Role of microRNAs in major brain diseases, focusing on neuroinflammation and neuronal apoptosis.

MicroRNAs are non-coding small RNA molecules that play a significant role in regulating gene expression. Increasing lines of evidence have highlighted the microRNA dysregulation and neuroinflammation-associated apoptosis in common brain diseases, including Parkinson's disease, Alzheimer's disease, epilepsy, traumatic brain injury, depression, and migraine. In fact, microRNAs regulate multiple physiological and pathological processes, thus implicating them in both health and disease. Though studies have suggested that the alterations or modifications in microRNA-associated regulatory pathways might contribute to the disease pathogenesis, the underlying molecular mechanisms and the targeted genes remain exclusively unknown. We hope that the idea of using microRNAs as therapeutic targets for brain disorders is not far from reality, but important issues must be addressed before moving into clinical practice. The aim of this review is to enlighten the molecular mechanisms and targeted genes of microRNA implicated in the multifaceted brain disorders. Moreover, several microRNAs have been reported to be up-regulated following disease, but their targeted pathways have not been elucidated yet. This review also highlighted microRNAs that are expected to warrant further exploration of their mechanism of action. This comprehensive overview of the prediction of microRNAs' functions might be helpful in providing more efficient insight for the development of microRNA-based therapeutic interventions for neuropsychiatric and neurodegenerative diseases.