OXIDATIVE STRESS AFFECTS CARDIAC LOOPING IN ZEBRAFISH EMBRYOS

HERRERA, IDALIA; ARMESTO, RUBINA; CAVIGLIA, AGUSTÍN; BINOLFI, ANDRES; LOMBARDO, VERÓNICA A.

Valparaiso

Congreso; Latin American Society for Developmental Biology (LASDB) 2024; 2024

Latin American Society for Developmental Biology (LASDB)

Cardiac looping is an essential and highly conserved process in all vertebrates. Abnormalities in this process lead to congenital heart defects in humans (1). Increased levels of reactive oxygen species during pregnancy influence embryo development, specifically in cardiac development (2,3). Zebrafish presents multiple advantages for studying heart morphogenesis, including external embryogenesis, accessibility of the embryonic heart, and the ability to survive several days with an abnormal heart (4). The aim of this study is to characterize the cardiac looping and evaluate the effect of oxidative stress on this process. We recorded images of live embryos expressing a fluorescent protein within myocardial tissue (5) to characterize the early stages of heart development. We quantified the degree of cardiac looping (6) and established morphological parameters to describe the atrio-ventricular relative position in order to generate a cardiac stage predictor. Additionally, we evaluated cardio-physiological changes during heart looping, including heart rate, blood flow, and red blood cell maturation. Exposure of zebrafish embryos to acute or gradual oxidative stress revealed a lower degree of cardiac looping and a decrease in heart rate, as well as, abnormalities in the red blood cell maturation when compared treated vs. controls embryos. We also noted changes in the number of cardiomyocytes and perturbed spatial organization of the atrioventricular canal. Overall, the parameterization of cardiac looping provide valuable benchmarks to analyze cardiac morphology in live embryos and to evaluate perturbations elicited by genetic, pharmacological or environmental effects.Referencias: (1) Ramsdell, Dev Biol, 2005, 288:1-20. (2) Erickson et al., 2008 Cell, 133, 462–474 (3) Hobbs et al., 2005 The American Journal of Clinical Nutrition, 81, 147-153 (4) Bakkers, Cardiovascular Research, 2011, 10.1093/cvr/cvr098. (5) Huang et al., Dev Dyn., 2003, 228, 30-40. (6) Lombardo et al., Development, 2019. (7) Dietrich et al., Dev Cell, 2014, 30:367-377.