严重烧伤大鼠骨骼肌成肌细胞增殖活性检测及蛋白激酶B表达分析  

Changes in proliferative activity of myoblasts and expression of Akt in skeletal muscle of rats after severe burn injury

作　　者：段红杰[1] 柴家科[1] 盛志勇[1] 梁黎明[1] 尹会男[1] 申传安[1] 

机构地区：[1]解放军总医院第一附属医院全军烧伤研究所,北京100048

出　　处：《中华外科杂志》2009年第16期1261-1264,共4页Chinese Journal of Surgery

基　　金：国家自然科学基金面上项目（30571919）;北京市自然科学基金资助项目（7072077）

摘　　要：目的分析严重烧伤后大鼠骨骼肌成肌细胞增殖活性变化和蛋白激酶B（Akt）及磷酸化Akt（pAkt）表达水平，探讨烧伤后骨骼肌萎缩的机制。方法雄性Wistar大鼠120只随机分为烧伤组和对照组，每组60只。烧伤组根据文献的方法建立40％Ⅲ°烫伤（以下简称烧伤）模型。烧伤后立即腹腔注射生理盐水40ml／kg进行复苏，创面外用碘伏。对照组除浸入37℃温水外，其余程序均与烧伤组相同。每组每个时间点10只大鼠，于伤后第0、1、4、7、10、14天取其胫骨前肌并称重。采用免疫组织化学双标法检测烧伤后骨骼肌增殖细胞核抗原（PCNA）表达情况以反映成肌细胞增殖活性。用Western Blot检测总Akt及pAkt表达水平并进行分析。结果严重烧伤后大鼠胫骨前肌重量显著下降，于伤后第4天达到最低（P〈0．01）。骨骼肌成肌细胞增殖活性于伤后第1天即显著下降（P〈0．01），第7天后逐渐升高至对照水平。骨骼肌总Akt表达水平伤后无显著变化（P〉0．05）。其活性形式pAkt表达在伤后第4天前两组均几乎检测不到，而烧伤第7天后显著升高（P〈0．01）。结论严重烧伤后早期骨骼肌萎缩明显，成肌细胞增殖活性下降是其原因之一。磷酸化Akt在烧伤早期促成肌细胞增殖作用减弱，创面修复期则显著增强，可部分解释成肌细胞增殖活性的变化。Objective To investigate changes in proliferative activity of myoblasts in skeletal muscle and potential role of phosphorylated Akt on it, so that a better understanding in mechanisms of skeletal muscle atrophy after burn injury will be got. Methods One hundred and twenty Wistar rats were randomly divided into 2 groups： control and severe thermal injury group. Rats in severe thermal injury group were subjected to a 40% total body surface area full-thickness scald injury, and Tibialis Anterior （TA） muscles were collected on 0, 1, 4, 7, 10, 14 days post-injury. After muscle mass determined, immunohistochemical double staining was used for detection of Proliferative Cell Nuclear Antigen （PCNA） of myoblasts. Protein expression of total Akt and phosphorylated Akt was determined by Western Blot. Results Burn injury induced significant reduction of TA muscle mass and maximal reduction of it appeared by 4 days after injury （P 〈 0. 01 ）. Proliferative activity of myoblasts decreased significantly from the first day postinjury （P 〈 0. 01 ） and increased slowly to basal level of controls after 7 days post-injury. The phosphorylated Akt was undetectable in both of controls and injured samples before 4 days but increased significantly after 7 days post-injury （ P 〈 0.01 ）, though total Akt expression had no significant alteration at any time points （ P 〉 0. 05 ）. Conclusions Decrease in proliferative activity of myoblasts may be one of the contributors of significant atrophy of skeletal muscle after burn injury. Effect of phosphorylated Akt on proliferation attenuated in early stage and increased significantly in later stage after burn injury may partly explain the changes in proliferative activity of myoblasts.

关 键 词：烧伤 成肌细胞 细胞增殖 蛋白激酶类 

分 类 号：R686[医药卫生—骨科学]