Chapters authored
A Novel Concept of Fundus-Ovary-Salpinx-Para-Aorta Implantation Promoting Unit during Human Embryo Implantation
Human embryo implantation is mainly regulated by the endocrine system. Since the ovary, fallopian tube, and fundus can directly communicate through the mesosalpinx and ovarian ligament, the local concentration of progesterone in the pathway of the developing embryo is considered to be higher than in systemic blood circulation. The immune system promotes embryo implantation by stimulating progesterone production of the ovary and by inducing endometrial differentiation. The recognition of the developing embryo in the fallopian tube by the immune system is achieved through the para-aortic lymph nodes. On the basis of the above evidence, the autologous immune cells activated in vitro were demonstrated to improve clinical pregnancy rates in patients with repeated implantation failures. In addition, the autonomic nerve system that innervates the fundus, the ovary, and the fallopian tube from the para-aortic region is proposed to regulate the environment of the pathway of the developing embryo. From these findings, we suppose that a unique unilateral functional unit to promote human embryo implantation exists in the pathway of the developing embryo including the para-aortic regions and propose naming this novel functional unit the Fundus-Ovary-Salpinx-Para-aorta Implantation Promoting unit (FOSPa-IP unit).
Part of the book: New Discoveries in Embryology
The Role of Autophagy in Maintaining Pregnancy
Autophagy is an evolutionarily conserved process in eukaryotes by which cytoplasmic cargo sequestered inside double-membrane vesicles is delivered to the lysosome for degradation. In early pregnancy, trophoblasts and the fetus experience hypoxic and low-nutrient conditions; nevertheless, extravillous trophoblasts (EVTs) invade the uterine myometrium up to one-third of its depth and migrate along the lumina of spiral arterioles, replacing the maternal endothelial lining. An enhancement of autophagy induced by physiological hypoxia takes part in the invasion and vascular remodeling in EVTs. On the other hand, soluble endoglin, which increased in sera in preeclamptic cases, suppresses EVT-invasion or -vascular remodeling by inhibiting autophagy In vitro. In addition, a substance selectively degraded by autophagy, p62/SQSTM1, accumulates in EVT cells in preeclamptic placental biopsy samples showing impaired autophagy in vivo. Thus, alternation of autophagy could affect fates of mothers and babies. Recently increasing evidence of modulating autophagy has accumulated during pregnancy. In this chapter, we introduce the role of autophagy in embryogenesis, implantation, and maintaining pregnancy.
Part of the book: Autophagy in Current Trends in Cellular Physiology and Pathology