褪黑素调控牙乳头细胞向成牙本质细胞分化和矿化作用的线粒体机制研究

Clinical and experimental evidences suggest melatonin(MT) involved in regulation of teeth grow,and it has draw great attentions ,but underlying mechanism was unclear.Regulation of mitochondrial function was an important mechanism of melatonin to modulate cell functions. Regulating mitochondrial functions of stem cell could alter its metabolism thus to regulate differentiation of stem cell.Our previous study found that MT was able to promote differentiation and mineralization of dental papilla cells(DPCs) and activity of mitochondrial respiratory complexes I and IV.And these said effect could not be affected by MT membrane receptor antagonist(J Pineal Res.2013,online, IF=5.8).So,whether melatonin promoted differentiation of DPCs by regulating mitochondrial functions?The underlying pathway? A direct effect on mitochondrial or a mediated one through MT nuclear receptor? On the base of the further study of MT DPCs differentiation and mineralization toward odontoblast ,using kinds of method including RNA interference technique,chemical antagonist,et al,to block MT nuclear receptor,mitochondrial biosynthetic signal pathway and inhibit activity of mitochondrial related enzyme respectively to observe effect of MT on promoting differentiation of DPCs.This study aim to discover mitochondrial mechanism and working site of MT on promoting DPCs differentiation and mineralization.This research hopefully provides new target point on teeth grow regulation and regeneration and further offers a new thinking for clinical dental restoration and regeneration.

临床和实验证据显示褪黑素(MT)参与调控牙齿发育，引起广泛关注，但机制不明。调节线粒体功能是MT调控细胞功能的重要途径，而调节干细胞线粒体功能，使其代谢状态改变，可调控其分化。我们前期研究发现，MT可促进牙乳头细胞(DPCs)分化和矿化，并促进DPCs呼吸链复合体Ⅰ和Ⅳ的活性，而其膜受体拮抗剂不影响此作用(J Pineal Res.2013,online,IF=5.8)。那么，MT是否通过调节线粒体功能促进DPCs分化？作用途径？是直接作用于线粒体还是经核受体介导？本项目在进一步研究MT调控DPCs向成牙本质细胞分化和矿化的基础上，采用siRNA技术及化学抑制剂等方法，分别阻断MT核受体、线粒体生物合成信号通路和抑制线粒体相关酶活性，观察其促分化、矿化效应的改变。以期阐明MT这种促分化和矿化作用的线粒体机制和作用位点，有望为调控牙齿发育和再生提供新靶点，并为临床牙修复和再生研究提供新思路。

临床和实验证据显示褪黑素(MT)参与调控牙齿发育，引起广泛关注，但机制不明。围绕MT是否通过调节线粒体结构、功能和生物合成调控牙乳头细胞（DPCs）向成牙本质细胞分化和矿化这一主线，深入探索MT调控DPCs增殖、分化和矿化的线粒体机制作用位点，最主要的研究进展是基本明确在牙齿发育形成过程中MT具有促DPCs向成牙本质细胞分化和矿化的作用，这种作用与MT调节线粒体功能和促进线粒体呼吸链酶复合物Ⅰ和Ⅳ活性有关，发现苹果酸酶2（ME2）是MT调控DPCs增殖、分化和矿化的线粒体机制位点之一，有望为调控牙齿发育和再生提供新靶点，并为临床牙修复和再生研究提供新思路。本项目各项研究内容均进展顺利，并已取得多项成果。从 2014~2017年在 life sciences，journal of molecular histology，neuroscience letters 等杂志发表论文10篇，其中Sci收录7篇，国内外学术交流7次。培养硕士研究生2名，博士研究生2名。