Transfer RNA-derived small RNAs (tsRNAs) are a recently discovered form of non-coding RNA capable of regulating myriad physiological processes. The role of tsRNAs in hMSC adipogenic differentiation, however, remains incompletely understood. The purpose of this study was to identify the novel tsRNA-16902 as a regulator of hMSC adipogenic differentiation. In this study, we conducted transcriptomic sequencing of hMSCs after inducing their adipogenic differentiation, and we were thereby able to clarify the molecular mechanism underlying the role of tsRNA-16902 in this context via a series of molecular biology methods. When we knocked down tsRNA-16902 expression, this impaired hMSC adipogenic differentiation and associated marker gene expression. Bioinformatics analyses further revealed tsRNA-16902 to target retinoic acid receptor γ (RARγ). Luciferase reporter assays also confirmed the ability of tsRNA-16902 to bind to the RARγ 3′-untranslated region. Consistent with this, RARγ overexpression led to impaired hMSC adipogenesis. Further analyses revealed that Smad2/3 phosphorylation was increased in cells that either overexpressed RARγ or in which tsRNA-16902 had been knocked down. We also assessed the adipogenic differentiation of hMSCs in which tsRNA-16902 was knocked down and at the same time a Smad2/3 inhibitor was added to disrupt Smad2/3 phosphorylation. The adipogenic differentiation of hMSCs in which tsRNA-16902 was knocked down was further enhanced upon the addition of a Smad2/3 signaling inhibitor relative to tsRNA-16902 knockdown alone. Through a comprehensive profiling analysis of tsRNAs that were differentially expressed in the context of hMSC adipogenic differentiation, we were able to identify tsRNA-16902 as a previously uncharacterized regulator of adipogenesis. tsRNA-16902 is able to regulate hMSC adipogenic differentiation by targeting RARγ via the Smad2/3 signaling pathway. Together, our results may thus highlight novel strategies of value for treating obesity.

中文翻译：

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一种新型 tsRNA-16902 调节人骨髓间充质干细胞的脂肪形成分化。

转移 RNA 衍生的小 RNA (tsRNA) 是最近发现的一种非编码 RNA，能够调节多种生理过程。然而，tsRNA 在 hMSC 脂肪形成分化中的作用仍不完全清楚。本研究的目的是确定新型 tsRNA-16902 作为 hMSC 脂肪形成分化的调节剂。在本研究中，我们在诱导 hMSCs 成脂分化后对其进行了转录组测序，从而通过一系列分子生物学方法阐明了 tsRNA-16902 在此背景下作用的分子机制。当我们敲低 tsRNA-16902 表达时，这会损害 hMSC 脂肪形成分化和相关标记基因表达。生物信息学分析进一步揭示 tsRNA-16902 以视黄酸受体 γ (RARγ) 为目标。荧光素酶报告基因检测还证实了 tsRNA-16902 与 RARγ 3'-非翻译区结合的能力。与此一致的是，RARγ 过度表达导致 hMSC 脂肪生成受损。进一步的分析表明，在过表达 RARγ 或 tsRNA-16902 被敲低的细胞中，Smad2/3 磷酸化增加。我们还评估了 hMSC 的脂肪形成分化，其中 tsRNA-16902 被敲低，同时添加 Smad2/3 抑制剂以破坏 Smad2/3 磷酸化。相对于单独敲低 tsRNA-16902，添加 Smad2/3 信号抑制剂后，敲低 tsRNA-16902 的 hMSC 的脂肪形成分化得到进一步增强。通过对 hMSC 脂肪形成分化背景下差异表达的 tsRNA 进行全面的分析，我们能够将 tsRNA-16902 鉴定为以前未表征的脂肪形成调节因子。tsRNA-16902 能够通过 Smad2/3 信号通路靶向 RARγ 来调节 hMSC 脂肪形成分化。总之，我们的结果可能会凸显治疗肥胖症的有价值的新策略。