METHODS: HLEC were cultured in vitro and then randomly divided into 3 groups. Normal group:normal cultured HLEC; control group: normal cultured HLEC transfected with empty vector; BHMT gene overexpression group(OE): HLEC transfected with BHMT gene overexpression. All groups were cultured in 10% FCS DMEM +5mmol/L Hcy for 16h. After cultured, BHMT mRNA expression was measured by qRT-PCR and Western blot, the cell proliferation was detected by EdU Assay Kit,The level of ROS and GSH of HLEC were measured by Flow Cytometer and Visible Spectrophotometers. The expression level of of protein(GRP78, Nrf2, Caspase-12)was measured by western blotting.

RESULTS: After cultured 16h, cell proliferation ability in OE group was increased by 30.0% compared with NC group(P<0.05).The expression of ROS in normal group(89.2043±0.3511)% was obviously higher than OE group(49.5625±0.4502)%, P<0.05, GSH activity in OE group was obviously higher than control group and normal group,(P<0.05). The expression level of GRP78 in the normal group and the control group was significantly higher than overexpression group. The expression level of Nrf2 in the normal group and the control group was significantly lower than overexpression group. The expression level of Caspase-12 in the overexpression group was significantly lower than that in the control group.

CONCLUSION: BHMT in vitro can prevent the oxidative damage of HLEC by high homocysteine, clear the ROS and decrease the ER stress reaction. Apoptosis of lens epithelial cells was inhibited. BHMT plays an important protective role in oxidative damaged HLEC induced by Hcy.