Abstract: Objective To investigate the expression of m⁶A methyltransferase-like protein 14(METTL14) in the hippocampus of depression-like mice, and to provide a theoretical basis for further study of the molecular mechanism of depression and new drug targets. Methods 1)Twenty-four male C57BL/6J mice were divided into control group and depression model group. The control group was fed normally, and the model group was kept in single animal cage for 4 months and added with Chronic Unpredictable Animal Stress (CUMS) to establish the depression-like model. 2)After modeling, depression-like behaviors in model group were tested using forced swimming test (FST), sucrose preference test (SPT)and tail suspension test (TST).3)Twenty-four hours after completion of behavioral test, the hippocampus tissues of mice were collected, and the expression of m⁶A methyltransferase-like protein METTL14 in the hippocampus of mice was detected by molecular biology experiments. Results 1)The mice in the model group showed significant depression-like behavior; 2)The expression of METTL14 in the hippocampus of the model group showed an increased mRNA expression with the increased m⁶A modification. 3)In the model group, the expression of METTL14 in hippocampal CA1, CA3 and DG districts increased and there was neuronal damage found. Conclusions m⁶A methylation function has been proved to be more active in the hippocampus of depressed mice.

Key words: N6-methyladenosine, methyltransferase-like protein 14(METTL14), depression disorder, RNA modification