Effect of neuregulin on apoptosis and expressions of STAT3 and GFAP in rats following cerebral ischemic reperfusion.

The aim is to investigate the effect of neuregulin-1beta (NRG-1beta) on the neuronal apoptosis and the expressions of signal transducer and activator of transcription (STAT3) and glial fibrillary acidic protein (GFAP) in rats following cerebral ischemia/reperfusion. The animal models of middle cerebral artery occlusion/reperfusion (MCAO/R) were established by an intraluminal filament method from left external-internal carotid artery in 100 cases of adult healthy male Wister rats. NRG-1beta was administered from the internal carotid artery (ICA) into MCA in the treatment group. The neuronal apoptosis was detected by terminal deoxynucleotidyl transference-mediated biotinylated deoxyuridine triphosphate nick-end labeling technique. The expression alternations of STAT3 and GFAP proteins were determined by fluorescent labeling analysis and Western blotting assay. Ischemic cerebral injury could induce neuronal apoptosis. Furthermore, with the duration of ischemia, the amount of apoptotic cells increased in the control group. These apoptotic cells distributed in various brain regions, especially the cortex, striatum, and hippocampus, while only a small amount of apoptotic cells could be observed in the treatment group, and there were significant differences compared with that in the control group (P < 0.01). The expressions of STAT3 and GFAP proteins in brain tissue gradually increased in the control group with the duration of ischemia. And NRG-1beta could elevate the expressional level of STAT3 and GFAP proteins in contrast to the control group (P < 0.05). NRG-1beta may play a neuroprotective role in cerebral ischemic insult by activating JAK/STAT signal transduction pathway, promoting the astrocyte gumnosis and regulating the anti-apoptosis mechanism in neurocytes.