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Sample records for bmp-2 independent mechanism

  1. Cell-mediated BMP-2 liberation promotes bone formation in a mechanically unstable implant environment.

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    Hägi, Tobias T; Wu, Gang; Liu, Yuelian; Hunziker, Ernst B

    2010-05-01

    The flexible alloplastic materials that are used in bone-reconstruction surgery lack the mechanical stability that is necessary for sustained bone formation, even if this process is promoted by the application of an osteogenic agent, such as BMP-2. We hypothesize that if BMP-2 is delivered gradually, in a cell-mediated manner, to the surgical site, then the scaffolding material's lack of mechanical stability becomes a matter of indifference. Flexible discs of Ethisorb were functionalized with BMP-2, which was either adsorbed directly onto the material (rapid release kinetics) or incorporated into a calcium-phosphate coating (slow release kinetics). Unstabilized and titanium-plate-stabilized samples were implanted subcutaneously in rats and retrieved up to 14 days later for a histomorphometric analysis of bone and cartilage volumes. On day 14, the bone volume associated with titanium-plate-stabilized discs bearing an adsorbed depot of BMP-2 was 10-fold higher than that associated with their mechanically unstabilized counterparts. The bone volume associated with discs bearing a coating-incorporated depot of BMP-2 was similar in the mechanically unstabilized and titanium-plate-stabilized groups, and comparable to that associated with the titanium-plate-stabilized discs bearing an adsorbed depot of BMP-2. Hence, if an osteogenic agent is delivered in a cell-mediated manner (via coating degradation), ossification can be promoted even within a mechanically unstable environment.

  2. BMP-2 functions independently of SHH signaling and triggers cell condensation and apoptosis in regenerating axolotl limbs

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    Finnson Kenneth

    2010-02-01

    Full Text Available Abstract Background Axolotls have the unique ability, among vertebrates, to perfectly regenerate complex body parts, such as limbs, after amputation. In addition, axolotls pattern developing and regenerating autopods from the anterior to posterior axis instead of posterior to anterior like all tetrapods studied to date. Sonic hedgehog is important in establishing this anterior-posterior axis of limbs in all tetrapods including axolotls. Interestingly, its expression is conserved (to the posterior side of limb buds and blastemas in axolotl limbs as in other tetrapods. It has been suggested that BMP-2 may be the secondary mediator of sonic hedgehog, although there is mounting evidence to the contrary in mice. Since BMP-2 expression is on the anterior portion of developing and regenerating limbs prior to digit patterning, opposite to the expression of sonic hedgehog, we examined whether BMP-2 expression was dependent on sonic hedgehog signaling and whether it affects patterning of the autopod during regeneration. Results The expression of BMP-2 and SOX-9 in developing and regenerating axolotl limbs corresponded to the first digits forming in the anterior portion of the autopods. The inhibition of sonic hedgehog signaling with cyclopamine caused hypomorphic limbs (during development and regeneration but did not affect the expression of BMP-2 and SOX-9. Overexpression of BMP-2 in regenerating limbs caused a loss of digits. Overexpression of Noggin (BMP inhibitor in regenerating limbs also resulted in a loss of digits. Histological analysis indicated that the loss due to BMP-2 overexpression was the result of increased cell condensation and apoptosis while the loss caused by Noggin was due to a decrease in cell division. Conclusion The expression of BMP-2 and its target SOX-9 was independent of sonic hedgehog signaling in developing and regenerating limbs. Their expression correlated with chondrogenesis and the appearance of skeletal elements has

  3. β3 integrin-mediated spreading induced by matrix-bound BMP-2 controls Smad signaling in a stiffness-independent manner.

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    Fourel, Laure; Valat, Anne; Faurobert, Eva; Guillot, Raphael; Bourrin-Reynard, Ingrid; Ren, Kefeng; Lafanechère, Laurence; Planus, Emmanuelle; Picart, Catherine; Albiges-Rizo, Corinne

    2016-03-14

    Understanding how cells integrate multiple signaling pathways to achieve specific cell differentiation is a challenging question in cell biology. We have explored the physiological presentation of BMP-2 by using a biomaterial that harbors tunable mechanical properties to promote localized BMP-2 signaling. We show that matrix-bound BMP-2 is sufficient to induce β3 integrin-dependent C2C12 cell spreading by overriding the soft signal of the biomaterial and impacting actin organization and adhesion site dynamics. In turn, αvβ3 integrin is required to mediate BMP-2-induced Smad signaling through a Cdc42-Src-FAK-ILK pathway. β3 integrin regulates a multistep process to control first BMP-2 receptor activity and second the inhibitory role of GSK3 on Smad signaling. Overall, our results show that BMP receptors and β3 integrin work together to control Smad signaling and tensional homeostasis, thereby coupling cell adhesion and fate commitment, two fundamental aspects of developmental biology and regenerative medicine.

  4. β3 integrin–mediated spreading induced by matrix-bound BMP-2 controls Smad signaling in a stiffness-independent manner

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    Fourel, Laure; Valat, Anne; Faurobert, Eva; Guillot, Raphael; Bourrin-Reynard, Ingrid; Ren, Kefeng; Lafanechère, Laurence; Planus, Emmanuelle; Albiges-Rizo, Corinne

    2016-01-01

    Understanding how cells integrate multiple signaling pathways to achieve specific cell differentiation is a challenging question in cell biology. We have explored the physiological presentation of BMP-2 by using a biomaterial that harbors tunable mechanical properties to promote localized BMP-2 signaling. We show that matrix-bound BMP-2 is sufficient to induce β3 integrin–dependent C2C12 cell spreading by overriding the soft signal of the biomaterial and impacting actin organization and adhesion site dynamics. In turn, αvβ3 integrin is required to mediate BMP-2–induced Smad signaling through a Cdc42–Src–FAK–ILK pathway. β3 integrin regulates a multistep process to control first BMP-2 receptor activity and second the inhibitory role of GSK3 on Smad signaling. Overall, our results show that BMP receptors and β3 integrin work together to control Smad signaling and tensional homeostasis, thereby coupling cell adhesion and fate commitment, two fundamental aspects of developmental biology and regenerative medicine. PMID:26953352

  5. BMP2 Transfer to Neighboring Cells and Activation of Signaling.

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    Alborzinia, Hamed; Shaikhkarami, Marjan; Hortschansky, Peter; Wölfl, Stefan

    2016-09-01

    Morphogen gradients and concentration are critical features during early embryonic development and cellular differentiation. Previously we reported the preparation of biologically active, fluorescently labeled BMP2 and quantitatively analyzed their binding to the cell surface and followed BMP2 endocytosis over time on the level of single endosomes. Here we show that this internalized BMP2 can be transferred to neighboring cells and, moreover, also activates downstream BMP signaling in adjacent cells, indicated by Smad1/5/8 phosphorylation and activation of the downstream target gene id1. Using a 3D matrix to modulate cell-cell contacts in culture we could show that direct cell-cell contact significantly increased BMP2 transfer. Using inhibitors of vesicular transport, transfer was strongly inhibited. Interestingly, cotreatment with the physiological BMP inhibitor Noggin increased BMP2 uptake and transfer, albeit activation of Smad signaling in neighboring cells was completely suppressed. Our findings present a novel and interesting mechanism by which morphogens such as BMP2 can be transferred between cells and how this is modulated by BMP antagonists such as Noggin, and how this influences activation of Smad signaling by BMP2 in neighboring cells. PMID:27306974

  6. Repressive BMP2 gene regulatory elements near the BMP2 promoter

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    The level of bone morphogenetic protein 2 (BMP2) profoundly influences essential cell behaviors such as proliferation, differentiation, apoptosis, and migration. The spatial and temporal pattern of BMP2 synthesis, particular in diverse embryonic cells, is highly varied and dynamic. We have identified GC-rich sequences within the BMP2 promoter region that strongly repress gene expression. These elements block the activity of a highly conserved, osteoblast enhancer in response to FGF2 treatment. Both positive and negative gene regulatory elements control BMP2 synthesis. Detecting and mapping the repressive motifs is essential because they impede the identification of developmentally regulated enhancers necessary for normal BMP2 patterns and concentration.

  7. Repressive BMP2 gene regulatory elements near the BMP2 promoter

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    Jiang, Shan [Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry (UMDNJ), New Jersey Medical School (NJMS), Newark, NJ (United States); Chandler, Ronald L. [Department of Molecular Physiology and Biophysics, Center for Human Genetics Research, Vanderbilt University School of Medicine, Nashville, TN (United States); Fritz, David T. [Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry (UMDNJ), New Jersey Medical School (NJMS), Newark, NJ (United States); Mortlock, Douglas P. [Department of Molecular Physiology and Biophysics, Center for Human Genetics Research, Vanderbilt University School of Medicine, Nashville, TN (United States); Rogers, Melissa B., E-mail: rogersmb@umdnj.edu [Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry (UMDNJ), New Jersey Medical School (NJMS), Newark, NJ (United States)

    2010-02-05

    The level of bone morphogenetic protein 2 (BMP2) profoundly influences essential cell behaviors such as proliferation, differentiation, apoptosis, and migration. The spatial and temporal pattern of BMP2 synthesis, particular in diverse embryonic cells, is highly varied and dynamic. We have identified GC-rich sequences within the BMP2 promoter region that strongly repress gene expression. These elements block the activity of a highly conserved, osteoblast enhancer in response to FGF2 treatment. Both positive and negative gene regulatory elements control BMP2 synthesis. Detecting and mapping the repressive motifs is essential because they impede the identification of developmentally regulated enhancers necessary for normal BMP2 patterns and concentration.

  8. Bmp2 and Bmp4 accelerate alveolar bone development.

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    Ou, Mingming; Zhao, Yibing; Zhang, Fangming; Huang, Xiaofeng

    2015-06-01

    Alveolar bone remodeling is a continuous process that takes place during development and in response to various physiological and pathological stimuli. However, detailed knowledge regarding the underlying mechanisms involved in alveolar bone development is still lacking. This study aims at improving our understanding of alveolar bone formation and the role of bone morphogenetic proteins (Bmps) in this process. Mice at embryonic (E) day 13.5 to postnatal (PN) day 15.5 were selected to observe the process of alveolar bone development. Alveolar bone development was found to be morphologically observable at E14.5. Molar teeth isolated from mice at PN7.5 were pretreated with Bmp2, Bmp4, Noggin, or BSA, and grafted subcutaneously into mice. The subcutaneously implanted tooth germs formed alveolar bone indicating the role of the dental follicle in alveolar bone development. Alveolar bone formation was increased after pretreatment with Bmp2 and Bmp4, but not with Noggin. Gene expression levels in dental follicle cells from murine molars were also determined by real-time RT-PCR. The expression levels of Runx2, Bsp, and Ocn were significantly higher in dental follicle cells cultured with Bmp2 or Bmp4, and significantly lower in those cultured with Noggin when compared with that of the BSA controls. Our results suggest that the dental follicle participates in alveolar bone formation and Bmp2/4 appears to accelerate alveolar bone development.

  9. Transforming growth factor β1 inhibits bone morphogenic protein (BMP-2 and BMP-7 signaling via upregulation of Ski-related novel protein N (SnoN: possible mechanism for the failure of BMP therapy?

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    Ehnert Sabrina

    2012-09-01

    Full Text Available Abstract Background Bone morphogenic proteins (BMPs play a key role in bone formation. Consequently, it was expected that topical application of recombinant human (rhBMP-2 and rhBMP-7 would improve the healing of complex fractures. However, up to 36% of fracture patients do not respond to this therapy. There are hints that a systemic increase in transforming growth factor β1 (TGFβ1 interferes with beneficial BMP effects. Therefore, in the present work we investigated the influence of rhTGFβ1 on rhBMP signaling in primary human osteoblasts, with the aim of more specifically delineating the underlying regulatory mechanisms. Methods BMP signaling was detected by adenoviral Smad-binding-element-reporter assays. Gene expression was determined by reverse transcription polymerase chain reaction (RT-PCR and confirmed at the protein level by western blot. Histone deacetylase (HDAC activity was determined using a test kit. Data sets were compared by one-way analysis of variance. Results Our findings showed that Smad1/5/8-mediated rhBMP-2 and rhBMP-7 signaling is completely blocked by rhTGFβ1. We then investigated expression levels of genes involved in BMP signaling and regulation (for example, Smad1/5/8, TGFβ receptors type I and II, noggin, sclerostin, BMP and activin receptor membrane bound inhibitor (BAMBI, v-ski sarcoma viral oncogene homolog (Ski, Ski-related novel protein N (SnoN and Smad ubiquitination regulatory factors (Smurfs and confirmed the expression of regulated genes at the protein level. Smad7 and SnoN were significantly induced by rhTGFβ1 treatment while expression of Smad1, Smad6, TGFβRII and activin receptor-like kinase 1 (Alk1 was reduced. Elevated SnoN expression was accompanied by increased HDAC activity. Addition of an HDAC inhibitor, namely valproic acid, fully abolished the inhibitory effect of rhTGFβ1 on rhBMP-2 and rhBMP-7 signaling. Conclusions rhTGFβ1 effectively blocks rhBMP signaling in osteoblasts. As possible

  10. BMP2 Regulation of CXCL12 Cellular, Temporal, and Spatial Expression is Essential During Fracture Repair

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    Myers, Timothy J; Longobardi, Lara; Willcockson, Helen; Temple, Joseph D; Tagliafierro, Lidia; Ye, Ping; Li, Tieshi; Esposito, Alessandra; Moats-Staats, Billie M; Spagnoli, Anna

    2016-01-01

    -reaching implications for understanding mechanisms regulating the selective recruitment of distinct cells into the repairing niches and the development of novel pharmacological (by targeting BMP2/CXCL12) and cellular (MSCs, endosteal cells) interventions to promote fracture healing. PMID:25967044

  11. BMP-2 Induced Expression of Alx3 That Is a Positive Regulator of Osteoblast Differentiation.

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    Takashi Matsumoto

    Full Text Available Bone morphogenetic proteins (BMPs regulate many aspects of skeletal development, including osteoblast and chondrocyte differentiation, cartilage and bone formation, and cranial and limb development. Among them, BMP-2, one of the most potent osteogenic signaling molecules, stimulates osteoblast differentiation, while it inhibits myogenic differentiation in C2C12 cells. To evaluate genes involved in BMP-2-induced osteoblast differentiation, we performed cDNA microarray analyses to compare BMP-2-treated and -untreated C2C12 cells. We focused on Alx3 (aristaless-like homeobox 3 which was clearly induced during osteoblast differentiation. Alx3, a homeobox gene related to the Drosophilaaristaless gene, has been linked to developmental functions in craniofacial structures and limb development. However, little is known about its direct relationship with bone formation. In the present study, we focused on the mechanisms of Alx3 gene expression and function during osteoblast differentiation induced by BMP-2. In C2C12 cells, BMP-2 induced increase of Alx3 gene expression in both time- and dose-dependent manners through the BMP receptors-mediated SMAD signaling pathway. In addition, silencing of Alx3 by siRNA inhibited osteoblast differentiation induced by BMP-2, as showed by the expressions of alkaline phosphatase (Alp, Osteocalcin, and Osterix, while over-expression of Alx3 enhanced osteoblast differentiation induced by BMP-2. These results indicate that Alx3 expression is enhanced by BMP-2 via the BMP receptors mediated-Smad signaling and that Alx3 is a positive regulator of osteoblast differentiation induced by BMP-2.

  12. BMP-2 Overexpression Augments Vascular Smooth Muscle Cell Motility by Upregulating Myosin Va via Erk Signaling

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    Ming Zhang

    2014-01-01

    Full Text Available Background. The disruption of physiologic vascular smooth muscle cell (VSMC migration initiates atherosclerosis development. The biochemical mechanisms leading to dysfunctional VSMC motility remain unknown. Recently, cytokine BMP-2 has been implicated in various vascular physiologic and pathologic processes. However, whether BMP-2 has any effect upon VSMC motility, or by what manner, has never been investigated. Methods. VSMCs were adenovirally transfected to genetically overexpress BMP-2. VSMC motility was detected by modified Boyden chamber assay, confocal time-lapse video assay, and a colony wounding assay. Gene chip array and RT-PCR were employed to identify genes potentially regulated by BMP-2. Western blot and real-time PCR detected the expression of myosin Va and the phosphorylation of extracellular signal-regulated kinases 1/2 (Erk1/2. Immunofluorescence analysis revealed myosin Va expression locale. Intracellular Ca2+ oscillations were recorded. Results. VSMC migration was augmented in VSMCs overexpressing BMP-2 in a dose-dependent manner. siRNA-mediated knockdown of myosin Va inhibited VSMC motility. Both myosin Va mRNA and protein expression significantly increased after BMP-2 administration and were inhibited by Erk1/2 inhibitor U0126. BMP-2 induced Ca2+ oscillations, generated largely by a “cytosolic oscillator”. Conclusion. BMP-2 significantly increased VSMCs migration and myosin Va expression, via the Erk signaling pathway and intracellular Ca2+ oscillations. We provide additional insight into the pathophysiology of atherosclerosis, and inhibition of BMP-2-induced myosin Va expression may represent a potential therapeutic strategy.

  13. Fibrin Hydrogel Based Bone Substitute Tethered with BMP-2 and BMP-2/7 Heterodimers

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    Lindsay S. Karfeld-Sulzer

    2015-03-01

    Full Text Available Current clinically used delivery methods for bone morphogenetic proteins (BMPs are collagen based and require large concentrations that can lead to dangerous side effects. Fibrin hydrogels can serve as osteoinductive bone substitute materials in non-load bearing bone defects in combination with BMPs. Two strategies to even further optimize such a fibrin based system include employing more potent BMP heterodimers and engineering growth factors that can be covalently tethered to and slowly released from a fibrin matrix. Here we present an engineered BMP-2/BMP-7 heterodimer where an N-terminal transglutaminase substrate domain in the BMP-2 portion provides covalent attachment to fibrin together with a central plasmin substrate domain, a cleavage site for local release of the attached BMP-2/BMP-7 heterodimer under the influence of cell-activated plasmin. In vitro and in vivo results revealed that the engineered BMP-2/BMP-7 heterodimer induces significantly more alkaline phosphatase activity in pluripotent cells and bone formation in a rat calvarial model than the engineered BMP-2 homodimer. Therefore, the engineered BMP-2/BMP-7 heterodimer could be used to reduce the amount of BMP needed for clinical effect.

  14. Establishment of Immortalized Mouse Bmp2 Knock-Out Dental Papilla Mesenchymal Cells Necessary for Study of Odontoblastic Differentiation and Odontogenesis

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    Wu, Lian; Wang, Feng; Donly, Kevin J.; Wan, Chunyan; Luo, Daoshu; Harris, Stephen E.; Macdougall, Mary; Chen, Shuo

    2016-01-01

    Bmp2 is essential for dentin formation. Bmp2 cKO mice exhibited similar phenotype to dentinogenesis imperfecta, showing dental pulp exposure, hypomineralized dentin, and delayed odontoblast differentiation. As it is relatively difficult to obtain lot of primary Bmp2 cKO dental papilla mesenchymal cells and to maintain a long-term culture of these primary cells, availability of immortalized deleted Bmp2 dental papilla mesenchymal cells is critical for studying the underlying mechanism of Bmp2 signal in odontogenesis. In this study, our goal was to generate an immortalized deleted Bmp2 dental papilla mesenchymal (iBmp2ko/ko dp) cell line by introducing Cre fluorescent protein (GFP) into the immortalized mouse floxed Bmp2 dental papilla mesenchymal (iBmp2fx/fx dp) cells. iBmp2ko/ko dp cells were confirmed by GFP and PCR. The deleted Bmp2 cells exhibited slow cell proliferation rate and cell growth was arrested in G2 phase. Expression of tooth-related marker genes and cell differentiation were decreased in the deleted cells. Importantly, extracellular matrix remodeling was impaired in the iBmp2ko/ko dp cells as reflected by the decreased Mmp-9 expression. In addition, with exogenous Bmp2 induction, these cell differentiation and mineralization were rescued as well as extracellular matrix remodeling was enhanced. Therefore, we for the first time described establishment of iBmpko/ko cells that are useful for study of mechanisms in regulating dental papilla mesenchymal cell lineages. PMID:26037045

  15. Establishment of Immortalized Mouse Bmp2 Knock-Out Dental Papilla Mesenchymal Cells Necessary for Study of Odontoblastic Differentiation and Odontogenesis.

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    Wu, Lian; Wang, Feng; Donly, Kevin J; Wan, Chunyan; Luo, Daoshu; Harris, Stephen E; MacDougall, Mary; Chen, Shuo

    2015-11-01

    Bmp2 is essential for dentin formation. Bmp2 cKO mice exhibited similar phenotype to dentinogenesis imperfecta, showing dental pulp exposure, hypomineralized dentin, and delayed odontoblast differentiation. As it is relatively difficult to obtain lot of primary Bmp2 cKO dental papilla mesenchymal cells and to maintain a long-term culture of these primary cells, availability of immortalized deleted Bmp2 dental papilla mesenchymal cells is critical for studying the underlying mechanism of Bmp2 signal in odontogenesis. In this study, our goal was to generate an immortalized deleted Bmp2 dental papilla mesenchymal (iBmp2(ko/ko)dp) cell line by introducing Cre recombinase and green fluorescent protein (GFP) into the immortalized mouse floxed Bmp2 dental papilla mesenchymal (iBmp2(fx/fx)dp) cells. iBmp2(ko/ko)dp cells were confirmed by GFP and PCR. The deleted Bmp2 cells exhibited slow cell proliferation rate and cell growth was arrested in G2 phase. Expression of tooth-related marker genes and cell differentiation were decreased in the deleted cells. Importantly, extracellular matrix remodeling was impaired in the iBmp2(ko/ko)dp cells as reflected by the decreased Mmp-9 expression. In addition, with exogenous Bmp2 induction, these cell differentiation and mineralization were rescued as well as extracellular matrix remodeling was enhanced. Therefore, we for the first time described establishment of iBmp(ko/ko) cells that are useful for study of mechanisms in regulating dental papilla mesenchymal cell lineages. PMID:26037045

  16. Bmp2 Is Required for Odontoblast Differentiation and Pulp Vasculogenesis

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    Yang, W; Harris, M.A.; Y. Cui; Mishina, Y; Harris, S.E.; Gluhak-Heinrich, J.

    2012-01-01

    Using the Bmp2 floxed/3.6Col1a1-Cre (Bmp2-cKOod) mouse model, we have observed severe defects in odontogenesis and dentin formation with the removal of the Bmp2 gene in early-polarizing odontoblasts. The odontoblasts in the Bmp2-cKOod do not mature properly and fail to form proper dentin with normal dentinal tubules and activate terminal differentiation, as reflected by decreased Osterix, Col1a1, and Dspp expression. There is less dentin, and the dentin is hypomineralized and patchy. We also ...

  17. PPARγ-Independent Mechanism

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    Christopher M. Hogan

    2011-01-01

    Full Text Available Acute and chronic lung inflammation is associated with numerous important disease pathologies including asthma, chronic obstructive pulmonary disease and silicosis. Lung fibroblasts are a novel and important target of anti-inflammatory therapy, as they orchestrate, respond to, and amplify inflammatory cascades and are the key cell in the pathogenesis of lung fibrosis. Peroxisome proliferator-activated receptor gamma (PPARγ ligands are small molecules that induce anti-inflammatory responses in a variety of tissues. Here, we report for the first time that PPARγ ligands have potent anti-inflammatory effects on human lung fibroblasts. 2-cyano-3, 12-dioxoolean-1, 9-dien-28-oic acid (CDDO and 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2 inhibit production of the inflammatory mediators interleukin-6 (IL-6, monocyte chemoattractant protein-1 (MCP-1, COX-2, and prostaglandin (PGE2 in primary human lung fibroblasts stimulated with either IL-1β or silica. The anti-inflammatory properties of these molecules are not blocked by the PPARγ antagonist GW9662 and thus are largely PPARγ independent. However, they are dependent on the presence of an electrophilic carbon. CDDO and 15d-PGJ2, but not rosiglitazone, inhibited NF-κB activity. These results demonstrate that CDDO and 15d-PGJ2 are potent attenuators of proinflammatory responses in lung fibroblasts and suggest that these molecules should be explored as the basis for novel, targeted anti-inflammatory therapies in the lung and other organs.

  18. BMP-2 and titanium particles synergistically activate osteoclast formation

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    Sun, S.X. [Affiliated Hospital of Ningxia Medical University, Department of Orthopedics, Yinchuan, Ningxia Hui Autonomous Region, China, Department of Orthopedics, Affiliated Hospital of Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region (China); Guo, H.H. [Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region, China, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region (China); Zhang, J. [Institute of Pathology, Xi' an Jiaotong University, Xi' an Shaanxi, China, Institute of Pathology, Xi' an Jiaotong University, Xi' an Shaanxi (China); Yu, B. [Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region, China, Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region (China); Sun, K.N.; Jin, Q.H. [Affiliated Hospital of Ningxia Medical University, Department of Orthopedics, Yinchuan, Ningxia Hui Autonomous Region, China, Department of Orthopedics, Affiliated Hospital of Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region (China)

    2014-05-09

    A previous study showed that BMP-2 (bone morphogenetic protein-2) and wear debris can separately support osteoclast formation induced by the receptor activator of NF-κB ligand (RANKL). However, the effect of BMP-2 on wear debris-induced osteoclast formation is unclear. In this study, we show that neither titanium particles nor BMP-2 can induce osteoclast formation in RAW 264.7 mouse leukemic monocyte macrophage cells but that BMP-2 synergizes with titanium particles to enhance osteoclast formation in the presence of RANKL, and that at a low concentration, BMP-2 has an optimal effect to stimulate the size and number of multinuclear osteoclasts, expression of osteoclast genes, and resorption area. Our data also clarify that the effects caused by the increase in BMP-2 on phosphorylated SMAD levels such as c-Fos expression increased throughout the early stages of osteoclastogenesis. BMP-2 and titanium particles stimulate the expression of p-JNK, p-P38, p-IkB, and P50 compared with the titanium group. These data suggested that BMP-2 may be a crucial factor in titanium particle-mediated osteoclast formation.

  19. BMP-2 Is Involved in Scleral Remodeling in Myopia Development.

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    Honghui Li

    Full Text Available The development of myopia is associated with scleral remodeling, but it is unclear which factors regulate this process. This study investigated bone morphogenetic protein-2 (BMP-2 expression in the sclera of guinea pigs with lens-induced myopia (LIM and after recovery from myopia and evaluated the effect of BMP-2 on extracellular matrix (ECM synthesis in human scleral fibroblasts (HSFs cultured in vitro. Lens-induced myopia was brought about in two groups of guinea pigs (the lens-induced myopia and myopia recovery groups by placing -4.00 D lenses on the right eye for three weeks. The left eye served as a contralateral control. In the recovery group, the lenses were removed after one week. The refractive power and axial length of the eyes were measured, and the BMP-2 expression levels in the sclera were measured. After three weeks, the lens-induced eyes acquired relative myopia in both groups of guinea pigs. Immunostaining of the eyeballs revealed significantly decreased BMP-2 expression in the posterior sclera of the myopic eyes compared to the contralateral eyes. One week after lens removal, BMP-2 expression recovered, and no differences were observed between the experimental and contralateral eyes in the recovery group. HSFs were cultured with BMP-2 or transforming growth factor-β1 (TGF-β1. Type I and type III collagen synthesis was significantly up-regulated following BMP-2 treatment in culture after one and two weeks, but the ratio of type III to type I collagen mRNA was not increased. Biosynthesis of glycosaminoglycan (GAG and aggrecan was increased in HSFs treated with BMP-2. Some chondrogenesis-associated genes expression increased in HSFs treated with BMP-2. From this study, we concluded that BMP-2 is involved in scleral remodeling in the development and recovery of lens-induced myopia.

  20. BMP-2 Is Involved in Scleral Remodeling in Myopia Development

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    Li, Honghui; Cui, Dongmei; Zhao, Feng; Huo, Lijun; Hu, Jianmin; Zeng, Junwen

    2015-01-01

    The development of myopia is associated with scleral remodeling, but it is unclear which factors regulate this process. This study investigated bone morphogenetic protein-2 (BMP-2) expression in the sclera of guinea pigs with lens-induced myopia (LIM) and after recovery from myopia and evaluated the effect of BMP-2 on extracellular matrix (ECM) synthesis in human scleral fibroblasts (HSFs) cultured in vitro. Lens-induced myopia was brought about in two groups of guinea pigs (the lens-induced myopia and myopia recovery groups) by placing -4.00 D lenses on the right eye for three weeks. The left eye served as a contralateral control. In the recovery group, the lenses were removed after one week. The refractive power and axial length of the eyes were measured, and the BMP-2 expression levels in the sclera were measured. After three weeks, the lens-induced eyes acquired relative myopia in both groups of guinea pigs. Immunostaining of the eyeballs revealed significantly decreased BMP-2 expression in the posterior sclera of the myopic eyes compared to the contralateral eyes. One week after lens removal, BMP-2 expression recovered, and no differences were observed between the experimental and contralateral eyes in the recovery group. HSFs were cultured with BMP-2 or transforming growth factor-β1 (TGF-β1). Type I and type III collagen synthesis was significantly up-regulated following BMP-2 treatment in culture after one and two weeks, but the ratio of type III to type I collagen mRNA was not increased. Biosynthesis of glycosaminoglycan (GAG) and aggrecan was increased in HSFs treated with BMP-2. Some chondrogenesis-associated genes expression increased in HSFs treated with BMP-2. From this study, we concluded that BMP-2 is involved in scleral remodeling in the development and recovery of lens-induced myopia. PMID:25965995

  1. BMP-2 Is Involved in Scleral Remodeling in Myopia Development

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    Honghui Li; Dongmei Cui; Feng Zhao; Lijun Huo; Jianmin Hu; Junwen Zeng

    2015-01-01

    The development of myopia is associated with scleral remodeling, but it is unclear which factors regulate this process. This study investigated bone morphogenetic protein-2 (BMP-2) expression in the sclera of guinea pigs with lens-induced myopia (LIM) and after recovery from myopia and evaluated the effect of BMP-2 on extracellular matrix (ECM) synthesis in human scleral fibroblasts (HSFs) cultured in vitro. Lens-induced myopia was brought about in two groups of guinea pigs (the lens-induced ...

  2. Mesenchymal stem cells with rhBMP-2 inhibits the growth of canine osteosarcoma cells

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    Grassi Rici Rose

    2012-02-01

    Full Text Available Abstract Background The bone morphogenetic proteins (BMPs belong to a unique group of proteins that includes the growth factor TGF-β. BMPs play important roles in cell differentiation, cell proliferation, and inhibition of cell growth. They also participate in the maturation of several cell types, depending on the microenvironment and interactions with other regulatory factors. Depending on their concentration gradient, the BMPs can attract various types of cells and act as chemotactic, mitogenic, or differentiation agents. BMPs can interfere with cell proliferation and the formation of cartilage and bone. In addition, BMPs can induce the differentiation of mesenchymal progenitor cells into various cell types, including chondroblasts and osteoblasts. The aim of this study was to analyze the effects of treatment with rhBMP-2 on the proliferation of canine mesenchymal stem cells (cMSCs and the tumor suppression properties of rhBMP-2 in canine osteocarcoma (OST cells. Osteosarcoma cell lines were isolated from biopsies and excisions of animals with osteosarcoma and were characterized by the Laboratory of Biochemistry and Biophysics, Butantan Institute. The mesenchymal stem cells were derived from the bone marrow of canine fetuses (cMSCs and belong to the University of São Paulo, College of Veterinary Medicine (FMVZ-USP stem cell bank. After expansion, the cells were cultured in a 12-well Transwell system; cells were treated with bone marrow mesenchymal stem cells associated with rhBMP2. Expression of the intracytoplasmic and nuclear markers such as Caspase-3, Bax, Bad, Bcl-2, Ki-67, p53, Oct3/4, Nanog, Stro-1 were performed by flow citometry. Results We evaluated the regenerative potential of in vitro treatment with rhBMP-2 and found that both osteogenic induction and tumor regression occur in stem cells from canine bone marrow. rhBMP-2 inhibits the proliferation capacity of OST cells by mechanisms of apoptosis and tumor suppression mediated by p

  3. Fabrication of Core-Shell PEI/pBMP2-PLGA Electrospun Scaffold for Gene Delivery to Periodontal Ligament Stem Cells

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    Qiao Xie

    2016-01-01

    Full Text Available Bone tissue engineering is the most promising technology for enhancing bone regeneration. Scaffolds loaded with osteogenic factors improve the therapeutic effect. In this study, the bioactive PEI (polyethylenimine/pBMP2- (bone morphogenetic protein-2 plasmid- PLGA (poly(D, L-lactic-co-glycolic acid core-shell scaffolds were prepared using coaxial electrospinning for a controlled gene delivery to hPDLSCs (human periodontal ligament stem cells. The pBMP2 was encapsulated in the PEI phase as a core and PLGA was employed to control pBMP2 release as a shell. First, the scaffold characterization and mechanical properties were evaluated. Then the gene release behavior was analyzed. Our results showed that pBMP2 was released at high levels in the first few days, with a continuous release behavior in the next 28 days. At the same time, PEI/pBMP2 showed high transfection efficiency. Moreover, the core-shell electrospun scaffold showed BMP2 expression for a much longer time (more than 28 days compared with the single axial electrospun scaffold, as evaluated by qRT-PCR and western blot after culturing with hPDLSCs. These results suggested that the core-shell PEI/pBMP2-PLGA scaffold fabricated by coaxial electrospinning had a good gene release behavior and showed a prolonged expression time with a high transfection efficiency.

  4. Effect of rhBMP-2 on tibial plateau fractures in a canine model.

    Science.gov (United States)

    Schaefer, Susan L; Lu, Yan; Seeherman, Howard; Li, X Jian; Lopez, Mandi J; Markel, Mark D

    2009-04-01

    This study was to determine the efficacy of recombinant human bone morphogenetic protien-2 (rhBMP-2)/calcium phosphate matrix (CPX) paste to accelerate healing in a canine articular fracture model with associated subchondral defect. rhBMP-2/CPX (BMP), CPX alone (CPX) or autogenous bone graft (ABG) was administered to a canine articular tibial plateau osteotomy with a subchondral defect in each of 21 female dogs. The unoperated contralateral limbs served as controls. Ground reaction forces, synovial fluid, radiographic changes, mechanical testing, bone density, and histology of bone and synovium were analyzed at 6 weeks after surgery. Radiographic analysis demonstrated that the BMP and CPX groups showed improved bony healing compared to the ABG group at week 6. Histomorphometric analysis demonstrated that the BMP group had significantly increased trabecular bone volume compared to the CPX and ABG groups. Mechanical testing revealed that the BMP group had significantly greater maximum failure loads than the ABG group. Histological analysis demonstrated that the BMP group had significantly less sub-synovial inflammation than CPX group. This study demonstrated that rhBMP-2/CPX accelerated healing of articular fractures with subchondral defect compared to ABG in most of the parameters evaluated, and had less subsynovial inflammation than the CPX alone in a canine model.

  5. Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye-Lim; Park, Hyun-Jung; Kwon, Arang [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Baek, Kyunghwa [Department of Pharmacology, College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangneung 210-702, Gangwondo (Korea, Republic of); Woo, Kyung Mi; Ryoo, Hyun-Mo; Kim, Gwan-Shik [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Baek, Jeong-Hwa, E-mail: baekjh@snu.ac.kr [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of)

    2014-05-01

    It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression, which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation. - Highlights: • EGF increases the expression level of Smurf1 in mesenchymal precursor cells. • EGF reduces the protein levels and transcriptional activity of Runx2 and Smad1. • EGF suppresses BMP2-induced osteogenic differentiation, which is rescued by Smurf1 knockdown.

  6. MRI of transforaminal lumbar interbody fusion: imaging appearance with and without the use of human recombinant bone morphogenetic protein-2 (rhBMP-2)

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Michael G.; Goldberg, Judd M.; Gaskin, Cree M.; Barr, Michelle S.; Alford, Bennett [University of Virginia, Department of Radiology and Medical Imaging, Charlottesville, VA (United States); Patrie, James T. [University of Virginia, Department of Public Health Sciences, Charlottesville, VA (United States); Shen, Francis H. [University of Virginia, Department of Orthopedic Surgery, Charlottesville, VA (United States)

    2014-09-15

    To describe the vertebral endplate and intervertebral disc space MRI appearance following TLIF, with and without the use of rhBMP-2, and to determine if the appearance is concerning for discitis/osteomyelitis. After institutional review board approval, 116 TLIF assessments performed on 75 patients with rhBMP-2 were retrospectively and independently reviewed by five radiologists and compared to 73 TLIF assessments performed on 45 patients without rhBMP-2. MRIs were evaluated for endplate signal, disc space enhancement, disc space fluid, and abnormal paraspinal soft tissue. Endplate edema-like signal was reported when T1-weighted hypointensity, T2-weighted hyperintensity, and endplate enhancement were present. Subjective concern for discitis/osteomyelitis on MRI was graded on a five-point scale. Generalized estimating equation binomial regression model analysis was performed with findings correlated with rhBMP-2 use, TLIF level, graft type, and days between TLIF and MRI. The rhBMP-2 group demonstrated endplate edema-like signal (OR 5.66; 95 % CI [1.58, 20.24], p = 0.008) and disc space enhancement (OR 2.40; 95 % CI [1.20, 4.80], p = 0.013) more often after adjusting for the TLIF level, graft type, and the number of days following TLIF. Both groups had a similar temporal distribution for endplate edema-like signal but disc space enhancement peaked earlier in the rhBMP-2 group. Disc space fluid was only present in the rhBMP-2 group. Neither group demonstrated abnormal paraspinal soft tissue and discitis/osteomyelitis was not considered likely in any patient. Endplate edema-like signal and disc space enhancement were significantly more frequent and disc space enhancement developed more rapidly following TLIF when rhBMP-2 was utilized. The concern for discitis/osteomyelitis was similar and minimal in both groups. (orig.)

  7. MRI of transforaminal lumbar interbody fusion: imaging appearance with and without the use of human recombinant bone morphogenetic protein-2 (rhBMP-2)

    International Nuclear Information System (INIS)

    To describe the vertebral endplate and intervertebral disc space MRI appearance following TLIF, with and without the use of rhBMP-2, and to determine if the appearance is concerning for discitis/osteomyelitis. After institutional review board approval, 116 TLIF assessments performed on 75 patients with rhBMP-2 were retrospectively and independently reviewed by five radiologists and compared to 73 TLIF assessments performed on 45 patients without rhBMP-2. MRIs were evaluated for endplate signal, disc space enhancement, disc space fluid, and abnormal paraspinal soft tissue. Endplate edema-like signal was reported when T1-weighted hypointensity, T2-weighted hyperintensity, and endplate enhancement were present. Subjective concern for discitis/osteomyelitis on MRI was graded on a five-point scale. Generalized estimating equation binomial regression model analysis was performed with findings correlated with rhBMP-2 use, TLIF level, graft type, and days between TLIF and MRI. The rhBMP-2 group demonstrated endplate edema-like signal (OR 5.66; 95 % CI [1.58, 20.24], p = 0.008) and disc space enhancement (OR 2.40; 95 % CI [1.20, 4.80], p = 0.013) more often after adjusting for the TLIF level, graft type, and the number of days following TLIF. Both groups had a similar temporal distribution for endplate edema-like signal but disc space enhancement peaked earlier in the rhBMP-2 group. Disc space fluid was only present in the rhBMP-2 group. Neither group demonstrated abnormal paraspinal soft tissue and discitis/osteomyelitis was not considered likely in any patient. Endplate edema-like signal and disc space enhancement were significantly more frequent and disc space enhancement developed more rapidly following TLIF when rhBMP-2 was utilized. The concern for discitis/osteomyelitis was similar and minimal in both groups. (orig.)

  8. Disequilibrium of BMP2 Levels in the Breast Stem Cell Niche Launches Epithelial Transformation by Overamplifying BMPR1B Cell Response

    Directory of Open Access Journals (Sweden)

    Marion Chapellier

    2015-02-01

    Full Text Available Understanding the mechanisms of cancer initiation will help to prevent and manage the disease. At present, the role of the breast microenvironment in transformation remains unknown. As BMP2 and BMP4 are important regulators of stem cells and their niches in many tissues, we investigated their function in early phases of breast cancer. BMP2 production by tumor microenvironment appeared to be specifically upregulated in luminal tumors. Chronic exposure of immature human mammary epithelial cells to high BMP2 levels initiated transformation toward a luminal tumor-like phenotype, mediated by the receptor BMPR1B. Under physiological conditions, BMP2 controlled the maintenance and differentiation of early luminal progenitors, while BMP4 acted on stem cells/myoepithelial progenitors. Our data also suggest that microenvironment-induced overexpression of BMP2 may result from carcinogenic exposure. We reveal a role for BMP2 and the breast microenvironment in the initiation of stem cell transformation, thus providing insight into the etiology of luminal breast cancer.

  9. Disequilibrium of BMP2 Levels in the Breast Stem Cell Niche Launches Epithelial Transformation by Overamplifying BMPR1B Cell Response

    Science.gov (United States)

    Chapellier, Marion; Bachelard-Cascales, Elodie; Schmidt, Xenia; Clément, Flora; Treilleux, Isabelle; Delay, Emmanuel; Jammot, Alexandre; Ménétrier-Caux, Christine; Pochon, Gaëtan; Besançon, Roger; Voeltzel, Thibault; Caron de Fromentel, Claude; Caux, Christophe; Blay, Jean-Yves; Iggo, Richard; Maguer-Satta, Véronique

    2015-01-01

    Summary Understanding the mechanisms of cancer initiation will help to prevent and manage the disease. At present, the role of the breast microenvironment in transformation remains unknown. As BMP2 and BMP4 are important regulators of stem cells and their niches in many tissues, we investigated their function in early phases of breast cancer. BMP2 production by tumor microenvironment appeared to be specifically upregulated in luminal tumors. Chronic exposure of immature human mammary epithelial cells to high BMP2 levels initiated transformation toward a luminal tumor-like phenotype, mediated by the receptor BMPR1B. Under physiological conditions, BMP2 controlled the maintenance and differentiation of early luminal progenitors, while BMP4 acted on stem cells/myoepithelial progenitors. Our data also suggest that microenvironment-induced overexpression of BMP2 may result from carcinogenic exposure. We reveal a role for BMP2 and the breast microenvironment in the initiation of stem cell transformation, thus providing insight into the etiology of luminal breast cancer. PMID:25601208

  10. Kinetics and thermodynamics studies on the BMP-2 adsorption onto hydroxyapatite surface with different multi-morphological features

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Zhiwei; Huangfu, Changxin; Wang, Yanying; Ge, Hongwei; Yao, Yao; Zou, Ping; Wang, Guangtu [College of Science, Sichuan Agricultural University, Ya' an 625014 (China); He, Hua [Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Wenjiang, Sichuan 611130 (China); Rao, Hanbing, E-mail: rhbscu@gmail.com [College of Science, Sichuan Agricultural University, Ya' an 625014 (China)

    2015-07-01

    The effect of the surface topography on protein adsorption process is of great significance for designing hydroxyapatite (HA) ceramic material surfaces. In this work, three different topographies of HA materials HA-sheet, HA-rod, and HA-whisker were synthesized and testified by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Brunauer–Emmett–Teller (BET) and a field emission scanning electron microscopy (FE-SEM). We have systematically investigated the adsorption kinetics and thermodynamics of bone morphogenetic proteins (BMP-2) on the three different topography surfaces of HA, respectively. The results showed that the maximum adsorption capacities of HA-sheet, HA-rod and HA-whisker were (219.96 ± 10.18), (247.13 ± 12.35), and (354.67 ± 17.73) μg · g{sup −1}, respectively. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated as well as discussed. It demonstrated that the adsorption of BMP-2 onto HA could be described by the pseudo second-order equation. Adsorption of BMP-2 onto HA followed the Langmuir isotherm. It confirmed that compared with other samples HA-whisker had more adsorption sites for its high specific surface area which could provide more opportunities for protein molecules. The adsorption processes were endothermic (ΔH > 0), spontaneous (ΔG < 0) and entropy increasing (ΔS > 0). A possible adsorption mechanism has been proposed. In addition, the BMP-2 could be adsorbed to the surface which existed slight conformational changes by FT-IR. - Highlights: • A novel protein adsorption studies based on sheet, rod and whisker of HA were designed. • Kinetic and thermodynamics parameters of BMP-2 and HA bonded materials were evaluated. • Surface topographies of the HA effect BMP-2 adsorption • The HA-whisker material had excellent adsorption performance for protein enrichment. • The electrostatic interaction is responsible for the

  11. rhBMP-2/CPC强化骨质疏松椎体力学强度的实验研究%The experimental study of the effect of rhBMP-2/CPC on biomechanical intensity for osteoporotic vertebrae

    Institute of Scientific and Technical Information of China (English)

    罗志强

    2011-01-01

    Objective To observe the dynamic efficacy of recombinant human bone morphogenetic protein-2/calcium phosphate cement ( rhBMP-2/CPC ) on the augment of biomechanical intensity of the lumbar vertebrae in ovariectomized sheep. Methods Twelve adult female sheep were ovariectomized and raised for 1 year after the surgery. Bone mineral densities ( BMD) of the lumbar vertebrae were measured before and after the surgery. L1-L6 were the experimental objects. The sheep in control group were offered no treatment. The sheep in CPC group were injected with CPC (2.0ml) via the transpedicular of the vertebra. The sheep in rhBMP-2/CPC group were injected with rhBMP-2/CPC (2. 0ml) via the transpedicular of the vertebra. Every 3 sheep were randomly killed on day 1, week 6, week 12, and week 24 after the surgery. The vertebra compression test was performed. The ultimate compressive stress ( σalt ) and energy absorption value ( EAV ) of the vertebrae in every group were measured. The biomechanical indexes were compared and analyzed among different methods at the same time and among different time points using same method. Results BMO of the sheep vertebrae significantly decreased at 1 year after the surgery ( P 0.05). However, aalt in rhBMP-2/CPC group was significantly higher than that in CPC group on week 24 ( P 0. 05). However, σalt in rhBMP-2/ CPC group on week 24 was significantly higher than that on other three time points in the same group ( P < 0. 05). Conclusion rhBMP-2/CPC not only improved the immediate mechanical strength of osteoporotic vertebrae, but also maintained the dynamic mechanical strength and further enhanced the lone-term mechanical strength of osteoporotic vertebrae, which could provide an ideal mechanical condition for firm bone fusion of the spine.%目的 观察人重组骨形态发生蛋白-2复合磷酸钙骨水泥(recombinant human bonemorphogenetic protein-2/calcium phosphate cement,rhBMP-2/CPC)强化骨质疏松绵羊腰椎生物力学

  12. Complexation and sequestration of BMP-2 from an ECM mimetic hyaluronan gel for improved bone formation.

    Directory of Open Access Journals (Sweden)

    Marta Kisiel

    Full Text Available Bone morphogenetic protein-2 (BMP-2 is considered a promising adjuvant for the treatment of skeletal non-union and spinal fusion. However, BMP-2 delivery in a conventional collagen scaffold necessitates a high dose to achieve an efficacious outcome. To lower its effective dose, we precomplexed BMP-2 with the glycosaminoglycans (GAGs dermatan sulfate (DS or heparin (HP, prior to loading it into a hyaluronic acid (HA hydrogel. In vitro release studies showed that BMP-2 precomplexed with DS or HP had a prolonged delivery compared to without GAG. BMP-2-DS complexes achieved a slightly faster release in the first 24 h than HP; however, both delivered BMP-2 for an equal duration. Analysis of the kinetic interaction between BMP-2 and DS or HP showed that HP had approximately 10 times higher affinity for BMP-2 than DS, yet it equally stabilized the protein, as determined by alkaline phosphatase activity. Ectopic bone formation assays at subcutaneous sites in rats demonstrated that HA hydrogel-delivered BMP-2 precomplexed with GAG induced twice the volume of bone compared with BMP-2 delivered uncomplexed to GAG.

  13. Biological activity of a genetically modified BMP-2 variant with inhibitory activity

    Directory of Open Access Journals (Sweden)

    Kübler Alexander C

    2009-02-01

    Full Text Available Abstract Background Alterations of the binding epitopes of bone morphogenetic protein-2 (BMP-2 lead to a modified interaction with the ectodomains of BMP receptors. In the present study the biological effect of a BMP-2 double mutant with antagonistic activity was evaluated in vivo. Methods Equine-derived collagenous carriers were loaded with recombinant human BMP-2 (rhBMP-2 in a well-known dose to provide an osteoinductive stimulus. The study was performed in a split animal design: carriers only coupled with rhBMP-2 (control were implanted into prepared cavities of lower limb muscle of rats, specimens coupled with rhBMP-2 as well as BMP-2 double mutant were placed into the opposite limb in the same way. After 28 days the carriers were explanted, measured radiographically and characterized histologically. Results As expected, the BMP-2 loaded implants showed a typical heterotopic bone formation. The specimens coupled with both proteins showed a significant decreased bone formation in a dose dependent manner. Conclusion The antagonistic effect of a specific BMP-2 double mutant could be demonstrated in vivo. The dose dependent influence on heterotopic bone formation by preventing rhBMP-2 induced osteoinduction suggests a competitive receptor antagonism.

  14. Enhancement of tendon-to-bone healing after anterior cruciate ligament reconstruction using bone marrow-derived mesenchymal stem cells genetically modified with bFGF/BMP2

    Science.gov (United States)

    Chen, Biao; Li, Bin; Qi, Yong-Jian; Ni, Qu-Bo; Pan, Zheng-Qi; Wang, Hui; Chen, Liao-Bin

    2016-01-01

    Many strategies, including various growth factors and gene transfer, have been used to augment healing after anterior cruciate ligament (ACL) reconstruction. The biological environment regulated by the growth factors during the stage of tendon-bone healing was considered important in controlling the integrating process. The purpose of this study was to evaluate the effects of bone marrow-derived mesenchymal stem cells (BMSCs) genetically modified with bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) on healing after ACL reconstruction. BMSCs were infected with an adenoviral vector encoding BMP2 (AdBMP2) or bFGF (AdbFGF). Then, the infected BMSCs were surgically implanted into the tendon-bone interface. At 12 weeks postoperatively, the formation of abundant cartilage-like cells, smaller tibial bone tunnel and significantly higher ultimate load and stiffness levels, through histological analysis, micro-computed tomography and biomechanical testing, were observed. In addition, the AdBMP2-plus-AdbFGF group had the smallest bone tunnel and the best mechanical properties among all the groups. The addition of BMP2 or bFGF by gene transfer resulted in better cellularity, new bone formation and higher mechanical property, which contributed to the healing process after ACL reconstruction. Furthermore, the co-application of these two genes was more powerful and efficient than either single gene therapy. PMID:27173013

  15. Enhancement of tendon-to-bone healing after anterior cruciate ligament reconstruction using bone marrow-derived mesenchymal stem cells genetically modified with bFGF/BMP2.

    Science.gov (United States)

    Chen, Biao; Li, Bin; Qi, Yong-Jian; Ni, Qu-Bo; Pan, Zheng-Qi; Wang, Hui; Chen, Liao-Bin

    2016-01-01

    Many strategies, including various growth factors and gene transfer, have been used to augment healing after anterior cruciate ligament (ACL) reconstruction. The biological environment regulated by the growth factors during the stage of tendon-bone healing was considered important in controlling the integrating process. The purpose of this study was to evaluate the effects of bone marrow-derived mesenchymal stem cells (BMSCs) genetically modified with bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) on healing after ACL reconstruction. BMSCs were infected with an adenoviral vector encoding BMP2 (AdBMP2) or bFGF (AdbFGF). Then, the infected BMSCs were surgically implanted into the tendon-bone interface. At 12 weeks postoperatively, the formation of abundant cartilage-like cells, smaller tibial bone tunnel and significantly higher ultimate load and stiffness levels, through histological analysis, micro-computed tomography and biomechanical testing, were observed. In addition, the AdBMP2-plus-AdbFGF group had the smallest bone tunnel and the best mechanical properties among all the groups. The addition of BMP2 or bFGF by gene transfer resulted in better cellularity, new bone formation and higher mechanical property, which contributed to the healing process after ACL reconstruction. Furthermore, the co-application of these two genes was more powerful and efficient than either single gene therapy. PMID:27173013

  16. Bone regeneration by implantation of adipose-derived stromal cells expressing BMP-2

    International Nuclear Information System (INIS)

    In this study, we reported that the adipose-derived stromal cells (ADSCs) genetically modified by bone morphogenetic protein 2 (BMP-2) healed critical-sized canine ulnar bone defects. First, the osteogenic and adipogenic differentiation potential of the ADSCs derived from canine adipose tissue were demonstrated. And then the cells were modified by the BMP-2 gene and the expression and bone-induction ability of BMP-2 were identified. Finally, the cells modified by BMP-2 gene were applied to a β-tricalcium phosphate (TCP) carrier and implanted into ulnar bone defects in the canine model. After 16 weeks, radiographic, histological, and histomorphometry analysis showed that ADSCs modified by BMP-2 gene produced a significant increase of newly formed bone area and healed or partly healed all of the bone defects. We conclude that ADSCs modified by the BMP-2 gene can enhance the repair of critical-sized bone defects in large animals

  17. Signaling Crosstalk between PPARγ and BMP2 in Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Ichiro Takada

    2012-01-01

    Full Text Available Recent studies have revealed that PPARγ’s transactivation function is regulated by extracellular signals. In particular, cytokines and Wnt family proteins suppress the ligand-inducible transactivation function of PPARγ and attenuate adipogenesis/osteoblastogenesis switching in mesenchymal stem cells (MSCs. For example, Wnt5a suppresses PPARγ transcriptional activity through the NLK/SETDB1/CHD7 pathway. Among these factors, BMP2 strongly induces bone formation, but the effect of BMP2 on PPARγ function remains unclear. We examined the effect of BMP2 and PPARγ in ST2 cells and found that PPARγ activation affected BMP2’s signaling pathway through epigenetic regulation. Although BMP2 did not interfere with PPARγ-mediated adipogenesis, BMP2 increased mRNA expression levels of PPARγ target genes (such as Fabp4 and Nr1h3 when cells were first treated with troglitazone (TRO. Moreover, PPARγ activation affected BMP2 through enhancement of histone activation markers (acetylated histone H3 and trimethylated Lys4 of histone H3 on the Runx2 promoter. After TRO treatment for three hours, BMP2 enhanced the levels of active histone marks on the promoter of a PPARγ target gene. These results suggest that the order of treatment with BMP2 and a PPARγ ligand is critical for adipogenesis and osteoblastogenesis switching in MSCs.

  18. BMP-2 induces versican and hyaluronan that contribute to post-EMT AV cushion cell migration.

    Directory of Open Access Journals (Sweden)

    Kei Inai

    Full Text Available Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM components, versican and hyaluronan (HA, and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.

  19. Bmp2 deletion causes an amelogenesis imperfecta phenotype via regulating enamel gene expression.

    Science.gov (United States)

    Guo, Feng; Feng, Junsheng; Wang, Feng; Li, Wentong; Gao, Qingping; Chen, Zhuo; Shoff, Lisa; Donly, Kevin J; Gluhak-Heinrich, Jelica; Chun, Yong Hee Patricia; Harris, Stephen E; MacDougall, Mary; Chen, Shuo

    2015-08-01

    Although Bmp2 is essential for tooth formation, the role of Bmp2 during enamel formation remains unknown in vivo. In this study, the role of Bmp2 in regulation of enamel formation was investigated by the Bmp2 conditional knock out (Bmp2 cKO) mice. Teeth of Bmp2 cKO mice displayed severe and profound phenotypes with asymmetric and misshaped incisors as well as abrasion of incisors and molars. Scanning electron microscopy analysis showed that the enamel layer was hypoplastic and enamel lacked a typical prismatic pattern. Teeth from null mice were much more brittle as tested by shear and compressive moduli. Expression of enamel matrix protein genes, amelogenin, enamelin, and enamel-processing proteases, Mmp-20 and Klk4 was reduced in the Bmp2 cKO teeth as reflected in a reduced enamel formation. Exogenous Bmp2 up-regulated those gene expressions in mouse enamel organ epithelial cells. This result for the first time indicates Bmp2 signaling is essential for proper enamel development and mineralization in vivo.

  20. Cell saver filtering of extravasated rhBMP-2 after degenerative scoliosis reconstruction

    Directory of Open Access Journals (Sweden)

    Gabriel Liu, MBBCh, MSc, FRCS, FAMS (Orth

    2015-06-01

    Full Text Available RhBMP-2 is a bone fusion enhancer commonly used in scoliosis reconstruction surgery. It is delivered via an absorbable collagen sponge but has been known to migrate away from its delivery site. RhBMP-2 extravasation in surgical drainage has been noted during first two days post-surgery. Cell savers are widely used in scoliosis reconstruction to limit transfusion requirements and are commonly deployed in cases where rhBMP-2 is used for fusion augmentation. It is not known whether rhBMP-2 is present in salvaged blood or filtered away during cell saver recycling. Through this case series of four patients who underwent scoliosis reconstruction, we assess cell saver efficacy in filtering rhBMP-2 molecules by quantifying the amount of rhBMP-2 present in salvaged blood obtained after postoperative drainage recycling by OrthoPAT® cell saver and comparing it to rhBMP-2 leakage in postoperative drainage without cell saver recycling. We report an almost 10-fold reduction of rhBMP-2 concentration in salvaged blood obtained after cell saver recycling of postoperative drainage, suggesting cell saver effectiveness in filtering rhBMP-2 molecules.

  1. Full regeneration of segmental bone defects using porous titanium implants loaded with BMP-2 containing fibrin gels

    Directory of Open Access Journals (Sweden)

    J van der Stok

    2015-03-01

    Full Text Available Regeneration of load-bearing segmental bone defects is a major challenge in trauma and orthopaedic surgery. The ideal bone graft substitute is a biomaterial that provides immediate mechanical stability, while stimulating bone regeneration to completely bridge defects over a short period. Therefore, selective laser melted porous titanium, designed and fine-tuned to tolerate full load-bearing, was filled with a physiologically concentrated fibrin gel loaded with bone morphogenetic protein-2 (BMP-2. This biomaterial was used to graft critical-sized segmental femoral bone defects in rats. As a control, porous titanium implants were either left empty or filled with a fibrin gels without BMP-2. We evaluated bone regeneration, bone quality and mechanical strength of grafted femora using in vivo and ex vivo µCT scanning, histology, and torsion testing. This biomaterial completely regenerated and bridged the critical-sized bone defects within eight weeks. After twelve weeks, femora were anatomically re-shaped and revealed open medullary cavities. More importantly, new bone was formed throughout the entire porous titanium implants and grafted femora regained more than their innate mechanical stability: torsional strength exceeded twice their original strength. In conclusion, combining porous titanium implants with a physiologically concentrated fibrin gels loaded with BMP-2 improved bone regeneration in load-bearing segmental defects. This material combination now awaits its evaluation in larger animal models to show its suitability for grafting load-bearing defects in trauma and orthopaedic surgery.

  2. Clathrin-independent endocytosis: mechanisms and function

    DEFF Research Database (Denmark)

    Sandvig, Kirsten; Pust, Sascha; Skotland, Tore;

    2011-01-01

    having several functions of their own. This article aims at providing a brief update on the importance of clathrin-independent endocytic mechanisms, how the processes are regulated differentially, for instance on the poles of polarized cells, and the challenges in studying them.......It is now about 20 years since we first wrote reviews about clathrin-independent endocytosis. The challenge at the time was to convince the reader about its existence. Then the suggestion came up that caveolae might be responsible for the uptake. However, clearly this could not be the case since...... a large fraction of the clathrin-independent uptake is dynamin-independent. Today, two decades later, the field has developed considerably. New techniques have enabled a detailed analysis of several clathrin-independent endocytic mechanisms, and caveolae have been found to be mostly stable structures...

  3. Rat aortic smooth muscle cells cultured on hydroxyapatite differentiate into osteoblast-like cells via BMP-2-SMAD-5 pathway.

    Science.gov (United States)

    Nahar-Gohad, Pranjal; Gohad, Neeraj; Tsai, Chen-Chih; Bordia, Rajendra; Vyavahare, Naren

    2015-04-01

    Vascular calcification is an important pathological condition associated with increased risk of cardiovascular mortality. Hydroxyapatite (HA) found in such deposits is the same polymorph of calcium (Ca) found in bone, indicating calcification may involve mechanisms akin to bone formation. Vascular smooth muscle cells (Vsmcs) have been shown to undergo phenotypic change to osteoblast-like cells. However, the mechanisms underlying this phenotypic change are unclear, and whether the stimulus to become osteogenic is a result of loss of mineralization inhibitors or early mineral deposits is not known. Our aim in this study is to identify mechanisms and signal transduction pathways that cause differentiation of Vsmcs into osteoblast-like cells in the presence of HA. We first characterized vascular origin of Vsmcs by studying the expression of smooth muscle cell markers: myosin heavy chain and smooth muscle actin along with SM22α at both mRNA and protein levels. Vsmcs grown on HA exhibited progressive change in cellular morphology at 3-, 7-, and 14-day time points. Culturing of Vsmcs on HA disc resulted in decrease in media Ca levels and increased expression of Ca-sensing receptor (CaSR) on Vsmcs resulting in upregulation of intracellular CaSR signaling leading to increased BMP-2 secretion. BMP-2 pathway mediated differentiation of Vsmcs to osteoblast-like cells shown by expression of osteogenic markers like runt-related transcription factor 2, osteocalcin, and alkaline phosphatase at mRNA and protein levels. Blocking CaSR by NPS-2143 reduced BMP-2 secretion and blocking the BMP-2 pathway by LDN-193189, a BMP inhibitor, modulated expression of osteogenic markers confirming their role in osteogenesis of Vsmcs. PMID:25725805

  4. Mineralization of three-dimensional osteoblast cultures is enhanced by the interaction of 1α,25-dihydroxyvitamin D3 and BMP2 via two specific vitamin D receptors.

    Science.gov (United States)

    Chen, Jiaxuan; Dosier, Christopher R; Park, Jung Hwa; De, Subhendu; Guldberg, Robert E; Boyan, Barbara D; Schwartz, Zvi

    2016-01-01

    1α,25-Dihydroxyvitamin D3 [1α,25(OH)2D3] and bone morphogenetic protein-2 (BMP2) are both used to stimulate osteoblastic differentiation. 1α,25(OH)2D3 regulates osteoblasts through classical steroid hormone receptor mechanisms and through rapid responses that are mediated by two receptors, the traditional vitamin D receptor (VDR) and protein disulphide isomerase family A member 3 (Pdia3). The interaction between 1α,25(OH)2D3 and BMP2, especially in three-dimensional (3D) culture, and the roles of the two vitamin D receptors in this interaction are not well understood. We treated wild-type (WT), Pdia3-silenced (Sh-Pdia3) and VDR-silenced (Sh-VDR) pre-osteoblastic MC3T3-E1 cells with either 1α,25(OH)2D3, or BMP2, or with 1α,25(OH)2D3 and BMP2 together, and measured osteoblast marker expression in 2D culture and mineralization in a 3D poly(ε-caprolactone)-collagen scaffold model. Quantitative PCR showed that silencing Pdia3 or VDR had a differential effect on baseline expression of osteoblast markers. 1α,25(OH)2D3 + BMP2 caused a synergistic increase in osteoblast marker expression in WT cells, while silencing either Pdia3 or VDR attenuated this effect. 1α,25(OH)2D3 + BMP2 also caused a synergistic increase in Dlx5 in both silenced cell lines. Micro-computed tomography (μCT) showed that the mineralized volume of untreated Sh-Pdia3 and Sh-VDR 3D cultures was greater than that of WT. 1α,25(OH)2D3 reduced mineral in WT and Sh-VDR cultures; BMP2 increased mineralization; and 1α,25(OH)2D3 + BMP2 caused a synergistic increase, but only in WT cultures. SEM showed that mineralized matrix morphology in 3D cultures differed for silenced cells compared to WT cells. These data indicate a synergistic crosstalk between 1α,25(OH)2D3 and BMP2 toward osteogenesis and mineral deposition, involving both VDR and Pdia3.

  5. Expression of active hBMP2 in transgenic tobacco plants.

    Science.gov (United States)

    Suo, Guangli; Chen, Bing; Zhang, Jingyu; Gao, Yuan; Wang, Xia; He, Zhengquan; Dai, Jianwu

    2006-12-01

    Bone morphogenetic protein 2 (BMP2) is important for bone tissue repair. The goal of this research is to construct a high level human BMP2 (hBMP2) expression system using transgenic tobacco plants as a bioreactor. Cauliflower mosaic virus (CaMV) 35S promoter, alfalfa mosaic virus (AMV) enhancer, tobacco mosaic virus (TMV) enhancer, matrix attachment regions (MARs) sequence, and "Kozak" sequence were used to construct recombinant expression vectors and the high-expression vectors were screened out through GUS-fusions assay. The promoter is the most important factor; double-CaMV 35S promoter is more effective than single promoter. The AMV or TMV enhancer is able to promote the foreign protein expression. After four-step purification, the activated hBMP2 (0.02% total soluble protein) was obtained. Our results suggested that the transgenic tobacco has great potential to be used as a bioreactor to produce hBMP2. PMID:16819603

  6. Immortalization and characterization of mouse floxed Bmp2/4 osteoblasts

    International Nuclear Information System (INIS)

    Generation of a floxed Bmp2/4 osteoblast cell line is a valuable tool for studying the modulatory effects of Bmp2 and Bmp4 on osteoblast differentiation as well as relevant molecular events. In this study, primary floxed Bmp2/4 mouse osteoblasts were cultured and transfected with simian virus 40 large T-antigen. Transfection was verified by polymerase chain reaction (PCR) and immunohistochemistry. To examine the characteristics of the transfected cells, morphology, proliferation and mineralization were analyzed, expression of cell-specific genes including Runx2, ATF4, Dlx3, Osx, dentin matrix protein 1, bone sialoprotein, osteopontin, osteocalcin, osteonectin and collagen type I was detected. These results show that transfected floxed Bmp2/4 osteoblasts bypassed senescence with a higher proliferation rate, but retain the genotypic and phenotypic characteristics similar to the primary cells. Thus, we for the first time demonstrate the establishment of an immortalized mouse floxed Bmp2/4 osteoblast cell line.

  7. Immortalization and characterization of mouse floxed Bmp2/4 osteoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Li-An [Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, TX (United States); Department of Pediatric Dentistry, School of Stomatology, The Fourth Military Medical University, Xi-an (China); Yuan, Guohua; Yang, Guobin [Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, TX (United States); Key Laboratory of Oral Biomedical Engineering Ministry of Education, Wuhan (China); Ortiz-Gonzalez, Iris [Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, TX (United States); Yang, Wuchen; Cui, Yong [Department of Periodontics, Dental School, The University of Texas Health Science Center at San Antonio, TX (United States); MacDougall, Mary [Department of Oral/Maxillofacial Surgery, University of Alabama, Birmingham, AL (United States); Donly, Kevin J. [Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, TX (United States); Harris, Stephen [Department of Periodontics, Dental School, The University of Texas Health Science Center at San Antonio, TX (United States); Chen, Shuo, E-mail: chens0@uthscsa.edu [Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, TX (United States)

    2009-08-14

    Generation of a floxed Bmp2/4 osteoblast cell line is a valuable tool for studying the modulatory effects of Bmp2 and Bmp4 on osteoblast differentiation as well as relevant molecular events. In this study, primary floxed Bmp2/4 mouse osteoblasts were cultured and transfected with simian virus 40 large T-antigen. Transfection was verified by polymerase chain reaction (PCR) and immunohistochemistry. To examine the characteristics of the transfected cells, morphology, proliferation and mineralization were analyzed, expression of cell-specific genes including Runx2, ATF4, Dlx3, Osx, dentin matrix protein 1, bone sialoprotein, osteopontin, osteocalcin, osteonectin and collagen type I was detected. These results show that transfected floxed Bmp2/4 osteoblasts bypassed senescence with a higher proliferation rate, but retain the genotypic and phenotypic characteristics similar to the primary cells. Thus, we for the first time demonstrate the establishment of an immortalized mouse floxed Bmp2/4 osteoblast cell line.

  8. Effect of rhBMP-2 Immobilized Anorganic Bovine Bone Matrix on Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Jung-Bo Huh

    2015-07-01

    Full Text Available Anorganic bovine bone matrix (Bio-Oss® has been used for a long time for bone graft regeneration, but has poor osteoinductive capability. The use of recombinant human bone morphogenetic protein-2 (rhBMP-2 has been suggested to overcome this limitation of Bio-Oss®. In the present study, heparin-mediated rhBMP-2 was combined with Bio-Oss® in animal experiments to investigate bone formation performance; heparin was used to control rhBMP-2 release. Two calvarial defects (8 mm diameter were formed in a white rabbit model and then implanted or not (controls with Bio-Oss® or BMP-2/Bio-Oss®. The Bio-Oss® and BMP-2/Bio-Oss® groups had significantly greater new bone areas (expressed as percentages of augmented areas than the non-implanted controls at four and eight weeks after surgery, and the BMP-2/Bio-Oss® group (16.50 ± 2.87 (n = 6 had significantly greater new bone areas than the Bio-Oss® group (9.43 ± 3.73 (n = 6 at four weeks. These findings suggest that rhBMP-2 treated heparinized Bio-Oss® markedly enhances bone regeneration.

  9. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects.

    Science.gov (United States)

    Xiong, Long; Zeng, Jianhua; Yao, Aihua; Tu, Qiquan; Li, Jingtang; Yan, Liang; Tang, Zhiming

    2015-01-01

    The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2), a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 μm) with a core (60±18 μm) and a mesoporous shell (180±42 m(2)/g surface area) were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 μg/mg). There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option for bone graft substitutes in bone regeneration. PMID:25609957

  10. Effect of rhBMP-2 Immobilized Anorganic Bovine Bone Matrix on Bone Regeneration.

    Science.gov (United States)

    Huh, Jung-Bo; Yang, June-Jip; Choi, Kyung-Hee; Bae, Ji Hyeon; Lee, Jeong-Yeol; Kim, Sung-Eun; Shin, Sang-Wan

    2015-01-01

    Anorganic bovine bone matrix (Bio-Oss®) has been used for a long time for bone graft regeneration, but has poor osteoinductive capability. The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) has been suggested to overcome this limitation of Bio-Oss®. In the present study, heparin-mediated rhBMP-2 was combined with Bio-Oss® in animal experiments to investigate bone formation performance; heparin was used to control rhBMP-2 release. Two calvarial defects (8 mm diameter) were formed in a white rabbit model and then implanted or not (controls) with Bio-Oss® or BMP-2/Bio-Oss®. The Bio-Oss® and BMP-2/Bio-Oss® groups had significantly greater new bone areas (expressed as percentages of augmented areas) than the non-implanted controls at four and eight weeks after surgery, and the BMP-2/Bio-Oss® group (16.50 ± 2.87 (n = 6)) had significantly greater new bone areas than the Bio-Oss® group (9.43 ± 3.73 (n = 6)) at four weeks. These findings suggest that rhBMP-2 treated heparinized Bio-Oss® markedly enhances bone regeneration. PMID:26184187

  11. Low dose BMP-2 treatment for bone repair using a PEGylated fibrinogen hydrogel matrix.

    Science.gov (United States)

    Ben-David, Dror; Srouji, Samer; Shapira-Schweitzer, Keren; Kossover, Olga; Ivanir, Eran; Kuhn, Gisela; Müller, Ralph; Seliktar, Dror; Livne, Erella

    2013-04-01

    Bone repair strategies utilizing resorbable biomaterial implants aim to stimulate endogenous cells in order to gradually replace the implant with functional repair tissue. These biomaterials should therefore be biodegradable, osteoconductive, osteoinductive, and maintain their integrity until the newly formed host tissue can contribute proper function. In recent years there has been impressive clinical outcomes for this strategy when using osteoconductive hydrogel biomaterials in combination with osteoinductive growth factors such as human recombinant bone morphogenic protein (hrBMP-2). However, the success of hrBMP-2 treatments is not without risks if the factor is delivered too rapidly and at very high doses because of a suboptimal biomaterial. Therefore, the aim of this study was to evaluate the use of a PEGylated fibrinogen (PF) provisional matrix as a delivery system for low-dose hrBMP-2 treatment in a critical size maxillofacial bone defect model. PF is a semi-synthetic hydrogel material that can regulate the release of physiological doses of hrBMP-2 based on its controllable physical properties and biodegradation. hrBMP-2 release from the PF material and hrBMP-2 bioactivity were validated using in vitro assays and a subcutaneous implantation model in rats. Critical size calvarial defects in mice were treated orthotopically with PF containing 8 μg/ml hrBMP-2 to demonstrate the capacity of these bioactive implants to induce enhanced bone formation in as little as 6 weeks. Control defects treated with PF alone or left empty resulted in far less bone formation when compared to the PF/hrBMP-2 treated defects. These results demonstrate the feasibility of using a semi-synthetic biomaterial containing small doses of osteoinductive hrBMP-2 as an effective treatment for maxillofacial bone defects. PMID:23375953

  12. Effects of local delivery of BMP2, zoledronate and their combination on bone microarchitecture, biomechanics and bone turnover in osteoporotic rabbits.

    Science.gov (United States)

    Jing, Da; Hao, Xuguang; Xu, Fang; Liu, Jian; Xu, Fei; Luo, Erping; Meng, Guolin

    2016-01-01

    The hip fracture is one major clinical challenge associated with osteoporosis, resulting in heavy socioeconomic burdens and high mortality. Systemic therapies of anti-osteoporosis drugs are expensive, time-consuming and also evoke substantial side effects, which fails to provide early protection from fractures. Accumulating evidence demonstrates the high bioavailability and therapeutic efficacy of local drug delivery in accelerating facture healing and bone defect repair. This study aims at investigating the effects of local delivery of BMP2 and zoledronate (two promising anabolic/anti-catobolic reagents) encapsulated by fibrin sealants into femoral necks on regulating bone quality and remodeling in osteoporotic rabbits subjected to combined ovariectomy and glucocorticoid injection. We show that 6-week BMP2 delivery exhibited more prominent effect on mitigating trabecular bone microarchitecture deterioration and mechanical strength reduction of femoral necks than local zoledronate treatment. BMP2 plus zoledronate showed more significant improvement of bone microstructure, mechanical strength and bone formation rate at 12 weeks post injection than single BMP2 or zoledronate delivery via μCT, biomechanical, histomorphometric and serum biochemical analyses. This study enriches our knowledge for understanding the availability of local drug delivery for improving bone quantity and quality, which may lead to earlier, safer and more efficient protection from osteoporosis-induced fractures in clinics. PMID:27329730

  13. Effect of rhBMP-2 Immobilized Anorganic Bovine Bone Matrix on Bone Regeneration

    OpenAIRE

    Jung-Bo Huh; June-Jip Yang; Kyung-Hee Choi; Ji Hyeon Bae; Jeong-Yeol Lee; Sung-Eun Kim; Sang-Wan Shin

    2015-01-01

    Anorganic bovine bone matrix (Bio-Oss®) has been used for a long time for bone graft regeneration, but has poor osteoinductive capability. The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) has been suggested to overcome this limitation of Bio-Oss®. In the present study, heparin-mediated rhBMP-2 was combined with Bio-Oss® in animal experiments to investigate bone formation performance; heparin was used to control rhBMP-2 release. Two calvarial defects (8 mm diameter) were fo...

  14. Intestinal Mucosal Barrier Is Injured by BMP2/4 via Activation of NF-κB Signals after Ischemic Reperfusion

    Directory of Open Access Journals (Sweden)

    Kang Chen

    2014-01-01

    Full Text Available Intestinal ischemic reperfusion (I/R can cause dysfunction of the intestinal mucosal barrier; however, the mechanism of the intestinal mucosal barrier dysfunction caused by I/R remains unclear. In this study, using intestinal epithelial cells under anaerobic cultivation and an in vivo rat intestinal I/R model, we found that hypoxia and I/R increased the expression of BMP2/4 and upregulated BMP type Ia receptor and BMP type II receptor expression. We also found that exogenous BMP2/4 can activate the ERK and AKT signaling pathways in rat small intestine (IEC-6 cells, thereby activating NF-κB signaling, which leads to increased levels of inflammatory factors, such as TNF-α and IL-6. Furthermore, recombinant BMP2/4 decreased the expression of the tight junction protein occludin via the activation of the NF-κB pathway; these effects were abolished by treatment with the BMP-specific antagonist noggin or the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC. All these factors can destroy the intestinal mucosal barrier, thereby leading to weaker barrier function. On the basis of these data, we conclude that BMP2/4 may act as the pathogenic basis for intestinal mucosal barrier dysfunction when the intestines suffer an I/R injury. Our results provide background for the development pharmacologic interventions in the management of I/R injury.

