Cadmium Reduces VE-Cadherin Expression in Endothelial Cells Through Activation of the Notch Signaling Pathway.

Cadmium (Cd) is a toxic heavy metal which induces vascular disorders. Previous studies suggest that Cd in the bloodstream affects vascular endothelial cells (ECs), potentially contributing to vascular-related diseases. However, the molecular mechanisms of effects of Cd on ECs remain poorly understood. Notch signaling pathway abnormalities have been implicated in ECs disruption. The present study aims to investigate the effect of low Cd concentrations on the Notch signaling pathway in ECs. Mice were treated with low concentration of Cd (2.28 mg/kg), and tissues were collected for examination of mRNA and protein levels of Notch pathway components and VE-cadherin, a major junctional protein in ECs. We found that Cd treatment increases expression of NICD1, Hes1, Hey1, Hey2 and decreases expression of VE-cadherin in brain and kidney tissues. In vitro, a low concentration of Cd (1 μM) also induces increase expression of NICD1, Hes1, Hey1, Hey2, and decrease expression of VE-cadherin in human umbilical vein endothelial cells (HUVECs). Low concentration of Cd increased the permeability of HUVECs. We also found that Notch signaling negatively regulates the expression of VE-cadherin. In addition, DAPT, a Notch pathway inhibitor, prevents Cd-induced reduction in VE-cadherin expression in HUVECs. In summary, these findings revealed that Cd exposure decreases VE-cadherin expression through activation of the Notch signaling pathway.