PI3K/Akt/mTOR信号通路在大鼠急性骨骼肌钝挫伤修复中的作用  

The Effect of PI3K/Akt/mTOR Signaling Pathways on the Recovery of Skeletal Muscle Contusion in Rats

作　　者：张安宁[1] 罗雪林 黄思琴[1] 唐成林[1] 赵丹丹[1] 罗翱[1] 谭程方 代妮 于芒[3] Zhang An＇ning;Luo Xuelin;Huang Siqin;Tang Chenglin;Zhao DANDan;Luo Ao;Tan Chengfang;Dai Ni;Yu Mang(College of Traditional Chinese Medicine,Chongqing Medical University,Chongqing 400016,China;Community Health Service Center of Longmenhao Street of Nan＇ an District in Chongqing,Chongqing 400064,China;Center of Clinical Scientific Research,Stanford University,California,U.S.A 94305)

机构地区：[1]重庆医科大学中医药学院,重庆400016 [2]重庆市南岸区龙门浩街道社区卫生服务中心,重庆400064 [3]斯坦福大学临床科学研究中心,美国加州94305

出　　处：《中国运动医学杂志》2018年第7期594-600,共7页Chinese Journal of Sports Medicine

基　　金：国家自然科学基金资助项目(No.81403466;No.81273870);重庆市渝中区项目(No.20140117);重庆市卫计委项目(No.ZY20150250);重庆市教委项目(No.KJ1702033);重庆市科委项目(No:cstc2017jcyj AX0363)

摘　　要：目的:研究PI3K/Akt/mTOR信号通路在大鼠急性骨骼肌钝挫伤修复中的作用及变化趋势,探讨骨骼肌损伤修复的可能生物学机制。方法:SD大鼠随机分为正常对照组和损伤后1 d组、3 d组、5 d组、7 d组、14 d组,每组各6只,采用自制打击装置建立腓肠肌钝挫伤模型。HE染色观察各组腓肠肌的形态结构;免疫印迹检测各组腓肠肌中磷脂酰肌醇-3激酶(PI3K)、蛋白激酶B(Akt)、磷酸化的蛋白激酶B(P-Akt Ser473)、哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸化哺乳动物雷帕霉素靶蛋白(P-mTORSer2448)的蛋白表达量;逆转录实时定量聚合酶链反应检测腓肠肌中成肌分化抗原(MyoD)、肌细胞生成素(MyoG)的mRNA相对表达量。结果:(1)HE染色结果显示:损伤后1 d可见肌细胞变性坏死,炎性细胞浸润;损伤后3 d和5 d可见新生的成肌细胞和肌管;损伤后7 d和14 d可见新生肌细胞和胶原纤维。(2)免疫印迹结果显示:与正常对照组比较,损伤后1 d、3 d、14 d组的各蛋白表达量升高,差异无统计学意义(P>0.05);损伤后5 d组PI3K、Akt、P-Akt Ser473表达量显著升高(P<0.01),mTOR和P-mTORSer2448表达量显著升高(P<0.05);损伤后7 d组PI3K、P-Akt Ser473、mTOR、P-mTORSer2448表达量显著升高(P<0.05),Akt表达量显著升高(P<0.01)。(3)逆转录实时定量聚合酶链反应结果显示:与正常对照组比较,损伤后1 d组Myo D1和MyoG的mRNA表达量显著升高(P<0.05,P<0.01);损伤后3 d、5 d、7 d各组Myo D1和Myo G的mRNA表达量显著升高(P<0.01);损伤后14 d组MyoG的mRNA表达量显著升高(P<0.05),MyoD1的mRNA表达量升高,但无统计学意义(P>0.05)。结论:PI3K/Akt/mTOR信号通路具有时间规律性地正向调控骨骼肌钝挫伤后的自我修复,可以作为临床治疗及科学研究骨骼肌损伤的靶点。Objective To observe the effect and activity trends of the phosphoinositide3-kinase（PI3 K）/protein kinase B（Akt）/mammalian target of rapamycin（mTOR） signaling pathways on skeletalmuscle contusion in rats,and explore the possible biological mechanism of its recovery. Methods A total of thirty-six Sprague-Dawley rats were randomly divided into a normal control group（n=6） and acontusion group（n=30）. The acute contusion of gastrocnemius was established in the contusion groupby the self-made striking device. On the 1 st,3 rd,5 th,7 th and 14 th day after injury,injured gastrocne-mius muscles were collected and observed the morphological structures using the haematoxylin eosin（HE） staining. The expression of PI3 K,Akt,P-Akt Ser473,mTOR and P-mTORSer2448 were detectedusing the Western blotting. The relative expression of myogenic differentiation antigen 1（Myo D1） andmyogenin（Myo G） mRNA were tested using the reverse transcription real-time quantitative polymerasechain reaction（RT-q PCR）. Results The result of HE staining showed the degeneration and necrosisof muscle cells and inflammatory cells on the 1 st day after injury,the new myoblasts and myotubes onthe 3 rd and 5 th day after injury,as well as neonatal muscle cells on the 7 th and 14 th day after inju-ry. The result of Western blotting showed that the expression of every protein was up-regulated onthe1 st,3 rd and 14 th day after injury,but without significant differences（P〈0.05） in comparison with thenormal control group. Moreover,the expression of PI3 K,Akt and P-Akt Ser473 proteins were significant-ly higher on the 5 th day after injury（P〈0.01）,and the expression of mTOR and P-mTORSer2448 pro-teins were significantly higher on the 5 th day after injury compared with those in the normal controlgroup（P〈0.05）. The expressions of PI3 K,P-Akt Ser473,mTOR and P-mTORSer2448 proteins,as well asAkt were significantly higher on the 7 th day after injury in comparison with the normal control group（P〈0.05）. The r

关 键 词：骨骼肌钝挫伤 PI3K/Akt/mTOR信号通路 成肌分化抗原 肌细胞生成素 

分 类 号：R873[医药卫生—运动医学]