Effect of HMGB1 on the migration of vascular smooth muscle cells and its molecular mechanism / 重庆医学

ABSTRACT

Objective To investigate the effect of high mobility group box‐1(HMGB1) on the migration of vascular smooth cells (VSMCs) and the role of TLR4‐dependent PI3K/Akt pathway in the process .Methods Primary VSMCs were isolated from the thoracic aorta of male SD rats and cultured in vitro .Control group ,TLR4 siRNA transfected group ,control siRNA transfected group and PI3k inhibitor (LY294002) intervention group were stimulated by HMGB1 (0 .1-1 000 .0 ng/mL) .Expression of TLR4 mRNA was detected by RT‐PCR ,protein expression of TLR4 ,Akt ,pAkt ,PI3K were detected by Western blot .Activity of the im‐munoprecipitated PI3K enzyme was assessed in a competitive ELISA .The migration and cell viability of every groups were ob‐served .Results HMGB1 (0 .1 -1 000 .0 ng/mL) stimulated VSMCs migration in a dose‐dependent manner and incubation of VSMCs with 100 ng/mL caused a rapid migration (P< 0 .05) .At the concentrations used ,HMGB1 did not cause any cytotoxic effects (P<0 .05) .Migration of VSMCs toward HMGB1 was significantly inhibited by silencing of TLR4 (P<0 .05) .Pretreated cells with TLR4 siRNA or the PI3K inhibitor LY294002 could markedly block PI3K/Akt pathway activation and VSMCs migration mediated by HMGB1 (both P<0 .05) .Conclusion HMGB1 stimulated VSMCs migration in a dose‐dependent manner and TLR4‐dependent PI3K/Akt signaling pathway played an important role in the migration of VSMCs mediated by HMGB1 .This research indicates that TLR4‐dependent TLR4/PI3K/Akt signaling pathway could be the target in the treatment of obstructive cardiovascu‐lar disease .