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Sample records for tenascin-x collagen elastin

  1. Tenascin-X, Collagen, Elastin and the Ehlers-Danlos Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Bristow, James; Carey, William; Schalkwijk, Joost

    2005-08-31

    Tenascin-X is an extracellular matrix protein initially identified because of its overlap with the human CYP21B gene. Because studies of gene and protein function of other tenascins had been poorly predictive of essential functions in vivo, we used a genetic approach that critically relied on an understanding of the genomic locus to uncover an association between inactivating tenascin-X mutations and novel recessive and dominant forms of Ehlers-Danlos syndrome. Tenascin-X provides the first example of a gene outside of the fibrillar collagens and their processing enzymes that causes Ehlers-Danlos syndrome. Tenascin-X null mice recapitulate the skin findings of the human disease, confirming a causative role for this gene in Ehlers-Danlos syndrome. Further evaluation of these mice showed that tenascin-X is an important regulator of collagen deposition in vivo, suggesting a novel mechanism of disease in this form of Ehlers-Danlos syndrome. Further studies suggest that tenascin-X may do this through both direct and indirect interactions with the collagen fibril. Recent studies show that TNX effects on matrix extend beyond the collagen to the elastogenic pathway and matrix remodeling enzymes. Tenascin-X serves as a compelling example of how human experiments of nature can guide us to an understanding of genes whose function may not be evident from their sequence or in vitro studies of their encoded proteins.

  2. Electrospinning of collagen and elastin for tissue engineering applications

    NARCIS (Netherlands)

    Buttafoco, L.; Kolkman, N.G.; Engbers-Buijtenhuijs, P.; Poot, Andreas A.; Dijkstra, Pieter J.; Vermes, I.; Feijen, Jan

    2006-01-01

    Meshes of collagen and/or elastin were successfully prepared by means of electrospinning from aqueous solutions. Flow rate, applied electric field, collecting distance and composition of the starting solutions determined the morphology of the obtained fibres. Addition of PEO (Mw=8×106) and NaCl was

  3. 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.

  4. 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

  5. Fluorescence, aggregation properties and FT-IR microspectroscopy of elastin and collagen fibers.

    Science.gov (United States)

    Vidal, Benedicto de Campos

    2014-10-01

    Histological and histochemical observations support the hypothesis that collagen fibers can link to elastic fibers. However, the resulting organization of elastin and collagen type complexes and differences between these materials in terms of macromolecular orientation and frequencies of their chemical vibrational groups have not yet been solved. This study aimed to investigate the macromolecular organization of pure elastin, collagen type I and elastin-collagen complexes using polarized light DIC-microscopy. Additionally, differences and similarities between pure elastin and collagen bundles (CB) were investigated by Fourier transform-infrared (FT-IR) microspectroscopy. Although elastin exhibited a faint birefringence, the elastin-collagen complex aggregates formed in solution exhibited a deep birefringence and formation of an ordered-supramolecular complex typical of collagen chiral structure. The FT-IR study revealed elastin and CB peptide NH groups involved in different types of H-bonding. More energy is absorbed in the vibrational transitions corresponding to CH, CH2 and CH3 groups (probably associated with the hydrophobicity demonstrated by 8-anilino-1-naphtalene sulfonic acid sodium salt [ANS] fluorescence), and to νCN, δNH and ωCH2 groups of elastin compared to CB. It is assumed that the α-helix contribution to the pure elastin amide I profile is 46.8%, whereas that of the B-sheet is 20% and that unordered structures contribute to the remaining percentage. An FT-IR profile library reveals that the elastin signature within the 1360-1189cm(-1) spectral range resembles that of Conex-Toray aramid fibers. Copyright © 2014 Elsevier GmbH. All rights reserved.

  6. Arterial extracellular matrix: a mechanobiological study of the contributions and interactions of elastin and collagen.

    Science.gov (United States)

    Chow, Ming-Jay; Turcotte, Raphaël; Lin, Charles P; Zhang, Yanhang

    2014-06-17

    The complex network structure of elastin and collagen extracellular matrix (ECM) forms the primary load bearing components in the arterial wall. The structural and mechanobiological interactions between elastin and collagen are important for properly functioning arteries. Here, we examined the elastin and collagen organization, realignment, and recruitment by coupling mechanical loading and multiphoton imaging. Two-photon excitation fluorescence and second harmonic generation methods were performed with a multiphoton video-rate microscope to capture real time changes to the elastin and collagen structure during biaxial deformation. Enzymatic removal of elastin was performed to assess the structural changes of the remaining collagen structure. Quantitative analysis of the structural changes to elastin and collagen was made using a combination of two-dimensional fast Fourier transform and fractal analysis, which allows for a more complete understanding of structural changes. Our study provides new quantitative evidence, to our knowledge on the sequential engagement of different arterial ECM components in response to mechanical loading. The adventitial collagen exists as large wavy bundles of fibers that exhibit fiber engagement after 20% strain. The medial collagen is engaged throughout the stretching process, and prominent elastic fiber engagement is observed up to 20% strain after which the engagement plateaus. The fiber orientation distribution functions show remarkably different changes in the ECM structure in response to mechanical loading. The medial collagen shows an evident preferred circumferential distribution, however the fiber families of adventitial collagen are obscured by their waviness at no or low mechanical strains. Collagen fibers in both layers exhibit significant realignment in response to unequal biaxial loading. The elastic fibers are much more uniformly distributed and remained relatively unchanged due to loading. Removal of elastin produces

  7. Collagen and elastin cross-linking is altered during aberrant late lung development associated with hyperoxia.

    Science.gov (United States)

    Mižíková, Ivana; Ruiz-Camp, Jordi; Steenbock, Heiko; Madurga, Alicia; Vadász, István; Herold, Susanne; Mayer, Konstantin; Seeger, Werner; Brinckmann, Jürgen; Morty, Rory E

    2015-06-01

    Maturation of the lung extracellular matrix (ECM) plays an important role in the formation of alveolar gas exchange units. A key step in ECM maturation is cross-linking of collagen and elastin, which imparts stability and functionality to the ECM. During aberrant late lung development in bronchopulmonary dysplasia (BPD) patients and animal models of BPD, alveolarization is blocked, and the function of ECM cross-linking enzymes is deregulated, suggesting that perturbed ECM cross-linking may impact alveolarization. In a hyperoxia (85% O2)-based mouse model of BPD, blunted alveolarization was accompanied by alterations to lung collagen and elastin levels and cross-linking. Total collagen levels were increased (by 63%). The abundance of dihydroxylysinonorleucine collagen cross-links and the dihydroxylysinonorleucine-to-hydroxylysinonorleucine ratio were increased by 11 and 18%, respectively, suggestive of a profibrotic state. In contrast, insoluble elastin levels and the abundance of the elastin cross-links desmosine and isodesmosine in insoluble elastin were decreased by 35, 30, and 21%, respectively. The lung collagen-to-elastin ratio was threefold increased. Treatment of hyperoxia-exposed newborn mice with the lysyl oxidase inhibitor β-aminopropionitrile partially restored normal collagen levels, normalized the dihydroxylysinonorleucine-to-hydroxylysinonorleucine ratio, partially normalized desmosine and isodesmosine cross-links in insoluble elastin, and partially restored elastin foci structure in the developing septa. However, β-aminopropionitrile administration concomitant with hyperoxia exposure did not improve alveolarization, evident from unchanged alveolar surface area and alveoli number, and worsened septal thickening (increased by 12%). These data demonstrate that collagen and elastin cross-linking are perturbed during the arrested alveolarization of developing mouse lungs exposed to hyperoxia. Copyright © 2015 the American Physiological Society.

  8. 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

  9. 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

  10. Multiphoton microscopy observations of 3D elastin and collagen fiber microstructure changes during pressurization in aortic media.

    Science.gov (United States)

    Sugita, Shukei; Matsumoto, Takeo

    2017-06-01

    Elastin and collagen fibers play important roles in the mechanical properties of aortic media. Because knowledge of local fiber structures is required for detailed analysis of blood vessel wall mechanics, we investigated 3D microstructures of elastin and collagen fibers in thoracic aortas and monitored changes during pressurization. Using multiphoton microscopy, autofluorescence images from elastin and second harmonic generation signals from collagen were acquired in media from rabbit thoracic aortas that were stretched biaxially to restore physiological dimensions. Both elastin and collagen fibers were observed in all longitudinal-circumferential plane images, whereas alternate bright and dark layers were observed along the radial direction and were recognized as elastic laminas (ELs) and smooth muscle-rich layers (SMLs), respectively. Elastin and collagen fibers are mainly oriented in the circumferential direction, and waviness of collagen fibers was significantly higher than that of elastin fibers. Collagen fibers were more undulated in longitudinal than in radial direction, whereas undulation of elastin fibers was equibiaxial. Changes in waviness of collagen fibers during pressurization were then evaluated using 2-dimensional fast Fourier transform in mouse aortas, and indices of waviness of collagen fibers decreased with increases in intraluminal pressure. These indices also showed that collagen fibers in SMLs became straight at lower intraluminal pressures than those in EL, indicating that SMLs stretched more than ELs. These results indicate that deformation of the aorta due to pressurization is complicated because of the heterogeneity of tissue layers and differences in elastic properties of ELs, SMLs, and surrounding collagen and elastin.

  11. Muscle characteristics and altered myofascial force transmission in tenascin-X-deficient mice, a mouse model of Ehlers-Danlos syndrome.

    NARCIS (Netherlands)

    Huijing, P.A.; Voermans, N.C.; Baan, G.C.; Buse, T.E.; Engelen, B.G.M. van; Haan, A. de

    2010-01-01

    The Ehlers-Danlos syndrome is a group of inherited connective tissue disorders caused by defects in collagens or tenascin-X (TNX). Muscle involvement can be expected based on interactions between muscle and extracellular matrix molecules; however, muscle function has not yet been investigated

  12. Ultrasonic delineation of aortic microstructure: The relative contribution of elastin and collagen to aortic elasticity

    Science.gov (United States)

    Marsh, Jon N.; Takiuchi, Shin; Lin, Shiow Jiuan; Lanza, Gregory M.; Wickline, Samuel A.

    2004-05-01

    Aortic elasticity is an important factor in hemodynamic health, and compromised aortic compliance affects not only arterial dynamics but also myocardial function. A variety of pathologic processes (e.g., diabetes, Marfan's syndrome, hypertension) can affect aortic elasticity by altering the microstructure and composition of the elastin and collagen fiber networks within the tunica media. Ultrasound tissue characterization techniques can be used to obtain direct measurements of the stiffness coefficients of aorta by measurement of the speed of sound in specific directions. In this study we sought to define the contributions of elastin and collagen to the mechanical properties of aortic media by measuring the magnitude and directional dependence of the speed of sound before and after selective isolation of either the collagen or elastin fiber matrix. Formalin-fixed porcine aortas were sectioned for insonification in the circumferential, longitudinal, or radial direction and examined using high-frequency (50 MHz) ultrasound microscopy. Isolation of the collagen or elastin fiber matrices was accomplished through treatment with NaOH or formic acid, respectively. The results suggest that elastin is the primary contributor to aortic medial stiffness in the unloaded state, and that there is relatively little anisotropy in the speed of sound or stiffness in the aortic wall.

  13. Hydrogels for lung tissue engineering: Biomechanical properties of thin collagen-elastin constructs.

    Science.gov (United States)

    Dunphy, Siobhán E; Bratt, Jessica A J; Akram, Khondoker M; Forsyth, Nicholas R; El Haj, Alicia J

    2014-10-01

    In this study, collagen-elastin constructs were prepared with the aim of producing a material capable of mimicking the mechanical properties of a single alveolar wall. Collagen has been used in a wide range of tissue engineering applications; however, due to its low mechanical properties its use is limited to non load-bearing applications without further manipulation using methods such as cross-linking or mechanical compression. Here, it was hypothesised that the addition of soluble elastin to a collagen hydrogel could improve its mechanical properties. Hydrogels made from collagen only and collagen plus varying amounts elastin were prepared. Young׳s modulus of each membrane was measured using the combination of a non-destructive indentation and a theoretical model previously described. An increase in Young׳s modulus was observed with increasing concentration of elastin. The use of non-destructive indentation allowed for online monitoring of the elastic moduli of cell-seeded constructs over 8 days. The addition of lung fibroblasts into the membrane increased the stiffness of the hydrogels further and cell-seeded collagen hydrogels were found to have a stiffness equal to the theoretical value for a single alveolar wall (≈5kPa). Through provision of some of the native extracellular matrix components of the lung parenchyma these scaffolds may be able to provide an initial building block toward the regeneration of new functional lung tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Quantification of aortic and cutaneous elastin and collagen morphology in Marfan syndrome by multiphoton microscopy.

    Science.gov (United States)

    Cui, Jason Z; Tehrani, Arash Y; Jett, Kimberly A; Bernatchez, Pascal; van Breemen, Cornelis; Esfandiarei, Mitra

    2014-09-01

    In a mouse model of Marfan syndrome, conventional Verhoeff-Van Gieson staining displays severe fragmentation, disorganization and loss of the aortic elastic fiber integrity. However, this method involves chemical fixatives and staining, which may alter the native morphology of elastin and collagen. Thus far, quantitative analysis of fiber damage in aorta and skin in Marfan syndrome has not yet been explored. In this study, we have used an advanced noninvasive and label-free imaging technique, multiphoton microscopy to quantify fiber fragmentation, disorganization, and total volumetric density of aortic and cutaneous elastin and collagen in a mouse model of Marfan syndrome. Aorta and skin samples were harvested from Marfan and control mice aged 3-, 6- and 9-month. Elastin and collagen were identified based on two-photon excitation fluorescence and second-harmonic-generation signals, respectively, without exogenous label. Measurement of fiber length indicated significant fragmentation in Marfan vs. control. Fast Fourier transform algorithm analysis demonstrated markedly lower fiber organization in Marfan mice. Significantly reduced volumetric density of elastin and collagen and thinner skin dermis were observed in Marfan mice. Cutaneous content of elastic fibers and thickness of dermis in 3-month Marfan resembled those in the oldest control mice. Our findings of early signs of fiber degradation and thinning of skin dermis support the potential development of a novel non-invasive approach for early diagnosis of Marfan syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. 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.

  16. Fourier Transform Infrared Spectroscopy to Quantify Collagen and Elastin in an In Vitro Model of Extracellular Matrix Degradation in Aorta

    Science.gov (United States)

    Cheheltani, Rabee; McGoverin, Cushla M.; Rao, Jayashree; Vorp, David A.; Kiani, Mohammad F.; Pleshko, N.

    2014-01-01

    Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues. PMID:24761431

  17. Fourier transform infrared spectroscopy to quantify collagen and elastin in an in vitro model of extracellular matrix degradation in aorta.

    Science.gov (United States)

    Cheheltani, Rabee; McGoverin, Cushla M; Rao, Jayashree; Vorp, David A; Kiani, Mohammad F; Pleshko, Nancy

    2014-06-21

    Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues.

  18. First steps towards tissue engineering of small-diameter blood vessels: preparation of flat scaffolds of collagen and elastin by means of freeze drying

    NARCIS (Netherlands)

    Buttafoco, L.; Engbers-Buijtenhuijs, P.; Poot, Andreas A.; Dijkstra, Pieter J.; Daamen, W.F.; van Kuppevelt, T.H.; Vermes, I.; Feijen, Jan

    2006-01-01

    Porous scaffolds composed of collagen or collagen and elastin were prepared by freeze drying at temperatures between -18 and -196°C. All scaffolds had a porosity of 90-98% and a homogeneous distribution of pores. Freeze drying at -18°C afforded collagen and collagen/elastin matrices with average

  19. Three dimensional microstructural network of elastin, collagen, and cells in Achilles tendons.

    Science.gov (United States)

    Pang, Xin; Wu, Jian-Ping; Allison, Garry T; Xu, Jiake; Rubenson, Jonas; Zheng, Ming-Hao; Lloyd, David G; Gardiner, Bruce; Wang, Allan; Kirk, Thomas Brett

    2017-06-01

    Similar to most biological tissues, the biomechanical, and functional characteristics of the Achilles tendon are closely related to its composition and microstructure. It is commonly reported that type I collagen is the predominant component of tendons and is mainly responsible for the tissue's function. Although elastin has been found in varying proportions in other connective tissues, previous studies report that tendons contain very small quantities of elastin. However, the morphology and the microstructural relationship among the elastic fibres, collagen, and cells in tendon tissue have not been well examined. We hypothesize the elastic fibres, as another fibrillar component in the extracellular matrix, have a unique role in mechanical function and microstructural arrangement in Achilles tendons. It has been shown that elastic fibres present a close connection with the tenocytes. The close relationship of the three components has been revealed as a distinct, integrated and complex microstructural network. Notably, a "spiral" structure within fibril bundles in Achilles tendons was observed in some samples in specialized regions. This study substantiates the hierarchical system of the spatial microstructure of tendon, including the mapping of collagen, elastin and tenocytes, with 3-dimensional confocal images. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1203-1214, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  20. 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.

  1. 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.

  2. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart

    2017-01-01

    digestions were applied to evaluate the loadbearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R(2)≥0.99), while there was a nonlinear relationship to the internal...

  3. Details of the Collagen and Elastin Architecture in the Human Limbal Conjunctiva, Tenon's Capsule and Sclera Revealed by Two-Photon Excited Fluorescence Microscopy.

    Science.gov (United States)

    Park, Choul Yong; Marando, Catherine M; Liao, Jason A; Lee, Jimmy K; Kwon, Jiwon; Chuck, Roy S

    2016-10-01

    To investigate the architecture and distribution of collagen and elastin in human limbal conjunctiva, Tenon's capsule, and sclera. The limbal conjunctiva, Tenon's capsule, and sclera of human donor corneal buttons were imaged with an inverted two-photon excited fluorescence microscope. No fixation process was necessary. The laser (Ti:sapphire) was tuned at 850 nm for two-photon excitation. Backscatter signals of second harmonic generation (SHG) and autofluorescence (AF) were collected through a 425/30-nm and a 525/45-nm emission filter, respectively. Multiple, consecutive, and overlapping (z-stack) images were acquired. Collagen signals were collected with SHG, whereas elastin signals were collected with AF. The size and density of collagen bundles varied widely depending on depth: increasing from conjunctiva to sclera. In superficial image planes, collagen bundles were image planes (episclera and superficial sclera), collagen bundles were thicker (near 100 μm in width) and densely packed. Comparatively, elastin fibers were thinner and sparse. The orientation of elastin fibers was independent of collagen fibers in superficial layers; but in deep sclera, elastin fibers wove through collagen interbundle gaps. At the limbus, both collagen and elastin fibers were relatively compact and were distributed perpendicular to the limbal annulus. Two-photon excited fluorescence microscopy has enabled us to understand in greater detail the collagen and elastin architecture of the human limbal conjunctiva, Tenon's capsule, and sclera.

  4. Insoluble elastin reduces collagen scaffold stiffness, improves viscoelastic properties, and induces a contractile phenotype in smooth muscle cells.

    Science.gov (United States)

    Ryan, Alan J; O'Brien, Fergal J

    2015-12-01

    Biomaterials with the capacity to innately guide cell behaviour while also displaying suitable mechanical properties remain a challenge in tissue engineering. Our approach to this has been to utilise insoluble elastin in combination with collagen as the basis of a biomimetic scaffold for cardiovascular tissue engineering. Elastin was found to markedly alter the mechanical and biological response of these collagen-based scaffolds. Specifically, during extensive mechanical assessment elastin was found to reduce the specific tensile and compressive moduli of the scaffolds in a concentration dependant manner while having minimal effect on scaffold microarchitecture with both scaffold porosity and pore size still within the ideal ranges for tissue engineering applications. However, the viscoelastic properties were significantly improved with elastin addition with a 3.5-fold decrease in induced creep strain, a 6-fold increase in cyclical strain recovery, and with a four-parameter viscoelastic model confirming the ability of elastin to confer resistance to long term deformation/creep. Furthermore, elastin was found to result in the modulation of SMC phenotype towards a contractile state which was determined via reduced proliferation and significantly enhanced expression of early (α-SMA), mid (calponin), and late stage (SM-MHC) contractile proteins. This allows the ability to utilise extracellular matrix proteins alone to modulate SMC phenotype without any exogenous factors added. Taken together, the ability of elastin to alter the mechanical and biological response of collagen scaffolds has led to the development of a biomimetic biomaterial highly suitable for cardiovascular tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Impact of elastin incorporation into electrochemically aligned collagen fibers on mechanical properties and smooth muscle cell phenotype.

    Science.gov (United States)

    Nguyen, Thuy-Uyen; Bashur, Chris A; Kishore, Vipuil

    2016-03-17

    Application of tissue-engineered vascular grafts (TEVGs) for the replacement of small-diameter arteries is limited due to thrombosis and intimal hyperplasia. Previous studies have attempted to address the limitations of TEVGs by developing scaffolds that mimic the composition (collagen and elastin) of native arteries to better match the mechanical properties of the graft with the native tissue. However, most existing scaffolds do not recapitulate the aligned topography of the collagen fibers found in native vessels. In the current study, based on the principles of isoelectric focusing, two different types of elastin (soluble and insoluble) were incorporated into highly oriented electrochemically aligned collagen (ELAC) fibers and the effect of elastin incorporation on the mechanical properties of the ELAC fibers and smooth muscle cell (SMC) phenotype was investigated. The results indicate that elastin incorporation significantly decreased the modulus of ELAC fibers to converge upon that of native vessels. Further, a significant increase in yield strain and decrease in Young's modulus was observed on all fibers post SMC culture compared with before the culture. Real-time polymerase chain reaction results showed a significant increase in the expression of α-smooth muscle actin and calponin on ELAC fibers with insoluble elastin, suggesting that incorporation of insoluble elastin induces a contractile phenotype in SMCs after two weeks of culture on ELAC fibers. Immunofluorescence results showed that calponin expression increased with time on all fibers. In conclusion, insoluble elastin incorporated ELAC fibers have the potential to be used for the development of functional TEVGs for the repair and replacement of small-diameter arteries.

  6. Tissue response of defined collagen-elastin scaffolds in young and adult rats with special attention to calcification

    NARCIS (Netherlands)

    Daamen, WF; Nillesen, STM; Hafmans, T; Veerkamp, JH; van Luyn, MJA; van Kuppevelt, TH

    Collagen-elastin scaffolds may be valuable biomaterials for tissue engineering because they combine tensile strength with elasticity. In this study, the tissue response to and the calcification of these scaffolds were evaluated. In particular, the hypothesis was tested that calcification, a common

  7. Effect of pore size and cross-linking of a novel collagen-elastin dermal substitute on wound healing

    NARCIS (Netherlands)

    Boekema, B.K.H.L.; Vlig, M.; Damink, L.O.; Middelkoop, E.; Eummelen, L.; Buhren, A.V.; Ulrich, M.M.W.

    2014-01-01

    Collagen-elastin (CE) scaffolds are frequently used for dermal replacement in the treatment of full-thickness skin defects such as burn wounds. But little is known about the optimal pore size and level of cross-linking. Different formulations of dermal substitutes with unidirectional pores were

  8. A biomaterial composed of collagen and solubilized elastin enhances angiogenesis and elastic fiber formation without calcification.

    NARCIS (Netherlands)

    Daamen, W.F.; Nillesen, S.T.M.; Wismans, P.G.P.; Reinhardt, D.; Hafmans, T.G.M.; Veerkamp, J.H.; Kuppevelt, A.H.M.S.M. van

    2008-01-01

    Elastin is the prime protein in elastic tissues that contributes to elasticity of, for example, lung, aorta, and skin. Upon injury, elastic fibers are not readily replaced, which hampers tissue regeneration. Incorporation of solubilized elastin (hydrolyzed insoluble elastin fibers or elastin

  9. The contribution of vascular smooth muscle, elastin and collagen on the passive mechanics of porcine carotid arteries

    International Nuclear Information System (INIS)

    Kochová, P; Cimrman, R; Kuncová, J; Švíglerová, J; Miklíková, M; Liška, V; Tonar, Z

    2012-01-01

    The main components responsible for the mechanical behavior of the arterial wall are collagen, elastin, and smooth muscle cells (SMCs) in the medial layer. We determined the structural and mechanical changes in porcine carotid arteries after administration of Triton® X-100, elastase, and collagenase using the inflation–deflation test. The arteries were intraluminarly pressurized from 0 to 200 mmHg, and the outer diameter of the artery was measured. The pressure–strain elastic modulus was determined based on the pressure/diameter ratio. The intima–media thickness, wall thickness, thickness of the tunica adventitia layer, and the area fractions of SMCs, elastin, and collagen within the arterial wall (A A (SMC/elastin/collagen, wall)) were measured using stereological methods. The relative changes in the relevant components of the treated samples were as follows: the decrease in A A (SMC, wall) after administration of Triton® X-100 was 11% ± 7%, the decrease in A A (elastin, wall) after administration of elastase was 40% ± 22%, and the decrease in A A (collagen, wall) after the application of collagenase was 51% ± 22%. The Triton® X-100 treatment led to a decrease in the SMC content that was associated with enlargement of the arterial wall (outer diameter) for pressures up to 120 mmHg, and with mechanical stiffening of the arterial wall at higher pressures. Elastase led to a decrease in the elastin content that was associated with enlargement of the arterial wall, but not with stiffening or softening. Collagenase led to a decrease in collagen content that was associated with a change in the stiffness of the arterial wall, although the exact contribution of mechanical loading and the duration of treatment (enlargement) could not be quantified. (paper)

  10. Qualitative and quantitative assessment of collagen and elastin in annulus fibrosus of the physiologic and scoliotic intervertebral discs.

    Science.gov (United States)

    Kobielarz, Magdalena; Szotek, Sylwia; Głowacki, Maciej; Dawidowicz, Joanna; Pezowicz, Celina

    2016-09-01

    The biophysical properties of the annulus fibrosus of the intervertebral disc are determined by collagen and elastin fibres. The progression of scoliosis is accompanied by a number of pathological changes concerning these structural proteins. This is a major cause of dysfunction of the intervertebral disc. The object of the study were annulus fibrosus samples excised from intervertebral discs of healthy subjects and patients treated surgically for scoliosis in the thoracolumbar or lumbar spine. The research material was subjected to structural analysis by light microscopy and quantitative analysis of the content of collagen types I, II, III and IV as well as elastin by immunoenzymatic test (ELISA). A statistical analysis was conducted to assess the impact of the sampling site (Mann-Whitney test, α=0.05) and scoliosis (Wilcoxon matched pairs test, α=0.05) on the obtained results. The microscopic studies conducted on scoliotic annulus fibrosus showed a significant architectural distortion of collagen and elastin fibres. Quantitative biochemical assays demonstrated region-dependent distribution of only collagen types I and II in the case of healthy intervertebral discs whereas in the case of scoliotic discs region-dependent distribution concerned all examined proteins of the extracellular matrix. Comparison of scoliotic and healthy annulus fibrosus revealed a significant decrease in the content of collagen type I and elastin as well as a slight increase in the proportion of collagen types III and IV. The content of collagen type II did not differ significantly between both groups. The observed anomalies are a manifestation of degenerative changes affecting annulus fibrosus of the intervertebral disc in patients suffering from scoliosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Elastin and collagen fibre microstructure of the human aorta in ageing and disease: a review

    Science.gov (United States)

    Tsamis, Alkiviadis; Krawiec, Jeffrey T.; Vorp, David A.

    2013-01-01

    Aortic disease is a significant cause of death in developed countries. The most common forms of aortic disease are aneurysm, dissection, atherosclerotic occlusion and ageing-induced stiffening. The microstructure of the aortic tissue has been studied with great interest, because alteration of the quantity and/or architecture of the connective fibres (elastin and collagen) within the aortic wall, which directly imparts elasticity and strength, can lead to the mechanical and functional changes associated with these conditions. This review article summarizes the state of the art with respect to characterization of connective fibre microstructure in the wall of the human aorta in ageing and disease, with emphasis on the ascending thoracic aorta and abdominal aorta where the most common forms of aortic disease tend to occur. PMID:23536538

  12. One-stage reconstruction of soft tissue defects with the sandwich technique: Collagen-elastin dermal template and skin grafts

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Background : A full-thickness soft tissue defect closure often needs complex procedures. The use of dermal templates can be helpful in improving the outcome. Objective : The objective was to evaluate a sandwich technique combining the dermal collagen-elastin matrix with skin grafts in a one-stage procedure. Materials and Methods : Twenty-three patients with 27 wounds were enrolled in this prospective single-centre observational study. The mean age was 74.8 ± 17.2 years. Included were full-thickness defects with exposed bone, cartilage and/ or tendons. The dermal collagen-elastin matrix was applied onto the wound bed accomplished by skin transplants, i.e. ′sandwich′ transplantation. In six wounds, the transplants were treated with intermittent negative pressure therapy. Results : The size of defects was ≤875 cm 2 . The use of the dermal template resulted in a complete and stable granulation in 100% of wounds. Seventeen defects showed a complete closure and 19 achieved a complete granulation with an incomplete closure. There was a marked pain relief. No adverse events were noted due to the dermal template usage. Conclusions : Sandwich transplantation with the collagen-elastin matrix is a useful tool when dealing with full-thickness soft tissue defects with exposed bone, cartilage or tendons.

  13. The effect of a collagen-elastin matrix on adhesion formation after flexor tendon repair in a rabbit model.

    Science.gov (United States)

    Wichelhaus, Dagmar Alice; Beyersdoerfer, Sascha Tobias; Gierer, Philip; Vollmar, Brigitte; Mittlmeier, Th

    2016-07-01

    The outcome of flexor tendon surgery is negatively affected by the formation of adhesions which can occur during the healing of the tendon repair. In this experimental study, we sought to prevent adhesion formation by wrapping a collagen-elastin scaffold around the repaired tendon segment. In 28 rabbit hind legs, the flexor tendons of the third and fourth digits were cut and then repaired using a two-strand suture technique on the fourth digit and a four-strand technique on the third digit. Rabbits were randomly assigned to study and control groups. In the control group, the operation ended by closing the tendon sheath and the skin. In the study group, a collagen-elastin scaffold was wrapped around the repaired tendon segment in both digits. After 3 and 8 weeks, the tendons were harvested and processed histologically. The range of motion of the digits and the gap formation between the repaired tendon ends were measured. The formation of adhesions, infiltration of leucocytes and extracellular inflammatory response were quantified. At the time of tendon harvesting, all joints of the operated toes showed free range of motion. Four-strand core sutures lead to significantly less diastasis between the repaired tendon ends than two-strand core suture repairs. The collagen-elastin scaffold leads to greater gapping after 3 weeks compared to the controls treated without the matrix. Within the tendons treated with the collagen-elastin matrix, a significant boost of cellular and extracellular inflammation could be stated after 3 weeks which was reflected by a higher level of CAE positive cells and more formation of myofibroblasts in the αSMA stain in the study group. The inflammatory response subsided gradually and significantly until the late stage of the study. Both the cellular and extracellular inflammatory response was emphasized with the amount of material used for the repair. The use of a collagen-elastin matrix cannot be advised for the prevention of adhesion

  14. Biomimetic collagen/elastin meshes for ventral hernia repair in a rat model.

    Science.gov (United States)

    Minardi, Silvia; Taraballi, Francesca; Wang, Xin; Cabrera, Fernando J; Van Eps, Jeffrey L; Robbins, Andrew B; Sandri, Monica; Moreno, Michael R; Weiner, Bradley K; Tasciotti, Ennio

    2017-03-01

    Ventral hernia repair remains a major clinical need. Herein, we formulated a type I collagen/elastin crosslinked blend (CollE) for the fabrication of biomimetic meshes for ventral hernia repair. To evaluate the effect of architecture on the performance of the implants, CollE was formulated both as flat sheets (CollE Sheets) and porous scaffolds (CollE Scaffolds). The morphology, hydrophylicity and in vitro degradation were assessed by SEM, water contact angle and differential scanning calorimetry, respectively. The stiffness of the meshes was determined using a constant stretch rate uniaxial tensile test, and compared to that of native tissue. CollE Sheets and Scaffolds were tested in vitro with human bone marrow-derived mesenchymal stem cells (h-BM-MSC), and finally implanted in a rat ventral hernia model. Neovascularization and tissue regeneration within the implants was evaluated at 6weeks, by histology, immunofluorescence, and q-PCR. It was found that CollE Sheets and Scaffolds were not only biomechanically sturdy enough to provide immediate repair of the hernia defect, but also promoted tissue restoration in only 6weeks. In fact, the presence of elastin enhanced the neovascularization in both sheets and scaffolds. Overall, CollE Scaffolds displayed mechanical properties more closely resembling those of native tissue, and induced higher gene expression of the entire marker genes tested, associated with de novo matrix deposition, angiogenesis, adipogenesis and skeletal muscles, compared to CollE Sheets. Altogether, this data suggests that the improved mechanical properties and bioactivity of CollE Sheets and Scaffolds make them valuable candidates for applications of ventral hernia repair. Due to the elevated annual number of ventral hernia repair in the US, the lack of successful grafts, the design of innovative biomimetic meshes has become a prime focus in tissue engineering, to promote the repair of the abdominal wall, avoid recurrence. Our meshes (Coll

  15. Bat wing biometrics: using collagen-elastin bundles in bat wings as a unique individual identifier.

    Science.gov (United States)

    Amelon, Sybill K; Hooper, Sarah E; Womack, Kathryn M

    2017-05-29

    The ability to recognize individuals within an animal population is fundamental to conservation and management. Identification of individual bats has relied on artificial marking techniques that may negatively affect the survival and alter the behavior of individuals. Biometric systems use biological characteristics to identify individuals. The field of animal biometrics has expanded to include recognition of individuals based upon various morphologies and phenotypic variations including pelage patterns, tail flukes, and whisker arrangement. Biometric systems use 4 biologic measurement criteria: universality, distinctiveness, permanence, and collectability. Additionally, the system should not violate assumptions of capture-recapture methods that include no increased mortality or alterations of behavior. We evaluated whether individual bats could be uniquely identified based upon the collagen-elastin bundles that are visible with gross examination of their wings. We examined little brown bats ( Myotis lucifugus ), northern long-eared bats ( M. septentrionalis ), big brown bats ( Eptesicus fuscus ), and tricolored bats ( Perimyotis subflavus ) to determine whether the "wing prints" from the bundle network would satisfy the biologic measurement criteria. We evaluated 1,212 photographs from 230 individual bats comparing week 0 photos with those taken at weeks 3 or 6 and were able to confirm identity of individuals over time. Two blinded evaluators were able to successfully match 170 individuals in hand to photographs taken at weeks 0, 3, and 6. This study suggests that bats can be successfully re-identified using photographs taken at previous times. We suggest further evaluation of this methodology for use in a standardized system that can be shared among bat conservationists.

  16. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

    Science.gov (United States)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart; Heusinkveld, Maarten H G; Thorsted, Bjarne; Rosenstand, Kristoffer; Nissen, Inger; Hansen, Ulla M; Brewer, Jonathan R; Bagatolli, Luis A; Rasmussen, Lars M; Irmukhamedov, Akhmadjon; Reesink, Koen D; De Mey, Jo G R

    2017-07-01

    The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R 2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies. NEW & NOTEWORTHY This is the first study to quantitatively relate pressure

  17. Assessing Collagen and Elastin Pressure-dependent Microarchitectures in Live, Human Resistance Arteries by Label-free Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Thorsted, Bjarne; Brewer, Jonathan R

    2018-01-01

    The pathogenic contribution of resistance artery remodeling is documented in essential hypertension, diabetes and the metabolic syndrome. Investigations and development of microstructurally motivated mathematical models for understanding the mechanical properties of human resistance arteries...... in health and disease have the potential to aid understanding how disease and medical treatments affect the human microcirculation. To develop these mathematical models, it is essential to decipher the relationship between the mechanical and microarchitectural properties of the microvascular wall...... of interest. Image analyses are described for quantifying i) pressure-induced changes in internal elastic lamina branching angles and adventitial collagen straightness using Fiji and ii) collagen and elastin volume densities determined using Ilastik software. Preferably all mechanical and imaging measurements...

  18. Blackcurrant Anthocyanins Increase the Levels of Collagen, Elastin, and Hyaluronic Acid in Human Skin Fibroblasts and Ovariectomized Rats

    Directory of Open Access Journals (Sweden)

    Naoki Nanashima

    2018-04-01

    Full Text Available Blackcurrants (Ribes nigrum L. contain high levels of anthocyanin polyphenols, which have beneficial effects on health, owing to their antioxidant and anticarcinogenic properties. Phytoestrogens are plant-derived substances with estrogenic activity, which could have beneficial effects on the skin. Estradiol secretion decreases during menopause, reducing extracellular matrix (ECM component production by skin fibroblasts. Using a normal human female skin fibroblast cell line (TIG113 and ovariectomized rats, the present study investigated whether an anthocyanin-rich blackcurrant extract (BCE and four blackcurrant anthocyanins have novel phytoestrogenic activities that could benefit the skin in menopausal women. In TIG113 cells, a microarray and the Ingenuity® Pathway Analysis showed that 1.0 μg/mL of BCE upregulated the expression of many estrogen signaling-related genes. A quantitative RT-PCR analysis confirmed that BCE (1.0 or 10.0 μg/mL and four types of anthocyanins (10 μM altered the mRNA expression of ECM proteins and enzymes involved in ECM turnover. Immunofluorescence staining indicated that the anthocyanins stimulated the expression of ECM proteins, such as collagen (types I and III and elastin. Dietary administration of 3% BCE to ovariectomized rats for 3 months increased skin levels of collagen, elastin, and hyaluronic acid. This is the first study to show that blackcurrant phytoestrogens have beneficial effects on skin experimental models.

  19. Assessing Collagen and Elastin Pressure-Dependent Microarchitectures in Live, Human Resistance Arteries by Label-Free Fluorescence Microscopy

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Thorsted, Bjarne; Brewer, Jonathan R.

    2017-01-01

    The pathogenic contribution of resistance artery remodeling is documented in essential hypertension, diabetes and the metabolic syndrome. Investigations and development of microstructurally motivated mathematical models for understanding the mechanical properties of human resistance arteries...... in health and disease have the potential to aid understanding how disease and medical treatments affect the human microcirculation. To develop these mathematical models, it is essential to decipher the relationship between the mechanical and microarchitectural properties of the microvascular wall....... In this work, we describe an ex vivo method for passive mechanical testing and simultaneous label-free three-dimensional imaging of the microarchitecture of elastin and collagen in the arterial wall of isolated human resistance arteries. The imaging protocol can be applied to resistance arteries of any species...

  20. 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

  1. Evaluation of Elastin/Collagen Content in Human Dermis in-Vivo by Multiphoton Tomography—Variation with Depth and Correlation with Aging

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Pittet

    2014-08-01

    Full Text Available The aim of this study was to evaluate the influence of the depth of the dermis on the measured collagen and elastin levels and to establish the correlation between the amount of these two extracellular matrix (ECM components and age. Multiphoton Microscopy (MPM that measures the autofluorescence (AF and second harmonic generation (SHG was used to quantify the levels of elastin and collagen and to determine the SAAID (SHG-to-AF Aging Index of Dermis at two different skin depths. A 50 MHz ultrasound scanner was used for the calculation of the Sub Epidermal Non Echogenic Band (SENEB. The measurements of the skin mechanical properties were done with a cutometer. All measurements were performed on two groups of 30 healthy female volunteers. The MPM showed a decrease of the quantity of collagen and elastin as a function of depth of the dermis as well as age. The SAAID was lower for the older skin in the deeper dermis. Ultrasound imaging revealed a significant decrease of SENEB as a function of aging. The mechanical properties confirmed a loss of cutaneous elasticity and firmness. Although multiphoton microscopy is a powerful technique to study the characteristics of the dermis and its age-related damage, the location of the measurements (depth remains very important for the validation of these variations. These variations do not seem to be homogeneous according to the part of the dermis that is studied.

  2. Lung morphometry, collagen and elastin content: changes after hyperoxic exposure in preterm rabbits

    Directory of Open Access Journals (Sweden)

    Renata Suman Mascaretti

    2009-11-01

    Full Text Available INTRODUCTION: Elastic and collagen fiber deposition increases throughout normal lung development, and this fiber network significantly changes when development of the lung is disturbed. In preterm rats and lambs, prolonged hyperoxic exposure is associated with impaired alveolization and causes significant changes in the deposition and structure of elastic fibers. OBJECTIVES: To evaluate the effects of hyperoxic exposure on elastic and collagen fiber deposition in the lung interstitial matrix and in alveolarization in preterm rabbits. METHODS: After c-section, 28-day preterm New-Zealand-White rabbits were randomized into 2 study groups, according to the oxygen exposure, namely: Room air (oxygen = 21% or Oxygen (oxygen > 95%. The animals were killed on day 11 and their lungs were analyzed for the alveolar size (Lm, the internal surface area (ISA, the alveoli number, and the density and distribution of collagen and elastic fibers. RESULTS: An increase in the Lm and a decrease in the alveoli number were observed among rabbits that were exposed to hyperoxia with no differences regarding the ISA. No difference in the density of elastic fibers was observed after oxygen exposure, however there were fewer collagen fibers and an evident disorganization of fiber deposition. DISCUSSION: This model reproduces anatomo-pathological injuries representing the arrest of normal alveolar development and lung architecture disorganization by just a prolonged exposition to oxygen. CONCLUSIONS: In the preterm rabbit, prolonged oxygen exposure impaired alveolization and also lowered the proportion of collagen fibers, with an evident fiber network disorganization.

  3. 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.

  4. Isolation and purification of Bacillus thuringiensis var. israelensis IМV В-7465 peptidase with specificity toward elastin and collagen

    Directory of Open Access Journals (Sweden)

    N. А. Nidialkova

    2016-06-01

    Full Text Available Peptidase of Bacillus thuringiensis var. israelensis IМV В-7465 was isolated from culture supernatant using consecutive fractionations by an ammonium sulphate (60% saturation, ion-exchange chromatography and gel-filtration on the TSK-gels Toyoperl HW-55 and DEAE 650(M. Specific elastase (442 U∙mg of protein-1 and collagenase (212.7 U∙mg of protein-1 activities of the purified enzyme preparation were 8.0- and 6.1-fold, respectively higher than ones of the culture supernatant. Peptidase yields were 33.5% for elastase activity and 30.1% for collagenase activity. It was established that the enzyme is serine metal-dependent alkaline peptidase with Mr about 37 kDa. Maximal hydrolysis of elastin and collagen occurs at the optimum pH 8.0 and t° – 40 and 50 °С, respectively. The purified preparation has high stability at pH in the range of 7.0 to 10.0 and 40-50 °С.

  5. Induction of matrix metalloproteinase-2 by tenascin-X deficiency is mediated through the c-Jun N-terminal kinase and protein tyrosine kinase phosphorylation pathway

    International Nuclear Information System (INIS)

    Matsumoto, Ken-ichi; Minamitani, Takeharu; Orba, Yasuko; Sato, Mami; Sawa, Hirofumi; Ariga, Hiroyoshi

    2004-01-01

    The results of our previous study showed that tumor invasion and metastasis are promoted in extracellular matrix (ECM) tenascin-X-deficient (TNX-/-) mice via increased expression of matrix metalloproteinases (MMPs). However, little is known about the relationship between TNX deficiency and activation of MMP genes. In this study, we investigated the molecular mechanism by which TNX deficiency activates the MMP-2 gene. We examined the intracellular signaling pathways that regulate gene expression of the proteinase in isolated fibroblasts. Results of gelatin zymography showed that MMP-2 was induced to a greater extent in TNX-/- fibroblasts embedded in type I collagen than in wild-type fibroblasts. RT-PCR analysis revealed that the increased level of MMP-2 expression was caused at the transcription level. Conversely, stable overexpression of TNX in a fibroblast cell line reduced MMP-2 expression and suppressed MMP-2 promoter activity. In addition, treatment of TNX-/- fibroblasts with SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and genistein, a tyrosine kinase inhibitor, suppressed the increased level of proMMP-2 and increased MMP-2 promoter activity in TNX-/- fibroblasts. Furthermore, increased activation of JNK and tyrosine phosphorylation of certain proteins were observed in TNX-/- fibroblasts. These findings suggest that induction of MMP-2 by TNX deficiency is mediated, at least in part, through the JNK and protein tyrosine kinase phosphorylation pathway

  6. Effect of pore size and cross-linking of a novel collagen-elastin dermal substitute on wound healing.

    Science.gov (United States)

    Boekema, Bouke K H L; Vlig, Marcel; Olde Damink, Leon; Middelkoop, Esther; Eummelen, Lizette; Bühren, Anne V; Ulrich, Magda M W

    2014-02-01

    Collagen-elastin (CE) scaffolds are frequently used for dermal replacement in the treatment of full-thickness skin defects such as burn wounds. But little is known about the optimal pore size and level of cross-linking. Different formulations of dermal substitutes with unidirectional pores were tested in porcine full-thickness wounds in combination with autologous split skin mesh grafts (SSG). Effect on wound healing was evaluated both macro- and microscopically. CE scaffolds with a pore size of 80 or 100 μm resulted in good wound healing after one-stage grafting. Application of scaffolds with a larger average pore size (120 μm) resulted in more myofibroblasts and more foreign body giant cells (FBGC). Moderate crosslinking impaired wound healing as it resulted in more wound contraction, more FBGC and increased epidermal thickness compared to no cross-linking. In addition, take rate and redness were negatively affected compared to SSG only. Vascularization and the number of myofibroblasts were not affected by cross-linking. Surprisingly, stability of cross-linked scaffolds was not increased in the wound environment, in contrast to in vitro results. Cross-linking reduced the proliferation of fibroblasts in vitro, which might explain the reduced clinical outcome. The non-cross-linked CE substitute with unidirectional pores allowed one-stage grafting of SSG, resulting in good wound healing. In addition, only a very mild foreign body reaction was observed. Cross-linking of CE scaffolds negatively affected wound healing on several important parameters. The optimal non-cross-linked CE substitute is a promising candidate for future clinical evaluation.

  7. Development of a Tissue-Engineered Artificial Ligament: Reconstruction of Injured Rabbit Medial Collateral Ligament With Elastin-Collagen and Ligament Cell Composite Artificial Ligament.

    Science.gov (United States)

    Hirukawa, Masaki; Katayama, Shingo; Sato, Tatsuya; Inoue, Kota; Niwa, Kosuke; Ito, Naoya; Hattori, Tetsuya; Hosoi, Takashi; Unno, Hironori; Suzuki, Yoshiaki; Hasegawa, Masahiro; Miyamoto, Keiichi; Horiuchi, Takashi

    2018-04-16

    Ligament reconstruction using a tissue-engineered artificial ligament (TEAL) requires regeneration of the ligament-bone junction such that fixation devices such as screws and end buttons do not have to be used. The objective of this study was to develop a TEAL consisting of elastin-coated polydioxanone (PDS) sutures covered with elastin and collagen fibers preseeded with ligament cells. In a pilot study, a ring-type PDS suture with a 2.5 mm (width) bone insertion was constructed with/without elastin coating (Ela-coat and Non-coat) and implanted into two bone tunnels, diameter 2.4 mm, in the rabbit tibia (6 cases each) to access the effect of elastin on the bond strength. PDS specimens taken together with the tibia at 6 weeks after implantation indicated growth of bone-like hard tissues around bone tunnels accompanied with narrowing of the tunnels in the Ela-coat group and not in the Non-coat group. The drawout load of the Ela-coat group was significantly higher (28.0 ± 15.1 N, n = 4) than that of the Non-coat group (7.6 ± 4.6 N, n = 5). These data can improve the mechanical bulk property of TEAL through extracellular matrix formation. To achieve this TEAL model, 4.5 × 10 6 ligament cells were seeded on elastin and collagen fibers (2.5 cm × 2.5 cm × 80 µm) prior to coil formation around the elastin-coated PDS core sutures having ball-shape ends with a diameter of 2.5 mm. Cell-seeded and cell-free TEALs were implanted across the femur and the tibia through bone tunnels with a diameter of 2.4 mm (6 cases each). There was no incidence of TEAL being pulled in 6 weeks. Regardless of the remarkable degradation of PDS observed in the cell-seeded group, both the elastic modulus and breaking load of the cell-seeded group (n = 3) were comparable to those of the sham-operation group (n = 8) (elastic modulus: 15.4 ± 1.3 MPa and 18.5 ± 5.7 MPa; breaking load: 73.0 ± 23.4 N and 104.8 ± 21.8 N, respectively) and higher than those

  8. Surgical therapy by sandwich transplantation using a dermal collagen-elastin matrix and full thickness split grafts and gait rehabilitation with individualized orthesis

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2012-01-01

    Full Text Available Painful callosities of the feet (PCOF are a rare complaint in children with severe impairment of mobility and quality of life. There is no medical treatment available.We investigated the usefulness of a recently developed combined transplant technique-the sandwich transplantation with dermal collagen-elastin template in this rare condition. A 14-year-old boy suffered from PCOF for several years without any improvement by topical therapy, dermabrasion, and oral retinoids. He was unable to walk normally and suffered from severe pain. We performed a complete deep excision of the hyperkeratotic plantar tissue in general anaesthesia in combination with sandwich transplantation in the same setting. Dry sheets of collagen-elastin matrix (1 mm thickness were placed on the soft tissue defects and covered by full-thickness mesh graft transplants from the upper leg. An individualized orthosis was produced for gait rehabilitation. Two weeks after surgery the gait-related pain was reduced remarkably. Using the orthosis, the boy was able to walk pain-free even on staircase. Surgery of PCOF with sandwich transplantation and gait rehabilitation appears to be a promising strategy for this rare condition.

  9. Cultivation of Keratinocytes and Fibroblasts in a Three-Dimensional Bovine Collagen-Elastin Matrix (Matriderm® and Application for Full Thickness Wound Coverage in Vivo

    Directory of Open Access Journals (Sweden)

    Jasper Killat

    2013-07-01

    Full Text Available New skin substitutes for burn medicine or reconstructive surgery pose an important issue in plastic surgery. Matriderm® is a clinically approved three-dimensional bovine collagen-elastin matrix which is already used as a dermal substitute of full thickness burn wounds. The drawback of an avital matrix is the limited integration in full thickness skin defects, depending on the defect size. To further optimize this process, Matriderm® has also been studied as a matrix for tissue engineering of skin albeit long-term cultivation of the matrix with cells has been difficult. Cells have generally been seeded onto the matrix with high cell loss and minimal time-consuming migration. Here we developed a cell seeded skin equivalent after microtransfer of cells directly into the matrix. First, cells were cultured, and microinjected into Matriderm®. Then, cell viability in the matrix was determined by histology in vitro. As a next step, the skin substitute was applied in vivo into a full thickness rodent wound model. The wound coverage and healing was observed over a period of two weeks followed by histological examination assessing cell viability, proliferation and integration into the host. Viable and proliferating cells could be found throughout the entire matrix. The presented skin substitute resembles healthy skin in morphology and integrity. Based on this study, future investigations are planned to examine behaviour of epidermal stem cells injected into a collagen-elastin matrix under the aspects of establishment of stem cell niches and differentiation.

  10. A recessive form of the Ehlers-Danlos syndrome caused by tenascin-X deficiency.

    NARCIS (Netherlands)

    Schalkwijk, J.; Zweers, M.C.; Steijlen, P.M.; Dean, W.B.; Taylor, G.; Vlijmen-Willems, I.M.J.J. van; Haren, B. van; Miller, W.L.; Bristow, J.

    2001-01-01

    BACKGROUND: The Ehlers-Danlos syndrome is a heritable connective-tissue disorder caused by defects in fibrillar-collagen metabolism. Mutations in the type V collagen genes account for up to 50 percent of cases of classic Ehlers-Danlos syndrome, but many other cases are unexplained. We investigated

  11. Reconstruction of full-thickness defects with bovine-derived collagen/elastin matrix: a series of challenging cases and the first reported post-burn facial reconstruction.

    Science.gov (United States)

    Haik, Josef; Weissman, Oren; Hundeshagen, Gabriel; Farber, Nimrod; Harats, Moti; Rozenblatt, Shira M; Kamolz, Lars Peter; Winkler, Eyal; Zilinsky, Isaac

    2012-07-01

    Reconstruction of full-thickness defects may benefit from integration of dermal substitutes, which serve as a foundation for split-thickness skin grafts, thus enhancing short and long-term results. We present a series of 7 patients who were treated between 2010 and 2012 for complicated full-thickness defects by the second-generation collagen/elastin matrix Matriderm® covered by a split-thickness skin graft. The defects resulted from malignancy resection, trauma, and post-burn scar reconstruction. Overall graft take was excellent and no complications were noted regarding the dermal substitute. Graft quality was close to normal skin in terms of elasticity, pliability, texture, and color. Good contour and cushioning of defects in weight bearing areas was also achieved. Matriderm was found to be a useful adjunct to full-thickness defect reconstruction, especially in difficult areas where the desired result is a scar of the highest quality possible.

  12. Tissue turnover of collagen type I, III and elastin is elevated in the PCLS model of IPF and can be restored back to vehicle levels using a phosphodiesterase inhibitor

    DEFF Research Database (Denmark)

    Hansen, Niels Ulrik Brandt; Karsdal, Morten Asser; Brockbank, Sarah

    2016-01-01

    .T., two days apart. The rats were euthanized fourteen days after the last dose. PCLS were made and cultured for 48 h in: medium, medium + 100 μM IBMX (PDE inhibitor), or medium + 10 μM GM6001 (MMP inhibitor). Turnover of type I collagen (P1NP, C1M), type III collagen (iP3NP, C3M) and elastin degradation...... to the culture medium (P ≤ 0.05 - P ≤ 0.0001). Sirius Red and Orcein staining confirmed the presence of collagen and elastin deposition in the lungs of the animals receiving BLM. Conclusions: The protein fingerprint technology allows the assessment of ECM remodeling markers in the BLM PCLS model. By combining...

