The Proteoglycan Syndecan 4 Regulates Transient Receptor Potential Canonical 6 Channels via RhoA/Rho-associated Protein Kinase Signaling

Liu, Ying; Echtermeyer, Frank; Thilo, Florian; Theilmeier, Gregor; Schmidt, Antje; Schülein, Ralf; Jensen, Boye L.; Loddenkemper, Christoph; Jankowski, Vera; Marcussen, Niels; Gollasch, Maik; Arendshorst, William J.; Tepel, Martín

doi:10.1161/atvbaha.111.241018

Cited by 39 publications

(46 citation statements)

References 45 publications

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“…Recently, we showed an increased TRPC6 channel protein expression in podocytes from patients with diabetic nephropathy compared to control subjects [12]. We also reported that the expression of TRPC6 channels in podocytes can be modified by growth factors [12,13]. These finding supported the view that insulin-dependent changes of TRPC6 channels may be involved in the pathogenesis of diabetic nephropathy.…”

Section: Introductionsupporting

confidence: 70%

“…The cell preparation procedures had also been described by our group earlier [12,13]. The podocytes were maintained in RPMI 1640 medium without glucose (Gibco, Life Technologies, CA, USA) supplemented with 5.6 mmol/L D-glucose, 10 % fetal bovine serum, 100 units/mL penicillin, and 100 µg/ mL streptomycin (Biochrom AG, Berlin, Germany).…”

Section: Preparation Of Cellsmentioning

confidence: 99%

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Insulin Increases Expression of TRPC6 Channels in Podocytes by a Calcineurin-Dependent Pathway

Xia

Liu

et al. 2016

Cell Physiol Biochem

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Background/Aims: Insulin signaling to podocytes is relevant for the function of the glomerulus. Now, we tested the hypothesis that insulin increases the surface expression of canonical transient receptor potential canonical type 6 (TRPC6) channels in podocytes by a calcineurin-dependent pathway. Methods: We used quantitative RT-PCR, immunoblotting, immunofluorescence and fluorescence spectrophotometry in cultured podocytes. Activation of Nuclear Factor of Activated T-cells (NFATc1) was measured using a specific calorimetric assay. Results: Insulin increased the expression of TRPC6 transcripts and protein in podocytes. Insulin increased TRPC6 transcripts in a time and dose-dependent manner. The insulin-induced elevation of TRPC6 transcripts was blocked in the presence of tacrolimus, cyclosporine A, and NFAT-inhibitor (each p < 0.01 by ANOVA and Bonferroni's multiple comparison test). Transcripts of NOX4, another target gene of the calcineurin-NFAT pathway, were affected in a similar way. Immunoblotting showed that the administration of 100 nmol/L insulin increased TRPC6-proteins 2-fold within 48 hours. Insulin increased the activity of NFATc1 in nuclear extracts (p < 0.001) whereas tacrolimus, cyclosporine A, and NFAT-inhibitor blocked that insulin effect (p < 0.001; two way ANOVA). Immunofluorescence showed that insulin increased TRPC6-expression on the cell surface. Fluorescence-spectrophotometry and manganese quench experiments indicated that the increased TRPC6-expression after insulin administration was accompanied by an elevated transplasmamembrane cation influx. Insulin-stimulated surface expression of TRPC6 as well as transplasmamembrane cation influx could be reduced by pretreatment with tacrolimus. Conclusion: Insulin increases the expression of TRPC6 channels in podocytes by activation of the calcineurin-dependent pathway.

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Section: Introductionsupporting

confidence: 70%

Section: Preparation Of Cellsmentioning

confidence: 99%

Insulin Increases Expression of TRPC6 Channels in Podocytes by a Calcineurin-Dependent Pathway

Xia

Liu

et al. 2016

Cell Physiol Biochem

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“…However, the knockdown of zebrafish sdc3 and sdc4 alone or in combination has no effect on GFB function or podocyte phenotype. Similarly, Liu et al stated that podocyte foot processes, slit diaphragms, GBM and glomerular endothelium were structurally normal in Sdc4 −/− mice [34]. Even though endothelial cell fenestration per µm GBM was significantly reduced in sdc3-MO compared to CTRL-MO injected zebrafish larvae sdc3-MO injected fish maintained a functional filtration barrier.…”

Section: Discussionmentioning

confidence: 90%

Overexpression of TGF-β Inducible microRNA-143 in Zebrafish Leads to Impairment of the Glomerular Filtration Barrier by Targeting Proteoglycans

