Fengshi Gutong capsule alleviates osteoarthritis progression by targeting IGF2BP3 to regulate ANGPTL2 mRNA m6A methylation.

BACKGROUND

The Fengshi Gutong capsule (FSGTC), a commonly used traditional Chinese medicine formula for treating joint pain caused by osteoarthritis (OA), has demonstrated significant efficacy in both clinical and experimental studies. However, the specific mechanism through which FSGTC alleviates the pathological features of OA remains unclear.

PURPOSE: To elucidate the key pathological features of OA and determine the therapeutic effects of FSGTC and its underlying molecular mechanism, thereby providing new targets and strategies for clinical intervention.

STUDY

DESIGN

Methods

An OA rat model was used to investigate the in vivo effects of FSGTC. Histopathological and systemic inflammation and metabolic indices were evaluated. Bioinformatics and sequencing approaches were employed to identify key OA-associated genes and to uncover m6A-methylation-regulated targets in OA chondrocytes (OA-CHs). Network pharmacology and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) were used to identify the blood-absorbed bioactive compounds of FSGTC and to predict their potential targets and signalling pathways in OA. In vitro mechanistic validation was performed using CCK-8, immunofluorescence, flow cytometry, actinomycin D assay, dual-luciferase reporter assays, and the cellular thermal shift assay (CETSA).

RESULTS

FSGTC administration dose-dependently ameliorated cartilage damage, systemic lipid metabolism dysregulation, and inflammatory responses in OA rats. Bioinformatics analysis identified ANGPTL2 as a key OA-related gene modulated by m6A methylation, with IGF2BP3 being the predominant m6A reader protein regulating RNA stability. Ninety-six blood-absorbed constituents of FSGTC were identified. In vitro, IGF2BP3 mediated ANGPTL2 expression in an m6A-dependent manner, thereby activating IL-17, TNF-α, and PI3K/AKT signalling and collectively suppressing OA-CH proliferation, adipokine dysregulation, and the release of inflammatory cytokines. Furthermore, FSGTC exerted its therapeutic effects by regulating IGF2BP3.

CONCLUSION

FSGTC mitigated OA pathogenesis by targeting the IGF2BP3/ANGPTL2 axis, reducing m6A methylation of ANGPTL2 mRNA, promoting chondrocyte proliferation, and suppressing inflammation and adipokine imbalance.