Effects of PKC on TNF-α stimulated IP3 R1 protein expression in human mesangial cells

Abstract

Objective To explore the effects of TNF-α on the expression of IP3 R1 mRNA and protein in human mesangial cells (HMCs) and elucidate the role of protein kinase C (PKC) in this signal pathway.Methods Quantitative real-time polymerase chain reaction and immunoblot assay were used to examine the effects of TNF-α on IP3R1 mRNA and protein expression.Depletion PKC,the selective inhibitor of PKCα Safingol and inhibitor of PKCδ Rottlerin,overexpression of dominant negative mutant of PKC to examine the mechanism of signal transduction of TNF-α-regulated IP3 R1 in HMCs.PKCα activation was assayed by Western blot.Results TNF-α increased IP3R1 mRNA and protein expression in HMCs,effects that were blocked by prolonged incubted chronic PMA,Safingol and also by domain negative PKCα construct.TNF-α promoted PKCα activation with maximal PKCα phosphorylation that occurred 8 h post-stimulation.Conclusion TNF-α increased the expression of IP3 R1 and this was mediated through the PKCα activation signaling pathways in HMCs. Key words: Hepatorenal syndrome; TNF-α; Human mesangial cells; IP3 R1; PKCα