clade chains alpha1(I), alpha1(II), and alpha2(V). Two partially modified sites (A2 and A3) were found at Pro(944) in alpha1(II) and alpha2(V) and Pro(707) in alpha2(I) and alpha2(V), which differed from A1 in sequence motif. Significantly, the distance between sites 2 and 3, 237 residues, is close to the collagen D-period (234 residues). A search for additional D-periodic 3Hyp sites revealed a fourth site (A4) at Pro(470) in alpha2(V), 237 residues N-terminal to site 3. In contrast, human and bovine type III collagen contained no 3Hyp at any site, despite a candidate proline residue and recognizable A1 sequence motif. A conserved histidine in mammalian alpha1(III) at A1 may have prevented 3-hydroxylation because this site in chicken type III was fully hydroxylated, and tyrosine replaced histidine. All three B-clade type V/XI collagen chains revealed the same three sites of 3Hyp but at different loci and sequence contexts from those in A-clade collagen chains. Two of these B-clade sites were spaced apart by 231 residues. From these and other observations we propose a fundamental role for 3Hyp residues in the ordered self-assembly of collagen supramolecular structures.

  16. Role of surface layer collagen binding protein from indigenous Lactobacillus plantarum 91 in adhesion and its anti-adhesion potential against gut pathogen.

    Science.gov (United States)

    Yadav, Ashok Kumar; Tyagi, Ashish; Kaushik, Jai Kumar; Saklani, Asha Chandola; Grover, Sunita; Batish, Virender Kumar

    2013-12-14

    Human feacal isolates were ascertain as genus Lactobacillus using specific primer LbLMA1/R16-1 and further identified as Lactobacillus plantarum with species specific primers Lpl-3/Lpl-2. 25 L. plantarum strains were further assessed for hydrophobicity following the microbial adhesion to hydrocarbons (MATH) method and colonization potentials based on their adherence to immobilized human collagen type-1. Surface proteins were isolated from selected L. plantarum 91(Lp91) strain. The purified collagen binding protein (Cbp) protein was assessed for its anti-adhesion activity against enteric Escherichia coli 0157:H7 pathogen on immobilized collagen. Four L. plantarum strains displayed high degree of hydrophobicity and significant adhesion to collagen. A 72 kDa protein was purified which reduced 59.71% adhesion of E. coli 0157:H7 on immobilized collagen as compared to control well during adhesion assay. Cbp protein is the major influencing factor in inhibition of E. coli 0157:H7 adhesion with extracellular matrix (ECM) components. Hydrophobicity and adhesion potential are closely linked attributes precipitating in better colonization potential of the lactobacillus strains. Cbp is substantiated as a crucial surface protein contributing in adhesion of lactobacillus strains. The study can very well be the platform for commercialization of indigenous probiotic strain once their functional attributes are clinically explored. Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. Catabolic factors and osteoarthritis-conditioned medium inhibit chondrogenesis of human mesenchymal stem cells.

    Science.gov (United States)

    Heldens, Genoveva T H; Blaney Davidson, Esmeralda N; Vitters, Elly L; Schreurs, B Willem; Piek, Ester; van den Berg, Wim B; van der Kraan, Peter M

    2012-01-01

    Articular cartilage has a very limited intrinsic repair capacity leading to progressive joint damage. Therapies involving tissue engineering depend on chondrogenic differentiation of progenitor cells. This chondrogenic differentiation will have to survive in a diseased joint. We postulate that catabolic factors in this environment inhibit chondrogenesis of progenitor cells. We investigated the effect of a catabolic environment on chondrogenesis in pellet cultures of human mesenchymal stem cells (hMSCs). We exposed chondrogenically differentiated hMSC pellets, to interleukin (IL)-1α, tumor necrosis factor (TNF)-α or conditioned medium derived from osteoarthritic synovium (CM-OAS). IL-1α and TNF-α in CM-OAS were blocked with IL-1Ra or Enbrel, respectively. Chondrogenesis was determined by chondrogenic markers collagen type II, aggrecan, and the hypertrophy marker collagen type X on mRNA. Proteoglycan deposition was analyzed by safranin o staining on histology. IL-1α and TNF-α dose-dependently inhibited chondrogenesis when added at onset or during progression of differentiation, IL-1α being more potent than TNF-α. CM-OAS inhibited chondrogenesis on mRNA and protein level but varied in extent between patients. Inhibition of IL-1α partially overcame the inhibitory effect of the CM-OAS on chondrogenesis whereas the TNF-α contribution was negligible. We show that hMSC chondrogenesis is blocked by either IL-1α or TNF-α alone, but that there are additional factors present in CM-OAS that contribute to inhibition of chondrogenesis, demonstrating that catabolic factors present in OA joints inhibit chondrogenesis, thereby impairing successful tissue engineering.

  18. Biosynthesis of collagen by fibroblasts kept in culture

    International Nuclear Information System (INIS)

    Machado-Santelli, G.M.

    1978-01-01

    The sinthesis of collagen is studied in fibroblasts of different origins with the purpose of obtaining an appropriate system for the study of its biosynthesis and processing. The percentage of collagen synthesis vary according to the fibroblast origin. Experiences are performed with fibroblasts kept in culture from: chicken - and guinea pig embryos, carragheenin - induced granulomas in adult guinea pig and from human skin. The collagen pattern synthesized after acetic acid - or saline extractions in the presence of inhibitors is also determined. This pattern is then assayed by poliacrilamide - 5% - SDS gel electrophoresis accompanied by fluorography. The importance of the cell culture system in the elucidation of collagen biosynthesis is pointed out. (M.A.) [pt

  19. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  20. Demineralized dentin matrix composite collagen material for bone tissue regeneration.

    Science.gov (United States)

    Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

    2013-01-01

    Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

  1. The effects of collagen-rich extracellular matrix on the intracellular delivery of glycol chitosan nanoparticles in human lung fibroblasts.

    Science.gov (United States)

    Yhee, Ji Young; Yoon, Hong Yeol; Kim, Hyunjoon; Jeon, Sangmin; Hergert, Polla; Im, Jintaek; Panyam, Jayanth; Kim, Kwangmeyung; Nho, Richard Seonghun

    2017-01-01

    Recent progress in nanomedicine has shown a strong possibility of targeted therapy for obstinate chronic lung diseases including idiopathic pulmonary fibrosis (IPF). IPF is a fatal lung disease characterized by persistent fibrotic fibroblasts in response to type I collagen-rich extracellular matrix. As a pathological microenvironment is important in understanding the biological behavior of nanoparticles, in vitro cellular uptake of glycol chitosan nanoparticles (CNPs) in human lung fibroblasts was comparatively studied in the presence or absence of type I collagen matrix. Primary human lung fibroblasts from non-IPF and IPF patients (n=6/group) showed significantly increased cellular uptake of CNPs (>33.6-78.1 times) when they were cultured on collagen matrix. To elucidate the underlying mechanism of enhanced cellular delivery of CNPs in lung fibroblasts on collagen, cells were pretreated with chlorpromazine, genistein, and amiloride to inhibit clathrin-mediated endocytosis, caveolae-mediated endocytosis, and macropinocytosis, respectively. Amiloride pretreatment remarkably reduced the cellular uptake of CNPs, suggesting that lung fibroblasts mainly utilize the macropinocytosis-dependent mechanism when interacted with collagen. In addition, the internalization of CNPs was predominantly suppressed by a phosphoinositide 3-kinase (PI3K) inhibitor in IPF fibroblasts, indicating that enhanced PI3K activity associated with late-stage macropinocytosis can be particularly important for the enhanced cellular delivery of CNPs in IPF fibroblasts. Our study strongly supports the concept that a pathological microenvironment which surrounds lung fibroblasts has a significant impact on the intracellular delivery of nanoparticles. Based on the property of enhanced intracellular delivery of CNPs when fibroblasts are made to interact with a collagen-rich matrix, we suggest that CNPs may have great potential as a drug-carrier system for targeting fibrotic lung fibroblasts.

  2. ROCK inhibition stimulates SOX9/Smad3-dependent COL2A1 expression in inner meniscus cells.

    Science.gov (United States)

    Furumatsu, Takayuki; Maehara, Ami; Ozaki, Toshifumi

    2016-07-01

    Proper functioning of the meniscus depends on the composition and organization of its fibrocartilaginous extracellular matrix. We previously demonstrated that the avascular inner meniscus has a more chondrocytic phenotype compared with the outer meniscus. Inhibition of the Rho family GTPase ROCK, the major regulator of the actin cytoskeleton, stimulates the chondrogenic transcription factor Sry-type HMG box (SOX) 9-dependent α1(II) collagen (COL2A1) expression in inner meniscus cells. However, the crosstalk between ROCK inhibition, SOX9, and other transcription modulators on COL2A1 upregulation remains unclear in meniscus cells. The aim of this study was to investigate the role of SOX9-related transcriptional complex on COL2A1 expression under the inhibition of ROCK in human meniscus cells. Human inner and outer meniscus cells were prepared from macroscopically intact lateral menisci. Cells were cultured in the presence or absence of ROCK inhibitor (ROCKi, Y27632). Gene expression, collagen synthesis, and nuclear translocation of SOX9 and Smad2/3 were analyzed. Treatment of ROCKi increased the ratio of type I/II collagen double positive cells derived from the inner meniscus. In real-time PCR analyses, expression of SOX9 and COL2A1 genes was stimulated by ROCKi treatment in inner meniscus cells. ROCKi treatment also induced nuclear translocation of SOX9 and phosphorylated Smad2/3 in immunohistological analyses. Complex formation between SOX9 and Smad3 was increased by ROCKi treatment in inner meniscus cells. Chromatin immunoprecipitation analyses revealed that association between SOX9/Smad3 transcriptional complex with the COL2A1 enhancer region was increased by ROCKi treatment. This study demonstrated that ROCK inhibition stimulated SOX9/Smad3-dependent COL2A1 expression through the immediate nuclear translocation of Smad3 in inner meniscus cells. Our results suggest that ROCK inhibition can stimulates type II collagen synthesis through the cooperative activation

  3. Corrosion inhibition of 7000 series aluminium alloys with cerium diphenyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Julie-Anne [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Markley, Tracey [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); CSIRO, Division of Materials Science and Technology, Clayton, Victoria (Australia); Forsyth, Maria, E-mail: maria.forsyth@deakin.edu.au [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Howlett, Patrick C. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Hinton, Bruce R.W. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Defence Science and Technology Organisation, Melbourne, Victoria (Australia)

    2011-02-03

    Graphical abstract: Scanning electron micrographs of microtomed surface shows pristine surface free of corrosion related 'mud cracking' inset for an inhibited AA7050 specimen when only 150 ppm Ce(dpp)3 is present in 0.1 M NaCl solution. Display Omitted Research highlights: > The thin film of hydrolysis products of Ce(dpp)3 and aluminium oxide is proposed to cause the inhibition. > The film consists of discrete Ce rich particles and a thin film over the matrix of Ce, P and Al oxides. > Discrete deposition of Ce is specifically influenced by Cu rich intermetallics. - Abstract: Cerium diphenyl phosphate (Ce(dpp){sub 3}) has previously been shown to be a strong corrosion inhibitor for aluminium-copper magnesium alloy AA2024-T3 and AA7075 in chloride solutions. Surface characterisation including SEM and ToF-SIMS coupled with electrochemical impedance spectroscopy (EIS) measurements are used to propose a mechanism of corrosion inhibition which appears to involve the formation of a complex oxide film of aluminium and cerium also incorporating the organophosphate component. The formation of a thin complex film consisting of hydrolysis products of the Ce(dpp){sub 3} compound and aluminium oxide is proposed to lead to the observed inhibition. SEM analysis shows that some intermetallics favour the creation of thicker deposits predominantly containing cerium oxide compounds.

  4. Variation in the Helical Structure of Native Collagen

    Science.gov (United States)

    2014-02-24

    notochord were obtained in previous studies [4,10,20–22]. The scaled amplitudes of the central, meridional section of each data set were used to...including helical, structure) from rat tail tendon (collagen type I) and lamprey notochord (collagen type II) show several common features (Figure 5). Of...also a possible consequence of the type II collagen notochord samples being stretched, perhaps to a greater extant then the type I tendon samples to aid

  5. Collagen type IV at the fetal-maternal interface

    OpenAIRE

    Oefner, C M; Sharkey, A; Gardner, L; Critchley, H; Oyen, M; Moffett, A

    2015-01-01

    Introduction Extracellular matrix proteins play a crucial role in influencing the invasion of trophoblast cells. However the role of collagens and collagen type IV (col-IV) in particular at the implantation site is not clear. Methods Immunohistochemistry was used to determine the distribution of collagen types I, III, IV and VI in endometrium and decidua during the menstrual cycle and the first trimester of pregnancy. Expression of col-IV alpha chains during the reproductive cycle ...

  6. Collagen reorganization at the tumor-stromal interface facilitates local invasion

    Directory of Open Access Journals (Sweden)

    Inman David R

    2006-12-01

    Full Text Available Abstract Background Stromal-epithelial interactions are of particular significance in breast tissue as misregulation of these interactions can promote tumorigenesis and invasion. Moreover, collagen-dense breast tissue increases the risk of breast carcinoma, although the relationship between collagen density and tumorigenesis is not well understood. As little is known about epithelial-stromal interactions in vivo, it is necessary to visualize the stroma surrounding normal epithelium and mammary tumors in intact tissues to better understand how matrix organization, density, and composition affect tumor formation and progression. Methods Epithelial-stromal interactions in normal mammary glands, mammary tumors, and tumor explants in three-dimensional culture were studied with histology, electron microscopy, and nonlinear optical imaging methodologies. Imaging of the tumor-stromal interface in live tumor tissue ex vivo was performed with multiphoton laser-scanning microscopy (MPLSM to generate multiphoton excitation (MPE of endogenous fluorophores and second harmonic generation (SHG to image stromal collagen. Results We used both laser-scanning multiphoton and second harmonic generation microscopy to determine the organization of specific collagen structures around ducts and tumors in intact, unfixed and unsectioned mammary glands. Local alterations in collagen density were clearly seen, allowing us to obtain three-dimensional information regarding the organization of the mammary stroma, such as radiating collagen fibers that could not have been obtained using classical histological techniques. Moreover, we observed and defined three tumor-associated collagen signatures (TACS that provide novel markers to locate and characterize tumors. In particular, local cell invasion was found predominantly to be oriented along certain aligned collagen fibers, suggesting that radial alignment of collagen fibers relative to tumors facilitates invasion. Consistent

  7. Characterization of electron beam irradiated collagen-polyvinylpyrrolidone (PVP) and collagen-dextran (DEX) blends

    International Nuclear Information System (INIS)

    Dumitrascu, M.; Sima, E.; Minea, R.; Vancea, C.; Meltze, V.; Albu, M.G.

    2011-01-01

    Complete text of publication follows. The aim of the present study was to investigate the influence of electron beam irradiation on some blends of collagen-polyvinylpyrrolidone (PVP) and collagen-dextran (DEX). The blends were prepared by mixing different quantities of collagen, PVP and DEX in distilled water. After irradiation the obtained hydrogels were processed by controlled drying and freeze-drying. Both types of materials were characterized by FT-IR, FT-Raman, TG, DSC, water uptake and SEM. The intensity of the characteristic bands, in the range 2800-3600 cm -1 from FT-IR spectra, varied considerably as function of absorbed radiation dose. Raman spectra revealed the absence of the characteristic peak at 2700 cm -1 for irradiated blends at 30 kGy. Kinetic parameters were calculated from the TG, DTG and DSC data by means of isoconversion methods at different heating rates. Thereby a relation between absorbed radiation dose and activation energy was established. Water uptake studies were carried out in PBS solution (phosphate buffer saline) at 37 deg C and pH = 7.4 and the results revealed a decrease of the water uptake with increasing of absorbed radiation dose.

  8. Efficacy of ALK5 inhibition in myelofibrosis

    Science.gov (United States)

    Zhao, Wanke; Ho, Wanting Tina; Han, Ying; Murdun, Cem; Mailloux, Adam W.; Zhang, Ling; Wang, Xuefeng; Budhathoki, Anjali; Pradhan, Kith; Rapaport, Franck; Wang, Huaquan; Shao, Zonghong; Ren, Xiubao; Steidl, Ulrich; Levine, Ross L.; Zhao, Zhizhuang Joe; Verma, Amit; Epling-Burnette, Pearlie K.

    2017-01-01

    Myelofibrosis (MF) is a bone marrow disorder characterized by clonal myeloproliferation, aberrant cytokine production, extramedullary hematopoiesis, and bone marrow fibrosis. Although somatic mutations in JAK2, MPL, and CALR have been identified in the pathogenesis of these diseases, inhibitors of the Jak2 pathway have not demonstrated efficacy in ameliorating MF in patients. TGF-β family members are profibrotic cytokines and we observed significant TGF-β1 isoform overexpression in a large cohort of primary MF patient samples. Significant overexpression of TGF-β1 was also observed in murine clonal MPLW515L megakaryocytic cells. TGF-β1 stimulated the deposition of excessive collagen by mesenchymal stromal cells (MSCs) by activating the TGF-β receptor I kinase (ALK5)/Smad3 pathway. MSCs derived from MPLW515L mice demonstrated sustained overproduction of both collagen I and collagen III, effects that were abrogated by ALK5 inhibition in vitro and in vivo. Importantly, use of galunisertib, a clinically active ALK5 inhibitor, significantly improved MF in both MPLW515L and JAK2V617F mouse models. These data demonstrate the role of malignant hematopoietic stem cell (HSC)/TGF-β/MSC axis in the pathogenesis of MF, and provide a preclinical rationale for ALK5 blockade as a therapeutic strategy in MF. PMID:28405618

  9. Collagenous sprue: a clinicopathologic study of 12 cases.

    LENUS (Irish Health Repository)

    Maguire, Aoife A

    2012-02-01

    Collagenous sprue is a rare form of small bowel enteropathy characterized by chronic diarrhea and progressive malabsorption with little data available on its natural history. The pathologic lesion consists of subepithelial collagen deposition associated with variable alterations in villous architecture. The small bowel biopsies of 12 cases were reviewed. Clinical details, celiac serology, and T-cell receptor gene rearrangement study results, when available, were collated. There were 8 females and 4 males (age ranged from 41 to 84 y) who presented with chronic diarrhea and weight loss. Small intestinal biopsies showed subepithelial collagen deposition with varying degrees of villous atrophy and varying numbers of intraepithelial lymphocytes. Four patients had previous biopsies showing enteropathic changes without collagen deposition. Seven cases were associated with collagenous colitis and 1 also had features of lymphocytic colitis. Three patients also had collagen deposition in gastric biopsies. One case was associated with lymphocytic gastritis. Celiac disease (CD, gluten-sensitive enteropathy) was documented in 4 patients. Five patients made a clinical improvement with combinations of a gluten-free diet and immunosuppressive therapy. Two patients died of complications of malnutrition and 1 of another illness. Clonal T-cell populations were identified in 5 of 6 cases tested. Four of these patients improved clinically after treatment but 1 has died. Collagenous sprue evolved on a background of CD in 4 cases. There was no history of CD in others and these cases may be the result of a biologic insult other than gluten sensitivity. None has developed clinical evidence of lymphoma to date.

  10. Variation in the helical structure of native collagen.

    Directory of Open Access Journals (Sweden)

    Joseph P R O Orgel

    Full Text Available The structure of collagen has been a matter of curiosity, investigation, and debate for the better part of a century. There has been a particularly productive period recently, during which much progress has been made in better describing all aspects of collagen structure. However, there remain some questions regarding its helical symmetry and its persistence within the triple-helix. Previous considerations of this symmetry have sometimes confused the picture by not fully recognizing that collagen structure is a highly complex and large hierarchical entity, and this affects and is effected by the super-coiled molecules that make it. Nevertheless, the symmetry question is not trite, but of some significance as it relates to extracellular matrix organization and cellular integration. The correlation between helical structure in the context of the molecular packing arrangement determines which parts of the amino acid sequence of the collagen fibril are buried or accessible to the extracellular matrix or the cell. In this study, we concentrate primarily on the triple-helical structure of fibrillar collagens I and II, the two most predominant types. By comparing X-ray diffraction data collected from type I and type II containing tissues, we point to evidence for a range of triple-helical symmetries being extant in the molecules native environment. The possible significance of helical instability, local helix dissociation and molecular packing of the triple-helices is discussed in the context of collagen's supramolecular organization, all of which must affect the symmetry of the collagen triple-helix.

  11. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane – An Excellent Cell Substratum. The KERATINOCYTE proliferation and Differentiation into multiple layers is due to the presence of type - IV collagen in the amnion. Cultured FIBROBLASTS had good ...

  12. Recombinant gelatin and collagen from methylotrophic yeasts

    NARCIS (Netherlands)

    Bruin, de E.C.

    2002-01-01

    Based on its structural role and compatibility within the human body, collagen is a commonly used biomaterial in medical applications, such as cosmetic surgery, wound treatment and tissue engineering. Gelatin is in essence denatured and partly degraded collagen and is,

  13. Electrochemical deposition of mineralized BSA/collagen coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Junjun [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Lin, Jun; Li, Juan; Wang, Huiming [The First Affiliated Hospital of Medical College, Zhejiang University, Hangzhou 310003 (China); Cheng, Kui [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Weng, Wenjian, E-mail: wengwj@zju.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); The Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2016-09-01

    In this work, mineralized collagen coatings with different loading quantity of bovine serum albumin (BSA) were prepared via in situ electrochemical deposition on titanium substrate. The microstructure and BSA loading quantity of the coatings could be controlled by the electrochemical deposition parameters, such as deposition potential, BSA concentration and its adding sequence in the electrolyte. The BSA loading quantity in the coatings was obtained in the range of 0.0170–0.173 mg/cm{sup 2}, enhancing the cell adhesion and proliferation of the coatings with the simultaneous release. The distinct release behaviors of BSA were attributed to their gradient distribution with different mineralization degrees, which could be adjusted by the deposition process. These results suggest that in situ electrochemical deposition is a promising way to incorporate functional molecules into the mineralized collagen coatings and the mineralized BSA/collagen coatings are highly promising for improving the rhBMP-2 loading capability (1.8-fold). - Highlights: • BSA is incorporated into mineralized collagen coating by electrochemical deposition. • The loading amount of BSA in coatings can be adjusted in the range of 0-173 ng. • The BSA/collagen coating shows good cytocompatibility with free-albumin culture. • The incorporation process is put forward for some other molecules deposition.

  14. Mapuche Herbal Medicine Inhibits Blood Platelet Aggregation

    Directory of Open Access Journals (Sweden)

    Susan Skanderup Falkenberg

    2012-01-01

    Full Text Available 12 plant species traditionally used by the Mapuche people in Chile to treat wounds and inflammations have been evaluated for their direct blood platelet inhibition. Seven of the 12 tested plant species showed platelet inhibitory effect in sheep blood, and four of these were also able to inhibit the ADP- (5.0 μM and collagen- (2.0 μg/mL induced aggregations in human blood. These four species in respective extracts (in brackets were Blechnum chilense (MeOH, Luma apiculata (H2O, Amomyrtus luma (DCM : MeOH 1 : 1 and Cestrum parqui (DCM : MeOH 1 : 1. The platelet aggregating inhibitory effects of A. luma (DCM : MeOH 1 : 1, and L. apiculata (H2O were substantial and confirmed by inhibition of platelet surface activation markers.

  15. Urotensin II contributes to collagen synthesis and up-regulates Egr-1 expression in cultured pulmonary arterial smooth muscle cells through the ERK1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [Biomedical Engineering Institute, School of Control Science and Engineering, Shandong University, Jinan 250061 (China); Cai, Zhifeng; Liu, Mengmeng [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan 250012 (China); Zhao, Cuifen, E-mail: zhaocuifen@sdu.edu.cn [Department of Pediatrics, Qilu Hospital, Shandong University, Jinan 250012 (China); Li, Dong [Research Room of Hypothermia Medicine, Qilu Hospital, Shandong University, Jinan 250012 (China); Lv, Chenguang; Wang, Yuping; Xu, Tengfei [Biomedical Engineering Institute, School of Control Science and Engineering, Shandong University, Jinan 250061 (China)

    2015-11-27

    Aim: The objective of this study was to investigate the effects of urotensin II (UII) treatment on the proliferation and collagen synthesis of cultured rat pulmonary arterial smooth muscle cells (PASMCs) and to explore whether these effects are mediated by mitogen-activated protein kinase (MAPK) signaling pathways and early growth response 1 (Egr-1). Methods: The proliferation of cultured PASMCs stimulated with different doses of UII was detected by BrdU incorporation. The mRNA expression levels of procollagen I (procol I), procollagen III (procol III), extracellular regulated protein kinase 1/2 (ERK1/2), stress-stimulated protein kinase (Sapk), p38 MAPK (p38), and Egr-1 mRNA in cultured PASMCs after treatment with UII, the UII-specific antagonist urantide, and the ERK1/2 inhibitor PD98059 were detected by real-time polymerase chain reaction (PCR), and the protein expression levels of procol I, procol III, phosphorylated (p)-ERK1/2, p-Sapk, p-p38, and Egr-1 were detected by Western blotting. Results: Treatment with UII increased the proliferation of cultured PASMCs in a dose-dependent manner (P < 0.05). However, treatment with urantide and PD98059 inhibited the promoting effect of UII on PASMC proliferation (P < 0.05). Real-time PCR analysis showed that UII up-regulated the expression of procol I, procol III, ERK1/2, Sapk, and Egr-1 mRNA (P < 0.05), but not p38 mRNA. However, the up-regulating effect of UII was inhibited by PD98059 and urantide. Western blotting analysis showed that UII increased the synthesis of collagen I, collagen III, p-ERK1/2, p-Sapk, and Egr-1, and these effects also were inhibited by PD98059 and urantide (P < 0.05). Conclusions: Egr-1 participates in the UII-mediated proliferation and collagen synthesis of cultured rat PASMCs via activation of the ERK1/2 signaling pathway.

  16. Cartilage collagen damage in hip osteoarthritis similar to that seen in knee osteoarthritis; a case-control study of relationship between collagen, glycosaminoglycan and cartilage swelling.

    Science.gov (United States)

    Hosseininia, Shahrzad; Lindberg, Lisbeth R; Dahlberg, Leif E

    2013-01-09

    It remains to be shown whether OA shares molecular similarities between different joints in humans. This study provides evidence for similarities in cartilage molecular damage in osteoarthritic (OA) joints. Articular cartilage from osteoarthritic hip joints were analysed and compared to non-OA controls regarding collagen, glycosaminoglycan and water content. Femoral heads from 16 osteoarthritic (OA) and 20 reference patients were obtained from hip replacement surgery due to OA and femoral neck fracture, respectively. Cartilage histological changes were assessed by Mankin grading and denatured collagen type II immunostaining and cartilage was extracted by α-chymotrypsin. Hydroxyproline and Alcian blue binding assays were used to measure collagen and glycosaminoglycan (GAG) content, respectively. Mankin and immunohistology scores were significantly higher in hip OA samples than in reference samples. Cartilage water content was 6% higher in OA samples than in references. 2.5 times more collagen was extracted from OA than from reference samples. There was a positive association between water content and percentage of extractable collagen pool (ECP) in both groups. The amounts of collagen per wet and dry weights did not differ statistically between OA and reference cartilage. % Extractable collagen was not related to collagen per dry weight in either group. However when collagen was expressed by wet weight there was a negative correlation between % extractable and collagen in OA cartilage. The amount of GAG per wet weight was similar in both groups but the amount of GAG per dry weight was higher in OA samples compared to reference samples, which suggests a capacity for GAG biosynthesis in hip OA cartilage. Neither of the studied parameters was related to age in either group. Increased collagen extractability and water content in human hip cartilage is associated with OA pathology and can be observed at early stages of the degenerative hip OA process. Our results

  17. Platelets stimulate fibroblast-mediated contraction of collagen gels

    Directory of Open Access Journals (Sweden)

    Lundahl Joachim

    2003-10-01

    Full Text Available Abstract Background Platelets are thought to play a role in a variety of inflammatory conditions in the lung, some of which may lead to fibrosis. In the current study we tested the hypothesis that whole platelets and platelet lysate can mediate remodelling of extracellular matrix in vitro by affecting fibroblast-mediated contraction of a collagen gel. We also sought to determine to what extent platelet-derived growth factor (PDGF and transforming growth factor-β (TGF-β contribute to this effect. Methods Washed platelets, isolated from healthy blood donors, and platelet lysate (freezing and thawing, were cast together with human lung fibroblasts in three-dimensional collagen gels. The gels were then released and cultured for four days. PDGF and TGF-β1 concentrations were measured in culture supernatants by ELISA. Results Both platelets and platelet lysate augmented fibroblast-mediated gel contraction in a time and concentration dependent manner (19.9% ± 0.1 (mean ± SEM of initial area vs. 48.0% ± 0.4 at 48 hours; P 1 and PDGF-AA/AB were released in co-culture. PDGF-AA/AB had a maximum release at 24 hours whereas TGF-β1 release increased with longer culture periods. Neutralising antibodies to these mediators partially inhibited platelet-induced gel contraction. Conclusion We conclude that platelets may promote remodelling of extracellular matrix in vitro and that PDGF and TGF-β partially mediate this effect, also indicating a role for other mediators. The findings may be an important mechanism in regulating repair processes after injury.

  18. Immune response gene control of collagen reactivity in man: collagen unresponsiveness in HLA-DR4 negative nonresponders is due to the presence of T-dependent suppressive influences

    International Nuclear Information System (INIS)

    Solinger, A.M.; Stobo, J.D.

    1982-01-01

    To determine whether the failure to detect collagen reactivity in nonresponders represents an absence of collagen-reactive T cells or a preponderance of suppressive influences, the peripheral blood mononuclear cells from HLA-DR4 - individuals were subjected to three procedures capable of separating suppressive influences from LIF-secreting cells; irradiation (1000 rad), discontinuous gradient fractionation, and cytolysis with the monoclonal antibody OKT 8. Each procedure resulted in the specific appearance of reactivity to collagen, which was identical to that seen in HLA-DR4 + individuals with regard to its cellular requirements and antigenic specificity. Addition of unresponsive (i.e., nonirradiated or low-density T cells) to responsive (i.e., irradiated or high-density T cells) autologous populations resulted in specific suppression of collagen reactivity. Radiation-sensitive suppressive influences could not be detected in HLA-DR4 + collagen responders.These studies indicate that the expression of T-dependent reactivity to collagen in man reflects the net influence of collage-reactive vs collagen-suppressive T cells. Moreover, it is the influence of HLA-D-linked genes on the development of suppressive influences rather than on the development of collagen-reactive, LIF-secreting T cells that serves to distinguish HLA-DR4 + collagen responders from HLA-DR4 - collagen nonresponders

  19. Thread Embedding Acupuncture Inhibits Ultraviolet B Irradiation-Induced Skin Photoaging in Hairless Mice

    Directory of Open Access Journals (Sweden)

    Yoon-Jung Kim

    2015-01-01

    Full Text Available Thread embedding acupuncture (TEA is an acupuncture treatment applied to many diseases in Korean medical clinics because of its therapeutic effects by continuous stimulation to tissues. It has recently been used to enhance facial skin appearance and antiaging, but data from evidence-based medicine are limited. To investigate whether TEA therapy can inhibit skin photoaging by ultraviolet B (UVB irradiation, we performed analyses for histology, histopathology, in situ zymography and western blot analysis in HR-1 hairless mice. TEA treatment resulted in decreased wrinkle formation and skin thickness (Epidermis; P=0.001 versus UV in UVB irradiated mice and also inhibited degradation of collagen fibers (P=0.010 versus normal by inhibiting proteolytic activity of gelatinase matrix-metalloproteinase-9 (MMP-9. Western blot data showed that activation of c-Jun N-terminal kinase (JNK induced by UVB (P=0.002 versus normal group was significantly inhibited by TEA treatment (P=0.005 versus UV with subsequent alleviation of MMP-9 activation (P=0.048 versus UV. These results suggest that TEA treatment can have anti-photoaging effects on UVB-induced skin damage by maintenance of collagen density through regulation of expression of MMP-9 and related JNK signaling. Therefore, TEA therapy may have potential roles as an alternative treatment for protection against skin damage from aging.