  13. Elastin in the Liver

    Directory of Open Access Journals (Sweden)

    Jiri Kanta

    2016-10-01

    Full Text Available A characteristic feature of liver cirrhosis is the accumulation of large amounts of connective tissue with the prevailing content of type I collagen. Elastin is a minor connective tissue component in normal liver but it is actively synthesized by hepatic stellate cells and portal fibroblasts in diseased liver. The accumulation of elastic fibers in later stages of liver fibrosis may contribute to the decreasing reversibility of the disease with advancing time. Elastin is formed by polymerization of tropoelastin monomers. It is an amorphous protein highly resistant to the action of proteases that forms the core of elastic fibers. Microfibrils surrounding the core are composed of fibrillins that bind a number of proteins involved in fiber formation. They include microfibril-associated glycoproteins (MAGPs, microfibrillar-associated proteins (MFAPs and fibulins. Lysyl oxidase (LOX and lysyl oxidase-like proteins (LOXLs are responsible for tropoelastin cross-linking and polymerization. TGF-β complexes attached to microfibrils release this cytokine and influence the behavior of the cells in the neighborhood. The role of TGF-β as the main profibrotic cytokine in the liver is well-known and the release of the cytokines of TGF-β superfamily from their storage in elastic fibers may affect the course of fibrosis. Elastic fibres are often studied in the tissues where they provide elasticity and resilience but their role is no longer viewed as purely mechanical. Tropoelastin, elastin polymer and elastin peptides resulting from partial elastin degradation influence fibroblastic and inflammatory cells as well as angiogenesis. A similar role may be performed by elastin in the liver. This article reviews the results of the research of liver elastic fibers on the backgound of the present knowledge of elastin biochemistry and physiology. The regulation of liver elastin synthesis and degradation may be important for the outcome of liver fibrosis.

  14. Fabricated Elastin.

    Science.gov (United States)

    Yeo, Giselle C; Aghaei-Ghareh-Bolagh, Behnaz; Brackenreg, Edwin P; Hiob, Matti A; Lee, Pearl; Weiss, Anthony S

    2015-11-18

    The mechanical stability, elasticity, inherent bioactivity, and self-assembly properties of elastin make it a highly attractive candidate for the fabrication of versatile biomaterials. The ability to engineer specific peptide sequences derived from elastin allows the precise control of these physicochemical and organizational characteristics, and further broadens the diversity of elastin-based applications. Elastin and elastin-like peptides can also be modified or blended with other natural or synthetic moieties, including peptides, proteins, polysaccharides, and polymers, to augment existing capabilities or confer additional architectural and biofunctional features to compositionally pure materials. Elastin and elastin-based composites have been subjected to diverse fabrication processes, including heating, electrospinning, wet spinning, solvent casting, freeze-drying, and cross-linking, for the manufacture of particles, fibers, gels, tubes, sheets and films. The resulting materials can be tailored to possess specific strength, elasticity, morphology, topography, porosity, wettability, surface charge, and bioactivity. This extraordinary tunability of elastin-based constructs enables their use in a range of biomedical and tissue engineering applications such as targeted drug delivery, cell encapsulation, vascular repair, nerve regeneration, wound healing, and dermal, cartilage, bone, and dental replacement. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Recognizing the tenascin-X deficient type of Ehlers-Danlos syndrome: a cross-sectional study in 17 patients.

    Science.gov (United States)

    Demirdas, S; Dulfer, E; Robert, L; Kempers, M; van Beek, D; Micha, D; van Engelen, B G; Hamel, B; Schalkwijk, J; Loeys, B; Maugeri, A; Voermans, N C

    2017-03-01

    The tenascin-X (TNX) deficient type Ehlers-Danlos syndrome (EDS) is similar to the classical type of EDS. Because of the limited awareness among geneticists and the challenge of the molecular analysis of the TNXB gene, the TNX-deficient type EDS is probably to be under diagnosed. We therefore performed an observational, cross-sectional study. History and physical examination were performed. Results of serum TNX measurements were collected and mutation analysis was performed by a combination of next-generation sequencing (NGS), Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). Included were 17 patients of 11 families with autosomal recessive inheritance and childhood onset. All patients had hyperextensible skin without atrophic scarring. Hypermobility of the joints was observed in 16 of 17 patients. Deformities of the hands and feet were observed frequently. TNX serum level was tested and absent in 11 patients (seven families). Genetic testing was performed in all families; 12 different mutations were detected, most of which are suspected to lead to non-sense mRNA mediated decay. In short, patients with the TNX-deficient type EDS typically have generalized joint hypermobility, skin hyperextensibility and easy bruising. In contrast to the classical type, the inheritance pattern is autosomal recessive and atrophic scarring is absent. Molecular analysis of TNXB in a diagnostic setting is challenging. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Use of a collagen-elastin matrix as transport carrier system to transfer proliferating epidermal cells to human dermis in vitro.

    Science.gov (United States)

    Waaijman, Taco; Breetveld, Melanie; Ulrich, Magda; Middelkoop, Esther; Scheper, Rik J; Gibbs, Susan

    2010-01-01

    This in vitro study describes a novel cell culture, transport, and transfer protocol that may be highly suitable for delivering cultured proliferating keratinocytes and melanocytes to large open skin wounds (e.g., burns). We have taken into account previous limitations identified using other keratinocyte transfer techniques, such as regulatory issues, stability of keratinocytes during transport (single cell suspensions undergo terminal differentiation), ease of handling during application, and the degree of epidermal blistering resulting after transplantation (both related to transplanting keratinocyte sheets). Large numbers of proliferating epidermal cells (EC) (keratinocytes and melanocytes) were generated within 10-14 days and seeded onto a three-dimensional matrix composed of elastin and collagen types I, III, and V (Matriderm®), which enabled easy and stable transport of the EC for up to 24 h under ambient conditions. All culture conditions were in accordance with the regulations set by the Dutch Central Committee on Research Involving Human Subjects (CCMO). As an in vitro model system for clinical in vivo transfer, the EC were then transferred from Matriderm onto human acellular dermis during a period of 3 days. After transfer the EC maintained the ability to regenerate into a fully differentiated epidermis containing melanocytes on the human dermis. Proliferating keratinocytes were located in the basal layer and keratin-10 expression was located in differentiating suprabasal layers similar to that found in human epidermis. No blistering was observed (separation of the epidermis from the basement membrane). Keratin-6 expression was strongly upregulated in the regenerating epidermis similar to normal wound healing. In summary, we show that EC-Matriderm contains viable, metabolically active keratinocytes and melanocytes cultured in a manner that permits easy transportation and contains epidermal cells with the potential to form a pigmented reconstructed

  17. Preliminary results in single-step wound closure procedure of full-thickness facial burns in children by using the collagen-elastin matrix and review of pediatric facial burns.

    Science.gov (United States)

    Demircan, Mehmet; Cicek, Tugrul; Yetis, Muhammed Ikbal

    2015-09-01

    Management of full-thickness facial burns remains one of the greatest challenges. Controversy exists among surgeons regarding the use of early excision for facial burns. Unfortunately, delayed excision of deeper burns often results in more scarring and subsequent reconstruction becomes more difficult. A collagen-elastin matrix is used to improve the quality of the reconstructed skin, to reduce scarring and to prevent wound contraction. It serves as a foundation for split thickness skin graft and enhances short and long-term results. We report the usage of a collagen-elastin matrix during single-step wound closure technique of severe full-thickness facial burns in 15 children with large burned body surface area, and also we review the literature about pediatric facial burns. There were 15 pediatric patients with severe facial burns, 8 girls and 7 boys ranging in age from 10 months to 12 years, mean age 7 years and 6 months old. The facial burn surface area (FBSA) among the patients includes seven patients with 100%, five with 75%, and three with 50%. The average total body surface area (TBSA) for the patients was 72%, ranging between 50 and 90%. 5 of the patients' admissions were late, more than four days after burns while the rest of the patients were admitted within the first four days (acute admission time). The burns were caused by flame in eight of the patients, bomb blast in four, and scalding in three. All patients were treated by the simultaneous application of the collagen-elastin matrix and an unmeshed split thickness skin graft at Turgut Özal Medical Center, Pediatric Burn Center, Malatya, Turkey. After the treatment only two patients needed a second operation for revision of the grafts. All grafts transplanted to the face survived. The average Vancouver scar scales (VSS) were 2.55±1.42, ranging between one and six, in the first 10 of 15 patients at the end of 6 months postoperatively. VSS measurements of the last 5 patients were not taken since the 6

  18. Elastin Fiber Accumulation in Liver Correlates with the Development of Hepatocellular Carcinoma.

    Science.gov (United States)

    Yasui, Yutaka; Abe, Tokiya; Kurosaki, Masayuki; Higuchi, Mayu; Komiyama, Yasuyuki; Yoshida, Tsubasa; Hayashi, Tsuguru; Kuwabara, Konomi; Takaura, Kenta; Nakakuki, Natsuko; Takada, Hitomi; Tamaki, Nobuharu; Suzuki, Shoko; Nakanishi, Hiroyuki; Tsuchiya, Kaoru; Itakura, Jun; Takahashi, Yuka; Hashiguchi, Akinori; Sakamoto, Michiie; Izumi, Namiki

    2016-01-01

    The fibrosis stage, which is evaluated by the distribution pattern of collagen fibers, is a major predictor for the development of hepatocellular carcinoma (HCC) for patients with hepatitis C. Meanwhile, the role of elastin fibers has not yet been elucidated. The present study was conducted to determine the significance of quantifying both collagen and elastin fibers. We enrolled 189 consecutive patients with hepatitis C and advanced fibrosis. Using Elastica van Gieson-stained whole-slide images of pretreatment liver biopsies, collagen and elastin fibers were evaluated pixel by pixel (0.46 μm/pixel) using an automated computational method. Consequently, fiber amount and cumulative incidences of HCC within 3 years were analyzed. There was a significant correlation between collagen and elastin fibers, whereas variation in elastin fiber was greater than in collagen fiber. Both collagen fiber (p = 0.008) and elastin fiber (p elastin fiber (p = 0.002) in addition to higher collagen fiber (p = 0.05) showed significantly higher incidences of HCC. With regard to elastin fiber, this difference remained significant in F3 patients. Furthermore, for patients with a higher collagen fiber amount, higher elastin was a significant predictor for HCC development (p = 0.02). Computational analysis is a novel technique for quantification of fibers with the added value of conventional staging. Elastin fiber is a predictor for the development of HCC independently of collagen fiber and F stage.

  19. Liberation of Desmosine and Isodesmosine as Amino Acids from Insoluble Elastin by Elastolytic Proteases

    Science.gov (United States)

    Umeda, Hideyuki; Aikawa, Masanori; Libby, Peter

    2011-01-01

    The development of atherosclerotic lesions and abdominal aortic aneurysms involves degradation and loss of extracellular matrix components, such as collagen and elastin. Releases of the elastin cross-links desmosine (DES) and isodesmosine (IDE) may reflect elastin degradation in cardiovascular diseases. This study investigated the production of soluble elastin cross-linking structures by proteinases implicated in arterial diseases. Recombinant MMP-12 and neutrophil elastase liberated DES and IDE as amino acids from insoluble elastin. DES and IDE were also released from insoluble elastin exposed to monocyte/macrophage cell lines or human primary macrophages derived from peripheral blood monocytes. Elastin oxidized by reactive oxygen species (ROS) liberated more unconjugated DES and IDE than did non-oxidized elastin when incubated with MMP-12 or neutrophil elastase. These results support the exploration of free DES and IDE as biomarkers of elastin degradation. PMID:21726534

  20. The Effect of Static Stretch on Elastin Degradation in Arteries

    Science.gov (United States)

    Chow, Ming-Jay; Choi, Myunghwan; Yun, Seok Hyun; Zhang, Yanhang

    2013-01-01

    Previously we have shown that gradual changes in the structure of elastin during an elastase treatment can lead to important transition stages in the mechanical behavior of arteries [1]. However, in vivo arteries are constantly being loaded due to systolic and diastolic pressures and so understanding the effects of loading on the enzymatic degradation of elastin in arteries is important. With biaxial tensile testing, we measured the mechanical behavior of porcine thoracic aortas digested with a mild solution of purified elastase (5 U/mL) in the presence of a static stretch. Arterial mechanical properties and biochemical composition were analyzed to assess the effects of mechanical stretch on elastin degradation. As elastin is being removed, the dimensions of the artery increase by more than 20% in both the longitude and circumference directions. Elastin assays indicate a faster rate of degradation when stretch was present during the digestion. A simple exponential decay fitting confirms the time constant for digestion with stretch (0.11±0.04 h−1) is almost twice that of digestion without stretch (0.069±0.028 h−1). The transition from J-shaped to S-shaped stress vs. strain behavior in the longitudinal direction generally occurs when elastin content is reduced by about 60%. Multiphoton image analysis confirms the removal/fragmentation of elastin and also shows that the collagen fibers are closely intertwined with the elastin lamellae in the medial layer. After removal of elastin, the collagen fibers are no longer constrained and become disordered. Release of amorphous elastin during the fragmentation of the lamellae layers is observed and provides insights into the process of elastin degradation. Overall this study reveals several interesting microstructural changes in the extracellular matrix that could explain the resulting mechanical behavior of arteries with elastin degradation. PMID:24358135

  1. Induction of truncated form of tenascin-X (XB-S) through dissociation of HDAC1 from SP-1/HDAC1 complex in response to hypoxic conditions

    International Nuclear Information System (INIS)

    Kato, Akari; Endo, Toshiya; Abiko, Shun; Ariga, Hiroyoshi; Matsumoto, Ken-ichi

    2008-01-01

    ABSTRACT: XB-S is an amino-terminal truncated protein of tenascin-X (TNX) in humans. The levels of the XB-S transcript, but not those of TNX transcripts, were increased upon hypoxia. We identified a critical hypoxia-responsive element (HRE) localized to a GT-rich element positioned from - 1410 to - 1368 in the XB-S promoter. Using an electrophoretic mobility shift assay (EMSA), we found that the HRE forms a DNA-protein complex with Sp1 and that GG positioned in - 1379 and - 1378 is essential for the binding of the nuclear complex. Transfection experiments in SL2 cells, an Sp1-deficient model system, with an Sp1 expression vector demonstrated that the region from - 1380 to - 1371, an HRE, is sufficient for efficient activation of the XB-S promoter upon hypoxia. The EMSA and a chromatin immunoprecipitation (ChIP) assay showed that Sp1 together with the transcriptional repressor histone deacetylase 1 (HDAC1) binds to the HRE of the XB-S promoter under normoxia and that hypoxia causes dissociation of HDAC1 from the Sp1/HDAC1 complex. The HRE promoter activity was induced in the presence of a histone deacetylase inhibitor, trichostatin A, even under normoxia. Our results indicate that the hypoxia-induced activation of the XB-S promoter is regulated through dissociation of HDAC1 from an Sp1-binding HRE site

  2. GABA promotes elastin synthesis and elastin fiber formation in normal human dermal fibroblasts (HDFs).

    Science.gov (United States)

    Uehara, Eriko; Hokazono, Hideki; Hida, Mariko; Sasaki, Takako; Yoshioka, Hidekatsu; Matsuo, Noritaka

    2017-06-01

    The multiple physiological effects of γ-aminobutyric acid (GABA) as a functional food component have been recently reported. We previously reported that GABA upregulated the expression of type I collagen in human dermal fibroblasts (HDFs), and that oral administration of GABA significantly increased skin elasticity. However, details of the regulatory mechanism still remain unknown. In this study, we further examined the effects of GABA on elastin synthesis and elastin fiber formation in HDFs. Real-time PCR indicated that GABA significantly increased the expression of tropoelastin transcript in a dose-dependent manner. Additionally, the expression of fibrillin-1, fibrillin-2, and fibulin-5/DANCE, but not lysyl oxidase and latent transforming factor-β-binding protein 4, were also significantly increased in HDFs. Finally, immunohistochemical analysis confirmed that treatment with GABA dramatically increased the formation of elastic fibers in HDFs. Taken together, our results showed that GABA improves skin elasticity in HDFs by upregulating elastin synthesis and elastin fiber formation.

  3. Adherence of B16-F10 melanoma cells to elastin

    International Nuclear Information System (INIS)

    Zetter, B.R.; Netland, P.A.

    1986-01-01

    B16-F10 melanoma cells selectivity colonize lung tissue in vivo. The authors have previously shown that these cells adhere preferentially to lung tissue in vitro. To quantify the binding of B16-F10 cells to isolated components of lung tissue, the authors devised a dot-blot cell adhesion assay. Samples were absorbed to 4 mm dots of nylon based paper under non-denaturing conditions, blocked with albumin or hemoglobin, and incubated with radiolabelled cells for 30 min. at 4 0 C. 125 -I labelled B16-F10 cells demonstrated a dose dependent binding to mouse lung elastin. Autoradiography and scanning electron microscopy demonstrated that cells localized preferentially to the elastin dots. The melanoma cells bound more strongly to elastin relative to laminin, fibronectin, collagen types I and IV or heparan sulfate. Neither elastin-associated microfibrillar protein nor fragments of elastin produced by alkali or acid treatment demonstrated significant binding activity for these cells. The findings demonstrate that in addition to its unique mechanical properties that confer elasticity to tissues, elastin can also function as a cell adhesion molecule. The localization of elastin in the lung and its adhesive properties reported here suggest that elastin may facilitate the arrest and eventual colonization of circulating B16-F10 melanoma cells in the mouse lung

  4. Transplantation of bone marrow-derived mesenchymal stem cells expressing elastin alleviates pelvic floor dysfunction.

    Science.gov (United States)

    Jin, Minfei; Chen, Ying; Zhou, Yun; Mei, Yan; Liu, Wei; Pan, Chenhao; Hua, Xiaolin

    2016-04-05

    Pelvic floor dysfunction (PFD) is a group of clinical conditions including stress urinary incontinence (SUI) and pelvic organ prolapse (POP). The abnormality of collagen and elastin metabolism in pelvic connective tissues is implicated in SUI and POP. To reconstitute the connective tissues with normal distribution of collagen and elastin, we transduced elastin to bone marrow-derived mesenchymal stem cells (BMSC). Elastin-expressing BMSCs were then differentiated to fibroblasts using bFGF, which produced collagen and elastin. To achieve the sustained release of bFGF, we formulated bFGF in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP). In an in vitro cell culture system of 7 days, when no additional bFGF was administrated, the initial PLGA-loaded bFGF NP induced prolonged production of collagen and elastin from elastin-expressing BMSCs. In vivo, co-injection of PLGA-loaded bFGF NP and elastin-expressing BMSCs into the PFD rats significantly improved the outcome of urodynamic tests. Together, these results provided an efficient model of connective tissue engineering using BMSC and injectable PLGA-loaded growth factors. Our results provided the first instance of a multidisciplinary approach, combining both stem cell and nanoparticle technologies, for the treatment of PFD.

  5. On the mechanical role of de novo synthesized elastin in the urinary bladder wall

    NARCIS (Netherlands)

    Wognum, Silvia; Schmidt, David E.; Sacks, Michael S.

    2009-01-01

    The urinary bladder wall (UBW), which is composed of smooth muscle, collagen, and elastin, undergoes profound remodeling in response to changes in mechanical loading resulting from various pathologies. In our laboratory, we have observed the production of fibrillar elastin in the extracellular

  6. Investigation of water-soluble elastin as a multifunctional cosmetic material: Moisturizing and whitening effects.

    Science.gov (United States)

    Inoue, Asako; Hikima, Tomohiro; Taniguchi, Suguru; Nose, Takeru; Maeda, Iori

    Elastin and collagen are extracellular matrix proteins that are widely distributed in the body. Although elastin essentially functions as a skin moisturizer, there have been few reports on its other fundamental chemical and biological functions. In this study, we investigated the moisturizing and whitening (tyrosinase inhibition) effects of elastin to examine its usefulness as a cosmetic material. Water-soluble hot alkali pig aorta (HAPA)-elastin was prepared from pig aorta using the hot alkali method. HAPA-elastin showed a widely distributed molecular weight and had a coacervation property that mediated reversible self-assembly of its molecules with increasing temperature. Amino acid analysis of HAPA-elastin showed a high content (81.5%) of hydrophobic amino acids such as Gly, Ala, Val, and Pro. Des (desmosine) and Ide (isodesmosine), which are characteristic amino acids of elastin, accounted for more than 0.4% of the total amino acid content. HAPA-elastin showed a moisture-retaining property. The water content of skin samples treated with and without HAPA-elastin was 77.2% ± 7.8% and 49.4% ± 10.1%, respectively. HAPA-elastin also inhibited tyrosinase activity by 11.3% ± 3.9%. The results obtained indicate that elastin has a useful function as a cosmetic material.

  7. Broadband diffuse optical characterization of elastin for biomedical applications.

    Science.gov (United States)

    Konugolu Venkata Sekar, Sanathana; Beh, Joo Sin; Farina, Andrea; Dalla Mora, Alberto; Pifferi, Antonio; Taroni, Paola

    2017-10-01

    Elastin is a key structural protein of dynamic connective tissues widely found in the extracellular matrix of skin, arteries, lungs and ligaments. It is responsible for a range of diseases related to aging of biological tissues. The optical characterization of elastin can open new opportunities for its investigation in biomedical studies. In this work, we present the absorption spectra of elastin using a broadband (550-1350nm) diffuse optical spectrometer. Distortions caused by fluorescence and finite bandwidth of the laser source on estimated absorption were effectively accounted for in measurements and data analysis and compensated. A comprehensive summary and comparison between collagen and elastin is presented, highlighting distinct features for its accurate quantification in biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Elastin governs the mechanical response of medial collateral ligament under shear and transverse tensile loading.

    Science.gov (United States)

    Henninger, Heath B; Valdez, William R; Scott, Sara A; Weiss, Jeffrey A

    2015-10-01

    Elastin is a highly extensible structural protein network that provides near-elastic resistance to deformation in biological tissues. In ligament, elastin is localized between and along the collagen fibers and fascicles. When ligament is stretched along the primary collagen axis, elastin supports a relatively high percentage of load. We hypothesized that elastin may also provide significant load support under elongation transverse to the primary collagen axis and shear along the collagen axis. Quasi-static transverse tensile and shear material tests were performed to quantify the mechanical contributions of elastin during deformation of porcine medial collateral ligament. Dose response studies were conducted to determine the level of elastase enzymatic degradation required to produce a maximal change in the mechanical response. Maximal changes in peak stress occurred after 3h of treatment with 2U/ml porcine pancreatic elastase. Elastin degradation resulted in a 60-70% reduction in peak stress and a 2-3× reduction in modulus for both test protocols. These results demonstrate that elastin provides significant resistance to elongation transverse to the collagen axis and shear along the collagen axis while only constituting 4% of the tissue dry weight. The magnitudes of the elastin contribution to peak transverse and shear stress were approximately 0.03 MPa, as compared to 2 MPa for axial tensile tests, suggesting that elastin provides a highly anisotropic contribution to the mechanical response of ligament and is the dominant structural protein resisting transverse and shear deformation of the tissue. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI)

    OpenAIRE

    Protti, Andrea; Lavin, Begoña; Dong, Xuebin; Lorrio, Silvia; Robinson, Simon; Onthank, David; Shah, Ajay M; Botnar, Rene M

    2015-01-01

    BACKGROUND: Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin-specific contrast agent (Gd-...

  10. Extraction and characterization of elastin from poultry skin

    Energy Technology Data Exchange (ETDEWEB)

    Nadalian, Mehdi; Yusop, Salma Mohamad; Mustapha, Wan Aida Wan; Babji, Abdul Salam [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Azman, Mohd Azri [Strategic Livestock Research Centre, Malaysian Agricultural Research and Development Institute, MARDI Headquarters, 43400, Serdang, Selangor (Malaysia)

    2013-11-27

    Poultry by-products have a great economic potential that need to be exploited. Poultry skin could be utilized to produce elastin, which is often incorporated in the production of functional food or medicine due to its antioxidative properties. This study was conducted to determine the physicochemical and microstructural characteristics of elastins isolated from broiler and spent hen skin. Analyses including proximate and amino acid composition along with transmission electron microscopy (TEM) were carried out. In this study, elastin was successfully extracted from broiler and spent hen skin using three successive solvents extract of NaCl, acetone and NaOH respectively. It was apparent that the fat content of extracted elastin from broiler skin was higher (P < 0.05) than spent hen’s, with both samples recording less than 1% fat. Moreover, broiler skin elastin also had a higher protein content (68.3%) than spent hen’s (67.8%). Both skin sources contained glycine as the major amino acid (19–20%), followed by glutamic acid, proline, alanine and arginine. The results of TEM indicated that the use of collagenase enzyme or further purification efforts should be incorporated along with the extraction methods used because of the presence of collagen and other debris in the resultant elastin.

  11. Extraction and characterization of elastin from poultry skin

    International Nuclear Information System (INIS)

    Nadalian, Mehdi; Yusop, Salma Mohamad; Mustapha, Wan Aida Wan; Babji, Abdul Salam; Azman, Mohd Azri

    2013-01-01

    Poultry by-products have a great economic potential that need to be exploited. Poultry skin could be utilized to produce elastin, which is often incorporated in the production of functional food or medicine due to its antioxidative properties. This study was conducted to determine the physicochemical and microstructural characteristics of elastins isolated from broiler and spent hen skin. Analyses including proximate and amino acid composition along with transmission electron microscopy (TEM) were carried out. In this study, elastin was successfully extracted from broiler and spent hen skin using three successive solvents extract of NaCl, acetone and NaOH respectively. It was apparent that the fat content of extracted elastin from broiler skin was higher (P < 0.05) than spent hen’s, with both samples recording less than 1% fat. Moreover, broiler skin elastin also had a higher protein content (68.3%) than spent hen’s (67.8%). Both skin sources contained glycine as the major amino acid (19–20%), followed by glutamic acid, proline, alanine and arginine. The results of TEM indicated that the use of collagenase enzyme or further purification efforts should be incorporated along with the extraction methods used because of the presence of collagen and other debris in the resultant elastin

  12. Effect of Elastin Digestion on the Quasi-static Tensile Response of Medial Collateral Ligament

    Science.gov (United States)

    Henninger, Heath B.; Underwood, Clayton J.; Romney, Steven J.; Davis, Grant L.; Weiss, Jeffrey A.

    2014-01-01

    Elastin is a structural protein that provides resilience to biological tissues. We examined the contributions of elastin to the quasi-static tensile response of porcine medial collateral ligament through targeted disruption of the elastin network with pancreatic elastase. Elastase concentration and treatment time were varied to determine a dose response. Whereas elastin content decreased with increasing elastase concentration and treatment time, the change in peak stress after cyclic loading reached a plateau above 1 U/ml elastase and 6 hr treatment. For specimens treated with 2 U/ml elastase for 6 hr, elastin content decreased approximately 35%. Mean peak tissue strain after cyclic loading (4.8%, p≥0.300), modulus (275 MPa, p≥0.114) and hysteresis (20%, p≥0.553) were unaffected by elastase digestion, but stress decreased significantly after treatment (up to 2 MPa, p≤0.049). Elastin degradation had no effect on failure properties, but tissue lengthened under the same pre-stress. Stiffness in the linear region was unaffected by elastase digestion, suggesting that enzyme treatment did not disrupt collagen. These results demonstrate that elastin primarily functions in the toe region of the stress-strain curve, yet contributes load support in the linear region. The increase in length after elastase digestion suggests that elastin may pre-stress and stabilize collagen crimp in ligaments. PMID:23553827

  13. Chromosomal mapping of quantitative trait loci controlling elastin content in rat aorta.

    Science.gov (United States)

    Gauguier, Dominique; Behmoaras, Jacques; Argoud, Karène; Wilder, Steven P; Pradines, Christelle; Bihoreau, Marie Thérèse; Osborne-Pellegrin, Mary; Jacob, Marie Paule

    2005-03-01

    Extracellular matrix molecules such as elastin and collagens provide mechanical support to the vessel wall. In addition to its structural role, elastin is a regulator that maintains homeostasis through biologic signaling. Genetically determined minor modifications in elastin and collagen in the aorta could influence the onset and evolution of arterial pathology, such as hypertension and its complications. We previously demonstrated that the inbred Brown Norway (BN) rat shows an aortic elastin deficit in both abdominal and thoracic segments, partly because of a decrease in tropoelastin synthesis when compared with the LOU rat, that elastin gene polymorphisms in these strains do not significantly account for. After a genome-wide search for quantitative trait loci (QTL) influencing the aortic elastin, collagen, and cell protein contents in an F2 population derived from BN and LOU rats, we identified on chromosomes 2 and 14, 3 QTL specifically controlling elastin levels, and a further highly significant QTL on chromosome 17 linked to the level of cell proteins. We also mapped 3 highly significant QTL linked to body weight (on chromosomes 1 and 3) and heart weight (on chromosome 1) in the cross. This study demonstrates the polygenic control of the content of key components of the arterial wall. Such information represents a first step in understanding possible mechanisms involved in dysregulation of these parameters in arterial pathology.

  14. Elastin in large artery stiffness and hypertension

    Science.gov (United States)

    Wagenseil, Jessica E.; Mecham, Robert P.

    2012-01-01

    Large artery stiffness, as measured by pulse wave velocity (PWV), is correlated with high blood pressure and may be a causative factor in essential hypertension. The extracellular matrix components, specifically the mix of elastin and collagen in the vessel wall, determine the passive mechanical properties of the large arteries. Elastin is organized into elastic fibers in the wall during arterial development in a complex process that requires spatial and temporal coordination of numerous proteins. The elastic fibers last the lifetime of the organism, but are subject to proteolytic degradation and chemical alterations that change their mechanical properties. This review discusses how alterations in the amount, assembly, organization or chemical properties of the elastic fibers affect arterial stiffness and blood pressure. Strategies for encouraging or reversing alterations to the elastic fibers are addressed. Methods for determining the efficacy of these strategies, by measuring elastin amounts and arterial stiffness, are summarized. Therapies that have a direct effect on arterial stiffness through alterations to the elastic fibers in the wall may be an effective treatment for essential hypertension. PMID:22290157

  15. Ferroelectric switching of elastin

    Science.gov (United States)

    Liu, Yuanming; Cai, Hong-Ling; Zelisko, Matthew; Wang, Yunjie; Sun, Jinglan; Yan, Fei; Ma, Feiyue; Wang, Peiqi; Chen, Qian Nataly; Zheng, Hairong; Meng, Xiangjian; Sharma, Pradeep; Zhang, Yanhang; Li, Jiangyu

    2014-01-01

    Ferroelectricity has long been speculated to have important biological functions, although its very existence in biology has never been firmly established. Here, we present compelling evidence that elastin, the key ECM protein found in connective tissues, is ferroelectric, and we elucidate the molecular mechanism of its switching. Nanoscale piezoresponse force microscopy and macroscopic pyroelectric measurements both show that elastin retains ferroelectricity at 473 K, with polarization on the order of 1 μC/cm2, whereas coarse-grained molecular dynamics simulations predict similar polarization with a Curie temperature of 580 K, which is higher than most synthetic molecular ferroelectrics. The polarization of elastin is found to be intrinsic in tropoelastin at the monomer level, analogous to the unit cell level polarization in classical perovskite ferroelectrics, and it switches via thermally activated cooperative rotation of dipoles. Our study sheds light onto a long-standing question on ferroelectric switching in biology and establishes ferroelectricity as an important biophysical property of proteins. This is a critical first step toward resolving its physiological significance and pathological implications. PMID:24958890

  16. Development of Tissue-Engineered Ligaments: Elastin Promotes Regeneration of the Rabbit Medial Collateral Ligament.

    Science.gov (United States)

    Hirukawa, Masaki; Katayama, Shingo; Sato, Tatsuya; Yamada, Masayoshi; Kageyama, Satoshi; Unno, Hironori; Suzuki, Yoshiaki; Miura, Yoshihiro; Shiratsuchi, Eri; Hasegawa, Masahiro; Miyamoto, Keiichi; Horiuchi, Takashi

    2017-12-21

    When ligaments are injured, reconstructive surgery is sometimes required to restore function. Methods of reconstructive surgery include transplantation of an artificial ligament and autotransplantation of a tendon. However, these methods have limitations related to the strength of the bone-ligament insertion and biocompatibility of the transplanted tissue after surgery. Therefore, it is necessary to develop new reconstruction methods and pursue the development of artificial ligaments. Elastin is a major component of elastic fibers and ligaments. However, the role of elastin in ligament regeneration has not been described. Here, we developed a rabbit model of a medial collateral ligament (MCL) rupture and treated animal knees with exogenous elastin [100 µg/(0.5 mL·week)] for 6 or 12 weeks. Elastin treatment increased gene expression and protein content of collagen and elastin (gene expression, 6-fold and 42-fold, respectively; protein content, 1.6-fold and 1.9-fold, respectively), and also increased the elastic modulus of MCL increased with elastin treatment (2-fold) compared with the controls. Our data suggest that elastin is involved in the regeneration of damaged ligaments. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  17. Human elastin polypeptides improve the biomechanical properties of three-dimensional matrices through the regulation of elastogenesis.

    Science.gov (United States)

    Boccafoschi, Francesca; Ramella, Martina; Sibillano, Teresa; De Caro, Liberato; Giannini, Cinzia; Comparelli, Roberto; Bandiera, Antonella; Cannas, Mario

    2015-03-01

    The replacement of diseased tissues with biological substitutes with suitable biomechanical properties is one of the most important goal in tissue engineering. Collagen represents a satisfactory choice for scaffolds. Unfortunately, the lack of elasticity represents a restriction to a wide use of collagen for several applications. In this work, we studied the effect of human elastin-like polypeptide (HELP) as hybrid collagen-elastin matrices. In particular, we studied the biomechanical properties of collagen/HELP scaffolds considering several components involved in ECM remodeling (elastin, collagen, fibrillin, lectin-like receptor, metalloproteinases) and cell phenotype (myogenin, myosin heavy chain) with particular awareness for vascular tissue engineering applications. Elastin and collagen content resulted upregulated in collagen-HELP matrices, even showing an improved structural remodeling through the involvement of proteins to a ECM remodeling activity. Moreover, the hybrid matrices enhanced the contractile activity of C2C12 cells concurring to improve the mechanical properties of the scaffold. Finally, small-angle X-ray scattering analyses were performed to enable a very detailed analysis of the matrices at the nanoscale, comparing the scaffolds with native blood vessels. In conclusion, our work shows the use of recombinant HELP, as a very promising complement able to significantly improve the biomechanical properties of three-dimensional collagen matrices in terms of tensile stress and elastic modulus. © 2014 Wiley Periodicals, Inc.

  18. Matrix ageing and vascular impacts: focus on elastin fragmentation.

    Science.gov (United States)

    Duca, Laurent; Blaise, Sébastien; Romier, Béatrice; Laffargue, Muriel; Gayral, Stéphanie; El Btaouri, Hassan; Kawecki, Charlotte; Guillot, Alexandre; Martiny, Laurent; Debelle, Laurent; Maurice, Pascal

    2016-06-01

    Cardiovascular diseases (CVDs) are the leading cause of death worldwide and represent a major problem of public health. Over the years, life expectancy has considerably increased throughout the world, and the prevalence of CVD is inevitably rising with the growing ageing of the population. The normal process of ageing is associated with progressive deterioration in structure and function of the vasculature, commonly called vascular ageing. At the vascular level, extracellular matrix (ECM) ageing leads to molecular alterations in long half-life proteins, such as elastin and collagen, and have critical effects on vascular diseases. This review highlights ECM alterations occurring during vascular ageing with a specific focus on elastin fragmentation and also the contribution of elastin-derived peptides (EDP) in age-related vascular complications. Moreover, current and new pharmacological strategies aiming at minimizing elastin degradation, EDP generation, and associated biological effects are discussed. These strategies may be of major relevance for preventing and/or delaying vascular ageing and its complications. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  19. Elastin density: Link between histological and biomechanical properties of vaginal tissue in women with pelvic organ prolapse?

    Science.gov (United States)

    de Landsheere, Laurent; Brieu, Mathias; Blacher, Silvia; Munaut, Carine; Nusgens, Betty; Rubod, Chrystèle; Noel, Agnès; Foidart, Jean-Michel; Nisolle, Michelle; Cosson, Michel

    2016-04-01

    The aim of the study was to correlate histological and biomechanical characteristics of the vaginal wall in women with pelvic organ prolapse (POP). Tissue samples were collected from the anterior [point Ba; POP Questionnaire (POP-Q)] and/or posterior (point Bp; POP-Q) vaginal wall of 15 women who underwent vaginal surgery for POP. Both histological and biomechanical assessments were performed from the same tissue samples in 14 of 15 patients. For histological assessment, the density of collagen and elastin fibers was determined by combining high-resolution virtual imaging and computer-assisted digital image analysis. For biomechanical testing, uniaxial tension tests were performed to evaluate vaginal tissue stiffness at low (C0) and high (C1) deformation rates. Biomechanical testing highlights the hyperelastic behavior of the vaginal wall. At low strains (C0), vaginal tissue appeared stiffer when elastin density was low. We found a statistically significant inverse relationship between C0 and the elastin/collagen ratio (p = 0.048) in the lamina propria. However, at large strain levels (C1), no clear relationship was observed between elastin density or elastin/collagen ratio and stiffness, likely reflecting the large dispersion of the mechanical behavior of the tissue samples. Histological and biomechanical properties of the vaginal wall vary from patient to patient. This study suggests that elastin density deserves consideration as a relevant factor of vaginal stiffness in women with POP.

  20. Molecular-level characterization of elastin-like constructs and human aortic elastin

    DEFF Research Database (Denmark)

    Heinz, Andrea; Schräder, Christoph U; Baud, Stéphanie

    2014-01-01

    This study aimed to characterize the structures of two elastin-like constructs, one composed of a cross-linked elastin-like polypeptide and the other one of cross-linked tropoelastin, and native aortic elastin. The structures of the insoluble materials and human aortic elastin were investigated...... quantification revealed that the cross-linking degree of the two in vitro cross-linked materials was significantly lower than that of native elastin. Molecular dynamics simulations were performed, based on molecular species identified in the samples, to follow the formation of elastin cross-links. The results...... provide evidence for the significance of the GVGTP hinge region of domain 23 for the formation of elastin cross-links. Overall, this work provides important insight into structural similarities and differences between elastin-like constructs and native elastin. Furthermore, it represents a step toward...

  1. Circulating elastin peptides, role in vascular pathology.

    Science.gov (United States)

    Robert, L; Labat-Robert, J

    2014-12-01

    The atherosclerotic process starts with the degradation of elastic fibers. Their presence was demonstrated in the circulation as well as several of their biological properties elucidated. We described years ago a procedure to obtain large elastin peptides by organo-alkaline hydrolysis, κ-elastin. This method enabled also the preparation of specific antibodies used to determine elastin peptides, as well as anti-elastin antibodies in body fluids and tissue extracts. Elastin peptides were determined in a large number of human blood samples. Studies were carried out to explore their pharmacological properties. Similar recent studies by other laboratories confirmed our findings and arose new interest in circulating elastin peptides for their biological activities. This recent trend justified the publication of a review of the biological and pathological activities of elastin peptides demonstrated during our previous studies, subject of this article. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Palumbo, Fabio Salvatore; Pitarresi, Giovanna; Fiorica, Calogero; Rigogliuso, Salvatrice; Ghersi, Giulio; Giammona, Gaetano

    2013-01-01

    In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. The presence of α-elastin grafted to HA-EDA improves attachment, viability and proliferation of primary rat dermal fibroblasts and human umbilical artery smooth muscle cells. Biological performance of HA-EDA-g-α-elastin/EGDGE scaffold resulted comparable to that of a commercial collagen type I sponge (Antema®), chosen as a positive control. - Highlights: ► Hyaluronic acid (HA) has been functionalized with ethylenediamine (EDA). ► Amino groups of HA-EDA allow the reaction with α-elastin and ethylene glycol diglycidyl ether (EGDGE). ► Chemical scaffolds of HA-EDA-graft-α-elastin/EGDGE have been characterized. ► The presence of α-elastin affects porosity, swelling and enzymatic degradation of scaffolds. ► The presence of α-elastin improves attachment, viability and proliferation of fibroblasts and smooth muscle cells

  3. Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Palumbo, Fabio Salvatore [Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123, Palermo (Italy); Pitarresi, Giovanna, E-mail: giovanna.pitarresi@unipa.it [Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123, Palermo (Italy); Institute of Biophysics at Palermo, Italian National Research Council, Via Ugo La Malfa 153, 90146 Palermo (Italy); Fiorica, Calogero [Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123, Palermo (Italy); Rigogliuso, Salvatrice; Ghersi, Giulio [Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Sezione di Biologia Cellulare, Università degli Studi di Palermo, Viale delle Scienze ed. 16, 90128, Palermo (Italy); Giammona, Gaetano [Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123, Palermo (Italy); IBIM-CNR, Via Ugo La Malfa 153, 90146 Palermo (Italy)

    2013-07-01

    In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. The presence of α-elastin grafted to HA-EDA improves attachment, viability and proliferation of primary rat dermal fibroblasts and human umbilical artery smooth muscle cells. Biological performance of HA-EDA-g-α-elastin/EGDGE scaffold resulted comparable to that of a commercial collagen type I sponge (Antema®), chosen as a positive control. - Highlights: ► Hyaluronic acid (HA) has been functionalized with ethylenediamine (EDA). ► Amino groups of HA-EDA allow the reaction with α-elastin and ethylene glycol diglycidyl ether (EGDGE). ► Chemical scaffolds of HA-EDA-graft-α-elastin/EGDGE have been characterized. ► The presence of α-elastin affects porosity, swelling and enzymatic degradation of scaffolds. ► The presence of α-elastin improves attachment, viability and proliferation of fibroblasts and smooth muscle cells.

  4. Deficient Circumferential Growth Is the Primary Determinant of Aortic Obstruction Attributable to Partial Elastin Deficiency.

    Science.gov (United States)

    Jiao, Yang; Li, Guangxin; Korneva, Arina; Caulk, Alexander W; Qin, Lingfeng; Bersi, Matthew R; Li, Qingle; Li, Wei; Mecham, Robert P; Humphrey, Jay D; Tellides, George

    2017-05-01

    Williams syndrome is characterized by obstructive aortopathy attributable to heterozygous loss of ELN , the gene encoding elastin. Lesions are thought to result primarily from excessive smooth muscle cell (SMC) proliferation and consequent medial expansion, although an initially smaller caliber and increased stiffness of the aorta may contribute to luminal narrowing. The relative contributions of such abnormalities to the obstructive phenotype had not been defined. We quantified determinants of luminal stenosis in thoracic aortas of Eln -/- mice incompletely rescued by human ELN . Moderate obstruction was largely because of deficient circumferential growth, most prominently of ascending segments, despite increased axial growth. Medial thickening was evident in these smaller diameter elastin-deficient aortas, with medial area similar to that of larger diameter control aortas. There was no difference in cross-sectional SMC number between mutant and wild-type genotypes at multiple stages of postnatal development. Decreased elastin content was associated with medial fibrosis and reduced aortic distensibility because of increased structural stiffness but preserved material stiffness. Elastin-deficient SMCs exhibited greater contractile-to-proliferative phenotypic modulation in vitro than in vivo. We confirmed increased medial collagen without evidence of increased medial area or SMC number in a small ascending aorta with thickened media of a Williams syndrome subject. Deficient circumferential growth is the predominant mechanism for moderate obstructive aortic disease resulting from partial elastin deficiency. Our findings suggest that diverse aortic manifestations in Williams syndrome result from graded elastin content, and SMC hyperplasia causing medial expansion requires additional elastin loss superimposed on ELN haploinsufficiency. © 2017 American Heart Association, Inc.

  5. Prolyl hydroxylation in elastin is not random.

    Science.gov (United States)

    Schmelzer, Christian E H; Nagel, Marcus B M; Dziomba, Szymon; Merkher, Yulia; Sivan, Sarit S; Heinz, Andrea

    2016-10-01

    This study aimed to investigate the prolyl and lysine hydroxylation in elastin from different species and tissues. Enzymatic digests of elastin samples from human, cattle, pig and chicken were analyzed using mass spectrometry and bioinformatics tools. It was confirmed at the protein level that elastin does not contain hydroxylated lysine residues regardless of the species. In contrast, prolyl hydroxylation sites were identified in all elastin samples. Moreover, the analysis of the residues adjacent to prolines allowed the determination of the substrate site preferences of prolyl 4-hydroxylase. It was found that elastins from all analyzed species contain hydroxyproline and that at least 20%-24% of all proline residues were partially hydroxylated. Determination of the hydroxylation degrees of specific proline residues revealed that prolyl hydroxylation depends on both the species and the tissue, however, is independent of age. The fact that the highest hydroxylation degrees of proline residues were found for elastin from the intervertebral disc and knowledge of elastin arrangement in this tissue suggest that hydroxylation plays a biomechanical role. Interestingly, a proline-rich domain of tropoelastin (domain 24), which contains several repeats of bioactive motifs, does not show any hydroxyproline residues in the mammals studied. The results show that prolyl hydroxylation is not a coincidental feature and may contribute to the adaptation of the properties of elastin to meet the functional requirements of different tissues. The study for the first time shows that prolyl hydroxylation is highly regulated in elastin. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Elastin as a biomaterial for tissue engineering.

    NARCIS (Netherlands)

    Daamen, W.F.; Veerkamp, J.H.; Hest, J.C.M. van; Kuppevelt, A.H.M.S.M. van

    2007-01-01

    Biomaterials based upon elastin and elastin-derived molecules are increasingly investigated for their application in tissue engineering. This interest is fuelled by the remarkable properties of this structural protein, such as elasticity, self-assembly, long-term stability, and biological activity.

  7. Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering.

    Science.gov (United States)

    Palumbo, Fabio Salvatore; Pitarresi, Giovanna; Fiorica, Calogero; Rigogliuso, Salvatrice; Ghersi, Giulio; Giammona, Gaetano

    2013-07-01

    In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. The presence of α-elastin grafted to HA-EDA improves attachment, viability and proliferation of primary rat dermal fibroblasts and human umbilical artery smooth muscle cells. Biological performance of HA-EDA-g-α-elastin/EGDGE scaffold resulted comparable to that of a commercial collagen type I sponge (Antema®), chosen as a positive control. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Prolyl hydroxylation in elastin is not random

    DEFF Research Database (Denmark)

    Schmelzer, Christian E H; Nagel, Marcus B M; Dziomba, Szymon

    2016-01-01

    BACKGROUND: This study aimed to investigate the prolyl and lysine hydroxylation in elastin from different species and tissues. METHODS: Enzymatic digests of elastin samples from human, cattle, pig and chicken were analyzed using mass spectrometry and bioinformatics tools. RESULTS: It was confirmed...... at the protein level that elastin does not contain hydroxylated lysine residues regardless of the species. In contrast, prolyl hydroxylation sites were identified in all elastin samples. Moreover, the analysis of the residues adjacent to prolines allowed the determination of the substrate site preferences...... of prolyl 4-hydroxylase. It was found that elastins from all analyzed species contain hydroxyproline and that at least 20%-24% of all proline residues were partially hydroxylated. Determination of the hydroxylation degrees of specific proline residues revealed that prolyl hydroxylation depends on both...

  9. Isolation of intact elastin fibers devoid of microfibrils.

    NARCIS (Netherlands)

    Daamen, W.F.; Hafmans, T.G.M.; Veerkamp, J.H.; Kuppevelt, A.H.M.S.M. van

    2005-01-01

    Purification protocols for elastin generally result in greatly damaged elastin fibers and this likely influences the biological response. We here describe a novel protocol for the isolation of elastin whereby the fibers stay intact, and introduce the term "elastin fiber" for intact elastic fibers

  10. Aluminum Chloride Pretreatment of Elastin Inhibits Elastolysis by Matrix Metalloproteinases and Leads to Inhibition of Elastin-Oriented Calcification

    OpenAIRE

    Bailey, Michael; Xiao, Hui; Ogle, Matthew; Vyavahare, Naren

    2001-01-01

    Calcification of elastin occurs in many pathological cardiovascular diseases including atherosclerosis. We have previously shown that purified elastin when subdermally implanted in rats undergoes severe calcification and aluminum chloride (AlCl3) pretreatment of elastin inhibits calcification. In the present study we investigated whether matrix metalloproteinase (MMP) binding to elastin and elastin degradation is prevented by AlCl3 pretreatment. Subdermal implantation of AlCl3-pretreated elas...

  11. Hydroxyapatite and Calcified Elastin Induce Osteoblast-like Differentiation in Rat Aortic Smooth Muscle Cells

    Science.gov (United States)

    Lei, Yang; Sinha, Aditi; Nosoudi, Nasim; Grover, Ankit; Vyavahare, Naren

    2014-01-01

    Vascular calcification can be categorized into two different types. Intimal calcification related to atherosclerosis and elastin-specific medial arterial calcification (MAC). Osteoblast-like differentiation of vascular smooth muscle cells (VSMCs) has been shown in both types; however, how this relates to initiation of vascular calcification is unclear. We hypothesize that the initial deposition of hydroxyapatite-like mineral in MAC occurs on degraded elastin first and that causes osteogenic transformation of VSMCs. To test this, rat aortic smooth muscle cells (RASMCs) were cultured on hydroxyapatite crystals and calcified aortic elastin. Using RT-PCR and specific protein assays, we demonstrate that RASMCs lose their smooth muscle lineage markers like alpha smooth muscle actin (SMA) and myosin heavy chain (MHC) and undergo chondrogenic/osteogenic transformation. This is indicated by an increase in the expression of typical chondrogenic proteins such as aggrecan, collagen type II alpha 1(Col2a1) and bone proteins such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, when calcified conditions are removed, cells return to their original phenotype. Our data supports the hypothesis that elastin degradation and calcification precedes VSMCs' osteoblast-like differentiation. PMID:24447384

  12. Fingerprinting Desmosine-Containing Elastin Peptides

    Science.gov (United States)

    Schräder, Christoph U.; Heinz, Andrea; Majovsky, Petra; Schmelzer, Christian E. H.

    2015-05-01

    Elastin is a vital protein of the extracellular matrix of jawed vertebrates and provides elasticity to numerous tissues. It is secreted in the form of its soluble precursor tropoelastin, which is subsequently cross-linked in the course of the elastic fiber assembly. The process involves the formation of the two tetrafunctional amino acids desmosine (DES) and isodesmosine (IDES), which are unique to elastin. The resulting high degree of cross-linking confers remarkable properties, including mechanical integrity, insolubility, and long-term stability to the protein. These characteristics hinder the structural elucidation of mature elastin. However, MS2 data of linear and cross-linked peptides released by proteolysis can provide indirect insights into the structure of elastin. In this study, we performed energy-resolved collision-induced dissociation experiments of DES, IDES, their derivatives, and DES-/IDES-containing peptides to determine characteristic product ions. It was found that all investigated compounds yielded the same product ion clusters at elevated collision energies. Elemental composition determination using the exact masses of these ions revealed molecular formulas of the type CxHyN, suggesting that the pyridinium core of DES/IDES remains intact even at relatively high collision energies. The finding of these specific product ions enabled the development of a similarity-based scoring algorithm that was successfully applied on LC-MS/MS data of bovine elastin digests for the identification of DES-/IDES-cross-linked peptides. This approach facilitates the straightforward investigation of native cross-links in elastin.

  13. Multiscale mechanical integrity of human supraspinatus tendon in shear after elastin depletion.

    Science.gov (United States)

    Fang, Fei; Lake, Spencer P

    2016-10-01

    Human supraspinatus tendon (SST) exhibits region-specific nonlinear mechanical properties under tension, which have been attributed to its complex multiaxial physiological loading environment. However, the mechanical response and underlying multiscale mechanism regulating SST behavior under other loading scenarios are poorly understood. Furthermore, little is known about the contribution of elastin to tendon mechanics. We hypothesized that (1) SST exhibits region-specific shear mechanical properties, (2) fiber sliding is the predominant mode of local matrix deformation in SST in shear, and (3) elastin helps maintain SST mechanical integrity by facilitating force transfer among collagen fibers. Through the use of biomechanical testing and multiphoton microscopy, we measured the multiscale mechanical behavior of human SST in shear before and after elastase treatment. Three distinct SST regions showed similar stresses and microscale deformation. Collagen fiber reorganization and sliding were physical mechanisms observed as the SST response to shear loading. Measures of microscale deformation were highly variable, likely due to a high degree of extracellular matrix heterogeneity. After elastase treatment, tendon exhibited significantly decreased stresses under shear loading, particularly at low strains. These results show that elastin contributes to tendon mechanics in shear, further complementing our understanding of multiscale tendon structure-function relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Assessment of Myocardial Remodeling Using an Elastin/Tropoelastin Specific Agent with High Field Magnetic Resonance Imaging (MRI).

