title: Validation of murine and human placental explant cultures for use in sex steroid and phase II conjugation toxicology studies.
abstract: Human primary placental explant culture is well established for cytokine signaling and toxicity, but has not been validated for steroidogenic or metabolic toxicology. The technique has never been investigated in the mouse. We characterized human and mouse placental explants for up to 96 h in culture. Explant viability (Lactate dehydrogenase) and sex steroid levels were measured in media using spectrophotometry and ELISA, respectively. Expression and activities of the steroidogenic (3β-hydroxysteroid dehydrogenase, Cytochrome P45017A1, Cytochrome P45019), conjugation (UDP-glucuronosyltransferase, sulfotransferase (SULT)), and regeneration (β-glucuronidase, arylsulfatase C (ASC)) enzymes were determined biochemically in tissues with fluorimetric and spectrophotometric assays, and western blot. Explants were viable up to 96 h, but progesterone, estrone, and 17β-estradiol secretion decreased. Steroidogenic enzyme expression and activities were stable in mouse explants and similar to levels in freshly isolated tissues, but were lower in human explants than in fresh tissue (P<0.01). Human and mouse explants exhibited significantly less conjugation after 96 h, SULT was not detected in the mouse, and neither explants had active ASC, although proteins were expressed. Mouse explants may be useful for steroid biochemistry and endocrine disruption studies, but not metabolic conjugation. In contrast, human explants may be useful for studying conjugation for <48 h, but not for steroid/endocrine studies.
authors.affiliation: Cellular and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA; Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA; Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI 96816, USA.
authors.forename: Brittany L
authors.initials: BL
authors.lastname: Sato
authors.affiliation: Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Monika A
authors.initials: MA
authors.lastname: Ward
authors.affiliation: Cellular and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Astern
authors.affiliation: Obstetrics, Gynecology and Women's Health, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA; Natural Sciences and Mathematics, Chaminade University of Honolulu, 3140 Waialae Avenue, Honolulu, HI 96816, USA.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Kendal-Wright
authors.affiliation: Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813, USA; Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, 1960 East-West Road, Honolulu, HI 96822, USA; Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada. Electronic address: abby.collier@ubc.ca.
authors.forename: Abby C
authors.initials: AC
authors.lastname: Collier
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D004958:Estradiol / Q000032:analysis / Q000096:biosynthesis; D004965:Estrogen Antagonists / Q000009:adverse effects; D004970:Estrone / Q000032:analysis / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D005260:Female; D014453:Glucuronosyltransferase / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010920:Placenta / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000032:analysis / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D046509:Tissue Culture Techniques / Q000379:methods; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D004965:Estrogen Antagonists; D012739:Gonadal Steroid Hormones; D004970:Estrone; D011374:Progesterone; D004958:Estradiol; D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase; D014453:Glucuronosyltransferase
keywords: Conjugation; Ex vivo culture; Mouse; Placenta; Steroidogenesis