Key Specifications Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|R||ELISA, ICC, IH(P), RIA||Rb||Affinity Purified||Polyclonal Antibody|
|Presentation||Purified rabbit polyclonal. Contains no preservative.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Stable for 1 year at -20ºC from date of receipt.|
|Material Size||100 µg|
|Anti-Rat Collagen Type I - 2446738||2446738|
|Anti-Rat Collagen Type I - 1986132||1986132|
|Anti-Rat Collagen Type I - 2208759||2208759|
|Anti-Rat Collagen Type I - JC1618207||JC1618207|
|Anti-Rat Collagen Type I - JC1666024||JC1666024|
|Anti-Rat Collagen Type I - LV1555183||LV1555183|
|Anti-Rat Collagen Type I - LV1573176||LV1573176|
|Anti-Rat Collagen Type I - NG1734297||NG1734297|
|Anti-Rat Collagen Type I - NG1780721||NG1780721|
|Anti-Rat Collagen Type I - NG1925914||NG1925914|
|Anti-Rat Collagen Type I -2528756||2528756|
|Anti-Rat Collagen Type I -2659195||2659195|
|Anti-Rat Collagen Type I -2722829||2722829|
|Anti-Rat Collagen Type I -2728434||2728434|
|Anti-Rat Collagen Type I -2764015||2764015|
References | 23 Available | See All References
|Reference overview||Application||Species||Pub Med ID|
|An Autologous Muscle Tissue Expansion Approach for the Treatment of Volumetric Muscle Loss. |
Ward, CL; Ji, L; Corona, BT
BioResearch open access 4 198-208 2015
Volumetric muscle loss (VML) is a hallmark of orthopedic trauma with no current standard of care. As a potential therapy for some VML indications, autologous minced muscle grafts (1 mm(3) pieces of muscle) are effective in promoting remarkable de novo fiber regeneration. But they require ample donor muscle tissue and therefore may be limited in their application for large clinical VML. Here, we tested the hypothesis that autologous minced grafts may be volume expanded in a collagen hydrogel, allowing for the use of lesser autologous muscle while maintaining regenerative and functional efficacy. The results of the study indicate that 50% (but not 75%) less minced graft tissue suspended in a collagen hydrogel promoted a functional improvement similar to that of a 100% minced graft repair. However, approximately half of the number of fibers regenerated de novo with 50% graft repair. Moreover, the fibers that regenerated had a smaller cross-sectional area. These findings support the concept of using autologous minced grafts for the regeneration of muscle tissue after VML, but indicate the need to identify optimal carrier materials for expansion.
|Heterogeneity in arterial remodeling among sublines of spontaneously hypertensive rats. |
Bakker, EN; Groma, G; Spijkers, LJ; de Vos, J; van Weert, A; van Veen, H; Everts, V; Arribas, SM; VanBavel, E
PloS one 9 e107998 2014
Spontaneously hypertensive rats (SHR) have been used frequently as a model for human essential hypertension. However, both the SHR and its normotensive control, the Wistar Kyoto rat (WKY), consist of genetically different sublines. We tested the hypothesis that the pathophysiology of vascular remodeling in hypertension differs among rat sublines.We studied mesenteric resistance arteries of WKY and SHR from three different sources, at 6 weeks and 5 months of age. Sublines of WKY and SHR showed differences in blood pressure, body weight, vascular remodeling, endothelial function, and vessel ultrastructure. Common features in small mesenteric arteries from SHR were an increase in wall thickness, wall-to-lumen ratio, and internal elastic lamina thickness.Endothelial dysfunction, vascular stiffening, and inward remodeling of small mesenteric arteries are not common features of hypertension, but are subline-dependent. Differences in genetic background associate with different types of vascular remodeling in hypertensive rats.
