Inhibition of HDAC3 and ATXN3 by miR-25 prevents neuronal loss and ameliorates neurological recovery in cerebral stroke experimental rats.

HDAC3 plays important role in regulating memory and plasticity of neurons. We studied the role of miR-25 against HDAC3-induced neuronal injury in acute ischemic stroke. Subjects reported for acute stroke were included in the study. The rat model of middle cerebral artery occlusion was developed and received miR-25 agomir and antagomir treatments via intra-cerebroventricular injection. The brain tissues were processed and neuronal cells were isolated and submitted to oxygen glucose derivation-mediated injury. mRNA levels were studied by RT-PCR and protein levels by ELISA method. TUNEL and nuclear protein staining was done to find the ischemic area. Behavioral studies were carried out by Morris water maze test and beam balance test. Results suggested a significant increase in plasma miR-25 levels observed in acute ischemic stroke subjects. The levels of miR-25 were increased in the tissues of infarcted area of brain tissues of rats. However, the expression of miR-25 decreased in neuronal cells but increased in supernatant post-oxygen glucose deprivation. The treatment of miR-25 agomir decreased the infarct volume and apoptosis of neurons in MCAO rats, and it also improved the plasticity of neurons and axons, down-regulated ATXN3 and HDAC3 levels, and improved acetyl-H3K9 expression. In vitro outcomes suggested that miR-25 inhibited HDAC3 neurons and modulated the oxygen glucose deprivation injury in neurons. The treatment of RGFP966 increased the acetyl-H3K9 levels and prevented the miR-25 antagomir-induced injury. The study suggested miR-25 as an important predicting biomarker in acute ischemia injury. KEY POINTS: • HDAC3 is key regulator for neuronal health. • miR-25 was overexpressed in acute ischemic stroke condition. • miR-25 inhibits loss of neurons and provides neuronal recovery in animal model of stroke via inhibiting HDAC3 and ATXN3.