Ryan Alice S, Li Guoyan, Hafer-Macko Charlene, Ivey Frederick M
Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland; GRECC, MERCE, Baltimore, Maryland.
Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland; GRECC, MERCE, Baltimore, Maryland.
J Stroke Cerebrovasc Dis. 2017 May;26(5):962-968. doi: 10.1016/j.jstrokecerebrovasdis.2016.11.003. Epub 2016 Dec 9.
Peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC-1α) gene and Sirtuin-1 (SIRT-1) respond to physiological stimuli and regulate insulin resistance. Inflammatory markers tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and the soluble forms of intracellular adhesion molecule (sICAM-1) and vascular CAM-1 (sVCAM-1) are associated with increased risk of diabetes and coronary heart disease. Resistive training (RT) reduces hyperinsulinemia and improves insulin action in chronic stroke. Yet, the molecular mechanisms for this are unknown. This study will determine the effects of RT on skeletal muscle PGC-1α and SIRT-1 mRNA expression and inflammatory and vascular markers.
Stroke survivors (50-76 years) underwent a fasting blood draw for measurement of TNF-α, IL-6, CRP, serum amyloid A, sICAM-1, sVCAM-1, and bilateral vastus lateralis biopsies before and after RT. Participants were also assessed using bilateral multislice thigh computed tomography scans from the knee to the hip, a total body scan by dual-energy X-ray absorptiometry, and 1-repetition maximum strength testing. Subjects performed 2 sets of 3 lower extremity RT exercises 3 times per week for 12 weeks.
Bilateral leg press and leg extension strength increased ~30-50% with RT (P < .001). Body weight, total body fat mass, and fat-free mass did not change. Thigh muscle area and volume increased in both legs (P < .05). Nonparetic muscle PGC-1α mRNA expression increased 14% (P < .05) after RT and SIRT-1 mRNA decreased 24% (P < .05) and 31% (P < .01) in paretic and nonparetic muscles. There were no significant changes in plasma inflammation with training.
RT in chronic stroke induces changes in key skeletal muscle regulators of metabolism, without effecting circulating inflammation.
过氧化物酶体增殖物激活受体（PPAR）-γ 共激活因子（PGC-1α）基因和沉默调节蛋白 1（SIRT-1）对生理刺激作出反应并调节胰岛素抵抗。炎症标志物肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、C 反应蛋白（CRP）以及细胞间黏附分子的可溶性形式（sICAM-1）和血管细胞黏附分子-1（sVCAM-1）与糖尿病和冠心病风险增加相关。阻力训练（RT）可降低慢性卒中患者的高胰岛素血症并改善胰岛素作用。然而，其分子机制尚不清楚。本研究将确定 RT 对骨骼肌 PGC-1α 和 SIRT-1 mRNA 表达以及炎症和血管标志物的影响。
卒中幸存者（50 - 76 岁）在 RT 前后进行空腹采血以检测 TNF-α、IL-6、CRP、血清淀粉样蛋白 A、sICAM-1、sVCAM-1，并进行双侧股外侧肌活检。参与者还接受了从膝盖到髋部的双侧多层大腿计算机断层扫描、双能 X 线吸收法全身扫描以及 1 次重复最大力量测试。受试者每周进行 3 次，每次 2 组，每组 3 次下肢 RT 运动，共 12 周。
RT 后双侧腿举和腿伸展力量增加约 30 - 50%（P <.001）。体重、全身脂肪量和去脂体重未发生变化。双腿的大腿肌肉面积和体积增加（P <.05）。RT 后非瘫痪侧肌肉 PGC-1α mRNA 表达增加 14%（P <.05），瘫痪侧和非瘫痪侧肌肉中 SIRT-1 mRNA 分别降低 24%（P <.05）和 31%（P <.01）。训练后血浆炎症无显著变化。
慢性卒中患者进行 RT 可诱导关键骨骼肌代谢调节因子发生变化，而不影响循环炎症。
