Effects of PKC,VDR and their interaction on expression of NaDC1 in rat renal tubular epithelial NRE-52E cells

AIM: To investigate effects of protein kinase C (PKC), vitamin D receptor (VDR) and their interaction on expression of Na⁺/dicarboxylate contransporter 1 (NaDC1) in rat renal tubular epithelial NRE-52E cells. METHODS: Rat renal tubular epithelial cell line NRE-52E was cultured in vitro. PKC agonist and inhibitor were used to interfere with NRE-52E cells. VDR over-expression and shRNA vectors were used to transfect into NRE-52E cells. The protein expression of PKC, VDR and NaDC1 in the cells was determined by Western blot. RESULTS: The NRK-52E cells with stable VDR over-expression and stable VDR interference were successfully set up. Compared with control group, the protein expression of VDR and NaDC1 in PKC agonist group and VDR over-expression group was increased significantly (P<0.01), and that in VDR interference combined with PKC agonist group and VDR over-expression combined with PKC inhibitor group was between VDR interference group and VDR over-expression group. CONCLUSION: In rat renal tubular epithelial cell line NRE-52E, enhanced PKC activity induces protein expression of VDR, while decrease in PKC activity inhibits the protein expression of NaDC1. There is a significantly positive correlation between VDR and regulation of PKC and NaDC1 protein expression. When PKC and VDR interact with each other, high activity of PKC and over-expression of VDR are the main factors to promote or maintain NaDC1 protein expression in the NRE-52E cells.