Ketamine enhances dopamine D1 receptor expression by modulating microRNAs in a ketamine-induced schizophrenia-like mouse model.

The abnormal expression of the dopamine D1 receptor (DRD1) may be associated with schizophrenia. MicroRNAs (miRNAs) can post-transcriptionally regulate DRD1 expression. Here, we established a ketamine-induced schizophrenia-like behavior mouse model and investigated the changes in miR-15a-3p, miR-15b-3p, miR-16-1-3p, and DRD1 in response to ketamine. Administration of high-dose ketamine for seven consecutive days to mice simulated the main symptoms of schizophrenia. The mice exhibited increasing excitability and autonomous activity and reduced learning and memory, including spatial memory. Moreover, ketamine decreased miR-15a-3p, miR-15b-3p, and miR-16-1-3p expression levels in the prefrontal cortex (PFC) and miR-16-1-3p expression in the hippocampus, whereas DRD1 expression increased in these brain regions. In HT22 mouse hippocampal neuronal cells, ketamine induced a dose-dependent increase of endogenous DRD1, which was partially attenuated by a combination of miR-15b-3p and miR-16-1-3p mimics. Indeed, the miR-15b-3p and miR-16-1-3p mimics could significantly inhibit endogenous DRD1expression. We identified +72 to +78 bp (TGCTGCT) of the DRD1 3'UTR as the core regulatory region recognized by the target miRNAs. In summary, we developed a ketamine-induced schizophrenia-like behavior mouse model and found that ketamine inhibited the levels of miR-15a-3p, miR-15b-3p, miR-16-1-3p and increased DRD1 expression in mice.