|Autologous minced muscle grafts: a tissue engineering therapy for the volumetric loss of skeletal muscle. |
Corona, BT; Garg, K; Ward, CL; McDaniel, JS; Walters, TJ; Rathbone, CR
American journal of physiology. Cell physiology 305 C761-75 2013
Volumetric muscle loss (VML) results in a large void deficient in the requisite materials for regeneration for which there is no definitive clinical standard of care. Autologous minced muscle grafts (MG), which contain the essential components for muscle regeneration, may embody an ideal tissue engineering therapy for VML. The purpose of this study was to determine if orthotopic transplantation of MG acutely after VML in the tibialis anterior muscle of male Lewis rats promotes functional tissue regeneration. Herein we report that over the first 16 wk postinjury, MG transplantation 1) promotes remarkable regeneration of innervated muscle fibers within the defect area (i.e., de novo muscle fiber regeneration); 2) reduced evidence of chronic injury in the remaining muscle mass compared with nonrepaired muscles following VML (i.e., transplantation attenuated chronically upregulated transforming growth factor-β1 gene expression and the presence of centrally located nuclei in 30% of fibers observed in nonrepaired muscles); and 3) significantly improves net torque production (i.e., ∼55% of the functional deficit in nonrepaired muscles was restored). Additionally, voluntary wheel running was shown to reduce the heightened accumulation of extracellular matrix deposition observed within the regenerated tissue of MG-repaired sedentary rats 8 wk postinjury (collagen 1% area: sedentary vs. runner, ∼41 vs. 30%), which may have been the result of an augmented inflammatory response [i.e., M1 (CCR7) and M2 (CD163) macrophage expression was significantly greater in runner than sedentary MG-repaired muscles 2 wk postinjury]. These findings support further exploration of autologous minced MGs for the treatment of VML.
|Cessation of epithelial Bmp signaling switches the differentiation of crown epithelia to the root lineage in a β-catenin-dependent manner. |
Yang, Z; Hai, B; Qin, L; Ti, X; Shangguan, L; Zhao, Y; Wiggins, L; Liu, Y; Feng, JQ; Chang, JY; Wang, F; Liu, F
Molecular and cellular biology 33 4732-44 2013
The differentiation of dental epithelia into enamel-producing ameloblasts or the root epithelial lineage compartmentalizes teeth into crowns and roots. Bmp signaling has been linked to enamel formation, but its role in root epithelial lineage differentiation is unclear. Here we show that cessation of epithelial Bmp signaling by Bmpr1a depletion during the differentiation stage switched differentiation of crown epithelia into the root lineage and led to formation of ectopic cementum-like structures. This phenotype is related to the upregulation of Wnt/β-catenin signaling and epithelial-mesenchymal transition (EMT). Although epithelial β-catenin depletion during the differentiation stage also led to variable enamel defect and precocious/ectopic formation of fragmented root epithelia in some teeth, it did not cause ectopic cementogenesis and inhibited EMT in cultured dental epithelia. Concomitant epithelial β-catenin depletion rescued EMT and ectopic cementogenesis caused by Bmpr1a depletion. These data suggested that Bmp and Wnt/β-catenin pathways interact antagonistically in dental epithelia to regulate the root lineage differentiation and EMT. These findings will aid in the design of new strategies to promote functional differentiation in the regeneration and tissue engineering of teeth and will provide new insights into the dynamic interactions between the Bmp and Wnt/β-catenin pathways during cell fate decisions.
|A standardized rat model of volumetric muscle loss injury for the development of tissue engineering therapies. |
Wu, X; Corona, BT; Chen, X; Walters, TJ
BioResearch open access 1 280-90 2012
Soft tissue injuries involving volumetric muscle loss (VML) are defined as the traumatic or surgical loss of skeletal muscle with resultant functional impairment and represent a challenging clinical problem for both military and civilian medicine. In response, a variety of tissue engineering and regenerative medicine treatments are under preclinical development. A wide variety of animal models are being used, all with critical limitations. The objective of this study was to develop a model of VML that was reproducible and technically uncomplicated to provide a standardized platform for the development of tissue engineering and regenerative medicine solutions to VML repair. A rat model of VML involving excision of ∼20% of the muscle's mass from the superficial portion of the middle third of the tibialis anterior (TA) muscle was developed and was functionally characterized. The contralateral TA muscle served as the uninjured control. Additionally, uninjured age-matched control rats were also tested to determine the effect of VML on the contralateral limb. TA muscles were assessed at 2 and 4 months postinjury. VML muscles weighed 22.7% and 19.5% less than contralateral muscles at 2 and 4 months postinjury, respectively. These differences were accompanied by a reduction in peak isometric tetanic force (Po) of 28.4% and 32.5% at 2 and 4 months. Importantly, Po corrected for differences in body weight and muscle wet weights were similar between contralateral and age-matched control muscles, indicating that VML did not have a significant impact on the contralateral limb. Lastly, repair of the injury with a biological scaffold resulted in rapid vascularization and integration with the wound. The technical simplicity, reliability, and clinical relevance of the VML model developed in this study make it ideal as a standard model for the development of tissue engineering solutions for VML.
