Irisin Ameliorates Cerebral Vasospasm and Early Brain Injury in Rats with Experimental Subarachnoid Hemorrhage

Abstract

Irisin is a cytokine mainly secreted by skeletal muscles, widely distributed in the body with functions of anti-oxidation, anti-inflammation, prevention of reperfusion injury, immune stimulation, and reduction of cerebral infarction. In this study, rats with subarachnoid hemorrhage (SAH) were used as experimental subjects, and irisin was injected intraperitoneally to investigate irisin’s effect on cerebral vasospasm and early brain injury (EBI). After establishment of the animal model of SAH, animals were administered with irisin through intraperitoneal injection. The animal tissues were taken out to assess the morphological changes, and neurons apoptosis by TUNEL staining and Nissl staining. Brain edema score was used to assess the severity of brain injury, and the relationship between related signal pathways was detected by Western blot. Administration of irisin significantly reduced cerebral vasospasm and decreased neuronal apoptosis induced by SAH. Irisin inhibited the apoptosis of prefrontal cortex mitochondrial neurons, and decreased Bax/Bcl-2 and cytochrome C in the cytoplasm. The expressions of PSD-95 and GAP-43 and BDNF in brain tissues were decreased upon SAH, but their expressions were partially restored after treatment with irisin. Irisin decreases neuronal apoptosis and mitochondrial function with up-regulation of synapse proteins, thereby exerting a protective effect on EBI and SAH.