Analysis of crosstalk between embryo and mother through circulation system

人绒毛膜促性腺激素(HCG)由胚胎分泌，通过刺激妊娠黄体产生孕酮，维持子宫内膜的分化，在胚胎着床过程中发挥重要作用。这些事实表明，胚胎与母亲生殖器官之间通过血液循环系统的相互作用是成功妊娠的基本现象。另一方面，也有人指出，仅用人绒毛膜促性腺激素很难解释串扰的整个调节机制。然而，目前还没有其他的可溶性因素来调节胚胎和母亲之间的这种系统性串扰，特别是在怀孕早期。基于这些背景，我们进一步发现，外周血单个核细胞(PBMC)可能参与了串扰机制。孕妇PBMC促进黄体细胞孕酮生成及影响子宫内膜细胞分化以促进胚胎着床。此外，PBMC还可以在母体蜕膜中诱导绒毛外滋养细胞。这些发现提供了一个新的概念，即人类胚胎植入不仅受到内分泌的协同调节，还受到免疫系统的协同调节，有助于生殖医学的发展。

It has been generally accepted that human chorionic gonadotropin (hCG), which is secreted from embryo, plays an important role in establishment of embryo implantation by stimulating progesterone production from corpus luteum of pregnancy and maintaining subsequent endometrial differentiation. These facts indicate that the interaction between embryo and mother reproductive organs through blood circulation system is essential phenomenon for successful pregnancy. On the other hand, it has been pointed out that it is difficult to explain the whole regulation of crosstalk mechanism only by hCG. However, no other soluble factors have been proposed to mediate this systemic crosstalk between embryo and mother especially during early pregnancy.Based on these backgrounds, we further found that peripheral blood mononuclear cells (PBMC) could participate in the crosstalk mechanisms. PBMC in the pregnant women enhanced progesterone production by luteal cells and influence on differentiation of endometrial cells to facilitate embryo implantation. Furthermore, PBMC have been demonstrated to induce extravillous trophoblasts in the maternal deciduas.These findings provided a novel concept that human embryo implantation is co-operatively regulated by not only endocrine but also immune systems, contributing to reproductive medicine.