敲除Fto基因对糖尿病小鼠主动脉平滑肌收缩及钙调控异常的作用研究  

Effect of Fto gene knockout on calcium regulation and aortic smooth muscle contraction in diabetic mice

作　　者：郑燕湘 蔡泳江 王梓帆 邝素娟 杨慧[2] 饶芳 邓春玉 ZHENG Yanxiang;CAI Yongjiang;WANG Zifan;KUANG Sujuan;YANG Hui;RAO Fang;DENG Chunyu(School of Medicine,South China University of Technology,Guangzhou 510006,China;Guangdong Provincial People's Hospital(Guangdong Academy of Medical Sciences),Southern Medicl University,Guangzhou 510080,China;School of Pharmaceutical Sciences,Southern Medical University,Guangzhou 510515,China)

机构地区：[1]华南理工大学医学院,广东广州510006 [2]南方医科大学附属广东省人民医院(广东省医学科学院),广东广州510080 [3]南方医科大学药学院,广东广州510515

出　　处：《中国病理生理杂志》2024年第2期204-212,共9页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.82170415);广东省基础与应用基础研究基金(No.2021A1515011551)。

摘　　要：目的:探讨脂肪质量和肥胖相关基因(fat mass and obesity-associated gene,Fto)对糖尿病(diabetes mellitus,DM)小鼠主动脉平滑肌收缩功能异常的影响及其钙调控的作用机制。方法:利用Cre-loxP重组技术制备平滑肌特异性Fto基因敲除(smooth muscle-specific Fto gene knockout,Fto^(SMKO))小鼠。实验分3组:野生型(wild-type,WT)组、DM模型组和Fto^(SMKO-DM)组,每组各15只。Fto^(SMKO-DM)组和DM组小鼠通过腹腔注射链脲佐菌素制备1型DM模型;WT组小鼠注射等体积柠檬酸-柠檬酸钠缓冲液。应用离体血管环张力测定技术,观察不同药物对3组小鼠主动脉平滑肌收缩反应的影响;采用Western blot技术检测小鼠主动脉组织FTO蛋白的表达水平。结果:(1)DM小鼠主动脉FTO蛋白的表达显著升高(P<0.01)。(2)平滑肌特异性敲除Fto后,FTO蛋白基本不表达(P<0.01);DM组与WT组相比,空腹血糖水平显著升高(P<0.01),体重显著下降(P<0.05);Fto^(SMKO-DM)组与DM组相比,小鼠的体重和空腹血糖水平无显著差异(P>0.05)。(3)DM组与WT组相比,苯肾上腺素诱导的主动脉平滑肌收缩反应性增强;其中,非L型钙通道和钙库操纵性钙通道(store-operated calcium channels,SOCC)介导的血管平滑肌收缩反应增强;1,4,5-三磷酸肌醇受体(inositol 1,4,5-trisphosphate receptors,IP3R)介导肌浆网钙释放引起的血管平滑肌收缩反应增强;咖啡因激活兰尼碱受体(ryanodine receptors,RyR)介导肌浆网钙释放诱导的血管平滑肌收缩反应减弱(P<0.05)。(4)Fto^(SMKO-DM)组与DM组相比,苯肾上腺素诱导的主动脉平滑肌收缩反应性显著降低;其中,非L型钙通道和SOCC介导钙内流诱导的血管平滑肌收缩反应显著降低(P<0.05);咖啡因激活RyR介导肌浆网钙释放诱导的血管平滑肌收缩反应显著上升(P<0.05),而IP3R介导肌浆网钙释放诱导的血管平滑肌收缩反应不受影响(P>0.05)。结论:特异性敲除平滑肌Fto基因可降低DM小鼠主动脉平滑肌收缩高反�AIM:To investigate the influence of fat mass and obesity-associated(Fto)gene on the aberrant contraction of aortic smooth muscle in diabetes mellitus(DM)mice,and to explore the mechanism of Fto gene underlying the calcium regulation.METHODS:Smooth muscle-specific Fto gene knockout(FtoSMKO)mice were generated using CreloxP technology.The experiment involved 3 groups of mice:wild-type(WT)group,DM model group and Fto^(SMKO-DM) group,with 15 mice in each group.In DM group and Fto^(SMKO-DM) group,type 1 DM was induced by intraperitoneal injection of streptozotocin.The mice in WT group were injected with equal volume of citric acid-sodium citrate buffer solution.The influences of different drugs on the contraction responses of aortic smooth muscle in mice were analyzed using a multi-myograph system.The expression level of FTO protein in the aortic tissues was detected by Western blot.RESULTS:(1)Compared with WT mice,the expression levels of FTO protein in the aortic tissues of DM mice were significantly in-creased(P<0.01).(2)The expression level of FTO protein in smooth muscle was significantly decreased after knockout of Fto gene(P<0.01).Compared with WT group,the mice in DM group exhibited a significant decrease in body weight and a marked increase in fasting blood glucose level(P<0.05).There were no noticeable differences in body weight or fasting blood glucose level between Fto^(SMKO-DM)group and DM group(P>0.05).(3)The contraction responses of aortic smooth muscle in DM group were substantially increased by phenylephrine compared with WT group.Specifically,vaso-constriction responses mediated by non-L-type calcium channels and store-operated calcium channels(SOCC)were signifi-cantly enhanced in DM group.In addition,the responses mediated by inositol 1,4,5-trisphosphate receptors(IP3R),which facilitate calcium release from the sarcoplasmic reticulum,were significantly enhanced.However,the responses mediated by caffeine-activated ryanodine receptors(RyR),which also facilitate calcium release from the sarcoplasmic re

关 键 词：Fto基因 1型糖尿病 主动脉 钙库操纵性钙通道 肌浆网钙释放 

分 类 号：R587.1[医药卫生—内分泌] R543.5[医药卫生—内科学] R363.2[医药卫生—临床医学]