Hydrogen sulfide maintains dental pulp stem cell function via TRPV1-mediated calcium influx

Hydrogen sulfide (H₂S), an endogenous gasotransmitter, mediated a variety of biological processes through multiple signaling pathways, and aberrant H₂S metabolism has been associated with mesenchymal stem cell (MSC) dysfunction. Here we employed the small interfering RNA treatment for cystathionine β-synthase (CBS), cystathionine γ-lyase, the main enzymes to synthesize H₂S, and CBS-knockout mice to analyze the effect of H₂S on dental pulp homeostasis. We showed that H₂S deficiency attenuated dental pulp stem cell (DPSC) osteogenic/dentinogenic differentiation in vitro and in vivo with enhanced cell proliferation. Mechanically, H₂S facilitated the transient receptor potential action channel subfamily V member 1-mediated calcium (Ca²⁺⁾ influx, which subsequently activated the β-catenin pathway. While H₂S deficiency decreased Ca²⁺, resulting in glycogen synthase kinase-3β-mediated β-catenin degradation, which controls proliferation and differentiation of DPSCs. Consistently, H₂S-deficient mice displayed disturbed pattern of dental pulp and less dentin formation. In this study, we identified a previously unknown mechanism by which H₂S regulates DPSC lineage determination and dental pulp homeostasis.