Collagen Expression
Published by Anonymous on 2007/9/24 (2569 reads)
1: J Cell Physiol. 2007 Jun;211(3):585-9.
Therapies for bleomycin induced lung fibrosis through regulation of TGF-beta1 induced collagen gene expression.
Cutroneo KR, White SL, Phan SH, Ehrlich HP.
Department of Biochemistry, College of Medicine, 89 Beaumont Avenue, University of Vermont, Burlington, Vermont 05405, USA. kenneth.cutroneo@uvm.edu
This review describes normal and abnormal wound healing, the latter characterized by excessive fibrosis and scarring, which for lung can result in morbidity and sometimes mortality. The cells, the extracellular matrix (ECM) proteins, and the growth factors regulating the synthesis, degradation, and deposition of the ECM proteins will be discussed. Therapeutics with particular emphasis given to gene therapies and their effects on specific signaling pathways are described. Bleomycin (BM), a potent antineoplastic antibiotic increases TGF-beta1 transcription, TGF-beta1 gene expression, and TGF-beta protein. Like TGF-beta1, BM acts through the same distal promoter cis-element of the COL1A1 gene causing increased COL1 synthesis and lung fibrosis. Lung fibroblasts exist as subpopulations with one subset predominantly responding to fibrogenic stimuli which could be a specific cell therapeutic target for the onset and development of pulmonary fibrosis.
Publication Types:
Research Support, N.I.H., Extramural
Review
PMID: 17387717 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
2: J Soc Biol. 2005;199(4):329-36.
[Functional interactions between the TGF-beta signaling pathway via the Smads and TNF-alpha: implications for the regulation of type I collagen expression]
[Article in French]
Verrecchia F.
INSERM U697, Hôpital Saint-Louis, Pavillon Bazin, 1, avenue Claude Vellefaux, 75010 Paris. franck.verrecchia@stlouis.inserm.fr
The balance between production and degradation of type I collagen plays a critical role in the development and maintenance of organ and tissue integrity. Its also represents the most crucial element governing the process of tissue repair. TGF-beta, a key player in the physiopathology of tissue repair, enhances type I collagene gene expression. In contrast, TNF-alpha, whose matrix-remodelling function is opposite to that of TGF-beta, reduces type I collagen gene expression. This review focuses on transcriptional regulation of type I collagen by TGF-beta and TNF-alpha, and on the molecular mechanisms that control the antagonistic activity of TNF-alpha against TGF-beta-driven type I collagen gene expression.
Publication Types:
English Abstract
Review
PMID: 16738527 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
3: J Clin Immunol. 2005 Nov;25(6):592-603.
Molecular aspects of regulation of collagen gene expression in fibrosis.
Bhogal RK, Stoica CM, McGaha TL, Bona CA.
Department of Microbiology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029, USA.
Fibrosis, the hyper-accumulation of scar tissue, is characterized by the overproduction and deposition of type I and III collagen by fibroblasts and is the one of the main pathologic outcomes of the autoimmune disorder scleroderma. While the causes of fibrosis in scleroderma are unknown, cytokines such as TGF-beta, IL-4 and IL-13, play a crucial role in the stimulation of collagen production have been implicated in the disease process. In fibroblasts stimulation of collagen production by these cytokines is dependent on the Smad and STAT6 signaling pathways induced by TGF-beta and IL-4, IL-13 respectively. Furthermore, mounting evidence suggest cytokine crosstalk is relevant in the sclerotic process. Our laboratory demonstrated an increase in TGF-beta1 gene transcription from fibroblasts stimulated with IL-4. In addition, TSK/+ mice lacking the IL-4alpha receptor show impaired transcription of the TGF-beta1 gene and did not display fibrosis. Likewise, it appears that STAT6 plays a role in fibroblast TGF-beta1 transcription after IL-4 or IL-13 stimulation. These findings suggest that an epistatic interaction between IL-4 and TGF-beta may exist which is crucial for pathologic sclerotic activity.
Publication Types:
Research Support, N.I.H., Extramural
Review
PMID: 16380822 [PubMed - in process]
--------------------------------------------------------------------------------
4: Nephron Exp Nephrol. 2006;102(3-4):e71-5. Epub 2005 Nov 10.
Organ-specific collagen expression: implications for renal disease.
Alexakis C, Maxwell P, Bou-Gharios G.
Renal Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK.
Chronic kidney disease is characterized by progressive accumulation of extracellular matrix and scarring, leading to the loss of kidney function. Excess deposition of the collagen family of proteins is the hallmark of kidney fibrosis. In this review, we survey the collagens that are associated with renal disease and we highlight the use of a transgenic approach to identify cis-acting sequences in the collagen type I promoter which are capable of directing collagen type I expression specifically in the kidney. Ultimately it may be possible to use this approach to halt the accumulation of collagen selectively in this organ. 2006 S. Karger AG, Basel.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 16286786 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
5: Cell Signal. 2004 Aug;16(8):873-80.
TGF-beta and TNF-alpha: antagonistic cytokines controlling type I collagen gene expression.
Verrecchia F, Mauviel A.
INSERM U532, Institut de Recherche sur la Peau, Pavillon Bazin, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75475 Paris Cedex 10, France.
The balance between production and degradation of type I collagen plays a critical role in the development and maintenance of organ and tissue integrity. It also represents the most crucial element governing the process of tissue repair. The synthesis of type I collagen gene is highly regulated by different cytokines at the transcriptional level. Especially, transforming growth factor beta (TGF-beta), a key player in the physiopathology of tissue repair, enhances type I collagen gene expression. In contrast, tumor necrosis factor alpha (TNF-alpha), whose matrix-remodelling function is opposite to that of TGF-beta, reduces type I collagen gene expression. This review focuses on transcriptional regulation of type I collagen by TGF-beta and TNF-alpha and on the molecular mechanisms that control the antagonistic activity of TNF-alpha against TGF-beta-driven type I collagen gene expression.
