目的 通过人类胚胎干细胞（hESCs）向心肌细胞（CMs）的体外分化体系构建早期心脏发育模型，评估全氟辛烷磺酸（PFOS）对胚胎心脏的毒性效应以及维生素D（VitD）的潜在保护作用。 方法 将hESCs分别用含PFOS和PFOS + VitD干预的分化培养基对其进行诱导分化，在CMs分化的终末阶段（第8天）通过光学显微镜观察细胞分化情况，用实时荧光定量逆转录PCR（RT-qPCR）分别检测第8天心肌分化标志物（cTNT、α-actinin、NKX2.5）和线粒体复合物（UQCRC1、MTCO2、ATP5A1）的表达，通过ATP含量和线粒体活性氧水平检测心肌分化第2天线粒体代谢的表达。 结果 暴露于PFOS可显著抑制hESCs向CMs的分化能力，其毒性机制可能与线粒体功能损伤密切相关，而VitD具有拮抗该毒性效应的潜力。与对照组相比，PFOS暴露组中成熟CMs集落的密度显著降低，而在PFOS联合VitD处理组中，集落密度恢复至接近对照组水平。此外，RT-qPCR结果显示，VitD能够有效减少FOS所诱导的CMs分化标志物表达量的下降。线粒体功能检测进一步显示，PFOS暴露导致hESCs来源的心肌细胞（hESCs-CMs）的线粒体能量代谢效率显著下降，引发氧化应激，损害线粒体的正常功能，而联合VitD干预后线粒体功能能够恢复至正常水平。 结论 PFOS可抑制hESCs向CMs的分化过程。VitD能够通过调节线粒体相关信号通路，有效拮抗PFOS所致的毒性作用，从而恢复线粒体功能。

Objective This study utilized an in vitro differentiation model of human embryonic stem cells （hESCs） into cardiomyocytes （CMs） to establish an early heart development model. It was intended to assess the embryotoxicity of perfluorooctanesulfonic acid （PFOS） and the potential protective effect of vitamin D （VitD）. Methods hESCs were induced to differentiate using differentiation media containing either PFOS alone or a combination of PFOS and VitD. At the terminal stage （day 8） of cardiomyocyte differentiation， the differentiation process was observed under an optical microscope. Quantitative real - time reverse transcription polymerase chain reaction （RT-qPCR） was employed to detect the expression of myocardial differentiation marker proteins ［cardiac troponin T（cTNT）， α-actinin， NK2 homeobox 5 （NKX2.5）］ and mitochondrial complexes ［ubiquinol-cytochrome c reductase core protein 1 （UQCRC1）， cytochrome c oxidase subunit 2 （MTCO2）， ATP synthase subunit alpha （ATP5A1）］ on the 8th day. Mitochondrial metabolism during differentiation was evaluated by measuring the ATP levels and reactive oxygen species produced by mitochondria on the 2nd day. Results The results clearly indicated that exposure to PFOS significantly inhibited the differentiation capacity of hESCs into CMs. This toxic effect was strongly associated with mitochondrial dysfunction， whereas VitD showed the potential to counteract this toxicity. In comparison with the control group， the density of mature cardiomyocyte colonies was notably reduced in the PFOS-exposed group. Nevertheless， in the group treated with both PFOS and VitD， the colony density was restored to a level approaching that of the control. Moreover， RT-qPCR results demonstrated that VitD effectively mitigated the PFOS-induced decrease in the expression of cardiomyocyte differentiation markers. Mitochondrial function tests further disclosed that PFOS exposure resulted in a substantial decline in mitochondrial energy metabolism efficiency in CMs derived from hESCs， triggered oxidative stress， and impaired normal mitochondrial function. These effects were reversed to normal levels after co-intervention with VitD. Conclusions The findings clearly demonstrated that PFOS inhibited the differentiation of hESCs into CMs. VitD could effectively counteract the toxic effects induced by PFOS and restore mitochondrial function via the regulation of mitochondrial-related signaling pathways.