  20. Always cleave up your mess: targeting collagen degradation to treat tissue fibrosis

    Science.gov (United States)

    McKleroy, William; Lee, Ting-Hein

    2013-01-01

    Pulmonary fibrosis is a vexing clinical problem with no proven therapeutic options. In the normal lung there is continuous collagen synthesis and collagen degradation, and these two processes are precisely balanced to maintain normal tissue architecture. With lung injury there is an increase in the rate of both collagen production and collagen degradation. The increase in collagen degradation is critical in preventing the formation of permanent scar tissue each time the lung is exposed to injury. In pulmonary fibrosis, collagen degradation does not keep pace with collagen production, resulting in extracellular accumulation of fibrillar collagen. Collagen degradation occurs through both extracellular and intracellular pathways. The extracellular pathway involves cleavage of collagen fibrils by proteolytic enzyme including the metalloproteinases. The less-well-described intracellular pathway involves binding and uptake of collagen fragments by fibroblasts and macrophages for lysosomal degradation. The relationship between these two pathways and their relevance to the development of fibrosis is complex. Fibrosis in the lung, liver, and skin has been associated with an impaired degradative environment. Much of the current scientific effort in fibrosis is focused on understanding the pathways that regulate increased collagen production. However, recent reports suggest an important role for collagen turnover and degradation in regulating the severity of tissue fibrosis. The objective of this review is to evaluate the roles of the extracellular and intracellular collagen degradation pathways in the development of fibrosis and to examine whether pulmonary fibrosis can be viewed as a disease of impaired matrix degradation rather than a disease of increased matrix production. PMID:23564511

  1. Structure of collagen-glycosaminoglycan matrix and the influence to its integrity and stability.

    Science.gov (United States)

    Bi, Yuying; Patra, Prabir; Faezipour, Miad

    2014-01-01

    Glycosaminoglycan (GAG) is a chain-like disaccharide that is linked to polypeptide core to connect two collagen fibrils/fibers and provide the intermolecular force in Collagen-GAG matrix (C-G matrix). Thus, the distribution of GAG in C-G matrix contributes to the integrity and mechanical properties of the matrix and related tissue. This paper analyzes the transverse isotropic distribution of GAG in C-G matrix. The angle of GAGs related to collagen fibrils is used as parameters to qualify the GAGs isotropic characteristic in both 3D and 2D rendering. Statistical results included that over one third of GAGs were perpendicular directed to collagen fibril with symmetrical distribution for both 3D matrix and 2D plane cross through collagen fibrils. The three factors tested in this paper: collagen radius, collagen distribution, and GAGs density, were not statistically significant for the strength of Collagen-GAG matrix in 3D rendering. However in 2D rendering, a significant factor found was the radius of collagen in matrix for the GAGs directed to orthogonal plane of Collagen-GAG matrix. Between two cross-section selected from Collagen-GAG matrix model, the plane cross through collagen fibrils was symmetrically distributed but the total percentage of perpendicular directed GAG was deducted by decreasing collagen radius. There were some symmetry features of GAGs angle distribution in selected 2D plane that passed through space between collagen fibrils, but most models showed multiple peaks in GAGs angle distribution. With less GAGs directed to perpendicular of collagen fibril, strength in collagen cross-section weakened. Collagen distribution was also a factor that influences GAGs angle distribution in 2D rendering. True hexagonal collagen packaging is reported in this paper to have less strength at collagen cross-section compared to quasi-hexagonal collagen arrangement. In this work focus is on GAGs matrix within the collagen and its relevance to anisotropy.

  2. Dense tissue-like collagen matrices formed in cell-free conditions.

    Science.gov (United States)

    Mosser, Gervaise; Anglo, Anny; Helary, Christophe; Bouligand, Yves; Giraud-Guille, Marie-Madeleine

    2006-01-01

    A new protocol was developed to produce dense organized collagen matrices hierarchically ordered on a large scale. It consists of a two stage process: (1) the organization of a collagen solution and (2) the stabilization of the organizations by a sol-gel transition that leads to the formation of collagen fibrils. This new protocol relies on the continuous injection of an acid-soluble collagen solution into glass microchambers. It leads to extended concentration gradients of collagen, ranging from 5 to 1000 mg/ml. The self-organization of collagen solutions into a wide array of spatial organizations was investigated. The final matrices obtained by this procedure varied in concentration, structure and density. Changes in the liquid state of the samples were followed by polarized light microscopy, and the final stabilized gel states obtained after fibrillogenesis were analyzed by both light and electron microscopy. Typical organizations extended homogeneously by up to three centimetres in one direction and several hundreds of micrometers in other directions. Fibrillogenesis of collagen solutions of high and low concentrations led to fibrils spatially arranged as has been described in bone and derm, respectively. Moreover, a relationship was revealed between the collagen concentration and the aggregation of and rotational angles between lateral fibrils. These results constitute a strong base from which to further develop highly enriched collagen matrices that could lead to substitutes that mimic connective tissues. The matrices thus obtained may also be good candidates for the study of the three-dimensional migration of cells.

  3. Changes in collagen synthesis and degradation during skeletal muscle growth

    International Nuclear Information System (INIS)

    Laurent, G.J.; McAnulty, R.J.; Gibson, J.

    1985-01-01

    The changes in collagen metabolism during skeletal muscle growth were investigated by measuring rates of synthesis and degradation during stretch-induced hypertrophy of the anterior latissimus dorsi muscle of the adult chicken (Gallus domesticus). Synthesis rates were obtained from the uptake of tritiated proline injected intravenously with a flooding dose of unlabeled proline. Degradation of newly synthesized and ''mature'' collagen was estimated from the amount of hydroxyproline in the free pool as small molecular weight moieties. In normal muscle, the synthesis rate was 1.1 +/- 0.3%/day, with 49 +/- 7% of the newly produced collagen degraded rapidly after synthesis. During hypertrophy there was an increase of about fivefold in the rate of synthesis (P less than 0.01), a 60% decrease in the rate of degradation of newly synthesized collagen (P less than 0.02), and an increase of about fourfold in the amount of degradation of mature collagen (P less than 0.01). These results suggest an important role for degradative as well as synthetic processes in the regulation of collagen mass. They indicate that enhanced degradation of mature collagen is required for muscle growth and suggest a physiological role for the pathway whereby in normal muscle, a large proportion of newly produced collagen is rapidly degraded

  4. Stimulation of type I collagen activity in healing of pulp perforation

    OpenAIRE

    Kunarti, Sri

    2008-01-01

    Background: TGF-β1 is a connective tissue stimulant, potential regulator for tissue repair, and promoter in wound healing. The healing of pulp perforation is decided by quantity and quality of new collagen deposition. TGF-β1 upregulates collagen transcription. However, after several weeks production of type I collagen synthesis is stopped and enzymatic degradation of collagen matrix will occur. Purpose: Observe synthesis type I collagen during the process of pulp perforation healing in 7, 14,...

  5. High-contrast multimodel nonlinear optical imaging of collagen and elastin

    Energy Technology Data Exchange (ETDEWEB)

    Zhuo, S M [Key Laboratory of Optoelectronic Science and Technology for Medicine (Fujian Normal University), Ministry of Education, Fuzhou 350007 (China); Chen, J X [Key Laboratory of Optoelectronic Science and Technology for Medicine (Fujian Normal University), Ministry of Education, Fuzhou 350007 (China); Luo, T S [Key Laboratory of Optoelectronic Science and Technology for Medicine (Fujian Normal University), Ministry of Education, Fuzhou 350007 (China); Chen, H L [Key Laboratory of Optoelectronic Science and Technology for Medicine (Fujian Normal University), Ministry of Education, Fuzhou 350007 (China); Zhao, J J [Department of Skin, Affiliated Xiehe Hospital, Fujian Medical University, Fuzhou 350001 (China)

    2007-07-15

    Collagen and elastin, as the major components in the extracellular matrix (ECM), are intrinsic indicators of physiological and pathological states. Here, we have developed a high-contrast multimodel nonlinear optical imaging technique to imaging collagen and elastin by detecting simultaneously two photon-excited fluorescence (TPEF) from elastin and second-harmonic generation (SHG) from collagen. Our results show that this technique can obtain a high-contrast TPEF/SHG image in human dermis and permit direct visualization of collagen and elastin. It was shown that the technique can provide collagen and elastin structural information to determine collagen and elastin fibril orientation and distribution and acquire some morphometric properties. It was found that the in-depth TPEF/SHG imaging and 3-D reconstruction of TPEF/SHG images can extract more collagen and elastin structural and biochemical information. The study results suggest that the high-contrast multimodel nonlinear imaging provides a powerful tool to study ECM intrinsic components and has the potential to provide more important information for the diagnosis of tissue.

  6. High-contrast multimodel nonlinear optical imaging of collagen and elastin

    International Nuclear Information System (INIS)

    Zhuo, S M; Chen, J X; Luo, T S; Chen, H L; Zhao, J J

    2007-01-01

    Collagen and elastin, as the major components in the extracellular matrix (ECM), are intrinsic indicators of physiological and pathological states. Here, we have developed a high-contrast multimodel nonlinear optical imaging technique to imaging collagen and elastin by detecting simultaneously two photon-excited fluorescence (TPEF) from elastin and second-harmonic generation (SHG) from collagen. Our results show that this technique can obtain a high-contrast TPEF/SHG image in human dermis and permit direct visualization of collagen and elastin. It was shown that the technique can provide collagen and elastin structural information to determine collagen and elastin fibril orientation and distribution and acquire some morphometric properties. It was found that the in-depth TPEF/SHG imaging and 3-D reconstruction of TPEF/SHG images can extract more collagen and elastin structural and biochemical information. The study results suggest that the high-contrast multimodel nonlinear imaging provides a powerful tool to study ECM intrinsic components and has the potential to provide more important information for the diagnosis of tissue

  7. Collagenous gastritis in the pediatric age

    Directory of Open Access Journals (Sweden)

    Antonio Rosell-Camps

    2015-05-01

    Full Text Available Collagenous gastritis (CG is an uncommon condition known in the pediatric age. It is characterized by the presence of subepithelial collagen bands (> 10 μm associated with lymphoplasmacytic infiltration of the stomach's lamina propria. Symptoms manifested by patients with CG may be common with many other disorders. It typically manifests with epigastralgia, vomiting, and iron deficiency during pre-adolescence. This condition's pathophysiology remains unclear. In contrast to adults, where association with collagenous colitis and other autoimmune conditions is more common, pediatric involvement is usually confined to the stomach. Drugs of choice include proton pump inhibitors and corticoids. A case is reported of a 12-year-old girl with abdominal pain and ferritin deficiency who was diagnosed with CG based on gastric biopsy and experienced a favorable outcome.

  8. Thrombolytic therapy of acute myocardial infarction alters collagen metabolism

    DEFF Research Database (Denmark)

    Høst, N B; Hansen, S S; Jensen, L T

    1994-01-01

    The objective of the study was to monitor collagen metabolism after thrombolytic therapy. Sequential measurements of serum aminoterminal type-III procollagen propeptide (S-PIIINP) and carboxyterminal type-I procollagen propeptide (S-PICP) were made in 62 patients suspected of acute myocardial.......05). A less pronounced S-PIIINP increase was noted with tissue-plasminogen activator than with streptokinase. Thrombolytic therapy induces collagen breakdown regardless of whether acute myocardial infarction is confirmed or not. With confirmed acute myocardial infarction collagen metabolism is altered...... for at least 6 months. Furthermore, fibrin-specific and nonspecific thrombolytic agents appear to affect collagen metabolism differently....

  9. Increased cartilage type II collagen degradation in patients with osteogenesis imperfecta used as a human model of bone type I collagen alterations.

    Science.gov (United States)

    Rousseau, Jean-Charles; Chevrel, Guillaume; Schott, Anne-Marie; Garnero, Patrick

    2010-04-01

    We investigated whether cartilage degradation is altered in adult patients with mild osteogenesis imperfecta (OI) used as a human model of bone type I collagen-related osteoarthritis (OA). Sixty-four adult patients with OI (39% women, mean age+/-SD: 37+/-12 years) and 64 healthy age-matched controls (54% women, 39+/-7 years) were included. We also compared data in 87 patients with knee OA (73% women, 63+/-8 years, mean disease duration: 6 years) and 291 age-matched controls (80% women, 62+/-10 years). Urinary C-terminal cross-linked telopeptide of type II collagen (CTX-II), a marker of cartilage degradation, urinary helical peptide of type I collagen (Helix-I), a marker of bone resorption, and the urinary ratio between non-isomerised/isomerised (alpha/beta CTX-I) type I collagen C-telopeptide, a marker of type I collagen maturation, were measured. Patients with OI had CTX-II levels similar to those of subjects with knee OA (p=0.89; mean+/-SEM; 460+/-57 ng/mmol Cr for OI group and 547+/-32 ng/mmol Cr for OA group) and significantly higher than both young (144+/-7.8 ng/mmol Cr, p<0.0001) and old controls (247+/-7 ng/mmol Cr, p<0.0001). In patients with OI, increased Helix-I (p<0.0001) and alpha/beta CTX-I (p=0.0067) were independently associated with increased CTX-II and together explained 26% of its variance (p< 0.0001). In patients with knee OA, increased levels of alpha/beta CTX-I ratio were also associated with higher CTX-II levels. Adult patients with OI or knee OA are characterized by increased cartilage type II collagen degradation, which is associated with increased type I collagen degradation for OI and lower type I collagen maturation for both OI and OA. These data suggest that both quantitative and qualitative alterations of bone type I collagen metabolism are involved in increased cartilage degradation in patients with OI or knee OA. Copyright 2009 Elsevier Inc. All rights reserved.

  10. Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

    International Nuclear Information System (INIS)

    Fazely, F.

    1988-01-01

    The effects measured were the inhibition of tumor cell migration through the basement membrane (BM) and tumor cell degradative enzyme activity on 3 H-proline labeled collagenous and non collagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.09 μg/ml, and TC-106 cells at 0.08 μg/ml. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels almost 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more than retinol palmitate. Furthermore, A549 cells treated with retinol acetate, under conditions whereby an anti-invasive state was induced,showed an increase in the number of cellular retinoic acid binding proteins (CRABP), a decrease in the activity of type IV collagenase and ectosialyltransferase, and no change in the activity of transglutaminase

  11. Dual-specificity phosphatase 3 deficiency or inhibition limits platelet activation and arterial thrombosis.

    Science.gov (United States)

    Musumeci, Lucia; Kuijpers, Marijke J; Gilio, Karen; Hego, Alexandre; Théâtre, Emilie; Maurissen, Lisbeth; Vandereyken, Maud; Diogo, Catia V; Lecut, Christelle; Guilmain, William; Bobkova, Ekaterina V; Eble, Johannes A; Dahl, Russell; Drion, Pierre; Rascon, Justin; Mostofi, Yalda; Yuan, Hongbin; Sergienko, Eduard; Chung, Thomas D Y; Thiry, Marc; Senis, Yotis; Moutschen, Michel; Mustelin, Tomas; Lancellotti, Patrizio; Heemskerk, Johan W M; Tautz, Lutz; Oury, Cécile; Rahmouni, Souad

    2015-02-17

    A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. A better understanding of the molecular mechanisms leading to platelet activation is important for the development of improved therapies. Recently, protein tyrosine phosphatases have emerged as critical regulators of platelet function. This is the first report implicating the dual-specificity phosphatase 3 (DUSP3) in platelet signaling and thrombosis. This phosphatase is highly expressed in human and mouse platelets. Platelets from DUSP3-deficient mice displayed a selective impairment of aggregation and granule secretion mediated by the collagen receptor glycoprotein VI and the C-type lectin-like receptor 2. DUSP3-deficient mice were more resistant to collagen- and epinephrine-induced thromboembolism compared with wild-type mice and showed severely impaired thrombus formation on ferric chloride-induced carotid artery injury. Intriguingly, bleeding times were not altered in DUSP3-deficient mice. At the molecular level, DUSP3 deficiency impaired Syk tyrosine phosphorylation, subsequently reducing phosphorylation of phospholipase Cγ2 and calcium fluxes. To investigate DUSP3 function in human platelets, a novel small-molecule inhibitor of DUSP3 was developed. This compound specifically inhibited collagen- and C-type lectin-like receptor 2-induced human platelet aggregation, thereby phenocopying the effect of DUSP3 deficiency in murine cells. DUSP3 plays a selective and essential role in collagen- and C-type lectin-like receptor 2-mediated platelet activation and thrombus formation in vivo. Inhibition of DUSP3 may prove therapeutic for arterial thrombosis. This is the first time a protein tyrosine phosphatase, implicated in platelet signaling, has been targeted with a small-molecule drug. © 2014 American Heart Association, Inc.

