scholarly journals Intracellular signaling of transcription and secretion of type IV collagen after angiotensin II-induced cellular hypertrophy in cultured proximal tubular cells.

1991 ◽  
Vol 2 (3) ◽  
pp. 219-227 ◽  
Author(s):  
G Wolf ◽  
P D Killen ◽  
E G Neilson
Keyword(s):  
Angiotensin Ii ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Regulatory Elements ◽  
Collagen Type Iv ◽  
Intracellular Camp ◽  
Tubular Epithelium ◽  
Cellular Hypertrophy ◽  
Type Iv ◽  
Proximal Tubular

Physiologic concentrations of angiotensin II (AII) can induce cellular hypertrophy in murine proximal tubular epithelium (MCT cells). This response is characterized by an increase in cell size, new protein synthesis, and by the secretion of new basement membrane type IV collagen in the absence of cellular proliferation. The present study was undertaken to evaluate the second messengers of these AII-induced cellular events with special reference to the increase in type IV collagen secretion. In initial experiments we observed that pretreatment of MCT cells with agents that increase concentrations of intracellular cAMP, like forskolin, dibutyryl cAMP, and isobutyl-methyl-xanthine abolish AII-induced amino acid incorporation, but have no effect on control cells or on their proliferation. In addition, 10(-8) M AII significantly decreased the concentration of intracellular cAMP. Phorbolesters were without significant effect on the hypertrophy or proliferation of AII-stimulated MCT cells or their rested controls. The transfection of MCT cells with reporter genes containing regulatory elements for type IV collagen revealed that the stimulatory effects of AII on collagen type IV depend, at least to some extent, on an increase in gene transcription. Agents increasing intracellular cAMP concentrations inhibited the AII-induced increase in transcription and secretion of collagen type IV, but had no effect on MCT cells grown in media without AII. Our findings provide evidence that AII-induced changes in tubular epithelium leading to the secretion of type IV collagen are mediated by a decrease in intracellular cAMP.

scholarly journals Expression of collagen type IV in human kidney during prenatal development

2020 ◽  
pp. 111-111
Author(s):  
Vladimir Petrovic ◽  
Ivan Nikolic ◽  
Marko Jovic ◽  
Vladimir Zivkovic ◽  
Miodrag Jocic ◽  
...  
Keyword(s):  
Type Iv Collagen ◽  
Collagen Type ◽  
Kidney Tissue ◽  
Volume Density ◽  
Collagen Iv ◽  
Basement Membranes ◽  
Collagen Type Iv ◽  
Type Iv ◽  
Metanephric Kidney ◽  
Collecting System

Background / Aim. Type IV collagen belongs to the group of non-fibrillar collagens and is an important component of the basement membranes where it accounts for approximately 50% of its structural elements. The aim of the paper was to describe the expression and distribution of collagen type IV in embryonic and fetal metanephric kidney, and to determine the volume density of collagen type IV in kidney tissue in each trimester of development. Methods. The material consisted of 19 human embryos/fetuses, in the gestational age from 8th to 37th week. Kidney tissue specimens were routinely processed to paraffin molds and stained with hematoxylin and eosin and immunohistochemically using polyclonal anti-collagen IV antibody. Stained slides were examined using light microscope and images of the selected areas, under different lens magnification were captured with digital camera. Volume density of collagen type IV was determined by using ImageJ 1.48v and a plugin of the software which inserted a grid system with 336 points. For the data comparison One-Way Analysis of Variance was used. Results. Strong collagen IV immunopositivity was seen in all specimens, with a distribution in the basement membranes of urinary bud, parietal leaf of Bowman?s capsule, glomerular basement membrane, basement membrane of interstitial blood vessels, and basement membranes of nephron tubules and collecting ducts. No statistically significant difference in the volume density of type IV collagen was found between the different trimesters of development. Conclusion. The synthesis and secretion of collagen type IV simultaneously follows the development of nephron structures, collecting system and blood vessels. The volume density of collagen type IV remains constant throughout all the trimesters of metanephric kidney development, indicating that it plays a crucial role in normal development of nephron and collecting system structures, as well as in maintaining the normal kidney function.

