二甲双胍在降低2型糖尿病大鼠骨髓间充质干细胞氧化应激及促进骨再生中的作用机制：聚焦于NRF2-GPX7信号通路

Metformin's mechanism in reducing oxidative stress and promoting bone regeneration in T2DM rat BMMSCs: A focus on NRF2-GPX7 signaling pathway.

作者信息

Dong Kai, Li Xueying, Zhou Wenjuan, Liu Zhong Hao

机构信息

Department of Implantology, the affiliated Yantai Stomatological Hospital, Binzhou Medical University, Yantai, Shandong 264001, China.

出版信息

J Dent. 2025 Jul;158:105787. doi: 10.1016/j.jdent.2025.105787. Epub 2025 Apr 28.

DOI:10.1016/j.jdent.2025.105787

PMID:40306480

Abstract

OBJECTIVES

Metformin (MF) could improve the osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) and bone regeneration under diabetes mellitus (T2DM) environment, however, its specific mechanism has not been elucidated. The aim of this study was to investigate whether MF inhibited oxidative stress and promoted osteogenic differentiation of T2DM rats BMMSCs (Tr-BMMSCs) through NRF2-GPX7 pathway.

METHODS

BMMSCs were extracted from normal and diabetic rats. In vitro, the western blot analysis were first used to determine the effect of MF on the NRF2-GPX7 signaling pathway. Then, the levels of oxidative stress markers and ALP staining, alizarin red staining, immunofluorescence assay were performerd respectively to detect the role of NRF2-GPX7 pathway in the regulating effect of MF on the oxidative stress and osteogenic differentiation of Tr-BMMSCs. In vivo, the newly formed bone was evaluated by micro computed tomography, HE staining, Masson staining and immunohistochemistry through T2DM rat mandibular bone defect model.

RESULTS

In vitro assays revealed that MF significantly promoted the expression of NRF2, NQO1, HO-1 and GPX7. The NRF2 pathway inhibitor (ML385) significantly inhibited the antioxidant and osteogenic promotion effects of MF on Tr-BMMSCs, while GPX7 overexpression effectively reversed the inhibitory effect of ML385. In vivo experiments showed that ML385 completely inhibited the combined promoting effects of MF and Tr-BMMSCs on the mandibular defect regeneration in T2DM rats. However, when MF was used in combination with GPX7 overexpressed Tr-BMMSCs, both new bone mass and OCN expression were significantly increased, indicating that GPX7 overexpression effectively reversed the osteogenesis inhibition of ML385 on Tr-BMMSCs.

CONCLUSIONS

MF inhibits oxidative stress level and promots osteogenic differentiation of Tr-BMMSCs and the repair of mandible bone defects of T2DM rats through NRF2-GPX7 pathway.

摘要

目的

二甲双胍（MF）可改善糖尿病（T2DM）环境下骨髓间充质干细胞（BMMSCs）的成骨分化及骨再生，但其具体机制尚未阐明。本研究旨在探讨MF是否通过NRF2 - GPX7通路抑制氧化应激并促进T2DM大鼠BMMSCs（Tr - BMMSCs）的成骨分化。

方法

从正常和糖尿病大鼠中提取BMMSCs。体外实验中，首先采用蛋白质免疫印迹分析来确定MF对NRF2 - GPX7信号通路的影响。然后，分别检测氧化应激标志物水平、碱性磷酸酶（ALP）染色、茜素红染色及免疫荧光分析，以检测NRF2 - GPX7通路在MF对Tr - BMMSCs氧化应激和成骨分化调节作用中的作用。体内实验中，通过T2DM大鼠下颌骨缺损模型，采用显微计算机断层扫描、苏木精 - 伊红（HE）染色、马松（Masson）染色和免疫组织化学评估新形成的骨组织。

结果

体外实验表明，MF显著促进NRF2、NQO1、HO - 1和GPX7的表达。NRF2通路抑制剂（ML385）显著抑制MF对Tr - BMMSCs的抗氧化和成骨促进作用，而GPX7过表达有效逆转了ML385的抑制作用。体内实验表明，ML385完全抑制了MF和Tr - BMMSCs对T2DM大鼠下颌骨缺损再生的联合促进作用。然而，当MF与GPX7过表达的Tr - BMMSCs联合使用时，新骨量和骨钙素（OCN）表达均显著增加，表明GPX7过表达有效逆转了ML385对Tr - BMMSCs的成骨抑制作用。