A Study On Protein Expression Of Hmgb1 In Cultured Vascular Smooth Muscle Cells (vsmcs) Under Hypoxia And The Interventional Effect Of Nimodipine

Objective: To observe the effects of hypoxia on the expression of HMGB1 in cultured VSMCs.Method: The cultured VSMCs of rats were divided into six groups and they were cultured in normal condition and under hypoxic condition for 1, 4, 12, 24 and 48 hours. The levels of HMGB1 in the supernatant were measured by Western blot. Subsequently, we administrated nimodipine to pretreatment. The cells were divided into three groups: normal controlled group,hypoxic group and nimodipine-pretreated hypoxic group. HMGB1 were measured after 12 hours'hypoxic culture. The cell viability within 48h was examined by trypan blue exclusion test. Results: Compared with normal control, the expression of HMGB1 in the hypoxic culturedsupernatant was significantly increased ( P<0.05 ) . But the HMGB1 level in nimodipine-pretreated hypoxic group was lower than the hypoxic group(P<0.05).Within 48h, no differences in cell viability were found compared with control group by Trypan blue exclusion test.Conclusion: Hypoxia could significantly induce the expression of HMGB1 in cultured VSMCs and the expression increased gradually within 24h. Nimodipine can significantly decrease the expression of HMGB1 in hypoxic condition. We presumed that the mechanisms of brain protection by nimodipine may be contributed to the decrease of HMGB1 level.