Exosome secreted from adipose-derived stem cells attenuates diabetic nephropathy by promoting autophagy flux and inhibiting apoptosis in podocyte
Exosome secreted from adipose-derived stem cells attenuates diabetic nephropathy by promoting autophagy flux and inhibiting apoptosis in podocyte
复制标题
脂肪干细胞分泌的外泌体通过促进足细胞自噬流和抑制足细胞凋亡减轻糖尿病肾病
DOI：
10.1186/s13287-019-1177-1
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发表时间：
2019-03-15
影响因子：
7.5
通讯作者：
Huang, He
中科院分区：
文献类型：
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作者：
Jin, Juan;Shi, Yifen;Huang, He
研究证实，脂肪源性干细胞（ADSCs）移植可有效缓解小鼠肾纤维化和2型糖尿病。目前，来自尿源性干细胞（USCs）的外泌体可以保护1型糖尿病介导的肾损伤并减轻糖尿病肾病（DN）的足细胞损伤。来自USCs的外泌体已经发展成为治疗DN的策略，但adscs衍生的外泌体（ADSCs-Exo）在DN中的作用尚不清楚。本研究旨在探讨adscs来源的外泌体对DN的治疗作用及其分子机制。方法采用免疫荧光和流式细胞术对sadscs和外泌体进行鉴定。利用电子显微镜和纳米跟踪分析（NTA）分别观察外泌体的形态和数量。流式细胞术检测细胞凋亡。采用免疫荧光法和免疫印迹法检测足细胞自噬和信号转导。双荧光素酶报告基因检测检测miR-486与Smad1之间的调控关系。结果adscs - exo通过降低小鼠尿蛋白、血清肌酐（Scr）、血尿素氮（BUN）和足细胞凋亡水平来减轻自发性糖尿病。在体外实验中，ADSCs-Exo还能逆转高糖诱导的MPC5细胞活力下降和细胞凋亡增加。从作用机制上看，ADSCs-Exo可通过抑制MPC5和自发性糖尿病小鼠mTOR信号的激活，增强自噬通量，减轻足细胞损伤。最终，我们发现miR-486在体内和体外ADSCs以及ADSCs- exo介导的DN症状改善过程中是关键因子。miR-486通过靶向调节Smad1来降低Smad1的表达，Smad1的减少可以抑制mTOR的激活，导致自噬增加，足细胞凋亡减少。结论ADSCs-Exo通过增强miR-486的表达，从而抑制足细胞中Smad1/mTOR信号通路，从而明显改善DN症状。ADSCs-Exo可能是未来DN的主要治疗策略。
BackgroundIt is confirmed that adipose-derived stem cells (ADSCs) transplantation effectively relieves kidney fibrosis and type 2 diabetes disease in mice. Currently, exosome from urine-derived stem cells (USCs) can protect type 1 diabetes-mediated kidney injury and attenuate podocyte damage in diabetic nephropathy (DN). Exosome derived from USCs has evolved into the strategy for DN treatment, but the role of ADSCs-derived exosome (ADSCs-Exo) in DN remains unclear. The present study is aimed to investigate the therapeutic action and molecular mechanism of ADSCs-derived exosome on DN.MethodsADSCs and exosome were authenticated by immunofluorescence and flow cytometry. Morphology and the number of exosome were evaluated by electron microscope and Nanosight Tracking Analysis (NTA), respectively. Cell apoptosis was assessed using flow cytometry. Podocyte autophagy and signaling transduction were measured by immunofluorescence and immunoblotting. Dual Luciferase Reporter assay was employed to detect the regulatory relationship between miR-486 and Smad1.ResultsADSCs-Exo attenuated spontaneous diabetes by reducing levels of urine protein, serum creatinine (Scr), blood urea nitrogen (BUN), and podocyte apoptosis in mice. In in vitro experiment, ADSCs-Exo also reversed high glucose-induced decrease of cell viability and the increase of cell apoptosis in MPC5 cells. In terms of mechanism, ADSCs-Exo could enhance autophagy flux and reduce podocyte injury by inhibiting the activation of mTOR signaling in MPC5 and spontaneous diabetic mice. Eventually, we found that miR-486 was the key factors in ADSCs and in the process of ADSCs-Exo-mediated improvement of DN symptom in vivo and in vitro. miR-486 reduced Smad1 expression by target regulating Smad1 whose reduction could inhibit mTOR activation, leading to the increase of autophagy and the reduction of podocyte apoptosis.ConclusionsIn conclusion, we illustrated that ADSCs-Exo vividly ameliorated DN symptom by enhancing the expression of miR-486 which led to the inhibition of Smad1/mTOR signaling pathway in podocyte. Possibly, ADSCs-Exo was used as a main therapeutic strategy for DN in future.