Effects of angiotensin II on proximal tubular cells stably transfected with the c-mas oncogene

1992 ◽  
Vol 263 (5) ◽  
pp. F931-F938 ◽  
Author(s):  
G. Wolf ◽  
E. G. Neilson
Keyword(s):  
Angiotensin Ii ◽  
De Novo ◽  
Cell Phenotype ◽  
Scatchard Analysis ◽  
Tubular Epithelium ◽  
Ang Ii ◽  
Protein Signaling ◽  
Signaling Mechanism ◽  
Cellular Hypertrophy ◽  
Proximal Tubular

Angiotensin II (ANG II) normally induces cellular hypertrophy in proximal tubular epithelium by engaging receptor systems that use a G-protein-signaling mechanism. The c-mas oncogene also encodes part of a superfamily of vasoactive peptide receptor-like moieties that couple to G proteins. To determine whether the stable expression of the c-mas gene might alter or modify the induction of cellular hypertrophy by ANG II in tubular epithelium, a rat c-mas cDNA was cloned into the pSV2 expression vector for use in cell transfection. Scatchard analysis of ANG II binding revealed no significant differences in ANG II receptor number or in the dissociation constant between pSV2mas-transfected or wild-type MCT cells, but rather an increase in the number of receptors not replaceable by known inhibitors. ANG II also induced proliferation in pSV2mas-transfected MCT cells that was not blocked by conventional inhibitors and increased intracellular levels of inositol trisphosphate. ANG II, furthermore, did not increase de novo protein synthesis in pSV2-transfected MCT cells and failed to lower their intracellular concentration of adenosine 3',5'-cyclic monophosphate, both expected parameters of cellular hypertrophy. Our findings demonstrate that expression of c-mas in tubular epithelium can modulate tubular cell phenotype toward proliferation rather than hypertrophy. This effect is likely mediated by a reshuffling of the heterogeneity of ANG II receptors on the cell surface, or perhaps by the emergence of a new ANG II receptor, followed by alterations in the process of signal transduction.

Malotilate Prevents Accumulation of Type III pN-Collagen, Type IV Collagen, and Laminin in Carbon Tetrachloride-induced Pulmonary Fibrosis in Rats

1989 ◽  
Vol 139 (5) ◽  
pp. 1105-1111 ◽  
Author(s):  
Paavo Pääkkö ◽  
Raija Sormunen ◽  
Leila Risteli ◽  
Juha Risteli ◽  
Leena Ala-Kokko ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Pulmonary Fibrosis ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Collagen Type Iv ◽  
Type Iii ◽  
Type Iv

Extracellular matrix components in the heart of the white bass, Morone chrysops (Rafinesque)

1994 ◽  
Vol 72 (3) ◽  
pp. 449-454
Author(s):  
Dominic S. Raso ◽  
Louis Terracio ◽  
Thomas K. Borg
Keyword(s):  
Type Iv Collagen ◽  
Collagen Type ◽  
Periodic Acid ◽  
Longitudinal Axis ◽  
Collagen Type Iv ◽  
Histological Techniques ◽  
White Bass ◽  
Morone Chrysops ◽  
Type Iv ◽  
Extracellular Matrix Components

The distribution of laminin, collagen type IV, collagen bundles, proteoglycans, elastin, and periodic acid–Schiff's moieties (glycoproteins) within the heart of the adult white bass, Morone chrysops (Rafinesque), was investigated by means of immunohistochemical and histological techniques. Laminin and collagen type IV were heavily expressed within the epimysium and the basal lamina of the lining epicardial epithelium and valvular endothelium, moderately expressed within the myocardium, and slightly expressed within the subendocardium. This co-localized distribution of laminin and collagen type IV corresponds to the biochemically unidentified basal and external lamina observed in the hearts of other fish by previous ultrastructural investigations and is similar to the distribution observed in the hearts of birds and mammals. Also demonstrated was an interesting division of connective tissue components along the longitudinal axis of the atrioventricular valve, which is most likely intimately involved with the effective functioning and durability of the valve.

