组蛋白甲基转移酶G9a的抑制通过调节LINC00657/miR-204-5p/IGFBP5途径促进糖尿病性骨质疏松症中骨源干细胞的成骨潜能。

Inhibition of histone methyltransferase G9a promotes the osteogenic potential of bone-derived stem cells in diabetic-osteoporosis by regulating the LINC00657/miR-204-5p/IGFBP5 pathway.

作者信息

Qiao Mei-Qi, Wang Bin, Fan Jian-Pin, Gao Feng, Wang Shao-Jun, Guo Sheng-Yang, Xia Sheng-Li

机构信息

Graduate School, Shanghai University of Traditional Chinese Medicine, Shanghai, China.

Department of Orthopedics, Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China.

出版信息

Front Endocrinol (Lausanne). 2025 Aug 12;16:1625944. doi: 10.3389/fendo.2025.1625944. eCollection 2025.

DOI:10.3389/fendo.2025.1625944

PMID:40873948

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC12378076/

Abstract

BACKGROUND

Bone mesenchymal stem cells (BMSCs) from patients with diabetes often exhibit reduced osteogenic potential. This study aimed to investigate the mechanism of action of G9a, known as euchromatic histone lysine methyltransferase 2 (EHMT2), identify its key responsive long non-coding RNA in diabetic osteoporosis (DOP), and evaluate the effectiveness of the G9a inhibitor (UNC0638).

METHODS

The expression level of G9a in bone-derived MSCs (BMSCs) from osteoporosis patients with or without T2DM (T2DM-BMSCs, CON-BMSCs) was detected, and osteogenic differentiation was evaluated by osteogenic genes, ALP activity and calcification level. The key lncRNA, LINC00657, was screened based on previous transcriptome sequencing, qPCR and gene overexpression assay. The downstream miRNA and the target gene of LINC00657 were identified through transcriptome sequencing, bioinformatics analysis, dual luciferase reporter assay and gene overexpression assay. Rat DOP was constructed, and micro-CT, histochemical staining, immunofluorescence and qPCR were used to investigate the mechanism of UNC0638.

RESULTS

G9a expression was increased and LINC00657 expression was decreased in T2DM-BMSCs, compared with CON-BMSCs. UNC0638 treatment improved the osteogenic potential of T2DM-BMSCs and reversed the downregulation of LINC00657. LINC00657 overexpression reverses the inhibitory effect of EHMT2 on osteogenic differentiation. miR-204-5p and IGFBP5 were screened as downstream molecules of LINC00657. LINC00657 was able to sponge miR-204-5p and upregulated IGFBP5 expression, thereby promoting osteogenesis in T2DM-BMSCs. UNC0638 treatment alleviated osteoporosis in DOP rats, whereas LINC00657 knockdown inhibited its effect .

CONCLUSIONS

G9a inhibits the osteogenic potential of T2DM-BMSCs by regulating the LINC00657/miR-204-5p/IGFBP5 pathway and UNC0638 may be a potential agent for DOP treatment.

摘要

背景

糖尿病患者的骨间充质干细胞（BMSCs）通常表现出成骨潜能降低。本研究旨在探讨常染色质组蛋白赖氨酸甲基转移酶2（EHMT2）即G9a的作用机制，确定其在糖尿病性骨质疏松症（DOP）中的关键反应性长链非编码RNA，并评估G9a抑制剂（UNC0638）的有效性。

方法

检测伴有或不伴有2型糖尿病（T2DM-BMSCs，CON-BMSCs）的骨质疏松症患者骨源性间充质干细胞（BMSCs）中G9a的表达水平，并通过成骨基因、碱性磷酸酶（ALP）活性和钙化水平评估成骨分化。基于先前的转录组测序、qPCR和基因过表达试验筛选关键lncRNA即LINC00657。通过转录组测序、生物信息学分析、双荧光素酶报告基因试验和基因过表达试验鉴定LINC00657的下游miRNA和靶基因。构建大鼠DOP模型，采用显微CT、组织化学染色、免疫荧光和qPCR研究UNC0638的作用机制。

结果

与CON-BMSCs相比，T2DM-BMSCs中G9a表达增加，LINC00657表达降低。UNC0638处理可改善T2DM-BMSCs的成骨潜能，并逆转LINC00657的下调。LINC00657过表达可逆转EHMT2对成骨分化的抑制作用。筛选出miR-204-5p和胰岛素样生长因子结合蛋白5（IGFBP5）作为LINC00657的下游分子。LINC00657能够吸附miR-204-5p并上调IGFBP5表达，从而促进T2DM-BMSCs的成骨作用。UNC0638处理可减轻DOP大鼠的骨质疏松症，而LINC00657基因敲低则抑制其作用。