SIRT 1通过下调PPAR-γ受体提升人乳牙牙髓干细胞骨向分化效能

SIRT1 Enhances Osteogenesis in Stem Cells from Human Exfoliated Deciduous Teeth via Downregulation of Peroxisome Proliferator-Activated Receptor

目的:研究SIRT1对人乳牙牙髓干细胞(SHEDs)成骨分化效能的影响。方法:选取特异性SIRT1激活剂SRT1720和抑制剂EX527,预处理SHEDs 3 d后作为工作细胞用于实验。CCK-8实验检测SRT1720和EX527与SHEDs共培养1、2、3、7 d后的细胞增殖能力变化。筛选出最佳浓度为0.5μmol/L的SRT1720和EX527溶液,利用成骨诱导培养基诱导SHEDs骨向分化。通过碱性磷酸酶染色及定量检测,茜素红矿化结节染色等方法分别检测早、晚期成骨分化,通过RT-PCR检测骨向分化标志物ALP、Runx2、骨桥蛋白、Ⅰ型胶原、骨钙蛋白以及SIRT1、PPAR-γ等相关基因及蛋白表达水平,研究SIRT1调控SHEDs体外骨向分化的可能机制。结果:SIRT1激活剂组骨向分化标志物基因mRNA较SIRT1抑制剂组增强,表明随着SIRT1表达上调,SHEDs的成骨分化效能也一并上调,而PPAR-γ受体相应下调。结论:SIRT1的表达与SHEDs的骨向分化能力呈正相关,SIRT1促进骨向分化的作用与BMP信号通路中的PPAR-γ受体下调密切相关。

Objective:To identify the role of SIRT1 on osteogenic differentiation of stem cells from human exfoliated deciduous teeth.Methods:A defined concentration of SIRT1 activator(SRT1720)and inhibitor(EX527)is 0.5μmol/L.Then SRT1720 and EX527 were added to the experiment groups for preconditioning 3 days.We investigated the effects of SIRT1 on the osteogenic differentiation of SHEDs.Expression of osteoblastic differentiation markers was assessed by RT-PCR.Results:Activation of SIRT1 using SRT1720 increased the expression of osteoblastic differentiation markers,as assessed by alkaline phosphatase,Runt-related transcription factor-2,osteopontin,collagen type Iα1,and osteocalcin.In contrast,inhibition of SIRT1 using EX527 suppressed the expression of above-mentioned factors.Conclusion:SIRT1 is a key regulator of differentiation of stem cells from human exfoliated deciduous teeth.SIRT1 also regulated the expression of PPAR-γ.The SIRT1/PPAR-γpathway may be crucial for enhancement of osteogenesis.