|Intra-articular changes precede extra-articular changes in the biceps tendon after rotator cuff tears in a rat model. |
Cathryn D Peltz,Jason E Hsu,Miltiadis H Zgonis,Nicholas A Trasolini,David L Glaser,Louis J Soslowsky
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 21 2012
Biceps tendon pathology is common with rotator cuff tears. The mechanisms for biceps changes, and therefore its optimal treatment, are unknown. Our objective was to determine the effect of rotator cuff tears on regional biceps tendon pathology. We hypothesized that histologic and compositional changes would appear before organizational changes, both would appear before mechanical changes, and changes would begin at the tendon's insertion site.
|Induction of osteogenic differentiation of adipose derived stem cells by microstructured nitinol actuator-mediated mechanical stress. |
Strauß, S; Dudziak, S; Hagemann, R; Barcikowski, S; Fliess, M; Israelowitz, M; Kracht, D; Kuhbier, JW; Radtke, C; Reimers, K; Vogt, PM
PloS one 7 e51264 2012
The development of large tissue engineered bone remains a challenge in vitro, therefore the use of hybrid-implants might offer a bridge between tissue engineering and dense metal or ceramic implants. Especially the combination of the pseudoelastic implant material Nitinol (NiTi) with adipose derived stem cells (ASCs) opens new opportunities, as ASCs are able to differentiate osteogenically and therefore enhance osseointegration of implants. Due to limited knowledge about the effects of NiTi-structures manufactured by selective laser melting (SLM) on ASCs the study started with an evaluation of cytocompatibility followed by the investigation of the use of SLM-generated 3-dimensional NiTi-structures preseeded with ASCs as osteoimplant model. In this study we could demonstrate for the first time that osteogenic differentiation of ASCs can be induced by implant-mediated mechanical stimulation without support of osteogenic cell culture media. By use of an innovative implant design and synthesis via SLM-technique we achieved high rates of vital cells, proper osteogenic differentiation and mechanically loadable NiTi-scaffolds could be achieved.
|Structural and functional analysis of intra-articular interzone tissue in axolotl salamanders. |
Cosden-Decker, RS; Bickett, MM; Lattermann, C; MacLeod, JN
Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society 20 1347-56 2012
Knowledge of mechanisms directing diarthrodial joint development may be useful in understanding joint pathologies and identifying new therapies. We have previously established that axolotl salamanders can fully repair large articular cartilage lesions, which may be due to the presence of an interzone-like tissue in the intra-articular space. Study objectives were to further characterize axolotl diarthrodial joint structure and determine the differentiation potential of interzone-like tissue in a skeletal microenvironment.Diarthrodial joint morphology and expression of aggrecan, brother of CDO (BOC), type I collagen, type II collagen, and growth/differentiation factor 5 (GDF5) were examined in femorotibial joints of sexually mature (greater than 12 months) axolotls. Joint tissue cellularity was evaluated in individuals from 2 to 24 months of age. Chondrogenic potential of the interzone was evaluated by placing interzone-like tissue into 4 mm tibial defects.Cavitation reached completion in the femoroacetabular and humeroradial joints, but an interzone-like tissue was retained in the intra-articular space of distal limb joints. Joint tissue cellularity decreased to 7 months of age and then remained stable. Gene expression patterns of joint markers are broadly similar in developing mammals and mature axolotls. When interzone-like tissue was transplanted into critical size skeletal defects, an accessory joint developed within the defect site.These experiments indicate that mature axolotl diarthrodial joints are phenotypically similar to developing synovial joints in mammals. Generation of an accessory joint by interzone-like tissue suggests multipotent cellular differentiation potential similar to that of interzone cells in the mammalian fetus. The data support the axolotl as a novel vertebrate model for joint development and repair.
|Biceps tendon properties worsen initially but improve over time following rotator cuff tears in a rat model. |
Peltz CD, Hsu JE, Zgonis MH, Trasolini NA, Glaser DL, Soslowsky LJ.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society 29 874-9 2011
Damage to the biceps tendon is often seen in conjunction with rotator cuff tears. However, controversy exists regarding its role in the shoulder and its optimal treatment. A previous study determined that biceps tendons were detrimentally affected in the presence of rotator cuff tears in the rat model and this damage worsened over time. However, whether this damage progresses at later time points to provide a chronic model is unknown. The objective of this study was to determine the changes in the biceps tendon in the presence of a cuff tear over time. Our hypothesis was that histological, compositional, organizational, and mechanical properties would worsen with time. We detached the supraspinatus and infraspinatus tendons of 48 rats and evaluated these properties at 1, 4, 8, and 16 weeks postdetachment. Properties worsened through 8 weeks, but improved between 8 and 16 weeks. We therefore conclude that biceps tendon changes in this model are not truly chronic. Additionally, it has been shown that infraspinatus properties in this model return to normal by 16 weeks, when biceps properties improve, indicating that earlier repair of one or more of the rotator cuff tendons may lead to resolved pathology of the long head of the biceps tendon. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:874-879.
|Intrinsic repair of full-thickness articular cartilage defects in the axolotl salamander. |
R S Cosden,C Lattermann,S Romine,J Gao,S R Voss,J N MacLeod
Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society 19 2011
The ability to fully regenerate lost limbs has made the axolotl salamander (Ambystoma mexicanum) a valuable model for studies of tissue regeneration. The current experiments investigate the ability of these vertebrates to repair large articular cartilage defects and restore normal hyaline cartilage and joint structure independent of limb amputation.
|Matrix metalloproteinase-8 overexpression prevents proper tissue repair. |
Patricia L Danielsen,Anders V Holst,Henrik R Maltesen,Maria R Bassi,Peter J Holst,Katja M Heinemeier,Jørgen Olsen,Carl C Danielsen,Steen S Poulsen,Lars N Jorgensen,Magnus S Agren
Surgery 150 2011
The collagenolytic matrix metalloproteinase-8 (MMP-8) is essential for normal tissue repair but is often overexpressed in wounds with disrupted healing. Our aim was to study the impact of a local excess of this neutrophil-derived proteinase on wound healing using recombinant adenovirus-driven transduction of full-length Mmp8 (AdMMP-8).
|Cell-derived matrix enhances osteogenic properties of hydroxyapatite. |
Gregory Tour,Mikael Wendel,Ion Tcacencu
Tissue engineering. Part A 17 2011
The study aimed to evaluate osteogenic properties of hydroxyapatite (HA) scaffold combined with extracellular matrix (ECM) derived in vitro from rat primary calvarial osteoblasts or dermal fibroblasts. The cellular viability, and the ECM deposited onto synthetic HA microparticles were assessed by MTT, Glycosaminoglycan, and Hydroxyproline assays as well as immunohistochemistry and scanning electron microscopy after 21 days of culture. The decellularized HA-ECM constructs were implanted in critical-sized calvarial defects of Sprague-Dawley rats, followed by bone repair and local inflammatory response assessments by histomorphometry and immunohistochemistry at 12 weeks postoperatively. We demonstrated that HA supported cellular adhesion, growth, and ECM production in vitro, and the HA-ECM constructs significantly enhanced calvarial bone repair (p<0.05, Mann-Whitney U-test), compared with HA alone, despite the significantly increased number of CD68+ macrophages, and foreign body giant cells (p<0.05, Mann-Whitney U-test). Selective accumulation of bone sialoprotein, osteopontin, and periostin was observed at the tissue-HA interfaces. In conclusion, in vitro-derived ECM mimics the native bone matrix, enhances the osteogenic properties of the HA microparticles, and might modulate the local inflammatory response in a bone repair-favorable way. Our findings highlight the ability to produce functional HA-ECM constructs for bone tissue engineering applications.
|CCN3/CCN2 regulation and the fibrosis of diabetic renal disease. |
Riser BL, Najmabadi F, Perbal B, Rambow JA, Riser ML, Sukowski E, Yeger H, Riser SC, Peterson DR
Journal of cell communication and signaling 4 39-50 2010
Prior work in the CCN field, including our own, suggested to us that there might be co-regulatory activity and function as part of the actions of this family of cysteine rich cytokines. CCN2 is now regarded as a major pro-fibrotic molecule acting both down-stream and independent of TGF-beta1, and appears causal in the disease afflicting multiple organs. Since diabetic renal fibrosis is a common complication of diabetes, and a major cause of end stage renal disease (ESRD), we examined the possibility that CCN3 (NOV), might act as an endogenous negative regulator of CCN2 with the capacity to limit the overproduction of extracellular matrix (ECM), and thus prevent, or ameliorate fibrosis. We demonstrate, using an in vitro model of diabetic renal fibrosis, that both exogenous treatment with CCN3 and transfection with the over-expression of the CCN3 gene in mesangial cells markedly down-regulates CCN2 activity and blocks ECM over-accumulation stimulated by TGF-beta1. Conversely, TGF-beta1 treatment reduces endogenous CCN3 expression and increases CCN2 activity and matrix accumulation, indicating an important, novel yin/yang effect. Using the db/db mouse model of diabetic nephropathy, we confirm the expression of CCN3 in the kidney, with temporal localization that supports these in vitro findings. In summary, the results corroborate our hypothesis that one function of CCN3 is to regulate CCN2 activity and at the concentrations and conditions used down-regulates the effects of TGF-beta1, acting to limit ECM turnover and fibrosis in vivo. The findings suggest opportunities for novel endogenous-based therapy either by the administration, or the upregulation of CCN3.Full Text Article
|Periostin promotes a fibroblastic lineage pathway in atrioventricular valve progenitor cells. |
Norris, RA; Potts, JD; Yost, MJ; Junor, L; Brooks, T; Tan, H; Hoffman, S; Hart, MM; Kern, MJ; Damon, B; Markwald, RR; Goodwin, RL
Developmental dynamics : an official publication of the American Association of Anatomists 238 1052-63 2009
Differentiation of prevalvular mesenchyme into valve fibroblasts is an integral step towards the development of functionally mature cardiac valves. Although clinically relevant, little is known regarding the molecular and cellular mechanisms by which this process proceeds. Genes that are regulated in a spatio-temporal pattern during valve remodeling are candidates for affecting this differentiation process. Based on its expression pattern, we have focused our studies on the role of the matricellular gene, periostin, in regulating the differentiation of cushion mesenchymal cells into valve fibroblasts. Herein, we demonstrate that periostin expression is coincident with and regulates type I collagen protein production, a major component of mature valve tissue. Adenoviral-mediated knock-down of periostin in atrioventricular mesenchyme resulted in a decrease in collagen I protein expression and aberrant induction of myocyte markers indicating an alteration in AV mesenchyme differentiation. In vitro analyses using a novel "cardiotube" assay further demonstrated that expression of periostin regulates lineage commitment of valve precursor cells. In these cells, expression of periostin and collagen I are regulated, in part, by TGFbeta-3. We further demonstrate that TGFbeta-3, through a periostin/collagen pathway, enhances the viscoelastic properties of AV cushion tissue surface tension and plays a crucial role in regulating valve remodeling. Thus, data presented here demonstrate that periostin, a TGFbeta-3 responsive gene, functions as a crucial mediator of chick AV valve maturation via promoting mesenchymal-to-fibroblast differentiation while blocking differentiation of alternative cell types (myocytes).
|Urotensin II modulates hepatic fibrosis and portal hemodynamic alterations in rats. |
Kemp W, Kompa A, Phrommintikul A, Herath C, Zhiyuan J, Angus P, McLean C, Roberts S, Krum H
American journal of physiology. Gastrointestinal and liver physiology 297 G762-7 2009
The influence of circulating urotensin II (UII) on liver disease and portal hypertension is unknown. We aimed to evaluate whether UII executes a pathogenetic role in the development of hepatic fibrosis and portal hypertension. UII was administered by continuous infusion over 4 wk in 20 healthy rats divided into three treatment groups, controls (saline, n = 7), low dose (UII, 1 nmol.kg(-1).h(-1), n = 8), and high dose (UII, 3 nmol.kg(-1).h(-1), n = 5). Hemodynamic parameters and morphometric quantification of fibrosis were assessed, and profibrotic cytokines and fibrosis markers were assayed in hepatic tissue. UII induced a significant dose-dependent increase in portal venous pressure (5.8 +/- 0.4, 6.4 +/- 0.3, and 7.6 +/- 0.7, respectively, P = 0.03). High-dose UII infusion was associated with an increase in hepatic transcript for transforming growth factor-beta (P 0.05) and platelet-derived growth factor-beta (P = 0.06). Liver tissue hydroxyproline was elevated in the high-dose group (P 0.05). No systemic hemodynamic alterations were noted. We concluded that UII infusion elevates portal pressure and induces hepatic fibrosis in normal rats. This response-05-be mediated via induction of fibrogenic cytokines. These findings have pathophysiological implications in human liver disease where increased plasma UII levels have been observed.
|Partial hepatectomy-induced regeneration accelerates reversion of liver fibrosis involving participation of hepatic stellate cells. |
Suárez-Cuenca, Juan A, et al.
