Effect of burn injury on apoptosis and expression of apoptosis-related genes/proteins in skeletal muscles of rats
Effect of burn injury on apoptosis and expression of apoptosis-related genes/proteins in skeletal muscles of rats
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烧伤对大鼠骨骼肌细胞凋亡及凋亡相关基因/蛋白表达的影响
DOI：
10.1007/s10495-008-0277-7
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发表时间：
2009-01-01
期刊：
影响因子：
7.2
通讯作者：
Lin, Jing
中科院分区：
文献类型：
--
作者：
Duan, Hongjie;Chai, Jiake;Lin, Jing
本研究旨在探讨烧伤后骨骼肌细胞凋亡的发生及其可能机制。大鼠40%体表面积烧伤后，用透射电镜、原位末端标记法和细胞死亡ELISA法检测TA肌细胞凋亡。热损伤后第1天骨骼肌细胞出现凋亡，第4天达到高峰。ELISA法检测血清中TNF-α含量，发现烧伤后TNF-α迅速升高，sFasL/sFas比值随之升高。提示烧伤后早期TNF-α诱导细胞凋亡，晚期FasL诱导细胞凋亡。实时荧光定量PCR芯片和Western blotting检测骨骼肌中凋亡相关基因/蛋白，发现促凋亡基因/蛋白表达上调，包括TNF配体和受体家族中的Tnfrsf 1 a、Tnfrsf 1 b和Tnfsf 6，Bcl-2家族中的Bax和Bid，caspase家族中的caspase-3和caspase-6，死亡和锡德结构域家族中的Dapk 1、FADD和Cidea，CARD家族中的Apaf-1和Gadd 45 a，而抗凋亡基因Bnip 1表达较时间匹配对照组下调。此外，caspase-3、caspase-8和caspase-9活性的增加进一步证明了它们在骨骼肌细胞凋亡中的作用。烧伤后促凋亡基因/蛋白表达和caspase活性显著增加，提示死亡受体介导的信号通路及其他凋亡相关通路参与了烧伤后骨骼肌细胞凋亡。而Bcl-2l 1、Mcl-1、Nol-3、IL-10和Prok 2等抗凋亡基因表达也上调，提示烧伤后机体保护性反应的存在。总之，数据表明，细胞凋亡和促凋亡信号增强烧伤大鼠肌肉。为了进一步阐明介导萎缩反应的潜在凋亡机制，在建立潜在的治疗干预措施，可以预防和/或减少骨骼肌萎缩和保护其生理功能是重要的。
The purpose of this study was to investigate the occurrence and possible mechanisms of apoptosis in skeletal muscles after burn injury. After a 40% body surface area burn to rats, TA muscles were examined for apoptosis at varying times by TEM, TUNEL and cell death ELISA assay. Thermal injury was found to induce apoptosis in skeletal muscle on the first day and maximal apoptosis appeared 4 days post-injury. Apoptotic ligands in serum assessed by ELISA revealed rapidly increase of TNF-α and subsequent increase of sFasL to sFas ratio after burn injury. It implied TNF-α induced apoptosis in early stage and FasL induced apoptosis in later stage after burn injury. Apoptosis-related genes/proteins in skeletal muscles examined by real-time PCR array and Western blotting showed pro-apoptotic genes/proteins, including Tnfrsf1a, Tnfrsf1b and Tnfsf6 in TNF ligand and receptor family, Bax and Bid in Bcl-2 family, caspase-3 and caspase-6 in caspase family, Dapk1, FADD and Cidea in death and CIDE domain family, Apaf-1 in CARD family, and Gadd45a were up-regulated, while anti-apoptotic gene Bnip1 was down-regulated compared with that of time-matched controls. In addition, increment of caspase-3, caspase-8 and caspase-9 activity provided further evidence for their role in apoptosis in skeletal muscle. Significant increase in expression in pro-apoptotic genes/proteins and activity of caspases suggested that death receptor-mediated signaling pathways and other apoptotic related pathways participated in apoptosis in skeletal muscle after burn injury. However, it was found that some anti-apoptotic genes such as Bcl2l1, Mcl-1, Nol-3, Il-10 and Prok2 were also up-regulated, which might imply the co-existence of protective response of the body after burns. In conclusion, the data suggest that apoptosis and pro-apoptotic signaling are enhanced in muscles of burned rats. To further elucidate the underlying apoptotic mechanisms mediating the atrophic response is important in establishing potential therapeutic interventions that could prevent and/or reduce skeletal muscle wasting and preserve its physiological function.