Increased Expression of mir-34a-5p and Clinical Association in Acute Ischemic Stroke Patients and in a Rat Model.

BACKGROUND MiRNA is widely recognized as the most important regulator in various diseases. However, there has been little research regarding miRNA expression and its involvement in ischemic stroke. MATERIAL AND METHODS In this study, we investigated the pattern of miRNA-34a-5p expression along with its clinical application in human ischemic stroke and in an in vivo rat model. We recruited 102 cerebral ischemia patients and 97 health controls for this study. Clinical data were gathered and recorded with the help of questionnaires. Blood samples were obtained from patients within 72 h after cerebral ischemia. National Institutes of Health Stroke Scale (NIHSS), Acute Stroke Treatment (TOAST), and infarct volume were used to analyze the correlation of miRNA-34a-5p expression and clinical information. In addition, blood samples and brain tissues were collected from an established middle cerebral artery occlusion (MCAO) model consisting of 20 adult male mice at 24 h after the MCAO. Expression level of miRNA-34a-5p was detected by real-time polymerase chain reactions. RESULTS Results showed overexpression of miRNA-34a-5p in acute ischemic stroke patients blood samples compared to the controls (p<0.05). Also, large and small arterial strokes types demonstrated elevated miRNA-34a-5p expression levels. Further correlation analysis revealed a negative association between miRNA-34a-5p and NIHSS scores (r=-0.692 p<0.05) and infarct volume (r=-0.719, p<0.05). Moreover, in vivo experiment results showed significant up-regulated expression of miRNA-34a-5p in middle cerebral artery occlusion compared to controls, along with a positive correlation between miRNA-34a-5p in blood and brain (r=0.742, p<0.05). CONCLUSIONS Our results suggest there is a potential regulatory role of miRNA-34a-5p in acute ischemic stroke, which could serve as a therapeutic target or biomarker in stroke prognosis.