McFarlin Brian K, Flynn Michael G, Campbell Wayne W, Stewart Laura K, Timmerman Kyle L
Laboratory of Integrated Physiology, Department of Health and Human Performance [corrected] University of Houston, Houston, TX, USA.
Med Sci Sports Exerc. 2004 Nov;36(11):1876-83. doi: 10.1249/01.mss.0000145465.71269.10.
INTRODUCTION/PURPOSE: Regular exercise may offset age-associated increases in inflammatory cytokines and reduce the risk of developing diseases with an inflammatory etiology by exerting "anti-inflammatory" effects. Toll-like receptor 4 (TLR4) signaling stimulates inflammatory cytokine production, and may explain the "anti-inflammatory" effect attributed to regular exercise. Therefore, the purpose of the present study was to compare the effect of acute (3 sets, 9 exercises, 10 repetitions at 80% of the 1-repetition maximum) and chronic resistance exercise on TLR4 and inflammatory cytokines.
Venous blood samples were collected from trained (TR, N = 10) and untrained (UT, N = 10) older (65-80 yr) postmenopausal women: before (PRE), immediately post (POST), and 2 h (2H), 6 h (6H), and 24 h (24H) after completion of exercise. Cell-surface expression of TLR4 (two-color immunofluorescent cytometry), LPS (25 microg x mL(-1))-stimulated cytokine production (ELISA), plasma cytokines (ELISA), and mRNA expression of TLR4 and cytokines (RT-PCR) were determined for each sample.
TR had 124% less cell-surface TLR4 expression than UT (P < 0.05). A significant time effect was found for LPS-stimulated IL-6, IL-1beta, and TNF-alpha, where 6H was significantly greater than all other samples. No significant effects were found for plasma (IL-6 and TNF-alpha) or mRNA expression (IL-6, TNF-alpha, and IL-1beta) of inflammatory cytokines. When subjects were grouped according to cell-surface TLR4 expression (HI and LO), LPS-stimulated TNF-alpha (302%), IL-1beta (209%), and IL-6 (167%) production was greater for HI than LO (P < 0.05).
Regularly exercising older women expressed less cell-surface TLR4 but did not have lower plasma levels or produce less LPS-stimulated inflammatory cytokines at rest or in response to a single bout of resistance exercise. TLR4 changes may explain the "anti-inflammatory" effect that has recently been attributed to chronic (2x wk for previous 24 months) resistance exercise training.
引言/目的：规律运动可能抵消与年龄相关的炎性细胞因子增加，并通过发挥“抗炎”作用降低患炎性病因疾病的风险。Toll样受体4（TLR4）信号传导刺激炎性细胞因子产生，可能解释规律运动的“抗炎”作用。因此，本研究的目的是比较急性（3组，9项运动，以1次最大重复量的80%进行10次重复）和慢性抗阻运动对TLR4和炎性细胞因子的影响。
从训练有素（TR，N = 10）和未经训练（UT，N = 10）的65至80岁绝经后老年女性采集静脉血样本：运动前（PRE）、运动后即刻（POST）、运动后2小时（2H）、6小时（6H）和24小时（24H）。对每个样本测定TLR4的细胞表面表达（双色免疫荧光细胞术）、脂多糖（25μg·mL⁻¹）刺激的细胞因子产生（酶联免疫吸附测定）、血浆细胞因子（酶联免疫吸附测定）以及TLR4和细胞因子的mRNA表达（逆转录聚合酶链反应）。
TR组细胞表面TLR4表达比UT组少124%（P < 0.05）。发现脂多糖刺激的白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）有显著的时间效应，其中6H时显著高于所有其他样本。炎性细胞因子的血浆（IL-6和TNF-α）或mRNA表达（IL-6、TNF-α和IL-1β）未发现显著影响。当根据细胞表面TLR4表达对受试者进行分组（高表达组和低表达组）时，高表达组脂多糖刺激的TNF-α（302%）、IL-1β（209%）和IL-6（167%）产生量高于低表达组（P < 0.05）。
经常锻炼的老年女性细胞表面TLR4表达较少，但在静息状态或单次抗阻运动后，血浆水平并未降低，脂多糖刺激产生的炎性细胞因子也未减少。TLR4的变化可能解释了最近归因于慢性（前24个月每周2次）抗阻运动训练的“抗炎”作用。
