High expression of microRNA-208 is associated with cardiac hypertrophy via the negative regulation of the sex-determining region Y-box 6 protein
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- Published online on: July 17, 2015 https://doi.org/10.3892/etm.2015.2645
- Pages: 921-926
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Copyright: © Huang et al. This is an open access article distributed under the terms of Creative Commons Attribution License.
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Abstract
The aim of this study was to investigate the expression levels of microRNA-208 (miR-208) and sex-determining region Y‑box 6 (SOX6) in patients with progressive cardiac hypertrophy. A total of 50 patients with essential hypertension accompanied by left ventricular hypertrophy, and 30 healthy individuals were enrolled. Peripheral blood samples were collected in order to compare miR-208 expression levels between the cardiac hypertrophy patients and healthy individuals. In addition, an in vitro cellular model of cardiac hypertrophy was established to determine the association between miR‑208 and SOX6 expression. Rat cardiomyocytes were treated with phenylephrine (PE) to induce cardiac hypertrophy. Some of the hypertrophic cardiomyocytes were subsequently transfected with antagomiR-208, an miR-208 antagonist, in order to determine the effects of silencing miR-208 expression. Differences between healthy and hypertrophic cardiomyocyte morphology were evaluated using immunofluorescence staining. The mRNA expression levels of the hypertrophy‑associated genes β‑myosin heavy chain, α‑sarcomeric actin and atrial natriuretic peptide were determined using quantitative polymerase chain reaction (qPCR). The mRNA and protein expression levels of miR‑208 and SOX6 in peripheral blood and cardiomyocytes were detected using qPCR and western blot analysis, respectively. The expression levels of miR‑208 were significantly increased in the peripheral blood of patients with left ventricular hypertrophy (P<0.05). PE‑stimulated cardiomyocytes were significantly increased in size compared with normal cardiomyocytes. In the PE‑stimulated cardiomyocytes, miR‑208 expression levels were significantly increased (P<0.05). However, SOX6 expression levels were significantly decreased compared with those in normal cardiomyocytes (P<0.05). Following transfection with antagomiR‑208, SOX6 expression levels in the PE‑stimulated cardiomyocytes significantly increased, while the total mRNA and protein expression levels of hypertrophy‑associated genes significantly decreased (P<0.05). miR‑208 expression levels are increased in the peripheral blood of patients with cardiac hypertrophy. Therefore, the results of this study suggest that the expression levels of miR-208 are associated with cardiac hypertrophy by the negative regulation of SOX6.