Porphyromonas gingivalis Outer Membrane Vesicles Promote Gingival Fibroblasts Senescence via IL21R-AS1.

Abstract

Aims: Periodontitis, a chronic inflammatory disease, is associated with accelerated cellular senescence. This study aims to explore how Porphyromonas gingivalis (P. gingivalis) outer membrane vesicles (OMVs) induce senescence and senescence-associated secretory phenotype (SASP) in human gingival fibroblasts (HGFs), focusing on the role of lncRNAs in promoting periodontitis progression.

Methods: In vivo, gingival senescence was assessed via immunohistochemistry while bone loss was evaluated using micro-CT, HE and TRAP staining. In vitro, HGFs senescence was validated using CCK-8, SA-β-gal staining, western blot and immunofluorescence assays. IL21R-AS1 was transfected with targeted siRNAs and overexpression plasmids to verify its function. Dual-luciferase reporter assays and rescue experiments were conducted to elucidate the competing endogenous RNA (ceRNA) mechanism of IL21R-AS1. Upstream transcription factors of IL21R-AS1 were validated by CUT&Tag-qPCR and western blot.

Results: P. gingivalis OMVs induced gingival tissue senescence and alveolar bone loss in vivo. In vitro, P. gingivalis OMVs promoted HGFs senescence and SASP via IL21R-AS1. IL21R-AS1 acted as a ceRNA by sponging miR-500a-3p, thereby enhancing the regulation of FBXW7. Moreover, P. gingivalis OMVs activated TLR4 and increased PAX5 expression, leading to elevated IL21R-AS1 levels.

Conclusions: P. gingivalis OMVs promote HGFs senescence SASP by the upregulation of IL21R-AS1, which acts as a ceRNA, mediating the miR-500a-3p/FBXW7 axis and contributes to the progression of periodontitis. These findings offer novel insights into the molecular mechanisms of OMVs-induced senescence and periodontitis.