Localization by Immunofluorescent Microscopy of Several Collagen Types and of a Basement Membrane Proteoglycan in Rat Glomerular Epithelial and Mesangial Cell Cultures

1983 ◽  
Vol 6 (4) ◽  
pp. 163-170 ◽  
Author(s):  
J.B. Foidart ◽  
J.M. Foidart ◽  
J. Hassell ◽  
P. Mahieu
1996 ◽  
Vol 316 (3) ◽  
pp. 985-992 ◽  
Author(s):  
Nadia Abdel WAHAB ◽  
Katherine HARPER ◽  
Roger M. MASON

Post-mitotic cultures of human mesangial cells were maintained in media containing 4–30 mM D-glucose for up to 28 days. Changes in mRNA and protein levels for specific macromolecules occurred between 7 and 14 days after initiating hyperglycaemic conditions. Slot blot analysis showed 2–3-fold increases in mRNAs for collagen type I, fibronectin, versican and perlecan, whereas mRNA for decorin was increased by up to 20-fold. Levels of mRNAs for biglycan and syndecan were unaffected by hyperglycaemic culture. Reverse transcriptase PCR (RT–PCR) confirmed that decorin mRNA levels are greatly elevated and also showed increased transcription of the TGF-β1 gene in hyperglycaemic cultures. Western analysis and ELISA indicated accumulations of collagen types I and III, laminin and fibronectin in the cell layers and media of hyperglycaemic cultures with increasing time. Type IV collagen did not accumulate in either compartment of hyperglycaemic mesangial cell cultures. Collagen types I, III, and fibronectin did not accumulate in the cell layers of hyperglycaemic human dermal fibroblasts, indicating a cell-specific response in mesangial cultures. Decorin and versican, but not biglycan, were increased in the hyperglycaemic mesangial cell culture media. There were no apparent changes in core proteins for decorin and biglycan in fibroblast media. Transforming growth factor β1 (TGF-β1) in hyperglycaemic mesangial cell cultures increased 5-fold after 7 days, but decreased thereafter to only approx. 2-fold after 28 days. The changes in TGF-β1 mRNA, as detected by RT–PCR, and protein followed one another closely.


1988 ◽  
Vol 254 (2) ◽  
pp. 609-612 ◽  
Author(s):  
W H Baricos ◽  
G Murphy ◽  
Y W Zhou ◽  
H H Nguyen ◽  
S V Shah

Neutral metalloproteinases degrade components of the extracellular matrix, including collagen types I-V, fibronectin, laminin and proteoglycan. However, their ability to degrade intact glomerular basement membrane (GBM) has not previously been investigated. Incubation of [3H]GBM (50,000 c.p.m.; pH 7.5; 24 h at 37 degrees C) with purified gelatinase or stromelysin (2 units) resulted in significant GBM degradation: gelatinase, 46 +/- 2.2; stromelysin, 59 +/- 5.8 (means +/- S.E.M.; percentage release of non-sedimentable radioactivity; n = 4). In contrast, 2 units of collagenase released only 5.6 +/- 0.52% (n = 3) of the [3H]GBM radioactivity compared with 2.0 +/- 0.15% (n = 7) released from [3H]GBM incubated alone. Sephadex G-200 gel chromatography of supernatants obtained from incubations of [3H]GBM with either gelatinase or stromelysin confirmed the ability of these enzymes to degrade GBM and revealed both high-(800,000) and relatively low-(less than 20,000) Mr degradation products for both enzymes. GBM degradation by gelatinase and stromelysin was dose-dependent (range 0.02-2.0 units), near maximal between pH 6.0 and 8.6, and was completely inhibited (greater than 95%) by 2 mM-o-phenanthroline. Collagenase (2 units) did not enhance the degradation of GBM by either gelatinase (0.02 or 0.2 unit) or stromelysin (0.02 or 0.2 unit). Our results indicate that metalloproteinase-mediated GBM degradation by neutrophils and glomeruli may be attributable to gelatinase (neutrophils) and/or stromelysin (glomeruli) and suggest an important role for these proteinases in glomerular pathophysiology.


1985 ◽  
Vol 30 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Wolfgang Jelkmann ◽  
Armin Kurtz ◽  
Ulrich Förstermann ◽  
Josef Pfeilschifter ◽  
Christian Bauer

1994 ◽  
Vol 46 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Jeffrey I. Kreisberg ◽  
Robert A. Radnik ◽  
Suzanne H. Ayo ◽  
JoAnn Garoni ◽  
Pothana Saikumar

2019 ◽  
Vol 6 (4) ◽  
pp. 35 ◽  
Author(s):  
Michael Chute ◽  
Preetinder Aujla ◽  
Sayantan Jana ◽  
Zamaneh Kassiri

The extracellular matrix (ECM) provides structural support and a microenvironmentfor soluble extracellular molecules. ECM is comprised of numerous proteins which can be broadly classified as fibrillar (collagen types I and III) and non-fibrillar (basement membrane, proteoglycans, and glycoproteins). The basement membrane provides an interface between the cardiomyocytes and the fibrillar ECM, while proteoglycans sequester soluble growth factors and cytokines. Myocardial fibrosis was originally only linked to accumulation of fibrillar collagens, but is now recognized as the expansion of the ECM including the non-fibrillar ECM proteins. Myocardial fibrosis can be reparative to replace the lost myocardium (e.g., ischemic injury or myocardial infarction), or can be reactive resulting from pathological activity of fibroblasts (e.g., dilated or hypertrophic cardiomyopathy). Contribution of fibrillar collagens to fibrosis is well studied, but the role of the non-fibrillar ECM proteins has remained less explored. In this article, we provide an overview of the contribution of the non-fibrillar components of the extracellular space of the heart to highlight the potential significance of these molecules in fibrosis, with direct evidence for some, although not all of these molecules in their direct contribution to fibrosis.


2003 ◽  
Vol 161 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Yamato Kikkawa ◽  
Ismo Virtanen ◽  
Jeffrey H. Miner

In developing glomeruli, laminin α5 replaces laminin α1 in the glomerular basement membrane (GBM) at the capillary loop stage, a transition required for glomerulogenesis. To investigate domain-specific functions of laminin α5 during glomerulogenesis, we produced transgenic mice that express a chimeric laminin composed of laminin α5 domains VI through I fused to the human laminin α1 globular (G) domain, designated Mr51. Transgene-derived protein accumulated in many basement membranes, including the developing GBM. When bred onto the Lama5 −/− background, Mr51 supported GBM formation, preventing the breakdown that normally occurs in Lama5 −/− glomeruli. In addition, podocytes exhibited their typical arrangement in a single cell layer epithelium adjacent to the GBM, but convolution of glomerular capillaries did not occur. Instead, capillaries were distended and exhibited a ballooned appearance, a phenotype similar to that observed in the total absence of mesangial cells. However, here the phenotype could be attributed to the lack of mesangial cell adhesion to the GBM, suggesting that the G domain of laminin α5 is essential for this adhesion. Analysis of an additional chimeric transgene allowed us to narrow the region of the α5 G domain essential for mesangial cell adhesion to α5LG3-5. Finally, in vitro studies showed that integrin α3β1 and the Lutheran glycoprotein mediate adhesion of mesangial cells to laminin α5. Our results elucidate a mechanism whereby mesangial cells organize the glomerular capillaries by adhering to the G domain of laminin α5 in the GBM.


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