  15. Dexamethasone, BMP-2, and 1,25-dihydroxyvitamin D enhance a more differentiated osteoblast phenotype

    DEFF Research Database (Denmark)

    Jørgensen, Niklas Rye; Henriksen, Z; Sørensen, O H;

    2004-01-01

    D), 100 nM Dex, and/or 100 ng/ml BMP-2. The osteoblast phenotype was assessed as alkaline phosphatase (AP) activity/staining, production of osteocalcin and procollagen type 1 (P1NP), parathyroid hormone (PTH)-induced cyclic adenosine mono-phosphate (cAMP) production, and in vitro mineralization. AP...... activity was increased by Dex, but not by BMP-2 treatment. P1NP production was decreased after Dex treatment, while BMP-2 had no effect on P1NP levels. Osteocalcin production was low in cultures not stimulated with vitamin D. Dex or BMP-2 treatment alone did not affect the basic osteocalcin levels, but in...... osteoblastic cells with different phenotypic characteristics, and a selective activation of some of the most important genes and functions of the mature osteoblast can thus be performed in vitro....

  16. Sustained release of BMP-2 in bioprinted alginate for osteogenicity in mice and rats.

    Directory of Open Access Journals (Sweden)

    Michelle T Poldervaart

    Full Text Available The design of bioactive three-dimensional (3D scaffolds is a major focus in bone tissue engineering. Incorporation of growth factors into bioprinted scaffolds offers many new possibilities regarding both biological and architectural properties of the scaffolds. This study investigates whether the sustained release of bone morphogenetic protein 2 (BMP-2 influences osteogenicity of tissue engineered bioprinted constructs. BMP-2 loaded on gelatin microparticles (GMPs was used as a sustained release system, which was dispersed in hydrogel-based constructs and compared to direct inclusion of BMP-2 in alginate or control GMPs. The constructs were supplemented with goat multipotent stromal cells (gMSCs and biphasic calcium phosphate to study osteogenic differentiation and bone formation respectively. BMP-2 release kinetics and bioactivity showed continuous release for three weeks coinciding with osteogenicity. Osteogenic differentiation and bone formation of bioprinted GMP containing constructs were investigated after subcutaneous implantation in mice or rats. BMP-2 significantly increased bone formation, which was not influenced by the release timing. We showed that 3D printing of controlled release particles is feasible and that the released BMP-2 directs osteogenic differentiation in vitro and in vivo.

  17. Effect of a Novel Nonviral Gene Delivery of BMP-2 on Bone Healing

    Directory of Open Access Journals (Sweden)

    P. Schwabe

    2012-01-01

    Full Text Available Background. Gene therapeutic drug delivery approaches have been introduced to improve the efficiency of growth factors at the site of interest. This study investigated the efficacy and safety of a new nonviral copolymer-protected gene vector (COPROG for the stimulation of bone healing. Methods. In vitro, rat osteoblasts were transfected with COPROG + luciferase plasmid or COPROG + hBMP-2 plasmid. In vivo, rat tibial fractures were intramedullary stabilized with uncoated versus COPROG+hBMP-2-plasmid-coated titanium K-wires. The tibiae were prepared for biomechanical and histological analyses at days 28 and 42 and for transfection/safety study at days 2, 4, 7, 28, and 42. Results. In vitro results showed luciferase expression until day 21, and hBMP-2-protein was measured from day 2 – day 10. In vivo, the local application of hBMP-2-plasmid showed a significantly higher maximum load after 42 days compared to that in the control. The histomorphometric analysis revealed a significantly less mineralized periosteal callus area in the BMP-2 group compared to the control at day 28. The rt-PCR showed no systemic biodistribution of luciferase RNA. Conclusion. A positive effect on fracture healing by nonviral BMP-2 plasmid application from COPROG-coated implants could be shown in this study; however, the effect of the vector may be improved with higher plasmid concentrations. Transfection showed no biodistribution to distant organs and was considered to be safe.

  18. BMP-2 and BMP-2/7 Heterodimers Conjugated to a Fibrin/Hyaluronic Acid Hydrogel in a Large Animal Model of Mild Intervertebral Disc Degeneration.

    Science.gov (United States)

    Peeters, Mirte; Detiger, Suzanne E L; Karfeld-Sulzer, Lindsay S; Smit, Theo H; Yayon, Avner; Weber, Franz E; Helder, Marco N

    2015-01-01

    Intervertebral disc (IVD) degeneration is etiologically associated with low back pain and is currently only treated in severe cases with spinal fusion. Regenerative medicine attempts to restore degenerated tissue by means of cells, hydrogels, and/or growth factors and can therefore be used to slow, halt, or reverse the degeneration of the IVD in a minimally invasive manner. Previously, the growth factors bone morphogenetic proteins 2 and 7 (BMP-2, -7) were shown to enhance disc regeneration, in vitro and in vivo. Since BMPs have only a short in vivo half-life, and to prevent heterotopic ossification, we evaluated the use of a slow release system for BMP-2 homodimers and BMP-2/7 heterodimers for IVD regeneration. BMP growth factors were conjugated to a fibrin/hyaluronic acid (FB/HA) hydrogel and intradiscally injected in a goat model of mild IVD degeneration to study safety and efficacy. Mild degeneration was induced in five lumbar discs of seven adult Dutch milk goats, by injections with the enzyme chondroitinase ABC. After 12 weeks, discs were treated with either FB/HA-hydrogel only or supplemented with 1 or 5 μg/mL of BMP-2 or BMP-2/7. BMPs were linked to the FB/HA hydrogels using a transglutaminase moiety, to be released through an incorporated plasmin cleavage site. After another 12 weeks, goats were sacrificed and discs were assessed using radiography, MRI T2* mapping, and biochemical and histological analyses. All animals maintained weight throughout the study and no heterotopic bone formation or other adverse effects were noted during follow-up. Radiographs showed significant disc height loss upon induction of mild degeneration. MRI T2* mapping showed strong and significant correlations with biochemistry and histology as shown before. Surprisingly, no differences could be demonstrated in any parameter between intervention groups. To our knowledge, this is the first large animal study evaluating BMPs conjugated to an FB/HA-hydrogel for the treatment of

  19. Cardiogenic induction of pluripotent stem cells streamlined through a conserved SDF-1/VEGF/BMP2 integrated network.

    Directory of Open Access Journals (Sweden)

    Anca Chiriac

    Full Text Available BACKGROUND: Pluripotent stem cells produce tissue-specific lineages through programmed acquisition of sequential gene expression patterns that function as a blueprint for organ formation. As embryonic stem cells respond concomitantly to diverse signaling pathways during differentiation, extraction of a pro-cardiogenic network would offer a roadmap to streamline cardiac progenitor output. METHODS AND RESULTS: To resolve gene ontology priorities within precursor transcriptomes, cardiogenic subpopulations were here generated according to either growth factor guidance or stage-specific biomarker sorting. Innate expression profiles were independently delineated through unbiased systems biology mapping, and cross-referenced to filter transcriptional noise unmasking a conserved progenitor motif (55 up- and 233 down-regulated genes. The streamlined pool of 288 genes organized into a core biological network that prioritized the "Cardiovascular Development" function. Recursive in silico deconvolution of the cardiogenic neighborhood and associated canonical signaling pathways identified a combination of integrated axes, CXCR4/SDF-1, Flk-1/VEGF and BMP2r/BMP2, predicted to synchronize cardiac specification. In vitro targeting of the resolved triad in embryoid bodies accelerated expression of Nkx2.5, Mef2C and cardiac-MHC, enhanced beating activity, and augmented cardiogenic yield. CONCLUSIONS: Transcriptome-wide dissection of a conserved progenitor profile thus revealed functional highways that coordinate cardiogenic maturation from a pluripotent ground state. Validating the bioinformatics algorithm established a strategy to rationally modulate cell fate, and optimize stem cell-derived cardiogenesis.

  20. Transcriptional repression of Bmp2 by p21(Waf1/Cip1) links quiescence to neural stem cell maintenance.

    Science.gov (United States)

    Porlan, Eva; Morante-Redolat, José Manuel; Marqués-Torrejón, María Ángeles; Andreu-Agulló, Celia; Carneiro, Carmen; Gómez-Ibarlucea, Esther; Soto, Atenea; Vidal, Anxo; Ferrón, Sacri R; Fariñas, Isabel

    2013-11-01

    Relative quiescence and self renewal are defining features of adult stem cells, but their potential coordination remains unclear. Subependymal neural stem cells (NSCs) lacking cyclin-dependent kinase (CDK) inhibitor (CKI) 1a (p21) exhibit rapid expansion that is followed by their permanent loss later in life. Here we demonstrate that transcription of the gene encoding bone morphogenetic protein 2 (Bmp2) in NSCs is under the direct negative control of p21 through actions that are independent of CDK. Loss of p21 in NSCs results in increased levels of secreted BMP2, which induce premature terminal differentiation of multipotent NSCs into mature non-neurogenic astrocytes in an autocrine and/or paracrine manner. We also show that the cell-nonautonomous p21-null phenotype is modulated by the Noggin-rich environment of the subependymal niche. The dual function that we describe here provides a physiological example of combined cell-autonomous and cell-nonautonomous functions of p21 with implications in self renewal, linking the relative quiescence of adult stem cells to their longevity and potentiality.

  1. Sustained and promoter dependent bone morphogenetic protein expression by rat mesenchymal stem cells after BMP-2 transgene electrotransfer

    Directory of Open Access Journals (Sweden)

    E Ferreira

    2012-07-01

    Full Text Available Transplantation of mesenchymal stem cells (MSCs with electrotransferred bone morphogenetic protein-2 (BMP-2 transgene is an attractive therapeutic modality for the treatment of large bone defects: it provides both stem cells with the ability to form bone and an effective bone inducer while avoiding viral gene transfer. The objective of the present study was to determine the influence of the promoter driving the human BMP-2 gene on the level and duration of BMP-2 expression after transgene electrotransfer into rat MSCs. Cytomegalovirus, elongation factor-1α, glyceraldehyde 3-phosphate dehydrogenase, and beta-actin promoters resulted in a BMP-2 secretion rate increase of 11-, 78-, 66- and 36-fold over respective controls, respectively. In contrast, the osteocalcin promoter had predictable weak activity in undifferentiated MSCs but induced the strongest BMP-2 secretion rates in osteoblastically-differentiated MSCs. Regardless of the promoter driving the transgene, a plateau of maximal BMP-2 secretion persisted for at least 21 d after the hBMP-2 gene electrotransfer. The present study demonstrates the feasibility of gene electrotransfer for efficient BMP-2 transgene delivery into MSCs and for a three-week sustained BMP-2 expression. It also provides the first in vitro evidence for a safe alternative to viral methods that permit efficient BMP-2 gene delivery and expression in MSCs but raise safety concerns that are critical when considering clinical applications.

  2. Regulating the osteogenic function of rhBMP 2 by different titanium surface properties.

    Science.gov (United States)

    Xiao, Ming; Biao, Meina; Chen, Yangmei; Xie, Meiju; Yang, Bangcheng

    2016-08-01

    Bone morphogenetic protein 2 (BMP-2) is important for regulating the osteogenic differentiation of mesenchymal stem cells and the response of bone tissue. It adsorbs on the surface of biomedical implants immediately and plays a role of mediator between the materials surfaces and the host cells. Studies usually connect the material surface properties and the new bone formation directly. However, interaction between the adsorbed BMP-2 on the implant surface and the cells in the tissue is the key to explaining the osteogenic properties of the material. So, in this article, we investigated the conformational and functional changes induced by the surface modified titanium metals. We found that the α-helix and β-sheet structure of rhBMP-2 can be well maintained on the anodic oxidation treated titanium surface. The osteogenic function of rhBMP-2 can sustain for a relatively long time even though there is less amount adhere to the surface compared with that on the acid alkali treated titanium. Surface properties, especially the morphology enable a larger amount of rhBMP-2 to adsorb to the surface of the acid alkali treated titanium, but the conformation of the protein is severely influenced. The percentage of α-helix structure is also significantly decreased so that the efficacy of rhBMP-2 is only maintained in the early time. This study indicated that different surface modification of the surface could regulate the structure of rhBMP-2 and then further influence its osteogenic function. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1882-1893, 2016. PMID:26991341

  3. Binding Interactions of Keratin-Based Hair Fiber Extract to Gold, Keratin, and BMP-2.

    Directory of Open Access Journals (Sweden)

    Roche C de Guzman

    Full Text Available Hair-derived keratin biomaterials composed mostly of reduced keratin proteins (kerateines have demonstrated their utility as carriers of biologics and drugs for tissue engineering. Electrostatic forces between negatively-charged keratins and biologic macromolecules allow for effective drug retention; attraction to positively-charged growth factors like bone morphogenetic protein 2 (BMP-2 has been used as a strategy for osteoinduction. In this study, the intermolecular surface and bulk interaction properties of kerateines were investigated. Thiol-rich kerateines were chemisorbed onto gold substrates to form an irreversible 2-nm rigid layer for surface plasmon resonance analysis. Kerateine-to-kerateine cohesion was observed in pH-neutral water with an equilibrium dissociation constant (KD of 1.8 × 10(-4 M, indicating that non-coulombic attractive forces (i.e. hydrophobic and van der Waals were at work. The association of BMP-2 to kerateine was found to be greater (KD = 1.1 × 10(-7 M, within the range of specific binding. Addition of salts (phosphate-buffered saline; PBS shortened the Debye length or the electrostatic field influence which weakened the kerateine-BMP-2 binding (KD = 3.2 × 10(-5 M. BMP-2 in bulk kerateine gels provided a limited release in PBS (~ 10% dissociation in 4 weeks, suggesting that electrostatic intermolecular attraction was significant to retain BMP-2 within the keratin matrix. Complete dissociation between kerateine and BMP-2 occurred when the PBS pH was lowered (to 4.5, below the keratin isoelectric point of 5.3. This phenomenon can be attributed to the protonation of keratin at a lower pH, leading to positive-positive repulsion. Therefore, the dynamics of kerateine-BMP-2 binding is highly dependent on pH and salt concentration, as well as on BMP-2 solubility at different pH and molarity. The study findings may contribute to our understanding of the release kinetics of drugs from keratin biomaterials and allow for the

  4. No advantage to rhBMP-2 in addition to autogenous graft for fracture nonunion.

    Science.gov (United States)

    Takemoto, Richelle; Forman, Jordanna; Taormina, David P; Egol, Kenneth A

    2014-06-01

    Bone morphogenetic proteins are a necessary component of the fracture healing cascade. Few studies have delineated the efficacy of iliac crest bone graft and recombinant human bone morphogenetic protein 2 (rhBMP-2), especially, in comparison with the gold standard treatment of nonunion, which is autogenous bone graft alone. This study compared the outcome of patients with fracture nonunion treated with autogenous bone graft plus rhBMP-2 adjuvant vs patients treated with autogenous bone graft alone. A total of 118 consecutive patients who were to undergo long bone nonunion surgery with autogenous bone graft (50) or autogenous bone graft plus rhBMP-2 (68) were identified. Surgical intervention included either harvested iliac autogenous bone graft or autogenous bone graft plus 1.5 mg/mL of rhBMP-2 placed in and around the site of nonunion. No differences were found in the distribution of nonunion sites included within each group. Twelve-month follow-up was obtained on 100 of 118 patients (84.7%). Analyses of demographic characteristics (including tobacco), medical comorbidities, previous surgeries, and nonunion type (atrophic vs hypertrophic) did not differ. Postoperative complication rates did not differ. The percentage of patients who progressed to union did not differ. Mean time to union in the autogenous bone graft plus rhBMP-2 group was 6.6 months (±3.9) vs 5.4 (±2.7) months in the autogenous bone graft-only group (P=.06). Rates of revision (16.2% for rhBMP-2 plus autogenous bone graft vs 8% for autogenous bone graft) did not differ statistically (P=.19), nor did 12-month scores of pain and functional assessment. Although rhBMP-2 is a safe adjuvant, there was no benefit seen when rhBMP-2 was added to autogenous bone graft in the treatment of long bone nonunion. Given its high cost, rhBMP-2 should be reconsidered as an aid to autogenous bone graft in the treatment of nonunion. PMID:24972432

  5. Effects of codon modification on human BMP2 gene expression in tobacco plants.

    Science.gov (United States)

    Suo, Guangli; Chen, Bing; Zhang, Jingyu; Duan, Ziyuan; He, Zhengquan; Yao, Wei; Yue, Chaoyin; Dai, Jianwu

    2006-07-01

    Bone morphogenetic protein 2 (BMP2) has great potential in therapeutic applications. We are working on generating transgenic plants as a bioreactor to produce BMP2. We have studied the effects of codon optimization on the expression of human BMP2 (hBMP2) in tobacco plants. Three modified hBMP2 genes were transformed into tobacco under the control of either cauliflower mosaic virus 35S (CaMV35S) promoter or double-CaMV35S promoter plus alfalfa mosaic virus (AMV) enhancer. The fused beta-glucuronidase (GUS) reporter gene was used to facilitate the assay of protein expression. The results indicated that codon optimization could increase the protein expression level obviously under CaMV35S promoter. However, under relatively stronger initiation condition (double-CaMV35S promoter plus AMV enhancer), only the gene with the lowest degree of codon optimization could increase the protein expression level. Our findings suggest that the action of codon optimization may be influenced by the factors of promoter strength and A+T content in tobacco plants. PMID:16491379

  6. Tracheal cartilage regeneration and new bone formation by slow release of bone morphogenetic protein (BMP)-2.

    Science.gov (United States)

    Igai, Hitoshi; Chang, Sung Soo; Gotoh, Masashi; Yamamoto, Yasumichi; Yamamoto, Masaya; Tabata, Yasuhiko; Yokomise, Hiroyasu

    2008-01-01

    We investigated the efficiency of bone morphogenetic protein (BMP)-2 released slowly from gelatin sponge for tracheal cartilage regeneration. A 1-cm gap was made in the mid-ventral portion of each of 10 consecutive tracheal cartilages. In the control group (n = 4), the resulting gap was left untreated. In the gelatin group (n = 4), plain gelatin was implanted in the gap. In the BMP-2 group (n = 4), gelatin containing 100 microg BMP-2 was implanted. We euthanatized all dogs in each group at 1, 3, 6, and 12 months after the implantation, respectively, and then examined the implant site macro- and microscopically. In the BMP-2 group, regenerated fibrous cartilage and newly formed bone were observed at 1 and 12 months. Regenerated cartilage was observed at the ends of the host cartilage stumps, with newly formed bone in the middle portion. The gaps were filled with regenerated cartilage and newly formed bone. At 3 and 6 months, regenerated cartilage, but not newly formed bone, was evident. The regenerated cartilage was covered with perichondrium and showed continuity with the host cartilage. We succeeded in inducing cartilage regeneration and new bone formation in canine trachea by slow release of 100 microg BMP-2 from gelatin. PMID:18204324

  7. Gelatin Tight-Coated Poly(lactide-co-glycolide Scaffold Incorporating rhBMP-2 for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Juan Wang

    2015-03-01

    Full Text Available Surface coating is the simplest surface modification. However, bioactive molecules can not spread well on the commonly used polylactone-type skeletons; thus, the surface coatings of biomolecules are typically unstable due to the weak interaction between the polymer and the bioactive molecules. In this study, a special type of poly(lactide-co-glycolide (PLGA-based scaffold with a loosened skeleton was fabricated by phase separation, which allowed gelatin molecules to more readily diffuse throughout the structure. In this application, gelatin modified both the internal substrate and external surface. After cross-linking with glutaraldehyde, the surface layer gelatin was tightly bound to the diffused gelatin, thereby preventing the surface layer gelatin coating from falling off within 14 days. After gelatin modification, PLGA scaffold demonstrated enhanced hydrophilicity and improved mechanical properties (i.e., increased compression strength and elastic modulus in dry and wet states. Furthermore, a sustained release profile of recombinant human bone morphogenetic protein-2 (rhBMP-2 was achieved in the coated scaffold. The coated scaffold also supported the in vitro attachment, proliferation, and osteogenesis of rabbit bone mesenchymal stem cells (BMSCs, indicating the bioactivity of rhBMP-2. These results collectively demonstrate that the cross-linked-gelatin-coated porous PLGA scaffold incorporating bioactive molecules is a promising candidate for bone tissue regeneration.

  8. Local expression and role of BMP-2/4 in injured spinal cord.

    Science.gov (United States)

    Cui, Z S; Zhao, P; Jia, C X; Liu, H J; Qi, R; Cui, J W; Cui, J H; Peng, Q; Lin, B; Rao, Y J

    2015-08-07

    We investigated local changes in BMP-2/4 expression in rat spinal cords 1 week following injury to study the damage effects of BMP-2/4 in spinal cord injury (SCI). Sprague Dawley rats (45, 4 months old) were randomized into three groups comprising 15 rats each: a SHAM group, an SCI without noggin group (SCIO), and an SCI with noggin group (SCID). The SCIO and SCID groups were subjected to spinal cord hemisection, and motor activity was assessed using the BBB score. Expression of BMP-2/4 in each injured spinal cord section was examined by hematoxylin and eosin staining, immunohistochemistry, and western blot. There were no significant differences in BBB scores among the three groups (P > 0.05). Following hemisection, the BBB score in the SHAM group was significantly higher than in the other two groups on the 1st day after modeling (P 0.05). Seven days after modeling, the BBB score in the SHAM group was significantly higher than in the other two groups (P < 0.05), and the BBB score in the SCID group was obviously higher than in the SCIO group (P < 0.05). The expression of BMP-2/4 was highest in the SCIO group and lowest in the SHAM group (P < 0.05). SCI can cause severe impairment of motor activity in rats. Seven days after SCI, the local expression of BMP-2/4 had obviously increased; noggin can effectively inhibit the expression of BMP-2/4 and reduce impairment.

  9. The p38/MK2/Hsp25 pathway is required for BMP-2-induced cell migration.

    Directory of Open Access Journals (Sweden)

    Cristina Gamell

    Full Text Available BACKGROUND: Bone morphogenetic proteins (BMPs have been shown to participate in the patterning and specification of several tissues and organs during development and to regulate cell growth, differentiation and migration in different cell types. BMP-mediated cell migration requires activation of the small GTPase Cdc42 and LIMK1 activities. In our earlier report we showed that activation of LIMK1 also requires the activation of PAKs through Cdc42 and PI3K. However, the requirement of additional signaling is not clearly known. METHODOLOGY/PRINCIPAL FINDINGS: Activation of p38 MAPK has been shown to be relevant for a number of BMP-2's physiological effects. We report here that BMP-2 regulation of cell migration and actin cytoskeleton remodelling are dependent on p38 activity. BMP-2 treatment of mesenchymal cells results in activation of the p38/MK2/Hsp25 signaling pathway downstream from the BMP receptors. Moreover, chemical inhibition of p38 signaling or genetic ablation of either p38α or MK2 blocks the ability to activate the downstream effectors of the pathway and abolishes BMP-2-induction of cell migration. These signaling effects on p38/MK2/Hsp25 do not require the activity of either Cdc42 or PAK, whereas p38/MK2 activities do not significantly modify the BMP-2-dependent activation of LIMK1, measured by either kinase activity or with an antibody raised against phospho-threonine 508 at its activation loop. Finally, phosphorylated Hsp25 colocalizes with the BMP receptor complexes in lamellipodia and overexpression of a phosphorylation mutant form of Hsp25 is able to abolish the migration of cells in response to BMP-2. CONCLUSIONS: These results indicate that Cdc42/PAK/LIMK1 and p38/MK2/Hsp25 pathways, acting in parallel and modulating specific actin regulatory proteins, play a critical role in integrating responses during BMP-induced actin reorganization and cell migration.

  10. Perlecan domain 1 recombinant proteoglycan augments BMP-2 activity and osteogenesis

    Directory of Open Access Journals (Sweden)

    DeCarlo Arthur A

    2012-09-01

    Full Text Available Abstract Background Many growth factors, such as bone morphogenetic protein (BMP-2, have been shown to interact with polymers of sulfated disacharrides known as heparan sulfate (HS glycosaminoglycans (GAGs, which are found on matrix and cell-surface proteoglycans throughout the body. HS GAGs, and some more highly sulfated forms of chondroitin sulfate (CS, regulate cell function by serving as co-factors, or co-receptors, in GF interactions with their receptors, and HS or CS GAGs have been shown to be necessary for inducing signaling and GF activity, even in the osteogenic lineage. Unlike recombinant proteins, however, HS and CS GAGs are quite heterogenous due, in large part, to post-translational addition, then removal, of sulfate groups to various positions along the GAG polymer. We have, therefore, investigated whether it would be feasible to deliver a DNA pro-drug to generate a soluble HS/CS proteoglycan in situ that would augment the activity of growth-factors, including BMP-2, in vivo. Results Utilizing a purified recombinant human perlecan domain 1 (rhPln.D1 expressed from HEK 293 cells with HS and CS GAGs, tight binding and dose-enhancement of rhBMP-2 activity was demonstrated in vitro. In vitro, the expressed rhPln.D1 was characterized by modification with sulfated HS and CS GAGs. Dose-enhancement of rhBMP-2 by a pln.D1 expression plasmid delivered together as a lyophilized single-phase on a particulate tricalcium phosphate scaffold for 6 or more weeks generated up to 9 fold more bone volume de novo on the maxillary ridge in a rat model than in control sites without the pln.D1 plasmid. Using a significantly lower BMP-2 dose, this combination provided more than 5 times as much maxillary ridge augmentation and greater density than rhBMP-2 delivered on a collagen sponge (InFuse™. Conclusions A recombinant HS/CS PG interacted strongly and functionally with BMP-2 in binding and cell-based assays, and, in vivo, the pln.247 expression plasmid

  11. Combination therapy with BMP-2 and a systemic RANKL inhibitor enhances bone healing in a mouse critical-sized femoral defect.

    Science.gov (United States)

    Bougioukli, Sofia; Jain, Ashish; Sugiyama, Osamu; Tinsley, Brian A; Tang, Amy H; Tan, Matthew H; Adams, Douglas J; Kostenuik, Paul J; Lieberman, Jay R

    2016-03-01

    Recombinant human BMP-2 (rhBMP-2) is a potent osteoinductive agent, but has been associated not only with bone formation, but also osteoclastogenesis and bone resorption. Osteoprotegerin (OPG) is a RANKL inhibitor that blocks differentiation and function of osteoclasts. We hypothesized that the combination of local BMP-2 (recombinant protein or a product of gene therapy) plus systemic OPG-Fc is more effective than BMP-2 alone in promoting bone repair. To test this hypothesis we used a mouse critical-sized femoral defect model. Col2.3eGFP (osteoblastic marker) male mice were treated with rhBMP-2 (group I), rhBMP-2 and systemic OPG (group II), rhBMP-2 and delayed administration of OPG (group III), mouse BM cells transduced with a lentiviral vector containing the BMP-2 gene (LV-BMP-2; group IV), LV-BMP-2 and systemic OPG (group V), a carrier alone (group VI) and administration of OPG alone (group VII). All bone defects treated with BMP-2 (alone or combined with OPG) healed, whereas minimal bone formation was noted in animals treated with the carrier alone or OPG alone. MicroCT analysis showed that bone volume (BV) in rhBMP-2+OPG and LV-BMP-2+OPG groups was significantly higher compared to rhBMP-2 alone (p<0.01) and LV-BMP-2 alone (p<0.001). Similar results were observed in histomorphometry, with rhBMP-2 alone defects exhibiting significantly lower bone area (B.Ar) compared to rhBMP-2+OPG defects (p<0.005) and LV-BMP-2 defects having a significantly lower B.Ar compared to all BMP-2+OPG treated groups (p≤0.01). TRAP staining demonstrated a major osteoclast response in the groups that did not receive OPG (rhBMP-2, LV-BMP-2 and sponge alone) beginning as early as 7days post-operatively. In conclusion, we demonstrated that locally delivered BMP-2 (recombinant protein or gene therapy) in combination with systemically administered OPG improved bone healing compared to BMP-2 alone in a mouse critical-sized bone defect. These data indicate that osteoclasts can diminish

  12. Experimental Research on Ectopic Osteogenesis of BMP2-derived Peptide P24 Combined with PLGA Copolymers

    Institute of Scientific and Technical Information of China (English)

    DUAN Zhixia; ZHENG Qixin; GUO Xiaodong; YUAN Quan; CHEN Shunguang

    2007-01-01

    To experimentally evaluate the ectopic osteogenetic capacity of synthesized BMP2-derived peptide P24 combined with poly lactic-co-glycolic acid (PLGA), Wistar rats were divided into two groups: group A, in which BMP2-derived peptide P24/PLGA complex was implanted,and group B which received simple PLGA implant. The complex was respectively implanted into the back muscles of rats. Samples were taken the 1 st, 4 th, 8 th, and the 12 th week after the implantation.Their bone formation was detected by X-ray examination, and tissue response was histologically observed. Western blotting was used for the detection of the expression of collagen Ⅰ (Col- Ⅰ ) and osteopontin (OPN). There was acute inflammation in the tissue around both types of implants at early stage. The cartilage was found around implant areas 4 weeks after the implantation of BMP2-derived peptide p24/PLGA complex, 8 weeks after the implantation, osteoblasts were found, and 12 weeks after the implantation, typical trabecular bone structure was observed. In group B, after 12 weeks, no osteoblasts were found. It is concluded that PLGA is an ideal scaffold material for bone tissue engineering. BMP2-derived peptide can start endochondral ossification and is more effective in inducing ectopic osteogenesis.

  13. Biodegradable Chitosan Nanoparticle Coatings on Titanium for the Delivery of BMP-2

    Directory of Open Access Journals (Sweden)

    Nils Poth

    2015-01-01

    Full Text Available A simple method for the functionalization of a common implant material (Ti6Al4V with biodegradable, drug loaded chitosan-tripolyphosphate (CS-TPP nanoparticles is developed in order to enhance the osseointegration of endoprostheses after revision operations. The chitosan used has a tailored degree of acetylation which allows for a fast biodegradation by lysozyme. The degradability of chitosan is proven via viscometry. Characteristics and degradation of nanoparticles formed with TPP are analyzed using dynamic light scattering. The particle degradation via lysozyme displays a decrease in particle diameter of 40% after 4 days. Drug loading and release is investigated for the nanoparticles with bone morphogenetic protein 2 (BMP-2, using ELISA and the BRE luciferase test for quantification and bioactivity evaluation. Furthermore, nanoparticle coatings on titanium substrates are created via spray-coating and analyzed by ellipsometry, scanning electron microscopy and X-ray photoelectron spectroscopy. Drug loaded nanoparticle coatings with biologically active BMP-2 are obtained in vitro within this work. Additionally, an in vivo study in mice indicates the dose dependent induction of ectopic bone growth through CS-TPP-BMP-2 nanoparticles. These results show that biodegradable CS-TPP coatings can be utilized to present biologically active BMP-2 on common implant materials like Ti6Al4V.

  14. Preparation of porous bioceramics using reverse thermo-responsive hydrogels in combination with rhBMP-2 carriers: in vitro and in vivo evaluation.

    Science.gov (United States)

    Fu, Yin-Chih; Chen, Chung-Hwan; Wang, Chau-Zen; Wang, Yan-Hsiung; Chang, Je-Ken; Wang, Gwo-Jaw; Ho, Mei-Ling; Wang, Chih-Kuang

    2013-11-01

    Porous biphasic calcium phosphates (BCP) were fabricated using reverse thermo-responsive hydrogels with hydroxyapatite (HAp) and β-tricalcium (β-TCP) powder and planetary centrifugal mixer. This hydrogel mixture slurry will shrink and compress the HAp powder during the sintering process. The porous bioceramics are expected to have good mechanical properties after sintering at 1200°C. Reverse thermo-responsive hydrogels of poly[(N-isopropylacrylamide)-co-(methacrylic acid)] p(NiPAAm-MAA) were synthesized by free-radical cross-linking copolymerization, and their chemical properties were evaluated by nuclear magnetic resonance spectroscopy, infrared spectroscopy, and electrospray-ionization mass spectrometry. The lower critical solution temperature (LCST) of the hydrogel was determined using turbidity measurements. A thermogravimetric analysis was used to examine the thermal properties. The porous bioceramic properties were analyzed by X-ray diffraction, scanning electron microscopy, bulk density, compressive strength testing and cytotoxicity. The compressive strength and average porosity of the porous bioceramics were examined at approximately 6.8MPa and 66% under 10wt% p(NiPAAm-MAA)=99:1 condition. The ratio of HAp/β-TCP can adjust two different compositional behaviors during the 1200°C sintering process without resulting in cell toxicity. The (rhBMP-2)-HAp-PLGA carriers were fabricated as in our previous study of the double emulsion and drop-coating technique. Results of animal study included histological micrographs of the 1-mm defect in the femurs, with the rhBMP-2 carrier group, the bioceramic spacer group and the bioceramic spacer with rhBMP-2 carriers group showing better callus formation around the femur defect site than the control group. The optimal dual effects of the bone growth factors from osteoconductive bioceramics and osteoinductive rhBMP-2 carriers produced better bone formation. PMID:23880039

  15. Improving the osteogenic potential of BMP-2 with hyaluronic acid hydrogel modified with integrin-specific fibronectin fragment

    NARCIS (Netherlands)

    Kisiel, M.; Martino, M.M.; Ventura, M.; Hubbell, J.A.; Hilborn, J.; Ossipov, D.A.

    2013-01-01

    While human bone morphogenetic protein-2 (rhBMP-2) is a promising growth factor for bone regeneration, its clinical efficacy has recently shown to be below expectation. In order to improve the clinical translation of rhBMP-2, there exists strong motivation to engineer better delivery systems. Hyalur

  16. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

    Directory of Open Access Journals (Sweden)

    Shriram Nallamshetty

    Full Text Available The effects of retinoids, the structural derivatives of vitamin A (retinol, on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA and its precursor all trans retinaldehyde (Rald, exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1, the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT demonstrated that Aldh1a1-deficient (Aldh1a1(-/- female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/- mice. In serum assays, Aldh1a1(-/- mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/- mesenchymal stem cells (MSCs expressed significantly higher levels of bone morphogenetic protein 2 (BMP2 and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/- mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/- mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  17. Sphingosine 1-phosphate receptor activation enhances BMP-2-induced osteoblast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Chieri [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan); Iwasaki, Tsuyoshi, E-mail: tsuyo-i@huhs.ac.jp [Division of Pharmacotherapy, Department of Pharmacy, School of Pharmacy, Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe 650-8530 (Japan); Kitano, Sachie; Tsunemi, Sachi; Sano, Hajime [Division of Rheumatology, Department of Internal Medicine, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501 (Japan)

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer We investigated the role of S1P signaling for osteoblast differentiation. Black-Right-Pointing-Pointer Both S1P and FTY enhanced BMP-2-stimulated osteoblast differentiation by C2C12 cells. Black-Right-Pointing-Pointer S1P signaling enhanced BMP-2-stimulated Smad and ERK phosphorylation by C2C12 cells. Black-Right-Pointing-Pointer MEK/ERK signaling is a pathway underlying S1P signaling for osteoblast differentiation. -- Abstract: We previously demonstrated that sphingosine 1-phosphate (S1P) receptor-mediated signaling induced proliferation and prostaglandin productions by synovial cells from rheumatoid arthritis (RA) patients. In the present study we investigated the role of S1P receptor-mediated signaling for osteoblast differentiation. We investigated osteoblast differentiation using C2C12 myoblasts, a cell line derived from murine satellite cells. Osteoblast differentiation was induced by the treatment of bone morphogenic protein (BMP)-2 in the presence or absence of either S1P or FTY720 (FTY), a high-affinity agonist of S1P receptors. Osteoblast differentiation was determined by osteoblast-specific transcription factor, Runx2 mRNA expression, alkaline phosphatase (ALP) activity and osteocalcin production by the cells. Smad1/5/8 and extracellular signal-regulated kinase (ERK) 1/2 phosphorylation was examined by Western blotting. Osteocalcin production by C2C12 cells were determined by ELISA. Runx2 expression and ALP activity by BMP-2-stimulated C2C12 cells were enhanced by addition of either S1P or FTY. Both S1P and FTY enhanced BMP-2-induced ERK1/2 and Smad1/5/8 phosphorylation. The effect of FTY was stronger than that of S1P. S1P receptor-mediated signaling on osteoblast differentiation was inhibited by addition of mitogen-activated protein kinase/ERK kinase (MEK) 1/2 inhibitor, indicating that the S1P receptor-mediated MEK1/2-ERK1/2 signaling pathway enhanced BMP-2-Smad signaling. These results indicate that S1P

  18. Differential expression of Bmp2, Bmp4 and Bmp3 in embryonic development of mouse anterior and posterior palate

    Institute of Scientific and Technical Information of China (English)

    NIE Xu-guang

    2005-01-01

    Background The palate is differently regulated and developed along the anterior-posterior axis. The Bmp signal pathway plays a crucial role in palatogenesis. Conditioned-inactivation of Bmp type I receptor Alk2 or Alk3 in the neural crest or craniofacial region leads to palatal cleft in mice. However, how different Bmp members are involved in palatogenesis remains to be elucidated. In the present study, mRNA expression patterns of Bmp2, Bmp3 and Bmp4 in the developing anterior and posterior palates were examined and compared, focusing on the fusion stage. Methods To detect the expression of Bmp mRNA, antisense riboprobes were synthesized by in vitro transcription. Radioactive in situ hybridization was performed on sagital and coronal sections of mice head from E13 to E18. Results The expression of these Bmps were developmentally regulated in the anterior and posterior palates prior to, during and after palatal fusion. During palatal fusion, Bmp4 expression shifted from the anterior to the posterior palate, Bmp2 was highly expressed in both the anterior and posterior palates in this process, whereas Bmp3 was only localized in the posterior palate. They showed generally non-overlapping pattern in their expression domains. Thereafter, their expression was detected in both the anterior and posterior palates regulating osteogenesis and myogenesis respectively. Conclusions Bmp signalling is involved in palatogenesis in multiple stages and has multiple roles in regulating anterior and posterior palatal development. Disturbances of Bmp signalling during palatogenesis might be a possible mechanism of cleft palate.

  19. Bone formation of a porous Gelatin-Pectin-biphasic calcium phosphate composite in presence of BMP-2 and VEGF.

    Science.gov (United States)

    Amirian, Jhaleh; Linh, Nguyen Thuy Ba; Min, Young Ki; Lee, Byong-Taek

    2015-05-01

    A composite scaffold of gelatin (Gel)-pectin (Pec)-biphasic calcium phosphate (BCP) was fabricated for the successful delivery of growth factors. Bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) were coated on the Gel-Pec-BCP surface to investigate of effect of them on bone healing. Surface morphology was investigated by scanning electron microscopy, and BCP dispersion in the hydrogel scaffolds was measured by energy dispersive X-ray spectroscopy. The results obtained from Fourier transform infrared spectroscopy showed that BMP-2 and VEGF were successfully coated on Gel-Pec-BCP hydrogel scaffolds. MC3T3-E1 preosteoblasts were cultivated on the scaffolds to investigate the effect of BMP-2 and VEGF on cell viability and proliferation. VEGF and BMP-2 loaded on Gel-Pec-BCP scaffold facilitated increased cell spreading and proliferation compared to Gel-Pec-BCP scaffolds. In vivo, bone formation was examined using rat models. Bone formation was observed in Gel-Pec-BCP/BMP-2 and Gel-Pec-BCP/VEGF scaffolds within 4 weeks, and was greatest with Gel-Pec-BCP/BMP-2 scaffolds. In vitro and in vivo results suggest that Gel-Pec-BCP/BMP-2 and Gel-Pec-BCP/VEGF scaffolds could enhance bone regeneration.

  20. Preconditioning Human Mesenchymal Stem Cells with a Low Concentration of BMP2 Stimulates Proliferation and Osteogenic Differentiation In Vitro

    DEFF Research Database (Denmark)

    Lysdahl, Helle; Baatrup, Anette; Foldager, Casper Bindzus;

    2014-01-01

    treatment strategy in which human bone marrow-derived mesenchymal stem cells (hMSCs) are preconditioned with low concentrations of BMP2 for a short time in vitro. hMSCs in suspension were stimulated for 15 min with 10 and 20 ng/mL of BMP2. After the BMP2 was removed, the cells were seeded and cultured...... in osteogenesis was validated by findings of increased gene expression of SMAD1 and an increase in dual phosphorylation of ser 463 and ser 465 in the SMAD 1/5/8 pathway. We concluded that preconditioning hMSCs with BMP2 stimulates osteogenesis: proliferation with matrix secretion and matrix maturation of h......MSCs. This implies that preconditioning with BMP2 might be more effective at inducing proliferation and osteogenic differentiation of hMSCs than continuous stimulation. Preconditioning with BMP2 could benefit the clinical application of BMP2 since side effects from high-dose treatments could be avoided....

  1. Induction of chronic pancreatitis by pancreatic duct ligation activates BMP2, apelin, and PTHrP expression in mice.

    Science.gov (United States)

    Rastellini, Cristiana; Han, Song; Bhatia, Vandanajay; Cao, Yanna; Liu, Ka; Gao, Xuxia; Ko, Tien C; Greeley, George H; Falzon, Miriam

    2015-10-01

    Chronic pancreatitis (CP) is a devastating disease with no treatments. Experimental models have been developed to reproduce the parenchyma and inflammatory responses typical of human CP. For the present study, one objective was to assess and compare the effects of pancreatic duct ligation (PDL) to those of repetitive cerulein (Cer)-induced CP in mice on pancreatic production of bone morphogenetic protein-2 (BMP2), apelin, and parathyroid hormone-related protein (PTHrP). A second objective was to determine the extent of cross talk among pancreatic BMP2, apelin, and PTHrP signaling systems. We focused on BMP2, apelin, and PTHrP since these factors regulate the inflammation-fibrosis cascade during pancreatitis. Findings showed that PDL- and Cer-induced CP resulted in significant elevations in expression and peptide/protein levels of pancreatic BMP2, apelin, and PTHrP. In vivo mouse and in vitro pancreatic cell culture experiments demonstrated that BMP2 stimulated pancreatic apelin expression whereas apelin expression was inhibited by PTHrP exposure. Apelin or BMP2 exposure inhibited PTHrP expression, and PTHrP stimulated upregulation of gremlin, an endogenous inhibitor of BMP2 activity. Transforming growth factor-β (TGF-β) stimulated PTHrP expression. Together, findings demonstrated that PDL- and Cer-induced CP resulted in increased production of the pancreatic BMP2, apelin, and PTHrP signaling systems and that significant cross talk occurred among pancreatic BMP2, apelin, and PTHrP. These results together with previous findings imply that these factors interact via a pancreatic network to regulate the inflammation-fibrosis cascade during CP. More importantly, this network communicated with TGF-β, a key effector of pancreatic pathophysiology. This novel network may be amenable to pharmacologic manipulations during CP in humans. PMID:26229008

  2. Gene gun transferring-bone morphogenetic protein 2 (BMP-2) gene enhanced bone fracture healing in rabbits

    OpenAIRE

    Li, Wenju; Wei, Haifeng; Xia, Chunmei; Zhu, Xiaomeng; Hou, Guozhu; Xu, Feng; Xinghua SONG; Zhan, Yulin

    2015-01-01

    Purpose: Transferring the bone morphogenetic protein 2 (BMP-2) genes into the tissues or cells can improve the bone healing of the fracture has been widely accepted. We evaluated the efficiency of using gene gun to transfer the BMP-2 gene thereby affected the healing of a fractured bone. Methods: The vector coding for BMP-2 was constructed by a non-replicating encephalo-myocarditis virus (ECMV)-based vector. The segmental bone defect (1.5 cm) model was created by a wire-saw at the middle part...

  3. Vergleich von BMP-4 versus BMP-2 für die osteogene Differenzierung von Periostzellen

    OpenAIRE

    Klumpp, Florian (Alexander Stephan)

    2010-01-01

    Es ist heute bekannt, dass humane periostale mesenchymale Stammzellen (PMSCs) eine aussichtsreiche Grundlage für ein erfolgreiches Knochen Tissue Engineering darstellen. Dennoch ist die osteogene Differenzierung noch nicht vollständig be-schrieben. Da BMP-2 und BMP-4 nachweislich Regulatoren der Osteogenese sind, bestand die Aufgabe der vorliegenden Arbeit darin, die Wirkung derer auf die osteo-gene Differenzierung humaner PMSCs zu untersuchen. Isolierte humane PMSCs wurden mit Hilfe von o...

  4. BMP-2 in der Therapie der Pseudarthrose langer Röhrenknochen

    OpenAIRE

    Hellriegel, Tom

    2010-01-01

    Effective therapy for long bone non-unions is still a challenge in trauma and orthopedic surgery and treatment is time and cost-intensive. Complications can lead to ensuing health-related problems for the patient and their ability to work can be restricted. An innovative approach to stimulate bone regeneration is the application of growth factors. Bone morphogenetic protein-2 (BMP-2) has a high osteoinductive capacity and might stimulate human non-union healing. The purpose of this stud...

  5. Histone deacetylases control neurogenesis in embryonic brain by inhibition of BMP2/4 signaling.

    Directory of Open Access Journals (Sweden)

    Maya Shakèd

    Full Text Available BACKGROUND: Histone-modifying enzymes are essential for a wide variety of cellular processes dependent upon changes in gene expression. Histone deacetylases (HDACs lead to the compaction of chromatin and subsequent silencing of gene transcription, and they have recently been implicated in a diversity of functions and dysfunctions in the postnatal and adult brain including ocular dominance plasticity, memory consolidation, drug addiction, and depression. Here we investigate the role of HDACs in the generation of neurons and astrocytes in the embryonic brain. PRINCIPAL FINDINGS: As a variety of HDACs are expressed in differentiating neural progenitor cells, we have taken a pharmacological approach to inhibit multiple family members. Inhibition of class I and II HDACs in developing mouse embryos with trichostatin A resulted in a dramatic reduction in neurogenesis in the ganglionic eminences and a modest increase in neurogenesis in the cortex. An identical effect was observed upon pharmacological inhibition of HDACs in in vitro-differentiating neural precursors derived from the same brain regions. A reduction in neurogenesis in ganglionic eminence-derived neural precursors was accompanied by an increase in the production of immature astrocytes. We show that HDACs control neurogenesis by inhibition of the bone morphogenetic protein BMP2/4 signaling pathway in radial glial cells. HDACs function at the transcriptional level by inhibiting and promoting, respectively, the expression of Bmp2 and Smad7, an intracellular inhibitor of BMP signaling. Inhibition of the BMP2/4 signaling pathway restored normal levels of neurogenesis and astrogliogenesis to both ganglionic eminence- and cortex-derived cultures in which HDACs were inhibited. CONCLUSIONS: Our results demonstrate a transcriptionally-based regulation of BMP2/4 signaling by HDACs both in vivo and in vitro that is critical for neurogenesis in the ganglionic eminences and that modulates cortical

  6. BMP2 gene delivery to bone mesenchymal stem cell by chitosan-g-PEI nonviral vector

    Science.gov (United States)

    Yue, Jianhui; Wu, Jun; Liu, Di; Zhao, Xiaoli; Lu, William W.

    2015-04-01

    Nanotechnology has made a significant impact on the development of nanomedicine. Nonviral vectors have been attracting more attention for the advantage of biosafety in gene delivery. Polyethylenimine (PEI)-conjugated chitosan (chitosan-g-PEI) emerged as a promising nonviral vector and has been demonstrated in many tumor cells. However, there is a lack of study focused on the behavior of this vector in stem cells which hold great potential in regenerative medicine. Therefore, in this study, in vitro gene delivering effect of chitosan-g-PEI was investigated in bone marrow stem cells. pIRES2-ZsGreen1-hBMP2 dual expression plasmid containing both the ZsGreen1 GFP reporter gene and the BMP2 functional gene was constructed for monitoring the transgene expression level. Chitosan-g-PEI-mediated gene transfer showed 17.2% of transfection efficiency and more than 80% of cell viability in stem cells. These values were higher than that of PEI. The expression of the delivered BMP2 gene in stem cells enhanced the osteogenic differentiation. These results demonstrated that chitosan-g-PEI is capable of applying in delivering gene to stem cells and providing potential applications in stem cell-based gene therapy.

  7. A Receptor Tyrosine Kinase Inhibitor, Dovitinib (TKI-258), Enhances BMP-2-Induced Osteoblast Differentiation In Vitro

    Science.gov (United States)

    Lee, Yura; Bae, Kyoung Jun; Chon, Hae Jung; Kim, Seong Hwan; Kim, Soon Ae; Kim, Jiyeon

    2016-01-01

    Dovitinib (TKI258) is a small molecule multi-kinase inhibitor currently in clinical phase I/II/III development for the treatment of various types of cancers. This drug has a safe and effective pharmacokinetic/pharmacodynamic profile. Although dovitinib can bind several kinases at nanomolar concentrations, there are no reports relating to osteoporosis or osteoblast differentiation. Herein, we investigated the effect of dovitinib on human recombinant bone morphogenetic protein (BMP)-2-induced osteoblast differentiation in a cell culture model. Dovitinib enhanced the BMP-2-induced alkaline phosphatase (ALP) induction, which is a representative marker of osteoblast differentiation. Dovitinib also stimulated the translocation of phosphorylated Smad1/5/8 into the nucleus and phosphorylation of mitogen-activated protein kinases, including ERK1/2 and p38. In addition, the mRNA expression of BMP-4, BMP-7, ALP, and OCN increased with dovitinib treatment. Our results suggest that dovitinib has a potent stimulating effect on BMP-2-induced osteoblast differentiation and this existing drug has potential for repositioning in the treatment of bone-related disorders. PMID:27025387

  8. Research of quaternized chitosan based hybrid scaffold as a delivery system for rhBMP-2%壳聚糖季铵盐基杂化支架的制备及其作为rhBMP-2载体的研究*

    Institute of Scientific and Technical Information of China (English)

    胡园园; 王靖; 刘昌胜

    2014-01-01

    Quaternized chitosan was synthesized by the reaction of chitosan and glycidyltrimethylammonium chloride (GTMAC)and named as N-[(2-hydroxy-3-trimethylammonium)propyl]chitosan chloride (HTCC). A hydrogel system composed of HTCC andβ-glycerophosphate (β-GP)was obtained by intermolecular forces. Introduction ofβ-TCP granules improved the mechanical strength and controlled the swelling behavior and pro-longed the releasing period for rhBMP-2 of the hydrogel scaffold.Moreover,rhBMP-2 loaded scaffolds were as-sessed in ectopic bone formation.The results indicate that porous HTCC/β-GP/β-TCP/rhBMP-2 scaffolds are promising candidates for application in tissue engineering of bone.%采用环氧衍生物开环法制备壳聚糖季铵盐,通过其与甘油磷酸钠的分子间作用力交联成凝胶,冻干后得多孔支架,用于装载骨形态发生蛋白-2应用于骨修复领域;同时引入β-TCP 作为物理交联点,在提高支架力学强度的同时,更好地调控支架的溶胀行为,延长rhBMP-2的释放时间,并且在异位诱导成骨的动物实验中取得良好效果。

  9. A late role for bmp2b in the morphogenesis of semicircular canal ducts in the zebrafish inner ear.

    Directory of Open Access Journals (Sweden)

    Katherine L Hammond

    Full Text Available The Bone Morphogenetic Protein (BMP genes bmp2 and bmp4 are expressed in highly conserved patterns in the developing vertebrate inner ear. It has, however, proved difficult to elucidate the function of BMPs during ear development as mutations in these genes cause early embryonic lethality. Previous studies using conditional approaches in mouse and chicken have shown that Bmp4 has a role in semicircular canal and crista development, but there is currently no direct evidence for the role of Bmp2 in the developing inner ear.We have used an RNA rescue strategy to test the role of bmp2b in the zebrafish inner ear directly. Injection of bmp2b or smad5 mRNA into homozygous mutant swirl (bmp2b(-/- embryos rescues the early patterning defects in these mutants and the fish survive to adulthood. As injected RNA will only last, at most, for the first few days of embryogenesis, all later development occurs in the absence of bmp2b function. Although rescued swirl adult fish are viable, they have balance defects suggestive of vestibular dysfunction. Analysis of the inner ears of these fish reveals a total absence of semicircular canal ducts, structures involved in the detection of angular motion. All other regions of the ear, including the ampullae and cristae, are present and appear normal. Early stages of otic development in rescued swirl embryos are also normal.Our findings demonstrate a critical late role for bmp2b in the morphogenesis of semicircular canals in the zebrafish inner ear. This is the first demonstration of a developmental role for any gene during post-embryonic stages of otic morphogenesis in the zebrafish. Despite differences in the early stages of semicircular canal formation between zebrafish and amniotes, the role of Bmp2 in semicircular canal duct outgrowth is likely to be conserved between different vertebrate species.

  10. RhBMP-2 microspheres-loaded chitosan/collagen scaffold enhanced osseointegration: an experiment in dog.

    Science.gov (United States)

    Shi, Shanshan; Cheng, Xiangrong; Wang, Jiawei; Zhang, Wei; Peng, Lin; Zhang, Yufeng

    2009-01-01

    The purpose of this study is to develop a novel recombinant human bone morphogenetic protein-2 (rhBMP-2) sustained release scaffold for dental implant osseointegration, and to evaluate the effect of this scaffold on promoting bone formation. RhBMP-2 was encapsulated in the poly-D,L-lactide-co-glycolide (PLGA) biodegradable microspheres, which were subsequently dispersed in a chitosan/collagen composite scaffold. This rhBMP-2 microspheres-loaded scaffold (S-MB) was compared with a chitosan/collagen scaffold without microspheres that directly encapsulated rhBMP-2 (S-B) in vitro and in vivo. The microstructure of the new scaffold was examined with scanning electron microscopy. The release profile of rhBMP-2 in vitro was measured at interval periods. The effect of rhBMP-2 encapsulated scaffolds on enhancing bone formation through implantation in dogs' mandibles was identified by histological examination of the regenerated bone after 4 weeks of implantation. Due to PLGA microspheres being loaded, the S-MB exhibited lower values at porosity and swelling rate, as well as a higher effective release dose than that of the S-B. Bone density, bone-implant contact, and bone-fill values measured from dog experiments demonstrated that the S-MB induced bone regeneration more quickly and was timely substituted by new bone. It was concluded that this sustained carrier scaffold based on microspheres was more effective to induce implant osseointegration. PMID:18667455

  11. Bone marrow stromal cells with a combined expression of BMP-2 and VEGF-165 enhanced bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Caiwen; Zhou Huifang; Fu Yao; Gu Ping; Fan Xianqun [Department of Ophthalmology, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China); Liu Guangpeng [Key Laboratory of Tissue Engineering, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China); Zhang Peng [Center for Translational Medicine Research and Development, Shenzhen Institute of Advanced Technology, Chinese Academy of Science (China); Hou Hongliang; Tang Tingting, E-mail: drfanxianqun@126.com [Department of Orthopedics, Shanghai Ninth People' s Hospital, Shanghai JiaoTong University School of Medicine, Shanghai 200011 (China)

    2011-02-15

    Bone graft substitutes with osteogenic factors alone often exhibit poor bone regeneration due to inadequate vascularization. Combined delivery of osteogenic and angiogenic factors from biodegradable scaffolds may enhance bone regeneration. We evaluated the effects of bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF), combined with natural coral scaffolds, on the repair of critical-sized bone defects in rabbit orbits. In vitro expanded rabbit bone marrow stromal cells (BMSCs) were transfected with human BMP2 and VEGF165 genes. Target protein expression and osteogenic differentiation were confirmed after gene transduction. Rabbit orbital defects were treated with a coral scaffold loaded with BMP2-transduced and VEGF-transduced BMSCs, BMP2-expressing BMSCs, VEGF-expressing BMSCs, or BMSCs without gene transduction. Volume and density of regenerated bone were determined by micro-computed tomography at 4, 8, and 16 weeks after implantation. Neovascularity, new bone deposition rate, and new bone formation were measured by immunostaining, tetracycline and calcein labelling, and histomorphometric analysis at different time points. The results showed that VEGF increased blood vessel formation relative to groups without VEGF. Combined delivery of BMP2 and VEGF increased new bone deposition and formation, compared with any single factor. These findings indicate that mimicking the natural bone development process by combined BMP2 and VEGF delivery improves healing of critical-sized orbital defects in rabbits.

  12. 慢性肾脏病患者血清PTH与BMP-2的变化及意义

    Institute of Scientific and Technical Information of China (English)

    范旗; 赵燕凌; 甘西伦

    2008-01-01

    选择慢性肾脏病(CKD)患者65例和健康查体者20例(对照组),根据肾小球滤过率(GFR)将CKD患者分为五组,分别采用化学发光法和酶联免疫吸附法测定血清血清甲状旁腺激素(PTH)及骨形态发生蛋白-2(BMP-2)浓度,分析血清PTH及BMP-2浓度变化的规律.结果 CKD患者血清PTH、BMP-2浓度均明显高于对照组(P<0.01);CKD患者血清BMP-2浓度与PTH呈正相关(r=0.678,P=0.006).认为CKD患者血清PTH及BMP-2浓度随肾功能损害程度加重逐渐升高,提示PTH、BMP-2与CKD患者病情进展有一定关系.

  13. Experimental Comparison of Cranial Particulate Bone Graft, rhBMP-2, and Split Cranial Bone Graft for Inlay Cranioplasty.

    Science.gov (United States)

    Hassanein, Aladdin H; Couto, Rafael A; Kurek, Kyle C; Rogers, Gary F; Mulliken, John B; Greene, Arin K

    2013-05-01

    Background :  Particulate bone graft and recombinant human bone morphogenetic protein-2 (rhBMP-2) are options for inlay cranioplasty in children who have not developed a diploic space. The purpose of this study was to determine whether particulate bone graft or rhBMP-2 has superior efficacy for inlay cranioplasty and to compare these substances to split cranial bone. Methods :  A 17 mm × 17 mm critical-sized defect was made in the parietal bones of 22 rabbits and managed in four ways: Group I (no implant; n=5), Group II (particulate bone graft; n=5), Group III (rhBMP-2; n=7), and Group IV (split cranial bone graft; n=5). Animals underwent microcomputed tomography and histologic analysis 16 weeks after cranioplasty. Results :  Defects without an implant (Group I) demonstrated inferior ossification (41.4%; interquartile range [IQR], 28.9% to 42.5%) compared to those treated with particulate bone graft (Group II: 99.5%; IQR, 97.8% to 100%), rhBMP-2 (Group III: 99.6%; IQR, 99.5% to 100%), or split cranial bone (Group IV: 100%) (P inlay calvarial defect areas equally, although the thickness of bone healed with rhBMP-2 is inferior. Clinically, particulate bone graft or split cranial bone graft may be superior to rhBMP-2 for inlay cranioplasty.

  14. Bone marrow stromal cells with a combined expression of BMP-2 and VEGF-165 enhanced bone regeneration

    International Nuclear Information System (INIS)

    Bone graft substitutes with osteogenic factors alone often exhibit poor bone regeneration due to inadequate vascularization. Combined delivery of osteogenic and angiogenic factors from biodegradable scaffolds may enhance bone regeneration. We evaluated the effects of bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF), combined with natural coral scaffolds, on the repair of critical-sized bone defects in rabbit orbits. In vitro expanded rabbit bone marrow stromal cells (BMSCs) were transfected with human BMP2 and VEGF165 genes. Target protein expression and osteogenic differentiation were confirmed after gene transduction. Rabbit orbital defects were treated with a coral scaffold loaded with BMP2-transduced and VEGF-transduced BMSCs, BMP2-expressing BMSCs, VEGF-expressing BMSCs, or BMSCs without gene transduction. Volume and density of regenerated bone were determined by micro-computed tomography at 4, 8, and 16 weeks after implantation. Neovascularity, new bone deposition rate, and new bone formation were measured by immunostaining, tetracycline and calcein labelling, and histomorphometric analysis at different time points. The results showed that VEGF increased blood vessel formation relative to groups without VEGF. Combined delivery of BMP2 and VEGF increased new bone deposition and formation, compared with any single factor. These findings indicate that mimicking the natural bone development process by combined BMP2 and VEGF delivery improves healing of critical-sized orbital defects in rabbits.

  15. Plasma Treated High-Density Polyethylene (HDPE Medpor Implant Immobilized with rhBMP-2 for Improving the Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Jin-Su Lim

    2014-01-01

    Full Text Available We investigate the bone generation capacity of recombinant human bone morphogenetic protein-2 (rhBMP-2 immobilized Medpor surface through acrylic acid plasma-polymerization. Plasma-polymerization was carried out at a 20 W at an acrylic acid flow rate of 7 sccm for 5 min. The plasma-polymerized Medpor surface showed hydrophilic properties and possessed a high density of carboxyl groups. The rhBMP-2 was immobilized with covalently attached carboxyl groups using 1-ethyl-3-(3-dimethylaminopropyl carbodiimide and N-hydroxysuccinimide. Carboxyl groups and rhBMP-2 immobilization on the Medpor surface were identified by Fourier transform infrared spectroscopy. The activity of Medpor with rhBMP-2 immobilized was examined using an alkaline phosphatase assay on MC3T3-E1 cultured Medpor. These results showed that the rhBMP-2 immobilized Medpor increased the level of MC3T3-E1 cell differentiation. These results demonstrated that plasma surface modification has the potential to immobilize rhBMP-2 on polymer implant such as Medpor and can be used for the binding of bioactive nanomolecules in bone tissue engineering.

  16. Does Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) Use in Adult Spinal Deformity (ASD) Increase Complications and Are Complications Associated With Location of rhBMP-2 Use?: A Prospective, Multicenter Study of 279 Consecutive Patients.

    Science.gov (United States)

    Bess, Shay; Line, Breton G; Lafarge, Virginie; Schwab, Frank; Shaffrey, Christopher I; Hart, Robert A; Boachie-Adjei, Oheneba; Akbarnia, Behrooz A; Ames, Christopher P; Burton, Douglas C; Deverin, Vedat; Fu, Kai-Ming G; Gupta, Munish; Hostin, Richard; Kebaish, Khaled; Klineberg, Eric; Mundis, Gregory; O'Brien, Michael; Shelokov, Alexis; Smith, Justin S

    2013-11-18

    Study Design. Multi-center, prospective analysis of consecutive ASD patients.Objective. Evaluate complications associated with rhBMP-2 use in ASDSummary of Background Data. Off-label rhBMP-2 use is common, however under-reporting of rhBMP-2 associated complications has been recently scrutinized.Methods. ASD patients consecutively enrolled into a prospective, multicenter database, were evaluated for type and timing of acute perioperative complications. Inclusion criteria: age ≥ 18 years, ASD, spinal arthrodesis >4 levels, and ≥3 months follow-up. Patients divided into those receiving rhBMP-2 (BMP) or no rhBMP-2 (NOBMP). BMP divided into location of use: posterior (PBMP), interbody (IBMP), and interbody + posterior spine (I+PBMP). Correlations between acute perioperative complications and rhBMP-2 use including total dose, dose/level and location of use were evaluated.Results. 279 patients (mean age 57 years, mean spinal levels fused 12.0, mean follow-up 28.8 months) met inclusion criteria. BMP (n = 172; average posterior dose = 2.5 mg/level, average interbody dose = 5 mg/level) had similar age, smoking history, previous spine surgery, total spinal levels fused, estimated blood loss, and duration of hospital stay as NOBMP (n = 107; p>0.05). BMP had greater Charlson Comorbidity Index (1.9 vs. 1.2), greater scoliosis (43° vs. 38°), longer operative time (488.2 vs. 414.6 minutes), more osteotomies/patient (4.0 vs. 1.6) and greater percentage of anteroposterior fusion (APSF; 20.9% vs. 8.4%) than NOBMP, respectively (p0.05). Multivariate analysis demonstrated small to non-existent correlations between rhBMP-2 use and complications.Conclusions. RhBMP-2 use and location of rhBMP-2 use in ASD surgery, at reported doses, does not increase acute major, neurological or wound complications. Research is needed for higher rhBMP-2 dosing and long-term follow-up.

  17. Hereditary hemochromatosis type 1 phenotype modifiers in Italian patients. The controversial role of variants in HAMP, BMP2, FTL and SLC40A1 genes.

    Science.gov (United States)

    Radio, Francesca Clementina; Majore, Silvia; Aurizi, Caterina; Sorge, Fiammetta; Biolcati, Gianfranco; Bernabini, Sara; Giotti, Irene; Torricelli, Francesca; Giannarelli, Diana; De Bernardo, Carmelilia; Grammatico, Paola

    2015-06-01

    Hereditary hemochromatosis (HH) is a heterogeneous disorder of iron metabolism. The most common form of the disease is Classic or type 1 HH, mainly caused by a biallelic missense p.Cys282Tyr (c.845G>A) mutation in the HFE gene. However, the penetrance of p.Cys282Tyr/p.Cys282Tyr genotype is incomplete in terms of both biochemical and clinical expressivity. Lack of penetrance is thought to be caused by several genetic and environmental factors. Recently, a lot of evidences on HH genetic modifiers were produced, often without conclusive results. We investigated 6 polymorphisms (rs10421768 in HAMP gene, rs235756 in BMP2 gene, rs2230267 in FTL gene, rs1439816 in SLC40A1 gene, rs41295942 in TFR2 gene and rs2111833 in TMPRSS6 gene) with uncertain function in order to further evaluate their role in an independent cohort of 109 HH type 1 patients. Our results make it likely the role of rs10421768, rs235756, rs2230267 and rs1439816 polymorphisms, respectively in HAMP, BMP2, FTL and SLC40A1 genes in HH expressivity. In addition, previous and our findings support a hypothetical multifactorial model of HH, characterized by a principal gene (HFE in HH type 1) and minor genetic and environmental factors that still have to be fully elucidated.

  18. Osteogenic differentiation as a result of BMP-2 plasmid DNA based gene therapy in vitro and in vivo.

    Science.gov (United States)

    Wegman, F; Bijenhof, A; Schuijff, L; Oner, F C; Dhert, W J A; Alblas, J

    2011-03-15

    Bone regeneration is one of the major focus points in the field of regenerative medicine. A well-known stimulus of bone formation is bone morphogenetic protein-2 (BMP-2), which has already been extensively used in clinical applications. We investigated the possibility of achieving osteogenic differentiation both in vitro and in vivo as a result of prolonged presence of BMP-2 using plasmid DNA-based gene therapy. By delivering BMP-2 cDNA in an alginate hydrogel, a versatile formulation is developed. High transfection efficiencies of up to 95% were obtained in both human multipotent stromal cells (MSCs) and MG-63 cells using naked DNA in vitro. Over a period of 5 weeks, an increasing amount of biologically active BMP-2 was released from the cells and remained present in the gel. In vivo, transfected cells were found after both two and six weeks implantation in naked mice, even in groups without seeded cells, thus indicating in vivo transfection of endogenous cells. The protein levels were effective in inducing osteogenic differentiation in vitro, as seen by elevated alkaline phosphatase (ALP) production and in vivo, as demonstrated by the production of collagen I and osteocalcin in a mineralised alginate matrix. We conclude that BMP-2 cDNA incorporated in alginate hydrogel appears to be a promising new strategy for minimal-invasive delivery of growth factors in bone regeneration.

  19. Effects of rhBMP-2 on Mandibular Distraction Osteogenesis and its OPG Expression in Rabbits%rhBMP-2对兔下颌骨牵引成骨区骨保护素表达的影响

    Institute of Scientific and Technical Information of China (English)

    周蕊; 付颖; 李新

    2011-01-01

    目的:通过动物实验,研究应用外源性rhBMP-2对兔下颌骨牵引成骨区骨保护素( osteoprotegerin,OPG)的影响.方法:在48只成年大耳白兔的一侧下颌骨前部行骨切开术,分别将空白胶原、rhBMP-2 1.5 mg胶原复合物植入下颌骨切开处,用牵引器延长一侧下颌骨4 mm,稳定期第1、3、7、14天,分别处死各组动物,取牵引区新生骨痂行组织学及OPG免疫组化染色.结果:下颌牵引延长后牵引间隙均有新骨形成,应用rhBMP-2 1.5mg效果好.免疫组化染色OPG主要定位于成骨细胞的胞浆中.在同一时间内,应用rhBMP-2组较对照组有显著性差异(P<0.05).结论:动物实验表明,rhBMP-2能促进兔下颌骨牵引成骨区新骨的生成.%Objective: To investigate the effects of rhBMP- 2 on mandibular distraction osteogenesis and the expression of OPG in the period of distraction osteogenesis. Methods: Unilateral mandibular osteotomies were performed in 48 mature rabbit. rhBMP - 2 1. 5mg with the collagen carrier was implanted in the osteotomy side of mandibles. Only collagen sponge was implanted in the control group. The mandibles of 48 rabbits were lengthened by 4 mm using a distractor , The animals were killed on 1,3,7,14 days of consolidation period. The distracted calluses were harvested and processed for histological and immunohistochemistry study of OPG. Results: The regenerated bone was found in the distraction gap after mandibular lengthening. But the rhBMP-2 was better. Staining for OPG was localized in osteoblasts of the periosteal region after completion of distraction. The mandibular side treated with rhBMP-2 had greater amount of new bone formation than that treated with collagen sponge. OPG was found in the cytoplasm of osteoblasts and stained brown or dark brown by immunohistochemistry. At the same time, OPG expression indicated that there was siganificant difference between rhBMP-2 group and control group(P<0. 05). Conclusion: rhBMP -2 could accelerate

  20. Frame-independent mechanics:geometry on affine bundles

    OpenAIRE

    Grabowska, K.; Grabowski, J.; Urbanski, P.

    2005-01-01

    Main ideas of the differential geometry on affine bundles are presented. Affine counterparts of Lie algebroid and Poisson structures are introduced and discussed. The developed concepts are applied in a frame-independent formulation of the time-dependent and the Newtonian mechanics.

  1. Low-power GaAlAs laser irradiation promotes the proliferation and osteogenic differentiation of stem cells via IGF1 and BMP2.

    Directory of Open Access Journals (Sweden)

    Jyun-Yi Wu

    Full Text Available Low-power laser irradiation (LPLI has been found to induce various biological effects and cellular processes. Also, LPLI has been shown to promote fracture repair. Until now, it has been unclear how LPLI promotes bone formation and fracture healing. The aim of this study was to investigate the potential mechanism of LPLI-mediated enhancement of bone formation using mouse bone marrow mesenchymal stem cells (D1 cells. D1 cells were irradiated daily with a gallium-aluminum-arsenide (GaAlAs laser at dose of 0, 1, 2, or 4 J/cm(2. The lactate dehydrogenase (LDH assay showed no cytotoxic effects of LPLI on D1 cells, and instead, LPLI at 4 J/cm(2 significantly promoted D1 cell proliferation. LPLI also enhanced osteogenic differentiation in a dose-dependent manner and moderately increased expression of osteogenic markers. The neutralization experiments indicated that LPLI regulated insulin-like growth factor 1 (IGF1 and bone morphogenetic protein 2 (BMP2 signaling to promote cell proliferation and/or osteogenic differentiation. In conclusion, our study suggests that LPLI may induce IGF1 expression to promote both the proliferation and osteogenic differentiation of D1 cells, whereas it may induce BMP2 expression primarily to enhance osteogenic differentiation.

  2. BMP-2 regulates the formation of oral sulcus in mouse tongue by altering the balance between TIMP-1 and MMP-13.

    Science.gov (United States)

    Fukui, Tadayoshi; Suga, Takeo; Iida, Ryo-Hei; Morito, Mitsuhiko; Luan, Xianghong; Diekwisch, Thomas G H; Nakamura, Yoshiki; Yamane, Akira

    2010-08-01

    The aim of this study is to investigate whether BMP-2 regulates the oral sulcus formation of mouse embryonic tongue by modifying the expression of TIMP and MMP. The BMP-2 siRNA induced a 180% increase in the depth of oral sulcus cavity (P sulcus into the mesenchymal tissues consisting of tongue floor, whereas the recombinant BMP-2 suppressed the process in the organ culture system of mouse embryonic tongue. The BMP-2 siRNA induced a 60% decrease in the expression of TIMP-1 mRNA (P sulcus in the BMP-2 siRNA treated mandibles. The recombinant BMP-2 induced a 220% increases in the expression of TIMP-1 mRNA and the area of the immunostaining for TIMP-1 around the oral sulcus was larger in the mandibles treated with the recombinant BMP-2 than the vehicle. The BMP-2 siRNA induced a 60% increase in the expression of MMP-13 protein and a marked increase in the staining intensity for MMP-13 was observed in the epithelial region of the BMP-2 siRNA treated mandibles. The recombinant BMP-2 induced a 70% decrease in the expression of MMP-13 mRNA and the decrease was mainly observed in the tissues around oral sulcus. The expressions of BMP-2, TIMP-1, and MMP-13 were verified in the tissues around in vivo developing oral sulcus at E11, 12, and 13 by immunohistochemistry. These results suggest that BMP-2 regulates the formation of oral sulcus by altering the balance between TIMP-1 and MMP-13.

  3. BMP2基因修饰犬脂肪源性基质细胞修复自体大段骨缺损%Repairing canine segmental bone defects using BMP2 gene modified adipose-derived stromal cells

    Institute of Scientific and Technical Information of China (English)

    李慧武; 戴尅戎; 汤亭亭; 张晓玲; 唐坚; 孙晓江; 张双燕; 楼觉人

    2008-01-01

    Objective To evaluate osteogenetic effectiveness of porous β-tricalcium phosphate(β-TCP) ceramic mixed with human bone morphogenetic protein2 gene(Adv-hBMP2)modified adipose derived stromal cells (ADSCs) in the repair of critical-sized bone defects..Methods The ADSCs taken from the back of beagle dogs were modified by the BMP2 gene.The expression and bone-induction ability of BMP2 was identified by ELISA and ectopic bone formation in nude mice.The cells were applied to a β-tricalcium phosphate (TGP)carrier and implanted into ulnar bone defects in the canine model.18 ulnar bone defects were divided into three groups randomly and filled with granular TCP alone,granular TCP and ADSCs,or TCP and ADSCs transduced with Adv-hBMP2 respectively.All dogs were followed clinically and roentgenographically for 16 weeks and then sacrificed.Results ELISA and ectopic bone formation in nude mice showed the recombinant ADSCs could express BMP2 highly and stably.No bone defects healed after implanting granular TCP alone or granular TCP and ADSCs.In the TCP and ADSCs transduced with AdvhBMP2 group,two defects healed,four partly healed.Histological examination showed woven bone at the both end of the cortices but entirelv fibrous tissue in the middle in which defects filled with TCP alone or TCP and ADSCs.Defects filled with TCP and transduced ADSCs showed substatial new bone formation.Histomorphometry showed TCP combined with ADSCs did not significantly increase new bone area compared with TCP alone.TCP and recombinant ADSCs produced a significant increase in newly formed bone area.Conclusion ADSCs tansduced with BMP2 gene in a TCP carrier can enhance bone regeneratmn to repair the critically-sized bone defect.%目的 评价BMP2基因修饰的犬脂肪源性基质细胞(ADSCs)与β-磷酸三钙(β-TCP)复合修复自体大段骨缺损的疗效.方法 从比格犬背部脂肪组织中提取基质细胞,转染腺病毒介导的人BMP2基因(Adv-hBMP2),通过ELISA和裸鼠体内异位成骨实验鉴定BMP

  4. Surface delivery of tunable doses of BMP-2 from an adaptable polymeric scaffold induces volumetric bone regeneration.

    Science.gov (United States)

    Bouyer, Michael; Guillot, Raphael; Lavaud, Jonathan; Plettinx, Cedric; Olivier, Cécile; Curry, Véronique; Boutonnat, Jean; Coll, Jean-Luc; Peyrin, Françoise; Josserand, Véronique; Bettega, Georges; Picart, Catherine

    2016-10-01

    The rapid and effective bone regeneration of large non-healing defects remains challenging. Bioactive proteins, such as bone morphogenetic protein (BMP)-2, are proved their osteoinductivity, but their clinical use is currently limited to collagen as biomaterial. Being able to deliver BMP-2 from any other biomaterial would broaden its clinical use. This work presents a novel means for repairing a critical size volumetric bone femoral defect in the rat by combining a osteoinductive surface coating (2D) to a polymeric scaffold (3D hollow tube) made of commercially-available PLGA. Using a polyelectrolyte film as BMP-2 carrier, we tune the amount of BMP-2 loaded in and released from the polyelectrolyte film coating over a large extent by controlling the film crosslinking level and initial concentration of BMP-2 in solution. Using microcomputed tomography and quantitative analysis of the regenerated bone growth kinetics, we show that the amount of newly formed bone and kinetics can be modulated: an effective and fast repair was obtained in 1-2 weeks in the best conditions, including complete defect bridging, formation of vascularized and mineralized bone tissue. Histological staining and high-resolution computed tomography revealed the presence of bone regeneration inside and around the tube with spatially distinct organization for trabecular-like and cortical bones. The amount of cortical bone and its thickness increased with the BMP-2 dose. In view of the recent developments in additive manufacturing techniques, this surface-coating technology may be applied in combination with various types of polymeric or metallic scaffolds to offer new perspectives of bone regeneration in personalized medicine. PMID:27454063

  5. Betulinic acid synergically enhances BMP2-induced bone formation via stimulating Smad 1/5/8 and p38 pathways

    OpenAIRE

    Choi, Hyuck; Jeong, Byung-Chul; Kook, Min-Suk; Koh, Jeong-Tae

    2016-01-01

    Background Healing of bone defects is a dynamic and orchestrated process that relies on multiple growth factors and cell types. Bone morphogenetic protein 2 (BMP2) is a key growth factor for bone healing, which stimulates mesenchymal stem cells to differentiate into osteoblasts. Betulinic acid (BetA) is a natural pentacyclic triterpenoid from plants. This study aimed to examine combinatory effects of BetA and BMP2 on ectopic bone generation in mice. Results In MC3T3-E1 preosteoblast culture, ...

