scholarly journals Puromycin Aminonucleoside Suppresses Integrin Expression in Cultured Glomerular Epithelial Cells

2001 ◽  
Vol 12 (4) ◽  
pp. 758-766 ◽  
Author(s):  
UMA KRISHNAMURTI ◽  
BING ZHOU ◽  
WEI-WEI FAN ◽  
EFFIE TSILIBARY ◽  
ELIZABETH WAYNER ◽  
...  

Abstract. Puromycin aminonucleoside (PAN)-induced nephrosis is a well-described model of human idiopathic nephrotic syndrome, but the mechanism of PAN's effect is not completely understood. Because PAN injection into rats results in retraction of glomerular epithelial cell foot processes and glomerular epithelial cell detachment, it was hypothesized that PAN might alter the contacts between these cells and the glomerular basement membrane. The major integrin expressed by glomerular epithelial cells is α3β1, which mediates attachment of these cells to extracellular matrix proteins including type IV collagen. T-SV 40 immortalized human glomerular epithelial cells were used to study PAN's effects on α3β1 expression, as well as that of podocalyxin and the slit diaphragm component ZO-1. Glomerular epithelial cells were seeded into plastic flasks and allowed to attach and proliferate for 48 h. The cells were then incubated for another 48 h in media containing 0, 0.5, or 5.0 μg/ml PAN. PAN exposure resulted in dose-dependent decreases in α3 and β1 expression, both at the protein level and at the mRNA level. This was accompanied by a significant decrease in the adhesion of glomerular epithelial cells to type IV collagen. PAN did not affect ZO-1 protein expression. Treatment with PAN increased the expression of podocalyxin at the protein and mRNA levels. Reduced glomerular epithelial cell expression of α3β1 integrins and impaired adhesion to type IV collagen may contribute to the glomerular epithelial cell detachment from glomerular basement membrane seen in the PAN nephrosis model.

1992 ◽  
Vol 2 (9) ◽  
pp. 1388-1397
Author(s):  
R Johnson ◽  
H Yamabe ◽  
Y P Chen ◽  
C Campbell ◽  
K Gordon ◽  
...  

Cultured rat glomerular epithelial cells (GEC) were examined for their ability to release extracellular matrix-degrading proteinases with [3H]gelatin as substrate. GEC-conditioned media, under serum-free conditions, contained modest amounts of gelatinase activity (1 to 10 U/mg of protein); the activity was maximal at neutral pH, was inhibited by zinc chelators, was not inhibited by tissue inhibitor of metalloproteinase-2, and could not be further activated by trypsin or organomercurials. Gelatin substrate sodium dodecyl sulfate-polyacrylamide gels of GEC-conditioned medium revealed several zones of lysis, with molecular sizes of 150 kd (major band), and 220, 86 to 93, and 52 to 54 kd (minor bands). Northern blot analysis demonstrated that the GEC metalloproteinase(s) were distinct from the 68- to 72-kd type IV collagenase/gelatinase present in mesangial cells or the 92-kd type IV collagenase present in neutrophils. The GEC gelatinolytic activity also degraded insoluble type IV collagen in glomerular basement membrane in a dose-dependent manner. The major metalloproteinase activity responsible for the type IV collagen degradation has a molecular size of 150 kd with a type IV collagen substrate gel. Thus, GEC produce several neutral metalloproteinases, which, by virtue of their substrate specificity, may play an important role in glomerular basement membrane remodeling and in glomerular diseases characterized by alterations in basement membrane permeability.


1992 ◽  
Vol 262 (1) ◽  
pp. F131-F137 ◽  
Author(s):  
Y. Natori ◽  
Y. M. O'Meara ◽  
E. C. Manning ◽  
A. W. Minto ◽  
J. S. Levine ◽  
...  

To study the formation of basement membrane by glomerular epithelial cells (GECs), production and secretion of type IV collagen and laminin by rat GECs in culture were evaluated. GECs produced two chains of type IV collagen (180 and 170 kDa) in the ratio of approximately 2 to 1, when immunoprecipitated with antibody to type IV collagen of mouse Engelbreth-Holm-Swarm (EHS) sarcoma. GECs also produced proteins that were precipitated by antibody to EHS laminin, i.e., two bands each in the positions of the A and B chains of mouse laminin. On enzyme-linked immunosorbent assay (ELISA), type IV collagen and laminin were found mainly in the cell-associated fraction and in the subepithelial culture medium. Confluent GECs on membrane filters formed a tight barrier against the flux of macromolecules. Under these conditions, 80% of newly synthesized and secreted matrix proteins were detected in the basolateral medium. Moreover, treatment with ammonium chloride, which is known to affect polarized secretion, caused both type IV collagen and laminin to be secreted via the basolateral and apical surfaces in similar amounts. These results indicate that cultured GECs are polarized and that they produce and secrete basement membrane components via the basolateral side.


