Acta Veterinaria Hungarica 64 (4), pp. 497–513 (2016) DOI: 10.1556/004.2016.046 0236-6290/$ 20.00 © 2016 Akadémiai Kiadó, Budapest BISPHENOL A INFLUENCES OESTROGEN- AND THYROID HORMONE-REGULATED THYROID HORMONE RECEPTOR EXPRESSION IN RAT CEREBELLAR CELL CULTURE Virág SOMOGYI 1 , Tamás L. HORVÁTH 2,3 , István TÓTH 1 , Tibor BARTHA 1 , László Vilmos FRENYÓ 1 , Dávid Sándor KISS 1 , Gergely JÓCSÁK 1 , Annamária KERTI 2 , Frederick NAFTOLIN 4 and Attila ZSARNOVSZKY 2,3* 1 Department of Physiology and Biochemistry, University of Veterinary Medicine, Budapest, Hungary; 2 Department of Animal Physiology and Animal Health, Faculty of Agricultural and Environmental Sciences, Szent István University, Páter Károly u. 1, H-2100 Gödöllő, Hungary; 3 Section of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA; 4 Reproductive Biology Research, New York University, New York, NY, USA (Received 4 August 2016; accepted 2 November 2016) Thyroid hormones (THs) and oestrogens are crucial in the regulation of cerebellar development. TH receptors (TRs) mediate these hormone effects and are regulated by both hormone families. We reported earlier that THs and oestra- diol (E 2 ) determine TR levels in cerebellar cell culture. Here we demonstrate the effects of low concentrations (10 –10 M) of the endocrine disruptor (ED) bisphenol A (BPA) on the hormonal (THs, E 2 ) regulation of TRα,β in rat cerebellar cell cul- ture. Primary cerebellar cell cultures, glia-containing and glia-destroyed, were treated with BPA or a combination of BPA and E 2 and/or THs. Oestrogen recep- tor and TH receptor mRNA and protein levels were determined by real-time qPCR and Western blot techniques. The results show that BPA alone decreases, while BPA in combination with THs and/or E 2 increases TR mRNA expression. In contrast, BPA alone increased receptor protein expressions, but did not further increase them in combination with THs and/or E 2 . The modulatory effects of BPA were mediated by the glia; however, the degree of changes also depended on the specific hormone ligand used. The results signify the importance of the regulatory mechanisms interposed between transcription and translation and raise the possi- bility that BPA could act to influence nuclear hormone receptor levels independ- ently of ligand–receptor interaction. Key words: Endocrine disruptors, thyroid receptor, transcription, transla- tion, bisphenol A, rat cerebellum Thyroid hormones (THs) and oestrogens (mostly 17β-oestradiol, E 2 ) play critical roles in the regulation of central nervous system (CNS) development, in- * Corresponding author; Zsarnovszky.Attila@mkk.szie.hu; Phone: 0036 (28) 522-062/1620 (office); 0036 (30) 665-3717 (mobile); Fax: 0036 (28) 522-062