Therapeutic Effects of BMSCs Stimulated by Low‐Magnitude High‐Frequency Vibration on TMJOA

OBJECTIVE: To investigate the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) preconditioned with low-magnitude high-frequency (LMHF) vibration on temporomandibular joint osteoarthritis (TMJOA). METHODS: BMSCs with/without LMHF vibration were intra-articularly injected into TMJOA model rats. After 8 weeks, joint diameter was measured. Pathological alterations were observed through histological staining techniques (CXCR4, SOX9). In vitro, BMSCs and chondrocytes were co-cultured with LMHF vibration. Chondrocyte proliferation was assessed by CCK-8. In a tumor necrosis factor-α (TNF-α)-induced inflammatory microenvironment, signal transduction-related and autophagy-related proteins were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. RESULTS: The injection of LMHF vibrated BMSCs increases the joint diameter and alleviates TMJ tissue damage. The OA model led to an elevation in CXCR4 levels and a reduction in SOX9 in condyle cartilage, while vibrated BMSCs upregulated both. In vitro experiments, appropriate cyclic sinusoidal dynamic mechanical vibration enhanced the proliferative capacity of chondrocytes co-cultured with BMSCs. In inflammation, the vibration group downregulated chondrocyte MMP-13 and upregulated chondrocyte Collagen II/BMP7/β-catenin/Atg3, as well as BMSC Collagen X/BMP7/β-catenin/CXCR4/Beclin-1/Atg5-all protein levels exceeded those in the LiCl group. CONCLUSION: For cartilage tissue engineering, LMHF vibration serves as a promising strategy to rapidly expand cells with a reinforced chondrogenic phenotype.