Publication Types:
Review
PMID: 15157666 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
6: Cancer Treat Res. 2004;118:101-24.
Type I collagen-mediated changes in gene expression and function of prostate cancer cells.
Kiefer J, Alexander A, Farach-Carson MC.
Department of Biological Sciences, University of Delaware, USA.
In this study, cDNA microarrays were used to characterize gene expression changes elicited in prostate cancer cells by plating them on type I collagen. The results clearly reveal changes in the expression of genes associated with cellular signaling, cellular metabolism, gene transcription and gene translation which are indicative of cells that are actively proliferating. Together these results suggest that these changes in the gene expression profiles mediated by type I collagen may influence the proliferative capacity of prostate cancer cells in the bone microenvironment and facilitate development of prostate cancer bone metastases. Additionally, the microarray approach provides an invaluable tool to determine and track changes in gene expression in numerous disease states including prostate cancer. This technology is certain to facilitate discovery of new therapeutic gene targets.
Publication Types:
Comparative Study
Review
PMID: 15043190 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
7: Semin Cell Dev Biol. 2003 Oct;14(5):275-82.
HSP47 as a collagen-specific molecular chaperone: function and expression in normal mouse development.
Nagata K.
Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, Japan. nagata@frontier.kyoto-u.ac.jp
A large family of molecular chaperones can be divided into two major groups: general chaperone and substrate-specific chaperone. HSP47 is a collagen-specific molecular chaperone residing in the endoplasmic reticulum (ER). Recent studies revealed that HSP47 is essential molecular chaperone for mouse development and is essential for collagen molecular maturation in the ER. In the absence of HSP47, collagen microfibril formation and basement membrane formation are impaired in mouse embryos because the failure in the molecular maturation of types I and IV collagens, respectively. The tissue-specific expression of HSP47 is always correlated with that of various types of collagens and closely related with the collagen-related diseases including fibrosis in various organs. The importance of HSP47 in the therapeutic strategy for fibrotic diseases as well as for a marker of collagen-related autoimmune diseases will also be discussed.
Publication Types:
Review
PMID: 14986857 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
8: J Am Soc Nephrol. 2003 Jun;14 Suppl 1:S3-8.
Induced repatterning of type XVIII collagen associates with ectopic Sonic hedgehog and lung surfactant C gene expression and changes in epithelial epigenesis in the ureteric bud.
Vainio S, Lin Y, Pihlajaniemi T.
Biocenter Oulu, University of Oulu, Oulu, Finland. seppo.vaino@oulu.fi
How cell and tissue interactions lead to complex organ structures and differentiated cell types during organogenesis is one of the most fundamental questions in developmental biology. The embryonic lung and kidney of the mouse are useful models for studying the molecular mechanisms of morphogenesis, and in both of these organs, the epithelial bud undergoes a characteristic branching process. This review discusses the potential role of an extracellular matrix molecule, type XVIII collagen, in the generation of the branching patterns in the lung and kidney and how its experimental respecification in tissue recombinants between the ureteric bud and lung mesenchyme correlates with changes in expression of signaling molecules such as sonic hedgehog and changes in cell fate as judged by ectopic expression of the lung surfactant C gene.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 12761231 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
9: Adv Dent Res. 2001 Aug;15:55-8.
Human odontoblast culture method: the expression of collagen and matrix metalloproteinases (MMPs).
Tjäderhane L, Palosaari H, Wahlgren J, Larmas M, Sorsa T, Salo T.
Institute of Dentistry, University of Oulu, Oulu Municipal Health Center, Oulu, Finland. lst@cc.oulu.fi
Studies on mature human odontoblasts have suffered for the lack of in vitro models. We recently introduced a human odontoblast and pulp tissue organ culture method, in which the odontoblasts are cultured in the pulp chamber after removal of the pulp tissue, and the pulp tissue can be cultured separately (Tjäderhane et al., 1998a). With this method, we have studied the effects of growth factors on the expression of collagen and extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinases (MMPs), in mature human odontoblasts. TGF-beta 1 was selected because of its ability to regulate the response of the dentin-pulp complex to external irritation. The effect of TGF-beta 1 (10 ng/mL) on pro alpha 1(I) collagen mRNA was analyzed by quantitative PCR, and type I procollagen propeptide (PINP) was analyzed from conditioned culture media with RIA. Odontoblast media were also assayed for respective type III procollagen propeptide (PIIINP). TGF-beta had a negligible effect on collagen mRNA expression or protein synthesis, indicating that TGF-beta alone does not markedly induce dentin matrix formation per se in the human dentin-pulp complex (Palosaari et al., 2001). However, TGF-beta 1 seems to regulate MMP expression in mature human odontoblasts differentially. A strong down-regulation of MMP-8 (Palosaari et al., 2000), a modest down-regulation of MMP-20 (Tjäderhane et al., 2000), and considerable up-regulation of MMP-9, with no apparent effect on MMP-2 expression (Tjäderhane et al., 1998b), indicate that growth factors may affect the matrix synthesis by controlling the expression and activity of MMPs instead of collagen synthesis. The altered expression of MMPs may result in altered ECM formation, which in turn may contribute to the formation of atubular reparative dentin.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 12640741 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
10: Nippon Yakurigaku Zasshi. 2003 Jan;121(1):4-14.
[Therapeutic strategy for fibrotic diseases by regulating the expression of collagen-specific molecular chaperone HSP47]
[Article in Japanese]
Nagata K.
Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, Japan. nagata@frontier.kyoto-u.ac.jp
Through disruption of the hsp47 gene in mice, we found that HSP47, a collagen-specific molecular chaperone residing in the endoplasmic reticulum, is essential for mouse development. Improper triple helix formation was observed in hsp47-null embryos, and no collagen fibrils in the mesenchyme or basement membranes between the mesenchyme and epithelial cell layers were seen in those mice, which resulted in embryonic lethality. Interestingly, constitutive expression of HSP47 is always correlated with that of collagens in various cells or tissues. HSP47 is markedly up-regulated during the progression of fibrosis in the liver, kidney, lung, and so on. A preliminary experiment showed that down-regulation of HSP47 caused the reduction in the progression of fibrosis by down-regulating the accumulation of collagens in the tissues, which suggests a novel strategy for the therapy of fibrotic diseases including liver cirrhosis.
Publication Types:
English Abstract
Review
PMID: 12617032 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
11: Exp Biol Med (Maywood). 2002 May;227(5):301-14.
Factors involved in the regulation of type I collagen gene expression: implication in fibrosis.
Ghosh AK.
Section of Rheumatology, Department of Medicine, 1158 Molecular Biology Research Building, University of Illinois, 900 South Ashland Avenue, Chicago, IL 60607, USA. Ghoshak@uic.edu
Type I collagen, the major component of extracellular matrix in skin and other tissues, is a heterotrimer of two alpha1 and one alpha2 collagen polypeptides. The synthesis of both chains is highly regulated by different cytokines at the transcriptional level. Excessive synthesis and deposition of collagen in the dermal region causes thick and hard skin, a clinical manifestation of scleroderma. To better understand the causes of scleroderma or other tissue fibrosis, it is very important to investigate the molecular mechanisms that cause upregulation of the Type I collagen synthesis in these tissues. Several cis-acting regulatory elements and trans-acting protein factors, which are involved in basal as well as cytokine-modulated Type I collagen gene expression, have been identified and characterized. Hypertranscription of Type I collagen in scleroderma skin fibroblasts may be due to abnormal activities of different positive or negative transcription factors in response to different abnormally induced signaling pathways. In this review, I discuss the present day understanding about the involvement of different factors in the regulation of basal as well as cytokine-modulated Type I collagen gene expression and its implication in scleroderma research.
Publication Types:
Review
PMID: 11976400 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
12: Nephrol Dial Transplant. 2000;15 Suppl 6:66-8.
Regulation of type I collagen genes expression.
Rossert J, Terraz C, Dupont S.
INSERM U.489 and Department of Nephrology, Paris VI University, Assistance Publique-H pitaux de Paris, France.
Type I collagen is the major component of many extracellular matrices, and its accumulation characterizes most fibrotic processes. It is synthesized by a small number of discrete cell types, including fibroblasts, osteoblasts and odontoblasts. Analysis of transgenic mice harbouring different segments of the promoters of the mouse pro-alpha1 (I) and pro-alpha2 (I) genes has led to the conclusion that this tissue-specific expression is controlled by different cis-acting elements which are responsible for the expression of type I collagen genes in different type I collagen-producing cells. Transacting factors which bind to these different tissue-specific elements are still unknown, but they probably act by modifying the chromatin structure. In fibroblastic cells, various soluble molecules can modulate the transcription of type I collagen genes. Analysis of the pro-alpha1 (I) and pro-alpha2 (I) proximal promoters has led to the identification of different cis-acting elements which can modulate the expression of reporter genes, in transfection experiments. Among these cis-acting elements, a sequence located between -378 and -183 bp in the human pro-alpha2 (I) promoter appears to mediate the transcriptional effects of transforming growth factor-beta. It binds a large multimeric complex which contains Sp1, as well as AP1 and other DNA-binding proteins which have not yet been identified.
Publication Types:
Review
PMID: 11143996 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
13: Prog Mol Subcell Biol. 2000;25:89-104.
Expression of liver specific-genes in hepatocytes cultured in collagen gel matrix.
Gómez-Lechón MJ, Jover R, Donato T, Ponsoda X, Castell JV.
Unidad de Hepatología Experimental, Centro de Investigación, Valencia, Spain.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10986720 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
14: Biochem Soc Trans. 2000;28(4):350-3.
Recombinant expression systems for the production of collagen.
Bulleid NJ, John DC, Kadler KE.
School of Biological Sciences, Wellcome Trust Centre For Cell-Matrix Research, 2.205 Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PT, U.K. neil.bulleid@man.ac.uk
The ability of triple-helical collagen molecules to assemble into supramolecular structures forms the basis of commercial uses of collagen in the food industry and in medical applications such as cosmetic surgery and tissue repair. We have used cDNA techniques to engineer novel collagens with potentially enhanced biological properties; however, expression of fully functional novel molecules is difficult due to the complex nature of procollagen biosynthesis. This article outlines the application of various expression systems to procollagen production and details the use of the mammary gland as a suitable bioreactor for the synthesis of significant amounts of novel procollagens from cDNA constructs.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10961917 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
15: Springer Semin Immunopathol. 1999;21(4):397-414.
Alterations in the regulation of expression of the alpha 1(I) collagen gene (COL1A1) in systemic sclerosis (scleroderma).
Jimenez SA, Saitta B.
Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107-5541, USA. Sergio.Jimenez@mail.tju.edu
At present, the mechanisms that regulate the expression of collagen genes in normal and pathologic fibroblasts are not known. Thus, the detailed study of transcriptional regulation of COL1A1 in SSc cells will increase our current understanding of the pathophysiology of fibrotic diseases. These studies will yield valuable information regarding the important biological process of regulation of collagen gene expression under normal and pathologic conditions, a process that has remained elusive despite intense recent investigations. It is now evident that persistent overproduction of collagen is responsible for the progressive nature of tissue fibrosis in SSc. Up-regulation of collagen gene expression in SSc fibroblasts appears to be a critical event in this process. The coordinate transcriptional activation of numerous collagen genes suggests a fundamental alteration in the regulatory control of gene expression in SSc fibroblasts. Trans-acting nuclear factors which bind to cis-acting elements in enhancer (intronic) and promoter regions of the genes modulate the basal and inducible transcriptional activity of the collagen genes. The identification of the nuclear transcription factors that regulate normal collagen gene expression may provide promising approaches to the therapy of this incurable disease.
Publication Types:
Review
PMID: 10945033 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
16: Coron Artery Dis. 2000 Feb;11(1):57-68.
Greater than normal expression of the collagen-binding stress protein heat-shock protein-47 in the infarct zone in rats after experimentally-induced myocardial infarction.
Takeda K, Kusachi S, Ohnishi H, Nakahama M, Murakami M, Komatsubara I, Oka T, Doi M, Ninomiya Y, Tsuji T.
Department of Internal Medicine I, Okayama University Medical School, Japan.
BACKGROUND: The heat-shock protein with relative molecular mass 47,000 (HSP47) can bind to procollagen molecules in the endoplasmic reticulum, and acts as a molecular chaperone during the processing and secretion of procollagen. OBJECTIVE: To test our hypothesis that HSP47 is expressed in the myocardial infarct zone. METHODS: We induced myocardial infarction in male Sprague-Dawley rats by ligation of left coronary artery. The expression of HSP47 was examined by Northern blotting, in-situ hybridization, Western blotting and immunohistochemistry. The time-dependent change in the distribution of HSP47 messenger RNA (mRNA) signal was compared with the changes in expression of alpha 1(I) and alpha 1(III) collagen mRNA by in-situ hybridization. The hypoxic induction of HSP47 in cultured cardiac fibroblasts was examined by Northern-blot analysis. RESULTS: Northern blotting demonstrated that the expression of HSP47 mRNA had increased on day 2, reaching a maximum level around day 14 (induced 3.5-fold compared with the preligation hearts) and was maintained at a high level up to day 28. In-situ hybridization analysis revealed HSP47 mRNA signals in spindle-shaped mesenchymal cells located between surviving myocytes in the infarct's peripheral zone 24 h after the ligation, and in the entire infarct zone on day 14. The sequential changes in distribution of HSP47 mRNA signal were identical to those of the alpha 1(I) and alpha 1(III) collagen mRNA. Western blotting demonstrated that expression of HSP47 protein in the infarct zone had increased. Immunofluorescent staining revealed positivity for HSP47 in the infarct's peripheral zone on day 2 and in the entire infarct zone on day 14. Northern blotting revealed that the expression of HSP47 mRNA in cultured cardiac fibroblasts in hypoxic cultures was greater than that in normoxic cultures. CONCLUSION: The present data demonstrated that an increase in expression of HSP47 is produced by spindle-shaped mesenchymal cells in the infarct zone. Expression of HSP47 mRNA was concurrent with the expression of collagen mRNA of types I and III. Hypoxia is one of the factors which induces expression of HSP47.
Publication Types:
Review
PMID: 10715808 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
17: Trends Genet. 2000 Jan;16(1):21-7.
Cuticle collagen genes. Expression in Caenorhabditis elegans.
Johnstone IL.
Wellcome Centre for Molecular Parasitology, Anderson College, University of Glasgow, UK. gbga14@udcf.gla.ac.uk
Collagen is a structural protein used in the generation of a wide variety of animal extracellular matrices. The exoskeleton of the free-living nematode, Caenorhabditis elegans, is a complex collagen matrix that is tractable to genetic research. Mutations in individual cuticle collagen genes can cause exoskeletal defects that alter the shape of the animal. The complete sequence of the C. elegans genome indicates upwards of 150 distinct collagen genes that probably contribute to this structure. During the synthesis of this matrix, individual collagen genes are expressed in distinct temporal periods, which might facilitate the formation of specific interactions between distinct collagens.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10637627 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
18: Seikagaku. 1999 Jun;71(6):432-8.
[Diversified expression and function of minor fibrillar collagen]
[Article in Japanese]
Yoshioka H.
Department of Biochemistry, Oita Medical University.
Publication Types:
Review
PMID: 10432836 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
19: Blood. 1999 Jun 1;93(11):3575-7.
Platelet surface collagen receptor polymorphisms: variable receptor expression and thrombotic/hemorrhagic risk.
Santoro SA.
Division of Laboratory Medicine, Washington University School of Medicine, St Louis, MO, USA.
Publication Types:
Review
PMID: 10339460 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
20: Wound Repair Regen. 1998 May-Jun;6(3):186-93.
Perspective article: collagen expression by novel cell populations in the dermal wound environment.
Lindblad WJ.
Department of Pharmaceutical Sciences & Institute of Chemical Toxicology, Wayne State University, Detroit, MI 48202, USA.
Numerous collagenous structures must be reconstituted following injury to the skin in order to return function to this tissue. The basement membrane zone, vascular basement membranes, and the dense connective tissue of the dermis are examples of structures that contain a number of different collagen types and that may need replacement following injury. In addition, a scar is deposited at the site of damage in order to substitute for elements lost in the trauma and for elements that cannot be successfully replaced. Clearly, cells resident within the different compartments of the skin are able to synthesize and deposit collagen to reform these multiple structures. However, accumulating experimental evidence suggests that in addition to these resident cells, blood-borne cells may be responsible for the deposition of a portion of the newly synthesized collagen. Studies from this laboratory point to the activated monocyte as a potential source of collagen in the wound environment. Given the dynamics of the process, the hypothesis is proposed that during normal wound healing, the activated monocyte is a source of collagen essential for the rapid formation of a provisional matrix conducive for the subsequent formation of granulation tissue. Collagen synthesis also occurs by expanded populations of resident cells, under the influence of inflammatory cell-derived mediators, which results in the major accumulation of collagen during normal wound repair. However, if a chronic inflammatory state is initiated, the activated monocytes may remain in sufficient numbers to deposit collagen leading to a pathological lesion.
Publication Types:
Review
PMID: 9776862 [PubMed - indexed for MEDLINE]
Therapies for bleomycin induced lung fibrosis through regulation of TGF-beta1 induced collagen gene expression.
Cutroneo KR, White SL, Phan SH, Ehrlich HP.
Department of Biochemistry, College of Medicine, 89 Beaumont Avenue, University of Vermont, Burlington, Vermont 05405, USA. kenneth.cutroneo@uvm.edu
This review describes normal and abnormal wound healing, the latter characterized by excessive fibrosis and scarring, which for lung can result in morbidity and sometimes mortality. The cells, the extracellular matrix (ECM) proteins, and the growth factors regulating the synthesis, degradation, and deposition of the ECM proteins will be discussed. Therapeutics with particular emphasis given to gene therapies and their effects on specific signaling pathways are described. Bleomycin (BM), a potent antineoplastic antibiotic increases TGF-beta1 transcription, TGF-beta1 gene expression, and TGF-beta protein. Like TGF-beta1, BM acts through the same distal promoter cis-element of the COL1A1 gene causing increased COL1 synthesis and lung fibrosis. Lung fibroblasts exist as subpopulations with one subset predominantly responding to fibrogenic stimuli which could be a specific cell therapeutic target for the onset and development of pulmonary fibrosis.
Publication Types:
Research Support, N.I.H., Extramural
Review
PMID: 17387717 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
2: J Soc Biol. 2005;199(4):329-36.
[Functional interactions between the TGF-beta signaling pathway via the Smads and TNF-alpha: implications for the regulation of type I collagen expression]
[Article in French]
Verrecchia F.
INSERM U697, Hôpital Saint-Louis, Pavillon Bazin, 1, avenue Claude Vellefaux, 75010 Paris. franck.verrecchia@stlouis.inserm.fr
The balance between production and degradation of type I collagen plays a critical role in the development and maintenance of organ and tissue integrity. Its also represents the most crucial element governing the process of tissue repair. TGF-beta, a key player in the physiopathology of tissue repair, enhances type I collagene gene expression. In contrast, TNF-alpha, whose matrix-remodelling function is opposite to that of TGF-beta, reduces type I collagen gene expression. This review focuses on transcriptional regulation of type I collagen by TGF-beta and TNF-alpha, and on the molecular mechanisms that control the antagonistic activity of TNF-alpha against TGF-beta-driven type I collagen gene expression.
Publication Types:
English Abstract
Review
PMID: 16738527 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
3: J Clin Immunol. 2005 Nov;25(6):592-603.
Molecular aspects of regulation of collagen gene expression in fibrosis.
Bhogal RK, Stoica CM, McGaha TL, Bona CA.
Department of Microbiology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029, USA.
Fibrosis, the hyper-accumulation of scar tissue, is characterized by the overproduction and deposition of type I and III collagen by fibroblasts and is the one of the main pathologic outcomes of the autoimmune disorder scleroderma. While the causes of fibrosis in scleroderma are unknown, cytokines such as TGF-beta, IL-4 and IL-13, play a crucial role in the stimulation of collagen production have been implicated in the disease process. In fibroblasts stimulation of collagen production by these cytokines is dependent on the Smad and STAT6 signaling pathways induced by TGF-beta and IL-4, IL-13 respectively. Furthermore, mounting evidence suggest cytokine crosstalk is relevant in the sclerotic process. Our laboratory demonstrated an increase in TGF-beta1 gene transcription from fibroblasts stimulated with IL-4. In addition, TSK/+ mice lacking the IL-4alpha receptor show impaired transcription of the TGF-beta1 gene and did not display fibrosis. Likewise, it appears that STAT6 plays a role in fibroblast TGF-beta1 transcription after IL-4 or IL-13 stimulation. These findings suggest that an epistatic interaction between IL-4 and TGF-beta may exist which is crucial for pathologic sclerotic activity.
Publication Types:
Research Support, N.I.H., Extramural
Review
PMID: 16380822 [PubMed - in process]
--------------------------------------------------------------------------------
4: Nephron Exp Nephrol. 2006;102(3-4):e71-5. Epub 2005 Nov 10.
Organ-specific collagen expression: implications for renal disease.
Alexakis C, Maxwell P, Bou-Gharios G.
Renal Medicine, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK.
Chronic kidney disease is characterized by progressive accumulation of extracellular matrix and scarring, leading to the loss of kidney function. Excess deposition of the collagen family of proteins is the hallmark of kidney fibrosis. In this review, we survey the collagens that are associated with renal disease and we highlight the use of a transgenic approach to identify cis-acting sequences in the collagen type I promoter which are capable of directing collagen type I expression specifically in the kidney. Ultimately it may be possible to use this approach to halt the accumulation of collagen selectively in this organ. 2006 S. Karger AG, Basel.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 16286786 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
5: Cell Signal. 2004 Aug;16(8):873-80.
TGF-beta and TNF-alpha: antagonistic cytokines controlling type I collagen gene expression.
Verrecchia F, Mauviel A.
INSERM U532, Institut de Recherche sur la Peau, Pavillon Bazin, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75475 Paris Cedex 10, France.
The balance between production and degradation of type I collagen plays a critical role in the development and maintenance of organ and tissue integrity. It also represents the most crucial element governing the process of tissue repair. The synthesis of type I collagen gene is highly regulated by different cytokines at the transcriptional level. Especially, transforming growth factor beta (TGF-beta), a key player in the physiopathology of tissue repair, enhances type I collagen gene expression. In contrast, tumor necrosis factor alpha (TNF-alpha), whose matrix-remodelling function is opposite to that of TGF-beta, reduces type I collagen gene expression. This review focuses on transcriptional regulation of type I collagen by TGF-beta and TNF-alpha and on the molecular mechanisms that control the antagonistic activity of TNF-alpha against TGF-beta-driven type I collagen gene expression.
Publication Types:
Review
PMID: 15157666 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
6: Cancer Treat Res. 2004;118:101-24.
