A HUMAN IPSC-BASED ORGANOID PLATFORM FOR STUDYING MATERNAL HYPERGLYCEMIA-INDUCED CONGENITAL HEART DEFECTS - Congenital heart defects (CHD) are the most common type of birth defect, with cardiac malformation resulting from abnormal heat development contributed by genetic and/or environmental risk factors. The association of maternal diabetes with increased offspring CHD incidence is proposed to be attributed to factors including glucose imbalance and metabolic dysregulation. Murine studies on hyperglycemia have been beneficial in uncovering the phenotypic effects of maternal hyperglycemia on embryonic development, with reports that high glucose conditions are associated with general suppression of WNT signaling, apoptosis, and excessive reactive oxygen species (ROS) production. However, little is known about the effects of hyperglycemia on human stem cells in regard to cardiomyocyte determination, metabolism, and functionality. Additionally, there is little reports of these alterations using induced pluripotent stemcells (iPSCs), which provide an opportunityto observe cardiac progenitor cell (CPC) heterogeneity, multicellular crosstalk, and differentiated cell functionality at key development timepoints. We hypothesize that high glucose environments interfere with normal cardiac differentiation to cause altered cell lineage determination in iPSCs and iPSC-derived cardiomyocytes (iPSC- CMs). We propose use of immunofluorescence assays and staining to quantify mitochondrial metabolism, mitochondrial ROS production, and apoptosis marker amounts. Our goal is to investigate the impact of high glucose on human cardiomyocyte differentiation and crosstalk signaling abnormalities during 3D stem cell differentiation that could lead to impaired cardiac development. We will investigate differentially expressed genes at the single-cell resolutionin early and late differentiation in responseto high glucose doses in iPSC populations. Should our transcriptional profiling comparisons yield iPSC and iPSC-CM expression differences, the resulting phenotypes would provide insight into cardiac cell determination during hyperglycemic conditions. Understanding the hyperglycemia-response mechanisms is important in the onset of maternal hyperglycemia- associated CHD. These mechanisms would be further investigated through looking at cell lineage population composition in organoids and analyze response per lineage to narrow down what structures of the mature heart are affected.
