磷酸肌醇3激酶-Rac-Nadrin通路在血小板肌动蛋白细胞骨架重构中的作用

The role of phosphatidylinositol 3 kinase-Rac-Nadrin pathway in platelet cytoskeleton actin remodeling

目的 观察磷酸肌醇3激酶（PI3K）-Rac-Nadrin通路在血小板肌动蛋白（actin）细胞骨架重构和细胞形态改变中的作用.方法 选择健康成年志愿者50名,采集外周静脉血,提取洗涤血小板,取200μl经正常洗涤的血小板（3＆#215;1011/L）,设为A组,另取200μl洗涤后的血小板（3＆#215;1011/L）,用渥曼青霉素（100 nmol/L）预处理后15 min后,设为B组,将两组进行血小板聚集率的检测.提取经脂多糖（LPS）内毒素刺激聚集和铺展的两组血小板的总蛋白,进行比较,用鬼笔环肽（Phalloidin）和两组血小板的肌动蛋白丝（F-actin）特异性结合,采用共聚焦激光扫描显微镜分析两组血小板F-actin含量的变化.同时观察两组血小板内F-actin排列和分布的改变,以及血小板形态的变化.结果 血小板聚集仪检测两组血小板聚集率,结果显示,在渥曼青霉素作用下血小板聚集率明显降低（P＜0.05）,显示渥曼青霉素能够抑制血小板聚集.同时,经渥曼青霉素作用的A组血小板,其F-actin平均荧光强度明显降低,为B组的（58.8±6.9）％,差异有统计学意义（P＜0.05）.和B组比较,A组血小板骨架发生解聚,应力纤维的排列和分布以及血小板形态明显改变.结论 PI3 K-Rac-Nadrin通路在血小板F-actin细胞骨架重构中发挥重要作用.

Objective To investigate the effect of phosphatidylinositol 3 kinase （PI3K）-Rac-Nadrin pathway in platelet cytoskeletal actin remodeling.Methods The blood from 50 healthy volunteers were collected and the washed platelets were extracted by differential centrifugation.200 μl washed platelets （3 ＆#215; 1011/L） were collected as group A; another 200 μ l （3 ＆#215; 1011/L） were collected as Group B after pretreatment by Wortmannin （100 nmol/L） for 15 min.The aggregation rate of the two groups were detected.The total platelet protein of the two groups were extracted after stimulated by lipopolysaccharide （LPS） endotoxin （0.5 U/ml）.Then detect the content of F-actin in the two groups using confocal laser scanning microscopy after combining them to phalloidin.The platelet shape,arrangeent and distribution of F-actin in the two groups were also observed.Results The aggregation rate of platelets were significantly decreased by Wortmannin stimulation （P 〈 0.05）; At the same time,the mean fluorescence intensity of F-actin in group A decreased and about （58.8 ±6.9） % of group B,the difference was significant （P 〈 0.05）.Compared with group B,the platelet cytoskeleton in group A depolymerized,and the arrangement,the distribution of stress fiber and the morphology of platelet changed obviously.Conclusion PI3K-Rac-Nadrin pathway may play an important role in platelet cytoskeleton actin remodeling.