[Electrophysiological Effect of Citreoviridin on Human InducedPluripotent Stem Cell-derived Cardiomyocytes]

Citreoviridin (CTV) is a mycotoxin produced by various fungi, including Penicillium citreonigrum. One of the toxicities reportedly associated with CTV is neurotoxicity. CTV is also suspected to be associated with acute cardiac beriberi (also known as "Shoshin-kakke") and Keshan disease, which can have adverse effects on the heart, so the in vivo and in vitro toxicity of CTV on the heart or cardiomyocytes in experimental animal models have been reported. However, the toxicity of CTV for the human heart, especially its electrophysiological effect, remains poorly understood. Therefore, to investigate the electrophysiological effect of CTV on the human cardiomyocytes, we conducted a multi-electrode array (MEA) using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The MEA revealed that 30 μmol/L of CTV stopped the beating of hiPSC-CMs, and the field potential duration and first peak amplitude were shortened at 10 μmol/L. Before the hiPSC-CMs stopped beating, the length of the inter-spike interval varied two- to four-fold. These results demonstrated that CTV induced an electrophysiological disturbance on human cardiomyocytes. This is first paper to elucidate the electrophysiological effect of CTV on human heart directly and may aid in analyzing the risk associated with CTV to ensure food safety.