Overexpression of miR-132-3p contributes to neuronal protection in in vitro and in vivo models of Alzheimer's disease.

One of the neuropathological hallmarks of Alzheimer's disease (AD) is accumulation and deposition of amyloid-beta (Aβ1-42) plaques in the hippocampus. Recently, microRNAs (miRNAs), have been demonstrated to play an essential role in AD. We have previously demonstrated that miR-132-3p exerts neuroprotection via regulating histone deacetylase 3 (HDAC3) in a mouse model of AD. In the present study, we further unveiled neuroprotective roles of miR-132-3p in transgenic amyloid precursor protein/presenilin 1 (APP/PS1) mice compared with those in age-matched wild-type C57BL/6 mice. Lentiviral-mediated inhibition or overexpression of miR-132-3p in the hippocampus of APP/PS1 mice was used to explore the contributions of hippocampal miR-132-3p in spatial memory, amyloid burden, apoptosis, and the number of hippocampal cells in a mouse model of AD. Overexpression of hippocampal miR-132-3p ameliorated spatial memory deficits in the Morris water maze, reduced both Aβ1-42 accumulation and apoptosis, and promoted the numbers of hippocampal cells in the brains of APP/PS1 mice. Furthermore, trichostatin A (TSA) promoted the expression of miR-132-3p in Aβ1-42-burdened neurons while increasing the expression levels of synaptic proteins. Taken together, our results suggest that miR-132-3p may represent a promising therapeutic target for the treatment of AD.