Exp. Biol. Med. (Maywood), 233: 827-39 (2008) 2008
Hepatic fibrosis underlies most types of chronic liver diseases and is characterized by excessive deposition of extracellular matrix (ECM), altered liver architecture, and impaired hepatocyte proliferation; however, the fibrotic liver can still regenerate after partial hepatectomy (PH). Therefore, the present study was aimed at addressing whether a PH-induced regeneration normalizes ECM turnover and the possible involvement of hepatic stellate cells (HSC) during resolution of a pre-established fibrosis. Male Wistar rats were rendered fibrotic by intraperitoneal administration of swine serum for 9 weeks and subjected afterwards to 70% PH or sham-operation. Histological and morphometric analyses were performed, and parameters indicative of cell proliferation, collagen synthesis and degradation, and activation of HSC were determined. Liver collagen content was reduced to 75% after PH in cirrhotic rats when compared with sham-operated cirrhotic rats. The regenerating fibrotic liver oxidized actively free proline and had diminished transcripts for alpha-1 (I) collagen mRNA, resulting in decreased collagen synthesis. PH also increased collagenase activity, accounted for by higher amounts of pro-MMP-9, MMP-2, and MMP-13, which largely coincided with a lower expression of TIMP-1 and TIMP-2. Therefore, an early decreased collagen synthesis, mild ECM degradation, and active liver regeneration were followed by higher collagenolysis and limited deposition of ECM, probably associated with increased mitochondrial activity. Activated HSC readily increased during liver fibrosis and remained activated after liver regeneration, even during fibrosis resolution. In conclusion, stimulation of liver regeneration through PH restores the balance in ECM synthesis/degradation, leading to ECM remodeling and to an almost complete resolution of liver fibrosis. As a response to the regenerative stimulus, activated HSC seem to play a controlling role on ECM remodeling during experimental cirrhosis in rats. Therefore, pharmacological approaches for the resolution of liver fibrosis by blocking HSC activation should also evaluate possible effects on liver cell proliferation.
|Calcospherulites isolated from the mineralization front of bone induce the mineralization of type I collagen. |
Midura, RJ; Vasanji, A; Su, X; Wang, A; Midura, SB; Gorski, JP
Bone 41 1005-16 2007
Previous work has suggested that "calcospherulites" actively participate in the mineralization of developing and healing bone. This study sought to directly test this hypothesis by developing a method to isolate calcospherulites and analyzing their capacity to seed mineralization of fibrillar collagen. The periosteal surface of juvenile rat tibial diaphysis was enriched in spherulites of approximately 0.5-mum diameter exhibiting a Ca/P ratio of 1.3. Their identity as calcospherulites was confirmed by their uptake of calcein at the tibial mineralization front 24 h following in vivo injection. Periosteum was dissected and unmineralized osteoid removed by collagenase in order to expose calcospherulites. Calcein-labeled calcospherulites were then released from the mineralization front by dispase digestion and isolated via fluorescence flow sorting. X-ray diffraction analysis revealed they contained apatite crystals (c-axis length of 17.5+/-0.2 nm), though their Ca/P ratio of 1.3 is lower than that of hydroxyapatite. Much of their non-mineral phosphorous content was removed by ice-cold ethanol, elevating their Ca/P ratio to 1.6, suggesting the presence of phospholipids. Western blot analyses showed the presence of bone matrix proteins and type I collagen in these preparations. Incubating isolated calcospherulites in collagen hydrogels demonstrated that they could seed a mineralization reaction on type I collagen fibers in vitro. Ultrastructural analyses revealed crystals on the collagen fibers that were distributed rather uniformly along the fiber lengths. Furthermore, crystals were observed at distances well away from the observed calcospherulites. Our results directly support an active role for calcospherulites in inducing the mineralization of type I collagen fibers at the mineralization front of bone.
|Thy-1 expression by cardiac fibroblasts: lack of association with myofibroblast contractile markers. |
François Hudon-David,Fatiha Bouzeghrane,Patrick Couture,Gaétan Thibault
Journal of molecular and cellular cardiology 42 2007
The objective of this study was to investigate the presence of Thy-1 in the myocardium and on cardiac fibroblasts and to determine whether or not cardiac fibroblasts form a heterogeneous population in term of Thy-1 expression. Thy-1 expression was examined by immunohistology of ventricular sections from normal and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Thy-1 immunostaining was detected in connective tissue on alpha8 integrin-positive and discoidin domain receptor 2 (DDR2)-positive fibroblasts. Enhanced Thy-1 staining was observed in the hearts of DOCA-salt rats particularly in areas of interstitial fibrosis. Cardiac mRNA analysis confirmed the increased Thy-1 expression. On cultured cardiac fibroblasts, flow cytofluorometry showed that cells, from primary culture to passage 4, were double positive for Thy-1 and for both alpha8 integrin and DDR2. Analysis of isolated lipid rafts by detergent-free sucrose gradient indicated that Thy-1 protein was probably located in these structures, but it may be located on a membrane microdomain slightly different from those of caveolin-1, as revealed by immunocytochemistry. Differentiation of fibroblasts into myofibroblasts being a characteristic of cardiac fibrosis and scarring, cardiac fibroblasts were stimulated in the presence of transforming growth factor-beta (TGF-beta) or connective tissue growth factor. While the expression of smooth muscle alpha-actin and alpha8 integrin doubled, Thy-1 level, measured by Western blotting and flow cytofluorometry, was not influenced by TGF-beta. These results demonstrate that cardiac fibroblasts express Thy-1 and form a homogeneous population. Thy-1 expression also appears to be independent of fibroblast differentiation. The dichotomy between the increased Tthy-1 expression in the fibrotic area and the lack of association with fibroblast differentiation suggests that Thy-1 may represent a marker of fibroblast proliferation in the myocardium.
