Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA.
The Seven Hills School, Cincinnati, OH, USA.
Chemosphere. 2023 Jul;328:138562. doi: 10.1016/j.chemosphere.2023.138562. Epub 2023 Mar 31.
Bisphenol A (BPA) and its analogs are common environmental chemicals with many potential adverse health effects. The impact of environmentally relevant low dose BPA on human heart, including cardiac electrical properties, is not understood. Perturbation of cardiac electrical properties is a key arrhythmogenic mechanism. In particular, delay of cardiac repolarization can cause ectopic excitation of cardiomyocytes and malignant arrhythmia. This can occur as a result of genetic mutations (i.e., long QT (LQT) syndrome), or cardiotoxicity of drugs and environmental chemicals. To define the impact of low dose BPA on electrical properties of cardiomyocytes in a human-relevant model system, we examined the rapid effects of 1 nM BPA in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) using patch-clamp and confocal fluorescence imaging. Acute exposure to BPA delayed repolarization and prolonged action potential duration (APD) in hiPSC-CMs through inhibition of the hERG K channel. In nodal-like hiPSC-CMs, BPA acutely increased pacing rate through stimulation of the I pacemaker channel. Existing arrhythmia susceptibility determines the response of hiPSC-CMs to BPA. BPA resulted in modest APD prolongation but no ectopic excitation in baseline condition, while rapidly promoted aberrant excitations and tachycardia-like events in myocytes that had drug-simulated LQT phenotype. In hiPSC-CM-based human cardiac organoids, the effects of BPA on APD and aberrant excitation were shared by its analog chemicals, which are often used in "BPA-free" products, with bisphenol AF having the largest effects. Our results reveal that BPA and its analogs have repolarization delay-associated pro-arrhythmic toxicity in human cardiomyocytes, particularly in myocytes that are prone to arrhythmias. The toxicity of these chemicals depends on existing pathophysiological conditions of the heart, and may be particularly pronounced in susceptible individuals. An individualized approach is needed in risk assessment and protection.
双酚 A(BPA)及其类似物是常见的环境化学物质,具有许多潜在的不良健康影响。环境相关低剂量 BPA 对人类心脏的影响,包括心脏电生理特性,尚不清楚。心脏电生理特性的紊乱是关键的致心律失常机制。特别是,心脏复极的延迟会导致心肌细胞的异位兴奋和恶性心律失常。这可能是由于基因突变(即长 QT(LQT)综合征),或药物和环境化学物质的心脏毒性。为了在与人类相关的模型系统中定义低剂量 BPA 对心肌细胞电生理特性的影响,我们使用膜片钳和共聚焦荧光成像技术检查了 1 nM BPA 对人诱导多能干细胞衍生的心肌细胞(hiPSC-CMs)的快速作用。急性 BPA 暴露通过抑制 hERG K 通道延迟 hiPSC-CMs 的复极并延长动作电位时程(APD)。在类似结的 hiPSC-CMs 中,BPA 通过刺激 I 起搏通道急性增加起搏率。现有的心律失常易感性决定了 hiPSC-CMs 对 BPA 的反应。在基线条件下,BPA 导致 APD 适度延长但无异位兴奋,但在具有药物模拟 LQT 表型的心肌细胞中,迅速促进异常兴奋和心动过速样事件。在基于 hiPSC-CM 的人心肌类器官中,BPA 及其类似物对 APD 和异常兴奋的影响与其类似物化学物质共享,这些化学物质通常用于“无 BPA”产品,其中双酚 AF 的影响最大。我们的研究结果表明,BPA 及其类似物在人类心肌细胞中具有与复极延迟相关的致心律失常毒性,特别是在易发生心律失常的心肌细胞中。这些化学物质的毒性取决于心脏的现有病理生理状况,并且在易受影响的个体中可能更为明显。在风险评估和保护方面需要采取个体化方法。