Piccirillo Rosanna
Department of Neurosciences, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy.
Front Physiol. 2019 Mar 29;10:287. doi: 10.3389/fphys.2019.00287. eCollection 2019.
Skeletal muscle is a highly vascularized tissue that can secrete proteins called myokines. These muscle-secreted factors exert biological functions in muscle itself (autocrine effect) or on short- or long-distant organs (paracrine/endocrine effects) and control processes such as metabolism, angiogenesis, or inflammation. Widely differing diseases ranging from genetic myopathies to cancers are emerging as causing dysregulated secretion of myokines from skeletal muscles. Myokines are also involved in the control of muscle size and may be important to be restored to normal levels to alleviate muscle wasting in various conditions, such as cancer, untreated diabetes, chronic obstructive pulmonary disease, aging, or heart failure. Interestingly, many myokines are induced by exercise (muscle-derived exerkines) and some even by specific types of physical activity, but more studies are needed on this issue. Most exercise-induced myokines travel throughout the body by means of extracellular vesicles. Restoring myokines by physical activity may be added to the list of mechanisms by which exercise exerts preventative or curative effects against a large number of diseases, including the deleterious muscle wasting they may cause. Extending our understanding about which myokines could be usefully restored in certain diseases might help in prescribing more tailored exercise or myokine-based drugs.
骨骼肌是一种血管高度丰富的组织，能够分泌一类名为肌动蛋白的蛋白质。这些由肌肉分泌的因子在肌肉自身发挥生物学功能（自分泌效应），或对近处或远处的器官产生作用（旁分泌/内分泌效应），并控制诸如新陈代谢、血管生成或炎症等过程。从遗传性肌病到癌症等各种各样的疾病，正逐渐被发现会导致骨骼肌中肌动蛋白的分泌失调。肌动蛋白也参与肌肉大小的调控，恢复到正常水平对于缓解各种情况下的肌肉萎缩可能很重要，比如癌症、未经治疗的糖尿病、慢性阻塞性肺疾病、衰老或心力衰竭。有趣的是，许多肌动蛋白是由运动诱导产生的（肌肉衍生的运动因子），有些甚至是由特定类型的体育活动诱导产生的，但在这个问题上还需要更多的研究。大多数运动诱导产生的肌动蛋白通过细胞外囊泡在全身运输。通过体育活动恢复肌动蛋白可能会被纳入运动对大量疾病发挥预防或治疗作用的机制之中，包括疾病可能导致的有害的肌肉萎缩。深入了解哪些肌动蛋白在某些疾病中能够得到有效恢复，可能有助于开出更具针对性的运动处方或基于肌动蛋白的药物。