1988 ◽  
Vol 255 (4) ◽  
pp. F590-F596 ◽  
Author(s):  
B. S. Kasinath ◽  
A. K. Singh ◽  
Y. S. Kanwar ◽  
E. J. Lewis

It has been suggested that the glomerular basement membrane heparan sulfate proteoglycan (HSPG) is an important determinant of the glomerular permselectivity barrier. Derangements in the content of basement membrane heparan sulfate have been implicated in alterations in glomerular permselectivity seen in many glomerular diseases such as aminonucleoside nephrosis. The cellular origin and metabolism of the glomerular basement membrane HSPG have not been studied in detail. We have detected the expression of the proteoglycan by cloned glomerular visceral epithelial cells of the rat by employing a specific antibody against the core protein of HSPG isolated from the rat glomerular basement membrane. These findings suggest that in the rat in vivo glomerular visceral epithelial cells are one source of heparan sulfate present in the glomerular basement membrane. The effect of puromycin aminonucleoside (PAN) on the HSPG core protein content of the cloned glomerular epithelial cells was studied. By a quantitative immunoperoxidase method, the aminonucleoside caused a 28% reduction in the core protein content of the epithelial cells (P less than 0.01) following 72 h of incubation. However, the content of Heymann nephritis-related antigen, Fx1A was unchanged. Studies employing [3H]leucine incorporation showed that PAN was a weak inhibitor of de novo protein synthesis at 24 h of incubation, with complete recovery at 48 and 72 h. These data suggest that PAN effect on heparan sulfate core protein cannot be attributed to generalized inhibition of protein synthesis. The precise mechanism underlying the aminonucleoside effect on heparan sulfate core protein remains to be elucidated.


2007 ◽  
Vol 106 (3) ◽  
pp. e77-e87 ◽  
Author(s):  
Asa Ogawa ◽  
Minoru Sakatsume ◽  
Xingzhi Wang ◽  
Yunichi Sakamaki ◽  
Yutaka Tsubata ◽  
...  

2000 ◽  
Vol 69 (4) ◽  
pp. 679-684 ◽  
Author(s):  
Raghu Kalluri ◽  
Adriana Torre ◽  
Charles F. Shield ◽  
Eric D. Zamborsky ◽  
Michelle C. Werner ◽  
...  

2000 ◽  
Vol 1 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Michele Doucet ◽  
Irene Londoño ◽  
Amparo Gómez-Pascual ◽  
Moise Bendayan

In diabetes, the glomerular basement membrane undergoes thickening and structural alterations with loss of glomerular permselectivity properties. However, the onset of the alterations at early phases of diabetes is unclear. Aiming to determine the functional and structural alterations of the glomerular wall in the early stages of diabetes, we have studied the distribution of endogenous circulating albumin and type IV collagen in the glomerular basement membrane, using the immunocytochemical approach. The streptozotocin-injected hyperglycemic rat was our animal model. Renal tissues were examined after 10 days, 2, 4 and 6 months of hyperglycemia. Upon immunogold labelings, changes in the glomerular permeability to endogenous albumin were found altered as early as upon ten days of hyperglycemia. In contrast, no structural modifications were detected at this time point. Indeed, glomerular basement membrane thickening and an altered type IV collagen labeling distribution were only observed after four months of hyperglycemia, suggesting that functional alterations take place early in diabetes prior to any structural modification. In order to evaluate the reversibility of the glomerular alterations, two-month-old diabetic animals were treated with insulin. These animals showed a significant restoring of their glomerular permselectivity. Our results suggest a link between glycemic levels and alteration of glomerular permeability in early stages of diabetes, probably through high levels of glycated serum proteins.


2016 ◽  
Vol 12 (24) ◽  
pp. 98
Author(s):  
Afsana Munni

Glomerulonephritis disease is characterized by inflammation of glomeruli or small blood vessels in the kidney which causes kidney diseases. Glomerulonephritis disease deposits the anti-GBM auto antibody in the glomerular basement membrane. The type IV collagen is the main component of glomerular basement membrane that has α3 chain of type (IV) collagen of non-collagenous domain which contains N-terminal 7S domain, a triple helical collagenous domain, and a C- terminal non-collagenous glomerular domain (NC1). The amino terminal of α3 (IV) NC1 that induces the experimental autoimmuno glomerulonephritis (EAG) in rat model has been identified. The recombinant rat α3 (IV)NC1 antigen has nine amino acid span that is consistent with antibody or T cell epitope which is induced in EAG. The research is carried out on the recombinant rat α3 (IV) NC1 production, purification, quantification, and characterization. The circulation of Anti-GBM antibody in glomerular basement membrane can be measured by the ELISA assay. In addition, the recombinant rat antigen is secreted in HEK293 cell supernatant which is purified by Anti-FLAG M2 monoclonal IgG antibody affinity column. In addition, it is characterized and quantified by SDS-PAGE gel electrophoresis and Western blotting techniques.


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