Study on the Brain Protection of Granulocyte Colony-Stimulating Factor in Stroke after Alcohol Use Disorder

Abstract: Objective To examine the effects of granulocyte colony-stimulating factor (G-CSF) treatment on the expression of transforming growth factor-α (TGF-α) in microglia and its neuroprotective effects in stroke after alcohol use disorder (AUD) in rats. Methods Male Sprague-Dawley rats were used to establish an AUD model using the double bottle method. Based on the AUD model, the focal cerebral ischemia model of middle cerebral artery occlusion (MCAO) was established using the thread embolism method. TGF-α small interfering RNA (siRNA) or negative control siRNA was injected into the lateral ventricle 24 h before MCAO. G-CSF was injected intraperitoneally l h after ischemia-reperfusion injury. Rats were randomly divided into the AUD group (18 rats), the AUD+MCAO group (18 rats), the AUD+MCAO+G-CSF group (18 rats), the AUD+MCAO+G-CSF+TGF-α siRNA group (18 rats), and the AUD+MCAO+G-CSF+control siRNA group (6 rats). Alcohol intake, changes in alcohol preference, and neurological function scores of the rats were recorded. The volume of cerebral infarction 24 h after MCAO was measured by 2,3,5-triphenyltetrazolium chloride staining. The number of positive cells of transmembrane protein 119 (TMEM119), a specific marker of microglia in the cerebral cortex of the ischemic side, and the G-CSF receptor (G-CSFR), and the protein expression of TGF-α were observed by immunofluorescence staining. The expression levels of TMEM119 and TGF-α protein in brain tissue of the ischemic side were detected by Western blot. Results Alcohol intake and alcohol preference of rats gradually increased with the increase of drinking time. G-CSFR was significantly expressed in microglia. Compared with the AUD group, the fluorescence intensity of TMEM119 protein and TGF-α protein in the AUD+MCAO group was significantly enhanced, and the number of positive cells increased. Compared with the AUD+MCAO group, the volume of infarction in the AUD+MCAO+G-CSF group was significantly reduced, and the symptoms of neurological impairment improved. The fluorescence intensity of TMEM119 protein was significantly weakened, and the number of positive cells decreased. The fluorescence intensity of TGF-α protein was significantly enhanced, and the number of positive cells increased. Volume of cerebral infarction increased and neurological deficits aggravated in the rats after lateral ventricle injection of TGF-α siRNA. Conclusions G-CSF plays an important brain protective effect in stroke after AUD by increasing the expression of TGF-α in microglia.