Dkhil Mohamed A, Al-Quraishy Saleh, Abdel-Baki Abdel-Azeem, Ghanjati Foued, Arauzo-Bravo Marcos J, Delic Denis, Wunderlich Frank
Department of Zoology, College of Science, King Saud University, 11451 Riyadh, Saudi Arabia; Department of Zoology and Entomology, Faculty of Science, Helwan University, Cairo, Egypt.
Department of Zoology, College of Science, King Saud University, 11451 Riyadh, Saudi Arabia.
J Steroid Biochem Mol Biol. 2015 Jan;145:121-30. doi: 10.1016/j.jsbmb.2014.11.006. Epub 2014 Nov 6.
Testosterone (T) is known to masculinize the female phenotype of the liver, evidenced as up- and down-regulated expressions of male- and female-predominant genes, respectively, involved in hepatic metabolism. This study is aimed at identifying epigenetic modifications of promoters of these differently expressed genes in the liver after masculinization by T of adult female C57BL/6 mice using methylated DNA immunoprecipitation and NimbleGen microarrays. Among the 17,354 promoters examined, 82 promoters in the liver have been identified to be significantly changed by T (p<0.05), with 47 and 35 promoters exhibiting increased and decreased DNA methylation, respectively. Most of these promoters display the changes of DNA methylation in their Ups-regions, which are between +500 and +2000 bp upstream from the transcription start site (TSS) of the genes. Less T-induced modifications have been detected in the Cor-regions of the promoters, i.e., +500 to -500 bp around the TSS. Only 13 and 7 Cor-promoters are hyper- and hypo-methylated, respectively, among which are 10 hyper- and 5 hypo-methylated promoters of genes with annotated functions. Surprisingly, the promoters are largely unmethylated in those genes whose expression has been previously found to be permanently deregulated by T in the liver, as e.g. the T-upregulated male-predominant genes Cyp7b1, Cyp2d9, Cyp4a10, Ugt2b1, Ugt2b38, Hsd3b5, Slco1a1 as well as the T-downregulated female-predominant genes Cyp2b9, Cyp2b13, Cyp3a41, Cyp3a44, Fmo3, Sult2a2, respectively. Though methylatable, the promoter DNA of Ar, Esr1, and Esr2 remained unaffected by T. However, T decreases DNA-methylation of the Cor-promoter region of Ddc encoding the AR-coactivator dopa decarboxylase. Among the identified 15 Cor-promoters of genes with annotated functions are also those of Defb43, Cst11, and Sele involved in innate immunity. Our data support the view that T may exert long-lasting epigenetic effects on functions of the liver-inherent immune system.
已知睾酮（T）可使肝脏的雌性表型雄性化，表现为参与肝脏代谢的雄性和雌性优势基因的表达分别上调和下调。本研究旨在通过甲基化DNA免疫沉淀和NimbleGen微阵列，鉴定成年雌性C57BL/6小鼠经T雄性化后肝脏中这些差异表达基因启动子的表观遗传修饰。在检测的17354个启动子中，已确定肝脏中有82个启动子因T而发生显著变化（p<0.05），其中47个和35个启动子的DNA甲基化分别增加和减少。这些启动子大多在其上游区域（Ups区域）显示出DNA甲基化的变化，该区域位于基因转录起始位点（TSS）上游+500至+2000 bp之间。在启动子的核心区域（Cor区域），即TSS周围+500至-500 bp处，检测到较少的T诱导修饰。分别只有13个和7个Cor启动子发生高甲基化和低甲基化，其中有10个具有注释功能基因的启动子发生高甲基化，5个发生低甲基化。令人惊讶的是，在先前发现其表达在肝脏中被T永久失调的那些基因中，启动子大多未甲基化，例如T上调的雄性优势基因Cyp7b1、Cyp2d9、Cyp4a10、Ugt2b1、Ugt2b38、Hsd3b5、Slco1a1以及T下调的雌性优势基因Cyp2b9、Cyp2b13、Cyp3a41、Cyp3a44、Fmo3、Sult2a2。虽然可甲基化，但Ar、Esr1和Esr2的启动子DNA不受T影响。然而，T降低了编码AR共激活因子多巴脱羧酶的Ddc的Cor启动子区域的DNA甲基化。在鉴定出的15个具有注释功能基因的Cor启动子中，还有参与先天免疫的Defb43、Cst11和Sele的启动子。我们的数据支持这样一种观点，即T可能对肝脏固有免疫系统的功能产生持久的表观遗传效应。
