Effects of bisphenol a on neonatal cardiomyocytes beating rate and morphology

Abstract

Bisphenol A (BPA) has been utilised excessively at a global capacity of 2.9 billion kg/year. It is widely used in manufacturing polycarbonate polymers and epoxy resins. Hence, humans are potentially exposed to this chemical substance in their daily life. As a typical endocrine disruptor, BPA exhibits detectable hormone-like properties. Many studies have been linking BPA exposure in humans with the risk of developing cardiovascular disease, however the direct exposure of BPA on cardiomyocytes beating rates and morphology have not been entirely explored. Therefore, in this study, we aimed to investigate the effects of BPA on cells structure and function of neonatal rat cardiomyocytes culture. Cardiomyocytes were isolated from 0 to 2 days old newborn rats and treated with 0.001 to 100 µM concentration of BPA. All cardiomyocytes were subjected to immunostaining, beating frequency assessment assay, MTS assay and Scanning Electron microscopy (SEM). In immunostaining, cardiomyocytes showed positive staining for F-actin. This staining allows identification of the cells thus differentiate cardiomyocytes from other cell types. Significance effects of BPA on cardiomyocytes were observed in MTS assay (p<0.05) and beating rates (p<0.01). Significant reduction (48%-64%, ± 1.5280) was observed in beating rate of cardiomyocytes exposed to 0.1 to 100 µM of BPA. Meanwhile in MTS assay, significant reduction (54%, 0.067 ± 0.0026) in cell viability was observed in cells exposed to 0.1 µM of BPA only. Interestingly, under SEM, cardiomyocytes showed altered cell surface homogeneity after BPA exposure. Exposure of 0.1 to 100 µM BPA lead to flatten of cardiomyocytes cell surface and blurring of the cell borders. This study offers an in vitro evidence of BPA effects on cardiomyocytes morphology and beating rates, thus suggest the potential adverse effect of BPA exposure. However, further investigation would be required to understand how BPA effects normal cells morphology and beating rates of heart cells.