Effect of leptin on differentiation of human dental stem cells

OBJECTIVES: Mesenchymal stem cells (MSCs) were identified in adult human periodontal ligament and dental pulp that are considered as potential stem cell sources for future clinical applications in dentistry. Leptin is known as an important regulator of mesenchymal differentiation. The objective of this study was to elucidate the role of leptin on proliferation and differentiation of dental MSCs. MATERIALS AND METHODS: Enhancement of cemento/odontoblastic differentiation of dental stem cells by leptin was confirmed by alizarin red S staining and alkaline phosphatase activity staining. In contrast, leptin reduced adipogenesis in both dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) confirmed by oil red O staining and RT-PCR. The expression of adipogenic markers, lipoprotein lipase and proliferator-activated receptor gamma 2 (PPAR gamma 2), were suppressed in PDLSCs incubated on media supplemented with leptin for 2 weeks. RESULTS: Leptin had a relatively stronger osteogenesis promoting effect and adipogenesis suppressing effect in PDLSCs than in DPSCs. CONCLUSIONS: Collectively, leptin had a relatively stronger promoting effect on cemento/odontoblastic differentiation and a suppressing effect on adipogenesis in PDLSCs than in DPSCs. This study has provided evidence that leptin acts as an important modulator of dental MSCs differentiation. Oral Diseases (2011) 17, 662-669