microRNA-192 suppresses the expression of the farnesoid X receptor
microRNA-192 suppresses the expression of the farnesoid X receptor
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DOI：
10.1152/ajpgi.00297.2015
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发表时间：
2016-06-01
影响因子：
4.5
通讯作者：
Kullak-Ublick, Gerd A.
中科院分区：
文献类型：
--
作者：
Krattinger, Regina;Bostrom, Adrian;Kullak-Ublick, Gerd A.
Farnesoid X 受体（FXR、NR1H4）在肝脏和肠道胆汁酸稳态的调节中发挥重要作用，并可能对某些形式的癌症（如结肠癌）发挥保护作用。然而，FXR在细胞生长调节、细胞凋亡和癌变中的作用仍存在争议。与FXR类似，microRNA-192（miR-192）主要在肝脏和结肠中表达，在结肠癌的发病机制中发挥重要作用。在本研究中，我们研究了 FXR 受 miR-192 调节的程度。通过荧光素酶报告基因测定，在体外检查了 NR1H4-3' 非翻译区 (UTR) 内 miR-192-3p 的两个计算机预测结合位点。将野生型和突变形式的 NR1H4-3' UTR 亚克隆到 pmirGLO 载体中，并与 miR-192-3p 共转染到 Huh-7 细胞中。为了研究miR-192对FXR、FXR靶基因表达和细胞增殖的影响，用miR-192-5p和-3p模拟物或antagomir转染Huh-7和Caco-2细胞。此外，通过线性回归分析研究了 27 名患者的结肠腺癌组织中 FXR 和 miR-192 表达之间的相关性。 MiR-192-3p 特异性结合 NR1H4-3' UTR，并显着降低荧光素酶活性。转染 miR-192 导致 NR1H4 mRNA 和蛋白质水平以及 FXR 诱导型胆汁酸转运蛋白 OST α-OST β 和 OATP1B3 的 mRNA 水平显着降低。在结肠腺癌中检测到 NR1H4 mRNA 和 miR-192-3p 表达之间存在显着负相关。总之，microRNA-192 在体外和体内抑制 FXR 和 FXR 靶基因的表达。
Farnesoid X receptor (FXR, NR1H4) plays an important role in the regulation of bile acid homeostasis in liver and intestine and may exert protective effects against certain forms of cancer such as colon carcinoma. However, the role of FXR in cell growth regulation, apoptosis, and carcinogenesis is still controversial. Similar to FXR, microRNA-192 (miR-192) is mainly expressed in the liver and colon and plays an important role in the pathogenesis of colon carcinoma. In this study, we investigated the extent to which FXR is regulated by miR-192. Two in silico-predicted binding sites for miR-192-3p within the NR1H4-3' untranslated region (UTR) were examined in vitro by luciferase reporter assays. Wild-type and mutated forms of the NR1H4-3' UTR were subcloned into a pmirGLO vector and cotransfected into Huh-7 cells with miR-192-3p. To study the effects of miR-192 on the expression of FXR, FXR target genes and cell proliferation, Huh-7 and Caco-2 cells were transfected with miR-192-5p and -3p mimics or antagomirs. In addition, the correlation between FXR and miR-192 expression was studied by linear regression analyses in colonic adenocarcinoma tissue from 27 patients. MiR-192-3p bound specifically to the NR1H4-3' UTR and significantly decreased luciferase activity. Transfection with miR-192 led to significant decreases in NR1H4 mRNA and protein levels as well as the mRNA levels of the FXR-inducible bile acid transporters OST alpha-OST beta and OATP1B3. Significant inverse correlations were detected in colonic adenocarcinoma between NR1H4 mRNA and miR-192-3p expression. In summary, microRNA-192 suppresses the expression of FXR and FXR target genes in vitro and in vivo.