Protective effect of 4-Methoxy benzyl alcohol on the neurovascular unit after cerebral ischemia reperfusion injury

Abstract

ObjectiveCerebral ischemia reperfusion injury (CIRI) is a major cause of ischemic stroke (IS) deterioration. Considering the intricate mechanism of the pathological process of CIRI, most drugs only work on one target. The neurovascular unit (NVU) puts forward the concept of neuroprotection from nerve protection to global stabilization. The NVU plays an important role in maintaining the brain microenvironment. This would promote neuronal survival and overall neurological recovery, which would likely lead to the reduction of mortality rate. Previous studies have shown that 4-methoxy benzyl alcohol (4-MA) ameliorated neurological score and cerebral infarct volume and reduced the concentration of Evans blue (EB) in brain tissue. In this research, we investigated the effects of 4-MA on NVU microenvironment improvement in rats impaired by middle cerebral artery occlusion/reperfusion (MCAO/R). MethodsFirst, we established a rat model of middle cerebral artery occlusion (MCAO) so as to use Western blot analysis, immunofluorescence and transmission electron microscopy (TEM) evaluating the NVU's protection of 4-MA. Then we established a primary cortical neuron model of oxygen glucose deprivation and re-oxygenation (OGD/R) with the objective of identifying whether 4-MA exhibited anti-oxidant and anti-apoptotic effects on neurons. ResultsNVU ultra structural changes were improved by 4-MA. Immunofluorescence and western blot showed that 4-MA protected NVUs through enhancement of the expression of the symbolic neuronal proteins Microtubule Associated Protein-2(MAP-2), and attenuation of protein expression of Asy symbolic protein Glial Fibrillary Acidic Protein(GFAP). Furthermore, in the OGD/R model of I/R injury in vitro, 4-MA significantly increased Superoxide dismutase(SOD), Nitric Oxide(NO), B-cell lymphoma-2(Bcl-2), decreased Bcl-2-Associated X(Bax) and increased Bcl-2/Bax. Conclusion4-MA can play the role of anti-ischemic stroke drug by ameliorating the microenvironment of NVUs while its neuroprotective effects will contribute towards the inhibition of the antioxidant and anti-apoptotic activities.