作者:Tianpeng Zhang、Mengjing Zhao、Danyi Lu、Shuai Wang、Fangjun Yu、Lianxia Guo、Shijun Wen、Baojian Wu
DOI:10.1124/dmd.117.078105
日期:2018.3
Nuclear heme receptor reverse erythroblastosis virus (REV-ERB) α (a transcriptional repressor) is known to regulate cholesterol 7 α -hydroxylase (CYP7A1) and bile acid synthesis. However, the mechanism for REV-ERB α regulation of CYP7A1 remains elusive. Here, we investigate the role of LRH-1 in REV-ERB α regulation of CYP7A1 and cholesterol metabolism. We first characterized the tertiary amine N -(4-chloro-2-methylbenzyl)- N -(4-chlorobenzyl)-1-(5-nitrothiophen-2-yl)methanamine (GSK2945) as a highly specific Rev-erb α /REV-ERB α antagonist using cell-based assays and confirmed expression of Rev-erb α in mouse liver. GSK2945 treatment increased hepatic mouse cholesterol 7 α -hydroxylase (Cyp7a1) level and lowered plasma cholesterol in wild-type mice. Likewise, the compound increased the expression and microsomal activity of Cyp7a1 in hypercholesterolemic mice. This coincided with reduced plasma and liver cholesterol and enhanced production of bile acids. Increased levels of Cyp7a1/CYP7A1 were also found in mouse and human primary hepatocytes after GSK2945 treatment. In these experiments, we observed parallel increases in Lrh-1/LRH-1 (a known hepatic activator of Cyp7a1/CYP7A1) mRNA and protein. Luciferase reporter, mobility shift, and chromatin immunoprecipitation assays revealed that Lrh-1/LRH-1 was a direct Rev-erb α /REV-ERB α target gene. Furthermore, conditional deletion of Lrh-1 in the liver abrogated the regulatory effects of Rev-erb α on Cyp7a1 and cholesterol metabolism in mice. In conclusion, Rev-erb α regulates Cyp7a1 and cholesterol metabolism through its repression of the Lrh-1 receptor. Targeting the REV-ERB α /LRH-1 axis may represent a novel approach for management of cholesterol-related diseases.
核血红素受体逆成红细胞增多症病毒 (REV-ERB) α(一种转录抑制因子)已知可调节胆固醇 7 α-羟化酶 (CYP7A1) 和胆汁酸合成。然而,REV-ERB α 调节 CYP7A1 的机制仍不清楚。在这里,我们研究了 LRH-1 在 REV-ERB α 调节 CYP7A1 和胆固醇代谢中的作用。我们首先将叔胺 N-(4-氯-2-甲基苄基)-N-(4-氯苄基)-1-(5-硝基噻吩-2-基)甲胺 (GSK2945) 表征为高度特异性的 Rev-erb α / REV-ERB α 拮抗剂使用基于细胞的测定法证实了 Rev-erb α 在小鼠肝脏中的表达。 GSK2945 治疗可增加野生型小鼠肝脏胆固醇 7α-羟化酶 (Cyp7a1) 水平并降低血浆胆固醇。同样,该化合物增加了高胆固醇血症小鼠 Cyp7a1 的表达和微粒体活性。这与血浆和肝脏胆固醇的降低以及胆汁酸的产生增加相一致。 GSK2945 处理后,小鼠和人类原代肝细胞中 Cyp7a1/CYP7A1 水平也有所增加。在这些实验中,我们观察到 Lrh-1/LRH-1(一种已知的 Cyp7a1/CYP7A1 肝脏激活剂)mRNA 和蛋白质平行增加。荧光素酶报告基因、迁移率变化和染色质免疫沉淀分析表明,Lrh-1/LRH-1 是 Rev-erb α /REV-ERB α 的直接靶基因。此外,肝脏中 Lrh-1 的条件性缺失消除了 Rev-erb α 对小鼠 Cyp7a1 和胆固醇代谢的调节作用。总之,Rev-erb α 通过抑制 Lrh-1 受体来调节 Cyp7a1 和胆固醇代谢。靶向 REV-ERB α /LRH-1 轴可能代表一种治疗胆固醇相关疾病的新方法。