High glucose treatment induced nuclei aggregation of microvascular endothelial cells via foxo1a-klf2a pathway

BACKGROUNDHyperglycemia is a major contributor to endothelial dysfunction and blood vessel damage, leading to severe diabetic microvascular complications. Despite the growing body of research on the underlying mechanisms of endothelial cell dysfunction, the available drugs based on current knowledge fall short of effectively alleviating these complications. Therefore, our endeavor to explore novel insights into the cellular and molecular mechanisms of endothelial dysfunction is crucial for the field. METHODSIn this study, we carried out a high-resolution imaging and time-lapse imaging analysis of the behavior of endothelial cells in Tg(kdrl:ras-mCherry::fli1a:nEGFP) zebrafish embryos upon high glucose treatment. Genetic manipulation and chemical biology approaches were utilized to analyze the underlying mechanism of high-glucose-induced nuclei aggregation and aberrant migration of zebrafish endothelial cells and cultured human endothelial cells. Bioinformatical analysis of single-cell RNA sequencing data and molecular biological techniques to identify the target genes of Foxo1a. RESULTSIn this study, we observed that the high glucose treatment resulted in nuclei aggregation of endothelial cells in zebrafish intersegmental vessels (ISVs). Additionally, the aberrant migration of microvascular endothelial cells in high glucose-treated embryos, which might be a cause of nuclei aggregation, was discovered. High glucose-induced aggregation of vascular endothelial nuclei via foxo1a downregulation in zebrafish embryos. Then, we revealed that high glucose resulted in the downregulation of foxo1a expression and increased the expression of its direct downstream effector, klf2a, through which the aberrant migration and aggregation of vascular endothelial nuclei were caused. CONCLUSIONSHigh glucose treatment caused the nuclei of endothelial cells to aggregate in vivo, which resembles the crowded nuclei of endothelial cells in microaneurysms. High glucose suppresses foxo1a expression and increases the expression of its downstream effector, klf2a, thereby causing the aberrant migration and aggregation of vascular endothelial nuclei. Our findings provide a novel insight into the mechanism of microvascular complications in hyperglycemia.