Lipid-induced hepatocyte-derived extracellular vesicles regulate hepatic stellate cell via microRNAs targeting PPAR-γ.
Lipid-induced hepatocyte-derived extracellular vesicles regulate hepatic stellate cell via microRNAs targeting PPAR-γ.
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DOI：
10.1016/j.jcmgh.2015.07.007
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发表时间：
2015-11-01
影响因子：
7.2
通讯作者：
Feldstein AE
中科院分区：
文献类型：
--
作者：
Povero D;Panera N;Eguchi A;Johnson CD;Papouchado BG;de Araujo Horcel L;Pinatel EM;Alisi A;Nobili V;Feldstein AE
肝星状细胞(HSCs)在包括非酒精性脂肪性肝病(NAFLD)在内的各种慢性肝病的肝纤维化中起关键作用。肝纤维化的发展需要从静止的HSC到激活的HSCs的表型转换。NAFLD中HSC激活的触发机制仍然知之甚少。我们研究了脂肪毒性过程中肝细胞释放的胞外小泡(EVS)在HSC表型调控中的作用和分子机制。用差速离心法从富含脂肪的肝细胞中分离EVS，并与HSCs共同孵育。评估EV内化和HSC的激活、迁移和增殖。通过功能丧失和功能获得的研究，探讨EVS携带的靶向γ(PPAR-γ)的microRNAs对HSC的潜在作用。脂肪毒性过程中释放的肝细胞来源的EV被HSC有效地内化，导致它们的激活，这表现在促纤维化基因(胶原-I、α-平滑肌肌动蛋白和金属蛋白酶组织抑制物-2)的显著上调、增殖、趋化和伤口愈合反应。这些变化与EVS穿梭的miRNAs和抑制HSC中PPAR-γ的表达有关。肝细胞来源的EVmiRNA内容包括各种已知的抑制PPAR-γ表达的miRNA，其中miR-128-3p是最有效的转移。此外，功能丧失和功能增益研究证实miR-128-3p是EVS抑制PPAR-γ和激活肝星状细胞效应的中心调节器。我们的发现证明了高脂肪的肝细胞来源的EVS与肝纤维化之间的联系，并对开发治疗NAFLD和其他纤维化疾病的新的抗纤维化靶点具有潜在的意义。
Hepatic stellate cells (HSCs) play a key role in liver fibrosis in various chronic liver disorders including nonalcoholic fatty liver disease (NAFLD). The development of liver fibrosis requires a phenotypic switch from quiescent to activated HSCs. The trigger for HSC activation in NAFLD remain poorly understood. We investigated the role and molecular mechanism of extracellular vesicles (EVs) released by hepatocytes during lipotoxicity in modulation of HSC phenotype. EVs were isolated from fat-laden hepatocytes by differential centrifugation and incubated with HSCs. EV internalization and HSC activation, migration, and proliferation were assessed. Loss- and gain-of-function studies were performed to explore the potential role of peroxisome proliferator-activated receptor-γ (PPAR-γ)-targeting microRNAs (miRNAs) carried by EVs into HSC. Hepatocyte-derived EVs released during lipotoxicity are efficiently internalized by HSCs resulting in their activation, as shown by marked up-regulation of profibrogenic genes (collagen-I, α-smooth muscle actin, and tissue inhibitor of metalloproteinases-2), proliferation, chemotaxis, and wound-healing responses. These changes were associated with miRNAs shuttled by EVs and suppression of PPAR-γ expression in HSCs. The hepatocyte-derived EV miRNA content included various miRNAs that are known inhibitors of PPAR-γ expression, with miR-128-3p being the most efficiently transferred. Furthermore, loss- and gain-of-function studies identified miR-128-3p as a central modulator of the effects of EVs on PPAR-γ inhibition and HSC activation. Our findings demonstrate a link between fat-laden hepatocyte-derived EVs and liver fibrosis and have potential implications for the development of novel antifibrotic targets for NAFLD and other fibrotic diseases.