Novel mitoNEET ligand NL‐1 improves therapeutic outcomes in an aged rat model of cerebral ischemia/reperfusion injury

Abstract

Cerebral ischemic stroke is a leading cause of mortality and disability worldwide. Currently, there are a lack of drugs capable of reducing neuronal cell loss after ischemia/reperfusion‐injury after stroke. Previously, we identified mitoNEET, a [2Fe‐2S] redox mitochondrial protein, as a putative drug target for stroke. In this study, we tested the novel mitoNEET ligand, NL‐1, in a preclinical model of ischemic stroke with reperfusion using aged female rats. Using a transient middle cerebral artery occlusion (tMCAO), we induced a 2 h ischemic injury and then evaluated the effects of NL‐1 treatment on ischemic/reperfusion brain injury at 24 and 72 h. Test drugs were administered at time of reperfusion via IV dosing. Results demonstrated that NL‐1 (10 mg/kg) treatment markedly reduced infarct volume and hemispheric swelling in the brain as compared rats treated with vehicle or a lower concentration of NL‐1 (0.25 mg/kg). Surprisingly, the protective effect of NL‐1 was significantly improved when encapsulated in PLGA nanoparticles, where a 40‐fold lesser dose (0.25 mg/kg) of NL‐1 produced an equivalent effect as the 10 mg/kg dose. Evaluation of changes in blood‐brain barrier permeability and oxidative stress using immunohistochemical staining corroborated the protective actions of NL‐1, showing reduced extravasation of IgG and decreased levels of 4‐hydroxynonenal (4‐HNE) in the brains of aged female rats at 72 h after tMCAO with reperfusion. Our studies indicate that targeting mitoNEET following ischemia/reperfusion‐injury is a novel drug target pathway that warrants further investigation.