The promoting roles of GLP1R and GIPR in stemness maintenance and multiple lineage-specific differentiation of PDLSCs.

BACKGROUND: Periodontal ligament stem cells (PDLSCs) hold great promise for periodontal regeneration therapy. However, their self-renewal and multilineage differentiation capabilities are often compromised by adverse factors in the periodontal microenvironment. Therefore, identifying novel therapeutic targets and elucidating the underlying molecular mechanisms to protect the proliferative and differentiation potential of PDLSCs is of significant importance. METHODS: PDLSCs were exposed to electronic cigarette extract and various common oral stressors to evaluate the expression of glucagon such as peptide 1 receptor (GLP1R) and gastric inhibitory polypeptide receptor (GIPR). PDLSCs isolated from patients with periodontitis and PDLSCs from a mouse periodontitis model were also analyzed. Functional studies were performed by GLP1R or GIPR knockdown, overexpression, and treatment with single or dual receptor agonists, followed by assessment of cell proliferation and multilineage differentiation capacities. Transcriptome (RNA-seq), chromatin immunoprecipitation sequencing (ChIP-seq), and RNA immunoprecipitation sequencing (RIP-seq) were applied to delineate downstream signaling pathways and RNA–protein interactions. Protein synthesis regulation was further investigated by immunoprecipitation of interferon induced protein with tetratricopeptide repeats (IFIT)-associated translation initiation factors. For in vivo validation, wild-type and GLP1R/GIPR double-knockout periodontitis mice were transplanted with CRISPR-Cas9 mCherry-labeled PDLSCs and treated with receptor agonists. Disease severity and PDLSC fate were evaluated by histology and lineage tracing. Finally, a questionnaire-based survey was conducted in 150 patients with periodontitis, including 74 individuals with long-term use (> 1 month) of GLP1R or GLP1R/GIPR dual agonists (e.g., semaglutide, liraglutide, tirzepatide), to assess their periodontal outcomes. RESULTS: GLP1R and GIPR expression were markedly downregulated in PDLSCs exposed to multiple stressors and in PDLSCs isolated from periodontitis specimens. RNA-seq, ChIP-seq, and RIP-seq identified downstream pathways and RNA–protein interactions implicated in receptor-mediated regulation. Functionally, GIPR agonism promoted PDLSC proliferation via activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway, whereas GLP1R agonist enhanced multilineage differentiation capacity in vitro. Mechanistically, GLP1R knockdown induced robust upregulation of IFIT1/2/3, while GLP1R agonist suppressed IFIT expression. IFIT1/2/3 were shown to interact with eIF3C and to inhibit translation of differentiation-related mRNAs, linking GLP1R signaling to translational control of PDLSC fate. In vivo, transplantation experiments in both wild-type and GLP1R/GIPR double-knockout periodontitis mice demonstrated that single and dual receptor agonists significantly improved endogenous and exogenous PDLSC-mediated periodontal regeneration. Consistently, a clinical survey of 150 patients with periodontitis (74 receiving GLP1R or dual agonists) revealed significantly better periodontal staging and grading in treated individuals, with longer agonist exposure associated with greater improvement. CONCLUSIONS: Our findings uncover the different molecular roles of GIPR and GLP1R in self-renewal capacity and multipotency of PDLSCs, and open new avenues for developing therapeutic targets and strategies in oral tissue engineering and regenerative medicine. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s11658-026-00867-2.