Müller-Deile

Gellrich

Schenk

et al. 2016

Cell Physiol Biochem

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Background: TGF-β is known as an important stress factor of podocytes in glomerular diseases. Apart from activation of direct pro-apoptotic pathways we wanted to analyze micro-RNA (miRs) driven regulation of components involved in the integrity of the glomerular filtration barrier induced by TGF-β. Since miR-143-3p (miR-143) is described as a TGF-β inducible miR in other cell types, we examined this specific miR and its ability to induce glomerular pathology. Methods: We analyzed miR-143 expression in cultured human podocytes after stimulation with TGF-β. We also microinjected zebrafish eggs with a miR-143 mimic or with morpholinos specific for its targets syndecan and versican and compared phenotype and proteinuria development. Results: We detected a time dependent, TGF-β inducible expression of miR-143 in human podocytes. Targets of miR-143 relevant in glomerular biology are syndecans and versican, which are known components of the glycocalyx. We found that syndecan 1 and 4 were predominantly expressed in podocytes while syndecan 3 was largely expressed in glomerular endothelial cells. Versican could be detected in both cell types. After injection of a miR-143 mimic in zebrafish larvae, syndecan 3, 4 and versican were significantly downregulated. Moreover, miR-143 overexpression or versican knockdown by morpholino caused loss of plasma proteins, edema, podocyte effacement and endothelial damage. In contrast, knockdown of syndecan 3 and syndecan 4 had no effects on glomerular filtration barrier. Conclusion: Expression of versican and syndecan isoforms is indispensable for proper barrier function. Podocyte-derived miR-143 is a mediator for paracrine and autocrine cross talk between podocytes and glomerular endothelial cells and can alter expression of glomerular glycocalyx proteins.

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“…Similarly, RhoA facilitated membrane insertion of TRPC6 following the thrombin stimulation in endothelial cells (46) tein-coupled receptor activation in HEK293 cells (7). Also, a proteoglycan, syndecan 4, was shown to enhance the insertion of TRPC6 channels in the plasma membrane via a RhoAdependent pathway in podocytes (43). Another possibility is that RhoA modulates the channel activities of TRPC6 by posttranslational modifications such as phosphorylation.…”

Section: Discussionmentioning

confidence: 99%

Nuclear factor of activated T cells mediates RhoA-induced fibronectin upregulation in glomerular podocytes

Zhu

Aoudjit

et al. 2013

American Journal of Physiology-Renal Physiology

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Glomerulosclerosis is featured by accumulation of the extracellular matrixes in the glomerulus. We showed previously that activation of the small GTPase RhoA in podocytes induces heavy proteinuria and glomerulosclerosis in the mouse. In the current study, we investigated the mechanism by which RhoA stimulates the production of one of the extracellular matrixes, fibronectin, by podocytes, specifically testing the role of nuclear factor of activated T cells (NFAT). Expression of constitutively active RhoA in cultured podocytes activated the fibronectin promoter, upregulated fibronectin protein, and activated NFAT. Expression of constitutively active NFAT in podocytes also activated the fibronectin promoter and upregulated fibronectin protein. RhoA-induced NFAT activation and fibronectin upregulation were both dependent on the calcium/calmodulin pathway and Rho kinase. NFAT activation was also observed in vivo in the rat and mouse models of podocyte injury and proteinuria, and NFAT inhibition ameliorated fibronectin upregulation in the latter. RhoA activation induced a rise of intracellular calcium ion concentration ([Ca2+]i), which was at least in part dependent on the transient receptor potential canonical 6 (TRPC6) cation channel. The results indicate that RhoA activates NFAT by inducing a rise of [Ca2+]i in podocytes, which in turn contributes to fibronectin upregulation. This pathway may be responsible for the pathogenesis of certain glomerular diseases such as hypertension-mediated glomerulosclerosis.

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The Proteoglycan Syndecan 4 Regulates Transient Receptor Potential Canonical 6 Channels via RhoA/Rho-associated Protein Kinase Signaling

Cited by 39 publications

References 45 publications

Insulin Increases Expression of TRPC6 Channels in Podocytes by a Calcineurin-Dependent Pathway

Insulin Increases Expression of TRPC6 Channels in Podocytes by a Calcineurin-Dependent Pathway

Overexpression of TGF-β Inducible microRNA-143 in Zebrafish Leads to Impairment of the Glomerular Filtration Barrier by Targeting Proteoglycans

Nuclear factor of activated T cells mediates RhoA-induced fibronectin upregulation in glomerular podocytes

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