title: Liganded Thyroid Hormone Receptors Transactivate the DNA Methyltransferase 3a Gene in Mouse Neuronal Cells.
abstract: Thyroid hormone (T3) is essential for proper neurological development. The hormone, bound to its receptors, regulates gene transcription in part by modulating posttranslational modifications of histones. Methylation of DNA, which is established by the de novo DNA methyltransferase (DNMT)3a and DNMT3b, and maintained by DNMT1 is another epigenetic modification influencing gene transcription. The expression of Dnmt3a, but not other Dnmt genes, increases in mouse brain in parallel with the postnatal rise in plasma [T3]. We found that treatment of the mouse neuroblastoma cell line Neuro2a[TRβ1] with T3 caused rapid induction of Dnmt3a mRNA, which was resistant to protein synthesis inhibition, supporting that it is a direct T3-response gene. Injection of T3 into postnatal day 6 mice increased Dnmt3a mRNA in the brain by 1 hour. Analysis of two chromatin immunoprecipitation-sequencing datasets, and targeted analyses using chromatin immunoprecipitation, transfection-reporter assays, and in vitro DNA binding identified 2 functional T3-response elements (TREs) at the mouse Dnmt3a locus located +30.3 and +49.3 kb from the transcription start site. Thyroid hormone receptors associated with both of these regions in mouse brain chromatin, but with only 1 (+30.3 kb) in Neuro2a[TRβ1] cells. Deletion of the +30.3-kb TRE using CRISPR/Cas9 genome editing eliminated or strongly reduced the Dnmt3a mRNA response to T3. Bioinformatics analysis showed that both TREs are highly conserved among eutherian mammals. Thyroid regulation of Dnmt3a may be an evolutionarily conserved mechanism for modulating global changes in DNA methylation during postnatal neurological development.
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kyono
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Arasakumar
authors.initials: A
authors.lastname: Subramani
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Preeti
authors.initials: P
authors.lastname: Ramadoss
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Hollenberg
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Bonett
authors.affiliation: Neuroscience Graduate Program (Y.K., R.J.D.) and Department of Molecular, Cellular and Developmental Biology (A.S., R.J.D.), The University of Michigan, Ann Arbor, Michigan 48109; Division of Endocrinology, Diabetes and Metabolism (P.R., A.N.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02115; and Department of Biological Science (R.M.B.), The University of Tulsa, Tulsa, Oklahoma 74104.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Denver
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D045744:Cell Line, Tumor; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D017124:Conserved Sequence; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D000090205:DNA Methyltransferase 3A; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D020218:Response Elements; D015533:Transcriptional Activation; D014284:Triiodothyronine / Q000378:metabolism*
chemical_list: C000715535:Dnmt3a protein, mouse; D011988:Receptors, Thyroid Hormone; D014284:Triiodothyronine; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A