  6. 脊柱融合术患者BMP-2基因突变的检测及其意义%Mutational analysis of BMP-2 gene in the patients of spinal fusion

    Institute of Scientific and Technical Information of China (English)

    周传利; 陈晓亮

    2007-01-01

    目的 检测脊柱融合术患者的骨形态发生蛋白-2(BMP-2)基因突变状况.方法 从80例行脊柱融合术患者的术前空腹静脉血中提取DNA,采用聚合酶链反应-单链构象多态性分析(PCR-SSCP)及测序技术,检测其BMP-2基因部分编码区及其侧翼序列的突变.结果 脊柱融合术患者的外周静脉血中BMP-2基因有突变:TCG→GCG,TCA→TCG,并引起相应多肽的结构改变.结论 脊柱融合术患者中存在BMP-2基因突变及多态性分布,并有可能影响植骨融合效果.

  7. Influence of BMP-2 on early follicular development and mRNA expression of oocyte specific genes in bovine preantral follicles cultured in vitro.

    Science.gov (United States)

    Rossi, Rodrigo O D S; da Cunha, Ellen V; Portela, Antonia M L R; Passos, José R S; Costa, José J N; Silva, Anderson W B; Saraiva, Márcia V A; Peixoto, Christina A; Donato, Mariana A M; van den Hurk, Robert; Silva, José R V

    2016-03-01

    This study evaluates the effect of different concentrations (0, 10, 50 and 100ng/mL) of bone morphogenetic protein-2 (BMP-2) on primordial and secondary follicle development. It also investigates the effects of FSH and BMP-2 on the growth, morphology, ultrastructure and expression of mRNA for GDF9, NLRP5 and NPM2 genes in secondary follicles cultured for 18 days. The presence of BMP-2 at all tested concentrations increased the development of primordial follicles in vitro, but the highest concentration of BMP-2 (100 ng/mL) reduced the percentage of normal follicles when compared with tissues cultured with 10 ng/mL BMP-2. During culture of secondary follicles, in contrast to higher concentrations (50 or 100 ng/mL), 10 ng/mL BMP-2 kept the morphology of follicles during initial stages of in vitro culture. This concentration of BMP-2 also benefits maintenance of the ultrastructure of 18-day cultured follicles. The presence of both BMP-2 and FSH in culture medium resulted in a significant (PFSH and BMP-2 reduced follicular mRNA expression of GDF9 and NLRP5 when compared to follicles cultured in media containing only FSH. In combination with FSH, BMP-2 reduced the mRNA levels of NPM2, when compared to follicles cultured in control medium. It is concluded from these data that 10 ng/mL BMP-2 promotes the growth of primordial in vitro and it helps to maintain the ultrastructure of secondary follicles, while FSH is more important for better expression of follicular markers like GDF9 and NLRP5. PMID:26435174

  8. Expression of Human BMP-2 Gene in Different Tissues of Tobacco Plants%重组人BMP-2在烟草不同组织中的表达

    Institute of Scientific and Technical Information of China (English)

    高原; 索广力; 韩津; 何正权; 姚伟; 戴建武

    2006-01-01

    骨形态发生蛋白(BMPs)是一类调节骨组织发育的生长因子.BMP-2是BMP家族中诱骨活性最强的.在骨组织工程研究和临床应用中需要大量的BMP-2.因此,研究出一种能够有效地大量生产BMP-2的方法是十分必要的.随着植物分子生物学的进展,转基因植物被用作一种生物反应器来生产目的蛋白.以gus作为报告基因,研究了重组人bmp-2基因在烟草中的表达.通过GUS活性检测、半定量PCR和Western blotting分析了根、茎、叶组织中基因表达的水平,结果显示融合蛋白在根和茎组织中表达量显著高于叶组织.由于根和茎组织中蛋白组成与叶组织相比相对简单,提示其更易于进行目的蛋白的纯化.%The bone morphogenetic proteins (BMPs) are a family of growth factors that regulate the development of bone. BMP-2 is the most effective in the induction of bone tissue. A large amount of BMP-2 is needed for both bone tissue engineering research and clinical application. Thus, an effective way is necessary to produce sufficient BMP-2 protein. With the advance in plant biotechnology, transgenic plants have been targeted as a bioreactor to produce desired recombinant proteins. Here, the expression of recombinant human bmp-2 gene (rhbmp-2) was studied in tobacco plants using gus as a reporter gene. The difference of expression levels in root, stem and leaf tissues was analyzed by GUS activity assay, semi-quantitive RT-PCR and westem blotting.The results indicated that the expression levels of fusion protein in root and stem tissues were significantly higher than those in leaf tissue. For the protein compositions in root and stem tissues were simpler than those in leaf tissue,this suggested that the purification process with root and stem tissues would potentially be easier.

  9. Ectopic Bone Formation in vivo Induced by a Novel Synthetic Peptide Derived from BMP-2 Using Porous Collagen Scaffolds

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To investigate the osteoinductive and ectopicly osteogenic effects of a novel peptide P24 derived from bone morphogenetic protein 2 (BMP2), biodegradable collagen scaffolds (CS) were used to load BMP-2-derived peptide solutions with different concentrations (0.4 mg peptide/CS, 0.1 mg peptide/CS and pure CS, respectively), and the implants were implanted into muscular pockets on the back of Wistar rats.Radiographs and histological analysis were performed to evaluate the ectopic bone effects. Active ectopic bone formation was seen in both groups containing the peptide at different concentration (0.4 mg and 0.1 mg),whereas no bone formation and only fibrous tissue was seen in the pure CS group. The new bone formation induced by the peptide P24 displayed a dose-dependent and time-dependent efficiency. The new bone formation in the 0.4 mg peptide/CS group significantly increased than that of the 0.1 mg peptide/CS group. This novel BMP-2-derived peptide had excellent osteoinductive and ectopicly osteogenic properties which were similar to those of BMP2.

  10. Immunohistological Localization of BMP-2, BMP-7, and Their Receptors in Knee Joints with Focal Cartilage Lesions

    Directory of Open Access Journals (Sweden)

    Hagen Schmal

    2012-01-01

    Full Text Available Introduction. Although it is well known that BMP-2 and BMP-7 play significant roles in cartilage metabolism, data about intra-articular expression and localization of these proteins and their receptors in humans are rare. Methods. Biopsies of synovia and debrided cartilage were taken in patients undergoing autologous chondrocyte implantation. Expression of BMP-2, BMP-7, and their receptors BMPR-1A, BMPR-1B and BMPR-2 were semiquantitatively evaluated by immunohistological staining. Results. BMP-7 was equally highly expressed in all cartilage and synovial biopsies. Increased levels of BMPR-1A, but not of BMPR-1B, and BMPR-2, were found in all synovial and 47% of all cartilage samples (P=0.002. BMP-2 was positively scored in 47% of all cartilage and 40% of all synovial specimens. Defect size, KOSS, Henderson or Kellgren-Lawrence score did not statistically significant correlate with the expression of the analyzed proteins or Mankin and Pritzker scores. Duration of symptoms and localization of lesions were associated with KOSS (P<0.02, but there was no influence of these parameters on protein expression. Conclusions. BMP-2, BMP-7, and BMPR-1A were expressed in cartilage and synovia of knees with focal cartilage lesions. Although defect localization and duration of symptoms decisively influence KOSS, there was no associated alteration of protein expression observed.

  11. Vitapex can promote the expression of BMP-2 during the bone regeneration of periapical lesions in rats

    Directory of Open Access Journals (Sweden)

    Xianyin Xia

    2013-01-01

    Full Text Available Purpose: To investigate the effect of Vitapex on the healing of periapical lesions and the expression of bone morphogenetic protein (BMP-2 during the periapical bone regeneration. Materials and Methods: Periapical lesions were induced in Sprague-Dawley (S-D rats by an occlusal pulp exposure in the mandibular first molars and were verified by X-ray. Total of 36 rats were randomly divided into three groups, and they were obturated with Zinc Oxide Eugenol (ZOE, or with Vitapex, or non-treated as negative control group. The rats of three groups were randomly killed at week 0, 2, 4, and 8 after root canal therapy, and then the mandibles were processed for histological examination and immunohistochemistry analysis. Results: At week 0, only a few BMP-2 positive cells could be observed in all rats. While the expression of BMP-2 was dramatically increased in case of Vitapex group at week 2 and week 4, and then climaxed at week 8. However, no apparent changes were observed in ZOE group and negative group at week 2, 4, and 8. Conclusion: These observations suggested that Vitapex has a greater ability in inducing bone regeneration than ZOE by the expression of BMP-2 induction in the treatment of rats experimental periapical lesions.

  12. BMP-2-enhanced chondrogenesis involves p38 MAPK-mediated down-regulation of Wnt-7a pathway.

    Science.gov (United States)

    Jin, Eun-Jung; Lee, Sun-Young; Choi, Young-Ae; Jung, Jae-Chang; Bang, Ok-Sun; Kang, Shin-Sung

    2006-12-31

    The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates Wnt-7a/b-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of b-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with b-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of b-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of b-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells. PMID:17202865

  13. BMP2-loaded hollow hydroxyapatite microspheres exhibit enhanced osteoinduction and osteogenicity in large bone defects

    Directory of Open Access Journals (Sweden)

    Xiong L

    2015-01-01

    Full Text Available Long Xiong,1 Jianhua Zeng,1 Aihua Yao,2 Qiquan Tu,3 Jingtang Li,1 Liang Yan,4 Zhiming Tang1 1Department of Osteology, People’s Hospital of Jiangxi Province, Nanchang, Jiangxi, People’s Republic of China; 2School of Materials Science and Engineering, Tongji University, Shanghai, People’s Republic of China; 3Department of Osteology, People’s Hospital of Jiujiang County, Jiujiang, Jiangxi, People’s Republic of China; 4Department of Osteology, The Third Hospital of Nanchang City, Nanchang, Jiangxi, People’s Republic of China Abstract: The regeneration of large bone defects is an osteoinductive, osteoconductive, and osteogenic process that often requires a bone graft for support. Limitations associated with naturally autogenic or allogenic bone grafts have demonstrated the need for synthetic substitutes. The present study investigates the feasibility of using novel hollow hydroxyapatite microspheres as an osteoconductive matrix and a carrier for controlled local delivery of bone morphogenetic protein 2 (BMP2, a potent osteogenic inducer of bone regeneration. Hollow hydroxyapatite microspheres (100±25 µm with a core (60±18 µm and a mesoporous shell (180±42 m2/g surface area were prepared by a glass conversion technique and loaded with recombinant human BMP2 (1 µg/mg. There was a gentle burst release of BMP2 from microspheres into the surrounding phosphate-buffered saline in vitro within the initial 48 hours, and continued at a low rate for over 40 days. In comparison with hollow hydroxyapatite microspheres without BMP2 or soluble BMP2 without a carrier, BMP2-loaded hollow hydroxyapatite microspheres had a significantly enhanced capacity to reconstitute radial bone defects in rabbit, as shown by increased serum alkaline phosphatase; quick and complete new bone formation within 12 weeks; and great biomechanical flexural strength. These results indicate that BMP2-loaded hollow hydroxyapatite microspheres could be a potential new option

  14. Simultaneous gene transfer of bone morphogenetic protein (BMP) -2 and BMP-7 by in vivo electroporation induces rapid bone formation and BMP-4 expression

    OpenAIRE

    Kawai, Mariko; Bessho, Kazuhisa; Maruyama, Hiroki; Miyazaki, Jun-ichi; Yamamoto, Toshio

    2006-01-01

    Background: Transcutaneous in vivo electroporation is expected to be an effective gene-transfer method for promoting bone regeneration using the BMP-2 plasmid vector. To promote enhanced osteoinduction using this method, we simultaneously transferred cDNAs for BMP-2 and BMP-7, as inserts in the non-viral vector pCAGGS.

  15. Enhancement of the Regenerative Potential of Anorganic Bovine Bone Graft Utilizing a Polyglutamate-Modified BMP2 Peptide with Improved Binding to Calcium-Containing Materials.

    Science.gov (United States)

    Bain, Jennifer L; Bonvallet, Paul P; Abou-Arraj, Ramzi V; Schupbach, Peter; Reddy, Michael S; Bellis, Susan L

    2015-09-01

    Autogenous bone is the gold standard material for bone grafting in craniofacial and orthopedic regenerative medicine. However, due to complications associated with harvesting donor bone, clinicians often use commercial graft materials that may lose their osteoinductivity due to processing. This study was aimed to functionalize one of these materials, anorganic bovine bone (ABB), with osteoinductive peptides to enhance regenerative capacity. Two peptides known to induce osteoblastic differentiation of mesenchymal stem cells were evaluated: (1) DGEA, an amino acid motif within collagen I and (2) a biomimetic peptide derived from bone morphogenic protein 2 (BMP2pep). To achieve directed coupling of the peptides to the graft surface, the peptides were engineered with a heptaglutamate domain (E7), which confers specific binding to calcium moieties within bone mineral. Peptides with the E7 domain exhibited greater anchoring to ABB than unmodified peptides, and E7 peptides were retained on ABB for at least 8 weeks in vivo. To assess the osteoinductive potential of the peptide-conjugated ABB, ectopic bone formation was evaluated utilizing a rat subcutaneous pouch model. ABB conjugated with full-length recombinant BMP2 (rBMP2) was also implanted as a model for current clinical treatments utilizing rBMP2 passively adsorbed to carriers. These studies showed that E7BMP2pep/ABB samples induced more new bone formation than all other peptides, and an equivalent amount of new bone as compared with rBMP2/ABB. A mandibular defect model was also used to examine intrabony healing of peptide-conjugated ABB. Bone healing was monitored at varying time points by positron emission tomography imaging with (18)F-NaF, and it was found that the E7BMP2pep/ABB group had greater bone metabolic activity than all other groups, including rBMP2/ABB. Importantly, animals implanted with rBMP2/ABB exhibited complications, including inflammation and formation of cataract-like lesions in the eye, whereas

  16. In silico Mechano-Chemical Model of Bone Healing for the Regeneration of Critical Defects: The Effect of BMP-2.

    Directory of Open Access Journals (Sweden)

    Frederico O Ribeiro

    Full Text Available The healing of bone defects is a challenge for both tissue engineering and modern orthopaedics. This problem has been addressed through the study of scaffold constructs combined with mechanoregulatory theories, disregarding the influence of chemical factors and their respective delivery devices. Of the chemical factors involved in the bone healing process, bone morphogenetic protein-2 (BMP-2 has been identified as one of the most powerful osteoinductive proteins. The aim of this work is to develop and validate a mechano-chemical regulatory model to study the effect of BMP-2 on the healing of large bone defects in silico. We first collected a range of quantitative experimental data from the literature concerning the effects of BMP-2 on cellular activity, specifically proliferation, migration, differentiation, maturation and extracellular matrix production. These data were then used to define a model governed by mechano-chemical stimuli to simulate the healing of large bone defects under the following conditions: natural healing, an empty hydrogel implanted in the defect and a hydrogel soaked with BMP-2 implanted in the defect. For the latter condition, successful defect healing was predicted, in agreement with previous in vivo experiments. Further in vivo comparisons showed the potential of the model, which accurately predicted bone tissue formation during healing, bone tissue distribution across the defect and the quantity of bone inside the defect. The proposed mechano-chemical model also estimated the effect of BMP-2 on cells and the evolution of healing in large bone defects. This novel in silico tool provides valuable insight for bone tissue regeneration strategies.

  17. Retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP2 in mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Zhang Yingang; Guo Xiong; Liu Zheng; Wang Shijie

    2007-01-01

    Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP2 in mesenchymal stem cells. Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP2 vector by the optimized retroviral transduction protocol. Fluorescent microscopy's examination was to evaluate the results of the transduction, flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells. Bioactivity test from C2C12K4 cells was to show the expression and bio-activity of the fusion gene. Results Fluorescent microscopy showed the success of the transduction. By flow cytometer's analysis, the mean efficiency of the transduction with EGFP was (42.8±6.1)% SD. Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting, almost of those showed the expression of BMP2. Fluorescently and strongly bioactivity test for C2C12K4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control. Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting. Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP2, the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique, the expressed chimeric protein embraced the double bioactivity of EGFP and BMP2, and moreover, the expression had not attenuated over time.

  18. Repair of Rabbit Femoral Defects with a Novel BMP2-derived Oligopeptide P24

    Institute of Scientific and Technical Information of China (English)

    Zhixia DUAN; Qixin ZHENG; Xiaodong GUO; Changwen LI; Bin WU; Weigang WU

    2008-01-01

    In this study, the bioactivity of a novel BMP2-derived oligopeptide P24 was investigated by using the model of rabbit femoral defect after loaded in the biodegradable poly (lactic acid / glycolic acid / asparagic acid-co-polyethylene glycol) (PLGA-[ASP-PEG]). A 1.5-cm unilateral segmental bone defect was created in the left femoral diaphysis in each of the 30 new zealand white rabbits.The defects of 18 legs filled with BMP2-derived peptide P24 combined with PLGA-[ASP-PEG]scaffold serves as the experimental group, and the defects in the rest 12 rabbits filled with(PLGA-[ASP-PEG]) without P24 as control group. The bone-repairing capability in the target region of the two group was grossly, radiologically, histopathologically and biomechanically evaluated 4, 8and 12 weeks after the operation. Our results showed that in each group, primary healing of incision was achieved in the two groups. Radiographically, in experimental group, defects were filled with induced callus within 8 weeks, and a cortical bone-like structure was observed in some animals at the12th week. According to the standardized stage of bone defect repair, 9 (64.28%) achieved grade-4healing. In contrast, little bone formation was seen in the defects even 12 weeks after the operation,and 5 (62.50%) had grade 0 healing in this group. Histologically, tissue engineering material was mostly absorbed and cartilage was found around implants in the experimental group at the 4th week;8 weeks after operation, the engineering material was completely absorbed, and formation of woven bone was observed and typical trabecular bone structure could be seen. In control group, 8 weeks after operation, the defect was filled with fibrous tissues, and no bone-like structure was observed. Statistical analysis showed very significant difference in biomechanical indicators between the two groups (P<0.05). It is concluded that new oligopeptide P24 can induce excellent bone regeneration and promote bone repair.

  19. Independent analysis of mechanical data from atomic force microscopy

    International Nuclear Information System (INIS)

    Present atomic force microscopes are capable of acquiring large data volumes by point using point force–distance spectroscopic measurements. Even if different trade names and different technical implementations are used, for most of these techniques a force–distance curve in every image pixel is measured, this curve is immediately fitted by some theoretical dependence and results are displayed as a mechanical properties channel (Young modulus, adhesion, etc). Results are processed during the measurement directly in the scanning probe microscopy controller or, after it, by manufacturer provided software. In this paper, we present a software tool for independent numerical processing of such data, including more numerical models for the force–distance curve evaluation and including a simple estimate of uncertainties related to the fitting procedure. This can improve the reliability and the analytical possibilities of mechanical properties mapping methods in an atomic force microscopy. (paper)

  20. Effects of TiO2 sandblasted and acid-etched titanium on expression of bone morphogenetic protein 2 in human osteoblasts%TiO2喷砂酸蚀处理对钛片表面人成骨细胞BMP-2表达水平的影响

    Institute of Scientific and Technical Information of China (English)

    陆斌; 李建武; 郭义; 杨艳

    2013-01-01

    目的 探讨钛片经过TiO2喷砂酸蚀处理后对人成骨细胞系MG63细胞骨形态发生蛋白2(bone morphogenetic protein,BMP-2)表达水平的影响.方法 将钛片分为3组进行处理:机械打磨组、喷砂组及喷砂酸蚀组,分别进行机械打磨、TiO2喷砂和喷砂酸蚀处理.将人成骨细胞系MG63细胞接种于钛片表面,采用实时定量聚合酶链反应(real-time polymerase chain reaction,RT-PCR)、Western blot检测BMP-2 mRNA及蛋白表达水平.结果 喷砂组及喷砂酸蚀组BMP-2 mRNA及蛋白水平增高,与机械打磨组相比差异有统计学意义(P<0.05),而喷砂组与喷砂酸蚀组之间差异无统计学意义(P>0.05).结论 使用经过TiO2喷砂及喷砂酸蚀处理的钛片进行人成骨细胞培养可促进BMP-2表达.%Objective To explore the effect of TiO 2 sandblasted and acid -etched titanium on the expression of bone morphogenetic pro -tein 2 (BMP-2) in human MG63 cells.Methods Titanium discs (15 mm diameter and 1 mm thickness ) were divided into 3 groups: machine polished group , sandblasted group , sandblasted and acid -etched group.Titanium discs were treated with mechanical polishing , TiO2 sandblasting, sandblasting and acid-etching in three groups , respectively.MG63 cells were cultured on the titanium.The mRNA and protein expression of BMP-2 in MG63 cells were analyzed by real-time polymerase chain reaction (RT-PCR) and Western blot.Results The mRNA and protein levels of BMP -2 were significantly higher in sandblasted group and sandblasted and acid -etched group than in machine polished group ( P 0.05 ).Conclusion After sandblasting and acid -etching, titanium could promote the expression of BMP-2 in human osteoblast.

  1. Expression of human bone morphogenetic protein (BMP-2 and BMP-4 genes in transgenic bovine fibroblasts Expressão dos genes bone morphogenetic protein (BMP-2 e BMP-4 em fibroblastos bovinos transgênicos

    Directory of Open Access Journals (Sweden)

    C. Oleskovicz

    2004-08-01

    Full Text Available cDNAs dos genes bone morphogenetic protein-2 (BMP-2 e bone morphogenetic protein-4 (BMP-4 foram sintetizados a partir de RNA total extraído de tecidos ósseos de pacientes que apresentavam trauma facial (fraturas do maxilar entre o 7º e o 10º dia pós-trauma e clonados num vetor para expressão em células mamíferas, sob controle do promotor de citomegalovírus (CMV. Os vetores contendo os genes BMP-2 e o BMP-4 foram utilizados para a transfecção de fibroblastos bovinos. mRNAs foram indiretamente detectados por RT-PCR nas células transfectadas. As proteínas BMP-2 e BMP-4 foram detectadas mediante análises de Western blot. Os resultados demonstram a possibilidade de produção desses fatores de crescimento celular em fibroblastos bovinos. Essas células poderão ser utilizadas como fontes doadoras de material genético para a técnica de transferência nuclear na geração de animais transgênicos.

  2. Changes with Age and the Effect of Recombinant Human BMP-2 on Proteoglycan and Collagen Gene Expression in Rabbit Anulus Fibrosus Cells

    Institute of Scientific and Technical Information of China (English)

    Qin-Ming FEI; Xiao-Xing JIANG; Tong-Yi CHEN; Jun LI; Hideki MURAKAMI; Kai-Jow TSAI; William C. HUTTON

    2006-01-01

    In order to compare the difference between young and old intervertebral disc cells and their responsiveness to recombinant human bone morphogenetic protein-2 (rhBMP-2), disc cells were isolated from the anulus fibrosus (AF) and transition zones of lumbar discs from eight old and eight young New Zealand white rabbits. Compared with the cells from the young rabbits, cells from old rabbits respond less to rhBMP-2 treatment with respect to sulfated-glycosaminoglycan (sGAG) synthesis and aggrecan gene expression. But in collagen Ⅰ and collagen Ⅱ gene expressions, there are no significant differences between the old and the young. When comparing sGAG content, aggrecan, and collagen Ⅱ gene expression of the old AF cells after rhBMP-2 treatment with that of the young AF cells without rhBMP-2 treatment, the old AF cells with rhBMP-2 treatment have a greater capacity to synthesize sGAG bound in the cells and to release sGAG in the media, as well as to express aggrecan and collagen Ⅱ gene. It can be concluded that old AF cells after rhBMP-2 treatment have a greater capacity to synthesize sGAG and express aggrecan and collagen Ⅱ as compared to young AF cells without rhBMP-2 treatment. Thus rhBMP-2 can reverse the decline in the anabolic capacity of the disc cells with ageing. So it seems that rhBMP-2 has potential for use as an agent to retard a key component of disc degeneration and loss of disc matrix.

  3. Modality-independent neural mechanisms for novel phonetic processing.

    Science.gov (United States)

    Williams, Joshua T; Darcy, Isabelle; Newman, Sharlene D

    2015-09-16

    The present study investigates whether the inferior frontal gyrus is activated for phonetic segmentation of both speech and sign. Early adult second language learners of Spanish and American Sign Language at the very beginning of instruction were tested on their ability to classify lexical items in each language based on their phonetic categories (i.e., initial segments or location parameter, respectively). Conjunction analyses indicated that left-lateralized inferior frontal gyrus (IFG), superior parietal lobule (SPL), and precuneus were activated for both languages. Common activation in the left IFG suggests a modality-independent mechanism for phonetic segmentation. Additionally, common activation in parietal regions suggests spatial preprocessing of audiovisual and manuovisual information for subsequent frontal recoding and mapping. Taken together, we propose that this frontoparietal network is involved in domain-general segmentation of either acoustic or visual signal that is important to novel phonetic segmentation. PMID:25988835

  4. E. coli-Produced BMP-2 as a Chemopreventive Strategy for Colon Cancer: A Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Saravanan Yuvaraj

    2012-01-01

    Full Text Available Colon cancer is a serious health problem, and novel preventive and therapeutical avenues are urgently called for. Delivery of proteins with anticancer activity through genetically modified bacteria provides an interesting, potentially specific, economic and effective approach here. Interestingly, bone morphogenetic protein 2 (BMP-2 is an important and powerful tumour suppressor in the colon and is thus an attractive candidate protein for delivery through genetically modified bacteria. It has not been shown, however, that BMP production in the bacterial context is effective on colon cancer cells. Here we demonstrate that transforming E. coli with a cDNA encoding an ileal-derived mature human BMP-2 induces effective apoptosis in an in vitro model system for colorectal cancer, whereas the maternal organism was not effective in this respect. Furthermore, these effects were sensitive to cotreatment with the BMP inhibitor Noggin. We propose that prevention and treatment of colorectal cancer using transgenic bacteria is feasible.

  5. Effect of implantation of biodegradable magnesium alloy on BMP-2 expression in bone of ovariectomized osteoporosis rats

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yue, E-mail: 373073766@qq.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Ren, Ling, E-mail: lren@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Liu, Chang, E-mail: meixifan1971@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Yuan, Yajiang, E-mail: yuan925@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Lin, Xiao, E-mail: linx@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Tan, Lili, E-mail: lltan@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Chen, Shurui, E-mail: 272146792@qq.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Mei, Xifan, E-mail: meixifan1971@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China)

    2013-10-01

    The study was focused on the implantation of a biodegradable AZ31 magnesium alloy into the femoral periosteal of the osteoporosis modeled rats. The experimental results showed that after 4 weeks implantation of AZ31 alloy in the osteoporosis modeled rats, the expression of BMP-2 in bone tissues of the rats was much enhanced, even higher than the control group, which should promote the bone formation and be beneficial for reducing the harmful effect of osteoporosis. Results of HE stains showed that the implantation of AZ31 alloy did not have obvious pathological changes on both the liver and kidney of the animal. - Highlights: • Mg alloy greatly increased expression of BMP-2 in osteoporosis modeled rat bone. • Mg alloy showed good biological safety. • Mg alloy is beneficial for reducing the symptom of osteoporosis.

  6. Effect of implantation of biodegradable magnesium alloy on BMP-2 expression in bone of ovariectomized osteoporosis rats

    International Nuclear Information System (INIS)

    The study was focused on the implantation of a biodegradable AZ31 magnesium alloy into the femoral periosteal of the osteoporosis modeled rats. The experimental results showed that after 4 weeks implantation of AZ31 alloy in the osteoporosis modeled rats, the expression of BMP-2 in bone tissues of the rats was much enhanced, even higher than the control group, which should promote the bone formation and be beneficial for reducing the harmful effect of osteoporosis. Results of HE stains showed that the implantation of AZ31 alloy did not have obvious pathological changes on both the liver and kidney of the animal. - Highlights: • Mg alloy greatly increased expression of BMP-2 in osteoporosis modeled rat bone. • Mg alloy showed good biological safety. • Mg alloy is beneficial for reducing the symptom of osteoporosis

  7. Mandibular bone repair by implantation of rhBMP-2 in a slow release carrier of polylactic acid--an experimental study in rats.

    OpenAIRE

    Schliephake, Henning; Weich, Herbert A.; Dullin, Christian; Gruber, Rudolf; Frahse, Sarah

    2008-01-01

    The aim of the present study was to test the hypothesis that human recombinant bone morphogenic protein 2 (rhBMP-2) implanted in a slow release carrier of polylactic acid (PLA) can repair a non-healing defect in the rat mandible and maintain the thickness of an augmented volume. p-DL-lactic acid discs were produced and loaded with 48 and 96 microg rhBMP-2 and inserted into non-healing defects of the mandible of 45 Wistar rats. Fifteen rats received implants with 96 microg rhBMP-2 (Group 2), 4...

  8. Retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bone marrow mesenchymal stemcells(MSCs)are pluripotential stemcells that have the capacitytodifferentiate into chondrocytes and osteoblasts[1].Ithas been well documented that bone morphogeneticproteins(BMPs),a group of proteins belonging tothe TGF-βsuperfamily,can induce bone for mationbothin vivoandin vitroas well as promote osteo-blastic differentiation of MSC[2].HeterologousBMP2is successfully transferred to MSCs and genetherapy is employed based on repairing bony andcartilage defects,spinal fusion[3-5]....

  9. Repair of rabbit radial bone defects using true bone ceramics combined with BMP-2-related peptide and type I collagen

    International Nuclear Information System (INIS)

    An ideal bone graft material is the one characterized with good biocompatibility, biodegradation, osteoconductivity and osteoinductivity. In this study, a novel synthetic BMP-2-related peptide (designated P24) corresponding to residues of the knuckle epitope of BMP-2 was introduced into a biomimetic scaffold based on sintered bovine bone or true bone ceramics (TBC) and type I collagen (TBC/collagen I) using a simulated body fluid (SBF). Hydroxylapatite crystal mineralization with a Ca/P molar ratio of 1.63 was observed on the surface of P24/TBC/collagen I composite by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) techniques. Cell adhesion rate evaluation of bone marrow stromal cells (BMSCs) seeded on materials in vitro showed that the percentage of cells attached to P24/TBC/collagen I composite was significantly higher than that of the TBC/collagen I composite. A 10 mm unilateral segmental bone defect was created in the radius of New Zealand white rabbits and randomly implanted with three groups of biomaterials (Group A: P24/TBC/collagen I composite; Group B: TBC/collagen I composite and Group C: TBC alone). Based on radiographic evaluation and histological examination, the implants of P24/TBC/collagen I composite significantly stimulated bone growth, thereby confirming the enhanced rate of bone healing compared with that of TBC/collagen I composite and TBC alone. It was concluded that BMP-2-related peptide P24 could induce nucleation of calcium phosphate crystals on the surface of TBC/collagen I composite. The TBC/collagen I composite loaded with the synthetic BMP-2-related peptide is a promising scaffold biomaterial for bone tissue engineering.

  10. The expressions of IGF-1, BMP-2 and TGF-β1 in cartilage of condylar hyperplasia.

    Science.gov (United States)

    Meng, Q; Long, X; Deng, M; Cai, H; Li, J

    2011-01-01

    Condylar hyperplasia is a complex post-natal growth abnormality of the mandible and condyle, which leads to facial asymmetry. We investigated the distributions of insulin-like growth factors (IGF-1), bone morphogenetic protein-2 (BMP-2) and transforming growth factor-β1 (TGF-β1) in cartilage of condylar hyperplasia and revealed relationships between age and the cartilaginous thickness. Twenty patients with condylar hyperplasia were divided into four histopathological types. The cartilaginous thickness and age in different histological types were analysed, and the localizations of IGF-1, BMP-2 and TGF-β1 were detected by immunohistochemistry analysis. The cartilaginous thickness of condylar hyperplasia significantly increased. The cartilaginous thickness of type III was significantly thicker than type I and type II, Bivariate correlation revealed a significant correlations between age and the cartilaginous thickness (r = 0·68, P = 0·01). However, the expressions of IGF-1, BMP-2 and TGF-β1 were the strongest in type I. In almost all types of condylar hyperplasia, the presence of IGF-1 and BMP-2 was found mainly in the proliferative chondrocyte layer and the hypertrophic chondrocyte layer, and only a few in the calcified chondrocyte layer. The presence of TGF-β1 widely distributed from the fibrous articular surface to the calcified cartilage. These findings suggest that the proliferative activity of cartilage in condylar hyperplasia is strongly associated with age and cartilaginous thickness. Therefore, the four pathological types of condylar hyperplasia seem more likely to be four discontinuous stages. PMID:20626571

  11. 活血化瘀补肾壮骨中药促进BMP基因克隆转染犬牙髓细胞增殖的实验研究%THE EXPERIMENTAL STUDY ON THE PROMOTIVE EFFECT OF CHINESE TRADITION MEDICINE ON PROLIFERATION OF DOG DENTAL PULP CELLS TRANSFECTED BY BMP2 GENE

    Institute of Scientific and Technical Information of China (English)

    刁志虹; 高毅; 李威

    2012-01-01

    Objective To observe the effect of Chinese tradition medicine serum on the proliferation of dog dental pulp cells( DDPCs )transfected with pEGFP - Nl - BMP2 eukaryotic expression plasmid in vitro. To investigate the mechanism of Chinese tradition medicine on formation of dentin. Methods BMP2 - DDPCs were cultivated respectively in Chinese tradition medicine serum group( group A),non - medicine serum group( group B ) and fetal bovine serum group( group C ). The proliferation activity of BMP2 - DDPCs was detected respectively by the 3 -(4,5 - dimethythiazol -2-yl)-2,5-diphenyl tetrazolium bromide( MTT )after 24 hours ,48 hours and 72hours. Results After BMP2 - DDPCs were cultivated in three kinds of serum, there were no differences in the cells morphology, but there were differences in the number of the cells. With the prolongation of culture time, the number of the cells gradually increased in the 3 groups, among which medicine serum group increased more prominently. There were significant differences between Chinese traditional medicine serum group and the other two groups( P <0. 05 ). Conclusion The Chinese tradition medicine could promote proliferation of BMP2 - DDPCs and obviously increase the quantity of seed cells in dentin tissue engineering.%目的 观察活血化瘀补肾壮骨含药血清对骨形成蛋白2(bone morphogenetic proteins 2,BMP2)绿色荧光融合蛋白(green-fluorescent protein,GFP)真核表达质粒(pEGFP-N1-BMP2)在体外转染的犬牙髓细胞(dog dental pulp cells,DDPCs)增殖情况的影响,探讨活血化瘀补肾壮骨中药在牙本质改建形成中的作用机制.方法 将 BMP2-DDPCs分别于活血化瘀补肾壮骨含药血清组(A组)、无药血清组(B组)和胎牛血清组(C组)中培养.分别于24、48、72h用溴化-3-(4,5-二甲基噻唑基-2)-2,5二苯基四氮唑[3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide,MTT]法检测BMP2-DDPCs增殖活性.结果 BMP2-DDPCs分别在A、B、C 3组中

  12. The effects of 3D bioactive glass scaffolds and BMP-2 on bone formation in rat femoral critical size defects and adjacent bones

    International Nuclear Information System (INIS)

    Reconstruction of critical size defects in the load-bearing area has long been a challenge in orthopaedics. In the past, we have demonstrated the feasibility of using a biodegradable load-sharing scaffold fabricated from poly(propylene fumarate)/tricalcium phosphate (PPF/TCP) loaded with bone morphogenetic protein-2 (BMP-2) to successfully induce healing in those defects. However, there is limited osteoconduction observed with the PPF/TCP scaffold itself. For this reason, 13-93 bioactive glass scaffolds with local BMP-2 delivery were investigated in this study for inducing segmental defect repairs in a load-bearing region. Furthermore, a recent review on BMP-2 revealed greater risks in radiculitis, ectopic bone formation, osteolysis and poor global outcome in association with the use of BMP-2 for spinal fusion. We also evaluated the potential side effects of locally delivered BMP-2 on the structures of adjacent bones. Therefore, cylindrical 13-93 glass scaffolds were fabricated by indirect selective laser sintering with side holes on the cylinder filled with dicalcium phosphate dehydrate as a BMP-2 carrier. The scaffolds were implanted into critical size defects created in rat femurs with and without 10 μg of BMP-2. The x-ray and micro-CT results showed that a bridging callus was found as soon as three weeks and progressed gradually in the BMP group while minimal bone formation was observed in the control group. Degradation of the scaffolds was noted in both groups. Stiffness, peak load and energy to break of the BMP group were all higher than the control group. There was no statistical difference in bone mineral density, bone area and bone mineral content in the tibiae and contralateral femurs of the control and BMP groups. In conclusion, a 13-93 bioactive glass scaffold with local BMP-2 delivery has been demonstrated for its potential application in treating large bone defects. (paper)

  13. Experimental and computational investigation of the effect of hydrophobicity on aggregation and osteoinductive potential of BMP-2-derived peptide in a hydrogel matrix.

    Science.gov (United States)

    Moeinzadeh, Seyedsina; Barati, Danial; Sarvestani, Samaneh K; Karimi, Tahereh; Jabbari, Esmaiel

    2015-01-01

    An attractive approach to reduce the undesired side effects of bone morphogenetic proteins (BMPs) in regenerative medicine is to use osteoinductive peptide sequences derived from BMPs. Although the structure and function of BMPs have been studied extensively, there is limited data on structure and activity of BMP-derived peptides immobilized in hydrogels. The objective of this work was to investigate the effect of concentration and hydrophobicity of the BMP-2 peptide, corresponding to residues 73-92 of the knuckle epitope of BMP-2 protein, on peptide aggregation and osteogenic differentiation of human mesenchymal stem cells encapsulated in a polyethylene glycol (PEG) hydrogel. The peptide hydrophobicity was varied by capping PEG chain ends with short lactide segments. The BMP-2 peptide with a positive index of hydrophobicity had a critical micelle concentration (CMC) and formed aggregates in aqueous solution. Based on simulation results, there was a slight increase in the concentration of free peptide in solution with 1000-fold increase in peptide concentration. The dose-osteogenic response curve of the BMP-2 peptide was in the 0.0005-0.005 mM range, and osteoinductive potential of the BMP-2 peptide was significantly less than that of BMP-2 protein even at 1000-fold higher concentrations, which was attributed to peptide aggregation. Further, the peptide or PEG-peptide aggregates had significantly higher interaction energy with the cell membrane compared with the free peptide, which led to a higher nonspecific interaction with the cell membrane and loss of osteoinductive potential. Conjugation of the BMP-2 peptide to PEG increased CMC and osteoinductive potential of the peptide whereas conjugation to lactide-capped PEG reduced CMC and osteoinductive potential of the peptide. Experimental and simulation results revealed that osteoinductive potential of the BMP-2 peptide is correlated with its CMC and the free peptide concentration in aqueous medium and not the

  14. Experimental and computational investigation of the effect of hydrophobicity on aggregation and osteoinductive potential of BMP-2-derived peptide in a hydrogel matrix.

    Science.gov (United States)

    Moeinzadeh, Seyedsina; Barati, Danial; Sarvestani, Samaneh K; Karimi, Tahereh; Jabbari, Esmaiel

    2015-01-01

    An attractive approach to reduce the undesired side effects of bone morphogenetic proteins (BMPs) in regenerative medicine is to use osteoinductive peptide sequences derived from BMPs. Although the structure and function of BMPs have been studied extensively, there is limited data on structure and activity of BMP-derived peptides immobilized in hydrogels. The objective of this work was to investigate the effect of concentration and hydrophobicity of the BMP-2 peptide, corresponding to residues 73-92 of the knuckle epitope of BMP-2 protein, on peptide aggregation and osteogenic differentiation of human mesenchymal stem cells encapsulated in a polyethylene glycol (PEG) hydrogel. The peptide hydrophobicity was varied by capping PEG chain ends with short lactide segments. The BMP-2 peptide with a positive index of hydrophobicity had a critical micelle concentration (CMC) and formed aggregates in aqueous solution. Based on simulation results, there was a slight increase in the concentration of free peptide in solution with 1000-fold increase in peptide concentration. The dose-osteogenic response curve of the BMP-2 peptide was in the 0.0005-0.005 mM range, and osteoinductive potential of the BMP-2 peptide was significantly less than that of BMP-2 protein even at 1000-fold higher concentrations, which was attributed to peptide aggregation. Further, the peptide or PEG-peptide aggregates had significantly higher interaction energy with the cell membrane compared with the free peptide, which led to a higher nonspecific interaction with the cell membrane and loss of osteoinductive potential. Conjugation of the BMP-2 peptide to PEG increased CMC and osteoinductive potential of the peptide whereas conjugation to lactide-capped PEG reduced CMC and osteoinductive potential of the peptide. Experimental and simulation results revealed that osteoinductive potential of the BMP-2 peptide is correlated with its CMC and the free peptide concentration in aqueous medium and not the

  15. Improved Bone Formation in Osteoporotic Rabbits with the Bone Morphogenetic Protein-2 (rhBMP-2) Coated Titanium Screws Which Were Coated By Using Plasma Polymerization Technique

    OpenAIRE

    Salih Gulsen; Dilek Cokeliler; Hilal Goktas; Aysu Kucukturhan; Bilgehan Ozcil; Hakan Caner

    2014-01-01

    Delaying of bone fusion in osteoporotic patients underwent spinal stabilization surgery leads to screw loosening, and this causes pseudoarticulation, mobility and fibrosis at vertebral segments. To prevent these complications, the screws coated with recombinant bone morphogenetic protein-2 (rhBMP-2) could be used. To verify this hypothesis, we coated 5 Titanium screws with rhBMP-2 using plasma polymerization method, and also used 10 uncoated screws for making comparison between coated and unc...

  16. Medium-Term Function of a 3D Printed TCP/HA Structure as a New Osteoconductive Scaffold for Vertical Bone Augmentation: A Simulation by BMP-2 Activation

    Directory of Open Access Journals (Sweden)

    Mira Moussa

    2015-04-01

    Full Text Available Introduction: A 3D-printed construct made of orthogonally layered strands of tricalcium phosphate (TCP and hydroxyapatite has recently become available. The material provides excellent osteoconductivity. We simulated a medium-term experiment in a sheep calvarial model by priming the blocks with BMP-2. Vertical bone growth/maturation and material resorption were evaluated. Materials and methods: Titanium hemispherical caps were filled with either bare- or BMP-2 primed constructs and placed onto the calvaria of adult sheep (n = 8. Histomorphometry was performed after 8 and 16 weeks. Results: After 8 weeks, relative to bare constructs, BMP-2 stimulation led to a two-fold increase in bone volume (Bare: 22% ± 2.1%; BMP-2 primed: 50% ± 3% and a 3-fold decrease in substitute volume (Bare: 47% ± 5%; BMP-2 primed: 18% ± 2%. These rates were still observed at 16 weeks. The new bone grew and matured to a haversian-like structure while the substitute material resorbed via cell- and chemical-mediation. Conclusion: By priming the 3D construct with BMP-2, bone metabolism was physiologically accelerated, that is, enhancing vertical bone growth and maturation as well as material bioresorption. The scaffolding function of the block was maintained, leaving time for the bone to grow and mature to a haversian-like structure. In parallel, the material resorbed via cell-mediated and chemical processes. These promising results must be confirmed in clinical tests.

  17. Co-delivery of platelet-derived growth factor (PDGF-BB) and bone morphogenic protein (BMP-2) coated onto heparinized titanium for improving osteoblast function and osteointegration.

    Science.gov (United States)

    Kim, Sung Eun; Yun, Young-Pil; Lee, Jae Yong; Shim, June-Sung; Park, Kyeongsoon; Huh, Jung-Bo

    2015-12-01

    The aim of this study was to improve osteoblast function by delivering two growth factors, PDGF-BB and BMP-2, incorporated onto heparinized titanium (Hep-Ti) substrate. To achieve co-delivery of PDGF-BB and BMP-2, the surface of anodized Ti was immobilized with heparin, and then the two growth factors were coated onto the Hep-Ti surface. Incorporation of the two growth factors onto Hep-Ti was evaluated by SEM and XPS. Incorporated PDGF-BB and BMP-2 were released from the Hep-Ti substrate in a sustained manner. In vitro studies revealed that osteoblasts grown on PDGF-BB- and BMP-2-immobilized Hep-Ti increased ALP activity, calcium deposition, osteocalcin and osteopontin levels as compared to those grown on PDGF-BB alone- or BMP-2 alone-immobilized Hep-Ti. These results suggested that co-delivery of PDGF-BB and BMP-2 using Hep-Ti substrate will be a promising material for the enhancement of osteoblast function and osteointegration.

  18. Experimental study of human BMP-2 on osteogenic induction in BMSCs of dogs in vitro%人BMP-2体外定向诱导犬BMSCs向成骨方向分化的实验研究

    Institute of Scientific and Technical Information of China (English)

    许蕾; 韩建国; 李家锋

    2015-01-01

    Objective:To provide seed cells for bone tissue engineering in the late establishment by establishing the cul-ture system of bone marrow mesenchymal stem cells( BMSCs)of dogs in vitro,and using human BMP-2 to make them in-duced to differentiate into osteoblasts. Methods:The extraction of BMSCs of adult beagle dogs was made,then the whole marrow adherence method and density gradient centrifugation were used to isolate and culture BMSCs in vitro,and observe the cell growth morphology everyday. The third generation BMSCs with good growth form was divided into two groups. The experimental group were cultured with adding 200ng/ml human BMP-2 containing fetal bovine serum(FBS)while the control group were cultured only with complete medium containing FBS. Then we used the detection of alkaline phosphatase staining after 3 weeks′induction,alizarin red staining and Von-Kossa staining after 4 weeks′induction to identify the differentiation of osteoblasts. Results:After 3 weeks of induction of experimental group with alkaline phosphatase,staining showed the cyto-plasm of positive expression of black particles,and it was negative in the control group;After 4 weeks of induction of experi-mental group with alizarin red staining and Von-Kossa staining showed positive expression of calcium nodules,and it was negative in the control group. All the staining results in the experimental group showed the characteristics of osteoblasts. Conclusion:BMSCs of dogs,which are extracted and cultivated in vitro,can directionally differentiate into osteoblasts under the action of human BMP-2.%目的:通过将犬骨髓间充质干细胞( bone marrow mesenchymal stem cells,BMSCs)建立体外培养体系,运用人骨形态发生蛋白-2(bone morphogenetic protein-2,BMP-2)体外定向诱导分化为成骨细胞,为后期建立骨组织工程提供种子细胞。方法提取比格犬BMSCs,全骨髓贴壁法结合密度梯度离心法行体外分离培养,每日观察细

  19. Trehalose maintains bioactivity and promotes sustained release of BMP-2 from lyophilized CDHA scaffolds for enhanced osteogenesis in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Jun Zhao

    Full Text Available Calcium phosphate (Ca-P scaffolds have been widely employed as a supportive matrix and delivery system for bone tissue engineering. Previous studies using osteoinductive growth factors loaded Ca-P scaffolds via passive adsorption often experience issues associated with easy inactivation and uncontrolled release. In present study, a new delivery system was fabricated using bone morphogenetic protein-2 (BMP-2 loaded calcium-deficient hydroxyapatite (CDHA scaffold by lyophilization with addition of trehalose. The in vitro osteogenesis effects of this formulation were compared with lyophilized BMP-2/CDHA construct without trehalose and absorbed BMP-2/CDHA constructs with or without trehalose. The release characteristics and alkaline phosphatase (ALP activity analyses showed that addition of trehalose could sufficiently protect BMP-2 bioactivity during lyophilization and achieve sustained BMP-2 release from lyophilized CDHA construct in vitro and in vivo. However, absorbed BMP-2/CDHA constructs with or without trehalose showed similar BMP-2 bioactivity and presented a burst release. Quantitative real-time PCR (RT-qPCR and enzyme-linked immunosorbent assay (ELISA demonstrated that lyophilized BMP-2/CDHA construct with trehalose (lyo-tre-BMP-2 promoted osteogenic differentiation of bone marrow stromal cells (bMSCs significantly and this formulation could preserve over 70% protein bioactivity after 5 weeks storage at 25°C. Micro-computed tomography, histological and fluorescent labeling analyses further demonstrated that lyo-tre-BMP-2 formulation combined with bMSCs led to the most percentage of new bone volume (38.79% ± 5.32% and area (40.71% ± 7.14% as well as the most percentage of fluorochrome stained bone area (alizarin red S: 2.64% ± 0.44%, calcein: 6.08% ± 1.37% and mineral apposition rate (4.13 ± 0.62 µm/day in critical-sized rat cranial defects healing. Biomechanical tests also indicated the maximum stiffness (118.17 ± 15.02 Mpa and

  20. Matrix-immobilized BMP-2 on microcontact printed fibronectin as in vitro tool to study BMP-mediated signaling and cell migration

    Directory of Open Access Journals (Sweden)

    Kristin eHauff

    2015-05-01

    Full Text Available During development, bone morphogenetic proteins (BMPs exert important functions in several tissues by regulating signaling for cell differentiation and migration. In vivo the extracellular matrix (ECM not only provides a support for adherent cells, but also presents a reservoir of growth factors (GFs. Several constituents of the ECM provide adhesive cues, which serve as binding sites for cell transmembrane receptors, such as integrins, which convey adhesion-mediated signaling to the intracellular compartment. Integrins do not function alone but rather crosstalk and cooperate with other receptors, such as GF receptors, in regulating cell responses to extracellular signals. To this, we present here the immobilization of BMP-2 onto cellular fibronectin (cFN, a key protein of the ECM, to investigate their impact on GF-mediated signaling and migration.Following biotinylation, BMP-2 was linked to biotinylated cFN using NeutrAvidin (NA as cross-linker. Characterization with QCM-D and ELISA confirmed the efficient immobilization of BMP-2 on cFN over a period of 24 h.To validate the bioactivity of matrix-immobilized BMP-2 (iBMP-2 we investigated short- and long-term responses of C2C12 myoblasts in comparison to soluble BMP-2 (sBMP-2 or in absence of GFs. Similarly to sBMP-2, iBMP-2 triggered Smad 1/5 phosphorylation and translocation into the nucleus corresponding to the activation of BMP-mediated Smad-dependent pathway. Additionally, successful suppression of myotube formation was observed after six days.We next implemented this approach to fabricate cFN micro patterned stripes by soft lithography. These stripes only allowed cell-surface interaction on the pattern due to passivation of the surface in between, thus serving as platform for studies on directed cell migration. During a 10 h-period, cells showed an increased migratory activity upon BMP-2 exposure.Thus, this versatile tool retains the GF's bioactivity and allows the presentation of ECM

  1. Construction and identification of recombinant adenovirus vector co-expressing VEGF121 and BMP2 genes and its expression in HEK293 cells%VEGF121和BMP2双基因共表达重组腺病毒载体的构建及其在HEK293中的表达

    Institute of Scientific and Technical Information of China (English)

    栗刚; 吴秀成; 钟声; 王巍; 李媛; 刘丹平

    2011-01-01

    目的 构建人血管内皮生长因子121(VEGF121)与人骨形态发生蛋白2(BMP2)双基因共表达腺病毒载体Adv-BMP2-IRES-VEGF121,并观察其在人胚肾细胞株(HEK293)中的表达情况.方法 对腺病毒质粒pShuttle-CMV-BMP2的目的基因BMP2进行PCR扩增.腺病毒质粒pShuttle-CMV-VEGF121-IRES-hrGFP-1经Kpn I/Xba I酶切后,将BMP2片段定向导入pShuttle-CMV-VEGF121-IRES,构建pShuttle-CMV-V EGF121-IRES-BMP2,并注入大肠杆菌DH5a中扩增,提取质粒.通过酶切分析、PCR检测和序列分析进行鉴定.将构建所得的质粒转染HEK293,采用RT-PCR法检测HEK293中的BMP2、VEGF121 mRNA,Western blot法检测其蛋白.结果 成功构建了Adv-BMP2-IRES-VEGF121.酶切分析及DNA序列测定证实重组质粒构建正确.质粒转染后的HEK293 BMP2和VEGF121表达阳性.结论 成功构建了Adv-BMP2-IRES-VEGF121,其转染HEK293后,VEGF121、BMP2在HEK293中共表达阳性.%Objective To construct and identify the adenovirus shuttle plasmid pShuttle-CMV-VEGF121-IRES-BMP2 and its express in HEK293 cells.Methods The DNA fragments of human BMP2 gene were changed restriction sites and subcloned by PCR.The human BMP2 genes and pShuttle-CMV-VEGF121-IRES were ligated into the plasmid by directional cloning method.The inserted target genes in the plasmid were verified by restriction enzyme digestion and nucleotide sequencing.The correct recombinant express plasmid was transfected to HEK293 cells.The expression of VEGF121, BMP2 mRNA were detected by RT-PCR, the VEGF121, BMP2 protein were detected by Western blotting.Results The adenovirus shuttle plasmid was constructed correctly.The VEGF121, BMP2 mRNA and protein were expressed in HEK293 cells.Conclusion The adenovirus shuttle plasmid is constructed, VEGF121, BMP2 mRNA and protein are successfully expressed in HEK293 cells.

  2. BMP2, 4 and 6 and BMPR1B are altered from early stages of bovine cystic ovarian disease development.

    Science.gov (United States)

    Díaz, Pablo U; Hein, Gustavo J; Belotti, Eduardo M; Rodríguez, Fernanda M; Rey, Florencia; Amweg, Ayelén N; Matiller, Valentina; Baravalle, María E; Ortega, Hugo H; Salvetti, Natalia R

    2016-10-01

    Cystic ovarian disease (COD) is an important cause of subfertility in dairy cattle. Bone morphogenetic proteins (BMPs), mainly BMP2, BMP4 and BMP6, play a key role in female fertility. In this study, we hypothesized that an altered BMP system is associated with ovarian alterations contributing to COD pathogenesis. Therefore, we examined the expression of BMP2, BMP4 and BMP6 and BMP receptor 1B (BMPR1B) in the ovaries of animals with spontaneous or ACTH-induced COD, as well as during the development of the disease, in a model of follicular persistence induced by low doses of progesterone (at 5, 10 and 15 days of follicular persistence). Results showed changes in BMP2, BMP4 and BMP6 expression during folliculogenesis, in granulosa and theca cells in the COD groups, as well as at different stages of follicular persistence. Results also showed changes in BMPR1B expression in developing follicles in animals with COD, and at the initial stages of follicular persistence (P5). Comparison between groups showed significant differences, mainly in BMP4 and BMP6 expression, in granulosa and theca cells of different follicular categories. The expression of these BMPs also increased in cystic and persistent follicles, in relation to antral follicles of the control group. BMPR1B showed high expression in cystic follicles. Together, these results may indicate an alteration in BMPs, especially in BMP4 and BMP6, as well as in BMPR1B, which occurs early in folliculogenesis and incipiently during the development of COD, which could be a major cause of recurrence of this disease in cattle.Free Spanish abstract: A Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/early/2016/08/01/REP-15-0315/suppl/DC1. PMID:27486268

  3. Enhancement of Tendon–Bone Healing for Anterior Cruciate Ligament (ACL Reconstruction Using Bone Marrow-Derived Mesenchymal Stem Cells Infected with BMP-2

    Directory of Open Access Journals (Sweden)

    Shiyi Chen

    2012-10-01

    Full Text Available At present, due to the growing attention focused on the issue of tendon–bone healing, we carried out an animal study of the use of genetic intervention combined with cell transplantation for the promotion of this process. Here, the efficacy of bone marrow stromal cells infected with bone morphogenetic protein-2 (BMP-2 on tendon–bone healing was determined. A eukaryotic expression vector containing the BMP-2 gene was constructed and bone marrow-derived mesenchymal stem cells (bMSCs were infected with a lentivirus. Next, we examined the viability of the infected cells and the mRNA and protein levels of BMP-2-infected bMSCs. Gastrocnemius tendons, gastrocnemius tendons wrapped by bMSCs infected with the control virus (bMSCs+Lv-Control, and gastrocnemius tendons wrapped by bMSCs infected with the recombinant BMP-2 virus (bMSCs+Lv-BMP-2 were used to reconstruct the anterior cruciate ligament (ACL in New Zealand white rabbits. Specimens from each group were harvested four and eight weeks postoperatively and evaluated using biomechanical and histological methods. The bMSCs were infected with the lentivirus at an efficiency close to 100%. The BMP-2 mRNA and protein levels in bMSCs were significantly increased after lentiviral infection. The bMSCs and BMP-2-infected bMSCs on the gastrocnemius tendon improved the biomechanical properties of the graft in the bone tunnel; specifically, bMSCs infected with BMP-2 had a positive effect on tendon–bone healing. In the four-week and eight-week groups, bMSCs+Lv-BMP-2 group exhibited significantly higher maximum loads of 29.3 ± 7.4 N and 45.5 ± 11.9 N, respectively, compared with the control group (19.9 ± 6.4 N and 21.9 ± 4.9 N (P = 0.041 and P = 0.001, respectively. In the eight-week groups, the stiffness of the bMSCs+Lv-BMP-2 group (32.5 ± 7.3 was significantly higher than that of the bMSCs+Lv-Control group (22.8 ± 7.4 or control groups (12.4 ± 6.0 (p = 0.036 and 0.001, respectively. Based on the

  4. BMP-2,3,4,5在颌面部神经鞘瘤中的表达分析%Analysis of the Expression of BMP-2,3,4,5 in Nerve Sheath Tumors of Maxillofacial Region

    Institute of Scientific and Technical Information of China (English)

    金岩; 吕红兵; Tipoe GL; 李媛

    2000-01-01

    目的:探讨BMPs家族成员与外周神经肿瘤的关系。方法:用原位杂交方法对BMP-2,3,4,5在人良、恶性神经鞘瘤中的表达进行观察。结果:显示BMP-2,3,4,5 mRNA在外周神经的良恶性神经鞘瘤中均有分布。良性肿瘤中,呈栅栏状排列,肿瘤细胞聚集的区域BMPs表达升高;恶性肿瘤中BMPs的表达高于良性肿瘤。结论:确定了BMPs在外周神经肿瘤中的表达和分布,揭示部分BMPs可能参与了外周神经肿瘤的发生发展过程。

  5. BMP2 and VEGF promote angiogenesis but retard terminal differentiation of osteoblasts in bone regeneration by up-regulating Id1

    Institute of Scientific and Technical Information of China (English)

    Xiaobin Song; Shaohua Liu; Xun Qu; Yingwei Hu; Xiaoying Zhang; TaoWang; FengcaiWei

    2011-01-01

    Inadequate vascularization limits the repair of bone defects,In order to improve angiogenesis and accelerate osteogenesis,the synergism of co-cultured cells with genetic modification in bone regeneration was investigated in this study.Endothelial progenitor cells (EPCs) and bone marrow stem cells (BMSCs) were transfected with the genes of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP2) by adenovirus,respectively.The co-cultured cells,designated as four groups including BMSC + EPC,Ad-BMP2-BMSC +EPC,BMSC + Ad-VEGF-EPC,and Ad-BMP2-BMSC + Ad-VEGF-EPC groups,were seeded on an alginate gel and then implanted into rat intramuscularly to evaluate the effects on angiogenesis and osteogenesis.Both VEGF and BMP2 could induce the overexpression of inhibitor of DNA-binding 1(Id1) gene which significantly promoted tube formation in vitro and increase the amount of blood vessels in the Ad-BMP2-BMSC + Ad-VEGF-EPC group after implantation.Nevertheless,overexpression of Id1 retarded the terminal differentiation of osteoblasts and the bone formation.Later,osteogenic gene expression at transcriptional level,calcium nodules,and alkaline phosphatase (ALP) activity showed a gradual decrease and the amount of newly formed osteogenesis area exhibited a small increase in the Ad-BMP2-BMSC + Ad-VEGF-EPC group.This finding suggests that a balanced regulation of Id1 expression in VEGF-EPCs and BMP2-BMSCs may be critical to cell-based and gene-based approaches for bone regeneration.

  6. Simultaneous gene transfer of bone morphogenetic protein (BMP -2 and BMP-7 by in vivo electroporation induces rapid bone formation and BMP-4 expression

    Directory of Open Access Journals (Sweden)

    Miyazaki Jun-ichi

    2006-08-01

    Full Text Available Abstract Background Transcutaneous in vivo electroporation is expected to be an effective gene-transfer method for promoting bone regeneration using the BMP-2 plasmid vector. To promote enhanced osteoinduction using this method, we simultaneously transferred cDNAs for BMP-2 and BMP-7, as inserts in the non-viral vector pCAGGS. Methods First, an in vitro study was carried out to confirm the expression of BMP-2 and BMP-7 following the double-gene transfer. Next, the individual BMP-2 and BMP-7 plasmids or both together were injected into rat calf muscles, and transcutaneous electroporation was applied 8 times at 100 V, 50 msec. Results In the culture system, the simultaneous transfer of the BMP-2 and BMP-7 genes led to a much higher ALP activity in C2C12 cells than did the transfer of either gene alone. In vivo, ten days after the treatment, soft X-ray analysis showed that muscles that received both pCAGGS-BMP-2 and pCAGGS-BMP-7 had better-defined opacities than those receiving a single gene. Histological examination showed advanced ossification in calf muscles that received the double-gene transfer. BMP-4 mRNA was also expressed, and RT-PCR showed that its level increased for 3 days in a time-dependent manner in the double-gene transfer group. Immunohistochemistry confirmed that BMP-4-expressing cells resided in the matrix between muscle fibers. Conclusion The simultaneous transfer of BMP-2 and BMP-7 genes using in vivo electroporation induces more rapid bone formation than the transfer of either gene alone, and the increased expression of endogenous BMP-4 suggests that the rapid ossification is related to the induction of BMP-4.

  7. The effect of SDF-1α on low dose BMP-2 mediated bone regeneration by release from heparinized mineralized collagen type I matrix scaffolds in a murine critical size bone defect model.

    Science.gov (United States)

    Zwingenberger, Stefan; Langanke, Robert; Vater, Corina; Lee, Geoffrey; Niederlohmann, Eik; Sensenschmidt, Markus; Jacobi, Angela; Bernhardt, Ricardo; Muders, Michael; Rammelt, Stefan; Knaack, Sven; Gelinsky, Michael; Günther, Klaus-Peter; Goodman, Stuart B; Stiehler, Maik

    2016-09-01

    The treatment of critical size bone defects represents a challenge. The growth factor bone morphogenetic protein 2 (BMP-2) is clinically established but has potentially adverse effects when used at high doses. The aim of this study was to evaluate if stromal derived factor-1 alpha (SDF-1α) and BMP-2 released from heparinized mineralized collagen type I matrix (MCM) scaffolds have a cumulative effect on bone regeneration. MCM scaffolds were functionalized with heparin, loaded with BMP-2 and/or SDF-1α and implanted into a murine critical size femoral bone defect (control group, low dose BMP-2 group, low dose BMP-2 + SDF-1α group, and high dose BMP-2 group). After 6 weeks, both the low dose BMP-2 + SDF-1α group (5.8 ± 0.6 mm³, p = 0.0479) and the high dose BMP-2 group (6.5 ± 0.7 mm³, p = 0.008) had a significantly increased regenerated bone volume compared to the control group (4.2 ± 0.5 mm³). There was a higher healing score in the low dose BMP-2 + SDF-1α group (median grade 8; Q1-Q3 7-9; p = 0.0357) than in the low dose BMP-2 group (7; Q1-Q3 5-9) histologically. This study showed that release of BMP-2 and SDF-1α from heparinized MCM scaffolds allows for the reduction of the applied BMP-2 concentration since SDF-1α seems to enhance the osteoinductive potential of BMP-2. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2126-2134, 2016. PMID:27060915

  8. Effect of rhBMP- 2 on bone regeneration and osseointegration in peri- implant defects- histological observation%rhBMP-2在种植体周围骨缺损修复中应用的组织学观察

    Institute of Scientific and Technical Information of China (English)

    黄元瑾; 章锦才; 刘曙光; 蔡德鸿

    2012-01-01

    目的:研究rhBMP- 2及不同载体在种植体周围骨缺损修复中的应用.方法:在beagle犬下颌骨植入种植体,颊侧形成裂开性骨缺损,置入复合了不同浓度rhBMP- 2的珊瑚羟基磷灰石人造骨(CHA)或可吸收胶原海绵(ACS).种植体植入后2、4、8、12 周,获取含种植体骨标本,进行组织学观察.结果:2 周时,rhBMP- 2组可见极少量的新生骨组织.4 周时,rhBMP- 2/ACS组新骨组织由牙槽骨顶端向缺损区中心方向生长;rhBMP- 2/CHA组人造骨颗粒内部和周围出现呈岛状生长的新生骨组织.8 周时,rhBMP- 2/ACS组的新骨形成大片状结构;rhBMP- 2/CHA组人造骨颗粒周围较多骨岛形成.12 周时,rhBMP- 2组的缺损区内骨量和骨高度进一步增加,与种植体形成骨性结合.浓度为0.05 mg/ml和0.2 mg/ml,载体为CHA或ACS促进骨再生作用差异无统计学意义.结论:以CHA或ACS为载体rhBMP- 2能促进种植体周围骨缺损区内的骨组织再生并与种植体表面较好地结合.%Objective: To investigate the effects of rhBMP-2 in bone formation and osseointegration in peri-implant defects. Methods: 8 implants were placed in each of 8 beagle dogs. Dehiscence defects were surgically created on the buccal side of each implant. rhBMP-2 at 0. 05 mg/ml or 0. 2 mg/ml was combined into absorbable collagen sponge( ACS ) or coraline hydroxyapatite( CHA ) respectively and applied into the defects. ACS or CHA alone were used as the control. Animals were sacrificed 2,4,8 and 12 weeks after implantation respectively, non- decalcified ground sections of the bone samples with the implants were made and observed under microscope. Results: 2 weeks after implantation, the newly generated bone was minimal. 4 weeks after implantation, in rhBMP-2/ACS group formations of trabeculae of woven bone could be seen in the defects, in rhBMP-2/CHA the CHA particles were surrounded by newly formed bone. 8 weeks after implantation, in rhBMP-2/ACS group the newly formed bone

  9. Abrogation of epithelial BMP2 and BMP4 causes Amelogenesis Imperfecta by reducing MMP20 and KLK4 expression

    Science.gov (United States)

    Xie, Xiaohua; Liu, Chao; Zhang, Hua; Jani, Priyam H.; Lu, Yongbo; Wang, Xiaofang; Zhang, Bin; Qin, Chunlin

    2016-01-01

    Amelogenesis Imperfecta (AI) can be caused by the deficiencies of enamel matrix proteins, molecules responsible for the transportation and secretion of enamel matrix components, and proteases processing enamel matrix proteins. In the present study, we discovered the double deletion of bone morphogenetic protein 2 (Bmp2) and bone morphogenetic protein 4 (Bmp4) in the dental epithelium by K14-cre resulted in hypoplastic enamel and reduced density in X-ray radiography as well as shortened enamel rods under scanning electron microscopy. Such enamel phenotype was consistent with the diagnosis of hypoplastic amelogenesis imperfecta. Histological and molecular analyses revealed that the removal of matrix proteins in the mutant enamel was drastically delayed, which was coincided with the greatly reduced expression of matrix metalloproteinase 20 (MMP20) and kallikrein 4 (KLK4). Although the expression of multiple enamel matrix proteins was down-regulated in the mutant ameloblasts, the cleavage of ameloblastin was drastically impaired. Therefore, we attributed the AI primarily to the reduction of MMP20 and KLK4. Further investigation found that BMP/Smad4 signaling pathway was down-regulated in the K14-cre;Bmp2f/f;Bmp4f/fameloblasts, suggesting that the reduced MMP20 and KLK4 expression may be due to the attenuated epithelial BMP/Smad4 signaling. PMID:27146352

  10. Scaffold-mediated BMP-2 minicircle DNA delivery accelerated bone repair in a mouse critical-size calvarial defect model.

    Science.gov (United States)

    Keeney, Michael; Chung, Michael T; Zielins, Elizabeth R; Paik, Kevin J; McArdle, Adrian; Morrison, Shane D; Ransom, Ryan C; Barbhaiya, Namrata; Atashroo, David; Jacobson, Gunilla; Zare, Richard N; Longaker, Michael T; Wan, Derrick C; Yang, Fan

    2016-08-01

    Scaffold-mediated gene delivery holds great promise for tissue regeneration. However, previous attempts to induce bone regeneration using scaffold-mediated non-viral gene delivery rarely resulted in satisfactory healing. We report a novel platform with sustained release of minicircle DNA (MC) from PLGA scaffolds to accelerate bone repair. MC was encapsulated inside PLGA scaffolds using supercritical CO2 , which showed prolonged release of MC. Skull-derived osteoblasts transfected with BMP-2 MC in vitro result in higher osteocalcin gene expression and mineralized bone formation. When implanted in a critical-size mouse calvarial defect, scaffolds containing luciferase MC lead to robust in situ protein production up to at least 60 days. Scaffold-mediated BMP-2 MC delivery leads to substantially accelerated bone repair as early as two weeks, which continues to progress over 12 weeks. This platform represents an efficient, long-term nonviral gene delivery system, and may be applicable for enhancing repair of a broad range of tissues types. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2099-2107, 2016. PMID:27059085

  11. Interplay between self-assembled structure of bone morphogenetic protein-2 (BMP-2) and osteoblast functions in three-dimensional titanium alloy scaffolds: Stimulation of osteogenic activity.

    Science.gov (United States)

    Nune, K C; Kumar, A; Murr, L E; Misra, R D K

    2016-02-01

    Three-dimensional cellular scaffolds are receiving significant attention in bone tissue engineering to treat segmental bone defects. However, there are indications of lack of significant osteoinductive ability of three-dimensional cellular scaffolds. In this regard, the objective of the study is to elucidate the interplay between bone morphogenetic protein (BMP-2) and osteoblast functions on 3D mesh structures with different porosities and pore size that were fabricated by electron beam melting. Self-assembled dendritic microstructure with interconnected cellular-type morphology of BMP-2 on 3D scaffolds stimulated osteoblast functions including adhesion, proliferation, and mineralization, with prominent effect on 2-mm mesh. Furthermore, immunofluorescence studies demonstrated higher density and viability of osteoblasts on lower porosity mesh structure (2 mm) as compared to 3- and 4-mm mesh structures. Enhanced filopodia cellular extensions with extensive cell spreading was observed on BMP-2 treated mesh structures, a behavior that is attributed to the unique self-assembled structure of BMP-2 that effectively communicates with the cells. The study underscores the potential of BMP-2 in imparting osteoinductive capability to the 3D printed scaffolds.

  12. Sustained release of VH and rhBMP-2 from nanoporous magnesium-zinc-silicon xerogels for osteomyelitis treatment and bone repair.

    Science.gov (United States)

    Li, Fengqian; Wu, Wen; Xiang, Li; Weng, Gan; Hong, Hua; Jiang, Hong; Qian, Jun

    2015-01-01

    Nanoporous magnesium-zinc-silicon (n-MZS) xerogels with a pore size ∼4 nm, a surface area of 718 cm(2)/g, and a pore volume of 1.24 cm(3)/g were synthesized by a sol-gel method. The n-MZS xerogels had high capacity to load vancomycin hydrochloride (VH) and human bone morphogenetic protein-2 (rhBMP-2), after soaking in phosphate buffered saline (PBS) for 24 hours (1.5 and 0.8 mg/g, respectively). Moreover, the n-MZS xerogels exhibited the sustained release of VH and rhBMP-2 as compared with magnesium-zinc-silicon (MZS) xerogels without nanopores (showing a burst release). The VH/rhBMP-2/n-MZS system not only exhibited a good antibacterial property but also promoted the MG63 cell proliferation and differentiation demonstrating good bactericidal activity and cytocompatibility. The results suggested that n-MZS with larger surface area and high pore volume might be a promising carrier for loading and sustained release of VH and rhBMP-2. Hence, the VH/rhBMP-2/n-MZS system might be one of the promising biomaterials for osteomyelitis treatment and bone repair.

  13. Mechanism involved in enhancement of osteoblast differentiation by hyaluronic acid

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Michinao [Division of Maxillofacial Diagnostic and Surgical Science, Department of Oral and Maxillofacial Surgery, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Ariyoshi, Wataru [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Iwanaga, Kenjiro [Division of Maxillofacial Diagnostic and Surgical Science, Department of Oral and Maxillofacial Surgery, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Okinaga, Toshinori [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Habu, Manabu [Division of Maxillofacial Diagnostic and Surgical Science, Department of Oral and Maxillofacial Surgery, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Yoshioka, Izumi [Division of Oral and Maxillofacial Surgery, Department of Medicine of Sensory and Motor Organs, University of Miyazaki, Kiyotake, Miyazaki 889-1692 (Japan); Tominaga, Kazuhiro [Division of Maxillofacial Diagnostic and Surgical Science, Department of Oral and Maxillofacial Surgery, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Oral Bioresearch Center, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Nishihara, Tatsuji, E-mail: tatsujin@kyu-dent.ac.jp [Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental College, Kitakyushu 803-8580 (Japan); Oral Bioresearch Center, Kyushu Dental College, Kitakyushu 803-8580 (Japan)

    2011-02-25

    Research highlights: {yields} In this study was to investigate the effects of HA on osteoblast differentiation induced by BMP-2. {yields} MG63 cells were incubated with BMP-2 and HA for various time periods. {yields} Phosphorylation of Smad 1/5/8, p38, and ERK proteins was determined by western blot analysis. To elucidate the nuclear translocation of phosphorylated Smad 1/5/8, stimulated cells were subjected to immunofluorescence microscopy. {yields} HA enhanced BMP-2 induces osteoblastic differentiation in MG63 cells via down-regulation of BMP-2 antagonists and ERK phosphorylation. -- Abstract: Objectives: Bone morphogenetic protein-2 (BMP-2) is expected to be utilized to fill bone defects and promote healing of fractures. However, it is unable to generate an adequate clinical response for use in bone regeneration. Recently, it was reported that glycosaminoglycans, including heparin, heparan sulfate, keratan sulfate, dermatan sulfate, chondroitin-4-sulfate, chondroitin-6-sulfate, and hyaluronic acid (HA), regulate BMP-2 activity, though the mechanism by which HA regulates osteogenic activities has not been fully elucidated. The aim of this study was to investigate the effects of HA on osteoblast differentiation induced by BMP-2. Materials and methods: Monolayer cultures of osteoblastic lineage MG63 cells were incubated with BMP-2 and HA for various time periods. To determine osteoblastic differentiation, alkaline phosphatase (ALP) activity in the cell lysates was quantified. Phosphorylation of Smad 1/5/8, p38, and ERK proteins was determined by Western blot analysis. To elucidate the nuclear translocation of phosphorylated Smad 1/5/8, stimulated cells were subjected to immunofluorescence microscopy. To further elucidate the role of HA in enhancement of BMP-2-induced Smad signaling, mRNA expressions of the BMP-2 receptor antagonists noggin and follistatin were detected using real-time RT-PCR. Results: BMP-2-induced ALP activation, Smad 1/5/8 phosphorylation, and

  14. Gene delivery nanocarriers of bioactive glass with unique potential to load BMP2 plasmid DNA and to internalize into mesenchymal stem cells for osteogenesis and bone regeneration

    Science.gov (United States)

    Kim, Tae-Hyun; Singh, Rajendra K.; Kang, Min Sil; Kim, Joong-Hyun; Kim, Hae-Won

    2016-04-01

    The recent development of bioactive glasses with nanoscale morphologies has spurred their specific applications in bone regeneration, for example as drug and gene delivery carriers. Bone engineering with stem cells genetically modified with this unique class of nanocarriers thus holds great promise in this avenue. Here we report the potential of the bioactive glass nanoparticle (BGN) system for the gene delivery of mesenchymal stem cells (MSCs) targeting bone. The composition of 15% Ca-added silica, proven to be bone-bioactive, was formulated into surface aminated mesoporous nanospheres with enlarged pore sizes, to effectively load and deliver bone morphogenetic protein-2 (BMP2) plasmid DNA. The enlarged mesopores were highly effective in loading BMP2-pDNA with an efficiency as high as 3.5 wt% (pDNA w.r.t. BGN), a level more than twice than for small-sized mesopores. The BGN nanocarriers released the genetic molecules in a highly sustained manner (for as long as 2 weeks). The BMP2-pDNA/BGN complexes were effectively internalized to rat MSCs with a cell uptake level of ~73%, and the majority of cells were transfected to express the BMP2 protein. Subsequent osteogenesis of the transfected MSCs was demonstrated by the expression of bone-related genes, including bone sialoprotein, osteopontin, and osteocalcin. The MSCs transfected with BMP2-pDNA/BGN were locally delivered inside a collagen gel to the target calvarium defects. The results showed significantly improved bone regeneration, as evidenced by the micro-computed tomographic, histomorphometric and immunohistochemical analyses. This study supports the excellent capacity of the BGN system as a pDNA-delivery nanocarrier in MSCs, and the engineered system, BMP2-pDNA/BGN with MSCs, may be considered a new promising candidate to advance the therapeutic potential of stem cells through genetic modification, targeting bone defects and diseases.The recent development of bioactive glasses with nanoscale morphologies has

  15. Effect of rhBMP2 and rhTGF-β1 on alkaline phosphatase activity of human dental pulp cells in vitro%rhBMP2和rhTGF-β1联合应用对人牙髓细胞碱性磷酸酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    刘嘉利; 张郁; 王晓方; 汪平

    2000-01-01

    目的:探讨rhBMP2和rhTGF-β1联合应用对人牙髓细胞ALPase活性的影响.方法:采用酶动力学的方法,比较不同浓度rhBMP2和rhTGF-β1单独或联合应用对人牙髓细胞的ALPase活性的影响.结果 :rhBMP2对人牙髓细胞的ALPase活性呈浓度依赖性增强,rhTGF-β1对人牙髓细胞ALPase活性的影响与其本身浓度有关 .当rhTGF-β1浓度为1μg/L与rhBMP2联合应用时, ALPa se活性比rhBMP2单独应用明显增高.结论:rhBMP2、rhTGF-β1单独及联合应用于人牙髓细胞时,对人牙髓细胞的ALPase活性作用不同,其对人牙髓细胞的生理功能可能有调节作用.

