MiR-128-3p activates autophagy in rat brain cells after focal cerebral ischemia reperfusion through targeting Atg1

Autophagy is reported to be beneficial for functional recovery in rats after CIR. Increasing evidence suggests that microRNAs are widely involved in rat brains of CIR model. Rat CIR models were established using middle cerebral artery occlusion (MCAO). To evaluate whether the models were successfully established, neurological function score, TTC staining and the water contents were determined. Electron microscopy was applied to explore the presence of autophagosomes. The expression of autophagy-related proteins was determined using Western blot. TargetScan program was used to predict the potential miRs that bind the 3'untranslated region of Atg1. RT-PCR and luciferase assay was applied to explore the level of miRs and the relative luciferase units. The CIR rat models were successfully established through neurological function score, TTC staining and the water contents analysis. Authophagosomes were significantly increased in rat brains of CIR models. Furthermore, the expression of Atg1/pULK1 and LC3II was significantly enhanced in rat brains of CIR models. More importantly, only miR-128-3p was found to be significantly decreased in rat brains of CIR models. Luciferase assay revealed that Atg1 was a target gene of miR-128-3p. To conclude, reduction of miR-128-3p expression contributed to brain cell autophagy mainly by targeting Atg1 after CIR.