Rearrangements of the Cytoskeleton and Cell Contacts Induce Process Formation during Differentiation of Conditionally Immortalized Mouse Podocyte Cell Lines

Mündel, Peter; Reiser, Jochen; Borja, Aimée Zúñiga Mejı́a; Pavenstädt, Hermann; Davidson, Gary; Kriz, Wilhelm; Zeller, Rolf

doi:10.1006/excr.1997.3739

Cited by 822 publications

(909 citation statements)

References 24 publications

Supporting

Mentioning

881

Contrasting

Unclassified

Order By: Relevance

“…27 Production of HIV-1 constructs has been described previously. 9 The podocytes used in these experiments are from an established line of pNL4-3:d1443 and pHR-CMV-IRES2-GFP-⌬B-infected podocytes.…”

Section: Conditionally Immortalized Murine Podocytes With Hiv-1-exprementioning

confidence: 99%

HIV-1 Upregulates VEGF in Podocytes

Korgaonkar

Feng²,

Ross³

et al. 2008

Journal of the American Society of Nephrology

View full text Add to dashboard Cite

Section: Conditionally Immortalized Murine Podocytes With Hiv-1-exprementioning

confidence: 99%

HIV-1 Upregulates VEGF in Podocytes

Korgaonkar

Feng²,

Ross³

et al. 2008

Journal of the American Society of Nephrology

View full text Add to dashboard Cite

“…Equal volumes were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by Western blotting. The same protocol was also used for cultured mouse podocytes 18 transiently transfected with the Fugene-6 transfection method (Roche, Mannheim, Germany) with a cDNA construct containing rat nephrin. 19 Cholesterol depletion was performed by pretreating the total glomerular membranes with 0.2% saponin (Sigma, St. Louis, MO) for 10 minutes on ice before TX-100 extraction.…”

Section: Preparation Of Total Glomerular Membranes and Tx-100 Flotatimentioning

confidence: 99%

Involvement of Lipid Rafts in Nephrin Phosphorylation and Organization of the Glomerular Slit Diaphragm

Simons

Schwarz

Kriz

et al. 2001

The American Journal of Pathology

Self Cite

146

126

View full text Add to dashboard Cite

NPHS1 has recently been identified as the gene whose mutations cause congenital nephrotic syndrome of the Finnish type. The respective gene product nephrin is a transmembrane protein expressed in glomerular podocytes and primarily localized to the glomerular slit diaphragm. This interpodocyte junction functions in the glomerular filtration by restricting the passage of plasma proteins into the urinary space in a size-selective manner. The functional role of nephrin in this filtration process is so far not very well understood. In this study, we show that nephrin associates in an oligomerized form with signaling microdomains, also known as lipid rafts, and that these localize to the slit diaphragm. We also show that the nephrin-containing rafts can be immunoisolated with the 27A antibody recognizing a podocyte-specific 9-Oacetylated GD3 ganglioside. In a previous study it has been shown that the in vivo injection of this antibody leads to morphological changes of the filtration slits resembling foot process effacement. Here, we report that, in this model of foot process effacement, nephrin dislocates to the apical pole of the narrowed filtration slits and also that it is tyrosine phosphorylated. We suggest that lipid rafts are important in the spatial organization of the glomerular slit diaphragm under physiological and pathological conditions. One of the main functions of the kidney is formation of the primary urine in the glomerulus by plasma ultrafiltration. The structural correlate of ultrafiltration is the glomerular capillary wall with its distinctly layered filtration barrier. It consists of the fenestrated vascular endothelium, the glomerular basement membrane, and a layer of morphologically highly specialized epithelial cells, podocytes.Podocytes form a tight network of multiple interdigitating cellular extensions, called foot processes, which are bridged by so-called "slit diaphragms." 1 The filtration barrier is freely permeable for water, small solutes, and ions but does not allow passage for proteins larger than albumin and other large molecules. The charge selectivity in this process has been attributed to the glomerular basement membrane whereas the slit diaphragm supposedly plays a major role in the size selectivity. 2,3 The importance of the filtration barrier is reflected by a number of human diseases in which the filtration barrier function is disrupted resulting in the loss of plasma proteins into the urine. Patients with persistent proteinuria ultimately develop a nephrotic syndrome with a variety of symptoms including edema, hypoalbuminemia, and hyperlipidemia. 4