    Science.gov (United States)

    Protti, Andrea; Lavin, Begoña; Dong, Xuebin; Lorrio, Silvia; Robinson, Simon; Onthank, David; Shah, Ajay M; Botnar, Rene M

    2015-08-13

    Well-defined inflammation, proliferation, and maturation phases orchestrate the remodeling of the injured myocardium after myocardial infarction (MI) by controlling the formation of new extracellular matrix. The extracellular matrix consists mainly of collagen but also fractions of elastin. It is thought that elastin is responsible for maintaining elastic properties of the myocardium, thus reducing the risk of premature rupture. An elastin/tropoelastin-specific contrast agent (Gd-ESMA) was used to image tropoelastin and mature elastin fibers for in vivo assessment of extracellular matrix remodeling post-MI. Gd-ESMA enhancement was studied in a mouse model of myocardial infarction using a 7 T MRI scanner and results were compared to those achieved after injection of a nonspecific control contrast agent, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). In the infarcted tissue, Gd-ESMA uptake (measured as R1 relaxation rate) steadily increased from day 3 to day 21 as a result of the synthesis of elastin/tropoelastin. R1 values were in good agreement with histological findings. A similar R1 behavior was observed in the remote myocardium. No mature cross-linked elastin was found at any time point. In contrast, Gd-DTPA uptake was only observed in the infarct with no changes in R1 values between 3 and 21 days post-MI. We demonstrate the feasibility of in vivo imaging of extracellular matrix remodeling post-MI using a tropoelastin/elastin binding MR contrast agent, Gd-ESMA. We found that tropoelastin is the main contributor to the increased MRI signal at late stages of MI where its augmentation in areas of infarction was in good agreement with the R1 increase. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  15. Regulation of elastin synthesis in developing sheep nuchal ligament by elastin mRNA levels

    International Nuclear Information System (INIS)

    Davidson, J.M.; Smith, K.; Shibahara, S.; Tolstoshev, P.; Crystal, R.G.

    1982-01-01

    Levels of elastin production in explant culture of fetal sheep nuchal ligament and corresponding levels of translatable elastin mRNA were determined in parallel studies during a period of rapid growth of the embryo. The identity of the explant culture and cell-free proucts was confirmed by peptide mapping, immunoprecipitation, and the characteristic lack of histidine and methionine. Elastin production was quantitated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radioimmune precipitation. The translation products could be labeled with methionine only when NH 2 -terminally donated as f-Met-tRNA/sup Met//sub f/. Explant cultures showed a large rise in elastin production from 70 days after conception to 150 days after conception. Cell free translation of RNA demonstrated a parallel in elastin mRNA levels and in elastin mRNA per cell. It appears, therefore, that the marked emphasis the differentiating muchal ligament places on elastin production is modulated, at least in part, by the quantities of available elastin in mRNA

  16. Biophysical characterization of a de novo elastin

    Science.gov (United States)

    Greenland, Kelly Nicole

    Natural human elastin is found in tissue such as the lungs, arteries, and skin. This protein is formed at birth with no mechanism present to repair or supplement the initial quantity formed. As a result, the functionality and durability of elastin's elasticity is critically important. To date, the mechanics of this ability to stretch and recoil is not fully understood. This study utilizes de novo protein design to create a small library of simplistic versions of elastin-like proteins, demonstrate the elastin-like proteins, maintain elastin's functionality, and inquire into its structure using solution nuclear magnetic resonance (NMR). Elastin is formed from cross-linked tropoelastin. Therefore, the first generation of designed proteins consisted of one protein that utilized homogony of interspecies tropoelastin by using three common domains, two hydrophobic and one cross-linking domains. Basic modifications were made to open the hydrophobic region and also to make the protein easier to purify and characterize. The designed protein maintained its functionality, self-aggregating as the temperature increased. Uniquely, the protein remained self-aggregated as the temperature returned below the critical transition temperature. Self-aggregation was additionally induced by increasing salt concentrations and by modifying the pH. The protein appeared to have little secondary structure when studied with solution NMR. These results fueled a second generation of designed elastin-like proteins. This generation contained variations designed to study the cross-linking domain, one specific hydrophobic domain, and the effect of the length of the elastin-like protein. The cross-linking domain in one variation has been significantly modified while the flanking hydrophobic domains have remained unchanged. This characterization of this protein will answer questions regarding the specificity of the homologous nature of the cross-linking domain of tropoelastin across species. A second

  17. 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.

  18. Diversity in the organization of elastin bundles and intramembranous muscles in bat wings.

    Science.gov (United States)

    Cheney, Jorn A; Allen, Justine J; Swartz, Sharon M

    2017-04-01

    Unlike birds and insects, bats fly with wings composed of thin skin that envelops the bones of the forelimb and spans the area between the limbs, digits, and sometimes the tail. This skin is complex and unusual; it is thinner than typical mammalian skin and contains organized bundles of elastin and embedded skeletal muscles. These elements are likely responsible for controlling the shape of the wing during flight and contributing to the aerodynamic capabilities of bats. We examined the arrangement of two macroscopic architectural elements in bat wings, elastin bundles and wing membrane muscles, to assess the diversity in bat wing skin morphology. We characterized the plagiopatagium and dactylopatagium of 130 species from 17 families of bats using cross-polarized light imaging. This method revealed structures with distinctive relative birefringence, heterogeneity of birefringence, variation in size, and degree of branching. We used previously published anatomical studies and tissue histology to identify birefringent structures, and we analyzed their architecture across taxa. Elastin bundles, muscles, neurovasculature, and collagenous fibers are present in all species. Elastin bundles are oriented in a predominantly spanwise or proximodistal direction, and there are five characteristic muscle arrays that occur within the plagiopatagium, far more muscle than typically recognized. These results inform recent functional studies of wing membrane architecture, support the functional hypothesis that elastin bundles aid wing folding and unfolding, and further suggest that all bats may use these architectural elements for flight. All species also possess numerous muscles within the wing membrane, but the architecture of muscle arrays within the plagiopatagium varies among families. To facilitate present and future discussion of these muscle arrays, we refine wing membrane muscle nomenclature in a manner that reflects this morphological diversity. The architecture of the

  19. Lung matrix and vascular remodeling in mechanically ventilated elastin haploinsufficient newborn mice

    Science.gov (United States)

    Hilgendorff, Anne; Parai, Kakoli; Ertsey, Robert; Navarro, Edwin; Jain, Noopur; Carandang, Francis; Peterson, Joanna; Mokres, Lucia; Milla, Carlos; Preuss, Stefanie; Alcazar, Miguel Alejandre; Khan, Suleman; Masumi, Juliet; Ferreira-Tojais, Nancy; Mujahid, Sana; Starcher, Barry; Rabinovitch, Marlene

    2014-01-01

    Elastin plays a pivotal role in lung development. We therefore queried if elastin haploinsufficient newborn mice (Eln+/−) would exhibit abnormal lung structure and function related to modified extracellular matrix (ECM) composition. Because mechanical ventilation (MV) has been linked to dysregulated elastic fiber formation in the newborn lung, we also asked if elastin haploinsufficiency would accentuate lung growth arrest seen after prolonged MV of neonatal mice. We studied 5-day-old wild-type (Eln+/+) and Eln+/− littermates at baseline and after MV with air for 8–24 h. Lungs of unventilated Eln+/− mice contained ∼50% less elastin and ∼100% more collagen-1 and lysyl oxidase compared with Eln+/+ pups. Eln+/− lungs contained fewer capillaries than Eln+/+ lungs, without discernible differences in alveolar structure. In response to MV, lung tropoelastin and elastase activity increased in Eln+/+ neonates, whereas tropoelastin decreased and elastase activity was unchanged in Eln+/− mice. Fibrillin-1 protein increased in lungs of both groups during MV, more in Eln+/− than in Eln+/+ pups. In both groups, MV caused capillary loss, with larger and fewer alveoli compared with unventilated controls. Respiratory system elastance, which was less in unventilated Eln+/− compared with Eln+/+ mice, was similar in both groups after MV. These results suggest that elastin haploinsufficiency adversely impacts pulmonary angiogenesis and that MV dysregulates elastic fiber integrity, with further loss of lung capillaries, lung growth arrest, and impaired respiratory function in both Eln+/+ and Eln+/− mice. Paucity of lung capillaries in Eln+/− newborns might help explain subsequent development of pulmonary hypertension previously reported in adult Eln+/− mice. PMID:25539853

  20. Genetic Modifiers of Cardiovascular Phenotype Caused by Elastin Haploinsufficiency Act by Extrinsic Noncomplementation*

    Science.gov (United States)

    Kozel, Beth A.; Knutsen, Russell H.; Ye, Li; Ciliberto, Christopher H.; Broekelmann, Thomas J.; Mecham, Robert P.

    2011-01-01

    Elastin haploinsufficiency causes the cardiovascular complications associated with Williams-Beuren syndrome and isolated supravalvular aortic stenosis. Significant variability exists in the vascular pathology in these individuals. Using the Eln+/− mouse, we sought to identify the source of this variability. Following outcrossing of C57Bl/6J Eln+/−, two backgrounds were identified whose cardiovascular parameters deviated significantly from the parental strain. F1 progeny of the C57Bl/6J; Eln+/−x129X1/SvJ were more hypertensive and their arteries less compliant. In contrast, Eln+/− animals crossed to DBA/2J were protected from the pathologic changes associated with elastin insufficiency. Among the crosses, aortic elastin and collagen content did not correlate with quantitative vasculopathy traits. Quantitative trait locus analysis performed on F2 C57; Eln+/−x129 intercrosses identified highly significant peaks on chromosome 1 (LOD 9.7) for systolic blood pressure and on chromosome 9 (LOD 8.7) for aortic diameter. Additional peaks were identified that affect only Eln+/−, including a region upstream of Eln on chromosome 5 (LOD 4.5). Bioinformatic analysis of the quantitative trait locus peaks revealed several interesting candidates, including Ren1, Ncf1, and Nos1; genes whose functions are unrelated to elastic fiber assembly, but whose effects may synergize with elastin insufficiency to predispose to hypertension and stiffer blood vessels. Real time RT-PCR studies show background-specific increased expression of Ncf1 (a subunit of the NOX2 NAPDH oxidase) that parallel the presence of increased oxidative stress in Eln+/− aortas. This finding raises the possibility that polymorphisms in genes affecting the generation of reactive oxygen species alter cardiovascular function in individuals with elastin haploinsufficiency through extrinsic noncomplementation. PMID:22049077

  1. Comparison of five procedures for the purification of insoluble elastin.

    NARCIS (Netherlands)

    Daamen, W.F.; Hafmans, T.G.M.; Veerkamp, J.H.; Kuppevelt, A.H.M.S.M. van

    2001-01-01

    Elastin is an insoluble, highly cross-linked protein, providing elasticity to organs like lung. aorta, and ligaments. Despite its remarkable mechanical properties. elastin has found little use as a biomaterial. Purification of intact elastin from elastic fibres presents a major challenge, among

  2. Interaction between fatty acid and the elastin network

    NARCIS (Netherlands)

    Vreeswijk, van J.

    1995-01-01

    The aim of the present study was to investigate the interaction between salts of fatty acids (FAS) and elastin. Absorption of fatty acids in elastin may affect the elasticity of elastin-containing tissue. Such phenomena could, for instance, be of relevance for the understanding of the

  3. Microablation of collagen-based substrates for soft tissue engineering

    International Nuclear Information System (INIS)

    Kumar, Vivek A; Caves, Jeffrey M; Naik, Nisarga; Haller, Carolyn A; Chaikof, Elliot L; Martinez, Adam W

    2014-01-01

    Noting the abundance and importance of collagen as a biomaterial, we have developed a facile method for the production of a dense fibrillar extracellular matrix mimicking collagen–elastin hybrids with tunable mechanical properties. Through the use of excimer-laser technology, we have optimized conditions for the ablation of collagen lamellae without denaturation of protein, maintenance of fibrillar ultrastructure and preservation of native D-periodicity. Strengths of collagen–elastin hybrids ranged from 0.6 to 13 MPa, elongation at break from 9 to 70% and stiffness from 2.9 to 94 MPa, allowing for the design of a wide variety of tissue specific scaffolds. Further, large (centimeter scale) lamellae can be fabricated and embedded with recombinant elastin to generate collagen–elastin hybrids. Exposed collagen in hybrids act as cell adhesive sites for rat mesenchymal stem cells that conform to ablate waveforms. The ability to modulate these features allows for the generation of a class of biopolymers that can architecturally and physiologically replicate native tissue. (communication)

  4. Measurement of cross-linked elastin synthesis in bleomycin-induced pulmonary fibrosis using a highly sensitive assay for desmosine and isodesmosine

    International Nuclear Information System (INIS)

    Cantor, J.O.; Osman, M.; Keller, S.; Cerreta, J.M.; Mandl, I.; Turino, G.M.

    1984-01-01

    Cross-linked elastin synthesis was measured in the intratracheal bleomycin model of interstitial pulmonary fibrosis by incorporation of 14C-lysine into the elastin-specific crosslinks, desmosine and isodesmosine. Detection of the labeled crosslinks was facilitated by development of a highly sensitive assay utilizing thin-layer electrophoresis. The results indicate that crosslinked elastin synthesis is significantly elevated from controls (p less than 0.05) at 1 to 3 weeks after exposure to bleomycin and returns to normal by 5 weeks. The increases in labeled elastin synthesis are not directly related to changes in either total lung protein synthesis or the pool size of the 14C-lysine. In comparison with collagen and glycosaminoglycan synthesis in this model of lung injury, maximal increases in cross-linked elastin formation occur later, but overlap with the elevated synthesis of these other connective tissue components. The marked increase from normal in cross-linked elastin synthesis in this model suggests that this tissue component is an important part of the fibrotic response of the pulmonary parenchyma and may play a role in the observed alterations in lung structure and function

  5. Soluble elastin peptides in cardiovascular homeostasis: Foe or ally.

    Science.gov (United States)

    Qin, Zhenyu

    2015-05-01

    Elastin peptides, also known as elastin-derived peptides or elastokines, are soluble polypeptides in blood and tissue. The blood levels of elastin peptides are usually low but can increase during cardiovascular diseases, such as atherosclerosis, aortic aneurysm and diabetes with vascular complications. Generally, elastin peptides are derived from the degradation of insoluble elastic polymers. The biological activities of elastin peptides are bidirectional, e.g., a pro-inflammatory effect on monocyte migration induction vs. a protective effect on vasodilation promotion. However, recent in vivo studies have demonstrated that elastin peptides promote the formation of atherosclerotic plaques in hypercholesterolemic mice and induce hyperglycemia and elevations in plasma lipid levels in fasted mice. More important, the detrimental effects induced by elastin peptides can be largely inhibited by genetic or pharmacological blockade of the elastin receptor complex or by neutralization of an antibody against elastin peptides. These studies indicate new therapeutic strategies for the treatment of cardiovascular diseases by targeting elastin peptide metabolism. Therefore, the goal of this review is to summarize current knowledge about elastin peptides relevant to cardiovascular pathologies to further delineate their potential application in cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. In vitro myogenesis induced by human recombinant elastin-like proteins.

    Science.gov (United States)

    D'Andrea, Paola; Scaini, Denis; Ulloa Severino, Luisa; Borelli, Violetta; Passamonti, Sabina; Lorenzon, Paola; Bandiera, Antonella

    2015-10-01

    Mammalian adult skeletal muscle has a limited ability to regenerate after injury, usage or trauma. A promising strategy for successful regenerative technology is the engineering of bio interfaces that mimic the characteristics of the extracellular matrix. Human elastin-like polypeptides (HELPs) have been synthesized as biomimetic materials that maintain some peculiar properties of the native protein. We developed a novel Human Elastin Like Polypeptide obtained by fusing the elastin-like backbone to a domain present in the α2 chain of type IV collagen, containing two RGD motives. We employed this peptide as adhesion substrate for C2C12 myoblasts and compared its effects to those induced by two other polypeptides of the HELP series. Myoblast adhered to all HELPs coatings, where they assumed morphology and cytoarchitecture that depended on the polypeptide structure. Adhesion to HELPs stimulated at a different extent cell proliferation and differentiation, the expression of Myosin Heavy Chain and the fusion of aligned fibers into multinucleated myotubes. Adhesion substrates significantly altered myotubes stiffness, measured by Atomic Force Microscopy, and differently affected the cells Ca(2+) handling capacity and the maturation of excitation-contraction coupling machinery, evaluated by Ca(2+) imaging. Overall, our findings indicate that the properties of HELP biopolymers can be exploited for dissecting the molecular connections underlying myogenic differentiation and for designing novel substrates for skeletal muscle regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Small leucine-rich repeat proteoglycans associated with mature insoluble elastin serve as binding sites for galectins.

    Science.gov (United States)

    Itoh, Aiko; Nonaka, Yasuhiro; Ogawa, Takashi; Nakamura, Takanori; Nishi, Nozomu

    2017-11-01

    We previously reported that galectin-9 (Gal-9), an immunomodulatory animal lectin, could bind to insoluble collagen preparations and exerted direct cytocidal effects on immune cells. In the present study, we found that mature insoluble elastin is capable of binding Gal-9 and other members of the human galectin family. Lectin blot analysis of a series of commercial water-soluble elastin preparations, PES-(A) ~ PES-(E), revealed that only PES-(E) contained substances recognized by Gal-9. Gal-9-interacting substances in PES-(E) were affinity-purified, digested with trypsin and then analyzed by reversed-phase HPLC. Peptide fragments derived from five members of the small leucine-rich repeat proteoglycan family, versican, lumican, osteoglycin/mimecan, prolargin, and fibromodulin, were identified by N-terminal amino acid sequence analysis. The results indicate that Gal-9 and possibly other galectins recognize glycans attached to small leucine-rich repeat proteoglycans associated with insoluble elastin and also indicate the possibility that mature insoluble elastin serves as an extracellular reservoir for galectins.

  8. Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS.

    Science.gov (United States)

    Nielsen, M J; Lehmann, J; Leeming, D J; Schierwagen, R; Klein, S; Jansen, C; Strassburg, C P; Bendtsen, F; Møller, S; Sauerbruch, T; Karsdal, M A; Krag, A; Trebicka, J

    2015-11-01

    Progressive fibrosis increases hepatic resistance and causes portal hypertension with complications. During progressive fibrosis remodeling and deposition of collagens and elastin occur. Elastin remodeling is crucially involved in fibrosis progression in animal models and human data. This study investigated the association of circulating elastin with the clinical outcome in cirrhotic patients with severe portal hypertension receiving transjugular intrahepatic porto-systemic shunt (TIPS). We analyzed portal and hepatic venous samples of 110 cirrhotic patients obtained at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. Circulating levels of ELM showed a gradient across the liver before TIPS with higher levels in the hepatic vein. Interestingly, the circulating ELM levels remained unchanged after TIPS. The circulating levels of ELM in portal and hepatic veins correlated with platelet counts and inversely with serum sodium. Hepatic venous levels of ELM were higher in CHILD C compared to CHILD A and B and were associated with the presence of ascites. Patients with high levels of ELM in the hepatic veins before TIPS showed poorer survival. In multivariate analysis ELM levels in the hepatic veins and MELD were independent predictors of mortality in these patients. This study demonstrated that circulating levels of ELM are not associated with hemodynamic changes, but might reflect fibrosis remodeling and predict survival in patients with severe portal hypertension receiving TIPS independently of MELD.

  9. MicroRNA-181b Controls Atherosclerosis and Aneurysms Through Regulation of TIMP-3 and Elastin.

    Science.gov (United States)

    Di Gregoli, Karina; Mohamad Anuar, Nur Najmi; Bianco, Rosaria; White, Stephen J; Newby, Andrew C; George, Sarah J; Johnson, Jason L

    2017-01-06

    Atherosclerosis and aneurysms are leading causes of mortality worldwide. MicroRNAs (miRs) are key determinants of gene and protein expression, and atypical miR expression has been associated with many cardiovascular diseases; although their contributory role to atherosclerotic plaque and abdominal aortic aneurysm stability are poorly understood. To investigate whether miR-181b regulates tissue inhibitor of metalloproteinase-3 expression and affects atherosclerosis and aneurysms. Here, we demonstrate that miR-181b was overexpressed in symptomatic human atherosclerotic plaques and abdominal aortic aneurysms and correlated with decreased expression of predicted miR-181b targets, tissue inhibitor of metalloproteinase-3, and elastin. Using the well-characterized mouse atherosclerosis models of Apoe - /- and Ldlr -/- , we observed that in vivo administration of locked nucleic acid anti-miR-181b retarded both the development and the progression of atherosclerotic plaques. Systemic delivery of anti-miR-181b in angiotensin II-infused Apoe -/- and Ldlr -/- mice attenuated aneurysm formation and progression within the ascending, thoracic, and abdominal aorta. Moreover, miR-181b inhibition greatly increased elastin and collagen expression, promoting a fibrotic response and subsequent stabilization of existing plaques and aneurysms. We determined that miR-181b negatively regulates macrophage tissue inhibitor of metalloproteinase-3 expression and vascular smooth muscle cell elastin production, both important factors in maintaining atherosclerotic plaque and aneurysm stability. Validation studies in Timp3 -/- mice confirmed that the beneficial effects afforded by miR-181b inhibition are largely tissue inhibitor of metalloproteinase-3 dependent, while also revealing an additional protective effect through elevating elastin synthesis. Our findings suggest that the management of miR-181b and its target genes provides therapeutic potential for limiting the progression of

  10. 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...

  11. Degradation of tropoelastin and skin elastin by neprilysin

    DEFF Research Database (Denmark)

    Mora Huertas, Angela C.; Schmelzer, Christian E. H.; Luise, Chiara

    2018-01-01

    was to investigate the degradation of fibrillar skin elastin by neprilysin and the influence of the donor's age on the degradation process using mass spectrometry and bioinformatics approaches. The results showed that cleavage by neprilysin is dependent on previous damage of elastin. While neprilysin does not cleave...... young and intact skin elastin well, it degrades elastin fibers from older donors, which may further promote aging processes. With regards to the cleavage behavior of neprilysin, a strong preference for Gly at P1 was found, while Gly, Ala and Val were well accepted at P1' upon cleavage of tropoelastin...... and skin elastin. The results of the study indicate that the progressive release of bioactive elastin peptides by neprilysin upon skin aging may enhance local tissue damage and accelerate extracellular matrix aging processes....

  12. Molecular-level insights into aging processes of skin elastin

    DEFF Research Database (Denmark)

    Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang

    2016-01-01

    Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating...... the influence of intrinsic (chronological aging) and extrinsic factors (sun exposure) on the morphology and susceptibility of elastin towards enzymatic degradation. Elastin was isolated from biopsies derived from sun-protected or sun-exposed skin of differently aged individuals. The morphology of the elastin...... pronounced in sun-exposed tissue. Marker peptides were identified, which showed an age-related increase or decrease in their abundances and provide insights into the progression of the aging process of elastin fibers. Strong age-related cleavage occurs in hydrophobic tropoelastin domains 18, 20, 24 and 26...

  13. Electrospun biodegradable microfibers induce new collagen formation in a rat abdominal wall defect model

    DEFF Research Database (Denmark)

    Tarpø, Cecilie Lærke Glindtvad; Chen, Menglin; Nygaard, Jens Vinge

    2018-01-01

    and effect on collagen and elastin production of a degradable mesh releasing basic fibroblast growth factor (bFGF). Implantation of biodegradable mesh with or without bFGF in their core has been conducted in 40 rats in an abdominal wall defect model. Samples were explanted after 4, 8, and 24 weeks...

  14. [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.

  15. Elastin as a self-organizing biomaterial: use of recombinantly expressed human elastin polypeptides as a model for investigations of structure and self-assembly of elastin.

    Science.gov (United States)

    Keeley, Fred W; Bellingham, Catherine M; Woodhouse, Kimberley A

    2002-02-28

    Elastin is the major extracellular matrix protein of large arteries such as the aorta, imparting characteristics of extensibility and elastic recoil. Once laid down in tissues, polymeric elastin is not subject to turnover, but is able to sustain its mechanical resilience through thousands of millions of cycles of extension and recoil. Elastin consists of ca. 36 domains with alternating hydrophobic and cross-linking characteristics. It has been suggested that these hydrophobic domains, predominantly containing glycine, proline, leucine and valine, often occurring in tandemly repeated sequences, are responsible for the ability of elastin to align monomeric chains for covalent cross-linking. We have shown that small, recombinantly expressed polypeptides based on sequences of human elastin contain sufficient information to self-organize into fibrillar structures and promote the formation of lysine-derived cross-links. These cross-linked polypeptides can also be fabricated into membrane structures that have solubility and mechanical properties reminiscent of native insoluble elastin. Understanding the basis of the self-organizational ability of elastin-based polypeptides may provide important clues for the general design of self-assembling biomaterials.

  16. Elastin binds to a multifunctional 67-kilodalton peripheral membrane protein

    International Nuclear Information System (INIS)

    Mecham, R.P.; Hinek, A.; Entwistle, R.; Wrenn, D.S.; Griffin, G.L.; Senior, R.M.

    1989-01-01

    Elastin binding proteins from plasma membranes of elastin-producing cells were isolated by affinity chromatography on immobilized elastin peptides. Three proteins of 67, 61, and 55 kDa were released from the elastin resin by guanidine/detergent, soluble elastin peptides, synthetic peptide VGVAPG, or galactoside sugars, but not by synthetic RGD-containing peptide or sugars not related to galactose. All three proteins incorporated radiolabel upon extracellular iodination and contained [ 3 H]leucine following metabolic labeling, confirming that each is a synthetic product of the cell. The 67-kDa protein could be released from the cell surface with lactose-containing buffers, whereas solubilization of the 61- and 55-kDa components required the presence of detergent. Although all three proteins were retained on elastin affinity columns, the 61- and 55-kDa components were retained only in the presence of 67-kDa protein, suggesting that the 67-kDa protein binds elastin and the 61- and 55-kDa proteins bind to the 67-kDa protein. The authors propose that the 67-, 61-, and 55-kDa proteins constitute an elastin-receptor complex that forms a transmembrane link between the extracellular matrix and the intracellular compartment

  17. Acquired Localized Cutis Laxa due to Increased Elastin Turnover

    DEFF Research Database (Denmark)

    Nygaard, Rie Harboe; Maynard, Scott; Schjerling, Peter

    2016-01-01

    Cutis laxa is a rare disease characterized by abnormal skin wrinkling and laxity, due to decreased elastin synthesis or structural extracellular matrix defects. We have explored elastin metabolism in a case of adult onset cutis laxa localized to the upper body of a woman. For this purpose, we...... obtained skin biopsies from affected and unaffected skin areas of the patient and analyzed these with microscopy, polymerase chain reaction, western blotting and cell culture experiments. Skin from the affected area lacked elastin fibers in electron microscopy but had higher mRNA expression of elastin...... and total RNA. Levels of an apparent tropoelastin degradation product were higher in the affected area. Fibroblast cultures from the affected area were able to produce elastin and showed higher proliferation and survival after oxidative and UVB stress compared to fibroblasts from the unaffected area...

  18. Cues for cellular assembly of vascular elastin networks

    Science.gov (United States)

    Kothapalli, Chandrasekhar R.

    Elastin, a structural protein distributed in the extracellular matrix of vascular tissues is critical to the maintenance of vascular mechanics, besides regulation of cell-signaling pathways involved in injury response and morphogenesis. Thus, congenital absence or disease-mediated degradation of vascular elastin and its malformation within native vessels due to innately poor elastin synthesis by adult vascular cells compromise vascular homeostasis. Current elastin regenerative strategies using tissue engineering principles are limited by the progressive destabilization of tropoelastin mRNA expression in adult vascular cells and the unavailability of scaffolds that can provide cellular cues necessary to up-regulate elastin synthesis and regenerate faithful mimics of native elastin. Since our earlier studies demonstrated the elastogenic utility of hyaluronan (HA)-based cues, we have currently sought to identify a unique set of culture conditions based on HA fragments (0.756-2000 kDa), growth factors (TGF-beta1, IGF-1) and other biomolecules (Cu2+ ions, LOX), which will together enhance synthesis, crosslinking, maturation and fibrous elastin matrix formation by adult SMCs, under both healthy and inflammatory conditions. It was observed that TGF-beta1 (1 ng/mL) together with HA oligomers (0.2 microg/mL) synergistically suppressed SMC proliferation, enhanced tropoelastin (8-fold) and matrix elastin synthesis (5.5-fold), besides improving matrix yield (4.5-fold), possibly by increasing production and activity of lysyl oxidase (LOX). Though addition of IGF-1 alone did not offer any advantage, HA fragments (20-200 kDa) in the presence of IGF-1 stimulated tropoelastin and soluble elastin synthesis more than 2.2-fold, with HMW HA contributing for ˜5-fold increase in crosslinked matrix elastin synthesis. Similarly, 0.1 M of Cu2+ ions, alone or together with HA fragments stimulated synthesis of tropoelastin (4-fold) and crosslinked matrix elastin (4.5-fold), via increases in

  19. Effect of glucose on the biomechanical function of arterial elastin.

    Science.gov (United States)

    Wang, Yunjie; Zeinali-Davarani, Shahrokh; Davis, Elaine C; Zhang, Yanhang

    2015-09-01

    Elastin is essential to provide elastic support for blood vessels. As a remarkably long-lived protein, elastin can suffer from cumulative effects of exposure to biochemical damages, which can greatly compromise its biomechanical properties. Non-enzymatic glycation is one of the main mechanisms of aging and its effect is magnified in diabetic patients. The purpose of this study is to investigate the effects of glucose on mechanical properties of isolated porcine aortic elastin. Elastin samples were incubated in 2 M glucose solution and were allowed to equilibrate for 4, 7, 14, 21 or 28 days at 37 °C. Equibiaxial tensile tests were performed to study the changes of elastic properties of elastin due to glycation. Significant decreases in tissue dimension were observed after 7 days glucose incubation. Elastin samples treated for 14, 21 or 28 days demonstrate a significant increase in hysteresis in the stress-stretch curves, indicating a greater energy loss due to glucose treatment. Both the longitudinal and the circumferential directions show significant increases in tangent modulus with glucose treatment, however only significant increases are observed after 7 days for the circumferential direction. An eight-chain statistical mechanics based microstructural model was used to study the hyperelastic and orthotropic behavior of the glucose-treated elastin and the material parameters were estimated using a nonlinear least squares method. Material parameters in the model were related to elastin density and fiber orientation, and, hence, the possible microstructural changes in glucose-treated elastin. Estimated material parameters show a general increasing trend in elastin density per unit volume with glucose incubation. The simulation results also indicate that more elastic fibers are aligned in the longitudinal and circumferential directions, rather than in the radial direction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Molecular-level insights into aging processes of skin elastin.

    Science.gov (United States)

    Mora Huertas, Angela C; Schmelzer, Christian E H; Hoehenwarter, Wolfgang; Heyroth, Frank; Heinz, Andrea

    2016-01-01

    Skin aging is characterized by different features including wrinkling, atrophy of the dermis and loss of elasticity associated with damage to the extracellular matrix protein elastin. The aim of this study was to investigate the aging process of skin elastin at the molecular level by evaluating the influence of intrinsic (chronological aging) and extrinsic factors (sun exposure) on the morphology and susceptibility of elastin towards enzymatic degradation. Elastin was isolated from biopsies derived from sun-protected or sun-exposed skin of differently aged individuals. The morphology of the elastin fibers was characterized by scanning electron microscopy. Mass spectrometric analysis and label-free quantification allowed identifying differences in the cleavage patterns of the elastin samples after enzymatic digestion. Principal component analysis and hierarchical cluster analysis were used to visualize differences between the samples and to determine the contribution of extrinsic and intrinsic aging to the proteolytic susceptibility of elastin. Moreover, the release of potentially bioactive peptides was studied. Skin aging is associated with the decomposition of elastin fibers, which is more pronounced in sun-exposed tissue. Marker peptides were identified, which showed an age-related increase or decrease in their abundances and provide insights into the progression of the aging process of elastin fibers. Strong age-related cleavage occurs in hydrophobic tropoelastin domains 18, 20, 24 and 26. Photoaging makes the N-terminal and central parts of the tropoelastin molecules more susceptible towards enzymatic cleavage and, hence, accelerates the age-related degradation of elastin. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Insights into the degradation of human elastin by matrilysin-1

    DEFF Research Database (Denmark)

    Heinz, Andrea; Taddese, Samuel; Sippl, Wolfgang

    2011-01-01

    Human matrilysin-1 (MMP-7) is one of the most potent elastases besides macrophage elastase in the family of matrix metalloproteinases (MMPs). It has been reported to provide macrophages with the highest elastinolytic capacity and plays key roles in diseases such as emphysema and cancer. Describin...... into the degradation of human elastin by MMP-7 and may aid in the development of approaches to treat elastin-degrading diseases.......Human matrilysin-1 (MMP-7) is one of the most potent elastases besides macrophage elastase in the family of matrix metalloproteinases (MMPs). It has been reported to provide macrophages with the highest elastinolytic capacity and plays key roles in diseases such as emphysema and cancer. Describing...... the enzymatic turnover of matrix components helps to understand the molecular basis of disease processes. Hence, in this work, the cleavage behavior of MMP-7 with respect to its natural substrate human elastin was investigated using mass spectrometric (MS) techniques and molecular modeling. Elastin peptides...

  2. Effects of brachytherapy on gene expressions of elastin and elastase

    International Nuclear Information System (INIS)

    Li Junming; Zhou Jingqun; Hu Bin; Li Shuguo

    2004-01-01

    Objective: To study the effects of brachytherapy on the gene expressions of elastin and elastase in cultured rat vascular smooth muscle cells (VSMCs). Methods: Rat VSMCs cultured in DMEM containing 10% FBS were irradiated by 60 Co γ-rays at 0, 7, 14, 28 Gy respectively. Then mRNA levels of elastin and elastase were determined by reverse transcription competitive PCR(RT-PCR). Results: Brachytherapy inhibited the expressions of elastase. Elastase mRNA decreased 25.3% and 50.1% in VSMC irradiated with 14, 28 Gy, respectively (P<0.05). The elastin mRNA level increased 80.7% and 102.3% in VSMC irradiated with 14, 25 Gy, respectively (P<0.05). Conclusion: Brachytherapy inhabits the expressions of elastase and increased elastin in VSMC cells

  3. Does human leukocyte elastase degrade intact skin elastin?

    DEFF Research Database (Denmark)

    Schmelzer, Christian E H; Jung, Michael C; Wohlrab, Johannes

    2012-01-01

    This study aimed to investigate the susceptibility of intact fibrillar human elastin to human leukocyte elastase and cathepsin G. Elastin is a vital protein of the extracellular matrix of vertebrates, and provides exceptional properties including elasticity and tensile strength to many tissues...... and organs, including the aorta, lung, cartilage, elastic ligaments and skin, and is thus critical for their long-term function. Mature elastin is an insoluble and extremely durable protein that undergoes very little turnover, but sustained exposure to proteases may lead to irreversible and severe damage......, and thus to functional loss of the elastic fiber network. Hence, it is a key issue to understand which enzymes actually initiate elastolysis under certain pathological conditions or during intrinsic aging. In this paper, we provide a complete workflow for isolation of pure and intact elastin from very...

  4. Electrospun polydioxanone-elastin blends: potential for bioresorbable vascular grafts

    Energy Technology Data Exchange (ETDEWEB)

    Sell, S A [Virginia Commonwealth University, Richmond, VA 23298 (United States); McClure, M J [Virginia Commonwealth University, Richmond, VA 23298 (United States); Barnes, C P [Virginia Commonwealth University, Richmond, VA 23298 (United States); Knapp, D C [Virginia Commonwealth University, Richmond, VA 23298 (United States); Walpoth, B H [University Hospital, 1211 Geneva 14 (Switzerland); Simpson, D G [Virginia Commonwealth University, Richmond, VA 23298 (United States); Bowlin, G L [Virginia Commonwealth University, Richmond, VA 23298 (United States)

    2006-06-15

    An electrospun cardiovascular graft composed of polydioxanone (PDO) and elastin has been designed and fabricated with mechanical properties to more closely match those of native arterial tissue, while remaining conducive to tissue regeneration. PDO was chosen to provide mechanical integrity to the prosthetic, while elastin provides elasticity and bioactivity (to promote regeneration in vitro/in situ). It is the elastic nature of elastin that dominates the low-strain mechanical response of the vessel to blood flow and prevents pulsatile energy from being dissipated as heat. Uniaxial tensile and suture retention tests were performed on the electrospun grafts to demonstrate the similarities of the mechanical properties between the grafts and native vessel. Dynamic compliance measurements produced values that ranged from 1.2 to 5.6%/100 mmHg for a set of three different mean arterial pressures. Results showed the 50:50 ratio to closely mimic the compliance of native femoral artery, while grafts that contained less elastin exceeded the suture retention strength of native vessel. Preliminary cell culture studies showed the elastin-containing grafts to be bioactive as cells migrated through their full thickness within 7 days, but failed to migrate into pure PDO scaffolds. Electrospinning of the PDO and elastin-blended composite into a conduit for use as a small diameter vascular graft has extreme potential and warrants further investigation as it thus far compares favorably to native vessel.

  5. Comparison of three types of chondrocytes in collagen scaffolds for cartilage tissue engineering

    International Nuclear Information System (INIS)

    Zhang Lu; Spector, Myron

    2009-01-01

    The objective of this study was to compare the chondrogenesis in type I and II collagen scaffolds seeded with chondrocytes from three types of cartilage, after four weeks of culture: auricular (AU), articular (AR) and meniscal (ME). Related aims were to investigate the expression of a contractile muscle actin isoform, α-smooth muscle actin (SMA), in the cells in the scaffold and to determine the presence of a lubricating glycoprotein, lubricin, in the constructs. Adult goat AU, AR and ME chondrocytes were seeded into two types of collagen scaffolds: type II collagen and type I/III collagen. After four weeks of culture, the constructs were prepared for histochemical and immunohistochemical analysis of the distribution of glycosaminoglycan (GAG), types I and II collagen, elastin, SM and lubricin. AU constructs contained substantially more tissue than the AR and ME samples. The AU constructs exhibited neocartilage, but no elastin. There were no notable differences between the type I and II collagen scaffolds. Novel findings were the expression of SMA by the AU cells in the scaffolds and the presence of lubricin in the AR and AU constructs. AU cells have the capability to produce cartilage in collagen scaffolds under conditions in which there is little histogenesis by AR and ME cells.

  6. Comparison of three types of chondrocytes in collagen scaffolds for cartilage tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lu [Department of Plastic and Reconstructive Surgery, Shanghai Tissue Engineering Center, Shanghai 9th People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China); Spector, Myron, E-mail: luzhangmd@gmail.co [Tissue Engineering, VA Boston Healthcare System, Boston, MA (United States)

    2009-08-15

    The objective of this study was to compare the chondrogenesis in type I and II collagen scaffolds seeded with chondrocytes from three types of cartilage, after four weeks of culture: auricular (AU), articular (AR) and meniscal (ME). Related aims were to investigate the expression of a contractile muscle actin isoform, alpha-smooth muscle actin (SMA), in the cells in the scaffold and to determine the presence of a lubricating glycoprotein, lubricin, in the constructs. Adult goat AU, AR and ME chondrocytes were seeded into two types of collagen scaffolds: type II collagen and type I/III collagen. After four weeks of culture, the constructs were prepared for histochemical and immunohistochemical analysis of the distribution of glycosaminoglycan (GAG), types I and II collagen, elastin, SM and lubricin. AU constructs contained substantially more tissue than the AR and ME samples. The AU constructs exhibited neocartilage, but no elastin. There were no notable differences between the type I and II collagen scaffolds. Novel findings were the expression of SMA by the AU cells in the scaffolds and the presence of lubricin in the AR and AU constructs. AU cells have the capability to produce cartilage in collagen scaffolds under conditions in which there is little histogenesis by AR and ME cells.

  7. Elastin in the human intervertebral disk. A histological and biochemical study comparing it with elastin in the human yellow ligament.

    Science.gov (United States)

    Mikawa, Y; Hamagami, H; Shikata, J; Yamamuro, T

    1986-01-01

    The elastic fiber and elastin in the human yellow ligament and intervertebral disk were studied histologically and biochemically. The elastic fiber in the human intervertebral disk, which until now had not been clearly identified microscopically, was observed clearly. We found the distribution of the elastic fiber in the intervertebral disk to be very sparse and irregular, and its diameter was small, being about one-tenth of that found in the yellow ligament. The elastin contents of the yellow ligament and intervertebral disk were 46.7% +/- 0.9% and 1.7% +/- 0.2% respectively (mean +/- SE) of the total dry weight. The amino acid composition of elastin in the yellow ligament is similar to that of other tissue, as reported in the literature; however, that found in the intervertebral disk is significantly different. It would appear, therefore, that the elastin in the intervertebral disk is of a different type from that found elsewhere.

  8. Procyanidins-crosslinked aortic elastin scaffolds with distinctive anti-calcification and biological properties.

    Science.gov (United States)

    Wang, Xiaoya; Zhai, Wanyin; Wu, Chengtie; Ma, Bing; Zhang, Jiamin; Zhang, Hongfeng; Zhu, Ziyan; Chang, Jiang

    2015-04-01

    Elastin, a main component of decellularized extracellular matrices and elastin-containing materials, has been used for tissue engineering applications due to their excellent biocompatibility. However, elastin is easily calcified, leading to the decrease of life span for elastin-based substitutes. How to inhibit the calcification of elastin-based scaffolds, but maintain their good biocompatibility, still remains significantly challenging. Procyanidins (PC) are a type of natural polyphenols with crosslinking ability. To investigate whether pure elastin could be crosslinked by PC with anti-calcification effect, PC was first used to crosslink aortic elastin. Results show that PC can crosslink elastin and effectively inhibit elastin-initiated calcification. Further experiments reveal the possible mechanisms for the anti-calcification of PC crosslinking including (1) inhibiting inflammation cell attachment, and secretion of inflammatory factors such as MMPs and TNF-α, (2) preventing elastin degradation by elastase, and (3) direct inhibition of mineral nucleation in elastin. Moreover, the PC-crosslinked aortic elastin maintains natural structure with high pore volume (1111 μL/g), large pore size (10-300 μm) and high porosity (75.1%) which facilitates recellularization of scaffolds in vivo, and displays excellent hemocompatibility, anti-thrombus and anti-inflammatory potential. The advantages of PC-crosslinked porous aortic elastin suggested that it can serve as a promising scaffold for tissue engineering. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  9. Elastin distribution in the normal uterus, uterine leiomyomas, adenomyosis and adenomyomas: a comparison.

    Science.gov (United States)

    Zheng, Wei-Qiang; Ma, Rong; Zheng, Jian-Ming; Gong, Zhi-Jing

    2006-04-01

    To describe the histologic distribution of elastin in the nonpregnant human uterus, uterine leiomyomas, adenomyosis and adenomyomas. Uteri were obtained from women undergoing hysterectomy for benign conditions, including 26 cases of uterine leiomyomas, 24 cases of adenomyosis, 18 adenomyomas and 6 cases of autopsy specimens. Specific histochemical staining techniques were employed in order to demonstrate the distribution of elastin. The distribution of elastin components in the uterus was markedly uneven and showed a decreasing gradient from outer to inner myometrium. No elastin was present within leiomyomas, adenomyomas or adenomyosis. The distribution of elastin may help explain the normal function of the myometrium in labor. It implies that the uneven distribution of elastin components and absence of elastin within leiomyomas, adenomyomas and adenomyosis could be of some clinical significance. The altered elastin distribution in disease states may help explain such symptoms as dysmenorrhea in uterine endometriosis.

  10. Aortic microcalcification is associated with elastin fragmentation in Marfan syndrome.

    Science.gov (United States)

    Wanga, Shaynah; Hibender, Stijntje; Ridwan, Yanto; van Roomen, Cindy; Vos, Mariska; van der Made, Ingeborg; van Vliet, Nicole; Franken, Romy; van Riel, Luigi Amjg; Groenink, Maarten; Zwinderman, Aeilko H; Mulder, Barbara Jm; de Vries, Carlie Jm; Essers, Jeroen; de Waard, Vivian

    2017-11-01

    Marfan syndrome (MFS) is a connective tissue disorder in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery (elastin fragments play a causal role in aortic calcification in MFS, and that microcalcification serves as a marker for aortic disease severity. To address this hypothesis, we analysed MFS patient and mouse aortas. MFS patient aortic tissue showed enhanced microcalcification in areas with extensive elastic lamina fragmentation in the media. A causal relationship between medial injury and microcalcification was revealed by studies in vascular smooth muscle cells (SMCs); elastin peptides were shown to increase the activity of the calcification marker alkaline phosphatase (ALP) and reduce the expression of the calcification inhibitor matrix GLA protein in human SMCs. In murine Fbn1 C1039G/+ MFS aortic SMCs, Alpl mRNA and activity were upregulated as compared with wild-type SMCs. The elastin peptide-induced ALP activity was prevented by incubation with lactose or a neuraminidase inhibitor, which inhibit the elastin receptor complex, and a mitogen-activated protein kinase kinase-1/2 inhibitor, indicating downstream involvement of extracellular signal-regulated kinase-1/2 (ERK1/2) phosphorylation. Histological analyses in MFS mice revealed macrocalcification in the aortic root, whereas the ascending aorta contained microcalcification, as identified with the near-infrared fluorescent bisphosphonate probe OsteoSense-800. Significantly, microcalcification correlated strongly with aortic diameter, distensibility, elastin breaks, and phosphorylated ERK1/2. In conclusion, microcalcification co-localizes with aortic elastin degradation in MFS aortas of humans and mice, where elastin-derived peptides induce a calcification process in SMCs via the elastin receptor complex and ERK1/2 activation. We propose microcalcification as a novel imaging marker to monitor local elastin degradation and

  11. Serological assessment of neutrophil elastase activity on elastin during lung ECM remodeling.

    Science.gov (United States)

    Kristensen, Jacob H; Karsdal, Morten A; Sand, Jannie Mb; Willumsen, Nicholas; Diefenbach, Claudia; Svensson, Birte; Hägglund, Per; Oersnes-Leeming, Diana J

    2015-05-03

    During the pathological destruction of lung tissue, neutrophil elastase (NE) degrades elastin, one of the major constituents of lung parenchyma. However there are no non-invasive methods to quantify NE degradation of elastin. We selected specific elastin fragments generated by NE for antibody generation and developed an ELISA assay (EL-NE) for the quantification of NE-degraded elastin. Monoclonal antibodies were developed against 10 NE-specific cleavage sites on elastin. One EL-NE assay was tested for analyte stability, linearity and intra- and inter-assay variation. The NE specificity was demonstrated using elastin cleaved in vitro with matrix metalloproteinases (MMPs), cathepsin G (CatG), NE and intact elastin. Clinical relevance was assessed by measuring levels of NE-generated elastin fragments in serum of patients diagnosed with idiopathic pulmonary fibrosis (IPF, n = 10) or lung cancer (n = 40). Analyte recovery of EL-NE for human serum was between 85% and 104%, the analyte was stable for four freeze/thaw cycles and after 24 h storage at 4°C. EL-NE was specific for NE-degraded elastin. Levels of NE-generated elastin fragments for elastin incubated in the presence of NE were 900% to 4700% higher than those seen with CatG or MMP incubation or in intact elastin. Serum levels of NE-generated elastin fragments were significantly increased in patients with IPF (137%, p = 0.002) and in patients with lung cancer (510%, p elastin. The EL-NE assay was able to specifically quantify NE-degraded elastin in serum. Serum levels of NE-degraded elastin might be used to detect excessive lung tissue degradation in lung cancer and IPF.

  12. Monoclonal anti-elastin antibody labelled with technetium-99m

    International Nuclear Information System (INIS)

    Oliveira, Marcia B.N. de; Silva, Claudia R. da; Araujo, Adriano C. de; Bernardo Filho, Mario; Porto, Luis Cristovao M.S.; Gutfilen, Bianca; Souza, J.E.Q.; Frier, Malcolm

    1999-01-01

    Technetium-99m ( 99m Tc) is widely employed in nuclear medicine due to its desirable physical, chemical and biological properties. Moreover, it is easily available and normally is inexpensive. A reducing agent is necessary to label cells and molecules with 99m Tc and stannous chloride (Sn C L 2 ) is usually employed. Elastin is the functional protein component of the elastic fiber and it is related with some diseases such as arteriosclerosis, pulmonary emphysema and others. The present study refers to the preparation of the 99m Tc labeled monoclonal anti-elastin antibody. The monoclonal antibody was incubated with an excess of 2-iminothiolane. The free thiol groups created, were capable of binding with the reduced technetium. Labeling was an exchange reaction with 99m Tc-glucoheptonate. The labeled preparation was left at 4 deg C for one hour. Then, it was passed through a Sephadex G50 column. Various fractions were collected and counted. A peak corresponding to the radiolabeled antibody was obtained. Stability studies of the labelled anti-elastin were performed at 0,3 6, 24 hours, at both 4 deg C or room temperature. The biodistribution pattern of the 99m Tc-anti-elastin was studied in healthy male Swiss mice. The immunoreactivity was also determined. An useful labeled-anti-elastin was obtained to future immunoscintigraphic investigations. (author)

  13. Molecular modeling of protein materials: case study of elastin

    International Nuclear Information System (INIS)

    Tarakanova, Anna; Buehler, Markus J

    2013-01-01

    Molecular modeling of protein materials is a quickly growing area of research that has produced numerous contributions in fields ranging from structural engineering to medicine and biology. We review here the history and methods commonly employed in molecular modeling of protein materials, emphasizing the advantages for using modeling as a complement to experimental work. We then consider a case study of the protein elastin, a critically important ‘mechanical protein’ to exemplify the approach in an area where molecular modeling has made a significant impact. We outline the progression of computational modeling studies that have considerably enhanced our understanding of this important protein which endows elasticity and recoil to the tissues it is found in, including the skin, lungs, arteries and the heart. A vast collection of literature has been directed at studying the structure and function of this protein for over half a century, the first molecular dynamics study of elastin being reported in the 1980s. We review the pivotal computational works that have considerably enhanced our fundamental understanding of elastin's atomistic structure and its extraordinary qualities—focusing on two in particular: elastin's superb elasticity and the inverse temperature transition—the remarkable ability of elastin to take on a more structured conformation at higher temperatures, suggesting its effectiveness as a biomolecular switch. Our hope is to showcase these methods as both complementary and enriching to experimental approaches that have thus far dominated the study of most protein-based materials. (topical review)

  14. Elastin hydrolysate derived from fish enhances proliferation of human skin fibroblasts and elastin synthesis in human skin fibroblasts and improves the skin conditions.

    Science.gov (United States)

    Shiratsuchi, Eri; Nakaba, Misako; Yamada, Michio

    2016-03-30

    Recent studies have shown that certain peptides significantly improve skin conditions, such as skin elasticity and the moisture content of the skin of healthy woman. This study aimed to investigate the effects of elastin hydrolysate on human skin. Proliferation and elastin synthesis were evaluated in human skin fibroblasts exposed to elastin hydrolysate and proryl-glycine (Pro-Gly), which is present in human blood after elastin hydrolysate ingestion. We also performed an ingestion test with elastin hydrolysate in humans and evaluated skin condition. Elastin hydrolysate and Pro-Gly enhanced the proliferation of fibroblasts and elastin synthesis. Maximal proliferation response was observed at 25 ng mL(-1) Pro-Gly. Ingestion of elastin hydrolysate improved skin condition, such as elasticity, number of wrinkles, and blood flow. Elasticity improved by 4% in the elastin hydrolysate group compared with 2% in the placebo group. Therefore, elastin hydrolysate activates human skin fibroblasts and has beneficial effects on skin conditions. © 2015 Society of Chemical Industry.

  15. Serological assessment of neutrophil elastase activity on elastin during lung ECM remodeling

    DEFF Research Database (Denmark)

    Kristensen, Jacob Hull; Karsdal, Morten A.; Sand, Jannie M. B.

    2015-01-01

    Background: During the pathological destruction of lung tissue, neutrophil elastase (NE) degrades elastin, one of the major constituents of lung parenchyma. However there are no non-invasive methods to quantify NE degradation of elastin. We selected specific elastin fragments generated by NE for ...

  16. Design of an elastin-layered dermal regeneration template.

    Science.gov (United States)

    Mithieux, Suzanne M; Weiss, Anthony S

    2017-04-01

    We demonstrate a novel approach for the production of tunable quantities of elastic fibers. We also show that exogenous tropoelastin is rate-limiting for elastin synthesis regardless of the age of the dermal fibroblast donor. Additionally, we provide a strategy to further enhance synthesis by older cells through the application of conditioned media. We show that this approach delivers an elastin layer on one side of the leading dermal repair template for contact with the deep dermis in order to deliver prefabricated elastic fibers to a physiologically appropriate site during subsequent surgery. This system is attractive because it provides for the first time a viable path for sufficient, histologically detectable levels of patient elastin into full-thickness wound sites that have until now lacked this elastic underlayer. The scars of full thickness wounds typically lack elasticity. Elastin is essential for skin elasticity and is enriched in the deep dermis. This paper is significant because it shows that: (1) we can generate elastic fibers in tunable quantities, (2) tropoelastin is the rate-limiting component in elastin synthesis in vitro, (3) we can generate elastin fibers regardless of donor age, (4) we describe a novel approach to further increase the numbers and thickness of elastic fibers for older donors, (5) we improve on Integra Dermal Regeneration Template and generate a new hybrid biomaterial intended to subsequently surgically deliver these elastic fibers, (6) the elastic fiber layer is presented on the side of Integra that is intended for delivery into its physiologically appropriate site i.e. the deep dermis. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Preparation of alpha-elastin nanoparticles by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Mari [Department of Biological Science, Graduate school of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan); Okamoto, Kouji [Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502 (Japan); Furuta, Masakazu [Department of Biological Science, Graduate school of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan)], E-mail: mfuruta@b.s.osakafu-u.ac.jp

    2009-12-15

    Nanoparticles were prepared by utilizing the thermosensitive aggregation of alpha-elastin and gamma ray crosslinking. Three different heating process, 'Slow heating', 'Fast heating', and 'Heat shock', were applied for the aggregation of the alpha-elastin and examined to yield nanoparticles by gamma rays crosslinking. As a result, only 'Slow heating' process yielded nanoparticles with diameters of about ca. 300 nm above cloud point (CP) and about ca. 100 nm below CP, and a narrow size distribution above 1.0 mg/ml concentration (exclude 1.0 mg/ml)

  18. Preparation of alpha-elastin nanoparticles by gamma irradiation

    International Nuclear Information System (INIS)

    Fujimoto, Mari; Okamoto, Kouji; Furuta, Masakazu

    2009-01-01

    Nanoparticles were prepared by utilizing the thermosensitive aggregation of alpha-elastin and gamma ray crosslinking. Three different heating process, 'Slow heating', 'Fast heating', and 'Heat shock', were applied for the aggregation of the alpha-elastin and examined to yield nanoparticles by gamma rays crosslinking. As a result, only 'Slow heating' process yielded nanoparticles with diameters of about ca. 300 nm above cloud point (CP) and about ca. 100 nm below CP, and a narrow size distribution above 1.0 mg/ml concentration (exclude 1.0 mg/ml).

