Insulin increases filtration barrier permeability via TRPC6-dependent activation of PKGIα signaling pathways

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1863

Article

Rogacka, Dorota¹  Audzeyenka, Irena¹  Rachubik, Patrycja¹  Rychlowski, Michal²  Kasztan, Malgorzata³  Jankowski, Maciej¹  Angielski, Stefan¹  Piwkowska, Agnieszka¹ 

[1] Polish Acad Sci, Mossakowski Med Res Ctr, Lab Mol & Cellular Nephrol, Gdansk, Poland

[2] Univ Gdansk, Med Univ Gdansk, Intercollegiate Fac Biotechnol, Lab Virus Mol Biol, Gdansk, Poland

[3] Univ Alabama Birmingham, Dept Med Cardiorenal Physiol & Med, Birmingham, AL USA

关键词: Insulin;    Filtration barrier permeability;    Podocyte;    Protein kinase G type I alpha;    TRPC6;    NADPH oxidase;   

DOI  :  10.1016/j.bbadis.2017.03.002

来源: Elsevier

【 摘 要 】

Podocytes are dynamic polarized cells on the surface of glomerular capillaries and an essential component of the glomerular filtration barrier. Insulin increases the activation of protein kinase G type la (PI(GIce) subunits, leading to podocyte dysfunction. In addition, accumulating evidence suggests that TRPC6 channels are crucial mediators of podocyte calcium handling and involved in the regulation of glomerular filtration. Therefore, we investigated whether TRPC6 is involved in the regulation of filtration barrier permeability by insulin via the PKGIet-dependent manner. TRPC channel inhibitor SKF96365 abolished insulin-dependent glomerular albumin permeability and transepithelial albumin flux in cultured rat podocytes. Insulin-evoked albumin permeability across podocyte monolayers was also blocked using TRPC6 siRNA. The effect of insulin on albumin permeability was mimicked by treating podocytes with TRPC channel activator (oleolyl-2-acetyl-sn-glycerol, OAG). Insulin or OAG treatment rapidly increased the superoxide generation through activation of NADH oxidase. TRPC inhibitor SKF96365 or siRNA knockdown of TRPC6 attenuated insulin-dependent increase of ROS production. Furthermore, TRPC inhibitor or downregulation of TRPC6 blocked insulin-induced rearrangement of the actin cytoskeleton and attenuated oxidative activation of PKGIot and changes in the phosphorylation of PKG target proteins MYPT1 and MLC. Moreover insulin regulated the PKGIoe interaction with TRPC6 in cultured rat podocytes. Taken together, our data suggest a key role of TRPC6 channels in the mediation of insulin-dependent activation of PKGI alpha signaling pathways. Overall, we have identified a potentially important mechanism that may explain disturbances in filtration barrier permeability in many diseases with increased expression of TRPC6 and chronic Ca2+ overload. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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