State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Beijing Key Laboratory of Drug Target and Screening Research, Institute of Materia Medica of Peking Union Medical College, Beijing, 100050, PR China.
School of Biological Sciences, The University of Hong Kong, 6N01 Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.
Biochem Biophys Res Commun. 2019 Jun 25;514(2):407-414. doi: 10.1016/j.bbrc.2019.04.155. Epub 2019 May 2.
Skeletal muscle secretes myokines, which are involved in metabolism and muscle function regulation. The role of fasting on myokine expression in skeletal muscle is largely unknown. In this study, we used gastrocnemius skeletal muscle RNA sequencing data from fasting male mice in the Gene Expression Omnibus (GEO) database. Adopted male and female C57BL/6J mice that fasted for 24 h were included to examine the effect of fasting on myokine expression in slow-twitch soleus and fast-twitch tiabialis anterior (TA) skeletal muscle. We found that fasting significantly affected many myokines in muscle. Fasting reduced Fndc5 and Igf1 gene expression in soleus and TA muscles in both male and female mice without muscle phenotype or gender differences, but Il6, Mstn and Erfe expression was influenced by fasting with fibre type- and gender-dependent effects. Fasting also induced muscle atrophy marker genes Murf1 and Fbxo32 and reduced myogenesis factor Mef2 expression without muscle fibre or gender differences. We further found that the expression of transcription factors Pgc1α, Pparα, Pparγ and Pparδ had muscle fibre type-dependent effects, and the expression of Pgc1α and Pparα had gender-dependent effects. The sophisticated expression pattern of myokines would partially explain the complicated cross-talk between skeletal muscle and other organs in different genders and muscles phenotypes, and it is worth further investigation.
骨骼肌分泌肌因子，参与代谢和肌肉功能调节。禁食对骨骼肌中肌因子表达的影响在很大程度上是未知的。在这项研究中，我们使用了 GEO 数据库中禁食雄性小鼠的腓肠肌骨骼肌 RNA 测序数据。纳入了禁食 24 小时的雄性和雌性 C57BL/6J 小鼠，以研究禁食对慢收缩比目鱼肌和快收缩胫骨前肌（TA）骨骼肌中肌因子表达的影响。我们发现禁食显著影响肌肉中的许多肌因子。禁食降低了雌雄小鼠比目鱼肌和 TA 肌肉中 Fndc5 和 Igf1 基因的表达，而 Il6、Mstn 和 Erfe 的表达则受禁食影响，具有纤维类型和性别依赖性。禁食还诱导了肌萎缩标志物基因 Murf1 和 Fbxo32 的表达，并降低了不分肌肉纤维或性别的成肌因子 Mef2 的表达。我们进一步发现，转录因子 Pgc1α、Pparα、Pparγ 和 Pparδ 的表达具有纤维类型依赖性，而 Pgc1α 和 Pparα 的表达具有性别依赖性。肌因子复杂的表达模式部分解释了不同性别和肌肉表型的骨骼肌与其他器官之间复杂的相互作用，值得进一步研究。
