Department of Chemistry and Biochemistry, São Paulo State University (UNESP), Institute of Biosciences, Campus Botucatu, Brazil.
Área de Periodontia, Departamento de Prótese e Periodontia, Faculdade de Odontologia de Piracicaba, Universidade de Campinas, Piracicaba, São Paulo, 13414-018, Brazil.
Mol Cell Endocrinol. 2018 Dec 15;478:151-167. doi: 10.1016/j.mce.2018.08.008. Epub 2018 Aug 22.
We therefore investigated whether there is synergism between triiodothyronine (T3) hormone and trophic molecules released from mechanically-stressed endothelial cells (EC-enriched medium) in osteogenic phenotype by mapping classical repertory of genes. Although there are studies reporting the efficiency of T3 hormone on bone cells, it is scarce considering their effect in conjunction with other physiologically active molecules, such as those released by the active endothelial cells. To address this issue, human bone marrow-derived mesenchymal stem cells (hBMSCs) were treated with EC-enriched medium subjected to shear-stress up to 72 h in vitro, in conjunction or not with T3 hormone. Although our results found an important synergism considering these parameters on modulating key bone-related gene markers, such as on the alkaline phosphatase (ALP) behavior (at both mRNA and protein content), contributing for osteoblast differentiation, important genes such as OSTERIX and RUNX2 were significantly down-expressed, while a over-expression of RANKL was found when the conjunction effect of T3 and endothelial paracrine signaling was considered. In addition, T3 hormone over expressed both OCT4 and NANOG genes in a DNA epigenetic-independent manner. However, we observed a dynamic reprogramming of DNMT1, DNMT3A, DNMT3B and TET1, important DNA-related epigenetic markers. Specifically, T3 hormone alone up-modulated TET2 transcripts profile. Complimentarily, expression of microRNA (miRs) processing-related genes also was modulated, as well as miR-10b, miR-22, miR-21, miR-143 and miR-145 transcriptional related profiles. Altogether, our results suggested a positive effect of mechanically-stressed endothelial cells-induced paracrine signaling on T3 hormone-obtaining osteogenic phenotype, contributing to understanding the paradoxal effect of T3 hormone on the bone physiology.
因此，我们通过绘制经典基因谱来研究三碘甲状腺原氨酸（T3）激素与机械应激内皮细胞（富含 EC 的培养基）释放的营养分子在成骨表型中的协同作用。虽然有研究报道 T3 激素对骨细胞的效率，但考虑到它们与其他生理活性分子（如活性内皮细胞释放的分子）结合的效果，这种研究很少。为了解决这个问题，我们将人骨髓间充质干细胞（hBMSCs）用富含 EC 的培养基处理，在体外进行长达 72 小时的剪切应力处理，同时或不与 T3 激素一起处理。尽管我们的结果发现，考虑到这些参数对调节关键骨相关基因标志物的协同作用非常重要，例如碱性磷酸酶（ALP）的行为（在 mRNA 和蛋白含量方面），有助于成骨细胞分化，但重要基因如 OSTERIX 和 RUNX2 的表达明显下调，而当考虑 T3 和内皮旁分泌信号的联合作用时，发现 RANKL 过度表达。此外，T3 激素以 DNA 表观遗传独立的方式过度表达 OCT4 和 NANOG 基因。然而，我们观察到 DNA 相关表观遗传标记物 DNMT1、DNMT3A、DNMT3B 和 TET1 的动态重编程。具体来说，T3 激素单独上调 TET2 转录本谱。补充地，miRNA（miRs）加工相关基因的表达也被调节，以及 miR-10b、miR-22、miR-21、miR-143 和 miR-145 转录相关谱。总之，我们的结果表明机械应激内皮细胞诱导的旁分泌信号对 T3 激素获得成骨表型有积极影响，有助于理解 T3 激素对骨生理学的矛盾作用。
