Activation of TRPV4 to drive pyroptosis-dependent orthodontic tooth remodeling.

ObjectiveOrthodontic tooth movement (OTM) relies on mechanotransduction and inflammatory responses within the periodontal ligament (PDL). This study aimed to elucidate the role of transient receptor potential vanilloid 4 (TRPV4) in mediating mechanical force-induced pyroptosis in human PDL (hPDL) cells and its functional impact on osteoclast activation during OTM.MethodshPDL cells were isolated from premolars extracted for orthodontic reasons and characterized for stem cell properties (CD73+/CD90+/CD105+; CD34-/CD45-). An in vitro OTM model was established by applying compressive force (0-2.0†g/cm(2)). Pyroptosis was assessed via qRT-PCR, Western blot, and immunofluorescence for NLRP3, caspase-1, GSDMD, and IL-1β. Osteoclast differentiation was evaluated in hPDL-PBMC co-cultures using TRAP staining, ELISA (RANKL/OPG), and gene expression analysis (CTSK/TRAP). TRPV4 activation was modulated using agonist GSK1016790A.ResultsCompressive force (1.5†g/cm(2), 24†h) significantly upregulated pyroptosis markers (NLRP3, cleaved caspase-1, N-GSDMD, IL-1β) and inflammatory mediators (COX2, TNF-α, IL-6, and IL-8). TRPV4 activation was mechanosensitive and enhanced by GSK1016790A, which amplified pyroptosis and subsequent RANKL secretion. In co-cultures, hPDL pyroptosis promoted osteoclast differentiation, evidenced by increased TRAP + multinucleated cells and elevated CTSK/TRAP expression.ConclusionMechanical force activates TRPV4 to drive NLRP3/caspase-1-dependent pyroptosis in hPDL cells, which accelerates osteoclastogenesis via RANKL signaling. Targeting TRPV4-pyroptosis axis may represent a novel strategy to optimize orthodontic treatment efficiency.