  12. FTIR spectro-imaging of collagen scaffold formation during glioma tumor development.

    Science.gov (United States)

    Noreen, Razia; Chien, Chia-Chi; Chen, Hsiang-Hsin; Bobroff, Vladimir; Moenner, Michel; Javerzat, Sophie; Hwu, Yeukuang; Petibois, Cyril

    2013-11-01

    Evidence has recently emerged that solid and diffuse tumors produce a specific extracellular matrix (ECM) for division and diffusion, also developing a specific interface with microvasculature. This ECM is mainly composed of collagens and their scaffolding appears to drive tumor growth. Although collagens are not easily analyzable by UV-fluorescence means, FTIR imaging has appeared as a valuable tool to characterize collagen contents in tissues, specially the brain, where ECM is normally devoid of collagen proteins. Here, we used FTIR imaging to characterize collagen content changes in growing glioma tumors. We could determine that C6-derived solid tumors presented high content of triple helix after 8-11 days of growth (typical of collagen fibrils formation; 8/8 tumor samples; 91 % of total variance), and further turned to larger α-helix (days 12-15; 9/10 of tumors; 94 % of variance) and β-turns (day 18-21; 7/8 tumors; 97 % of variance) contents, which suggest the incorporation of non-fibrillar collagen types in ECM, a sign of more and more organized collagen scaffold along tumor progression. The growth of tumors was also associated to the level of collagen produced (P < 0.05). This study thus confirms that collagen scaffolding is a major event accompanying the angiogenic shift and faster tumor growth in solid glioma phenotypes.

  13. RELATIONS BETWEEN INVITRO CYTOTOXICITY AND CROSS-LINKED DERMAL SHEEP COLLAGENS

    NARCIS (Netherlands)

    VANLUYN, MJA; VANWACHEM, PB; DAMINK, LO; DIJKSTRA, PJ; FEIJEN, J; NIEUWENHUIS, P

    Collagen-based biomaterials have found various applications in the biomedical field. However, collagen-based biomaterials may induce cytotoxic effects. This study evaluated possible cytotoxic effects of (crosslinked) dermal sheep collagen (DSC) using a 7-d-methylcellulose cell culture with human

  14. Effects of advanced glycation end-product inhibition and cross-link breakage in diabetic rats

    DEFF Research Database (Denmark)

    Oturai, P S; Christensen, M; Rolin, B

    2000-01-01

    ), and a breaker of already formed AGE cross-links, N-phenacylthiazolium bromide (PTB), were investigated in streptozotocin-diabetic female Wistar rats. Diabetes for 24 weeks resulted in decreased tail collagen pepsin solubility, reflecting the formation of AGE cross-linking. Collagen solubility was significantly...... ameliorated by treatment with NNC39-0028, whereas PTB had no effect. Increased urinary albumin excretion (UAE) in diabetic rats was observed in serial measurements throughout the study period, and was not reduced by any treatment. Vascular dysfunction in the eye, measured as increased clearance of 125I......-albumin, was induced by diabetes. NNC39-0028 did not affect this abnormality. This study demonstrated a pharmacological inhibition of collagen solubility alterations in diabetic rats without affecting diabetes-induced pathophysiology such as the increase in UAE or albumin clearance. Treatment with PTB, a specific...

  15. Isolation and Characterization of Collagen from Chicken Feet

    OpenAIRE

    P. Hashim; M. S. Mohd Ridzwan; J. Bakar

    2014-01-01

    Collagen was isolated from chicken feet by using papain and pepsin enzymes in acetic acid solution at 4°C for 24h with a yield of 18.16% and 22.94% by dry weight, respectively. Chemical composition and characteristics of chicken feet collagen such as amino acid composition, SDS-PAGE patterns, FTIR spectra and thermal properties were evaluated. The chicken feet collagen is rich in the amino acids glycine, glutamic acid, proline and hydroxyproline. Electrophoresis pattern demonstrated two disti...

  16. Osteoblast-secreted collagen upregulates paracrine Sonic hedgehog signaling by prostate cancer cells and enhances osteoblast differentiation

    Directory of Open Access Journals (Sweden)

    Zunich Samantha M

    2012-07-01

    Full Text Available Abstract Background Induction of osteoblast differentiation by paracrine Sonic hedgehog (Shh signaling may be a mechanism through which Shh-expressing prostate cancer cells initiate changes in the bone microenvironment and promote metastases. A hallmark of osteoblast differentiation is the formation of matrix whose predominant protein is type 1 collagen. We investigated the formation of a collagen matrix by osteoblasts cultured with prostate cancer cells, and its effects on interactions between prostate cancer cells and osteoblasts. Results In the presence of exogenous ascorbic acid (AA, a co-factor in collagen synthesis, mouse MC3T3 pre-osteoblasts in mixed cultures with human LNCaP prostate cancer cells or LNCaP cells modified to overexpress Shh (LNShh cells formed collagen matrix with distinct fibril ultrastructural characteristics. AA increased the activity of alkaline phosphatase and the expression of the alkaline phosphatase gene Akp2, markers of osteoblast differentiation, in MC3T3 pre-osteoblasts cultured with LNCaP or LNShh cells. However, the AA-stimulated increase in Akp2 expression in MC3T3 pre-osteoblasts cultured with LNShh cells far exceeded the levels observed in MC3T3 cells cultured with either LNCaP cells with AA or LNShh cells without AA. Therefore, AA and Shh exert a synergistic effect on osteoblast differentiation. We determined whether the effect of AA on LNShh cell-induced osteoblast differentiation was mediated by Shh signaling. AA increased the expression of Gli1 and Ptc1, target genes of the Shh pathway, in MC3T3 pre-osteoblasts cultured with LNShh cells to at least twice their levels without AA. The ability of AA to upregulate Shh signaling and enhance alkaline phosphatase activity was blocked in MC3T3 cells that expressed a dominant negative form of the transcription factor GLI1. The AA-stimulated increase in Shh signaling and Shh-induced osteoblast differentiation was also inhibited by the specific collagen synthesis

  17. Insights into early extracellular matrix evolution: spongin short chain collagen-related proteins are homologous to basement membrane type IV collagens and form a novel family widely distributed in invertebrates.

    Science.gov (United States)

    Aouacheria, Abdel; Geourjon, Christophe; Aghajari, Nushin; Navratil, Vincent; Deléage, Gilbert; Lethias, Claire; Exposito, Jean-Yves

    2006-12-01

    Collagens are thought to represent one of the most important molecular innovations in the metazoan line. Basement membrane type IV collagen is present in all Eumetazoa and was found in Homoscleromorpha, a sponge group with a well-organized epithelium, which may represent the first stage of tissue differentiation during animal evolution. In contrast, spongin seems to be a demosponge-specific collagenous protein, which can totally substitute an inorganic skeleton, such as in the well-known bath sponge. In the freshwater sponge Ephydatia mülleri, we previously characterized a family of short-chain collagens that are likely to be main components of spongins. Using a combination of sequence- and structure-based methods, we present evidence of remote homology between the carboxyl-terminal noncollagenous NC1 domain of spongin short-chain collagens and type IV collagen. Unexpectedly, spongin short-chain collagen-related proteins were retrieved in nonsponge animals, suggesting that a family related to spongin constitutes an evolutionary sister to the type IV collagen family. Formation of the ancestral NC1 domain and divergence of the spongin short-chain collagen-related and type IV collagen families may have occurred before the parazoan-eumetazoan split, the earliest divergence among extant animal phyla. Molecular phylogenetics based on NC1 domain sequences suggest distinct evolutionary histories for spongin short-chain collagen-related and type IV collagen families that include spongin short-chain collagen-related gene loss in the ancestors of Ecdyzosoa and of vertebrates. The fact that a majority of invertebrates encodes spongin short-chain collagen-related proteins raises the important question to the possible function of its members. Considering the importance of collagens for animal structure and substratum attachment, both families may have played crucial roles in animal diversification.

  18. Experimental and quantum chemical studies on corrosion inhibition ...

    Indian Academy of Sciences (India)

    Abstract. The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also ...

  19. Experimental and quantum chemical studies on corrosion inhibition

    Indian Academy of Sciences (India)

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to ...

  20. Cartilage collagen damage in hip osteoarthritis similar to that seen in knee osteoarthritis; a case–control study of relationship between collagen, glycosaminoglycan and cartilage swelling

    Directory of Open Access Journals (Sweden)

    Hosseininia Shahrzad

    2013-01-01

    Full Text Available Abstract Background It remains to be shown whether OA shares molecular similarities between different joints in humans. This study provides evidence for similarities in cartilage molecular damage in osteoarthritic (OA joints. Methods Articular cartilage from osteoarthritic hip joints were analysed and compared to non-OA controls regarding collagen, glycosaminoglycan and water content. Femoral heads from 16 osteoarthritic (OA and 20 reference patients were obtained from hip replacement surgery due to OA and femoral neck fracture, respectively. Cartilage histological changes were assessed by Mankin grading and denatured collagen type II immunostaining and cartilage was extracted by α-chymotrypsin. Hydroxyproline and Alcian blue binding assays were used to measure collagen and glycosaminoglycan (GAG content, respectively. Results Mankin and immunohistology scores were significantly higher in hip OA samples than in reference samples. Cartilage water content was 6% higher in OA samples than in references. 2.5 times more collagen was extracted from OA than from reference samples. There was a positive association between water content and percentage of extractable collagen pool (ECP in both groups. The amounts of collagen per wet and dry weights did not differ statistically between OA and reference cartilage. % Extractable collagen was not related to collagen per dry weight in either group. However when collagen was expressed by wet weight there was a negative correlation between % extractable and collagen in OA cartilage. The amount of GAG per wet weight was similar in both groups but the amount of GAG per dry weight was higher in OA samples compared to reference samples, which suggests a capacity for GAG biosynthesis in hip OA cartilage. Neither of the studied parameters was related to age in either group. Conclusions Increased collagen extractability and water content in human hip cartilage is associated with OA pathology and can be observed at

  1. Collagen-binding proteins of Streptococcus mutans and related streptococci.

    Science.gov (United States)

    Avilés-Reyes, A; Miller, J H; Lemos, J A; Abranches, J

    2017-04-01

    The ability of Streptococcus mutans to interact with collagen through the expression of collagen-binding proteins (CBPs) bestows this oral pathogen with an alternative to the sucrose-dependent mechanism of colonization classically attributed to caries development. Based on the abundance and distribution of collagen throughout the human body, stringent adherence to this molecule grants S. mutans with the opportunity to establish infection at different host sites. Surface proteins, such as SpaP, WapA, Cnm and Cbm, have been shown to bind collagen in vitro, and it has been suggested that these molecules play a role in colonization of oral and extra-oral tissues. However, robust collagen binding is not achieved by all strains of S. mutans, particularly those that lack Cnm or Cbm. These observations merit careful dissection of the contribution from these different CBPs towards tissue colonization and virulence. In this review, we will discuss the current understanding of mechanisms used by S. mutans and related streptococci to colonize collagenous tissues, and the possible contribution of CBPs to infections in different sites of the host. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Embroidered polymer-collagen hybrid scaffold variants for ligament tissue engineering.

    Science.gov (United States)

    Hoyer, M; Drechsel, N; Meyer, M; Meier, C; Hinüber, C; Breier, A; Hahner, J; Heinrich, G; Rentsch, C; Garbe, L-A; Ertel, W; Schulze-Tanzil, G; Lohan, A

    2014-10-01

    Embroidery techniques and patterns used for scaffold production allow the adaption of biomechanical scaffold properties. The integration of collagen into embroidered polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) scaffolds could stimulate neo-tissue formation by anterior cruciate ligament (ACL) cells. Therefore, the aim of this study was to test embroidered P(LA-CL) and PDS scaffolds as hybrid scaffolds in combination with collagen hydrogel, sponge or foam for ligament tissue engineering. ACL cells were cultured on embroidered P(LA-CL) and PDS scaffolds without or with collagen supplementation. Cell adherence, vitality, morphology and ECM synthesis were analyzed. Irrespective of thread size, ACL cells seeded on P(LA-CL) scaffolds without collagen adhered and spread over the threads, whereas the cells formed clusters on PDS and larger areas remained cell-free. Using the collagen hydrogel, the scaffold colonization was limited by the gel instability. The collagen sponge layers integrated into the scaffolds were hardly penetrated by the cells. Collagen foams increased scaffold colonization in P(LA-CL) but did not facilitate direct cell-thread contacts in the PDS scaffolds. The results suggest embroidered P(LA-CL) scaffolds as a more promising basis for tissue engineering an ACL substitute than PDS due to superior cell attachment. Supplementation with a collagen foam presents a promising functionalization strategy. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. A novel role of sesamol in inhibiting NF-κB-mediated signaling in platelet activation

    Directory of Open Access Journals (Sweden)

    Chang Chao-Chien

    2011-12-01

    Full Text Available Abstract Background Platelet activation is relevant to a variety of coronary heart diseases. Our previous studies revealed that sesamol possesses potent antiplatelet activity through increasing cyclic AMP formation. Although platelets are anucleated cells, they also express the transcription factor, NF-κB, that may exert non-genomic functions in platelet activation. Therefore, we further investigated the inhibitory roles of sesamol in NF-κB-mediated platelet function. Methods Platelet aggregation, Fura 2-AM fluorescence, and immunoblotting analysis were used in this study. Results NF-κB signaling events, including IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation, were markedly activated by collagen (1 μg/ml in washed human platelets, and these signaling events were attenuated by sesamol (2.5~25 μM. Furthermore, SQ22536 and ODQ, inhibitors of adenylate cyclase and guanylate cyclase, respectively, strongly reversed the sesamol (25 μM-mediated inhibitory effects of IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation stimulated by collagen. The protein kinase A (PKA inhibitor, H89, also reversed sesamol-mediated inhibition of IκBα degradation. Moreover, BAY11-7082, an NF-κB inhibitor, abolished IκBα degradation, phospholipase C (PLCγ2 phosphorylation, protein kinase C (PKC activation, [Ca2+]i mobilization, and platelet aggregation stimulated by collagen. Preincubation of platelets with the inhibitors, SQ22536 and H89, both strongly reversed sesamol-mediated inhibition of platelet aggregation and [Ca2+]i mobilization. Conclusions Sesamol activates cAMP-PKA signaling, followed by inhibition of the NF-κB-PLC-PKC cascade, thereby leading to inhibition of [Ca2+]i mobilization and platelet aggregation. Because platelet activation is not only linked to hemostasis, but also has a relevant role in inflammation and metastasis, our data demonstrating that inhibition of NF-κB interferes with platelet function may

  4. Second-harmonic generation imaging of collagen in ancient bone.

    Science.gov (United States)

    Thomas, B; McIntosh, D; Fildes, T; Smith, L; Hargrave, F; Islam, M; Thompson, T; Layfield, R; Scott, D; Shaw, B; Burrell, C L; Gonzalez, S; Taylor, S

    2017-12-01

    Second-harmonic generation imaging (SHG) captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  5. Tendon collagen synthesis declines with immobilization in elderly humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

    2017-01-01

    -80 yr) were randomly assigned to NSAIDs (ibuprofen 1,200 mg/day; Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 wk and retrained for 6 wk. Tendon collagen protein synthesis, mechanical properties, size, expression of genes related to collagen turnover and remodeling, and signal...... intensity (from magnetic resonance imaging) were investigated. Tendon collagen synthesis decreased (P ... immobilization in both groups, whereas scleraxis mRNA decreased with inactivity in the Plc group only (P collagen protein synthesis decreased after 2 wk of immobilization, whereas tendon stiffness and modulus were only marginally reduced, and NSAIDs had no influence upon this...

  6. MT1-MMP promotes cell growth and ERK activation through c-Src and paxillin in three-dimensional collagen matrix

    International Nuclear Information System (INIS)

    Takino, Takahisa; Tsuge, Hisashi; Ozawa, Terumasa; Sato, Hiroshi

    2010-01-01

    Membrane-type 1 matrix metalloproteinase (MT1-MMP) is essential for tumor invasion and growth. We show here that MT1-MMP induces extracellular signal-regulated kinase (ERK) activation in cancer cells cultured in collagen gel, which is indispensable for their proliferation. Inhibition of MT1-MMP by MMP inhibitor or small interfering RNA suppressed activation of focal adhesion kinase (FAK) and ERK in MT1-MMP-expressing cancer cells, which resulted in up-regulation of p21 WAF1 and suppression of cell growth in collagen gel. Cell proliferation was also abrogated by the inhibitor against ERK pathway without affecting FAK phosphorylation. MT1-MMP and integrin α v β 3 were shown to be involved in c-Src activation, which induced FAK and ERK activation in collagen gel. These MT1-MMP-mediated signal transductions were paxillin dependent, as knockdown of paxillin reduced cell growth and ERK activation, and co-expression of MT1-MMP with paxillin induced ERK activation. The results suggest that MT1-MMP contributes to proliferation of cancer cells in the extracellular matrix by activating ERK through c-Src and paxillin.

  7. Effects of hydroxysafflor yellow A on proliferation and collagen synthesis of rat vascular adventitial fibroblasts induced by angiotensin II.

    Science.gov (United States)

    Yuan, Wendan; Yang, Dongxia; Sun, Xuhong; Liu, Wei; Wang, Liang; Li, Xiaoyan; Man, Xuejing; Fu, Qiang

    2014-01-01

    1) examine the effects of hydroxysafflor yellow A (HSYA) on the proliferation, collagen and cytokine synthesis of vascular adventitial fibroblasts as induced by angiotensin II (Ang II) in normal Sprague-Dawley (SD) rats in vitro, and 2) to assess the effects of HSYA on morphological changes and collagen accumulation of vascular adventitia in spontaneously hypertensive rats (SHR) in vivo. In vitro experiment, vascular adventitial fibroblasts from SD rats were isolated, cultured, and divided into control groups, model groups and HSYA groups. Cell morphology of adventitial fibroblasts was assessed using laser confocal microscopy, while cell proliferation with the MTT assay, and collagen synthesis was determined using hydroxyproline chromatometry. Immunocytochemistry and reverse transcription PCR were used for detecting the expression of TGF-β1, MMP-1, α-SMA and NF-κB in adventitial fibroblasts. In vivo experiment, vascular adventitia proliferation and collagen synthesis were analyzed using hematoxylin-eosin and Sirius staining. Our results showed that: 1) in vitro experiment of SD rats, HSYA inhibited proliferative activity and collagen synthesis of adventitial fibroblasts as induced by Ang II, and the inhibitory effects of HSYA on the increased expression of MMP-1, TGF-β1, α-SMA and NF-κB p65 as induced by Ang II were assessed, and 2) in vivo experiment of SHR, histological analysis displayed fewer pathological changes of vascular adventitia in HSYA treatment groups as compared with no HSYA treatment groups, and MMP-1, TGF-β1, α-SMA and NF-κB p65 expression significantly reduced after HSYA treatment (P adventitia components. This study provides experimental evidence demonstrating that HSYA has the capacity to decrease vascular adventitia proliferation and hyperplasia during vascular remodeling.

  8. Reinforcement of a porous collagen scaffold with surface-activated PLA fibers.

    Science.gov (United States)

    Liu, Xi; Huang, Changbin; Feng, Yujie; Liang, Jie; Fan, Yujiang; Gu, Zhongwei; Zhang, Xingdong

    2010-01-01

    A hybrid porous collagen scaffold mechanically reinforced with surface-activated poly(lactic acid) (PLA) fiber was prepared. PLA fibers, 20 mum in diameter and 1 mm in length, were aminolyzed with hexanediamine to introduce free amino groups on the surfaces. After the amino groups were transferred to aldehyde groups by treatment with glutaraldehyde, different amounts (1.5, 3, 5 and 8 mg) of surface-activated PLA fibers were homogeneously mixed with 2 ml type-I collagen solution (pH 2.8, 0.6 wt%). This mixture solution was then freeze-dried and cross-linked to obtain collagen sponges with surface-activated PLA fiber. Scanning electron microscopy observation indicated that the collagen sponges had a highly interconnected porous structure with an average pore size of 170 mum, irrespective of PLA fiber incorporation. The dispersion of surface-activated PLA fibers was homogeneous in collagen sponge, in contrast to unactivated PLA fibers. The compression modulus test results showed that, compared with unactivated PLA fibers, the surface-activated PLA fibers enhanced the resistance of collagen sponge to compression more significantly. Cytotoxicity assay by MTT test showed no cytotoxicity of these collagen sponges. L929 mouse fibroblast cell-culture studies in vitro revealed that the number of L929 cells attached to the collagen sponge with surface-activated PLA fibers, both 6 h and 24 h after seeding, was higher than that in pure collagen sponge and sponge with unactivated PLA fibers. In addition, a better distribution of cells infiltrated in collagen sponge with surface-activated PLA fibers was observed by histological staining. These results indicated that the collagen sponge reinforced with surface-activated PLA fibers is a promising biocompatible scaffold for tissue engineering.

  9. Scleroderma fibroblasts: Some aspects of in vitro assessment of collagen synthesis

    International Nuclear Information System (INIS)

    Krieg, T.; Max-Planck-Institut fuer Biochemie, Muenchen; Luderschmidt, C.; Braun-Falco, O.; Weber, L.; Mueller, P.K.

    1981-01-01

    Fibroblasts were cultured from skin biopsies of patients with systemic sclerosis in different stages of the disease. In vitro synthesis of collagen was checked after a pulse with tritiated proline. The ratio between type I and type III collagen was normal in all patients. Six of seven cultures derived from patients in the active state showed an increased synthesis of collagen relative to other proteins. Addition of serum (normal and diseased) to the culture medium did not stimulate synthesis of collagen in any culture with normal collagen synthesis. (orig.) [de

  10. Scleroderma fibroblasts: some aspects of in vitro assessment of collagen synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krieg, T.; Luderschmidt, C.; Braun-Falco, O.; Weber, L.; Mueller, P.K.

    1981-01-01

    Fibroblasts were cultured from skin biopsies of patients with systemic sclerosis in different stages of the disease. In vitro synthesis of collagen was checked after a pulse with tritiated proline. The ratio between type I and type III collagen was normal in all patients. Six of seven cultures derived from patients in the active state showed an increased synthesis of collagen relative to other proteins. Addition of serum (normal and diseased) to the culture medium did not stimulate synthesis of collagen in any culture with normal collagen synthesis.

  11. Effect of administration of oral contraceptives in vivo on collagen synthesis in tendon and muscle connective tissue in young women

    DEFF Research Database (Denmark)

    Hansen, M; Miller, B F; Holm, L

    2009-01-01

    concentrations of estradiol and progesterone (control, n = 12). Subjects performed 1 h of one-legged kicking exercise. The next day collagen fractional synthesis rates (FSR) in tendon and muscle connective tissue were measured after a flooding dose of [(13)C]proline followed by biopsies from the patellar tendon......, body composition, and exercise-training status were included. The two groups were either habitual users of oral contraceptives exposed to a high concentration of synthetic estradiol and progestogens (OC, n = 11), or non-OC-users tested in the follicular phase of the menstrual cycle characterized by low...... bioavailability of IGF-I in OC. In conclusion, synthetic female sex hormones administered as OC had an inhibiting effect on collagen synthesis in tendon, bone, and muscle connective tissue, which may be related to a lower bioavailability of IGF-I....

  12. Supernatants from culture of type I collagen-stimulated PBMC from patients with cutaneous systemic sclerosis versus localized scleroderma demonstrate suppression of MMP-1 by fibroblasts.

    Science.gov (United States)

    Brown, Monica; Postlethwaite, Arnold E; Myers, Linda K; Hasty, Karen A

    2012-06-01

    Systemic sclerosis (SSc) is a chronic fibrosing disease characterized by vasculopathy, autoimmunity, and an accumulation of collagen in tissues. Numerous studies have shown that compared to healthy or diseased controls, the peripheral blood mononuclear cells (PBMC) from patients with SSc produce a variety of cytokines or proliferate when cultured with solubilized type I collagen (CI) or constituent α1(II) and α2(I) polypeptide chains. The purpose of this study was to determine whether PBMC isolated from patients with SSc and cultured in vitro with soluble CI elaborated soluble mediators that inhibit the production of collagenase (i.e., matrix metalloproteinase, MMP-1) by fibroblasts. Supernatants of CI-stimulated PBMC from juvenile and adult diffuse cutaneous (dc)SSc patients significantly reduced MMP-1 production by SSc dermal fibroblasts, while supernatants of CI-stimulated PBMC from patients with localized scleroderma (LS) did not. CI-stimulated PBMC culture supernatants from patients with dcSSc in contrast to patients with LS exhibited increased levels of platelet-derived growth factor (PDGF)-AA, PDGF-BB, TNF-α, IL-13, and EGF. Prolonged culture of SSc dermal fibroblasts with recombinant PDGF-BB or IL-13 inhibited the induction of MMP-1 in response to subsequent TNF-α stimulation. These data suggest that therapies aimed at reducing these cytokines may decrease collagen accumulation in SSc, preventing the development of chronic fibrosis.

  13. Characterizing the collagen stabilizing effect of crosslinked chitosan nanoparticles against collagenase degradation.

    Science.gov (United States)

    Kishen, Anil; Shrestha, Suja; Shrestha, Annie; Cheng, Calvin; Goh, Cynthia

    2016-08-01

    Antibacterial and chelating properties of chitosan has been widely studied for various dental applications. To characterize the interaction between chitosan-nanoparticles (CSnp) and collagen, and understand their stabilizing effect against collagenase degradation for dentin matrix stabilization. Phase-1: a single Type I collagen-fibril model was used to study the interaction with CSnp along with carbodiimides crosslinking treatment. Degradation of the crosslinked fibrils was studied with bacterial collagenase enzyme and monitored using Fourier Transform Infrared (FTIR) spectroscopy, turbidity measurement (400nm), ninhydrin assay and Atomic Force Microscopy (AFM). Interaction of CSnp with collagenase and Type I collagen, were evaluated using SDS-PAGE, and proteolytic cleavage potential of a synthetic peptide. Phase-2: degradation of dentin collagen crosslinked with/without CSnp was evaluated using FTIR, ninhydrin assay and Scanning Electron Microscopy (SEM). Glutaraldehyde crosslinking was used as a positive control. Both native collagen-fibrils and dentin collagen after crosslinking showed higher resistance to collagenase degradation, as observed in turbidity measurements and FTIR spectra. AFM images showed the interaction of CSnp with single collagen-fibril and crosslinked collagen resisted collagenase degradation up to 54h. The collagen and collagenase both formed complexes with CSnp resulting in thickening of bands and reduction in collagen degradation. CSnp treated collagenase showed significantly reduced cleavage of the fluorescent peptides. Dentin collagen was coated with CSnp following crosslinking with significant increase in resistance to collagenase degradation. Crosslinked CSnp on collagen stabilized and enhanced the resistance of dentin matrix against bacterial collagenase degradation due to non-specific interaction with both collagen and collagenase. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  14. Resliced image space construction for coronary artery collagen fibers.

    Science.gov (United States)

    Luo, Tong; Chen, Huan; Kassab, Ghassan S

    2017-01-01

    Collagen fibers play an important role in the biomechanics of the blood vessel wall. The objective of this study was to determine the 3D microstructure of collagen fibers in the media and adventitia of coronary arteries. We present a novel optimal angle consistence algorithm to reform image slices in the visualization and analysis of 3D collagen images. 3D geometry was reconstructed from resliced image space where the 3D skeleton was extracted as the primary feature for accurate reconstruction of geometrical parameters. Collagen fibers (range 80-200) were reconstructed from the porcine coronary artery wall for the measurement of various morphological parameters. Collagen waviness and diameters were 1.37 ± 0.19 and 2.61 ± 0.89 μm, respectively. The biaxial distributions of orientation had two different peaks at 110.7 ± 25.2° and 18.4 ± 19.3°. Results for width, waviness, and orientation were found to be in good agreement with manual measurements. In addition to accurately measuring 2D features more efficiently than the manual approach, the present method produced 3D features that could not be measured in the 2D manual approach. These additional parameters included the tilt angle (5.10 ± 2.95°) and cross-sectional area (CSA; 5.98 ± 3.79 μm2) of collagen fibers. These 3D collagen reconstructions provide accurate and reliable microstructure for biomechanical modeling of vessel wall mechanics.

  15. A biomimetic strategy to form calcium phosphate crystals on type I collagen substrate

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhang [Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore, 5 Lower Kent Ridge Road 119074, Singapore (Singapore); Neoh, Koon Gee [Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge 119260, Singapore (Singapore); Kishen, Anil, E-mail: anil.kishen@utoronto.ca [Discipline of Endodontics, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON (Canada)

    2010-07-20

    Objective: The aim of this study is to induce mineralization of collagen by introducing phosphate groups onto type I collagen from eggshell membrane (ESM) by treating with sodium trimetaphosphate (STMP). This strategy is based on the hypothesis that phosphate groups introduced on collagen can mimic the nucleating role of phosphorylated non-collagenous proteins bound to collagen for inducing mineralization in natural hard tissue. Method: The collagen membrane was phosphorylated by treating it with a solution of STMP and saturated calcium hydroxide. The phosphorylated collagen was subsequently exposed to a mineralization solution and the pattern of mineralization on the surface of phosphorylated collagen substrate was analyzed. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and microhardness test were used to characterize the collagen substrate and the pattern of minerals formed on the collagen surface. Results: The FTIR and EDX results indicated that the phosphate groups were incorporated onto the collagen surface by treatment with STMP. During the mineralization process, the plate-like mineral, octacalcium phosphate (OCP), which was initially formed on the surface of ESM, was later transformed into needle-like hydroxyapatite (HAP) as indicated by the SEM, FESEM, EDX and XRD findings. The microhardness test displayed significant increase in the Knoop hardness number of the mineralized collagen. Conclusions: Phosphate groups can be introduced onto type I collagen surface by treating it with STMP and such phosphorylated collagen can induce the mineralization of type I collagen.

  16. LBL coating of type I collagen and hyaluronic acid on aminolyzed PLLA to enhance the cell-material interaction

    Directory of Open Access Journals (Sweden)

    M. Y. Zhao

    2014-05-01

    Full Text Available The aim of the present work is to assemble extracellular matrix components onto poly (L-lactic acid (PLLA films using layer-by-layer (LBL depositing method to enhance the cell-material interaction. To introduce charges onto the hydrophobic and neutral PLLA surface so that the electronic assembly can be processed, poly (ethylene imine (PEI was covalently bonded to modify the PLLA films. Positively charged collagen I (Col I was then deposited onto the aminolyzed PLLA film surface in a LBL assembly manner using hyaluronic acid (HA as a negatively charged polyelectrolyte. The PEI modification efficiency was monitored via X-ray photoelectron spectroscopy (XPS measurements. The results of Surface Plasmon Resonance (SPR and Water contact angle (WCA monitoring the LBL assemble process presented that the HA/Col I deposited alternately onto the PLLA surface. The surface topography of the films was observed by Atomic force microscope (AFM. In vitro osteoblast culture found that the presence of Col I layer greatly improved the cytocompatibility of the PLLA films in terms of cell viability, cell proliferation and Alkaline Phosphatase (ALP expression. Furthermore, osteoblast extensions were found to be directed by contact guidance of the aligned Col I fibrils. Thus, these very flexible systems may allow broad applications for improve the bioactivity of polymeric materials, which might be a potential application for bone tissue engineering.

  17. Collagen cross-linking: insights on the evolution of metazoan extracellular matrix.

    Science.gov (United States)

    Rodriguez-Pascual, Fernando; Slatter, David Anthony

    2016-11-23

    Collagens constitute a large family of extracellular matrix (ECM) proteins that play a fundamental role in supporting the structure of various tissues in multicellular animals. The mechanical strength of fibrillar collagens is highly dependent on the formation of covalent cross-links between individual fibrils, a process initiated by the enzymatic action of members of the lysyl oxidase (LOX) family. Fibrillar collagens are present in a wide variety of animals, therefore often being associated with metazoan evolution, where the emergence of an ancestral collagen chain has been proposed to lead to the formation of different clades. While LOX-generated collagen cross-linking metabolites have been detected in different metazoan families, there is limited information about when and how collagen acquired this particular modification. By analyzing telopeptide and helical sequences, we identified highly conserved, potential cross-linking sites throughout the metazoan tree of life. Based on this analysis, we propose that they have importantly contributed to the formation and further expansion of fibrillar collagens.

  18. Collagen matrix as a tool in studying fibroblastic cell behavior.

    Science.gov (United States)

    Kanta, Jiří

    2015-01-01

    Type I collagen is a fibrillar protein, a member of a large family of collagen proteins. It is present in most body tissues, usually in combination with other collagens and other components of extracellular matrix. Its synthesis is increased in various pathological situations, in healing wounds, in fibrotic tissues and in many tumors. After extraction from collagen-rich tissues it is widely used in studies of cell behavior, especially those of fibroblasts and myofibroblasts. Cells cultured in a classical way, on planar plastic dishes, lack the third dimension that is characteristic of body tissues. Collagen I forms gel at neutral pH and may become a basis of a 3D matrix that better mimics conditions in tissue than plastic dishes.

  19. Metal-chelating active packaging film enhances lysozyme inhibition of Listeria monocytogenes.

    Science.gov (United States)

    Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2014-07-01

    Several studies have demonstrated that metal chelators enhance the antimicrobial activity of lysozyme. This study examined the effect of metal-chelating active packaging film on the antimicrobial activity of lysozyme against Listeria monocytogenes. Polypropylene films were surface modified by photoinitiated graft polymerization of acrylic acid (PP-g-PAA) from the food contact surface of the films to impart chelating activity based on electrostatic interactions. PP-g-PAA exhibited a carboxylic acid density of 113 ± 5.4 nmol cm(-2) and an iron chelating activity of 53.7 ± 9.8 nmol cm(-2). The antimicrobial interaction of lysozyme and PP-g-PAA depended on growth media composition. PP-g-PAA hindered lysozyme activity at low ionic strength (2.48-log increase at 64.4 mM total ionic strength) and enhanced lysozyme activity at moderate ionic strength (5.22-log reduction at 120 mM total ionic strength). These data support the hypothesis that at neutral pH, synergy between carboxylate metal-chelating films (pKa(bulk) 6.45) and lysozyme (pI 11.35) is optimal in solutions of moderate to high ionic strength to minimize undesirable charge interactions, such as lysozyme absorption onto film. These findings suggest that active packaging, which chelates metal ions based on ligand-specific interactions, in contrast to electrostatic interactions, may improve antimicrobial synergy. This work demonstrates the potential application of metal-chelating active packaging films to enhance the antimicrobial activity of membrane-disrupting antimicrobials, such as lysozyme.

  20. The Biological Behaviors of Rat Dermal Fibroblasts Can Be Inhibited by High Levels of MMP9

    Directory of Open Access Journals (Sweden)

    Sheng-Neng Xue

    2012-01-01

    Full Text Available Aims. To explore the effects of the high expression of MMP9 on biological behaviors of fibroblasts. Methods. High glucose and hyperhomocysteine were used to induce MMP9 expression in skin fibroblasts. Cell proliferation was detected by flow cytometry and cell viability by CCK-8. ELISA assay was used to detect collagen (hydroxyproline secretion. Scratch test was employed to evaluate horizontal migration of cells and transwell method to evaluate vertical migration of cells. Results. The mRNA and protein expressions of MMP9 and its protease activity were significantly higher in cells treated with high glucose and hyperhomocysteine than those in control group. At the same time, the S-phase cell ratio, proliferation index, cell viability, collagen (hydroxyproline secretion, horizontal migration rate, and the number of vertical migration cells decreased in high-glucose and hyperhomocysteine-treated group. Tissue inhibitor of metalloproteinase 1 (TIMP1, which inhibits the activity of MMP9, recovered the above biological behaviors. Conclusions. High expression of MMP9 in skin fibroblasts could be induced by cultureing in high glucose and hyperhomocysteine medium, which inhibited cell biological behaviors. Inhibitions could be reversed by TIMP1. The findings suggested that MMP9 deters the healing of diabetic foot ulcers by inhibiting the biological behaviors of fibroblasts.

  1. Assembly of collagen into microribbons: effects of pH and electrolytes.

    Science.gov (United States)

    Jiang, Fengzhi; Hörber, Heinrich; Howard, Jonathon; Müller, Daniel J

    2004-12-01

    Collagen represents the major structural protein of the extracellular matrix. Elucidating the mechanism of its assembly is important for understanding many cell biological and medical processes as well as for tissue engineering and biotechnological approaches. In this work, conditions for the self-assembly of collagen type I molecules on a supporting surface were characterized. By applying hydrodynamic flow, collagen assembled into ultrathin ( approximately 3 nm) highly anisotropic ribbon-like structures coating the entire support. We call these novel collagen structures microribbons. High-resolution atomic force microscopy topographs show that subunits of these microribbons are built by fibrillar structures. The smallest units of these fibrillar structures have cross-sections of approximately 3 x 5nm, consistent with current models of collagen microfibril formation. By varying the pH and electrolyte of the buffer solution during the self-assembly process, the microfibril density and contacts formed within this network could be controlled. Under certain electrolyte compositions the microribbons and microfibers display the characteristic D-periodicity of approximately 65 nm observed for much thicker collagen fibrils. In addition to providing insight into the mechanism of collagen assembly, the ultraflat collagen matrices may also offer novel ways to bio-functionalize surfaces.

  2. Second-harmonic generation imaging of collagen in ancient bone

    Directory of Open Access Journals (Sweden)

    B. Thomas

    2017-12-01

    Full Text Available Second-harmonic generation imaging (SHG captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  3. An Ectosteric Inhibitor of Cathepsin K Inhibits Bone Resorption in Ovariectomized Mice

    DEFF Research Database (Denmark)

    Panwar, Preety; Xue, Liming; Søe, Kent

    2017-01-01

    The potent cathepsin K (CatK) inhibitor, Tanshinone IIA sulfonic sodium (T06), was tested for its in vitro and in vivo antiresorptive activities. T06 binds in an ectosteric site of CatK remote from its active site and selectively inhibits collagen degradation with an IC50 value of 2.7±0.2μM (CatK...

  4. Enhancing amine terminals in an amine-deprived collagen matrix.

    LENUS (Irish Health Repository)

    Tiong, William H C

    2008-10-21

    Collagen, though widely used as a core biomaterial in many clinical applications, is often limited by its rapid degradability which prevents full exploitation of its potential in vivo. Polyamidoamine (PAMAM) dendrimer, a highly branched macromolecule, possesses versatile multiterminal amine surface groups that enable them to be tethered to collagen molecules and enhance their potential. In this study, we hypothesized that incorporation of PAMAM dendrimer in a collagen matrix through cross-linking will result in a durable, cross-linked collagen biomaterial with free -NH 2 groups available for further multi-biomolecular tethering. The aim of this study was to assess the physicochemical properties of a G1 PAMAM cross-linked collagen matrix and its cellular sustainability in vitro. Different amounts of G1 PAMAM dendrimer (5 or 10 mg) were integrated into bovine-derived collagen matrices through a cross-linking process, mediated by 5 or 25 mM 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) in 5 mM N-hydroxysuccinimide (NHS) and 50 mM 2-morpholinoethane sulfonic acid buffer at pH 5.5. The physicochemical properties of resultant matrices were investigated with scanning electron microscopy (SEM), collagenase degradation assay, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectra, and ninhydrin assay. Cellular sustainability of the matrices was assessed with Alamar Blue assay and SEM. There was no significant difference in cellular behavior between the treated and nontreated groups. However, the benefit of incorporating PAMAM in the cross-linking reaction was limited when higher concentrations of either agent were used. These results confirm the hypothesis that PAMAM dendrimer can be incorporated in the collagen cross-linking process in order to modulate the properties of the resulting cross-linked collagen biomaterial with free -NH 2 groups available for multi-biomolecular tethering.

  5. Peroxidasin-mediated crosslinking of collagen IV is independent of NADPH oxidases

    Directory of Open Access Journals (Sweden)

    Gábor Sirokmány

    2018-06-01

    Full Text Available Collagen IV is a major component of the basement membrane in epithelial tissues. The NC1 domains of collagen IV protomers are covalently linked together through sulfilimine bonds, the formation of which is catalyzed by peroxidasin. Although hydrogen peroxide is essential for this reaction, the exact source of the oxidant remains elusive. Members of the NOX/DUOX NADPH oxidase family are specifically devoted to the production of superoxide and hydrogen peroxide. Our aim in this study was to find out if NADPH oxidases contribute in vivo to the formation of collagen IV sulfilimine crosslinks. We used multiple genetically modified in vivo model systems to provide a detailed assessment of this question. Our data indicate that in various peroxidasin-expressing tissues sulfilimine crosslinks between the NC1 domains of collagen IV can be readily detected in the absence of functioning NADPH oxidases. We also analyzed how subatmospheric oxygen levels influence the collagen IV network in collagen-producing cultured cells with rapid matrix turnover. We showed that collagen IV crosslinks remain intact even under strongly hypoxic conditions. Our hypothesis is that during collagen IV network formation PXDN cooperates with a NOX/DUOX-independent H2O2 source that is functional also at very low ambient oxygen levels. Keywords: Peroxidasin, NADPH oxidase, Hydrogen peroxide, Collagen IV, Sulfilimine

  6. Regulation of collagen biosynthesis in cultured bovine aortic smooth muscle cells

    International Nuclear Information System (INIS)

    Stepp, M.A.

    1986-01-01

    Aortic smooth muscles cells have been implicated in the etiology of lesions which occur in atherosclerosis and hypertension. Both diseases involve proliferation of smooth muscle cells and accumulation of excessive amounts of extracellular matrix proteins, including collagen type I and type III produced by the smooth muscle cells. To better understand the sites of regulation of collagen biosynthesis and to correlate these with the growth rate of the cells, cultured bovine aortic smooth muscle cells were studied as a function of the number of days (3 to 14) in second passage. Cells grew rapidly up to day 6 when confluence was reached. The total incorporation of [ 3 H]-proline into proteins was highest at day 3 and decreased to a constant level after the cultures reached confluence. In contrast, collagen protein production was lowest before confluence and continued to increase over the entire time course of the experiments. cDNA clones for the α1 and α2 chains of type I and the α1 chain of type III collagen were used to quantitate the steady state level of collagen mRNAs. RNA was tested in a cell-free translation system. Changes in the translational activity of collagen mRNAs parallelled the observed increases in collagen protein production. Thus, at later time points, collagen mRNAs are more active in directing synthesis of preprocollagens, even though less collagen mRNA is present. The conclusion is that the site of regulation of the expression of collagen genes is a function of the growth rate of cultured smooth muscle cells

  7. The influence of conditioning film on antifouling properties of the polyurethane film modified by chondroitin sulfate in urine

    Science.gov (United States)

    Yuan, Huihui; Qian, Bin; Chen, Huaying; Lan, Minbo

    2017-12-01

    The encrustation and induced infection severely impact on the therapeutic effectiveness and service life of urinary stents due to the fast formation of conditioning film on urinary stents after implantation. The composition and properties of conditioning film have great influence on antifouling properties of stent materials. In our previous work, we modified polyurethane films by chondroitin sulfate (PU-CS) with different CS grafting densities to verify its anti-fouling properties. To obtain the in-depth understanding of encrustation on urinary stents, we investigated the impact of the composition and properties of conditioning film on the following inorganic salt deposition and bacteria adhesion in urine. The results showed that quantity of proteins and polysaccharides in conditioning films, and the roughness, water contact angle and zeta potential of PU-CSs covered with corresponding conditioning film decreased with the increase of CS grafting density on PU films.PU-CS(3) with highest CS grafting density (3.70 g/cm2) had the highest bacteria inhibition rate and least inorganic salt deposition among the PU-CSs in artificial urine. Moreover, inorganic salts depositing on the PU-CS(3) were less and smaller than those on other films. Bacteria were not detectable until day 21 in real urine. Meanwhile, the pH value was elevated. The results suggested that the component of conditioning films was more important than other surface properties such as hydrophilicity, zeta potential and roughness for inorganic salt deposition and bacteria adhesion. Moreover, the anti-encrustation properties of the surface was promoted by proteins and inhibited by polysaccharides.

  8. Postnatal development of depth-dependent collagen density in ovine articular cartilage

    Directory of Open Access Journals (Sweden)

    Kranenbarg Sander

    2010-10-01

    Full Text Available Abstract Background Articular cartilage (AC is the layer of tissue that covers the articulating ends of the bones in diarthrodial joints. Adult AC is characterised by a depth-dependent composition and structure of the extracellular matrix that results in depth-dependent mechanical properties, important for the functions of adult AC. Collagen is the most abundant solid component and it affects the mechanical behaviour of AC. The current objective is to quantify the postnatal development of depth-dependent collagen density in sheep (Ovis aries AC between birth and maturity. We use Fourier transform infra-red micro-spectroscopy to investigate collagen density in 48 sheep divided over ten sample points between birth (stillborn and maturity (72 weeks. In each animal, we investigate six anatomical sites (caudal, distal and rostral locations at the medial and lateral side of the joint in the distal metacarpus of a fore leg and a hind leg. Results Collagen density increases from birth to maturity up to our last sample point (72 weeks. Collagen density increases at the articular surface from 0.23 g/ml ± 0.06 g/ml (mean ± s.d., n = 48 at 0 weeks to 0.51 g/ml ± 0.10 g/ml (n = 46 at 72 weeks. Maximum collagen density in the deeper cartilage increases from 0.39 g/ml ± 0.08 g/ml (n = 48 at 0 weeks to 0.91 g/ml ± 0.13 g/ml (n = 46 at 72 weeks. Most collagen density profiles at 0 weeks (85% show a valley, indicating a minimum, in collagen density near the articular surface. At 72 weeks, only 17% of the collagen density profiles show a valley in collagen density near the articular surface. The fraction of profiles with this valley stabilises at 36 weeks. Conclusions Collagen density in articular cartilage increases in postnatal life with depth-dependent variation, and does not stabilize up to 72 weeks, the last sample point in our study. We find strong evidence for a valley in collagen densities near the articular surface that is present in the youngest

  9. Enalapril alters the formation of the collagen matrix in spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    Alfredo de Souza Bomfim

    2003-07-01

    Full Text Available OBJECTIVE: To assess the effect of the inhibition of the angiotensin-converting enzyme on the collagen matrix (CM of the heart of newborn spontaneously hypertensive rats (SHR during embryonic development. METHODS: The study comprised the 2 following groups of SHR (n=5 each: treated group - rats conceived from SHR females treated with enalapril maleate (15 mg. kg-1.day-1 during gestation; and nontreated group - offspring of nontreated females. The newborns were euthanized within the first 24 hours after birth and their hearts were removed and processed for histological study. Three fields per animal were considered for computer-assisted digital analysis and determination of the volume densities (Vv of the nuclei and CM. The images were segmented with the aid of Image Pro Plus® 4.5.029 software (Media Cybernetics. RESULTS: No difference was observed between the treated and nontreated groups in regard to body mass, cardiac mass, and the relation between cardiac and body mass. A significant reduction in the Vv[matrix] and a concomitant increase in the Vv[nuclei] were observed in the treated group as compared with those in the nontreated group. CONCLUSION: The treatment with enalapril of hypertensive rats during pregnancy alters the collagen content and structure of the myocardium of newborns.

  10. Crosslinked collagen–gelatin–hyaluronic acid biomimetic film for cornea tissue engineering applications

    International Nuclear Information System (INIS)

    Liu, Yang; Ren, Li; Wang, Yingjun

    2013-01-01

    Cornea disease may lead to blindness and keratoplasty is considered as an effective treatment method. However, there is a severe shortage of donor corneas worldwide. This paper presents the crosslinked collagen (Col)–gelatin (Gel)–hyaluronic acid (HA) films developed by making use of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as the crosslinker. The test results on the physical and biological properties indicate that the CGH631 film (the mass ratio of Col:Gel:HA = 6:3:1) has appropriate optical performance, hydrophilicity and mechanical properties. The diffusion properties of the CGH631 film to NaCl and tryptophan are also satisfactory and the measured data are 2.43 × 10 −6 cm 2 /s and 7.97 × 10 −7 cm 2 /s, respectively. In addition, cell viability studies demonstrate that the CGH631 film has good biocompatibility, on which human corneal epithelial cells attached and proliferated well. This biocompatible film may have potential use in cornea tissue engineering. - Highlights: ► Crosslinked collagen–gelatin–hyaluronic acid films were fabricated in this study. ► The film had appropriate physical properties. ► Diffusion coefficient of the film was comparable with the human cornea. ► HCEC viability studies confirmed the biocompatibility of the film.

  11. Effects of isopropanol on collagen fibrils in new parchment

    Directory of Open Access Journals (Sweden)

    Gonzalez Lee G

    2012-03-01

    Full Text Available Abstract Background Isopropanol is widely used by conservators to relax the creases and folds of parchment artefacts. At present, little is known of the possible side effects of the chemical on parchments main structural component- collagen. This study uses X-ray Diffraction to investigate the effects of a range of isopropanol concentrations on the dimensions of the nanostructure of the collagen component of new parchment. Results It is found in this study that the packing features of the collagen molecules within the collagen fibril are altered by exposure to isopropanol. The results suggest that this chemical treatment can induce a loss of structural water from the collagen within parchment and thus a rearrangement of intermolecular bonding. This study also finds that the effects of isopropanol treatment are permanent to parchment artefacts and cannot be reversed with rehydration using deionised water. Conclusions This study has shown that isopropanol induces permanent changes to the packing features of collagen within parchment artefacts and has provided scientific evidence that its use to remove creases and folds on parchment artefacts will cause structural change that may contribute to long-term deterioration of parchment artefacts. This work provides valuable information that informs conservation practitioners regarding the use of isopropanol on parchment artefacts.

