Melatonin Increased Autophagy Level to Facilitate Osteogenesis of Inflamed PDLSCs Through TMEM110 Signaling Pathways

Periodontal ligament stem cells (PDLSCs) bring new hope to patients with poor periodontium recovery and impaired regeneration. However, the complex inflammatory microenvironment continually inhibits stem cell function and hinders stem cell therapy effectiveness. Melatonin is a naturally occurring neurohormone that participates in the regulation of a large spectrum of biological functions. We investigated the effect of melatonin on periodontium regeneration both in vitro and in vivo. The results showed that melatonin promoted periodontitis recovery and enhanced the osteogenesis of inflamed PDLSCs (Inf-PDLSCs) depending on concentrations. Further mechanistic exploration indicated that autophagy activation played a significant role in enhancing the osteogenic differentiation of Inf-PDLSCs after melatonin treatment. Additionally, melatonin-induced upregulation of TEME110 participated in the initiation of autophagy activation and enhancement of osteogenesis in Inf-PDLSCs. Collectively, the results of our study provide evidence that melatonin-mediated osteogenesis of Inf-PDLSCs is important for periodontal tissue regeneration. Moreover, melatonin as a therapeutic drug for periodontitis treatment deserves further investigation.