Decreased autophagy impairs osteogenic differentiation of adipose-derived stem cells via Notch signaling in diabetic osteoporosis mice
Decreased autophagy impairs osteogenic differentiation of adipose-derived stem cells via Notch signaling in diabetic osteoporosis mice
复制标题
在糖尿病骨质疏松小鼠中，自噬减少通过 Notch 信号传导损害脂肪干细胞的成骨分化
DOI：
10.1016/j.cellsig.2021.110138
复制
发表时间：
2021
影响因子：
4.8
通讯作者：
Jingang Xiao
中科院分区：
文献类型：
--
作者：
Pengcheng Rao;Fangzhi Lou;Daowen Luo;Chenglong Huang;Kui Huang;Zhihao Yao;Jingang Xiao
研究背景2型糖尿病骨质疏松症（Dop）小鼠脂肪干细胞（ASC）成骨分化能力减弱。一些研究表明自噬和Notch信号通路在细胞增殖、分化和成骨中起重要作用。然而，自噬和Notch信号在Dop ASCs成骨分化中的机制尚不清楚。因此，揭示Dop ASCs中自噬、Notch信号通路与成骨之间的潜在相关性，探讨其分子机制具有重要意义。材料与方法通过高糖高脂饮食和链脲佐菌素注射建立经显微CT和HE & Masson染色证实的糖尿病骨质疏松C57 BL/6小鼠模型。从Dop小鼠的腹股沟皮下脂肪获得ASC。通过茜素红（成骨）、油红O（脂肪生成）和阿尔新蓝（软骨生成）染色评价ASC的多分化潜能。通过细胞计数试剂盒-8测定评估细胞活力。使用mTOR抑制剂Torin 1刺激自噬信号通路。DAPT是一种γ-分泌酶抑制剂，用于抑制Notch信号通路活性。自噬、Notch信号通路和成骨因子的基因和蛋白表达通过实时定量PCR、蛋白质印迹和免疫荧光microscopic.ResultsOur研究结果显示Dop ASCs的自噬和成骨分化能力呈下降趋势，均被Torin 1所拯救。Notch信号在Dop ASC中被抑制，但当自噬被激活时上调。自噬激活后，DAPT处理导致Notch信号通路活化降低，Dop ASCs成骨分化能力减弱。结论自噬下调抑制Notch信号通路，导致Dop ASCs成骨分化能力降低，Torin 1可通过激活自噬挽救这一过程。我们的研究结果有助于理解Dop ASCs成骨分化能力受损的机制。
BackgroundThe osteogenic differentiation ability of adipose-derived stem cells (ASCs) is attenuated in type 2 diabetic osteoporosis (Dop) mice. Several studies suggest autophagy and Notch signaling pathway play vital roles in cell proliferation, differentiation, and osteogenesis. However, the mechanisms of autophagy and Notch signaling in the osteogenic differentiation of Dop ASCs were unclear. Thus, it is meaningful to reveal potential correlations between autophagy, Notch signaling, and osteogenesis, and explore involved molecular mechanisms in Dop ASCs.Materials and methodsThe diabetic osteoporosis C57BL/6 mouse model, which was confirmed by micro-CT and HE & Masson staining, was established through high-sugar and high-fat diet and streptozotocin injection. ASCs were obtained from the inguinal subcutaneous fat of Dop mice. The multi-differentiation potential of ASCs was evaluated by staining with Alizarin Red (osteogenesis), Oil Red O (adipogenesis), and Alcian blue (chondrogenesis). Cell viability was assessed by Cell Counting Kit-8 assay. Torin1, an inhibitor of mTOR, was used to stimulate the autophagy signaling pathway. DAPT, a γ-secretase inhibitor, was used to suppress Notch signaling pathway activity. Gene and protein expression of autophagy, Notch signaling pathway, and osteogenic factors were detected by real-time quantitative PCR, western blot, and immunofluorescence microscopy.ResultsOur findings showed autophagy and osteogenic differentiation ability of Dop ASCs exhibited downward trends that were both rescued by Torin1. Notch signaling was suppressed in Dop ASCs, but upregulated when autophagy was activated. After activation of autophagy, DAPT treatment led to decreased Notch signaling pathway activation and attenuated osteogenic differentiation ability in Dop ASCs.ConclusionsDownregulated autophagy suppressed Notch signaling, leading to a reduced osteogenic differentiation capacity of Dop ASCs, and Torin1 can rescue this process by activating autophagy. Our findings contribute to understanding the mechanism underlying impairment of the osteogenic differentiation ability of Dop ASCs.