Induction of cardiotoxicity in zebrafish embryos by 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene through the JAK-STAT and NOTCH signaling pathways

1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) is the primary molecular metabolite of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), a pesticide used to control the spread of dengue and Zika viruses, and can be detected in the majority of human blood samples. However, whether p,p'-DDE affects embryonic cardiac development remains unknown. This study aimed to explore the cardiotoxicity of p,p'-DDE and its potential mechanisms of action in zebrafish embryos. We demonstrated for the first time that zebrafish embryos exposed to p,p'-DDE exhibited cardiac development abnormalities, including morphological and functional abnormalities, such as pericardial edema, thinning of the ventricular wall, reduced erythrocyte intensity, and increased heart rate. The results of Kyoto Encyclopedia of Genes and Genomes analysis of differentially expressed genes and qRT-PCR showed that JAK-STAT-related genes (il17d, socs3a, and bcl2b) and Notch-related genes (notch1a, notch1b, bmp10, efnb2a, tbx2b, and tbx5a) were altered after p,p'-DDE treatment, leading to reduced proliferation and increased apoptosis of cardiomyocytes and irregular formation of ventricular and abnormal atrioventricular junctions. These results were verified using acridine orange staining, 5-ethynyl-2'-deoxyuridine assays, and whole-mount in situ hybridization. Our research suggests that p,p'-DDE affects cardiac development in zebrafish embryos and that its cardiotoxicity may be associated with the JAK-STAT and Notch signaling pathways. Our findings may provide the basis for future population-based cohort studies.