  19. Vascular nanomedicine: Site specific delivery of elastin stabilizing therapeutics to damaged arteries

    Science.gov (United States)

    Sinha, Aditi

    Elastin, a structural protein in the extra-cellular matrix, plays a critical role in the normal functioning of blood vessels. Apart from performing its primary function of providing resilience to arteries, it also plays major role in regulating cell-cell and cell-matrix interactions, response to injury, and morphogenesis. Medial arterial calcification (MAC) and abdominal aortic aneurysm (AAA) are two diseases where the structural and functional integrity of elastin is severely compromised. Although the clinical presentation of MAC and AAA differ, they have one common underlying causative mechanism---pathological degradation of elastin. Hence prevention of elastin degradation in the early stages of MAC and AAA can mitigate, partially if not wholly, the fatal consequences of both the diseases. The work presented here is motivated by the overwhelming statistics of people afflicted by elastin associated cardiovascular diseases and the unavailability of cure for the same. Overall goal of our research is to understand role of elastin degradation in cardiovascular diseases and to develop a targeted vascular drug delivery system that is minimally invasive, biodegradable, and non-toxic, that prevents elastin from degradation. Our hope is that such treatment will also help regenerate elastin, thereby providing a multi-fold treatment option for elasto-degenerative vascular diseases. For this purpose, we have first confirmed the combined role of degraded elastin and hyperglycemia in the pathogenesis of MAC. We have shown that in the absence of degraded elastin and TGF-beta1 (abundantly present in diabetic arteries) vascular smooth muscle cells maintain their homeostatic state, regardless of environmental glucose concentrations. However simultaneous exposure to glucose, elastin peptides and TGF-beta1 causes the pathological transgenesis of vascular cells to osteoblast-like cells. We show that plant derived polyphenols bind to vascular elastin with great affinity resulting in

  20. Elastin aging and lipid oxidation products in human aorta

    Directory of Open Access Journals (Sweden)

    Kamelija Zarkovic

    2015-04-01

    Full Text Available Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA, (4-hydroxynonenal, malondialdehyde, acrolein, form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development.

  1. Processing and characterization of α-elastin electrospun membranes

    Science.gov (United States)

    Araujo, J.; Padrão, J.; Silva, J. P.; Dourado, F.; Correia, D. M.; Botelho, G.; Gomez Ribelles, J. L.; Lanceros-Méndez, S.; Sencadas, V.

    2014-06-01

    Elastin isolated from fresh bovine ligaments was dissolved in a mixture of 1,1,1,3,3,3-Hexafluoro-2-propanol and water were electrospun into fiber membranes under different processing conditions. Fiber mats of randomly and aligned fibers were obtained with fixed and rotating ground collectors and fibrils were composed by thin ribbons whose width depends on electrospinning conditions; fibrils with 721 nm up to 2.12 μm width were achieved. After cross-linking with glutaraldehyde, α-elastin can uptake as much as 1700 % of PBS solution and a slight increase on fiber thickness was observed. The glass transition temperature of electrospun fiber mats was found to occur at ˜80 °C. Moreover, α-Elastin showed to be a perfect elastomeric material, and no mechanical hysteresis was found in cycle mechanical measurements. The elastic modulus obtained for random and aligned fibers mats in a PBS solution was 330±10 kPa and 732±165 kPa, respectively. Finally, the electrospinning and cross-linking process does not inhibit MC-3T3-E1 cell adhesion. Cell culture results showed good cell adhesion and proliferation in the cross-linked elastin fiber mats.

  2. Computational smart polymer design based on elastin protein mutability.

    Science.gov (United States)

    Tarakanova, Anna; Huang, Wenwen; Weiss, Anthony S; Kaplan, David L; Buehler, Markus J

    2017-05-01

    Soluble elastin-like peptides (ELPs) can be engineered into a range of physical forms, from hydrogels and scaffolds to fibers and artificial tissues, finding numerous applications in medicine and engineering as "smart polymers". Elastin-like peptides are attractive candidates as a platform for novel biomaterial design because they exhibit a highly tunable response spectrum, with reversible phase transition capabilities. Here, we report the design of the first virtual library of elastin-like protein models using methods for enhanced sampling to study the effect of peptide chemistry, chain length, and salt concentration on the structural transitions of ELPs, exposing associated molecular mechanisms. We describe the behavior of the local molecular structure under increasing temperatures and the effect of peptide interactions with nearest hydration shell water molecules on peptide mobility and propensity to exhibit structural transitions. Shifts in the magnitude of structural transitions at the single-molecule scale are explained from the perspective of peptide-ion-water interactions in a library of four unique elastin-like peptide systems. Predictions of structural transitions are subsequently validated in experiment. This library is a valuable resource for recombinant protein design and synthesis as it elucidates mechanisms at the single-molecule level, paving a feedback path between simulation and experiment for smart material designs, with applications in biomedicine and diagnostic devices. Copyright © 2017. Published by Elsevier Ltd.

  3. A cytokine axis regulates elastin formation and degradation

    Science.gov (United States)

    Sproul, Erin P.; Argraves, W. Scott

    2013-01-01

    Underlying the dynamic regulation of tropoelastin expression and elastin formation in development and disease are transcriptional and post-transcriptional mechanisms that have been the focus of much research. Of particular importance is the cytokine–governed elastin regulatory axis in which the pro-elastogenic activities of transforming growth factor β-1 (TGFβ1) and insulin-like growth factor-I (IGF-I) are opposed by anti-elastogenic activities of basic fibroblast growth factor (bFGF/FGF-2), heparin-binding epidermal growth factor-like growth factor (HB-EGF), EGF, PDGF-BB, TGFα, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and noncanonical TGFβ1 signaling. A key mechanistic feature of the regulatory axis is that cytokines influence elastin formation through effects on the cell cycle involving control of cyclin–cyclin dependent kinase complexes and activation of the Ras/MEK/ERK signaling pathway. In this article we provide an overview of the major cytokines/growth factors that modulate elastogenesis and describe the underlying molecular mechanisms for their action on elastin production. PMID:23160093

  4. Quantitative comparison of structure and dynamics of elastin following three isolation schemes by 13C solid state NMR and MALDI mass spectrometry.

    Science.gov (United States)

    Papaioannou, A; Louis, M; Dhital, B; Ho, H P; Chang, E J; Boutis, G S

    2015-05-01

    Methods for isolating elastin from fat, collagen, and muscle, commonly used in the design of artificial elastin based biomaterials, rely on exposing tissue to harsh pH levels and temperatures that usually denature many proteins. At present, a quantitative measurement of the modifications to elastin following isolation from other extracellular matrix constituents has not been reported. Using magic angle spinning (13)C NMR spectroscopy and relaxation methodologies, we have measured the modification in structure and dynamics following three known purification protocols. Our experimental data reveal that the (13)C spectra of the hydrated samples appear remarkably similar across the various purification methods. Subtle differences in the half maximum widths were observed in the backbone carbonyl suggesting possible structural heterogeneity across the different methods of purification. Additionally, small differences in the relative signal intensities were observed between purified samples. Lyophilizing the samples results in a reduction of backbone motion and reveals additional differences across the purification methods studied. These differences were most notable in the alanine motifs indicating possible changes in cross-linking or structural rigidity. The measured correlation times of glycine and proline moieties are observed to also vary considerably across the different purification methods, which may be related to peptide bond cleavage. Lastly, the relative concentration of desmosine cross-links in the samples quantified by MALDI mass spectrometry is reported. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Fibrillar, fibril-associated and basement membrane collagens of the arterial wall: architecture, elasticity and remodeling under stress.

    Science.gov (United States)

    Osidak, M S; Osidak, E O; Akhmanova, M A; Domogatsky, S P; Domogatskaya, A S

    2015-01-01

    The ability of a human artery to pass through 150 million liters of blood sustaining 2 billion pulsations of blood pressure with minor deterioration depends on unique construction of the arterial wall. Viscoelastic properties of this construction enable to re-seal the occuring damages apparently without direct immediate participance of the constituent cells. Collagen structures are considered to be the elements that determine the mechanoelastic properties of the wall in parallel with elastin responsible for elasticity and resilience. Collagen scaffold architecture is the function-dependent dynamic arrangement of a dozen different collagen types composing three distinct interacting forms inside the extracellular matrix of the wall. Tightly packed molecules of collagen types I, III, V provide high tensile strength along collagen fibrils but toughness of the collagen scaffold as a whole depends on molecular bonds between distinct fibrils. Apart of other macromolecules in the extracellular matrix (ECM), collagen-specific interlinks involve microfilaments of collagen type VI, meshwork-organized collagen type VIII, and FACIT collagen type XIV. Basement membrane collagen types IV, XV, XVIII and cell-associated collagen XIII enable transmission of mechanical signals between cells and whole artery matrix. Collagen scaffold undergoes continuous remodeling by decomposition promoted with MMPs and reconstitution from newly produced collagen molecules. Pulsatile stress-strain load modulates both collagen synthesis and MMP-dependent collagen degradation. In this way the ECM structure becomes adoptive to mechanical challenges. The mechanoelastic properties of the arterial wall are changed in atherosclerosis concomitantly with collagen turnover both type-specific and dependent on the structure. Improving the feedback could be another approach to restore sufficient blood circulation.

  6. Use of versican variant V3 and versican antisense expression to engineer cultured human skin containing increased content of insoluble elastin.

    Science.gov (United States)

    Merrilees, Mervyn J; Falk, Ben A; Zuo, Ning; Dickinson, Michelle E; May, Barnaby C H; Wight, Thomas N

    2017-01-01

    Skin substitutes for repair of dermal wounds are deficient in functional elastic fibres. We report that the content of insoluble elastin in the dermis of cultured human skin can be increased though the use of two approaches that enhance elastogenesis by dermal fibroblasts, forced expression of versican variant V3, which lacks glycosaminoglycan (GAG) chains, and forced expression of versican antisense to decrease levels of versican variant V1 with GAG chains. Human dermal fibroblasts transduced with V3 or anti-versican were cultured under standard conditions over a period of 4 weeks to produce dermal sheets, with growth enhanced though multiple seedings for the first 3 weeks. Human keratinocytes, cultured in supplemented media, were added to the 4-week dermal sheets and the skin layer cultured for a further week. At 5 weeks, keratinocytes were multilayered and differentiated, with desmosome junctions thoughout and keratin deposits in the upper squamous layers. The dermal layer was composed of layered fibroblasts surrounded by extracellular matrix of collagen bundles and, in control cultures, small scattered elastin deposits. Forced expression of V3 and versican antisense slowed growth, decreased versican V1 expression, increased tropoelastin expression and/or the deposition of large aggregates of insoluble elastin in the dermal layer, and increased tissue stiffness, as measured by nano-indentation. Skin sheets were also cultured on Endoform Dermal Template™, the biodegradable wound dressing made from the lamina propria of sheep foregut. Skin structure and the enhanced deposition of elastin by forced expression of V3 and anti-versican were preserved on this supportive substrate. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Enhanced elastin synthesis and maturation in human vascular smooth muscle tissue derived from induced-pluripotent stem cells.

    Science.gov (United States)

    Eoh, Joon H; Shen, Nian; Burke, Jacqueline A; Hinderer, Svenja; Xia, Zhiyong; Schenke-Layland, Katja; Gerecht, Sharon

    2017-04-01

    Obtaining vascular smooth muscle tissue with mature, functional elastic fibers is a key obstacle in tissue-engineered blood vessels. Poor elastin secretion and organization leads to a loss of specialization in contractile smooth muscle cells, resulting in over proliferation and graft failure. In this study, human induced-pluripotent stem cells (hiPSCs) were differentiated into early smooth muscle cells, seeded onto a hybrid poly(ethylene glycol) dimethacrylate/poly (l-lactide) (PEGdma-PLA) scaffold and cultured in a bioreactor while exposed to pulsatile flow, towards maturation into contractile smooth muscle tissue. We evaluated the effects of pulsatile flow on cellular organization as well as elastin expression and assembly in the engineered tissue compared to a static control through immunohistochemistry, gene expression and functionality assays. We show that culturing under pulsatile flow resulted in organized and functional hiPSC derived smooth muscle tissue. Immunohistochemistry analysis revealed hiPSC-smooth muscle tissue with robust, well-organized cells and elastic fibers and the supporting microfibril proteins necessary for elastic fiber assembly. Through qRT-PCR analysis, we found significantly increased expression of elastin, fibronectin, and collagen I, indicating the synthesis of necessary extracellular matrix components. Functionality assays revealed that hiPSC-smooth muscle tissue cultured in the bioreactor had an increased calcium signaling and contraction in response to a cholinergic agonist, significantly higher mature elastin content and improved mechanical properties in comparison to the static control. The findings presented here detail an effective approach to engineering elastic human vascular smooth muscle tissue with the functionality necessary for tissue engineering and regenerative medicine applications. Obtaining robust, mature elastic fibers is a key obstacle in tissue-engineered blood vessels. Human induced-pluripotent stem cells have

  8. Alternative Splicing and Tissue-specific Elastin Misassembly Act as Biological Modifiers of Human Elastin Gene Frameshift Mutations Associated with Dominant Cutis Laxa*

    Science.gov (United States)

    Sugitani, Hideki; Hirano, Eiichi; Knutsen, Russell H.; Shifren, Adrian; Wagenseil, Jessica E.; Ciliberto, Christopher; Kozel, Beth A.; Urban, Zsolt; Davis, Elaine C.; Broekelmann, Thomas J.; Mecham, Robert P.

    2012-01-01

    Elastin is the extracellular matrix protein in vertebrates that provides elastic recoil to blood vessels, the lung, and skin. Because the elastin gene has undergone significant changes in the primate lineage, modeling elastin diseases in non-human animals can be problematic. To investigate the pathophysiology underlying a class of elastin gene mutations leading to autosomal dominant cutis laxa, we engineered a cutis laxa mutation (single base deletion) into the human elastin gene contained in a bacterial artificial chromosome. When expressed as a transgene in mice, mutant elastin was incorporated into elastic fibers in the skin and lung with adverse effects on tissue function. In contrast, only low levels of mutant protein incorporated into aortic elastin, which explains why the vasculature is relatively unaffected in this disease. RNA stability studies found that alternative exon splicing acts as a modifier of disease severity by influencing the spectrum of mutant transcripts that survive nonsense-mediated decay. Our results confirm the critical role of the C-terminal region of tropoelastin in elastic fiber assembly and suggest tissue-specific differences in the elastin assembly pathway. PMID:22573328

  9. Basic components of connective tissues and extracellular matrix: elastin, fibrillin, fibulins, fibrinogen, fibronectin, laminin, tenascins and thrombospondins.

    Science.gov (United States)

    Halper, Jaroslava; Kjaer, Michael

    2014-01-01

    Collagens are the most abundant components of the extracellular matrix and many types of soft tissues. Elastin is another major component of certain soft tissues, such as arterial walls and ligaments. Many other molecules, though lower in quantity, function as essential components of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its muldomain structure plays a role of "master organizer" in matrix assembly as it forms a bridge between cell surface receptors, e.g., integrins, and compounds such collagen, proteoglycans and other focal adhesion molecules. It also plays an essential role in the assembly of fibrillin-1 into a structured network. Laminins contribute to the structure of the extracellular matrix (ECM) and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin by thrombin, it also binds to a variety of compounds, particularly to various growth factors, and as such fibrinogen is a player in cardiovascular and extracellular matrix physiology. Elastin, an insoluble polymer of the monomeric soluble precursor tropoelastin, is the main component of elastic fibers in matrix tissue where it provides elastic recoil and resilience to a variety of connective tissues, e.g., aorta and ligaments. Elastic fibers regulate activity of TGFβs through their association with fibrillin microfibrils. Elastin also plays a role in cell adhesion, cell migration, and has the ability to participate in cell signaling. Mutations in the elastin gene lead to cutis laxa. Fibrillins represent the predominant core of the microfibrils in elastic as well as non

  10. High-performance liquid chromatographic quantitation of desmosine plus isodesmosine in elastin and whole tissue hydrolysates

    International Nuclear Information System (INIS)

    Soskel, N.T.

    1987-01-01

    Quantitation of desmosine and isodesmosine, the major crosslinks in elastin, has been of interest because of their uniqueness and use as markers of that protein. Accurate measurement of these crosslinks may allow determination of elastin degradation in vivo and elastin content in tissues, obviating lengthy extraction procedures. We have developed a method of quantitating desmosine plus isodesmosine in hydrolysates of tissue and insoluble elastin using high-performance liquid chromatographic separation and absorbance detection that is rapid (21-35 min) and sensitive (accurate linearity from 100 pmol to 5 nmol). This method has been used to quantitate desmosines in elastin from bovine nuchal ligament and lung and in whole aorta from hamsters. The ability to completely separate [ 3 H]lysine from desmosine plus isodesmosine allows the method to be used to study incorporation of lysine into crosslinks in elastin

  11. 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...

  12. Transmural variation in elastin fiber orientation distribution in the arterial wall.

    Science.gov (United States)

    Yu, Xunjie; Wang, Yunjie; Zhang, Yanhang

    2018-01-01

    The complex three-dimensional elastin network is a major load-bearing extracellular matrix (ECM) component of an artery. Despite the reported anisotropic behavior of arterial elastin network, it is usually treated as an isotropic material in constitutive models. Our recent multiphoton microscopy study reported a relatively uniform elastin fiber orientation distribution in porcine thoracic aorta when imaging from the intima side (Chow et al., 2014). However it is questionable whether the fiber orientation distribution obtained from a small depth is representative of the elastin network structure in the arterial wall, especially when developing structure-based constitutive models. To date, the structural basis for the anisotropic mechanical behavior of elastin is still not fully understood. In this study, we examined the transmural variation in elastin fiber orientation distribution in porcine thoracic aorta and its association with elastin anisotropy. Using multi-photon microscopy, we observed that the elastin fibers orientation changes from a relatively uniform distribution in regions close to the luminal surface to a more circumferential distribution in regions that dominate the media, then to a longitudinal distribution in regions close to the outer media. Planar biaxial tensile test was performed to characterize the anisotropic behavior of elastin network. A new structure-based constitutive model of elastin network was developed to incorporate the transmural variation in fiber orientation distribution. The new model well captures the anisotropic mechanical behavior of elastin network under both equi- and nonequi-biaxial loading and showed improvements in both fitting and predicting capabilities when compared to a model that only considers the fiber orientation distribution from the intima side. We submit that the transmural variation in fiber orientation distribution is important in characterizing the anisotropic mechanical behavior of elastin network and

  13. Mechanical contribution of lamellar and interlamellar elastin along the mouse aorta.

    Science.gov (United States)

    Clark, T E; Lillie, M A; Vogl, A W; Gosline, J M; Shadwick, R E

    2015-10-15

    The mechanical properties of aortic elastin vary regionally, but the microstructural basis for this variation is unknown. This study was designed to identify the relative contributions of lamellar and interlamellar elastin to circumferential load bearing in the mouse thoracic and abdominal aortas. Forces developed in uniaxial tests of samples of fresh and autoclaved aorta were correlated with elastin content and morphology obtained from histology and multiphoton laser scanning microscopy. Autoclaving should render much of the interlamellar elastin mechanically incompetent. In autoclaved tissue force per unit sample width correlated with lamellar elastin content (P≪0.001) but not total elastin content. In fresh tissue at low strain where elastin dominates the mechanical response, forces were higher than in the autoclaved tissue, but force did not correlate with total elastin content. Therefore although interlamellar elastin likely contributed to the stiffness in the fresh aorta, its contribution appeared not in proportion to its quantity. In both fresh and autoclaved tissue, elastin stiffness consistently decreased along the abdominal aorta, a key area for aneurysm development, and this difference could not be fully accounted for on the basis of either lamellar or total elastin content. These findings are relevant to the development of mathematical models of arterial mechanics, particularly for mouse models of arterial diseases involving elastic tissue. In microstructural based models the quantity of each mural constituent determines its contribution to the total response. This study shows elastin's mechanical response cannot necessarily be accounted for on the basis of fibre quantity, orientation, and modulus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Measurement of MMP-9 and -12 degraded elastin (ELM) provides unique information on lung tissue degradation

    DEFF Research Database (Denmark)

    Skjøt-Arkil, Helene; Clausen, Rikke E; Nguyen, Quoc Hai Trieu

    2012-01-01

    Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part...... are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases....

  15. Induction and regulation of murine emphysema by elastin peptides.

    Science.gov (United States)

    Sellami, Mehdi; Meghraoui-Kheddar, Aïda; Terryn, Christine; Fichel, Caroline; Bouland, Nicole; Diebold, Marie-Daniele; Guenounou, Moncef; Héry-Huynh, Stéphanie; Le Naour, Richard

    2016-01-01

    Emphysema is the major component of chronic obstructive pulmonary disease (COPD). During emphysema, elastin breakdown in the lung tissue originates from the release of large amounts of elastase by inflammatory cells. Elevated levels of elastin-derived peptides (EP) reflect massive pulmonary elastin breakdown in COPD patients. Only the EP containing the GXXPG conformational motif with a type VIII β-turn are elastin receptor ligands inducing biological activities. In addition, the COOH-terminal glycine residue of the GXXPG motif seems a prerequisite to the biological activity. In this study, we endotracheally instilled C57BL/6J mice with GXXPG EP and/or COOH-terminal glycine deleted-EP whose sequences were designed by molecular dynamics and docking simulations. We investigated their effect on all criteria associated with the progression of murine emphysema. Bronchoalveolar lavages were recovered to analyze cell profiles by flow cytometry and lungs were prepared to allow morphological and histological analysis by immunostaining and confocal microscopy. We observed that exposure of mice to EP elicited hallmark features of emphysema with inflammatory cell accumulation associated with increased matrix metalloproteinases and desmosine expression and of remodeling of parenchymal tissue. We also identified an inactive COOH-terminal glycine deleted-EP that retains its binding-activity to EBP and that is able to inhibit the in vitro and in vivo activities of emphysema-inducing EP. This study demonstrates that EP are key actors in the development of emphysema and that they represent pharmacological targets for an alternative treatment of emphysema based on the identification of EP analogous antagonists by molecular modeling studies. Copyright © 2016 the American Physiological Society.

  16. Elastin aging and lipid oxidation products in human aorta.

    Science.gov (United States)

    Zarkovic, Kamelija; Larroque-Cardoso, Pauline; Pucelle, Mélanie; Salvayre, Robert; Waeg, Georg; Nègre-Salvayre, Anne; Zarkovic, Neven

    2015-01-01

    Vascular aging is associated with structural and functional modifications of the arteries, and by an increase in arterial wall thickening in the intima and the media, mainly resulting from structural modifications of the extracellular matrix (ECM) components. Among the factors known to accumulate with aging, advanced lipid peroxidation end products (ALEs) are a hallmark of oxidative stress-associated diseases such as atherosclerosis. Aldehydes generated from the peroxidation of polyunsaturated fatty acids (PUFA), (4-hydroxynonenal, malondialdehyde, acrolein), form adducts on cellular proteins, leading to a progressive protein dysfunction with consequences in the pathophysiology of vascular aging. The contribution of these aldehydes to ECM modification is not known. This study was carried out to investigate whether aldehyde-adducts are detected in the intima and media in human aorta, whether their level is increased in vascular aging, and whether elastin fibers are a target of aldehyde-adduct formation. Immunohistological and confocal immunofluorescence studies indicate that 4-HNE-histidine-adducts accumulate in an age-related manner in the intima, media and adventitia layers of human aortas, and are mainly expressed in smooth muscle cells. In contrast, even if the structure of elastin fiber is strongly altered in the aged vessels, our results show that elastin is not or very poorly modified by 4-HNE. These data indicate a complex role for lipid peroxidation and in particular for 4-HNE in elastin homeostasis, in the vascular wall remodeling during aging and atherosclerosis development. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Circulating Anti-Elastin Antibody Levels and Arterial Disease Characteristics: Associations with Arterial Stiffness and Atherosclerosis.

    Science.gov (United States)

    Lee, Seung-Hyun; Shin, Kihyuk; Park, Sungha; Kang, Seok-Min; Choi, Donghoon; Lee, Seung-Hyo; Lee, Sang-Hak

    2015-11-01

    Elastin is a major arterial structural protein, and elastin-derived peptides are related to arterial change. We previously reported on a novel assay developed using aortic elastin peptides; however, its clinical implications remain unclear. In this study, we assessed whether anti-elastin antibody titers reflect the risk of coronary artery disease (CAD) or its characteristics. We included 174 CAD patients and 171 age- and sex-matched controls. Anti-elastin antibody titers were quantified by enzyme-linked immunosorbent assay. Parameters of arterial stiffness, including the augmentation index (AI) and heart-to-femoral pulse wave velocity (hfPWV), were measured non-invasively. The clinical and angiographic characteristics of CAD patients were also evaluated. Associations between anti-elastin levels and vascular characteristics were examined by linear regression analysis. The median blood level of anti-elastin was significantly lower in the CAD group than in the controls [197 arbitrary unit (a.u.) vs. 63 a.u., pelastin were significantly lower in men and in subjects with hypertension, diabetes mellitus, hyperlipidemia, or high hfPWV. Nevertheless, anti-elastin levels were not dependent on atherothrombotic events or the angiographic severity of CAD. In a multivariate analysis, male sex (β=-0.38, pelastin levels. Lower levels of anti-elastin are related to CAD. The association between antibody titers and CAD is linked to arterial stiffness rather than the advancement of atherosclerosis.

  18. Elastin structure and its involvement in skin photoageing.

    Science.gov (United States)

    Weihermann, A C; Lorencini, M; Brohem, C A; de Carvalho, C M

    2017-06-01

    Skin aging is a complex process that may be caused by factors that are intrinsic and extrinsic to the body. Ultraviolet (UV) radiation represents one of the main sources of skin damage over the years and characterizes a process known as photoaging. Among the changes that affect cutaneous tissue with age, the loss of elastic properties caused by changes in elastin production, increased degradation and/or processing produces a substantial impact on tissue esthetics and health. The occurrence of solar elastosis is one of the main markers of cutaneous photoaging and is characterized by disorganized and non-functional deposition of elastic fibers. The occurrence of UV radiation-induced alternative splicing of the elastin gene, which leads to inadequate synthesis of the proteins required for the correct assembly of elastic fibers, is a potential explanation for this phenomenon. Innovative studies have been fundamental for the elucidation of rarely explored photoaging mechanisms and have enabled the identification of effective therapeutic alternatives such as cosmetic products. This review addresses cutaneous photoaging and the changes that affect elastin in this process. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. 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...

  20. Dimerization effects on coacervation property of an elastin-derived synthetic peptide (FPGVG)5.

    Science.gov (United States)

    Suyama, Keitaro; Taniguchi, Suguru; Tatsubo, Daiki; Maeda, Iori; Nose, Takeru

    2016-04-01

    Elastin, a core protein of the elastic fibers, exhibits the coacervation (temperature-dependent reversible association/dissociation) under physiological conditions. Because of this characteristic, elastin and elastin-derived peptides have been considered to be useful as base materials for developing various biomedical products, skin substitutes, synthetic vascular grafts, and drug delivery systems. Although elastin-derived polypeptide (Val-Pro-Gly-Val-Gly)n also has been known to demonstrate coacervation property, a sufficiently high (VPGVG)n repetition number (n>40) is required for coacervation. In the present study, a series of elastin-derived peptide (Phe-Pro-Gly-Val-Gly)5 dimers possessing high coacervation potential were newly developed. These novel dimeric peptides exhibited coacervation at significantly lower concentrations and temperatures than the commonly used elastin-derived peptide analogs; this result suggests that the coacervation ability of the peptides is enhanced by dimerization. Circular dichroism (CD) measurements indicate that the dimers undergo similar temperature-dependent and reversible conformational changes when coacervation occurs. The molecular dynamics calculation results reveal that the sheet-turn-sheet motif involving a type II β-turn-like structure commonly observed among the dimers and caused formation of globular conformation of them. These synthesized peptide dimers may be useful not only as model peptides for structural analysis of elastin and elastin-derived peptides, but also as base materials for developing various temperature-sensitive biomedical and industrial products. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  1. Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders.

    Science.gov (United States)

    Kristensen, J H; Larsen, L; Dasgupta, B; Brodmerkel, C; Curran, M; Karsdal, M A; Sand, J M B; Willumsen, N; Knox, A J; Bolton, C E; Johnson, S R; Hägglund, P; Svensson, B; Leeming, D J

    2015-11-01

    Elastin is a signature protein of the lungs. Matrix metalloproteinase-7 (MMP-7) is important in lung defence mechanisms and degrades elastin. However, MMP-7 activity in regard to elastin degradation has never been quantified serologically in patients with lung diseases. An assay for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer. Monoclonal antibodies (mABs) were raised against eight carefully selected MMP-7 cleavage sites on elastin. After characterisation and validation of the mABs, one mAB targeting the ELM7 fragment was chosen. ELM7 fragment levels were assessed in serum samples from patients diagnosed with IPF (n=123, baseline samples, CTgov reg. NCT00786201), and lung cancer (n=40) and compared with age- and sex-matched controls. The ELM7 assay was specific towards in vitro MMP-7 degraded elastin and the ELM7 neoepitope but not towards other MMP-7 derived elastin fragments. Serum ELM7 levels were significantly increased in IPF (113%, pelastin fragments can be quantified in serum and may reflect pathological lung tissue turnover in several important lung diseases. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  2. Elastin cross-linking in the skin from patients with amyotrophic lateral sclerosis

    Science.gov (United States)

    Ono, S.; Yamauchi, M.

    1994-01-01

    Two cross-links unique to elastin, desmosine and isodesmosine were measured and compared in skin tissue (left upper arm) from 10 patients with amyotrophic lateral sclerosis (ALS) and from seven age-matched controls. The contents of desmosine and isodesmosine were significantly decreased (p elastin is affected in ALS.

  3. Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders

    DEFF Research Database (Denmark)

    Kristensen, J.H.; Larsen, L.; Dasgupta, B.

    2015-01-01

    for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer. Design and methods:  Monoclonal antibodies (mABs) were raised against eight carefully selected...

  4. Elastins from patients with Williams-Beuren syndrome and healthy individuals differ on the molecular level

    DEFF Research Database (Denmark)

    Heinz, Andrea; Huertas, Angela C Mora; Schräder, Christoph U

    2016-01-01

    Williams-Beuren syndrome (WBS) is a congenital disorder, which involves the heterozygous deletion of the elastin gene and other genes on chromosome 7. Clinical symptoms that are associated with hemizygosity of the essential extracellular matrix protein elastin include premature aging of the skin...... and supravalvular aortic stenosis. However, only little is known about the molecular basis of structural abnormalities in the connective tissue of WBS patients. Therefore, for the first time this study aimed to systematically characterize and compare the structure and amount of elastin present in skin and aortic...... tissue from WBS patients and healthy individuals. Elastin fibers were isolated from tissue biopsies, and it was found that skin of WBS patients contains significantly less elastin compared to skin of healthy individuals. Scanning electron microscopy and mass spectrometric measurements combined...

  5. Collagen like peptide bioconjugates for targeted drug delivery applications

    Science.gov (United States)

    Luo, Tianzhi

    the coil/globule conformational transition of the PDEGMEMA building block above its LCST with stabilization of the nanostructures by the hydrophilic CLP. To the best of our knowledge, this is the first report on such assembled nanostructures from collagen-like peptide containing copolymers. Due to the strong propensity for CLPs to bind to natural collagen via strand invasion processes, these nanosized vesicles may be used as drug carriers for targeted delivery. In addition to synthetic polymers, the collagen like peptide is then conjugated with a thermoresponsive elastin-like peptide (ELP). The resulting ELP-CLP diblock conjugates show a remarkable reduction in the inverse transition temperature of the ELP domain, attributed to the anchoring effect of the CLP triple helix. The lower transition temperature of the conjugate enables facile formation of well-defined vesicles at physiological temperature and the unexpected resolubilization of the vesicles at elevated temperatures upon unfolding of the CLP domain. Given the ability of CLPs to modify collagens, this work provides not only a simple and versatile avenue for controlling the inverse transition behavior of elastin-like peptides, but also suggest future opportunities for these thermoresponsive nanostructures in biologically relevant environments. In the last section, the potential of using the ELP-CLP nanoparticles as drug delivery vehicles for targeting collagen containing matrices is evaluated. A sustained release of clinically relevant amount of encapsulated modelled drug is achieved within three weeks, followed by a thermally controlled burst release. As expected, the ELP-CLP nanoparticles show strong retention on collagen substrate, via specific binding through collagen triple helix hybridization. Additionally, cell viability and proliferation studies using fibroblasts and chondrocytes suggest the nanoparticles are non-cytotoxic. Additionally, almost no TNF-alpha expression from macrophages is observed

  6. Elastin receptor (S-gal) occupancy by elastin peptides modulates T-cell response during murine emphysema.

    Science.gov (United States)

    Meghraoui-Kheddar, Aïda; Pierre, Alexandre; Sellami, Mehdi; Audonnet, Sandra; Lemaire, Flora; Le Naour, Richard

    2017-09-01

    Chronic obstructive pulmonary disease and emphysema are associated with increased elastin peptides (EP) production because of excessive breakdown of lung connective tissue. We recently reported that exposure of mice to EP elicited hallmark features of emphysema. EP effects are largely mediated through a receptor complex that includes the elastin-binding protein spliced-galactosidase (S-gal). In previous studies, we established a correlation between cytokine production and S-gal protein expression in EP-treated immune cells. In this study, we investigated the S-gal-dependent EP effects on T-helper (Th) and T-cytotoxic (Tc) responses during murine EP-triggered pulmonary inflammation. C57BL/6J mice were endotracheally instilled with the valine-glycine-valine-alanine-proline-glycine (VGVAPG) elastin peptide, and, 21 days after treatment, local and systemic T-lymphocyte phenotypes were analyzed at cytokine and transcription factor expression levels by multicolor flow cytometry. Exposure of mice to the VGVAPG peptide resulted in a significant increase in the proportion of the CD4 + and CD8 + T cells expressing the cytokines IFN-γ or IL-17a and the transcription factors T-box expressed in T cells or retinoic acid-related orphan receptor-γt (RORγt) without effects on IL-4 and Gata-binding protein 3 to DNA sequence [A/T]GATA[A/G] expression. These effects were maximized when each T-cell subpopulation was challenged ex vivo with EP, and they were inhibited in vivo when an analogous peptide antagonizing the EP/S-gal interactions was instilled together with the VGVAPG peptide. This study demonstrates that, during murine emphysema, EP-S-gal interactions contribute to a Th-1 and Th-17 proinflammatory T-cell response combined with a Tc-1 response. Our study also highlights the S-gal receptor as a putative pharmacological target to modulate such an immune response. Copyright © 2017 the American Physiological Society.

  7. Chitosan/γ-poly(glutamic acid) scaffolds with surface-modified albumin, elastin and poly-l-lysine for cartilage tissue engineering.

    Science.gov (United States)

    Kuo, Yung-Chih; Ku, Hao-Fu; Rajesh, Rajendiran

    2017-09-01

    Cartilage has limited ability to self-repair due to the absence of blood vessels and nerves. The application of biomaterial scaffolds using biomimetic extracellular matrix (ECM)-related polymers has become an effective approach to production of engineered cartilage. Chitosan/γ-poly(glutamic acid) (γ-PGA) scaffolds with different mass ratios were prepared using genipin as a cross-linker and a freeze-drying method, and their surfaces were modified with elastin, human serum albumin (HSA) and poly-l-lysine (PLL). The scaffolds were formed through a complex between NH 3 + of chitosan and COO - of γ-PGA, confirmed by Fourier transform infrared spectroscopy, and exhibited an interconnected porous morphology in field emission scanning electron microscopy analysis. The prepared chitosan/γ-PGA scaffolds, at a 3:1 ratio, obtained the required porosity (90%), pore size (≥100μm), mechanical strength (compressive strength>4MPa, Young's modulus>4MPa) and biodegradation (30-60%) for articular cartilage tissue engineering applications. Surface modification of the scaffolds showed positive indications with improved activity toward cell proliferation (deoxyribonucleic acid), cell adhesion and ECM (glycoaminoglycans and type II collagen) secretion of bovine knee chondrocytes compared with unmodified scaffolds. In caspase-3 detection, elastin had a higher inhibitory effect on chondrocyte apoptosis in vitro, followed by HSA, and then PLL. We concluded that utilizing chitosan/γ-PGA scaffolds with surface active biomolecules, including elastin, HSA and PLL, can effectively promote the growth of chondrocytes, secrete ECM and improve the regenerative ability of cartilaginous tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Elastin Degradation by Cathepsin V Requires Two Exosites*

    Science.gov (United States)

    Du, Xin; Chen, Nelson L. H.; Wong, Andre; Craik, Charles S.; Brömme, Dieter

    2013-01-01

    Cathepsin V is a highly effective elastase and has been implicated in physiological and pathological extracellular matrix degradation. However, its mechanism of action remains elusive. Whereas human cathepsin V exhibits a potent elastolytic activity, the structurally homologous cathepsin L, which shares a 78% amino acid sequence, has only a minimal proteolytic activity toward insoluble elastin. This suggests that there are distinct structural domains that play an important role in elastinolysis. In this study, a total of 11 chimeras of cathepsins V and L were generated to identify elastin-binding domains in cathepsin V. Evaluation of these chimeras revealed two exosites contributing to the elastolytic activity of cathepsin V that are distant from the active cleft of the protease and are located in surface loop regions. Replacement of exosite 1 or 2 with analogous residues from cathepsin L led to a 75 and 43% loss in the elastolytic activity, respectively. Replacement of both exosites yielded a non-elastase variant similar to that of cathepsin L. Identification of these exosites may contribute to the design of inhibitors that will only affect the elastolytic activity of cysteine cathepsins without interfering with other physiological protease functions. PMID:24121514

  9. Elastin overexpression by cell-based gene therapy preserves matrix and prevents cardiac dilation

    Science.gov (United States)

    Li, Shu-Hong; Sun, Zhuo; Guo, Lily; Han, Mihan; Wood, Michael F G; Ghosh, Nirmalya; Alex Vitkin, I; Weisel, Richard D; Li, Ren-Ke

    2012-01-01

    After a myocardial infarction, thinning and expansion of the fibrotic scar contribute to progressive heart failure. The loss of elastin is a major contributor to adverse extracellular matrix remodelling of the infarcted heart, and restoration of the elastic properties of the infarct region can prevent ventricular dysfunction. We implanted cells genetically modified to overexpress elastin to re-establish the elastic properties of the infarcted myocardium and prevent cardiac failure. A full-length human elastin cDNA was cloned, subcloned into an adenoviral vector and then transduced into rat bone marrow stromal cells (BMSCs). In vitro studies showed that BMSCs expressed the elastin protein, which was deposited into the extracellular matrix. Transduced BMSCs were injected into the infarcted myocardium of adult rats. Control groups received either BMSCs transduced with the green fluorescent protein gene or medium alone. Elastin deposition in the infarcted myocardium was associated with preservation of myocardial tissue structural integrity (by birefringence of polarized light; P elastin showed the greatest functional improvement (P elastin in the infarcted heart preserved the elastic structure of the extracellular matrix, which, in turn, preserved diastolic function, prevented ventricular dilation and preserved cardiac function. This cell-based gene therapy provides a new approach to cardiac regeneration. PMID:22435995

  10. Elastin Is Differentially Regulated by Pressure Therapy in a Porcine Model of Hypertrophic Scar.

    Science.gov (United States)

    Carney, Bonnie C; Liu, Zekun; Alkhalil, Abdulnaser; Travis, Taryn E; Ramella-Roman, Jessica; Moffatt, Lauren T; Shupp, Jeffrey W

    Beneficial effects of pressure therapy for hypertrophic scars have been reported, but the mechanisms of action are not fully understood. This study evaluated elastin and its contribution to scar pliability. The relationship between changes in Vancouver Scar Scale (VSS) scores of pressure-treated scars and differential regulation of elastin was assessed. Hypertrophic scars were created and assessed weekly using VSS and biopsy procurement. Pressure treatment began on day 70 postinjury. Treated scars were compared with untreated shams. Treatment lasted 2 weeks, through day 84, and scars were assessed weekly through day 126. Transcript and protein levels of elastin were quantified. Pressure treatment resulted in lower VSS scores compared with sham-treated scars. Pliability (VSSP) was a key contributor to this difference. At day 70 pretreatment, VSSP = 2. Without treatment, sham-treated scars became less pliable, while pressure-treated scars became more pliable. The percentage of elastin in scars at day 70 was higher than in uninjured skin. Following treatment, the percentage of elastin increased and continued to increase through day 126. Untreated sham scars did not show a similar increase. Quantification of Verhoeff-Van Gieson staining corroborated the findings and immunofluorescence revealed the alignment of elastin fibers. Pressure treatment results in increased protein level expression of elastin compared with sham-untreated scars. These findings further characterize the extracellular matrix's response to the application of pressure as a scar treatment, which will contribute to the refinement of rehabilitation practices and ultimately improvements in functional and psychosocial outcomes for patients.

  11. Insights into the role of elastin in vocal fold health and disease

    Science.gov (United States)

    Moore, Jaime

    2011-01-01

    Elastic fibers are large, complex and surprisingly poorly understood extracellular matrix (ECM) macromolecules. The elastin fiber, generated from a single human gene - elastin (ELN), is a self assembling integral protein that endows critical mechanic proprieties to elastic tissues and organs such as the skin, lungs, and arteries. The biology of elastic fibers is complex because they have multiple components, a tightly regulated developmental deposition, a multi-step hierarchical assembly and unique biomechanical functions. Elastin is present in vocal folds, where it plays a pivotal role in the quality of phonation. This review article provides an overview of the genesis of elastin and its wide- ranging structure and function. Specific distribution within the vocal fold lamina propria across the lifespan in normal and pathological states and its contribution to vocal fold biomechanics will be examined. Elastin and elastin-derived molecules are increasingly investigated for their application in tissue engineering. The properties of various elastin– based materials will be discussed and their current and future applications evaluated. A new level of understanding of the biomechanical properties of vocal fold elastin composites and their molecular basis should lead to new strategies for elastic fiber repair and regeneration in aging and disease. PMID:21708449

  12. Elastin is a key regulator of outward remodeling in arteriovenous fistulas.

    Science.gov (United States)

    Wong, C Y; Rothuizen, T C; de Vries, M R; Rabelink, T J; Hamming, J F; van Zonneveld, A J; Quax, P H A; Rotmans, J I

    2015-04-01

    Maturation failure is the major limitation of arteriovenous fistulas (AVFs) as hemodialysis access conduits. Indeed, 30-50% of AVFs fail to mature due to intimal hyperplasia and insufficient outward remodeling. Elastin has emerged as an important determinant of vascular remodeling. Here the role of elastin in AVF remodeling in elastin haplodeficient (eln(+/-)) mice undergoing AVF surgery has been studied. Unilateral AVFs between the branch of the jugular vein and carotid artery in an end to side manner were created in wild-type (WT) C57BL/6 (n = 11) and in eln(+/-) mice (n = 9). Animals were killed at day 21 and the AVFs were analyzed histologically and at an mRNA level using real-time quantitative polymerase chain reaction. Before AVF surgery, a marked reduction in elastin density in the internal elastic lamina (IEL) of eln(+/-) mice was observed. AVF surgery resulted in fragmentation of the venous internal elastic lamina in both groups while the expression of the tropoelastin mRNA was 53% lower in the eln(+/-) mice than in WT mice (p elastin has an important role in vascular remodeling following AVF creation, in which a lower amount of elastin results in enhanced outward remodeling. Interventions targeting elastin degradation might be a viable option in order to improve AVF maturation. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  13. Measurement of MMP-9 and -12 degraded elastin (ELM) provides unique information on lung tissue degradation

    Science.gov (United States)

    2012-01-01

    Background Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases. Methods Elastin fragments were identified by mass-spectrometry and one sequence, generated by MMP-9 and -12 (ELN-441), was selected for monoclonal antibody generation and used in the development of an ELISA. Soluble and insoluble elastin from lung was cleaved in vitro and the time-dependent release of fragments was assessed in the ELN-441 assay. The release of ELN-441 in human serum from patients with chronic obstructive pulmonary disease (COPD) (n = 10) and idiopathic pulmonary fibrosis (IPF) (n = 29) were compared to healthy matched controls (n = 11). Results The sequence ELN-441 was exclusively generated by MMP-9 and -12 and was time-dependently released from soluble lung elastin. ELN-441 levels were 287% higher in patients diagnosed with COPD (p elastin. This fragment was elevated in serum from patients with the lung diseases IPF and COPD, however these data needs to be validated in larger clinical settings. PMID:22818364

  14. An evaluation of meniscal collagenous structure using optical projection tomography

    International Nuclear Information System (INIS)

    Andrews, Stephen HJ; Ronsky, Janet L; Rattner, Jerome B; Shrive, Nigel G; Jamniczky, Heather A

    2013-01-01

    also visualized using this technique, as their elastin content fluoresces more brightly than collagen at the 425 nm wavelength used by the OPT scanner. OPT was capable of imaging the collagenous structure, as well as blood vessels in the bovine meniscus. Collagenous structure variability, including transition zones between structural regions not previously described in the meniscus, was identified using this novel technique

  15. Effect of gamma radiation on tissue elastin content and serum elastolytic activity in rats

    International Nuclear Information System (INIS)

    Drozdz, M.; Olczyk, K.; Piwowarczyk, B.; Stawiarska, B.

    1981-01-01

    The elastin content of aorta, heart, skin and lungs as well as the serum elastolytic activity were determined in rats exposed to radiation. It was found that a single irradiation of rats with gamma rays (500 r) caused a decrease of the elastin content in all examined tissues. The serum elastolytic activity in the irradiated rats was increased. It is suggested that elastin degradation following radiation may be caused by changes in its molecular structure and possibly, due to increased serum elastolytic activity. (author)

  16. Moyamoya disease and artery tortuosity as rare phenotypes in a patient with an elastin mutation.

    Science.gov (United States)

    Ishiwata, Tsukasa; Tanabe, Nobuhiro; Shigeta, Ayako; Yokota, Hajime; Tsushima, Kenji; Terada, Jiro; Sakao, Seiichiro; Morisaki, Hiroko; Morisaki, Takayuki; Tatsumi, Koichiro

    2016-07-01

    Sporadic and familial elastin mutations can occur in large vessel stenosis such as supravalvular aortic stenosis and narrowing of the descending aorta. However, there are very few reports regarding the arteriopathy of cerebral, pulmonary or abdominal arteries in elastin mutations. We herein report the case of a Japanese female patient presenting with multiple arteriopathy including moyamoya disease, a tortuosity of abdominal arteries and pulmonary hypertension due to peripheral pulmonary artery stenosis. This case suggests the possible progression of cerebral arteriopathy including moyamoya disease in patients with elastin mutations. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Cancer Nano technology Using Elastin-Like Polypeptides

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2014-01-01

    Despite progress in understanding cancer biology, this knowledge has not translated into comparable advances in the clinic. Two fundamental problems currently stalling the efficient treatment of cancer have been detecting cancer early enough for successful treatment and avoiding excessive toxicity to normal tissues. In view of this, cancer still remains one of the leading causes of mortality worldwide, affecting over 10 million new patients every year. Clearly the development of novel approaches for early detection and treatment of cancer is urgently needed to increase patient survival. Recently, nano technology-based systems have emerged as novel therapeutic modalities for cancer treatment. Tiny man made nanoparticles, much smaller than a virus, are being developed to package, transport, and deliver imaging and therapeutic agents. Co-inclusion of these agents, into nano carriers might be advantageous because they increase solubility of hydrophobic drugs, enhance permeability across physiological barriers, alter drug biodistribution, increase local bioavailability and reduce side effects. Initial findings have been promising and nanoparticles have been shown to deliver therapeutic agents to target cells and effect tumor growth. To this end our lab is investigating a class of biodegradable and biocompatible polymers known as elastin-like polypeptides (ELP). Elastin like polypeptide is a bio polymer derived from the structural motif found in mammalian elastin protein and has a sequence dependent transition temperature that can be used as nano carriers to treat diseases. ELPs are characterized by the pentameric repeat VPGXG, where X can be any amino acid. All functional ELPs undergo inverse phase transition whereby below its transition temperature, they exist in a solubilized form while above its transition temperature they undergo phase separation which leads to their aggregation in solution. This process is reversible. Phase transition can also be triggered by other

  18. 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.

  19. The action of neutrophil serine proteases on elastin and its precursor

    DEFF Research Database (Denmark)

    Heinz, Andrea; Jung, Michael C; Jahreis, Günther

    2012-01-01

    This study aimed to investigate the degradation of the natural substrates tropoelastin and elastin by the neutrophil-derived serine proteases human leukocyte elastase (HLE), proteinase 3 (PR3) and cathepsin G (CG). Focus was placed on determining their cleavage site specificities using mass...... spectrometric techniques. Moreover, the release of bioactive peptides from elastin by the three proteases was studied. Tropoelastin was comprehensively degraded by all three proteases, whereas less cleavage occurred in mature cross-linked elastin. An analysis of the cleavage site specificities of the three...... proteases in tropoelastin and elastin revealed that HLE and PR3 similarly tolerate hydrophobic and/or aliphatic amino acids such as Ala, Gly and Val at P(1), which are also preferred by CG. In addition, CG prefers the bulky hydrophobic amino acid Leu and accepts the bulky aromatic amino acids Phe and Tyr...

  20. In vitro cross-linking of elastin peptides and molecular characterization of the resultant biomaterials

    DEFF Research Database (Denmark)

    Heinz, Andrea; Ruttkies, Christoph K H; Jahreis, Günther

    2013-01-01

    -link desmosine or isodesmosine was unexpected, however, could be confirmed by tandem mass spectrometry and molecular dynamics simulations. CONCLUSIONS: The study demonstrated that it is possible to produce biopolymers containing polyfunctional cross-links characteristic of mature elastin from small elastin......BACKGROUND: Elastin is a vital protein and the major component of elastic fibers which provides resilience to many vertebrate tissues. Elastin's structure and function are influenced by extensive cross-linking, however, the cross-linking pattern is still unknown. METHODS: Small peptides containing...... and the insoluble polymers, after digestion with pancreatic elastase or trypsin, were furthermore comprehensively characterized on the molecular level using MALDI-TOF/TOF mass spectrometry. RESULTS: MS(2) data was used to develop the software PolyLinX, which is able to sequence not only linear and bifunctionally...

  1. Elastin-Like Recombinamers As Smart Drug Delivery Systems.

    Science.gov (United States)

    Arias, F Javier; Santos, Mercedes; Ibanez-Fonseca, Arturo; Pina, Maria Jesus; Serrano, Sofía

    2018-02-19

    Drug delivery systems that are able to control the release of bioactive molecules and designed to carry drugs to target sites are of particular interest for tissue therapy. Moreover, systems comprising materials that can respond to environmental stimuli and promote self-assembly and higher order supramolecular organization are especially useful in the biomedical field. Objetive: This review focuses on biomaterials suitable for this purpose and that include elastin-like recombinamers (ELRs), a class of proteinaceous polymers bioinspired by natural elastin, designed using recombinant technologies. The self-assembly and thermoresponsive behaviour of these systems, along with their biodegradability, biocompatibility and well-defined composition as a result of their tailormade design, make them particularly attractive for controlled drug delivery. ELR-based delivery systems that allow targeted delivery are reviewed, especially ELR-drug recombinant fusion constructs, ELR-drug systems chemically bioconjugated in their monomeric and soluble forms, and drug encapsulation by nanoparticle-forming ELRs. Subsequently, the review focuses on those drug carriers in which smart release is triggered by pH or temperature with a particular focus on cancer treatments. Systems for controlled drug release based on depots and hydrogels that act as both a support and reservoir in which drugs can be stored will be described, and their applications in drug delivery discussed. Finally, smart drug-delivery systems not based on ELRs, including those comprising proteins, synthetic polymers and non-polymeric systems, will also be briefly discussed. Several different constructions based on ELRs are potential candidates for controlled drug delivery to be applied in advanced biomedical treatments. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Induction of protein body formation in plant leaves by elastin-like polypeptide fusions

    Directory of Open Access Journals (Sweden)

    Joensuu Jussi J

    2009-08-01

    Full Text Available Abstract Background Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants. Results The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system. Conclusion An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach

  3. Remote Exosites of the Catalytic Domain of Matrix Metalloproteinase-12 Enhance Elastin Degradation┼

    Science.gov (United States)

    Fulcher, Yan G.; Van Doren, Steven R.