  16. Off-label innovation: characterization through a case study of rhBMP-2 for spinal fusion.

    Science.gov (United States)

    Schnurman, Zane; Smith, Michael L; Kondziolka, Douglas

    2016-09-01

    OBJECTIVE Off-label therapies are widely used in clinical practice by spinal surgeons. Some patients and practitioners have advocated for increased regulation of their use, and payers have increasingly questioned reimbursment for off-label therapies. In this study, the authors applied a model that quantifies publication data to analyze the developmental process from initial on-label use to off-label innovation, using as an example recombinant human bone morphogenetic protein 2 (rhBMP-2) because of its wide off-label use. METHODS As a case study of off-label innovation, the developmental patterns of rhBMP-2 from FDA-approved use for anterior lumbar interbody fusion to several of its off-label uses, including posterolateral lumbar fusion, anterior cervical discectomy and fusion, and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion, were evaluated using the "progressive scholarly acceptance" (PSA) model. In this model, PSA is used as an end point indicating acceptance of a therapy or procedure by the relevant scientific community and is reached when the total number of peer-reviewed studies devoted to refinement or improvement of a therapy surpasses the total number assessing initial efficacy. Report characteristics, including the number of patients studied and study design, were assessed in addition to the time to and pattern of community acceptance, and results compared with previous developmental study findings. Disclosures and reported conflicts of interest for all articles were reviewed, and these data were also used in the analysis. RESULTS Publication data indicated that the acceptance of rhBMP-2 off-label therapies occurred more rapidly and with less evidence than previously studied on-label therapies. Additionally, the community appeared to respond more robustly (by rapidly changing publication patterns) to reports of adverse events than to new questions of efficacy. CONCLUSIONS The development of off-label therapies, including the

  17. Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional beta-TCP

    Energy Technology Data Exchange (ETDEWEB)

    Xu Lulu; Jin Zuolin; Duan Yinzhong [Department of Orthodontics, Stomatological College, Fourth Military Medical University, Xi' an 710032 (China); Liu Hongchen; Wang Dongsheng; E Lingling [Department of Stomatology, China PLA General Hospital, Beijing 100853 (China); Xu Lin, E-mail: jinzuolin88@yahoo.com.c, E-mail: duanyinzhong@yahoo.com.c [Department of Stomatology, the First Hospital of PLA, Lanzhou 730000 (China)

    2009-12-15

    The aim of this study was to investigate the effects of BMP-2 and dexamethasone (Dex) on osteogenic differentiation of rat dental follicle progenitor cells (RDFCs) seeded on three-dimensional beta-TCP. The alkaline phosphatase (ALP), the calcium and phosphonium, the osteocalcin in media of the third passage RDFCs on biomaterial beta-TCP after 1-3, 3-7, 7-14 days of culture were examined respectively. The growth of cells on the scaffolds was observed by scanning electron microscope (SEM) after 3, 7 days of culture and by implanting in the backs of severe combined immunodeficient (SCID) mice for bone regeneration. The third passage RDFCs could be seen adhered, extended and proliferated on the beta-TCP by scanning electron microscopy. The ALP activity, the calcium and phosphoniums and the osteocalcin content of dexamethasone (10{sup -8} M) or/and BMP-2 (100 ng ml{sup -1}) were significantly higher than their existence in the control group. They were the significantly highest among four groups after joint application of BMP-2 and dexamethasone. After 8 weeks of implantation, the percentage of the new bones formed area in the RDFCs+beta-TCP+BMP-2+Dex group was significantly higher than that in the RDFCs+beta-TCP+BMP-2 group. In contrast, beta-TCP, RDFCs+beta-TCP+Dex and control constructs lacked new bone formation by histological staining and histomorphometric analysis. The BMP-2+Dex could significantly promote osteogenic differentiation of RDFCs on beta-TCP. beta-TCP supported fast cellular adhesion, proliferation and differentiation of RDFCs. The feasibility of its application in periodontal tissue engineering was also proved.

  18. Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional β-TCP

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effects of BMP-2 and dexamethasone (Dex) on osteogenic differentiation of rat dental follicle progenitor cells (RDFCs) seeded on three-dimensional β-TCP. The alkaline phosphatase (ALP), the calcium and phosphonium, the osteocalcin in media of the third passage RDFCs on biomaterial β-TCP after 1-3, 3-7, 7-14 days of culture were examined respectively. The growth of cells on the scaffolds was observed by scanning electron microscope (SEM) after 3, 7 days of culture and by implanting in the backs of severe combined immunodeficient (SCID) mice for bone regeneration. The third passage RDFCs could be seen adhered, extended and proliferated on the β-TCP by scanning electron microscopy. The ALP activity, the calcium and phosphoniums and the osteocalcin content of dexamethasone (10-8 M) or/and BMP-2 (100 ng ml-1) were significantly higher than their existence in the control group. They were the significantly highest among four groups after joint application of BMP-2 and dexamethasone. After 8 weeks of implantation, the percentage of the new bones formed area in the RDFCs+β-TCP+BMP-2+Dex group was significantly higher than that in the RDFCs+β-TCP+BMP-2 group. In contrast, β-TCP, RDFCs+β-TCP+Dex and control constructs lacked new bone formation by histological staining and histomorphometric analysis. The BMP-2+Dex could significantly promote osteogenic differentiation of RDFCs on β-TCP. β-TCP supported fast cellular adhesion, proliferation and differentiation of RDFCs. The feasibility of its application in periodontal tissue engineering was also proved.

  19. Diabetes mellitus affects the biomechanical function of the callus and the expression of TGF-beta1 and BMP2 in an early stage of fracture healing

    OpenAIRE

    Xu, M. T.; Sun, S.; Zhang, L.; Xu, F.; Du, S.L.; Zhang, X. D.; Wang, D. W.

    2015-01-01

    Transforming growth factor beta 1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) are important regulators of bone repair and regeneration. In this study, we examined whether TGF-β1 and BMP-2 expressions were delayed during bone healing in type 1 diabetes mellitus. Tibial fractures were created in 95 diabetic and 95 control adult male Wistar rats of 10 weeks of age. At 1, 2, 3, 4, and 5 weeks after fracture induction, five rats were sacrificed from each group. The expressions of TGF-β1 and ...

  20. Regulació de la migració cel·lular induïda per BMP-2

    OpenAIRE

    Gamell Fullà, Cristina

    2009-01-01

    EN CATALÀ :Les proteïnes morfogenètiques òssies (BMPs) són membres de la superfamília del TGF-beta i s'ha demostrat que participen en la determinació i especificació de varis teixits i òrgans durant el desenvolupament dels vertebrats i que regulen la proliferació, l'apoptosi i la diferenciació de múltiples tipus cel·lulars. Les BMPs van ser originàriament identificades per a la seva habilitat d'induir la formació ectòpica d'os i entre ells, BMP-2, -4 and -7 resulten essencials perquè tingui l...

  1. The origin of bmp16, a novel Bmp2/4 relative, retained in teleost fish genomes

    Directory of Open Access Journals (Sweden)

    Meyer Axel

    2009-12-01

    Full Text Available Abstract Background Whole genome sequences have allowed us to have an overview of the evolution of gene repertoires. The target of the present study, the TGFβ superfamily, contains many genes involved in vertebrate development, and provides an ideal system to explore the relationships between evolution of gene repertoires and that of developmental programs. Results As a result of a bioinformatic survey of sequenced vertebrate genomes, we identified an uncharacterized member of the TGFβ superfamily, designated bmp16, which is confined to teleost fish species. Our molecular phylogenetic study revealed a high affinity of bmp16 to the Bmp2/4 subfamily. Importantly, further analyses based on the maximum-likelihood method unambiguously ruled out the possibility that this teleost-specific gene is a product of teleost-specific genome duplication. This suggests that the absence of a bmp16 ortholog in tetrapods is due to a secondary loss. In situ hybridization showed embryonic expression of the zebrafish bmp16 in the developing swim bladder, heart, tail bud, and ectoderm of pectoral and median fin folds in pharyngula stages, as well as gut-associated expression in 5-day embryos. Conclusion Comparisons of expression patterns revealed (1 the redundancy of bmp16 expression with its homologs in presumably plesiomorphic expression domains, such as the fin fold, heart, and tail bud, which might have permitted its loss in the tetrapod lineage, and (2 the loss of craniofacial expression and gain of swim bladder expression of bmp16 after the gene duplication between Bmp2, -4 and -16. Our findings highlight the importance of documenting secondary changes of gene repertoires and expression patterns in other gene families.

  2. Partial Agonists Activate PPARgamma Using a Helix 12 Independent Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Bruning, J.B.; Chalmers, M.J.; Prasad, S.; Bushby, S.A.; Kamenecka, T.A.; He, Y.; Nettles, K.W.; Griffin, P.R.

    2009-05-28

    Binding to helix 12 of the ligand-binding domain of PPAR{gamma} is required for full agonist activity. Previously, the degree of stabilization of the activation function 2 (AF-2) surface was thought to correlate with the degree of agonism and transactivation. To examine this mechanism, we probed structural dynamics of PPAR{gamma} with agonists that induced graded transcriptional responses. Here we present crystal structures and amide H/D exchange (HDX) kinetics for six of these complexes. Amide HDX revealed each ligand induced unique changes to the dynamics of the ligand-binding domain (LBD). Full agonists stabilized helix 12, whereas intermediate and partial agonists did not at all, and rather differentially stabilized other regions of the binding pocket. The gradient of PPAR{gamma} transactivation cannot be accounted for solely through changes to the dynamics of AF-2. Thus, our understanding of allosteric signaling must be extended beyond the idea of a dynamic helix 12 acting as a molecular switch.

  3. Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study

    Directory of Open Access Journals (Sweden)

    Nam-Ho Kim

    2015-01-01

    Full Text Available This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL. After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ values were recorded and vertical bone height (VBH, mm, bone-to-implant contact ratio (BIC, %, and bone volume (BV, % in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm, BIC (%, and BV (% were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration.

  4. Improved Bone Formation in Osteoporotic Rabbits with the Bone Morphogenetic Protein-2 (rhBMP-2 Coated Titanium Screws Which Were Coated By Using Plasma Polymerization Technique

    Directory of Open Access Journals (Sweden)

    Salih Gulsen

    2014-06-01

    Full Text Available Delaying of bone fusion in osteoporotic patients underwent spinal stabilization surgery leads to screw loosening, and this causes pseudoarticulation, mobility and fibrosis at vertebral segments. To prevent these complications, the screws coated with recombinant bone morphogenetic protein-2 (rhBMP-2 could be used. To verify this hypothesis, we coated 5 Titanium screws with rhBMP-2 using plasma polymerization method, and also used 10 uncoated screws for making comparison between coated and uncoated screws in different groups. And 15 skeletally mature white New Zealand female rabbits were assigned into three different groups: Group 1(N = 5: No osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 1; group 2 (N = 5: Osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 2; group 3 (N = 5 rhBMP-2 coated Titanium screw inserted into right sacrum of each rabbit in group 3. In summary, using of these coated screws provides new bone formation, but causes less fibrosis and less inflammation than uncoated screws at the interface between the coated screw and bone. Then the plasma polymerization technique provides controlled releasing of rhBMP-2 from the screw to the bone tissue in osteoporotic rabbits.

  5. Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study

    Science.gov (United States)

    Kim, Nam-Ho; Lee, So-Hyoun; Ryu, Jae-Jun; Choi, Kyung-Hee; Huh, Jung-Bo

    2015-01-01

    This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA) implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL). After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group) were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ) values were recorded and vertical bone height (VBH, mm), bone-to-implant contact ratio (BIC, %), and bone volume (BV, %) in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm), BIC (%), and BV (%) were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration. PMID:26504807

  6. Mesoporous calcium–silicon xerogels with mesopore size and pore volume influence hMSC behaviors by load and sustained release of rhBMP-2

    Directory of Open Access Journals (Sweden)

    Song W

    2015-03-01

    Full Text Available Wenhua Song,1,* Xiangde Li,1,* Jun Qian,1 Guoyu Lv,2 Yonggang Yan,2 Jiacan Su,3 Jie Wei1 1Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of China; 2College of Physical Science and Technology, Sichuan University, Chengdu, People’s Republic of China; 3Changhai Hospital, Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this paper Abstract: Mesoporous calcium–silicon xerogels with a pore size of 15 nm (MCS-15 and pore volume of 1.43 cm3/g were synthesized by using 1,3,5-mesitylene (TMB as the pore-expanding agent. The MCS-15 exhibited good degradability with the weight loss of 50 wt% after soaking in Tris-HCl solution for 56 days, which was higher than the 30 wt% loss shown by mesoporous calcium–silicon xerogels with a pore size of 4 nm (MCS-4. The pore size and pore volume of MCS-15 had significant influences on load and release of recombinant human bone morphogenetic protein-2 (rhBMP-2. The MCS-15 had a higher capacity to encapsulate a large amount of rhBMP-2; it could adsorb 45 mg/g of rhBMP-2 in phosphate-buffered saline after 24 hours, which was more than twice that with MCS-4 (20 mg/g. Moreover, the MCS-15 system exhibited sustained release of rhBMP-2 as compared with MCS-4 system (showing a burst release. The MCS-15/rhBMP-2 system could promote the proliferation and differentiation of human mesenchymal stem cells, showing good cytocompatibility and bioactivity. The results indicated that MCS-15, with larger mesopore size and higher pore volume, might be a promising carrier for loading and sustained release of rhBMP-2, which could be used as bone repair material with built-in osteoinduction function in bone reconstruction. Keywords: mesoporous calcium–silicon xerogels, pore size, pore volume, load-release, rhBMP-2

  7. Dual Delivery of BMP-2 and bFGF from a New Nano-Composite Scaffold, Loaded with Vascular Stents for Large-Size Mandibular Defect Regeneration

    Directory of Open Access Journals (Sweden)

    Hang Zhao

    2013-06-01

    Full Text Available The aim of this study was to investigate the feasibility and advantages of the dual delivery of bone morphogenetic protein-2 (BMP-2 and basic fibroblast growth factor (bFGF from nano-composite scaffolds (PLGA/PCL/nHA loaded with vascular stents (PLCL/Col/nHA for large bone defect regeneration in rabbit mandibles. Thirty-six large bone defects were repaired in rabbits using engineering bone composed of allogeneic bone marrow mesenchymal stem cells (BMSCs, bFGF, BMP-2 and scaffolds composed of PLGA/PCL/nHA loaded with PLCL/Col/nHA. The experiments were divided into six groups: BMSCs/bFGF/BMP-2/scaffold, BMSCs/BMP-2/scaffold, BMSCs/bFGF/scaffold, BMSCs/scaffold, scaffold alone and no treatment. Sodium alginate hydrogel was used as the carrier for BMP-2 and bFGF and its features, including gelling, degradation and controlled release properties, was detected by the determination of gelation and degradation time coupled with a controlled release study of bovine serum albumin (BSA. AlamarBlue assay and alkaline phosphatase (ALP activity were used to evaluate the proliferation and osteogenic differentiation of BMSCs in different groups. X-ray and histological examinations of the samples were performed after 4 and 12 weeks post-implantation to clarify new bone formation in the mandible defects. The results verified that the use of sodium alginate hydrogel as a controlled release carrier has good sustained release ability, and the combined application of bFGF and BMP-2 could significantly promote the proliferation and osteogenic differentiation of BMSCs (p < 0.05 or p < 0.01. In addition, X-ray and histological examinations of the samples exhibited that the dual release group had significantly higher bone formation than the other groups. The above results indicate that the delivery of both growth factors could enhance new bone formation and vascularization compared with delivery of BMP-2 or bFGF alone, and may supply a promising way of repairing large

  8. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Si, Lina; Shi, Jin; Gao, Wenqun [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Zheng, Min [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Liu, Lingjuan; Zhu, Jing [Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Tian, Jie, E-mail: jietian@cqmu.edu.cn [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China)

    2014-07-18

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  9. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    International Nuclear Information System (INIS)

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  10. Mandibular bone repair by implantation of rhBMP-2 in a slow release carrier of polylactic acid--an experimental study in rats.

    Science.gov (United States)

    Schliephake, Henning; Weich, Herbert A; Dullin, Christian; Gruber, Rudolf; Frahse, Sarah

    2008-01-01

    The aim of the present study was to test the hypothesis that human recombinant bone morphogenic protein 2 (rhBMP-2) implanted in a slow release carrier of polylactic acid (PLA) can repair a non-healing defect in the rat mandible and maintain the thickness of an augmented volume. p-DL-lactic acid discs were produced and loaded with 48 and 96 microg rhBMP-2 and inserted into non-healing defects of the mandible of 45 Wistar rats. Fifteen rats received implants with 96 microg rhBMP-2 (Group 2), 48 microg rhBMP-2 (Group 1) and blank implants without BMP (Group 0) each on one side of the mandible. Unfilled defects of the same size on the contralateral sides of the mandibles served as empty controls. After 6, 13 and 26 weeks, implants of each group were retrieved from five animals each and submitted to flat panel detector computed tomography. Bone formation and thickness of augmentation was assessed by computer-assisted histomorphometry. In Group 2 significantly more bone was produced than in Group 1. Implants of Group 1 induced significantly more bone than the blank controls only after 6 weeks, whereas the difference was not significant after 13 and 26 weeks. Differences between Group 2 and Group 1 were clearly significant after 26 weeks. The thickness of bone tissue was maintained in Group 2 whereas it decreased in Group 1 and was negligible in Group 0. It is concluded that the PLA implants with 96 microg rhBMP-2 were able to bridge a non-healing defect in the rat mandible and maintained the thickness of an augmented volume. However, continuous supply of osteogenic signals appears to be required to compensate for adverse effects during polymer degradation. PMID:17936352

  11. Chondrocyte outgrowth into a gelatin scaffold in a single impact load model of damage/repair – effect of BMP-2

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    Vincent Thea

    2007-12-01

    Full Text Available Abstract Background Articular cartilage has little capacity for repair in vivo, however, a small number of studies have shown that, in vitro, a damage/repair response can be induced. Recent work by our group has shown that cartilage can respond to single impact load and culture by producing repair cells on the articular surface. The purpose of this study was to identify whether chondrocyte outgrowth into a 3D scaffold could be observed following single impact load and culture. The effect of bone morphogenic-2 (BMP-2 on this process was investigated. Methods Cartilage explants were single impact loaded, placed within a scaffold and cultured for up to 20 days +/- BMP-2. Cell numbers in the scaffold, on and extruding from the articular surface were quantified and the immunohistochemistry used to identify the cellular phenotype. Results Following single impact load and culture, chondrocytes were observed in a 3D gelatin scaffold under all culture conditions. Chondrocytes were also observed on the articular surface of the cartilage and extruding out of the parent cartilage and on to the cartilage surface. BMP-2 was demonstrated to quantitatively inhibit these events. Conclusion These studies demonstrate that articular chondrocytes can be stimulated to migrate out of parent cartilage following single impact load and culture. The addition of BMP-2 to the culture medium quantitatively reduced the repair response. It may be that the inhibitory effect of BMP-2 in this experimental model provides a clue to the apparent inability of articular cartilage to heal itself following damage in vivo.

  12. Sustained release of VH and rhBMP-2 from nanoporous magnesium–zinc–silicon xerogels for osteomyelitis treatment and bone repair

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    Li FQ

    2015-06-01

    Full Text Available Fengqian Li,1,* Wen Wu,2,* Li Xiang,1 Gan Weng,1 Hua Hong,3 Hong Jiang,4 Jun Qian31Department of Pharmacy, Shanghai Xuhui Dahua Hospital, 2Department of Orthopaedics, Ninth People’s Hospital, School of Medicine, Shanghai Jiaotong University, 3Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, 4School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People’s Republic of China*Co-first authors contributed equally to this workAbstract: Nanoporous magnesium–zinc–silicon (n-MZS xerogels with a pore size of ~4 nm, a surface area of 718 cm2/g, and a pore volume of 1.24 cm3/g were synthesized by a sol–gel method. The n-MZS xerogels had high capacity to load vancomycin hydrochloride (VH and human bone morphogenetic protein-2 (rhBMP-2, after soaking in phosphate buffered saline (PBS for 24 hours (1.5 and 0.8 mg/g, respectively. Moreover, the n-MZS xerogels exhibited the sustained release of VH and rhBMP-2 as compared with magnesium–zinc–silicon (MZS xerogels without nanopores (showing a burst release. The VH/rhBMP-2/n-MZS system not only exhibited a good antibacterial property but also promoted the MG63 cell proliferation and differentiation demonstrating good bactericidal activity and cytocompatibility. The results suggested that n-MZS with larger surface area and high pore volume might be a promising carrier for loading and sustained release of VH and rhBMP-2. Hence, the VH/rhBMP-2/n-MZS system might be one of the promising biomaterials for osteomyelitis treatment and bone repair.Keywords: nanoporous xerogels, sustained release, drugs, osteomyelitis, bone regeneration, bactericidal activity, cytocompatibility

  13. BMP-2基因修饰自体BMSCs移植促进兔下颌骨牵张成骨新骨形成的实验研究%EXPERIMENTAL STUDY ON TRANSPLANTATION OF BMP-2 GENE TRANSFECTED AUTOGENOUS BONE MESENCHYMAL STEM CELLS FOR PROMOTING BONE REGENERATION IN RABBIT MANDIBULAR DISTRACTION OSTEOGENESIS

    Institute of Scientific and Technical Information of China (English)

    黄旋平; 周诺; 江献芳; 杨媛媛; 李华; 谢庆条

    2012-01-01

    目的:检测骨形态发生蛋白-2(BMP-2)基因mRNA及其蛋白的表达,探讨BMP-2基因修饰自体骨髓间充质干细胞(BMSCs)移植对兔下颌骨牵张成骨新骨形成的促进作用.方法:取新西兰白兔36只随机分为3组,每组12只.建立牵张成骨动物模型,在固定期第2天,实验组于牵张间隙注射200 μL的BMP-2基因修饰的自体BMSCs液;对照组注射等量自体BMSCs液;空白组注射等量生理盐水.分别于固定2,6周通过逆转录多聚酶链式反应(RT-PCR)、免疫组化等手段检测BMP-2基因mRNA及其蛋白的表达情况.结果:实验组牵张间隙新生骨组织均可见BMP-2基因mRNA和其蛋白强阳性表达.结论:BMP-2基因修饰的自体BMSCs移植能有效促进兔下颌骨牵张成骨新骨形成.%Objective:To examine the expressions of both bone morphogenetic protein-2 (BMP-2) gene mR-NA and related proteins and investigate the promotive effect of transplantation of BMP-2 gene transfected autogenous bone mesenchymal stem cells on bone regeneration in rabbit mandibular distraction osteogene-sis. Methods: Thirty-six New Zealand's white rabbits were randomly divided into three groups with twelve in each. All objects -were prepared into distraction osteogenesis surgical model on right mandibles. On the 2nd day of consolidation, experimental, control, and blank groups -were injected -with the same amount of 200 juL of the solution with BMP-2 gene transfected autogenous bone mesenchymal stem cells, the solution with autogenous bone mesenchymal stem cells, and physiological saline at distraction gap, respectively. The expressions of BMP-2 mRNA and related proteins -were examined by RT-PCR and immunohistochem-istry at the ends of the 2nd and 6th -week consolidations, respectively. Results: Strongly positive expression of both BMP-2 gene mRNA and related proteins were confirmed on regenerated bone in distraction gap. Conclusion: The transplantation of BMP-2 gene transfected autogenous bone

  14. Wnt1 and BMP2: two factors recruiting multipotent neural crest progenitors isolated from adult bone marrow.

    Science.gov (United States)

    Glejzer, A; Laudet, E; Leprince, P; Hennuy, B; Poulet, C; Shakhova, O; Sommer, L; Rogister, B; Wislet-Gendebien, S

    2011-06-01

    Recent studies have shown that neural crest-derived progenitor cells can be found in diverse mammalian tissues including tissues that were not previously shown to contain neural crest derivatives, such as bone marrow. The identification of those "new" neural crest-derived progenitor cells opens new strategies for developing autologous cell replacement therapies in regenerative medicine. However, their potential use is still a challenge as only few neural crest-derived progenitor cells were found in those new accessible locations. In this study, we developed a protocol, based on wnt1 and BMP2 effects, to enrich neural crest-derived cells from adult bone marrow. Those two factors are known to maintain and stimulate the proliferation of embryonic neural crest stem cells, however, their effects have never been characterized on neural crest cells isolated from adult tissues. Using multiple strategies from microarray to 2D-DIGE proteomic analyses, we characterized those recruited neural crest-derived cells, defining their identity and their differentiating abilities. PMID:20976520

  15. Evaluation of a Novel HA/ZrO2-Based Porous Bioceramic Artificial Vertebral Body Combined with a rhBMP-2/Chitosan Slow-Release Hydrogel

    Science.gov (United States)

    Shi, Yihui; Quan, Renfu; Xie, Shangju; Li, Qiang; Cao, Guoping; Zhuang, Wei; Zhang, Liang; Shao, Rongxue; Yang, Disheng

    2016-01-01

    A new HA/ZrO2-based porous bioceramic artificial vertebral body (AVB), carried a recombinant human bone morphogenetic protein-2 (rhBMP-2)/chitosan slow-release hydrogel was prepared to repair vertebral bone defect in beagles. An ionic cross-linking was used to prepare the chitosan hydrogel (CS gel) as the rhBMP-2 slow-release carrier. The vertebral body defects were implanted with the rhBMP-2-loaded AVB in group A, or a non-drug-loaded AVB in group B, or autologous iliac in group C. The encapsulation rate of rhBMP-2 in rhBMP-2-loaded CS gel was 91.88±1.53%, with a drug load of 39.84±2.34 ng/mg. At 6, 12, 24 weeks postoperatively, radiography showed that the bone calluses gradually increased with time in group A, where the artificial vertebral body had completely fused with host-bone at 24 weeks after surgery. In group C, an apparent bone remodeling was occurred in the early stages, and the graft-bone and host-bone had also fused completely at 24 weeks postoperatively. In group B, fusion occurred less than in groups A and C. At 24 weeks after surgery, micro-computed tomography (Micro-CT) revealed that the volume of newly-formed bone in group A was significantly more than in group B (p<0.05). At 24 weeks after surgery, ultra-compressive strengths of the operated segments were 14.03±1.66 MPa in group A, 8.62±1.24 MPa in group B, and 13.78±1.43 MPa in group C. Groups A and C were both significantly higher than group B (p < 0.05). At 24 weeks postoperatively, the hard tissue sections showed that the AVB of group A had tightly fused with host bone, and that pores of the AVB had been filled with abundant nearly mature bone, and that the new bone structured similarly to a trabecular framework, which was similar to that in group C. In contrast, implant fusion of the AVB in group B was not as apparent as group A. In conclusion, the novel HA/ZrO2-based porous bioceramic AVB carried the rhBMP-2-loaded CS gel can promote the repair of bony defect, and induce bone tissue to

  16. TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants and arrests downstream differentiation at an early stage of hypertrophy.

    Directory of Open Access Journals (Sweden)

    Nahoko Shintani

    Full Text Available BACKGROUND: Synovial explants furnish an in-situ population of mesenchymal stem cells for the repair of articular cartilage. Although bone morphogenetic protein 2 (BMP-2 induces the chondrogenesis of bovine synovial explants, the cartilage formed is neither homogeneously distributed nor of an exclusively hyaline type. Furthermore, the downstream differentiation of chondrocytes proceeds to the stage of terminal hypertrophy, which is inextricably coupled with undesired matrix mineralization. With a view to optimizing BMP-2-induced chondrogenesis, the modulating influences of fibroblast growth factor 2 (FGF-2 and transforming growth factor beta 1 (TGF-ß1 were investigated. METHODOLOGY/PRINCIPAL FINDINGS: Explants of bovine calf metacarpal synovium were exposed to BMP-2 (200 ng/ml for 4 (or 6 weeks. FGF-2 (10 ng/ml or TGF-ß1 (10 ng/ml was introduced at the onset of incubation and was present either during the first week of culturing alone or throughout its entire course. FGF-2 enhanced the BMP-2-induced increase in metachromatic staining for glycosaminoglycans (GAGs only when it was present during the first week of culturing alone. TGF-ß1 enhanced not only the BMP-2-induced increase in metachromasia (to a greater degree than FGF-2, but also the biochemically-assayed accumulation of GAGs, when it was present throughout the entire culturing period; in addition, it arrested the downstream differentiation of cells at an early stage of hypertrophy. These findings were corroborated by an analysis of the gene- and protein-expression levels of key cartilaginous markers and by an estimation of individual cell volume. CONCLUSIONS/SIGNIFICANCE: TGF-ß1 enhances the BMP-2-induced chondrogenesis of bovine synovial explants, improves the hyaline-like properties of the neocartilage, and arrests the downstream differentiation of cells at an early stage of hypertrophy. With the prospect of engineering a mature, truly articular type of cartilage in the context of

  17. Efficacy of rhBMP-2 loaded PCL/PLGA/β-TCP guided bone regeneration membrane fabricated by 3D printing technology for reconstruction of calvaria defects in rabbit

    International Nuclear Information System (INIS)

    We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml−1) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks. (paper)

  18. Efficacy of rhBMP-2 loaded PCL/PLGA/β-TCP guided bone regeneration membrane fabricated by 3D printing technology for reconstruction of calvaria defects in rabbit.

    Science.gov (United States)

    Shim, Jin-Hyung; Yoon, Min-Chul; Jeong, Chang-Mo; Jang, Jinah; Jeong, Sung-In; Cho, Dong-Woo; Huh, Jung-Bo

    2014-11-10

    We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml(-1)) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks.

  19. Brain alterations and clinical symptoms of dementia in diabetes: Abeta/tau-dependent and independent mechanisms

    Directory of Open Access Journals (Sweden)

    Naoyuki eSato

    2014-09-01

    Full Text Available Emerging evidence suggests that diabetes affects cognitive function and increases the incidence of dementia. However, the mechanisms by which diabetes modifies cognitive function still remains unclear. Morphologically, diabetes is associated with neuronal loss in the frontal and temporal lobes including the hippocampus, and aberrant functional connectivity of the posterior cingulate cortex and medial frontal/temporal gyrus. Clinically, diabetic patients show decreased executive function, information processing, planning, visuospatial construction, and visual memory. Therefore, in comparison with the characteristics of AD brain structure and cognition, diabetes seems to affect cognitive function through not only simple AD pathological feature-dependent mechanisms, but also independent mechanisms. As an Abeta/tau-independent mechanism, diabetes compromises cerebrovascular function, increases subcortical infarction and might alter the blood brain barrier (BBB. Diabetes also affects glucose metabolism, insulin signaling and mitochondrial function in the brain. Diabetes also modifies metabolism of Abeta and tau and causes Abeta/tau-dependent pathological changes. Moreover, there is evidence that suggests an interaction between Abeta/tau-dependent and independent mechanisms. Therefore, diabetes modifies cognitive function through Abeta/tau-dependent and independent mechanisms. Interaction between these two mechanisms forms a vicious cycle.

  20. The effects of substrate-streching strain on the BMP-2 mRNA expression in three kinds of mouse cell lines%基底拉伸应变对小鼠三种骨组织细胞BMP-2 mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    闫玉仙; 宋梅; 郭春; 郭勇; 宫元伟; 李瑞欣; 张西正

    2010-01-01

    目的 研究基底拉伸应变对小鼠成骨细胞系MC3T3-E1、破骨细胞系RAW264.7及骨细胞MLO-Y4三种细胞BMP-2 mRNA表达的影响.方法 三种细胞随机分为0 με、1 000 με、1 500 με、2 000 με、2 500 με和5 000 με组,最佳拉伸时间和周期为1次/d,每次1 h,连续3 d,频率为0.5 Hz.采用卫生装备研究所自行设计研制的四点弯曲装置对小鼠三种细胞进行拉伸加载.采用RT-PCR技术分别研究不同应变对小鼠三种细胞BMP-2 mRNA表达.结果 MC3T3-E1细胞RT-PCR结果显示:1 500 με、2 000 με组和2 500 με组与0 με组相比BMP-2 mRNA表达显著增强(P<0.01);5 000 με组与0 με组相比BMP-2 mRNA表达显著降低(P<0.01);RAW264.7细胞RT-PCR结果显示:1 500 με、2 000 με组和2 500 με组与0 με组相比BMP-2 mRNA表达显著降低(P<0.01);5 000με组与0 με组相比BMP-2 mRNA表达显著降低(P<0.01);MLO-Y4细胞BMP2基因表达结果与MC3T3-E1一致.结论 ①BMP-2在成骨细胞系MC3T3-E1、破骨细胞系RAW-264.7及骨细胞系MLO-Y4三种细胞中均有表达;②1 500 με、2 000 με、2 500 με三种生理剂量的拉伸应变可以显著增加MC3T3-E1、MLO-Y4 细胞BMP-2的表达,并呈剂量依赖性,超生理剂量5 000 με可以显著降低MC3T3-E1、MLO-Y4细胞BMP-2的表达;③相同的力学拉伸作用条件下,BMP-2在RAW-264.7细胞中表达与MC3T3-E1、MLO-Y4细胞的表达趋势相反.

  1. Posterior tooth replacement with dental implants in sites augmented with rhBMP-2 at time of extraction--a case series.

    Science.gov (United States)

    Levin, Barry P; Tawil, Peter

    2012-02-01

    This case series demonstrates seven molar-site implants placed in six consecutively treated patients. All sites were augmented with rhBMP-2 (1.50 mg/cc)/ACS (recombinant human Bone Morphogenetic Protein-2/Absorbable Collagen Sponge) at extraction to regenerate bone-facilitating implant placement. In four patients, osteotomies were initiated with trephines to evaluate qualitatively for native bone and for the absence of residual ACS. All sites facilitated implant placement after augmentation. All seven implants achieved primary stabilization and were functionally loaded. No implants were lost or developed complications. It can be concluded that augmenting molar extraction sockets with rhBMP-2/ACS can allow standard implant placement in the posterior dentition that is capable of withstanding a functional load.

  2. Self-assembled Biodegradable Nanoparticles and Polysaccharides as Biomimetic ECM Nanostructures for the Synergistic effect of RGD and BMP-2 on Bone Formation.

    Science.gov (United States)

    Wang, Zhenming; Dong, Li; Han, Lu; Wang, Kefeng; Lu, Xiong; Fang, Liming; Qu, Shuxin; Chan, Chun Wai

    2016-01-01

    Producing biomimetic extracellular matrix (ECM) is an effective approach to improve biocompatibility of medical devices. In this study, biomimetic ECM nanostructures are constructed through layer-by-layer self-assembling positively charged chitosan (Chi), negatively charged oxidized sodium alginate (OAlg), and positively charged bovine serum albumin (BSA)-based nanoparticles. The BSA-based nanoparticles in the self-assembled films not only result in porous nanostructures similar to natural ECM, but also preserve the activity and realize the sustained release of Bone morphogenetic protein-2 (BMP-2). The results of bone marrow stem cells (BMSCs) culture demonstrate that the penta-peptide glycine-arginine-glycine-aspartate-serine (GRGDS) grafted Chi/OAlg films favor cell adhesion and proliferation. GRGDS and BMP-2 in biomimetic ECM nanostructures synergistically promote BMSC functions and new bone formation. The RGD and BMP incorporated biomimetic ECM coatings could be applied on a variety of biomedical devices to improve the bioactivity and biocompatibility. PMID:27121121

  3. Treatment of critically sized femoral defects with recombinant BMP-2 delivered by a modified mPEG-PLGA biodegradable thermosensitive hydrogel

    OpenAIRE

    Peng, Kuo-Ti; Hsieh, Meng-Yow; Lin, Carl T.; Chen, Chin-Fu; Lee, Mel S.; Huang, Yi-You; CHANG, PEY-JIUM

    2016-01-01

    Background Reconstruction of a segmental fracture with massive bone loss is still a challenge for orthopaedic surgeons. The aim of our study was to develop a suitable biodegradable thermosensitive hydrogel system as a carrier for bone morphogenetic protein (BMP)-2 delivery in the treatment of critical-sized femoral defects. Methods A block copolymer composed of monomethoxypoly(ethylene glycol) (mPEG), poly(lactic-co-glycolic acid) (PLGA) and 2, 2’-Bis (2-oxazolin) (Box) was synthesized by rin...

  4. The Value of SPECT/CT in Monitoring Prefabricated Tissue-Engineered Bone and Orthotopic rhBMP-2 Implants for Mandibular Reconstruction.

    Directory of Open Access Journals (Sweden)

    Miao Zhou

    Full Text Available Bone tissue engineering shows good prospects for mandibular reconstruction. In recent studies, prefabricated tissue-engineered bone (PTEB by recombinant human bone morphogenetic proteins (rhBMPs applied in vivo has found to be an effective alternative for autologous bone grafts. However, the optimal time to transfer PTEB for mandibular reconstruction is still not elucidated. Thus, here in an animal experiment of rhesus monkey, the suitable transferring time for PTEB to reconstruct mandibular defects was evaluated by 99mTc-MDP SPECT/CT, and its value in monitoring orthotopic rhBMP-2 implants for mandibular reconstruction was also evaluated. The result of SPECT/CT showed higher 99mTc-MDP uptake, indicating osteoinductivity, in rhBMP-2 incorporated demineralized freeze-dried bone allograft (DFDBA and coralline hydroxyapatite (CHA implants than those without BMP stimulation. 99mTc-MDP uptake of rhBMP-2 implant peaked at 8 weeks following implantation while CT showed the density of these implants increased after 13 weeks' prefabrication. Histology confirmed that mandibular defects were repaired successfully with PTEB or orthotopically rhBMP-2 incorporated CHA implants, in accordance with SPECT/CT findings. Collectively, data shows 99mTc-MDP SPECT/CT is a sensitive and noninvasive tool to monitor osteoinductivity and bone regeneration of PTEB and orthotopic implants. The PTEB achieved peak osteoinductivity and bone density at 8 to 13 weeks following ectopic implantation, which would serve as a recommendable time frame for its transfer to mandibular reconstruction.

  5. Effect of recombinant human bone morphogenetic protein 2/polylactide-co-glycolic acid (rhBMP-2/PLGA) with core decompression on repair of rabbit femoral head necrosis

    Institute of Scientific and Technical Information of China (English)

    Zhao-Xun; Pan; Hong-Xin; Zhang; Ye-Xin; Wang; Long-Di; Zhai; Wei; Du

    2014-01-01

    Objective:To observe the effect of recombinant human bone morphogenetic protein 2/polylactide-co-glycolic acid(rhBMP-2/PLGA) with core decompression on repair of rabbit femoral head necrosis.Methods:Bilateral femoral head necrosis models of rabbit were established by steroid injection.A total of 48 rabbits(96 femoral head necrosis) were randomly divided into 4groups:Group A,control group with12 rabbits,24 femoral head necrosis;Group B,treated with rhBMP-2/PLCA implantation after core depression,with 12 rabbits,24 femoral head necrosis;Group C,treated with rhBMP-2 implantation after core depression,with 12 rabbits,24 femoral head necrosis;Croup D treated with core depression group without implantation,with 12 rabbits,24 femoral head necrosis.All animals were sacrificed after 12 weeks.The ability of repairing bone defect was evaluated by X-ray radiograph.Bone mineral density analysis of the defect regions were used to evaluate the level of ossification.The morphologic change and bone formation was assessed by HE staining.The angiogenesis was evaluated by VEGF immunohistochemistry.Results:The osteogenetic ability and quality of femoral head necrosis in group B were better than those of other groups after 12 weeks by X-ray radiograph and morphologic investigation.And the angiogenesis in group B was better than other groups.Group C had similar osteogenetic quality of femoral head necrosis and angiogenesis with group D.Conclusions:The treatment of rhBMP-2/PLCA implantation after core depression can promote the repair of rabbit femoral head necrosis.It is a promising and efficient synthetic bone material to treat the femoral head necrosis.

  6. Background Independent Quantum Mechanics, Classical Geometric Forms and Geometric Quantum Mechanics-I

    OpenAIRE

    Pandya, Aalok

    2008-01-01

    The geometry of the symplectic structures and Fubini-Study metric is discussed. Discussion in the paper addresses geometry of Quantum Mechanics in the classical phase space. Also, geometry of Quantum Mechanics in the projective Hilbert space has been discussed for the chosen Quantum states. Since the theory of classical gravity is basically geometric in nature and Quantum Mechanics is in no way devoid of geometry, the explorations pertaining to more and more geometry in Quantum Mechanics coul...

  7. The effect of a slow mode of BMP-2 delivery on the inflammatory response provoked by bone-defect-filling polymeric scaffolds.

    Science.gov (United States)

    Wu, Gang; Liu, Yuelian; Iizuka, Tateyuki; Hunziker, Ernst Bruno

    2010-10-01

    We investigated the inflammatory response to, and the osteoinductive efficacies of, four polymers (collagen, Ethisorb, PLGA and Polyactive) that bore either an adsorbed (fast-release kinetics) or a calcium-phosphate-coating-incorporated (slow-release kinetics) depot of BMP-2. Titanium-plate-supported discs of each polymer (n = 6 per group) were implanted at an ectopic (subcutaneous) ossification site in rats (n = 48). Five weeks later, they were retrieved for a histomorphometric analysis of the volumes of ectopic bone and foreign-body giant cells (a gauge of inflammatory reactivity), and the degree of polymer degradation. For each polymer, the osteoinductive efficacy of BMP-2 was higher when it was incorporated into a coating than when it was directly adsorbed onto the material. This mode of BMP-2 carriage was consistently associated with an attenuation of the inflammatory response. For coated materials, the volume density of foreign-body giant cells was inversely correlated with the volume density of bone (r(2) = 0.96), and the volume density of bone was directly proportional to the surface-area density of the polymer (r(2) = 0.97). Following coating degradation, other competitive factors, such as the biocompatibility and the biodegradability of the polymer itself, came into play.

  8. Heliox improves pulmonary mechanics in a pediatric porcine model of induced severe bronchospasm and independent lung mechanical ventilation

    OpenAIRE

    Orsini, Anthony J; Stefano, John L; Leef, Kathleen H; Jasani, Melinda; Ginn, Andrew; Tice, Lisa; Nadkarni, Vinay M.

    1999-01-01

    Background: A helium-oxygen gas mixture (heliox) has low gas density and low turbulence and resistance through narrowed airways. The effects of heliox on pulmonary mechanics following severe methacholine-induced bronchospasm were investigated and compared to those of a nitrogen-oxygen gas mixture (nitrox) in an innovative pediatric porcine, independent lung, mechanical ventilation model. Results: All of the lungs showed evidence of severe bronchospasm after methacholine challenge. Prospective...

  9. High-purity magnesium interference screws promote fibrocartilaginous entheses regeneration in the anterior cruciate ligament reconstruction rabbit model via accumulation of BMP-2 and VEGF.

    Science.gov (United States)

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Wu, Hongliu; Ni, Jiahua; Hou, Peng; Zhang, Yuanzhuang; Liu, Jingyi; Xu, Haidong; Liu, Shen; Zhang, Xiaonong; Zheng, Yufeng; Chai, Yimin

    2016-03-01

    Interference screw in the fixation of autologous tendon graft to the bone tunnel is widely accepted for the reconstruction of anterior cruciate ligament (ACL), but the regeneration of fibrocartilaginous entheses could hardly be achieved with the traditional interference screw. In the present work, biodegradable high-purity magnesium (HP Mg) showed good cytocompatibility and promoted the expression of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF), fibrocartilage markers (Aggrecan, COL2A1 and SOX-9), and glycosaminoglycan (GAG) production in vitro. The HP Mg screw was applied to fix the semitendinosus autograft to the femoral tunnel in a rabbit model of ACL reconstruction with titanium (Ti) screw as the control. The femur-tendon graft-tibia complex was retrieved at 3, 6, 9 and 12 weeks. Gross observation and range of motion (ROM) of the animal model reached normal levels at 12 weeks. No sign of host reaction was found in the X-ray scanning. The HP Mg group was comparable to the Ti group with respect to biomechanical properties of the reconstructed ACL, and the ultimate load to failure and stiffness increased 12 weeks after surgery. In the histological analysis, the HP Mg group formed distinct fibrocartilage transition zones at the tendon-bone interface 12 weeks after surgery, whereas a disorganized fibrocartilage layer was found in the Ti group. In the immunohistochemical analysis, highly positive staining of BMP-2, VEGF and the specific receptor for BMP-2 (BMPR1A) was shown at the tendon-bone interface of the HP Mg group compared with the Ti group. Furthermore, the HP Mg group had significantly higher expression of BMP-2 and VEGF than the Ti group in the early phase of tendon-bone healing, followed by enhanced expression of fibrocartilage markers and GAG production. Therefore we proposed that the stimulation of BMP-2 and VEGF by Mg ions was responsible for the fibrochondrogenesis of Mg materials. HP Mg was promising as a

  10. Novel mechanism for temperature-independent transitions in flexible molecules: role of thermodynamic fluctuations

    OpenAIRE

    Teslenko, V. I.; Petrov, E. G.; A. Verkhratsky; Krishtal, O. A.

    2010-01-01

    Novel physical mechanism is proposed for explanation of temperature-independent transition reactions in molecular systems. The mechanism becomes effective in the case of conformation transitions between quasi-isoenergetic molecular states. It is shown that at room temperatures, stochastic broadening of molecular energy levels predominates the energy of low frequency vibrations accompanying the transition. This leads to a cancellation of temperature dependence in the stochastically averaged ra...

  11. Multifunctional Thin Film Biomatrice Biosensor in a Degradable Scaffold Containing Bone Morphogenetic Protein-2 (BMP-2) for Controlled Release in Skeletal Tissue Engineering

    Science.gov (United States)

    McDaniel, Harvey; Lomax, Linda

    2001-03-01

    Bone morphonogenetic proteins (BMP-2) have been under investigation for three decades. Deminerialized bone and extracts of deminerialized bone are o steoinductive with a temporal sequence of bone induction. Native and recombi nant BMP's have shown the ability, thru growth and differentiative factors t o induce de novo bone formation both invitro and invivo. Their principle fun ction is to induce transformation of undifferentiated mesenchymal cells into osteoblasts. Native and recombinant BMP's, when purified and used without carrier disp erse after implantation and exert no effect on bone induction. The delivery system provides the missing component to successsfully applying osteogenic p roteins for clinical need. Biological and physio-chemical properties are str ictly adhered tofor a successful delivery system. The BMP delivery system ca rrier for osteo inductive payload provided; 1)non tumorgenic genecity, 2) no n immunogenecity, 3) water insoluble, 4) biosorbability with predictable enz ymatic degradation, and 5) an optimized surface for compatibility, cell migr ation and attachment with a negative surface change that encouraged target c ell attachment. Being a controlled Release System, it binded the proteins wi th predictible BMP released kinetics. Porosity with interconnecting voids pr otected the BMP from noon specific proteolysis and promoted rapid vascular a nd mesenchymal invasion. Far wide ranging clinical applications of mechanica l and biofunctional requirements were met with the BMP delivery system. Cohe sion and malleability were reqiured forcontour augmentation, and reconstruct ion of the discontinuity defects, prevented dislocation and retained the sha pe and bone replaced the system. Biological systems have elastic activity associated with them. The activi ty was current associated with a time dependant biological/biochemical react ion (enzymic activity). Bioelectric phoenomena associated with charged molec ules in a biologic structure caused

  12. Mechanical forces stimulate endothelial microparticle generation via caspase-dependent apoptosis-independent mechanism

    OpenAIRE

    Vion, Anne Clémence; Birukova, Anna A.; Boulanger, Chantal M; Birukov, Konstantin G.

    2013-01-01

    Microparticle release by vascular endothelium has been implicated in various cardiovascular pathologies. Ventilator-induced lung injury (VILI) is a life-threatening complication of mechanical ventilation at high tidal volumes associated with excessive mechanical stretch of pulmonary vascular endothelial cells. However, a role of VILI-relevant levels of cyclic stretch in microparticle generation by vascular endothelium remains unknown. We report microparticle formation by human pulmonary endot...

  13. Engineering interpenetrating network hydrogels as biomimetic cell niche with independently tunable biochemical and mechanical properties.

    Science.gov (United States)

    Tong, Xinming; Yang, Fan

    2014-02-01

    Hydrogels have been widely used as artificial cell niche to mimic extracellular matrix with tunable properties. However, changing biochemical cues in hydrogels developed-to-date would often induce simultaneous changes in mechanical properties, which do not support mechanistic studies on stem cell-niche interactions. Here we report the development of a PEG-based interpenetrating network (IPN), which is composed of two polymer networks that can independently and simultaneously crosslink to form hydrogels in a cell-friendly manner. The resulting IPN hydrogel allows independently tunable biochemical and mechanical properties, as well as stable and more homogeneous presentation of biochemical ligands in 3D than currently available methods. We demonstrate the potential of our IPN platform for elucidating stem cell-niche interactions by modulating osteogenic differentiation of human adipose-derived stem cells. The versatility of such IPN hydrogels is further demonstrated using three distinct and widely used polymers to form the mechanical network while keeping the biochemical network constant.

  14. Effects of recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) in grade III open tibia fractures treated with unreamed nails-A clinical and health-economic analysis.

    Science.gov (United States)

    Alt, Volker; Borgman, Benny; Eicher, Alexander; Heiss, Christian; Kanakaris, Nikolaos K; Giannoudis, Peter V; Song, Fujian

    2015-11-01

    Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is licensed in Europe for open tibia fractures treated with unreamed nails. However, there is limited data available on the specific use of rhBMP-2 in combination with unreamed nails for open tibia fractures. The intention of the current study was to evaluate the medical and health-economic effects of rhBMP-2 in Gustilo-Anderson grade III open tibia fractures treated with unreamed nails based on individual patient data from two previously published studies. Linear regression analysis was performed on raw data of 90 patients that were either treated by standard of care with soft tissue management and unreamed nailing (SOC group) (n=50) or with rhBMP-2 in addition to soft tissue management and unreamed nailing (rhBMP-2 group) (n=40). For all types of revision, a significant lower percentage of patients (27.5%) of the rhBMP-2 group had to be revised compared to 48% of the patients of the SOC group (p=0.04). When only invasive secondary interventions such as bone grafting and nail exchange were considered, there was also a statistically significant reduction in the rhBMP-2 group with a revision rate of 10.0% (4 of 40 patients) compared to the SOC group with a revision rate of 28.0% (14 of 50 patients) (p=0.01). Mean fracture healing time of 228 days in the rhBMP-2 compared to 266 days in the SOC group was not statistically significant (p=0.24). Health-economic analysis based on a societal perspective with calculation of overall treatment costs after initial surgery and including productivity losses revealed savings of €6,239 per patient for Germany and €4,752 for the UK in favour of rhBMP-2 which was mainly driven by reduction of productivity losses. In conclusion, rhBMP-2 reduces secondary interventions in patients with grade III open tibia fractures treated with an unreamed nail and its use leads to financial savings for Germany and the UK from a societal perspective. PMID:26374949

  15. Heterotopic ossification following single-level anterior cervical discectomy and fusion: results from the prospective, multicenter, historically controlled trial comparing allograft to an optimized dose of rhBMP-2.

    Science.gov (United States)

    Arnold, Paul M; Anderson, Karen K; Selim, Abdulhafez; Dryer, Randall F; Kenneth Burkus, J

    2016-09-01

    OBJECTIVE Heterotopic ossification (HO) has been reported following total hip, knee, cervical, and lumbar arthroplasty, as well as following posterolateral lumbar fusion using recombinant human bone morphogenetic protein-2 (rhBMP-2). Data regarding HO following anterior cervical discectomy and fusion (ACDF) with rhBMP-2 are sparse. A subanalysis was done of the prospective, multicenter, investigational device exemption trial that compared rhBMP-2 on an absorbable collagen sponge (ACS) versus allograft in ACDF for patients with symptomatic single-level cervical degenerative disc disease. METHODS To assess differences in types of HO observed in the treatment groups and effects of HO on functional and efficacy outcomes, clinical outcomes from previous disc replacement studies were compared between patients who received rhBMP-2/ACS versus allograft. Rate, location, grade, and size of ossifications were assessed preoperatively and at 24 months, and correlated with clinical outcomes. RESULTS Heterotopic ossification was primarily anterior in both groups. Preoperatively in both groups, and including osteophytes in the target regions, HO rates were high at 40.9% and 36.9% for the rhBMP-2/ACS and allograft groups, respectively (p = 0.350). At 24 months, the rate of HO in the rhBMP-2/ACS group was higher than in the allograft group (78.6% vs 59.2%, respectively; p disc spaces significantly reduced range of motion, more so in the rhBMP-2/ACS group. At 24 months, HO negatively affected Neck Disability Index scores (excluding neck/arm pain scores), neurological status, and overall success in patients in the rhBMP-2/ACS group, but not in patients in the allograft group. CONCLUSIONS Implantation of rhBMP-2/ACS at 1.5 mg/ml with polyetheretherketone spacer and titanium plate is effective in inducing fusion and improving pain and function in patients undergoing ACDF for symptomatic single-level cervical degenerative disc disease. At 24 months, the rate and dimensions (length and

  16. Generation of an rhBMP-2-loaded beta-tricalcium phosphate/hydrogel composite and evaluation of its efficacy on peri-implant bone formation

    International Nuclear Information System (INIS)

    Dental implant insertion on a site with low bone quality or bone defect should be preceded by a bone graft or artificial bone graft insertion to heal the defect. We generated a beta-tricalcium phosphate (β-TCP) and poloxamer 407-based hydrogel composite and penetration of the β-TCP/hydrogel composite into the peri-implant area of bone was evaluated by porous bone block experiments. The maximum penetration depth for porous bone blocks and dense bone blocks were 524 μm and 464 μm, respectively. We report the in-vivo performance of a composite of β-TCP/hydrogel composite as a carrier of recombinant human bone morphogenetic protein (rhBMP-2), implanted into a rabbit tibial defect model. Three holes drilled into each tibia of eight male rabbits were (1) grafted with dental implant fixtures; (2) filled with β-TCP/hydrogel composite (containing 5 μg of rhBMP-2), followed by grafting of the dental implant fixtures. Four weeks later, bone-implant contact ratio and peri-implant bone formation were analyzed by radiography, micro-CT and histology of undecalcified specimens. The micro-CT results showed a significantly higher level of trabecular thickness and new bone and peri-implant new bone formation in the experimental treatment compared to the control treatment. Histomorphometry revealed a significantly higher bone-implant contact ratio and peri-implant bone formation with the experimental treatment. The use of β-TCP/poloxamer 407 hydrogel composite as a carrier of rhBMP-2 significantly promoted new bone formation around the dental implant fixture and it also improved the quality of the new bone formed in the tibial marrow space. (paper)

  17. The multifaceted effects of agmatine on functional recovery after spinal cord injury through Modulations of BMP-2/4/7 expressions in neurons and glial cells.

    Directory of Open Access Journals (Sweden)

    Yu Mi Park

    Full Text Available Presently, few treatments for spinal cord injury (SCI are available and none have facilitated neural regeneration and/or significant functional improvement. Agmatine (Agm, a guanidinium compound formed from decarboxylation of L-arginine by arginine decarboxylase, is a neurotransmitter/neuromodulator and been reported to exert neuroprotective effects in central nervous system injury models including SCI. The purpose of this study was to demonstrate the multifaceted effects of Agm on functional recovery and remyelinating events following SCI. Compression SCI in mice was produced by placing a 15 g/mm(2 weight for 1 min at thoracic vertebra (Th 9 segment. Mice that received an intraperitoneal (i.p. injection of Agm (100 mg/kg/day within 1 hour after SCI until 35 days showed improvement in locomotor recovery and bladder function. Emphasis was made on the analysis of remyelination events, neuronal cell preservation and ablation of glial scar area following SCI. Agm treatment significantly inhibited the demyelination events, neuronal loss and glial scar around the lesion site. In light of recent findings that expressions of bone morphogenetic proteins (BMPs are modulated in the neuronal and glial cell population after SCI, we hypothesized whether Agm could modulate BMP- 2/4/7 expressions in neurons, astrocytes, oligodendrocytes and play key role in promoting the neuronal and glial cell survival in the injured spinal cord. The results from computer assisted stereological toolbox analysis (CAST demonstrate that Agm treatment dramatically increased BMP- 2/7 expressions in neurons and oligodendrocytes. On the other hand, BMP- 4 expressions were significantly decreased in astrocytes and oligodendrocytes around the lesion site. Together, our results reveal that Agm treatment improved neurological and histological outcomes, induced oligodendrogenesis, protected neurons, and decreased glial scar formation through modulating the BMP- 2/4/7 expressions following

  18. A Cytochrome P450-Independent Mechanism of Acetaminophen-Induced Injury in Cultured Mouse Hepatocytes.

    Science.gov (United States)

    Miyakawa, Kazuhisa; Albee, Ryan; Letzig, Lynda G; Lehner, Andreas F; Scott, Michael A; Buchweitz, John P; James, Laura P; Ganey, Patricia E; Roth, Robert A

    2015-08-01

    Mouse hepatic parenchymal cells (HPCs) have become the most frequently used in vitro model to study mechanisms of acetaminophen (APAP)-induced hepatotoxicity. It is universally accepted that APAP hepatocellular injury requires bioactivation by cytochromes P450 (P450s), but this remains unproven in primary mouse HPCs in vitro, especially over the wide range of concentrations that have been employed in published reports. The aim of this work was to test the hypothesis that APAP-induced hepatocellular death in vitro depends solely on P450s. We evaluated APAP cytotoxicity and APAP-protein adducts (a biomarker of metabolic bioactivation by P450) using primary mouse HPCs in the presence and absence of a broad-spectrum inhibitor of P450s, 1-aminobenzotriazole (1-ABT). 1-ABT abolished formation of APAP-protein adducts at all concentrations of APAP (0-14 mM), but eliminated cytotoxicity only at small concentrations (≦5 mM), indicating the presence of a P450-independent mechanism at larger APAP concentrations. P450-independent cell death was delayed in onset relative to toxicity observed at smaller concentrations. p-Aminophenol was detected in primary mouse HPCs exposed to large concentrations of APAP, and a deacetylase inhibitor [bis (4-nitrophenyl) phosphate (BNPP)] significantly reduced cytotoxicity. In conclusion, APAP hepatocellular injury in vitro occurs by at least two mechanisms, a P450-dependent mechanism that operates at concentrations of APAP ≦ 5 mM and a P450-independent mechanism that predominates at larger concentrations and is slower in onset. p-Aminophenol most likely contributes to the latter mechanism. These findings should be considered in interpreting results from APAP cytotoxicity studies in vitro and in selecting APAP concentrations for use in such studies. PMID:26065700

  19. CONSTRUCTION OF RECOMBINANT PLASMID pcDNA3.1/BMP-2 AND ITS INVOLVEMENT IN DIFFERENTIATION OF HUMAN DENTAL PULP-DERIVED CELLS INTO AN ODONTOBLASTIC LINEAGE

    Directory of Open Access Journals (Sweden)

    Boy M. Bachtiar

    2009-06-01

    Full Text Available Experimental studies have shown that dental pulp tissue has potential to regenerate dentine in response to adverse stimuli, such as caries and associated operative procedures. However, the potential of dental pulp regeneration seems to be limited by regenerative capacity of the cell involved. In this study, we report the effect of transfection of a recombinant plasmid containing human BMP-2 gene in proliferation and differentiation of dental pulp tissue in vitro. The regenerative capacity was analyzed by ALP production and calcium content. Results showed that the transfected dental pulp cell was able to differentiate into the odontoblast phenotype, indicating the presence of odontoblast progentitor cells in dental pulp tissue.

  20. The toxic effects of Tris-(2,3-dibromopropyl)isocyanurate(TBC) on genes expression of bmp2b and bmp4 of zebrafish embryos

    Institute of Scientific and Technical Information of China (English)

    JIA Wan-jun

    2016-01-01

    We exposed zebrafish embryos to Tris-(2,3-dibromopropyl)isocyanurate(TBC)at the concentration of 20ppb, 100ppb, 400ppb, 1000ppb for 120h and 0.1%DMSO was set as the control group. Bmp2b and bmp4 were chosen perform RT-PCR to determine their genes expression level. The results showed that, TBC influenced their genes expression level in some extent and it significantly raised the genes expression level at the concentration of 20ppb.

  1. Various mechanisms in cyclopeptide production from precursors synthesized independently of non-ribosomal peptide synthetases

    Institute of Scientific and Technical Information of China (English)

    Wenyan Xu; Liling Li; Liangcheng Du; Ninghua Tan

    2011-01-01

    An increasing number of cyclopeptides have been discovered as products of ribosomal synthetic pathway.The biosynthetic study of these cyclopeptides has revealed interesting new mechanisms for cyclization.This review highlighted the recent discoveries in cyclization mechanisms for cyclopeptides synthesized independently of non-ribosomal peptide synthetases,including endopeptidase-catalyzed cyclization,intein-mediated cyclization,and peptide synthetase-catalyzed cyclization.This information may help to design hybrid ribosomal and non-ribosomal biosynthetic systems to produce novel cyclopeptides with various bioactivities.

  2. 转染Ad-hBMP2的脂肪干细胞与壳聚糖/磷酸三钙复合物支架的相容性%Compatibility of Adipose-derived Stem Cells Transfected by Ad-hBMP2 Gene and CTCP Scaffold in vitro

    Institute of Scientific and Technical Information of China (English)

    方忠; 杨琴; 熊伟; 李光辉; 廖晖; 李锋; 肖骏

    2012-01-01

    Objective To observe the biological behavior of cultured adipose-derived stem cells(ADSCs)transfected by Ad-hBMP2 combined with chitosan/tricalcium phosphate(CTCP)scaffold and investigate the feasibility of the composite for cartilage tissue engineering. Methods The ADSCsQ X 106/mL) transfected with Ad-hBMP2 plasmid vector were co-cultured with the CTCP scaffold. The adhesion and proliferation of ADSCs, and the morphological changes were observed. RT-PCR, Western blot and immunohistochemistry were applied to detect the expression of Osteocalcin and collagen I in the scaffold. Results The poriferous CTCP scaffold has macro and micro poriferous structures,and the porous rate was 83%. The ADSCs transfected by Ad-hBMP2 have been successfully cultured in vitro. The induced cells adhered to the surface of the scaffold and proliferated well. The RT-PCR,Western blot and immunohistochemistry revealed that the expression of Osteocalcin and collagen I was detected after the co-culture. Conclusion The poriferous CTCP scaffold with excellent property should be a good "matrix" for ADSCs transfected by Ad-hBMP2, and could be used for bone tissue engineering.%目的 探讨转染腺病毒骨形态发生蛋白(Ad-hBMP2)基因的脂肪干细胞(ADSCs)与壳聚糖/磷酸三钙(CTCP)复合物支架的相容性,以期为ADSCs修复骨缺损寻找理想的组织工程骨支架材料.方法 将壳聚糖与磷酸三钙进行复合制成CTCP复合物材料,再将其与转染Ad-hBMP2的ADSCs(密度1×106/mL)复合培养,进行细胞复合物支架的一般与超微形态学观察,观察细胞粘附能力、增殖活力,RT-PCR及Western blot测定成骨细胞骨钙素和Ⅰ型胶原水平.结果 CTCP支架孔径200~350 μm,孔隙率83%;电镜显示转染Ad-hBMP2的ADSCs与CTCP复合物在体外培养期间支架无塌陷及形变,且其在支架上粘附、增殖良好,并能分泌细胞外基质如骨钙素和Ⅰ型胶原等;随着培养时间延长,骨的组织学特征

  3. 核心结合因子α1在BMP-2调控细胞外基质蛋白表达中的作用%Study of cbfα1 on the expression of extracellular matrix proteins in dental papilla cells induced by BMP-2 in vitro

    Institute of Scientific and Technical Information of China (English)

    余擎; 朱庆林; 孙汉堂; 田宇; 何文喜; 肖明振

    2008-01-01

    目的:探讨核心结合因子α1(cbfa1)在BMP-2调控体外培养的牙乳头细胞表达细胞外基质蛋白中的作用.方法:采用反义核酸技术,体外阻断培养的牙乳头细胞中cbfα1的表达,分别用RT-PCR、Western印迹等方法观察200ng/mL BMP-2作用6h后细胞中相关基质蛋白,碱性磷酸酶(ALP)、骨钙素(OC)、骨连蛋白(ON)、骨桥素(OPN)、骨涎蛋白(BSP)、牙本质基质蛋白1(DMP-1)以及牙本质涎磷蛋白(DSPP)的表达,采用SPSS 11.0软件包对数据进行方差分析.结果:外源性BMP-2能明显上调牙乳头细胞中ALP、OC含量以及OPN、BSP和ON的表达,当反义阻断cbfα1的表达时,ALP、OC、OPN和BSP的表达显著降低(P<0.01).结论:cbfα1参与了BMP-2调控体外培养的牙乳头细胞表达细胞外基质蛋白的信号转导过程.

  4. Gq-mediated Akt translocation to the membrane: a novel PIP3-independent mechanism in platelets.

    Science.gov (United States)

    Badolia, Rachit; Manne, Bhanu Kanth; Dangelmaier, Carol; Chernoff, Jonathan; Kunapuli, Satya P

    2015-01-01

    Akt is an important signaling molecule regulating platelet aggregation. Akt is phosphorylated after translocation to the membrane through Gi signaling pathways by a phosphatidylinositol-3,4,5-trisphosphate (PIP3)-dependent mechanism. However, Akt is more robustly phosphorylated by thrombin compared with adenosine 5'-diphosphate in platelets. This study investigated the mechanisms of Akt translocation as a possible explanation for this difference. Stimulation of washed human platelets with protease-activated receptor agonists caused translocation of Akt to the membrane rapidly, whereas phosphorylation occurred later. The translocation of Akt was abolished in the presence of a Gq-selective inhibitor or in Gq-deficient murine platelets, indicating that Akt translocation is regulated downstream of Gq pathways. Interestingly, phosphatidylinositol 3-kinase (PI3K) inhibitors or P2Y12 antagonist abolished Akt phosphorylation without affecting Akt translocation to the membrane, suggesting that Akt translocation occurs through a PI3K/PIP3/Gi-independent mechanism. An Akt scaffolding protein, p21-activated kinase (PAK), translocates to the membrane after stimulation with protease-activated receptor agonists in a Gq-dependent manner, with the kinetics of translocation similar to that of Akt. Coimmunoprecipitation studies showed constitutive association of PAK and Akt, suggesting a possible role of PAK in Akt translocation. These results show, for the first time, an important role of the Gq pathway in mediating Akt translocation to the membrane in a novel Gi/PI3K/PIP3-independent mechanism.

  5. A combined moving mechanism with independent movement in longitudinal direction and transverse direction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To make the detecting robot move on the surface of the finned tubes, a novel combined moving mechanism is developed. The combined moving mechanism is composed of sprocket wheel and drum-like small wheel installed on the chain. It can make the robot move independently in the direction parallel to the tubes and in the direction perpendicular to the tubes. This paper made a detailed discussion on the composition of the combined moving mechanism, the design method of the conjugate outline curve and the circular-arc outline curve of the drum-like small wheel that meshes with the tubes. The error of the circular-arc outline curve is also analyzed.

  6. Prickle isoforms control the direction of tissue polarity by microtubule independent and dependent mechanisms

    Science.gov (United States)

    Sharp, Katherine A.; Axelrod, Jeffrey D.

    2016-01-01

    ABSTRACT Planar cell polarity signaling directs the polarization of cells within the plane of many epithelia. While these tissues exhibit asymmetric localization of a set of core module proteins, in Drosophila, more than one mechanism links the direction of core module polarization to the tissue axes. One signaling system establishes a polarity bias in the parallel, apical microtubules upon which vesicles containing core proteins traffic. Swapping expression of the differentially expressed Prickle isoforms, Prickle and Spiny-legs, reverses the direction of core module polarization. Studies in the proximal wing and the anterior abdomen indicated that this results from their differential control of microtubule polarity. Prickle and Spiny-legs also control the direction of polarization in the distal wing (D-wing) and the posterior abdomen (P-abd). We report here that this occurs without affecting microtubule polarity in these tissues. The direction of polarity in the D-wing is therefore likely determined by a novel mechanism independent of microtubule polarity. In the P-abd, Prickle and Spiny-legs interpret at least two directional cues through a microtubule-polarity-independent mechanism. PMID:26863941

  7. Two independent killing mechanisms of Candida albicans by human neutrophils: evidence from innate immunity defects.

    Science.gov (United States)

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; van Houdt, Michel; Verkuijlen, Paul J J H; Herbst, Martin; Liese, Johannes G; van de Veerdonk, Frank L; Roos, Dirk; van den Berg, Timo K; Kuijpers, Taco W

    2014-07-24

    Invasive fungal infections, accompanied by high rates of mortality, represent an increasing problem in medicine. Neutrophils are the major effector immune cells in fungal killing. Based on studies with neutrophils from patients with defined genetic defects, we provide evidence that human neutrophils use 2 distinct and independent phagolysosomal mechanisms to kill Candida albicans. The first mechanism for the killing of unopsonized C albicans was found to be dependent on complement receptor 3 (CR3) and the signaling proteins phosphatidylinositol-3-kinase and caspase recruitment domain-containing protein 9 (CARD9), but was independent of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. The second mechanism for the killing of opsonized C albicans was strictly dependent on Fcγ receptors, protein kinase C (PKC), and reactive oxygen species production by the NADPH oxidase system. Each of the 2 pathways of Candida killing required Syk tyrosine kinase activity, but dectin-1 was dispensable for both of them. These data provide an explanation for the variable clinical presentation of fungal infection in patients suffering from different immune defects, including dectin-1 deficiency, CARD9 deficiency, or chronic granulomatous disease. PMID:24948657

  8. IFNγ inhibits Th17 differentiation and function via Tbet-dependent and Tbet-independent mechanisms

    Science.gov (United States)

    Yeh, Wen-I; McWilliams, Ian L.; Harrington, Laurie E.

    2015-01-01

    The transcription factor Tbet is critical for the differentiation of Th1 CD4 T cells and is associated with the induction of multiple autoimmune diseases, including experimental autoimmune encephalomyelitis (EAE). Herein, we demonstrate that Tbet suppresses IL-17A and Th17 differentiation both in vitro and in vivo in a cell-intrinsic manner, and that in fact, Tbet is not necessary for EAE induction. Moreover, we find that IFNγ inhibits the production of IL-17A and IL-17F in a STAT1-dependent, Tbet-independent manner. These findings illustrate multiple mechanisms utilized by developing Th1 cells to silence the Th17 program. PMID:24369297

  9. How to check quantum mechanics independently (Reply to arXiv:1505.04293)

    CERN Document Server

    Ozhigov, Yuri I

    2015-01-01

    This is the reply to the paper of Andrei Khrennikov arXiv:1505.04293 in which he expresses dissatisfaction with that the rough data in quantum experiments is not easily available and compares it with the open rough data in genetics. I try to explain why quantum experiments rough data is closed and why it differs radically from the biological. I also tried to answer the more thorny issue: is it possible to check quantum mechanics independently of other humans, e.g. trusting nobody.

  10. Ret-dependent and Ret-independent mechanisms of Gfl-induced sensitization

    Directory of Open Access Journals (Sweden)

    Meadows Rena M

    2011-03-01

    Full Text Available Abstract Background The GDNF family ligands (GFLs are regulators of neurogenic inflammation and pain. We have previously shown that GFLs increase the release of the sensory neuron neuropeptide, calcitonin gene-related peptide (CGRP from isolated mouse DRG. Results Inhibitors of the mitogen-activated protein kinase (MAPK pathway abolished the enhancement of CGRP release by GDNF. Neurturin-induced enhancement in the stimulated release of CGRP, used as an indication of sensory neuronal sensitization, was abolished by inhibition of the phosphatidylinositol-3 kinase (PI-3K pathway. Reduction in Ret expression abolished the GDNF-induced sensitization, but did not fully inhibit the increase in stimulus-evoked release of CGRP caused by neurturin or artemin, indicating the presence of Ret-independent GFL-induced signaling in sensory neurons. Integrin β-1 and NCAM are involved in a component of Ret-independent GFL signaling in sensory neurons. Conclusions These data demonstrate the distinct and variable Ret-dependent and Ret-independent signaling mechanisms by which GFLs induce sensitization of sensory neurons. Additionally, there is a clear disconnect between intracellular signaling pathway activation and changes in sensory neuronal function.

  11. TFIIB-facilitated recruitment of preinitiation complexes by a TAF-independent mechanism.

    Science.gov (United States)

    Hori, Roderick T; Xu, Shuping; Hu, Xianyuan; Pyo, Sung

    2004-01-01

    Gene activators contain activation domains that are thought to recruit limiting components of the transcription machinery to a core promoter. VP16, a viral gene activator, has served as a model for studying the mechanistic aspects of transcriptional activation from yeast to human. The VP16 activation domain can be divided into two modules--an N-terminal subdomain (VPN) and a C-terminal subdomain (VPC). This study demonstrates that VPC stimulates core promoters that are either independent or dependent on TAFs (TATA-box Binding Protein-Associated Factors). In contrast, VPN only activates the TAF-independent core promoter and this activity increases in a synergistic fashion when VPN is dimerized (VPN2). Compared to one copy of VPN (VPN1), VPN2 also displays a highly cooperative increase in binding hTFIIB. The increased TFIIB binding correlates with VPN2's increased ability to recruit a complex containing TFIID, TFIIA and TFIIB. However, VPN1 and VPN2 do not increase the assembly of a complex containing only TFIID and TFIIA. The VPN subdomain also facilitates assembly of a complex containing TBP:TFIIA:TFIIB, which lacks TAFs, and provides a mechanism that could function at TAF-independent promoters. Taken together, these results suggest the interaction between VPN and TFIIB potentially initiate a network of contacts allowing the activator to indirectly tether TFIID or TBP to DNA.

  12. Evidence for icaADBC-Independent Biofilm Development Mechanism in Methicillin-Resistant Staphylococcus aureus Clinical Isolates

    OpenAIRE

    Fitzpatrick, Fidelma; Humphreys, Hilary; O'Gara, James P.

    2005-01-01

    Synthesis of a polysaccharide adhesin by icaADBC-encoded enzymes is currently the best-understood mechanism of staphylococcal biofilm development. In four methicillin-resistant Staphylococcus aureus isolates, environmental activation of icaADBC did not always correlate with increased biofilm production. Moreover, glucose-mediated biofilm development in these isolates was icaADBC independent. Apparently, an environmentally regulated, ica-independent mechanism(s) of biofilm development exists i...

