TGF-β1改善体外培养小鼠胚胎种植率及其作用机制的研究

Effect of TGF-β1 on Embryo Implantation and Development in Mice in vitro

目的探讨TGF-β1在体外对小鼠胚胎发育及胚胎种植的影响及其作用机制。方法①收集小鼠2-细胞期胚胎,在含不同剂量TGF-β1的M16培养液中进行体外培养,观察胚胎发育情况,并进行胚胎移植,观察着床率;②测定移植后小鼠外周血及胚胎种植部位母胎界面IL-10/INF-γ水平。结果①1 ng/mL和10 ng/mLTGF-β1能提高2-细胞期胚胎体外发育速率、质量和胚胎着床率。其中TGF-β1 10 ng/mL时作用最显著,TGF-β1浓度过高对体外胚胎发育不利;②M16+TGF-β1 10 ng/mL组体外培养囊胚移植后母胎界面INF-γ低于M16组,差异有统计学意义〔(30.89±11.31)pg/mL vs.(43.23±18.09)pg/mL,P<0.05〕。两组间IL-10水平无明显差异。结论①小鼠胚胎体外培养基中加入适宜浓度TGF-β1可提高2-细胞期胚胎体外发育速率、质量和胚胎着床率;②TGF-β1可能通过促进体外胚胎发育速率和质量,改善胚胎和内膜发育同步性,促进母胎界面Th1/Th2平衡向Th2偏移而促进胚胎着床。

Objective To investigate the role of TGF-β1 in embryo implantation and development in vitro in mice.Methods Mouse embryos at 2-cell stage were cultured in the media of M16 with exposure to different levels of TGF-β1（0,1,10 and 50 ng/mL）.The percentage of embryos reaching fixed stages（early blastocyst,expanding blastocyst and hatched blastocyst） was monitored 68 h and 92 h after the culture.The expanding blastocys cultured for 68 h in M16 without TGF-β1 and those with 10 ng/mL of TGF-β1 were transferred to pseudopregnant mice.On the 6^th day post transfer,the successful rates of implantation were counted.The level of IL-10/IFN-γ in the serum and maternal-fetus interface of the mice was detected by ELISA on the 6^th day post transfer.Results TGF-β1 improved embryo growth in vitro.TGF-β1 at a level of 10 ng/mL had the maximum impact,with 15.6%,68.09%,1.42% of embryos reaching early,expanding,and hatched stage,respectively,68 h after culture,and 6.38%,28.37%,53.19% of embryos reaching early,expanding,and hatched stage,respectively,92 h after culture.The promoting effect declined when TGF-β1 reached 50 ng/mL.The successful rate of implantation of embryos cultured in M16 with TGF-β1 was significantly higher than those cultured in M16 without TGF-β1（35.42% vs.17.19%,P0.05）.The embryos cultured in M16 with TGF-β1 had significantly lower level of IFN-γ in the maternal-fetus interface than those cultured in M16 without TGF-β1（（30.89±11.31） pg/mL vs.（43.23±18.09） pg/mL,P0.05）.Conclusion TGFβ1 at an appropriate dose improves embryo implantation in mice in vitro.The mechanism may involve the improvement of the quality of embryos and their development,and decrease of IFN-γ synthesis in maternal-fetal interface,a chemical that could cause Th2 bias.