Effects of α-SMA on proliferation and apoptosis of renal tubular epithelial cells induced by high glucose

SUO Yan; GU Youyou; WAMG Su

doi:10.3969/j.issn.1002-266X.2017.30.004

Abstract：Objective To investigate the effects and mechanism of α-smooth muscle actin (α-SMA) on the proliferation and apoptosis of renal tubular epithelial cells induced by high glucose.Methods We cultured the human renal tubular epithelial cells and divided them into the low glucose group, high glucose group, and interference group.In the interference group, we transfected the α-SMA siRNA into the renal tubular epithelial cells.After transfection, the high glucose group and the interference group were cultured in the high glucose DMEM cell culture medium with D-glucose concentration of 25 mmol/L, the low sugar group was cultured in the low glucose DMEM cell culture medium with D-glucose concentration of 5.6 mmol/L, and they were all cultured for 48 h.MTT assay was used to detect cell proliferation.The apoptosis was detected by flow cytometry and apoptosis rate was calculated.Western blotting was used to detected the Caspase-3, Bcl-2-related X protein (Bax) and Toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB protein expression.The DCFH-DA was used to detected ROS level.The levels of TNF-α and IL-8 in the supernatant were detected by ELISA.Results The cell proliferation in the high glucose group and the interference group were lower than that in the low sugar group (P<0.01), the ability of cell proliferation in the interference group was higher than that in the high glucose group (P<0.01).The apoptosis rate in the high glucose group and the interference group was higher than that in the low sugar group (P<0.01), and the rate of apoptosis in the interference group was lower than that in the high glucose group (P<0.01).The expression of Caspase-3, Bax, TLR4, and NF-κB protein in the high glucose group and the interference group was higher than that in the low sugar group (all P<0.01), the expressions of Caspase-3, Bax, TLR4, and NF-κ B protein in the interference group was lower than that in the high glucose group (all P<0.01).The levels of ROS and TNF-α, IL-8 in the supernatant in the high glucose group and the interference group were higher than those in the low sugar group (all P<0.01), the levels of ROS, and TNF-α, IL-8 in the supernatant of the interference group were lower than those in the high glucose group (all P<0.01).Conclusion Interfering with α-SMA can partially reverse the effect of high glucose on the proliferation and apoptosis of renal tubular epithelial cells by decreasing the intracellular ROS level and inhibiting the TLR4/NF-κB signaling pathway.