title: CCAAT/enhancer-binding protein β is involved in the breed-dependent transcriptional regulation of 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase in adrenal gland of preweaning piglets.
abstract: The enzyme 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase (3β-HSD) catalyzes the biosynthesis of all steroid hormones. The molecular mechanisms regulating porcine adrenal 3β-HSD expression in different breeds are still poorly understood. In this study, we aimed to compare the expression of 3β-HSD between preweaning purebred Large White (LW) and Erhualian (EHL) piglets and to explore the potential factors regulating 3β-HSD transcription. EHL had significantly higher serum levels of cortisol (P<0.01) and testosterone (P<0.01), which were associated with significantly higher expression of 3β-HSD mRNA (P<0.01) and protein (P<0.05) in the adrenal gland, compared with LW piglets. The 5' flanking region of the porcine 3β-HSD gene showed significant sequence variations between breeds, and the sequence of EHL demonstrated an elevated promoter activity (P<0.05) in luciferase reporter gene assay. Higher adrenal expression of 3β-HSD in EHL was accompanied with higher CCAAT/enhancer binding protein β (C/EBPβ) expression (P<0.05), enriched histone H3 acetylation (P<0.05) and C/EBPβ binding to 3β-HSD promoter (P<0.05). In addition, higher androgen receptor (AR) (P=0.06) and lower glucocorticoid receptor (GR) (P<0.05) were detected in EHL. Co-immunoprecipitation analysis revealed interactions of C/EBPβ with both AR and GR. These results indicate that the C/EBPβ binding to 3β-HSD promoter is responsible, at least in part, for the breed-dependent 3β-HSD expression in adrenal gland of piglets. The sequence variations of 3β-HSD promoter and the interactions of AR and/or GR with C/EBPβ may also participate in the regulation.
authors.affiliation: Key Laboratory of Animal Physiology & Biochemistry, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Xian
authors.initials: X
authors.lastname: Li
authors.forename: Runsheng
authors.initials: R
authors.lastname: Li
authors.forename: Yimin
authors.initials: Y
authors.lastname: Jia
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Sun
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Yang
authors.forename: Qinwei
authors.initials: Q
authors.lastname: Sun
authors.forename: Ruqian
authors.initials: R
authors.lastname: Zhao
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D000311:Adrenal Glands; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism*; D008297:Male; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D013552:Swine
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D010088:Oxidoreductases; D015067:17-Hydroxysteroid Dehydrogenases; D015096:3-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase
keywords: 3β-HSD; 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4)-isomerase; AGP; AR; ARE; Adrenal gland; C/EBPβ; CCAAT/enhancer binding protein β; COX-2; ChIP; DAX-1; EHL; Erhualian; FXR; GATA-6; GR; GRE; LW; Large White; NET; PPIA; Pig; SF-1; STAT5A; STAT5B; StAR; androgen receptor; androgen response element; chromatin immunoprecipitation; cyclooxygenase 2; dosage-sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome gene 1; farnesoid X receptor; glucocorticoid receptor; glucocorticoid response element; norepinephrine transporter; peptidylprolyl isomerase A; signal transducer and activator of transcription protein 5A; signal transducer and activator of transcription protein 5B; steroidogenic acute regulatory protein; steroidogenic factor 1; transcription factor GATA-6; α1-acid glycoprotein