|Epithelial-to-mesenchymal transition and oxidative stress in chronic allograft nephropathy. |
Arjang Djamali, Shannon Reese, Joseph Yracheta, Terry Oberley, Debra Hullett, Bryan Becker
American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons 5 500-9 2005
Epithelial-to-mesenchymal transition (EMT) and oxidative stress contribute to kidney tissue fibrosis in various forms of native kidney disease. However, their role in chronic allograft nephropathy (CAN) remains somewhat uncertain. To address this question, kidney transplants were performed in 3-month-old rats, using the Fisher 344 --> Lewis model of CAN. Six-month posttransplant, kidney allografts displayed significant tubular atrophy, interstitial fibrosis and vascular wall thickening. Allograft recipients had significantly higher levels of serum creatinine (4.7 +/- 1.3 versus 0.59 +/- 0.08 mg/dL, p = 0.03) and proteinuria (380 +/- 102 versus 30.2 +/- 8 mg/dL, p = 0.04) compared to syngeneic grafts. Semiquantitative PCR, immunoblot and immunohistochemical analyses demonstrated increased alpha-smooth muscle actin (alpha-SMA) mRNA and protein levels coupled with reduced E-cadherin mRNA and protein immunoreactivity, confirming the presence of CAN-associated EMT. Allograft alpha-SMA levels were increased as early as 1-2 weeks posttransplant. Immunohistochemical studies for collagen type I and III, superoxide anion (O(2) (-)), inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) confirmed that tubular O(2) (-), eNOS and iNOS, and interstitial collagen I, III and O(2) (-) levels were significantly increased in CAN-associated EMT. In conclusion, these observations suggest that CAN-associated EMT may be a link between oxidative stress and allograft fibrosis.
|Enhanced expression of fibrillin-1, a constituent of the myocardial extracellular matrix in fibrosis. |
Bouzeghrane, F; Reinhardt, DP; Reudelhuber, TL; Thibault, G
American journal of physiology. Heart and circulatory physiology 289 H982-91 2005
Fibrillin-1 localization in the myocardium and the modulation of its expression in cardiac fibrosis were examined. In normal rat hearts, fibrillin-1 was abundant throughout the myocardium as thin fibers that crossed over the perimysium and around arteries. After cardiac fibrosis was induced in rats by either 14-day ANG II infusion or 21-day DOCA-salt treatment [a high endothelin-1 (ET-1) model], fibrillin-1 immunostaining was stronger in the interstitium (2.8-fold and 4.4-fold increases, respectively, in each model), extended between myocytes, and accumulated in microscopic scars and in the perivascular area of both ventricles. mRNA analysis confirmed its enhanced ventricular expression in both groups of rats (2.5-fold and 6.6-fold increments, respectively, in each model). In 1B normotensive and 2C hypertensive transgenic mice, two lines expressing an ANG II fusion protein in cardiac myocytes, strong fibrillin-1 immunoreactivity was observed in the interstitium and around arteries (3.7-fold and 7-fold increases, respectively). ANG II and transforming growth factor-beta1 enhanced fibrillin-1 synthesis by cardiac fibroblasts. Some fibrillin-1 fragments interacted with RGD-dependent integrins, including alpha(8)beta(1)-integrin, of cardiac fibroblasts but not necessarily through the RGD motif. Our findings illustrate that fibrillin-1 is an important constituent of the myocardium. In vitro and in vivo evidence suggests that ANG II can directly induce fibrillin-1 expression in cardiac fibroblasts. This protein can thus contribute to reactive and reparative processes.
