TableS2. Cell proteome from EPS-stimulated C2C12 myotubes and their controls.

<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>TableS2.</b> Cell proteome from EPS-stimulated C2C12 myotubes and their controls.

**胸腺素β-4（TMSB4X）作为人类运动因子与生长因子的发现**
骨骼肌作为一种内分泌器官，可分泌运动诱导因子（exerkines），这类因子在器官间串扰中发挥核心调控作用。本研究采用基于质谱（mass spectrometry, MS）的蛋白质组学技术对分泌组进行表征，并在收缩型C2C12肌管的培养基中鉴定出胸腺素β-4（TMSB4X）为上调幅度最高的分泌蛋白。无论受试者的胰岛素抵抗状态或运动模式如何，运动人群的血浆中TMSB4X水平均会出现急性升高。给小鼠注射TMSB4X既未改善饮食诱导肥胖相关的代谢紊乱，也未在体内（in vivo）增强肌肉再生能力。但TMSB4X可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（World Anti-Doping Agency, WADA）列为违禁生长因子的分类结果一致。因此，本研究证实TMSB4X是一种人类运动因子，在细胞间串扰中具备潜在调控功能。
本数据集包含：**表S2**：EPS刺激后的C2C12肌管细胞蛋白质组及其对照样本数据。