MSRB2 Ameliorates H₂O₂-induced Chondrocyte Oxidative Stress and Suppresses Apoptosis in Osteoarthritis

ABSTRACT

Background

Chondrocyte oxidative stress and apoptosis are critical factors contributing to the pathogenesis of osteoarthritis (OA). Methionine sulfoxide reductase B2 (MSRB2) is a mitochondrial protein that protects cells from oxidative stress and is involved in apoptosis. This study aimed to investigated the expression of MSRB2 in articular cartilage tissues and elucidated its effect on H₂O₂-stimulated chondrocytes.

Methods

Human chondrocytes were cultured in Dulbecco’s modified Eagle’s medium (DMEM)/F12. MSRB2 overexpression in chondrocytes was achieved by transfecting with an MSRB2 overexpression plasmid. Western blot, quantitative RT-PCR, Immunofluorescence staining, and TUNEL assay were employed in this study.

Results

MSRB2 expression was found to be reduced in OA patients. Furthermore, overexpression of MSRB2 in H₂O₂-induced chondrocytes mitigated apoptosis and enhanced cell viability. Elevated MSRB2 expression diminished chondrocyte ROS contents, decreased cytochrome C (Cyc) in the cytoplasm, and regulated mitochondrial membrane potential to maintain mitochondrial homeostasis. Interestingly, knockdown of charged multivesicular body protein 5 (CHMP5) led to a decreased inMSRB2 expression in chondrocytes. Additionally, protein levels of CHMP5 and MSRB2 were reduced in H₂O₂-stimulated chondrocytes, and silencing CHMP5 reduced MSRB2 expression. Knockdown of CHMP5 increased cleaved caspase-3 expression in H₂O₂-induced chondrocytes and elevated TUNEL-positive chondrocytes.

Conclusion

MSRB2 decreased in OA, and overexpression of MSRB2 alleviated oxidative stress and apoptosis of chondrocyte.

KEYWORDS:

• Apoptosis
• chondrocyte
• MSRB2
• osteoarthritis
• oxidative stress

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Conceptualization: Keke Huang, Wenhan Fu, Hao Tang, Zongsheng Yin, Weilu Gao. Methodology: Keke Huang, Wenhan Fu, Anquan Wang, Hao Tang. Formal analysis and investigation: Wenhan Fu, Anquan Wang, Gongwen Du, Li Yin. Writing – original draft preparation: Keke Huang, Wenhan Fu. Writing – review and editing: Keke Huang, Wenhan Fu, Weilu Gao. Supervision: Li Yin, Zongsheng Yin, Weilu Gao.

Data availability statement

The data used or analyzed during the current study are available from the corresponding author on reasonable request.

Ethical approval

Human articular cartilage tissue collection and the experiments was approved by Ethical Committee of Anhui Medical University and following the guidelines of the Declaration of Helsinki.

Additional information

Funding

This research was funded by the Scientific Research Fund Project of Anhui Medical University [No. 2020xkj181], the Basic and Clinical Cooperative Research Promotion Plan of Anhui Medical University [No. 2021xkjT003] and the National Natural Science Foundation of China [No. 81871785].