WTAP-induced upregulation of KDR ameliorates angiotensin II-induced apoptosis, oxidative stress and ferroptosis of human brain microvascular endothelial cells

Abstract

Intracranial aneurysms (IAs) are a significant cause of morbidity and mortality, often leading to subarachnoid hemorrhage and subsequent neurological deficits. The kinase insert domain receptor (KDR) plays a crucial role in vascular cell function during IA. However, the mechanism responsible for KDR’s role in IA remains unclear. Human brain microvascular endothelial cells (hBMECs) were treated with angiotensin II (Ang II) to simulate an in vitro IA model. Quantitative real-time PCR (qRT-PCR) was used to analyze the mRNA expression levels of KDR and Wilms’ tumor 1-associating protein (WTAP). Western blotting was employed to detect the protein expression of KDR and WTAP. Cell viability was assessed using a cell counting kit-8 assay, while cell apoptosis and mitochondrial membrane potential were measured by flow cytometry. Fluorometric assay was conducted to evaluate reactive oxygen species (ROS) levels. Colorimetric assays were used to determine the levels of reduced glutathione (GSH) and malondialdehyde (MDA), as well as Fe2+ levels. Methylated RNA immunoprecipitation (MeRIP) assay and dual-luciferase reporter assay were performed to validate m6A modification of KDR mRNA and the regulatory effect of WTAP on KDR. Treatment with Ang II induced apoptosis, oxidative stress, and ferroptosis in hBMECs. KDR and WTAP expression were significantly reduced in the arterial wall tissues of IA patients and in Ang II-treated hBMECs. Overexpression of KDR attenuated Ang II-induced apoptosis, oxidative stress, and ferroptosis in hBMECs. In addition, WTAP was found to promote KDR expression in a m6A-dependent manner. Moreover, overexpression of WTAP protected hBMECs from Ang II-induced apoptosis, oxidative stress, and ferroptosis by upregulating KDR. WTAP-induced upregulation of KDR mitigated Ang II-induced apoptosis, oxidative stress, and ferroptosis in hBMECs. These findings suggest that targeting the WTAP-KDR axis could have significant clinical implications for the prevention and treatment of IA. Ang II treatment induced hBMEC apoptosis, oxidative stress and ferroptosis. Ectopic KDR expression attenuated Ang II-induced hBMEC apoptosis, oxidative stress and ferroptosis. WTAP promoted KDR expression in a m6A-dependent manner. WTAP overexpression protected against Ang II-induced hBMEC apoptosis, oxidative stress and ferroptosis by regulating KDR.