Study on the intervention effect and action mechanism of miR-125b-5p on knee osteoarthritis model rats

Abstract

Background:
Knee osteoarthritis (KOA) is a degenerative joint disease characterized by cartilage degradation, synovial inflammation, and subchondral bone remodeling. MicroRNAs (miRNAs) have been implicated in the regulation of KOA pathogenesis. miR-125b-5p has been suggested to play a role in cartilage homeostasis and inflammatory responses, but its therapeutic potential and mechanism remain unclear.
Objective:
To investigate the intervention effect and underlying mechanism of miR-125b-5p in a rat model of knee osteoarthritis.
Methods:
A KOA model was established in rats by [method, e.g., anterior cruciate ligament transection + medial meniscectomy]. Rats were randomly assigned into control, KOA model, and KOA + miR-125b-5p intervention groups. The intervention group received intra-articular injections of miR-125b-5p mimics or inhibitors. Joint morphology was assessed by histological staining (HE, Safranin O–Fast green) and scored using the OARSI system. Expression levels of inflammatory cytokines, cartilage matrix proteins (e.g., collagen II, aggrecan), and signaling pathway molecules were measured by qPCR, western blot, and immunohistochemistry.
Results:
Rats in the KOA + miR-125b-5p mimic group showed significantly improved cartilage structure, reduced OARSI scores, and lower levels of inflammatory cytokines (IL-1β, TNF-α) compared to the untreated KOA group (p < 0.05). miR-125b-5p intervention upregulated collagen II and aggrecan expression while downregulating MMP-13. Mechanistically, miR-125b-5p appeared to modulate the [e.g., NF-κB, MAPK, or PI3K/Akt] signaling pathway to exert its protective effects.
Conclusion:
miR-125b-5p exerts a protective effect on cartilage in KOA model rats by reducing inflammation and extracellular matrix degradation, possibly through regulation of the [specific pathway]. These findings suggest that miR-125b-5p may be a promising therapeutic target for knee osteoarthritis.
Keywords:
miR-125b-5p, knee osteoarthritis, cartilage, microRNA, rat model, mechanism