Distribution of laminin, collagen type IV, collagen type I, and fibronectin in chicken cardiac jelly/basement membrane

1989 ◽  
Vol 224 (3) ◽  
pp. 417-425 ◽  
Author(s):  
Charles D. Little ◽  
Dominique M. Piquet ◽  
Lynn A. Davis ◽  
Luanne Walters ◽  
Christopher J. Drake
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Collagen Type I ◽  
Collagen Type Iv ◽  
Type I ◽  
Type Iv

Role of collagen type IV in the pathogenesis of increased prenasal thickness in Down syndrome fetuses: sonographic and immunohistological findings

2017 ◽  
Vol 45 (2) ◽  
Author(s):  
Ron Maymon ◽  
Sonia Mendlovic ◽  
Yaakov Melcer ◽  
Tal Sarig-Meth ◽  
Lilian Habler ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Blood Vessels ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Control Group ◽  
Collagen Type Iv ◽  
Type Iv ◽  
Products Of Conception ◽  
Tissue Specimens

AbstractObjective:The present study aims to compare the presence and localization of collagen type IV in the prenasal tissue of fetuses with and without Down syndrome (DS).Methods:Products of conception were obtained from mid-gestation uterine evacuations of 14 DS fetuses and 15 unaffected controls. Microdissection of the prenasal area and an analysis of the prenasal tissue specimens were performed by a single pathologist, blinded to the karyotype results. Immunohistological presence and localization of type IV collagen were analyzed in the basement membrane (BM), blood vessels, and stroma of the tissues.Results:There were no statistically significant differences in the presence and localization of antibodies for collagen IV in the blood vessels and stroma between the two groups. However, the presence and localization of type IV collagen in the BM of the prenasal skin were significantly higher in DS specimens compared to the control group (P=0.023). When combining both groups altogether, a significant correlation was found between the increased prenasal thickness (PT) and the high presence and location of collagen type IV, irrespective of the karyotype results (Spearman’s correlation; R=0.459; P=0.012).Conclusion:Using the immunohistochemistry technique, we were able to confirm the overexpression of collagen type IV in the BM of the prenasal area. This may explain the sonographic finding of increased PT seen mainly in DS fetuses.

scholarly journals Type IV Collagen, Type IV Collagenase Activity and Ability of Cell Proliferation in Human Thyroid Tumours

2002 ◽  
Vol 25 (4) ◽  
pp. 304-308 ◽  
Author(s):  
Takeshi Kusunoki ◽  
Shozo Nishida ◽  
Saori Kimoto-Kinoshita ◽  
Kiyotaka Murata ◽  
Takao Satou ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Human Thyroid ◽  
Collagen Type Iv ◽  
Collagenase Activity ◽  
Type Iv Collagenase ◽  
Type Iv

scholarly journals Evidence for the location of a binding sequence for the α2β1 integrin of endothelial cells, in the β1 subunit of laminin

1995 ◽  
Vol 309 (3) ◽  
pp. 765-771 ◽  
Author(s):  
P A Underwood ◽  
F A Bennett ◽  
A Kirkpatrick ◽  
P A Bean ◽  
B A Moss
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Type Iv Collagen ◽  
Collagen Type ◽  
Collagen Type Iv ◽  
Collagen Types ◽  
Type Iv ◽  
Integrin Binding Site ◽  
Beta 1 Integrin ◽  
Laminin 1

To date no specific location on laminin 1 for the binding of alpha 2 beta 1 integrin has been described, although recent evidence supports a location in the E1XNd fragment of the cross region. We have identified a peptide sequence from this region, in the beta 1 chain of laminin 1, YGYYGDALR, which inhibits the adhesion of endothelial cells to laminin 1 and type-IV collagen. A structurally related sequence from the CNBr-cleaved fragment CB3 of the alpha 1 chain of collagen type IV, FYFDLR, inhibits endothelial cell adhesion to both collagen types I and IV and laminin 1. The CB3 fragment containing the FYFDLR sequence has been shown to contain binding sites for both alpha 1 beta 1 and alpha 2 beta 1 integrins. Present experiments with anti-integrin antibodies indicate that the alpha 2 beta 1 integrin on endothelial cells can account for all the cell binding to collagen types I and IV, and that this integrin makes a major contribution towards the adhesion of these cells to laminin 1. We therefore propose that the peptide FYFDLR participates in alpha 2 beta 1 binding to collagen type IV and that the putatively structurally similar peptide, YGYYGDALR, participates in alpha 2 beta 1 binding to laminin 1. This is the first account of structurally related peptide sequences from laminin 1 and type-IV collagen which show reciprocal inhibition of cell adhesion to either ligand and which might form part of a common integrin-binding site, as well as the first suggestion of a precise location contributing to the alpha 2 beta 1 integrin binding site on laminin 1.

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