Type I collagen-mediated changes in gene expression and function of prostate cancer cells.
Kiefer J, Alexander A, Farach-Carson MC.
Department of Biological Sciences, University of Delaware, USA.
In this study, cDNA microarrays were used to characterize gene expression changes elicited in prostate cancer cells by plating them on type I collagen. The results clearly reveal changes in the expression of genes associated with cellular signaling, cellular metabolism, gene transcription and gene translation which are indicative of cells that are actively proliferating. Together these results suggest that these changes in the gene expression profiles mediated by type I collagen may influence the proliferative capacity of prostate cancer cells in the bone microenvironment and facilitate development of prostate cancer bone metastases. Additionally, the microarray approach provides an invaluable tool to determine and track changes in gene expression in numerous disease states including prostate cancer. This technology is certain to facilitate discovery of new therapeutic gene targets.
Publication Types:
Comparative Study
Review
PMID: 15043190 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
7: Semin Cell Dev Biol. 2003 Oct;14(5):275-82.
HSP47 as a collagen-specific molecular chaperone: function and expression in normal mouse development.
Nagata K.
Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, Japan. nagata@frontier.kyoto-u.ac.jp
A large family of molecular chaperones can be divided into two major groups: general chaperone and substrate-specific chaperone. HSP47 is a collagen-specific molecular chaperone residing in the endoplasmic reticulum (ER). Recent studies revealed that HSP47 is essential molecular chaperone for mouse development and is essential for collagen molecular maturation in the ER. In the absence of HSP47, collagen microfibril formation and basement membrane formation are impaired in mouse embryos because the failure in the molecular maturation of types I and IV collagens, respectively. The tissue-specific expression of HSP47 is always correlated with that of various types of collagens and closely related with the collagen-related diseases including fibrosis in various organs. The importance of HSP47 in the therapeutic strategy for fibrotic diseases as well as for a marker of collagen-related autoimmune diseases will also be discussed.
Publication Types:
Review
PMID: 14986857 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
8: J Am Soc Nephrol. 2003 Jun;14 Suppl 1:S3-8.
Induced repatterning of type XVIII collagen associates with ectopic Sonic hedgehog and lung surfactant C gene expression and changes in epithelial epigenesis in the ureteric bud.
Vainio S, Lin Y, Pihlajaniemi T.
Biocenter Oulu, University of Oulu, Oulu, Finland. seppo.vaino@oulu.fi
How cell and tissue interactions lead to complex organ structures and differentiated cell types during organogenesis is one of the most fundamental questions in developmental biology. The embryonic lung and kidney of the mouse are useful models for studying the molecular mechanisms of morphogenesis, and in both of these organs, the epithelial bud undergoes a characteristic branching process. This review discusses the potential role of an extracellular matrix molecule, type XVIII collagen, in the generation of the branching patterns in the lung and kidney and how its experimental respecification in tissue recombinants between the ureteric bud and lung mesenchyme correlates with changes in expression of signaling molecules such as sonic hedgehog and changes in cell fate as judged by ectopic expression of the lung surfactant C gene.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 12761231 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
9: Adv Dent Res. 2001 Aug;15:55-8.
Human odontoblast culture method: the expression of collagen and matrix metalloproteinases (MMPs).
Tjäderhane L, Palosaari H, Wahlgren J, Larmas M, Sorsa T, Salo T.
Institute of Dentistry, University of Oulu, Oulu Municipal Health Center, Oulu, Finland. lst@cc.oulu.fi
Studies on mature human odontoblasts have suffered for the lack of in vitro models. We recently introduced a human odontoblast and pulp tissue organ culture method, in which the odontoblasts are cultured in the pulp chamber after removal of the pulp tissue, and the pulp tissue can be cultured separately (Tjäderhane et al., 1998a). With this method, we have studied the effects of growth factors on the expression of collagen and extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinases (MMPs), in mature human odontoblasts. TGF-beta 1 was selected because of its ability to regulate the response of the dentin-pulp complex to external irritation. The effect of TGF-beta 1 (10 ng/mL) on pro alpha 1(I) collagen mRNA was analyzed by quantitative PCR, and type I procollagen propeptide (PINP) was analyzed from conditioned culture media with RIA. Odontoblast media were also assayed for respective type III procollagen propeptide (PIIINP). TGF-beta had a negligible effect on collagen mRNA expression or protein synthesis, indicating that TGF-beta alone does not markedly induce dentin matrix formation per se in the human dentin-pulp complex (Palosaari et al., 2001). However, TGF-beta 1 seems to regulate MMP expression in mature human odontoblasts differentially. A strong down-regulation of MMP-8 (Palosaari et al., 2000), a modest down-regulation of MMP-20 (Tjäderhane et al., 2000), and considerable up-regulation of MMP-9, with no apparent effect on MMP-2 expression (Tjäderhane et al., 1998b), indicate that growth factors may affect the matrix synthesis by controlling the expression and activity of MMPs instead of collagen synthesis. The altered expression of MMPs may result in altered ECM formation, which in turn may contribute to the formation of atubular reparative dentin.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 12640741 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
10: Nippon Yakurigaku Zasshi. 2003 Jan;121(1):4-14.
[Therapeutic strategy for fibrotic diseases by regulating the expression of collagen-specific molecular chaperone HSP47]
[Article in Japanese]
Nagata K.
Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, Japan. nagata@frontier.kyoto-u.ac.jp
Through disruption of the hsp47 gene in mice, we found that HSP47, a collagen-specific molecular chaperone residing in the endoplasmic reticulum, is essential for mouse development. Improper triple helix formation was observed in hsp47-null embryos, and no collagen fibrils in the mesenchyme or basement membranes between the mesenchyme and epithelial cell layers were seen in those mice, which resulted in embryonic lethality. Interestingly, constitutive expression of HSP47 is always correlated with that of collagens in various cells or tissues. HSP47 is markedly up-regulated during the progression of fibrosis in the liver, kidney, lung, and so on. A preliminary experiment showed that down-regulation of HSP47 caused the reduction in the progression of fibrosis by down-regulating the accumulation of collagens in the tissues, which suggests a novel strategy for the therapy of fibrotic diseases including liver cirrhosis.
