MicroRNA-4532 Inhibition Protects Human Lens Epithelial Cells From Ultra-violet-induced Oxidative Injury Via Activating SIRT6-Nrf2 Signaling

Aims: To investigate whether the activation of SIRT6-Nrf2 by inhibiting micro RNA-4532(miR-4532)could protect human lens epithelial cells(HLECs)from oxidative stress injury induced by ultraviolet(UV)and to analyze its molecular mechanism.Methods: We detected the expression of miR-4532,SIRT6,and Nrf2 in HLECs cells by immunoblotting and real-time quantitative PCR.After miR-4532 was inhibited or overexpressed,HLECs were given UV radiation to observe cell survival rate and apoptosis situation;The sh RNA strategy was used to silence SIRT6 in HLECs and observe its effect on the inhibition of miR-4532;CRISPR/Cas9 method was used to knock out the SIRT6 and Nrf2 genes respectively and observe its protective effect on the inhibition of miR-4532 influences.Results:(1)miR-4532 targets SIRT6 gene and inhibits Nrf2 signaling pathway in HLECs.(2)Inhibition of miR-4532 increased the expression of SIRT6 in HLECs and activate the Nrf2 signaling pathway;(3)Inhibition of miR-4532 can reduce UV-induced oxidative stress in HLECs,and overexpression of miR-4532 can aggravate UV-induced HLECs oxidative injury;(4)Overexpression of SIRT6 can reduce UV-induced oxidative stress injury in HLECs;(5)Inhibition of miR-4532 can protect HELCs from UV-induced oxidative stress injury by up-regulating SIRT6protein;(6)The protective effect of miR-4532 is reduced after SIRT6 is knocked down.(7)Nrf2 gene knockout does not affect SIRT6 gene expression;(8)By knocking down Nrf2 gene,the protective effect of miR-4532 inhibition is reduced.Conclusions:SIRT6 is the main target gene of miR-4532 in HLECs.Inhibiting miR-4532 can protect human lens epithelial cells from UV-induced oxidative stress by activating SIRT6-Nrf2 signaling pathway repetition.