title: AMPK signaling pathway is rapidly activated by T3 and regulates the cardiomyocyte growth.
abstract: Previous studies have indicated that AMP-activated protein kinase (AMPK) plays a critical role in the control of cardiac hypertrophy mediated by different stimuli such as thyroid hormone (TH). Although the classical effects of TH mediating cardiac hypertrophy occur by transcriptional mechanisms, recent studies have identified other responses to TH, which are more rapid and take place in seconds or minutes evidencing that TH rapidly modulates distinct signaling pathway, which might contribute to the regulation of cardiomyocyte growth. Here, we evaluated the rapid effects of TH on AMPK signaling pathway in cultured cardiomyocytes and determined the involvement of AMPK in T3-induced cardiomyocyte growth. We found for the first time that T3 rapidly activated AMPK signaling pathway. The use of small interfering RNA against AMPK resulted in increased cardiomyocyte hypertrophy while the pharmacological stimulation of AMPK attenuated this process, demonstrating that AMPK contributes to regulation of T3-induced cardiomyocyte growth.
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.
authors.forename: Ana Paula Cremasco
authors.initials: AP
authors.lastname: Takano
authors.forename: Gabriela Placoná
authors.initials: GP
authors.lastname: Diniz
authors.forename: Maria Luiza Morais
authors.initials: ML
authors.lastname: Barreto-Chaves
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D006332:Cardiomegaly / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D061251:Primary Cell Culture; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects*; D014284:Triiodothyronine / Q000494:pharmacology*
chemical_list: D034741:RNA, Small Interfering; D014284:Triiodothyronine; D055372:AMP-Activated Protein Kinases
keywords: AMPK; Cardiomyocyte hypertrophy; Thyroid hormone