  13. 辽宁绒山羊BMP-2基因的克隆及序列比较分析%Cloning and Sequence Analyzing of B MP-2 Gene from Liaoning Cashmere Goats

    Institute of Scientific and Technical Information of China (English)

    薛冰; 郭丹; 王春艳; 郑旭; 高月; 张世伟

    2012-01-01

    根据GenBank上绵羊的BMP-2基因序列设计特异性引物,以辽宁绒山羊基因组DNA为模板,利用聚合酶链式反应,成功克隆了常年长绒型和季节长绒型辽宁绒山羊BMP-2部分基因片段,丰富了绒山羊BMP-2基因序列。经与绵羊、牛、鼠、猪和人的BMP-2基因进行的比对结果表明,季节与常年长绒型辽宁绒山羊的BMP-2基因同源片段的同源性达到99.7%,二者与绵羊同源性为98.2%和98.4%;与牛同源性为98.2%和97.9%;与鼠同源性为86.3%和86%;与人同源性为88.1%和88.1%。结果表明,辽宁绒山羊BMP-2基因部分核苷酸序列与其他哺乳动物同源性很高,与绵羊、牛的同源性高达97%以上,这与它们的种属关系相近一致。与人、鼠的同源性也在86%以上,说明BMP-2基因在不同物种之间具有较高的保守性。%According to the BMP-2 gene sequence of sheep on the GenBank, specific primers were designed and perennial and seasonal long-staple Cashmere goat BMP type-2 partial gene fragments were successfully cloned from the Liaoning cashmere goat genomic DNA, using the polymerase chain reaction. With the sheep, cat- tie, rats, pigs and human BMP-2 gene than on the results show that seasonal and perennial long-staple type of Liaoning cashmere goats homologous fragment of BMP-2 homology 99.7%, respeciively homology with the sheep was 98.2% and 98.4%; and bovine homology was 98.2% and 97.9%; and rat homolgy 86.3% and 86%; and human homology was 88.1% and 88.1%. The results showed that BMP-2 in Liaoning Cashmere goat gene partial nucleotide sequence homology with other mammals, which is similar to their relationship of species, and BMP-2 gene were conserved in different species.

  14. Implant Composed of Demineralized Bone and Mesenchymal Stem Cells Genetically Modified with AdBMP2/AdBMP7 for the Regeneration of Bone Fractures in Ovis aries

    Science.gov (United States)

    Hernandez-Hurtado, Adelina A.; Lara-Arias, Jorge; Romero-Diaz, Viktor J.; Abrego-Guerra, Adalberto; Vilchez-Cavazos, Jose F.; Elizondo-Riojas, Guillermo; Martinez-Rodriguez, Herminia G.; Espinoza-Juarez, Marcela A.; Mendoza Lemus, Oscar F.

    2016-01-01

    Adipose-derived mesenchymal stem cells (ADMSCs) are inducible to an osteogenic phenotype by the bone morphogenetic proteins (BMPs). This facilitates the generation of implants for bone tissue regeneration. This study evaluated the in vitro osteogenic differentiation of ADMSCs transduced individually and in combination with adenoviral vectors expressing BMP2 and BMP7. Moreover, the effectiveness of the implant containing ADMSCs transduced with the adenoviral vectors AdBMP2/AdBMP7 and embedded in demineralized bone matrix (DBM) was tested in a model of tibial fracture in sheep. This graft was compared to ewes implanted with untransduced ADMSCs embedded in the same matrix and with injured but untreated animals. In vivo results showed accelerated osteogenesis in the group treated with the AdBMP2/AdBMP7 transduced ADMSC graft, which also showed improved restoration of the normal bone morphology.

  15. COX-independent mechanisms of cancer chemoprevention by anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    Evrim eGurpinar

    2013-07-01

    Full Text Available Epidemiological and clinical studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs, including cyclooxygenase (COX-2 selective inhibitors, reduce the risk of developing cancer. Experimental studies in human cancer cell lines and rodent models of carcinogenesis support these observations by providing strong evidence for the antineoplastic properties of NSAIDs. The involvement of COX-2 in tumorigenesis and its overexpression in various cancer tissues suggest that inhibition of COX-2 is responsible for the chemopreventive efficacy of these agents. However, the precise mechanisms by which NSAIDs exert their antiproliferative effects are still a matter of debate. Numerous other studies have shown that NSAIDs can act through COX-independent mechanisms. This review provides a detailed description of the major COX-independent molecular targets of NSAIDs and discusses how these targets may be involved in their anticancer effects. Toxicities resulting from COX inhibition and the suppression of prostaglandin synthesis preclude the long-term use of NSAIDs for cancer chemoprevention. Furthermore, chemopreventive efficacy is incomplete and treatment often leads to the development of resistance. Identification of alternative NSAID targets and elucidation of the biochemical processes by which they inhibit tumor growth could lead to the development of safer and more efficacious drugs for cancer chemoprevention.

  16. Thermal fluctuations affect the transcriptome through mechanisms independent of average temperature.

    Science.gov (United States)

    Sørensen, Jesper Givskov; Schou, Mads Fristrup; Kristensen, Torsten Nygaard; Loeschcke, Volker

    2016-01-01

    Terrestrial ectotherms are challenged by variation in both mean and variance of temperature. Phenotypic plasticity (thermal acclimation) might mitigate adverse effects, however, we lack a fundamental understanding of the molecular mechanisms of thermal acclimation and how they are affected by fluctuating temperature. Here we investigated the effect of thermal acclimation in Drosophila melanogaster on critical thermal maxima (CTmax) and associated global gene expression profiles as induced by two constant and two ecologically relevant (non-stressful) diurnally fluctuating temperature regimes. Both mean and fluctuation of temperature contributed to thermal acclimation and affected the transcriptome. The transcriptomic response to mean temperatures comprised modification of a major part of the transcriptome, while the response to fluctuations affected a much smaller set of genes, which was highly independent of both the response to a change in mean temperature and to the classic heat shock response. Although the independent transcriptional effects caused by fluctuations were relatively small, they are likely to contribute to our understanding of thermal adaptation. We provide evidence that environmental sensing, particularly phototransduction, is a central mechanism underlying the regulation of thermal acclimation to fluctuating temperatures. Thus, genes and pathways involved in phototransduction are likely of importance in fluctuating climates. PMID:27487917

  17. A new heterologous fibrin sealant as scaffold to recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins for the repair of tibial bone defects.

    Science.gov (United States)

    Machado, Eduardo Gomes; Issa, João Paulo Mardegan; Figueiredo, Fellipe Augusto Tocchini de; Santos, Geovane Ribeiro Dos; Galdeano, Ewerton Alexandre; Alves, Mariana Carla; Chacon, Erivelto Luis; Ferreira Junior, Rui Seabra; Barraviera, Benedito; Cunha, Marcelo Rodrigues da

    2015-04-01

    Tissue engineering has special interest in bone tissue aiming at future medical applications Studies have focused on recombinant human bone morphogenetic protein-2 (rhBMP-2) and natural latex proteins due to the osteogenic properties of rhBMP-2 and the angiogenic characteristic of fraction 1 protein (P-1) extracted from the rubber tree Hevea brasiliensis. Furthermore, heterologous fibrin sealant (FS) has been shown as a promising alternative in regenerative therapies. The aim of this study was to evaluate these substances for the repair of bone defects in rats. A bone defect measuring 3mm in diameter was created in the proximal metaphysis of the left tibia of 60 rats and was implanted with rhBMP-2 or P-1 in combination with a new heterologous FS derived from snake venom. The animals were divided into six groups: control (unfilled bone defect), rhBMP-2 (defect filled with 5μg rhBMP-2), P-1 (defect filled with 5μg P-1), FS (defect filled with 8μg FS), FS/rhBMP-2 (defect filled with 8μg FS and 5μg rhBMP-2), FS/P-1 (defect filled with 8μg FS and 5μg P-1). The animals were sacrificed 2 and 6 weeks after surgery. The newly formed bone projected from the margins of the original bone and exhibited trabecular morphology and a disorganized arrangement of osteocyte lacunae. Immunohistochemical analysis showed intense expression of osteocalcin in all groups. Histometric analysis revealed a significant difference in all groups after 2 weeks (p0.05). A statistically significant difference (p<0.05) was observed in all groups after 6 weeks in relation to the volume of newly formed bone in the surgical area. In conclusion, the new heterologous fibrin sealant was found to be biocompatible and the combination with rhBMP-2 showed the highest osteogenic and osteoconductive capacity for bone healing. These findings suggest a promising application of this combination in the regeneration surgery. PMID:25825118

  18. 丝素蛋白增强型磷酸钙复合rhBMP-2用于绵羊腰椎椎体间融合的实验研究%Experimental study on lumbar interbody fusion with silk fibroin enhanced calcium phosphate cement composite loaded with recombinant human bone morphogenetic protein-2 in sheep

    Institute of Scientific and Technical Information of China (English)

    陈亮; 顾勇; 陈晓庆; 干旻峰; 朱雪松; 杨惠林; 唐天驷

    2010-01-01

    Objective To evaluate the osteogenic characteristics of an injectable silk fibroin (SF) enhanced calcium phosphate cement (CPC) composite loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) on lumbar interbody fusion in sheep. Methods Twenty-four mature sheep were randomly divided into two groups. Each sheep underwent L1.2, L3.4 and L5.6 lumber interbody fusion, and the three disc spaces were randomly implanted with three of the following materials: SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP2 and autogenous iliac crest bone. One group was killed at 6 months and the other at 12 months. The fusion segments were observed and analyzed by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. Results The fusion rates of SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP-2 and autogenous bone assessed by manual palpation were 0, 33.33%, 55.56% and 77.78% respectively at 6 months. At 12 months, the fusion rates improved to 11.11%, 44.44%, 77.78% and 77.78%, respectively.The biomechanical results showed that fusion stiffness was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC in 4 degrees of freedom (flexion, extension, right bending, and left bending) at 6 months. The SF/CPC/rhBMP-2 composite showed similar stiffness as autograft, which was significantly greater than CPC/rhBMP-2 and SF/CPC at 12 nonths. Both CPC/rhBMP-2 and SF/CPC/rhBMP-2 showed significantly greater stiffness at 12 months compared with that of at 6 months. The results showed that bone volume was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC at 6 months. There was significant difference among ceramic residue among SF/CPC, CPC/rhBMP-2 and SF/CPC/rhBMP-2, with SF/CPC the greatest and SF/CPC/thBMP-2 the least. At 12 months, the bone volume of SF/CPC/rhBMP-2 composite was comparable with autograft, and greater than that of CPC/rhBMP-2 and SF/CPC. The bone volume of SF/CPC, CPC/rhBMP

  19. Delta-like 1/fetal antigen 1(DLK1/FA1) inhibits BMP2 induced osteoblast differentiation through modulation of NFκB signaling pathway

    DEFF Research Database (Denmark)

    Qiu, Weimin; Abdallah, Basem; Kassem, Moustapha

    as assessed by reduced Alp activity and osteogenic gene expression including Alp, Col1a1, Runx2 and Bglap. In addition, DLK1/FA1 inhibited BMP signaling as demonstrated by reduced gene expression of BMP-responsive genes: Junb and Id1, reduced BMP2 induced luciferase activity in C2C12 BMP luciferase reporter....... Besides, we observed that DLK1/FA1 induced strong NFκB activity evidenced by NFκB responsive luciferase reporter assay and real-time RT-PCR analysis of NFκB target genes. The inhibitory effect of NFκB signaling on BMP signaling was confirmed by luciferase assay in C2C12 BMP luciferase reporter cells...

  20. Construction and identification of human BMP2-IRES-HIF1αmu adenovirus expressing carrier and its expression in HEK293 cells%人BMP2-IRES-HIF1αmu腺病毒表达载体的构建及其在HEK293细胞中的表达

    Institute of Scientific and Technical Information of China (English)

    李全营; 李谌; 郭威; 吴秀成; 王巍; 刘丹平

    2011-01-01

    目的 构建人BMP2-IRES-HIF1 αmu腺病毒表达载体,并转染HEK293细胞,为下一步转染骨髓基质细胞和体内实验打下基础.方法 PCR扩增HIF1αmu片段,用BstXⅠ和XbaⅠ双酶切回收目的片段.pIRES2-EGFP用BstXⅠ和Xba Ⅰ进行双酶切后回收大片段.将上述回收的目的基因与载体片段连接,然后转化感受态大肠杆菌DH5α扩增;PCR扩增BMP2片段,用Nhe Ⅰ和BamH Ⅰ双酶切后回收目的片段.把目的基因与载体片段连接,转化感受态大肠杆菌DH5α扩增重组腺病毒表达载体,通过酶切分析、PCR和测序进行鉴定.将构建好的质粒转染HEK293细胞,检测病毒液滴度.结果 构建了人BMP2-1RES-HIF1 αmu腺病毒表达载体,转染HEK293细胞见绿色荧光表达.结论 成功构建了人BMP2 -IRES-HIF1 αmu腺病毒表达载体,酶切分析及DNA测序证实质粒构建正确,质粒成功转染HEK293细胞,并见绿色荧光蛋白表达.%Objective To construct and identify human BMP2-IRES-HIFlotmu Adenovirus expressing carrier, trans-feet it in HEK293 cells, and determinate the virus droplet degrees. Methods PCR was used to amplify HIFlamu segments, BstX I and Xba I double enzyme cut pIRES2-EGFP and recycling purpose extract. Connecting the recovery target gene with carrier segment. Then introduced it into E. Coli for amplification. PCR was used to amplify BMP2 segments, Nhe I and BamH I double enzyme cut and recycling purpose extract. Connecting the recovery target gene with carrier segment. Then introduced it into E. Coli for amplification and restructuring adenovirus expressing carrier. Using the enzyme cut analysis, PCR for identification. The correct recombinant express plasmid was transfected into HEK293 cells, and detecting the virus droplet degrees. Results The adenovirus shuttle plasmid was constructed. Green fluorescent expression was seen in transfected HEK293 cells. Conclusion The adenovirus shuttle plasmid is constructed, it is successfully expressed in HEK

  1. Characteristics and Stimulation Potential with BMP-2 and BMP-7 of Tenocyte-Like Cells Isolated from the Rotator Cuff of Female Donors

    Science.gov (United States)

    Klatte-Schulz, Franka; Pauly, Stephan; Scheibel, Markus; Greiner, Stefan; Gerhardt, Christian; Hartwig, Jelka; Schmidmaier, Gerhard; Wildemann, Britt

    2013-01-01

    Tendon bone healing of the rotator cuff is often associated with non-healing or recurrent defects, which seems to be influenced by the patient’s age and sex. The present study aims to examine cellular biological characteristics of tenocyte-like cells that may contribute to this impaired rotator cuff healing. Moreover, a therapeutic approach using growth factors could possibly stimulate tendon bone healing. Therefore, our second aim was to identify patient groups who would particularly benefit from growth factor stimulation. Tenocyte-like cells isolated from supraspinatus tendons of female donors younger and older than 65 years of age were characterized with respect to different cellular biological parameters, such as cell density, cell count, marker expression, collagen-I protein synthesis, and stem cell potential. Furthermore, cells of the donor groups were stimulated with BMP-2 and BMP-7 (200 and 1000 ng/ml) in 3D-culture and analyzed for cell count, marker expression and collagen-I protein synthesis. Female donors older than 65 years of age showed significantly decreased cell count and collagen-I protein synthesis compared to cells from donors younger than 65 years. Cellular biological parameters including cell count, collagen-I and –III expression, and collagen-I protein synthesis of cells from both donor groups were stimulated with BMP-2 and BMP-7. The cells from donors older than 65 years revealed a decreased stimulation potential for cell count compared to the younger group. Cells from female donors older than 65 years of age showed inferior cellular biological characteristics. This may be one reason for a weaker healing potential observed in older female patients and should be taken into consideration for tendon bone healing of the rotator cuff. PMID:23825642

  2. Characteristics and stimulation potential with BMP-2 and BMP-7 of tenocyte-like cells isolated from the rotator cuff of female donors.

    Directory of Open Access Journals (Sweden)

    Franka Klatte-Schulz

    Full Text Available Tendon bone healing of the rotator cuff is often associated with non-healing or recurrent defects, which seems to be influenced by the patient's age and sex. The present study aims to examine cellular biological characteristics of tenocyte-like cells that may contribute to this impaired rotator cuff healing. Moreover, a therapeutic approach using growth factors could possibly stimulate tendon bone healing. Therefore, our second aim was to identify patient groups who would particularly benefit from growth factor stimulation. Tenocyte-like cells isolated from supraspinatus tendons of female donors younger and older than 65 years of age were characterized with respect to different cellular biological parameters, such as cell density, cell count, marker expression, collagen-I protein synthesis, and stem cell potential. Furthermore, cells of the donor groups were stimulated with BMP-2 and BMP-7 (200 and 1000 ng/ml in 3D-culture and analyzed for cell count, marker expression and collagen-I protein synthesis. Female donors older than 65 years of age showed significantly decreased cell count and collagen-I protein synthesis compared to cells from donors younger than 65 years. Cellular biological parameters including cell count, collagen-I and -III expression, and collagen-I protein synthesis of cells from both donor groups were stimulated with BMP-2 and BMP-7. The cells from donors older than 65 years revealed a decreased stimulation potential for cell count compared to the younger group. Cells from female donors older than 65 years of age showed inferior cellular biological characteristics. This may be one reason for a weaker healing potential observed in older female patients and should be taken into consideration for tendon bone healing of the rotator cuff.

  3. N-cadherin mediated distribution of beta-catenin alters MAP kinase and BMP-2 signaling on chondrogenesis-related gene expression.

    Science.gov (United States)

    Modarresi, Rozbeh; Lafond, Toulouse; Roman-Blas, Jorge A; Danielson, Keith G; Tuan, Rocky S; Seghatoleslami, M Reza

    2005-05-01

    We have examined the effect of calcium-dependent adhesion, mediated by N-cadherin, on cell signaling during chondrogenesis of multipotential embryonic mouse C3H10T1/2 cells. The activity of chondrogenic genes, type II collagen, aggrecan, and Sox9 were examined in monolayer (non-chondrogenic), and micromass (chondrogenic) cultures of parental C3H10T1/2 cells and altered C3H10T1/2 cell lines that express a dominant negative form of N-cadherin (delta390-T1/2) or overexpress normal N-cadherin (MNCD2-T1/2). Our findings show that missexpression or inhibition of N-cadherin in C3H10T1/2 cells results in temporal and spatial changes in expression of the chondrogenic genes Sox9, aggrecan, and collagen type II. We have also analyzed activity of the serum response factor (SRF), a nuclear target of MAP kinase signaling implicated in chondrogenesis. In semi-confluent monolayer cultures (minimum cell-cell contact) of C3H10T1/2, MNCD2-T1/2, or delta390-T1/2 cells, there was no significant change in the pattern of MAP kinase or bone morphogenetic protein-2 (BMP-2) regulation of SRF. However, in micromass cultures, the effect of MAP kinase and BMP-2 on SRF activity was proportional to the nuclear localization of beta-catenin, a Wnt stabilized cytoplasmic factor that can associate with lymphoid enhancer-binding factor (LEF) to serve as a transcription factor. Our findings suggest that the extent of adherens junction formation mediated by N-cadherin can modulate the potential Wnt-induced nuclear activity of beta-catenin. PMID:15723280

  4. HSET overexpression fuels tumor progression via centrosome clustering-independent mechanisms in breast cancer patients

    Science.gov (United States)

    Pannu, Vaishali; Rida, Padmashree C.G.; Ogden, Angela; Turaga, Ravi Chakra; Donthamsetty, Shashikiran; Bowen, Nathan J.; Rudd, Katie; Gupta, Meenakshi V.; Reid, Michelle D.; Cantuaria, Guilherme; Walczak, Claire E.; Aneja, Ritu

    2015-01-01

    Human breast tumors harbor supernumerary centrosomes in almost 80% of tumor cells. Although amplified centrosomes compromise cell viability via multipolar spindles resulting in death-inducing aneuploidy, cancer cells tend to cluster extra centrosomes during mitosis. As a result cancer cells display bipolar spindle phenotypes to maintain a tolerable level of aneuploidy, an edge to their survival. HSET/KifC1, a kinesin-like minus-end directed microtubule motor has recently found fame as a crucial centrosome clustering molecule. Here we show that HSET promotes tumor progression via mechanisms independent of centrosome clustering. We found that HSET is overexpressed in breast carcinomas wherein nuclear HSET accumulation correlated with histological grade and predicted poor progression-free and overall survival. In addition, deregulated HSET protein expression was associated with gene amplification and/or translocation. Our data provide compelling evidence that HSET overexpression is pro-proliferative, promotes clonogenic-survival and enhances cell-cycle kinetics through G2 and M-phases. Importantly, HSET co-immunoprecipitates with survivin, and its overexpression protects survivin from proteasome-mediated degradation, resulting in its increased steady-state levels. We provide the first evidence of centrosome clustering-independent activities of HSET that fuel tumor progression and firmly establish that HSET can serve both as a potential prognostic biomarker and as a valuable cancer-selective therapeutic target. PMID:25788277

  5. Progesterone modulates the LPS-induced nitric oxide production by a progesterone-receptor independent mechanism.

    Science.gov (United States)

    Wolfson, Manuel Luis; Schander, Julieta Aylen; Bariani, María Victoria; Correa, Fernando; Franchi, Ana María

    2015-12-15

    Genital tract infections caused by Gram-negative bacteria induce miscarriage and are one of the most common complications of human pregnancy. LPS administration to 7-day pregnant mice induces embryo resorption after 24h, with nitric oxide playing a fundamental role in this process. We have previously shown that progesterone exerts protective effects on the embryo by modulating the inflammatory reaction triggered by LPS. Here we sought to investigate whether the in vivo administration of progesterone modulated the LPS-induced nitric oxide production from peripheral blood mononuclear cells from pregnant and non-pregnant mice. We found that progesterone downregulated LPS-induced nitric oxide production by a progesterone receptor-independent mechanism. Moreover, our results suggest a possible participation of glucocorticoid receptors in at least some of the anti-inflammatory effects of progesterone.

  6. Vascular Calcification in Chronic Kidney Disease is Induced by Bone Morphogenetic Protein-2 via a Mechanism Involving the Wnt/β-Catenin Pathway

    Directory of Open Access Journals (Sweden)

    Shu Rong

    2014-11-01

    Full Text Available Background: Vascular calcification (VC, in which vascular smooth muscle cells (VSMCs undergo a phenotypic transformation into osteoblast-like cells, is one of the emergent risk factors for the accelerated atherosclerosis process characteristic of chronic kidney disease (CKD. Phosphate is an important regulator of VC. Methods: The expression of different smooth muscle cell or osteogenesis markers in response to high concentrations of phosphate or exogenous bone morphogenetic protein 2 (BMP-2 was examined by qRT-PCR and western blotting in rat VSMCs. Osteocalcin secretion was measured by radioimmunoassay. Differentiation and calcification of VSMCs were examined by alkaline phosphatase (ALP activity assay and Alizarin staining. Short hairpin RNA-mediated silencing of β-catenin was performed to examine the involvement of Wnt/β-catenin signaling in VSMC calcification and osteoblastic differentiation induced by high phosphate or BMP-2. Apoptosis was determined by TUNEL assay and immunofluorescence imaging. Results: BMP-2 serum levels were significantly higher in CKD patients than in controls. High phosphate concentrations and BMP-2 induced VSMC apoptosis and upregulated the expression of β-catenin, Msx2, Runx2 and the phosphate cotransporter Pit1, whereas a BMP-2 neutralization antibody reversed these effects. Knockdown of β-catenin abolished the effect of high phosphate and BMP-2 on VSMC apoptosis and calcification. Conclusions: BMP-2 plays a crucial role in calcium deposition in VSMCs and VC in CKD patients via a mechanism involving the Wnt/β-catenin pathway.

  7. GM-CSF and phorbol esters modulate GM-CSF receptor expression by independent mechanisms.

    Science.gov (United States)

    Brizzi, M F; Arduino, C; Avanzi, G C; Bussolino, F; Pegoraro, L

    1991-07-01

    Human granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.1 nM) down-modulates its receptor in IL-3/GM-CSF dependent M-07e cells, in KG-1 cells and normal granulocytes, whereas phorbol esters 12-O-tetradecanoylphorbol-13-acetate (TPA) (2 nM) down-modulates the GM-CSF receptor in M-07e cells and granulocytes but not in KG-1 cells. As data analysis shows by nonlinear regression, the decreased binding ability depends on a reduction of the binding sites with no significant change of their dissociation constant. To gain insight into the mechanisms involved in the GM-CSF receptor regulation, we investigated the role of protein kinase C (PKC). GM-CSF, unlike TPA, was unable to activate PKC in all the cells studied. Moreover, unlike TPA, GM-CSF was still able to down-modulate its receptor in cells where PKC was inhibited by 1-(5-isoquinolonesulphonyl)-2-methylpiperazine (H7) and staurosporine or in cells where PKC was exhausted by prolonged incubation with 1 microM TPA. Finally, the receptor re-expression rate was accelerated by protein kinases inhibitors. These results, taken together, indicate the presence of a PKC-dependent and -independent down-modulation mechanism and a negative role of the endogeneous protein kinases in GM-CSF receptor re-expression.

  8. Clofibrate Induces Heme Oxygenase 1 Expression through a PPARα-Independent Mechanism in Human Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    2013-11-01

    Full Text Available Background and Aims: Clofibrate, an established PPARα ligand, has recently been shown to have anticancer activity yet its mechanisms of action remain to be characterized. This study examined the effect of clofibrate on heme oxygenase-1 (HO-1 gene expression in A2780 (human ovarian cancer and DU145 (human prostate cancer cells. Methods and Results: We demonstrate that clofibrate induces HO-1 expression in a concentration- and time-dependent manner. The induction of HO-1 by clofibrate was detected at both mRNA and protein levels and the HO-1 gene promoter activity was also dramatically induced by clofibrate, indicating that clofibrate up-regulates HO-1 gene transcription. Surprisingly, the induction of HO-1 by clofibrate was mediated by the Nrf2 signaling pathway, not by the PPARα pathway. This was primarily demonstrated by siRNA knockdown of Nrf2 expression that significantly attenuated clofibrate-induced HO-1 gene transcription, and siRNA knockdown of PPARα that had no effect on clofibrate-induced HO-1 promoter activity. Furthermore, deletion of the antioxidant response elements (AREs in the HO-1 gene promoter diminished clofibrate-induced HO-1 transcription and deletion of the PPAR response elements (PPREs had no such effect. Likewise, application of PPARα antagonists had no effect on clofibrate-induced HO-1 expression. Conclusion: Clofibrate induces HO-1 gene expression in cancer cells through a PPARα-independent mechanism and the Nrf2 signaling pathway is indispensible for this induction.

  9. Evidence for a novel mechanism independent of myocardial iron in β-thalassemia cardiac pathogenesis.

    Directory of Open Access Journals (Sweden)

    Ekatherina Stoyanova

    Full Text Available Human β-thalassemia major is one of the most prevalent genetic diseases characterized by decrease/absence of β-globin chain production with reduction of erythrocyte number. The main cause of death of treated β-thalassemia major patients with chronic blood transfusion is early cardiac complications that have been attributed to secondary iron overload despite optimal chelation. Herein, we investigated pathophysiological mechanisms of cardiovascular dysfunction in a severe murine model of β-thalassemia from 6 to 15-months of age in the absence of confounding effects related to transfusion. Our longitudinal echocardiography analysis showed that β-thalassemic mice first display a significant increase of cardiac output in response to limited oxygen-carrying erythrocytes that progressed rapidly to left ventricular hypertrophy and structural remodeling. Following this compensated hypertrophy, β-thalassemic mice developed age-dependent deterioration of left ventricular contractility and dysfunction that led toward decompensated heart failure. Consistently, murine β-thalassemic hearts histopathology revealed cardiac remodeling with increased interstitial fibrosis but virtual absence of myocardial iron deposits. Importantly, development of thalassemic cardiac hypertrophy and dysfunction independently of iron overload has uncoupled these cardiopathogenic processes. Altogether our study on β-thalassemia major hemoglobinopathy points to two successive phases resulting from severe chronic anemia and from secondarily induced mechanisms as pathophysiologic contributors to thalassemic cardiopathy.

  10. Potential mechanism for pentachlorophenol-induced carcinogenicity: a novel mechanism for metal-independent production of hydroxyl radicals.

    Science.gov (United States)

    Zhu, Ben-Zhan; Shan, Guo-Qiang

    2009-06-01

    The hydroxyl radical ((*)OH) has been considered to be one of the most reactive oxygen species produced in biological systems. It has been shown that (*)OH can cause DNA, protein, and lipid oxidation. One of the most widely accepted mechanisms for (*)OH production is through the transition metal-catalyzed Fenton reaction. Pentachlorophenol (PCP) was one of the most widely used biocides, primarily for wood preservation. PCP is now ubiquitously present in our environment and even found in people who are not occupationally exposed to it. PCP has been listed as a priority pollutant by the U.S. Environmental Protection Agency (EPA) and classified as a group 2B environmental carcinogen by the International Association for Research on Cancer (IARC). The genotoxicity of PCP has been attributed to its two major quinoid metabolites: tetrachlorohydroquinone and tetrachloro-1,4-benzoquinone (TCBQ). Although the redox cycling of PCP quinoid metabolites to generate reactive oxygen species is believed to play an important role, the exact molecular mechanism underlying PCP genotoxicity is not clear. Using the salicylate hydroxylation assay and electron spin resonance (ESR) secondary spin-trapping methods, we found that (*)OH can be produced by TCBQ and H(2)O(2) independent of transition metal ions. Further studies showed that TCBQ, but not its corresponding semiquinone radical, the tetrachlorosemiquinone radical (TCSQ(*)), is essential for (*)OH production. The major reaction product between TCBQ and H(2)O(2) was identified to be trichloro-hydroxy-1,4-benzoquinone (TrCBQ-OH), and H(2)O(2) was found to be the source and origin of the oxygen atom inserted into this reaction product. On the basis of these data, we propose that (*)OH production by TCBQ and H(2)O(2) is not through a semiquinone-dependent organic Fenton reaction but rather through the following novel mechanism: a nucleophilic attack of H(2)O(2) to TCBQ, leading to the formation of an unstable trichloro-hydroperoxyl-1

  11. Effects of administration rhBMP-2/rhVEGF165 on tendon-bone healing after anterior cruciate ligament reconstruction in rabbits%rhBMP-2联合rhVEGF165对兔前交叉韧带重建后腱-骨愈合的影响

    Institute of Scientific and Technical Information of China (English)

    周平; 赵其纯; 尚希福; 王姚斐; 李旭; 纪小枫; 凌晓冬; 朱亚林

    2013-01-01

    目的 探讨局部联合应用重组人骨形态发生蛋白(rhBMP)-2和重组人血管内皮生长因子165 (rhVEGF165) 对兔前叉韧带重建后腱-骨早期愈合的影响.方法 78只健康成年雄性新西兰大白兔,随机分为VB、B、V、F及正常组,前4组建立双膝自体半腱肌前交叉韧带重建模型,正常组未行手术.VB组腱-骨界面注入以纤维蛋白胶(FG)为载体的rhBMP-2/rhVEGF165混合物;B组注入rhBMP-2和FG混合物;V组注入rhVEGF165和FG混合物;F组单纯注入FG.术后第2、4、8周,每组随机抽取6只兔子,右膝标本行组织学观察,左膝标本行生物力学测试.结果 术后第2周:VB组腱-骨连接紧密,成纤维细胞大量增生;B组连接紧密,可见少量软骨细胞;V、F组连接疏松,主要为纤维血管组织构成.术后第4周:VB组腱-骨界面初步形成四层结构;V、B、F组则主要由成熟的成纤维细胞构成,腱-骨连接紧密,骨隧道壁出现一定量成骨反应;术后第8周:VB组四层结构更明显,可见潮线;B组骨隧道壁侧成骨反应进步加强;V、F组腱-骨界面宽度进步变窄,成纤维细胞数目明显减少.直至术后第4、8周,VB组平均最大载负荷及刚度才较V、B、F组大(P<0.05),均低于正常组;同时V、B组生物力学性能优于F组(P<0.05).结论 rhBMP-2联合rhVEGF165对兔前交叉韧带重建术后腱-骨早期愈合具有促进作用,且联合效应强于各自单独效应.%Objective To explore effects of local administration rhBMP-2/rhVEGF165 on tendon-bone ealy healing after anterior cruciate ligament reconsctruction in rabbits. Methods Seventy eight male New Zealand white rabbits were randomly divided into Group VB,B,V,F and normal group. Bilateral anterior cruciate ligaments of each animal were removed and reconstructed with autogenetic tendon of semitendinosus muscles while normal group did not receive any operation. The fibrin glue ( FG ) containing rhBMP-2/rhVEGF165 was injected into tendon-bone interface

  12. Evolutionary Conservation of a GPCR-Independent Mechanism of Trimeric G Protein Activation.

    Science.gov (United States)

    Coleman, Brantley D; Marivin, Arthur; Parag-Sharma, Kshitij; DiGiacomo, Vincent; Kim, Seongseop; Pepper, Judy S; Casler, Jason; Nguyen, Lien T; Koelle, Michael R; Garcia-Marcos, Mikel

    2016-03-01

    Trimeric G protein signaling is a fundamental mechanism of cellular communication in eukaryotes. The core of this mechanism consists of activation of G proteins by the guanine-nucleotide exchange factor (GEF) activity of G protein coupled receptors. However, the duration and amplitude of G protein-mediated signaling are controlled by a complex network of accessory proteins that appeared and diversified during evolution. Among them, nonreceptor proteins with GEF activity are the least characterized. We recently found that proteins of the ccdc88 family possess a Gα-binding and activating (GBA) motif that confers GEF activity and regulates mammalian cell behavior. A sequence similarity-based search revealed that ccdc88 genes are highly conserved across metazoa but the GBA motif is absent in most invertebrates. This prompted us to investigate whether the GBA motif is present in other nonreceptor proteins in invertebrates. An unbiased bioinformatics search in Caenorhabditis elegans identified GBAS-1 (GBA and SPK domain containing-1) as a GBA motif-containing protein with homologs only in closely related worm species. We demonstrate that GBAS-1 has GEF activity for the nematode G protein GOA-1 and that the two proteins are coexpressed in many cells of living worms. Furthermore, we show that GBAS-1 can activate mammalian Gα-subunits and provide structural insights into the evolutionarily conserved determinants of the GBA-G protein interface. These results demonstrate that the GBA motif is a functional GEF module conserved among highly divergent proteins across evolution, indicating that the GBA-Gα binding mode is strongly constrained under selective pressure to mediate receptor-independent G protein activation in metazoans. PMID:26659249

  13. Pramipexole inhibits MPTP toxicity in mice by dopamine D3 receptor dependent and independent mechanisms.

    Science.gov (United States)

    Ramirez, Andres D; Wong, Stephen K-F; Menniti, Frank S

    2003-08-15

    The role of dopamine D3 receptors was investigated in mediating the neuroprotective effect of the dopamine D2/D3 receptor agonist (S)-2-amino-4,5,6,7-tetrahydro-6-propylamine-benzothiazole (pramipexole) in vivo. Pramipexole retained the ability to inhibit 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopamine depletion in mice in which the dopamine D3 receptor had been deleted. However, the neuroprotective efficacy was reduced in the dopamine D3 receptor-deleted mice compared to that in littermates expressing the wildtype receptor. Furthermore, the dopamine D3 receptor selective antagonist 2-(3-[4-(2-tert-butyl-6-trifluoromethyl-4-pyrimidinyl)-1-piperazinyl]propylthio)-4-pyrimidinol (A-437203) partially inhibited the neuroprotective effect of pramipexole in dopamine D3 receptor expressing mice but not in receptor-deleted mice. These results indicate that pramipexole protects dopamine neurons from MPTP-induced toxicity by mechanisms that are both dependent and independent of an interaction with dopamine D3 receptors. PMID:12954356

  14. Cinnamaldehyde modulates LPS-induced systemic inflammatory response syndrome through TRPA1-dependent and independent mechanisms.

    Science.gov (United States)

    Mendes, Saulo J F; Sousa, Fernanda I A B; Pereira, Domingos M S; Ferro, Thiago A F; Pereira, Ione C P; Silva, Bruna L R; Pinheiro, Aruanã J M C R; Mouchrek, Adriana Q S; Monteiro-Neto, Valério; Costa, Soraia K P; Nascimento, José L M; Grisotto, Marcos A G; da Costa, Robson; Fernandes, Elizabeth S

    2016-05-01

    Cinnamaldehyde is a natural essential oil suggested to possess anti-bacterial and anti-inflammatory properties; and to activate transient receptor potential ankyrin 1 (TRPA1) channels expressed on neuronal and non-neuronal cells. Here, we investigated the immunomodulatory effects of cinnamaldehyde in an in vivo model of systemic inflammatory response syndrome (SIRS) induced by lipopolysaccharide. Swiss mice received a single oral treatment with cinnamaldehyde 1 h before LPS injection. To investigate whether cinnamaldehyde effects are dependent on TRPA1 activation, animals were treated subcutaneously with the selective TRPA1 antagonist HC-030031 5 min prior to cinnamaldehyde administration. Vehicle-treated mice were used as controls. Cinnamaldehyde ameliorated SIRS severity in LPS-injected animals. Diminished numbers of circulating mononuclear cells and increased numbers of peritoneal mononuclear and polymorphonuclear cell numbers were also observed. Cinnamaldehyde augmented the number of peritoneal Ly6C(high) and Ly6C(low) monocyte/macrophage cells in LPS-injected mice. Reduced levels of nitric oxide, plasma TNFα and plasma and peritoneal IL-10 were also detected. Additionally, IL-1β levels were increased in the same animals. TRPA1 antagonism by HC-030031 reversed the changes in the number of circulating and peritoneal leukocytes in cinnamaldehyde-treated animals, whilst increasing the levels of peritoneal IL-10 and reducing peritoneal IL-1β. Overall, cinnamaldehyde modulates SIRS through TRPA1-dependent and independent mechanisms. PMID:26922677

  15. Involvement of a joker mutation in a polymerase-independent lethal mutagenesis escape mechanism.

    Science.gov (United States)

    Agudo, Rubén; de la Higuera, Ignacio; Arias, Armando; Grande-Pérez, Ana; Domingo, Esteban

    2016-07-01

    We previously characterized a foot-and-mouth disease virus (FMDV) with three amino acid replacements in its polymerase (3D) that conferred resistance to the mutagenic nucleoside analogue ribavirin. Here we show that passage of this mutant in the presence of high ribavirin concentrations resulted in selection of viruses with the additional replacement I248T in 2C. This 2C substitution alone (even in the absence of replacements in 3D) increased FMDV fitness mainly in the presence of ribavirin, prevented an incorporation bias in favor of A and U associated with ribavirin mutagenesis, and conferred the ATPase activity of 2C decreased sensitivity to ribavirin-triphosphate. Since in previous studies we described that 2C with I248T was selected under different selective pressures, this replacement qualifies as a joker substitution in FMDV evolution. The results have identified a role of 2C in nucleotide incorporation, and have unveiled a new polymerase-independent mechanism of virus escape to lethal mutagenesis. PMID:27136067

  16. Chronic central administration of Ghrelin increases bone mass through a mechanism independent of appetite regulation.

    Directory of Open Access Journals (Sweden)

    Hyung Jin Choi

    Full Text Available Leptin plays a critical role in the central regulation of bone mass. Ghrelin counteracts leptin. In this study, we investigated the effect of chronic intracerebroventricular administration of ghrelin on bone mass in Sprague-Dawley rats (1.5 μg/day for 21 days. Rats were divided into control, ghrelin ad libitum-fed (ghrelin ad lib-fed, and ghrelin pair-fed groups. Ghrelin intracerebroventricular infusion significantly increased body weight in ghrelin ad lib-fed rats but not in ghrelin pair-fed rats, as compared with control rats. Chronic intracerebroventricular ghrelin infusion significantly increased bone mass in the ghrelin pair-fed group compared with control as indicated by increased bone volume percentage, trabecular thickness, trabecular number and volumetric bone mineral density in tibia trabecular bone. There was no significant difference in trabecular bone mass between the control group and the ghrelin ad-lib fed group. Chronic intracerebroventricular ghrelin infusion significantly increased the mineral apposition rate in the ghrelin pair-fed group as compared with control. In conclusion, chronic central administration of ghrelin increases bone mass through a mechanism that is independent of body weight, suggesting that ghrelin may have a bone anabolic effect through the central nervous system.

  17. Attenuation of natural killer cell functions by capsaicin through a direct and TRPV1-independent mechanism.

    Science.gov (United States)

    Kim, Hun Sik; Kwon, Hyung-Joon; Kim, Gye Eun; Cho, Mi-Hyang; Yoon, Seung-Yong; Davies, Alexander J; Oh, Seog Bae; Lee, Heuiran; Cho, Young Keol; Joo, Chul Hyun; Kwon, Seog Woon; Kim, Sun Chang; Kim, Yoo Kyum

    2014-07-01

    The assessment of the biological activity of capsaicin, the compound responsible for the spicy flavor of chili pepper, produced controversial results, showing either carcinogenicity or cancer prevention. The innate immune system plays a pivotal role in cancer pathology and prevention; yet, the effect of capsaicin on natural killer (NK) cells, which function in cancer surveillance, is unclear. This study found that capsaicin inhibited NK cell-mediated cytotoxicity and cytokine production (interferon-γ and tumor necrosis factor-α). Capsaicin impaired the cytotoxicity of NK cells, thereby inhibiting lysis of standard target cells and gastric cancer cells by modulating calcium mobilization in NK cells. Capsaicin also induced apoptosis in gastric cancer cells, but that effect required higher concentrations and longer exposure times than those required to trigger NK cell dysfunction. Furthermore, capsaicin inhibited the cytotoxicity of isolated NK cells and of an NK cell line, suggesting a direct effect on NK cells. Antagonists of transient receptor potential vanilloid subfamily member 1 (TRPV1), a cognate capsaicin receptor, or deficiency in TRPV1 expression failed to prevent the defects induced by capsaicin in NK cells expressing functional TRPV1. Thus, the mechanism of action of capsaicin on NK cells is largely independent of TRPV1. Taken together, capsaicin may have chemotherapeutic potential but may impair NK cell function, which plays a central role in tumor surveillance. PMID:24743513

  18. Phagocytosis-dependent and independent mechanisms underlie the microglial cell damage caused by carbon nanotube agglomerates.

    Science.gov (United States)

    Shigemoto-Mogami, Yukari; Hoshikawa, Kazue; Hirose, Akihiko; Sato, Kaoru

    2016-01-01

    Although carbon nanotubes (CNTs) are used in many fields, including energy, healthcare, environmental technology, materials, and electronics, the adverse effects of CNTs in the brain are poorly understood. In this study, we investigated the effects of CNTs on cultured microglia, as microglia are the first responders to foreign materials. We compared the effects of sonicated suspensions of 5 kinds of CNTs and their flow-through filtered with a 0.22 µm membrane filter on microglial viability. We found that sonicated suspensions caused microglial cell damage, but their flow-through did not. The number of microglial aggregates was well correlated with the extent of the damage. We also determined that the CNT agglomerates consisted of two groups: one was phagocytosed by microglia and caused microglial cell damage, and the other caused cell damage without phagocytosis. These results suggest that phagocytosis-dependent and independent mechanisms underlie the microglial cell damage caused by CNT agglomerates and it is important to conduct studies about the relationships between physical properties of nanomaterial-agglomerates and cell damage. PMID:27432236

  19. WRN loss induces switching of telomerase-independent mechanisms of telomere elongation.

    Directory of Open Access Journals (Sweden)

    April Renee Sandy Gocha

    Full Text Available Telomere maintenance can occur in the presence of telomerase or in its absence, termed alternative lengthening of telomeres (ALT. ALT adds telomere repeats using recombination-based processes and DNA repair proteins that function in homologous recombination. Our previous work reported that the RecQ-like BLM helicase is required for ALT and that it unwinds telomeric substrates in vitro. WRN is also a RecQ-like helicase that shares many biochemical functions with BLM. WRN interacts with BLM, unwinds telomeric substrates, and co-localizes to ALT-associated PML bodies (APBs, suggesting that it may also be required for ALT processes. Using long-term siRNA knockdown of WRN in three ALT cell lines, we show that some, but not all, cell lines require WRN for telomere maintenance. VA-13 cells require WRN to prevent telomere loss and for the formation of APBs; Saos-2 cells do not. A third ALT cell line, U-2 OS, requires WRN for APB formation, however WRN loss results in p53-mediated apoptosis. In the absence of WRN and p53, U-2 OS cells undergo telomere loss for an intermediate number of population doublings (50-70, at which point they maintain telomere length even with the continued loss of WRN. WRN and the tumor suppressor BRCA1 co-localize to APBs in VA-13 and U-2 OS, but not in Saos-2 cells. WRN loss in U-2 OS is associated with a loss of BRCA1 from APBs. While the loss of WRN significantly increases telomere sister chromatid exchanges (T-SCE in these three ALT cell lines, loss of both BRCA1 and WRN does not significantly alter T-SCE. This work demonstrates that ALT cell lines use different telomerase-independent maintenance mechanisms that variably require the WRN helicase and that some cells can switch from one mechanism to another that permits telomere elongation in the absence of WRN. Our data suggest that BRCA1 localization may define these mechanisms.

  20. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Science.gov (United States)

    You, Jae Sung; Frey, John W; Hornberger, Troy A

    2012-01-01

    Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA) may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k) T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis. PMID:23077579

  1. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Directory of Open Access Journals (Sweden)

    Jae Sung You

    Full Text Available Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.

  2. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Science.gov (United States)

    You, Jae Sung; Frey, John W; Hornberger, Troy A

    2012-01-01

    Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA) may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k) T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.

  3. Dichloroacetate Stimulates Glycogen Accumulation in Primary Hepatocytes through an Insulin-Independent Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Lingohr, Melissa K.(Washington State University); Bull, Richard J.(SELF-EMPLOYED CONSULTANTS); Kato-Weinstein, Junko (UNIVERSITY PROGRAMS); Thrall, Brian D.(BATTELLE (PACIFIC NW LAB))

    2002-01-01

    Dichloroacetate (DCA), a by-product of water chlorination, causes liver cancer in B6C3F1 mice. A hallmark response observed in mice exposed to carcinogenic doses of DCA is an accumulation of hepatic glycogen content. To distinguish whether the in vivo glycogenic effect of DCA was dependent on insulin and insulin signaling proteins, experiments were conducted in isolated hepatocytes where insulin concentrations could be controlled. In hepatocytes isolated from male B6C3F1 mice, DCA increased glycogen levels in a dose-related manner, independently of insulin. The accumulation of hepatocellular glycogen induced by DCA was not the result of decreased glycogenolysis, since DCA had no effect on the rate of glucagon-stimulated glycogen breakdown. Glycogen accumulation caused by DCA treatment was not hindered by inhibitors of extracellular-regulated protein kinase kinase (Erk1/2 kinase or MEK) or p70 kDa S6 protein kinase (p70(S6K)), but was completely blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitors, LY294002 and wortmannin. Similarly, insulin-stimulated glycogen deposition was not influenced by the Erk1/2 kinase inhibitor, PD098509, or the p70(S6K) inhibitor, rapamycin. Unlike DCA-stimulated glycogen deposition, PI3K-inhibition only partially blocked the glycogenic effect of insulin. DCA did not cause phosphorylation of the downstream PI3K target protein, protein kinase B (PKB/Akt). The phosphorylation of PKB/Akt did not correlate to insulin-stimulated glycogenesis either. Similar to insulin, DCA in the medium decreased IR expression in isolated hepatocytes. The results indicate DCA increases hepatocellular glycogen accumulation through a PI3K-dependent mechanism that does not involve PKB/Akt and is, at least in part, different from the classical insulin-stimulated glycogenesis pathway. Somewhat surprisingly, insulin-stimulated glycogenesis also appears not to involve PKB/Akt in isolated murine hepatocytes.

  4. A Novel Human TGF-β1 Fusion Protein in Combination with rhBMP-2 Increases Chondro-Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

    Science.gov (United States)

    Claros, Silvia; Rico-Llanos, Gustavo A.; Becerra, José; Andrades, José A.

    2014-01-01

    Transforming growth factor-beta (TGF-β) is involved in processes related to the differentiation and maturation of osteoprogenitor cells into osteoblasts. Rat bone marrow (BM) cells were cultured in a collagen-gel containing 0.5% fetal bovine serum (FBS) for 10 days in the presence of rhTGF (recombinant human TGF)-β1-F2, a fusion protein engineered to include a high-affinity collagen-binding decapeptide derived from von Willebrand factor. Subsequently, cells were moderately expanded in medium with 10% FBS for 4 days and treated with a short pulse of rhBMP (recombinant human bone morphogenetic protein)-2 for 4 h. During the last 2 days, dexamethasone and β-glycerophosphate were added to potentiate osteoinduction. Concomitant with an up-regulation of cell proliferation, DNA synthesis levels were determined. Polymerase chain reaction was performed to reveal the possible stemness of these cells. Osteogenic differentiation was evaluated in terms of alkaline phosphatase activity and mineralized matrix formation as well as by mRNA expression of osteogenic marker genes. Moreover, cells were placed inside diffusion chambers and implanted subcutaneously into the backs of adult rats for 4 weeks. Histological study provided evidence of cartilage and bone-like tissue formation. This experimental procedure is capable of selecting cell populations from BM that, in the presence of rhTGF-β1-F2 and rhBMP-2, achieve skeletogenic potential in vitro and in vivo. PMID:24968268

  5. A Novel Human TGF-β1 Fusion Protein in Combination with rhBMP-2 Increases Chondro-Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Silvia Claros

    2014-06-01

    Full Text Available Transforming growth factor-beta (TGF-β is involved in processes related to the differentiation and maturation of osteoprogenitor cells into osteoblasts. Rat bone marrow (BM cells were cultured in a collagen-gel containing 0.5% fetal bovine serum (FBS for 10 days in the presence of rhTGF (recombinant human TGF-β1-F2, a fusion protein engineered to include a high-affinity collagen-binding decapeptide derived from von Willebrand factor. Subsequently, cells were moderately expanded in medium with 10% FBS for 4 days and treated with a short pulse of rhBMP (recombinant human bone morphogenetic protein-2 for 4 h. During the last 2 days, dexamethasone and β-glycerophosphate were added to potentiate osteoinduction. Concomitant with an up-regulation of cell proliferation, DNA synthesis levels were determined. Polymerase chain reaction was performed to reveal the possible stemness of these cells. Osteogenic differentiation was evaluated in terms of alkaline phosphatase activity and mineralized matrix formation as well as by mRNA expression of osteogenic marker genes. Moreover, cells were placed inside diffusion chambers and implanted subcutaneously into the backs of adult rats for 4 weeks. Histological study provided evidence of cartilage and bone-like tissue formation. This experimental procedure is capable of selecting cell populations from BM that, in the presence of rhTGF-β1-F2 and rhBMP-2, achieve skeletogenic potential in vitro and in vivo.

  6. The mechanism of kaolin clay flocculation by a cation-independent bioflocculant produced by Chryseobacterium daeguense W6

    Directory of Open Access Journals (Sweden)

    Weijie Liu

    2015-03-01

    Full Text Available In recent years, several novel cation-independent bioflocculants have been reported, which can avoid the secondary contamination caused by addition of cations. However, compared with cation-dependent bioflocculants, the flocculating mechanism of cation-independent bioflocculants is largely unknown. In this study, a cation-independent bioflocculant MBF-W6 produced by Chryseobacterium daeguense W6 was used as a model to investigate the flocculating mechanism. The results showed that the major flocculating component of MBF-W6 is a complex of proteins and polysaccharides. The zeta potential results indicated that kaolin clay particles were not precipitated due to charge neutralization and the bridging mediated by cations did not play a major role in the flocculating process. These results are consistent with the fact that MBF-W6 is a cation-independent bioflocculant. Further scanning electron microscopic observation showed that MBF-W6 induced flocs formed tight packed structure, suggesting that the kaolin clay particles maybe directly attached and bridged by bioflocculant MBF-W6. In addition, we also found out that Fe3+ ions inhibit the flocculating activity of MBF-W6 by affecting –COO− and –NH groups. Therefore this study can improve our understanding on flocculating mechanism of cation-independent bioflocculants.

  7. Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

    Science.gov (United States)

    Lehrberg, Jeffrey; Gardiner, David M

    2015-01-01

    We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response. PMID:25923915

  8. Regulation of Axolotl (Ambystoma mexicanum) Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

    Science.gov (United States)

    Lehrberg, Jeffrey; Gardiner, David M

    2015-01-01

    We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

  9. Regulation of Axolotl (Ambystoma mexicanum Limb Blastema Cell Proliferation by Nerves and BMP2 in Organotypic Slice Culture.

    Directory of Open Access Journals (Sweden)

    Jeffrey Lehrberg

    Full Text Available We have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. Blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. Because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possible to test the response of blastema cells to signaling molecules present in serum, as well as those produced by nerves. We also were able to investigate the response of blastema cells to experimentally regulated changes in BMP signaling. Blastema cells responded to all of these signals by increasing the rate of proliferation and the level of expression of the blastema marker gene, Prrx-1. The organotypic slice culture model provides the opportunity to identify and characterize the spatial and temporal co-regulation of pathways in order to induce and enhance a regenerative response.

  10. Independent risk of mechanical ventilation for AIDS-related Pneumocystis carinii pneumonia associated with bronchoalveolar lavage neutrophilia

    DEFF Research Database (Denmark)

    Bang, D.; Emborg, J.; Elkjaer, J.;

    2001-01-01

    %). In a logistic regression analysis, higher age, increased bronchoalveolar lavage (BAL) neutrophilia and a positive BAL cytomegalovirus CMV culture were associated with the need of MV. In multivariate analyses, only BAL neutrophilia remained independently predictive of mechanical ventilation. In conclusion, short...

  11. Effect of recombinant human bone morphogenetic protein 2/poly-lactide-co-glycolic acid (rhBMP-2/PLGA) with core decompression on repair of rabbit femoral head necrosis

    Institute of Scientific and Technical Information of China (English)

    Zhao-Xun Pan; Hong-Xin Zhang; Ye-Xin Wang; Long-Di Zhai; Wei Du

    2014-01-01

    Objective:To observe the effect of recombinant human bone morphogenetic protein 2/poly-lactide-co-glycolic acid (rhBMP-2/PLGA) with core decompression on repair of rabbit femoral head necrosis. Methods: Bilateral femoral head necrosis models of rabbit were established by steroid injection. A total of 48 rabbits (96 femoral head necrosis) were randomly divided into 4 groups: Group A, control group with12 rabbits, 24 femoral head necrosis;Group B, treated with rhBMP-2/PLGA implantation after core depression, with 12 rabbits, 24 femoral head necrosis;Group C, treated with rhBMP-2 implantation after core depression, with 12 rabbits, 24 femoral head necrosis;Group D treated with core depression group without implantation, with 12 rabbits, 24 femoral head necrosis. All animals were sacrificed after 12 weeks. The ability of repairing bone defect was evaluated by X-ray radiograph. Bone mineral density analysis of the defect regions were used to evaluate the level of ossification. The morphologic change and bone formation was assessed by HE staining. The angiogenesis was evaluated by VEGF immunohistochemistry. Results: The osteogenetic ability and quality of femoral head necrosis in group B were better than those of other groups after 12 weeks by X-ray radiograph and morphologic investigation. And the angiogenesis in group B was better than other groups. Group C had similar osteogenetic quality of femoral head necrosis and angiogenesis with group D. Conclusions:The treatment of rhBMP-2/PLGA implantation after core depression can promote the repair of rabbit femoral head necrosis. It is a promising and efficient synthetic bone material to treat the femoral head necrosis.

  12. Histological and radiographic evaluation of the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2 in a scaffold of inorganic bone and after stimulation with low-power laser light

    Directory of Open Access Journals (Sweden)

    Bengtson Antonio

    2010-01-01

    Full Text Available Objective: The present study histologically and radiologically evaluates the muscle tissue of rats after implantation of bone morphogenic protein (rhBMP-2 in a natural inorganic bone mineral scaffold from a bull calf femur and irradiation with low-power light laser. Materials and Methods: The right and left hind limbs of 16 rats were shaved and an incision was made in the muscle on the face corresponding to the median portion of the tibia, into which rhBMP-2 in a scaffold of inorganic bone was implanted. Two groups of limbs were formed: control (G1 and laser irradiation (G2. G2 received diode laser light applied in the direction of the implant, at a dose of 8 J/cm2 for three minutes. On the 7th, 21st, 40th and 112th days after implantation, hind limbs of 4 animals were radiographed and their implants removed together with the surrounding tissue for study under the microscope. The histological results were graded as 0=absence, 1=slight presence, 2=representative and 3=very representative, with regard to the following events: formation of osteoid structure, acute inflammation, chronic inflammation, fibrin deposition, neovascularization, foreign-body granuloma and fibrosis. Results: There were no statistically significant differences in these events at each evaluation times, between the two groups (P > 0.05; Mann-Whitney test. Nevertheless, it could be concluded that the natural inorganic bone matrix with rhBMP-2, from the femur of a bull calf, is a biocompatible combination. Conclusions: Under these conditions, the inductive capacity of rhBMP-2 for cell differentiation was inhibited. There was a slight acceleration in tissue healing in the group that received irradiation with low-power laser light.

  13. Study on the Drug-loading Pattern of BMP2 Slow-release Microspheres%载骨形态发生蛋白2缓释微球载药形式研究

    Institute of Scientific and Technical Information of China (English)

    陈发明; 吴织芬; 王勤涛; 金岩; 王国芳; 杜岩

    2005-01-01

    目的:探讨右旋糖酐-甲基丙烯酸缩水甘油酯载骨形态发生蛋白 2(BMP2-DEX-GMA)凝胶微球的载药形式.方法:采用放射免疫分析法测定.结果: BMP2-DEX-GMA凝胶微球载药形式为内部包埋(DE)与表面吸附(DA)并存,且随着粒径增大, DA减少、 DE增加,但统计学检验结果显示粒径为 20μ m~ 40μ m的凝胶微球载药形式 DA、 DE间比较无显著性差异(P>0. 05).结论:粒径的改变可以影响 BMP2-DEX-GMA凝胶微球的载药形式,但不会改变其释药特征,尚需对载药材料进行改性才能实现对药物的控释.

  14. The use of a path independent integral in non-linear fracture mechanics

    International Nuclear Information System (INIS)

    The use of the Rice J-intergral to assess conditions at a crack tip in an elastic or non-linear elastic body is well known. The integral equals the energy release rate and is path independent for any contour surrounding the crack tip provided no other singularities are encompassed. The path independence propertiy breaks down, however, in more general situations such as in three dimensional stress systems, plasticity unloading, thermal or creep states. Hence the required crack tip characteristics represented by the value of the integral round a contour whose radius about the tip tends to zero, is not reproduced along contours away from the tip. Consequently, an alternative integral, designated J*, has been proposed which equals J for elastic cases and in the other cases cited above remains path independent. A computer program for calculating the J and J* integrals has been developed as an extension to the BERSAFE finite element system. A full analysis of the cracked structure including plasticity, creep and thermal strains is conducted and the results are stored on a permanent data set. The integral values may then be calculated using the post-processor program for any number of contours and load or time steps, without recourse to further expensive computations. (Auth. )

  15. Modality-independent reduction mechanisms of primary sensory evoked fields in a one-back task.

    Science.gov (United States)

    Hanke, David; Huonker, Ralph; Weiss, Thomas; Witte, Otto W; Götz, Theresa

    2016-01-01

    Attentional modulation of early, primary sensory components is still a topic of debate, as studies have produced conflicting results concerning the existence of a modulation within the primary somatosensory cortex and its direction. We previously showed that attention to tactile stimuli in a stream with visual stimuli leads to a reduction of primary somatosensory components when discrimination of different stimulus locations is requested. The question arises whether this effect is universal and independent from the distracting or attended modality. To test this, we compared the magnitude of primary somatosensory evoked fields (somatosensory P50m) in a one-back task after tactile finger stimulation during attention to tactile stimuli vs. auditory distraction in 28 volunteers. In comparison to acoustic distraction, we found a significantly decreased primary somatosensory activity when attending to tactile stimuli. Strikingly, similar results were produced within the auditory modality: when attention was focused on acoustic targets, primary auditory (auditory P50m) fields were lower as compared to the situation when attention was directed to the tactile stimulation. Our results clearly indicate that the type of task, independent from the modality, is actually the crucial factor for the direction of modulation of early sensory components by attention. Therefore, our finding of reduced primary sensory components in a discrimination task represents a universal effect independent from the distracting or attended modality.

  16. Two independent mechanisms for motion-in-depth perception: evidence from individual differences

    Directory of Open Access Journals (Sweden)

    Harold T Nefs

    2010-10-01

    Full Text Available Our forward-facing eyes allow us the advantage of binocular visual information: using the tiny differences between right and left eye views to learn about depth and location in three dimensions. Our visual systems also contain specialized mechanisms to detect motion-in-depth from binocular vision, but the nature of these mechanisms remains controversial. Binocular motion-in-depth perception could theoretically be based on first detecting binocular disparity and then monitoring how it changes over time. The alternative is to monitor the motion in the right and left eye separately and then compare these motion signals. Here we used an individual differences approach to test whether the two sources of information are processed via dissociated mechanisms, and to measure the relative importance of those mechanisms. Our results suggest the existence of two distinct mechanisms, each contributing to the perception of motion in depth in most observers. Additionally, for the first time, we demonstrate the relative prevalence of the two mechanisms within a normal population. In general, visual systems appear to rely mostly on the mechanism sensitive to changing binocular disparity, but perception of motion in depth is augmented by the presence of a less sensitive mechanism that uses interocular velocity differences. Occasionally, we find observers with the opposite pattern of sensitivity. More generally this work showcases the power of the individual differences approach in studying the functional organisation of cognitive systems.

  17. Serotonin regulates C. elegans fat and feeding through independent molecular mechanisms

    DEFF Research Database (Denmark)

    Srinivasan, Supriya; Sadegh, Leila; Elle, Ida C;

    2008-01-01

    We investigated serotonin signaling in C. elegans as a paradigm for neural regulation of energy balance and found that serotonergic regulation of fat is molecularly distinct from feeding regulation. Serotonergic feeding regulation is mediated by receptors whose functions are not required for fat...... feeding behavior. These findings suggest that, as in mammals, C. elegans feeding behavior is regulated by extrinsic and intrinsic cues. Moreover, obesity and thinness are not solely determined by feeding behavior. Rather, feeding behavior and fat metabolism are coordinated but independent responses...

  18. BMP Signaling Modulates Hepcidin Expression in Zebrafish Embryos Independent of Hemojuvelin

    Science.gov (United States)

    Gibert, Yann; Lattanzi, Victoria J.; Zhen, Aileen W.; Vedder, Lea; Brunet, Frédéric; Faasse, Sarah A.; Babitt, Jodie L.; Lin, Herbert Y.; Hammerschmidt, Matthias; Fraenkel, Paula G.

    2011-01-01

    Hemojuvelin (Hjv), a member of the repulsive-guidance molecule (RGM) family, upregulates transcription of the iron regulatory hormone hepcidin by activating the bone morphogenetic protein (BMP) signaling pathway in mammalian cells. Mammalian models have identified furin, neogenin, and matriptase-2 as modifiers of Hjv's function. Using the zebrafish model, we evaluated the effects of hjv and its interacting proteins on hepcidin expression during embryonic development. We found that hjv is strongly expressed in the notochord and somites of the zebrafish embryo and that morpholino knockdown of hjv impaired the development of these structures. Knockdown of hjv or other hjv-related genes, including zebrafish orthologs of furin or neogenin, however, failed to decrease hepcidin expression relative to liver size. In contrast, overexpression of bmp2b or knockdown of matriptase-2 enhanced the intensity and extent of hepcidin expression in zebrafish embryos, but this occurred in an hjv-independent manner. Furthermore, we demonstrated that zebrafish hjv can activate the human hepcidin promoter and enhance BMP responsive gene expression in vitro, but is expressed at low levels in the zebrafish embryonic liver. Taken together, these data support an alternative mechanism for hepcidin regulation during zebrafish embryonic development, which is independent of hjv. PMID:21283739

  19. The use of a path independent integral in non-linear fracture mechanics

    International Nuclear Information System (INIS)

    A computer program for calculating the J and J* integrals has been developed as an extension to the BERSAFE finite element system. A full analysis of the cracked structure including plasticity, creep and thermal strains is conducted and the results are stored on a permanent data set. The integral values may then be calculated using the post-processor program for any number of contours and load or time steps, without recourse to further expensive computations. Numerical examples are presented comparing the J and J* integrals for a number of cracked plates under thermal, plastic and creep environments. To demonstrate the accuracy for a simple thermo-elastic case, a centre cracked plate subject to a symmetric quadratic gradient is included. Here, the J integral is shown to be path dependent whereas good independence is seen for the J* integral. The case of an elastic-plastic plate is invetigated to demonstrate path independence for both integrals in non-linear elasticity, and the effects of unloading are discussed. An alternative method for obtaining the change of potential energy over a small crack extension is briefly mentioned and compared to the J and J* results in this case. An axisymmetric bar with an internal penny-shaped crack subjected to tension is discussed under elastic-plastic materials behavior

  20. Topoisomerase 1 Regulates Gene Expression in Neurons through Cleavage Complex-Dependent and -Independent Mechanisms

    Science.gov (United States)

    Mabb, Angela M.; Simon, Jeremy M.; King, Ian F.; Lee, Hyeong-Min; An, Lin-Kun; Philpot, Benjamin D.; Zylka, Mark J.

    2016-01-01

    Topoisomerase 1 (TOP1) inhibitors, including camptothecin and topotecan, covalently trap TOP1 on DNA, creating cleavage complexes (cc’s) that must be resolved before gene transcription and DNA replication can proceed. We previously found that topotecan reduces the expression of long (>100 kb) genes and unsilences the paternal allele of Ube3a in neurons. Here, we sought to evaluate overlap between TOP1cc-dependent and -independent gene regulation in neurons. To do this, we utilized Top1 conditional knockout mice, Top1 knockdown, the CRISPR-Cas9 system to delete Top1, TOP1 catalytic inhibitors that do not generate TOP1cc’s, and a TOP1 mutation (T718A) that stabilizes TOP1cc’s. We found that topotecan treatment significantly alters the expression of many more genes, including long neuronal genes, immediate early genes, and paternal Ube3a, when compared to Top1 deletion. Our data show that topotecan has a stronger effect on neuronal transcription than Top1 deletion, and identifies TOP1cc-dependent and -independent contributions to gene expression. PMID:27231886

  1. Topoisomerase 1 Regulates Gene Expression in Neurons through Cleavage Complex-Dependent and -Independent Mechanisms.

    Directory of Open Access Journals (Sweden)

    Angela M Mabb

    Full Text Available Topoisomerase 1 (TOP1 inhibitors, including camptothecin and topotecan, covalently trap TOP1 on DNA, creating cleavage complexes (cc's that must be resolved before gene transcription and DNA replication can proceed. We previously found that topotecan reduces the expression of long (>100 kb genes and unsilences the paternal allele of Ube3a in neurons. Here, we sought to evaluate overlap between TOP1cc-dependent and -independent gene regulation in neurons. To do this, we utilized Top1 conditional knockout mice, Top1 knockdown, the CRISPR-Cas9 system to delete Top1, TOP1 catalytic inhibitors that do not generate TOP1cc's, and a TOP1 mutation (T718A that stabilizes TOP1cc's. We found that topotecan treatment significantly alters the expression of many more genes, including long neuronal genes, immediate early genes, and paternal Ube3a, when compared to Top1 deletion. Our data show that topotecan has a stronger effect on neuronal transcription than Top1 deletion, and identifies TOP1cc-dependent and -independent contributions to gene expression.

  2. B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson HL

    2012-05-01

    Full Text Available Heather L Wilson1,21Vaccine and Infectious Disease Organization-International Vaccine Center, 2Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: For many years, central dogma defined multiple sclerosis (MS as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens, through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis.Keywords: autoantibodies, antibody targets, clinically isolated MS, primary progressive MS, secondary progressive MS, relapsing and remitting MS, T cells, T regulatory cells

  3. Independently evolved upper jaw protrusion mechanisms show convergent hydrodynamic function in teleost fishes.

    Science.gov (United States)

    Staab, Katie Lynn; Holzman, Roi; Hernandez, L Patricia; Wainwright, Peter C

    2012-05-01

    A protrusible upper jaw has independently evolved multiple times within teleosts and has been implicated in the success of two groups in particular: Acanthomorpha and Cypriniformes. We use digital particle image velocimetry (DPIV) to compare suction feeding flow dynamics in a representative of each of these clades: goldfish and bluegill. Using DPIV, we contrast the spatial pattern of flow, the temporal relationship between flow and head kinematics, and the contribution of jaw protrusion to the forces exerted on prey. As expected, the spatial patterns of flow were similar in the two species. However, goldfish were slower to reach maximal kinematic excursions, and were more flexible in the relative timing of jaw protrusion, other jaw movements and suction flows. Goldfish were also able to sustain flow speeds for a prolonged period of time as compared with bluegill, in part because goldfish generate lower peak flow speeds. In both species, jaw protrusion increased the force exerted on the prey. However, slower jaw protrusion in goldfish resulted in less augmentation of suction forces. This difference in force exerted on prey corresponds with differences in trophic niches and feeding behavior of the two species. The bluegill uses powerful suction to capture insect larvae whereas the goldfish uses winnowing to sort through detritus and sediment. The kinethmoid of goldfish may permit jaw protrusion that is independent of lower jaw movement, which could explain the ability of goldfish to decouple suction flows (due to buccal expansion) from upper jaw protrusion. Nevertheless, our results show that jaw protrusion allows both species to augment the force exerted on prey, suggesting that this is a fundamental benefit of jaw protrusion to suction feeders. PMID:22496281

  4. Acetylcholinesterase Regulates Skeletal In Ovo Development of Chicken Limbs by ACh-Dependent and -Independent Mechanisms

    Science.gov (United States)

    Spieker, Janine; Ackermann, Anica; Salfelder, Anika; Vogel-Höpker, Astrid; Layer, Paul G.

    2016-01-01

    Formation of the vertebrate limb presents an excellent model to analyze a non-neuronal cholinergic system (NNCS). Here, we first analyzed the expression of acetylcholinesterase (AChE) by IHC and of choline acetyltransferase (ChAT) by ISH in developing embryonic chicken limbs (stages HH17-37). AChE outlined formation of bones, being strongest at their distal tips, and later also marked areas of cell death. At onset, AChE and ChAT were elevated in two organizing centers of the limb anlage, the apical ectodermal ridge (AER) and zone of polarizing activity (ZPA), respectively. Thereby ChAT was expressed shortly after AChE, thus strongly supporting a leading role of AChE in limb formation. Then, we conducted loss-of-function studies via unilateral implantation of beads into chicken limb anlagen, which were soaked in cholinergic components. After varying periods, the formation of cartilage matrix and of mineralizing bones was followed by Alcian blue (AB) and Alizarin red (AR) stainings, respectively. Both acetylcholine (ACh)- and ChAT-soaked beads accelerated bone formation in ovo. Notably, inhibition of AChE by BW284c51, or by the monoclonal antibody MAB304 delayed cartilage formation. Since bead inhibition of BChE was mostly ineffective, an ACh-independent action during BW284c51 and MAB304 inhibition was indicated, which possibly could be due to an enzymatic side activity of AChE. In conclusion, skeletogenesis in chick is regulated by an ACh-dependent cholinergic system, but to some extent also by an ACh-independent aspect of the AChE protein. PMID:27574787

  5. Utilizing a reference material for assessing absolute tumor mechanical properties in modality independent elastography

    Science.gov (United States)

    Kim, Dong Kyu; Weis, Jared A.; Yankeelov, Thomas E.; Miga, Michael I.

    2014-03-01

    There is currently no reliable method for early characterization of breast cancer response to neoadjuvant chemotherapy (NAC) [1,2]. Given that disruption of normal structural architecture occurs in cancer-bearing tissue, we hypothesize that further structural changes occur in response to NAC. Consequently, we are investigating the use of modalityindependent elastography (MIE) [3-8] as a method for monitoring mechanical integrity to predict long term outcomes in NAC. Recently, we have utilized a Demons non-rigid image registration method that allows 3D elasticity reconstruction in abnormal tissue geometries, making it particularly amenable to the evaluation of breast cancer mechanical properties. While past work has reflected relative elasticity contrast ratios [3], this study improves upon that work by utilizing a known stiffness reference material within the reconstruction framework such that a stiffness map becomes an absolute measure. To test, a polyvinyl alcohol (PVA) cryogel phantom and a silicone rubber mock mouse tumor phantom were constructed with varying mechanical stiffness. Results showed that an absolute measure of stiffness could be obtained based on a reference value. This reference technique demonstrates the ability to generate accurate measurements of absolute stiffness to characterize response to NAC. These results support that `referenced MIE' has the potential to reliably differentiate absolute tumor stiffness with significant contrast from that of surrounding tissue. The use of referenced MIE to obtain absolute quantification of biomarkers is also translatable across length scales such that the characterization method is mechanics-consistent at the small animal and human application.

  6. Parathyroid hormone stimulate osteoblast differentiation by up-regulation of BMP2 expression and function%骨形态发生蛋白2介导甲状旁腺素促进成骨细胞分化的实验研究

    Institute of Scientific and Technical Information of China (English)

    徐莹; 田野; 孟凌新

    2012-01-01

    Objective To study the important role of BMP2 in the PTH-induced osteoblast differentiation. Methods MC3T3-E1 cells were divided into 4 groups: 1) Controls; 2) PTH treatment; 3) Dorso-morphin treatment; 4) PTH + Dorsomorphin treatment. Gene and protein expression levels of BMP2, BMP2 downstream genes and osteoblastic genes and protein expressions were detected by Real-time PCR and Western blot respectively. Alkaline phosphatase (ALP) staining was performed to detect ALP activity. 12xSBE-OC luciferase activity was measured using dual luciferase reporter assays. Results The expression level of BMP2 and osteoblastic marker genes was higher in the PTH group than in controls. PTH also increases 12xSBE-OC luciferase activity significantly. In the other hand, the expression of BMP2, BMP2 downstream genes and osteoblastic genes was lower in Dorsomorphin and PTH + Dorsomorphin group, than in controls. However, the expression was similar in Dorsomorphin and PTH + Dorsomorphin groups. Conclusion PTH stimulates osteoblast differentiation by up-regulating BMP2 expression and function.%目的 探讨骨形态发生蛋白2(BMP2)在甲状旁腺素(PTH)促进成骨细胞分化过程中的重要介导作用.方法培养MC3T3-E1细胞,分为4组:1)盐水对照组;2)PTH组;3)6-[4-[2-(1-哌啶基)乙氧基]苯基]-3-(4-吡啶基)吡唑并[1,5-a]嘧啶 (Dorsomorphin) 组;4) PTH+Dorsomorphin组.Real-time PCR法和Westernblot方法检测细胞BMP2BMP2下游基因和成骨因子的表达,碱性磷酸酶(ALP)染色方法检测细胞ALP的活性;双荧光素酶报告基因检测方法检测12xSBE-OC荧光素酶的活性.结果:PTH组BMP-2、成骨因子的表达及其12xSBE-OC荧光素酶的活性,明显高于盐水对照组.Dorsomorphin组和PTH+Dorsomorphin组BMP-2BMP-2下游基因和成骨因子的表达,均明显低于盐水对照组;但其表达于两组间无明显差别.结论 BMP2介导PTH促进成骨细胞的分化,PTH可通过上调BMP2的表达,提高其功能,促进成骨细胞的成熟分化.

  7. A novel COX-independent mechanism of sulindac sulfide involves cleavage of epithelial cell adhesion molecule protein.

    Science.gov (United States)

    Liggett, Jason L; Min, Kyung-Won; Smolensky, Dmitriy; Baek, Seung Joon

    2014-08-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are extensively used over the counter to treat headaches and inflammation as well as clinically to prevent cancer among high-risk groups. The inhibition of cyclooxygenase (COX) activity by NSAIDs plays a role in their anti-tumorigenic properties. NSAIDs also have COX-independent activity which is not fully understood. In this study, we report a novel COX-independent mechanism of sulindac sulfide (SS), which facilitates a previously uncharacterized cleavage of epithelial cell adhesion molecule (EpCAM) protein. EpCAM is a type I transmembrane glycoprotein that has been implemented as an over-expressed oncogene in many cancers including colon, breast, pancreas, and prostate. We found EpCAM to be down-regulated by SS in a manner that is independent of COX activity, transcription regulation, de novo protein synthesis, and proteasomal degradation pathway. Our findings clearly demonstrate that SS drives cleavage of the extracellular portion of EpCAM near the N-terminus. This SS driven cleavage is blocked by a deleting amino acids 55-81 as well as simply mutating arginine residues at positions 80 and 81 to alanine of EpCAM. Proteolysis of EpCAM by SS may provide a novel mechanism by which NSAIDs affect anti-tumorigenesis at the post-translational level. PMID:24859349

  8. Brain Alterations and Clinical Symptoms of Dementia in Diabetes: Aβ/Tau-Dependent and Independent Mechanisms

    OpenAIRE

    NaoyukiSato

    2014-01-01

    Emerging evidence suggests that diabetes affects cognitive function and increases the incidence of dementia. However, the mechanisms by which diabetes modifies cognitive function still remains unclear. Morphologically, diabetes is associated with neuronal loss in the frontal and temporal lobes including the hippocampus, and aberrant functional connectivity of the posterior cingulate cortex and medial frontal/temporal gyrus. Clinically, diabetic patients show decreased executive function, info...