|Transforming growth factor-beta-dependent events in vascular remodeling following arterial injury. |
Sarah T Ryan, Victor E Koteliansky, Philip J Gotwals, Volkhard Lindner, Sarah T Ryan, Victor E Koteliansky, Philip J Gotwals, Volkhard Lindner
Journal of vascular research 40 37-46 2003
Constrictive remodeling has been identified as a major contributor to restenosis following angioplasty. Characterization of transforming growth factor-beta (TGF-beta)-mediated cellular events in the adventitia and their contribution to vascular remodeling, however, has not previously been studied in detail. The balloon catheter denudation model was performed on rat carotid artery, and groups of rats were treated with vehicle or a TGF-beta inhibitor, a soluble TGF-beta receptor type II (TGF-beta R:Fc). Adventitial cell proliferation, which peaked 4 days after injury, was characterized by the de novo formation of several cell layers surrounding the outer adventitia and this process was not dependent upon TGF-beta activity. These neoadventitial cells expressed an abundance of collagen type I and a fetal isoform of fibronectin containing the EIIIA domain, and the expression of both proteins was suppressed in the presence of TGF-beta R:Fc. Lumenal narrowing was apparent 14 days after injury. Inhibition of TGF-beta signaling promoted vessel enlargement. As a result, lumen size did not change despite neointima formation. In conclusion, adventitial fibrosis with abundant collagen matrix deposition but not adventitial cell proliferation is dependent upon endogenous TGF-beta activity. Furthermore, inhibition of TGF-beta signaling prevents injury-induced reduction in lumen area by promoting vessel enlargement.
|Intraglomerular pressure and mesangial stretching stimulate extracellular matrix formation in the rat. |
Riser, B L, et al.
J. Clin. Invest., 90: 1932-43 (1992) 1992
To define the interplay of glomerular hypertension and hypertrophy with mesangial extracellular matrix (ECM) deposition, we examined the effects of glomerular capillary distention and mesangial cell stretching on ECM synthesis. The volume of microdissected rat glomeruli (Vg), perfused ex vivo at increasing flows, was quantified and related to the proximal intraglomerular pressure (PIP). Glomerular compliance, expressed as the slope of the positive linear relationship between PIP and Vg was 7.68 x 10(3) microns 3/mmHg. Total Vg increment (PIP 0-150 mmHg) was 1.162 x 10(6) microns 3 or 61% (n = 13). A 16% increase in Vg was obtained over the PIP range equivalent to the pathophysiological limits of mean transcapillary pressure difference. A similar effect of renal perfusion on Vg was also noted histologically in tissue from kidneys perfused/fixed in vivo. Cultured mesangial cells undergoing cyclic stretching increased their synthesis of protein, total collagen, and key components of ECM (collagen IV, collagen I, laminin, fibronectin). Synthetic rates were stimulated by cell growth and the degree of stretching. These results suggest that capillary expansion and stretching of mesangial cells by glomerular hypertension provokes increased ECM production which is accentuated by cell growth and glomerular hypertrophy. Mesangial expansion and glomerulosclerosis might result from this interplay of mechanical and metabolic forces.
|Immunohistochemical study of the biological fate of a subcutaneous bovine collagen implant in rat. |
Vialle-Presles, M J, et al.
Histochemistry, 91: 177-84 (1989) 1989
The biological fate of a bovine collagen implant (Zyderm Collagen Implant ZCI), injected subcutaneously into rats, was studied by the immunoperoxidase technique using specific antibodies against the bovine implant and against types I, III, IV, V collagens, fibronectin and elastin. The implant remained in the animals until the end of the experiment (90 days), with no visible modification, as demonstrated by immunoperoxidase labelling and scanning electron microscopy. A slight inflammatory reaction was visible around the implant 24 h after injection and within the implant 3 days after injection. Fibroblast invasion began 7 days after injection. The chronology of the deposition in the implant of the host (rat) extracellular matrix components was as follows: by 24 h after injection, fibronectin was observed throughout the implant; types I and V collagens appeared on the 7th day, and, in contrast to surrounding connective tissue, type V collagen labelling was obtained without acid pretreatment of the section. Types III and IV collagens were detected inside the implant only 30 days after injection. At the end of the experiment (90 days), there was abundant types I and IV collagens after fibroblast migration, and abundant type IV collagen demonstrating an important vascularization. No elastic fibres could be detected inside the implant but they appeared as a dense network around the implant in host connective tissue.
|Anti-Collagen Type I - Data Sheet|