转化生长因子-β受体Ⅱ在饥饿诱导体外肌萎缩中的作用  

The role of Transforming Growth Factor-β Receptor Ⅱ in Fasting-induced Muscle Atrophy in Vitro

作　　者：李文炯[1] 张鹏[1] 刘红菊[1] 李景龙[1] 罗维[1] 王晶[1] 陈晓萍[1] 

机构地区：[1]中国航天员科研训练中心,航天医学基础与应用国家重点实验室,北京100094

出　　处：《航天医学与医学工程》2013年第6期441-444,共4页Space Medicine & Medical Engineering

基　　金：国家自然科学基金面上项目(31171144;81272177);航天医学基础与应用国家重点实验室研究基金(SMFA10A01);中国航天医学工程预先研究项目(2012SY54A1601)

摘　　要：目的探讨转化生长因子-β受体Ⅱ(TβRⅡ)在饥饿诱导体外肌萎缩中的作用。方法应用差速贴壁和混合酶消化方法,体外分离培养野生小鼠(WT)和TβRⅡ骨骼肌特异敲除小鼠(KO)的骨骼肌原代细胞,并体外诱导WT和KO小鼠成肌细胞成肌分化形成多核肌管;用公认的饥饿法诱导肌管萎缩,制备体外肌萎缩模型;采用Real-time PCR技术,分析在饥饿诱导体外肌管萎缩形成过程中,Atrogin-1和MuRF1 mRNA表达的差异性变化。结果 1)与野生型对照组相比,骨骼肌特异性TβRⅡ基因敲除成肌细胞的体外分化能力增强,形成多核肌管的数量较多、肌管面积较大(P<0.01);2)骨骼肌特异性TβRⅡ基因敲除可显著对抗饥饿诱导的肌管面积减少,对抗体外肌萎缩(P<0.01);3)饥饿处理后,尽管野生型和基因敲除型肌管中萎缩特异基因Atrogin-1和MuRF1 mRNA表达均有显著增加(P<0.01),但骨骼肌特异性TβRⅡ基因敲除的萎缩肌管中Atrogin-1和MuRF1 mRNA表达水平较野生型显著减少(P<0.01)。结论 TβRⅡ基因敲除可通过抑制萎缩特异基因Atrogin-1和MuRF1 mRNA表达对抗饥饿诱导的体外肌萎缩,提示TβRⅡ在饥饿诱导的体外肌萎缩发生中起着重要的作用。Objective To explore the effect of transforming growth factor-β receptor Ⅱ （ TβRⅡ ） on fasting-in- duced muscle atrophy in vitro. Methods With the method of direct mixed enzyme digestion and differential ve- locity adherent, myoblasts from wild type mouse （WT） and muscle-specificTβRⅡ knockout mouse （KO） were isolated and cultivated. They were differentiated into multinucleated myotubes in vitro. The myotubes were induced into atrophy and in vitro model of muscle atrophy was prepared with general accepted starvation method. Analyzing the formation process of starvation induced myotube atrophy, the difference changes of At- rogin-1 and MuRF1 mRNA expressions between WT and KO myotubes were detected with real-time PCR. Re- sults 1 ） Compared with WT myotubes, differentiation capacity of KO myotubes was enhanced in vitro, moreo- ver, muhinucleated myotubes derived from KO displayed larger quantities and area （ P 〈 0.01 ） ; 2 ） TβRⅡ knockout could significantly resist the decrease of fasting induced atrophy myotube area in vitro （ P 〈 0.01 ） ; 3 ） The upregulation of Atrogin-1 and MuRF1 mRNA expression were remarkable both in the WT and KO myo- tubes after 6 hours treatment by PBS （P 〈0.01 ） , however, Atrogin-1 and MuRF1 mRNA expression of KO atrophy myotubes were decreased significantly （ P 〈 0.01 ） compared with WT myotubes. Conclusion TβRⅡ knockout can resist against the fasting induced muscle atrophy in vitro by inhibiting Atrogin-1 and MuRF1 mR- NA expression. It is suggested that TβRⅡ plays an important role in fasting-induced muscle atrophy in vitro.

关 键 词：转化生长因子-β受体Ⅱ 成肌分化 饥饿 肌萎缩 

分 类 号：R685[医药卫生—骨科学]