摘要
背景:低氧复合运动可上调解偶联蛋白3的表达,提高骨骼肌线粒体对低氧的抵抗力,但其生物学效应及作用机制尚不清楚。目的:观察单纯低氧及低氧复合运动对骨骼肌线粒体力能学及解偶联蛋白3表达的影响,并探讨NO-ATF1信号通路在其中的生物学效应。方法:将60只SD大鼠随机分成常氧对照组、单纯低氧组、低氧复合运动训练组、低氧+L-NAME组和低氧复合运动训练+L-NAME组。低氧干预为常压低氧帐篷,模拟11.3%的氧体积分数;运动干预为低氧帐篷内跑台训练;L-NAME干预为饮用水中添加一氧化氮合酶抑制剂左旋硝基精氨酸甲酯。各种干预持续4周,硝酸还原酶法测定骨骼肌一氧化氮含量,荧光素酶发光法检测线粒体ATP合成活力,二氯荧光素法检测线粒体过氧化氢生成速率,实时荧光定量PCR法检测骨骼肌激活转录因子1和解偶联蛋白3 mRNA的表达,Western blot法检测骨骼肌磷酸化激活转录因子1和线粒体解偶联蛋白3蛋白的表达。结果与结论:低氧复合运动显著上调骨骼肌解偶联蛋白3的表达及线粒体ATP的合成活力,抑制线粒体过氧化氢的产生,同时增加骨骼肌一氧化氮含量及激活转录因子1磷酸化水平,左旋硝基精氨酸甲酯抑制了低氧复合运动对线粒体的保护效应。说明低氧复合运动可通过NO-ATF1途径上调解偶联蛋白3的表达提高骨骼肌线粒体对低氧的抵抗力。
BACKGROUND： Hypoxic exercise can upregulate uncoupling proteins 3 expression, and promote the resistance of skeletal muscle mitochondria to hypoxia, but its biological effect and mechanism are still unclear. OBJECTIVE： To observe the effect of hypoxia alone and hypoxic exercise on mitochondrial energetics and uncoupling proteins 3 expression, and to discuss the biological effect of NO-ATF1 signaling pathway in this process. METHODS： Sixty SD rats were randomly divided into five groups： normoxia control group, hypoxia group, hypoxic exercise group, hypoxia ＋ L-NAME group and hypoxic exercise ＋ L-NAME group. Animals in the hypoxia group were subjected to hypoxia exposure in normobaric hypoxic tent with 11.3% O2. Those in the hypoxic exercise groups were exercised on a motor-driven rodent treadmill in the normobaric hypoxic tent with11.3% O2. And the drinking water for L-NAME animals contained L-NAME at dose of 1 g/L. All these interventions lasted for 4 weeks. The content of nitric oxide （NO） was measured with nitrate reductase method. Adenodine triphospate （ATP） synthesis capacity was determined using a bioluminescence technique. Mitochondrial H2O2 generation was determined using dichlorofluorescein （DCF）. The expression of uncoupling proteins 3 （UCP3） and ATF1 in muscle were detected by real-time quantitative PCR. And the phosphorylation of ATF1 and mitochondrial UCP3 protein expression were measured by Western-blotting. RESULTS AND CONCLUSION： Exercise training in hypoxia markedly enhanced mitochondrial UCP3 expression and ATP synthesis capacity, and suppressed mitochondrial H2O2 generation, which accompanied with elevated NO content and ATF1 phosphorylation level. L-NAME restrained the protective effect of hypoxic exercise on mitochondria. These findings indicated that hypoxic exercise can increase uncoupling proteins 3 expression through the NO-ATF1 signaling pathway so as to increase the mitochondrial resistance to hypoxia.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2010年第41期7643-7648,共6页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
国家自然科学基金项目(30270638)
武警医学院科研基金(WY2009-11)~~
