缺血性脑卒中患者外周血CBX7的表达水平变化及其通过Nrf2/HO-1通路对神经元凋亡的影响

The expression level changes of CBX7 in peripheral blood of patients with ischemic stroke and its effect on neuronal apoptosis through Nrf2/HO-1 pathway

ObjectiveTo study the effect of CBX7 on oxygen-glucose deprivation/reperfusion(OGD/R)in neurons and its possible mechanism.Methods Peripheral blood samples were collected from patients with ischemic stroke(IS group)and healthy people(control group), and then peripheral blood mononuclear cells were separated. After OGD/R treatment, rat hippocampal neurons were transfected with CBX7 specific siRNA(OGD/R+si-CBX7 group)and its negative control(OGD/R+NC group). In addition, a ZnPP interference group(OGD/R+si-CBX7+ZnPP group)and a control group were included. RT-PCR was used to detect the mRNA expression of CBX7 in cells. Western blot was used to detect the expressions of CBX7, Bax, Bcl-2 and Nrf2/HO-1 pathway related proteins in cells. CCK-8 kit was used to detect cell viability. Flow cytometry was used to detect apoptosis.Results Compared with the control group, the levels of of CBX7 mRNA and protein in peripheral blood of the IS group were significantly increased(P<0.05). However, in OGD/R group, the levels of CBX7 mRNA and protein, the apoptosis rate and Bax protein expression were significantly increased(P<0.05)while cell proliferation ability(24 h, 48 h and 72 h), the expressions of Bcl-2, Nrf2 and HO-1 protein were significantly reduced(P<0.05)compared with control group. Compared with OGD/R+NC group, the levels of CBX7 mRNA and protein expression, cell apoptosis rate and Bax protein expression were significantly reduced(P<0.05)in OGD/R+si-CBX7 group, while cell proliferation ability(48 h and 72 h)and the levels of Bcl-2, Nrf2 and HO-1 proteins were significantly increased(P<0.05). Compared with the OGD/R+si-CBX7 group, the cell proliferation ability(24 h, 48 h and 72 h)and the expressions of Bcl-2, Nrf2 and HO-1 in OGD/R+si-CBX7+ZnPP group were significantly decreased(P<0.05), while the apoptosis rate and the expression of Bax protein were significantly increased(P<0.05).Conclusion Knocking down of CBX7 inhibits OGD/R-induced neuronal apoptosis by activating Nrf2/HO-1 pathway.