Force-induced periodontal ligament stem cell extracellular vesicles regulate bone remodeling via miR-122-5p-associated macrophage glycolysis

Mechanical force drives tissue remodeling, but the communication axis between mechanically stressed structural cells and immune cells remains poorly defined. During orthodontic tooth movement (OTM), how periodontal ligament stem cells (PDLSCs) convey compressive-force signals to macrophages remains unresolved. This study investigated how mechanical compression alters PDLSC-derived extracellular vesicles (EVs) and whether these EV preparations influence macrophage inflammatory and metabolic phenotypes during OTM remodeling. Mouse OTM models were used to evaluate systemic GW4869 treatment and local miR-122-5p antagonism. EVs obtained from control or mechanically compressed PDLSCs were characterized and then applied to THP-1-derived macrophages and mouse bone-marrow-derived macrophages. Small RNA sequencing, mimic- and inhibitor-based experiments, extracellular flux analysis, glucose uptake imaging, and pharmacological stabilization of PKM2 tetramers were used to assess inflammatory and metabolic responses. Systemic GW4869 treatment was associated with reduced M1-like macrophage accumulation and bone resorption in vivo. Mechanical compression increased PDLSC-EV particle output and altered the particle-to-protein ratio and zeta potential. Under equal-protein dosing conditions, Force-EV preparations promoted pro-inflammatory activation, glucose uptake, basal glycolytic utilization, and glycolytic ATP production in macrophages, while reducing glycolytic reserve and mitochondrial ATP production. miR-122-5p was identified in the sequencing screen and shown to contribute to selected inflammatory and metabolic responses. TEPP-46-mediated stabilization of tetrameric PKM2 attenuated several Force-EV-associated responses, which were accompanied by altered PKM2/HIF-1α expression and nuclear localization. The principal inflammatory and metabolic features were reproduced in mouse bone-marrow-derived macrophages. Local miR-122-5p antagonism also reduced tooth movement and F4/80⁺INOS⁺ macrophage accumulation. Mechanical compression altered PDLSC-derived EV output and physicochemical characteristics. Force-EV preparations promoted macrophage pro-inflammatory activation and increased basal glycolytic utilization, with miR-122-5p contributing to this phenotype. Together, the in vitro and in vivo findings implicate EV-associated miR-122-5p and PKM2/HIF-1α-associated metabolic regulation in orthodontic remodeling.