miR-122 regulates collagen production via targeting hepatic stellate cells and suppressing P4HA1 expression.
miR-122 regulates collagen production via targeting hepatic stellate cells and suppressing P4HA1 expression.
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DOI：
10.1016/j.jhep.2012.11.011
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发表时间：
2013-03
影响因子：
25.7
通讯作者：
Li, Song
中科院分区：
文献类型：
--
作者：
Li, Jiang;Ghazwani, Mohammed;Zhang, Yifei;Lu, Jianqin;Li, Jilong;Fan, Jie;Gandhi, Chandrashekhar R.;Li, Song
microRNA（miRNAs）通过影响靶基因的表达参与多种生物学过程。miR-122在肝癌发生中的作用已被广泛研究。然而，miR-122在肝纤维化中的作用仍然未知。通过实时PCR评估miR-122、脯氨酰4-羟化酶亚基α 1（P4 HA 1）和CCAAT/增强子结合蛋白α（C/EBPα）的mRNA表达水平。Western blot和免疫荧光法检测P4 HA 1、C/EBPα和Ⅰ型胶原α 1（COL 1A 1）蛋白表达水平。MTT法检测细胞增殖情况。染色质免疫沉淀法（ChIP）检测C/EBPα与miR-122启动子的结合活性。miR-122的表达在反式激活的HSC和用CCl 4处理的小鼠的肝脏中显著降低。过表达miR-122可抑制LX 2细胞的增殖。我们还证明了P4 HA 1是miR-122的靶基因。在HSC和小鼠肝脏中，PAHA 1的mRNA表达水平与miR-122的表达水平呈负相关。过表达miR-122可通过靶向P4 HA 1 mRNA的3′-UTR结合位点显著抑制P4 HA 1的表达。我们进一步表明，miR-122过表达导致胶原成熟和ECM产生减少。最后，在活化的HSC中，C/EBPα与miR-122启动子的结合活性显著降低。我们的研究表明，miR-122可能在负调节HSC中胶原蛋白的产生中起重要作用，并且在HSC中靶向表达miR-122可能代表治疗肝纤维化的新策略。
MicroRNAs (miRNAs) have been shown to be involved in many biological processes by affecting their target gene expression. miR-122 has been extensively studied in hepatocarcinogenesis. However, the role of miR-122 in liver fibrosis remains unknown. The mRNA expression levels of miR-122, prolyl 4-hydroxylase subunit alpha-1 (P4HA1), and CCAAT/enhancer binding protein alpha (C/EBPα) were assessed by real-time PCR. The protein expression levels of P4HA1, C/EBPα and collagen, type I, alpha 1 (COL1A1) were analyzed by Western blot and immunofluorescence. MTT assay was used to assess cell proliferation. Chromatin immunoprecipitation (ChIP) assay was used to examine the binding activity of C/EBPα to miR-122 promoter. miR-122 expression was significantly reduced in transactivated HSCs and in the livers of mice treated with CCl4. Overexpression of miR-122 inhibited the proliferation of LX2 cells. We also demonstrated that P4HA1 was a target gene of miR-122. The mRNA expression level of PAHA1 inversely correlated with that of miR-122 in HSCs and in the mouse liver. Overexpression of miR-122 markedly attenuated the expression of P4HA1 via targeting a binding site located at 3′-UTR of P4HA1 mRNA. We further showed that miR-122 overexpression led to decreased collagen maturation and ECM production. Finally, the binding activity of C/EBPα to miR-122 promoter was significantly decreased in activated HSCs. Our study suggests that miR-122 may play an important role in negatively regulating collagen production in HSCs and that targeted expression of miR-122 in HSCs may represent a new strategy for the treatment of liver fibrosis.
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影响因子：
3.7
作者：
Li L;Zhang K;Cai XJ;Feng M;Zhang Y;Zhang M
通讯作者：
Zhang M
影响因子：
5
作者：
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影响因子：
11.2
作者：
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通讯作者：
Negrini, Massimo
影响因子：
13.5
作者：
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通讯作者：
Okita, K
影响因子：
13.5
作者：
Roderburg, Christoph;Urban, Gerd-Willem;Luedde, Tom
通讯作者：
Luedde, Tom