Diverse and Composite Roles of miRNA in Non-Neuronal Cells and Neuronal Synapses in Alzheimer’s Disease

Neurons interact with astrocytes, microglia, and vascular cells. These interactions become unbalanced in disease states, resulting in damage to neurons and synapses, and contributing to cognitive impairment. Importantly, synaptic loss and synaptic dysfunction have been considered for years as a main pathological factor of cognitive impairment in Alzheimer’s disease (AD). Recently, miRNAs have emerged as essential regulators of physiological and pathological processes in the brain. Focusing on the role of miRNAs in regulating synaptic functions, as well as different cell types in the brain, offers opportunities for the early prevention, diagnosis, and potential treatment of AD-related cognitive impairment. Here, we review the recent research conducted on miRNAs regulating astrocytes, microglia, cerebrovasculature, and synaptic functions in the context of AD-related cognitive impairment. We also review potential miRNA-related biomarkers and therapeutics, as well as emerging imaging technologies relevant for AD research.