title: Potential role of estrogen in regulation of the insulin-like growth factor2-H19 locus in the rat testis.
abstract: The selective estrogen receptor modulator, tamoxifen, has been shown to reduce DNA methylation at Insulin-like growth factor 2/H19 differentially methylated region (Igf2/H19 DMR) in the spermatozoa of the Holtzman rats. Since imprint at this locus is acquired during spermatogenesis in the male germ-line, we hypothesized role for estrogen signaling in the methylation dynamics in the testis. The present study was designed to identify putative estrogen response elements (ERE) at Igf2/H19 DMR and their interaction with DNA methylation pathway. Here, we demonstrate presence of functional ERE at 2637/2655 base pair on Igf2/H19 DMR in testicular germ cells, which was found to bind to estrogen receptor beta (ER beta) in the chromatin immunoprecipitation assay. Tamoxifen attenuated ER beta-ERE association thereby acting as an estrogen antagonist at this locus. Further mechanistic study involving colocalization and immunoprecipitation assay revealed interaction of ER beta and Dnmt1 in the testis. The study provides evidence for the role for estrogen in acquisition of imprint at Igf2/H19 DMR in testis and help in understanding molecular mechanism of environmental estrogens impacting male fertility.
authors.affiliation: Division of Neuroendocrinology, National Institute for Research in Reproductive Health, Indian Council of Medical Research, JM Road, Parel, Mumbai, Maharashtra 400 012, India.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Pathak
authors.forename: Ryan
authors.initials: R
authors.lastname: D'Souza
authors.forename: Mandar
authors.initials: M
authors.lastname: Ankolkar
authors.forename: Reshma
authors.initials: R
authors.lastname: Gaonkar
authors.forename: Nafisa H
authors.initials: NH
authors.lastname: Balasinor
mesh_terms: D000818:Animals; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D018392:Genomic Imprinting; D005854:Germ Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D020218:Response Elements; D015398:Signal Transduction / Q000502:physiology; D013737:Testis / Q000166:cytology / Q000502:physiology*
chemical_list: D047629:Estrogen Receptor beta; D004967:Estrogens; D007335:Insulin-Like Growth Factor II; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; C000619382:Dnmt1 protein, rat