Identification of a suitable cell source and bioactive agents guiding cell differentiation towards tenogenic phenotype represents a prerequisite for advancement of cell-based therapies for tendon repair. Human adipose-derived stem cells (hASCs) are a promising, yet intrinsically heterogenous population with diversified differentiation capacities. In this work, we investigated antigenically-defined subsets of hASCs expressing markers related to tendon phenotype or associated with pluripotency that might be more prone to tenogenic differentiation, when compared to unsorted hASCs. Subpopulations positive for tenomodulin (TNMD+ hASCs) and stage specific early antigen 4 (SSEA-4+ hASCs), as well as unsorted ASCs were cultured up to 21 days in basic medium or media supplemented with TGF-β3 (10 ng/ml), or GDF-5 (50 ng/ml). Cell response was evaluated by analysis of expression of tendon-related markers at gene level and protein level by real time RT-PCR, western blot, and immunocytochemistry. A significant upregulation of scleraxis was observed for both subpopulations and unsorted hASCs in the presence of TGF-β3. More prominent alterations in gene expression profile in response to TGF-β3 were observed for TNMD+ hASCs. Subpopulations evidenced an increased collagen III and TNC deposition in basal medium conditions in comparison with unsorted hASCs. In the particular case of TNMD+ hASCs, GDF-5 seems to influence more the deposition of TNC. Within hASCs populations, discrete subsets could be distinguished offering varied sensitivity to specific biochemical stimulation leading to differential expression of tenogenic components suggesting that cell subsets may have distinctive roles in the complex biological responses leading to tenogenic commitment to be further explored in cell based strategies for tendon tissues.

中文翻译：

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评价人脂肪来源的干细胞的选定亚群的肌腱分化潜能。

鉴定合适的细胞来源和生物活性剂，指导细胞向肌腱表型的分化，这是推进基于细胞的肌腱修复疗法的先决条件。人脂肪来源的干细胞（hASCs）是一种有前途的但本质上具有异质性的种群，具有多样化的分化能力。在这项工作中，我们调查了与未分类的hASC相比，表达与肌腱表型相关的标记或与多能性相关的标记的hASC的抗原定义子集，这些标记可能更倾向于肌腱分化。在基础培养基或补充了TGF-β3（10 ng / ml）的培养基中培养Tenomodulin（TNMD + hASCs）和阶段特异性早期抗原4（SSEA-4 + hASCs）阳性的亚群以及未分选的ASCs长达21天，或GDF-5（50 ng / ml）。通过实时RT-PCR，蛋白质印迹和免疫细胞化学分析肌腱相关标志物在基因水平和蛋白质水平的表达来评估细胞反应。在存在TGF-β3的情况下，亚群和未分选的hASCs的硬皮病均显着上调。对于TNMD + hASCs，观察到响应TGF-β3的基因表达谱中更显着的变化。与未分选的hASC相比，亚群表明在基础培养基条件下胶原III和TNC沉积增加。在TNMD + hASC的特殊情况下，GDF-5似乎对TNC的沉积影响更大。在hASC人群中，