    2011-01-01

    How does matrix metalloproteinase-12 (MMP-12 or metalloelastase) degrade elastin with high specific activity? NMR suggested soluble elastin to cover surfaces of MMP-12 far from its active site. Two of these surfaces have been found, by mutagenesis guided by the BINDSIght approach, to affect degradation and affinity for elastin substrates but not a small peptide substrate. Main exosite 1 has been extended out to Asp124 that binds calcium. Novel exosite 2 comprises residues from the II–III loop and β-strand I near the back of the catalytic domain. The high exposure of these distal exosites may make them accessible to elastin made more flexible by partial hydrolysis. Importantly, combination of a lesion at each of exosites 1 and 2 and active site decreased catalytic competence towards soluble elastin by 13- to 18-fold to the level of MMP-3, homologue and poor elastase. Double mutant cycle analysis of conservative mutations of Met156 (exosite 2) and either Asp124 (exosite 1) or Ile180 (active site) had additive effects. Compared to polar substitutions observed in other MMPs, Met156 enhanced affinity and Ile180 kcat for soluble elastin. Both residues detracted from the higher folding stability with polar mutations. This resembles the trend in enzymes of an inverse relationship between folding stability and activity. Restoring Asp124 from combination mutants enhanced kcat for soluble elastin. In elastin degradation, exosites 1 and 2 contributed independently of each other and Ile180 at the active site, but with partial coupling to Ala182 near the active site. The concept of weak, separated interactions coalescing somewhat independently can be extended to this proteolytic digestion of a protein from fibrils. PMID:21967233

  4. Fibril Formation by pH and Temperature Responsive Silk-Elastin Block Copolymers

    NARCIS (Netherlands)

    Golinska, M.D.; Pham, T.T.H.; Werten, M.W.T.; Wolf, de F.A.; Cohen Stuart, M.A.; Gucht, van der J.

    2013-01-01

    In this report, we study the self-assembly of two silk-elastin-like proteins: one is a diblock S24E40 composed of 24 silk-like (S) repeats and 40 elastin-like (E) repeats; the other is a triblock S12C4E40, in which the S and E blocks are separated by a random coil block (C4). Upon lowering the pH,

  5. Proline-poor hydrophobic domains modulate the assembly and material properties of polymeric elastin.

    Science.gov (United States)

    Muiznieks, Lisa D; Reichheld, Sean E; Sitarz, Eva E; Miao, Ming; Keeley, Fred W

    2015-10-01

    Elastin is a self-assembling extracellular matrix protein that provides elasticity to tissues. For entropic elastomers such as elastin, conformational disorder of the monomer building block, even in the polymeric form, is essential for elastomeric recoil. The highly hydrophobic monomer employs a range of strategies for maintaining disorder and flexibility within hydrophobic domains, particularly involving a minimum compositional threshold of proline and glycine residues. However, the native sequence of hydrophobic elastin domain 30 is uncharacteristically proline-poor and, as an isolated polypeptide, is susceptible to formation of amyloid-like structures comprised of stacked β-sheet. Here we investigated the biophysical and mechanical properties of multiple sets of elastin-like polypeptides designed with different numbers of proline-poor domain 30 from human or rat tropoelastins. We compared the contributions of these proline-poor hydrophobic sequences to self-assembly through characterization of phase separation, and to the tensile properties of cross-linked, polymeric materials. We demonstrate that length of hydrophobic domains and propensity to form β-structure, both affecting polypeptide chain flexibility and cross-link density, play key roles in modulating elastin mechanical properties. This study advances the understanding of elastin sequence-structure-function relationships, and provides new insights that will directly support rational approaches to the design of biomaterials with defined suites of mechanical properties. © 2015 Wiley Periodicals, Inc.

  6. A Quantitative Study of the Relationship between the Distribution of Different Types of Collagen and the Mechanical Behavior of Rabbit Medial Collateral Ligaments

    Science.gov (United States)

    Wan, Chao; Hao, Zhixiu; Wen, Shizhu; Leng, Huijie

    2014-01-01

    The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen), and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments. The main objective of this study was to determine whether the collagen type distribution is correlated with the mechanical properties of ligaments. Using axial tensile tests and picrosirius red staining-polarization observations, the mechanical behaviors and the ratios of the various types of collagen were investigated for twenty-four rabbit medial collateral ligaments from twenty-four rabbits of different ages, respectively. One-way analysis of variance was used in the comparison of the Young's modulus in the linear region of the stress-strain curves and the ratios of type I and III collagen for the specimens (the mid-substance specimens of the ligaments) with different ages. A multiple linear regression was performed using the collagen contents (the ratios of type I and III collagen) and the Young's modulus of the specimens. During the maturation of the ligaments, the type I collagen content increased, and the type III collagen content decreased. A significant and strong correlation () was identified by multiple linear regression between the collagen contents (i.e., the ratios of type I and type III collagen) and the mechanical properties of the specimens. The collagen content of ligaments might provide a new perspective for evaluating the linear modulus of global stress-strain curves for ligaments and open a new door for studying the mechanical behaviors and functions of connective tissues. PMID:25062068

  7. A quantitative study of the relationship between the distribution of different types of collagen and the mechanical behavior of rabbit medial collateral ligaments.

    Science.gov (United States)

    Wan, Chao; Hao, Zhixiu; Wen, Shizhu; Leng, Huijie

    2014-01-01

    The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen), and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments. The main objective of this study was to determine whether the collagen type distribution is correlated with the mechanical properties of ligaments. Using axial tensile tests and picrosirius red staining-polarization observations, the mechanical behaviors and the ratios of the various types of collagen were investigated for twenty-four rabbit medial collateral ligaments from twenty-four rabbits of different ages, respectively. One-way analysis of variance was used in the comparison of the Young's modulus in the linear region of the stress-strain curves and the ratios of type I and III collagen for the specimens (the mid-substance specimens of the ligaments) with different ages. A multiple linear regression was performed using the collagen contents (the ratios of type I and III collagen) and the Young's modulus of the specimens. During the maturation of the ligaments, the type I collagen content increased, and the type III collagen content decreased. A significant and strong correlation (R2 = 0.839, P < 0.05) was identified by multiple linear regression between the collagen contents (i.e., the ratios of type I and type III collagen) and the mechanical properties of the specimens. The collagen content of ligaments might provide a new perspective for evaluating the linear modulus of global stress-strain curves for ligaments and open a new door for studying the mechanical behaviors and functions of connective tissues.

  8. A quantitative study of the relationship between the distribution of different types of collagen and the mechanical behavior of rabbit medial collateral ligaments.

    Directory of Open Access Journals (Sweden)

    Chao Wan

    Full Text Available The mechanical properties of ligaments are key contributors to the stability and function of musculoskeletal joints. Ligaments are generally composed of ground substance, collagen (mainly type I and III collagen, and minimal elastin fibers. However, no consensus has been reached about whether the distribution of different types of collagen correlates with the mechanical behaviors of ligaments. The main objective of this study was to determine whether the collagen type distribution is correlated with the mechanical properties of ligaments. Using axial tensile tests and picrosirius red staining-polarization observations, the mechanical behaviors and the ratios of the various types of collagen were investigated for twenty-four rabbit medial collateral ligaments from twenty-four rabbits of different ages, respectively. One-way analysis of variance was used in the comparison of the Young's modulus in the linear region of the stress-strain curves and the ratios of type I and III collagen for the specimens (the mid-substance specimens of the ligaments with different ages. A multiple linear regression was performed using the collagen contents (the ratios of type I and III collagen and the Young's modulus of the specimens. During the maturation of the ligaments, the type I collagen content increased, and the type III collagen content decreased. A significant and strong correlation (R2 = 0.839, P < 0.05 was identified by multiple linear regression between the collagen contents (i.e., the ratios of type I and type III collagen and the mechanical properties of the specimens. The collagen content of ligaments might provide a new perspective for evaluating the linear modulus of global stress-strain curves for ligaments and open a new door for studying the mechanical behaviors and functions of connective tissues.

  9. Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

    Science.gov (United States)

    Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

    2016-10-01

    Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P Elastin-like polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

  10. Mechanistic Insights into Elastin Degradation by Pseudolysin, the Major Virulence Factor of the Opportunistic Pathogen Pseudomonas aeruginosa

    Science.gov (United States)

    Yang, Jie; Zhao, Hui-Lin; Ran, Li-Yuan; Li, Chun-Yang; Zhang, Xi-Ying; Su, Hai-Nan; Shi, Mei; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong

    2015-01-01

    Pseudolysin is the most abundant protease secreted by Pseudomonas aeruginosa and is the major extracellular virulence factor of this opportunistic human pathogen. Pseudolysin destroys human tissues by solubilizing elastin. However, the mechanisms by which pseudolysin binds to and degrades elastin remain elusive. In this study, we investigated the mechanism of action of pseudolysin on elastin binding and degradation by biochemical assay, microscopy and site-directed mutagenesis. Pseudolysin bound to bovine elastin fibers and preferred to attack peptide bonds with hydrophobic residues at the P1 and P1’ positions in the hydrophobic domains of elastin. The time-course degradation processes of both bovine elastin fibers and cross-linked human tropoelastin by pseudolysin were further investigated by microscopy. Altogether, the results indicate that elastin degradation by pseudolysin began with the hydrophobic domains on the fiber surface, followed by the progressive disassembly of macroscopic elastin fibers into primary structural elements. Moreover, our site-directed mutational results indicate that five hydrophobic residues in the S1-S1’ sub-sites played key roles in the binding of pseudolysin to elastin. This study sheds lights on the pathogenesis of P. aeruginosa infection. PMID:25905792

  11. Temperature-sensitive elastin-mimetic dendrimers: Effect of peptide length and dendrimer generation to temperature sensitivity.

    Science.gov (United States)

    Kojima, Chie; Irie, Kotaro; Tada, Tomoko; Tanaka, Naoki

    2014-06-01

    Dendrimers are synthetic macromolecules with unique structure, which are a potential scaffold for peptides. Elastin is one of the main components of extracellular matrix and a temperature-sensitive biomacromolecule. Previously, Val-Pro-Gly-Val-Gly peptides have been conjugated to a dendrimer for designing an elastin-mimetic dendrimer. In this study, various elastin-mimetic dendrimers using different length peptides and different dendrimer generations were synthesized to control the temperature dependency. The elastin-mimetic dendrimers formed β-turn structure by heating, which was similar to the elastin-like peptides. The elastin-mimetic dendrimers exhibited an inverse phase transition, largely depending on the peptide length and slightly depending on the dendrimer generation. The elastin-mimetic dendrimers formed aggregates after the phase transition. The endothermal peak was observed in elastin-mimetic dendrimers with long peptides, but not with short ones. The peptide length and the dendrimer generation are important factors to tune the temperature dependency on the elastin-mimetic dendrimer. Copyright © 2013 Wiley Periodicals, Inc.

  12. 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...

  13. 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...

  14. [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.

  15. 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

  16. Light Scattering Characterization of Elastin-Like Polypeptide Trimer Micelles

    Science.gov (United States)

    Tsuper, Ilona; Terrano, Daniel; Maraschky, Adam; Holland, Nolan; Streletzky, Kiril

    The elastin-like polypeptides (ELP) nanoparticles are composed of three-armed star polypeptides connected by a negatively charged foldon. Each of the three arms extending from the foldon domain includes 20 repeats of the (GVGVP) amino acid sequence. The ELP polymer chains are soluble at room temperature and become insoluble at the transition temperature (close to 50 ° C), forming micelles. The size and shape of the micelle are dependent on the temperature and the pH of the solution, and on the concentration of the phosphate buffered saline (PBS). The depolarized dynamic light scattering (DDLS) was employed to study the structure and dynamics of micelles at 62 ° C. The solution was maintained at an approximate pH level of 7.3 - 7.5, while varying PBS concentration. At low salt concentrations (60 mM) displayed an apparent elongation of the micelles evident by a significant VH signal, along with a surge in the apparent Rh. A model of micelle growth (and potential elongation) with increase in salt concentration is considered.

  17. Development of elastin-like recombinamer films with antimicrobial activity

    DEFF Research Database (Denmark)

    Costa, André; Machado, Raul; Ribeiro, Artur

    2015-01-01

    In the present work we explored the ABP-CM4 peptide properties from Bombyx mori for the creation of biopolymers with broad antimicrobial activity. An antimicrobial recombinant protein-based polymer (rPBP) was designed by cloning the DNA sequence coding for ABP-CM4 in frame with the N......-terminus of the elastin-like recombinamer consisting of 200 repetitions of the pentamer VPAVG, here named A200. The new rPBP, named CM4-A200, was purified via a simplified nonchromatographic method, making use of the thermoresponsive behavior of the A200 polymer. ABP-CM4 peptide was also purified through...... the incorporation of a formic acid cleavage site between the peptide and the A200 sequence. In soluble state the antimicrobial activity of both CM4-A200 polymer and ABP-CM4 peptide was poorly effective. However, when the CM4-A200 polymer was processed into free-standing films high antimicrobial activity against...

  18. Aspartic acid racemisation in purified elastin from arteries as basis for age estimation.

    Science.gov (United States)

    Dobberstein, R C; Tung, S-M; Ritz-Timme, S

    2010-07-01

    Aspartic acid racemisation (AAR) results in an age-dependent accumulation of D: -aspartic acid in durable human proteins and can be used as a basis for age estimation. Routinely, age estimation based on AAR is performed by analysis of dentine. However, in forensic practise, teeth are not always available. Non-dental tissues for age estimation may be suitable for age estimation based on AAR if they contain durable proteins that can be purified and analysed. Elastin is such a durable protein. To clarify if purified elastin from arteries is a suitable sample for biochemical age estimation, AAR was determined in purified elastin from arteries from individuals of known age (n = 68 individuals, including n = 15 putrefied corpses), considering the influence of different stages of atherosclerosis and putrefaction on the AAR values. AAR was found to increase with age. The relationship between AAR and age was good enough to serve as basis for age estimation, but worse than known from dentinal proteins. Intravital and post-mortem degradation of elastin may have a moderate effect on the AAR values. Age estimation based on AAR in purified elastin from arteries may be a valuable additional tool in the identification of unidentified cadavers, especially in cases where other methods cannot be applied (e.g., no available teeth and body parts).

  19. Tyrosinase-Mediated Construction of a Silk Fibroin/Elastin Nanofiber Bioscaffold.

    Science.gov (United States)

    Hong, Yanqing; Zhu, Xueke; Wang, Ping; Fu, Haitian; Deng, Chao; Cui, Li; Wang, Qiang; Fan, Xuerong

    2016-04-01

    Elastin has characteristics of elasticity, biological activity, and mechanical stability. In the present work, tyrosinase-mediated construction of a bioscaffold with silk fibroin and elastin was carried out, aiming at developing a novel medical biomaterial. The efficiency of enzymatic oxidation of silk fibroin and the covalent reaction between fibroin and elastin were examined by spectrophotometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and size exclusion chromatography (SEC). The properties of composite air-dried and nanofiber scaffolds were investigated. The results reveal that elastin was successfully bonded to silk fibroins, resulting in an increase in molecular weight of fibroin proteins. ATR-FTIR spectra indicated that tyrosinase treatment impacted the conformational structure of fibroin-based membrane. The thermal behaviors and mechanical properties of the tyrosinase-treated scaffolds were also improved compared with the untreated group. NIH/3T3 cells exhibited optimum densities when grown on the nanofiber scaffold, implying that the nanofiber scaffold has enhanced biocompatibility compared to the air-dried scaffold. A biological nanofiber scaffold constructed from tyrosinase-treated fibroin and elastin could potentially be utilized in biomedical applications.

  20. Oxygenation decreases elastin secretion from rat ductus arteriosus smooth muscle cells.

    Science.gov (United States)

    Kawakami, Shoji; Minamisawa, Susumu

    2015-08-01

    The ductus arteriosus (DA), a fetal arterial connection between the main pulmonary artery and the descending aorta, normally closes immediately after birth. The oxygen concentration in the blood rises after birth, and in the DA this increase in oxygen concentration causes functional closure, which is induced by smooth muscle contraction. Previous studies have demonstrated that hypoxia and/or oxygenation affect vascular remodeling of various vessels. Therefore, we hypothesized that the rise in oxygen concentration would affect the vascular structure of the DA due to production of proteins secreted from DA smooth muscle cells (SMC). Liquid chromatography-tandem mass spectrometry was used to comprehensively investigate the secreted proteins in the supernatant of rat DA SMC harvested under hypoxic conditions (1% oxygen) or under normoxic conditions (21% oxygen). We found that the rise in oxygen concentration reduced the secretion of elastin from DA SMC. On reverse transcription-polymerase chain reaction, the expression of elastin mRNA was not significantly changed in DA SMC from hypoxic to normoxic conditions. Given that elastin forms internal elastic lamina and elastic fibers in the vascular muscle layers, and that a rise in oxygen concentration reduced the secretion of elastin, this suggests that the rise in blood oxygen concentration after birth reduces the secretion of elastin, and therefore may play a role in DA structural remodeling after birth. © 2015 Japan Pediatric Society.

  1. Study of human lung elastin degradation by different elastases using high-performance liquid chromatography/mass spectrometry

    NARCIS (Netherlands)

    Barroso, Begona; Abello, Nicolas; Bischoff, Rainer

    2006-01-01

    Elastin is a structural insoluble protein which gives elasticity to tissues and organs. Although its hydrophobic and highly cross-linked nature makes it a very durable polymer, degradation of elastin in relation with several pathological conditions, such as pulmonary emphysema, has been documented.

  2. Neutrophil elastase-induced elastin degradation mediates macrophage influx and lung injury in 60% O2-exposed neonatal rats.

    Science.gov (United States)

    Masood, Azhar; Yi, Man; Belcastro, Rosetta; Li, Jun; Lopez, Lianet; Kantores, Crystal; Jankov, Robert P; Tanswell, A Keith

    2015-07-01

    Neutrophil (PMNL) influx precedes lung macrophage (LM) influx into the lung following exposure of newborn pups to 60% O2. We hypothesized that PMNL were responsible for the signals leading to LM influx. This was confirmed when inhibition of PMNL influx with a CXC chemokine receptor-2 antagonist, SB-265610, also prevented the 60% O2-dependent LM influx, LM-derived nitrotyrosine formation, and pruning of small arterioles. Exposure to 60% O2 was associated with increased lung contents of neutrophil elastase and α-elastin, a marker of denatured elastin, and a decrease in elastin fiber density. This led us to speculate that neutrophil elastase-induced elastin fragments were the chemokines that led to a LM influx into the 60% O2-exposed lung. Inhibition of neutrophil elastase with sivelestat or elafin attenuated the LM influx. Sivelestat also attenuated the 60% O2-induced decrease in elastin fiber density. Daily injections of pups with an antibody to α-elastin prevented the 60% O2-dependent LM influx, impaired alveologenesis, and impaired small vessel formation. This suggests that neutrophil elastase inhibitors may protect against neonatal lung injury not only by preventing structural elastin degradation, but also by blocking elastin fragment-induced LM influx, thus preventing tissue injury from LM-derived peroxynitrite formation. Copyright © 2015 the American Physiological Society.

  3. 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...

  4. Elastin and Mechanics of Pig Pericardial Resistance Arteries (pPRA)

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Leurgans, Thomas; Rosenstand, Kristoffer

    Resistance arteries are remodeled in hypertension and diabetes. Elastin was reported to play a role herein. The parietal pericardium is opened during cardio-thoracic surgeries and might be a valuable biopsy for research in cardio-vascular diseases. We tested the hypothesis that resistance arteries...... can be isolated from the pericardium to study the micro-architecture of elastin and vascular wall mechanics. The pericardium of pigs served to test the hypothesis. pPRAs were microdissected. Their structure was examined using multiphoton excitation fluorescence microscopy. Diameter......-tension and pressure-diameter-length relationships were recorded in myographs. Findings are compared to rodent mesenteric resistance arteries and –basilar arteries (rMRA, rBA) with comparable lumen diameter (±300µm at 100mmHg). pPRA have no clear external elastic lamina (present in rMRA, but not rBA), scant elastin...

  5. Elastin-like polypeptides: A strategic fusion partner for biologics.

    Science.gov (United States)

    Yeboah, Agnes; Cohen, Rick I; Rabolli, Charles; Yarmush, Martin L; Berthiaume, Francois

    2016-08-01

    Elastin-like peptides (ELPs) are derivatives of tropoelastin with a unique property that allows them to stay soluble below a certain critical temperature but reversibly form aggregates above that temperature. Since they are derived from tropoelastin, ELPs are biocompatible, non-toxic, and non-immunogenic. The unique properties of ELPs have made them a desirable class of fusion tags used in several biomedical applications including targeted drug delivery and enhancing the half-life of protein drugs. The most significant property of an ELP is that when fused to other proteins, the phase transition property of the ELP is maintained, and the target protein can be purified using the thermally driven property of the ELP. The ELP tag purification process is simple and inexpensive, and involves cycling the protein above and below the transition temperature of the ELP fusion followed by centrifugation to obtain the desired protein, without any need for chromatography. Consequently, using ELPs as a purification tag should be potentially interesting to biopharmaceutical companies who spend a significant percentage of their manufacturing costs on expensive protein purification techniques such as chromatography and filtration. However, ELP tags have not yet been used for commercial protein purification due to some challenges of translating this technique, which has been demonstrated mostly in academic laboratories, to a biotechnology manufacturing environment. The article first reviews the state-of-the-art in protein "ELPylation," and discusses some applications which have benefitted from using ELP as a fusion tag. Then, the article discusses the main advantages of using ELP as a purification tag, and evaluates the remaining hurdles for its implementation in industrial protein production. Biotechnol. Bioeng. 2016;113: 1617-1627. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Elastin-derived peptides are new regulators of insulin resistance development in mice

    DEFF Research Database (Denmark)

    Blaise, Sébastien; Romier, Béatrice; Kawecki, Charlotte

    2013-01-01

    . In the current study, we show that elastin-derived peptides (EDPs) may be involved in the development of insulin resistance (IRES) in mice. In chow-fed mice, acute or chronic intravenous injections of EDPs induced hyperglycemic effects associated with glucose uptake reduction and IRES in skeletal muscle, liver......, and adipose tissue. Based on in vivo, in vitro, and in silico approaches, we propose that this IRES is due to interaction between the insulin receptor (IR) and the neuraminidase-1 subunit of the elastin receptor complex triggered by EDPs. This interplay was correlated with decreased sialic acid levels...

  7. Neutrophil elastase and elastin-derived peptides in BAL fluid and emphysematous changes on CT scans

    International Nuclear Information System (INIS)

    Betsuyaku, Tomoko; Nishimura, Masaharu; Yoshioka, Aya; Takeyabu, Kimihiro; Miyamoto, Kenji; Kawakami, Yoshikazu

    1996-01-01

    We examined the relationship between neutrophil elastase, elastin-derived peptides in bronchoalveolar lavage (BAL) fluid, and the development of pulmonary emphysema. The level of neutrophil elastase was higher in asymptomatic current smokers with emphysematous changes on computed tomographic scans than in current smokers without emphysematous changes, and was found to be correlated with the level of elastin-derived peptides in BAL fluid. Subjects with high levels of neutrophil elastase in BAL fluid had faster annual declines in FEV 1 . We conclude that the level of neutrophil elastase in BAL fluid can be used to differentiate asymptomatic cigarette smokers who are at risk for pulmonary emphysema from those who are not. (author)

  8. Biaxial Stretch Improves Elastic Fiber Maturation, Collagen Arrangement, and Mechanical Properties in Engineered Arteries.

    Science.gov (United States)

    Huang, Angela H; Balestrini, Jenna L; Udelsman, Brooks V; Zhou, Kevin C; Zhao, Liping; Ferruzzi, Jacopo; Starcher, Barry C; Levene, Michael J; Humphrey, Jay D; Niklason, Laura E

    2016-06-01

    Tissue-engineered blood vessels (TEVs) are typically produced using the pulsatile, uniaxial circumferential stretch to mechanically condition and strengthen the arterial grafts. Despite improvements in the mechanical integrity of TEVs after uniaxial conditioning, these tissues fail to achieve critical properties of native arteries such as matrix content, collagen fiber orientation, and mechanical strength. As a result, uniaxially loaded TEVs can result in mechanical failure, thrombus, or stenosis on implantation. In planar tissue equivalents such as artificial skin, biaxial loading has been shown to improve matrix production and mechanical properties. To date however, multiaxial loading has not been examined as a means to improve mechanical and biochemical properties of TEVs during culture. Therefore, we developed a novel bioreactor that utilizes both circumferential and axial stretch that more closely simulates loading conditions in native arteries, and we examined the suture strength, matrix production, fiber orientation, and cell proliferation. After 3 months of biaxial loading, TEVs developed a formation of mature elastic fibers that consisted of elastin cores and microfibril sheaths. Furthermore, the distinctive features of collagen undulation and crimp in the biaxial TEVs were absent in both uniaxial and static TEVs. Relative to the uniaxially loaded TEVs, tissues that underwent biaxial loading remodeled and realigned collagen fibers toward a more physiologic, native-like organization. The biaxial TEVs also showed increased mechanical strength (suture retention load of 303 ± 14.53 g, with a wall thickness of 0.76 ± 0.028 mm) and increased compliance. The increase in compliance was due to combinatorial effects of mature elastic fibers, undulated collagen fibers, and collagen matrix orientation. In conclusion, biaxial stretching is a potential means to regenerate TEVs with improved matrix production, collagen organization, and mechanical

  9. High levels of biomarkers of collagen remodeling are associated with increased mortality in COPD – results from the ECLIPSE study

    DEFF Research Database (Denmark)

    Sand, Jannie M B; Leeming, Diana J; Byrjalsen, Inger

    2016-01-01

    with mortality in COPD and measured neo-epitopes originating from ECM proteins associated with lung tissue remodeling. METHODS: Biomarkers of ECM remodeling were assessed in a subpopulation (n = 1000) of the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) cohort. Validated......BACKGROUND: There is a need to identify individuals with COPD at risk for disease progression and mortality. Lung tissue remodeling is associated with the release of extracellular matrix (ECM) fragments into the peripheral circulation. We hypothesized that ECM remodeling was associated...... immunoassays measuring serological neo-epitopes produced by proteolytic cleavage associated with degradation of collagen type I, III, IV, and VI, elastin, and biglycan, and formation of collagen type VI as well as fibrinogen and C-reactive protein were used. Multivariate models were used to assess...

  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. 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...

  12. Phase separation and mechanical properties of an elastomeric biomaterial from spider wrapping silk and elastin block copolymers.

    Science.gov (United States)

    Muiznieks, Lisa D; Keeley, Fred W

    2016-10-01

    Elastin and silk spidroins are fibrous, structural proteins with elastomeric properties of extension and recoil. While elastin is highly extensible and has excellent recovery of elastic energy, silks are particularly strong and tough. This study describes the biophysical characterization of recombinant polypeptides designed by combining spider wrapping silk and elastin-like sequences as a strategy to rationally increase the strength of elastin-based materials while maintaining extensibility. We demonstrate a thermo-responsive phase separation and spontaneous colloid-like droplet formation from silk-elastin block copolymers, and from a 34 residue disordered region of Argiope trifasciata wrapping silk alone, and measure a comprehensive suite of tensile mechanical properties from cross-linked materials. Silk-elastin materials exhibited significantly increased strength, toughness, and stiffness compared to an elastin-only material, while retaining high failure strains and low energy loss upon recoil. These data demonstrate the mechanical tunability of protein polymer biomaterials through modular, chimeric recombination, and provide structural insights into mechanical design. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 693-703, 2016. © 2016 Wiley Periodicals, Inc.

  13. A wrinkle in flight: the role of elastin fibres in the mechanical behaviour of bat wing membranes.

    Science.gov (United States)

    Cheney, Jorn A; Konow, Nicolai; Bearnot, Andrew; Swartz, Sharon M

    2015-05-06

    Bats fly using a thin wing membrane composed of compliant, anisotropic skin. Wing membrane skin deforms dramatically as bats fly, and its three-dimensional configurations depend, in large part, on the mechanical behaviour of the tissue. Large, macroscopic elastin fibres are an unusual mechanical element found in the skin of bat wings. We characterize the fibre orientation and demonstrate that elastin fibres are responsible for the distinctive wrinkles in the surrounding membrane matrix. Uniaxial mechanical testing of the wing membrane, both parallel and perpendicular to elastin fibres, is used to distinguish the contribution of elastin and the surrounding matrix to the overall membrane mechanical behaviour. We find that the matrix is isotropic within the plane of the membrane and responsible for bearing load at high stress; elastin fibres are responsible for membrane anisotropy and only contribute substantially to load bearing at very low stress. The architecture of elastin fibres provides the extreme extensibility and self-folding/self-packing of the wing membrane skin. We relate these findings to flight with membrane wings and discuss the aeromechanical significance of elastin fibre pre-stress, membrane excess length, and how these parameters may aid bats in resisting gusts and preventing membrane flutter. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  14. Thermo-responsive human α-elastin self-assembled nanoparticles for protein delivery.

    Science.gov (United States)

    Kim, Jae Dong; Jung, Youn Jae; Woo, Chang Hee; Choi, Young Chan; Choi, Ji Suk; Cho, Yong Woo

    2017-01-01

    Self-assembled nanoparticles based on PEGylated human α-elastin were prepared as a potential vehicle for sustained protein delivery. The α-elastin was extracted from human adipose tissue and modified with methoxypolyethyleneglycol (mPEG) to control particle size and enhance the colloidal stability. The PEGylated human α-elastin showed sol-to-particle transition with a lower critical solution temperature (LCST) of 25°C-40°C in aqueous media. The PEGylated human α-elastin nanoparticles (PhENPs) showed a narrow size distribution with an average diameter of 330±33nm and were able to encapsulate significant amounts of insulin and bovine serum albumin (BSA) upon simple mixing at low temperature in water and subsequent heating to physiological temperature. The release profiles of insulin and BSA showed sustained release for 72h. Overall, the thermo-responsive self-assembled PhENPs provide a useful tool for a range of protein delivery and tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Mechanical, structural, and dynamical modifications of cholesterol exposed porcine aortic elastin.

    Science.gov (United States)

    Bilici, Kubra; Morgan, Steven W; Silverstein, Moshe C; Wang, Yunjie; Sun, Hyung Jin; Zhang, Yanhang; Boutis, Gregory S

    2016-11-01

    Elastin is a protein of the extracellular matrix that contributes significantly to the elasticity of connective tissues. In this study, we examine dynamical and structural modifications of aortic elastin exposed to cholesterol by NMR spectroscopic and relaxation methodologies. Macroscopic measurements are also presented and reveal that cholesterol treatment may cause a decrease in the stiffness of tissue. 2 H NMR relaxation techniques revealed differences between the relative populations of water that correlate with the swelling of the tissue following cholesterol exposure. 13 C magic-angle-spinning NMR spectroscopy and relaxation methods indicate that cholesterol treated aortic elastin is more mobile than control samples. Molecular dynamics simulations on a short elastin repeat VPGVG in the presence of cholesterol are used to investigate the energetic and entropic contributions to the retractive force, in comparison to the same peptide in water. Peptide stiffness is observed to reduce following cholesterol exposure due to a decrease in the entropic force. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. The coupled bio-chemo-electro-mechanical behavior of glucose exposed arterial elastin

    International Nuclear Information System (INIS)

    Zhang, Yanhang; Li, Jiangyu; Boutis, Gregory S

    2017-01-01

    Elastin, the principle protein component of the elastic fiber, is a critical extracellular matrix (ECM) component of the arterial wall providing structural resilience and biological signaling essential in vascular morphogenesis and maintenance of mechanical homeostasis. Pathogenesis of many cardiovascular diseases have been associated with alterations of elastin. As a long-lived ECM protein that is deposited and organized before adulthood, elastic fibers can suffer from cumulative effects of biochemical exposure encountered during aging and/or disease, which greatly compromise their mechanical function. This review article covers findings from recent studies of the mechanical and structural contribution of elastin to vascular function, and the effects of biochemical degradation. Results from diverse experimental methods including tissue-level mechanical characterization, fiber-level nonlinear optical imaging, piezoelectric force microscopy, and nuclear magnetic resonance are reviewed. The intriguing coupled bio-chemo-electro-mechanical behavior of elastin calls for a multi-scale and multi-physical understanding of ECM mechanics and mechanobiology in vascular remodeling. (topical review)

  17. Small Artery Elastin Distribution and Architecture-Focus on Three Dimensional Organization.

    Science.gov (United States)

    Hill, Michael A; Nourian, Zahra; Ho, I-Lin; Clifford, Philip S; Martinez-Lemus, Luis; Meininger, Gerald A

    2016-11-01

    The distribution of ECM proteins within the walls of resistance vessels is complex both in variety of proteins and structural arrangement. In particular, elastin exists as discrete fibers varying in orientation across the adventitia and media as well as often resembling a sheet-like structure in the case of the IEL. Adding to the complexity is the tissue heterogeneity that exists in these structural arrangements. For example, small intracranial cerebral arteries lack adventitial elastin while similar sized arteries from skeletal muscle and intestinal mesentery exhibit a complex adventitial network of elastin fibers. With regard to the IEL, several vascular beds exhibit an elastin sheet with punctate holes/fenestrae while in others the IEL is discontinuous and fibrous in appearance. Importantly, these structural patterns likely sub-serve specific functional properties, including mechanosensing, control of external forces, mechanical properties of the vascular wall, cellular positioning, and communication between cells. Of further significance, these processes are altered in vascular disorders such as hypertension and diabetes mellitus where there is modification of ECM. This brief report focuses on the three-dimensional wall structure of small arteries and considers possible implications with regard to mechanosensing under physiological and pathophysiological conditions. © 2016 John Wiley & Sons Ltd.

  18. The coupled bio-chemo-electro-mechanical behavior of glucose exposed arterial elastin

    Science.gov (United States)

    Zhang, Yanhang; Li, Jiangyu; Boutis, Gregory S.

    2017-04-01

    Elastin, the principle protein component of the elastic fiber, is a critical extracellular matrix (ECM) component of the arterial wall providing structural resilience and biological signaling essential in vascular morphogenesis and maintenance of mechanical homeostasis. Pathogenesis of many cardiovascular diseases have been associated with alterations of elastin. As a long-lived ECM protein that is deposited and organized before adulthood, elastic fibers can suffer from cumulative effects of biochemical exposure encountered during aging and/or disease, which greatly compromise their mechanical function. This review article covers findings from recent studies of the mechanical and structural contribution of elastin to vascular function, and the effects of biochemical degradation. Results from diverse experimental methods including tissue-level mechanical characterization, fiber-level nonlinear optical imaging, piezoelectric force microscopy, and nuclear magnetic resonance are reviewed. The intriguing coupled bio-chemo-electro-mechanical behavior of elastin calls for a multi-scale and multi-physical understanding of ECM mechanics and mechanobiology in vascular remodeling.

  19. Knockdown of versican 1 blocks cigarette-induced loss of insoluble elastin in human lung fibroblasts.

    Science.gov (United States)

    Xu, Lu-lu; Lu, Yun-tao; Zhang, Jing; Wu, Lian; Merrilees, Mervyn J; Qu, Jie-ming

    2015-08-15

    COPD lung is characterized by loss of alveolar elastic fibers and an increase in the chondroitin sulfate (CS) matrix proteoglycan versican V1 (V1). V1 is a known inhibitor of elastic fiber deposition and this study investigates the effects of knockdown of V1, and add-back of CS, on CCL-210 lung fibroblasts treated with cigarette smoke extract (CSE) as a model for COPD. CSE inhibited fibroblast proliferation, viability, tropoelastin synthesis, and elastin deposition, and increased V1 synthesis and secretion. V1 siRNA decreased V1 and constituent CS, did not affect tropoelastin production, but blocked the CSE-induced loss in insoluble elastin. Exogenous CS reduced insoluble elastin, even in the presence of V1 siRNA. These findings confirm that V1 and CS impair the assembly of tropoelastin monomers into insoluble fibers, and further demonstrate that specific knockdown of V1 alleviates the impaired assembly of elastin seen in cultures of pulmonary fibroblasts exposed to CSE, indicating a regulatory role for this protein in the pathophysiology of COPD. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Modulated growth, stability and interactions of liquid-like coacervate assemblies of elastin

    NARCIS (Netherlands)

    Muiznieks, L.D.; Cirulis, J.T.; Reinhardt, D.P.; Wuite, G.J.L.; Pomes, R.; Keeley, F.W.

    2014-01-01

    Elastin self-assembles from monomers into polymer networks that display elasticity and resilience. The first major step in assembly is a liquid-liquid phase separation known as coacervation. This process represents a continuum of stages from initial phase separation to early growth of droplets by

  1. Longevity of elastin in human intervertebral disc as probed by the racemization of aspartic acid

    DEFF Research Database (Denmark)

    Sivan, Sarit-Sara; Van El, Benno; Merkher, Yulia

    2012-01-01

    BACKGROUND: Aging and degeneration of human intervertebral disc (IVD) are associated with biochemical changes, including racemization and glycation. These changes can only be counteracted by protein turnover. Little is known about the longevity of IVD elastin in health or disease. Yet, such knowl...

  2. Elastin Based Cell-laden Injectable Hydrogels with Tunable Gelation, Mechanical and Biodegradation Properties

    Science.gov (United States)

    Fathi, Ali; Mithieux, Suzanne M.; Wei, Hua; Chrzanowski, Wojciech; Valtchev, Peter; Weiss, Anthony S.; Dehghani, Fariba

    2015-01-01

    Injectable hydrogels made from extracellular matrix proteins such as elastin show great promise for various biomedical applications. Use of cytotoxic reagents, fixed gelling behavior, and lack of mechanical strength in these hydrogels are the main associated drawbacks. The aim of this study was to develop highly cytocompatible and injectable elastin-based hydrogels with alterable gelation characteristics, favorable mechanical properties and structural stability for load bearing applications. A thermoresponsive copolymer, poly(N-isopropylacrylamide-co-polylactide-2-hydroxyethyl methacrylate-co-oligo(ethylene glycol)monomethyl ether methacrylate, was functionalized with succinimide ester groups by incorporating N-acryloxysuccinimide monomer. These ester groups were exploited to covalently bond this polymer, denoted as PNPHO, to different proteins with primary amine groups such as α-elastin in aqueous media. The incorporation of elastin through covalent bond formation with PNPHO promotes the structural stability, mechanical properties and live cell proliferation within the structure of hydrogels. Our results demonstrated that elastin-co-PNPHO solutions were injectable through fine gauge needles and converted to hydrogels in situ at 37 °C in the absence of any crosslinking reagent. By altering PNPHO content, the gelling time of these hydrogels can be finely tuned within the range of 2 to 15 min to ensure compatibility with surgical requirements. In addition, these hydrogels exhibited compression moduli in the range of 40 to 145 kPa, which are substantially higher than those of previously developed elastin-based hydrogels. These hydrogels were highly stable in the physiological environment with the evidence of 10 wt% mass loss in 30 days of incubation in a simulated environment. This class of hydrogels is in vivo bioabsorbable due to the gradual increase of the lower critical solution temperature of the copolymer to above 37 °C due to the cleavage of polylactide from

  3. Effect of gamma irradiation dose on the fabrication of α-elastin nanoparticles by gamma-ray crosslinking

    International Nuclear Information System (INIS)

    Fujimoto, Mari; Takeda, Mayuko; Okamoto, Kouji; Furuta, Masakazu

    2011-01-01

    Nanoparticles were prepared utilizing the thermosensitive aggregation of α-elastin and gamma-ray crosslinking. We investigated the effect of the α-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of α-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 o C/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

  4. Effect of gamma irradiation dose on the fabrication of {alpha}-elastin nanoparticles by gamma-ray crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Mari; Takeda, Mayuko [Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan); Okamoto, Kouji [Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502 (Japan); Furuta, Masakazu, E-mail: mfuruta@b.s.osakafu-u.ac.j [Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan)

    2011-02-15

    Nanoparticles were prepared utilizing the thermosensitive aggregation of {alpha}-elastin and gamma-ray crosslinking. We investigated the effect of the {alpha}-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of {alpha}-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 {sup o}C/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

  5. Gene expression levels of elastin and fibulin-5 according to differences between carotid plaque regions.

    Science.gov (United States)

    Sivrikoz, Emre; Timirci-Kahraman, Özlem; Ergen, Arzu; Zeybek, Ümit; Aksoy, Murat; Yanar, Fatih; İsbir, Turgay; Kurtoğlu, Mehmet

    2015-01-01

    The purpose of this study was to investigate the gene expression levels of elastin and fibulin-5 according to differences between carotid plaque regions and to correlate it with clinical features of plaque destabilization. The study included 44 endarterectomy specimens available from operated symptomatic carotid artery stenoses. The specimens were separated according to anatomic location: internal carotid artery (ICA), external carotid artery (ECA) and common carotid artery (CCA), and then stored in liquid nitrogen. The amounts of cDNA for elastin and fibulin-5 were determined by Quantitative real-time PCR (Q-RT-PCR). Target gene copy numbers were normalized using hypoxanthine-guanine phosphoribosyltransferase (HPRT1) gene. The delta-delta CT method was applied for relative quantification. Q-RT-PCR data showed that relative fibulin-5 gene expression was increased in ICA plaque regions when compared to CCA regions but not reaching significance (p=0.061). At the same time, no differences were observed in elastin mRNA level between different anatomic plaque regions (p>0.05). Moreover, elastin and fibulin-5 mRNA expression and clinical parameters were compared in ICA plaques versus CCA and ECA regions, respectively. Up-regulation of elastin and fibulin-5 mRNA levels in ICA were strongly correlated with family history of cardiovascular disease when compared to CCA (p<0.05). Up-regulation of fibulin-5 in ICA was significantly associated with diabetes, and elevated triglycerides and very low density lipoprotein (VLDL) when compared to ECA (p<0.05). The clinical significance is the differences between the proximal and distal regions of the lesion, associated with the ICA, CCA and ECA respectively, with increased fibulin-5 in the ICA region. Copyright © 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  6. 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....

  7. 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 ...

  8. Pulmonary alveolar macrophages (PAM) engulf and regain elastin particles and do not respond to some stimuli of neutrophil (PMN) elastinolysis

    International Nuclear Information System (INIS)

    Tricomi, S.M.; Hyers, T.M.; Yu, S.Y.; Liao, J.J.

    1986-01-01

    Elastin degradation by PMN and by PAM differs in the proteinases produced and in the method of cellular attack on the substrate. To further characterize the elastinolytic mechanisms of these two cells, 14 C-labelled bovine ligament elastin was dried onto 24-well culture plates and live cells were placed on the substrate in culture medium. Incubation times were 4 hours for PMN and 20 hours for PAM. Elastinolytic activity was determined by counting 14 C-elastin peptides in the supernatant. By lidocaine release of PAM from the surface, 14 C-elastin retained by the cell was measured. Studies on rabbit PAM showed that 40% of dpm remain associated with the cell at 20 hours. Transmission electron microscopy of human PAM confirmed that PAM can engulf and retain elastin particles at 4 and 24 hours of incubation when in close contact with the substrate. Of the number of dpm released by PMN in 4 hours, PAM in 20 hours released only 23% of that number into supernatant and retained 17% closely associated with the cell after lidocaine treatment. Platelet factor 4, a protein released by platelets upon aggregation which stimulates activity of PMN elastase on elastin, was shown to enhance elastinolysis by whole PMN by 57% at 10 μg/ml in this assay. Platelet factor 4 did not enhance elastinolysis by PAM at concentrations up to 100 μg/ml

  9. Development of short and highly potent self-assembling elastin-derived pentapeptide repeats containing aromatic amino acid residues.

    Science.gov (United States)

    Taniguchi, Suguru; Watanabe, Noriko; Nose, Takeru; Maeda, Iori

    2016-01-01

    Tropoelastin is the primary component of elastin, which forms the elastic fibers that make up connective tissues. The hydrophobic domains of tropoelastin are thought to mediate the self-assembly of elastin into fibers, and the temperature-mediated self-assembly (coacervation) of one such repetitive peptide sequence (VPGVG) has been utilized in various bio-applications. To elucidate a mechanism for coacervation activity enhancement and to develop more potent coacervatable elastin-derived peptides, we synthesized two series of peptide analogs containing an aromatic amino acid, Trp or Tyr, in addition to Phe-containing analogs and tested their functional characteristics. Thus, position 1 of the hydrophobic pentapeptide repeat of elastin (X(1)P(2)G(3)V(4)G(5)) was substituted by Trp or Tyr. Eventually, we acquired a novel, short Trp-containing elastin-derived peptide analog (WPGVG)3 with potent coacervation ability. From the results obtained during this process, we determined the importance of aromaticity and hydrophobicity for the coacervation potency of elastin-derived peptide analogs. Generally, however, the production of long-chain synthetic polypeptides in quantities sufficient for commercial use remain cost-prohibitive. Therefore, the identification of (WPGVG)3, which is a 15-mer short peptide consisting simply of five natural amino acids and shows temperature-dependent self-assembly activity, might serve as a foundation for the development of various kinds of biomaterials. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  10. MiR-29-mediated elastin down-regulation contributes to inorganic phosphorus-induced osteoblastic differentiation in vascular smooth muscle cells.

    Science.gov (United States)

    Sudo, Ryo; Sato, Fumiaki; Azechi, Takuya; Wachi, Hiroshi

    2015-12-01

    Vascular calcification increases the risk of cardiovascular mortality. We previously reported that expression of elastin decreases with progression of inorganic phosphorus (Pi)-induced vascular smooth muscle cell (VSMC) calcification. However, the regulatory mechanisms of elastin mRNA expression during vascular calcification remain unclear. MicroRNA-29 family members (miR-29a, b and c) are reported to mediate elastin mRNA expression. Therefore, we aimed to determine the effect of miR-29 on elastin expression and Pi-induced vascular calcification. Calcification of human VSMCs was induced by Pi and evaluated measuring calcium deposition. Pi stimulation promoted Ca deposition and suppressed elastin expression in VSMCs. Knockdown of elastin expression by shRNA also promoted Pi-induced VSMC calcification. Elastin pre-mRNA measurements indicated that Pi stimulation suppressed elastin expression without changing transcriptional activity. Conversely, Pi stimulation increased miR-29a and miR-29b expression. Inhibition of miR-29 recovered elastin expression and suppressed calcification in Pi-treated VSMCs. Furthermore, over-expression of miR-29b promoted Pi-induced VSMC calcification. RT-qPCR analysis showed knockdown of elastin expression in VSMCs induced expression of osteoblast-related genes, similar to Pi stimulation, and recovery of elastin expression by miR-29 inhibition reduced their expression. Our study shows that miR-29-mediated suppression of elastin expression in VSMCs plays a pivotal role in osteoblastic differentiation leading to vascular calcification. © 2015 The Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  11. Temperature induced conformational transitions of elastin-like polypentapeptides studied by Raman and NMR spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dybal, Jiří; Schmidt, Pavel; Kurková, Dana; Kříž, Jaroslav; Rodríguez-Cabello, J. C.; Alonso, M.

    2002-01-01

    Roč. 16, 3-4 (2002), s. 251-255 ISSN 0712-4813 R&D Projects: GA ČR GA203/00/1320; GA AV ČR IAA4050208 Institutional research plan: CEZ:AV0Z4050913 Keywords : quantum chemical calculations * elastin -like polypentapeptides * Raman spectra Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.567, year: 2002

  12. Generation of hydrogen peroxide in the developing rat heart: the role of elastin metabolism

    Czech Academy of Sciences Publication Activity Database

    Wilhelm, J.; Ošťádalová, Ivana; Vytášek, R.; Vajner, L.

    2011-01-01

    Roč. 358, 1-2 (2011), s. 215-220 ISSN 0300-8177 R&D Projects: GA MŠk(CZ) 1M0510 Grant - others:GA ČR(CZ) GAP303/11/0298 Program:GA Institutional research plan: CEZ:AV0Z50110509 Keywords : rat heart * ontogenetic development * hydrogen peroxide * elastin * fluorescence Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.057, year: 2011

  13. Antibodies to elastin peptides in sera of Belgian Draught horses with chronic progressive lymphoedema.

    Science.gov (United States)

    van Brantegem, L; de Cock, H E V; Affolter, V K; Duchateau, L; Hoogewijs, M K; Govaere, J; Ferraro, G L; Ducatelle, R

    2007-09-01

    Chronic progressive lymphoedema (CPL) is a recently recognised disease of the lymphatic system characterised by lesions in the skin of the lower legs in several draught horse breeds, including the Belgian Draught hourse. Clinical signs slowly progress and result in severe disfigurement of the limbs. Ideally, supportive treatment should be started early in the disease process. However early diagnosis and monitoring progression of CPL is still a challenge. Elastin changes, characterised by morphological alterations as well as increased desmosine levels, in the skin of the distal limbs of horses affected with CPL are probably associated with a marked release of elastin degradation products, which elicit production of circulating anti-elastin antibodies (AEAbs) in the serum. An enzyme-linked immunosorbent assay (ELISA) for detection of serum AEAbs may document elastin breakdown. An ELISA technique was used to evaluate levels of AEAbs in sera of 97 affected Belgian Draught horses that were clinically healthy except for possible skin lesions, associated with CPL in their distal limbs. The horses were divided into 5 groups according to the severity of these skin lesions: normal horses (Group 1, n = 36), horses with mild lesions (Group 2, n = 43), horses with moderate lesions (Group 3, n = 8), horses with severe lesions (Group 4, n = 10) and, as a control, healthy Warmblood horses, unaffected by the disease (Group 5, n = 83). Horses with clinical signs of CPL had significantly higher AEAb levels compared to clinically normal Belgian Draught horses and to healthy Warmblood horses. These levels correlated with severity of lesions. CPL in draught horses is associated with an increase of serum AEAbs. Evaluation of serum levels of AEAbs by ELISA might be a useful diagnostic aid for CPL. Pathological degradation of elastic fibres, resulting in deficient support of the distal lymphatics, is proposed as a contributing factor for CPL in Belgian Draught horses.

  14. The Elastin Receptor Complex: a unique matricellular receptor with high anti-tumoral potential

    Directory of Open Access Journals (Sweden)

    Amandine eScandolera

    2016-03-01

    Full Text Available Elastin, one of the longest-lived proteins, confers elasticity to tissues with high mechanical constraints. During aging or pathophysiological conditions such as cancer progression, this insoluble polymer of tropoelastin undergoes an important degradation leading to the release of bioactive elastin-derived peptides (EDP, named elastokines. EDP exhibit several biological functions able to drive tumor development by regulating cell proliferation, invasion, survival, angiogenesis, and matrix metalloproteinase expression in various tumor and stromal cells. Although several receptors have been suggested to bind elastokines (αvβ3 and αvβ5 integrins, galectin-3, their main receptor remains the Elastin Receptor Complex (ERC. This heterotrimer comprises a peripheral subunit, named Elastin Binding Protein (EBP, associated to the Protective Protein/Cathepsin A (PPCA. The latter is bound to a membrane-associated protein called Neuraminidase-1 (Neu-1. The pro-tumoral effects of elastokines have been linked to their binding onto EBP. Additionally, Neu-1 sialidase activity is essential for their signal transduction. Consistently, EDP-EBP interaction and Neu-1 activity emerge as original anti-tumoral targets. Interestingly, besides its direct involvement in cancer progression, the ERC also regulates diabetes outcome and thrombosis, an important risk factor for cancer development and a vascular process highly increased in patients suffering from cancer. In this review, we will describe ERC and elastokines involvement in cancer development suggesting that this unique receptor would be a promising therapeutic target. We will also discuss the pharmacological concepts aiming at blocking its pro-tumoral activities. Finally, its emerging role in cancer-associated complications and pathologies such as diabetes and thrombotic events will be also considered.

  15. Elastin Cables Define the Axial Connective Tissue System in the Murine Lung.

    Science.gov (United States)

    Wagner, Willi; Bennett, Robert D; Ackermann, Maximilian; Ysasi, Alexandra B; Belle, Janeil; Valenzuela, Cristian D; Pabst, Andreas; Tsuda, Akira; Konerding, Moritz A; Mentzer, Steven J

    2015-11-01

    The axial connective tissue system is a fiber continuum of the lung that maintains alveolar surface area during changes in lung volume. Although the molecular anatomy of the axial system remains undefined, the fiber continuum of the lung is central to contemporary models of lung micromechanics and alveolar regeneration. To provide a detailed molecular structure of the axial connective tissue system, we examined the extracellular matrix of murine lungs. The lungs were decellularized using a 24 hr detergent treatment protocol. Systematic evaluation of the decellularized lungs demonstrated no residual cellular debris; morphometry demonstrated a mean 39 ± 7% reduction in lung dimensions. Scanning electron microscopy (SEM) demonstrated an intact structural hierarchy within the decellularized lung. Light, fluorescence, and SEM of precision-cut lung slices demonstrated that alveolar duct structure was defined by a cable line element encased in basement membrane. The cable line element arose in the distal airways, passed through septal tips and inserted into neighboring blood vessels and visceral pleura. The ropelike appearance, collagenase resistance and anti-elastin immunostaining indicated that the cable was an elastin macromolecule. Our results indicate that the helical line element of the axial connective tissue system is composed of an elastin cable that not only defines the structure of the alveolar duct, but also integrates the axial connective tissue system into visceral pleura and peripheral blood vessels. © 2015 Wiley Periodicals, Inc.

  16. Elastin-like polypeptides: the power of design for smart cell encapsulation.

    Science.gov (United States)

    Bandiera, Antonella

    2017-01-01

    Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

  17. High-yield recombinant expression and purification of marginally soluble, short elastin-like polypeptides.

    Science.gov (United States)

    Bahniuk, Markian S; Alshememry, Abdullah K; Unsworth, Larry D

    2016-12-01

    The protocol described here is designed as an extension of existing techniques for creating elastin-like polypeptides. It allows for the expression and purification of elastin-like polypeptide (ELP) constructs that are poorly expressed or have very low transition temperatures. DNA concatemerization has been modified to reduce issues caused by methylation sensitivity and inefficient cloning. Linearization of the modified expression vector has been altered to greatly increase cleavage efficiency. The purification regimen is based upon using denaturing metal affinity chromatography to fully solubilize and, if necessary, pre-concentrate the target peptide before purification by inverse temperature cycling (ITC). This protocol has been used to express multiple leucine-containing elastin-like polypeptides, with final yields of 250-660 mg per liter of cells, depending on the specific construct. This was considerably greater than previously reported yields for similar ELPs. Due to the relative hydrophobicity of the tested constructs, even compared with commonly employed ELPs, conventional methods would not have been able to be purify these peptides.