Publication Types:
English Abstract
Review
PMID: 12617032 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
11: Exp Biol Med (Maywood). 2002 May;227(5):301-14.
Factors involved in the regulation of type I collagen gene expression: implication in fibrosis.
Ghosh AK.
Section of Rheumatology, Department of Medicine, 1158 Molecular Biology Research Building, University of Illinois, 900 South Ashland Avenue, Chicago, IL 60607, USA. Ghoshak@uic.edu
Type I collagen, the major component of extracellular matrix in skin and other tissues, is a heterotrimer of two alpha1 and one alpha2 collagen polypeptides. The synthesis of both chains is highly regulated by different cytokines at the transcriptional level. Excessive synthesis and deposition of collagen in the dermal region causes thick and hard skin, a clinical manifestation of scleroderma. To better understand the causes of scleroderma or other tissue fibrosis, it is very important to investigate the molecular mechanisms that cause upregulation of the Type I collagen synthesis in these tissues. Several cis-acting regulatory elements and trans-acting protein factors, which are involved in basal as well as cytokine-modulated Type I collagen gene expression, have been identified and characterized. Hypertranscription of Type I collagen in scleroderma skin fibroblasts may be due to abnormal activities of different positive or negative transcription factors in response to different abnormally induced signaling pathways. In this review, I discuss the present day understanding about the involvement of different factors in the regulation of basal as well as cytokine-modulated Type I collagen gene expression and its implication in scleroderma research.
Publication Types:
Review
PMID: 11976400 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
12: Nephrol Dial Transplant. 2000;15 Suppl 6:66-8.
Regulation of type I collagen genes expression.
Rossert J, Terraz C, Dupont S.
INSERM U.489 and Department of Nephrology, Paris VI University, Assistance Publique-H pitaux de Paris, France.
Type I collagen is the major component of many extracellular matrices, and its accumulation characterizes most fibrotic processes. It is synthesized by a small number of discrete cell types, including fibroblasts, osteoblasts and odontoblasts. Analysis of transgenic mice harbouring different segments of the promoters of the mouse pro-alpha1 (I) and pro-alpha2 (I) genes has led to the conclusion that this tissue-specific expression is controlled by different cis-acting elements which are responsible for the expression of type I collagen genes in different type I collagen-producing cells. Transacting factors which bind to these different tissue-specific elements are still unknown, but they probably act by modifying the chromatin structure. In fibroblastic cells, various soluble molecules can modulate the transcription of type I collagen genes. Analysis of the pro-alpha1 (I) and pro-alpha2 (I) proximal promoters has led to the identification of different cis-acting elements which can modulate the expression of reporter genes, in transfection experiments. Among these cis-acting elements, a sequence located between -378 and -183 bp in the human pro-alpha2 (I) promoter appears to mediate the transcriptional effects of transforming growth factor-beta. It binds a large multimeric complex which contains Sp1, as well as AP1 and other DNA-binding proteins which have not yet been identified.
Publication Types:
Review
PMID: 11143996 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
13: Prog Mol Subcell Biol. 2000;25:89-104.
Expression of liver specific-genes in hepatocytes cultured in collagen gel matrix.
Gómez-Lechón MJ, Jover R, Donato T, Ponsoda X, Castell JV.
Unidad de Hepatología Experimental, Centro de Investigación, Valencia, Spain.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10986720 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
14: Biochem Soc Trans. 2000;28(4):350-3.
Recombinant expression systems for the production of collagen.
Bulleid NJ, John DC, Kadler KE.
School of Biological Sciences, Wellcome Trust Centre For Cell-Matrix Research, 2.205 Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PT, U.K. neil.bulleid@man.ac.uk
The ability of triple-helical collagen molecules to assemble into supramolecular structures forms the basis of commercial uses of collagen in the food industry and in medical applications such as cosmetic surgery and tissue repair. We have used cDNA techniques to engineer novel collagens with potentially enhanced biological properties; however, expression of fully functional novel molecules is difficult due to the complex nature of procollagen biosynthesis. This article outlines the application of various expression systems to procollagen production and details the use of the mammary gland as a suitable bioreactor for the synthesis of significant amounts of novel procollagens from cDNA constructs.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10961917 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
15: Springer Semin Immunopathol. 1999;21(4):397-414.
Alterations in the regulation of expression of the alpha 1(I) collagen gene (COL1A1) in systemic sclerosis (scleroderma).
Jimenez SA, Saitta B.
Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107-5541, USA. Sergio.Jimenez@mail.tju.edu
At present, the mechanisms that regulate the expression of collagen genes in normal and pathologic fibroblasts are not known. Thus, the detailed study of transcriptional regulation of COL1A1 in SSc cells will increase our current understanding of the pathophysiology of fibrotic diseases. These studies will yield valuable information regarding the important biological process of regulation of collagen gene expression under normal and pathologic conditions, a process that has remained elusive despite intense recent investigations. It is now evident that persistent overproduction of collagen is responsible for the progressive nature of tissue fibrosis in SSc. Up-regulation of collagen gene expression in SSc fibroblasts appears to be a critical event in this process. The coordinate transcriptional activation of numerous collagen genes suggests a fundamental alteration in the regulatory control of gene expression in SSc fibroblasts. Trans-acting nuclear factors which bind to cis-acting elements in enhancer (intronic) and promoter regions of the genes modulate the basal and inducible transcriptional activity of the collagen genes. The identification of the nuclear transcription factors that regulate normal collagen gene expression may provide promising approaches to the therapy of this incurable disease.
