Department of Orthopedics, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, People's Republic of China.
Department of Vascular Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, People's Republic of China.
Drug Des Devel Ther. 2020 Oct 28;14:4579-4591. doi: 10.2147/DDDT.S258024. eCollection 2020.
Steroids are known to inhibit osteogenic differentiation and subsequent bone formation in bone mesenchymal stem cells (BMSCs). However, little is known about the role of BMSC exosomes (Exos) and tRNA-derived small RNAs (tsRNAs) in steroid-induced osteonecrosis of the femoral head (SONFH). The objective of this study was to characterize the tsRNA expression profiles of plasma Exos collected from SONFH patients and healthy individuals using small RNA sequencing and further explore the effect of BMSC Exos carrying specific tsRNAs on osteogenic differentiation.
Based on insights from small RNA sequencing, five differentially expressed (DE) tsRNAs were selected for quantitative real-time polymerase chain reaction (qRT-PCR). The regulatory networks associated with interactions of the tsRNAs-mRNA-pathways were reconstructed. The osteogenesis and adipogenesis in BMSCs were detected via ALP and oil red O staining methods, respectively.
A total of 345 DE small RNAs were screened, including 223 DE tsRNAs. The DE tsRNAs were enriched in Wnt signaling pathway and osteogenic differentiation. We identified five DE tsRNAs, among which tsRNA-10277 was significantly downregulated in plasma Exos of SONFH patients compared to that in healthy individuals. Dexamethasone-induced BMSCs were associated with an increased fraction of lipid droplets and decreased osteogenic differentiation, whereas BMSC Exos restored the osteogenic differentiation of that. After treatment of tsRNA-10277-loaded BMSC Exos, the lipid droplets and osteogenic differentiation ability were found to be decreased and enhanced in dexamethasone-induced BMSCs, respectively.
An altered tsRNA profile might be involved in the pathophysiology of SONFH. tsRNA-10277-loaded BMSC Exos enhanced osteogenic differentiation ability of dexamethasone-induced BMSCs. Our results provide novel insights into the osteogenic effect of BMSC Exos carrying specific tsRNAs on SONFH.
已知类固醇可抑制骨髓间充质干细胞（BMSCs）的成骨分化和随后的骨形成。然而，关于 BMSC 外泌体（Exos）和 tRNA 衍生的小 RNA（tsRNAs）在类固醇诱导的股骨头坏死（SONFH）中的作用知之甚少。本研究旨在通过小 RNA 测序来描述从 SONFH 患者和健康个体中收集的血浆 Exos 的 tsRNA 表达谱，并进一步探讨携带特定 tsRNA 的 BMSC Exos 对成骨分化的影响。
基于小 RNA 测序的见解，选择了 5 个差异表达（DE）的 tsRNA 进行定量实时聚合酶链反应（qRT-PCR）。重建与 tsRNA-mRNA-通路相互作用相关的调控网络。通过碱性磷酸酶（ALP）和油红 O 染色方法检测 BMSCs 的成骨和脂肪生成。
筛选出 345 个 DE 小 RNA，包括 223 个 DE tsRNA。DE tsRNA 富集在 Wnt 信号通路和成骨分化中。我们鉴定出 5 个 DE tsRNA，其中 tsRNA-10277 在 SONFH 患者的血浆 Exos 中与健康个体相比明显下调。地塞米松诱导的 BMSCs 与脂滴分数增加和成骨分化减少有关，而 BMSC Exos 恢复了其成骨分化能力。用负载 tsRNA-10277 的 BMSC Exos 处理后，发现地塞米松诱导的 BMSCs 中的脂滴和成骨分化能力分别降低和增强。
改变的 tsRNA 谱可能参与 SONFH 的病理生理学。负载 tsRNA-10277 的 BMSC Exos 增强了地塞米松诱导的 BMSCs 的成骨分化能力。我们的研究结果为携带特定 tsRNA 的 BMSC Exos 对 SONFH 的成骨作用提供了新的见解。
