RESUMEN
AIM:To study the effect of netrin-1 on the damage of renal tubular epithelial cells induced by high glucose.METHODS:Human renal tubular epithelial HK-2 cells were treated with high glucose.Real-time PCR and Western blot were used to detect the expression level of netrin-1 in the cells.HK-2 cells were infected with netrin-1-overexpressing lentivirus, and the effect of netrin-1 over-expression on the HK-2 cells treated with high glucose was observed.The apoptosis rate was analyzed by flow cytometry.The protein level of cleaved caspase-3 was determined by Western blot.lactate dehydrogenase (LDH) activity in the culture medium was measured by 2, 4-binitrobenzene hydrazine method.The content of malondialdehyde (MDA) in the culture medium was detected by thiobarbituric acid method.The concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the culture medium were measured by ELISA.RE-SULTS:The expression of netrin-1 at mRNA and protein levels in the HK-2 cells after high glucose treatment was significantly lower than that in the control cells (P<0.05).Infection with netrin-1-over-expressing lentivirus up-regulated the expression of netrin-1 in the HK-2 cells treated with high glucose.High glucose promoted the secretion of IL-1βand TNF-α, decreased the levels of LDH and MDA in the cell culture supernatant, and induced apoptosis and activation of caspase-3 in renal tubular epithelial cells (P<0.05).After the HK-2 cells with up-regulation of netrin-1 were induced by high glucose, the IL-1βand TNF-αsecretion, the levels of LDH and MDA in the culture medium, the apoptosis, and the level of activated caspase-3 protein in the cells were all decreased, as compared with the control cells (P<0.05).CONCLU-SION:Up-regulation of netrin-1 expression attenuates oxidative damage and inflammatory injury, and reduces apoptosis induced by high glucose in renal tubular epithelial cells.