阻断NF-κB信号对急性大强度运动后泛素蛋白酶体途径降解骨骼肌蛋白质的影响  

The Effect of Blocking NF-κB Signal on Protein Degradation by Ubiquitin-proteasome Pathway in Skeletal Muscle after an Acute High Intensity Exercise

作　　者：朱荣[1] 

机构地区：[1]温州医学院体育科学学院,浙江温州325035

出　　处：《北京体育大学学报》2014年第1期76-81,共6页Journal of Beijing Sport University

基　　金：浙江省自然科学基金课题(LY12C11002);温州医学院科研启动基金课题(QTJ09018)

摘　　要：目的:研究核转录因子NF-κB信号在一次大强度运动后泛素蛋白酶体途径降解骨骼肌蛋白质的作用。方法:42只雄性SD大鼠随机分为2组,对照组24只和注射组18只,进行1次大强度上坡跑运动(25m/min,5%坡度,1 h)。运动前1 h,注射组腹腔注射0.25 ml/100 g体重的8%PDTC(NF-κB信号阻断剂)溶液;对照组腹腔注射0.25 ml/100 g体重pH7.4PBS溶液。运动前从对照组中取材6只,做为安静时对照,运动后即刻和运动后1、6 h分别从每组取材6只。用EMSA测定腓肠肌细胞核NF-κB结合DNA活性,Western Blot测定细胞质IκBα蛋白含量,Real-Time PCR测定MuRF1、MAFbxmRNA含量,HPLC测定肌肉3-MH含量。结果:1)对照组IκBα蛋白含量在运动后即刻(P<0.01)、运动后1 h(P<0.01)较安静时非常显著降低,注射组IκBα蛋白含量在运动后即刻(P<0.05)运动后1 h(P<0.01)显著高于对照组。2)对照组运动后1 h细胞核NF-κB结合DNA能力非常显著高于安静时(P<0.01)和运动后即刻(P<0.01),注射组运动后即刻(P<0.05)、运动后1 h(P<0.01)显著低于同时间的对照组。3)对照组运动后1、6 h腓肠肌MAFbx、MuRF1 mRNA含量较安静时和运动后即刻非常显著升高(P<0.01),而注射组运动后1 h显著低于对照组(P<0.05)。4)对照组运动后即刻、运动后6 h3-MH含量非常显著高于安静时和运动后1 h(P<0.01)。注射组运动后6 h显著低于对照组(P<0.05)。结论:1次大强度运动后,骨骼肌泛素连接酶基因表达增加,激活泛素蛋白酶体途径活性,加强蛋白质降解。阻断NF-κB信号,可降低泛素连接酶基因表达,有助于减少运动后骨骼肌蛋白质降解。Objective： This research aimed to detect the role of NF-κB in protein degradation by ubiquitin-protea- some pathway in skeletal muscle after an acute exercise. Method： Forty-two male SD rats were randomly divided into two groups, control group （C; n =24） and inject group （P; n = 18）, to participate one hour treadmill exercise. The exercise speed was 25m/min with 5% uphill. Rats in P group and in C group were injected with pyrrolidine dithiocarbamate （PDTC, 0. 25ml/100 g. w ,8%, i. p. ） and PBS （0. 25ml/100 g. w, i. p. ） respectively one hour before exercise. Six rats from C group were killed before exercise as the quiet control, sis rats were killed immediate after exercise, 1 hour and 6 hours after exercise respectively. EMSA was used to measure banding DNA ability of NF-κB was measured by EMSA, IκBct protein level in cytoplasm was assayed by Westernblot, the content of MuRF1, MAFbx mRNA were detected by Real-Time PCR, and the content of 3 - MH in gastrocnemius was identified by high-efficiency liquid chromatography. Results ： 1 ） IκBα protein level was decreased significantly immediately after exercise and 1 hour later after exercise compared with paralleled control groups （ P 〈 0.01, P 〈 0. 01 ）, but were increased significantly in P group compared with in C group immediately after exercise （ P 〈0. 05 ） and 1 hour later after exercise（P 〈0. 01 ）. 2） The banding DNA ability of NF-κB in cell core was increased significantly in 1 hour later exercise group compared with rest C group, and right after exercise group （ P 〈 0. 01 ）, but was decreased significantly in P group compared with C groups at immediate postexercise（P 〈 0.05） and 1 h postexercise（P 〈 0. 01 ）. 3 ） The gene expressions of MAFbx,MuRF1 mRNA were increased significantly at lh and 6h postexercise than rest and postexercise in C group （P 〈 0.01 ）, but were decreased significantly in P group than in C group after 1 hour later after exercise （P 〈 0. 05）. 4） The co

关 键 词：NF—κB 信号阻断 大强度运动 骨骼肌 泛素蛋白酶体途径 骨骼肌蛋白质降解 动物实验 细胞质 IκBα蛋白 腓肠肌 

分 类 号：G804.2[文化科学—运动人体科学]