  12. Higher iron bioavailability of a human-like collagen iron complex.

    Science.gov (United States)

    Zhu, Chenhui; Yang, Fan; Fan, Daidi; Wang, Ya; Yu, Yuanyuan

    2017-07-01

    Iron deficiency remains a public health problem around the world due to low iron intake and/or bioavailability. FeSO 4 , ferrous succinate, and ferrous glycinate chelate are rich in iron but have poor bioavailability. To solve the problem of iron deficiency, following previous research studies, a thiolated human-like collagen-ironcomplex supplement with a high iron content was prepared in an anaerobic workstation. In addition, cell viability tests were evaluated after conducting an MTT assay, and a quantitative analysis of the thiolated human-like collagen-iron digesta samples was performed using the SDS-PAGE method coupled with gel filtration chromatography. The iron bioavailability was assessed using Caco-2 cell monolayers and iron-deficiency anemia mice models. The results showed that (1) one mole of thiolated human-like collagen-iron possessed approximately 35.34 moles of iron; (2) thiolated human-like collagen-iron did not exhibit cytotoxity and (3) thiolated human-like collagen- iron digesta samples had higher bioavailability than other iron supplements, including FeSO 4 , ferrous succinate, ferrous glycine chelate and thiolated human-like collagen-Fe iron. Finally, the iron bioavailability was significantly enhanced by vitamin C. These results indicated that thiolated human-like collagen-iron is a promising iron supplement for use in the future.

  13. Tumor cell invasion of collagen matrices requires coordinate lipid agonist-induced G-protein and membrane-type matrix metalloproteinase-1-dependent signaling

    Directory of Open Access Journals (Sweden)

    Anthis Nicholas J

    2006-12-01

    Full Text Available Abstract Background Lysophosphatidic acid (LPA and sphingosine 1-phosphate (S1P are bioactive lipid signaling molecules implicated in tumor dissemination. Membrane-type matrix metalloproteinase 1 (MT1-MMP is a membrane-tethered collagenase thought to be involved in tumor invasion via extracellular matrix degradation. In this study, we investigated the molecular requirements for LPA- and S1P-regulated tumor cell migration in two dimensions (2D and invasion of three-dimensional (3D collagen matrices and, in particular, evaluated the role of MT1-MMP in this process. Results LPA stimulated while S1P inhibited migration of most tumor lines in Boyden chamber assays. Conversely, HT1080 fibrosarcoma cells migrated in response to both lipids. HT1080 cells also markedly invaded 3D collagen matrices (~700 μm over 48 hours in response to either lipid. siRNA targeting of LPA1 and Rac1, or S1P1, Rac1, and Cdc42 specifically inhibited LPA- or S1P-induced HT1080 invasion, respectively. Analysis of LPA-induced HT1080 motility on 2D substrates vs. 3D matrices revealed that synthetic MMP inhibitors markedly reduced the distance (~125 μm vs. ~45 μm and velocity of invasion (~0.09 μm/min vs. ~0.03 μm/min only when cells navigated 3D matrices signifying a role for MMPs exclusively in invasion. Additionally, tissue inhibitors of metalloproteinases (TIMPs-2, -3, and -4, but not TIMP-1, blocked lipid agonist-induced invasion indicating a role for membrane-type (MT-MMPs. Furthermore, MT1-MMP expression in several tumor lines directly correlated with LPA-induced invasion. HEK293s, which neither express MT1-MMP nor invade in the presence of LPA, were transfected with MT1-MMP cDNA, and subsequently invaded in response to LPA. When HT1080 cells were seeded on top of or within collagen matrices, siRNA targeting of MT1-MMP, but not other MMPs, inhibited lipid agonist-induced invasion establishing a requisite role for MT1-MMP in this process. Conclusion LPA is a

  14. Structure–mechanics relationships of collagen fibrils in the osteogenesis imperfecta mouse model

    Science.gov (United States)

    Andriotis, O. G.; Chang, S. W.; Vanleene, M.; Howarth, P. H.; Davies, D. E.; Shefelbine, S. J.; Buehler, M. J.; Thurner, P. J.

    2015-01-01

    The collagen molecule, which is the building block of collagen fibrils, is a triple helix of two α1(I) chains and one α2(I) chain. However, in the severe mouse model of osteogenesis imperfecta (OIM), deletion of the COL1A2 gene results in the substitution of the α2(I) chain by one α1(I) chain. As this substitution severely impairs the structure and mechanics of collagen-rich tissues at the tissue and organ level, the main aim of this study was to investigate how the structure and mechanics are altered in OIM collagen fibrils. Comparing results from atomic force microscopy imaging and cantilever-based nanoindentation on collagen fibrils from OIM and wild-type (WT) animals, we found a 33% lower indentation modulus in OIM when air-dried (bound water present) and an almost fivefold higher indentation modulus in OIM collagen fibrils when fully hydrated (bound and unbound water present) in phosphate-buffered saline solution (PBS) compared with WT collagen fibrils. These mechanical changes were accompanied by an impaired swelling upon hydration within PBS. Our experimental and atomistic simulation results show how the structure and mechanics are altered at the individual collagen fibril level as a result of collagen gene mutation in OIM. We envisage that the combination of experimental and modelling approaches could allow mechanical phenotyping at the collagen fibril level of virtually any alteration of collagen structure or chemistry. PMID:26468064

  15. Preparation and structure characterization of soluble bone collagen ...

    African Journals Online (AJOL)

    In this study, G-25 gel chromatography, X-diffraction, scanning electron microscopy (SEM), UV and Fourier transform infrared spectroscopy (FTIR) were used to analyze soluble collagen peptides chelating calcium. Collagen peptide hydrolysis can be divided into four components using G-25 gel chromatography.

  16. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  17. Anion embedded sol-gel films on Al for corrosion protection

    International Nuclear Information System (INIS)

    Sheffer, Mari; Groysman, Alec; Starosvetsky, David; Savchenko, Natali; Mandler, Daniel

    2004-01-01

    We report here on the successful incorporation of organic anions into a sol-gel film on Al as a means of enhancing the protection against corrosion. Following our previous study where we showed that hydrophobic sol-gel films provided pronounced corrosion inhibition, we studied the corrosion inhibition that phenylphosphonic acid (PPA) has when embedded inside a thin sol-gel coating on Al. The anion of this organic anion tends to stay inside a phenyltrimethoxysilane (PTMOS) based sol-gel film due to π-interactions. Our findings, which are derived primarily from potentiodynamic polarization measurements, electrochemical noise, scanning electron microscopy measurements and Auger electron spectroscopy (AES), clearly show that the organic phosphonate adds to the protection efficiency of the sol-gel film

  18. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  19. Collagen derived serum markers in carcinoma of the prostate

    DEFF Research Database (Denmark)

    Rudnicki, M; Jensen, L T; Iversen, P

    1995-01-01

    Three new collagen markers deriving from the collagenous matrix, e.g. carboxyterminal propeptide of type I procollagen (PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP), and aminoterminal propeptide of type III procollagen (PIIINP) were used for the diagnose......, ICTP, and PICP did not differ between these two groups. In patients with metastatic prostatic cancer all five markers were increased compared to the level measured in patients with localized cancer (p

  20. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride

    International Nuclear Information System (INIS)

    Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-01-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen. - Highlights: • Acylated collagen retained the unique triple helix conformation. • Acylated collagen had stronger thermostability than native collagen. • Amide I was the most sensitive band to the temperature for acylated collagen. • Amide II was the most sensitive band to the temperature for native collagen. • Auto-peak at 1680 cm −1 for acylated collagen disappeared at higher temperature

  1. Collagen synthesis in CBA mouse heart after total thoracic irradiation

    International Nuclear Information System (INIS)

    Murray, J.C.; Parkins, C.S.; Institute of Cancer Research, Sutton

    1988-01-01

    CBA mice were irradiated to the whole thorax with single doses of 240 kVp X-rays in the dose range 8-16 Gy. Collagen and total protein synthesis rates in the heart were measured at 2-monthly intervals using a radio-isotope incorporation techniques. Doses of 10 Gy or greater caused a slight increase in collagen synthesis, followed by significantly reduced collagen synthesis by 16 weeks or longer after treatment. The depression in synthesis appeared correspondingly earlier with increasing dose. Total protein synthesis in heart followed similar patterns although changes were not statistically significant, indicating that the changes reflected alterations to collagen synthesis specifally, and not protein synthesis in geneal. Total hydroxyproline measurements showed no significant changes in heart collagen at any time as a result of X-irradiation. 18 refs.; 7 figs

  2. Silicone Substrate with Collagen and Carbon Nanotubes Exposed to Pulsed Current for MSC Osteodifferentiation

    Directory of Open Access Journals (Sweden)

    Daniyal Jamal

    2017-01-01

    Full Text Available Autologous human adipose tissue-derived mesenchymal stem cells (MSCs have the potential for clinical translation through their induction into osteoblasts for regeneration. Bone healing can be driven by biophysical stimulation using electricity for activating quiescent adult stem cells. It is hypothesized that application of electric current will enhance their osteogenic differentiation, and addition of conductive carbon nanotubes (CNTs to the cell substrate will provide increased efficiency in current transmission. Cultured MSCs were seeded and grown onto fabricated silicone-based composites containing collagen and CNT fibers. Chemical inducers, namely, glycerol phosphate, dexamethasone, and vitamin C, were then added to the medium, and pulsatile submilliampere electrical currents (about half mA for 5 cycles at 4 mHz, twice a week were applied for two weeks. Calcium deposition indicative of MSC differentiation and osteoblastic activity was quantified through Alizarin Red S and spectroscopy. It was found that pulsed current significantly increased osteodifferentiation on silicone-collagen films without CNTs. Under no external current, the presence of 10% (m/m CNTs led to a significant and almost triple upregulation of calcium deposition. Both CNTs and current parameters did not appear to be synergistic. These conditions of enhanced osteoblastic activities may further be explored ultimately towards future therapeutic use of MSCs.

  3. Evaluation of antibacterial and cytotoxic effects of nano-sized bioactive glass/collagen composites releasing tetracycline hydrochloride.

    Science.gov (United States)

    Rivadeneira, J; Di Virgilio, A L; Audisio, M C; Boccaccini, A R; Gorustovich, A A

    2014-06-01

    To evaluate the antibacterial efficacy of silicate bioactive glass nanoparticles/collagen composites functionalized with tetracycline hydrochloride (TCH). Different concentrations of tetracycline hydrochloride (TCH) were incorporated on silicate bioactive glass nanoparticles/collagen composites by dipping these biomaterials for 48 h at 37°C in a solution of simulated body fluid (SBF) plus 0·05, 0·20 or 0·35 mg ml(-1) of the antibiotic. TCH release was assessed in double-distilled water at 37°C up to 72 h. The antibacterial activity of the samples has been evaluated in two ways: inhibition zone test and plate count method. The experiments were performed in vitro up to 48 h on four staphylococci strains (Staphylococcus aureus ATCC29213, ATCC25923, ATCC6538P and Staphylococcus epidermidis ATCC12228). The new composites were also tested for cytotoxicity on MG-63 human osteosarcoma cells. The results showed that the incorporation and release of TCH was dependent on the initial concentration of TCH in SBF. The biomaterials also inhibited the Staph. aureus cell growth even though the efficacy was similar for all concentration. On the other hand, no cytotoxic effects were found on osteoblast-like cells, even at the highest concentration. Considering all results, it can be concluded that the new composite acts as a suitable bioactive carrier of TCH and could have potential in the prevention of biomaterial related infections. The results suggest a potential application as wound dressing. © 2014 The Society for Applied Microbiology.

  4. Double thermal transitions of type I collagen in acidic solution.

    Science.gov (United States)

    Liu, Yan; Liu, Lingrong; Chen, Mingmao; Zhang, Qiqing

    2013-01-01

    Contributed equally to this work. To further understand the origin of the double thermal transitions of collagen in acidic solution induced by heating, the denaturation of acidic soluble collagen was investigated by micro-differential scanning calorimeter (micro-DSC), circular dichroism (CD), dynamic laser light scattering (DLLS), transmission electron microscopy (TEM), and two-dimensional (2D) synchronous fluorescence spectrum. Micro-DSC experiments revealed that the collagen exhibited double thermal transitions, which were located within 31-37 °C (minor thermal transition, T(s) ∼ 33 °C) and 37-55 °C (major thermal transition, T(m) ∼ 40 °C), respectively. The CD spectra suggested that the thermal denaturation of collagen resulted in transition from polyproline II type structure to unordered structure. The DLLS results showed that there were mainly two kinds of collagen fibrillar aggregates with different sizes in acidic solution and the larger fibrillar aggregates (T(p2) = 40 °C) had better heat resistance than the smaller one (T(p1) = 33 °C). TEM revealed that the depolymerization of collagen fibrils occurred and the periodic cross-striations of collagen gradually disappeared with increasing temperature. The 2D fluorescence correlation spectra were also applied to investigate the thermal responses of tyrosine and phenylalanine residues at the molecular level. Finally, we could draw the conclusion that (1) the minor thermal transition was mainly due to the defibrillation of the smaller collagen fibrillar aggregates and the unfolding of a little part of triple helices; (2) the major thermal transition primarily arose from the defibrillation of the larger collagen fibrillar aggregates and the complete denaturation of the majority part of triple helices.

  5. Joint immobilization inhibits spontaneous hyaline cartilage regeneration induced by a novel double-network gel implantation.

    Science.gov (United States)

    Arakaki, Kazunobu; Kitamura, Nobuto; Kurokawa, Takayuki; Onodera, Shin; Kanaya, Fuminori; Gong, Jian-Ping; Yasuda, Kazunori

    2011-02-01

    We have recently discovered that spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect in the rabbit, when we implant a novel double-network (DN) gel plug at the bottom of the defect. To clarify whether joint immobilization inhibits the spontaneous hyaline cartilage regeneration, we conducted this study with 20 rabbits. At 4 or 12 weeks after surgery, the defect in the mobile knees was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen, while no cartilage tissues were observed in the defect in the immobilized knees. Type-2 collagen, Aggrecan, and SOX9 mRNAs were expressed only in the mobile knees at each period. This study demonstrated that joint immobilization significantly inhibits the spontaneous hyaline cartilage regeneration induced by the DN gel implantation. This fact suggested that the mechanical environment is one of the significant factors to induce this phenomenon.

  6. Parathyroid hormone blocks the stimulatory effect of insulin-like growth factor-I on collagen synthesis in cultured 21-day fetal rat calvariae

    International Nuclear Information System (INIS)

    Kream, B.E.; Petersen, D.N.; Raisz, L.G.

    1990-01-01

    We examined the interaction of parathyroid hormone (PTH) and recombinant human insulin-like growth factor I (IGF-I) on collagen synthesis in 21-day fetal rat calvariae as assessed by measuring the incorporation of [ 3 H]proline into collagenase-digestible protein. After 96 hours of culture, 10 nM PTH antagonized the stimulation of collagen synthesis and partially blocked the increase in dry weight produced by 10 nM IGF-I. The effect of PTH to block IGF-I stimulated collagen synthesis was observed in the central bone of calvariae and was mimicked by forskolin and phorbol 12-myristate 13-acetate, but not by 1,25-dihydroxyvitamin D3, transforming growth factor-alpha or dexamethasone. Our data are consistent with the concept that the direct effect of PTH is to inhibit basal CDP labeling and fully oppose IGF-I stimulated CDP labeling. The finding that this effect of PTH is mimicked by forskolin and PMA suggests that this block in IGF-I stimulation of CDP labeling involves both cAMP and protein kinase C mediated pathways

  7. The Collagen Binding Proteins of Streptococcus mutans and Related Streptococci

    Science.gov (United States)

    Avilés-Reyes, Alejandro; Miller, James H.; Lemos, José A.; Abranches, Jacqueline

    2016-01-01

    Summary The ability of Streptococcus mutans to interact with collagen through the expression of collagen-binding proteins (CBPs) bestows this oral pathogen with an alternative to the sucrose-dependent mechanism of colonization classically attributed to caries development. Based on the abundance and distribution of collagen throughout the human body, stringent adherence to this molecule grants S. mutans with the opportunity to establish infection at different host sites. Surface proteins, such as SpaP, WapA, Cnm and Cbm, have been shown to bind collagen in vitro, and it has been suggested that these molecules play a role in colonization of oral and extra-oral tissues. However, robust collagen binding is not achieved by all strains of S. mutans, particularly those that lack Cnm or Cbm. These observations merit careful dissection of the contribution from these different CBPs towards tissue colonization and virulence. In this review, we will discuss the current understanding of mechanisms utilized by S. mutans and related streptococci to colonize collagenous tissues, and the possible contribution of CBPs to infections in different sites of the host. PMID:26991416

  8. Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    Local hemostatics for osseous tissue should preferably be absorbable and biocompatible and should not inhibit osteogenesis. The tissue response and effect on demineralized bone-induced heterotopic osteogenesis in the abdominal muscle of 120 male Wistar rats by different local hemostatics were...... evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed...

