title: Melatonin influences proliferation and differentiation of rat dental papilla cells in vitro and dentine formation in vivo by altering mitochondrial activity.
abstract: Melatonin mediates a variety of biological processes ranging from the control of circadian rhythms to immune regulation. Melatonin also influences bone formation and osteointegration of dental implants. However, the effects of melatonin on dentine formation have not been examined. This study investigated the effects of melatonin on the proliferation and differentiation of rat dental papilla cells (rDPCs) in vitro and dentine formation in vivo. We found that melatonin (0, 10(-12) , 10(-10) ,10(-8)  m) induced a dose-dependent reduction in rDPCs proliferation, increased alkaline phosphatase (ALP) activity, the expression of dentine sialoprotein (DSP), and mineralized matrix formation in vitro. In vivo melatonin (50 mg/kg, BW, i.p.) inhibited dentine formation. Melatonin (10(-8 ) m) suppressed the activity of complex I and IV in the basal medium (OS-) and enhanced the activity of complex I and complex IV in osteogenic medium (OS+). These results demonstrate that melatonin suppresses the proliferation and promotes differentiation of rDPCs, the mechanisms of which may be related to activity of mitochondrial complex I and complex IV.
authors.affiliation: Department of pediatric dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhou
authors.forename: Wenguo
authors.initials: W
authors.lastname: Fan
authors.forename: Weiguo
authors.initials: W
authors.lastname: Dong
authors.forename: Shenli
authors.initials: S
authors.lastname: Fu
authors.forename: Hongwen
authors.initials: H
authors.lastname: He
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D003771:Dental Papilla / Q000166:cytology*; D003804:Dentin / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley