胱硫醚β合成酶通过ATG5巯基化促进自噬缓解阿尔茨海默病  

Cystathionine β synthase promotes autophagy to alleviate Alzheimer’s disease through ATG5 sulfhydration

作　　者：杜亚云 刘晓丽 朱席琳[1] 伍晓盼 刘英[1] DU Ya-yun;LIU Xiao-li;ZHU Xi-lin;WU Xiao-pan;LIU Ying(State Key Laboratory of Medical Molecular Biology,Institute of Basic Medical Sciences CAMS,School of Basic Medicine PUMC,Beijing 100005,China)

机构地区：[1]中国医学科学院基础医学研究所北京协和医学院基础学院医学分子生物学国家重点实验室

出　　处：《基础医学与临床》2019年第7期983-988,共6页Basic and Clinical Medicine

基　　金：中国医学科学院医学与健康科技创新工程项目(2016-I2M-1-004)

摘　　要：目的探究胱硫醚β合成酶(CBS)对阿尔茨海默病的影响及其作用机制。方法用Western blot检测CBS的过表达效果及其对淀粉样蛋白前体蛋白(APP)的影响,检测CBS对自噬标志物LC3的影响;用ELISA检测CBS对细胞上清中Aβ1-42的影响;用亚甲基蓝法检测H2S的生成;用生物素转换及Western blot实验验证H2S对自噬相关蛋白5(ATG5)的巯基化作用。用侧脑室注射质粒的方法在小鼠体内过表达CBS;用Y迷宫实验验证CBS对小鼠学习记忆能力的影响。结果CBS降低了细胞上清中Aβ1-42的水平(P<0.05);抑制了APP的表达(P<0.05);CBS促进了H2S的生成(P<0.01),CBS促进了ATG5的巯基化;CBS促进了自噬标志物LC3的表达,抑制了P62的表达,促进了自噬水平;CBS促进阿尔茨海默病模型小鼠的学习记忆能力(P<0.05)。结论CBS通过促进硫化氢生成促进了ATG5第19位半胱氨酸发生巯基化,进而促进自噬,缓解了阿尔茨海默病的病理进程。Objective To explore the effect of CBS on Alzheimer’s disease and its mechanism.Methods Western blot was used to detect the over-expression of CBS and its effect on amyloid precursor protein(APP),LC3 and P62.The effect of CBS on Aβ1-42 in cell supernatant was detected by ELISA.The formation of H2S was detected by methylene blue method;The sulfhydration of ATG5 by H2S was verified by biotin conversion experiment and Western blot experiment.CBS was over-expressed in mice by injection of plasmid into the lateral ventricle;Y-maze test was used to verify the effect of CBS on learning and memory ability in mice.Results CBS significantly decreased the level of Aβ1-42 in the cell supernatant(P<0.05)and inhibited the expression of APP(P<0.05);CBS promoted the formation of H2S(P<0.01);CBS promoted sulfhydration of ATG5;CBS promoted the expression of LC3 and inhibited the expression of P62,CBS promoted the level of autophagy;CBS also significantly promoted learning and memory ability of Alzheimer’s disease model mice(P<0.05).Conclusions CBSpromotes the sulfhydration of cysteine at position 19 of ATG5 by promoting the formation of hydrogen sulfide,thereby promoting autophagy and alleviating Alzheimer’s disease.

关 键 词：胱硫醚Β合成酶 自噬相关蛋白5 巯基化 细胞自噬 阿尔茨海默病 

分 类 号：Q74[生物学—分子生物学]