BACKGROUND: The calpain family members (Calpains) and FoxO transcription factors (FoxOs) play important roles during muscle atrophy.OBJECTIVE: To investigate the different expression patterns and correlations of Calpains (Calpain 1, Calpain 2, Calpain 3) and FoxO transcription factors (FoxO1 and FoxO3a) during gastrocnemius muscle atrophy induced by sciatic nerve injury and cardiotoxin injection.METHODS: The gastrocnemius muscle atrophic models were established by sciatic nerve injury and cardiotoxin injection. The Mrna level of Calpains and FoxOs were detected by real time quantitative PCR at 3, 7,14 and 21 days after injury. The linear regression analysis was performed to conduct the correlations between Calpains and FoxOs.RESULTS AND CONCLUSION: The expression level of Calpain 1 (CAPN1), Calpain 2 (CAPN2) and FoxO3a Mrna reached to peak at 7 days after sciatic nerve injury, and then decreased gradually; the Mrna level of Calpain 3 (CAPN3) and FoxO1 reached to peak at 14 days after sciatic nerve injury, then declined. After cardiotoxin injection, the expression level of CAPN1, CAPN2 and FoxO3a Mrna rapidly reached to peak at 3 days after cardiotoxin injection and then slowly went back down; the Mrna level of FoxO1 found its climax at 7 days after cardiotoxin injection, while that of CAPN3 instantly got to its lowest point at 3 days after cardiotoxin injection. The result of linear regression analysis showed that there was a significant positive correlation between the expression of CAPN3 and FoxO1 Mrna (r=0.901 5) during gastrocnemius muscle atrophy induced by sciatic nerve injury; And after cardiotoxin injection, the strong positive correlation existed between the Mrna level of CAPN1, CAPN2 and that of FoxO3a (r=0.8987, r=0.9374) respectively. The present study indicated that the mRNAs alteration of CAPN1 and CAPN2 was similar in the two different muscle injury models, while CANP3 displayed a different expression pattern.%背景:钙蛋白酶家族和FoxO 转录因子在肌萎缩过程中发挥着重要的作用.目的:观察钙蛋白酶家族成员及FoxO 转录因子(FoxO1 和FoxO3a) 在心脏毒素注射与坐骨神经夹伤致腓肠肌失功能损伤中表达的变化.方法:分别采用坐骨神经夹伤和心脏毒素注射建立大鼠腓肠肌功能损伤模型,于造模后的第3,7,14,21 天取大鼠腓肠肌进行实时荧光定量PCR 检测,并采用线性回归法进行相关性分析.结果与结论:结果显示,腓肠肌组织中的钙蛋白酶Ⅰ、钙蛋白酶Ⅱ和FoxO3a mRNA 在坐骨神经夹伤7 d 达到高峰,随后下降;钙蛋白酶Ⅲ和FoxO1 mRNA 在坐骨神经夹伤后14 d 达到高峰,随后下降.钙蛋白酶Ⅰ、钙蛋白酶Ⅱ、FoxO3a mRNA 在心脏毒素注射后第3 天达高峰,随后逐渐下降;FoxO1 mRNA 在心脏毒素注射后7 d 时达最高;而钙蛋白酶Ⅲ mRNA 在心脏毒素注射后3 d 时表达显著下降,随后逐渐恢复至正常水平.线性回归分析结果显示,在失神经肌损伤过程中钙蛋白酶Ⅲ的表达与FoxO1 呈正相关(r=0.901 5) ;在心脏毒素注射肌损伤过程中钙蛋白酶Ⅰ(r=0.898 7) 和钙蛋白酶Ⅱ(r=0.937 4) 表达趋势与FoxO3a 呈正相关.可见,在不同的肌损伤模型中,钙蛋白酶Ⅰ和钙蛋白酶Ⅱ的表达趋势相似,而钙蛋白酶Ⅲ的表达不同.
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