Abstract Background Atherosclerotic plaque rupture is driven by disturbed blood flow which induces multiple pathological changes in endothelial cells (ECs). GATA4 is a pleiotropic transcription factor that regulates fundamental cellular processes including survival, migration, proliferation, inflammation and endothelial-to-mesenchymal transition (EndMT). However, the potential role of GATA4 and its downstream networks in atherosclerosis is unknown. Aims Elucidate whether GATA4 drives plaque phenotypes associated with instability and assess the role of EndMT in this process. Methods In this study, endothelial specific Gata4 knock out mice were used for study, and 8-10 weeks old mice were exposed to the Western diet for 8 weeks, then given tamoxifen to activate Cre to cause deletion of Gata4. They were fed Western diet for a further 6 weeks to drive atheroprogression. Then the brachiocephalic artery and aortic sinus were dissected from mice. Plaque phenotypes were defined by histological staining of cross-sections made from brachiocephalic plaques and aortic sinus plaques. Mouse aortas were digested and used flow cytometry to sort single endothelial cells before scRNA-seq analysis. Results To investigate the role of Gata4 in plaque progression, we analysed histology staining after EC-specific genetic deletion of Gata4 in both female and male mice. Gata4 ECKO ApoE-/- mice exhibited a significant increase in plaque burden in brachiocephalic arteries and aortic sinus compared to controls in females. scRNA-seq analysis of pooled data from Gata4 ECKO ApoE-/- mice and control mice revealed that clusters 2, 7, and 9 were enriched in cells from control mice, whereas clusters 3 and 5 contained a higher proportion of cells from Gata4 ECKO ApoE-/- mice. We next analysed the distribution of EndMT markers and classical EC markers among clusters. Cluster 4 ,7 ,8 and 9 were enriched with EndMT markers and cluster 7, 9 are Gata4 regulated clusters. We conclude that Gata4 drives the emergence of endothelial cell subsets characterized by EndMT-associated gene expression. Conclusions Our findings shows that GATA4 plays a critical role in limiting plaque growth while also contributing to features of plaque stability. GATA4 promotes clusters associated with forms of EndMT in advanced atherosclerotic lesions.
Tian et al. (Fri,) studied this question.