Hedgehog signaling pathway: A research review on a new therapeutic target for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by progressive joint destruction, with existing therapies limited by adverse effects and incomplete efficacy. The Hedgehog signaling pathway, abnormally activated in RA, plays a pivotal pathogenic role by promoting synovial fibroblast proliferation/invasion, amplifying inflammatory responses, inducing chondrocyte matrix degradation, and enhancing angiogenesis. This review summarizes therapeutic strategies targeting this pathway, including small-molecule inhibitors (Smo/Gli antagonists), gene therapy (CRISPR-Cas, SMO-siRNA), and emerging approaches (mesenchymal stem cells, natural products). Key findings highlight the pathway's crosstalk with JAK-STAT, IL-6 signaling, and MAPK pathways, as well as challenges such as off-target tissue toxicity, drug resistance, and unclear mechanisms underlying natural product activity. Conclusion: Targeting Hedgehog signaling holds promise for RA therapy, with future directions focusing on optimizing synovium-specific delivery, exploring combination regimens, and clarifying cell-type-specific regulatory mechanisms to accelerate clinical translation.