Publication Types:
Review
PMID: 10945033 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
16: Coron Artery Dis. 2000 Feb;11(1):57-68.
Greater than normal expression of the collagen-binding stress protein heat-shock protein-47 in the infarct zone in rats after experimentally-induced myocardial infarction.
Takeda K, Kusachi S, Ohnishi H, Nakahama M, Murakami M, Komatsubara I, Oka T, Doi M, Ninomiya Y, Tsuji T.
Department of Internal Medicine I, Okayama University Medical School, Japan.
BACKGROUND: The heat-shock protein with relative molecular mass 47,000 (HSP47) can bind to procollagen molecules in the endoplasmic reticulum, and acts as a molecular chaperone during the processing and secretion of procollagen. OBJECTIVE: To test our hypothesis that HSP47 is expressed in the myocardial infarct zone. METHODS: We induced myocardial infarction in male Sprague-Dawley rats by ligation of left coronary artery. The expression of HSP47 was examined by Northern blotting, in-situ hybridization, Western blotting and immunohistochemistry. The time-dependent change in the distribution of HSP47 messenger RNA (mRNA) signal was compared with the changes in expression of alpha 1(I) and alpha 1(III) collagen mRNA by in-situ hybridization. The hypoxic induction of HSP47 in cultured cardiac fibroblasts was examined by Northern-blot analysis. RESULTS: Northern blotting demonstrated that the expression of HSP47 mRNA had increased on day 2, reaching a maximum level around day 14 (induced 3.5-fold compared with the preligation hearts) and was maintained at a high level up to day 28. In-situ hybridization analysis revealed HSP47 mRNA signals in spindle-shaped mesenchymal cells located between surviving myocytes in the infarct's peripheral zone 24 h after the ligation, and in the entire infarct zone on day 14. The sequential changes in distribution of HSP47 mRNA signal were identical to those of the alpha 1(I) and alpha 1(III) collagen mRNA. Western blotting demonstrated that expression of HSP47 protein in the infarct zone had increased. Immunofluorescent staining revealed positivity for HSP47 in the infarct's peripheral zone on day 2 and in the entire infarct zone on day 14. Northern blotting revealed that the expression of HSP47 mRNA in cultured cardiac fibroblasts in hypoxic cultures was greater than that in normoxic cultures. CONCLUSION: The present data demonstrated that an increase in expression of HSP47 is produced by spindle-shaped mesenchymal cells in the infarct zone. Expression of HSP47 mRNA was concurrent with the expression of collagen mRNA of types I and III. Hypoxia is one of the factors which induces expression of HSP47.
Publication Types:
Review
PMID: 10715808 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
17: Trends Genet. 2000 Jan;16(1):21-7.
Cuticle collagen genes. Expression in Caenorhabditis elegans.
Johnstone IL.
Wellcome Centre for Molecular Parasitology, Anderson College, University of Glasgow, UK. gbga14@udcf.gla.ac.uk
Collagen is a structural protein used in the generation of a wide variety of animal extracellular matrices. The exoskeleton of the free-living nematode, Caenorhabditis elegans, is a complex collagen matrix that is tractable to genetic research. Mutations in individual cuticle collagen genes can cause exoskeletal defects that alter the shape of the animal. The complete sequence of the C. elegans genome indicates upwards of 150 distinct collagen genes that probably contribute to this structure. During the synthesis of this matrix, individual collagen genes are expressed in distinct temporal periods, which might facilitate the formation of specific interactions between distinct collagens.
Publication Types:
Research Support, Non-U.S. Gov't
Review
PMID: 10637627 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
18: Seikagaku. 1999 Jun;71(6):432-8.
[Diversified expression and function of minor fibrillar collagen]
[Article in Japanese]
Yoshioka H.
Department of Biochemistry, Oita Medical University.
Publication Types:
Review
PMID: 10432836 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
19: Blood. 1999 Jun 1;93(11):3575-7.
Platelet surface collagen receptor polymorphisms: variable receptor expression and thrombotic/hemorrhagic risk.
Santoro SA.
Division of Laboratory Medicine, Washington University School of Medicine, St Louis, MO, USA.
Publication Types:
Review
PMID: 10339460 [PubMed - indexed for MEDLINE]
--------------------------------------------------------------------------------
20: Wound Repair Regen. 1998 May-Jun;6(3):186-93.
Perspective article: collagen expression by novel cell populations in the dermal wound environment.
Lindblad WJ.
Department of Pharmaceutical Sciences & Institute of Chemical Toxicology, Wayne State University, Detroit, MI 48202, USA.
Numerous collagenous structures must be reconstituted following injury to the skin in order to return function to this tissue. The basement membrane zone, vascular basement membranes, and the dense connective tissue of the dermis are examples of structures that contain a number of different collagen types and that may need replacement following injury. In addition, a scar is deposited at the site of damage in order to substitute for elements lost in the trauma and for elements that cannot be successfully replaced. Clearly, cells resident within the different compartments of the skin are able to synthesize and deposit collagen to reform these multiple structures. However, accumulating experimental evidence suggests that in addition to these resident cells, blood-borne cells may be responsible for the deposition of a portion of the newly synthesized collagen. Studies from this laboratory point to the activated monocyte as a potential source of collagen in the wound environment. Given the dynamics of the process, the hypothesis is proposed that during normal wound healing, the activated monocyte is a source of collagen essential for the rapid formation of a provisional matrix conducive for the subsequent formation of granulation tissue. Collagen synthesis also occurs by expanded populations of resident cells, under the influence of inflammatory cell-derived mediators, which results in the major accumulation of collagen during normal wound repair. However, if a chronic inflammatory state is initiated, the activated monocytes may remain in sufficient numbers to deposit collagen leading to a pathological lesion.
Publication Types:
Review
PMID: 9776862 [PubMed - indexed for MEDLINE]
| Navigate through the articles | |
Collagen Interactions
|
Collagen Structure
|
|
|