【摘要】 目的研究蛋白酶体亚基RC2在失神经骨骼肌中的变化规律及其意义。方法将48只SD大鼠,建立右下肢腓肠肌失神经支配模型,随机分为8组,每组6只,术后0 d为对照组,术后1、2、3、4、5、6、14 d为实验组；分别采用实时定量PCR和Western blot检测RC2在转录和蛋白水平的变化规律。结果RC2的mRNA从失神经后第1天开始表达上调,3 d达到高峰,为对照组的4．98倍,随后逐渐下降,14 d时降为对照组的0．42倍；各实验组与对照组相比,差异有统计学意义(P＜0．05)。RC2在蛋白水平的变化与转录水平有着相同的趋势,但是变化幅度较转录水平为低。失神经后3 d达到高峰,为对照组的2．70倍,随后缓慢下降,14 d时降为正常侧的O．35倍；失神经术后1、6 d与对照组相比,差异无统计学意义(P＞0．05)。2～5、14 d与对照组相比,差异有统计学意义(P＜0．05)。结论蛋白酶体亚基RC2在失神经骨骼肌早期表达增强,提示泛素-蛋白酶体途径在失神经骨骼肌早期的蛋白快速降解中占有重要地位。更多还原

【Abstract】 Objective To observe expression of proteasome subunit RC2 in denervated skeletal muscles,and investigate the molecular mechanism of skeletal muscle wasting.Methods A model of gastrocnemius muscle denervation at the right lower limb was established in 48 rats.They were divided into 8 groups with 6 each.The subsequent changes in RC2 mRNA and protein levels were determined by real-time quantitative PCR and Western blot, respectively.Results Expression of proteasome subunit RC2 mRNA in rat denervated gastrocnemius muscle was upregulated gradually,peaked in 3 days,then decreased (4.98 folds and 0.42 fold at day 3 and day 14,respectively; P＜0.05).The changes of protein levels were similar to that of mRNA levels,but the amplitude of changes was lower (2.70 folds and 0.35 fold at day 3 and day 14,respectively;P＜0.05).Conclusion After denervation, expression of proteasome subunit RC2 in skeletal muscle was upregulated.This supports the concept that denervation- induced muscle atrophy is,at least in part,regulated by the ubiquitin-proteasome proteolytic pathway.更多还原