  18. Double-hydrophobic elastin-like polypeptides with added functional motifs: Self-assembly and cytocompatibility.

    Science.gov (United States)

    Le, Duc H T; Tsutsui, Yoko; Sugawara-Narutaki, Ayae; Yukawa, Hiroshi; Baba, Yoshinobu; Ohtsuki, Chikara

    2017-09-01

    We have recently developed a novel double-hydrophobic elastin-like triblock polypeptide called GPG, designed after the uneven distribution of two different hydrophobic domains found in elastin, an extracellular matrix protein providing elasticity and resilience to tissues. Upon temperature trigger, GPG undergoes a sequential self-assembling process to form flexible beaded nanofibers with high homogeneity and excellent dispersibility in water. Given that GPG might be a potential elastin-mimetic material, we sought to explore the biological activities of this block polypeptide. Besides GPG, several functionalized derivatives were also constructed by fusing functional motifs such as KAAK or KAAKGRGDS at the C-terminal of GPG. Although the added motifs affected the kinetics of fiber formation and β-sheet contents, all three GPGs assembled into beaded nanofibers at the physiological temperature. The resulting GPG nanofibers preserved their beaded structures in cell culture medium; therefore, they were coated on polystyrene substrates to study their cytocompatibility toward mouse embryonic fibroblasts, NIH-3T3. Among the three polypeptides, GPG having the cell-binding motif GRGDS derived from fibronectin showed excellent cell adhesion and cell proliferation properties compared to other conventional materials, suggesting its promising applications as extracellular matrices for mammalian cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2475-2484, 2017. © 2017 Wiley Periodicals, Inc.

  19. Intracranial arteries in individuals with the elastin gene hemideletion of Williams syndrome.

    Science.gov (United States)

    Wint, D P; Butman, J A; Masdeu, J C; Meyer-Lindenberg, A; Mervis, C B; Sarpal, D; Morris, C A; Berman, K F

    2014-01-01

    Williams syndrome, a rare genetic disorder with a striking neurobehavioral profile characterized by extreme sociability and impaired visuospatial construction abilities, is caused by a hemideletion that includes the elastin gene, resulting in frequent supravavular aortic stenosis and other stenotic arterial lesions. Strokes have been reported in Williams syndrome. Although the extracranial carotid artery has been studied in a sample of patients with Williams syndrome, proximal intracranial arteries have not. Using MRA, we studied the intracranial vessels in 27 participants: 14 patients with Williams syndrome (age range, 18-44 years; mean age, 27.3 ± 9.1; 43% women) and 13 healthy control participants with similar age and sex distribution (age range, 22-52 years; mean age, 33.4 ± 7.6; 46% women). All participants with Williams syndrome had hemideletions of the elastin gene. Blinded to group allocation or to any other clinical data, a neuroradiologist determined the presence of intracranial vascular changes in the 2 groups. The Williams syndrome group and the healthy control group had similar patency of the proximal intracranial arteries, including the internal carotid and vertebral arteries; basilar artery; and stem and proximal branches of the anterior cerebral artery, MCA, and posterior cerebral arteries. The postcommunicating segment of the anterior cerebral artery was longer in the Williams syndrome group. Despite the elastin haploinsufficiency, the proximal intracranial arteries in Williams syndrome preserve normal patency.

  20. Quantitative and qualitative evaluation of dermal elastin of draught horses with chronic progressive lymphoedema.

    Science.gov (United States)

    De Cock, H E V; Van Brantegem, L; Affolter, V K; Oosterlinck, M; Ferraro, G L; Ducatelle, R

    2009-01-01

    Chronic progressive lymphoedema (CPL) in horses, a disease of certain draught breeds, is associated with altered elastin metabolism. The characteristic lesions are seen in the skin of the lower (distal) limbs. This study was based on horses of susceptible breeds, with and without CPL, and on horses of a non-susceptible breed. Skin samples were obtained for examination from the neck (considered a non-affected region) and from the distal limb. The skin lesions were characterized histologically and the dermal elastic fibres were evaluated morphologically and quantitatively. In all horses the mean elastin concentrations were highest in the superficial dermis, gradually decreasing in the mid-dermis and deep dermis. As compared with horses of a non-susceptible breed, affected horses had increased amounts of dermal elastin in both the distal limb and neck, while non-affected horses of a susceptible breed had decreased amounts. The findings support an earlier hypothesis that CPL of horses is a generalized disease. Reduced efficiency of the elastic network in supporting the dermal lymphatics may explain the development of CPL.

  1. Elastin: a possible genetic biomarker for more severe ligament injuries in elite soccer. A pilot study

    Science.gov (United States)

    Artells, Rosa; Pruna, Ricard; Dellal, Alexandre; Maffulli, Nicola

    2016-01-01

    Summary Background The study of new genetic biomarkers in genes related to connective tissue repair and regeneration may help to identify individuals with greater predisposition to injury, who may benefit from targeted preventive measures, and those who require longer recovery time following a muscle, ligament or tendon injury. The present study investigated whether single nucleotide polymorphisms of the Elastin gene could be related to MCL injury. Methods 60 top class football players were studied to identify single nucleotide polymorphisms for the Elastin (ELN) gene using Allelic Discrimination analysis. Each player was followed for 7 seasons, and each MCL injury was noted. Results Ligament injury rate, severity and recovery time are related to specific genotypes observed in the elastin gene, especially the ELN-AA (16 MCL) and the ELN-AG (3 MCL). Players with the ELN-GG genotype sustained no MCL injury during the 7 seasons of the study. Conclusions The identification of polymorphisms in the ELN gene may be used as a novel tool to better define an athlete’s genotype, and help to plan training and rehabilitation programmes to prevent or minimize MCL ligament injuries, and optimize the therapeutic and rehabilitation process after soft tissue injuries, and manage the workloads during trainings and matches. PMID:27900291

  2. 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...

  3. 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.

  4. Pentagalloyl glucose increases elastin deposition, decreases reactive oxygen species and matrix metalloproteinase activity in pulmonary fibroblasts under inflammatory conditions.

    Science.gov (United States)

    Parasaram, Vaideesh; Nosoudi, Nasim; Chowdhury, Aniqa; Vyavahare, Naren

    2018-04-30

    Emphysema is characterized by degradation of lung alveoli that leads to poor airflow in lungs. Irreversible elastic fiber degradation by matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity leads to loss of elasticity and drives the progression of this disease. We investigated if a polyphenol, pentagalloyl glucose (PGG) can increase elastin production in pulmonary fibroblasts. We also studied the effect of PGG treatment in reducing MMP activity and ROS levels in cells. We exposed rat pulmonary fibroblasts to two different types of inflammatory environments i.e., tumor necrosis factor-α (TNF-α) and cigarette smoke extract (CSE) to mimic the disease. Parameters like lysyl oxidase (LOX) and elastin gene expression, MMP-9 activity in the medium, lysyl oxidase (LOX) activity and ROS levels were studied to assess the effect of PGG on pulmonary fibroblasts. CSE inhibited lysyl oxidase (LOX) enzyme activity that resulted in a decreased elastin formation. Similarly, TNF-α treated cells showed less elastin in the cell layers. Both these agents caused increase in MMP activity and ROS levels in cells. However, when supplemented with PGG treatment along with these two inflammatory agents, we saw a significant increase in elastin deposition, reduction in both MMP activity and ROS levels. Thus PGG, which has anti-inflammatory, anti-oxidant properties coupled with its ability to aid in elastic fiber formation, can be a multifunctional drug to potentially arrest the progression of emphysema. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. 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...

  6. Elephantiasis, elastin, and chronic wound healing: 19th century and contemporary viewpoints relevant to hypotheses concerning lymphedema, leprosy, erysipelas, and psoriasis--review and reflections.

    Science.gov (United States)

    Ryan, T J

    2009-03-01

    Both wound healing and lymphedema have fibrosis of the skin in common. They also share destruction of elastin by elastases from neutrophils as a significant feature. These are not new observations, and the writings of Unna and Kaposi are recalled. The contemporary observations on elastin by Gerli and his team are discussed in the light of these much earlier opinions.

  7. 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.

  8. Impaired elastin deposition in Fstl1-/- lung allograft under the renal capsule.

    Directory of Open Access Journals (Sweden)

    Yan Geng

    Full Text Available Lung alveolar development in late gestation is a process important to postnatal survival. Follistatin-like 1 (Fstl1 is a matricellular protein of the Bmp antagonist class, which is involved in the differentiation/maturation of alveolar epithelial cells during saccular stage of lung development. This study investigates the role of Fstl1 on elastin deposition in mesenchyme and subsequent secondary septation in the late gestation stage of terminal saccular formation. To this aim, we modified the renal capsule allograft model for lung organ culture by grafting diced E15.5 distal lung underneath the renal capsule of syngeneic host and cultured up to 7 days. The saccular development of the diced lung allografts, as indicated by the morphology, epithelial and vascular developments, occurred in a manner similar to that in utero. Fstl1 deficiency caused atelectatic phenotype companied by impaired epithelial differentiation in D3 Fstl1(-/- lung allografts, which is similar to that of E18.5 Fstl1(-/- lungs, supporting the role of Fstl1 during saccular stage. Inhibition of Bmp signaling by intraperitoneal injection of dorsomorphin in the host mice rescued the pulmonary atelectasis of D3 Fstl1(-/- allografts. Furthermore, a marked reduction in elastin expression and deposition was observed in walls of air sacs of E18.5 Fstl1(-/- lungs and at the tips of the developing alveolar septae of D7 Fstl1(-/- allografts. Thus, in addition to its role on alveolar epithelium, Fstl1 is crucial for elastin expression and deposition in mesenchyme during lung alveologenesis. Our data demonstrates that the modified renal capsule allograft model for lung organ culture is a robust and efficient technique to increase our understanding of saccular stage of lung development.

  9. Polymorphisms in the human tropoelastin gene modify in vitro self-assembly and mechanical properties of elastin-like polypeptides.

    Directory of Open Access Journals (Sweden)

    David He

    Full Text Available Elastin is a major structural component of elastic fibres that provide properties of stretch and recoil to tissues such as arteries, lung and skin. Remarkably, after initial deposition of elastin there is normally no subsequent turnover of this protein over the course of a lifetime. Consequently, elastic fibres must be extremely durable, able to withstand, for example in the human thoracic aorta, billions of cycles of stretch and recoil without mechanical failure. Major defects in the elastin gene (ELN are associated with a number of disorders including Supravalvular aortic stenosis (SVAS, Williams-Beuren syndrome (WBS and autosomal dominant cutis laxa (ADCL. Given the low turnover of elastin and the requirement for the long term durability of elastic fibres, we examined the possibility for more subtle polymorphisms in the human elastin gene to impact the assembly and long-term durability of the elastic matrix. Surveys of genetic variation resources identified 118 mutations in human ELN, 17 being non-synonymous. Introduction of two of these variants, G422S and K463R, in elastin-like polypeptides as well as full-length tropoelastin, resulted in changes in both their assembly and mechanical properties. Most notably G422S, which occurs in up to 40% of European populations, was found to enhance some elastomeric properties. These studies reveal that even apparently minor polymorphisms in human ELN can impact the assembly and mechanical properties of the elastic matrix, effects that over the course of a lifetime could result in altered susceptibility to cardiovascular disease.

  10. Prophylactic effects of elastin peptide derived from the bulbus arteriosus of fish on vascular dysfunction in spontaneously hypertensive rats.

    Science.gov (United States)

    Takemori, Kumiko; Yamamoto, Ei; Ito, Hiroyuki; Kometani, Takashi

    2015-01-01

    To determine the prophylactic effects of an elastin peptide derived from the bulbus arteriosus of bonitos and prolylglycine (PG), a degradation product of elastin peptide, on vascular dysfunction in spontaneously hypertensive rats (SHRs). Male 15-week-old SHR/Izm rats were fed without (control group) or with elastin peptide (1 g/kg body weight) for 5 weeks (EP group), or were infused via an osmotic mini-pump for 4 weeks with PG (PG group) or saline (control group). Using thoracic aortas, we assessed endothelial changes by scanning electron microscopy. Vascular reactivity (contraction and relaxation) and pressure-induced distension was compared. mRNA production levels of endothelial nitric oxide synthase (eNOS) and intercellular adhesion molecule-1 (ICAM-1) were investigated by real-time-polymerase chain reaction. Aortas of the EP group displayed limited endothelial damage compared with that in the control group. Under treatment of SHRs with elastin peptide, the effect of phenylephrine returned closer to the normal level observed in normotensive Wistar-Kyoto (WKY/Izm) rats. mRNA production of eNOS (but not ICAM-1) was greater in the EP group than in the control group. Endothelial damage was suppressed and pressure-induced vascular distension was greater in the PG group than in the corresponding control group. These results suggest that elastin peptide from bonitos elicits prophylactic affects hypertension-associated vascular dysfunction by targeting the eNOS signaling pathway. PG may be a key mediator of the beneficial effects of elastin peptide. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Synthetic ligands of the elastin receptor induce elastogenesis in human dermal fibroblasts via activation of their IGF-1 receptors.

    Science.gov (United States)

    Qa'aty, Nour; Vincent, Matthew; Wang, Yanting; Wang, Andrew; Mitts, Thomas F; Hinek, Aleksander

    2015-12-01

    We have previously reported that a mixture of peptides obtained after chemical or enzymatic degradation of bovine elastin, induced new elastogenesis in human skin. Now, we investigated the elastogenic potential of synthetic peptides mimicking the elastin-derived, VGVAPG sequence, IGVAPG sequence that we found in the rice bran, and a similar peptide, VGVTAG that we identified in the IGF-1-binding protein-1 (IGFBP-1). We now demonstrate that treatment with each of these xGVxxG peptides (recognizable by the anti-elastin antibody), up-regulated the levels of elastin-encoding mRNA, tropoelastin protein, and the deposition of new elastic fibers in cultures of human dermal fibroblasts and in cultured explants of human skin. Importantly, we found that such induction of new elastogenesis may involve two parallel signaling pathways triggered after activation of IGF-1 receptor. In the first one, the xGVxxG peptides interact with the cell surface elastin receptor, thereby causing the downstream activation of the c-Src kinase and a consequent cross-activation of the adjacent IGF-1R, even in the absence of its principal ligand. In the second pathway their hydrophobic association with the N-terminal domain (VGVTAG) of the serum-derived IGFBP-1 induces conformational changes of this IGF-1 chaperone allowing for the release of its cargo and a consequent ligand-specific phosphorylation of IGF-1R. We present a novel, clinically relevant mechanism in which products of partial degradation of dermal elastin may stimulate production of new elastic fibers by dermal fibroblasts. Our findings particularly encourage the use of biologically safe synthetic xGVxxG peptides for regeneration of the injured or aged human skin. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Lysyl Oxidase Induces Vascular Oxidative Stress and Contributes to Arterial Stiffness and Abnormal Elastin Structure in Hypertension: Role of p38MAPK.

    Science.gov (United States)

    Martínez-Revelles, Sonia; García-Redondo, Ana B; Avendaño, María S; Varona, Saray; Palao, Teresa; Orriols, Mar; Roque, Fernanda R; Fortuño, Ana; Touyz, Rhian M; Martínez-González, Jose; Salaices, Mercedes; Rodríguez, Cristina; Briones, Ana M

    2017-09-01

    Vascular stiffness, structural elastin abnormalities, and increased oxidative stress are hallmarks of hypertension. Lysyl oxidase (LOX) is an elastin crosslinking enzyme that produces H 2 O 2 as a by-product. We addressed the interplay between LOX, oxidative stress, vessel stiffness, and elastin. Angiotensin II (Ang II)-infused hypertensive mice and spontaneously hypertensive rats (SHR) showed increased vascular LOX expression and stiffness and an abnormal elastin structure. Mice over-expressing LOX in vascular smooth muscle cells (TgLOX) exhibited similar mechanical and elastin alterations to those of hypertensive models. LOX inhibition with β-aminopropionitrile (BAPN) attenuated mechanical and elastin alterations in TgLOX mice, Ang II-infused mice, and SHR. Arteries from TgLOX mice, Ang II-infused mice, and/or SHR exhibited increased vascular H 2 O 2 and O 2 .- levels, NADPH oxidase activity, and/or mitochondrial dysfunction. BAPN prevented the higher oxidative stress in hypertensive models. Treatment of TgLOX and Ang II-infused mice and SHR with the mitochondrial-targeted superoxide dismutase mimetic mito-TEMPO, the antioxidant apocynin, or the H 2 O 2 scavenger polyethylene glycol-conjugated catalase (PEG-catalase) reduced oxidative stress, vascular stiffness, and elastin alterations. Vascular p38 mitogen-activated protein kinase (p38MAPK) activation was increased in Ang II-infused and TgLOX mice and this effect was prevented by BAPN, mito-TEMPO, or PEG-catalase. SB203580, the p38MAPK inhibitor, normalized vessel stiffness and elastin structure in TgLOX mice. We identify LOX as a novel source of vascular reactive oxygen species and a new pathway involved in vascular stiffness and elastin remodeling in hypertension. LOX up-regulation is associated with enhanced oxidative stress that promotes p38MAPK activation, elastin structural alterations, and vascular stiffness. This pathway contributes to vascular abnormalities in hypertension. Antioxid. Redox Signal. 27

  13. Tuning Thermoresponsive Properties of Cationic Elastin-like Polypeptides by Varying Counterions and Side-Chains.

    Science.gov (United States)

    Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

    2017-05-17

    We report the synthesis of methionine-containing recombinant elastin-like polypeptides (ELPs) of different lengths that contain periodically spaced methionine residues. These ELPs were chemoselectively alkylated at all methionine residues to give polycationic derivatives. Some of these samples were found to possess solubility transitions in water, where the temperature of these transitions varied with ELP concentration, nature of the methionine alkylating group, and nature of the sulfonium counterions. These studies show that introduction and controlled spacing of methionine sulfonium residues into ELPs can be used as a means both to tune their solubility transition temperatures in water using a variety of different parameters and to introduce new side-chain functionality.

  14. 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 ...

  15. Fibulin-4 E57K Knock-in Mice Recapitulate Cutaneous, Vascular and Skeletal Defects of Recessive Cutis Laxa 1B with both Elastic Fiber and Collagen Fibril Abnormalities.

    Science.gov (United States)

    Igoucheva, Olga; Alexeev, Vitali; Halabi, Carmen M; Adams, Sheila M; Stoilov, Ivan; Sasaki, Takako; Arita, Machiko; Donahue, Adele; Mecham, Robert P; Birk, David E; Chu, Mon-Li

    2015-08-28

    Fibulin-4 is an extracellular matrix protein essential for elastic fiber formation. Frameshift and missense mutations in the fibulin-4 gene (EFEMP2/FBLN4) cause autosomal recessive cutis laxa (ARCL) 1B, characterized by loose skin, aortic aneurysm, arterial tortuosity, lung emphysema, and skeletal abnormalities. Homozygous missense mutations in FBLN4 are a prevalent cause of ARCL 1B. Here we generated a knock-in mouse strain bearing a recurrent fibulin-4 E57K homozygous missense mutation. The mutant mice survived into adulthood and displayed abnormalities in multiple organ systems, including loose skin, bent forelimb, aortic aneurysm, tortuous artery, and pulmonary emphysema. Biochemical studies of dermal fibroblasts showed that fibulin-4 E57K mutant protein was produced but was prone to dimer formation and inefficiently secreted, thereby triggering an endoplasmic reticulum stress response. Immunohistochemistry detected a low level of fibulin-4 E57K protein in the knock-in skin along with altered expression of selected elastic fiber components. Processing of a precursor to mature lysyl oxidase, an enzyme involved in cross-linking of elastin and collagen, was compromised. The knock-in skin had a reduced level of desmosine, an elastin-specific cross-link compound, and ultrastructurally abnormal elastic fibers. Surprisingly, structurally aberrant collagen fibrils and altered organization into fibers were characteristics of the knock-in dermis and forelimb tendons. Type I collagen extracted from the knock-in skin had decreased amounts of covalent intermolecular cross-links, which could contribute to the collagen fibril abnormalities. Our studies provide the first evidence that fibulin-4 plays a role in regulating collagen fibril assembly and offer a preclinical platform for developing treatments for ARCL 1B. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. The association of elastin gene variants with two angiographic subtypes of polypoidal choroidal vasculopathy.

    Directory of Open Access Journals (Sweden)

    Suiho Yanagisawa

    Full Text Available To compare the association of elastin (ELN gene variants between two different angiographic phenotypes of polypoidal choroidal vasculopathy (PCV.We included 411 treatment-naïve PCV patients and 350 controls in the present study. PCV was classified into two phenotypes (152 Type 1 and 259 Type 2 according to the presence or absence of feeding vessels found in indocyanine-green angiography. Single nucleotide polymorphisms (SNPs in the ELN region including rs868005, rs884843, rs2301995, rs13239907 and rs2856728 were genotyped using TaqMan Genotyping Assays.In the allelic association analyses, rs868005 showed the strongest association with Type 2 PCV (allelic odds ratio 1.56; p = 7.4x10(-6, while no SNP was significantly associated with Type 1 PCV. Genotype association analyses revealed the significant association of rs868005 with Type 2 PCV in log additive model and predominant model (odds ratio 1.75; p = 1.5x10(-6 and odds ratio 1.60; p = 0.0044, respectively, but not with Type 1 PCV. These findings were further corroborated by another control group in the literature.There may be significantly different associations in genetic variants of elastin between two angiographic phenotypes of PCV.

  17. Modulated growth, stability and interactions of liquid-like coacervate assemblies of elastin.

    Science.gov (United States)

    Muiznieks, Lisa D; Cirulis, Judith T; van der Horst, Astrid; Reinhardt, Dieter P; Wuite, Gijs J L; Pomès, Régis; Keeley, Fred W

    2014-06-01

    Elastin self-assembles from monomers into polymer networks that display elasticity and resilience. The first major step in assembly is a liquid-liquid phase separation known as coacervation. This process represents a continuum of stages from initial phase separation to early growth of droplets by coalescence and later "maturation" leading to fiber formation. Assembly of tropoelastin-rich globules is on pathway for fiber formation in vivo. However, little is known about these intermediates beyond their size distribution. Here we investigate the contribution of sequence and structural motifs from full-length tropoelastin and a set of elastin-like polypeptides to the maturation of coacervate assemblies, observing their growth, stability and interaction behavior, and polypeptide alignment within matured globules. We conclude that maturation is driven by surface properties, leading to stabilization of the interface between the hydrophobic interior and aqueous solvent, potentially through structural motifs, and discuss implications for droplet interactions in fiber formation. Copyright © 2014. Published by Elsevier B.V.

  18. 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.

  19. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  20. Deposition of insoluble elastin by pulmonary fibroblasts from patients with COPD is increased by treatment with versican siRNA.

    Science.gov (United States)

    Wu, Lian; Zhang, Jing; Qu, Jie Ming; Bai, Chun-Xue; Merrilees, Mervyn J

    2017-01-01

    A reduced content of alveolar elastic fibers is a key feature of COPD lung. Despite continued elastogenic potential by alveolar fibroblasts in the lung affected by COPD, repair of elastic fibers does not take place, which is due to increased levels of the chondroitin sulfate proteoglycan versican that inhibits the assembly of tropoelastin into fibers. In this study, primary pulmonary fibroblast cell lines from COPD and non-COPD patients were treated with a small interfering RNA (siRNA) against versican to determine if knockdown of versican could restore the deposition of insoluble elastin. Versican siRNA treatment reduced versican expression and secretion by pulmonary fibroblasts from both COPD and non-COPD patients ( P elastin in the COPD cell cultures ( P elastin (tropoelastin) in either the COPD or non-COPD cell cultures, supporting a role for versican in inhibiting assembly but not synthesis of tropoelastin. These results suggest that removal or knockdown of versican may be a possible therapeutic strategy for increasing deposition of insoluble elastin and stimulating repair of elastic fibers in COPD lung.

  1. Circulating Elastin Fragments Are Not Affected by Hepatic, Renal and Hemodynamic Changes, But Reflect Survival in Cirrhosis with TIPS

    DEFF Research Database (Denmark)

    Nielsen, M J; Lehmann, J; Leeming, D J

    2015-01-01

    at TIPS insertion and 2 weeks later. The circulating levels of elastin fragments (ELM) were determined using specific monoclonal ELISA. The relationship of ELM with clinical short-time follow-up and long-term outcome was investigated. RESULTS: Circulating levels of ELM showed a gradient across the liver...

  2. Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

    Directory of Open Access Journals (Sweden)

    Shinya Yano

    2015-01-01

    Full Text Available Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO. First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC, a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.

  3. Deposition of insoluble elastin by pulmonary fibroblasts from patients with COPD is increased by treatment with versican siRNA

    Directory of Open Access Journals (Sweden)

    Wu L

    2017-01-01

    Full Text Available Lian Wu,1,2 Jing Zhang,3 Jie Ming Qu,4 Chun-xue Bai,3 Mervyn J Merrilees5 1Department of Community and Health Services, Unitec, 2Department of Pharmacology & Clinical Pharmacology, University of Auckland, Auckland, New Zealand; 3Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 4Department of Pulmonary Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China; 5Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand Abstract: A reduced content of alveolar elastic fibers is a key feature of COPD lung. Despite continued elastogenic potential by alveolar fibroblasts in the lung affected by COPD, repair of elastic fibers does not take place, which is due to increased levels of the chondroitin sulfate proteoglycan versican that inhibits the assembly of tropoelastin into fibers. In this study, primary pulmonary fibroblast cell lines from COPD and non-COPD patients were treated with a small interfering RNA (siRNA against versican to determine if knockdown of versican could restore the deposition of insoluble elastin. Versican siRNA treatment reduced versican expression and secretion by pulmonary fibroblasts from both COPD and non-COPD patients (P<0.01 and significantly increased deposition of insoluble elastin in the COPD cell cultures (P<0.05. The treatment, however, did not significantly affect production of soluble elastin (tropoelastin in either the COPD or non-COPD cell cultures, supporting a role for versican in inhibiting assembly but not synthesis of tropoelastin. These results suggest that removal or knockdown of versican may be a possible therapeutic strategy for increasing deposition of insoluble elastin and stimulating repair of elastic fibers in COPD lung. Keywords: pulmonary fibroblasts, COPD, elastin, versican

  4. Collagen and Glycosaminoglycan Profiles in the Canine Cervix during Different Stages of the Estrous Cycle and in Open- and Closed-Cervix Pyometra

    Science.gov (United States)

    LINHARATTANARUKSA, Pichanun; SRISUWATANASAGUL, Sayamon; PONGLOWHAPAN, Suppawiwat; KHALID, Muhammad; CHATDARONG, Kaywalee

    2013-01-01

    ABSTRACT The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson’s trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra. PMID:24152876

  5. Helicase-like transcription factor (Hltf regulates G2/M transition, Wt1/Gata4/Hif-1a cardiac transcription networks, and collagen biogenesis.

    Directory of Open Access Journals (Sweden)

    Rebecca A Helmer

    Full Text Available HLTF/Hltf regulates transcription, remodels chromatin, and coordinates DNA damage repair. Hltf is expressed in mouse brain and heart during embryonic and postnatal development. Silencing Hltf is semilethal. Seventy-four percent of congenic C57BL/6J Hltf knockout mice died, 75% within 12-24 hours of birth. Previous studies in neonatal (6-8 hour postpartum brain revealed silencing Hltf disrupted cell cycle progression, and attenuated DNA damage repair. An RNA-Seq snapshot of neonatal heart transcriptome showed 1,536 of 20,000 total transcripts were altered (p < 0.05 - 10 up- and 1,526 downregulated. Pathway enrichment analysis with MetaCore™ showed Hltf's regulation of the G2/M transition (p=9.726E(-15 of the cell cycle in heart is nearly identical to its role in brain. In addition, Brca1 and 12 members of the Brca1 associated genome surveillance complex are also downregulated. Activation of caspase 3 coincides with transcriptional repression of Bcl-2. Hltf loss caused downregulation of Wt1/Gata4/Hif-1a signaling cascades as well as Myh7b/miR499 transcription. Hltf-specific binding to promoters and/or regulatory regions of these genes was authenticated by ChIP-PCR. Hif-1a targets for prolyl (P4ha1, P4ha2 and lysyl (Plod2 collagen hydroxylation, PPIase enzymes (Ppid, Ppif, Ppil3 for collagen trimerization, and lysyl oxidase (Loxl2 for collagen-elastin crosslinking were downregulated. However, transcription of genes for collagens, fibronectin, Mmps and their inhibitors (Timps was unaffected. The collective downregulation of genes whose protein products control collagen biogenesis caused disorganization of the interstitial and perivascular myocardial collagen fibrillar network as viewed with picrosirius red-staining, and authenticated with spectral imaging. Wavy collagen bundles in control hearts contrasted with collagen fibers that were thin, short and disorganized in Hltf null hearts. Collagen bundles in Hltf null hearts were tangled and

  6. 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.

  7. 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.

  8. 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...

  9. 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)

  10. 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.

  11. Exploring the Properties of Genetically Engineered Silk-Elastin-Like Protein Films.

    Science.gov (United States)

    Machado, Raul; da Costa, André; Sencadas, Vitor; Pereira, Ana Margarida; Collins, Tony; Rodríguez-Cabello, José Carlos; Lanceros-Méndez, Senentxu; Casal, Margarida

    2015-12-01

    Free standing films of a genetically engineered silk-elastin-like protein (SELP) were prepared using water and formic acid as solvents. Exposure to methanol-saturated air promoted the formation of aggregated β-strands rendering aqueous insolubility and improved the mechanical properties leading to a 10-fold increase in strain-to-failure. The films were optically clear with resistivity values similar to natural rubber and thermally stable up to 180 °C. Addition of glycerol showed to enhance the flexibility of SELP/glycerol films by interacting with SELP molecules through hydrogen bonding, interpenetrating between the polymer chains and granting more conformational freedom. This detailed characterization provides cues for future and unique applications using SELP based biopolymers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Effect of Sequence Blockiness on the Morphologies of Surface-grafted Elastin-like Polypeptides

    Science.gov (United States)

    Albert, Julie; Sintavanon, Kornkanok; Mays, Robin; MacEwan, Sarah; Chilkoti, Ashutosh; Genzer, Jan

    2014-03-01

    The inter- and intra- molecular interactions among monomeric units of copolymers and polypeptides depend strongly on monomer sequence distribution and dictate the phase behavior of these species both in solution and on surfaces. To study the relationship between sequence and phase behavior, we have designed a series of elastin-like polypeptides (ELPs) with controlled monomer sequences that mimic copolymers with various co-monomer sequence distributions and attached them covalently to silicon substrates from buffer solutions at temperatures below and above the bulk ELPs' lower critical solution temperatures (LCSTs). The dependence of ELP grafting density on solution temperature was examined by ellipsometry and the resultant surface morphologies were examined in air and under water with atomic force microscopy. Depositions performed above the LCST resulted in higher grafting densities and greater surface roughness of ELPs relative to depositions carried out below the LCST. In addition, we are using gradient substrates to examine the effect of ELP grafting density on temperature responsiveness.

  13. Elastin-like polypeptides: Therapeutic applications for an emerging class of nanomedicines.

    Science.gov (United States)

    Despanie, Jordan; Dhandhukia, Jugal P; Hamm-Alvarez, Sarah F; MacKay, J Andrew

    2016-10-28

    Elastin-like polypeptides (ELPs) constitute a genetically engineered class of 'protein polymers' derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain soluble below a transition temperature (T t ) but form amorphous coacervates above T t . Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields. Copyright © 2015. Published by Elsevier B.V.

  14. Cutis laxa: reduced elastin gene expression in skin fibroblast cultures as determined by hybridizations with a homologous cDNA and an exon 1-specific oligonucleotide

    International Nuclear Information System (INIS)

    Olsen, D.R.; Fazio, M.J.; Shamban, A.T.; Rosenbloom, J.; Uitto, J.

    1988-01-01

    Fibroblast cultures were established from six patients with cutis laxa, and elastin gene expression was analyzed by RNA hybridizations with a 2.5-kilobase human elastin cDNA or an exon 1-specific 35-base oligomer. Northern analyses using either probe detected mRNA transcripts of ∼ 3.5 kilobases, and no qualitative difference between the control and cutis laxa mRNAs was detected. However, quantitation of the elastin mRNA abundance by slot blot hybridizations revealed markedly reduced levels in all cutis laxa cell strains. Assuming equal translational activity of the control and cutix laxa mRNAs, the reduced mRNA levels could result in diminished elastin production, providing an explanation for the paucity of elastic fibers in the skin and other tissues in cutis laxa

  15. Routes towards Novel Collagen-Like Biomaterials

    Directory of Open Access Journals (Sweden)

    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. Enzymatic cross-linking of human recombinant elastin (HELP) as biomimetic approach in vascular tissue engineering.

    Science.gov (United States)

    Bozzini, Sabrina; Giuliano, Liliana; Altomare, Lina; Petrini, Paola; Bandiera, Antonella; Conconi, Maria Teresa; Farè, Silvia; Tanzi, Maria Cristina

    2011-12-01

    The use of polymers naturally occurring in the extracellular matrix (ECM) is a promising strategy in regenerative medicine. If compared to natural ECM proteins, proteins obtained by recombinant DNA technology have intrinsic advantages including reproducible macromolecular composition, sequence and molecular mass, and overcoming the potential pathogens transmission related to polymers of animal origin. Among ECM-mimicking materials, the family of recombinant elastin-like polymers is proposed for drug delivery applications and for the repair of damaged elastic tissues. This work aims to evaluate the potentiality of a recombinant human elastin-like polypeptide (HELP) as a base material of cross-linked matrices for regenerative medicine. The cross-linking of HELP was accomplished by the insertion of cross-linking sites, glutamine and lysine, in the recombinant polymer and generating ε-(γ-glutamyl) lysine links through the enzyme transglutaminase. The cross-linking efficacy was estimated by infrared spectroscopy. Freeze-dried cross-linked matrices showed swelling ratios in deionized water (≈2500%) with good structural stability up to 24 h. Mechanical compression tests, performed at 37°C in wet conditions, in a frequency sweep mode, indicated a storage modulus of 2/3 kPa, with no significant changes when increasing number of cycles or frequency. These results demonstrate the possibility to obtain mechanically resistant hydrogels via enzymatic crosslinking of HELP. Cytotoxicity tests of cross-linked HELP were performed with human umbilical vein endothelial cells, by use of transwell filter chambers for 1-7 days, or with its extracts in the opportune culture medium for 24 h. In both cases no cytotoxic effects were observed in comparison with the control cultures. On the whole, the results suggest the potentiality of this genetically engineered HELP for regenerative medicine applications, particularly for vascular tissue regeneration.

  17. Electrospun silk-elastin-like fibre mats for tissue engineering applications

    International Nuclear Information System (INIS)

    Machado, Raul; Da Costa, André; Padrão, Jorge; Gomes, Andreia; Casal, Margarida; Sencadas, Vitor; Costa, Carlos M; Lanceros-Méndez, Senentxu; Garcia-Arévalo, Carmen; Rodríguez-Cabello, José Carlos

    2013-01-01

    Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing its dependence on the concentration and solvent used. Treatment with methanol-saturated air was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570–720%), water vapour transmission rate (1083 g/m 2 /day) and mechanical properties (modulus of elasticity ∼126 MPa). Furthermore, the methanol-treated SELP fibre mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fibre mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications. (paper)

  18. Elastin-like Polypeptide Linkers for Single-Molecule Force Spectroscopy.

    Science.gov (United States)

    Ott, Wolfgang; Jobst, Markus A; Bauer, Magnus S; Durner, Ellis; Milles, Lukas F; Nash, Michael A; Gaub, Hermann E

    2017-06-27

    Single-molecule force spectroscopy (SMFS) is by now well established as a standard technique in biophysics and mechanobiology. In recent years, the technique has benefitted greatly from new approaches to bioconjugation of proteins to surfaces. Indeed, optimized immobilization strategies for biomolecules and refined purification schemes are being steadily adapted and improved, which in turn has enhanced data quality. In many previously reported SMFS studies, poly(ethylene glycol) (PEG) was used to anchor molecules of interest to surfaces and/or cantilever tips. The limitation, however, is that PEG exhibits a well-known trans-trans-gauche to all-trans transition, which results in marked deviation from standard polymer elasticity models such as the worm-like chain, particularly at elevated forces. As a result, the assignment of unfolding events to protein domains based on their corresponding amino acid chain lengths is significantly obscured. Here, we provide a solution to this problem by implementing unstructured elastin-like polypeptides as linkers to replace PEG. We investigate the suitability of tailored elastin-like polypeptides linkers and perform direct comparisons to PEG, focusing on attributes that are critical for single-molecule force experiments such as linker length, monodispersity, and bioorthogonal conjugation tags. Our results demonstrate that by avoiding the ambiguous elastic response of mixed PEG/peptide systems and instead building the molecular mechanical systems with only a single bond type with uniform elastic properties, we improve data quality and facilitate data analysis and interpretation in force spectroscopy experiments. The use of all-peptide linkers allows alternative approaches for precisely defining elastic properties of proteins linked to surfaces.

  19. 3D silicon doped hydroxyapatite scaffolds decorated with Elastin-like Recombinamers for bone regenerative medicine.

    Science.gov (United States)

    Vila, Mercedes; García, Ana; Girotti, Alessandra; Alonso, Matilde; Rodríguez-Cabello, Jose Carlos; González-Vázquez, Arlyng; Planell, Josep A; Engel, Elisabeth; Buján, Julia; García-Honduvilla, Natalio; Vallet-Regí, María

    2016-11-01

    The current study reports on the manufacturing by rapid prototyping technique of three-dimensional (3D) scaffolds based on silicon substituted hydroxyapatite with Elastin-like Recombinamers (ELRs) functionalized surfaces. Silicon doped hydroxyapatite (Si-HA), with Ca 10 (PO 4 ) 5.7 (SiO 4 ) 0.3 (OH) 1.7 h 0.3 nominal formula, was surface functionalized with two different types of polymers designed by genetic engineering: ELR-RGD that contain cell attachment specific sequences and ELR-SN A 15/RGD with both hydroxyapatite and cells domains that interact with the inorganic phase and with the cells, respectively. These hybrid materials were subjected to in vitro assays in order to clarify if the ELRs coating improved the well-known biocompatible and bone regeneration properties of calcium phosphates materials. The in vitro tests showed that there was a total and homogeneous colonization of the 3D scaffolds by Bone marrow Mesenchymal Stromal Cells (BMSCs). In addition, the BMSCs were viable and able to proliferate and differentiate into osteoblasts. Bone tissue engineering is an area of increasing interest because its main applications are directly related to the rising life expectancy of the population, which promotes higher rates of several bone pathologies, so innovative strategies are needed for bone tissue regeneration therapies. Here we use the rapid prototyping technology to allow moulding ceramic 3D scaffolds and we use different bio-polymers for the functionalization of their surfaces in order to enhance the biological response. Combining the ceramic material (silicon doped hydroxyapatite, Si-HA) and the Elastin like Recombinamers (ELRs) polymers with the presence of the integrin-mediate adhesion domain alone or in combination with SNA15 peptide that possess high affinity for hydroxyapatite, provided an improved Bone marrow Mesenchymal Stromal Cells (BMSCs) differentiation into osteoblastic linkage. Copyright © 2016 Acta Materialia Inc. Published by Elsevier

  20. 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

  1. Laser welding and collagen crosslinks

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, K.M.; Last, J.A. [California Univ., Davis, CA (United States). Dept. of Medicine; Small, W. IV; Maitland, D.J.; Heredia, N.J.; Da Silva, L.B.; Matthews, D.L. [Lawrence Livermore National Lab., CA (United States)

    1997-02-20

    Strength and stability of laser-welded tissue may be influenced, in part, by effects of laser exposure on collagen crosslinking. We therefore studied effects of diode laser exposure (805 nm, 1-8 watts, 30 seconds) + indocyanine green dye (ICG) on calf tail tendon collagen crosslinks. Effect of ICG dye alone on crosslink content prior to laser exposure was investigated; unexpectedly, we found that ICG-treated tissue had significantly increased DHLNL and OHP, but not HLNL. Laser exposure after ICG application reduced elevated DHLNL and OHP crosslink content down to their native levels. The monohydroxylated crosslink HLNL was inversely correlated with laser output (p<0.01 by linear regression analysis). DHLNL content was highly correlated with content of its maturational product, OHP, suggesting that precursor-product relations are maintained. We conclude that: (1)ICG alone induces DHLNL and OHP crosslink formation; (2)subsequent laser exposure reduces the ICG-induced crosslinks down to native levels; (3)excessive diode laser exposure destroys normally occurring HLNL crosslinks.

  2. 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.

  3. 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,

  4. 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.

  5. Acute Myocardial Infarction and Pulmonary Diseases Result in Two Different Degradation Profiles of Elastin as Quantified by Two Novel ELISAs

    DEFF Research Database (Denmark)

    Skjøt-Arkil, Helene; Clausen, Rikke E; Rasmussen, Lars M

    2013-01-01

    and ELM-2 ELISAs was evaluated in patients with acute myocardial infarction (AMI), no AMI, high coronary calcium, or low coronary calcium. The serological release of ELM-2 in patients with chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF) was compared to controls. RESULTS......BACKGROUND: Elastin is a signature protein of the arteries and lungs, thus it was hypothesized that elastin is subject to enzymatic degradation during cardiovascular and pulmonary diseases. The aim was to investigate if different fragments of the same protein entail different information associated...... and no correlation was observed between ELM-2 and ELM. ELM-2 was not elevated in the COPD and IPF patients and was not correlated to ELM. ELM was shown to be correlated with smoking habits (ppulmonary diseases...

  6. 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...

  7. Thermoresponsive self-assembly of short elastin-like polypentapeptides and their poly(ethylene glycol) derivatives

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Brus, Jiří; Kostka, Libor; Koňák, Čestmír; Urbanová, Martina; Šlouf, Miroslav

    2007-01-01

    Roč. 7, č. 1 (2007), s. 56-69 ISSN 1616-5187 R&D Projects: GA ČR GA204/05/2255; GA AV ČR IAA100500501 Institutional research plan: CEZ:AV0Z40500505 Keywords : elastin -like peptides * self-assembly * poly(ethylene glycol) Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.831, year: 2007

  8. Role of Matrix Metalloproteinases-1 and -2 in Interleukin-13–Suppressed Elastin in Airway Fibroblasts in Asthma

    Science.gov (United States)

    Slade, David; Church, Tony D.; Francisco, Dave; Heck, Karissa; Sigmon, R. Wesley; Ghio, Michael; Murillo, Anays; Firszt, Rafael; Lugogo, Njira L.; Que, Loretta; Sunday, Mary E.; Kraft, Monica

    2016-01-01

    Elastin synthesis and degradation in the airway and lung parenchyma contribute to airway mechanics, including airway patency and elastic recoil. IL-13 mediates many features of asthma pathobiology, including airway remodeling, but the effects of IL-13 on elastin architecture in the airway wall are not known. We hypothesized that IL-13 modulates elastin expression in airway fibroblasts from subjects with allergic asthma. Twenty-five subjects with mild asthma (FEV1, 89 ± 3% predicted) and 30 normal control subjects (FEV1, 102 ± 2% predicted) underwent bronchoscopy with endobronchial biopsy. Elastic fibers were visualized in airway biopsy specimens using Weigert’s resorcin-fuchsin elastic stain. Airway fibroblasts were exposed to IL-13; a pan-matrix metalloproteinase (MMP) inhibitor (GM6001); specific inhibitors to MMP-1, -2, -3, and -8; and combinations of IL-13 with MMP inhibitors in separate conditions in serum-free media for 48 hours. Elastin (ELN) expression as well as MMP secretion and activity were quantified. Results of this study show that elastic fiber staining of airway biopsy tissue was significantly associated with methacholine PC20 (i.e., the provocative concentration of methacholine resulting in a 20% fall in FEV1 levels) in patients with asthma. IL-13 significantly suppressed ELN expression in asthmatic airway fibroblasts as compared with normal control fibroblasts. The effect of IL-13 on ELN expression was significantly correlated with postbronchodilator FEV1/FVC in patients with asthma. MMP inhibition significantly stimulated ELN expression in patients with asthma as compared with normal control subjects. Specific inhibition of MMP-1 and MMP-2, but not MMP-3 or MMP-8, reversed the IL-13–induced suppression of ELN expression. In asthma, MMP-1 and MMP-2 mediate IL-13–induced suppression of ELN expression in airway fibroblasts. PMID:26074138

  9. Role of Matrix Metalloproteinases-1 and -2 in Interleukin-13-Suppressed Elastin in Airway Fibroblasts in Asthma.

    Science.gov (United States)

    Ingram, Jennifer L; Slade, David; Church, Tony D; Francisco, Dave; Heck, Karissa; Sigmon, R Wesley; Ghio, Michael; Murillo, Anays; Firszt, Rafael; Lugogo, Njira L; Que, Loretta; Sunday, Mary E; Kraft, Monica

    2016-01-01

    Elastin synthesis and degradation in the airway and lung parenchyma contribute to airway mechanics, including airway patency and elastic recoil. IL-13 mediates many features of asthma pathobiology, including airway remodeling, but the effects of IL-13 on elastin architecture in the airway wall are not known. We hypothesized that IL-13 modulates elastin expression in airway fibroblasts from subjects with allergic asthma. Twenty-five subjects with mild asthma (FEV1, 89 ± 3% predicted) and 30 normal control subjects (FEV1, 102 ± 2% predicted) underwent bronchoscopy with endobronchial biopsy. Elastic fibers were visualized in airway biopsy specimens using Weigert's resorcin-fuchsin elastic stain. Airway fibroblasts were exposed to IL-13; a pan-matrix metalloproteinase (MMP) inhibitor (GM6001); specific inhibitors to MMP-1, -2, -3, and -8; and combinations of IL-13 with MMP inhibitors in separate conditions in serum-free media for 48 hours. Elastin (ELN) expression as well as MMP secretion and activity were quantified. Results of this study show that elastic fiber staining of airway biopsy tissue was significantly associated with methacholine PC20 (i.e., the provocative concentration of methacholine resulting in a 20% fall in FEV1 levels) in patients with asthma. IL-13 significantly suppressed ELN expression in asthmatic airway fibroblasts as compared with normal control fibroblasts. The effect of IL-13 on ELN expression was significantly correlated with postbronchodilator FEV1/FVC in patients with asthma. MMP inhibition significantly stimulated ELN expression in patients with asthma as compared with normal control subjects. Specific inhibition of MMP-1 and MMP-2, but not MMP-3 or MMP-8, reversed the IL-13-induced suppression of ELN expression. In asthma, MMP-1 and MMP-2 mediate IL-13-induced suppression of ELN expression in airway fibroblasts.

  10. Acute Myocardial Infarction and Pulmonary Diseases Result in Two Different Degradation Profiles of Elastin as Quantified by Two Novel ELISAs.

    Directory of Open Access Journals (Sweden)

    Helene Skjøt-Arkil

    Full Text Available Elastin is a signature protein of the arteries and lungs, thus it was hypothesized that elastin is subject to enzymatic degradation during cardiovascular and pulmonary diseases. The aim was to investigate if different fragments of the same protein entail different information associated to two different diseases and if these fragments have the potential of being diagnostic biomarkers.Monoclonal antibodies were raised against an identified fragment (the ELM-2 neoepitope generated at the amino acid position '552 in elastin by matrix metalloproteinase (MMP -9/-12. A newly identified ELM neoepitope was generated by the same proteases but at amino acid position '441. The distribution of ELM-2 and ELM, in human arterial plaques and fibrotic lung tissues were investigated by immunohistochemistry. A competitive ELISA for ELM-2 was developed. The clinical relevance of the ELM and ELM-2 ELISAs was evaluated in patients with acute myocardial infarction (AMI, no AMI, high coronary calcium, or low coronary calcium. The serological release of ELM-2 in patients with chronic obstructive pulmonary disease (COPD or idiopathic pulmonary fibrosis (IPF was compared to controls.ELM and ELM-2 neoepitopes were both localized in diseased carotid arteries and fibrotic lungs. In the cardiovascular cohort, ELM-2 levels were 66% higher in serum from AMI patients compared to patients with no AMI (p<0.01. Levels of ELM were not significantly increased in these patients and no correlation was observed between ELM-2 and ELM. ELM-2 was not elevated in the COPD and IPF patients and was not correlated to ELM. ELM was shown to be correlated with smoking habits (p<0.01.The ELM-2 neoepitope was related to AMI whereas the ELM neoepitope was related to pulmonary diseases. These results indicate that elastin neoepitopes generated by the same proteases but at different amino acid sites provide different tissue-related information depending on the disease in question.

  11. Heat Shock Protein 90 Inhibitor Decreases Collagen Synthesis of Keloid Fibroblasts and Attenuates the Extracellular Matrix on the Keloid Spheroid Model.

    Science.gov (United States)

    Lee, Won Jai; Lee, Ju Hee; Ahn, Hyo Min; Song, Seung Yong; Kim, Yong Oock; Lew, Dae Hyun; Yun, Chae-Ok

    2015-09-01

    The 90-kDa heat-shock protein (heat-shock protein 90) is an abundant cytosolic chaperone, and inhibition of heat-shock protein 90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) compromises transforming growth factor (TGF)-β-mediated transcriptional responses by enhancing TGF-β receptor I and II degradation, thus preventing Smad2/3 activation. In this study, the authors evaluated whether heat-shock protein 90 regulates TGF-β signaling in the pathogenesis and treatment of keloids. Keloid fibroblasts were treated with 17-AAG (10 μM), and mRNA levels of collagen types I and III were determined by real-time reverse- transcriptase polymerase chain reaction. Also, secreted TGF-β1 was assessed by enzyme-linked immunosorbent assay. The effect of 17-AAG on protein levels of Smad2/3 complex was determined by Western blot analysis. In addition, in 17-AAG-treated keloid spheroids, the collagen deposition and expression of major extracellular matrix proteins were investigated by means of Masson trichrome staining and immunohistochemistry. The authors found that heat-shock protein 90 is overexpressed in human keloid tissue compared with adjacent normal tissue, and 17-AAG decreased mRNA levels of type I collagen, secreted TGF-ß1, and Smad2/3 complex protein expression in keloid fibroblasts. Masson trichrome staining revealed that collagen deposition was decreased in 17-AAG-treated keloid spheroids, and immunohistochemical analysis showed that expression of collagen types I and III, elastin, and fibronectin was markedly decreased in 17-AAG-treated keloid spheroids. These results suggest that the antifibrotic action of heat-shock protein 90 inhibitors such as 17-AAG may have therapeutic effects on keloids.

  12. Alternative splicing of human elastin mRNA indicated by sequence analysis of cloned genomic and complementary DNA

    International Nuclear Information System (INIS)

    Indik, Z.; Yeh, H.; Ornstein-goldstein, N.; Sheppard, P.; Anderson, N.; Rosenbloom, J.C.; Peltonen, L.; Rosenbloom, J.

    1987-01-01

    Poly(A) + RNA, isolated from a single 7-mo fetal human aorta, was used to synthesize cDNA by the RNase H method, and the cDNA was inserted into λgt10. Recombinant phage containing elastin sequences were identified by hybridization with cloned, exon-containing fragments of the human elastin gene. Three clones containing inserts of 3.3, 2.7, and 2.3 kilobases were selected for further analysis. Three overlapping clones containing 17.8 kilobases of the human elastin gene were also isolated from genomic libraries. Complete sequence analysis of the six clones demonstrated that: (i) the cDNA encompassed the entire translated portion of the mRNA encoding 786 amino acids, including several unusual hydrophilic amino acid sequences not previously identified in porcine tropoelastin, (ii) exons encoding either hydrophobic or crosslinking domains in the protein alternated in the gene, and (iii) a great abundance of Alu repetitive sequences occurred throughout the introns. The data also indicated substantial alternative splicing of the mRNA. These results suggest the potential for significant variation in the precise molecular structure of the elastic fiber in the human population

  13. Serological neo-epitope extracellular matrix related markers reflecting collagen or elastin degradation are elevated in a mouse model of allergic asthma exacerbation

    NARCIS (Netherlands)

    Weckmann, M.; Rønnow, S.; Bülow-Sand, J.M.; Wegmann, M.; Lunding, L.; Burgess, J.; Bahmer, T.; Leeming, D.J.; Kopp, M.V.

    2018-01-01

    Asthma is a chronic inflammatory disease, characterized by symptoms including increased mucus production, reversible airway obstruction and lung inflammation: all of which are exaggerated during asthma exacerbations. Extracellular matrix remodeling is associated with the release of ECM protein

  14. Bio-inspired synthesis of hybrid silica nanoparticles templated from elastin-like polypeptide micelles

    Science.gov (United States)

    Han, Wei; MacEwan, Sarah R.; Chilkoti, Ashutosh; López, Gabriel P.

    2015-07-01

    The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well-defined spherical micelles. Genetically encoded incorporation of the silaffin R5 peptide at the hydrophilic terminus of the diblock ELP leads to presentation of the silaffin R5 peptide on the coronae of the micelles, which results in localized condensation of silica and the formation of near-monodisperse, discrete, sub-100 nm diameter hybrid ELP-silica particles. This synthesis method, can be carried out under mild reaction conditions suitable for bioactive materials, and will serve as the basis for the development and application of functional nanomaterials. Beyond silicification, the general strategies described herein may also be adapted for the synthesis of other biohybrid nanomaterials as well.The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomimetic silaffin peptides in these block copolymers enables the formation of hybrid organic-inorganic materials, which can potentially enhance the utility and stability of self-assembled nanostructures. We demonstrate the design, synthesis and characterization of amphiphilic elastin-like polypeptide (ELP) diblock copolymers that undergo temperature-triggered self-assembly into well

  15. Expression and Purification of Neurotrophin-Elastin-Like Peptide Fusion Proteins for Neural Regeneration.

    Science.gov (United States)

    Johnson, Tamina; Koria, Piyush

    2016-04-01

    Neural injuries such as spinal cord injuries, traumatic brain injuries, or nerve transection injuries pose a major health problem. Neurotrophins such as nerve growth factor (NGF) or brain-derived neurotrophic factor (BDNF) have been shown to improve the outcome of neural injuries in several pre-clinical models, but their use in clinics is limited by the lack of a robust delivery system that enhances their bioavailability and half-life. We describe two fusion proteins comprising NGF or BDNF fused with elastin-like peptides (ELPs). The aim of this study was to investigate the biological activity of neurotrophin-ELP (N-ELP) fusion proteins via in vitro culture models. NGF and BDNF were cloned in front of an elastin-like polypeptide sequence V40C2. These proteins were expressed in bacteria as inclusion bodies. These fusion proteins underwent solubilization via 8 M urea and purification via inverse transition cycling (ITC). We measured the particle size and the effect of temperature on precipitated particles using dynamic light scattering (DLS). We used western blot analysis to confirm the specificity of NGF-ELP to tropomyosin receptor kinase A (TrkA) antibody and to confirm the specificity of BDNF-ELP to TrkB antibody. PC12 cells were used to perform a neurite outgrowth assay to determine the biological activity of NGF-ELP. Bioactivity of BDNF-ELP was ascertained via transfecting human epithelial kidney (HEK 293-T) cells to express the TrkB receptor. The proteins were successfully purified to high homogeneity by exploiting the phase transition property of ELPs and urea, which solubilize inclusion bodies. Using PC12 neurite outgrowth assay, we further demonstrated that the biological activity of NGF was retained in the fusion. Similarly, BDNF-ELP phosphorylated the TrkB receptor, suggesting the biological activity of BDNF was also retained in the fusion. We further show that owing to the phase transition property of ELPs in the fusion, these proteins self-assembled into

  16. Peroxisome proliferator-activated receptor δ modulates MMP-2 secretion and elastin expression in human dermal fibroblasts exposed to ultraviolet B radiation.

    Science.gov (United States)

    Ham, Sun Ah; Yoo, Taesik; Hwang, Jung Seok; Kang, Eun Sil; Paek, Kyung Shin; Park, Chankyu; Kim, Jin-Hoi; Do, Jeong Tae; Seo, Han Geuk

    2014-10-01

    Changes in skin connective tissues mediated by ultraviolet (UV) radiation have been suggested to cause the skin wrinkling normally associated with premature aging of the skin. Recent investigations have shown that peroxisome proliferator-activated receptor (PPAR) δ plays multiple biological roles in skin homeostasis. We attempted to investigate whether PPARδ modulates elastin protein levels and secretion of matrix metalloproteinase (MMP)-2 in UVB-irradiated human dermal fibroblasts (HDFs) and mouse skin. These studies were undertaken in primary HDFs or HR-1 hairless mice using Western blot analyses, small interfering (si)RNA-mediated gene silencing, and Fluorescence microscopy. In HDFs, UVB irradiation induced increased secretion of MMP-2 and reduced levels of elastin. Activation of PPARδ by GW501516, a ligand specific for PPARδ, markedly attenuated UVB-induced MMP-2 secretion with a concomitant increase in the level of elastin. These effects were reduced by the presence of siRNAs against PPARδ or treatment with GSK0660, a specific inhibitor of PPARδ. Furthermore, GW501516 elicited a dose- and time-dependent increase in the expression of elastin. Modulation of MMP-2 secretion and elastin levels by GW501516 was associated with a reduction in reactive oxygen species (ROS) production in HDFs exposed to UVB. Finally, in HR-1 hairless mice, administration of GW501516 significantly reduced UVB-induced MMP-2 expression with a concomitant increase in elastin levels, and these effects were significantly reduced by the presence of GSK0660. Our results suggest that PPARδ-mediated modulation of MMP-2 secretion and elastin expression may contribute to the maintenance of skin integrity by inhibiting ROS generation. Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. In vitro colonization of the muscle extracellular matrix components by Escherichia coli O157:H7: the influence of growth medium, temperature and pH on initial adhesion and induction of biofilm formation by collagens I and III.

    Directory of Open Access Journals (Sweden)

    Caroline Chagnot

    Full Text Available Enterohemorrhagic Escherichia coli (EHEC O157:H7 are responsible for repeated food-poisoning cases often caused by contaminated burgers. EHEC infection is predominantly a pediatric illness, which can lead to life-threatening diseases. Ruminants are the main natural reservoir for EHEC and food contamination almost always originates from faecal contamination. In beef meat products, primary bacterial contamination occurs at the dehiding stage of slaughtering. The extracellular matrix (ECM is the most exposed part of the skeletal muscles in beef carcasses. Investigating the adhesion to the main muscle fibrous ECM proteins, insoluble fibronectin, collagen I, III and IV, laminin-α2 and elastin, results demonstrated that the preceding growth conditions had a great influence on subsequent bacterial attachment. In the tested experimental conditions, maximal adhesion to fibril-forming collagens I or III occurred at 25°C and pH 7. Once initially adhered, exposure to lower temperatures, as applied to meat during cutting and storage, or acidification, as in the course of post-mortem physiological modifications of muscle, had no effect on detachment, except at pHu. In addition, dense biofilm formation occurred on immobilized collagen I or III and was induced in growth medium supplemented with collagen I in solution. From this first comprehensive investigation of EHEC adhesion to ECM proteins with respect to muscle biology and meat processing, new research directions for the development of innovative practices to minimize the risk of meat contamination are further discussed.

  5. Photoreactive elastin-like proteins for use as versatile bioactive materials and surface coatings.

    Science.gov (United States)

    Raphel, Jordan; Parisi-Amon, Andreina; Heilshorn, Sarah

    2012-10-07

    Photocrosslinkable, protein-engineered biomaterials combine a rapid, controllable, cytocompatible crosslinking method with a modular design strategy to create a new family of bioactive materials. These materials have a wide range of biomedical applications, including the development of bioactive implant coatings, drug delivery vehicles, and tissue engineering scaffolds. We present the successful functionalization of a bioactive elastin-like protein with photoreactive diazirine moieties. Scalable synthesis is achieved using a standard recombinant protein expression host followed by site-specific modification of lysine residues with a heterobifunctional N-hydroxysuccinimide ester-diazirine crosslinker. The resulting biomaterial is demonstrated to be processable by spin coating, drop casting, soft lithographic patterning, and mold casting to fabricate a variety of two- and three-dimensional photocrosslinked biomaterials with length scales spanning the nanometer to millimeter range. Protein thin films proved to be highly stable over a three-week period. Cell-adhesive functional domains incorporated into the engineered protein materials were shown to remain active post-photo-processing. Human adipose-derived stem cells achieved faster rates of cell adhesion and larger spread areas on thin films of the engineered protein compared to control substrates. The ease and scalability of material production, processing versatility, and modular bioactive functionality make this recombinantly engineered protein an ideal candidate for the development of novel biomaterial coatings, films, and scaffolds.

  6. Sequence Directionality Dramatically Affects LCST Behavior of Elastin-Like Polypeptides.

    Science.gov (United States)

    Li, Nan K; Roberts, Stefan; Quiroz, Felipe Garcia; Chilkoti, Ashutosh; Yingling, Yaroslava G

    2018-04-30

    Elastin-like polypeptides (ELP) exhibit an inverse temperature transition or lower critical solution temperature (LCST) transition phase behavior in aqueous solutions. In this paper, the thermal responsive properties of the canonical ELP, poly(VPGVG), and its reverse sequence poly(VGPVG) were investigated by turbidity measurements of the cloud point behavior, circular dichroism (CD) measurements, and all-atom molecular dynamics (MD) simulations to gain a molecular understanding of mechanism that controls hysteretic phase behavior. It was shown experimentally that both poly(VPGVG) and poly(VGPVG) undergo a transition from soluble to insoluble in aqueous solution upon heating above the transition temperature ( T t ). However, poly(VPGVG) resolubilizes upon cooling below its T t , whereas the reverse sequence, poly(VGPVG), remains aggregated despite significant undercooling below the T t . The results from MD simulations indicated that a change in sequence order results in significant differences in the dynamics of the specific residues, especially valines, which lead to extensive changes in the conformations of VPGVG and VGPVG pentamers and, consequently, dissimilar propensities for secondary structure formation and overall structure of polypeptides. These changes affected the relative hydrophilicities of polypeptides above T t , where poly(VGPVG) is more hydrophilic than poly(VPGVG) with more extended conformation and larger surface area, which led to formation of strong interchain hydrogen bonds responsible for stabilization of the aggregated phase and the observed thermal hysteresis for poly(VGPVG).

  7. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Koushik; Balog, Eva Rose M.; Sista, Prakash; Williams, Darrick J.; Martinez, Jennifer S., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov; Rocha, Reginaldo C., E-mail: jenm@lanl.gov, E-mail: rcrocha@lanl.gov [Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kelly, Daniel [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-01

    We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP) as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca{sup 2+} or Cu{sup 2+}, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  8. Temperature-dependent morphology of hybrid nanoflowers from elastin-like polypeptides

    Directory of Open Access Journals (Sweden)

    Koushik Ghosh

    2014-02-01

    Full Text Available We report a method for creating hybrid organic-inorganic “nanoflowers” using calcium or copper ions as the inorganic component and a recombinantly expressed elastin-like polypeptide (ELP as the organic component. Polypeptides provide binding sites for the dynamic coordination with metal ions, and then such noncovalent complexes become nucleation sites for primary crystals of metal phosphates. We have shown that the interaction between the stimuli-responsive ELP and Ca2+ or Cu2+, in the presence of phosphate, leads to the growth of micrometer-sized particles featuring nanoscale patterns shaped like flower petals. The morphology of these flower-like composite structures is dependent upon the temperature of growth and has been characterized by scanning electron microscopy. The composition of nanoflowers has also been analyzed by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The temperature-dependent morphologies of these hybrid nanostructures, which arise from the controllable phase transition of ELPs, hold potential for morphological control of biomaterials in emerging applications such as tissue engineering and biocatalysis.

  9. Subarachnoid hemorrhage: tests of association with apolipoprotein E and elastin genes

    Directory of Open Access Journals (Sweden)

    Sauerbeck Laura

    2007-07-01

    Full Text Available Abstract Background Apolipoprotein E (APOE and elastin (ELN are plausible candidate genes involved in the pathogenesis of stroke. We tested for association of variants in APOE and ELN with subarachnoid hemorrhage (SAH in a population-based study. We genotyped 12 single nucleotide polymorphisms (SNPs on APOE and 10 SNPs on ELN in a sample of 309 Caucasian individuals, of whom 107 are SAH cases and 202 are age-, race-, and gender-matched controls from the Greater Cincinnati/Northern Kentucky region. Associations were tested at genotype, allele, and haplotype levels. A genomic control analysis was performed to check for spurious associations resulting from population substructure. Results At the APOE locus, no individual SNP was associated with SAH after correction for multiple comparisons. Haplotype analysis revealed significant association of the major haplotype (Hap1 in APOE with SAH (p = 0.001. The association stemmed from both the 5' promoter and the 3' region of the APOE gene. APOE ε2 and ε 4 were not significantly associated with SAH. No association was observed for ELN at genotype, allele, or haplotype level and our study failed to confirm previous reports of ELN association with aneurysmal SAH. Conclusion This study suggests a role of the APOE gene in the etiology of aneurysmal SAH.

  10. Elastin-like polypeptide switches: A design strategy to detect multimeric proteins.

    Science.gov (United States)

    Dhandhukia, Jugal P; Brill, Dab A; Kouhi, Aida; Pastuszka, Martha K; MacKay, J Andrew

    2017-09-01

    Elastin-Like Polypeptides (ELPs) reversibly phase separate in response to changes in temperature, pressure, concentration, pH, and ionic species. While powerful triggers, biological microenvironments present a multitude of more specific biological cues, such as antibodies, cytokines, and cell-surface receptors. To develop better biosensors and bioresponsive drug carriers, rational strategies are required to sense and respond to these target proteins. We recently reported that noncovalent association of two ELP fusion proteins to a "chemical inducer of dimerization" small molecule (1.5 kDa) induces phase separation at physiological temperatures. Having detected a small molecule, here we present the first evidence that ELP multimerization can also detect a much larger (60 kDa) protein target. To demonstrate this strategy, ELPs were biotinylated at their amino terminus and mixed with tetrameric streptavidin. At a stoichiometric ratio of [4:1], two to three biotin-ELPs associate with streptavidin into multimeric complexes with an apparent K d of 5 nM. The increased ELP density around a streptavidin core strongly promotes isothermal phase separation, which was tuned to occur at physiological temperature. This phase separation reverses upon saturation with excess streptavidin, which only favors [1:1] complexes. Together, these findings suggest that ELP association with multimeric biomolecules is a viable strategy to deliberately engineer ELPs that respond to multimeric protein substrates. © 2017 The Protein Society.

  11. EMILIN2 (Elastin microfibril interface located protein, potential modifier of thrombosis

    Directory of Open Access Journals (Sweden)

    Hoover-Plow Jane L

    2011-05-01

    Full Text Available Abstract Background Elastin microfibril interface located protein 2 (EMILIN2 is an extracellular glycoprotein associated with cardiovascular development. While other EMILIN proteins are reported to play a role in elastogenesis and coagulation, little is known about EMILIN2 function in the cardiovascular system. The objective of this study was to determine whether EMILIN2 could play a role in thrombosis. Results EMILIN2 mRNA was expressed in 8 wk old C57BL/6J mice in lung, heart, aorta and bone marrow, with the highest expression in bone marrow. In mouse cells, EMILIN2 mRNA expression in macrophages was higher than expression in endothelial cells and fibroblasts. EMILIN2 was identified with cells and extracellular matrix by immunohistochemistry in the carotid and aorta. After carotid ferric chloride injury, EMILIN2 was abundantly expressed in the thrombus and inhibition of EMILIN2 increased platelet de-aggregation after ADP-stimulated platelet aggregation. Conclusions These results suggest EMILIN2 could play a role in thrombosis as a constituent of the vessel wall and/or a component of the thrombus.

  12. Using elastin protein to develop highly efficient air cathodes for lithium-O2 batteries

    International Nuclear Information System (INIS)

    Guo, Guilue; Ang, Huixiang; Tan, Huiteng; Zhang, Yu; Guo, Yuanyuan; Fong, Eileen; Yan, Qingyu; Yao, Xin

    2016-01-01

    Transition metal-nitrogen/carbon (M-N/C, M = Fe, Co) catalysts are synthesized using environmentally friendly histidine-tag-rich elastin protein beads, metal sulfate and water soluble carbon nanotubes followed by post-annealing and acid leaching processes. The obtained catalysts are used as cathode materials in lithium-O 2 batteries. It has been discovered that during discharge, Li 2 O 2 nanoparticles first nucleate and grow around the bead-decorated CNT regions (M-N/C centres) and coat on the catalysts at a high degree of discharge. The Fe-N/C catalyst-based cathodes deliver a capacity of 12 441 mAh g −1 at a current density of 100 mA g −1 . When they were cycled at a limited capacity of 800 mAh g −1 at current densities of 200 or 400 mA g −1 , these cathodes showed stable charge voltages of ∼3.65 or 3.90 V, corresponding to energy efficiencies of ∼71.2 or 65.1%, respectively. These results are considerably superior to those of the cathodes based on bare annealed CNTs, which prove that the Fe-N/C catalysts developed here are promising for use in non-aqueous lithium-O 2 battery cathodes. (paper)

  13. Double network physical gels from elastin-like polypeptide block copolymers: nanoscale control of thermoresponsive reinforcement

    Science.gov (United States)

    Glassman, Matthew; Olsen, Bradley

    2014-03-01

    Triblock copolymers with associative protein midblocks and thermoresponsive endblocks form shear thinning hydrogels with a low yield stress at low temperatures, but can be reinforced by a self-assembled network of the endblock aggregates. Here, we compare the use of bioengineered elastin-like polypeptides (ELPs) to synthetic poly(N-isopropylacrylamide) (PNIPAM) as endblocks to control the self-assembly of the reinforcing network. The temperature dependence of the mechanics of these hydrogels is a strong function of the domain size and morphology in the endblock network. Despite the architectural similarities, triblock ELP fusions and PNIPAM bioconjugates exhibit distinct reinforcement maxima at fixed block composition and polymer concentration, and these differences can be attributed to the nanostructural features of the two systems. Furthermore, in ELP fusions, the amino acid sequence can be readily modified to manipulate the solvation kinetics of the endblock domains. Finally, various endblocks have been combined to form triblock terpolymer hydrogels, demonstrating how the choice of thermoresponsive blocks can be used to tune the reinforcement of shear thinning hydrogels.

  14. Structural and interaction parameters of thermosensitive native α-elastin biohybrid microgel

    Science.gov (United States)

    Balaceanu, Andreea; Singh, Smriti; Demco, Dan E.; Möller, Martin

    2014-09-01

    The structural and water interaction parameters for native, α-elastin biohybrid microgel crosslinked with hydrophilic and hydrophobic crosslinkers are obtained from the volume phase transition temperature behaviour, 1H high-resolution magic-angle sample spinning transverse magnetization relaxation NMR, and modified Flory-Rehner swelling theory. Firstly, considering a homogeneous morphology the number of subchains in the biohybrid microgel, the residual water in deswollen state as a function of crosslink density and the temperature dependence of the Flory biopolymer-water interaction parameters are reported for the biohybrid microgels prepared with hydrophilic (PEG-DGE) and hydrophobic (BS3) crosslinkers. The Flory-Rehner classical approach is subsequently modified taking into account the heterogeneities observed by NMR transverse relaxation measurements. Two differently mobile regions are determined, a hydrophobic domain and a crosslinking domain with relative reduced mobility. For the first time, the influence of chain mobility on the Flory interaction parameter is investigated through a modified Flory state equation. The contributions of amino-acids located in the hydrophobic and crosslinking domains in the polypeptide sequence are separated while analyzing the biopolymer-water interaction.

  15. Using elastin protein to develop highly efficient air cathodes for lithium-O2 batteries

    Science.gov (United States)

    Guo, Guilue; Yao, Xin; Ang, Huixiang; Tan, Huiteng; Zhang, Yu; Guo, Yuanyuan; Fong, Eileen; Yan, Qingyu

    2016-01-01

    Transition metal-nitrogen/carbon (M-N/C, M = Fe, Co) catalysts are synthesized using environmentally friendly histidine-tag-rich elastin protein beads, metal sulfate and water soluble carbon nanotubes followed by post-annealing and acid leaching processes. The obtained catalysts are used as cathode materials in lithium-O2 batteries. It has been discovered that during discharge, Li2O2 nanoparticles first nucleate and grow around the bead-decorated CNT regions (M-N/C centres) and coat on the catalysts at a high degree of discharge. The Fe-N/C catalyst-based cathodes deliver a capacity of 12 441 mAh g-1 at a current density of 100 mA g-1. When they were cycled at a limited capacity of 800 mAh g-1 at current densities of 200 or 400 mA g-1, these cathodes showed stable charge voltages of ˜3.65 or 3.90 V, corresponding to energy efficiencies of ˜71.2 or 65.1%, respectively. These results are considerably superior to those of the cathodes based on bare annealed CNTs, which prove that the Fe-N/C catalysts developed here are promising for use in non-aqueous lithium-O2 battery cathodes.

  16. Proliferative activity of elastin-like-peptides depends on charge and phase transition.

    Science.gov (United States)

    Yuan, Yuan; Koria, Piyush

    2016-03-01

    Elastin-like-peptides (ELPs) are stimulus-responsive protein-based polymers and are attractive biomaterials due to their biocompatibility and unique properties. This study shows that in addition to their physical properties, ELPs have biological activities that are conducive to tissue regeneration. Specifically, we found that ELPs induce fibroblast proliferation via cell surface heparan sulfate proteoglycans (HSPG). Furthermore, our data suggests that ELP based materials with differential proliferative potential can be designed by controlling the interaction of ELPs with HSPGs by incorporating either hydrophobic or positively charged residues within the ELP sequence. Fibroblast proliferation is important for granulation tissue formation which is important in chronic wounds as well as in healing of other tissues. The customizable biological activity of ELPs coupled with their unique physical properties will enable us to design novel, sustainable and cost effective therapies for different tissue regeneration applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 697-706, 2016. © 2015 Wiley Periodicals, Inc.

  17. Toughening of Thermoresponsive Arrested Networks of Elastin-Like Polypeptides To Engineer Cytocompatible Tissue Scaffolds.

    Science.gov (United States)

    Glassman, Matthew J; Avery, Reginald K; Khademhosseini, Ali; Olsen, Bradley D

    2016-02-08

    Formulation of tissue engineering or regenerative scaffolds from simple bioactive polymers with tunable structure and mechanics is crucial for the regeneration of complex tissues, and hydrogels from recombinant proteins, such as elastin-like polypeptides (ELPs), are promising platforms to support these applications. The arrested phase separation of ELPs has been shown to yield remarkably stiff, biocontinuous, nanostructured networks, but these gels are limited in applications by their relatively brittle nature. Here, a gel-forming ELP is chain-extended by telechelic oxidative coupling, forming extensible, tough hydrogels. Small angle scattering indicates that the chain-extended polypeptides form a fractal network of nanoscale aggregates over a broad concentration range, accessing moduli ranging from 5 kPa to over 1 MPa over a concentration range of 5-30 wt %. These networks exhibited excellent erosion resistance and allowed for the diffusion and release of encapsulated particles consistent with a bicontinuous, porous structure with a broad distribution of pore sizes. Biofunctionalized, toughened networks were found to maintain the viability of human mesenchymal stem cells (hMSCs) in 2D, demonstrating signs of osteogenesis even in cell media without osteogenic molecules. Furthermore, chondrocytes could be readily mixed into these gels via thermoresponsive assembly and remained viable in extended culture. These studies demonstrate the ability to engineer ELP-based arrested physical networks on the molecular level to form reinforced, cytocompatible hydrogel matrices, supporting the promise of these new materials as candidates for the engineering and regeneration of stiff tissues.

  18. Micellar Self-Assembly of Recombinant Resilin-/Elastin-Like Block Copolypeptides.

    Science.gov (United States)

    Weitzhandler, Isaac; Dzuricky, Michael; Hoffmann, Ingo; Garcia Quiroz, Felipe; Gradzielski, Michael; Chilkoti, Ashutosh

    2017-08-14

    Reported here is the synthesis of perfectly sequence defined, monodisperse diblock copolypeptides of hydrophilic elastin-like and hydrophobic resilin-like polypeptide blocks and characterization of their self-assembly as a function of structural parameters by light scattering, cryo-TEM, and small-angle neutron scattering. A subset of these diblock copolypeptides exhibit lower critical solution temperature and upper critical solution temperature phase behavior and self-assemble into spherical or cylindrical micelles. Their morphologies are dictated by their chain length, degree of hydrophilicity, and hydrophilic weight fraction of the ELP block. We find that (1) independent of the length of the corona-forming ELP block there is a minimum threshold in the length of the RLP block below which self-assembly does not occur, but that once that threshold is crossed, (2) the RLP block length is a unique molecular parameter to independently tune self-assembly and (3) increasing the hydrophobicity of the corona-forming ELP drives a transition from spherical to cylindrical morphology. Unlike the self-assembly of purely ELP-based block copolymers, the self-assembly of RLP-ELPs can be understood by simple principles of polymer physics relating hydrophilic weight fraction and polymer-polymer and polymer-solvent interactions to micellar morphology, which is important as it provides a route for the de novo design of desired nanoscale morphologies from first principles.

  19. Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus.

    Science.gov (United States)

    Price, Daniel L; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G; Yu, Yong A; Szalay, Aladar A; Cappello, Joseph; Fong, Yuman; Wong, Richard J

    2016-02-01

    Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. © 2014 Wiley Periodicals, Inc.

  20. Elastin-like-polypeptide based fusion proteins for osteogenic factor delivery in bone healing.

    Science.gov (United States)

    McCarthy, Bryce; Yuan, Yuan; Koria, Piyush

    2016-07-08

    Modern treatments of bone injuries and diseases are becoming increasingly dependent on the usage of growth factors to stimulate bone growth. Bone morphogenetic protein-2 (BMP-2), a potent osteogenic inductive protein, exhibits promising results in treatment models, but recently has had its practical efficacy questioned due to the lack of local retention, ectopic bone formation, and potentially lethal inflammation. Where a new delivery technique of the BMP-2 is necessary, here we demonstrate the viability of an elastin-like peptide (ELP) fusion protein containing BMP-2 for delivery of the BMP-2. This fusion protein retains the performance characteristics of both the BMP-2 and ELP. The fusion protein was found to induce osteogenic differentiation of mesenchymal stem cells as evidenced by the production of alkaline phosphatase and extracellular calcium deposits in response to treatment by the fusion protein. Retention of the ELPs inverse phase transition property has allowed for expression of the fusion protein within a bacterial host (such as Escherichia coli) and easy and rapid purification using inverse transition cycling. The fusion protein formed self-aggregating nanoparticles at human-body temperature. The data collected suggests the viability of these fusion protein nanoparticles as a dosage-efficient and location-precise noncytotoxic delivery vehicle for BMP-2 in bone treatment. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1029-1037, 2016. © 2016 American Institute of Chemical Engineers.

  1. 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.

  2. 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

  3. 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.

  4. 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)

  5. 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...

  6. Glycine functionalized alumina nanoparticles stabilize collagen in ...

    Indian Academy of Sciences (India)

    Al2O3 nanoparticles thereby suggesting ... 1. Introduction. Collagen is a naturally occurring skin protein in animal tis- ... easily adsorb on the surface of the nanoparticles and amino .... [19,23], agglomeration is prevented by the electrostatic.

  7. Mechanistic Insight into the Elastin Degradation Process by the Metalloprotease Myroilysin from the Deep-Sea Bacterium Myroides profundi D25

    Science.gov (United States)

    Yang, Jie; Zhao, Hui-Lin; Tang, Bai-Lu; Chen, Xiu-Lan; Su, Hai-Nan; Zhang, Xi-Ying; Song, Xiao-Yan; Zhou, Bai-Cheng; Xie, Bin-Bin; Weiss, Anthony S.; Zhang, Yu-Zhong

    2015-01-01

    Elastases have been widely studied because of their important uses as medicine and meat tenderizers. However, there are relatively few studies on marine elastases. Myroilysin, secreted by Myroides profundi D25 from deep-sea sediment, is a novel elastase. In this study, we examined the elastin degradation mechanism of myroilysin. When mixed with insoluble bovine elastin, myroilysin bound hydrophobically, suggesting that this elastase may interact with the hydrophobic domains of elastin. Consistent with this, analysis of the cleavage pattern of myroilysin on bovine elastin and recombinant tropoelastin revealed that myroilysin preferentially cleaves peptide bonds with hydrophobic residues at the P1 and/or P1′ positions. Scanning electron microscopy (SEM) of cross-linked recombinant tropoelastin degraded by myroilysin showed preferential damages of spherules over cross-links, as expected for a hydrophobic preference. The degradation process of myroilysin on bovine elastin fibres was followed by light microscopy and SEM, revealing that degradation begins with the formation of crevices and cavities at the fibre surface, with these openings increasing in number and size until the fibre breaks into small pieces, which are subsequently fragmented. Our results are helpful for developing biotechnological applications for myroilysin. PMID:25793427

  8. Evaluation of a biomimetic 3D substrate based on the Human Elastin-like Polypeptides (HELPs) model system for elastolytic activity detection.

    Science.gov (United States)

    Corich, Lucia; Busetti, Marina; Petix, Vincenzo; Passamonti, Sabina; Bandiera, Antonella

    2017-08-10

    Elastin is a fibrous protein that confers elasticity to tissues such as skin, arteries and lung. It is extensively cross-linked, highly hydrophobic and insoluble. Nevertheless, elastin can be hydrolysed by bacterial proteases in infectious diseases, resulting in more or less severe tissue damage. Thus, development of substrates able to reliably and specifically detect pathogen-secreted elastolytic activity is needed to improve the in vitro evaluation of the injury that bacterial proteases may provoke. In this work, two human biomimetic elastin polypeptides, HELP and HELP1, as well as the matrices derived from HELP, have been probed as substrates for elastolytic activity detection. Thirty strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients were analyzed in parallel with standard substrates, to detect proteolytic and elastolytic activity. Results point to the HELP-based 3D matrix as an interesting biomimetic model of elastin to assess bacterial elastolytic activity in vitro. Moreover, this model substrate enables to further elucidate the mechanism underlying elastin degradation at molecular level, as well as to develop biomimetic material-based devices responsive to external stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Effects of solvent concentration and composition on protein dynamics: 13C MAS NMR studies of elastin in glycerol-water mixtures.

    Science.gov (United States)

    Demuth, Dominik; Haase, Nils; Malzacher, Daniel; Vogel, Michael

    2015-08-01

    We use (13)C CP MAS NMR to investigate the dependence of elastin dynamics on the concentration and composition of the solvent at various temperatures. For elastin in pure glycerol, line-shape analysis shows that larger-scale fluctuations of the protein backbone require a minimum glycerol concentration of ~0.6 g/g at ambient temperature, while smaller-scale fluctuations are activated at lower solvation levels of ~0.2 g/g. Immersing elastin in various glycerol-water mixtures, we observe at room temperature that the protein mobility is higher for lower glycerol fractions in the solvent and, thus, lower solvent viscosity. When decreasing the temperature, the elastin spectra approach the line shape for the rigid protein at 245 K for all studied samples, indicating that the protein ceases to be mobile on the experimental time scale of ~10(-5) s. Our findings yield evidence for a strong coupling between elastin fluctuations and solvent dynamics and, hence, such interaction is not restricted to the case of protein-water mixtures. Spectral resolution of different carbon species reveals that the protein-solvent couplings can, however, be different for side chain and backbone units. We discuss these results against the background of the slaving model for protein dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

    DEFF Research Database (Denmark)

    Rørdam Preil, Simone; Faarvang Thorsen, Anne-Sofie; Christiansen, Anne Lindegaard

    2017-01-01

    BACKGROUND: Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression i......BACKGROUND: Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered m......RNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM. METHODS: Blood samples from 302 type 2 diabetic patients were...... analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index. RESULTS: T2DM...

  11. 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.

  12. 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.

  13. 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....

  14. Imaging Prostate Cancer Microenvironment by Collagen Hybridization

    Science.gov (United States)

    2015-10-01

    diagnosis, staging, and treatment of numerous connective tissue disorders and diseases. Standard antibody staining methods that rely on epitopes of a...CMP can be used to detect mechanical damage to collagen in tendon which could be used for diagnostic and therapeutics of musculoskeletal injury which...13. SUPPLEMENTARY NOTES 14. ABSTRACT The major goal of the proposed work is to develop new PCa imaging methods based on the collagen mimetic peptide

  15. Oriented collagen fibers direct tumor cell intravasation

    KAUST Repository

    Han, Weijing

    2016-09-24

    In this work, we constructed a Collagen I-Matrigel composite extracellular matrix (ECM). The composite ECM was used to determine the influence of the local collagen fiber orientation on the collective intravasation ability of tumor cells. We found that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).

  16. 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.

  17. 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.

  18. Dual stimuli-sensitive dendrimers: Photothermogenic gold nanoparticle-loaded thermo-responsive elastin-mimetic dendrimers.

    Science.gov (United States)

    Fukushima, Daichi; Sk, Ugir Hossain; Sakamoto, Yasuhiro; Nakase, Ikuhiko; Kojima, Chie

    2015-08-01

    Dendrimers are synthetic macromolecules with unique structures that can work as nanoplatforms for both photothermogenic gold nanoparticles (AuNPs) and thermosensitive elastin-like peptides (ELPs) with valine-proline-glycine-valine-glycine (VPGVG) repeats. In this study, photothermogenic AuNPs were loaded into thermo-responsive elastin-mimetic dendrimers (dendrimers conjugating ELPs at their periphery) to produce dual stimuli-sensitive nanoparticles. Polyamidoamine G4 dendrimers were modified with acetylated VPGVG and (VPGVG)2, and the resulting materials were named ELP1-den and ELP2-den, respectively. The AuNPs were prepared by the reduction of Au ions using a dendrimer-nanotemplated method. The AuNP-loaded elastin-mimetic dendrimers exhibited photothermal properties. ELP1-den and ELP2-den showed similar temperature-dependent changes in their conformations. Phase transitions were observed at around 55°C and 35°C for the AuNP-loaded ELP1-den and AuNP-loaded ELP2-den, respectively, but not for the corresponding PEGylated dendrimer. In contrast to the AuNP-loaded PEGylated dendrimer, AuNP-loaded ELP2-den readily associated with cells and induced efficient photocytotoxicity at 37°C. The cell association and the photocytotoxicity properties of AuNP-loaded ELP2-den could be controlled by temperature. These results therefore suggest that dual stimuli-sensitive dendrimer nanoparticles of this type could be used for photothermal therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Structure of the Elastin-Contractile Units in the Thoracic Aorta and How Genes That Cause Thoracic Aortic Aneurysms and Dissections Disrupt This Structure.

    Science.gov (United States)

    Karimi, Ashkan; Milewicz, Dianna M

    2016-01-01

    The medial layer of the aorta confers elasticity and strength to the aortic wall and is composed of alternating layers of smooth muscle cells (SMCs) and elastic fibres. The SMC elastin-contractile unit is a structural unit that links the elastin fibres to the SMCs and is characterized by the following: (1) layers of elastin fibres that are surrounded by microfibrils; (2) microfibrils that bind to the integrin receptors in focal adhesions on the cell surface of the SMCs; and (3) SMC contractile filaments that are linked to the focal adhesions on the inner side of the membrane. The genes that are altered to cause thoracic aortic aneurysms and aortic dissections encode proteins involved in the structure or function of the SMC elastin-contractile unit. Included in this gene list are the genes encoding protein that are structural components of elastin fibres and microfibrils, FBN1, MFAP5, ELN, and FBLN4. Also included are genes that encode structural proteins in the SMC contractile unit, including ACTA2, which encodes SMC-specific α-actin and MYH11, which encodes SMC-specific myosin heavy chain, along with MYLK and PRKG1, which encode kinases that control SMC contraction. Finally, mutations in the gene encoding the protein linking integrin receptors to the contractile filaments, FLNA, also predispose to thoracic aortic disease. Thus, these data suggest that functional SMC elastin-contractile units are important for maintaining the structural integrity of the aorta. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. Controlling the Size and Shape of the Elastin-Like Polypeptide based Micelles

    Science.gov (United States)

    Streletzky, Kiril; Shuman, Hannah; Maraschky, Adam; Holland, Nolan

    Elastin-like polypeptide (ELP) trimer constructs make reliable environmentally responsive micellar systems because they exhibit a controllable transition from being water-soluble at low temperatures to aggregating at high temperatures. It has been shown that depending on the specific details of the ELP design (length of the ELP chain, pH and salt concentration) micelles can vary in size and shape between spherical micelles with diameter 30-100 nm to elongated particles with an aspect ratio of about 10. This makes ELP trimers a convenient platform for developing potential drug delivery and bio-sensing applications as well as for understanding micelle formation in ELP systems. Since at a given salt concentration, the headgroup area for each foldon should be constant, the size of the micelles is expected to be proportional to the volume of the linear ELP available per foldon headgroup. Therefore, adding linear ELPs to a system of ELP-foldon should result in changes of the micelle volume allowing to control micelle size and possibly shape. The effects of addition of linear ELPs on size, shape, and molecular weight of micelles at different salt concentrations were studied by a combination of Dynamic Light Scattering and Static Light Scattering. The initial results on 50 µM ELP-foldon samples (at low salt) show that Rh of mixed micelles increases more than 5-fold as the amount of linear ELP raised from 0 to 50 µM. It was also found that a given mixture of linear and trimer constructs has two temperature-based transitions and therefore displays three predominant size regimes.

  6. Light Scattering Study of Mixed Micelles Made from Elastin-Like Polypeptide Linear Chains and Trimers

    Science.gov (United States)

    Terrano, Daniel; Tsuper, Ilona; Maraschky, Adam; Holland, Nolan; Streletzky, Kiril

    Temperature sensitive nanoparticles were generated from a construct (H20F) of three chains of elastin-like polypeptides (ELP) linked to a negatively charged foldon domain. This ELP system was mixed at different ratios with linear chains of ELP (H40L) which lacks the foldon domain. The mixed system is soluble at room temperature and at a transition temperature (Tt) will form swollen micelles with the hydrophobic linear chains hidden inside. This system was studied using depolarized dynamic light scattering (DDLS) and static light scattering (SLS) to determine the size, shape, and internal structure of the mixed micelles. The mixed micelle in equal parts of H20F and H40L show a constant apparent hydrodynamic radius of 40-45 nm at the concentration window from 25:25 to 60:60 uM (1:1 ratio). At a fixed 50 uM concentration of the H20F, varying H40L concentration from 5 to 80 uM resulted in a linear growth in the hydrodynamic radius from about 11 to about 62 nm, along with a 1000-fold increase in VH signal. A possible simple model explaining the growth of the swollen micelles is considered. Lastly, the VH signal can indicate elongation in the geometry of the particle or could possibly be a result from anisotropic properties from the core of the micelle. SLS was used to study the molecular weight, and the radius of gyration of the micelle to help identify the structure and morphology of mixed micelles and the tangible cause of the VH signal.

  7. Bat wing biometrics: using collagen–elastin bundles in bat wings as a unique individual identifier

    Science.gov (United States)

    Hooper, Sarah E.; Womack, Kathryn M.

    2017-01-01

    Abstract The ability to recognize individuals within an animal population is fundamental to conservation and management. Identification of individual bats has relied on artificial marking techniques that may negatively affect the survival and alter the behavior of individuals. Biometric systems use biological characteristics to identify individuals. The field of animal biometrics has expanded to include recognition of individuals based upon various morphologies and phenotypic variations including pelage patterns, tail flukes, and whisker arrangement. Biometric systems use 4 biologic measurement criteria: universality, distinctiveness, permanence, and collectability. Additionally, the system should not violate assumptions of capture–recapture methods that include no increased mortality or alterations of behavior. We evaluated whether individual bats could be uniquely identified based upon the collagen–elastin bundles that are visible with gross examination of their wings. We examined little brown bats (Myotis lucifugus), northern long-eared bats (M. septentrionalis), big brown bats (Eptesicus fuscus), and tricolored bats (Perimyotis subflavus) to determine whether the “wing prints” from the bundle network would satisfy the biologic measurement criteria. We evaluated 1,212 photographs from 230 individual bats comparing week 0 photos with those taken at weeks 3 or 6 and were able to confirm identity of individuals over time. Two blinded evaluators were able to successfully match 170 individuals in hand to photographs taken at weeks 0, 3, and 6. This study suggests that bats can be successfully re-identified using photographs taken at previous times. We suggest further evaluation of this methodology for use in a standardized system that can be shared among bat conservationists. PMID:29674784

  8. 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

  9. Biophysical behavior of Scomberoides commersonianus skin collagen.

    Science.gov (United States)

    Kolli, Nagamalleswari; Joseph, K Thomas; Ramasami, T

    2002-06-01

    Some biophysical characteristics of the skin collagen from Scomberoides commersonianus were measured and compared to those of rat tail tendon. Stress-strain data indicate that the strain at break as well as the tensile strength of the fish skin without scales increased significantly. The maximum tension in case of rat skin is at least a factor of two higher than that observed in fish skin. The much lower hydrothermal isometric tension measurements observed in fish skin are attributable to a lesser number of heat stable crosslinks. Stress relaxation measurements in the fish skin indicate that more than one relaxation process may be involved in the stabilization of collagenous matrix. The observed differences in the biophysical behavior of fish skin may well arise from combination of changes in extent of hydroxylation of proline in collagen synthesis, hydrogen bond network and fibril orientation as compared to rat tail tendon.

  10. 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.

  11. 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.

  12. 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.

  13. In vivo guided vascular regeneration with a non-porous elastin-like polypeptide hydrogel tubular scaffold.

    Science.gov (United States)

    Mahara, Atsushi; Kiick, Kristi L; Yamaoka, Tetsuji

    2017-06-01

    Herein, we demonstrate a new approach for small-caliber vascular reconstruction using a non-porous elastin-like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin-like polypeptide, (Val-Pro-Gly-Ile-Gly) n , for compliance matching and antithrombogenicity and an Arg-Gly-Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β-[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non-porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small-diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746-1755, 2017. © 2017 Wiley Periodicals, Inc.

  14. Expression and purification of short hydrophobic elastin-like polypeptides with maltose-binding protein as a solubility tag.

    Science.gov (United States)

    Bataille, Laure; Dieryck, Wilfrid; Hocquellet, Agnès; Cabanne, Charlotte; Bathany, Katell; Lecommandoux, Sébastien; Garbay, Bertrand; Garanger, Elisabeth

    2015-06-01

    Elastin-like polypeptides (ELPs) are biodegradable polymers with interesting physico-chemical properties for biomedical and biotechnological applications. The recombinant expression of hydrophobic elastin-like polypeptides is often difficult because they possess low transition temperatures, and therefore form aggregates at sub-ambient temperatures. To circumvent this difficulty, we expressed in Escherichia coli three hydrophobic ELPs (VPGIG)n with variable lengths (n=20, 40, and 60) in fusion with the maltose-binding protein (MBP). Fusion proteins were soluble and yields of purified MBP-ELP ranged between 66 and 127mg/L culture. After digestion of the fusion proteins by enterokinase, the ELP moiety was purified by using inverse transition cycling. The purified fraction containing ELP40 was slightly contaminated by traces of undigested fusion protein. Purification of ELP60 was impaired because of co-purification of the MBP tag during inverse transition cycling. ELP20 was successfully purified to homogeneity, as assessed by gel electrophoresis and mass spectrometry analyses. The transition temperature of ELP20 was measured at 15.4°C in low salt buffer. In conclusion, this method can be used to produce hydrophobic ELP of low molecular mass. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Immune-tolerant elastin-like polypeptides (iTEPs) and their application as CTL vaccine carriers.

    Science.gov (United States)

    Cho, S; Dong, S; Parent, K N; Chen, M

    2016-01-01

    Cytotoxic T lymphocyte (CTL) vaccine carriers are known to enhance the efficacy of vaccines, but a search for more effective carriers is warranted. Elastin-like polypeptides (ELPs) have been examined for many medical applications but not as CTL vaccine carriers. We aimed to create immune tolerant ELPs using a new polypeptide engineering practice and create CTL vaccine carriers using the ELPs. Four sets of novel ELPs, termed immune-tolerant elastin-like polypeptide (iTEP) were generated according to the principles dictating humoral immunogenicity of polypeptides and phase transition property of ELPs. The iTEPs were non-immunogenic in mice. Their phase transition feature was confirmed through a turbidity assay. An iTEP nanoparticle (NP) was assembled from an amphiphilic iTEP copolymer plus a CTL peptide vaccine, SIINFEKL. The NP facilitated the presentation of the vaccine by dendritic cells (DCs) and enhanced vaccine-induced CTL responses. A new ELP design and development practice was established. The non-canonical motif and the immune tolerant nature of the iTEPs broaden our insights about ELPs. ELPs, for the first time, were successfully used as carriers for CTL vaccines. It is feasible to concurrently engineer both immune-tolerant and functional peptide materials. ELPs are a promising type of CTL vaccine carriers.

  16. Elastin-derived peptides promote abdominal aortic aneurysm formation by modulating M1/M2 macrophage polarization1

    Science.gov (United States)

    Dale, Matthew A; Xiong, Wanfen; Carson, Jeffrey S; Suh, Melissa K; Karpisek, Andrew D.; Meisinger, Trevor M.; Casale, George P.; Baxter, B. Timothy

    2016-01-01

    Abdominal aortic aneurysm (AAA) is a dynamic vascular disease characterized by inflammatory cell invasion and extracellular matrix (ECM) degradation. Damage to elastin in the ECM results in release of elastin-derived peptides (EDPs), which are chemotactic for inflammatory cells such as monocytes. Their effect on macrophage polarization is less well known. Pro-inflammatory M1 macrophages initially are recruited to sites of injury but, if their effects are prolonged, they can lead to chronic inflammation that prevents normal tissue repair. Conversely, anti-inflammatory M2 macrophages reduce inflammation and aid in wound healing. Thus, a proper M1/M2 ratio is vital for tissue homeostasis. AAA tissue reveals a high M1/M2 ratio where pro-inflammatory cells and their associated markers dominate. In the present study, in vitro treatment of bone marrow-derived macrophages with EDPs induced M1 macrophage polarization. By using C57Bl/6 mice, antibody-mediated neutralization of EDPs reduced aortic dilation, matrix metalloproteinase activity, and pro-inflammatory cytokine expression at early and late time points after aneurysm induction. Furthermore, direct manipulation of the M1/M2 balance altered aortic dilation. Injection of M2 polarized macrophages reduced aortic dilation after aneurysm induction. EDPs promoted a pro-inflammatory environment in aortic tissue by inducing M1 polarization and neutralization of EDPs attenuated aortic dilation. The M1/M2 imbalance is vital to aneurysm formation. PMID:27183603

  17. 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)

  18. 8-methoxypsoralen and ultraviolet A radiation activate the human elastin promoter in transgenic mice: in vivo and in vitro evidence for gene induction

    International Nuclear Information System (INIS)

    Bernstein, E.F.; Brown, D.B.; Takeuchi, Tsunemichi; Kong, S.K.; Uitto, Jouni; Gasparro, F.P.

    1996-01-01

    Treatment of skin diseases with the combination of 8-methoxypsoralen and ultraviolet A radiation (PUVA) results in clinical alterations in treated skin that resemble those observed in chronically photodamaged skin. The PUVA-treated patients develop nonmelanoma skin cancers, pigmentary alterations and wrinkling characteristic of sun-induced changes. The major alteration in the dermis of sun-damaged skin is the deposition of abnormal elastic fibers, termed solar elastosis. Up-regulation of elastin promoter activity in dermal fibroblasts explains the excess elastic tissue but not the reason for the aberrant morphology of the elastotic material. In order to study photoaging in an experimental system we utilized a transgenic mouse line that expresses the human elastin promoter/chloramphenicol acetyltransferase construct in a tissue-specific and developmentally regulated manner. Although UVB radiation has been demonstrated to increase promoter activity in vitro, UVA fails to demonstrate a similar effect at the doses utilized. In this study, we demonstrate the ability of PUVA treatment to up regulate elastin promoter activity both in vitro and in vivo. These data help to explain the development of photoaging in sun-protected PUVA-treated skin. We attribute the up-regulation of elastin promoter activity in response to PUVA to the formation of DNA photoadducts, which do not occur in response to UVA radiation alone. (UK)

  19. MicroRNA-29 facilitates transplantation of bone marrow-derived mesenchymal stem cells to alleviate pelvic floor dysfunction by repressing elastin.

    Science.gov (United States)

    Jin, Minfei; Wu, Yuelin; Wang, Jun; Ye, Weiping; Wang, Lei; Yin, Peipei; Liu, Wei; Pan, Chenhao; Hua, Xiaolin

    2016-11-17

    Pelvic floor dysfunction (PFD) is a condition affecting many women worldwide, with symptoms including stress urinary incontinence (SUI) and pelvic organ prolapse (POP). We have previously demonstrated stable elastin-expressing bone marrow-derived mesenchymal stem cells (BMSCs) attenuated PFD in rats, and aim to further study the effect of microRNA-29a-3p regulation on elastin expression and efficacy of BMSC transplantation therapy. We inhibited endogenous microRNA-29a-3p in BMSCs and investigated its effect on elastin expression by RT-PCR and Western blot. MicroRNA-29-inhibited BMSCs were then transplanted into PFD rats, accompanied by sustained release of bFGF using formulated bFGF in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP), followed by evaluation of urodynamic tests. MicroRNA-29a-3p inhibition resulted in upregulated expression and secretion of elastin in in vitro culture of BMSCs. After co-injection with PLGA-loaded bFGF NP into the PFD rats in vivo, microRNA-29a-3p-inhibited BMSCs significantly improved the urodynamic test results. Our multidisciplinary study, combining microRNA biology, genetically engineered BMSCs, and nanoparticle technology, provides an excellent stem cell-based therapy for repairing connective tissues and treating PFD.

  20. 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

  1. 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

  2. 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....

  3. Collagen gene interactions and endurance running performance

    African Journals Online (AJOL)

    to complete any of the individual components (3.8 km swim, 180 km bike or 42.2 km run) of the 226 km event. The major ... may affect normal collagen fibrillogenesis and alter the mechanical properties of ... using a XP Thermal Cycler (Block model XP-G, BIOER Technology Co.,. Japan). ..... New insights into the function of.

  4. The collagenic architecture of human dura mater.

    Science.gov (United States)

    Protasoni, Marina; Sangiorgi, Simone; Cividini, Andrea; Culuvaris, Gloria Tiffany; Tomei, Giustino; Dell'Orbo, Carlo; Raspanti, Mario; Balbi, Sergio; Reguzzoni, Marcella

    2011-06-01

    Human dura mater is the most external meningeal sheet surrounding the CNS. It provides an efficient protection to intracranial structures and represents the most important site for CSF turnover. Its intrinsic architecture is made up of fibrous tissue including collagenic and elastic fibers that guarantee the maintenance of its biophysical features. The recent technical advances in the repair of dural defects have allowed for the creation of many synthetic and biological grafts. However, no detailed studies on the 3D microscopic disposition of collagenic fibers in dura mater are available. The authors report on the collagenic 3D architecture of normal dura mater highlighting the orientation, disposition in 3 dimensions, and shape of the collagen fibers with respect to the observed layer. Thirty-two dura mater specimens were collected during cranial decompressive surgical procedures, fixed in 2.5% Karnovsky solution, and digested in 1 N NaOH solution. After a routine procedure, the specimens were observed using a scanning electron microscope. The authors distinguished the following 5 layers in the fibrous dura mater of varying thicknesses, orientation, and structures: bone surface, external median, vascular, internal median, and arachnoid layers. The description of the ultrastructural 3D organization of the different layers of dura mater will give us more information for the creation of synthetic grafts that are as similar as possible to normal dura mater. This description will be also related to the study of the neoplastic invasion.

  5. 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.

  6. Multiscale structure and mechanics of collagen

    NARCIS (Netherlands)

    Amuasi, H.E.

    2012-01-01

    While we are 70% water, in a very real sense collagen is the stuff we are made of. It is the most abundant protein in multicellular organisms, such as ourselves, making up roughly 25% of our total protein content. If you have ever wondered how the human body holds together all its different parts in

  7. Peroxidase enzymes regulate collagen extracellular matrix biosynthesis.

    Science.gov (United States)

    DeNichilo, Mark O; Panagopoulos, Vasilios; Rayner, Timothy E; Borowicz, Romana A; Greenwood, John E; Evdokiou, Andreas

    2015-05-01

    Myeloperoxidase and eosinophil peroxidase are heme-containing enzymes often physically associated with fibrotic tissue and cancer in various organs, without any direct involvement in promoting fibroblast recruitment and extracellular matrix (ECM) biosynthesis at these sites. We report herein novel findings that show peroxidase enzymes possess a well-conserved profibrogenic capacity to stimulate the migration of fibroblastic cells and promote their ability to secrete collagenous proteins to generate a functional ECM both in vitro and in vivo. Mechanistic studies conducted using cultured fibroblasts show that these cells are capable of rapidly binding and internalizing both myeloperoxidase and eosinophil peroxidase. Peroxidase enzymes stimulate collagen biosynthesis at a post-translational level in a prolyl 4-hydroxylase-dependent manner that does not require ascorbic acid. This response was blocked by the irreversible myeloperoxidase inhibitor 4-amino-benzoic acid hydrazide, indicating peroxidase catalytic activity is essential for collagen biosynthesis. These results suggest that peroxidase enzymes, such as myeloperoxidase and eosinophil peroxidase, may play a fundamental role in regulating the recruitment of fibroblast and the biosynthesis of collagen ECM at sites of normal tissue repair and fibrosis, with enormous implications for many disease states where infiltrating inflammatory cells deposit peroxidases. Copyright © 2015 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Reduced collagen accumulation after major surgery

    DEFF Research Database (Denmark)

    Jorgensen, L N; Kallehave, F; Karlsmark, T

    1996-01-01

    .01)). This decline was significantly higher in the six patients who had a postoperative infection (median 3.02 (range -0.06 to 6.14) versus 0.36 (range -1.56 to 12.60) micrograms/cm, P = 0.02). This study shows that major surgery is associated with impairment of subcutaneous collagen accumulation in a test wound...

