title: MiRNA-208a and miRNA-208b are triggered in thyroid hormone-induced cardiac hypertrophy - role of type 1 Angiotensin II receptor (AT1R) on miRNA-208a/α-MHC modulation.
abstract: Hyperthyroidism promotes cardiac hypertrophy and the Angiotensin type 1 receptor (AT1R) has been demonstrated to mediate part of this response. Recent studies have uncovered a potentially important role for the microRNAs (miRNAs) in the control of diverse aspects of cardiac function. Then, the objective of the present study was to investigate the action promoted by hyperthyroidism on β-MHC/miR-208b expression and on α-MHC/miR-208a expression, as well as the possible contribution of the AT1R in this event. The findings of this study confirmed that AT1R is a key mediator of the cardiac hypertrophy induced by hyperthyroidism. Additionally, we demonstrated that like β-MHC, miR-208b was down-regulated in the hyperthyroid group. Similarly, like the expression of its host gene, α-MHC, miR-208a expression was up-regulated in response to hyperthyroidism. Finally, our data suggest for the first time that AT1R mediates the hyperthyroidism-induced increase on cardiac miRNA-208a/α-MHC levels, while does not influence on the reduction of miRNA-208b/β-MHC levels.
authors.affiliation: Laboratory of Cell Biology and Functional Anatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-900, Brazil. gpdiniz@usp.br
authors.forename: Gabriela Placoná
authors.initials: GP
authors.lastname: Diniz
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Takano
authors.forename: Maria Luiza Morais
authors.initials: ML
authors.lastname: Barreto-Chaves
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006332:Cardiomegaly / Q000150:complications / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D006980:Hyperthyroidism / Q000150:complications / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D061251:Primary Cell Culture; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology; D013963:Thyroid Hormones / Q000378:metabolism*
chemical_list: C569395:MIRN208 microRNA, rat; D035683:MicroRNAs; D044140:Receptor, Angiotensin, Type 1; D013963:Thyroid Hormones; D018995:Myosin Heavy Chains