Nicotinamide Mononucleotide Adenylyltransferase 1 Regulates Cerebral Ischemia–Induced Blood–Brain Barrier Disruption Through NAD+/SIRT1 Signaling Pathway

Abstract

The molecular mechanisms of blood-brain barrier (BBB) disruption in the early stage after ischemic stroke are poorly understood. In the present study, we investigated the potential role of nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) in ischemia-induced BBB damage using an animal middle cerebral artery occlusion (MCAO) model of ischemic stroke. Recombinant human NMNAT1 (rh-NMNAT1) was administered intranasally and Sirtuin 1 (SIRT1) siRNA was administered by intracerebroventricular injection. Our results indicate that rh-NMNAT1 reduced infarct volume, improved functional outcome and decreased BBB permeability in mice after ischemic stroke. Furthermore, rh-NMNAT1 prevented the loss of tight junction proteins (occludin and claudin-5) and reduced cell apoptosis in ischemic microvessels. NMNAT1-mediated BBB permeability was correlated with the elevation of nicotinamide adenine dinucleotide (NAD+)/NADH ratio and SIRT1 level in brain microvascular endothelial cells. In addition, rh-NMNAT1 treatment signi cantly decreased the levels of acetylated nuclear factor-κB, acetylated p53 and matrix metalloproteinase-9 in ischemic microvessels. Moreover, the protective effects of rh-NMNAT1 could be reversed by SIRT1 siRNA. In conclusion, these ndings indicate that rh-NMNAT1 protects BBB integrity after cerebral ischemia via the NAD+/SIRT1 signaling pathway in brain microvascular endothelial cells. NMNAT1 may be a novel potential therapeutic target for reducing BBB disruption after ischemic stroke.

A novel link between silent information regulator 1 and autophagy in cerebral ischemia-reperfusion

“…SIRT1/VEGF pathway was demonstrated to promote angiogenesis by increasing microvascular density in the boundary ischemic area after cerebral I/R injury in MCAO-induced Sprag-Dawley rats ( Zheng et al, 2018 ). Moreover, the NAD + /SIRT1 signaling pathway also was reported to regulate ischemia-induced blood-brain barrier disruption in ischemic mice ( Zhang et al, 2022a ).…”