模拟失重大鼠颈总动脉平滑肌细胞溶酶体改变  

Lysosomal remodeling in vascular smooth muscle cells of carotid artery in simulated weightless rats

作　　者：谷政慧 李方方 谢小萍 暴军香 GU Zheng-hui;LI Fang-fang;XIE Xiao-ping;BAO Jun-xiang(Department of Aerospace Hygiene,School of Aerospace Medicine,Air Force Medical University,Xi’an 710032,Shaanxi,China)

机构地区：[1]空军军医大学航空航天医学系航空航天卫生学教研室,陕西西安710032

出　　处：《心脏杂志》2020年第6期620-625,630,共7页Chinese Heart Journal

基　　金：国家自然科学基金项目资助(81671856)。

摘　　要：目的研究尾部悬吊模拟失重大鼠颈总动脉(carotid aorta,CA)平滑肌细胞溶酶体数量、分布及相关分子的基因和蛋白表达改变。方法采用4周尾部悬吊大鼠模拟失重对心血管系统的影响,通过电镜、Western blot技术、免疫组织化学染色和实时定量聚合酶链反应(quantitative real-time polymerase chain reaction,qRT-PCR)检测CA平滑肌细胞溶酶体数量和分布、溶酶体相关膜蛋白(lysosomal associated membrane protein,LAMP)1,驱动蛋白kinesin-1,转录因子(transcription factor,TF)EB、TFE3以及溶酶体相关基因的蛋白表达、分布和mRNA水平变化。结果电镜结果显示,与对照(control,CTR)组相比,悬吊(hindlimb unloading tail suspension,HU)组大鼠CA平滑肌细胞溶酶体数量明显减少;Western blot和免疫组化则显示CA的LAMP1蛋白表达显著降低(P<0.05),且主要为中膜改变(P<0.05),内膜无明显变化;kinesin-1蛋白表达显著增加(P<0.05)。qRT-PCR显示,溶酶体相关基因表达显著增加(P<0.05)。与CTR相比,TFEB和TFE3蛋白表达在HU大鼠CA中显著降低(P<0.05),基因表达显著增加(P<0.05)。结论HU大鼠CA平滑肌细胞溶酶体数量减少,相关蛋白表达降低,但基因转录水平增加,可能参与动脉重塑改变。AIM To investigate the changes of lysosomal number and distribution,transcription and protein levels of lysosomal associated molecules in vascular smooth muscle cells of carotid artery(CA)in simulated weightless rats by hindlimb unloading tail suspension(HU)for 4 weeks.METHODS 4 weeks’HU rat model was used to simulate the effect of weightlessness on the cardiovascular system.Transmission electron microscopy,western blotting,immunohistochemical staining and quantitative real-time polymerase chain reaction(qRT-PCR)were conducted to examine the number and distribution of lysosomes,the protein level of lysosomal associated membrane protein 1(LAMP1),lysosomal motor protein kinesin-1,transcription factor EB(TFEB)and E3(TFE3),and mRNA abundance of TFEB,TFE3 and lysosome related genes in vascular smooth muscle cells of CA.RESULTS Transmission electron microscopy showed that compared to the control(CTR)group,the number of lysosomes of vascular smooth muscle cells of CA was decreased in HU group.Western blot analysis and immunohistochemical staining also indicated that the protein level of LAMP1 of CA were decreased in HU group compared to the CTR(P<0.05),mainly decreased in the media(P<0.05)while that of intima showed no significant difference.In addition,the expression level of kinesin-1 displayed increased(P<0.05).qRT-PCR results showed that compared to the CTR group,the mRNA abundance of lysosomal related genes was increased in CA(P<0.05).Compared to the CTR,the protein levels of TFEB and TFE3 were reduced both in CA of HU rats(P<0.05),while the transcription levels of TFEB and TFE3 were increased in CA(P<0.05).CONCLUSION The number of lysosomes and protein expression level of lysosomal associated molecules of CA vascular smooth muscle cells are reduced in HU group,but the transcription level displays increament,which may contribute to the remodeling of vascular wall.

关 键 词：模拟失重 大鼠 颈总动脉 平滑肌细胞 溶酶体 

分 类 号：R852.22[医药卫生—航空、航天与航海医学]