Analysis of microRNAs -15b, -16, -21, -221 and -222 as molecular markers in the blood of rats submitted to focal cerebral ischemia associated with alcoholism

Abstract

One of the main global causes of mortality is cerebral ischemia. Studies report that alcohol abuse causes health problems, aggravating the conditions of neurological diseases. The role of microRNAs has been highlighted in the literature as biomarkers in various types of diseases, including neurological disorders. Evidence of dysregulation of serum miRNAs related to apoptosis in experimental brain ischemia associated with alcoholism is scarce. We evaluated the gene expression of miRNA-15b and 16 (apoptotic) and miRNA-21, -221 and -222 (anti-apoptotic) in the blood after experimental induction of temporary focal ischemia (90 minutes) by occlusion of the middle cerebral artery in rats, followed by reperfusion for 48 hours, associated with a chronic alcoholism model. Fifty-six rats were randomly divided into seven experimental groups: Control (C); Sham (S); Ischemic (I); Ischemia-reperfusion (IR), Alcoholic (A); Alcoholic and ischemic (I + A); Ischemiareperfusion and Alcoholic (IR+A). The blood samples were collected for gene expression analysis of some serum miRNAs by PCR in real time. The serum expression of miRNA-16 was higher in the IR group compared to C and S groups (P < 0.05) but no association with chronic alcoholism was found. The serum expressions of miRNA-21, -221 and -222 were low in all groups and were not correlated with ischemic injury and/or chronic alcoholism. The serum expressions of miRNA-15b, -21, -221 and -222 were similar among the experimental groups, with no correlation with ischemia, with or without reperfusion, and/or alcoholism. The overexpression of miRNA-16 in the blood of I and IR groups demonstrated a correlation with the ischemic process, mainly after reperfusion for 48 hours, associated or not with alcoholism.