show abstract

“…Our findings suggest that CDK4 podocytes are useful tools to study podocyte biology. Furthermore, the role of cell-cell contact in podocyte gene expression may have relevance for podocyte function in vivo.cyclin-dependent kinase 4; SV40 large T antigen; nephrin; synaptopodin; Wilms tumor-1; P-cadherin PODOCYTE CULTURES, ESPECIALLY podocyte cell lines transformed by thermosensitive SV40 large T antigen (SV40 T), have been widely used to study podocyte biology (19,25). However, as we recently reported in studies on a generation of mouse and human podocyte cell lines, podocytes transformed by thermosensitive SV40 T (tsT) exhibit phenotypic differences compared with podocytes in vivo, with reduced expression of certain differentiation marker genes (13, 24).…”

mentioning

confidence: 99%

“…PODOCYTE CULTURES, ESPECIALLY podocyte cell lines transformed by thermosensitive SV40 large T antigen (SV40 T), have been widely used to study podocyte biology (19,25). However, as we recently reported in studies on a generation of mouse and human podocyte cell lines, podocytes transformed by thermosensitive SV40 T (tsT) exhibit phenotypic differences compared with podocytes in vivo, with reduced expression of certain differentiation marker genes (13,24).…”

mentioning

confidence: 99%

Cell-cell contact regulates gene expression in CDK4-transformed mouse podocytes

Sakairi

Abe

Jat

et al. 2010

American Journal of Physiology-Renal Physiology

View full text Add to dashboard Cite

We transformed mouse podocytes by ectopic expression of cyclin-dependent kinase 4 (CDK4). Compared with podocytes transformed with a thermo-sensitive SV40 large T antigen mutant tsA58U19 (tsT podocytes), podocytes transformed with CDK4 (CDK4 podocytes) exhibited significantly higher expression of nephrin mRNA. Synaptopodin mRNA expression was significantly lower in CDK4 podocytes and in tsT podocytes under growth-permissive conditions (33°C) compared with tsT podocytes under growth-restricted conditions (37°C), which suggests a role for cell cycle arrest in synaptopodin mRNA expression. Confluent CDK4 podocytes showed significantly higher mRNA expression levels for nephrin, synaptopodin, Wilms tumor 1, podocalyxin, and P-cadherin compared with subconfluent cultures. We carried out experiments to clarify roles of various factors in the confluent podocyte cultures; our findings indicate that cell-cell contact promotes expression of five podocyte marker genes studied, that cellular quiescence increases synaptopodin and podocalyxin mRNA expression, and that soluble factors play a role in nephrin mRNA expression. Our findings suggest that CDK4 podocytes are useful tools to study podocyte biology. Furthermore, the role of cell-cell contact in podocyte gene expression may have relevance for podocyte function in vivo.cyclin-dependent kinase 4; SV40 large T antigen; nephrin; synaptopodin; Wilms tumor-1; P-cadherin PODOCYTE CULTURES, ESPECIALLY podocyte cell lines transformed by thermosensitive SV40 large T antigen (SV40 T), have been widely used to study podocyte biology (19,25). However, as we recently reported in studies on a generation of mouse and human podocyte cell lines, podocytes transformed by thermosensitive SV40 T (tsT) exhibit phenotypic differences compared with podocytes in vivo, with reduced expression of certain differentiation marker genes (13, 24).Cyclin-dependent kinase 4 (CDK4), a catalytic subunit of the cyclin D-CDK4 serine/threonine kinase complex, is a critical regulator of the cell cycle. CDK4 is the first kinase activated by mitogenic signals. The kinase activity of CDK4 is specifically involved in progression through G1, via phosphorylation of retinoblastoma (Rb) family members (4). Recently, Ramirez et al. (22) immortalized human bronchial epithelial cells by ectopic expression of CDK4 and human telomerase (hTERT). Microarray analysis showed that CDK4/hTERTimmortalized cells showed significantly different gene expression profiles compared with cells immortalized with human papiloma viral oncoproteins E6/E7 or SV40T and that CDK4-transformed cells clustered with primary bronchial epithelial cells. In addition, recent studies showed that cells immortalized with CDK4 are useful tools to study physiology and pathophysiology (8,23,30).We set out to develop an alternative approach to transforming podocytes by comparing the phenotype among primary cells, CDK4-transformed podocytes (CDK4-podocytes) and thermosensitive SV40 T mutant tsA58U19 (tsT-podocytes). We found that CDK4-podocytes and tsT-podocyt...

show abstract

Rearrangements of the Cytoskeleton and Cell Contacts Induce Process Formation during Differentiation of Conditionally Immortalized Mouse Podocyte Cell Lines

Cited by 822 publications

References 24 publications

HIV-1 Upregulates VEGF in Podocytes

HIV-1 Upregulates VEGF in Podocytes

Involvement of Lipid Rafts in Nephrin Phosphorylation and Organization of the Glomerular Slit Diaphragm

Cell-cell contact regulates gene expression in CDK4-transformed mouse podocytes

Contact Info

Product

Resources

About