Ferroptosis inhibits cementoblast mineralization via cGAS-STING/GPX4 axis.

Abstract

BACKGROUND: To explore the potential role of cGAS-STING/GPX4 axis-mediated ferroptosis in cementoblast mineralization under compressive force and to determine its involvement in orthodontically induced inflammatory external root resorption (OIIERR). METHODOLOGY: An immortalized murine cementoblast cell line (OCCM-30) was subjected to a 2 g/cmcompressive force for 24 h to establish an in vitro loading model. Western blot was used to detect proteins associated with mineralization (RUNX2, OPN, OCN) and components of the cGAS-STING/GPX4 axis. Ferroptosis was assessed by measuring ROS, Fe, and MDA levels. Mitochondrial damage was examined via mitochondrial membrane potential analysis and mtDNA linkage evaluation. To further investigate the role of cGAS-STING/GPX4 axis-mediated ferroptosis, STING knockdown and Ferrostatin-1 (Fer-1) were employed. In vivo, an OIIERR mouse model was established, and the STING inhibitor H-151 was administered to assess the involvement of cGAS-STING/GPX4 axis-mediated ferroptosis in OIIERR. RESULTS: Compressive force significantly reduced RUNX2, OPN, OCN, and GPX4 expression, while increasing ROS, Fe, and MDA levels. Mitochondrial dysfunction, including decreased membrane potential and cytoplasmic mtDNA leakage, was observed. Western blot analysis showed that compressive force significantly upregulated cGAS, p-STING, p-TBK1 and p-IRF3 in OCCM-30 cells. Knockdown of STING or Fer-1 treatment restored mineralization under compressive force. In vivo, immunohistochemical staining confirmed the activation of cGAS-STING/GPX4 axis in the OIIERR group. Notably, administration of H-151 reduced the expression of pathway-related proteins and effectively mitigated root resorption. CONCLUSIONS: Compressive force inhibits cementoblast mineralization by inducing ferroptosis via the cGAS-STING/GPX4 axis. Furthermore, H-151 effectively suppresses OIIERR in mice. Targeting cGAS-STING/GPX4 axis-mediated ferroptosis may serve as a potential therapeutic strategy for OIIERR treatment.