Effect of SnoN protein on high-glucose-induced expression of fibronectin in primary cultured rat renal tubular cells

AIM: To investigate the effect of Ski-related novel protein N(SnoN) on high-glucose-induced expression of fibronetin (FN) in primary cultured rat renal tubular cells (RTECs). METHODS: The primary renal cells were cultured, and the cell types were indentified to be RTECs. The cells were divided into 3 groups: normal-glucose group (DMEM+2% FBS), high-glucose group (19.5 mmol/L D-glucose+DMEM+2% FBS) and high-osmotic group (19.5 mmol/L D-mannitol+DMEM+2% FBS). The cells were harvested at 30 min, 2 h, 12 h, 24 h, 48 h, 72 h and 96 h. SnoN expression in primary cultured RTECs was knocked down by RNA interference, then the cells were divided into 4 groups: normal-glucose group, high-glucose group, control siRNA group and SnoN siRNA group. The protein expressions of SnoN and FN in RTECs was examined by the methods of Western blotting, immunocytochemistry staining and immunofluorescence cytochemistry. RT-PCR was used to examine the mRNA expression of FN and SnoN. RESULTS: The RTECs constituted the major cell type of cultured cells. SnoN protein was decreased in a time-dependent manner in RTECs under high-glucose condition. The FN protein and mRNA levels raised in high-glucose group and sustained through entire experiment. Moderate reduction of SnoN in RTECs was observed by RNAi strategy, which greatly up-regulated the expression of FN (P<0.05). CONCLUSION: The down-regulation of SnoN participates high-glucose-induced expression of FN in RTECs.