title: Neonatal Persistent Exposure to 6-Propyl-2-thiouracil, a Thyroid-Disrupting Chemical, Differentially Modulates Expression of Hepatic Catalase and C/EBP-β in Adult Rats.
abstract: Persistent exposure of rats to 6-propyl-2-thiouracil (PTU) from birth resulted in decreases in plasma thyroid hormone (TH) levels and hepatic expression of catalase and CCAAT enhancer binding protein β (C/EBP-β). Catalase promoter region (-185 to +52) that contains binding sites for C/EBP-β showed an augmentation in the methylation level along with a change in methylation pattern of CpG islands in response to PTU treatment. PTU withdrawal on 30 days of birth restored TH levels and C/EBP-β to control rats in adulthood. Although catalase expression was restored to some extent in adult rats in response to PTU withdrawal, a permanent change in its promoter CpG methylation pattern was recorded. The results suggest that downregulation of adult hepatic catalase gene in response to persistent neonatal PTU exposure may not solely be attributed to thyroid-disrupting properties of PTU. It is possible that besides thyroid-disrupting behavior, PTU may impair expression of hepatic catalase by altering methylation pattern of its promoter.
authors.affiliation: Department of Biotechnology, Utkal University, Bhubaneswar, 751 004, India. chainyg@gmail.com.
authors.forename: Suresh Kumar
authors.initials: SK
authors.lastname: Bunker
authors.affiliation: Department of Biotechnology, Utkal University, Bhubaneswar, 751 004, India.
authors.forename: Jagneshwar
authors.initials: J
authors.lastname: Dandapat
authors.affiliation: Department of Biotechnology, Utkal University, Bhubaneswar, 751 004, India.
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Sahoo
authors.affiliation: Department of Biotechnology, Utkal University, Bhubaneswar, 751 004, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Roy
authors.affiliation: Department of Biotechnology, Utkal University, Bhubaneswar, 751 004, India.
authors.forename: Gagan B N
authors.initials: GB
authors.lastname: Chainy
mesh_terms: D000818:Animals; D001665:Binding Sites; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000096:biosynthesis* / Q000235:genetics; D002374:Catalase / Q000096:biosynthesis* / Q000235:genetics; D018899:CpG Islands; D019175:DNA Methylation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D011401:Promoter Regions, Genetic; D011441:Propylthiouracil / Q000008:administration & dosage*; D051381:Rats; D013961:Thyroid Gland / Q000187:drug effects* / Q000473:pathology; D013963:Thyroid Hormones / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D013963:Thyroid Hormones; D011441:Propylthiouracil; D002374:Catalase
keywords: C/EBP-β; Catalase; Liver; Neonatal PTU exposure; Promoter methylation; Rat