  9. Immunoadsorption for collagen and rheumatic diseases.

    Science.gov (United States)

    Yamaji, Ken

    2017-10-01

    The field of therapeutics has seen remarkable progress in the recent years, which has made mainstream drug treatment possible for collagen and rheumatic diseases. However, treatment of intractable cases where drug effectiveness is poor is a challenge. Furthermore, organ damage, concurrent illnesses or allergic reactions make adequate drug therapy impossible. For such cases, therapeutic apheresis is very significant, and it is important how this should be valued related to drug therapies. Therapeutic apheresis for collagen and rheumatic diseases involves the removal of factors that cause and exacerbate the disease; the aim of immunoadsorption, in particular, is to improve the clinical condition of patients with autoimmune disease by selectively removing pathogenic immune complexes and autoantibodies from their plasma. Immunoadsorption, in particular, unlike plasma exchange and DFPP, utilizes a high-affinity column that selectively removes autoantibodies and immune complexes, leaving other plasma components intact. There is no need to replenish fresh frozen plasma or blood products such as albumin and gamma globulin preparations. Immunoadsorption is thus superior in terms of safety, as the risk of infection or allergic reaction relating to these preparations can be avoided. We anticipate future investigations of application of synchronized therapy using drugs and therapeutic apheresis, most notably immunoadsorption, in combination to treat intractable clinical conditions such as collagen and rheumatic diseases. In this paper, our discussion includes the indications for immunoadsorption such as collagen and rheumatic diseases, the relevant conditions and types, as well as the latest understanding related to methods and clinical efficacy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Collagen-induced arthritis in mice

    NARCIS (Netherlands)

    Bevaart, Lisette; Vervoordeldonk, Margriet J.; Tak, Paul P.

    2010-01-01

    Collagen-induced arthritis (CIA) in mice is an animal model for rheumatoid arthritis (RA) and can be induced in DBA/1 and C57BL/6 mice using different protocols. The CIA model can be used to unravel mechanisms involved in the development of arthritis and is frequently used to study the effect of new

  12. 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

  13. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-10-01

    Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5

  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. 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

  16. Compared With Elastin Stains, h-Caldesmon and Desmin Offer Superior Detection of Vessel Invasion in Gastric, Pancreatic, and Colorectal Adenocarcinomas.

    Science.gov (United States)

    Ekinci, Özgür; Öğüt, Betül; Çelik, Bülent; Dursun, Ayşe

    2018-06-01

    The presence of vessel invasion is considered indicative of a poor prognosis in many malignant tumors. We aimed to compare the sensitivity of elastin stains (van Gieson's and orcein methods) with 2 smooth muscle markers (h-caldesmon and desmin) in gastric, pancreatic, and colorectal adenocarcinoma specimens. We used 27 (29.3%) gastric, 35 (38.0%) pancreatic, and 30 (32.6%) colorectal resection specimens. We applied a provisional classification of vessel invasion patterns: type A, a focus with a nearby artery unaccompanied by a vein; type T, a focus at the invasive front without an unaccompanied artery; and type X, foci that only appeared by any of the 4 stains used. There were 369 foci. The smooth muscle markers were more sensitive than the elastin stains, and h-caldesmon more sensitive than desmin, in all types. Among the 139 type A foci, 33 (23.7%) were positive by desmin and h-caldesmon, whereas the elastin stains were not ( P = .001). h-Caldesmon was the only positive marker in 11 (7.9%; P = .011). Among the 78 type T foci, 21 (26.9%) were positive by desmin and h-caldesmon, when both elastin stains were negative ( P = .000). In 16 (20.5%) foci, h-caldesmon was the only positive marker ( P = .002). Among 152 type X foci, 91 (59.9%) were positive by all markers, 26 (17.1%) by both desmin and h-caldesmon, and 9 (5.9%) by only the 2 elastin stains ( P = .001). We recommend these stains for suspect foci in gastric, pancreatic, and colorectal adenocarcinoma specimens. They might highlight both predictable and unpredictable foci.

  17. Is cardiovascular disease in patients with diabetes associated with serum levels of MMP-2, LOX, and the elastin degradation products ELM and ELM-2?

    Science.gov (United States)

    Preil, Simone Andrea Rørdam; Thorsen, Anne-Sofie Faarvang; Christiansen, Anne Lindegaard; Poulsen, Mikael Kjær; Karsdal, Morten Asser; Leeming, Diana Julie; Rasmussen, Lars Melholt

    2017-11-01

    Diabetes mellitus type 2 (T2DM) is a significant risk factor for the development of cardiovascular diseases (CVDs). In a previous microarray study of internal mammary arteries from patients with and without T2DM, we observed several elastin-related genes with altered mRNA-expression in diabetic patients, namely matrix metalloproteinase 2 (MMP-2), lysyl oxidase (LOX) and elastin itself. In this study we investigate whether the serum concentrations of elastin-related proteins correlate to signs of CVD in patients with T2DM. Blood samples from 302 type 2 diabetic patients were analysed for MMP-2, LOX, and the elastin degradation products ELM and ELM2. The results were investigated for correlations to signs of CVD in different vascular territories, as determined by myocardial perfusion scintigraphy, carotid artery thickness and ankle-brachial blood pressure index. T2DM patients with peripheral arterial disease (low ankle-brachial index) (PAD) display higher levels of MMP-2 and ELM compared to patients without PAD. However, none of the proteins or degradation products correlated with myocardial ischemia or a combined measure of CVD-signs, including myocardial ischemia, increased carotid thickness and decreased ankle-brachial blood pressure. Our results suggest that the diabetic environment affects the circulating amounts of MMP-2 and ELM in patients with PAD. However, the same connection could not be seen in diabetic patients with CVD broadly identified in three vascular territories. LOX and ELM-2 did not correlate to any type of CVD. Overall, serum levels of elastin-related molecules are only remotely related to CVD in type 2 diabetes.

  18. 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

  19. 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....

  20. 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...

  1. Measurement of conformational constraints in an elastin-mimetic protein by residue-pair selected solid-state NMR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Mei [Iowa State University, Department of Chemistry (United States)], E-mail: mhong@iastate.edu; McMillan, R. Andrew; Conticello, Vincent P. [Emory University, Department of Chemistry (United States)

    2002-02-15

    We introduce a solid-state NMR technique for selective detection of a residue pair in multiply labeled proteins to obtain site-specific structural constraints. The method exploits the frequency-offset dependence of cross polarization to achieve {sup 13}CO{sub i} {sup {yields}} {sup 15}N{sub i} {sup {yields}} {sup 13}C{alpha}{sub i} transfer between two residues. A {sup 13}C, {sup 15}N-labeled elastin mimetic protein (VPGVG){sub n} is used to demonstrate the method. The technique selected the Gly3 C{alpha} signal while suppressing the Gly5 C{alpha} signal, and allowed the measurement of the Gly3 C{alpha} chemical shift anisotropy to derive information on the protein conformation. This residue-pair selection technique should simplify the study of protein structure at specific residues.

  2. Measurement of conformational constraints in an elastin-mimetic protein by residue-pair selected solid-state NMR

    International Nuclear Information System (INIS)

    Hong, Mei; McMillan, R. Andrew; Conticello, Vincent P.

    2002-01-01

    We introduce a solid-state NMR technique for selective detection of a residue pair in multiply labeled proteins to obtain site-specific structural constraints. The method exploits the frequency-offset dependence of cross polarization to achieve 13 CO i → 15 N i → 13 Cα i transfer between two residues. A 13 C, 15 N-labeled elastin mimetic protein (VPGVG) n is used to demonstrate the method. The technique selected the Gly3 Cα signal while suppressing the Gly5 Cα signal, and allowed the measurement of the Gly3 Cα chemical shift anisotropy to derive information on the protein conformation. This residue-pair selection technique should simplify the study of protein structure at specific residues

  3. Nucleation and growth of elastin-like peptide fibril multilayers: an in situ atomic force microscopy study

    International Nuclear Information System (INIS)

    Yang Guocheng; Yip, Christopher M; Wong, Michael K; Lin, Lauren E

    2011-01-01

    Controlling how molecules assemble into complex supramolecular architectures requires careful consideration of the subtle inter- and intra-molecular interactions that control their association. This is particularly crucial in the context of assembly at interfaces, where both surface chemistry and structure can play a role in directing structure formation. We report here the results of a study into the self-assembly of the elastin-like peptide EP I on structurally modified highly ordered pyrolytic graphite, including the role of spatial confinement on fibril nucleation and the growth of oriented fibril multilayers. In situ atomic force microscopy performed in fluid and at elevated temperature provided direct evidence of frustrated fibril nuclei and oriented growth of independent fibril domains. These results portend the application of this in situ strategy for studies of the nucleation and growth mechanisms of other fibril- and amyloid-forming proteins.

  4. 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

  5. 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...

  6. 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.

  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. 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.

  9. Induction of macrophage chemotaxis by aortic extracts from patients with Marfan syndrome is related to elastin binding protein.

    Directory of Open Access Journals (Sweden)

    Gao Guo

    Full Text Available Marfan syndrome is an autosomal dominantly inherited disorder of connective tissue with prominent skeletal, ocular, and cardiovascular manifestations. Aortic aneurysm and dissection are the major determinants of premature death in untreated patients. In previous work, we showed that extracts of aortic tissues from the mgR mouse model of Marfan syndrome showed increased chemotactic stimulatory activity related to the elastin-binding protein. Aortic samples were collected from 6 patients with Marfan syndrome and 8 with isolated aneurysms of the ascending aorta. Control samples were obtained from 11 organ donors without known vascular or connective tissue diseases. Soluble proteins extracted from the aortic samples of the two patient groups were compared against buffer controls and against the aortic samples from controls with respect to the ability to induce macrophage chemotaxis as measured using a modified Boyden chamber, as well as the reactivity to a monoclonal antibody BA4 against bioactive elastin peptides using ELISA. Samples from Marfan patients displayed a statistically significant increase in chemotactic inductive activity compared to control samples. Additionally, reactivity to BA4 was significantly increased. Similar statistically significant increases were identified for the samples from patients with idiopathic thoracic aortic aneurysm. There was a significant correlation between the chemotactic index and BA4 reactivity, and the increases in chemotactic activity of extracts from Marfan patients could be inhibited by pretreatment with lactose, VGVAPG peptides, or BA4, which indicates the involvement of EBP in mediating the effects. Our results demonstrate that aortic extracts of patients with Marfan syndrome can elicit macrophage chemotaxis, similar to our previous study on aortic extracts of the mgR mouse model of Marfan syndrome (Guo et al., Circulation 2006; 114:1855-62.

  10. Induction of Macrophage Chemotaxis by Aortic Extracts from Patients with Marfan Syndrome Is Related to Elastin Binding Protein

    Science.gov (United States)

    Guo, Gao; Gehle, Petra; Doelken, Sandra; Martin-Ventura, José Luis; von Kodolitsch, Yskert; Hetzer, Roland; Robinson, Peter N.

    2011-01-01

    Marfan syndrome is an autosomal dominantly inherited disorder of connective tissue with prominent skeletal, ocular, and cardiovascular manifestations. Aortic aneurysm and dissection are the major determinants of premature death in untreated patients. In previous work, we showed that extracts of aortic tissues from the mgR mouse model of Marfan syndrome showed increased chemotactic stimulatory activity related to the elastin-binding protein. Aortic samples were collected from 6 patients with Marfan syndrome and 8 with isolated aneurysms of the ascending aorta. Control samples were obtained from 11 organ donors without known vascular or connective tissue diseases. Soluble proteins extracted from the aortic samples of the two patient groups were compared against buffer controls and against the aortic samples from controls with respect to the ability to induce macrophage chemotaxis as measured using a modified Boyden chamber, as well as the reactivity to a monoclonal antibody BA4 against bioactive elastin peptides using ELISA. Samples from Marfan patients displayed a statistically significant increase in chemotactic inductive activity compared to control samples. Additionally, reactivity to BA4 was significantly increased. Similar statistically significant increases were identified for the samples from patients with idiopathic thoracic aortic aneurysm. There was a significant correlation between the chemotactic index and BA4 reactivity, and the increases in chemotactic activity of extracts from Marfan patients could be inhibited by pretreatment with lactose, VGVAPG peptides, or BA4, which indicates the involvement of EBP in mediating the effects. Our results demonstrate that aortic extracts of patients with Marfan syndrome can elicit macrophage chemotaxis, similar to our previous study on aortic extracts of the mgR mouse model of Marfan syndrome (Guo et al., Circulation 2006; 114:1855-62). PMID:21647416

  11. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Yu-Sheng [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Savitha, S. [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Department of Biotechnology, Sree Sastha Institute of Engineering and Technology, Chennai (India); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Sadhasivam, S. [Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Lin, Feng-Huei, E-mail: double@ntu.edu.tw [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); Division of Biomedical Engineering and Nanomedicine Research, National Health Research Institutes, Miaoli 350, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China); Shieh, Ming-Jium [Institute of Biomedical Engineering, College of Engineering, National Taiwan University, Taipei 100, Taiwan (China); College of Medicine, National Taiwan University Hospital, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, College of Medicine, National Taiwan University, Taipei 100, Taiwan (China)

    2014-05-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration.

  12. Design and synthesis of elastin-like polypeptides for an ideal nerve conduit in peripheral nerve regeneration

    International Nuclear Information System (INIS)

    Hsueh, Yu-Sheng; Savitha, S.; Sadhasivam, S.; Lin, Feng-Huei; Shieh, Ming-Jium

    2014-01-01

    The study involves design and synthesis of three different elastin like polypeptide (ELP) gene monomers namely ELP1, ELP2 and ELP3 that encode for ELP proteins. The formed ELPs were assessed as an ideal nerve conduit for peripheral nerve regeneration. ELP1 was constructed with a small elongated pentapeptide carrying VPGVG sequence to mimic the natural polypeptide ELP. The ELP2 was designed by the incorporation of 4-penta peptide chains to improve the biocompatibility and mechanical strength. Thus, the third position in unique VPGVG was replaced with alanine to VPAVG and in a similar way modified to VPGKG, VPGEG and VPGIG with the substitution of lysine, glutamic acid and isoleucine. In ELP3, fibronectin C5 domain endowed with REDV sequence was introduced to improve the cell attachment. The ELP1, ELP2 and ELP3 proteins expressed by Escherichia coli were purified by inverse transition cycling (ITC). The purified ELPs were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The Schwann cell (SC) morphology and cell adhesion were assessed by fabrication of ELP membrane cross-linked with glutaraledhyde. The Schwann cell proliferation was measured by WST-1 assay. Immunofluorostaining of Schwann cells was accomplished with SC specific phenotypic marker, S100. - Highlights: • Design and synthesis of three gene monomers of elastin like polypeptides (ELP1, 2 and 3) were reported. • Molecular weight of ITC purified ELP1, ELP2 and ELP3 was in the range of 37–38 kDa. • Schwann cell adhesion was found to be prominent in ELP3 and could be used as nerve conduit for peripheral nerve regeneration

  13. Identification of vimentin- and elastin-like transcripts specifically expressed in developing notochord of Atlantic salmon (Salmo salar L.).

    Science.gov (United States)

    Sagstad, Anita; Grotmol, Sindre; Kryvi, Harald; Krossøy, Christel; Totland, Geir K; Malde, Ketil; Wang, Shou; Hansen, Tom; Wargelius, Anna

    2011-11-01

    The notochord functions as the midline structural element of all vertebrate embryos, and allows movement and growth at early developmental stages. Moreover, during embryonic development, notochord cells produce secreted factors that provide positional and fate information to a broad variety of cells within adjacent tissues, for instance those of the vertebrae, central nervous system and somites. Due to the large size of the embryo, the salmon notochord is useful to study as a model for exploring notochord development. To investigate factors that might be involved in notochord development, a normalized cDNA library was constructed from a mix of notochords from ∼500 to ∼800 day°. From the 1968 Sanger-sequenced transcripts, 22 genes were identified to be predominantly expressed in the notochord compared to other organs of salmon. Twelve of these genes were found to show expressional regulation around mineralization of the notochord sheath; 11 genes were up-regulated and one gene was down-regulated. Two genes were found to be specifically expressed in the notochord; these genes showed similarity to vimentin (acc. no GT297094) and elastin (acc. no GT297478). In-situ results showed that the vimentin- like transcript was expressed in both chordocytes and chordoblasts, whereas the elastin- like transcript was uniquely expressed in the chordoblasts lining the notochordal sheath. In salmon aquaculture, vertebral deformities are a common problem, and some malformations have been linked to the notochord. The expression of identified transcripts provides further insight into processes taking place in the developing notochord, prior to and during the early mineralization period.

  14. 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

  15. 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.

  16. Collagen markers in peritoneal dialysis patients

    DEFF Research Database (Denmark)

    Graff, J; Joffe, P; Fugleberg, S

    1995-01-01

    Possible relationships between the dialysate-to-plasma creatinine equilibration ratio (D/Pcreatinine 4 hour), duration of peritoneal dialysis treatment, number of peritonitis episodes, and mass appearance rates of three connective tissue markers [carboxyterminal propeptide of type I procollagen...... (PICP), aminoterminal propeptide of type III procollagen (PIIINP), and carboxyterminal telopeptide of type I collagen (ICTP)] were studied in 19 nondiabetic peritoneal dialysis patients. The absence of correlation between the mass appearance rates of the markers and the duration of dialysis treatment...... as well as the number of peritonitis episodes supports the concept that peritoneal dialysis does not cause persistent changes in the deposition and degradation rates of collagen. A correlation between the D/Pcreatinine 4 hr and the PICP mass appearance rates was found. Since it is unlikely...

  17. Imaging Prostate Cancer Microenvironment by Collagen Hybridization

    Science.gov (United States)

    2016-12-01

    of collagen II remodeling in Rheumatoid arthritis and other cartilage-related diseases or wound repair. We did observe trends in the CMP...proteins in vitro and in vivo has been prepared and submitted to Molecular Pharmaceutics . What do you plan to do during the next reporting period to...or care of human subjects, vertebrate animals, biohazards, and/or select agents Nothing to report. PRODUCTS Journal publications: Lucas L

  18. Collagen Fiber Orientation in Primate Long Bones.

    Science.gov (United States)

    Warshaw, Johanna; Bromage, Timothy G; Terranova, Carl J; Enlow, Donald H

    2017-07-01

    Studies of variation in orientation of collagen fibers within bone have lead to the proposition that these are preferentially aligned to accommodate different kinds of load, with tension best resisted by fibers aligned longitudinally relative to the load, and compression best resisted by transversely aligned fibers. However, previous studies have often neglected to consider the effect of developmental processes, including constraints on collagen fiber orientation (CFO), particularly in primary bone. Here we use circularly polarized light microscopy to examine patterns of CFO in cross-sections from the midshaft femur, humerus, tibia, radius, and ulna in a range of living primate taxa with varied body sizes, phylogenetic relationships and positional behaviors. We find that a preponderance of longitudinally oriented collagen is characteristic of both periosteal primary and intracortically remodeled bone. Where variation does occur among groups, it is not simply understood via interpretations of mechanical loads, although prioritized adaptations to tension and/or shear are considered. While there is some suggestion that CFO may correlate with body size, this relationship is neither consistent nor easily explicable through consideration of size-related changes in mechanical adaptation. The results of our study indicate that there is no clear relationship between CFO and phylogenetic status. One of the principle factors accounting for the range of variation that does exist is primary tissue type, where slower depositing bone is more likely to comprise a larger proportion of oblique to transverse collagen fibers. Anat Rec, 300:1189-1207, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Calcaneal Tendon Collagen Fiber Morphometry and Aging

    Czech Academy of Sciences Publication Activity Database

    Hadraba, Daniel; Janáček, Jiří; Filová, Eva; Lopot, F.; Paesen, R.; Fanta, O.; Jarman, A.; Nečas, A.; Ameloot, M.; Jelen, K.

    2017-01-01

    Roč. 23, č. 5 (2017), s. 1040-1047 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA16-14758S; GA MŠk(CZ) LO1309; GA MŠk(CZ) LM2015062 Institutional support: RVO:67985823 ; RVO:68378041 Keywords : collagen * aging * crimp * fiber orientation * tendon Subject RIV: EB - Genetics ; Molecular Biology; BO - Biophysics (UEM-P) OBOR OECD: Developmental biology; Biophysics (UEM-P) Impact factor: 1.891, year: 2016

  20. The OmpL37 surface-exposed protein is expressed by pathogenic Leptospira during infection and binds skin and vascular elastin.

    Science.gov (United States)

    Pinne, Marija; Choy, Henry A; Haake, David A

    2010-09-07

    Pathogenic Leptospira spp. shed in the urine of reservoir hosts into freshwater can be transmitted to a susceptible host through skin abrasions or mucous membranes causing leptospirosis. The infection process involves the ability of leptospires to adhere to cell surface and extracellular matrix components, a crucial step for dissemination and colonization of host tissues. Therefore, the elucidation of novel mediators of host-pathogen interaction is important in the discovery of virulence factors involved in the pathogenesis of leptospirosis. In this study, we assess the functional roles of transmembrane outer membrane proteins OmpL36 (LIC13166), OmpL37 (LIC12263), and OmpL47 (LIC13050), which we recently identified on the leptospiral surface. We determine the capacity of these proteins to bind to host tissue components by enzyme-linked immunosorbent assay. OmpL37 binds elastin preferentially, exhibiting dose-dependent, saturating binding to human skin (K(d), 104±19 nM) and aortic elastin (K(d), 152±27 nM). It also binds fibrinogen (K(d), 244±15 nM), fibrinogen fragment D (K(d), 132±30 nM), plasma fibronectin (K(d), 359±68 nM), and murine laminin (K(d), 410±81 nM). The binding to human skin elastin by both recombinant OmpL37 and live Leptospira interrogans is specifically enhanced by rabbit antiserum for OmpL37, suggesting the involvement of OmpL37 in leptospiral binding to elastin and also the possibility that host-generated antibodies may promote rather than inhibit the adherence of leptospires to elastin-rich tissues. Further, we demonstrate that OmpL37 is recognized by acute and convalescent leptospirosis patient sera and also by Leptospira-infected hamster sera. Finally, OmpL37 protein is detected in pathogenic Leptospira serovars and not in saprophytic Leptospira. Thus, OmpL37 is a novel elastin-binding protein of pathogenic Leptospira that may be promoting attachment of Leptospira to host tissues.

  1. Chemical Stabilisation of Collagen as a Biomimetic

    Directory of Open Access Journals (Sweden)

    R. Gordon Paul

    2003-01-01

    Full Text Available Collagen is the most abundant protein in animals and because of its high mechanical strength and good resistance to degradation has been utilized in a wide range of products in industry whilst its low antigenicity has resulted in its widespread use in medicine. Collagen products can be purified from fibres, molecules reconstituted as fibres or from specific recombinant polypeptides with preferred properties. A common feature of all these biomaterials is the need for stable chemical cross-linking to control the mechanical properties and the residence time in the body, and to some extent the immunogenicity of the device. This can be achieved by a number of different cross-linking agents that react with specific amino acid residues on the collagen molecule imparting individual biochemical, thermal and mechanical characteristics to the biomaterial. In this review we have summarised the major techniques for testing these characteristics and the mechanisms involved in the variety of cross-linking reactions to achieve particular properties..

  2. A elasticidade do ligamento colateral medial da articulação do cotovelo de cão não advém de elastina The elasticity of the medial collateral ligament of the canine elbow joint does not come from elastin

    Directory of Open Access Journals (Sweden)

    Paloma Souza Costa

    2008-09-01

    Full Text Available A literatura relata que ligamentos consistem de tecido conjuntivo denso, composto por água, colágeno tipos I e III, diversas proteoglicanas, pouca elastina e várias outras substâncias. Além disso, os ligamentos, quando testados in vitro com tensão longitudinal e unidirecional, apresentam um comportamento mecânico não-linear, ou seja, as fibras colágenas são alongadas aos poucos, perdendo seu padrão ondulado, até que todas estejam no limite máximo de tração e iniciem o rompimento. Portanto, no presente estudo avaliou-se a presença de fibras elásticas (elastina no ligamento colateral medial do cotovelo de cães adultos para ponderar se a elasticidade do referido ligamento deve-se à presença de fibras elásticas ou às propriedades elásticas do colágeno ou à combinação de ambas. Foram utilizadas quatro articulações, de machos e fêmeas em igual proporção, das quais foram adquiridas as amostras das porções médias dos ligamentos colaterais mediais para a rotina histológica. Os cortes foram corados pela técnica de Weigert, e não foi observada a presença de fibras elásticas, detectável por esta técnica à microscopia de luz. Concluiu-se que a elasticidade do ligamento colateral medial do cotovelo de cão deve-se, principalmente, ao padrão ondulado das fibras colágenas, devido à quantidade ínfima ou até à inexistência de fibras elásticas nesta estrutura.The literature reports that ligaments consist of connective tissue, composed by water, Type I and III collagen, several proteoglycans, some elastin and other substances. Ligaments tested in vitro with longitudinal and unidirectional tension exhibit non-linear mechanical behavior; the collagen fibers are stretched little by little, losing their undulating pattern, until reaching the maximum limit of traction and failure begins. The aim of the present study was to assess the presence of elastin in the medial collateral ligament of the elbow in adult dogs to

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Collagenous colitis: histopathology and clinical course.

    Science.gov (United States)

    Goff, J S; Barnett, J L; Pelke, T; Appelman, H D

    1997-01-01

    Collagenous colitis is a chronic diarrheal disease characterized by a normal or near-normal mucosa endoscopically and microscopic inflammation in the lamina propria, surface epithelial injury and a thick subepithelial collagen layer. The symptoms of collagenous colitis vary in duration and intensity, and long periods of remission have been described, but long-term follow-up data are limited. Our goal was to determine the natural clinical history of collagenous colitis and to determine whether there was a relationship between histopathologic changes and course of disease. Cases were identified at the University of Michigan Hospitals using surgical pathology records before 1992. All charts, including medical records from other hospitals, were reviewed, and a telephone interview was conducted with each locatable patient (pt). Biopsy specimens were reviewed by two pathologists for degree of collagen layer thickness, epithelial damage, and inflammation. There were 31 patients (26 F, 5 M) with a mean age of 66 yr (range 33-83) and a mean duration of symptoms of 5.4 yr at the time of diagnosis. Of the 31 patients, 18 (56%) had some form of arthritis, and 22 (71%) were using NSAIDS regularly at the time of diagnosis. Follow-up interviews were conducted at least 2 yr after diagnosis (mean 3.5 yr, range 2-5 yr) with 27 of 31 patients (3 could not be located, 1 died). Two definable groups of patients were identified: (1) those with either spontaneous or treatment-related symptom resolution (63%), and (2) those with ongoing or intermittent symptoms requiring at least intermittent therapy (37%). There was no significant difference between the two groups with regard to sex, age, associated diseases, and use of medications. Patients with symptom resolution (mean duration 3.1 yr) had been treated with antidiarrheals (6), sulfasalazine (3), discontinuation of NSAIDS (3), reversal of jejunoilial bypass (1), or nothing (4). Those with ongoing symptoms experienced a wide range of

  8. 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.

  9. 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)....

  10. Human pigmentation: A side effect adapted from a primitive organism′s survival, acting through cell attachment with an affinity for the keratinocyte and for elastin: Part I

    Directory of Open Access Journals (Sweden)

    Sanju Arianayagam

    2014-01-01

    Full Text Available Pigmentation featured millions of years ago and perhaps began with an amoeba frightening off a predator with some agent such as dopamine to prevent its attachment for phagocytosis by an enemy. This paper suggests that the environmental forces of grip and stick deserve greater emphasis and that mechanical forces involved in grip and stick or release from attachment, all point to control of proteases underlying pigmentation. There is an affinity for elastin as a pathway for melanin to exit its peripheral location in the epidermis into lymphatics and play a humeral role in defense mechanisms. The hair follicle follows the epidermal-dermal pattern of behavior with an affinity for elastin, a controlling function of melanin and through the bulge, an influence of mechanical forces and control by protease inhibitors.

  11. 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.

  12. Membrane-Based Inverse Transition Cycling: An Improved Means for Purifying Plant-Derived Recombinant Protein-Elastin-Like Polypeptide Fusions

    Directory of Open Access Journals (Sweden)

    Udo Conrad

    2011-04-01

    Full Text Available Elastin-like peptide (ELP was fused to two different avian flu H5N1 antigens and expressed in transgenic tobacco plants. The presence of the ELP tag enhanced the accumulation of the heterologous proteins in the tobacco leaves. An effective membrane-based Inverse Transition Cycling was developed to recover the ELPylated antigens and antibodies from plant material. The functionality of both the ELPylated neuraminidase and an ELPylated nanobody was demonstrated.

  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. 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...

  15. 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...

  16. 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....

  17. Measurement of the exchange rate of waters of hydration in elastin by 2D T{sub 2}-T{sub 2} correlation nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sun Cheng; Boutis, Gregory S, E-mail: gboutis@brooklyn.cuny.edu [Brooklyn College, Department of Physics, 2900 Bedford Avenue, Brooklyn, NY 11210 (United States)

    2011-02-15

    We report on a direct measurement of the exchange rate of waters of hydration in elastin by T{sub 2}-T{sub 2} exchange spectroscopy. The exchange rates in bovine nuchal ligament elastin and aortic elastin at temperatures near, below and at the physiological temperature are reported here. Using an inverse Laplace transform (ILT) algorithm, we are able to identify four components in the relaxation times. While three of the components are in good agreement with previous measurements that used multi-exponential fitting, the ILT algorithm distinguishes a fourth component having relaxation times close to that of free water and is identified as water between fibers. With the aid of scanning electron microscopy, a model is proposed that allows for the application of a two-site exchange analysis between any two components for the determination of exchange rates between reservoirs. The results of the measurements support a model (described by Urry and Parker 2002 J. Muscle Res. Cell Motil. 23 543-59) wherein the net entropy of waters of hydration should increase with increasing temperature in the inverse temperature transition.

  18. Measurement of the exchange rate of waters of hydration in elastin by 2D T2-T2 correlation nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Sun Cheng; Boutis, Gregory S

    2011-01-01

    We report on a direct measurement of the exchange rate of waters of hydration in elastin by T 2 -T 2 exchange spectroscopy. The exchange rates in bovine nuchal ligament elastin and aortic elastin at temperatures near, below and at the physiological temperature are reported here. Using an inverse Laplace transform (ILT) algorithm, we are able to identify four components in the relaxation times. While three of the components are in good agreement with previous measurements that used multi-exponential fitting, the ILT algorithm distinguishes a fourth component having relaxation times close to that of free water and is identified as water between fibers. With the aid of scanning electron microscopy, a model is proposed that allows for the application of a two-site exchange analysis between any two components for the determination of exchange rates between reservoirs. The results of the measurements support a model (described by Urry and Parker 2002 J. Muscle Res. Cell Motil. 23 543-59) wherein the net entropy of waters of hydration should increase with increasing temperature in the inverse temperature transition.

  19. Human umbilical cord-derived mesenchymal stem cells protect from hyperoxic lung injury by ameliorating aberrant elastin remodeling in the lung of O2-exposed newborn rat.

    Science.gov (United States)

    Hou, Chen; Peng, Danyi; Gao, Li; Tian, Daiyin; Dai, Jihong; Luo, Zhengxiu; Liu, Enmei; Chen, Hong; Zou, Lin; Fu, Zhou

    2018-01-08

    The incidence and mortality rates of bronchopulmonary dysplasia (BPD) remain very high. Therefore, novel therapies are imminently needed to improve the outcome of this disease. Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) show promising therapeutic effects on oxygen-induced model of BPD. In our experiment, UC-MSCs were intratracheally delivered into the newborn rats exposed to hyperoxia, a well-established BPD model. This study demonstrated that UC-MSCs reduce elastin expression stimulated by 90% O 2 in human lung fibroblasts-a (HLF-a), and inhibit HLF-a transdifferentiation into myofibroblasts. In addition, the therapeutic effects of UC-MSCs in neonatal rats with BPD, UC-MSCs could inhibit lung elastase activity and reduce aberrant elastin expression and deposition in the lung of BPD rats. Overall, this study suggested that UC-MSCs could ameliorate aberrant elastin expression in the lung of hyperoxia-induced BPD model which may be associated with suppressing increased TGFβ1 activation. Copyright © 2017. Published by Elsevier Inc.

  20. Measurement of the Exchange Rate of Waters of Hydration in Elastin by 2D T(2)-T(2) Correlation Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Sun, Cheng; Boutis, Gregory S

    2011-02-28

    We report on the direct measurement of the exchange rate of waters of hydration in elastin by T(2)-T(2) exchange spectroscopy. The exchange rates in bovine nuchal ligament elastin and aortic elastin at temperatures near, below and at the physiological temperature are reported. Using an Inverse Laplace Transform (ILT) algorithm, we are able to identify four components in the relaxation times. While three of the components are in good agreement with previous measurements that used multi-exponential fitting, the ILT algorithm distinguishes a fourth component having relaxation times close to that of free water and is identified as water between fibers. With the aid of scanning electron microscopy, a model is proposed allowing for the application of a two-site exchange analysis between any two components for the determination of exchange rates between reservoirs. The results of the measurements support a model (described elsewhere [1]) wherein the net entropy of bulk waters of hydration should increase upon increasing temperature in the inverse temperature transition.

  1. 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

  2. Metal stabilization of collagen and de novo designed mimetic peptides

    OpenAIRE

    Parmar, Avanish S.; Xu, Fei; Pike, Douglas H.; Belure, Sandeep V.; Hasan, Nida F.; Drzewiecki, Kathryn E.; Shreiber, David I.; Nanda, Vikas

    2015-01-01

    We explore the design of metal binding sites to modulate triple-helix stability of collagen and collagen-mimetic peptides. Globular proteins commonly utilize metals to connect tertiary structural elements that are well separated in sequence, constraining structure and enhancing stability. It is more challenging to engineer structural metals into fibrous protein scaffolds, which lack the extensive tertiary contacts seen in globular proteins. In the collagen triple helix, the structural adjacen...

  3. Von Willebrand protein binds to extracellular matrices independently of collagen.

    OpenAIRE

    Wagner, D D; Urban-Pickering, M; Marder, V J

    1984-01-01

    Von Willebrand protein is present in the extracellular matrix of endothelial cells where it codistributes with fibronectin and types IV and V collagen. Bacterial collagenase digestion of endothelial cells removed fibrillar collagen, but the pattern of fibronectin and of von Willebrand protein remained undisturbed. Exogenous von Willebrand protein bound to matrices of different cells, whether rich or poor in collagen. von Willebrand protein also decorated the matrix of cells grown in the prese...

  4. 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.

  5. 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

  6. 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 ...

  7. [Biophysical principles of collagen cross-linking].

    Science.gov (United States)

    Spörl, E; Raiskup-Wolf, F; Pillunat, L E

    2008-02-01

    The reduced mechanical stability of the cornea in keratoconus or in keratectasia after Lasik may be increased by photooxidative cross-linking of corneal collagen. The biophysical principles are compiled for the safe and effective application of this new treatment method. The setting of the therapy parameters should be elucidated from the absorption behaviour of the cornea. The safety of the method for the endothelium cells and the lens will be discussed. The induced cross-links are shown to be the result of changes in the physico-chemical properties of the cornea. To reach a high absorption of the irradiation energy in the cornea, riboflavin of a concentration of 0.1% and UV light of a wavelength of 370 nm, corresponding to the relative maximum of absorption of riboflavin, were used. An irradiance of 3 mW/cm(2) and an irradiation time of 30 min lead to an increase of the mechanical stiffness. The endothelium cells will be protected due to the high absorption within the cornea, that means the damaging threshold of the endothelium cells will not be reached in a 400 microm thick stroma. As evidence for cross-links we can consider the increase of the biomechanical stiffness, the increased resistance against enzymatic degradation, a higher shrinkage temperature, a lower swelling rate and an increased diameter of collagen fibres. The therapy parameters were tested experimentally and have been proven clinically in the corneal collagen cross-linking. These parameters should be respected to reach a safe cross-linking effect without damage of the adjacent tissues.

  8. Release of antibiotics from collagen dressing.

    Science.gov (United States)

    Grzybowski, J; Antos-Bielska, M; Ołdak, E; Trafny, E A

    1997-01-01

    Our new collagen dressing has been developed recently. Three types (A, B, and C) of the dressing were prepared in this study. Each type contained bacitracin, neomycin or colistin. The antibiotic was input into: i. collagen sponge (CS)--type A, ii. layer of limited hydrophobicity (LLH)--type B, and iii. into both CS and LLH layers--type C. The final concentration of the antibiotic that resulted from the loading level was 2 mg/cm2 for the dressings of type A and B and 4 mg/cm2 for the dressing of type C. The antibiotics were then extracted from the pieces of dressings for two days through dialysis membrane. Susceptibility of 54 bacterial strains (S. aureus, P. aeruginosa, and Acinetobacter) isolated from burn wounds were tested to the three antibiotics used for preparation of the dressings. The results of the study evidenced that efficiency of released of antibiotics into the extracts depended on the kind of antibiotic and on the type of dressing. The concentration of the antibiotics proved to be much higher than MIC90 values of the bacterial isolates tested in respect to their susceptibility. The dressing containing mixture of the three antibiotics in two layers--CS and LLH is now considered as potentially effective for care of infected wounds. It may be useful for the treatment of infected wounds or for profilaxis of contaminated wounds, ensuring: i. sufficient antimicrobial activity in wound, and ii. optimal wound environment for the presence of collagenic biomaterial on the damaged tissue.

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. 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

  14. 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.

  15. 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.

  16. 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....

  17. 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...

  18. 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....

  19. 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...

  20. 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.

  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. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies......, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability....

  3. Prediction of collagen orientation in articular cartilage by a collagen remodeling algorithm

    NARCIS (Netherlands)

    Wilson, W.; Driessen, N.J.B.; Donkelaar, van C.C.; Ito, K.

    2006-01-01

    Tissue engineering is a promising method to treat damaged cartilage. So far it has not been possible to create tissue-engineered cartilage with an appropriate structural organization. It is envisaged that cartilage tissue engineering will significantly benefit from knowledge of how the collagen

  4. 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.

  5. Ameloblasts express type I collagen during amelogenesis.

    Science.gov (United States)

    Assaraf-Weill, N; Gasse, B; Silvent, J; Bardet, C; Sire, J Y; Davit-Béal, T

    2014-05-01

    Enamel and enameloid, the highly mineralized tooth-covering tissues in living vertebrates, are different in their matrix composition. Enamel, a unique product of ameloblasts, principally contains enamel matrix proteins (EMPs), while enameloid possesses collagen fibrils and probably receives contributions from both odontoblasts and ameloblasts. Here we focused on type I collagen (COL1A1) and amelogenin (AMEL) gene expression during enameloid and enamel formation throughout ontogeny in the caudate amphibian, Pleurodeles waltl. In this model, pre-metamorphic teeth possess enameloid and enamel, while post-metamorphic teeth possess enamel only. In first-generation teeth, qPCR and in situ hybridization (ISH) on sections revealed that ameloblasts weakly expressed AMEL during late-stage enameloid formation, while expression strongly increased during enamel deposition. Using ISH, we identified COL1A1 transcripts in ameloblasts and odontoblasts during enameloid formation. COL1A1 expression in ameloblasts gradually decreased and was no longer detected after metamorphosis. The transition from enameloid-rich to enamel-rich teeth could be related to a switch in ameloblast activity from COL1A1 to AMEL synthesis. P. waltl therefore appears to be an appropriate animal model for the study of the processes involved during enameloid-to-enamel transition, especially because similar events probably occurred in various lineages during vertebrate evolution.

  6. 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

  7. Rapid and simple purification of elastin-like polypeptides directly from whole cells and cell lysates by organic solvent extraction.

    Science.gov (United States)

    VerHeul, Ross; Sweet, Craig; Thompson, David H

    2018-03-26

    Elastin-like polypeptides (ELP) are a well-known class of proteins that are being increasingly utilized in a variety of biomedical applications, due to their beneficial physicochemical properties. A unifying feature of ELP is their demonstration of a sequence tunable inverse transition temperature (Tt) that enables purification using a simple, straightforward process called inverse transition cycling (ITC). Despite the utility of ITC, the process is inherently limited to ELP with an experimentally accessible Tt. Since the underlying basis for the ELP Tt is related to its high overall hydrophobicity, we anticipated that ELP would be excellent candidates for purification by organic extraction. We report the first method for rapidly purifying ELP directly from whole E. coli cells or clarified lysates using pure organic solvents and solvent mixtures, followed by aqueous back extraction. Our results show that small ELP and a large ELP-fusion protein can be isolated in high yield from whole cells or cell lysates with greater than 95% purity in less than 30 min and with very low levels of LPS and DNA contamination.

  8. Regeneration of hyaline cartilage promoted by xenogeneic mesenchymal stromal cells embedded within elastin-like recombinamer-based bioactive hydrogels.

    Science.gov (United States)

    Pescador, David; Ibáñez-Fonseca, Arturo; Sánchez-Guijo, Fermín; Briñón, Jesús G; Arias, Francisco Javier; Muntión, Sandra; Hernández, Cristina; Girotti, Alessandra; Alonso, Matilde; Del Cañizo, María Consuelo; Rodríguez-Cabello, José Carlos; Blanco, Juan Francisco

    2017-08-01

    Over the last decades, novel therapeutic tools for osteochondral regeneration have arisen from the combination of mesenchymal stromal cells (MSCs) and highly specialized smart biomaterials, such as hydrogel-forming elastin-like recombinamers (ELRs), which could serve as cell-carriers. Herein, we evaluate the delivery of xenogeneic human MSCs (hMSCs) within an injectable ELR-based hydrogel carrier for osteochondral regeneration in rabbits. First, a critical-size osteochondral defect was created in the femora of the animals and subsequently filled with the ELR-based hydrogel alone or with embedded hMSCs. Regeneration outcomes were evaluated after three months by gross assessment, magnetic resonance imaging and computed tomography, showing complete filling of the defect and the de novo formation of hyaline-like cartilage and subchondral bone in the hMSC-treated knees. Furthermore, histological sectioning and staining of every sample confirmed regeneration of the full cartilage thickness and early subchondral bone repair, which was more similar to the native cartilage in the case of the cell-loaded ELR-based hydrogel. Overall histological differences between the two groups were assessed semi-quantitatively using the Wakitani scale and found to be statistically significant (p hyaline cartilage in osteochondral lesions.

  9. Preparation and characterization of porous crosslinked collagenous matrices containing bioavailable chondroitin sulphate

    NARCIS (Netherlands)

    Pieper, J.S.; Oosterhof, A.; Dijkstra, Pieter J.; Veerkamp, J.H.; van Kuppevelt, T.H.

    1999-01-01

    Porous collagen matrices with defined physical, chemical and biological characteristics are interesting materials for tissue engineering. Attachment of glycosaminoglycans (GAGs) may add to these characteristics and valorize collagen. In this study, porous type I collagen matrices were crosslinked

  10. Effect of Mechanical Stretching of the Skin on Collagen Fibril ...

    African Journals Online (AJOL)

    Stabilization of collagen fibres during development and through growth to maturation has now become fairly documented. In vitro effect of mechanical stretching of ratsf skin on oxidative deamination of ε-NH2-groups of lysine and hydroxylysine, and functional properties of its type . collagen were studied. Experiments were ...

  11. 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.

  12. Effects of recombinant human collagen VI from Escherichia coli on ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... In this study, we reported the cloning and over expression of a gene coding for human collagen peptide. (CP6) in Escherichia coli and investigated the protective effects of CP6 on UVA-irradiated human skin fibroblasts cells. The collagen peptide (CP6) was highly soluble and the expression level was.

  13. 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

  14. 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 ...

  15. The collagen microfibril model, a tool for biomaterials scientists

    Science.gov (United States)

    Animal hides, a major byproduct of the meat industry, are a rich source of collagen, a structural protein of the extracellular matrix that gives strength and form to the skin, tendons and bones of mammals. The structure of fibrous collagen, a long triple helix that self-associates in a staggered arr...

  16. Postnatal development of collagen structure in ovine articular cartilage

    NARCIS (Netherlands)

    Turnhout, van M.C.; Schipper, H.; Engel, B.; Buist, W.; Kranenbarg, S.; Leeuwen, van J.L.

    2010-01-01

    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

  17. Postnatal development of collagen structure in ovine articular cartilage

    NARCIS (Netherlands)

    Turnhout, van M.C.; Schipper, H.; Engel, B.; Buist, W.; Kranenbarg, S.; Leeuwen, van J.L.

    2010-01-01

    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

  18. Collagen levels are normalized after decompression of experimentally obstructed colon

    DEFF Research Database (Denmark)

    Rehn, Martin; Ågren, Sven Per Magnus; Syk, I

    2011-01-01

    Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction.......Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction....

  19. 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.

  20. 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.

  1. Penta-fibrillar assembly: A Building block collagen based materials

    Indian Academy of Sciences (India)

    There is a smartness in the way the penta-fibrils behave in collagen based biomaterials. It is one of the intriguing nano material with a size of about 4 nano meter diagonal size. There are several intermolecular forces that participate in the penta fibrillar assembly, which derive importance in smart behavior of collagen.

  2. Collagenous colitis as a possible cause of toxic megacolon.

    LENUS (Irish Health Repository)

    Fitzgerald, S C

    2009-03-01

    Collagenous colitis is a microscopic colitis characterized by normal appearing colonic mucosa on endoscopy. It is regarded as a clinically benign disease which rarely results in serious complications. We report a case of toxic megacolon occurring in a patient with collagenous colitis. This is the first reported case of toxic megacolon occurring in this subset of patients.

  3. Eucalyptus globulus extract protects against UVB-induced photoaging by enhancing collagen synthesis via regulation of TGF-β/Smad signals and attenuation of AP-1.

    Science.gov (United States)

    Park, Bom; Hwang, Eunson; Seo, Seul A; Cho, Jin-Gyeong; Yang, Jung-Eun; Yi, Tae-Hoo

    2018-01-01

    UV irradiation triggers the overproduction of matrix metalloproteinases and collagen degradation, which in turn causes increased pigmentation, dryness, and deep wrinkling of the skin. These chronic symptoms are collectively referred to as photoaging. Eucalyptus globulus is an evergreen tree that is widely used in cosmetics because of its antimicrobial activity. In this study, we investigated the protective effect of 50% ethanol extracts of Eucalyptus globulus on UV-induced photoaging in vitro and in vivo. Normal human dermal fibroblasts were treated with Eucalyptus globulus at concentrations ranging from 1 to 100 μg/mL after UVB or non-UVB irradiation. We found that Eucalyptus globulus suppressed the expression of MMPs and IL-6, but increased the expression of TGF-β1 and procollagen type 1. In addition, Eucalyptus globulus inhibited activation of the AP-1 transcription factor, an inducer of MMPs. Eucalyptus globulus was also found to regulate TGF-β/Smad signaling by reversing the activity of negative Smad regulators. Lastly, in vivo studies showed that topical application of Eucalyptus globulus on UVB-irradiated hairless mice reduced wrinkle formation and dryness by down-regulating MMP-1 and up-regulating expression of elastin, TGF-β1, and procollagen type 1. Taken together, these data suggest that Eucalyptus globulus may be a useful agent in cosmetic products. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The efficacy of a novel collagen-gelatin scaffold with basic fibroblast growth factor for the treatment of vocal fold scar.

    Science.gov (United States)

    Hiwatashi, Nao; Hirano, Shigeru; Mizuta, Masanobu; Kobayashi, Toshiki; Kawai, Yoshitaka; Kanemaru, Shin-Ichi; Nakamura, Tatsuo; Ito, Juichi; Kawai, Katsuya; Suzuki, Shigehiko

    2017-05-01

    Vocal fold scar remains a therapeutic challenge. Basic fibroblast growth factor (bFGF) was reported to have regenerative effects for vocal fold scar, although it has the disadvantage of rapid absorption in vivo. A collagen-gelatin sponge (CGS) can compensate for the disadvantage by providing a sustained release system. The current study evaluated the efficacy of CGS combined with bFGF on vocal fold scar, using rat fibroblasts for an in vitro model and a canine in vivo model. We prepared fibroblasts from scarred vocal folds (sVFs) in rats and showed that bFGF accelerated cell proliferation and suppressed expression levels of cleaved caspase 3 and α-smooth muscle actin. Has 1, Has 3, Fgf2, Hgf and Vegfa mRNA levels were significantly upregulated, while Col1a1 and Col3a1 were dose-dependently downregulated, with a maximum effect at 100 ng/ml bFGF. In an in vivo assay, 6 weeks after lamina propria stripping, beagles were divided into three groups: CGS alone (CGS group); CGS with bFGF (7 µg/cm 2 ; CGS + bFGF group); or a sham-treated group. Vibratory examination revealed that the glottal gap was significantly reduced in the bFGF group and the two implanted groups, whereas the CGS + bFGF group showed higher mucosal wave amplitude. Histological examination revealed significantly restored hyaluronic acid and elastin redistribution in the CGS + bFGF group and reductions in dense collagen deposition. These results provide evidence that CGS and bFGF combination therapy may have therapeutic potential and could be a promising tool for treating vocal fold scar. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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....

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Goodpasture's autoimmune disease - A collagen IV disorder.

    Science.gov (United States)

    Pedchenko, Vadim; Richard Kitching, A; Hudson, Billy G

    2018-05-12

    Goodpasture's (GP) disease is an autoimmune disorder characterized by the deposition of pathogenic autoantibodies in basement membranes of kidney and lung eliciting rapidly progressive glomerulonephritis and pulmonary hemorrhage. The principal autoantigen is the α345 network of collagen IV, which expression is restricted to target tissues. Recent discoveries include a key role of chloride and bromide for network assembly, a novel posttranslational modification of the antigen, a sulfilimine bond that crosslinks the antigen, and the mechanistic role of HLA in genetic susceptibility and resistance to GP disease. These advances provide further insights into molecular mechanisms of initiation and progression of GP disease and serve as a basis for developing of novel diagnostic tools and therapies for treatment of Goodpasture's disease. Copyright © 2017. Published by Elsevier B.V.

  17. Subclinical pulmonary involvement in collagen vascular diseases

    International Nuclear Information System (INIS)

    Dansin, E.; Wallaert, B.; Jardin, M.R.; Remy, J.; Hatron, P.Y.; Tonnel, A.B.

    1990-01-01

    A recruitment of immune and inflammatory cells into alveolar spaces has been reported in patients with collagen vascular diseases (CVD) and a normal chest radiograph. These findings defined the concept of subclinical alveolitis (SCA). To determine whether SCA may be associated with CT signs of interstitial lung disease (ILD), the authors of this paper compared bronchoalveolar lavage (BAL) findings and high-resolution (HRCT) scans in 36 patients with CVD and normal chest radiographs (systemic sclerosis [SS, n = 21], rheumatoid arthritis [RA, n = 9], primary Sjogren's syndrome [PS, n = 6]). HRCT scans were obtained in supine and prone positions. Results of BAL revealed SCA in 17/36 patients (47%); lymphocyte SCA in 4/36 (24%); neutrophil SCA in 7/36 (41%); and mixed SCA in 6/36 (35%)

  18. Cutaneous collagenous vasculopathy: A rare case report

    Directory of Open Access Journals (Sweden)

    Kinjal Deepak Rambhia

    2016-01-01

    Full Text Available Cutaneous collagenous vasculopathy (CCV is a distinct, rare, and underdiagnosed condition. We report a case of CCV in a 50-year-old woman presenting as asymptomatic, erythematous to hyperpigmented nonblanchable macules over both the lower extremities. The clinical differential diagnosis of the lesions was pigmented purpuric dermatoses (Schamberg's purpura and cutaneous small vessel vasculitis. Histology of the lesions revealed dilated superficial dermal vessels with abundant pink hyaline material in the vessel wall, which stained with periodic acid Schiff stain. The patient was diagnosed as CCV. This condition remains largely underdiagnosed and is commonly mistaken for pigmented purpuric dermatosis or generalized essential telangiectasia. Emphasis on the differentiation of CCV from its clinical and histological mimicks is made.

  19. Corneal collagen crosslinking and pigment dispersion syndrome.

    Science.gov (United States)

    LaHood, Benjamin R; Moore, Sacha

    2017-03-01

    We describe the case of a keratoconus patient with pigment dispersion syndrome (PDS) who was treated for progressive corneal ectasia with corneal collagen crosslinking (CXL). Pigment dispersion syndrome has been shown to have associated morphologic changes of the corneal endothelium. Corneal CXL has the potential to cause toxicity to the corneal endothelium, and adjacent pigment might increase the likelihood of damage. In this case, the presence of PDS had no detrimental effect on the outcome of treatment, and no complications were observed at 12 months follow-up, indicating that it may be safe to perform corneal CXL in the setting of PDS. This is an important observation as the number of indications for corneal CXL grows. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  1. Isolation and Characterization of Collagen and Antioxidant Collagen Peptides from Scales of Croceine Croaker (Pseudosciaena crocea

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2013-11-01

    Full Text Available Acid soluble collagen (ASC from scales of croceine croaker (ASC-C was successfully isolated with the yield of 0.37% ± 0.08% (dry weight basis, and characterized as type I collagen on the basis of amino acid analysis and electrophoretic pattern. The antioxidant hydrolysate of ASC-C (ACH was prepared through a two-stage in vitro digestion (4-h trypsin followed by 4-h pepsin, and three antioxidant peptides (ACH-P1, ACH-P2, and ACH-P3 were further isolated from ACH using ultrafiltration, gel chromatography, and RP-HPLC, and their amino acid sequences were identified as GFRGTIGLVG (ACH-P1, GPAGPAG (ACH-P2, and GFPSG (ACH-P3. ACH-P1, ACH-P2, and ACH-P3 showed good scavenging activities on hydroxyl radical (IC50 0.293, 0.240, and 0.107 mg/mL, respectively, DPPH radical (IC50 1.271, 0.675, and 0.283 mg/mL, respectively, superoxide radical (IC50 0.463, 0.099, and 0.151 mg/mL, respectively, and ABTS radical (IC50 0.421, 0.309, and 0.210 mg/mL, respectively. ACH-P3 was also effectively against lipid peroxidation in the model system. The antioxidant activities of three collagen peptides were due to the presence of hydrophobic amino acid residues within the peptide sequences. The collagen peptides might be used as antioxidant for the therapy of diseases associated with oxidative stress, or reducing oxidative changes during storage.

  2. 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.

  3. 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.

  4. 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.

  5. 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