  9. Iron-Induced Damage in Cardiomyopathy: Oxidative-Dependent and Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Elena Gammella

    2015-01-01

    Full Text Available The high incidence of cardiomyopathy in patients with hemosiderosis, particularly in transfusional iron overload, strongly indicates that iron accumulation in the heart plays a major role in the process leading to heart failure. In this context, iron-mediated generation of noxious reactive oxygen species is believed to be the most important pathogenetic mechanism determining cardiomyocyte damage, the initiating event of a pathologic progression involving apoptosis, fibrosis, and ultimately cardiac dysfunction. However, recent findings suggest that additional mechanisms involving subcellular organelles and inflammatory mediators are important factors in the development of this disease. Moreover, excess iron can amplify the cardiotoxic effect of other agents or events. Finally, subcellular misdistribution of iron within cardiomyocytes may represent an additional pathway leading to cardiac injury. Recent advances in imaging techniques and chelators development remarkably improved cardiac iron overload detection and treatment, respectively. However, increased understanding of the pathogenic mechanisms of iron overload cardiomyopathy is needed to pave the way for the development of improved therapeutic strategies.

  10. Psychostimulants affect dopamine transmission through both dopamine transporter-dependent and independent mechanisms.

    Science.gov (United States)

    dela Peña, Ike; Gevorkiana, Ruzanna; Shi, Wei-Xing

    2015-10-01

    The precise mechanisms by which cocaine and amphetamine-like psychostimulants exert their reinforcing effects are not yet fully defined. It is widely believed, however, that these drugs produce their effects by enhancing dopamine neurotransmission in the brain, especially in limbic areas such as the nucleus accumbens, by inducing dopamine transporter-mediated reverse transport and/or blocking dopamine reuptake though the dopamine transporter. Here, we present the evidence that aside from dopamine transporter, non-dopamine transporter-mediated mechanisms also participate in psychostimulant-induced dopamine release and contribute to the behavioral effects of these drugs, such as locomotor activation and reward. Accordingly, psychostimulants could increase norepinephrine release in the prefrontal cortex, the latter then alters the firing pattern of dopamine neurons resulting in changes in action potential-dependent dopamine release. These alterations would further affect the temporal pattern of dopamine release in the nucleus accumbens, thereby modifying information processing in that area. Hence, a synaptic input to a nucleus accumbens neuron may be enhanced or inhibited by dopamine depending on its temporal relationship to dopamine release. Specific temporal patterns of dopamine release may also be required for certain forms of synaptic plasticity in the nucleus accumbens. Together, these effects induced by psychostimulants, mediated through a non-dopamine transporter-mediated mechanism involving norepinephrine and the prefrontal cortex, may also contribute importantly to the reinforcing properties of these drugs. PMID:26209364

  11. A new mechanism for low and temperature-independent elastic modulus.

    Science.gov (United States)

    Zhang, Liangxiang; Wang, Dong; Ren, Xiaobing; Wang, Yunzhi

    2015-01-01

    The first Elinvar alloy, FeNiCr, which has invariant elastic modulus over a wide temperature range, was discovered almost 100 years ago by Guillaume. The physical origin of such an anomaly has been attributed to the magnetic phase transition taking place in the system. However, the recent discovery of non-magnetic Elinvar such as multi-functional β-type Ti alloys has imposed a new challenge to the existing theories. In this study we show that random field from stress-carrying defects could suppress the sharp first-order martensitic transformation into a continuous strain glass transition, leading to continued formation and confined growth of nano-domains of martensite in a broad temperature range. Accompanying such a unique transition, there is a gradual softening of the elastic modulus over a wide temperature range, which compensates the normal modulus hardening due to anharmonic atomic vibration, resulting in a low and temperature-independent elastic modulus. The abundance of austenite/martensite interfaces are found responsible for the low elastic modulus. PMID:26108371

  12. The hydrogen tunneling splitting in malonaldehyde: A full-dimensional time-independent quantum mechanical method

    Science.gov (United States)

    Wu, Feng; Ren, Yinghui; Bian, Wensheng

    2016-08-01

    The accurate time-independent quantum dynamics calculations on the ground-state tunneling splitting of malonaldehyde in full dimensionality are reported for the first time. This is achieved with an efficient method developed by us. In our method, the basis functions are customized for the hydrogen transfer process which has the effect of greatly reducing the size of the final Hamiltonian matrix, and the Lanczos method and parallel strategy are used to further overcome the memory and central processing unit time bottlenecks. The obtained ground-state tunneling splitting of 24.5 cm-1 is in excellent agreement with the benchmark value of 23.8 cm-1 computed with the full-dimensional, multi-configurational time-dependent Hartree approach on the same potential energy surface, and we estimate that our reported value has an uncertainty of less than 0.5 cm-1. Moreover, the role of various vibrational modes strongly coupled to the hydrogen transfer process is revealed.

  13. A new mechanism for low and temperature-independent elastic modulus.

    Science.gov (United States)

    Zhang, Liangxiang; Wang, Dong; Ren, Xiaobing; Wang, Yunzhi

    2015-06-25

    The first Elinvar alloy, FeNiCr, which has invariant elastic modulus over a wide temperature range, was discovered almost 100 years ago by Guillaume. The physical origin of such an anomaly has been attributed to the magnetic phase transition taking place in the system. However, the recent discovery of non-magnetic Elinvar such as multi-functional β-type Ti alloys has imposed a new challenge to the existing theories. In this study we show that random field from stress-carrying defects could suppress the sharp first-order martensitic transformation into a continuous strain glass transition, leading to continued formation and confined growth of nano-domains of martensite in a broad temperature range. Accompanying such a unique transition, there is a gradual softening of the elastic modulus over a wide temperature range, which compensates the normal modulus hardening due to anharmonic atomic vibration, resulting in a low and temperature-independent elastic modulus. The abundance of austenite/martensite interfaces are found responsible for the low elastic modulus.

  14. 聚乳酸及其复合物修复下颌骨缺损的实验研究%THE EXPERIMENTAL STUDY OF REPAIRING THE MANDIBULAR BONE DEFECT USING PLA-rhBMP-2

    Institute of Scientific and Technical Information of China (English)

    黄相道; 刘境华; 赵明; 王会信

    2001-01-01

    Purpose A new synthetic material consists of Polylac tic acid[PLA] and recombinant human bone morphogenetic protein-2[PLA-rhBMP -2]. The capacity of repairing bone defect of biodegradable PLA and the effica cy of PLA as a carrier for bone morphogenetic protein [BMP] are determined wit h detecting the osteogenetic process. Materials and Methods Eighteen rabbits were picked up and divided i nto three groups randomly. The defects of 12mm×6mm size were made at bilateral mandibul ar edges. PLA-rhBMP-2, PLA were implanted in the defect respectively. The 18 r abbits were killed at 2,4,8 and 12 weeks after implanting. The sample was analyz ed by the methods of X-rays and histological examination. Results After 2 weeks, the new bone began to form in the defects. A fter 8 weeks, bulk bone could be obviously observed. After 12 weeks, most of the PLA in the defects were already biodegraded. The defects were restored with n ew bone. The results in PLA-rhBMP-2 group were better than those of other grou ps. Conclusions PLA could be a promising carrier for BMP. PLA-rhBM P-2 has also been considered a better biodegradable material for repairing mand ibular defect.%目的 聚乳酸与骨形成蛋白复合,研究该材料修复颌骨缺损的能力,探讨聚乳酸作为骨形成蛋白载体的有效性。方法 18只日本大耳白兔,随机分组,在双侧下颌骨体部形成12mm×6mm的缺损,分别植入聚乳酸-人骨形成蛋白-2复合物(PLA-rhBMP-2)、单纯聚乳酸(PLA),于2、4、8、12周分批处死。通过X线、组织学染色等方法进行观察。结果 PLA-rhBMP-2植入组于术后2周,缺损区部分新骨形成;术后8周,大片新骨形成并开始改建,术后12周,PLA大部分降解,由骨组织修复。结果优于对照组。结论 PLA可作为BMP的有效载体,PLA-rhBMP-2是良好的颌骨缺损修复材料。

  15. Performance pressure and caffeine both affect cognitive performance, but likely through independent mechanisms.

    Science.gov (United States)

    Boere, Julia J; Fellinger, Lizz; Huizinga, Duncan J H; Wong, Sebastiaan F; Bijleveld, Erik

    2016-02-01

    A prevalent combination in daily life, performance pressure and caffeine intake have both been shown to impact people's cognitive performance. Here, we examined the possibility that pressure and caffeine affect cognitive performance via a shared pathway. In an experiment, participants performed a modular arithmetic task. Performance pressure and caffeine intake were orthogonally manipulated. Findings indicated that pressure and caffeine both negatively impacted performance. However, (a) pressure vs. caffeine affected performance on different trial types, and (b) there was no hint of an interactive effect. So, though the evidence is indirect, findings suggest that pressure and caffeine shape performance via distinct mechanisms, rather than a shared one.

  16. Cellular Metabolism and Dose Reveal Carnitine-Dependent and -Independent Mechanisms of Butyrate Oxidation in Colorectal Cancer Cells.

    Science.gov (United States)

    Han, Anna; Bennett, Natalie; MacDonald, Amber; Johnstone, Megan; Whelan, Jay; Donohoe, Dallas R

    2016-08-01

    Dietary fiber has been suggested to suppress colorectal cancer development, although the mechanisms contributing to this beneficial effect remain elusive. Butyrate, a fermentation product of fiber, has been shown to have anti-proliferative and pro-apoptotic effects on colorectal cancer cells. The metabolic fate of butyrate in the cell is important in determining whether, it acts as an HDAC inhibitor or is consumed as a short-chain fatty acid. Non-cancerous colonocytes utilize butyrate as the primary energy source whereas cancerous colonocytes increase glucose utilization through the Warburg effect. In this study, we show that butyrate oxidation is decreased in cancerous colonocytes compared to non-cancerous colonocytes. We demonstrate that colorectal cancer cells utilize both a carnitine-dependent and carnitine-independent mechanism that contributes to butyrate oxidation. The carnitine-dependent mechanism is contingent on butyrate concentration. Knockdown of CPT1A in colorectal cancer cells abolishes butyrate oxidation. In terms of selectivity, the carnitine-dependent mechanism only regulated butyrate oxidation, as acetate and propionate oxidation were carnitine-independent. Carnitine decreased the action of butyrate as an HDAC inhibitor and suppressed induction of H3 acetylation by butyrate in colorectal cancer cells. Thus, diminished oxidation of butyrate is associated with decreased HDAC inhibition and histone acetylation. In relation to the mechanism, we find that dichloroacetate, which decreases phosphorylation of pyruvate dehydrogenase, increased butyrate oxidation and that this effect was carnitine-dependent. In conclusion, these data suggest that colorectal cancer cells decrease butyrate oxidation through inhibition of pyruvate dehydrogenase, which is carnitine-dependent, and provide insight into why butyrate shows selective effects toward colorectal cancer cells. J. Cell. Physiol. 231: 1804-1813, 2016. © 2015 Wiley Periodicals, Inc. PMID:26661480

  17. Comparison of conventional mechanical ventilation and synchronous independent lung ventilation (SILV) in the treatment of unilateral lung injury.

    Science.gov (United States)

    Hurst, J M; DeHaven, C B; Branson, R D

    1985-08-01

    Eight patients presenting with severe unilateral pulmonary injury responded poorly to conventional mechanical ventilation. Synchronous independent lung ventilation (SILV) was employed to provide support of ventilation and oxygenation without creating the ventilation/perfusion (V/Q) mismatch observed during conventional ventilation. All patients demonstrated improved oxygenation (mean increase, 80 torr) during SILV with the FIO2 unchanged from previous therapy. Invasive hemodynamic monitoring in five of eight patients showed no difference in the commonly measured cardiopulmonary parameters with the two forms of mechanical ventilation. Peak inspiratory pressure (PIP), continuous positive airway pressure (CPAP), and pressure change secondary to tidal volume delivery to the uninvolved lung were significantly less during SILV. SILV is an effective method of improving oxygenation in patients with severe unilateral pulmonary injury. PMID:3894680

  18. Arsenic increased lipid peroxidation in rat tissues by a mechanism independent of glutathione levels.

    Science.gov (United States)

    Ramos, O; Carrizales, L; Yáñez, L; Mejía, J; Batres, L; Ortíz, D; Díaz-Barriga, F

    1995-01-01

    The role of lipid peroxidation in the mechanism of arsenic toxicity was investigated in female rats pretreated with N-acetylcysteine (NAC, a glutathione [GSH] inducer) or with buthionine sulfoximine (BSO, a GSH depletor). Rats were challenged with sodium arsenite, and sacrificed 1 hr after this treatment. Results showed that arsenic decreased GSH levels and increased lipid peroxidation in liver, kidney, and heart, with a larger effect at 18.2 mg/kg than at 14.8 mg/kg for lipid peroxidation induction. In the liver of rats treated with arsenic, pretreatment with NAC increased the levels of GSH and decreased lipid peroxidation. In kidney and heart, NAC pretreatment protected the tissues against arsenic-induced depletion of GSH levels, but the same degree of protection was not found for lipid peroxidation induction. In its turn, BSO had an additive effect with arsenic in lowering the levels of GSH in the liver and kidney, but an inverse correlation between GSH levels and lipid peroxidation was found only in liver. Arsenic content in tissues of rats pretreated with NAC was lower than in rats treated only with arsenic. In rats with depleted levels of GSH (BSO-pretreated rats), a shift in arsenic tissue distribution was found, with higher levels in skin and lower levels in kidney. A clear tendency for a positive correlation between arsenic concentration and lipid peroxidation levels was found in liver, kidney, and heart. PMID:7621808

  19. Transgenic Mice Overexpressing Serum Retinol-Binding Protein Develop Progressive Retinal Degeneration through a Retinoid-Independent Mechanism.

    Science.gov (United States)

    Du, Mei; Otalora, Laura; Martin, Ashley A; Moiseyev, Gennadiy; Vanlandingham, Phillip; Wang, Qilong; Farjo, Rafal; Yeganeh, Alexander; Quiambao, Alexander; Farjo, Krysten M

    2015-08-01

    Serum retinol-binding protein 4 (RBP4) is the sole specific transport protein for retinol in the blood, but it is also an adipokine with retinol-independent, proinflammatory activity associated with obesity, insulin resistance, type 2 diabetes, and cardiovascular disease. Moreover, two separate studies reported that patients with proliferative diabetic retinopathy have increased serum RBP4 levels compared to patients with mild or no retinopathy, yet the effect of increased levels of RBP4 on the retina has not been studied. Here we show that transgenic mice overexpressing RBP4 (RBP4-Tg mice) develop progressive retinal degeneration, characterized by photoreceptor ribbon synapse deficiency and subsequent bipolar cell loss. Ocular retinoid and bisretinoid levels are normal in RBP4-Tg mice, demonstrating that a retinoid-independent mechanism underlies retinal degeneration. Increased expression of pro-interleukin-18 (pro-IL-18) mRNA and activated IL-18 protein and early-onset microglia activation in the retina suggest that retinal degeneration is driven by a proinflammatory mechanism. Neither chronic systemic metabolic disease nor other retinal insults are required for RBP4 elevation to promote retinal neurodegeneration, since RBP4-Tg mice do not have coincident retinal vascular pathology, obesity, dyslipidemia, or hyperglycemia. These findings suggest that elevation of serum RBP4 levels could be a risk factor for retinal damage and vision loss in nondiabetic as well as diabetic patients. PMID:26055327

  20. C-reactive protein protects mice against pneumococcal infection via both phosphocholine-dependent and phosphocholine-independent mechanisms.

    Science.gov (United States)

    Gang, Toh B; Hanley, Gregory A; Agrawal, Alok

    2015-05-01

    The mechanism of action of C-reactive protein (CRP) in protecting mice against lethal Streptococcus pneumoniae infection is unknown. The involvement of the phosphocholine (PCh)-binding property of CRP in its antipneumococcal function previously has been explored twice, with conflicting results. In this study, using three different intravenous sepsis mouse models, we investigated the role of the PCh-binding property of CRP by employing a CRP mutant incapable of binding to PCh. The ability of wild-type CRP to protect mice against infection was found to differ in the three models; the protective ability of wild-type CRP decreased when the severity of infection was increased, as determined by measuring mortality and bacteremia. In the first animal model, in which we used 25 μg of CRP and 10(7) CFU of pneumococci, both wild-type and mutant CRP protected mice against infection, suggesting that the protection was independent of the PCh-binding activity of CRP. In the second model, in which we used 25 μg of CRP and 5 × 10(7) CFU of pneumococci, mutant CRP was not protective while wild-type CRP was, suggesting that the protection was dependent on the PCh-binding activity of CRP. In the third model, in which we used 150 μg of CRP and 10(7) CFU of pneumococci, mutant CRP was as protective as wild-type CRP, again indicating that the protection was independent of the PCh-binding activity of CRP. We conclude that both PCh-dependent and PCh-independent mechanisms are involved in the CRP-mediated decrease in bacteremia and the resulting protection of mice against pneumococcal infection.

  1. C-reactive protein protects mice against pneumococcal infection via both phosphocholine-dependent and phosphocholine-independent mechanisms.

    Science.gov (United States)

    Gang, Toh B; Hanley, Gregory A; Agrawal, Alok

    2015-05-01

    The mechanism of action of C-reactive protein (CRP) in protecting mice against lethal Streptococcus pneumoniae infection is unknown. The involvement of the phosphocholine (PCh)-binding property of CRP in its antipneumococcal function previously has been explored twice, with conflicting results. In this study, using three different intravenous sepsis mouse models, we investigated the role of the PCh-binding property of CRP by employing a CRP mutant incapable of binding to PCh. The ability of wild-type CRP to protect mice against infection was found to differ in the three models; the protective ability of wild-type CRP decreased when the severity of infection was increased, as determined by measuring mortality and bacteremia. In the first animal model, in which we used 25 μg of CRP and 10(7) CFU of pneumococci, both wild-type and mutant CRP protected mice against infection, suggesting that the protection was independent of the PCh-binding activity of CRP. In the second model, in which we used 25 μg of CRP and 5 × 10(7) CFU of pneumococci, mutant CRP was not protective while wild-type CRP was, suggesting that the protection was dependent on the PCh-binding activity of CRP. In the third model, in which we used 150 μg of CRP and 10(7) CFU of pneumococci, mutant CRP was as protective as wild-type CRP, again indicating that the protection was independent of the PCh-binding activity of CRP. We conclude that both PCh-dependent and PCh-independent mechanisms are involved in the CRP-mediated decrease in bacteremia and the resulting protection of mice against pneumococcal infection. PMID:25690104

  2. Dopamine induces neutrophil apoptosis through a dopamine D-1 receptor-independent mechanism.

    LENUS (Irish Health Repository)

    Sookhai, S

    2012-02-03

    BACKGROUND: For the normal resolution of an acute inflammatory response, neutrophil (PMN) apoptosis is essential to maintain immune homeostasis and to limit inappropriate host tissue damage. A delay in PMN apoptosis has been implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS). Dopamine, a biogenic amine with known cardiovascular and neurotransmitter properties, is used in patients with SIRS to maintain hemodynamic stability. We sought to determine whether dopamine may also have immunoregulatory properties capable of influencing PMN apoptosis, function, and activation state in patients with SIRS. METHODS: PMNs were isolated from healthy volunteers and patients with SIRS and treated with varying doses of dopamine and a dopamine D-1 receptor agonist, fenoldopam. PMN apoptosis was assessed every 6 hours with use of propidium iodide DNA staining and PMN function was assessed with use of respiratory burst activity, phagocytosis ability, and CD11a, CD11b, and CD18 receptor expression as functional markers. RESULTS: There was a significant delay in PMN apotosis in patients with SIRS compared with controls. Treatment of isolated PMNs from both healthy controls and patients with SIRS with 10 and 100 mumol\\/L dopamine induced apoptosis. PMN ingestive and cytocidal capacity were both decreased in patients with SIRS compared with controls. Treatment with dopamine significantly increased phagocytic function. Fenoldopam did not induce PMN apoptosis. CONCLUSION: Our data demonstrate for the first time that dopamine induces PMN apoptosis and modulates PMN function both in healthy controls and in patients with SIRS. These results indicate that dopamine may be beneficial during SIRS through a nonhemodynamic PMN-dependent proapoptotic mechanism.

  3. Cardioprotection by H2S Donors: Nitric Oxide-Dependent and ‑Independent Mechanisms.

    Science.gov (United States)

    Chatzianastasiou, Athanasia; Bibli, Sofia-Iris; Andreadou, Ioanna; Efentakis, Panagiotis; Kaludercic, Nina; Wood, Mark E; Whiteman, Matthew; Di Lisa, Fabio; Daiber, Andreas; Manolopoulos, Vangelis G; Szabó, Csaba; Papapetropoulos, Andreas

    2016-09-01

    Hydrogen sulfide (H2S) is a signaling molecule with protective effects in the cardiovascular system. To harness the therapeutic potential of H2S, a number of donors have been developed. The present study compares the cardioprotective actions of representative H2S donors from different classes and studies their mechanisms of action in myocardial injury in vitro and in vivo. Exposure of cardiomyocytes to H2O2 led to significant cytotoxicity, which was inhibited by sodium sulfide (Na2S), thiovaline (TV), GYY4137 [morpholin-4-ium 4 methoxyphenyl(morpholino) phosphinodithioate], and AP39 [(10-oxo-10-(4-(3-thioxo-3H-1,2-dithiol5yl)phenoxy)decyl) triphenylphospho-nium bromide]. Inhibition of nitric oxide (NO) synthesis prevented the cytoprotective effects of Na2S and TV, but not GYY4137 and AP39, against H2O2-induced cardiomyocyte injury. Mice subjected to left anterior descending coronary ligation were protected from ischemia-reperfusion injury by the H2S donors tested. Inhibition of nitric oxide synthase (NOS) in vivo blocked only the beneficial effect of Na2S. Moreover, Na2S, but not AP39, administration enhanced the phosphorylation of endothelial NOS and vasodilator-associated phosphoprotein. Both Na2S and AP39 reduced infarct size in mice lacking cyclophilin-D (CypD), a modulator of the mitochondrial permeability transition pore (PTP). Nevertheless, only AP39 displayed a direct effect on mitochondria by increasing the mitochondrial Ca(2+) retention capacity, which is evidence of decreased propensity to undergo permeability transition. We conclude that although all the H2S donors we tested limited infarct size, the pathways involved were not conserved. Na2S had no direct effects on PTP opening, and its action was nitric oxide dependent. In contrast, the cardioprotection exhibited by AP39 could result from a direct inhibitory effect on PTP acting at a site different than CypD. PMID:27342567

  4. Regulation of p73 by Hck through kinase-dependent and independent mechanisms

    Directory of Open Access Journals (Sweden)

    Radha Vegesna

    2007-05-01

    Full Text Available Abstract Background p73, a p53 family member is a transcription factor that plays a role in cell cycle, differentiation and apoptosis. p73 is regulated through post translational modifications and protein interactions. c-Abl is the only known tyrosine kinase that phosphorylates and activates p73. Here we have analyzed the role of Src family kinases, which are involved in diverse signaling pathways, in regulating p73. Results Exogenously expressed as well as cellular Hck and p73 interact in vivo. In vitro binding assays show that SH3 domain of Hck interacts with p73. Co-expression of p73 with Hck or c-Src in mammalian cells resulted in tyrosine phosphorylation of p73. Using site directed mutational analysis, we determined that Tyr-28 was the major site of phosphorylation by Hck and c-Src, unlike c-Abl which phosphorylates Tyr-99. In a kinase dependent manner, Hck co-expression resulted in stabilization of p73 protein in the cytoplasm. Activation of Hck in HL-60 cells resulted in tyrosine phosphorylation of endogenous p73. Both exogenous and endogenous Hck localize to the nuclear as well as cytoplasmic compartment, just as does p73. Ectopically expressed Hck repressed the transcriptional activity of p73 as determined by promoter assays and semi-quantitative RT-PCR analysis of the p73 target, Ipaf and MDM2. SH3 domain- dependent function of Hck was required for its effect on p73 activity, which was also reflected in its ability to inhibit p73-mediated apoptosis. We also show that Hck interacts with Yes associated protein (YAP, a transcriptional co-activator of p73, and shRNA mediated knockdown of YAP protein reduces p73 induced Ipaf promoter activation. Conclusion We have identified p73 as a novel substrate and interacting partner of Hck and show that it regulates p73 through mechanisms that are dependent on either catalytic activity or protein interaction domains. Hck-SH3 domain-mediated interactions play an important role in the inhibition of p73

  5. piRNA biogenesis during adult spermatogenesis in mice is independent of the ping-pong mechanism

    Institute of Scientific and Technical Information of China (English)

    Ergin Beyret; Na Liu; Haifan Lin

    2012-01-01

    piRNAs,a class of small non-coding RNAs associated with PIWI proteins,have broad functions in germline development,transposon silencing,and epigenetic regulation.In diverse organisms,a subset of piRNAs derived from repeat sequences are produced via the interplay between two PIWI proteins.This mechanism,termed "ping-pong"cycle,operates among the PIWI proteins of the primordial mouse testis; however,its involvement in postnatal testes remains elusive.Here we show that adult testicular piRNAs are produced independent of the ping-pong mechanism.We identified and characterized large populations of piRNAs in the adult and postnatal developing testes associated with MILI and MIWI,the only PIWI proteins detectable in these testes.No interaction between MILI and MIWI or sequence feature for the ping-pong mechanism among their piRNAs was detected in the adult testis.The majority of MILI-and MIWI-associated piRNAs originate from the same DNA strands within the same loci.Both populations of piRNAs are biased for 5′ Uracil but not for Adenine on the 10th nucleotide position,and display no complementarity.Furthermore,in Miwi mutants,MILI-associated piRNAs are not downregulated,but instead upregulated.These results indicate that the adult testicular piRNAs are predominantly,if not exclusively,produced by a primary processing mechanism instead of the ping-pong mechanism.In this primary pathway,biogenesis of MILI-and MIWI-associated piRNAs may compete for the same precursors; the types of piRNAs produced tend to be non-selectively dictated by the available precursors in the cell; and precursors with introns tend to be spliced before processed into piRNAs.

  6. Inhibition of different histone acetyltransferases (HATs) uncovers transcription-dependent and -independent acetylation-mediated mechanisms in memory formation.

    Science.gov (United States)

    Merschbaecher, Katja; Hatko, Lucyna; Folz, Jennifer; Mueller, Uli

    2016-02-01

    Acetylation of histones changes the efficiency of the transcription processes and thus contributes to the formation of long-term memory (LTM). In our comparative study, we used two inhibitors to characterize the contribution of different histone acetyl transferases (HATs) to appetitive associative learning in the honeybee. For one we applied garcinol, an inhibitor of the HATs of the p300 (EP300 binding protein)/CBP (CREB-binding protein) family, and the HATs of the PCAF (p300/CBP-associated factor) family. As comparative agent we applied C646, a specific inhibitor that selectively blocks HATS of the p300/CBP family. Immunochemical analysis reveals differences in histone H3 acetylation in the honeybee brain, in response to the injection of either C646 or garcinol. Behavioral assessment reveals that the two drugs cause memory impairment of different nature when injected after associative conditioning: processes disturbed by garcinol are annihilated by the established transcription blocker actinomycin D and thus seem to require transcription processes. Actions of C646 are unaltered by actinomycin D, and thus seem to be independent of transcription. The outcome of our different approaches as summarized suggests that distinct HATs contribute to different acetylation-mediated processes in memory formation. We further deduce that the acetylation-mediated processes in memory formation comprise transcription-dependent and transcription-independent mechanisms.

  7. Energy Taxis toward Host-Derived Nitrate Supports a Salmonella Pathogenicity Island 1-Independent Mechanism of Invasion

    Science.gov (United States)

    Rivera-Chávez, Fabian; Lopez, Christopher A.; Zhang, Lillian F.; García-Pastor, Lucía; Chávez-Arroyo, Alfredo; Lokken, Kristen L.; Tsolis, Renée M.

    2016-01-01

    ABSTRACT Salmonella enterica serovar Typhimurium can cross the epithelial barrier using either the invasion-associated type III secretion system (T3SS-1) or a T3SS-1-independent mechanism that remains poorly characterized. Here we show that flagellum-mediated motility supported a T3SS-1-independent pathway for entering ileal Peyer’s patches in the mouse model. Flagellum-dependent invasion of Peyer’s patches required energy taxis toward nitrate, which was mediated by the methyl-accepting chemotaxis protein (MCP) Tsr. Generation of nitrate in the intestinal lumen required inducible nitric oxide synthase (iNOS), which was synthesized constitutively in the mucosa of the terminal ileum but not in the jejunum, duodenum, or cecum. Tsr-mediated invasion of ileal Peyer’s patches was abrogated in mice deficient for Nos2, the gene encoding iNOS. We conclude that Tsr-mediated energy taxis enables S. Typhimurium to migrate toward the intestinal epithelium by sensing host-derived nitrate, thereby contributing to invasion of Peyer’s patches. PMID:27435462

  8. Novel naproxen/esomeprazole magnesium compound pellets based on acid-independent mechanism: in vitro and in vivo evaluation.

    Science.gov (United States)

    Lu, Jing; Kan, Shuling; Zhao, Yi; Zhang, Wenli; Liu, Jianping

    2016-09-01

    The purpose of this study was to develop the novel naproxen/esomeprazole magnesium compound pellets (novel-NAP/EMZ) depending on EMZ acid-independent mechanism which has been proved to be predominate in the mechanism of co-therapy with nonsteroidal anti-inflammatory drug. The novel-NAP/EMZ compound pellets, composed of NAP colon-specific pellets (NAP-CSPs) and EMZ modified-release pellets (EMZ-MRPs), were prepared by fluid-bed coating technology with desired in vitro release profiles. The resulting pellets were filled into hard gelatin capsules for in vivo evaluation in rats and compared with the reference compound pellets, consisted of NAP enteric-coated pellets (NAP-ECPs) and EMZ immediate-release pellets (EMZ-IRPs). The reference compound pellets were prepared simulating the drug delivery system of VIMOVO(®). In vivo pharmacokinetics, EMZ-MRPs had significantly larger AUC0-t (p pellets, the novel-NAP/EMZ compound pellets did not show distinct differences in histological mucosal morphology. However, biochemical tests exhibited enhanced total antioxidant capacity, increased nitric oxide content and reduced malondialdehyde level for novel-NAP/EMZ compound pellets, indicating that the acid-independent action took effect. The gastric pH values of novel-NAP/EMZ compound pellets were at a low and stable level, which could ensure normal physiological range of human gastric pH. As a result, the novel-NAP/EMZ compound pellets may be a more suitable formulation with potential advantages by improving bioavailability of drug and further reducing undesirable gastrointestinal damages. PMID:26902772

  9. Novel naproxen/esomeprazole magnesium compound pellets based on acid-independent mechanism: in vitro and in vivo evaluation.

    Science.gov (United States)

    Lu, Jing; Kan, Shuling; Zhao, Yi; Zhang, Wenli; Liu, Jianping

    2016-09-01

    The purpose of this study was to develop the novel naproxen/esomeprazole magnesium compound pellets (novel-NAP/EMZ) depending on EMZ acid-independent mechanism which has been proved to be predominate in the mechanism of co-therapy with nonsteroidal anti-inflammatory drug. The novel-NAP/EMZ compound pellets, composed of NAP colon-specific pellets (NAP-CSPs) and EMZ modified-release pellets (EMZ-MRPs), were prepared by fluid-bed coating technology with desired in vitro release profiles. The resulting pellets were filled into hard gelatin capsules for in vivo evaluation in rats and compared with the reference compound pellets, consisted of NAP enteric-coated pellets (NAP-ECPs) and EMZ immediate-release pellets (EMZ-IRPs). The reference compound pellets were prepared simulating the drug delivery system of VIMOVO(®). In vivo pharmacokinetics, EMZ-MRPs had significantly larger AUC0-t (p pellets, the novel-NAP/EMZ compound pellets did not show distinct differences in histological mucosal morphology. However, biochemical tests exhibited enhanced total antioxidant capacity, increased nitric oxide content and reduced malondialdehyde level for novel-NAP/EMZ compound pellets, indicating that the acid-independent action took effect. The gastric pH values of novel-NAP/EMZ compound pellets were at a low and stable level, which could ensure normal physiological range of human gastric pH. As a result, the novel-NAP/EMZ compound pellets may be a more suitable formulation with potential advantages by improving bioavailability of drug and further reducing undesirable gastrointestinal damages.

  10. 糖尿病对大鼠牙槽骨缺损修复中骨形态发生蛋白-2表达影响的研究%Effects of diabetes on expression of BMP-2 during bone healing of alveolar defect in rats

    Institute of Scientific and Technical Information of China (English)

    聂莹; 张志宏; 袁晟; 鲍军燕

    2011-01-01

    Objective To investigate the effects of diabetes on the expression of bone morphogenetic protein - 2 (BMP-2) during the various bone healing periods of alveolar defect. Methods 48 male SD rats were randomly divided into diabetes group ( n = 24) and control group( n=24). Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ) ,and alveolar defect was created through the diabetic duration time. 6 rats in each group were scarified respectively at the lth ,2th ,4th ,8th week ,then the alveolar bone were processed for histological examination. The expression of BMP-2 in different periods( 1,2,4,8 weeks)of alveolar defect healing of rats was investigated through immunohistochemistry method. The optical density (OD) of BMP-2 was analysed and compared between groups. Results Osteopenia in diabetes group were observed. The OD of BMP - 2 in the control group was statistically greater than that in the test group 1 and 2 weeks after alveolar defect. After 4 and 8 weeks, the expression of BMP-2 in the control group decreased,and no statistical difference was found in BMP -2 expression between these two groups. Conclusions Diabetes may affect the formation of BMP-2 ,leading to a reduction in bone healing. Diabetes is able to affect the differentiation of mesenchymal stem cells,leading to less osseointegration. Therefore, primary stability was decreased.%目的 观察糖尿病(diabetes mellitus,DM)对实验性大鼠牙槽骨缺损修复过程中不同时期骨形态发生蛋白-2(bone morphogenetic protein-2,BMP-2)表达的影响.方法 将48 只雄性SD大鼠随机分为DM组和对照组,每组24 只,DM组大鼠经腹腔注射链脲佐菌素造成DM大鼠模型,建模成功后行大鼠牙槽骨骨缺损制备,2 组均分别于骨缺损制备后1、2、4、8 周各取6 只大鼠处死,取术区组织.苏木精-伊红染色(hematoxylin-eosin staining,HE染色)镜下观察缺损区内新生骨样组织形成情况;用免疫组化法检测术后1、2、4

  11. Autologous serum improves bone formation in a primary stable silica-embedded nanohydroxyapatite bone substitute in combination with mesenchymal stem cells and rhBMP-2 in the sheep model

    Directory of Open Access Journals (Sweden)

    Boos AM

    2014-11-01

    Full Text Available Anja M Boos,1,* Annika Weigand,1,* Gloria Deschler,1 Thomas Gerber,2 Andreas Arkudas,1 Ulrich Kneser,1 Raymund E Horch,1 Justus P Beier11Department of Plastic and Hand Surgery, University Hospital of Erlangen, Friedrich-Alexander-University of Erlangen-Nürnberg FAU, Erlangen, 2Institute of Physics, University of Rostock, Rostock, Germany *These authors contributed equally to this work Abstract: New therapeutic strategies are required for critical size bone defects, because the gold standard of transplanting autologous bone from an unharmed area of the body often leads to several severe side effects and disadvantages for the patient. For years, tissue engineering approaches have been seeking a stable, axially vascularized transplantable bone replacement suitable for transplantation into the recipient bed with pre-existing insufficient conditions. For this reason, the arteriovenous loop model was developed and various bone substitutes have been vascularized. However, it has not been possible thus far to engineer a primary stable and axially vascularized transplantable bone substitute. For that purpose, a primary stable silica-embedded nanohydroxyapatite (HA bone substitute in combination with blood, bone marrow, expanded, or directly retransplanted mesenchymal stem cells, recombinant human bone morphogenetic protein 2 (rhBMP-2, and different carrier materials (fibrin, cell culture medium, autologous serum was tested subcutaneously for 4 or 12 weeks in the sheep model. Autologous serum lead to an early matrix change during degradation of the bone substitute and formation of new bone tissue. The best results were achieved in the group combining mesenchymal stem cells expanded with 60 µg/mL rhBMP-2 in autologous serum. Better ingrowth of fibrovascular tissue could be detected in the autologous serum group compared with the control (fibrin. Osteoclastic activity indicating an active bone remodeling process was observed after 4 weeks, particularly

  12. Mechanical prophylaxis is a heparin-independent risk for anti-platelet factor 4/heparin antibody formation after orthopedic surgery.

    Science.gov (United States)

    Bito, Seiji; Miyata, Shigeki; Migita, Kiyoshi; Nakamura, Mashio; Shinohara, Kazuhito; Sato, Tomotaro; Tonai, Takeharu; Shimizu, Motoyuki; Shibata, Yasuhiro; Kishi, Kazuhiko; Kubota, Chikara; Nakahara, Shinnosuke; Mori, Toshihito; Ikeda, Kazuo; Ota, Shusuke; Minamizaki, Takeshi; Yamada, Shigeru; Shiota, Naofumi; Kamei, Masataka; Motokawa, Satoru

    2016-02-25

    Platelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366. PMID:26659923

  13. BMP-2联合温热化疗对SW480中GDF15和TFF3表达的影响%Effect of bone morphogenetic protein-2 combined with hyperthermic chemotherapy on GDF15 and TFF3 expression in SW480

    Institute of Scientific and Technical Information of China (English)

    毕德利; 王亚旭; 舒宁波; 谢凯

    2012-01-01

    目的:探讨骨形态发生蛋白-2(Bone morphogenetic protein-2,BMP-2)联合温热化疗对SW480中GDF15和TFF3表达的影响.方法:BMP-2作用于大肠癌SW480细胞系,置于43℃温热化疗30 min,培养6h.(1)流式细胞法检测SW480细胞的凋亡;(2) Western blot法检测GDF15和TFF3蛋白表达情况;(3) RT-PCR半定量检测GDF15和TFF3的mRNA表达.结果:BMP-2联合43℃温热化疗后SW480细胞凋亡增加,GDF15和TFF3蛋白表达水平下降,GDF15和TFF3的mRNA表达亦下调.结论:BMP-2联合温热化疗通过抑制大肠癌SW480的GDF15和TFF3蛋白及其相关基因表达,增强抑制SW480的增殖及转移复发的作用;温热疗法联合化疗对GDF15和TFF3表达抑制有协同作用.%Objective: To explore the effect of bone morphogenetic protein-2(BMP-2) combined with hyperthermic chemotherapy on GDF15 and TFF3 expression in SW480. Methods:BMP-2 was acted on SW480 colorectal cancer cell lines,placed in 43 t hyperthermic chemotherapy for 30 min and cultured for 6 h. (1 )Apoptosis of SW480 cells was detected by flow cytometry assay; (2)GDF15 and TFF3 protein expressions were detected by Western blot; (3)GDF15 and TFF3 mRNA expressions were detected by RT-PCR. Results: SW480 cells apoptosis was increased, GDF15 and TFF3 protein levels were decreased after BMP-2 combined with 43 t hyperthermic chemotherapy. GDF 15 and TFF3 mRNA expressions were also reduced. Conclusions: BMP-2 combined hyperthermic chemotherapy can inhibit proliferation and metastasis of SW480 by inhibiting GDF15 and TFF3 protein and mRNA expressions. Hyperthermia combined with chemotherapy has synergistic effect on the inhibition of GDF15 and TFF3 expression.

  14. β-adrenergic receptor activation in immortalized human urothelial cells stimulates inflammatory responses by PKA-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Porter James E

    2005-08-01

    -AR agonist isoproterenol. However, the increased production of iNOS and COX-2 by isoproterenol is not blocked when UROtsa cells are preincubated with inhibitors of PKA. Therefore, UROtsa cell β-AR activation significantly increases the amount of iNOS and COX-2 produced by a PKA-independent mechanism. Consequently, this immortalized human urothelial cell line can be useful in characterizing potential AR signaling mechanisms associated with chronic inflammatory diseases of the bladder.

  15. Protection of cortical cells by equine estrogens against glutamate-induced excitotoxicity is mediated through a calcium independent mechanism

    Directory of Open Access Journals (Sweden)

    Perrella Joel

    2005-05-01

    Full Text Available Abstract Background High concentrations of glutamate can accumulate in the brain and may be involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease. This form of neurotoxicity involves changes in the regulation of cellular calcium (Ca2+ and generation of free radicals such as peroxynitrite (ONOO-. Estrogen may protect against glutamate-induced cell death by reducing the excitotoxic Ca2+ influx associated with glutamate excitotoxicity. In this study, the inhibition of N-methyl-D-aspartate (NMDA receptor and nitric oxide synthase (NOS along with the effect of 17β-estradiol (17β-E2 and a more potent antioxidant Δ8, 17β-estradiol (Δ8, 17β-E2 on cell viability and intracellular Ca2+ ([Ca2+]i, following treatment of rat cortical cells with glutamate, was investigated. Results Primary rat cortical cells were cultured for 7–12 days in Neurobasal medium containing B27 supplements. Addition of glutamate (200 μM decreased cell viability to 51.3 ± 0.7% compared to control. Treatment with the noncompetitive NMDAR antagonist, MK-801, and the NOS inhibitor, L-NAME, completely prevented cell death. Pretreatment (24 hrs with 17β-E2 and Δ8, 17β-E2 (0.01 to 10 μM significantly reduced cell death. 17β-E2 was more potent than Δ8, 17β-E2. Glutamate caused a rapid 2.5 fold increase in [Ca2+]i. Treatment with 0.001 to 10 μM MK-801 reduced the initial Ca2+ influx by 14–41% and increased cell viability significantly. Pretreatment with 17β-E2 and Δ8, 17β-E2 had no effect on Ca2+ influx but protected the cortical cells against glutamate-induced cell death. Conclusion Glutamate-induced cell death in cortical cultures can occur through NMDAR and NOS-linked mechanisms by increasing nitric oxide and ONOO-. Equine estrogens: 17β-E2 and Δ8, 17β-E2, significantly protected cortical cells against glutamate-induced excitotoxicity by a mechanism that appears to be independent of Ca2+ influx. To our knowledge, this is a first

  16. Mechanical loading induced expression of bone morphogenetic protein-2,alkaline phosphatase activity,and collagen synthesis in osteoblastic MC3T3-E1 cells

    Institute of Scientific and Technical Information of China (English)

    LU Hong-fei; MAI Zhi-hui; XU Ye; WANG Wei; AI Hong

    2012-01-01

    Background Bone morphogenetic protein(BMP)-2,alkaline phosphatase(ALP),and collagen typeⅠ?are known to play a critical role in the process of bone remodeling.However,the relationship between mechanical strain and the expression of BMP-2,ALP,and COL-Ⅰ?in osteoblasts was still unknown.The purpose of this study was to investigate the effects of different magnitudes of mechanical strain on osteoblast morphology and on the expression of BMP-2,ALP,and COL-Ⅰ.Methods Osteoblast-like cells were flexed at four deformation rates(0,6%,12%,and 18% elongation).The expression of BMP-2 mRNA,ALP,and COL-Ⅰ?in osteoblast-like cells were determined by real-time quantitative reverse transcription polymerase chain reaction,respectively.The results were subjected to analysis of variance(ANOVA)using SPSS 13.0 statistical software.Results The cells changed to fusiform and grew in the direction of the applied strain after the mechanical strain was loaded.Expression level of the BMP-2,ALP,and COL-Ⅰ?increased magnitude-dependently with mechanical loading in the experimental groups,and the 12% elongation group had the highest expression(P<0.05).Conclusion Mechanical strain can induce morphological change and a magnitude-dependent increase in the expression of BMP-2,ALP,and COL-Ⅰ?mRNA in osteoblast-like cells,which might influence bone remodeling in orthodontic treatment.

  17. Senescent mesenchymal cells accumulate in human fibrosis by a telomere-independent mechanism and ameliorate fibrosis through matrix metalloproteinases.

    Science.gov (United States)

    Pitiyage, Gayani Nadika; Slijepcevic, Predrag; Gabrani, Aliya; Chianea, Yaghoub Gozaly; Lim, Kue Peng; Prime, Stephen Stewart; Tilakaratne, Wanninayake Mudiyanselage; Fortune, Farida; Parkinson, Eric Kenneth

    2011-04-01

    Fibrosis can occur in many organs, where it is a debilitating and preneoplastic condition. The senescence of activated fibroblasts has been proposed to ameliorate fibrosis via the innate immune system but its role in humans has not been investigated. The availability of oral submucous fibrosis (OSMF) biopsies at different stages of disease progression allowed us to test the hypothesis that senescent fibroblasts accumulate with the progression of human fibrosis in vivo, and also to examine the mechanism of senescence. We tested the hypothesis that senescent cells may ameliorate fibrosis by increasing the secretion of matrix metalloproteinases (MMPs). We have used a combination of in situ immunodetection techniques, drug treatments, fluorescence-activated cell sorting and enzyme-linked absorbance assays on tissue samples and fibroblast cultures. We report a novel panning technique, based on fibronectin adhesion rates, to enrich and deplete senescent cells from fibroblast populations. Senescent fibroblasts, as determined by the presence of senescence-associated heterochromatic foci, accumulated with OSMF progression (R(2) = 0.98) and possessed a reduced replicative lifespan in vitro. Unlike wounds, however, OSMF fibroblasts were quiescent in vivo and consistent with this observation, possessed functional telomeres of normal length. Senescence was associated in vivo and in vitro with oxidative damage, DNA damage foci and p16(INK4A) accumulation and required the production of reactive oxygen species (ROS), perhaps from damaged mitochondria, but not the continuous presence of the disease stimulus (areca nut and tobacco), the tissue environment or other cell types. Depletion of OSMF fibroblasts of senescent cells showed that these cells accounted for 25-83 times more MMP-1 and -2 than their pre-senescent counterparts. The results show that the accumulation of senescent fibroblasts in human fibrosis occurs by a telomere-independent mechanism involving ROS and may locally

  18. Crocetin induces cytotoxicity and enhances vincristine-induced cancer cell death via p53-dependent and -independent mechanisms

    Institute of Scientific and Technical Information of China (English)

    Ying-jia ZHONG; Yong QIN; Lin-chuan; LIAO Xia WANG; Fang SHI; Xue-lian ZHENG; Qiong WANG; Lan YANG; Hong SUN; Fan HE; Lin ZHANG; Yong LIN

    2011-01-01

    To investigate the anticancer effect of crocetin,a major ingredient in saffron,and its underlying mechanisms.Methods:Cervical cancer cell line HeLa,non-small cell lung cancer cell line A549 and ovarian cancer cell line SKOV3 were treated with crocetin alone or in combination with vincristine.Cell proliferation was examined using MTT assay.Cell cycle distribution and sub-G1 fraction were analyzed using flow cytometric analysis after propidium iodide staining.Apoptosis was detected using the Annexin V-FITC Apoptosis Detection Kit with flow cytometry.Cell death was measured based on the release of lactate dehydrogenase (LDH).The expression levels of p53 and p21wAF1/Cip1 as well as caspase activation were examined using Western blot analysis.Results:Treatment of the 3 types of cancer cells with crocetin (60-240 μmol/L) for 48 h significantly inhibited their proliferation in a concentration-dependent manner.Crocetin (240 μmol/L) significantly induced cell cycle arrest through p53-dependent and -independent mechanisms accompanied with p21WAF1/Cip1 induction.Crocetin (120-240 μmoVL) caused cytotoxicity in the 3 types of cancer cells by enhancing apoptosis in a time-dependent manner.In the 3 types of cancer cells,crocetin (60 μmol/L) significantly enhanced the cytotoxicity induced by vincristine (1 μmol/L).Furthermore,this synergistic effect was also detected in the vincristine-resistant breast cancer cell line MCF-7/VCR.Conclusion:Ccrocetin is a potential anticancer agent,which may be used as a chemotherapeutic drug or as a chemosensitizer for vin-cristine.

  19. Macrophage control of phagocytosed mycobacteria is increased by factors secreted by alveolar epithelial cells through nitric oxide independent mechanisms.

    Directory of Open Access Journals (Sweden)

    Dagbjort H Petursdottir

    Full Text Available Tissue-resident macrophages are heterogeneous with tissue-specific and niche-specific functions. Thus, simplified models of macrophage activation do not explain the extent of heterogeneity seen in vivo. We focus here on the respiratory tract and ask whether factors secreted by alveolar epithelial cells (AEC can influence the functionality of resident pulmonary macrophages (PuM. We have previously reported that factors secreted by AEC increase control of intracellular growth of BCG in macrophages. In the current study, we also aimed to investigate possible mechanisms by which AEC-derived factors increase intracellular control of BCG in both primary murine interstitial macrophages, and bone marrow-derived macrophages and characterize further the effect of these factors on macrophage differentiation. We show that; a in contrast to other macrophage types, IFN-γ did not increase intracellular growth control of Mycobacterium bovis, Bacillus Calmette-Guérin (BCG by interstitial pulmonary macrophages although the same macrophages could be activated by factors secreted by AEC; b the lack of response of pulmonary macrophages to IFN-γ was apparently regulated by suppressor of cytokine signaling (SOCS1; c AEC-derived factors did not induce pro-inflammatory pathways induced by IFN-γ e.g. expression of inducible nitric oxide synthase (iNOS, secretion of nitric oxide (NO, or IL-12, d in contrast to IFN-γ, intracellular bacterial destruction induced by AEC-derived factors was not dependent on iNOS transcription and NO production. Collectively, our data show that PuM were restricted in inflammatory responses mediated by IFN-γ through SOCS1 and that factors secreted by AEC- enhanced the microbicidal capacities of macrophages by iNOS independent mechanisms.

  20. Isolation of TRPV1 independent mechanisms of spontaneous and asynchronous glutamate release at primary afferent to NTS synapses.

    Science.gov (United States)

    Fenwick, Axel J; Wu, Shaw-Wen; Peters, James H

    2014-01-01

    Cranial visceral afferents contained within the solitary tract (ST) contact second-order neurons in the nucleus of the solitary tract (NTS) and release the excitatory amino acid glutamate via three distinct exocytosis pathways; synchronous, asynchronous, and spontaneous release. The presence of TRPV1 in the central terminals of a majority of ST afferents conveys activity-dependent asynchronous glutamate release and provides a temperature sensitive calcium conductance which largely determines the rate of spontaneous vesicle fusion. TRPV1 is present in unmyelinated C-fiber afferents and these facilitated forms of glutamate release may underlie the relative strength of C-fibers in activating autonomic reflex pathways. However, pharmacological blockade of TRPV1 signaling eliminates only ~50% of the asynchronous profile and attenuates the temperature sensitivity of spontaneous release indicating additional thermosensitive calcium influx pathways may exist which mediate these forms of vesicle release. In the present study we isolate the contribution of TRPV1 independent forms of glutamate release at ST-NTS synapses. We found ST afferent innervation at NTS neurons and synchronous vesicle release from TRPV1 KO mice was not different to control animals; however, only half of TRPV1 KO ST afferents completely lacked asynchronous glutamate release. Further, temperature driven spontaneous rates of vesicle release were not different from 33 to 37°C between control and TRPV1 KO afferents. These findings suggest additional temperature dependent mechanisms controlling asynchronous and thermosensitive spontaneous release at physiological temperatures, possibly mediated by additional thermosensitive TRP channels in primary afferent terminals.

  1. In vivo experimental study of hollow porous femoral prosthesis filled with rhBMP-2%中空多孔股骨柄假体骨长入方式的在体实验研究

    Institute of Scientific and Technical Information of China (English)

    蔡谞; 王达文; 樊宇平; 赵斌; 王岩

    2008-01-01

    Objective To study hone formation and osteointegration at the interface and inside the hollow porous femoral porsthesis filled with recombinant human bone morphogentic protein-2 (rhBMP-2). Methods 18 health adult hybrid dogs were divided into 3 groups randomly. Each animal received total hip arthroplasty at right hip joint. The femoral stems implanted were solid center prosthesis (group A), hollow porous prosthesis filled with cancellous bone taken from the femur head and neck (group B), and hollow porous prosthesis filled with gelfoam and 5 mg rhBMP-2(group C), respectively. All prosthesis were made of CoCrMo alloy with hydroxyapatite coating at the proximal half. The animals were sacrificed at 2,4,8 months post operation and X-ray of the femur samples were taken. The histological changes, interface osseointega- tion rate and bone ingrowth rate round and inside prosthesis were evaluated. Results The bone formation of group C was faster than group A and B histologically. The interface osteointegration rate of group C was sig- nificantly higher than that of group A and B (P< 0.05) at 2, 4 months, but there was no significantly differ- ence between them at 8 months (P 0.05). Also the bone ingrowth rate of group C was higher than that of group B(P<0.05), but no significant difference at 8 months(P 0.05). There was nosignificant difference be- tween goup A and B at interface osteointegration rate. Conclusion The hollow porous femoral prosthesis filled with rhBMP-2 can enhance interface osteointegration and bone ingrowth effectively, which can make the prosthesis fast fixed in the bone bed right at the early stage. And this may provide reliable experimental evidence for developing a kind of hollow porous femoral prosthesis for human.%目的 观察多孔中空人工股骨柄假体周围骨床骨质经界面长入金属空腔及其在腔室内成骨的特征,比较腔内复合骨诱导因子(rhBMP-2)与自身骨长入的成骨差异.方法 健康成年杂交犬18

  2. 重组人BMP-2诱导C3H10T1/2间质干细胞定向成骨分化早期基因表达谱分析%Identification and analysis of gene expression profiles for early osteoblastic differentiation on C3H10T1/2 mesenchymal stem cells induced by rhBMP-2

    Institute of Scientific and Technical Information of China (English)

    左长清; 汪宗桂; 钟月春; 卢旱云; 戴忠; 吴铁; 崔燎

    2014-01-01

    目的 研究间质干细胞早期定向成骨分化基因表达谱,为研究基因对早期成骨定向分化调控机制提供实验基础.方法 分别提取重组人骨形成蛋白2(rhBMP-2)诱导组和对照组C3H10T1/2细胞总RNA,进行扩增标记后,与ArraySTAR小鼠基因芯片杂交,应用生物信息学软件GeneSpring和GATHER对基因芯片数据进行分析.应用STRING在线软件对差异表达基因构建蛋白互作网络并进行网络分析.结果 C3H10T1/2早期成骨分化中,主要富集发育、器官形成等分子功能本体以及细胞因子-细胞因子受体作用信号通路.成骨分化1d和4d均上调表达基因42个,下调表达基因45个.网络分析研究表明:Egfr、Cxcl 12等信号分子参与调控rhBMP-2诱导成骨分化.结论 筛选的差异表达基因和信号分子对早期成骨分化调控具有重要作用,为进一步全面解析早期成骨定向分化提供实验基础.

  3. Induction of tryptase and histmine release from human colon mast cells by IgE dependent or independent mechanisms

    Institute of Scientific and Technical Information of China (English)

    Shao-Heng He; Hua Xie; Yong-Song He

    2004-01-01

    AIM: To investigate the tryptase and histamine release ability of human colon mast cells upon IgE dependent or independent activation and the potential mechanisms.METHODS: Enzymatically dispersed cells from human colons were challenged with anti-IgE or calcium ionophore A23187, and the cell supernatants after challenge were collected. Both concentration dependent and time course studies with anti-IgE or calcium ionophore A23187 were performed. Tryptase release was determined with a sandwich ELISA procedure and histamine release was measured usina a glass fibre-based fluorometric assay.RESULTS: Both anti-IgE and calcium ionophore were able to induce dose dependent release of histamine from colon mast cells with up to approximately 60% and 25% net histamine release being achieved with 1 μg/mL calcium ionophore and 10 μg/mL anti-IgE, respectively. Dose dependent release of tryptase was also observed with up to approximately 19 ng/mL and 21 ng/mL release of tryptase being achieved with 10 μg/mL anti-IgE and 1 μg/mL calcium ionophore, respectively. Time course study revealed that both tryptase and histamine release from colon mast cells stimulated by anti-IgE initiated within 10 sec and reached their maximum release at 6 min following challenge. Pretreatment of cells with metabolic inhibitors abolished the actions of anti-IgE as well as calcium ionophore. Tryptase and histamine release, particularly that induced by calcium ionophore was inhibited by pretreatment of cells with pertussis toxin.CONCLUSION: Both anti-IgE and calcium ionophore are able to induce significant release of tryptase and histamine from colon mast cells, indicating that this cell type is likely to contribute to the pathogenesis of colitis and other mast cell associated intestinal diseases.

  4. Regulation of Raf-1 and Raf-1 mutants by Ras-dependent and Ras-independent mechanisms in vitro.

    Science.gov (United States)

    Dent, P; Reardon, D B; Morrison, D K; Sturgill, T W

    1995-08-01

    The serine/threonine kinase Raf-1 functions downstream from Ras to activate mitogen-activated protein kinase kinase, but the mechanisms of Raf-1 activation are incompletely understood. To dissect these mechanisms, wild-type and mutant Raf-1 proteins were studied in an in vitro system with purified plasma membranes from v-Ras- and v-Src-transformed cells (transformed membranes). Wild-type (His)6- and FLAG-Raf-1 were activated in a Ras- and ATP-dependent manner by transformed membranes; however, Raf-1 proteins that are kinase defective (K375M), that lack an in vivo site(s) of regulatory tyrosine (YY340/341FF) or constitutive serine (S621A) phosphorylation, that do not bind Ras (R89L), or that lack an intact zinc finger (CC165/168SS) were not. Raf-1 proteins lacking putative regulatory sites for an unidentified kinase (S259A) or protein kinase C (S499A) were activated but with apparently reduced efficiency. The kinase(s) responsible for activation by Ras or Src may reside in the plasma membrane, since GTP loading of plasma membranes from quiescent NIH 3T3 cells (parental membranes) induced de novo capacity to activate Raf-1. Wild-type Raf-1, possessing only basal activity, was not activated by parental membranes in the absence of GTP loading. In contrast, Raf-1 Y340D, possessing significant activity, was, surprisingly, stimulated by parental membranes in a Ras-independent manner. The results suggest that activation of Raf-1 by phosphorylation may be permissive for further modulation by another membrane factor, such as a lipid. A factor(s) extracted with methanol-chloroform from transformed membranes or membranes from Sf9 cells coexpressing Ras and SrcY527F significantly enhanced the activity of Raf-1 Y340D or active Raf-1 but not that of inactive Raf-1. Our findings suggest a model for activation of Raf-1, wherein (i) Raf-1 associates with Ras-GTP, (ii) Raf-1 is activated by tyrosine and/or serine phosphorylation, and (iii) Raf-1 activity is further increased by a

  5. Subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement and gelatin sponge as the carrier of recombinant bone morphogenetic protein-2 in rats:A comparative study%两种材料复合rhBMP-2诱导大鼠皮下异位成骨的比较研究

    Institute of Scientific and Technical Information of China (English)

    李想; 董纪元; 彭江; 汪爱媛; 睢翔; 赵斌; 刘道宏

    2011-01-01

    Objective To analyze the difference in subcutaneous ectopic osteogenesis induced by porous calcium phosphate cement (CPC) and gelatin sponge as a carrier of recombinant bone morphogenetic protein-2 (rhBMP-2). Methods Thirty Sprague Dawley rats with an average body weight of 200g were divided into groups A-D. CPC+rhBMP-2, CPC, gelatin sponge+rhBMP-2, and gelatin sponge were implanted into the rats after anesthesia. Ten rats were killed 2, 4 and 8 weeks after they were fed under sterile environment. Bone tissue samples were collected from the implantation sites. Tissue mineral density (TMD) and trabecular thickness were detected with micro-CT scanner and analyzed with SPSS 1 OX) statistical software. Bone tissue was fixed in 4% paraformaldehyde for 2 days, embedded in paraffin, and cut into sections. The sections were stained with H&E to observe their histological change. Results The tissue mineral density and trabecular thickness of the samples with rhBMP-2 were higher in two experimental groups 2,4 and 8 weeks after implantation, which increased with the prolongation of time (P<0.05). Conclusion Porous CPC can be used as a carrier of rhBMP-2 for osteogenesis.%目的 分析多孔自固化磷酸钙骨水泥(Calcium Phosphate Cement,CPC)和明胶海绵复合重组人骨形态发生蛋白(Recombinantion Humen Bone Morphogenetic Protein-2,rhBMP-2)诱导大鼠皮下异位成骨的区别.方法 平均质量200g SD大鼠30只,麻醉后分别植入A:多孔CPC复合rhBMP-2(2μg);B:多孔CPC;C:明胶海绵复合rhBMP-2(2μg);D:空白明胶海绵,无菌喂养后分别于2、4、8周各处死10只.对植入部位组织取材,分别进行micro-CT扫描,并使用Micview V2.1三维重建处理软件扫及ABA骨形态分析软件检测,记录组织骨密度(Tissue Mineral Density,TMD)及骨小梁厚度(Trabecular Thickness,Tb.Th).运用SPSS10.0统计软件进行统计学分析.后行甲醛固定2周,石蜡包埋切片,HE染色进行组织学观察.结果 在2、4、8周时,加入rhBMP

  6. Allogeneic Platelet Releasate Preparations Derived via a Novel Rapid Thrombin Activation Process Promote Rapid Growth and Increased BMP-2 and BMP-4 Expression in Human Adipose-Derived Stem Cells.

    Science.gov (United States)

    McLaughlin, Michael; Gagnet, Paul; Cunningham, Elizabeth; Yeager, Randi; D'Amico, Michael; Guski, Katie; Scarpone, Michael; Kuebler, Daniel

    2016-01-01

    The administration of human adipose-derived stem cells (ASCs) represents a promising regenerative therapy for the treatment of orthopedic injuries. While ASCs can be easily isolated from liposuction-derived adipose tissue, most clinical applications will likely require in vitro culture expansion of these cells using nonxenogeneic components. In this study, platelet releasate was generated using a novel rapid thrombin activation method (tPR). ASCs grown in media supplemented with tPR proliferated much faster than ASCs grown in media supplemented with 10% fetal bovine serum. The cells also retained the ability to differentiate along chondrogenic, adipogenic, and osteogenic lineages. The tPR cultured ASCs displayed elevated expression of BMP-4 (5.7 ± 0.97-fold increase) and BMP-2 (4.7 ± 1.3-fold increase) and decreased expression of PDGF-B (4.0 ± 1.4-fold decrease) and FGF-2 (33 ± 9.0-fold decrease). No significant changes in expression were seen with TGF-β and VEGF. This pattern of gene expression was consistent across different allogeneic tPR samples and different ASC lines. The use of allogeneic rapidly activated tPR to culture ASCs is associated with both an increased cell yield and a defined gene expression profile making it an attractive option for cell expansion prior to cell-based therapy for orthopedic applications.

  7. Allogeneic Platelet Releasate Preparations Derived via a Novel Rapid Thrombin Activation Process Promote Rapid Growth and Increased BMP-2 and BMP-4 Expression in Human Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Michael McLaughlin

    2016-01-01

    Full Text Available The administration of human adipose-derived stem cells (ASCs represents a promising regenerative therapy for the treatment of orthopedic injuries. While ASCs can be easily isolated from liposuction-derived adipose tissue, most clinical applications will likely require in vitro culture expansion of these cells using nonxenogeneic components. In this study, platelet releasate was generated using a novel rapid thrombin activation method (tPR. ASCs grown in media supplemented with tPR proliferated much faster than ASCs grown in media supplemented with 10% fetal bovine serum. The cells also retained the ability to differentiate along chondrogenic, adipogenic, and osteogenic lineages. The tPR cultured ASCs displayed elevated expression of BMP-4 (5.7 ± 0.97-fold increase and BMP-2 (4.7 ± 1.3-fold increase and decreased expression of PDGF-B (4.0 ± 1.4-fold decrease and FGF-2 (33 ± 9.0-fold decrease. No significant changes in expression were seen with TGF-β and VEGF. This pattern of gene expression was consistent across different allogeneic tPR samples and different ASC lines. The use of allogeneic rapidly activated tPR to culture ASCs is associated with both an increased cell yield and a defined gene expression profile making it an attractive option for cell expansion prior to cell-based therapy for orthopedic applications.

  8. Quercetin and epigallocatechin gallate inhibit glucose uptake and metabolism by breast cancer cells by an estrogen receptor-independent mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Liliana, E-mail: lilianam87@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Araújo, Isabel, E-mail: isa.araujo013@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Costa, Tito, E-mail: tito.fmup16@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Correia-Branco, Ana, E-mail: ana.clmc.branco@gmail.com [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Faria, Ana, E-mail: anafaria@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Chemistry Investigation Centre (CIQ), Faculty of Sciences of University of Porto, Rua Campo Alegre, 4169-007 Porto (Portugal); Faculty of Nutrition and Food Sciences of University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Martel, Fátima, E-mail: fmartel@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal); Keating, Elisa, E-mail: keating@med.up.pt [Department of Biochemistry (U38-FCT), Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto (Portugal)

    2013-07-15

    In this study we characterized {sup 3}H-2-deoxy-D-glucose ({sup 3}H -DG) uptake by the estrogen receptor (ER)-positive MCF7 and the ER-negative MDA-MB-231 human breast cancer cell lines and investigated the effect of quercetin (QUE) and epigallocatechin gallate (EGCG) upon {sup 3}H-DG uptake, glucose metabolism and cell viability and proliferation. In both MCF7 and MDA-MB-231 cells {sup 3}H-DG uptake was (a) time-dependent, (b) saturable with similar capacity (V{sub max}) and affinity (K{sub m}), (c) potently inhibited by cytochalasin B, an inhibitor of the facilitative glucose transporters (GLUT), (d) sodium-independent and (e) slightly insulin-stimulated. This suggests that {sup 3}H-DG uptake by both cell types is mediated by members of the GLUT family, including the insulin-responsive GLUT4 or GLUT12, while being independent of the sodium-dependent glucose transporter (SGLT1). QUE and EGCG markedly and concentration-dependently inhibited {sup 3}H-DG uptake by MCF7 and by MDA-MB-231 cells, and both compounds blocked lactate production by MCF7 cells. Additionally, a 4 h-treatment with QUE or EGCG decreased MCF7 cell viability and proliferation, an effect that was more potent when glucose was available in the extracellular medium. Our results implicate QUE and EGCG as metabolic antagonists in breast cancer cells, independently of estrogen signalling, and suggest that these flavonoids could serve as therapeutic agents/adjuvants even for ER-negative breast tumors. -- Highlights: • Glucose uptake by MCF7 and MDA-MB-231 cells is mainly mediated by GLUT1. • QUE and EGCG inhibit cellular glucose uptake thus abolishing the Warburg effect. • This process induces cytotoxicity and proliferation arrest in MCF7 cells. • The flavonoids’ effects are independent of estrogen receptor signalling.

  9. Geometry- and diffraction-independent ionization probabilities in intense laser fields: probing atomic ionization mechanisms with effective intensity matching

    OpenAIRE

    Bryan, W. A.; Stebbings, S. L.; English, E.M.L.; Goodworth, T. R. J.; Newell, W. R.; McKenna, J; Suresh, M.; Srigengan, B.; Williams, I. D.; Turcu, I. C. E.; Smith, J M; Divall, E. J.; Hooker, C. J.; Langley, A. J.

    2005-01-01

    We report a novel experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm^2 to 10 PW/cm^2 using Effective Intensity Matching (EIM), which is coupled with Intensity Selective Scanning (ISS) to recover the geometry-independent probability of ionization. Such measurements, made possible by...

  10. Role of bone morphogenetic protein 2 in early acetabulum development and dysplastic acetabulum remodeling%BMP-2在髋臼软骨发育早期及发育不良髋臼软骨可逆性恢复过程中的作用研究

    Institute of Scientific and Technical Information of China (English)

    莫越强; 裴新红; 马瑞雪

    2015-01-01

    目的 研究BMP-2在髋臼软骨发育早期及发育不良髋臼软骨可逆性恢复过程中的作用.方法 通过伸髋内收、模拟襁褓体位固定新生大鼠双后肢,建立发育不良髋臼软骨模型.将髋臼标本经HE染色后观察比较正常及发育不良髋臼软骨组织形态学变化特点,同时用ELISA方法和PCR方法分别检测BMP-2、BMP-4、BMP-6、BMP-7的分泌及基因表达情况.将捆绑不同时间后的大鼠松绑,其中部分当场处死,其余大鼠继续喂养,最终至30日龄,建立发育不良髋臼软骨可逆性恢复模型.研究其髋臼软骨组织形态学恢复及BMP-2分泌变化情况.结果 正常大鼠髋臼软骨呈半圆形、容积大、表面光滑.发育不良髋臼软骨髋臼上缘肥厚,软骨发生变性,与周围组织分界不清.髋臼软骨BMP-2的分泌在正常大鼠7日龄和9日龄时出现高峰,分别为(13.7±0.29) ng/ml和(13.9±0.38) ng/ml.而在发育不良髋臼软骨中这一分泌高峰消失.在发育不良髋臼软骨可逆性恢复组,捆绑4d和6d的大鼠,BMP-2的分泌高峰出现延迟,都在15日龄时出现;而在捆绑8d及以上的大鼠,在松绑后继续喂养至30日龄,髋臼软骨组织形态无法恢复正常,并且BMP-2的分泌高峰未出现.结论 BMP-2的分泌可能是髋臼软骨早期发育情况的生物学标记之一.%Objective To explore the early-stage acetabulum development in normal and dysplastic acetabula and elucidate the function of bone morphogenetic protein 2 (BMP-2) in early acetabulum development and dysplastic acetabulum remodeling.Methods The rat model of dysplastic acetabulum was established by maintaining hips in a swaddling position.By analyzing the cartilage histologic characteristics,early-stage acetabulum developments were examined in normal and dysplastic acetabulum animals.Meantime,the mRNA expression and chondrocyte secretion of functional BMP-2,bone morphogenetic protein 4 (BMP-4),bone morphogenetic protein 6 (BMP-6) and bone

  11. Geometry- and diffraction-independent ionization probabilities in intense laser fields: probing atomic ionization mechanisms with effective intensity matching

    CERN Document Server

    Bryan, W A; English, E M L; Goodworth, T R J; Newell, W R; McKenna, J A; Suresh, M; Srigengan, B; Williams, I D; Turcu, I C E; Smith, J M; Divall, E J; Hooker, C J; Langley, A J

    2005-01-01

    We report a novel experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm^2 to 10 PW/cm^2 using Effective Intensity Matching (EIM), which is coupled with Intensity Selective Scanning (ISS) to recover the geometry-independent probability of ionization. Such measurements, made possible by quantifying diffraction effects in the laser focus, are compared directly to theoretical predictions of multiphoton, tunnel and field ionization, and a remarkable agreement demonstrated. EIM-ISS allows the straightforward quantification of the probability of recollision ionization in a linearly polarized laser pulse. Furthermore, probability of ionization is discussed in terms of the Keldysh adiabaticity parameter, gamma, and the influence of the precursor ionic states present in recollision ionization is observed for th...

  12. Mechanical stress triggers cardiomyocyte autophagy through angiotensin II type 1 receptor-mediated p38MAP kinase independently of angiotensin II.

    Directory of Open Access Journals (Sweden)

    Li Lin

    Full Text Available Angiotensin II (Ang II type 1 (AT1 receptor is known to mediate a variety of physiological actions of Ang II including autophagy. However, the role of AT1 receptor in cardiomyocyte autophagy triggered by mechanical stress still remains elusive. The aim of this study was therefore to examine whether and how AT1 receptor participates in cardiomyocyte autophagy induced by mechanical stresses. A 48-hour mechanical stretch and a 4-week transverse aorta constriction (TAC were imposed to cultured cardiomyocytes of neonatal rats and adult male C57B/L6 mice, respectively, to induce cardiomyocyte hypertrophy prior to the assessment of cardiomyocyte autophagy using LC3b-II. Losartan, an AT1 receptor blocker, but not PD123319, the AT2 inhibitor, was found to significantly reduce mechanical stretch-induced LC3b-II upregulation. Moreover, inhibition of p38MAP kinase attenuated not only mechanical stretch-induced cardiomyocyte hypertrophy but also autophagy. To the contrary, inhibition of ERK and JNK suppressed cardiac hypertrophy but not autophagy. Intriguingly, mechanical stretch-induced autophagy was significantly inhibited by Losartan in the absence of Ang II. Taken together, our results indicate that mechanical stress triggers cardiomyocyte autophagy through AT1 receptor-mediated activation of p38MAP kinase independently of Ang II.

  13. Human osteoblast-like cells respond to mechanical strain with increased bone matrix protein production independent of hormonal regulation

    Science.gov (United States)

    Harter, L. V.; Hruska, K. A.; Duncan, R. L.

    1995-01-01

    Exposure of osteosarcoma cell lines to chronic intermittent strain increases the activity of mechano-sensitive cation (SA-cat) channels. The impact of mechano-transduction on osteoblast function has not been well studied. We analyzed the expression and production of bone matrix proteins in human osteoblast-like osteosarcoma cells, OHS-4, in response to chronic intermittent mechanical strain. The OHS-4 cells exhibit type I collagen production, 1,25-Dihydroxyvitamin D-inducible osteocalcin, and mineralization of the extracellular matrix. The matrix protein message level was determined from total RNA isolated from cells exposed to 1-4 days of chronic intermittent strain. Northern analysis for type I collagen indicated that strain increased collagen message after 48 h. Immunofluorescent labeling of type I collagen demonstrated that secretion was also enhanced with mechanical strain. Osteopontin message levels were increased several-fold by the application of mechanical load in the absence of vitamin D, and the two stimuli together produced an additive effect. Osteocalcin secretion was also increased with cyclic strain. Osteocalcin levels were not detectable in vitamin D-untreated control cells. However, after 4 days of induced load, significant levels of osteocalcin were observed in the medium. With vitamin D present, osteocalcin levels were 4 times higher in the medium of strained cells compared to nonstrained controls. We conclude that mechanical strain of osteoblast-like cells is sufficient to increase the transcription and secretion of matrix proteins via mechano-transduction without hormonal induction.

  14. Independent risk of mechanical ventilation for AIDS-related Pneumocystis carinii pneumonia associated with bronchoalveolar lavage neutrophilia

    DEFF Research Database (Denmark)

    Bang, D; Emborg, J; Elkjaer, J;

    2001-01-01

    The use of mechanical ventilation (MV) for AIDS-related Pneumocystis carinii pneumonia (PCP) has varied over time. The introduction of adjunctive corticosteroid therapy has changed the pathophysiology of PCP. In the present study, we attempted to identify factors predictive of severe respiratory...

  15. Independent Evolution of Suction Feeding in Neobatrachia: Feeding Mechanisms in Two Species of Telmatobius (Anura:Telmatobiidae).

    Science.gov (United States)

    Barrionuevo, José Sebastián

    2016-02-01

    The most common feeding mechanism among aquatic vertebrates as fishes, turtles, and salamanders is inertial suction. However, among the more than 6,400 species of anurans, suction feeding occurs only in pipids. Pipidae is a small basal lineage relative to Neobatrachia, an enormous clade that contains about 96% of extant anurans. The Andean neobatrachian frogs of the genus Telmatobius include strictly aquatic and semiaquatic species. Diet analyses indicate that some species of Telmatobius feed on strictly aquatic prey, but until now their feeding mechanisms have been unknown. Herein, the feeding mechanisms in two species of Telmatobius, that represent the two predominant modes of life in the genus, are explored. The semiaquatic T. oxycephalus and the fully aquatic T. rubigo are studied using high-speed cinematography and standard anatomical techniques to provide a qualitative approach to feeding behavior and a detailed morphological description of the mouth, tongue, hyoid and related muscles. T. oxycephalus uses similar mechanisms of aquatic prey capture as do the vast majority of anurans that are capable of forage in water, whereas the fully aquatic T. rubigo is an inertial suction feeder. This is the first report of an objective record of this unique feeding behavior in a Neobatrachian. Several morphological characters seem to be related with this function and are convergent with those of pipids. PMID:26575038

  16. How the inverse seesaw mechanism can reveal itself natural, canonical, and independent of the right-handed neutrino mass

    Science.gov (United States)

    Dias, A. G.; de S. Pires, C. A.; Rodrigues da Silva, P. S.

    2011-09-01

    The common lore in the literature of neutrino mass generation is that the canonical seesaw mechanism beautifully offers an explanation for the tiny neutrino mass but at the cost of introducing right-handed neutrinos at a scale that is out of range for the current experiments. The inverse seesaw mechanism is an interesting alternative to the canonical one once it leads to tiny neutrino masses with the advantage of being testable at the TeV scale. However, this last mechanism suffers from an issue of naturalness concerning the scale responsible for such small masses, namely, the parameter μ that is related to lepton number violation and is supposed to be at the keV scale, much lower than the electroweak one. However, no theoretical framework was built that offers an explanation for obtaining this specific scale. In this work, we propose a variation of the inverse seesaw mechanism by assuming a minimal scalar and fermionic set of singlet fields, along with a Z5⊗Z2 symmetry, that allows a dynamical explanation for the smallness of μ, recovering the neat canonical seesaw formula and with right-handed (RH) neutrinos free to be at the electroweak scale, thus testable at LHC and current neutrino experiments.

  17. Tissue transglutaminase is involved in mechanical load-induced osteogenic differentiation of human ligamentum flavum cells.

    Science.gov (United States)

    Chao, Yuan-Hung; Huang, Shih-Yung; Yang, Ruei-Cheng; Sun, Jui-Sheng

    2016-07-01

    Mechanical load-induced osteogenic differentiation might be the key cellular event in the calcification and ossification of ligamentum flavum. The aim of this study was to investigate the influence of tissue transglutaminase (TGM2) on mechanical load-induced osteogenesis of ligamentum flavum cells. Human ligamentum flavum cells were obtained from 12 patients undergoing lumbar spine surgery. Osteogenic phenotypes of ligamentum flavum cells, such as alkaline phosphatase (ALP), Alizarin red-S stain, and gene expression of osteogenic makers were evaluated following the administration of mechanical load and BMP-2 treatment. The expression of TGM2 was evaluated by real-time PCR, Western blotting, and enzyme-linked immunosorbent assay (ELISA) analysis. Our results showed that mechanical load in combination with BMP-2 enhanced calcium deposition and ALP activity. Mechanical load significantly increased ALP and OC gene expression on day 3, whereas BMP-2 significantly increased ALP, OPN, and Runx2 on day 7. Mechanical load significantly induced TGM2 gene expression and enzyme activity in human ligamentum flavum cells. Exogenous TGM2 increased ALP and OC gene expression; while, inhibited TG activity significantly attenuated mechanical load-induced and TGM2-induced ALP activity. In summary, mechanical load-induced TGM2 expression and enzyme activity is involved in the progression of the calcification of ligamentum flavum.

  18. The Fibrotic Phenotype Induced by IGFBP-5 Is Regulated by MAPK Activation and Egr-1-Dependent and -Independent Mechanisms

    OpenAIRE

    Yasuoka, Hidekata; Hsu, Eileen; Ruiz, Ximena D.; Steinman, Richard A; Augustine M K Choi; Feghali-Bostwick, Carol A.

    2009-01-01

    We have previously shown that insulin-like growth factor (IGF) binding protein- 5 (IGFBP-5) is overexpressed in lung fibrosis and induces the production of extracellular matrix components, such as collagen and fibronectin, both in vitro and in vivo. The exact mechanism by which IGFBP-5 exerts these novel fibrotic effects is unknown. We thus examined the signaling cascades that mediate IGFBP-5-induced fibrosis. We demonstrate for the first time that IGFBP-5 induction of extracellular matrix oc...

  19. Independent Directors

    DEFF Research Database (Denmark)

    Ringe, Wolf-Georg

    2013-01-01

    This paper re-evaluates the corporate governance concept of ‘board independence’ against the disappointing experiences during the 2007-08 financial crisis. Independent or outside directors had long been seen as an essential tool to improve the monitoring role of the board. Yet the crisis revealed...... independence. It would redefine independence to include those directors that are independent of the firm's controller, but, at the same time, it would require them to be more accountable to (minority) shareholders....

  20. HIV-1 Nef down-modulates C-C and C-X-C chemokine receptors via ubiquitin and ubiquitin-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Prabha Chandrasekaran

    Full Text Available Human and Simian Immunodeficiency virus (HIV-1, HIV-2, and SIV encode an accessory protein, Nef, which is a pathogenesis and virulence factor. Nef is a multivalent adapter that dysregulates the trafficking of many immune cell receptors, including chemokine receptors (CKRs. Physiological endocytic itinerary of agonist occupied CXCR4 involves ubiquitinylation of the phosphorylated receptor at three critical lysine residues and dynamin-dependent trafficking through the ESCRT pathway into lysosomes for degradation. Likewise, Nef induced CXCR4 degradation was critically dependent on the three lysines in the C-terminal -SSLKILSKGK- motif. Nef directly recruits the HECT domain E3 ligases AIP4 or NEDD4 to CXCR4 in the resting state. This mechanism was confirmed by ternary interactions of Nef, CXCR4 and AIP4 or NEDD4; by reversal of Nef effect by expression of catalytically inactive AIP4-C830A mutant; and siRNA knockdown of AIP4, NEDD4 or some ESCRT-0 adapters. However, ubiquitinylation dependent lysosomal degradation was not the only mechanism by which Nef downregulated CKRs. Agonist and Nef mediated CXCR2 (and CXCR1 degradation was ubiquitinylation independent. Nef also profoundly downregulated the naturally truncated CXCR4 associated with WHIM syndrome and engineered variants of CXCR4 that resist CXCL12 induced internalization via an ubiquitinylation independent mechanism.

  1. In vitro evidence supports the presence of glucokinase-independent glucosensing mechanisms in hypothalamus and hindbrain of rainbow trout.

    Science.gov (United States)

    Otero-Rodiño, Cristina; Velasco, Cristina; Álvarez-Otero, Rosa; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2016-06-01

    We previously obtained evidence in rainbow trout for the presence and response to changes in circulating levels of glucose (induced by intraperitoneal hypoglycaemic and hyperglycaemic treatments) of glucosensing mechanisms based on liver X receptor (LXR), mitochondrial production of reactive oxygen species (ROS) leading to increased expression of uncoupling protein 2 (UCP2), and sweet taste receptor in the hypothalamus, and on sodium/glucose co-transporter 1 (SGLT-1) in hindbrain. However, these effects of glucose might be indirect. Therefore, we evaluated the response of parameters related to these glucosensing mechanisms in a first experiment using pooled sections of hypothalamus and hindbrain incubated for 6 h at 15°C in modified Hanks' medium containing 2, 4 or 8 mmol l(-1) d-glucose. The responses observed in some cases were consistent with glucosensing capacity. In a second experiment, pooled sections of hypothalamus and hindbrain were incubated for 6 h at 15°C in modified Hanks' medium with 8 mmol l(-1) d-glucose alone (control) or containing 1 mmol l(-1) phloridzin (SGLT-1 antagonist), 20 µmol l(-1) genipin (UCP2 inhibitor), 1 µmol l(-1) trolox (ROS scavenger), 100 µmol l(-1) bezafibrate (T1R3 inhibitor) and 50 µmol l(-1) geranyl-geranyl pyrophosphate (LXR inhibitor). The response observed in the presence of these specific inhibitors/antagonists further supports the proposal that critical components of the different glucosensing mechanisms are functioning in rainbow trout hypothalamus and hindbrain. PMID:27026717

  2. Myosin-binding protein C displaces tropomyosin to activate cardiac thin filaments and governs their speed by an independent mechanism

    OpenAIRE

    Mun, Ji Young; Previs, Michael J.; Yu, Hope Y.; Gulick, James; Tobacman, Larry S.; Beck Previs, Samantha; Robbins, Jeffrey; Warshaw, David M.; Craig, Roger

    2014-01-01

    Myosin-binding protein C (MyBP-C) is a component of myosin filaments, one of the two sets of contractile elements whose relative sliding is the basis of muscle contraction. In the heart, MyBP-C modulates contractility in response to cardiac stimulation; mutations in MyBP-C lead to cardiac disease. The mechanism by which MyBP-C modulates cardiac contraction is not understood. Using electron microscopy and a light microscopic assay for filament sliding, we demonstrate that MyBP-C binds to the o...

  3. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism.

    Science.gov (United States)

    Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E; Szabó, Éva; Virág, László

    2016-08-01

    A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5J/cm(2)) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ-34+UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and -8. In conclusion, PJ-34 is a photosensitizer and PJ-34+UVA causes DNA damage and caspase-mediated cell death independently of PARP-1 inhibition. PMID:27427773

  4. Genetically modified mesenchymal stem cells induce mechanically stable posterior spine fusion

    OpenAIRE

    Sheyn, D; Rüthemann, M; Mizrahi, O; Kallai, I; Zilberman, Y.; Tawackoli, W; Kanim, L E A; Zhao, L; Bae, H; Pelled, G.; Snedeker, J G; Gazit, D.

    2010-01-01

    Most spine fusion procedures involve the use of prosthetic fixation devices combined with autologous bone grafts rather than biological treatment. We had shown that spine fusion could be achieved by injection of bone morphogenetic protein-2 (BMP-2)-expressing mesenchymal stem cells (MSCs) into the paraspinal muscle. In this study, we hypothesized that posterior spinal fusion achieved using genetically modified MSCs would be mechanically comparable to that realized using a mechanical fixation....

  5. A new human NHERF1 mutation decreases renal phosphate transporter NPT2a expression by a PTH-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Marie Courbebaisse

    Full Text Available BACKGROUND: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1 binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. METHODS: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. RESULTS: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. CONCLUSIONS: Our results indicate that the PDZ1 domain is critical for NHERF1-NPT2a interaction in humans and for the control of NPT2a expression at the plasma membrane. Thus we have identified a new mechanism of renal phosphate loss and shown that different mutations in NHERF1 can alter renal phosphate reabsorption via distinct mechanisms.

  6. DEHP exposure impairs mouse oocyte cyst breakdown and primordial follicle assembly through estrogen receptor-dependent and independent mechanisms

    International Nuclear Information System (INIS)

    Highlights: • DEHP inhibits primordial folliculogenesis in vivo and in vitro. • Estrogen receptors participate in the effect of DEHP on early ovarian development. • DEHP exposure impairs the expression of Notch2 signaling components. • DEHP exposure disrupts the proliferation of pregranulosa precursor cells. - Abstract: Estrogen plays an essential role in the development of mammalian oocytes, and recent studies suggest that it also regulates primordial follicle assembly in the neonatal ovaries. During the last decade, potential exposure of humans and animals to estrogen-like endocrine disrupting chemicals has become a growing concern. In the present study, we focused on the effect of diethylhexyl phthalate (DEHP), a widespread plasticizer with estrogen-like activity, on germ-cell cyst breakdown and primordial follicle assembly in the early ovarian development of mouse. Neonatal mice injected with DEHP displayed impaired cyst breakdown. Using ovary organ cultures, we revealed that impairment was mediated through estrogen receptors (ERs), as ICI 182,780, an efficient antagonist of ER, reversed this DEHP-mediated effect. DEHP exposure reduced the expression of ERβ, progesterone receptor (PR), and Notch2 signaling components. Finally, DEHP reduced proliferation of pregranulosa precursor cells during the process of primordial folliculogenesis. Together, our results indicate that DEHP influences oocyte cyst breakdown and primordial follicle formation through several mechanisms. Therefore, exposure to estrogen-like chemicals during fetal or neonatal development may adversely influence early ovarian development

  7. DEHP exposure impairs mouse oocyte cyst breakdown and primordial follicle assembly through estrogen receptor-dependent and independent mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xinyi [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); Department of Histology and Embryology, College of Basic Medicine, Chongqing Medical University, Chongqing 400016 (China); Liao, Xinggui; Chen, Xuemei; Li, Yanli; Wang, Meirong; Shen, Cha; Zhang, Xue; Wang, Yingxiong; Liu, Xueqing [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); He, Junlin, E-mail: hejunlin_11@aliyun.com [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China)

    2015-11-15

    Highlights: • DEHP inhibits primordial folliculogenesis in vivo and in vitro. • Estrogen receptors participate in the effect of DEHP on early ovarian development. • DEHP exposure impairs the expression of Notch2 signaling components. • DEHP exposure disrupts the proliferation of pregranulosa precursor cells. - Abstract: Estrogen plays an essential role in the development of mammalian oocytes, and recent studies suggest that it also regulates primordial follicle assembly in the neonatal ovaries. During the last decade, potential exposure of humans and animals to estrogen-like endocrine disrupting chemicals has become a growing concern. In the present study, we focused on the effect of diethylhexyl phthalate (DEHP), a widespread plasticizer with estrogen-like activity, on germ-cell cyst breakdown and primordial follicle assembly in the early ovarian development of mouse. Neonatal mice injected with DEHP displayed impaired cyst breakdown. Using ovary organ cultures, we revealed that impairment was mediated through estrogen receptors (ERs), as ICI 182,780, an efficient antagonist of ER, reversed this DEHP-mediated effect. DEHP exposure reduced the expression of ERβ, progesterone receptor (PR), and Notch2 signaling components. Finally, DEHP reduced proliferation of pregranulosa precursor cells during the process of primordial folliculogenesis. Together, our results indicate that DEHP influences oocyte cyst breakdown and primordial follicle formation through several mechanisms. Therefore, exposure to estrogen-like chemicals during fetal or neonatal development may adversely influence early ovarian development.

  8. Inhibitory effect of fluvoxamine on β-casein expression via a serotonin-independent mechanism in human mammary epithelial cells.

    Science.gov (United States)

    Chiba, Takeshi; Maeda, Tomoji; Kimura, Soichiro; Morimoto, Yasunori; Sanbe, Atsushi; Ueda, Hideo; Kudo, Kenzo

    2015-11-01

    Selective serotonin reuptake inhibitors (SSRIs) are widely used as a first-line therapy in postpartum depression. The objective of this study was to determine the mechanism underlying the inhibitory effects of the SSRI, fluvoxamine, on β-casein expression, an indicator of lactation, in MCF-12A human mammary epithelial cells. Expression levels of serotonin (5-hydroxytryptamine; 5-HT) transporter, an SSRI target protein, and tryptophan hydroxylase 1, a rate-limiting enzyme in 5-HT biosynthesis, were increased in MCF-12A cells by prolactin treatment. Treatment with 1 μM fluvoxamine for 72 h significantly decreased protein levels of β-casein and phosphorylated signal transducer and activator transcription 5 (pSTAT5). Extracellular 5-HT levels were significantly increased after exposure to 1 μM fluvoxamine, in comparison with those of untreated and vehicle-treated cells; however, extracellular 5-HT had little effect on the decrease in β-casein expression. Expression of glucose-related protein 78/binding immunoglobulin protein, a regulator of endoplasmic reticulum (ER) stress, was significantly increased after treatment with 1 μM fluvoxamine for 48 h. Exposure to tunicamycin, an inducer of ER stress, also decreased expression of β-casein and pSTAT5 in a manner similar to fluvoxamine. Our results indicate that fluvoxamine suppresses β-casein expression in MCF-12A cells via inhibition of STAT5 phosphorylation caused by induction of ER stress. Further studies are required to confirm the effect of fluvoxamine on the function of mammary epithelial cells. PMID:26415980

  9. IFITM Proteins Inhibit Entry Driven by the MERS-Coronavirus Spike Protein: Evidence for Cholesterol-Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Florian Wrensch

    2014-09-01

    Full Text Available The interferon-inducible transmembrane (IFITM proteins 1, 2 and 3 inhibit the host cell entry of several enveloped viruses, potentially by promoting the accumulation of cholesterol in endosomal compartments. IFITM3 is essential for control of influenza virus infection in mice and humans. In contrast, the role of IFITM proteins in coronavirus infection is less well defined. Employing a retroviral vector system for analysis of coronavirus entry, we investigated the susceptibility of human-adapted and emerging coronaviruses to inhibition by IFITM proteins. We found that entry of the recently emerged Middle East respiratory syndrome coronavirus (MERS-CoV is sensitive to inhibition by IFITM proteins. In 293T cells, IFITM-mediated inhibition of cellular entry of the emerging MERS- and SARS-CoV was less efficient than blockade of entry of the globally circulating human coronaviruses 229E and NL63. Similar differences were not observed in A549 cells, suggesting that cellular context and/or IFITM expression levels can impact inhibition efficiency. The differential IFITM-sensitivity of coronaviruses observed in 293T cells afforded the opportunity to investigate whether efficiency of entry inhibition by IFITMs and endosomal cholesterol accumulation correlate. No such correlation was observed. Furthermore, entry mediated by the influenza virus hemagglutinin was robustly inhibited by IFITM3 but was insensitive to accumulation of endosomal cholesterol, indicating that modulation of cholesterol synthesis/transport did not account for the antiviral activity of IFITM3. Collectively, these results show that the emerging MERS-CoV is a target of the antiviral activity of IFITM proteins and demonstrate that mechanisms other than accumulation of endosomal cholesterol can contribute to viral entry inhibition by IFITMs.

  10. Bishop Independence

    OpenAIRE

    Harris Liam H.; Perkins Stephanie; Roach Paul A.; Jones Siˆan K.

    2013-01-01

    Bishop Independence concerns determining the maximum number of Bishops that can be placed on a board such that no Bishop can attack any other Bishop. This paper presents the solution to the Bishop Independence problem, determining the Bishop Independence number, for all sizes of boards on the following topologies: the cylinder, the M¨obius strip, the torus, the Klein bottle and the surface of a cube.

  11. House dust mite major allergens Der p 1 and Der p 5 activate human airway-derived epithelial cells by protease-dependent and protease-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Timmerman J André B

    2006-03-01

    Full Text Available Abstract House dust mite allergens (HDM cause bronchoconstriction in asthma patients and induce an inflammatory response in the lungs due to the release of cytokines, chemokines and additional mediators. The mechanism how HDM components achieve this is largely unknown. The objective of this study was to assess whether HDM components of Dermatophagoides pteronissinus with protease activity (Der p 1 and unknown enzymatic activity (Der p 2, Der p 5 induce biological responses in a human airway-derived epithelial cell line (A549, and if so, to elucidate the underlying mechanism(s of action. A549 cells were incubated with HDM extract, Der p 1, recombinant Der p 2 and recombinant Der p 5. Cell desquamation was assessed by microscopy. The proinflammatory cytokines, IL-6 and IL-8, were measured by ELISA. Intracellular Ca2+ levels were assessed in A549 cells and in mouse fibroblasts expressing the human protease activated receptor (PAR1, PAR2 or PAR4. HDM extract, Der p 1 and Der p 5 dose-dependently increased the production of IL-6 and IL-8. Added simultaneously, Der p 1 and Der p 5 further increased the production of IL-6 and IL-8. The action of Der p 1 was blocked by cysteine-protease inhibitors, while that of Der p 5 couldn't be blocked by either serine- or cysteine protease inhibitors. Der p 5 only induced cell shrinking, whereas HDM extract and Der p1 also induced cell desquamation. Der p 2 had no effect on A549 cells. Der p 1's protease activity causes desquamation and induced the release of IL6 and IL-8 by a mechanism independent of Ca2+ mobilisation and PAR activation. Der p 5 exerts a protease-independent activation of A549 that involves Ca2+ mobilisation and also leads to the production of these cytokines. Together, our data indicate that allergens present in HDM extracts can trigger protease-dependent and protease-independent signalling pathways in A549 cells.

  12. The human insulin mRNA is partly translated via a cap- and eIF4A-independent mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Fred, Rikard G., E-mail: Rikard.Fred@mcb.uu.se [Department of Medical Cell Biology, Uppsala University, Biomedicum, Husargatan 3 Box 571, SE-751 23 Uppsala (Sweden); Sandberg, Monica [Department of Medical Cell Biology, Uppsala University, Biomedicum, Husargatan 3 Box 571, SE-751 23 Uppsala (Sweden); Pelletier, Jerry [Department of Biochemistry, McGill University, RM 810, McIntyre Medical Sciences Building, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G1Y6 (Canada); Welsh, Nils [Department of Medical Cell Biology, Uppsala University, Biomedicum, Husargatan 3 Box 571, SE-751 23 Uppsala (Sweden)

    2011-09-09

    Highlights: {yields} The polypyrimidine tract binding protein binds to the 5'-UTR of the insulin mRNA. {yields} Insulin mRNA can be translated via a cap-independent mechanism. {yields} The fraction cap-independent insulin synthesis increases during conditions of stress. {yields} The {beta}-cell is able to uphold basal insulin biosynthesis under conditions of stress. -- Abstract: The aim of this study was to investigate whether cap-independent insulin mRNA translation occurs in human pancreatic islets at basal conditions, during stimulation at a high glucose concentration and at conditions of nitrosative stress. We also aimed at correlating cap-independent insulin mRNA translation with binding of the IRES trans-acting factor polypyrimidine tract binding protein (PTB) to the 5'-UTR of insulin mRNA. For this purpose, human islets were incubated for 2 h in the presence of low (1.67 mM) or high glucose (16.7 mM). Nitrosative stress was induced by addition of 1 mM DETA/NO and cap-dependent mRNA translation was inhibited with hippuristanol. Insulin biosynthesis rates were determined by radioactive labeling and immunoprecipitation. PTB affinity to insulin mRNA 5'-UTR was assessed by a magnetic micro bead pull-down procedure. We observed that in the presence of 1.67 mM glucose, approximately 70% of the insulin mRNA translation was inhibited by hippuristanol. Corresponding value from islets incubated at 16.7 mM glucose was 93%. DETA/NO treatment significantly decreased the translation of insulin by 85% in high glucose incubated islets, and by 50% at a low glucose concentration. The lowered insulin biosynthesis rates of DETA/NO-exposed islets were further suppressed by hippuristanol with 55% at 16.7 mM glucose but not at 1.67 mM glucose. Thus, hippuristanol-induced inhibition of insulin biosynthesis was less pronounced in DETA/NO-treated islets as compared to control islets. We observed also that PTB bound specifically to the insulin mRNA 5'-UTR in vitro

  13. The human insulin mRNA is partly translated via a cap- and eIF4A-independent mechanism

    International Nuclear Information System (INIS)

    Highlights: → The polypyrimidine tract binding protein binds to the 5'-UTR of the insulin mRNA. → Insulin mRNA can be translated via a cap-independent mechanism. → The fraction cap-independent insulin synthesis increases during conditions of stress. → The β-cell is able to uphold basal insulin biosynthesis under conditions of stress. -- Abstract: The aim of this study was to investigate whether cap-independent insulin mRNA translation occurs in human pancreatic islets at basal conditions, during stimulation at a high glucose concentration and at conditions of nitrosative stress. We also aimed at correlating cap-independent insulin mRNA translation with binding of the IRES trans-acting factor polypyrimidine tract binding protein (PTB) to the 5'-UTR of insulin mRNA. For this purpose, human islets were incubated for 2 h in the presence of low (1.67 mM) or high glucose (16.7 mM). Nitrosative stress was induced by addition of 1 mM DETA/NO and cap-dependent mRNA translation was inhibited with hippuristanol. Insulin biosynthesis rates were determined by radioactive labeling and immunoprecipitation. PTB affinity to insulin mRNA 5'-UTR was assessed by a magnetic micro bead pull-down procedure. We observed that in the presence of 1.67 mM glucose, approximately 70% of the insulin mRNA translation was inhibited by hippuristanol. Corresponding value from islets incubated at 16.7 mM glucose was 93%. DETA/NO treatment significantly decreased the translation of insulin by 85% in high glucose incubated islets, and by 50% at a low glucose concentration. The lowered insulin biosynthesis rates of DETA/NO-exposed islets were further suppressed by hippuristanol with 55% at 16.7 mM glucose but not at 1.67 mM glucose. Thus, hippuristanol-induced inhibition of insulin biosynthesis was less pronounced in DETA/NO-treated islets as compared to control islets. We observed also that PTB bound specifically to the insulin mRNA 5'-UTR in vitro, and that this binding corresponded well with

  14. A QM/MM investigation of the catalytic mechanism of metal-ion-independent core 2 β1,6-N-acetylglucosaminyltransferase.

    Science.gov (United States)

    Tvaroška, Igor; Kozmon, Stanislav; Wimmerová, Michaela; Koča, Jaroslav

    2013-06-17

    β1,6-GlcNAc-transferase (C2GnT) is an important controlling factor of biological functions for many glycoproteins and its activity has been found to be altered in breast, colon, and lung cancer cells, in leukemia cells, in the lymhomonocytes of multiple sclerosis patients, leukocytes from diabetes patients, and in conditions causing an immune deficiency. The result of the action of C2GnT is the core 2 structure that is essential for the further elongation of the carbohydrate chains of O-glycans. The catalytic mechanism of this metal-ion-independent glycosyltransferase is of paramount importance and is investigated here by using quantum mechanical (QM) (density functional theory (DFT))/molecular modeling (MM) methods with different levels of theory. The structural model of the reaction site used in this report is based on the crystal structures of C2GnT. The entire enzyme-substrate system was subdivided into two different subsystems: the QM subsystem containing 206 atoms and the MM region containing 5914 atoms. Three predefined reaction coordinates were employed to investigate the catalytic mechanism. The calculated potential energy surfaces discovered the existence of a concerted SN 2-like mechanism. In this mechanism, a nucleophilic attack by O6 facilitated by proton transfer to the catalytic base and the separation of the leaving group all occur almost simultaneously. The transition state for the proposed reaction mechanism at the M06-2X/6-31G** (with diffuse functions on the O1', O5', OGlu , and O6 atoms) level was located at C1-O6=1.74 Å and C1-O1=2.86 Å. The activation energy for this mechanism was estimated to be between 20 and 29 kcal mol⁻¹, depending on the method used. These calculations also identified a low-barrier hydrogen bond between the nucleophile O6H and the catalytic base Glu320, and a hydrogen bond between the N-acetamino group and the glycosidic oxygen of the donor in the TS. It is proposed that these interactions contribute to a

  15. Loss of p19(Arf facilitates the angiogenic switch and tumor initiation in a multi-stage cancer model via p53-dependent and independent mechanisms.

    Directory of Open Access Journals (Sweden)

    Danielle B Ulanet

    Full Text Available The Arf tumor suppressor acts as a sensor of oncogenic signals, countering aberrant proliferation in large part via activation of the p53 transcriptional program, though a number of p53-independent functions have been described. Mounting evidence suggests that, in addition to promoting tumorigenesis via disruptions in the homeostatic balance between cell proliferation and apoptosis of overt cancer cells, genetic alterations leading to tumor suppressor loss of function or oncogene gain of function can also incite tumor development via effects on the tumor microenvironment. In a transgenic mouse model of multi-stage pancreatic neuroendocrine carcinogenesis (PNET driven by inhibition of the canonical p53 and Rb tumor suppressors with SV40 large T-antigen (Tag, stochastic progression to tumors is limited in part by a requirement for initiation of an angiogenic switch. Despite inhibition of p53 by Tag in this mouse PNET model, concomitant disruption of Arf via genetic knockout resulted in a significantly accelerated pathway to tumor formation that was surprisingly not driven by alterations in tumor cell proliferation or apoptosis, but rather via earlier activation of the angiogenic switch. In the setting of a constitutional p53 gene knockout, loss of Arf also accelerated tumor development, albeit to a lesser degree. These findings demonstrate that Arf loss of function can promote tumorigenesis via facilitating angiogenesis, at least in part, through p53-independent mechanisms.

  16. Endocytic Trafficking towards the Vacuole Plays a Key Role in the Auxin Receptor SCFTIR-Independent Mechanism of Lateral Root Formation in A.thaliana

    Institute of Scientific and Technical Information of China (English)

    Patricio Pérez-Henríquez; Natasha V.Raikhel; Lorena Norambuena

    2012-01-01

    Plants' developmental plasticity plays a pivotal role in responding to environmental conditions.One of the most plastic plant organs is the root system.Different environmental stimuli such as nutrients and water deficiency may induce lateral root formation to compensate for a low level of water and/or nutrients.It has been shown that the hormone auxin tunes lateral root development and components for its signaling pathway have been identified.Using chemical biology,we discovered an Arabidopsis thaliana lateral root formation mechanism that is independent of the auxin receptor SCFTIR.The bioactive compound Sortin2 increased lateral root occurrence by acting upstream from the morphological marker of lateral root primordium formation,the mitotic activity.The compound did not display auxin activity.At the cellular level,Sortin2 accelerated endosomal trafficking,resulting in increased trafficking of plasma membrane recycling proteins to the vacuole.Sortin2 affected Late endosome/PVC/MVB trafficking and morphology.Combining Sortin2 with well-known drugs showed that endocytic trafficking of Late E/PVC/MVB towards the vacuole is pivotal for Sortin2induced SCFTIR-independent lateral root initiation.Our results revealed a distinctive role for endosomal trafficking in the promotion of lateral root formation via a process that does not rely on the auxin receptor complex SCFTIR.

  17. Deriving time dependent Schrödinger equation from Wave-Mechanics, Schrödinger time independent equation, Classical and Hamilton-Jacobi equations

    Directory of Open Access Journals (Sweden)

    Nilesh P. BARDE

    2015-05-01

    Full Text Available The concept of time dependent Schrödinger equation (TDSE illustrated in literature and even during class room teaching is mostly either complex or meant for advanced learners. This article is intended to enlighten the concept to the beginners in the field and further to improve knowledge about detailed steps for abstract mathematical formulation used which helps in understanding to derive TDSE using various tools and in more comprehensible manner. It is shown that TDSE may be derived using wave mechanics, time independent equation, classical & Hamilton-Jacobi’s equations. Similar attempts have been done earlier by some researchers. However, this article provides a comprehensive, lucid and well derived derivation, derived using various approaches, which would make this article unique.

  18. 交通运输系统廉政风险防控机制初探%Independent Risk Prevention and Control Mechanism of the Transportation System

    Institute of Scientific and Technical Information of China (English)

    谭涵予

    2012-01-01

    交通领域的腐败问题,给社会带来了巨大危害.为遏制交通腐败,降低廉政风险,本文把现代风险管理理论和质量管理办法引入预防腐败体系建设,为建立科学、可行、可持续的预防腐败廉政风险防控机制探索思路.%The problem of corruption in the transport sector brought great harm to the society. To curb the traffic corruption and reduce the integrity risk, this paper introduced modern risk management theory and quality management approach to preventing corruption, and explored ideas to establish a scientific and feasible, sustainable independent risk prevention and control mechanism.

  19. 浅谈独立学院公共危机事件的管理机制%On the management mechanism of Independent Colleges’ public crisis events

    Institute of Scientific and Technical Information of China (English)

    季海雁

    2014-01-01

    高校作为一个特殊的团体,类似小型社会,随着其内外环境变化,高校不断受到冲击,危机事件时有发生,并有逐年增加的趋势。公共危机事件发生不仅影响师生的生活质量,威胁师生的生命安全,而且对学校声誉产生严重的负面效应[1]。作为特殊性质的高校中的独立学院,是高等院校一种新的办学模式,是教育改革的创新,由于其民办性和独立自主的运行机制决定了在处理此类事件的过程中具有一定的特殊性,如何建立相对应的行之有效的危机事件处理机制,对危机事件进行有效的预防和处理,是各独立学院需要迫切解决的问题。%As a special organization, college and university like small societies that influenced by crisis events occasionally when their internal and external environment changes, which is with a tendency to increase by years. Public crisis events not only affect the life quality and life safety of teachers and students, but have serious negative effects on school reputation [1]. With a special nature of colleges and universities independent college is a new higher education model that is an innovation of the education reform, its private and independent operating mechanism determines that it has certain particularity in the process of dealing with crisis events. How to establish an effective crisis treatment mechanism correspondingly to prevent and deal with the crisis events is a problem that need independent colleges to solve urgently.

  20. 知识共享型企业自主创新微观动力机制运行研究%Research on Operation of Micro - dynamic Mechanisms Constitution of Enterprises Independent Innovation Based on Knowledge Sharing

    Institute of Scientific and Technical Information of China (English)

    魏华飞; 韩夏; 方文敏

    2012-01-01

    知识经济社会中,知识流动、知识共享与知识创新成为企业自主创新的最主要来源.自主创新动力机制包括宏观动力机制和微观动力机制.宏观动力机制由政府机制、市场机制和社会机制等组成,微观动力机制包括创新机制、人才引进和开发机制、人才激励机制和自主创新动态管理机制.企业需要有效整合和运行自主创新微观动力机制,促进企业知识共享和知识创新,并在此基础上进行自主创新活动和提升自主创新能力.%In the society of knowledge economy, enterprises independent innovation to be achieved needs to rely on the knowledge innovation by creative talents and knowledge flowing and sharing within them. The dynamic mechanism includes the macro - dynamic mechanism and micro - dynamic mechanism. Macro — dynamic mechanism is made up of government mechanism, market mechanism and social mechanism and so on. Micro - dynamic mechanism of enterprise independent innovation includes innovative mechanisms based on market demand and customer satisfaction, creative talents and development mechanism, innovative talents excitation mechanism and independent innovation dynamic management mechanism. The enterprise needs to effectively integrate and operate micro - dynamic mechanism of independent innovation to promote enterprise knowledge sharing and knowledge innovation, which can improve the ability and effect of independent innovation.

  1. All-Trans Retinoic Acid Induces Proliferation, Survival, and Migration in A549 Lung Cancer Cells by Activating the ERK Signaling Pathway through a Transcription-Independent Mechanism

    Science.gov (United States)

    Quintero Barceinas, Reyna Sara; García-Regalado, Alejandro; Aréchaga-Ocampo, Elena; Villegas-Sepúlveda, Nicolás; González-De la Rosa, Claudia Haydée

    2015-01-01

    All-trans retinoic acid (ATRA) has been used as an antineoplastic because of its ability to promote proliferation, inhibition, and differentiation, primarily in leukemia; however, in other types of cancer, such as lung cancer, treatment with ATRA is restricted because not all the patients experience the same results. The ERK signaling pathway is dysregulated in cancer cells, including lung cancer, and this dysregulation promotes proliferation and cell invasion. In this study, we demonstrate that treatment with ATRA can activate the ERK signaling pathway by a transcription-independent mechanism through a signaling cascade that involves RARα and PI3K, promoting growth, survival, and migration in lung cancer cells. Until now, this mechanism was unknown in lung cancer cells. The inhibition of the ERK signaling pathway restores the beneficial effects of ATRA, reduces proliferation, increases apoptosis, and blocks the cell migration process in lung cancer cells. In conclusion, our results suggest that the combination of ATRA with ERK inhibitor in clinical trials for lung cancer is warranted. PMID:26557664

  2. Production, characterization, and flocculation mechanism of cation independent, pH tolerant, and thermally stable bioflocculant from Enterobacter sp. ETH-2.

    Directory of Open Access Journals (Sweden)

    Wei Tang

    Full Text Available Synthetic high polymer flocculants, frequently utilized for flocculating efficiency and low cost, recently have been discovered as producing increased risk to human health and the environment. Development of a more efficient and environmentally sound alternative flocculant agent is investigated in this paper. Bioflocculants are produced by microorganisms and may exhibit a high rate of flocculation activity. The bioflocculant ETH-2, with high flocculating activity (2849 mg Kaolin particle/mg ETH-2, produced by strain Enterobacter sp. isolated from activated sludge, was systematically investigated with regard to its production, characterization, and flocculation mechanism. Analyses of microscopic observation, zeta potential and ETH-2 structure demonstrates the bridging mechanism, as opposed to charge neutralization, was responsible for flocculation of the ETH-2. ETH-2 retains high molecular weight (603 to 1820 kDa and multi-functional groups (hydroxyl, amide and carboxyl that contributed to flocculation. Polysaccharides mainly composed of mannose, glucose, and galactose, with a molar ratio of 1:2.9:9.8 were identified as the active constituents in bioflocculant. The structure of the long backbone with active sites of polysaccharides was determined as a primary basis for the high flocculation activity. Bioflocculant ETH-2 is cation independent, pH tolerant, and thermally stable, suggesting a potential fit for industrial application.

  3. Dose-Dependent AMPK-Dependent and Independent Mechanisms of Berberine and Metformin Inhibition of mTORC1, ERK, DNA Synthesis and Proliferation in Pancreatic Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Ming Ming

    Full Text Available Natural products represent a rich reservoir of potential small chemical molecules exhibiting anti-proliferative and chemopreventive properties. Here, we show that treatment of pancreatic ductal adenocarcinoma (PDAC cells (PANC-1, MiaPaCa-2 with the isoquinoline alkaloid berberine (0.3-6 µM inhibited DNA synthesis and proliferation of these cells and delay the progression of their cell cycle in G1. Berberine treatment also reduced (by 70% the growth of MiaPaCa-2 cell growth when implanted into the flanks of nu/nu mice. Mechanistic studies revealed that berberine decreased mitochondrial membrane potential and intracellular ATP levels and induced potent AMPK activation, as shown by phosphorylation of AMPK α subunit at Thr-172 and acetyl-CoA carboxylase (ACC at Ser79. Furthermore, berberine dose-dependently inhibited mTORC1 (phosphorylation of S6K at Thr389 and S6 at Ser240/244 and ERK activation in PDAC cells stimulated by insulin and neurotensin or fetal bovine serum. Knockdown of α1 and α2 catalytic subunit expression of AMPK reversed the inhibitory effect produced by treatment with low concentrations of berberine on mTORC1, ERK and DNA synthesis in PDAC cells. However, at higher concentrations, berberine inhibited mitogenic signaling (mTORC1 and ERK and DNA synthesis through an AMPK-independent mechanism. Similar results were obtained with metformin used at doses that induced either modest or pronounced reductions in intracellular ATP levels, which were virtually identical to the decreases in ATP levels obtained in response to berberine. We propose that berberine and metformin inhibit mitogenic signaling in PDAC cells through dose-dependent AMPK-dependent and independent pathways.

  4. Choosing Independence

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Milo Djukanovic, Prime Minister of Montenegro, won a key referendum May 21 when voters in his tiny, mountainous nation endorsed a plan to split from Serbia and become an independent state. This marked a final step in the breakup of the former Yugoslavia formed by six republics.

  5. Shear stress stimulates phosphorylation of endothelial nitric-oxide synthase at Ser1179 by Akt-independent mechanisms: role of protein kinase A

    Science.gov (United States)

    Boo, Yong Chool; Sorescu, George; Boyd, Nolan; Shiojima, Ichiro; Walsh, Kenneth; Du, Jie; Jo, Hanjoong

    2002-01-01

    Recently, we have shown that shear stress stimulates NO(*) production by the protein kinase B/Akt (Akt)-dependent mechanisms in bovine aortic endothelial cells (BAEC) (Go, Y. M., Boo, Y. C., Park, H., Maland, M. C., Patel, R., Pritchard, K. A., Jr., Fujio, Y., Walsh, K., Darley-Usmar, V., and Jo, H. (2001) J. Appl. Physiol. 91, 1574-1581). Akt has been believed to regulate shear-dependent production of NO(*) by directly phosphorylating endothelial nitric-oxide synthase (eNOS) at the Ser(1179) residue (eNOS-S(1179)), but a critical evaluation using specific inhibitors or dominant negative mutants (Akt(AA) or Akt(AAA)) has not been reported. In addition, other kinases, including protein kinase A (PKA) and AMP kinase have also shown to phosphorylate eNOS-S(1179). Here, we show that shear-dependent phosphorylation of eNOS-S(1179) is mediated by an Akt-independent, but a PKA-dependent, mechanism. Expression of Akt(AA) or Akt(AAA) in BAEC by using recombinant adenoviral constructs inhibited phosphorylation of eNOS-S(1179) if cells were stimulated by vascular endothelial growth factor (VEGF), but not by shear stress. As shown before, expression of Akt(AA) inhibited shear-dependent NO(*) production, suggesting that Akt is still an important regulator in NO production. Further studies showed that a selective inhibitor of PKA, H89, inhibited shear-dependent phosphorylation of eNOS-S(1179) and NO(*) production. In contrast, H89 did not inhibit phosphorylation of eNOS-S(1179) induced by expressing a constitutively active Akt mutant (Akt(Myr)) in BAEC, showing that the inhibitor did not affect the Akt pathway. 8-Bromo-cAMP alone phosphorylated eNOS-S(1179) within 5 min without activating Akt, in an H89-sensitive manner. Collectively, these results demonstrate that shear stimulates phosphorylation of eNOS-S(1179) in a PKA-dependent, but Aktindependent manner, whereas the NO(*) production is regulated by the mechanisms dependent on both PKA and Akt. A coordinated interaction

  6. Desensitization-resistant and -sensitive GPCR-mediated inhibition of GABA release occurs by Ca2+-dependent and -independent mechanisms at a hypothalamic synapse.

    Science.gov (United States)

    Pennock, Reagan L; Hentges, Shane T

    2016-06-01

    Whereas the activation of Gαi/o-coupled receptors commonly results in postsynaptic responses that show acute desensitization, the presynaptic inhibition of transmitter release caused by many Gαi/o-coupled receptors is maintained during agonist exposure. However, an exception has been noted where GABAB receptor (GABABR)-mediated inhibition of inhibitory postsynaptic currents (IPSCs) recorded in mouse proopiomelanocortin (POMC) neurons exhibit acute desensitization in ∼25% of experiments. To determine whether differential effector coupling confers sensitivity to desensitization, voltage-clamp recordings were made from POMC neurons to compare the mechanism by which μ-opioid receptors (MORs) and GABABRs inhibit transmitter release. Neither MOR- nor GABABR-mediated inhibition of release relied on the activation of presynaptic K(+) channels. Both receptors maintained the ability to inhibit release in the absence of external Ca(2+) or in the presence of ionomycin-induced Ca(2+) influx, indicating that inhibition of release can occur through a Ca(2+)-independent mechanism. Replacing Ca(2+) with Sr(2+) to disrupt G-protein-mediated inhibition of release occurring directly at the release machinery did not alter MOR- or GABAB -mediated inhibition of IPSCs, suggesting that reductions in evoked release can occur through the inhibition of Ca(2+) channels. Additionally, both receptors inhibited evoked IPSCs in the presence of selective blockers of N- or P/Q-type Ca(2+) channels. Altogether, the results show that MORs and GABABRs can inhibit transmitter release through the inhibition of calcium influx and by direct actions at the release machinery. Furthermore, since both the desensitizing and nondesensitizing presynaptic receptors are similarly coupled, differential effector coupling is unlikely responsible for differential desensitization of the inhibition of release. PMID:26912590

  7. Independent preferences

    DEFF Research Database (Denmark)

    Vind, Karl

    1991-01-01

    A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic ...... theory based on additive preferences - expected utility, discounted utility - has been generalized to preferences which are not total or transitive. Other economic applications of the theorem are given......A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic...

  8. Insulin-Like Growth Factor-I Induces Arginase Activity in Leishmania amazonensis Amastigote-Infected Macrophages through a Cytokine-Independent Mechanism

    Directory of Open Access Journals (Sweden)

    Celia Maria Vieira Vendrame

    2014-01-01

    Full Text Available Leishmania (Leishmania amazonensis exhibits peculiarities in its interactions with hosts. Because amastigotes are the primary form associated with the progression of infection, we studied the effect of insulin-like growth factor (IGF-I on interactions between L. (L. amazonensis amastigotes and macrophages. Upon stimulation of infected macrophages with IGF-I, we observed decreased nitric oxide production but increased arginase expression and activity, which lead to increased parasitism. However, stimulation of amastigote-infected macrophages with IGF-I did not result in altered cytokine levels compared to unstimulated controls. Because IGF-I is present in tissue fluids and also within macrophages, we examined the possible effect of this factor on phosphatidylserine (PS exposure on amastigotes, seen previously in tissue-derived amastigotes leading to increased parasitism. Stimulation with IGF-I induced PS exposure on amastigotes but not on promastigotes. Using a PS-liposome instead of amastigotes, we observed that the PS-liposome but not the control phosphatidylcholine-liposome led to increased arginase activity in macrophages, and this process was not blocked by anti-TGF-β antibodies. Our results suggest that in L. (L. amazonensis amastigote-infected macrophages, IGF-I induces arginase activity directly in amastigotes and in macrophages through the induction of PS exposure on amastigotes in the latter, which could lead to the alternative activation of macrophages through cytokine-independent mechanisms.

  9. Aged Muscle Demonstrates Fiber-Type Adaptations in Response to Mechanical Overload, in the Absence of Myofiber Hypertrophy, Independent of Satellite Cell Abundance.

    Science.gov (United States)

    Lee, Jonah D; Fry, Christopher S; Mula, Jyothi; Kirby, Tyler J; Jackson, Janna R; Liu, Fujun; Yang, Lin; Dupont-Versteegden, Esther E; McCarthy, John J; Peterson, Charlotte A

    2016-04-01

    Although sarcopenia, age-associated loss of muscle mass and strength, is neither accelerated nor exacerbated by depletion of muscle stem cells, satellite cells, we hypothesized that adaptation in sarcopenic muscle would be compromised. To test this hypothesis, we depleted satellite cells with tamoxifen treatment of Pax7(CreER)-DTA mice at 4 months of age, and 20 months later subjected the plantaris muscle to 2 weeks of mechanical overload. We found myofiber hypertrophy was impaired in aged mice regardless of satellite cell content. Even in the absence of growth, vehicle-treated mice mounted a regenerative response, not apparent in tamoxifen-treated mice. Further, myonuclear accretion occurred in the absence of growth, which was prevented by satellite cell depletion, demonstrating that myonuclear addition is insufficient to drive myofiber hypertrophy. Satellite cell depletion increased extracellular matrix content of aged muscle that was exacerbated by overload, potentially limiting myofiber growth. These results support the idea that satellite cells regulate the muscle environment, and that their loss during aging may contribute to fibrosis, particularly during periods of remodeling. Overload induced a fiber-type composition improvement, independent of satellite cells, suggesting that aged muscle is very responsive to exercise-induced enhancement in oxidative capacity, even with an impaired hypertrophic response. PMID:25878030

  10. Arginine Vasopressin-Independent Mechanism of Impaired Water Excretion in a Patient with Sarcoidosis Complicated by Central Diabetes Insipidus and Glucocorticoid Deficiency

    Directory of Open Access Journals (Sweden)

    Katsunobu Yoshioka

    2011-01-01

    Full Text Available A 28-year-old man was admitted to our hospital because of reduced livido and increased fatigability. Four months before admission, he noticed polyuria, which was gradually relieved by admission. Magnetic resonance imaging revealed enhancing lesion centrally in the pituitary stalk. Biopsy from the skin revealed noncaseating granuloma composed of epithelioid cells, and a diagnosis of sarcoidosis was made. Although plasma arginine vasopressin (AVP was undetectable after administration of hypertonic saline, urinary output was within normal range (1.5 to 2.2 L/day. The urine osmolality became above plasma levels during the hypertonic saline test. Hormonal provocative tests revealed partial glucocorticoid deficiency. Soon after the glucocorticoid therapy was begun, moderate polyuria (from 3.5–4.0 liters daily occurred. At this time, plasma AVP was undetectable, and urine osmolality was consistently below plasma levels during the hypertonic saline test. In conclusion, we showed in human study that masked diabetes insipidus could be mediated by AVP-independent mechanisms.

  11. Engagement of major histocompatibility complex class I and class II molecules up-regulates intercellular adhesion of human B cells via a CD11/CD18-independent mechanism.

    Science.gov (United States)

    Alcover, A; Juillard, V; Acuto, O

    1992-02-01

    We have studied the role of major histocompatibility complex (MHC) molecules in the regulation of intercellular adhesion of human B cells. We found that molecules able to bind to MHC class II molecules, such as monoclonal antibodies or staphylococcal enterotoxins, induced rapid and sustained homotypic adhesion of Epstein-Barr virus (EBV)-transformed B cell lines as well as peripheral blood B lymphocytes. Moreover, anti-MHC class I monoclonal antibodies also stimulated intercellular adherence. Adhesion induced upon MHC engagement was faster and stronger than that triggered by phorbol esters. It needed active metabolism, but divalent cations were not required. Monoclonal antibodies directed against LFA-1 (CD11a/CD18) or its ligand ICAM-1 (CD54) did not inhibit MHC class II-induced homotypic adhesion of various EBV-transformed B cell lines, nor of a variant of the B cell line Raji expressing very low LFA-1 surface levels. Moreover, EBV-transformed B cells from a severe lymphocyte adhesion deficiency patient, lacking surface CD11/CD18, also aggregated in response to anti-MHC class I or class II monoclonal antibodies. Together these data indicate that engagement of MHC molecules may transduce signals to B cells resulting in up-regulation of intercellular adhesion, via an LFA-1-independent mechanism. This may play a role in the stabilization of T cell/antigen-presenting cell conjugates at the moment of antigen recognition.

  12. Thiamine increases the resistance of baker's yeast Saccharomyces cerevisiae against oxidative, osmotic and thermal stress, through mechanisms partly independent of thiamine diphosphate-bound enzymes.

    Science.gov (United States)

    Wolak, Natalia; Kowalska, Ewa; Kozik, Andrzej; Rapala-Kozik, Maria

    2014-12-01

    Numerous recent studies have established a hypothesis that thiamine (vitamin B1 ) is involved in the responses of different organisms against stress, also suggesting that underlying mechanisms are not limited to the universal role of thiamine diphosphate (TDP) in the central cellular metabolism. The current work aimed at characterising the effect of exogenously added thiamine on the response of baker's yeast Saccharomyces cerevisiae to the oxidative (1 mM H2 O2 ), osmotic (1 M sorbitol) and thermal (42 °C) stress. As compared to the yeast culture in thiamine-free medium, in the presence of 1.4 μM external thiamine, (1) the relative mRNA levels of major TDP-dependent enzymes under stress conditions vs. unstressed control (the 'stress/control ratio') were moderately lower, (2) the stress/control ratio was strongly decreased for the transcript levels of several stress markers localised to the cytoplasm, peroxisomes, the cell wall and (with the strongest effect observed) the mitochondria (e.g. Mn-superoxide dismutase), (3) the production of reactive oxygen and nitrogen species under stress conditions was markedly decreased, with the significant alleviation of concomitant protein oxidation. The results obtained suggest the involvement of thiamine in the maintenance of redox balance in yeast cells under oxidative stress conditions, partly independent of the functions of TDP-dependent enzymes.

  13. DNA-histone complexes as ligands amplify cell penetration and nuclear targeting of anti-DNA antibodies via energy-independent mechanisms.

    Science.gov (United States)

    Zannikou, Markella; Bellou, Sofia; Eliades, Petros; Hatzioannou, Aikaterini; Mantzaris, Michael D; Carayanniotis, George; Avrameas, Stratis; Lymberi, Peggy

    2016-01-01

    We have generated three monoclonal cell-penetrating antibodies (CPAbs) from a non-immunized lupus-prone (NZB × NZW)F1 mouse that exhibited high anti-DNA serum titres. These CPAbs are polyreactive because they bind to DNA and other cellular components, and localize mainly in the nucleus of HeLa cells, albeit with a distinct nuclear labelling profile. Herein, we have examined whether DNA-histone complexes (DHC) binding to CPAbs, before cell entry, could modify the cell penetration of CPAbs or their nuclear staining properties. By applying confocal microscopy and image analysis, we found that extracellular binding of purified CPAbs to DHC significantly enhanced their subsequent cell-entry, both in terms of percentages of positively labelled cells and fluorescence intensity (internalized CPAb amount), whereas there was a variable effect on their nuclear staining profile. Internalization of CPAbs, either alone or bound to DHC, remained unaltered after the addition of endocytosis-specific inhibitors at 37° or assay performance at 4°, suggesting the involvement of energy-independent mechanisms in the internalization process. These findings assign to CPAbs a more complex pathogenetic role in systemic lupus erythematosus where both CPAbs and nuclear components are abundant.

  14. 2'-O methylation of the viral mRNA cap by West Nile virus evades ifit1-dependent and -independent mechanisms of host restriction in vivo.

    Directory of Open Access Journals (Sweden)

    Kristy J Szretter

    Full Text Available Prior studies have shown that 2'-O methyltransferase activity of flaviviruses, coronaviruses, and poxviruses promotes viral evasion of Ifit1, an interferon-stimulated innate immune effector protein. Viruses lacking 2'-O methyltransferase activity exhibited attenuation in primary macrophages that was rescued in cells lacking Ifit1 gene expression. Here, we examined the role of Ifit1 in restricting pathogenesis in vivo of wild type WNV (WNV-WT and a mutant in the NS5 gene (WNV-E218A lacking 2'-O methylation of the 5' viral RNA cap. While deletion of Ifit1 had marginal effects on WNV-WT pathogenesis, WNV-E218A showed increased replication in peripheral tissues of Ifit1⁻/⁻ mice after subcutaneous infection, yet this failed to correlate with enhanced infection in the brain or lethality. In comparison, WNV-E218A was virulent after intracranial infection as judged by increased infection in different regions of the central nervous system (CNS and a greater than 16,000-fold decrease in LD(50 values in Ifit1⁻/⁻ compared to wild type mice. Ex vivo infection experiments revealed cell-type specific differences in the ability of an Ifit1 deficiency to complement the replication defect of WNV-E218A. In particular, WNV-E218A infection was impaired in both wild type and Ifit1⁻/⁻ brain microvascular endothelial cells, which are believed to participate in blood-brain barrier (BBB regulation of virus entry into the CNS. A deficiency of Ifit1 also was associated with increased neuronal death in vivo, which was both cell-intrinsic and mediated by immunopathogenic CD8⁺ T cells. Our results suggest that virulent strains of WNV have largely evaded the antiviral effects of Ifit1, and viral mutants lacking 2'-O methylation are controlled in vivo by Ifit1-dependent and -independent mechanisms in different cell types.

  15. Anti-apoptotic activity of caffeic acid, ellagic acid and ferulic acid in normal human peripheral blood mononuclear cells: a Bcl-2 independent mechanism.

    Science.gov (United States)

    Khanduja, Krishan Lal; Avti, Pramod Kumar; Kumar, Surender; Mittal, Nidhi; Sohi, Kiranjit Kaur; Pathak, Chander Mohan

    2006-02-01

    Polyphenols have been shown to induce apoptosis in a variety of tumor cells including leukemia both in vitro and in vivo. However, their action on normal human peripheral blood mononuclear cells (PBMCs) during oxidative stress remains to be explored. In this study, we have evaluated the anti-apoptotic and radical scavenging activities of dietary phenolics, namely caffeic acid (CA), ellagic acid (EA) and ferulic acid (FA). H2O2-induced apoptosis in normal human PBMCs was assayed by phosphotidylserine externalization, nucleosomal damage and DNA fragmentation. Incubation of PBMCs with 5 mM H2O2 led to increased Annexin-V binding to externalized phosphatidyl serine (PS), an event of pre-apoptotic stage of the cell. Peripheral blood mononuclear cells pretreated with phenolics could resist H2O2-induced apoptotic damage. Caffeic acid (60 and 120 microM) and EA (100 and 200 microM) caused no change in externalization of PS, whereas FA (100 and 200 microM) increased externalization of PS in PBMCs treated with H2O2. The effects of phenolics were abolished to a large extent by culturing the PBMCs for 24 h after washing the phenolics from the medium. Inhibitory activities of these phenolics on lipid peroxidation were in the order of EAindependent mechanism. PMID:16459021

  16. Parathyroid Hormone Induces Bone Cell Motility and Loss of Mature Osteocyte Phenotype through L-Calcium Channel Dependent and Independent Mechanisms.

    Directory of Open Access Journals (Sweden)

    Matthew Prideaux

    results show that PTH induces loss of the mature osteocyte phenotype and promotes the motility of these cells. These two effects are mediated through different mechanisms. The loss of phenotype effect is independent and the cell motility effect is dependent on calcium signaling.

  17. 'Independence' Panorama

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for 'Independence' Panorama (QTVR) This is the Spirit 'Independence' panorama, acquired on martian days, or sols, 536 to 543 (July 6 to 13, 2005), from a position in the 'Columbia Hills' near the summit of 'Husband Hill.' The summit of 'Husband Hill' is the peak near the right side of this panorama and is about 100 meters (328 feet) away from the rover and about 30 meters (98 feet) higher in elevation. The rocky outcrops downhill and on the left side of this mosaic include 'Larry's Lookout' and 'Cumberland Ridge,' which Spirit explored in April, May, and June of 2005. The panorama spans 360 degrees and consists of 108 individual images, each acquired with five filters of the rover's panoramic camera. The approximate true color of the mosaic was generated using the camera's 750-, 530-, and 480-nanometer filters. During the 8 martian days, or sols, that it took to acquire this image, the lighting varied considerably, partly because of imaging at different times of sol, and partly because of small sol-to-sol variations in the dustiness of the atmosphere. These slight changes produced some image seams and rock shadows. These seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see. However, it is often not possible or practical to smooth out such seams for regions of rock, soil, rover tracks or solar panels. Such is the nature of acquiring and assembling large panoramas from the rovers.

  18. Age-Independent Cartilage Generation for Synovium-Based Autologous Chondrocyte Implantation.

    Science.gov (United States)

    Hunziker, Ernst B; Lippuner, Kurt; Keel, Marius J B; Shintani, Nahoko

    2015-07-01

    The articular cartilage layer of synovial joints is commonly lesioned by trauma or by a degenerative joint disease. Attempts to repair the damage frequently involve the performance of autologous chondrocyte implantation (ACI). Healthy cartilage must be first removed from the joint, and then, on a separate occasion, following the isolation of the chondrocytes and their expansion in vitro, implanted within the lesion. The disadvantages of this therapeutic approach include the destruction of healthy cartilage-which may predispose the joint to osteoarthritic degeneration-the necessarily restricted availability of healthy tissue, the limited proliferative capacity of the donor cells-which declines with age-and the need for two surgical interventions. We postulated that it should be possible to induce synovial stem cells, which are characterized by high, age-independent, proliferative and chondrogenic differentiation capacities, to lay down cartilage within the outer juxtasynovial space after the transcutaneous implantation of a carrier bearing BMP-2 in a slow-release system. The chondrocytes could be isolated on-site and immediately used for ACI. To test this hypothesis, Chinchilla rabbits were used as an experimental model. A collagenous patch bearing BMP-2 in a slow-delivery vehicle was sutured to the inner face of the synovial membrane. The neoformed tissue was excised 5, 8, 11 and 14 days postimplantation for histological and histomorphometric analyses. Neoformed tissue was observed within the outer juxtasynovial space already on the 5th postimplantation day. It contained connective and adipose tissues, and a central nugget of growing cartilage. Between days 5 and 14, the absolute volume of cartilage increased, attaining a value of 12 mm(3) at the latter juncture. Bone was deposited in measurable quantities from the 11th day onwards, but owing to resorption, the net volume did not exceed 1.5 mm(3) (14th day). The findings confirm our hypothesis. The quantity of

  19. The effects of BMP-2 gene medication on the reconstruction of osteolytic bone defect around implant%假体周围骨溶解性骨缺损的转骨形态发生蛋白-2基因治疗

    Institute of Scientific and Technical Information of China (English)

    严孟宁; 戴尅戎; 汤亭亭

    2008-01-01

    目的 模拟假体周围骨溶解环境,观察骨形态发生蛋白-2(BMP-2)基因治疗假体周围骨溶解性骨缺损的效果.方法 成年雄性Beagle犬6条,于股骨外髁造成假体周围3mm骨缺损区.1条动物的左侧缺损区植入1ml平均直径1μm的钛合金颗粒混悬液,右侧植入1ml磷酸盐缓冲液(PBS),观察造模结果;其他5条动物双侧植入1ml钛合金颗粒混悬液,于术后2个月取出假体,植入转BMP-2基因冻干骨或单纯冻干骨,二次术后3个月取材,行组织学、组织形态计量学观察植骨愈合替代及界面骨整合情况.结果 颗粒造模术后2个月可见典型的骨溶解界膜组织形成.翻修术后3个月,冻干骨组见较多植骨残余,假体-骨界面基本为软组织界膜,假体骨接触率(BIC)为(1.38±1.22)%;基因治疗组见少量植骨残余,假体-骨界面有点状骨接触,BIC为(12.96±1.61)%,两组差异有统计学意义(P<0.01).结论 采用BMP-2基因治疗可提高假体周围骨溶解性骨缺损的界面骨整合.%Objective With the osteolystic model,the simulating revision was done to investigate the effects of BMP-2 gene therapy on the reconstruction of periprosthetic bone defect.Methods A 3 mm bone defect around Ti alloy implant was created in both femoral lateral condyla of 6 adult Beagle dogs.One animal was left as a model to evaluate the effects of particles on the defect,with 1 ml Ti alloy particles averaged diameter of 1μm implanted on the left bone defect and 1 ml PBS on the right.Ten defects of the other 5 animals were implanted 1 ml Ti alloy particle and the revisions were done 2 months postoperatively.With the impaction grafting technique,two defects of each animal were reconstructed with freeze-dried allograft (FDB group),freeze-dried allograft loading autogenous bone marrow stromal cells transfected by Adv-BMP2 gene (gene group) respectively.The allograft healing and osseointegration of bone-implant interface were evaluated by histological

  20. 17 beta-estradiol-BSA conjugates and 17 beta-estradiol regulate growth plate chondrocytes by common membrane associated mechanisms involving PKC dependent and independent signal transduction.

    Science.gov (United States)

    Sylvia, V L; Walton, J; Lopez, D; Dean, D D; Boyan, B D; Schwartz, Z

    2001-01-01

    ]-thymidine incorporation, and the effect was dose-dependent. E(2)-BSA caused time-dependent increases in PKC in RC and GC cells; effects were observed within three minutes in RC cells and within one minute in GC cells. Response to E(2) was more robust in RC cells, whereas in GC cells, E(2) and E(2)-BSA caused a comparable increase in PKC. GDP beta S inhibited the activation of PKC in E(2)-BSA-stimulated RC and GC cells. GTP gamma S increased PKC in E(2)-BSA-stimulated GC cells, but had no effect in E(2)-BSA-stimulated RC cells. The phosphatidylinositol-specific PLC inhibitor U73122 blocked E(2)-BSA-stimulated PKC activity in both RC and GC cells, whereas the phosphatidylcholine-specific PLC inhibitor D609 had no effect. Neither the PLD inhibitor wortmannin nor the phosphatidylinositol 3-kinase inhibitor LY294022 had any effect on E(2)-BSA-stimulated PKC activity in either RC or GC cells. The classical estrogen receptor antagonist ICI 182780 was unable to block the stimulatory effect of E(2)-BSA on PKC. Moreover, the classical receptor agonist diethylstilbestrol (DES) had no effect on PKC, nor did it alter the stimulatory effect of E(2)-BSA. The specificity of the membrane response to E(2) was also demonstrated by showing that the membrane receptor for 1 alpha,25-(OH)(2)D(3) was not involved. These data indicate that the rapid nongenomic effect of E(2)-BSA on PKC activity in RC and GC cells is dependent on G-protein-coupled PLC and support the hypothesis that many of the effects of E(2) involve membrane-associated mechanisms independent of classical estrogen receptors. (c) 2001 Wiley-Liss, Inc.

  1. Repetitive recombinant human bone morphogenetic protein 2 injections improve the callus microarchitecture and mechanical stiffness in a sheep model of distraction osteogenesis

    Directory of Open Access Journals (Sweden)

    Marc-Frederic Pastor

    2012-03-01

    Full Text Available Evidence suggests that recombinant human bone morphogenetic protein 2 (rhBMP-2 increases the mechanical integrity of callus tissue during bone healing. This effect may be either explained by an increase of callus formation or a modification of the trabecular microarchitecture. Therefore the purpose of the study was to evaluate the potential benefit of rhBMP-2 on the trabecular microarchitecture and on multidirectional callus stiffness. Further we asked, whether microarchitecture changes correlate with optimized callus stiffness. In this study a tibial distraction osteogenesis (DO model in 12 sheep was used to determine, whether percutaneous injection of rhBMP-2 into the distraction zone influences the microarchitecture of the bone regenerate. After a latency period of 4 days, the tibiae were distracted at a rate of 1.25 mm/day over a period of 20 days, resulting in total lengthening of 25 mm. The operated limbs were randomly assigned to one treatment groups and one control group: (A triple injection of rhBMP-2 (4 mg rhBMP-2/injection and (B no injection. The tibiae were harvested after 74 days and scanned by μCT (90 μm/voxel. In addition, we conducted a multidirectional mechanical testing of the tibiae by using a material testing system to assess the multidirectional strength. The distraction zones were tested for torsional stiffness and bending stiffness antero-posterior (AP and medio-lateral (ML direction, compression strength and maximum axial torsion. Statistical analysis was performed using multivariate analysis of variance (ANOVA followed by student’s t-test and Regression analysis using power functions with a significance level of P<0.05. Triple injections of rhBMP-2 induced significant changes in the trabecular architecture of the regenerate compared with the control: increased trabecular number (Tb.N. (treatment group 1.73 mm/1 vs. control group 1.2 mm/1, increased cortical bone volume fraction (BV/TV (treatment group 0.68 vs

  2. Construction of Remuneration Mechanism with Stimulation Function for Independent Director%构建具有激励作用的独立董事薪酬机制研究

    Institute of Scientific and Technical Information of China (English)

    张晓明; 李辽宁; 李辉

    2011-01-01

    This article firstly analyzes the practice risks of independent director from four aspects which are closely related to the remuneration mechanism for independent director. These four aspects are law risk, reputation risk, market risk and economical risk. Secondly, this article analyzes the current situation and problems of the remuneration for independent director based on the statistics of remuneration for independent director from listed companies' annual reports for 2009. These listed companies are respectively located in Zhejiang province, Shaanxi province and Qinghai province. Finally we reconstruct the remuneration mechanism for independent director with three parts including fixedly payed remuneration, delayedly payed remuneration and stock notion.%从法律法规风险、声誉风险、市场风险和经济风险四个方面分析了与构建独立董事薪酬机制紧密相关的独立董事执业风险。对浙江、陕西、青海三省2009年上市公司独立董事薪酬的相关数据做了统计,分析了我国独立董事薪酬的现状以及存在的问题。重构了由固定薪酬、延期支付薪酬、股票期权构成的具有激励作用的独立董事薪酬机制。

  3. Comparison of Effects of Mechanical Stretching on Osteogenic Potential of ASCs and BMSCs

    Institute of Scientific and Technical Information of China (English)

    Brian E. Grottkau; Xingmei Yang; Liang Zhang; Ling Ye; Yunfeng Lin

    2013-01-01

    Mechanical forces play critical roles in the development and remodeling processes of bone. As an alternative cell source for bone engineering, adipose-derived stem cells (ASCs) should be fully investigated for their responses to mechanical stress. Similarly, the osteogenic potential, stimulated by mechanical stress, should be compared with bone marrow stromal cells (BMSCs), which have been clinically used for bone tissue engineering. In this study, ASCs and BMSCs were osteogenic-induced for 48 hours, and then subjected to uniaxial mechanical stretching for 2 or 6 hours. Cell orientation, osteogenic regulatory genes, osteogenic genes and ALP activities were measured and compared between ASCs and BMSCs. ASCs could align in a perpendicular way to the direction of stretching stress, while BMSCs did not present a specific alignment. Both 2 and 6 hours mechanical stretching could enhance the mRNA expression of Osx and Runx2 in BMSCs and ASCs, while OCN mRNA only increased in ASCs after 6 hours mechanical loading. Mechanical stretching enhanced the BMP-2 mRNA expression in ASCs, while only after 6 hours of mechanical loading significantly increased the BMP-2 gene expression in BMSCs. Significant differences only exist between ASCs and BMSCs loaded at 2 hours of mechanical stretching. It is concluded that ASCs are more rapid responders to mechanical stress, and have greater potential than BMSCs in osteogenesis when stimulated by mechanical stretching, indicating their usefulness for bone study in a rat model.

  4. Empirical Study on Incentive Mechanism for Compensation of Independent Director%独立董事薪酬激励机制实证分析

    Institute of Scientific and Technical Information of China (English)

    王建明

    2011-01-01

    Using a econometric model and the data about listed companies in Shanghai Stock Market,this paper studies empirically the factors influencing compensation of independent directors. The result shows as follows: the compensation level of independent directors is positive correlation with that of senior managers and supervisors, and is negative correlation with the shareholding level of senior managers (the compensation level of independent directors in state-owned listed companies is higher than that in non-state-owned listed companies (the enhancing of ownership concentration degree helps to decrease the compensation level of independent directors;performance and general manager turnover have no impacts on it.%利用面板计量模型以及2005-2009年我国沪市上市公司的相关数据,实证检验了上市公司独立董事薪酬的影响因素.研究发现:独立董事的薪酬激励水平与高管薪酬水平、监事薪酬水平显著正相关,与高管持股水平显著负相关;国有上市公司独立董事的薪酬要高于非国有上市公司,股权集中程度的提高会显著降低独立董事的薪酬水平;公司业绩及总经理变更对独立董事薪酬均没有显著影响.

  5. Restoration of segmental bone defects by using chitosan-coated pressed calcium sulfate pellet com-bined with rhBMP-2%壳聚糖包衣加压硫酸钙片复合重组人骨形态发生蛋白-2修复兔节段性骨缺损

    Institute of Scientific and Technical Information of China (English)

    崔旭; 张伯勋

    2009-01-01

    Objective To compare the effect of calcium sulfate pellets made by different methods in repair of segmental radial defect of rabbits. Methods Eighty white New Zealand rabbits were sub-jected to defects of middle part of the left radial bone and divided into four groups according to repair ma-terials: control group (Group A, implanted with no artificial bone substitute), uncoated pressed calcium sulfate pellets (Group B), coated pressed calcium sulfate pellets (Group C) and coated pressed calcium sulfate pellets combined with rhBMP-2 (Group D). Histologic examination and biological test were done at 4, 8 and 12 weeks after operation. The data were processed with mono-factor variance analysis. Re-sults New bone formation was found on the defected bone in Group D and Group C, with better in Group D. The bone strength test showed that the anti-bending strength was (39.6±1.7) % in Group C and (47.5±2.1) % in Group D, which were higher than (21.3±2.7) % in Group A and (23.6±3.3) % in Group B, with higher anti-bending strength in Group D than that in Group C (F = 125.3 ,P <0.01). Conclusions For restoration of segmental bone defects, chitosan-coated pressed calcium sulfate pellet shows relatively high density and slightly slow resorption, which closely coincides with the growth rate of new bone. The coated pellet combined with rhBMP-2 can enhance its osteogeneais in restoring segmental Done defects.%目的 比较不同方法 制备的硫酸钙片修复兔桡骨节段性骨缺损的效果. 方法 新西兰大白兔80只随机数字表法分为A、B、C、D组,造成左桡骨中段骨缺损,采用三种经不同方法 制备的硫酸钙片修复.A组:空白对照组;B组:加压方法 制备的硫酸钙组;C组:壳聚糖包衣的加压硫酸钙组;D组:壳聚糖包衣的复合重组人骨形态发生蛋白-2(rhBMP-2)加压硫酸钙组.术后4,8,12周进行组织学检查和生物力学测试,实验数据采用单因素方差分析. 结果 D组、C组骨缺损愈合,而

  6. Independence Logic and Abstract Independence Relations

    OpenAIRE

    Paolini, Gianluca

    2014-01-01

    We continue the work on the relations between independence logic and the model-theoretic analysis of independence, generalizing the results of [15] and [16] to the framework of abstract independence relations for an arbitrary AEC. We give a model-theoretic interpretation of the independence atom and characterize under which conditions we can prove a completeness result with respect to the deductive system that axiomatizes independence in team semantics and statistics.

  7. Angiotensin II type 1 receptor is required for the cardiac fibrosis triggered by mechanical stress independent of Ang II in mice

    Institute of Scientific and Technical Information of China (English)

    YE Yong; YUAN Jie; JIANG Guo-liang; HUANG Jia-yuan; ZHANG Wei-jing; GE Jun-bo; ZOU Yun-zeng; GONG Hui; WU Jian; DING Zhi-wen; SHEN Yi; YIN Pei-pei; WANG Xing-xu; YOU Jie-yun; WANG Shi-jun

    2016-01-01

    AIM:We investigated how AT 1-R stimulated by mechanical stresses induces cardiac fibrosis .METHODS:We produced in vivo cardiac pressure overload model in angiotensinogen knockout ( ATG-/-) mice and in vitro mechanically-stretched cell model in cultured neonatal cardiac cells of ATG-/-mice both lack the participation of Ang II .RESULTS: Pressure overload for 4 weeks in ATG-/-mice induced myocardial hypertrophy accompanied by the significant interstitial fibrosis , however , the TGF-β, a key regulatory factor of fibrosis, was not significantly increased in these ATG-/-mice.Meanwhile, the inhibitor for AT1-R significantly inhibited mechani-cal stress-induced cardiac fibrosis in these ATG-/-models whereas inhibition of TGF-βdid not.CONCLUSION:The results showed that mechanical stress-induced fibrotic responses through AT 1-R required the phosphorylation of Smad 2 but not the involvement of TGF-β.

  8. Hypoxia-mediated down-regulation of Bid and Bax in tumors occurs via hypoxia-inducible factor 1-dependent and -independent mechanisms and contributes to drug resistance

    DEFF Research Database (Denmark)

    Erler, Janine Terra; Cawthorne, Christopher J; Williams, Kaye J;

    2004-01-01

    of the Bcl-2 protein family. Oxygen deprivation of human colon cancer cells in vitro provoked decreased mRNA and protein levels of proapoptotic Bid and Bad. Hypoxia-inducible factor 1 (HIF-1) was dispensable for the down-regulation of Bad but required for that of Bid, consistent with the binding of HIF-1......alpha to a hypoxia-responsive element (positions -8484 to -8475) in the bid promoter. Oxygen deprivation resulted in proteosome-independent decreased expression of Bax in vitro, consistent with a reduction in global translation efficiency. The physiological relevance of Bid and Bax down...

  9. Construction of Long-term Mechanism of Party Building Work in Independent Colleges——Thinking of Party Building Work in Guangxi Independent Colleage%独立院校党建工作长效机制的构建——基于广西独立学院党建工作的思考

    Institute of Scientific and Technical Information of China (English)

    金飞

    2011-01-01

    独立学院作为我国高等教育体系中的一支新生力量,由于办学机制的独特性,使得其在党建工作方面还存在着体制不完善、经验缺失、力量薄弱等一系列问题。因此,要提高独立学院党建工作的效能,提升基层党组织的战斗堡垒作用,办出适应独立学院发展的党建工作特色,建构独立学院党建工作的长效机制显得尤为重要和迫切。%Independent Colleges of higher education system as a new force, because the school system is unique, making it party-building work in the system, there are still imperfect, experience loss, weakness and other issues. Therefore, to improve the performance of independent college party-building work to enhance the role of grassroots organizations fighting force, to do independent development of the Institute to adapt the work of party building features, construction work of Independent Colleges party building long-term mechanism is particularly important and urgent.

  10. Game Analysis of IPO Inquiry System into Independent Placement Mechanism%引入自主配售机制后IPO询价制度的博弈分析

    Institute of Scientific and Technical Information of China (English)

    陈俊枝

    2015-01-01

    2013年11月,我国IPO询价制度引入主承销商自主配售机制。本文运用博弈论模型,对引入自主配售机制后的IPO询价制度进行了分析,认为自主配售机制是一种激励相容机制,有助于形成市场博弈机制,使询价制度更好地为新股提供定价服务,促使新股发行市场良性发展。监管层应该完善事前审核,加强事中监管,重视事后法律执行,确立规范化的检查机制,指导主承销商遵循市场三公原则。%In November 2013, IPO inquiry system in China introduced the main underwriter independent allot-ment mechanism. This paper uses game theory model, IPO Placing inquiry system after the introduction of indepen-dent mechanisms were analyzed. I come to the conclusion that independent placement mechanism is not only a punish-ment and incentive mechanism,helping to form the market game mechanism,making better service for the new pric-ing inquiry system and prompting the IPO market benign development. Regulators should perfect prior audit,strength-en the supervision of matter and attach importance to law enforcement, establish the standardized examination mecha-nism,and guide the lead underwriters follow market three-fair principles.

  11. Light-dependent and -independent behavioral effects of extremely low frequency magnetic fields in a land snail are consistent with a parametric resonance mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Prato, F.S.; Thomas, A.W. [Univ. of Western Ontario, London, Ontario (Canada)]|[St. Joseph`s Health Centre, London, Ontario (Canada); Kavaliers, M. [Univ. of Western Ontario, London, Ontario (Canada); Cullen, A.P. [Univ. of Waterloo, Ontario (Canada). School of Optometry

    1997-05-01

    Exposure to extremely low frequency (ELF) magnetic fields has been shown to attenuate endogenous opioid peptide mediated antinociception or analgesia in the terrestrial pulmonate snail, Cepaea nemoralis. Here the authors examine the roles of light in determining this effect and address the mechanisms associated with mediating the effects of the ELF magnetic fields in both the presence and absence of light. Specifically, they consider whether the magnetic field effects involve an indirect induced electric current mechanism or a direct effect such as a parametric resonance mechanism (PRM). They exposed snails in both the presence and absence of light at three different frequencies (30, 60, and 120 Hz) with static field values (B{sub DC}) and ELF magnetic field amplitude (peak) and direction (B{sub AC}) set according to the predictions of the PRM for Ca{sup 2+}. Analgesia was induced in snails by injecting them with an enkephalinase inhibitor, which augments endogenous opioid (enkephalin) activity. They found that the magnetic field exposure reduced this opioid-induced analgesia significantly more if the exposure occurred in the presence rather than the absence of light. However, the percentage reduction in analgesia in both the presence and absence of light was not dependent on the ELF frequency. This finding suggests that in both the presence and the absence of light the effect of the ELF magnetic field was mediated by a direct magnetic field detection mechanism such as the PRM rather than an induced current mechanism.

  12. Study on Mechanism of SMEs Promoting Independent Innovation Capability Based on RJVs%联合体视角下我国中小企业自主创新能力提升机制研究

    Institute of Scientific and Technical Information of China (English)

    马宗国; 李静

    2016-01-01

    It has an important theoretical and practical significance to research the mechanism of SM Es so as to improve in-dependent innovation capability based on the perspective of RJVs . The paper combines with multiple cases study and grounded theory to make theoretical assumptions and analyze decoding for Certus group ,Macmic company and xunlei com-pany .The research shows that :internal mechanism ,external mechanism and coordination mechanism are three main mechanisms to improve the independent innovation capability of SM Es in our country .Based on this ,the paper constructs the mechanism model ,and clears about the relationship of the three main mechanisms .%基于联合体(RJVs)视角,研究中小企业自主创新能力提升机制,对增强我国中小企业自主创新能力具有重要意义.结合多案例研究法和扎根理论,对赛特斯集团、宏微科技公司和迅雷公司进行理论假设和译码分析.结果表明:内部机制、外部机制和协调机制是提升我国中小企业自主创新能力的3个主要机制.基于此,构建了中小企业RJV s自主创新能力提升机制模型,明确了三者之间的相互关系.

  13. How-to Guide. National Institutional Frameworks for the Kyoto Protocol Flexible Mechanisms in Eastern Europe and the Commonwealth of Independent States. Part 2

    International Nuclear Information System (INIS)

    The goal of this Guide is to help national climate change policy makers and UNDP country offices understand the requirements and processes for establishing national institutional frameworks for implementing the Kyoto Protocol in Eastern Europe and the CIS. In particular the guide is designed to assist countries that will be hosting and approving Clean Development Mechanism (CDM) and Joint Implementation (JI) projects in designing the necessary procedures for project review and evaluation, including criteria for assessing a project's contribution to sustainable development.

  14. The ent-15α-Acetoxykaur-16-en-19-oic Acid Relaxes Rat Artery Mesenteric Superior via Endothelium-Dependent and Endothelium-Independent Mechanisms

    OpenAIRE

    Êurica Adélia Nogueira Ribeiro; Edla de Azevedo Herculano; Cintia Danieli Ferreira da Costa; Fabiola Fialho Furtado; Emídio Vasconcelos Leitão da-Cunha; José Maria Barbosa-Filho; Marcelo Sobral da Silva; Isac Almeida de Medeiros

    2012-01-01

    The objective of the study was to investigate the mechanism of the relaxant activity of the ent-15 α -acetoxykaur-16-en-19-oic acid (KA-acetoxy). In rat mesenteric artery rings, KA-acetoxy induced a concentration-dependent relaxation in vessels precontracted with phenylephrine. In the absence of endothelium, the vasorelaxation was significantly shifted to the right without reduction of the maximum effect. Endothelium-dependent relaxation was significantly attenuated by pretreatment with L-NAM...

  15. How the Inverse See-Saw Mechanism Can Reveal Itself Natural, Canonical and Independent of the Right-Handed Neutrino Mass

    CERN Document Server

    Dias, A G; da Silva, P S Rodrigues

    2011-01-01

    The common lore in the literature of neutrino mass generation is that the canonical see-saw mechanism beautifully offers an explanation for the tiny neutrino mass but at the cost of introducing right-handed neutrinos at a scale that is out of range for the current experiments. Then comes an alternative, the inverse see-saw, which also leads to tiny neutrino masses with the advantage of being testable at TeV scale. However, this last mechanism suffers from an issue of naturalness concerning the scale responsible for such small masses namely, the parameter $\\mu$ that is related to lepton number violation and is supposed to be at keV scale, much lower than the electroweak one. However, no theoretical framework was built that offers an explanation for obtaining this specific scale. In this work we propose a variation of the inverse see-saw mechanism, by assuming a minimal scalar and fermionic set of singlet fields, along with a $Z_5\\otimes Z_2$ symmetry, that allows a dynamical explanation for the smallness of $\\...

  16. Cas Ilgly Induces Apoptosis in Glioma C6 Cells In Vitro and In Vivo through Caspase-Dependent and Caspase-Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Cristina Trejo-Solís

    2005-06-01

    Full Text Available In this work, we investigated the effects of Casiopeina Il-gly (Cas ILgly—a new copper compound exhibiting antineoplastic activity—on glioma C6 cells under both in vitro and in vivo conditions, as an approach to identify potential therapeutic agents against malignant glioma. The exposure of C6 cells to Cas Ilgly significantly inhibited cell proliferation, increased reactive oxygen species (ROS formation, and induced apoptosis in a dose-dependent manner. In cultured C6 cells, Cas Ilgly caused mitochondrio-nuclear translocation of apoptosis induction factor (AIF and endonuclease G at all concentrations tested; in contrast, fragmentation of nucleosomal DNA, cytochrome c release, and caspase-3 activation were observed at high concentrations. Administration of N-acetyl-l-cystein, an antioxidant, resulted in significant inhibition of AIF translocation, nucleosomal DNA fragmentation, and caspase-3 activation induced by Cas Ilgly. These results suggest that caspase-dependent and caspase-independent pathways both participate in apoptotic events elicited by Cas Ilgly. ROS formation induced by Cas Ilgly might also be involved in the mitochondrio-nuclear translocation of AIF and apoptosis. In addition, treatment of glioma C6-positive rats with Cas Ilgly reduced tumor volume and mitotic and cell proliferation indexes, and increased apoptotic index. Our findings support the use of Cas Ilgly for the treatment of malignant gliomas.

  17. China local government independent bond issue's mechanism design%我国地方政府自主发债的制度设计

    Institute of Scientific and Technical Information of China (English)

    黄芳娜

    2012-01-01

    中国地方政府债务问题已经引起了决策层和国内外经济学家的高度重视,债务规模已经十分庞大。防范和化解地方政府债务风险,解决地方财政资金不足,规范地方政府举债行为,就要赋予地方政府自主发债权,并且明确地方政府自主发债的制度设计,制定一套包括发行主体、发行规模、发行利率、发行期限、发行方式等在内的规范、科学的制度。%Chinese sub-national government debt issue has caused decision-makers and domestic and international economists highly valued.Size of the debt has been enormous.To prevent and reduce the risk of sub-national government debt,to solve inadequate financial resources,and to regulate sub-national government borrowing act,sub-national government must be given the self-made claims.We must clear system design of independent bonds.A set standardized and scientific system should be formulated including issue subject,issue size,issue rate,issue duration and issue methods etc.

  18. SHIP-deficient dendritic cells, unlike wild type dendritic cells, suppress T cell proliferation via a nitric oxide-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Frann Antignano

    Full Text Available BACKGROUND: Dendritic cells (DCs not only play a crucial role in activating immune cells but also suppressing them. We recently investigated SHIP's role in murine DCs in terms of immune cell activation and found that TLR agonist-stimulated SHIP-/- GM-CSF-derived DCs (GM-DCs were far less capable than wild type (WT, SHIP+/+ GM-DCs at activating T cell proliferation. This was most likely because SHIP-/- GM-DCs could not up-regulate MHCII and/or co-stimulatory receptors following TLR stimulation. However, the role of SHIP in DC-induced T cell suppression was not investigated. METHODOLOGY/PRINCIPAL FINDINGS: In this study we examined SHIP's role in DC-induced T cell suppression by co-culturing WT and SHIP-/- murine DCs, derived under different conditions or isolated from spleens, with αCD3+ αCD28 activated WT T cells and determined the relative suppressive abilities of the different DC subsets. We found that, in contrast to SHIP+/+ and -/- splenic or Flt3L-derived DCs, which do not suppress T cell proliferation in vitro, both SHIP+/+ and -/- GM-DCs were capable of potently suppressing T cell proliferation. However, WT GM-DC suppression appeared to be mediated, at least in part, by nitric oxide (NO production while SHIP-/- GM-DCs expressed high levels of arginase 1 and did not produce NO. Following exhaustive studies to ascertain the mechanism of SHIP-/- DC-mediated suppression, we could conclude that cell-cell contact was required and the mechanism may be related to their relative immaturity, compared to SHIP+/+ GM-DCs. CONCLUSIONS: These findings suggest that although both SHIP+/+ and -/- GM-DCs suppress T cell proliferation, the mechanism(s employed are different. WT GM-DCs suppress, at least in part, via IFNγ-induced NO production while SHIP-/- GM-DCs do not produce NO and suppression can only be alleviated when contact is prevented.

  19. P-Selectin Cross-Links PSGL-1 and Enhances Neutrophil Adhesion to Fibrinogen and ICAM-1 in a Src Kinase-Dependent, but GPCR-Independent Mechanism

    OpenAIRE

    Xu, Tao; Zhang, Lei; Geng, Zhen H; Wang, Hai-Bo; Wang, Jin-Tao; Chen, Ming; Geng, Jian-Guo

    2007-01-01

    Endothelial and platelet P-selectin (CD62P) and leukocyte integrin αMβ2 (CD11bCD18, Mac-1) are cell adhesion molecules essential for host defense and innate immunity. Upon inflammatory challenges, P-selectin binds to PSGL-1 (P-selectin glycoprotein ligand-1, CD162) to mediate neutrophil rolling, during which integrins become activated by extracellular stimuli for their firm adhesion in a G-protein coupled receptor (GPCR)-dependent mechanism. Here we show that cross-linking of PSGL-1 by dimeri...

  20. Regulatory T Cell-Dependent and -Independent Mechanisms of Immune Suppression by CD28/B7 and CD40/CD40L Costimulation Blockade.

    Science.gov (United States)

    Vogel, Isabel; Verbinnen, Bert; Van Gool, Stefaan; Ceuppens, Jan L

    2016-07-15

    Blocking of costimulatory CD28/B7 and CD40/CD40L interactions is an experimental approach to immune suppression and tolerance induction. We previously reported that administration of a combination of CTLA-4Ig and MR1 (anti-CD40L mAb) for blockade of these interactions induces tolerance in a fully mismatched allogeneic splenocyte transfer model in mice. We now used this model to study whether regulatory T cells (Tregs) contribute to immune suppression and why both pathways have to be blocked simultaneously. Mice were injected with allogeneic splenocytes, CD4(+) T cells, or CD8(+) T cells and treated with MR1 mAb and different doses of CTLA-4Ig. The graft-versus-host reaction of CD4(+) T cells, but not of CD8(+) T cells, was inhibited by MR1. CTLA-4Ig was needed to cover CD8(+) T cells but had only a weak effect on CD4(+) T cells. Consequently, only the combination provided full protection when splenocytes were transferred. Importantly, MR1 and low-dose CTLA-4Ig treatment resulted in a relative increase in Tregs, and immune suppressive efficacy was abolished in the absence of Tregs. High-dose CTLA-4Ig treatment, in contrast, prevented Treg expansion and activity, and in combination with MR1 completely inhibited CD4(+) and CD8(+) T cell activation in a Treg-independent manner. In conclusion, MR1 and CTLA-4Ig act synergistically as they target different T cell populations. The contribution of Tregs to immune suppression by costimulation blockade depends on the concentration of CTLA-4Ig and thus on the degree of available CD28 costimulation. PMID:27288533

  1. Molecular mechanisms of 6-hydroxydopamine-induced cytotoxicity in PC12 cells: involvement of hydrogen peroxide-dependent and -independent action.

    Science.gov (United States)

    Saito, Yoshiro; Nishio, Keiko; Ogawa, Yoko; Kinumi, Tomoya; Yoshida, Yasukazu; Masuo, Yoshinori; Niki, Etsuo

    2007-03-01

    The neurotoxin 6-hydroxydopamine (6-OHDA) has been widely used to generate an experimental model of Parkinson's disease. It has been reported that reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide (H2O2), generated from 6-OHDA are involved in its cytotoxicity; however, the contribution and role of ROS in 6-OHDA-induced cell death have not been fully elucidated. In the present study using PC12 cells, we observed the generation of 50 microM H2O2 from a lethal concentration of 100 microM 6-OHDA within a few minutes, and compared the sole effect of H2O2 with 6-OHDA. Catalase, an H2O2-removing enzyme, completely abolished the cytotoxic effect of H2O2, while a significant but partial protective effect was observed against 6-OHDA. 6-OHDA induced peroxiredoxin oxidation, cytochrome c release, and caspase-3 activation. Catalase exhibited a strong inhibitory effect against the peroxiredoxin oxidation, and cytochrome c release induced by 6-OHDA; however, caspase-3 activation was not effectively inhibited by catalase. On the other hand, 6-OHDA-induced caspase-3 activation was inhibited in the presence of caspase-8, caspase-9, and calpain inhibitors. These results suggest that the H2O2 generated from 6-OHDA plays a pivotal role in 6-OHDA-induced peroxiredoxin oxidation, and cytochrome c release, while H2O2- and cytochrome c-independent caspase activation pathways are involved in 6-OHDA-induced neurotoxicity. These findings may contribute to explain the importance of generated H2O2 and secondary products as a second messenger of 6-OHDA-induced cell death signal linked to Parkinson's disease.

  2. S-adenosyl-methionine decreases ethanol-induced apoptosis in primary hepatocyte cultures by a c-Jun N-terminal kinase activity-independent mechanism

    Institute of Scientific and Technical Information of China (English)

    María del Pilar Cabrales-Romero; Lucrecia Márquez-Rosado; Samia Fattel-Fazenda; Cristina Trejo-Solís; Evelia Arce-Popoca; Leticia Alemén-Lazarini; Saúl Villa-Trevi(n)o

    2006-01-01

    AIM: To determine the role of c-Jun N-terminal kinase (JNK) activity in ethanol-induced apoptosis and the modulation of this signaling cascade by S-Adenosylmethionine (AdoMet).METHODS: Primary hepatocyte cultures were pretreated with 100 μmol/L SP600125, a selective JNK inhibitor, 1 mL/L DMSO or 4 mmol/L AdoMet and then exposed to 100 mmo/L ethanol. Hepatocyte apoptosis was determined by the TUNEL and DNA ladder assays.JNK activity and its inhibition by SP600125 and AdoMet were determined by Western blot analysis of c-jun phosphorylation and Bid fragmentation. SP600125 and AdoMet effects on the apoptotic signaling pathway were determined by Western blot analysis of cytochrome c release and pro-caspase 3 fragmentation. The AdoMet effect on glutathione levels was measured by Ellman's method and reactive oxygen species (ROS) generation by cell cytometry.RESULTS: The exposure of hepatocytes to ethanol induced JNK activation, c-jun phosphorylation, Bid fragmentation, cytochrome c release and pro-caspase 3 cleavage; these effects were diminished by SP600125, and caused a significant decreasein ethanol-induced apoptosis (P< 0.05). AdoMet exerted an antioxidant effect maintaining glutathione levels and decreasing ROS generation, without a significant effect on JNK activity,and prevented cytochrome c release and pro-caspase 3 cleavage.CONCLUSION: The JNK signaling cascade is a key component of the proapoptotic signaling pathway induced by ethanol. JNK activation may be independent from ROS generation, since AdoMet which exerted antioxidant properties did not have a significant effect on JNK activity. JNK pathway modulator agents and AdoMet may be components of promising therapies for alcoholic liver disease (ALD) treatment.

  3. SMAX1-LIKE7 Signals from the Nucleus to Regulate Shoot Development in Arabidopsis via Partially EAR Motif-Independent Mechanisms.

    Science.gov (United States)

    Liang, Yueyang; Ward, Sally; Li, Ping; Bennett, Tom; Leyser, Ottoline

    2016-07-01

    Strigolactones (SLs) are hormonal signals that regulate multiple aspects of shoot architecture, including shoot branching. Like many plant hormonal signaling systems, SLs act by promoting ubiquitination of target proteins and their subsequent proteasome-mediated degradation. Recently, SMXL6, SMXL7, and SMXL8, members of the SMAX1-LIKE (SMXL) family of chaperonin-like proteins, have been identified as proteolytic targets of SL signaling in Arabidopsis thaliana However, the mechanisms by which these proteins regulate downstream events remain largely unclear. Here, we show that SMXL7 functions in the nucleus, as does the SL receptor, DWARF14 (D14). We show that nucleus-localized D14 can physically interact with both SMXL7 and the MAX2 F-box protein in a SL-dependent manner and that disruption of specific conserved domains in SMXL7 affects its localization, SL-induced degradation, and activity. By expressing and overexpressing these SMXL7 protein variants, we show that shoot tissues are broadly sensitive to SMXL7 activity, but degradation normally buffers the effect of increasing SMXL7 expression. SMXL7 contains a well-conserved EAR (ETHYLENE-RESPONSE FACTOR Amphiphilic Repression) motif, which contributes to, but is not essential for, SMXL7 functionality. Intriguingly, different developmental processes show differential sensitivity to the loss of the EAR motif, raising the possibility that there may be several distinct mechanisms at play downstream of SMXL7. PMID:27317673

  4. Retinoic acid protects human breast cancer cells against etoposide-induced apoptosis by NF-kappaB-dependent but cIAP2-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Gronemeyer Hinrich

    2010-01-01

    cancer therapy-mediated apoptosis in breast cancer cells, independently of cIAP2. Our data support the use of NF-kappaB pathway activation as a marker for screening that will help to develop novel retinoids, or retinoid-based combination therapies with improved efficacy.

  5. A cAMP-independent carbohydrate-driven mechanism inhibits tnaA expression and TnaA enzyme activity in Escherichia coli.

    Science.gov (United States)

    Li, Gang; Young, Kevin D

    2014-09-01

    When Escherichia coli is grown in a medium lacking glucose or another preferred carbohydrate, the concentration of cAMP-cAMP receptor protein (cAMP-CRP) increases, and this latter complex regulates the expression of more than 180 genes. To respond rapidly to changes in carbohydrate availability, E. coli must maintain a suitable intracellular concentration of cAMP by either exporting or degrading excess cAMP. Currently, cAMP export via the TolC protein is thought to be more efficient at reducing these levels than is CpdA-mediated degradation of cAMP. Here, we compared the contributions of TolC and CpdA by measuring the expression of cAMP-regulated genes that encode tryptophanase (TnaA) and β-galactosidase. In the presence of exogenous cAMP, a tolC mutant produced intermediate levels of these enzymes, suggesting that cAMP levels were held in check by CpdA. Conversely, a cpdA mutant produced much higher amounts of these enzymes, indicating that CpdA was more efficient than TolC at reducing cAMP levels. Surprisingly, expression of the tnaA gene halted rapidly when glucose was added to cells lacking both TolC and CpdA, even though under these conditions cAMP could not be removed by either pathway and tnaA expression should have remained high. This result suggests the existence of an additional mechanism that eliminates intracellular cAMP or terminates expression of some cAMP-CRP-regulated genes. In addition, adding glucose and other carbohydrates rapidly inhibited the function of pre-formed TnaA, indicating that TnaA is regulated by a previously unknown carbohydrate-dependent post-translational mechanism.

  6. 15-Deoxy-Δ12,14-prostaglandin J2 induces renal epithelial cell death through NF-κB-dependent and MAPK-independent mechanism

    International Nuclear Information System (INIS)

    The peroxisome proliferator-activated receptor-γ (PPARγ) ligand 15d-PGJ2 induces cell death in renal proximal tubular cells. However, the underlying molecular mechanism(s) remains unidentified. The present study was undertaken to examine the roles of reactive oxygen species (ROS), mitogen-activated protein kinase, and NF-κB in opossum kidney (OK) cell death induced by 15d-PGJ2. Treatment of OK cells with 15d-PGJ2 resulted in a concentration- and time-dependent cell death, which was largely attributed to apoptosis. 15d-PGJ2 increased ROS production and the effect was inhibited by catalase and N-acetylcysteine. The 15d-PGJ2-induced cell death was also prevented by these antioxidants, suggesting that the cell death was associated with ROS generation. The PPARγ antagonist GW9662 did not prevent the 15d-PGJ2-induced cell death. 15d-PGJ2 caused a transient activation of extracellular signal-regulated kinase (ERK). However, inhibitors (PD98059 and U0126) of MEK, an ERK upstream kinase, did not alter the 15d-PGJ2-induced cell death. Transfection with constitutively active MEK and dominant-negative MEK had no effect on the cell death. 15d-PGJ2 inhibited the NF-κB transcriptional activity, which was accompanied by an inhibition of nuclear translocation of the NF-κB subunit p65 and impairment in DNA binding. Inhibition of NF-κB with a NF-κB specific inhibitor pyrrolidinecarbodithioate and transfection with IκBα (S32A/36A) caused cell death. These results suggest that the 5d-PGJ2-induced OK cell death was associated with ROS production and NF-κB inhibition, but not with MAPK activation

  7. Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Wei, You-Dong; Liu, Yi-Yun; Ren, Yi-Fei; Liang, Zi-Hong; Wang, Hai-Yang; Zhao, Li-Bo; Xie, Peng

    2016-01-01

    Background and Purpose Recombinant tissue plasminogen activator (rtPA) is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA) on cerebral infarction besides its thrombolysis property in mechanical animal stroke. Methods Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger’s test were obtained to detect publication bias. Results We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate. Conclusions This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA. PMID:27387385

  8. Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Mei-Xue Dong

    Full Text Available Recombinant tissue plasminogen activator (rtPA is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA on cerebral infarction besides its thrombolysis property in mechanical animal stroke.Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger's test were obtained to detect publication bias.We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate.This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA.

  9. Administration of N-acetylserotonin and melatonin alleviate chronic ketamine-induced behavioural phenotype accompanying BDNF-independent and dependent converging cytoprotective mechanisms in the hippocampus.

    Science.gov (United States)

    Choudhury, Arnab; Singh, Seema; Palit, Gautam; Shukla, Shubha; Ganguly, Surajit

    2016-01-15

    Though growing evidence implicates both melatonin (MLT) and its immediate precursor N-acetylserotonin (NAS) in the regulation of hippocampal neurogenesis, their comparative mechanistic relationship with core behavioural correlates of psychiatric disorders is largely unknown. To address this issue, we investigated the ability of these indoleamines to mitigate the behavioral phenotypes associated with NMDA-receptor (NMDAR) hypofunction in mice. We demonstrated that exogenous MLT and NAS treatments attenuated the NMDAR antagonist (ketamine) induced immobility in the forced swim test (FST) but not the classical striatum-related hyperlocomotor activity phenotype. The MLT/NAS-mediated protection of the phenotype in FST could be correlated to the ability of these indoleamines to counteract the deleterious effects of chronic ketamine on pro-survival molecular events by restoring the activities in MEK-ERK and PI3K-AKT pathways in the hippocampus. MLT seems to modulate these pathways by promoting accumulation of the mature form of BDNF above the control (vehicle-treated) levels, perhaps via MLT receptor-dependent mechanisms and in the process overcoming the ketamine-induced down-regulation of BDNF. In contrast, NAS appears to partly restore the ketamine-induced decrease of BDNF to the control levels. In spite of this fundamental difference in modulating BDNF levels in the upstream events, both MLT and NAS seem to overlap in the TrkB-induced downstream pro-survival mechanisms in the hippocampus, providing protection against NMDAR-hypofunction related cellular events. Perhaps, this also signifies the physiological importance of robust MLT synthesizing machinery that converts serotonin to MLT, in ensuring positive impact on hippocampus-related symptoms in psychiatric disorders.

  10. The ent-15α-Acetoxykaur-16-en-19-oic Acid Relaxes Rat Artery Mesenteric Superior via Endothelium-Dependent and Endothelium-Independent Mechanisms

    Science.gov (United States)

    Ribeiro, Êurica Adélia Nogueira; Herculano, Edla de Azevedo; da Costa, Cintia Danieli Ferreira; Furtado, Fabiola Fialho; da-Cunha, Emídio Vasconcelos Leitão; Barbosa-Filho, José Maria; da Silva, Marcelo Sobral; de Medeiros, Isac Almeida

    2012-01-01

    The objective of the study was to investigate the mechanism of the relaxant activity of the ent-15α-acetoxykaur-16-en-19-oic acid (KA-acetoxy). In rat mesenteric artery rings, KA-acetoxy induced a concentration-dependent relaxation in vessels precontracted with phenylephrine. In the absence of endothelium, the vasorelaxation was significantly shifted to the right without reduction of the maximum effect. Endothelium-dependent relaxation was significantly attenuated by pretreatment with L-NAME, an inhibitor of the NO-synthase (NOS), indomethacin, an inhibitor of the cyclooxygenase, L-NAME + indomethacin, atropine, a nonselective antagonist of the muscarinic receptors, ODQ, selective inhibitor of the guanylyl cyclase enzyme, or hydroxocobalamin, a nitric oxide scavenger. The relaxation was completely reversed in the presence of L-NAME + 1 mM L-arginine or L-arginine, an NO precursor. Diterpene-induced relaxation was not affected by TEA, a nonselective inhibitor of K+ channels. The KA-acetoxy antagonized CaCl2-induced contractions in a concentration-dependent manner and also inhibited an 80 mM KCl-induced contraction. The KA-acetoxy did not interfere with Ca2+ release from intracellular stores. The vasorelaxant induced by KA-acetoxy seems to involve the inhibition of the Ca2+ influx and also, at least in part, by endothelial muscarinic receptors activation, NO and PGI2 release. PMID:23346202

  11. The ent-15α-Acetoxykaur-16-en-19-oic Acid Relaxes Rat Artery Mesenteric Superior via Endothelium-Dependent and Endothelium-Independent Mechanisms

    Directory of Open Access Journals (Sweden)

    Êurica Adélia Nogueira Ribeiro

    2012-01-01

    Full Text Available The objective of the study was to investigate the mechanism of the relaxant activity of the ent-15α-acetoxykaur-16-en-19-oic acid (KA-acetoxy. In rat mesenteric artery rings, KA-acetoxy induced a concentration-dependent relaxation in vessels precontracted with phenylephrine. In the absence of endothelium, the vasorelaxation was significantly shifted to the right without reduction of the maximum effect. Endothelium-dependent relaxation was significantly attenuated by pretreatment with L-NAME, an inhibitor of the NO-synthase (NOS, indomethacin, an inhibitor of the cyclooxygenase, L-NAME + indomethacin, atropine, a nonselective antagonist of the muscarinic receptors, ODQ, selective inhibitor of the guanylyl cyclase enzyme, or hydroxocobalamin, a nitric oxide scavenger. The relaxation was completely reversed in the presence of L-NAME + 1 mM L-arginine or L-arginine, an NO precursor. Diterpene-induced relaxation was not affected by TEA, a nonselective inhibitor of K+ channels. The KA-acetoxy antagonized CaCl2-induced contractions in a concentration-dependent manner and also inhibited an 80 mM KCl-induced contraction. The KA-acetoxy did not interfere with Ca2+ release from intracellular stores. The vasorelaxant induced by KA-acetoxy seems to involve the inhibition of the Ca2+ influx and also, at least in part, by endothelial muscarinic receptors activation, NO and PGI2 release.

  12. Drosophila lipophorin receptors mediate the uptake of neutral lipids in oocytes and imaginal disc cells by an endocytosis-independent mechanism.

    Directory of Open Access Journals (Sweden)

    Esmeralda Parra-Peralbo

    Full Text Available Lipids are constantly shuttled through the body to redistribute energy and metabolites between sites of absorption, storage, and catabolism in a complex homeostatic equilibrium. In Drosophila, lipids are transported through the hemolymph in the form of lipoprotein particles, known as lipophorins. The mechanisms by which cells interact with circulating lipophorins and acquire their lipidic cargo are poorly understood. We have found that lipophorin receptor 1 and 2 (lpr1 and lpr2, two partially redundant genes belonging to the Low Density Lipoprotein Receptor (LDLR family, are essential for the efficient uptake and accumulation of neutral lipids by oocytes and cells of the imaginal discs. Females lacking the lpr2 gene lay eggs with low lipid content and have reduced fertility, revealing a central role for lpr2 in mediating Drosophila vitellogenesis. lpr1 and lpr2 are transcribed into multiple isoforms. Interestingly, only a subset of these isoforms containing a particular LDLR type A module mediate neutral lipid uptake. Expression of these isoforms induces the extracellular stabilization of lipophorins. Furthermore, our data indicate that endocytosis of the lipophorin receptors is not required to mediate the uptake of neutral lipids. These findings suggest a model where lipophorin receptors promote the extracellular lipolysis of lipophorins. This model is reminiscent of the lipolytic processing of triglyceride-rich lipoproteins that occurs at the mammalian capillary endothelium, suggesting an ancient role for LDLR-like proteins in this process.

  13. Cathepsin G Induces Cell Aggregation of Human Breast Cancer MCF-7 Cells via a 2-Step Mechanism: Catalytic Site-Independent Binding to the Cell Surface and Enzymatic Activity-Dependent Induction of the Cell Aggregation

    Directory of Open Access Journals (Sweden)

    Riyo Morimoto-Kamata

    2012-01-01

    Full Text Available Neutrophils often invade various tumor tissues and affect tumor progression and metastasis. Cathepsin G (CG is a serine protease secreted from activated neutrophils. Previously, we have shown that CG induces the formation of E-cadherin-mediated multicellular spheroids of human breast cancer MCF-7 cells; however, the molecular mechanisms involved in this process are unknown. In this study, we investigated whether CG required its enzymatic activity to induce MCF-7 cell aggregation. The cell aggregation-inducing activity of CG was inhibited by pretreatment of CG with the serine protease inhibitors chymostatin and phenylmethylsulfonyl fluoride. In addition, an enzymatically inactive S195G (chymotrypsinogen numbering CG did not induce cell aggregation. Furthermore, CG specifically bound to the cell surface of MCF-7 cells via a catalytic site-independent mechanism because the binding was not affected by pretreatment of CG with serine protease inhibitors, and cell surface binding was also detected with S195G CG. Therefore, we propose that the CG-induced aggregation of MCF-7 cells occurs via a 2-step process, in which CG binds to the cell surface, independently of its catalytic site, and then induces cell aggregation, which is dependent on its enzymatic activity.

  14. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  15. 5-HT3 and 5-HT4 antagonists inhibit peristaltic contractions in guinea-pig distal colon by mechanisms independent of endogenous 5-HT

    Directory of Open Access Journals (Sweden)

    Tiong Cheng Sia

    2013-08-01

    Full Text Available Recent studies have shown that endogenous serotonin is not required for colonic peristalsis in vitro, nor gastrointestinal (GI transit in vivo. However, antagonists of 5-Hydroxytryptamine (5-HT receptors can inhibit peristalsis and GI-transit in mammals, including humans. This raises the question of how these antagonists inhibit GI-motility and transit, if depletion of endogenous 5-HT does not cause any significant inhibitory changes to either GI-motility or transit ? We investigated the mechanism by which 5-HT3 and 5-HT4 antagonists inhibit distension-evoked peristaltic contractions in guinea-pig distal colon. In control animals, repetitive peristaltic contractions of the circular muscle were evoked in response to fixed fecal pellet distension. Distension-evoked peristaltic contractions were unaffected in animals with mucosa and submucosal plexus removed, that were also treated with reserpine (to deplete neuronal 5-HT. In control animals, peristaltic contractions were blocked temporarily by ondansetron (1-10µM and SDZ-205-557 (1-10µM in many animals. Interestingly, after this temporary blockade, and whilst in the continued presence of these antagonists, peristaltic contractions recovered, with characteristics no different from controls. Surprisingly, similar effects were seen in mucosa-free preparations, which had no detectable 5-HT, as detected by mass spectrometry. In summary, distension-evoked peristaltic reflex contractions of the circular muscle layer of the guinea-pig colon can be inhibited temporarily, or permanently, in the same preparation by selective 5-HT3 and 5-HT4 antagonists, depending on the concentration of the antagonists applied. These effects also occur in preparations that lack any detectable 5-HT. We suggest caution should be exercised when interpreting the effects of 5-HT3 and 5-HT4 antagonists; and the role of endogenous 5-HT, in the generation of distension-evoked colonic peristalsis.

  16. 完善独立学院管理机制:宏观制度改革对策%Independent Institutes Management Mechanism Improvement:Countermeasure of Macro-Systems Reform

    Institute of Scientific and Technical Information of China (English)

    李国年; 马云珍; 肖昊

    2012-01-01

      独立学院管理机制是独立学院管理所依托的制度性结构及其构成方式。完善独立学院管理机制是办好独立学院的必然要求。当前,独立学院管理机制还存在一些问题,主要表现是决策主体错位和决策缺位、动力杠杆结构性缺失和约束缺失。这些问题之所以产生,其较深层的正式的宏观制度根源主要是现实高校产权制度和高等教育管理体制存在的弊端,其较隐蔽的非正式的宏观制度性根源主要是现实法治观念淡薄和“高等教育准公共产品论”造成的困境。因此,完善独立学院管理机制的相关宏观制度改革,在正式制度方面主要是建立现代独立学院产权制度和主体机制互补型高等教育管理体制;在非正式制度方面主要是优化法治环境和树立科学的高等教育产品观。%  Independent institutes management mechanism is the framework and the institutional structure on which Independent institutes management depends. It's an inevitable requirement for running Independent Institutes well to improve the management mechanism. At present, Independent institutes management mechanism still has some problems which have the main performance of decision-making mainstay misalign-ment and decision-making absence, power lever structural loss and constraint lack. The deeper-seated causes of these problems are the formal macro-institutional roots which mainly are the deficiencies of university property rights system and higher education managerial system, and the coverter informal macro-institutional roots which are difficult positions that caused by the realistic light conception of rule and higher education quasi-public products theory. Therefore, the relevant macro-system reform of improving Independent Institutes operating mechanism is to establish a complementary management system of modern university property rights system and mechanism of higher education subject

  17. Relaxation to bradykinin in bovine pulmonary supernumerary arteries can be mediated by both a nitric oxide-dependent and -independent mechanism

    Science.gov (United States)

    Tracey, A; Bunton, D; Irvine, J; MacDonald, A; Shaw, A M

    2002-01-01

    The aim of the present study was to determine the relative contribution of prostanoids, nitric oxide and K+ channels in the bradykinin-induced relaxation of bovine pulmonary supernumerary arteries. In endothelium-intact, but not denuded rings, bradykinin produced a concentration-dependent relaxation (pEC50, 9.6±0.1), which was unaffected by the cyclo-oxygenase inhibitor indomethacin. The nitric oxide scavenger hydroxocobalamin (200 μM, pEC50, 8.5±0.2) and the nitric oxide synthase inhibitor L-NAME (100 μM, pEC50, 8.9±0.1) and the combination of L-NAME and hydroxocobalamin (pEC50, 8.1±0.2) produced rightward shifts in the bradykinin concentration response curve. The guanylyl cyclase inhibitor ODQ (10 μM, pEC50, 9.6±0.4) did not affect the response to bradykinin. Elevating the extracellular [K+] to 30 mM did not affect the response to bradykinin but abolished the response when ODQ or L-NAME was present. The K+ channel blocker apamin (100 nM), combined with charybdotoxin (100 nM), produced a small reduction in the maximum response to bradykinin but they abolished the response to bradykinin when ODQ, L-NAME or hydroxocobalamin were present. Apamin (100 nM) combined with iberiotoxin (100 nM) also reduced the response to bradykinin in the presence of hydroxocobalamin or L-NAME. The concentration response curve for sodium nitroprusside-induced relaxation was abolished by ODQ (10 μM) and shifted to the right by apamin and charybdotoxin. These studies suggest that in bovine pulmonary supernumerary arteries bradykinin can stimulate the formation of nitric oxide and activate an EDHF-like mechanism and that either of these pathways alone can mediate the bradykinin-induced relaxation. In addition nitric oxide, acting through guanylyl cyclase, can activate an apamin/charbydotoxin-sensitive K+ channel in this tissue. PMID:12359636

  18. Independence and Product Systems

    OpenAIRE

    Skeide, Michael

    2003-01-01

    Starting from elementary considerations about independence and Markov processes in classical probability we arrive at the new concept of conditional monotone independence (or operator-valued monotone independence). With the help of product systems of Hilbert modules we show that monotone conditional independence arises naturally in dilation theory.

  19. Powerful Independent Directors

    OpenAIRE

    Kathy Fogel; Liping Ma; Randall Morck

    2014-01-01

    Shareholder valuations are economically and statistically positively correlated with independent directors’ power, gauged by social network power centrality. Powerful independent directors’ sudden deaths reduce shareholder value significantly; other independent directors’ deaths do not. More powerful independent directors Granger cause higher valuations; the converse is not true. Further tests associate more powerful independent directors with less value-destroying M&A, less free cash flow re...

  20. Central Bank independence

    OpenAIRE

    Vasile DEDU; Tiberiu STOICA

    2012-01-01

    In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR) has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disin...

  1. 复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙人工骨结合带血供组织修复羊大段骨缺损的试验研究%An experimental research of composite of BMP-2 and PLGA/tricalcium phosphate with vascularized ulna or vascularized periosteum in repairing large segmental defect of sheeps' radius

    Institute of Scientific and Technical Information of China (English)

    徐建强; 张树明; 周密; 李长庚

    2012-01-01

    Objective To study the effects of the composite of PLGA-TCP-BMP-2 artificial bone with vascularized ulna or vascularized periosteum in repairing the large segmental defect of sheep's radius. Methods Thirty millimeter defects were made in middle segments of sheep's radius and ulna. In group A, artificial bone with vascularized ulna were implanted into the radial defects. Artificial bone with vascularized periosteum were implanted into the radial defects in group B. Artificial bone were implanted into the radial defects in group C. No material was implanted in group D. Plates were used to fix the bone. X ray was used to evaluate the repairing effects. Animals were sacrificed 24 weeks after operation to make CT analysis and histological evaluation. Radiological and scoring histological systems were used to evaluate the plains. Results Twenty four weeks after surgery, radiological scoring systems revealed that group A was better than other groups. Evaluation of the morphologic features of the regenerating bone showed that active osteogenesis occurred at the site of bone defect and complete bony union was confirmed in animals of group A. In group B, corporation between new bone and fracture site could be seen. However, the lamellar bone was rather slim. In group C, new lamellar bone and lacuna were found in deranged alignment. In group D, deranged collagenous fibrous tissue, instead of osseointegration was found at the site of bone defect. Within the porous structure in animals of group A, B, and C, no residual artificial materials or muscle fibers were observed. According to histological scoring systems revealed that group A was better than other groups. Scores of group D was lower than other groups. Conclusion The composite of BMP-2 and PLGA/tricalcium phosphate with vascularized ulna or vascularized periosteum could repair large segmental defect of sheeps' radius satisfactorily.%目的 研究复合骨形态蛋白-2的聚乳酸-乙醇酸共聚物/磷酸三钙(PLGA-TCP-BMP

  2. 基于VbMoICA的机械故障盲源分离研究%Blind separation of mechanical fault sources based on variational Bayesian mixture of independent component analysers

    Institute of Scientific and Technical Information of China (English)

    岳秀廷; 李志农; 陈金刚

    2012-01-01

    用独立分量分析(ICA)分解和表示数据时,假设整个数据分布完全可以用一个坐标系来描述.然而,当观测数据是由许多自相似的、非高斯的流形组成时,则硬是用一个单独的、全局的表示是不合适的,这样会产生一个次优的表示.针对ICA在盲源分离中的不足,在变分贝叶斯理论的基础上提出了一种基于变分贝叶斯混合独立分量分析的机械故障源盲分离方法.该方法是考虑到源信号来自于多个坐标系,然后在多个坐标系下建立独立分量分析混合模型对观测信号进行学习分离.实验结果表明,本文提出的方法是非常有效的.%Decomposing and representing data using independent component analysers(ICA)assumes that the whole data distribution is adequately described by one coordinate frame.However,if the observed data consists of various self-similar,non-Gaussian manifolds, enforcing a single, global representation is not appropriate and will produce a sub-optimal representation.In order to make up the lack of independent component analyser in blind sources separations, blind separation of mechanical fault sources based on variational Bayesian mixture of independent component analysers is presented based on variational Bayesian theory in this paper.Conside.ring the source signals coming from multiple frames, the method creats a mixture model of independent component analysers in multiple frameworks for learning the observed signals and separating thenuThe experimental results show that the method proposed in this paper is very effective.

  3. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  4. Are Independent Fiscal Institutions Really Independent?

    Directory of Open Access Journals (Sweden)

    Slawomir Franek

    2015-08-01

    Full Text Available In the last decade the number of independent fiscal institutions (known also as fiscal councils has tripled. They play an important oversight role over fiscal policy-making in democratic societies, especially as they seek to restore public finance stability in the wake of the recent financial crisis. Although common functions of such institutions include a role in analysis of fiscal policy, forecasting, monitoring compliance with fiscal rules or costing of spending proposals, their roles, resources and structures vary considerably across countries. The aim of the article is to determine the degree of independence of such institutions based on the analysis of the independence index of independent fiscal institutions. The analysis of this index values may be useful to determine the relations between the degree of independence of fiscal councils and fiscal performance of particular countries. The data used to calculate the index values will be derived from European Commission and IMF, which collect sets of information about characteristics of activity of fiscal councils.

  5. Dependence and Independence

    OpenAIRE

    Grädel, E.; Väänänen, J.

    2010-01-01

    We introduce an atomic formula intuitively saying that given variables are independent from given other variables if a third set of variables is kept constant. We contrast this with dependence logic. We show that our independence atom gives rise to a natural logic capable of formalizing basic intuitions about independence and dependence.

  6. Central Bank independence

    Directory of Open Access Journals (Sweden)

    Vasile DEDU

    2012-08-01

    Full Text Available In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disinflation process, as headline inflation dropped inside the targeted band of 3% ± 1 percentage point recently.

  7. 浅析独立学院机械类毕业生就业现状及应对策略%Independent institute mechanical graduate employment status and coping strategies

    Institute of Scientific and Technical Information of China (English)

    任杨杨

    2015-01-01

    “就业乃民生之本”,大学生就业问题是当前政府、社会、高校等各方关注的焦点。独立学院人才培养方向多以应用型人才为主,突出学院自身特色与品牌建设,学生就业是根本亦是关键。本文从我校机械工程学院2012届至2014届毕业生就业现状出发,通过毕业生跟踪调查回访,探索提升机械专业毕业生就业质量的应对策略。%University students' employment problem is the current focus of the government, society and universities pay attention. Independent college personnel training direction mainly applied talents, highlight the characteristics of college itself and brand building, student employment is a fundamental also is the key. This article from the mechanical engineering college class of 2012 to 2014 graduate employment situation, followed by graduates pay a return visit, explore improving the quality of mechanical professional graduate employment coping strategies.

  8. Board independence and innovation

    OpenAIRE

    Coelho, Mariana Campos Carvalho

    2015-01-01

    Legislation introduced in the U.S. in 2002/2003 significantly changed board composition of public firms by imposing a 50% independent directors’ ratio. Research on the effect of independent directors is not consensual, implying that this exogenous shock is a unique opportunity to study their importance. This study answers the question of whether or not independent directors can effectively mitigate agency conflicts between shareholders and the management, having a positive impact on the choic...

  9. What is Stochastic Independence?

    OpenAIRE

    Franz, Uwe

    2002-01-01

    The notion of a tensor product with projections or with inclusions is defined. It is shown that the definition of stochastic independence relies on such a structure and that independence can be defined in an arbitrary category with a tensor product with inclusions or projections. In this context, the classifications of quantum stochastic independence by Muraki, Ben Ghorbal, and Sch\\"urmann become classifications of the tensor products with inclusions for the categories of algebraic probabilit...

  10. Gravity Independent Compressor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and demonstrate a small, gravity independent, vapor compression refrigeration system using a linear motor compressor which effectively...

  11. Study on Class Advisers' Role Positioning and Working Mechanism in Independent Colleges%独立学院班主任角色定位及工作机制探究

    Institute of Scientific and Technical Information of China (English)

    葛文霞

    2014-01-01

    班主任是高校教育的关键实施者之一,在学生成长成才的过程中占据特殊位置,发挥重要作用。本文着眼于独立学院的班主任工作问题,认为班主任同时肩负班级管理者、心理辅导者、学业指导者、生活帮助者以及人生导师五种角色,进而提出,学校管理者可以从四个方面入手实现班主任工作机制的高效运作,即加强班主任工作规范,建设高素质的班主任队伍,制定行之有效的评价体系,完善激励机制等。%The class adviser is one of the key implementers of education in colleges and universities, occupies a special po-sition and plays an important role in the process of students' growth. This article focuses on the work problems of class ad-visers in independent colleges. According to the article, class adviser should be a class manager, psychological mentor, aca-demic guider, life assistant and life coach at the same time. Further, the school managers can realize the efficient operation of the class advisers' working mechanism from four aspects, that is, strengthening the job specification, building a high-qual-ity teacher team, formulating an effective evaluation system, and improving the incentive mechanism.

  12. Regulation of the tumor marker Fascin by the viral oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) depends on promoter activation and on a promoter-independent mechanism.

    Science.gov (United States)

    Mohr, Caroline F; Gross, Christine; Bros, Matthias; Reske-Kunz, Angelika B; Biesinger, Brigitte; Thoma-Kress, Andrea K

    2015-11-01

    Adult T-cell leukemia/lymphoma is a highly infiltrative neoplasia of CD4(+) T-lymphocytes that occurs in about 5% of carriers infected with the deltaretrovirus human T-cell leukemia virus type 1 (HTLV-1). The viral oncoprotein Tax perturbs cellular signaling pathways leading to upregulation of host cell factors, amongst them the actin-bundling protein Fascin, an invasion marker of several types of cancer. However, transcriptional regulation of Fascin by Tax is poorly understood. In this study, we identified a triple mode of transcriptional induction of Fascin by Tax, which requires (1) NF-κB-dependent promoter activation, (2) a Tax-responsive region in the Fascin promoter, and (3) a promoter-independent mechanism sensitive to the Src family kinase inhibitor PP2. Thus, Tax regulates Fascin by a multitude of signals. Beyond, using Tax-expressing and virus-transformed lymphocytes as a model system, our study is the first to identify the invasion marker Fascin as a novel target of PP2, an inhibitor of metastasis.

  13. Role of CD18-dependent and CD18-independent mechanisms in the increased leukocyte adhesiveness and in the variations of circulating white blood cell populations induced by anti-CD3 monoclonal antibodies.

    Science.gov (United States)

    Kinnaert, P; Pradier, O; Bournonville, B; Habrant, C; Goldman, M; Van Geertruyden, N

    1996-01-01

    Anti-CD3 antibodies induce a quick and profound depletion of peripheral blood mononuclear cells (PBMCs) that is not well understood. We studied the effect of OKT3, a mouse monoclonal antibody against the human CD3 complex, on the in vitro adhesion of human PBMCs to monolayers of fresh and fixed human umbilical vein endothelial cells (HUVECs). OKT3 induced an increased adhesiveness of PBMCs. This phenomenon was blocked with anti-CD18 antibodies, indicating the participation of beta 2 integrins. As this increased adhesiveness could explain the lymphopenia by adhesion of PBMCs to endothelial cells and their sequestration in some peripheral vascular beds, we studied the effect of anti-CD18 antibodies in vivo on mice injected with 145/2C11, a hamster monoclonal antibody against murine CD3. Mice treated with 145/2C11 presented with a transient granulocytopenia and a sustained reduction in PBMCs. A monoclonal anti-CD18 antibody prevented the granulocytopenia but had no effect on the drop in PBMCs. Consequently, the in vivo depletion of PBMCs after administration of an anti-CD3 monoclonal antibody involves CD18-independent mechanisms, while the transient drop in polymorphonuclear cells appears to be CD18-dependent. PMID:8819275

  14. Independence of Internal Auditors.

    Science.gov (United States)

    Montondon, Lucille; Meixner, Wilda F.

    1993-01-01

    A survey of 288 college and university auditors investigated patterns in their appointment, reporting, and supervisory practices as indicators of independence and objectivity. Results indicate a weakness in the positioning of internal auditing within institutions, possibly compromising auditor independence. Because the auditing function is…

  15. Auditors and Independence

    OpenAIRE

    World Bank

    2006-01-01

    Independence is a concept of fundamental importance in business relations and corporate governance. It is above all crucial in auditing, which provides a guarantee of the integrity of the numbers on which an efficient allocation of capital within the capital market system depends. The job of auditors is to express an independent opinion on whether financial statements are reliable and cred...

  16. Fostering Musical Independence

    Science.gov (United States)

    Shieh, Eric; Allsup, Randall Everett

    2016-01-01

    Musical independence has always been an essential aim of musical instruction. But this objective can refer to everything from high levels of musical expertise to more student choice in the classroom. While most conceptualizations of musical independence emphasize the demonstration of knowledge and skills within particular music traditions, this…

  17. A Graph-Based Inference Method for Conditional Independence

    OpenAIRE

    Shachter, Ross D.

    2013-01-01

    The graphoid axioms for conditional independence, originally described by Dawid [1979], are fundamental to probabilistic reasoning [Pearl, 19881. Such axioms provide a mechanism for manipulating conditional independence assertions without resorting to their numerical definition. This paper explores a representation for independence statements using multiple undirected graphs and some simple graphical transformations. The independence statements derivable in this system are equivalent to those...

  18. On Background Independence

    OpenAIRE

    Anderson, Edward

    2013-01-01

    This paper concerns what Background Independence itself is (as opposed to some particular physical theory that is background independent). The notions presented mostly arose from a layer-by-layer analysis of the facets of the Problem of Time in Quantum Gravity. Part of this coincides with two relational postulates which are thus identified as classical precursors of two of the facets of the Problem of Time. These are furthemore tied to the forms of each of the GR Hamiltonian and momentum cons...

  19. 3,3'-Diindolylmethane (DIM) and its ring-substituted halogenated analogs (ring-DIMs) induce differential mechanisms of survival and death in androgen-dependent and -independent prostate cancer cells.

    Science.gov (United States)

    Goldberg, Alexander A; Draz, Hossam; Montes-Grajales, Diana; Olivero-Verbél, Jesus; Safe, Stephen H; Sanderson, J Thomas

    2015-05-01

    We recently reported that novel ring-substituted analogs of 3,3'-diindolylmethane (ring-DIMs) induce apoptosis and necrosis in androgen-dependent and -independent prostate cancer cells. In this paper, we have focused on the mechanism(s) associated with ring-DIM-mediated cell death, and on identifying the specific intracellular target(s) of these compounds. The 4,4'- and 7,7'-dichloroDIMs and 4,4'- and 7,7'-dibromoDIMs induced the death of LNCaP, C42B and DU145 prostate cancer cells, but not that of immortalized normal human prostate epithelial (RWPE-1) cells. Ring-DIMs caused the early loss of mitochondrial membrane potential (MMP) and decreased mitochondrial ATP generation in prostate cancer cells. Cyclosporin A, an inhibitor of the mitochondrial permeability transition pore, inhibited ring-DIM-mediated cell death, and salubrinal, an inhibitor of ER stress, inhibited cell death mediated only by 4,4'-dihaloDIMs. We found that although salubrinal did not inhibit the onset of ER stress, it prevented 4,4'-dibromoDIM mediated loss of MMP. Salubrinal potentiated cell death in response to 7,7'-dihaloDIMs and DIM, and this effect concurred with increased loss of MMP. Using in silico 3-D docking affinity analysis, we identified Ca2+/calmodulin-dependent kinase II (CaMKII) as a potential direct target for the most toxic ring-DIM, 4,4'-dibromoDIM. An inhibitor of CaMKII, KN93, but not its inactive analog KN92, abrogated cell death mediated by 4,4'-dibromoDIM. The ring-DIMs induced ER stress and autophagy, but these processes were not necessary for ring-DIM-mediated cell death. Inhibition of autophagy with bafilomycin A1, 3-methyladenine or by LC3B gene silencing sensitized LNCaP and C42B, but not ATG5-deficient DU145 cells to ring-DIM- and DIM-mediated cell death. We propose that autophagy induced by the ring-DIMs and DIM has a cytoprotective function in prostate cancer cells. PMID:26124925

  20. 3,3′-Diindolylmethane (DIM) and its ring-substituted halogenated analogs (ring-DIMs) induce differential mechanisms of survival and death in androgen-dependent and –independent prostate cancer cells

    Science.gov (United States)

    Montes-Grajales, Diana; Olivero-Verbél, Jesus; Safe, Stephen H.; Sanderson, J. Thomas

    2015-01-01

    We recently reported that novel ring-substituted analogs of 3,3′-diindolylmethane (ring-DIMs) induce apoptosis and necrosis in androgen-dependent and –independent prostate cancer cells. In this paper, we have focused on the mechanism(s) associated with ring-DIM-mediated cell death, and on identifying the specific intracellular target(s) of these compounds. The 4,4′- and 7,7′-dichloroDIMs and 4,4′- and 7,7′-dibromoDIMs induced the death of LNCaP, C42B and DU145 prostate cancer cells, but not that of immortalized normal human prostate epithelial (RWPE-1) cells. Ring-DIMs caused the early loss of mitochondrial membrane potential (MMP) and decreased mitochondrial ATP generation in prostate cancer cells. Cyclosporin A, an inhibitor of the mitochondrial permeability transition pore, inhibited ring-DIM-mediated cell death, and salubrinal, an inhibitor of ER stress, inhibited cell death mediated only by 4,4′-dihaloDIMs. We found that although salubrinal did not inhibit the onset of ER stress, it prevented 4,4′-dibromoDIM mediated loss of MMP. Salubrinal potentiated cell death in response to 7,7′-dihaloDIMs and DIM, and this effect concurred with increased loss of MMP. Using in silico 3-D docking affinity analysis, we identified Ca2+/calmodulin-dependent kinase II (CaMKII) as a potential direct target for the most toxic ring-DIM, 4,4′-dibromoDIM. An inhibitor of CaMKII, KN93, but not its inactive analog KN92, abrogated cell death mediated by 4,4′-dibromoDIM. The ring-DIMs induced ER stress and autophagy, but these processes were not necessary for ring-DIM-mediated cell death. Inhibition of autophagy with bafilomycin A1, 3-methyladenine or by LC3B gene silencing sensitized LNCaP and C42B, but not ATG5-deficient DU145 cells to ring-DIM- and DIM-mediated cell death. We propose that autophagy induced by the ring-DIMs and DIM has a cytoprotective function in prostate cancer cells. PMID:26124925

  1. Independent technical review, handbook

    International Nuclear Information System (INIS)

    Purpose Provide an independent engineering review of the major projects being funded by the Department of Energy, Office of Environmental Restoration and Waste Management. The independent engineering review will address questions of whether the engineering practice is sufficiently developed to a point where a major project can be executed without significant technical problems. The independent review will focus on questions related to: (1) Adequacy of development of the technical base of understanding; (2) Status of development and availability of technology among the various alternatives; (3) Status and availability of the industrial infrastructure to support project design, equipment fabrication, facility construction, and process and program/project operation; (4) Adequacy of the design effort to provide a sound foundation to support execution of project; (5) Ability of the organization to fully integrate the system, and direct, manage, and control the execution of a complex major project

  2. Independent technical review, handbook

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    Purpose Provide an independent engineering review of the major projects being funded by the Department of Energy, Office of Environmental Restoration and Waste Management. The independent engineering review will address questions of whether the engineering practice is sufficiently developed to a point where a major project can be executed without significant technical problems. The independent review will focus on questions related to: (1) Adequacy of development of the technical base of understanding; (2) Status of development and availability of technology among the various alternatives; (3) Status and availability of the industrial infrastructure to support project design, equipment fabrication, facility construction, and process and program/project operation; (4) Adequacy of the design effort to provide a sound foundation to support execution of project; (5) Ability of the organization to fully integrate the system, and direct, manage, and control the execution of a complex major project.

  3. Molecular mechanism of metal-independent decomposition of lipid hydroperoxide by the carcinogenic halogenated quinones%致癌性卤代醌介导的脂质氢过氧化物分解的分子机制

    Institute of Scientific and Technical Information of China (English)

    刘庆林; 覃浩; 黄春华; 刘蒲; 朱本占

    2014-01-01

    Halogenated quinones are a class of carcinogenic intermediates and newly identified chlorination disinfection byproducts in drinking water. 13-Hydroperoxy-9, 11-octadecadienoic acid (13-HPODE) is the most extensively studied endogenous lipid hydroperoxide. Although it is well known that the decomposition of 13-HPODE can be catalyzed by transition metal ions, it is not clear whether halogenated quinones could enhance its decomposition independent of metal ions, and if so, what are the unique characteristics and similarities? We found that halogenated quinones such as 2,5-dichloro-1,4-benzoquinone ( DCBQ) could markedly enhance the decomposition of 13-HPODE and formation of the reactive lipid alkyl radicals such as pentyl and 7-carboxyheptyl radicals, and the genotoxic 4-hydroxy-2-nonenal ( HNE ) , through the complementary application of ESR spin-trapping, HPLC-MS and GC-MS methods. Interestingly, two chloroquinone-lipid alkoxyl conjugates were also detected and identified from the reaction between DCBQ and 13-HPODE. We propose that the enhanced decomposition of the endogenous lipid hydroperoxide 13-HPODE by halogenated quinones and formation of reactive lipid alkyl radicals and genotoxic HNE is through a novel metal-independent nucelophilic substitution coupled with homolytic decomposition mechanism, which may partly explain their potential genotoxicity and carcinogenicity.%卤代醌是许多卤芳香持久有机污染物的致癌代谢产物和饮用水消毒副产物.13-过氧羟基-9,11-十八碳二烯酸(13-HPODE)是最为广泛研究的内源性脂质过氧化物.众所周知,过渡金属离子可以催化分解13-HPODE,但尚不清楚卤代醌是否可以通过不依赖金属离子的途径促进其分解;若是如此,又有什么特异性和相似性?我们发现卤化醌如2,5-二氯-1,4-苯醌( DCBQ)可显著促进13-HPODE的分解.综合采用电子自旋共振-自旋捕获、HPLC-MS和GC-MS等分析方法,可检测到反

  4. The Critical Independence Number and an Independence Decomposition

    CERN Document Server

    Larson, Craig Eric

    2009-01-01

    An independent set $I_c$ is a \\textit{critical independent set} if $|I_c| - |N(I_c)| \\geq |J| - |N(J)|$, for any independent set $J$. The \\textit{critical independence number} of a graph is the cardinality of a maximum critical independent set. This number is a lower bound for the independence number and can be computed in polynomial-time. Any graph can be decomposed into two subgraphs where the independence number of one subgraph equals its critical independence number, where the critical independence number of the other subgraph is zero, and where the sum of the independence numbers of the subgraphs is the independence number of the graph. A proof of a conjecture of Graffiti.pc yields a new characterization of K\\"{o}nig-Egervary graphs: these are exactly the graphs whose independence and critical independence numbers are equal.

  5. Distro’: Independent Creativity for Independent Industr

    Directory of Open Access Journals (Sweden)

    Wiwik Sri Wulandari

    2014-11-01

    Full Text Available To shortened this introduction, ‘Distro’ is one of cultural phenomenon in theyoung generation nowadays. The word of ‘Distro’ is the shortened of DistributionOutlet. The phenomenon of ‘Distro’ has been some kind of new trends inproducing and distributing creative design products of goods amongst theyoungsters independently, in an independence industry that open for challengingand competitiveness for everyone. This field research has been done in the city ofYogyakarta, reknown as the second city in creative design products after the cityof Bandung. Yogyakarta is welknown as the students’ city as well as the capital cityof culture of Indonesia. As a students’ city it is normal that Yogyakarta is growingin numbers of young people who pursued to study here and enriched the cultureof the city to become more multicultural and the varieties of pluralism as well.This sociocultural phenomenon not only brought some dynamic changing tosociety, economy and cultural life of the city, but also social problems that needsto be overcome. My first research question then is about how the existence of‘Distro’ in Yogyakarta can be a positive answer for social problems that may arisesfrom the hegemony of globalization markets domestically? My second questionis how the creative product designs are being made and distributed creatively inindependent industry? Lastly, my third question is dealling with the genres ofthe design products and how it can be a new trend in art expression? ‘Distro’ is aproduct of culture and it is also creating cultural change in some aspects of the lifeof the youngsters who are ‘Distro’ enthusiasts. ‘Distro’ phenomenon basically is anoffensive to the hegemony of internationally branded product design which turnsto become more over-dominated to the domestic markets and industry and thus,‘Distro’ has the spirit of survival whilts at the same time producing opportunity ofenterpreneurship

  6. Model-independent differences

    DEFF Research Database (Denmark)

    Könemann, Patrick

    2009-01-01

    is fundamentally different. This paper reports on our ongoing work on model-independent diffs, i.e. a diff that does not directly refer to the models it was created from. Based on that, we present an idea of how the diff could be generalized, e.g. many atomic diffs are merged to a new, generalized diff. One use...

  7. Independent safety organization

    International Nuclear Information System (INIS)

    Brookhaven National Laboratory has conducted a study on the need and feasibility of an independent organization to investigate significant safety events for the Office for Analysis and Evaluation of Operational Data, USNRC. The study consists of three parts: the need for an independent organization to investigate significant safety events, alternative organizations to conduct investigations, and legislative requirements. The determination of need was investigated by reviewing current NRC investigation practices, comparing aviation and nuclear industry practices, and interviewing a spectrum of representatives from the nuclear industry, the regulatory agency, and the public sector. The advantages and disadvantages of alternative independent organizations were studied, namely, an Office of Nuclear Safety headed by a director reporting to the Executive Director for Operations (EDO) of NRC; an Office of Nuclear Safety headed by a director reporting to the NRC Commissioners; a multi-member NTSB-type Nuclear Safety Board independent of the NRC. The costs associated with operating a Nuclear Safety Board were also included in the study. The legislative requirements, both new authority and changes to the existing NRC legislative authority, were studied. 134 references

  8. Model-Independent Diffs

    DEFF Research Database (Denmark)

    Könemann, Patrick

    just contain a list of strings, one for each line, whereas the structure of models is defined by their meta models. There are tools available which are able to compute the diff between two models, e.g. RSA or EMF Compare. However, their diff is not model-independent, i.e. it refers to the models...

  9. Independence, Disengagement, and Discipline

    Science.gov (United States)

    Rubin, Ron

    2012-01-01

    School disengagement is linked to a lack of opportunities for students to fulfill their needs for independence and self-determination. Young people have little say about what, when, where, and how they will learn, the criteria used to assess their success, and the content of school and classroom rules. Traditional behavior management discourages…

  10. Bayesian Independent Component Analysis

    DEFF Research Database (Denmark)

    Winther, Ole; Petersen, Kaare Brandt

    2007-01-01

    In this paper we present an empirical Bayesian framework for independent component analysis. The framework provides estimates of the sources, the mixing matrix and the noise parameters, and is flexible with respect to choice of source prior and the number of sources and sensors. Inside the engine...

  11. Order Independence and Rationalizability

    NARCIS (Netherlands)

    Apt, K.R.

    2005-01-01

    Two natural strategy elimination procedures have been studied for strategic games. The first one involves the notion of (strict, weak, etc) dominance and the second the notion of rationalizability. In the case of dominance the criterion of order independence allowed us to clarify which notions and u

  12. 新型羟基和醌碳自由基产生的分子机理%A Novel Mechanism for Metal-Independent Production of Hydroxyl Radicals and Carbon-Centered Quinone Ketoxy Radicals

    Institute of Scientific and Technical Information of China (English)

    朱本占; 覃浩; 黄春华

    2011-01-01

    The hydroxyl radical (·OH) has been considered to be one of the most reactive oxygen species produced in biological systems. It has been shown that ·OH can cause oxidative damage to DNA and other macromolecules. One of the most widely accepted mechanisms for ·OH production is through the transition metal-catalyzed Fenton reaction. Pentachlorophenol (PCP) has been widely used as a wood preservative. Using e-lectron spin resonance (ESR) secondary spin-trapping methods, we found that ·OH can be produced by H2O2 and tetrachloro-1,4-benzoquinone (TCBQ) (one of the major carcinogenic metabolites of PCP) independent of transition metal ions. Further studies showed that TCBQ, but not its corresponding semiquinone radical, the tetrachlorosemi-quinone radical, is essential for ·OH production. Based on these data, we propose that ·OH production by H2O2 and TCBQ is through the following novel mechanism: a nucle-ophilic attack of H2O2 to TCBQ, forming a trichloro-hydroperoxyl-1,4-benzoquinone intermediate, which decomposes homolytically to produce ·OH. Through complementary application of ESR spin-trapping and other methods, we also detected and identified, for the first time, a novel carbon-centered quinone ketoxy radical.%羟基自由基((’)OH)被公认是生物系统中最具活性的活性氧物种,能导致生物体内DNA等生物大分子氧化损伤.目前,最被广泛接受的(')OH的产生机理是过渡金属离子催化的Fenton反应.五氯酚(PCP)是一种重要的生物杀灭剂,主要用作木材保护.采用电子自旋共振二级自旋捕获等分析手段,发现H2O2和五氯酚的代谢产物之一四氯苯醌(TCBQ)能通过不依赖于金属离子的途径产生(')OH;进一步的研究发现是TCBQ,而非其相应的半醌自由基对(')OH的产生极其重要.基于这些数据和分析,提出以下新型(')OH产生分子机理:H2O2对TCBQ进行亲核攻击形成不稳定的三氯氢过氧基苯醌中间产物,其可均裂产生(')OH.综合采

  13. The Critical Independence Number and an Independence Decomposition

    OpenAIRE

    Larson, Craig Eric

    2009-01-01

    An independent set $I_c$ is a \\textit{critical independent set} if $|I_c| - |N(I_c)| \\geq |J| - |N(J)|$, for any independent set $J$. The \\textit{critical independence number} of a graph is the cardinality of a maximum critical independent set. This number is a lower bound for the independence number and can be computed in polynomial-time. Any graph can be decomposed into two subgraphs where the independence number of one subgraph equals its critical independence number, where the critical in...

  14. TO BE INDEPENDENT

    Institute of Scientific and Technical Information of China (English)

    石波

    2000-01-01

    @@ Ⅰ. Introduction At present, in the college, English extensive reading class, most students are not used to being independent. They always ask the teacher to explain the passages sentence by sentence and they need a lot of time to use the dictionary. Yet, we should take the responsibility for the students by making clear the difference between intensive and extensive reading. The traditional teaching approaches pays more attention to the teacher-centered way;the teacher always plays a monodrama, and the teacher dominates the class. The students are lack initiative. Some students do not know where they could start from, and the others are short of fast-reading skills, always fixing their eyes on one word or one sentence. Under the new situation and new thinking, students should learn to be more independent.

  15. Quantum independent increment processes

    CERN Document Server

    Franz, Uwe

    2005-01-01

    This volume is the first of two volumes containing the revised and completed notes lectures given at the school "Quantum Independent Increment Processes: Structure and Applications to Physics". This school was held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald during the period March 9 – 22, 2003, and supported by the Volkswagen Foundation. The school gave an introduction to current research on quantum independent increment processes aimed at graduate students and non-specialists working in classical and quantum probability, operator algebras, and mathematical physics. The present first volume contains the following lectures: "Lévy Processes in Euclidean Spaces and Groups" by David Applebaum, "Locally Compact Quantum Groups" by Johan Kustermans, "Quantum Stochastic Analysis" by J. Martin Lindsay, and "Dilations, Cocycles and Product Systems" by B.V. Rajarama Bhat.

  16. Quantum independent increment processes

    CERN Document Server

    Franz, Uwe

    2006-01-01

    This is the second of two volumes containing the revised and completed notes of lectures given at the school "Quantum Independent Increment Processes: Structure and Applications to Physics". This school was held at the Alfried-Krupp-Wissenschaftskolleg in Greifswald in March, 2003, and supported by the Volkswagen Foundation. The school gave an introduction to current research on quantum independent increment processes aimed at graduate students and non-specialists working in classical and quantum probability, operator algebras, and mathematical physics. The present second volume contains the following lectures: "Random Walks on Finite Quantum Groups" by Uwe Franz and Rolf Gohm, "Quantum Markov Processes and Applications in Physics" by Burkhard Kümmerer, Classical and Free Infinite Divisibility and Lévy Processes" by Ole E. Barndorff-Nielsen, Steen Thorbjornsen, and "Lévy Processes on Quantum Groups and Dual Groups" by Uwe Franz.

  17. Do Independent Expert Directors Matter?

    OpenAIRE

    Masulis, Ronald; Ruzzier, Christian; Xiao, Sheng; ZHAO, SHAN

    2012-01-01

    The generally weak correlation between board independence and firm performance is a major empirical puzzle. One possible explanation is that director independence alone is not enough. To explore this possibility, we examine the full employment histories of independent directors at S&P 1500 companies. We define an independent expert director (IED) as an independent director who has worked in the same 2-digit SIC industry as the company where he/she serves as an independent director. We show th...

  18. Conditional Independence in Uncertainty Theories

    OpenAIRE

    Shenoy, Prakash P.

    2013-01-01

    This paper introduces the notions of independence and conditional independence in valuation-based systems (VBS). VBS is an axiomatic framework capable of representing many different uncertainty calculi. We define independence and conditional independence in terms of factorization of the joint valuation. The definitions of independence and conditional independence in VBS generalize the corresponding definitions in probability theory. Our definitions apply not only to probability theory, but al...

  19. Board independence and competence

    OpenAIRE

    Wagner, Alexander F

    2011-01-01

    This paper analyzes board independence and competence as distinct, but inextricably linked aspects of board effectiveness. Competent directors add shareholder value because they have better information about the quality of projects. While a CEO cares about shareholder value, he also wants his board to behave loyally to him by agreeing to projects that give him private benefits. Because many aspects of the CEO-board relationship are not contractible, the paper studies a model of relational con...

  20. Granger Independent Martingale Processes

    OpenAIRE

    Cherubini, Umberto; Gobbi, Fabio; Mulinacci, Sabrina; Romagnoli, Silvia

    2016-01-01

    We introduce a new class of processes for the evaluation of multivariate equity derivatives. The proposed setting is well suited for the application of the standard copula function theory to processes, rather than variables, and easily enables to enforce the martingale pricing requirement. The martingale condition is imposed in a general multidimensional Markov setting to which we only add the restriction of no-Granger-causality of the increments (Granger-independent increments). We call this...

  1. International exploration by independents

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller U.S. independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. The problems of communications and logistics caused by different cultures and by geographic distances must be carefully evaluated. A mid-term to long-term strategy tailored to the goals and the financial capabilities of the company should be prepared and followed by a careful planning of the operations. This paper addresses some aspects of foreign exploration that should be considered before an independent venture into the foreign field. It also provides some guidelines for conducting successful overseas operations. When properly assessed, foreign exploration is well within the reach of smaller U.S. independents and presents no greater risk than domestic exploration; the rewards, however, can be much larger. Furthermore, the Oil and Gas Journal surveys of the 300 largest U.S. petroleum companies show that companies with a consistent foreign exploration policy have fared better financially during difficult times

  2. Independent sets in hypergraphs

    CERN Document Server

    Balogh, József; Samotij, Wojciech

    2012-01-01

    Many important theorems in combinatorics, such as Szemer\\'edi's theorem on arithmetic progressions and the Erd\\H{o}s-Stone Theorem in extremal graph theory, can be phrased as statements about independent sets in uniform hypergraphs. In recent years, an important trend in the area has been to extend such classical results to the so-called sparse random setting. This line of research culminated recently in the breakthroughs of Conlon and Gowers and of Schacht, who developed general tools for solving problems of this type. In this paper, we provide a third, completely different approach to proving extremal and structural results in sparse random sets. We give a structural characterization of the independent sets in a large class of uniform hypergraphs by showing that every independent set is almost contained in one of a small number of relatively sparse sets. We then derive many interesting results as fairly straightforward consequences of this abstract theorem. In particular, we prove the well-known conjecture ...

  3. International exploration by independent

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller U.S. independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. Foreign finding costs per barrel usually are accepted to be substantially lower than domestic costs because of the large reserve potential of international plays. To get involved in overseas exploration, however, requires the explorationist to adapt to different cultural, financial, legal, operational, and political conditions. Generally, foreign exploration proceeds at a slower pace than domestic exploration because concessions are granted by a country's government, or are explored in partnership with a national oil company. First, the explorationist must prepare a mid- to long-term strategy, tailored to the goals and the financial capabilities of the company; next, is an ongoing evaluation of quality prospects in various sedimentary basins, and careful planning and conduct of the operations. To successfully explore overseas also requires the presence of a minimum number of explorationists and engineers thoroughly familiar with the various exploratory and operational aspects of foreign work. Ideally, these team members will have had a considerable amount of on-site experience in various countries and climates. Independents best suited for foreign expansion are those who have been financially successful in domestic exploration. When properly approached, foreign exploration is well within the reach of smaller U.S. independents, and presents essentially no greater risk than domestic exploration; however, the reward can be much larger and can catapult the company into the 'big leagues.'

  4. International exploration by independents

    International Nuclear Information System (INIS)

    Recent industry trends indicate that the smaller US independents are looking at foreign exploration opportunities as one of the alternatives for growth in the new age of exploration. It is usually accepted that foreign finding costs per barrel are substantially lower than domestic because of the large reserve potential of international plays. To get involved overseas requires, however, an adaptation to different cultural, financial, legal, operational, and political conditions. Generally foreign exploration proceeds at a slower pace than domestic because concessions are granted by the government, or are explored in partnership with the national oil company. First, a mid- to long-term strategy, tailored to the goals and the financial capabilities of the company, must be prepared; it must be followed by an ongoing evaluation of quality prospects in various sedimentary basins, and a careful planning and conduct of the operations. To successfully explore overseas also requires the presence on the team of a minimum number of explorationists and engineers thoroughly familiar with the various exploratory and operational aspects of foreign work, having had a considerable amount of onsite experience in various geographical and climatic environments. Independents that are best suited for foreign expansion are those that have been financially successful domestically, and have a good discovery track record. When properly approached foreign exploration is well within the reach of smaller US independents and presents essentially no greater risk than domestic exploration; the reward, however, can be much larger and can catapult the company into the big leagues

  5. Breast cancer oestrogen independence mediated by BCAR1 or BCAR3 genes is transmitted through mechanisms distinct from the oestrogen receptor signalling pathway or the epidermal growth factor receptor signalling pathway.

    NARCIS (Netherlands)

    L.C.J. Dorssers (Lambert); A. Brinkman (Arend); J. Veldscholte (Jos); M. Smid (Marcel); K.J. Dechering (Koen); A.J. van Agthoven (Ton)

    2005-01-01

    textabstractINTRODUCTION: Tamoxifen is effective for endocrine treatment of oestrogen receptor-positive breast cancers but ultimately fails due to the development of resistance. A functional screen in human breast cancer cells identified two BCAR genes causing oestrogen-independent proliferation. Th

  6. Extending Bell's Theorem: Ruling out Paramater Independent Hidden Variable Theories

    Science.gov (United States)

    Leegwater, G. J.

    2016-03-01

    Bell's Theorem may well be the best known result in the foundations of quantum mechanics. Here, it is presented as stating that for any hidden variable theory the combination of the conditions Parameter Independence, Outcome Independence, Source Independence and Compatibility with Quantum Theory leads to a contradiction. Based on work by Roger Colbeck and Renato Renner, an extension of Bell's Theorem is considered. In this extension the theorem is strengthened by replacing Outcome Independence by a strictly weaker condition.

  7. Independence in appearance

    DEFF Research Database (Denmark)

    Warming-Rasmussen, Bent; Quick, Reiner; Liempd, Dennis van

    2011-01-01

    article presents research contributions to the question whether the auditor is to continue to provide both audit and non-audit services (NAS) to an audit client. Research results show that this double function for the same audit client is a problem for stakeholders' confidence in auditor independence....... The green Paper proposes that a solution could be to prohibit NAS to audit clients. Research results indicate alternative possibilitiers: e.g. banning the most harmful non-audit services and / or limiting the relative share of fees from NAS...

  8. The importance of board independence

    NARCIS (Netherlands)

    Zijl, N.J.M.

    2012-01-01

    Although the attributed importance of board independence is high, a clear definition of independence does not exist. Furthermore, the aim and consequences of independence are the subject of discussion and empirical evidence about the impact of independence is weak and disputable. Despite this lack o

  9. [EFFICIENCY OF COMBINATION OF ROFLUMILAST AND QUERCETIN FOR CORRECTION OXYGEN- INDEPENDENT MECHANISMS AND PHAGOCYTIC ACTIVITY OF MACROPHAGE CELLS OF PATIENTS WITH ACUTE EXACERBATION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE WHEN COMBINED WITH CORONARY HEART