穿膜肽Tat以脂筏介导的巨胞饮方式进入骨髓间充质干细胞

Abstract

【中文摘要】艾滋病病毒的一个富含精氨酸的Tat多肽具有穿膜转导蛋白功能并能介导多种外源性物质进入细胞甚至细胞核.本研究的目的是探讨Tat多肽进入骨髓间充质干细胞的机制.将FITC标记的Tat分别和Alexa Fluor 546-标记的转铁蛋白(笼形蛋白介导的受体内吞方式入胞)、Alexa Fluor 594-标记的霍乱毒素B(脂筏介导的巨胞饮内化方式入胞)同兔骨髓间充质干细胞(BMSCs)共孵育.用激光共聚焦扫描显微镜可观察到在BMSCs中穿膜肽Tat和霍乱毒素B呈点状叠加而与转铁蛋白几乎无叠加,同时在细胞核部位观察到有绿色荧光的Tat,初步表明穿膜肽Tat以脂筏介导的内化方式进入BMSCs而非受体介导的内吞方式.另外,低温(4℃)、破坏ATP、β-环式糊精和诺考达唑内吞抑制剂的使用均可观察到BMSCs内吞Tat的量降低,也间接验证Tat以脂筏介导的内化方式进入BMSCs. 【Abstract】 Tat peptide derived from human immunodeficiency virus(HIV) could rapidly translocate the cell membrane,and localize into the nuclear even when coupled with micro-cargoes.In this paper,the internalized mechanism of Tat peptide in bone marrow stem cells(BMSCs) was studied by using confocal laser scanning microscopy(CLSM) and flow cytometry(FCM).It is found that Tat peptide could not co-localize with transferring(by clathrin-receptor mediated endocytosis),but Ctx B(by lipid raft mediated macrocytosis) in BMSCs...