Objective To review the research progress on lactylation modification in the pathogenesis of osteoarthritis (OA). Methods Relevant studies published in recent years on lactate metabolism and lactylation modification in OA were retrieved and analyzed, summarizing the molecular mechanisms of lactylation and its regulatory roles in different cells and pathological processes. Results Lactate, as the major metabolic product of glycolysis, not only participates in energy metabolism but also plays a crucial role in OA progression through lactylation modification. Lactate-driven histone and non-histone lactylation regulate gene transcription and cellular functions, contributing to chondrocyte metabolic reprogramming, extracellular matrix (ECM) synthesis and degradation, cell proliferation and apoptosis, as well as ferroptosis. In fibroblast-like synoviocytes, lactylation modification promotes cellular senescence and the release of inflammatory factors; in immune cells, lactylation regulates inflammatory responses by influencing macrophage polarization and intercellular communication. Overall, lactylation modification exhibits a dual effect in OA: it aggravates ECM degradation and inflammation on the one hand, but under specific microenvironments, it also promotes repair and regeneration. However, the site-specificity, cell-type heterogeneity, and cross-talk of lactylation with other epigenetic modifications remain to be further clarified. Conclusion Lactylation modification provides a novel perspective for understanding the metabolic and epigenetic mechanisms of OA and may serve as a potential biomarker and therapeutic target. Future studies combining multi-omics approaches to map the global lactylation landscape, together with small-molecule inhibitors, epigenetic editing tools, and regenerative medicine strategies, may enable precise regulation of lactylation, offering new strategies to delay or even reverse OA progression.
Objective To investigate the effects of 4-methylcatechol (4MC) on the migration and inflammatory response in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), as well as its underlying mechanisms of action. Methods RA-FLS was isolated from synovial tissue donated by RA patients, and the optimal concentration of 4MC was determined by cell counting kit 8 method for subsequent experiments, and the effect of 4MC on the migratory ability of RA-FLS was evaluated via a cell scratch assay. An inflammation model of RA-FLS was induced by tumor necrosis factor α (TNF-α). Real-time fluorescence quantitative PCR and ELISA were employed to detect the gene and protein expression levels of interleukin-1β (IL-1β) and IL-6 in RA-FLS and their culture supernatants, respectively, thereby investigating the anti-inflammatory effects of 4MC. Western blot was used to examine the expressions of nuclear factor κB (NF-κB) signaling pathway-related proteins, including inhibitor of NF-κB-α (IKBα), phosphorylated (P)-IκBα, NF-κB-inducing kinase α (IKKα), P-IKKαβ, P-p65, and p65. Cellular immunofluorescence was utilized to detect the expression and localization of p65 in RA-FLS, exploring whether 4MC exerts its anti-inflammatory effects by regulating the NF-κB signaling pathway. Finally, a collagen-induced arthritis (CIA) mouse model was established. The anti-RA effect of 4MC in vivo was evaluated by gross observation and histological examination. Results 4MC inhibited RA-FLS migration in a concentration-dependent manner. In the TNF-α-induced RA-FLS inflammation model, 4MC significantly decreased the gene and protein expression levels of IL-1β and IL-6. Furthermore, 4MC markedly reduced the ratios of P-IΚBα/IΚBα, P-IKKαβ/IKKα, and P-p65/p65, thereby blocking the transcriptional activity of p65 by inhibiting its nuclear translocation. This mechanism effectively suppressed the activation of the TNF-α-mediated NF-κB signaling pathway. Animal studies demonstrated that 4MC [10 mg/(kg·day)] significantly lowered serum levels of IL-1β, IL-6, and TNF-α, and alleviated arthritis severity and bone destruction in CIA mice. Conclusion 4MC not only inhibits the migration of RA-FLS but also mitigates their inflammatory response by suppressing the NF-κB signaling pathway, thereby effectively exerting its anti-RA effects.
