ESE-1 Regulates CREB-Mediated PTEN Expression to Activate the PI3K/Akt Pathway and Promote High-Glucose-Induced Endothelial Cell Injury.

Objective: Endothelial dysfunction is a central contributor to the vascular complications observed in individuals with diabetes. cAMP response element-binding protein (CREB) plays a crucial role in mediating hyperglycemia-induced endothelial dysfunction. Phosphatase and tensin homolog (PTEN) has been implicated in the regulation of endothelial inflammation, yet the precise mechanism by which CREB modulates PTEN to protect endothelial cells under high glucose conditions remains unknown. This study aims to elucidate this potential mechanism.

Methods: Human umbilical vein endothelial cells (HUVECs) were exposed to high glucose (30 mM) or normal glucose (5.5 mM) for 6 days. Cell viability and apoptosis were assessed via the Cell Counting Kit-8 and flow cytometry. To evaluate oxidative stress, the levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) were measured via commercial assay kits. The interaction between CREB and endothelial specific molecule 1 (ESE-1) was assessed via coimmunoprecipitation. Chromatin immunoprecipitation and luciferase reporter assays were used to investigate the transcriptional regulation of PTEN by ESE-1 and CREB. Western blotting was performed to analyze the expression of intercellular adhesion molecule-1 and E-selectin. The adhesion of HUVECs was evaluated via monocyte‒endothelial cell adhesion assays.

Results: Our findings revealed a direct interaction between CREB and ESE-1, which together regulate PTEN expression to activate the phosphoinositide 3-kinase/protein kinase B pathway. Under high-glucose conditions, we observed significant increases in oxidative stress, inflammatory responses, and adhesion in HUVECs. ESE-1 knockdown reversed these effects, restoring endothelial cell function. Moreover, the overexpression of PTEN in high glucose-treated HUVECs rescued the endothelial injury induced by ESE-1 knockdown, suggesting that PTEN plays a pivotal role in mediating the protective effects.

Conclusion: ESE-1, through the regulation of CREB-mediated PTEN expression, activates the PI3K/AKT pathway and modulates key processes such as oxidative stress, inflammation, and adhesion in endothelial cells under high-glucose stress.