Processing of miR17-92 Cluster in Hepatic Stellate Cells Promotes Hepatic Fibrogenesis During Alcohol-Induced Injury.
Processing of miR17-92 Cluster in Hepatic Stellate Cells Promotes Hepatic Fibrogenesis During Alcohol-Induced Injury.
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DOI：
10.1111/acer.13116
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
Schrum LW
中科院分区：
文献类型：
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作者：
Brandon-Warner E;Feilen NA;Culberson CR;Field CO;deLemos AS;Russo MW;Schrum LW
暴露于酒精及其代谢产物可引发肝损伤和纤维化。纤维化通过HSC活化介导，导致mRNA和microRNA（miR）表达的整体变化。miR在细胞中表达或穿梭至外泌体，其可在组织培养基和生物流体中检测到。肝损伤过程中miR的差异表达和加工及其下游效应的机制和功能仍然知之甚少。在暴露于酒精条件培养基（CM）的原代HSC和人LX 2细胞、来自啮齿动物酒精损伤模型的肝组织以及来自啮齿动物模型和ALD患者的组织培养基和血浆的外来体中检查pri-miR 17 -92和该簇的单个成员miR 17 a、18 a、19 a、20 a、19 b和92的表达。在用在胶原启动子下携带GFP-miR 19 b或GFP对照转基因的AAV 2载体转导的HSC中检查miR表达。在暴露于酒精-CM的原代HSC和LX 2细胞中，促纤维化标志物增强，伴随着miR 19 b表达降低和pri-miR 17 -92显著增加。在酒精诱导的肝损伤的啮齿动物模型中证实了增加的miR 17 -92。簇的个体成员在细胞和外来体中成反比。AAV 2介导的miR 19 b过表达抑制miR 17 -92并改变细胞和外泌体中单个簇成员的表达。从ALD患者分离的血浆外泌体中单个miR 17 -92簇成员的表达与在啮齿动物酒精损伤模型和体外观察到的相似。miR 19 b的重新引入抑制HSC活化并调节pri-miR 17 -92的表达以及细胞和外来体中单个簇成员的反向表达。对miR 17 -92加工的更好理解可以为单个miR和外泌体在肝损伤期间的作用提供机制见解，从而揭示新的治疗靶点。
Exposure to alcohol and its metabolites can initiate hepatic injury and fibrogenesis. Fibrosis is mediated through HSC activation, leading to global changes in mRNA and microRNA (miR) expression. miRs are expressed in cells or shuttled to exosomes which can be detected in tissue culture media and biological fluids. The mechanisms and function underlying the differential expression and processing of miRs and their downstream effects during hepatic injury remain poorly understood. Expression of pri-miR17-92 and individual members of this cluster, miR17a, 18a, 19a, 20a, 19b and 92 were examined in primary HSCs and human LX2 cells exposed to alcohol-conditioned media (CM), liver tissue from a rodent model of alcoholic injury, and in exosomes from tissue culture media and plasma of rodent models and patients with ALD. miR expression was examined in HSCs transduced with an AAV2 vector carrying GFP-miR19b or GFP-control transgene under the collagen promoter. Pro-fibrotic markers were enhanced in primary HSCs and LX2 cells exposed to alcohol-CM, concomitant with decreased miR19b expression and a significant increase in pri-miR17-92. Increased miR17-92 was confirmed in a rodent model of alcohol-induced liver injury. Individual members of the cluster were inversely proportionate in cells and exosomes. AAV2-mediated miR19b overexpression inhibited miR17-92 and altered expression of individual cluster members in cells and exosomes. Expression of individual miR17-92 cluster members in plasma exosomes isolated from patients with ALD were similar to those seen in a rodent model of alcoholic injury and in vitro. Reintroduction of miR19b inhibits HSC activation and modulates expression of pri-miR17-92 and the inverse expression of individual cluster members in cells and exosomes. Better understanding of miR17-92 processing may provide mechanistic insights to the role of individual miRs and exosomes during hepatic injury, revealing new therapeutic targets.