Medical Center of Hip, Luoyang Orthopedic-Traumatological Hospital, Orthopedics Hospital of Henan Province, Luoyang 471002, Henan, PR China.
Medical Center of Hip, Luoyang Orthopedic-Traumatological Hospital, Orthopedics Hospital of Henan Province, Luoyang 471002, Henan, PR China.
Life Sci. 2021 May 1;272:119204. doi: 10.1016/j.lfs.2021.119204. Epub 2021 Feb 10.
The involvement of several microRNAs (miRNAs) in osteogenic differentiation has been indicated recently. Also, exosomes, derived from different cells, could shuttle specific miRNAs to other cell systems. Nevertheless, the effect and mechanism of microRNA-935 (miR-935)-containing exosomes in osteoblasts remain basically unclear. The current work was set to inspect the relevance of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSC-exo) carrying miR-935 to osteoporotic rats.
The extracted BMSCs and purchased osteoblasts were cultured, followed by exosome isolation and identification. After cell grouping, osteoblasts were co-cultured with BMSCs. CCK-8, alizarin red staining as well as ALP staining were performed to detect osteoblast proliferation and activity. The binding connection between miR-935 and signal transducer and activator of transcription 1 (STAT1) was measured by dual-luciferase reporter gene assays. The expression profiles of miR-935, STAT1 and osteoblast-related proteins were assessed by RT-qPCR and Western blot. A rat model with osteoporosis was induced, and the BMD, BV/TV, Tb.N, Tb.Th and Tb.Sp values in rat bone tissues were observed by Micro-CT.
BMSC-exo inhibited STAT1 levels by the delivery of miR-935 into osteoblasts, while STAT1 silencing promoted ALP activity in osteoblasts and mineralized nodules. STAT1 was identified as a target gene of miR-935. Moreover, in vivo experiments showed that in ovariectomized rats, silencing of miR-935 significantly reduced BMD, BV/TV, Tb.N, Tb.Th and increased Tb.Sp.
BMSC-exo carry miR-935 to promote osteoblast proliferation and differentiation through targeting STAT1.
最近有研究表明，几种 microRNAs（miRNAs）参与成骨分化。此外，来源于不同细胞的外泌体可以将特定的 miRNAs 转运到其他细胞系统中。然而，载有 microRNA-935（miR-935）的外泌体在成骨细胞中的作用和机制基本不清楚。本研究旨在检测骨髓间充质干细胞（BMSC）来源的携带 miR-935 的外泌体（BMSC-exo）与骨质疏松症大鼠的相关性。
提取 BMSC 并购买成骨细胞，进行外泌体分离和鉴定。细胞分组后，将成骨细胞与 BMSC 共培养。通过 CCK-8、茜素红染色和碱性磷酸酶染色检测成骨细胞增殖和活性。通过双荧光素酶报告基因检测 miR-935 与信号转导和转录激活因子 1（STAT1）之间的结合关系。通过 RT-qPCR 和 Western blot 检测 miR-935、STAT1 和成骨相关蛋白的表达谱。通过 Micro-CT 观察大鼠骨组织中的骨密度（BMD）、骨体积/总体积（BV/TV）、Tb.N、Tb.Th 和 Tb.Sp 值，以诱导骨质疏松症大鼠模型。
BMSC-exo 通过将 miR-935 递送入成骨细胞来抑制 STAT1 水平，而 STAT1 沉默促进成骨细胞中的碱性磷酸酶活性和矿化结节。STAT1 被鉴定为 miR-935 的靶基因。此外，体内实验表明，在去卵巢大鼠中，沉默 miR-935 显著降低 BMD、BV/TV、Tb.N、Tb.Th，并增加 Tb.Sp。
BMSC-exo 通过靶向 STAT1 携带 miR-935 促进成骨细胞增殖和分化。