  9. Snail1 induced in breast cancer cells in 3D collagen I gel environment suppresses cortactin and impairs effective invadopodia formation.

    Science.gov (United States)

    Lee, Mi-Sook; Kim, Sudong; Kim, Baek Gil; Won, Cheolhee; Nam, Seo Hee; Kang, Suki; Kim, Hye-Jin; Kang, Minkyung; Ryu, Jihye; Song, Haeng Eun; Lee, Doohyung; Ye, Sang-Kyu; Jeon, Noo Li; Kim, Tai Young; Cho, Nam Hoon; Lee, Jung Weon

    2014-09-01

    Although an in vitro 3D environment cannot completely mimic the in vivo tumor site, embedding tumor cells in a 3D extracellular matrix (ECM) allows for the study of cancer cell behaviors and the screening of anti-metastatic reagents with a more in vivo-like context. Here we explored the behaviors of MDA-MB-231 breast cancer cells embedded in 3D collagen I. Diverse tumor environmental conditions (including cell density, extracellular acidity, or hypoxia as mimics for a continuous tumor growth) reduced JNKs, enhanced TGFβ1/Smad signaling activity, induced Snail1, and reduced cortactin expression. The reduced JNKs activity blocked efficient formation of invadopodia labeled with actin, cortactin, or MT1-MMP. JNKs inactivation activated Smad2 and Smad4, which were required for Snail1 expression. Snail1 then repressed cortactin expression, causing reduced invadopodia formation and prominent localization of MT1-MMP at perinuclear regions. MDA-MB-231 cells thus exhibited less efficient collagen I degradation and invasion in 3D collagen I upon JNKs inhibition. These observations support a signaling network among JNKs, Smads, Snail1, and cortactin to regulate the invasion of MDA-MB-231 cells embedded in 3D collagen I, which may be targeted during screening of anti-invasion reagents. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Pulmonary collagen metabolism in irradiated hamsters and those treated with corticosteroids

    International Nuclear Information System (INIS)

    Pickrell, J.A.; Straus, F.C.; Halliwell, W.H.; Jones, R.K.

    1976-01-01

    Syrian hamsters were exposed to 90 Y in fused aluminosilicate particles to produce pulmonary fibrosis. Irradiated hamsters and contols were treated with Depomedrol, arresting the developing fibrosis. All hamsters receiving steroid showed a reduced incorporation of 14 C-proline into noncollagen protein during the 3-19 wk period after exposure. Collagen synthesis relative to noncollagen protein synthesis was decreased five-fold in these animals at early times after exposure and during high steroid dosage, but had returned to control levels after considerable time at lower steroid dosage. Collagen synthesis in irradiated animals not receiving steroids was elevated during the same time period and collagen synthesis in irradiated hamsters treated with steroid was intermediate between that in radiation animals and in control or steroid animals. Collagen breakdown was elevated to the same level as in irradiated animals, and collagen content was normal and well below that of irradiated animals. These and previous data indicate that steroid treatment delays development of pulmonary fibrosis in animals irradiated with fibrogenic doses of 90 Y in fused aluminosilicate particles. Experiments incubating BAPN or Depomedrol with L-929 or WI-38 fibroblasts in vitro were performed to note any effect of these agents upon fibroblast proliferation, cellular collagen processing or collagen synthesis. Steroids frequently reduced fibroblast proliferation and altered cellular collagen processings to reflect an increased proportion of collagen breakdown products. These changes reflect the importance of fibroblast proliferation in developing pulmonary fibrosis

  11. Inelastic behaviour of collagen networks in cell–matrix interactions and mechanosensation

    Science.gov (United States)

    Mohammadi, Hamid; Arora, Pamma D.; Simmons, Craig A.; Janmey, Paul A.; McCulloch, Christopher A.

    2015-01-01

    The mechanical properties of extracellular matrix proteins strongly influence cell-induced tension in the matrix, which in turn influences cell function. Despite progress on the impact of elastic behaviour of matrix proteins on cell–matrix interactions, little is known about the influence of inelastic behaviour, especially at the large and slow deformations that characterize cell-induced matrix remodelling. We found that collagen matrices exhibit deformation rate-dependent behaviour, which leads to a transition from pronounced elastic behaviour at fast deformations to substantially inelastic behaviour at slow deformations (1 μm min−1, similar to cell-mediated deformation). With slow deformations, the inelastic behaviour of floating gels was sensitive to collagen concentration, whereas attached gels exhibited similar inelastic behaviour independent of collagen concentration. The presence of an underlying rigid support had a similar effect on cell–matrix interactions: cell-induced deformation and remodelling were similar on 1 or 3 mg ml−1 attached collagen gels while deformations were two- to fourfold smaller in floating gels of high compared with low collagen concentration. In cross-linked collagen matrices, which did not exhibit inelastic behaviour, cells did not respond to the presence of the underlying rigid foundation. These data indicate that at the slow rates of collagen compaction generated by fibroblasts, the inelastic responses of collagen gels, which are influenced by collagen concentration and the presence of an underlying rigid foundation, are important determinants of cell–matrix interactions and mechanosensation. PMID:25392399

  12. Chondrogenic differentiation of mesenchymal stem cells in a leakproof collagen sponge

    International Nuclear Information System (INIS)

    Chen Guoping; Akahane, Daisuke; Kawazoe, Naoki; Yamamoto, Katsuyuki; Tateishi, Tetsuya

    2008-01-01

    A three-dimensional culture of mesenchymal stem cells (MSCs) in a porous scaffold has been developed as a promising strategy for cartilage tissue engineering. The chondrogenic differentiation of MSCs derived from human bone marrow was studied by culturing the cells in a novel scaffold constructed of leakproof collagen sponge. All the surfaces of the collagen sponge except the top were wrapped with a membrane that has pores smaller than the cells to protect against cell leakage during cell seeding. The cells adhered to the collagen, distributed evenly, and proliferated to fill the spaces in the sponge. Cell seeding efficiency was greater than 95%. The MSCs cultured in the collagen sponge in the presence of TGF-β3 and BMP6 expressed a high level of genes encoding type II and type X collagen, sox9, and aggrecan. Histological examination by HE staining indicated that the differentiated cells showed a round morphology. The extracellular matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. These results suggest the chondrogenic differentiation of MSCs when cultured in the collagen sponge in the presence of TGF-β3 and BMP6

  13. Collagenous mucosal inflammatory diseases of the gastrointestinal tract.

    Science.gov (United States)

    Freeman, Hugh J

    2005-07-01

    Collagenous mucosal inflammatory diseases involve the columnar-lined gastric and intestinal mucosa and have become recognized increasingly as a significant cause of symptomatic morbidity, particularly in middle-aged and elderly women, especially with watery diarrhea. Still, mechanisms involved in the pathogenesis of this diarrhea remain poorly understood and require further elucidation. The prognosis and long-term outcome of these disorders has been documented only to a limited extent. Recent clinical and pathologic studies have indicated that collagenous mucosal inflammatory disease is a more extensive pathologic process that concomitantly may involve several sites in the gastric and intestinal mucosa. The dominant pathologic lesion is a distinct subepithelial hyaline-like deposit that has histochemical and ultrastructural features of collagen overlying a microscopically defined inflammatory process. An intimate relationship with other autoimmune connective tissue disorders is evident, particularly celiac disease. This is intriguing because these collagenous disorders have not been shown to be gluten dependent. Collagenous mucosal inflammatory disorders may represent a relatively unique but generalized inflammatory response to a multitude of causes, including celiac disease, along with a diverse group of pharmacologic agents. Some recent reports have documented treatment success but histopathologic reversal has been more difficult to substantiate owing to the focal, sometimes extensive nature, of this pathologic process.

  14. Differences in cytocompatibility between collagen, gelatin and keratin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanfang; Zhang, Weiwei; Yuan, Jiang, E-mail: jyuan@njnu.edu.cn; Shen, Jian, E-mail: jshen@njnu.edu.cn

    2016-02-01

    Keratins are cysteine-rich intermediate filament proteins found in the cytoskeleton of the epithelial cells and in the matrix of hair, feathers, wool, nails and horns. The natural abundance of cell adhesion sequences, RGD (Arg-Gly-Asp) and LDV (Leu-Asp-Val), makes them suitable for tissue engineering applications. The purpose of our study is to evaluate their cytocompatibility as compared to well-known collagen and gelatin proteins. Herein, collagen, gelatin and keratin were blended with poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and electrospun to afford nanofibrous mats, respectively. These PHBV/protein composite mats were characterized by field emission scanning electron microscopy (FE-SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and dynamic mechanical analysis (DMA). The cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. The data from MTT and BrDU revealed that collagen had significantly superior cytocompatibility as compared to gelatin and keratin. Gelatin showed a better cytocompatibility than keratin without statistical significance difference. Finally, we gave the reasons to account for the above conclusions. - Highlights: • Collagen, gelatin and keratin were coelectrospun with PHBV to afford nanofibrous mats. • Cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. • Collagen had significantly superior cytocompatibility as compared to gelatin and keratin.

  15. Biological effect of hydrolyzed collagen on bone metabolism.

    Science.gov (United States)

    Daneault, Audrey; Prawitt, Janne; Fabien Soulé, Véronique; Coxam, Véronique; Wittrant, Yohann

    2017-06-13

    Osteoporosis is a chronic and asymptomatic disease characterized by low bone mass and skeletal microarchitectural deterioration, increased risk of fracture, and associated comorbidities most prevalent in the elderly. Due to an increasingly aging population, osteoporosis has become a major health issue requiring innovative disease management. Proteins are important for bone by providing building blocks and by exerting specific regulatory function. This is why adequate protein intake plays a considerable role in both bone development and bone maintenance. More specifically, since an increase in the overall metabolism of collagen can lead to severe dysfunctions and a more fragile bone matrix and because orally administered collagen can be digested in the gut, cross the intestinal barrier, enter the circulation, and become available for metabolic processes in the target tissues, one may speculate that a collagen-enriched diet provides benefits for the skeleton. Collagen-derived products such as gelatin or hydrolyzed collagen (HC) are well acknowledged for their safety from a nutritional point of view; however, what is their impact on bone biology? In this manuscript, we critically review the evidence from literature for an effect of HC on bone tissues in order to determine whether HC may represent a relevant alternative in the design of future nutritional approaches to manage osteoporosis prevention.

  16. GH receptor blocker administration and muscle-tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Nielsen, Rie Harboe; Doessing, Simon; Goto, Kazushige

    2011-01-01

    The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans.......The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans....

  17. Tumor-Associated Macrophages Derived from Circulating Inflammatory Monocytes Degrade Collagen through Cellular Uptake

    DEFF Research Database (Denmark)

    Madsen, Daniel Hargbøl; Jürgensen, Henrik Jessen; Siersbæk, Majken Storm

    2017-01-01

    -associated macrophage (TAM)-like cells that degrade collagen in a mannose receptor-dependent manner. Accordingly, mannose-receptor-deficient mice display increased intratumoral collagen. Whole-transcriptome profiling uncovers a distinct extracellular matrix-catabolic signature of these collagen-degrading TAMs. Lineage......-ablation studies reveal that collagen-degrading TAMs originate from circulating CCR2+ monocytes. This study identifies a function of TAMs in altering the tumor microenvironment through endocytic collagen turnover and establishes macrophages as centrally engaged in tumor-associated collagen degradation. Madsen et...

  18. Polymerized-Type I Collagen Induces Upregulation of Foxp3-Expressing CD4 Regulatory T Cells and Downregulation of IL-17-Producing CD4+ T Cells (Th17 Cells in Collagen-Induced Arthritis

    Directory of Open Access Journals (Sweden)

    Janette Furuzawa-Carballeda

    2012-01-01

    Full Text Available Previous studies showed that polymerized-type I collagen (polymerized collagen exhibits potent immunoregulatory properties. This work evaluated the effect of intramuscular administration of polymerized collagen in early and established collagen-induced arthritis (CIA in mice and analyzed changes in Th subsets following therapy. Incidence of CIA was of 100% in mice challenged with type II collagen. Clinimorphometric analysis showed a downregulation of inflammation after administration of all treatments (P<0.05. Histological analysis showed that the CIA-mice group had extensive bone erosion, pannus and severe focal inflammatory infiltrates. In contrast, there was a remarkable reduction in the severity of arthritis in mice under polymerized collagen, methotrexate or methotrexate/polymerized collagen treatment. Polymerized Collagen but not methotrexate induced tissue joint regeneration. Polymerized Collagen and methotrexate/polymerized collagen but not methotrexate alone induces downregulation of CD4+/IL17A+ T cells and upregulation of Tregs and CD4+/IFN-γ+ T cells. Thus, Polymerized Collagen could be an effective therapeutic agent in early and established rheumatoid arthritis by exerting downregulation of autoimmune inflammation.

  19. Diffusion of MMPs on the surface of collagen fibrils: the mobile cell surface-collagen substratum interface.

    Directory of Open Access Journals (Sweden)

    Ivan E Collier

    Full Text Available Remodeling of the extracellular matrix catalyzed by MMPs is central to morphogenetic phenomena during development and wound healing as well as in numerous pathologic conditions such as fibrosis and cancer. We have previously demonstrated that secreted MMP-2 is tethered to the cell surface and activated by MT1-MMP/TIMP-2-dependent mechanism. The resulting cell-surface collagenolytic complex (MT1-MMP(2/TIMP-2/MMP-2 can initiate (MT1-MMP and complete (MMP-2 degradation of an underlying collagen fibril. The following question remained: What is the mechanism of substrate recognition involving the two structures of relatively restricted mobility, the cell surface enzymatic complex and a collagen fibril embedded in the ECM? Here we demonstrate that all the components of the complex are capable of processive movement on a surface of the collagen fibril. The mechanism of MT1-MMP movement is a biased diffusion with the bias component dependent on the proteolysis of its substrate, not adenosine triphosphate (ATP hydrolysis. It is similar to that of the MMP-1 Brownian ratchet we described earlier. In addition, both MMP-2 and MMP-9 as well as their respective complexes with TIMP-1 and -2 are capable of Brownian diffusion on the surface of native collagen fibrils without noticeable dissociation while the dimerization of MMP-9 renders the enzyme immobile. Most instructive is the finding that the inactivation of the enzymatic activity of MT1-MMP has a detectable negative effect on the cell force developed in miniaturized 3D tissue constructs. We propose that the collagenolytic complex (MT1-MMP(2/TIMP-2/MMP-2 represents a Mobile Cell Surface-Collagen Substratum Interface. The biological implications of MT1-MMP acting as a molecular ratchet tethered to the cell surface in complex with MMP-2 suggest a new mechanism for the role of spatially regulated peri-cellular proteolysis in cell-matrix interactions.

  20. Edaravone suppresses degradation of type II collagen.

    Science.gov (United States)

    Huang, Chen; Liao, Guangjun; Han, Jian; Zhang, Guofeng; Zou, Benguo

    2016-05-13

    Osteoarthritis (OA) is a degenerative joint disease affecting millions of people. The degradation and loss of type II collagen induced by proinflammatory cytokines secreted by chondrocytes, such as factor-α (TNF-α) is an important pathological mechanism to the progression of OA. Edaravone is a potent free radical scavenger, which has been clinically used to treat the neuronal damage following acute ischemic stroke. However, whether Edaravone has a protective effect in articular cartilage hasn't been reported before. In this study, we investigated the chondrocyte protective effects of Edaravone on TNF-α induced degradation of type Ⅱ collagen. And our results indicated that TNF-α treatment resulted in degradation of type Ⅱ collagen, which can be ameliorated by treatment with Edaravone in a dose dependent manner. Notably, it was found that the inhibitory effects of Edaravone on TNF-α-induced reduction of type Ⅱ collagen were mediated by MMP-3 and MMP-13. Mechanistically, we found that Edaravone alleviated TNF-α induced activation of STAT1 and expression of IRF-1. These findings suggest a potential protective effect of Edaravone in OA. Copyright © 2016. Published by Elsevier Inc.