MMP9 and Arthritis: The results showed that cDHPS dose-dependently remodeled Th17 and Treg homeostasis; decreased MMP3 and MMP8 levels in the synovial tissue and serum of CIA mice with type II collagen-induced arthritis; decreased MMP9, IL-1β, IL-6, IL-17, TNF-α, GM-CSF, M-CSF, CXCL12, and CCL5 levels in the synovial tissues and serum of CIA mice with type II collagen-induced arthritis; inhibited HIF-1α expression; and promoted the release of IL-10 and TGF-β1.