TableS3 Conditioned media proteome (secretome) from EPS-stimulated C2C12 myotubes and their controls prior to imputation.

<b>Discovery of Thymosin Beta-4 as a Human Exerkine and Growth Factor</b><br>Skeletal muscle is an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in inter-organ crosstalk. Using mass spectrometry (MS)-based proteomics, we characterized the secretome and identified thymosin beta-4 (TMSB4X) as the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in plasma of exercising humans irrespective of the insulin resistance condition or exercise mode. Treatment of mice with TMSB4X did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration <i>in vivo</i>. However, TMSB4X increased osteoblast proliferation and neurite outgrowth, consistent with its WADA-classification as a prohibited growth factor. Therefore, we report TMSB4X as a human exerkine with a potential role in cellular crosstalk.<br>The data contain: <b>TableS3</b> Conditioned media proteome (secretome) from EPS-stimulated C2C12 myotubes and their controls prior to imputation.

**胸腺素β4作为人类运动因子（exerkine）与生长因子的发现**<br>骨骼肌是一类内分泌器官，可分泌运动诱导因子（exerkine），这类因子在器官间串扰中发挥关键调控作用。本研究基于质谱法（MS）的蛋白质组学技术对分泌组进行了系统表征，并在收缩状态的C2C12肌管培养基中鉴定出胸腺素β4（TMSB4X）为上调幅度最高的分泌蛋白。无论胰岛素抵抗状态或运动模式如何，运动人群血浆中的TMSB4X水平均会急性升高。向小鼠施加TMSB4X治疗，既未改善饮食诱导肥胖相关的代谢紊乱，也未促进体内（in vivo）肌肉再生。但TMSB4X可显著促进成骨细胞增殖与神经突生长，这与其被世界反兴奋剂机构（WADA）列为违禁生长因子的分类一致。因此，本研究证实TMSB4X是一种人类运动因子，在细胞串扰中具有潜在功能。<br>本数据集包含：**表S3** 电脉冲刺激（EPS）处理的C2C12肌管及其对照组在缺失值插补前的条件培养基蛋白质组（分泌组）数据。