摘要
目的:探讨细胞外信号调节激酶5(ERK5)对体外血小板聚集及在体血栓的影响及机制。方法:采用Western blot对人血小板中ERK5的表达及其在血小板活化后的磷酸化水平进行检测;采用血小板聚集仪检测ERK5特异性抑制剂XMD8-92对血小板聚集及致密颗粒释放的影响;采用Fe Cl3颈动脉血栓模型检测ERK5对在体血栓的影响;采用Western blot检测XMD8-92对蛋白激酶B(Akt)和人第10号染色体缺失的磷酸酶及张力蛋白同源蛋白(PTEN)磷酸化的影响。结果:人血小板中存在ERK5的稳定表达,其磷酸化水平在血小板活化后显著升高(P<0.05)。XMD8-92可抑制多种血小板激活剂引起的血小板聚集和致密颗粒释放(P<0.05)。Western blot结果表明,XMD8-92可通过下调PTEN Ser370位点磷酸化而增强PTEN的活性,从而抑制Akt的磷酸化,这种抑制效果也通过血小板特异PTEN基因敲除小鼠得到了验证。在体血栓研究表明,XMD8-92经尾静脉给药,可显著延长小鼠第一次颈动脉血栓的形成时间。结论:ERK5可通过影响PTEN的磷酸化调节Akt的活化,进而影响到体外血小板的聚集和在体血栓的形成。
AIM:To investigate the role of extracellular signal-regulated kinase 5(ERK5) in platelet aggregation in vitro and arterial thrombosis in vivo.METHODS:The expression and phosphorylation levels of ERK5 in human platelet were detected by Western blot.The effects of ERK5 selective inhibitor XMD8-92 on platelet aggregation and dense granule secretion were detected by Chrono-Log aggregometer.The effect of ERK5 on in vivo thrombosis was analyzed using an Fe Cl3 artery thrombosis model.The effects of XMD8-92 on protein kinase B(PKB/Akt) and phosphatase and tensin homolog deleted on chromosome ten(PTEN) phosphorylation levels were determined by Western blot.RESULTS:ERK5 was stably expressed in human platelets and its phosphorylation level increased significantly after platelet activation(P 〈0.05).XMD8-92,a selective inhibitor of ERK5,inhibited platelet aggregation and dense granule secretion in response to several platelet stimulators(P 〈 0.05).The results of Western blot showed that XMD8-92 inhibited Akt phosphorylation level by down-regulating PTEN Ser370 phosphorylation and enhancing PTEN activity.The pathway was further confirmed using platelet specific PTEN deficiency mice.The first occlusion time was obviously extended in the mice intravenously given XMD8-92 in the Fe Cl3-induced carotid artery injury model.CONCLUSION:ERK5 plays a role in platelet activation and arterial thrombosis by influencing PTEN and Akt phosphorylation.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2017年第11期1958-1963,共6页
Chinese Journal of Pathophysiology
基金
国家自然科学基金资助项目(No.81270278)
上海市科委基金资助项目(No.16411965600)