The role of Wnt1-Ngn2-En1/2 in the simazine-induced injury to the dopaminergic neurons in early life of mice
OBJECTIVE:To investigate the role of the Wnt1-Ngn2-En1/2 signaling pathway in the herbicide simazine-induced damage to the dopaminergic neurons in embryonic and weaned mice.METHODS:Fifteen female and fifteen male healthy SPF Kunming mice were kept in containers in a 2:1 ratio.During pregnancy,three groups of maternal mice were randomized:control group(0.3％methyl cellulose solution),low-dose group(50 µg/kg)and high-dose group(200 µg/kg).The tissues of the offspring on the day 8.5(E8.5),day 12.5(E12.5),and postnatal day 21(PND21)of development were obtained.mRNA and protein expression of the Wnt1-Ngn2-En1/2 signaling pathway-related genes(Wnt1,Ngn2,En1,En2,Nr4a2 and Th)were detected using immunofluorescence hybridization(FISH),real-time fluorescence quantitative PCR(qPCR)and Western blot.Through an open field experiment,effect of the treated pregnant mice on the autonomic behavior of PND21 female and male mice were identified.RESULTS:Western blot and qPCR data in E8.5 demonstrated that in comparison to the control group,low simazine-exposed groups had a decrease in the mRNA and protein expression of Wnt1 and Ngn2(P＜0.05),and the high-dose group had a substantial decline in the expressions of Wnt1,Ngn2,En1 and En2(P＜0.05).The results of E12.5 embryo show the mRNA and protein expression of Nr4a2 and Th in the low-dose group declined as compared with the control group,(P＜0.05),and the expression of Nr4a2,Th,Wnt1,Ngn2,En1 and En2 in high-dose group decreased significantly compared with that in control group(P＜0.05).The FISH data verified that Wnt1 mRNA expression was substantially reduced in the low-dose and high-dose sections of E8.5 and E12.5 as opposed to that of the control group(P＜0.05).The high-dose group of PND21 offspring exhibited significantly reduced motor and self-exploration abilities in comparison to the male offspring of the control group(P＜0.05),and there was a notable down-regulation of Wnt1 and Th protein expressions(P＜0.05).CONCLUSION:Simazine affected the development of dopaminergic neurons in male offspring through the Wnt1-Ngn2-En1/2 signaling pathway,and damaged the ability of independent behavior of male mice.
万方数据
维普
