Keller Charlotte, Steensberg Adam, Hansen Anne K, Fischer Christian P, Plomgaard Peter, Pedersen Bente Klarlund
Department of Infectious Disease, Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Denmark.
J Appl Physiol (1985). 2005 Dec;99(6):2075-9. doi: 10.1152/japplphysiol.00590.2005. Epub 2005 Aug 11.
The cytokine interleukin-6 (IL-6) exerts it actions via the IL-6 receptor (IL-6R) in conjunction with the ubiquitously expressed gp130 receptor. IL-6 is tightly regulated in response to exercise, being affected by factors such as exercise intensity and duration, as well as energy availability. Although the IL-6 response to exercise has been extensively studied, little is known about the regulation of the IL-6R response. In the present study, we aimed to investigate the effect of exercise, training, and glycogen availability, factors known to affect IL-6, on the regulation of gene expression of the IL-6R in human skeletal muscle. Human subjects performed either 10 wk of training with an acute exercise bout before and after the training period, or a low-glycogen vs. normal-glycogen acute exercise trial. The IL-6R mRNA response was evaluated in both trials. In response to acute exercise, an increase in IL-6R mRNA levels was observed. Neither training nor intramuscular glycogen levels had an effect on the IL-6R mRNA response to exercise. However, after 10 wk of training, the skeletal muscle expressed a higher mRNA level of IL-6R compared with before training. The present study demonstrated that the IL-6R gene expression levels in skeletal muscle are increased in response to acute exercise, a response that is very well conserved, being affected by neither training status nor intramuscular glycogen levels, as opposed to IL-6. However, after the training period, IL-6R mRNA production was increased in skeletal muscle, suggesting a sensitization of skeletal muscle to IL-6 at rest.
细胞因子白细胞介素-6（IL-6）通过IL-6受体（IL-6R）并与广泛表达的gp130受体共同发挥作用。IL-6在运动反应中受到严格调控，受运动强度、持续时间以及能量可利用性等因素影响。尽管对运动时IL-6的反应已进行了广泛研究，但对IL-6R反应的调控却知之甚少。在本研究中，我们旨在探讨运动、训练和糖原可利用性（已知影响IL-6的因素）对人骨骼肌中IL-6R基因表达调控的影响。人类受试者进行了为期10周的训练，并在训练期前后各进行一次急性运动试验，或者进行低糖原与正常糖原的急性运动试验。在这两个试验中均评估了IL-6R mRNA的反应。急性运动后，观察到IL-6R mRNA水平升高。训练和肌内糖原水平均未对运动时的IL-6R mRNA反应产生影响。然而，经过10周训练后，与训练前相比，骨骼肌中IL-6R的mRNA水平更高。本研究表明，骨骼肌中IL-6R基因表达水平在急性运动时升高，这一反应非常保守，与IL-6不同，它不受训练状态和肌内糖原水平的影响。然而，在训练期后，骨骼肌中IL-6R mRNA的产生增加，这表明骨骼肌在静息状态下对IL-6变得更加敏感。
