Hydroxysafflor Yellow A Blocks HIF-1 α Induction of NOX2 and Protects ZO-1 Protein in Cerebral Microvascular Endothelium

• Published in: Antioxidants Vol. 11; no. 4; p. 728
• Main Authors: Li, Yi, Liu, Xiao-Tian, Zhang, Pei-Lin, Li, Yu-Chen, Sun, Meng-Ru, Wang, Yi-Tao, Wang, Sheng-Peng, Yang, Hua, Liu, Bao-Lin, Wang, Mei, Gao, Wen, Li, Ping
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07.04.2022; MDPI
• Subjects: Blood-brain barrier; Brain injury; Carthamus tinctorius; cerebral microvascular endothelium; CYBB protein; Endothelial cells; Endothelium; HIF-1α; hydroxysafflor yellow A; Hypoxia; Hypoxia-inducible factor 1a; Inflammation; Ischemia; Lipopolysaccharides; Microvasculature; NAD; NAD(P)H oxidase; NADH; NOX2; Oxidative stress; Proteasomes; Proteins; SIRT1 protein; Spleen; Stroke; Transcription; Traumatic brain injury; ZO-1; Zonula occludens-1 protein; United States > US; China; cerebral microvascular endothelium; HIF-1α; ZO-1; hydroxysafflor yellow A; NOX2
• ISSN: 2076-3921; 2076-3921
• DOI: 10.3390/antiox11040728

Zonula occludens-1 (ZO-1) is a tight junction protein in the cerebrovascular endothelium, responsible for blood-brain barrier function. Hydroxysafflor yellow A (HSYA) is a major ingredient of safflower ( L.) with antioxidative activity. This study investigated whether HSYA protected ZO-1 by targeting ROS-generating NADPH oxidases (NOXs). HSYA administration reduced cerebral vascular leakage with ZO-1 protection in mice after photothrombotic stroke, largely due to suppression of ROS-associated inflammation. In LPS-stimulated brain microvascular endothelial cells, HSYA increased the ratio of NAD /NADH to restore Sirt1 induction, which bound to Von Hippel-Lindau to promote HIF-1 degradation. NOX2 was the predominant isoform of NOXs in endothelial cells and HIF-1 transcriptionally upregulated p47phox and Nox2 subunits for the assembly of the NOX2 complex, but the signaling cascades were blocked by HSYA via HIF-1 inactivation. When oxidate stress impaired ZO-1 protein, HSYA attenuated carbonyl modification and prevented ZO-1 protein from 20S proteasomal degradation, eventually protecting endothelial integrity. In microvascular ZO-1 deficient mice, we further confirmed that HSYA protected cerebrovascular integrity and attenuated ischemic injury in a manner that was dependent on ZO-1 protection. HSYA blocked HIF-1 /NOX2 signaling cascades to protect ZO-1 stability, suggestive of a potential therapeutic strategy against ischemic brain injury.