In order to develop strategies to regenerate complex tissues in mammals, understanding the role of signaling in regeneration competent species and mammalian development is of critical importance. Fibroblast growth factor 8 (FGF-8) signaling has an essential role in limb morphogenesis and blastema outgrowth. Therefore, we aimed to study the effect of FGF-8b on the proliferation and differentiation of mesenchymal stem cells (MSCs), which have tremendous potential for therapeutic use of cell-based therapy. Rat adipose derived stem cells (ADSCs) and muscle progenitor cells (MPCs) were isolated and cultured in growth medium and various types of differentiation medium (osteogenic, chondrogenic, adipogenic, tenogenic, and myogenic medium) with or without FGF-8b supplementation. We found that FGF-8b induced robust proliferation regardless of culture medium. Genes related to limb development were upregulated in ADSCs by FGF-8b supplementation. Moreover, FGF-8b enhanced chondrogenic differentiation and suppressed adipogenic and tenogenic differentiation in ADSCs. Osteogenic differentiation was not affected by FGF-8b supplementation. FGF-8b was found to enhance myofiber formation in rat MPCs. Overall, this study provides foundational knowledge on the effect of FGF-8b in the proliferation and fate determination of MSCs and provides insight in its potential efficacy for musculoskeletal therapies.

为了制定哺乳动物复杂组织再生的策略，了解信号在再生能力物种和哺乳动物发育中的作用至关重要。成纤维细胞生长因子 8 (FGF-8) 信号传导在肢体形态发生和芽基生长中发挥重要作用。因此，我们的目的是研究 FGF-8b 对间充质干细胞 (MSC) 增殖和分化的影响，间充质干细胞在细胞疗法的治疗应用中具有巨大的潜力。分离大鼠脂肪干细胞 (ADSC) 和肌肉祖细胞 (MPC)，并在添加或不添加 FGF-8b 的生长培养基和各种类型的分化培养基（成骨、软骨、脂肪、肌腱和肌源培养基）中培养。我们发现无论培养基如何，FGF-8b 都会诱导强劲的增殖。通过补充 FGF-8b，ADSC 中与肢体发育相关的基因上调。此外，FGF-8b 增强 ADSC 中的软骨形成分化并抑制脂肪形成和肌腱分化。成骨分化不受 FGF-8b 补充的影响。研究发现 FGF-8b 可增强大鼠 MPC 中的肌纤维形成。总体而言，这项研究提供了有关 FGF-8b 在 MSC 增殖和命运决定中的影响的基础知识，并深入了解其对肌肉骨骼治疗的潜在功效。