Diminazene Alleviates Neuroinflammation in Ischemic Stroke by Inhibiting Astrocytic Endoplasmic Reticulum Stress and Oxidative Stress

Abstract

Acute ischemic stroke (AIS) is a common medical emergency worldwide, and reducing cerebral ischemia/reperfusion injury (CI/RI) is a crucial strategy for AIS treatment. Diminazene aceturate (DIZE) has demonstrated therapeutic potential in alleviating neurodegenerative diseases, but its specific functions in AIS remain a puzzle. This research aims to investigate the role and mechanisms of DIZE in CI/RI. C57BL/6J mice were treated with DIZE via intracerebroventricular injection for a week and middle cerebral artery occlusion/reperfusion (MCAO/R) models were established. Neurobehavioral tests, TTC staining and HE staining were adapted to detect neuroprotective effect of DIZE on MCAO/R mice. Primary cultures of astrocytes were prepared and exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate in vitro ischemia/reperfusion. The IL-1β, IL-6 and TNF-α levels were detected by qRT-PCR and ELISA. Oxidative stress and lipid peroxidation indicators were measured using commercial assay kits. Western blot and immunofluorescence staining were used to measure the related protein levels. We found that DIZE alleviated neuronal injury and suppressed both neuroinflammation and astrocyte reactive changes in MCAO/R mice. In vitro, DIZE inhibited the release of inflammatory factors in primary cultures of astrocytes subjected to OGD/R. Furthermore, DIZE inhibited endoplasmic reticulum stress-mediated IRE1α-NF-κB pathway, increased NRF2 levels and suppressed oxidative stress, which was consistently observed in vivo and in vitro. Our study indicated that DIZE exerts a protective effect on CI/RI, and this effect may be achieved by DIZE inhibiting endoplasmic reticulum stress and oxidative stress in astrocytes, thereby suppressing astrocyte-mediated neuroinflammation.