Abstract: Objective To investigate the effect of Txnip interference on high glucose (HG)-induced apoptosis in human kidney proximal tubular cell line (HK-2). Methods Cultured HK-2 were divided into normal glucose group（NG),high glucose group (HG), HG+contol plasmid vector(HG+C) and GH+ VDUP1 shRNA Plasmid (h) (HG+shRNA).Apoptosis of HK-2 was analyzed by DeadEnd? Fluorometric TUNEL System. ROS production was observed by flow cytometry. The expression levels of Txnip, caspase-3, cleaved caspase-3, Bax, Bcl-2, P38 MAPK, P-P38 MAPK and cytochrome c protein were observed by Western blot. The expression levels of Txnip, Bax, Bcl-2mRNA were observed by RT-PCR. Results Compared with normal glucose group (NG), the production of ROS, the number of cell apoptosis, the expression of cleaved caspase-3 and P-P38 MAPK, ratio of Bax/Bcl-2 and the release of cytochrome c from mitochondria to cytoplasm significantly increased in HK-2 in high glucose group (HG)(P<0.05). Txnip interference inhibited HG-induced ROS production, cell apoptosis, expression of cleaved caspase-3 and P-P38 MAPK, ratio of Bax/Bcl-2 and release of cytochrome c from mitochondria to cytoplasm in HK-2(P<0.05). Conclusions: Txnip interference can prevent HG-induced HK-2 apoptosis through decreasing ROS production, preserving mitochondrial function and inhibiting activation of P38 MAPK.

Key words: diabetic nephropathy, oxidative stress, human kidney proximal tubular cell line, apoptosis, mitochondria