MiR-200a-5p augments cardiomyocyte hypertrophy induced by glucose metabolism disorder via the regulation of selenoproteins.

Abstract

Selenium and selenoproteins are identified as potential determinants in pathological cellular hypertrophy. Cardiomyocytes hypertrophy is a compensatory form of heart disease characterized by increased size of cardiomyocytes. However, the link between cardiac hypertrophy and Se-specific microRNA (miRNA) remains to be characterized. In the current study, we established a miR-200a-5p mimic and an inhibitor cardiomyocytes model. Cardiomyocytes hypertrophy was induced in the miR-200a-5p mimic group. Hence, we detected the glucose level of cardiomyocytes to estimate the cellular glucose uptake. The effect of miR-200a-5p overexpression and the low expression on 25 selenoproteins mRNA levels was further explored using reverse transcription polymerase chain reaction. Overexpression of miR-200a-5p elevated glucose uptake and Txnrd2, 3 expression and reduced Sepp1, Seln, Selt, and Sep15 expression in cardiomyocytes. Contrary results were observed in cardiomyocytes with the knockdown of miR-200a-5p. We next assessed glucose metabolism-related genes in cardiomyocytes. The results showed that miR-200a-5p had a negative correlation with insulin-like growth factor gene-1, insulin-like growth factor binding protein (IGFBP)1, IGFBP2, IGFBP3, IGFBP4, and IGFBP5 and had a positive correlation with Akt, glucose transporter family (GLUT)2, GLUT3, and GLUT4. These results support the involvement of selenoproteins and glucose metabolism in the control of cardiomyocytes hypertrophy by Se-specific miRNA, suggesting that miR-200a-5p inhibited the expression of stress-related selenoproteins to alter glucose transport leading to glucose metabolism disorder, eventually inducing cardiomyocytes hypertrophy. Our finding highlights a pivotal role of Se-specific miRNA and selenoproteins in cardiac hypertrophy.