title: Investigation of testosterone, androstenone, and estradiol metabolism in HepG2 cells and primary culture pig hepatocytes and their effects on 17βHSD7 gene expression.
abstract: Steroid metabolism is important in various species. The accumulation of androgen metabolite, androstenone, in pig adipose tissue is negatively associated with pork flavor, odour and makes the meat unfit for human consumption. The 17β-hydroxysteroid dehydrogenase type 7 (17βHSD7) expressed abundantly in porcine liver, and it was previously suggested to be associated with androstenone levels. Understanding the enzymes and metabolic pathways responsible for androstenone as well as other steroids metabolism is important for improving the meat quality. At the same time, metabolism of steroids is known to be species- and tissue-specific. Therefore it is important to investigate between-species variations in the hepatic steroid metabolism and to elucidate the role of 17βHSD7 in this process. Here we used an effective methodological approach, liquid chromatography coupled with mass spectrometry, to investigate species-specific metabolism of androstenone, testosterone and beta-estradiol in HepG2 cell line, and pig cultured hepatocytes. Species- and concentration-depended effect of steroids on 17βHSD7 gene expression was also investigated. It was demonstrated that the investigated steroids can regulate the 17βHSD7 gene expression in HepG2 and primary cultured porcine hepatocytes in a concentration-dependent and species-dependent pattern. Investigation of steroid metabolites demonstrated that androstenone formed a 3'-hydroxy compound 3β-hydroxy-5α-androst-16-ene. Testosterone was metabolized to 4-androstene-3,17-dione. Estrone was found as the metabolite for β-estradiol. Inhibition study with 17βHSD inhibitor apigenin showed that apigenin didn't affect androstenone metabolism. Apigenin at high concentration (50 µM) tends to inhibit testosterone metabolism but this inhibition effect was negligible. Beta-estradiol metabolism was notably inhibited with apigenin at high concentration. The study also established that the level of testosterone and β-estradiol metabolites was markedly increased after co-incubation with high concentration of apigenin. This study established that 17βHSD7 is not the key enzyme responsible for androstenone and testosterone metabolism in porcine liver cells.
authors.affiliation: Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Sicong
authors.initials: S
authors.lastname: Li
authors.forename: Xinxing
authors.initials: X
authors.lastname: Dong
authors.forename: Ying
authors.initials: Y
authors.lastname: Bai
authors.forename: Ailiang
authors.initials: A
authors.lastname: Chen
authors.forename: Shuming
authors.initials: S
authors.lastname: Yang
authors.forename: Meiying
authors.initials: M
authors.lastname: Fang
authors.forename: Galia
authors.initials: G
authors.lastname: Zamaratskaia
authors.forename: Olena
authors.initials: O
authors.lastname: Doran
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors / Q000235:genetics*; D000738:Androsterone / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D047310:Apigenin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D013045:Species Specificity; D013256:Steroids / Q000378:metabolism* / Q000494:pharmacology*; D013552:Swine; D013739:Testosterone / Q000378:metabolism / Q000494:pharmacology
chemical_list: D013256:Steroids; D013739:Testosterone; D004958:Estradiol; D047310:Apigenin; D000738:Androsterone; D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase