Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
EGA Institute for Women's Health, Faculty of Population Health Sciences, University College London, London, UK.
Proc Biol Sci. 2023 Apr 26;290(1997):20230191. doi: 10.1098/rspb.2023.0191. Epub 2023 Apr 19.
The placenta has evolved to support the development of the embryo and fetus during the different intrauterine periods of life. By necessity, its development must precede that of the embryo. There is now evidence that during embryogenesis and organogenesis, the development of the human placenta is supported by histotrophic nutrition secreted from endometrial glands rather than maternal blood. These secretions provide a plentiful supply of glucose, lipids, glycoproteins and growth factors that stimulate rapid proliferation and differentiation of the villous trophoblast. Furthermore, evidence from endometrial gland organoids indicates that expression and secretion of these products are upregulated following sequential exposure to oestrogen, progesterone and trophoblastic and decidual hormones, in particular prolactin. Hence, a feed-forward signalling dialogue is proposed among the trophoblast, decidua and glands that enables the placenta to stimulate its own development, independent of that of the embryo. Many common complications of pregnancy represent a spectrum of disorders associated with deficient trophoblast proliferation. Increasing evidence suggests that this spectrum is mirrored by one of impaired decidualization, potentially compromising histotroph secretion through diminished prolactin secretion and reduced gland function. Optimizing endometrial wellbeing prior to conception may therefore help to prevent common pregnancy complications, such as miscarriage, growth restriction and pre-eclampsia.
胎盘在胚胎和胎儿的不同宫内发育期进化以支持其发育。因此，其发育必须先于胚胎。现在有证据表明，在胚胎发生和器官发生过程中，人胎盘的发育依赖于子宫内膜腺体分泌的组织营养，而不是母体血液。这些分泌物提供了大量的葡萄糖、脂质、糖蛋白和生长因子，刺激绒毛滋养层的快速增殖和分化。此外，来自子宫内膜腺类器官的证据表明，这些产物的表达和分泌在依次暴露于雌激素、孕激素和滋养层和蜕膜激素，特别是催乳素后被上调。因此，滋养层、蜕膜和腺体之间提出了一种正反馈信号对话，使胎盘能够在不依赖胚胎发育的情况下刺激自身的发育。妊娠的许多常见并发症代表了与滋养层增殖不足相关的一系列疾病。越来越多的证据表明，这种谱系与蜕膜化不足相匹配，可能通过催乳素分泌减少和腺体功能降低而损害组织营养分泌。因此，在受孕前优化子宫内膜健康状况可能有助于预防常见的妊娠并发症，如流产、生长受限和子痫前期。
