Protective effect of HMGB1 gene silence on astrocyte injury caused by oxygen-glucose deprivation/reoxygenation / 解放军医学杂志

ABSTRACT

Objective To investigate the protective effect of high mobility group box 1 (HMGB1) gene silence on astrocyte injury caused by oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. Methods Astrocytes were divided into control group, OGD/R group and HMGB1 siRNA group. Astrocytes in OGD/R group were cultured with glucose free DMEM under 1% O2 condition, then they were treated with OGD for 2, 4 and 6h respectively, and then reoxygenated for 24h. In HMGB1 siRNA group, astrocytes that transfected with HMGB1 small interference RNA (siRNA) lentivirus-vector were treated with OGD 6h, and then reoxygenated for 24h. After 24h reoxygenation, the mRNA and protein expression of HMGB1 in the astrocytes were determined by RT-PCR and Western blotting. HMGB1 protein in culture supernatant of astrocytes was determined by ELISA. The cell injury and survival rate were assessed by LDH activity (LDH%) and MTT assay. Results Compared with the astrocytes without transfection of HMGB1 siRNA lentivirus-vector, the protein expression of HMGB1 was suppressed by siRNA. Compared with the control group, with prolongation of the OGD time, the mRNA and protein expression of HMGB1 increased gradually (P<0.05) after OGD/R, and it further increased with elapse of time. OGD resulted in significant injuries with time extention, and the LDH% increased (P<0.05) with marked lowering of survival rate (P<0.05). Compared with the OGD/R group, cell injury in HMGB1 siRNA group alleviated remarkably, and survival rate was elevated significantly (P<0.01). Conclusion The expression of HMGB1 in astrocytes can be inhibited by siRNA, and over-expression of HMGB1 might be an important factor in OGD/R-induced cell injury.