γ-secretase inhibitor induces adipogenesis of adipose-derived stem cells by regulation of Notch and PPAR-γ
γ-secretase inhibitor induces adipogenesis of adipose-derived stem cells by regulation of Notch and PPAR-γ
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DOI：
10.1111/j.1365-2184.2009.00661.x
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发表时间：
2010-04-01
影响因子：
8.5
通讯作者：
Lin, Y.
中科院分区：
文献类型：
--
作者：
Huang, Y.;Yang, X.;Lin, Y.
目的：探讨Notch信号通路对小鼠脂肪干细胞（mASCs）成脂的抑制作用及其机制。材料与方法：在含胰岛素的分化培养基诱导mASCs成脂前3d，加入不同浓度的N-[N-（3，5-二氟苯乙酰基）-l-丙氨酰]-S-苯甘氨酸叔丁酯（DAPT）。油红-O染色分析脂肪形成过程和脂肪滴积聚能力。采用实时荧光定量PCR、Western blot和免疫荧光法检测Notch信号通路（Notch-1、-2、-3、-4、Hes-1和Hey-1）和脂肪生成相关因子（PPAR-gamma、DLK-1/Pref-1和Acrp）。此外，在脂肪形成诱导之前，DAPT促进PPAR-gamma的转录，而脂肪形成抑制剂DLK-1/Pref-1被进一步抑制。在分化的早期阶段（2-4天），在5和10 μ mDAPT预处理的病例中，mASC中的脂肪形成是先进的并且显著增强。在第4天，在分化的mASCs与DAPT预处理的情况下，我们还发现了促进激活的去过氧化物酶体增殖物激活受体-γ和抑制的羟乙基淀粉-1，DLK-1/Pref-1 mRNA和蛋白质expression.Conclusions：我们得出结论，阻断Notch信号与DAPT增强分化的mASCs在早期脂肪形成。这可能是由于DAPT通过抑制Notch-2-Hes-1通路抑制DLK-1/Pref-1和促进de-PPAR-γ活化而起作用。
Objective:To determine the inhibitory effect and mechanism of Notch signalling on adipogenesis of mouse adipose-derived stem cells (mASCs).Materials and methods:Varied concentrations of N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butylester (DAPT) were added to mASCs 3 days before adipogenic induction with insulin-containing differentiation medium. The process of adipogenesis and ability of lipid droplet accumulation were analysed using oil red-O staining. The Notch signalling pathway (Notch-1, -2, -3, -4, Hes-1 and Hey-1) and adipogenesis-related factors (PPAR-gamma, DLK-1/Pref-1 and Acrp) were tested using real-time PCR, Western blot analysis and immunofluorescence staining assays.Results:We demonstrated that Notch-2-Hes-1 signalling pathway was inhibited dose-dependently by DAPT in mASCs. In addition, transcription of PPAR-gamma was promoted by DAPT before adipogenic induction, while inhibitor of adipogenesis DLK-1/Pref-1 was further depressed. At early stages of differentiation (2-4 days), adipogenesis in mASCs was advanced and significantly enhanced in 5 and 10 mu m DAPT pre-treated cases. On day 4, in differentiated mASCs cases with DAPT pre-treatment, we also found promotion of activation of de-PPAR-gamma and depression of HES-1, DLK-1/Pref-1 mRNA and protein expression.Conclusions:We conclude that blocking Notch signalling with DAPT enhances adipogenesis of differentiated mASCs at an early stage. It may be due to depression of DLK-1/Pref-1 and promotion of de-PPAR-gamma activation, which work through inhibition of Notch-2-Hes-1 pathway by DAPT.