Background:
Vascular endothelial dysfunction is the initial factor involved in cardiovascular injury
in patients with diabetes. Retinoic acid is involved in improving vascular complications in patients with diabetes,
but its protective mechanism is still unclear. This study aimed to evaluate the effect and mechanism of
All-Trans Retinoic Acid (ATRA) on endothelial dysfunction induced by diabetes.
Methods:
In the present study, streptozotocin (STZ)-induced diabetic rats and high glucose (HG)-induced human
umbilical vein endothelial cells (HUVECs) were observed, and the effects of ATRA on HG-induced endothelial
dysfunction and ferroptosis were evaluated.
Results:
ATRA treatment improved impaired vasorelaxation in diabetic aortas in an endothelium-dependent
manner, and this effect was accompanied by an increase in the NO concentration and eNOS expression. Ferroptosis,
characterized by lipid peroxidation and iron overload induced by HG, was improved by ATRA administration,
and a ferroptosis inhibitor (ferrostatin-1, Fer-1) improved endothelial function to a similar extent as
ATRA. In addition, the inactivation of phosphoinositol-3-kinase (PI3K)/protein kinases B (AKT) and Yes-Associated
Protein (YAP) nuclear localization induced by HG were reversed by ATRA administration. Vascular
ring relaxation experiments showed that PI3K/AKT activation and YAP inhibition had similar effects on ferroptosis
and endothelial function. However, the vasodilative effect of retinoic acid was affected by PI3K/AKT
inhibition, and the inhibitory effects of ATRA on ferroptosis and the improvement of endothelial function
were dependent on the retinoic acid receptor.
Conclusion:
ATRA could improve vascular endothelial dysfunction by inhibiting PI3K/AKT/YAP-mediated
ferroptosis induced by HG, which provides a new idea for the treatment of vascular lesions in diabetes.