Expression Levels of miRNA132 in Depression Patients and Chronic Unpredictable Mild Stress Rats

Objective To investigate the expression levels of miRNA132 in patients with the first-episode major depressive disorder(MDD) and in chronic unpredictable mild stress(CUMS)rats.Methods Forty-one first-episode MDD patients(MDD group)were recruited from the outpatient departments of Hangzhou Seventh People's Hospital between March 2017 and May 2018,and 31 healthy volunteers(control group)were recruited.The patients' severity of symptoms was assessed with HAMD17.In addition,24 male SD rats were equally assigned into control group and CUMS group.The depression-like behaviors of rats was detected by sucrose preference test and forced swimming test.Plasma corticosterone levels of rats were assayed by ELISA.The expression levels of miRNA132 in the blood or prefrontal cortex were detected by quantitative real-time PCR.Results The expression level of miRNA132 in peripheral blood was significantly higher in MDD group(2.37±0.36)than in control group(1.34±0.16)(t=2.355,P=0.0213),and there was a positive correlation between miRNA132 levels and the HAMD17 score in MDD group(P=0.0004,rs=0.5303,n=41).The immobility time of CUMS group [(72.67±2.95)s] was significantly longer than that of control group [(40.00±5.49)s] in forced swim test(t=2.366,P=0.0395).The sucrose intake of CUMS group [(55.67±6.42)%] was significantly lower than that of control group [(98.21±1.28)%] in sucrose preference test(t=6.502,P<0.0001).The plasma corticosterone level in CUMS group [(1396.0±254.9)nmol/L] was significantly higher than that of control group [(557.3±158.4)nmol/L](t=2.795,P=0.0190).The miRNA132 levels in blood(2.32±0.88)and prefrontal cortex(2.80±0.76)of CUMS rats were significantly higher than those [1.18±0.36(t=2.273,P=0.0463)and 0.99±0.23(t=2.553,P=0.0287),respectively] of control group.Conclusions The expression trend of miRNA132 in peripheral blood is consistent between MDD patients and CUMS rats.In CUMS rats,the expression of miRNA132 in blood is also consistent with that in prefrontal cortex.The expression of miRNA132 in blood may reflect the change trend of miRNA132 expression in prefrontal cortex.