小鼠孕早期暴露量子点对妊娠结局和CD4+ CD25+ Treg细胞的影响

Effects of quantum dots on pregnancy outcomes and CD4+ CD25+ regulatory T cells in early pregnant mice

摘要:

目的  探讨小鼠孕早期暴露硫化锌量子点（QDs）对妊娠结局和外周血CD4+ CD25+ Treg细胞的影响。方法  制备成年健康孕鼠并将其随机分为高剂量QDs组、低剂量QDs组和对照组，分别于妊娠第3～5天尾静脉注射0.50和0.05μmol/L QDs，以及生理盐水各100μl，于妊娠第15天观察妊娠结局，并采用流式细胞术分析孕鼠外周血CD4+ CD25+ Treg细胞比例。结果  QDs可引起流产、吸收胎和死胎等不良妊娠结局，高剂量QDs使胚胎平均着床数、胎鼠均重及胎盘均重低于对照组，差异有统计学意义（P <0.05）；且QDs暴露孕鼠外周血CD4+ CD25+ Treg细胞的比例低于对照组，差异有统计学意义（P <0.05）。结论  小鼠孕早期暴露QDs具有胚胎毒性，且其毒性机制可能与降低外周血中CD4+ CD25+ Treg细胞比例、扰乱妊娠免疫耐受有关。

Abstract:

Objective To investigate the effects of quantum dots(QDs) on pregnancy outcomes and CD4+ CD25+ regulatory T cells in early pregnant mice. Methods The pregnant mice were randomly divided into three groups (QDs high-dose exposure group treated with 0.5 μmol/L QDs, 100 μl/mice per day; low-dose exposure group treated with 0.05 μmol/L QDs, 100 ul/mice per day; and normal saline group treated with 0.9% NS, 100 μl/mice per day). Solutions of the different treatment materials were administered by tail vein injection on the 3rd-5th GD. The pregnant outcomes were observed and CD4+ CD25+ regulatory T cells in the peripheral blood were detected by flow cytometry on the 15th GD. Results In the QDs exposure groups, the pregnant mice showed abnormal pregnancy outcomes (abortion, stillbirth and fetal absorption). The avrage number of embryo implantation, offspring's body weight and placental weight in the high-dose exposure group were significantly lower than those of the control group (P < 0.05). The proportion of CD4+ CD25+ regulatory T cells in CD4+ T cells in the QDs groups was significantly lower than that of the control group (P < 0.05). Conclusions The exposure of pregnant mice to QDs during early pregnancy is harmful to embryos. One of the toxicity mechanisms may be related to the decrease of CD4+ CD25+ regulatory T cells in the peripheral blood.