Mesenchymal stromal cells (MSCs) are promising candidates for cell-based therapies, mainly due to their unique biological properties such as multipotency, self-renewal and trophic/immunomodulatory effects. However, clinical use has proven complex due to limitations such as high variability of MSCs preparations and high number of cells required for therapies. These challenges could be circumvented with cell immortalization through genetic manipulation, and although many studies show that such approaches are safe, little is known about changes in other biological properties and functions of MSCs. In this study, we evaluated the impact of MSCs immortalization with the TERT gene on the purinergic system, which has emerged as a key modulator in a wide variety of pathophysiological conditions. After cell immortalization, MSCs-TERT displayed similar immunophenotypic profile and differentiation potential to primary MSCs. However, analysis of gene and protein expression exposed important alterations in the purinergic signaling of in vitro cultured MSCs-TERT. Immortalized cells upregulated the CD39/NTPDase1 enzyme and downregulated CD73/NT5E and adenosine deaminase (ADA), which had a direct impact on their nucleotide/nucleoside metabolism profile. Despite these alterations, adenosine did not accumulate in the extracellular space, due to increased uptake. MSCs-TERT cells presented an impaired in vitro immunosuppressive potential, as observed in an assay of co-culture with lymphocytes. Therefore, our data suggest that MSCs-TERT have altered expression of key enzymes of the extracellular nucleotides/nucleoside control, which altered key characteristics of these cells and can potentially change their therapeutic effects in tissue engineering in regenerative medicine.

中文翻译：

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TERT对间质基质细胞的永生化影响腺苷代谢并削弱其免疫抑制能力。

间充质基质细胞（MSCs）是基于细胞疗法的有希望的候选者，主要是由于它们独特的生物学特性，如多能性，自我更新和营养/免疫调节作用。但是，由于局限性，例如MSCs制剂的高变异性和治疗所需的大量细胞，临床应用已被证明是复杂的。这些挑战可以通过遗传操作通过细胞永生化来规避，尽管许多研究表明这种方法是安全的，但对MSC其他生物学特性和功能的变化知之甚少。在这项研究中，我们评估了TERT对MSC永生化的影响嘌呤能系统中的基因，已在多种病理生理条件下作为关键调节剂出现。细胞永生化后，MSCs-TERT表现出与原代MSC相似的免疫表型特征和分化潜能。然而，基因和蛋白质表达的分析暴露了体外培养的MSCs-TERT的嘌呤能信号传导中的重要变化。永生化细胞上调CD39 / NTPDase1酶，下调CD73 / NT5E和腺苷脱氨酶（ADA），这直接影响了它们的核苷酸/核苷代谢谱。尽管有这些改变，但由于摄取增加，腺苷并未积聚在细胞外空间中。如在与淋巴细胞共培养的分析中所观察到的，MSCs-TERT细胞的体外免疫抑制能力受损。因此，