Cardiac microRNA-133 is down-regulated in thyroid hormone-mediated cardiac hypertrophy partially via Type 1 Angiotensin II receptor

Autor(es)

Diniz, Gabriela Placona ^[1] ; Lino, Caroline Antunes ^[1] ; Guedes, Elaine Castilho ^[1] ; Moreira, Luana do Nascimento ^[1] ; Morais Barreto-Chaves, Maria Luiza ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Lab Cell Biol & Funct Anat, Dept Anat, Inst Biomed Sci, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BASIC RESEARCH IN CARDIOLOGY; v. 110, n. 5 SEP 2015.
• Citações Web of Science: 18

Resumo

Elevated thyroid hormone (TH) levels induce cardiac hypertrophy partially via type 1 Angiotensin II receptor (AT1R). MicroRNAs (miRNAs) are key regulators of cardiac homeostasis, and miR-133 has been shown to be involved in cardiac hypertrophy. However, the potential role of miR-133 in cardiac growth induced by TH is unknown. Thus, we aimed to investigate the miR-133 expression, as well as its potential role in cardiac hypertrophy in response to TH. Wistar rats were subjected to hyperthyroidism combined or not with the AT1R blocker. T-3 serum levels were assessed to confirm the hyperthyroid status. TH induced cardiac hypertrophy, as evidenced by higher cardiac weight/tibia length ratio and alpha-actin mRNA levels, which was prevented by AT1R blocker. miR-133 expression was decreased in TH-induced cardiac hypertrophy in part through the AT1R. Additionally, the cardiac mRNA levels of miR-133 targets, SERCA2a and calcineurin were increased in hyperthyroidism partially via AT1R, as evaluated by real-time RT-PCR. Interestingly, miR-133 levels were unchanged in T-3-induced cardiomyocyte hypertrophy in vitro. However, a gain-of-function study revealed that miR-133 mimic blunted the T-3-induced cardiomyocyte hypertrophy in vitro. Together, our data indicate that miR-133 expression is reduced in TH-induced cardiac hypertrophy partially by the AT1R and that miR-133 mimic prevents the cardiomyocyte hypertrophy in response to T-3 in vitro. These findings provide new insights regarding the mechanisms involved in the cardiac growth mediated by TH, suggesting that miR-133 plays a key role in TH-induced cardiomyocyte hypertrophy. (AU)

• Processo FAPESP: 09/14567-7 - Análise da expressão de microRNAs na hipertrofia cardíaca induzida pelo hormônio tiroideano in vivo e in vitro - participação do receptor AT1
• Beneficiário: Gabriela Placoná Diniz
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado