Sleep Deprivation Increased Dopamine D2 Receptor Expression through Downregulation of miR-9

Sleep-wake cycle is a complex process relates to a variety of neurotransmitters and receptors in the central nervous system (CNS), also involves a large number of gene transcription and translation. MicroRNAs (miRNAs) have emerged as important regulators of gene expression, which mediate translational repression and/or mRNA decay of a target gene. Dopamine D2 receptor (DRD2) gene is predicted as a target gene of a brain-enriched miRNA, miR-9, but their functions in sleep-wake cycle remain unknown. In this study, we reported that REM sleep deprivation decreases the level of miR-9 and this induction is associated with the expression of DRD2 proteins. Thus, miR-9 may control DRD2 gene translation in the prefrontal cortex for processing sleep deprivation. Our findings may have implications in understanding the biological relevance of the genetic associations of sleep disorders. Furthermore, miR-9 may be considered as potential drug targets for the treatment of disorders involving abnormal DRD2 function, such as insomnia.