人类白细胞抗原G的表观遗传学调控机制在子痫前期中的研究进展

子痫前期(PE)是引起围生期孕产妇和胎儿死亡的主要原因,但其具体的发病机制还未完全阐明,胎盘浅着床是目前子痫前期发病的一个重要理论。滋养细胞侵袭不足,螺旋动脉重铸障碍导致胎盘缺血缺氧是子痫前期发病的根本原因。人类白细胞抗原G(HLA-G)有维持母胎免疫耐受、促进滋养细胞侵袭功能,但子痫前期患者胎盘HLA-G表达明显下降。表观遗传学重点讨论DNA序列不变的情况下基因发生的可遗传性的改变,其中DNA甲基化、微小RNA、组蛋白修饰直接参与HLA-G表达调控。     

子痫前期PI3K/Akt通路相关非编码RNA的研究进展

子痫前期（pre-eclampsia）是妊娠期常见并发症之一,是导致孕产妇和围生儿死亡的重要原因。子痫前期的发生与胎盘滋养细胞功能障碍密切相关。胎盘滋养细胞侵袭不全和子宫螺旋动脉重铸异常是子痫前期发生的主要病理机制。磷脂酰肌醇3激酶/蛋白激酶B(phosphatidylinositol-3 kinase/protein kinase B,PI3K/Akt)通路对胎盘滋养细胞的增殖、存活、凋亡、迁移和侵袭等过程具有重要调节作用。非编码RNA(non-coding RNA,ncRNA)中的微小RNA、长链非编码RNA和环状RNA具有重要的多水平基因调控功能,在PI3K/Akt通路中发挥重要调节作用,影响胎盘滋养细胞的功能,与子痫前期的发生、发展相关。综述近年子痫前期PI3K/Akt通路相关ncRNA的研究进展,为探索和发现子痫前期发病机制中的关键分子提供参考。     

子痫前期发病机制研究进展

子痫前期是一种妊娠期特有疾病,滋养细胞对子宫螺旋动脉重塑障碍可能是子痫前期发病的根本原因,滋养细胞本身异常,以及滋养细胞与其所处微环境相互作用异常都可以导致滋养细胞重塑功能障碍;子痫前期临床表现是功能异常的胎盘释放到母体循环中的一些因子所引起,血管内皮生长因子1可溶性受体是最重要的子痫前期因子之一,有可能成为子痫前期早期诊断新指标.     

子痫前期发病机制研究进展

子痫前期是一种妊娠期特有疾病，滋养细胞对子宫螺旋动脉重塑障碍可能是子痫前期发病的根本原因，滋养细胞本身异常，以及滋养细胞与其所处微环境相互作用异常都可以导致滋养细胞重塑功能障碍：子痫前期临床表现是功能异常的胎盘释放到母体循环中的一些因子所引起，血管内皮生长因子1可溶性受体是最重要的子痫前期因子之一，有可能成为子痫前期早期诊断新指标。     

子痫前期胎盘学研究进展

子痫前期是一种妊娠期特有疾病,以高血压和蛋白尿为临床特征,可伴有全身多脏器损伤.由于其病因不明,除终止妊娠之外缺乏有效的临床治疗方法,始终是引起孕产妇死亡的主要原因之一.目前,子痫前期发病机制的"两阶段"理论已经得到普遍认同,即:第1阶段为胎盘形成的早期,滋养细胞对子宫内膜侵入过浅,子宫螺旋小动脉重铸障碍,导致胎盘"浅着床",是子痫前期发病的始动因素.     

子宫螺旋动脉重铸与病理妊娠

子宫螺旋动脉重铸是妊娠正常进行的关键环节,绒毛外滋养细胞的增殖和侵袭是血管重铸过程的必要条件。滋养细胞生物学功能的完整和调控机制的协调起着至关重要的作用。滋养细胞浸润不足,栓塞螺旋动脉不彻底,母-胎循环的发生提前,使绒毛受到直接的机械损伤,氧化应激作用间接地造成细胞机能障碍和损伤,出现胎盘退化变性;人肿瘤蛋白p53(TP53)介导细胞通路对细胞周期蛋白依赖性激酶抑制剂1A(CDKN1A)和Bax基因的异常表达,微小RNA-520(miR-520)过度调控滋养细胞的凋亡导致母体出现复发性流产。由滋养细胞分泌产生的基质金属蛋白酶9(MMP-9)的异常表达和大量炎性因子的释放造成了胎盘缺血缺氧,表现出子痫前期的相关症状。胎盘绒毛的血管密度、绒毛间隙体积的降低、滋养细胞分化程度下降、微环境缺氧以及突触缺陷因子1(SYDE1)呈低水平表达,可能是造成胎儿生长受限的重要原因。因此研究螺旋动脉重铸过程对病理妊娠的早期诊治有着重要意义。     

微粒调控中性粒细胞胞外诱捕网的表达在子痫前期发病中的作用研究进展

子痫前期是导致孕产妇和围生儿死亡的妊娠期特发性疾病之一,至今其具体发病机制尚未阐明。目前研究认为子痫前期发病主要与胎盘滋养细胞侵袭异常导致子宫螺旋小动脉重铸受阻、血管内皮细胞损伤、炎症免疫反应过度激活等有关。最新研究表明,微粒可导致子痫前期患者的全身炎症反应,并通过调节中性粒细胞胞外诱捕网的释放参与子痫前期的发病。同时相关研究显示,中性粒细胞活化并黏附到血管内皮细胞激发炎症反应是子痫前期患者血管内皮损伤的关键环节。当活化的中性粒细胞形成中性粒细胞胞外诱捕网过量或未被机体及时清除时,中性粒细胞胞外诱捕网附着于血管内皮上,引起内皮细胞凋亡,从而导致血管内皮细胞损伤。现对微粒调控中性粒细胞胞外诱捕网的释放在子痫前期发病中作用的研究进展进行综述。     

子宫螺旋动脉重铸障碍在复发性流产中的研究进展

复发性流产是一种常见的病理妊娠,其病因和发病机制至今尚未完全阐明。足够的子宫胎盘血供对于正常妊娠是至关重要的,这有赖于广泛的子宫螺旋动脉生理性重铸所形成高流量、低阻力的母胎血液循环系统。子宫螺旋动脉血流反映母胎之间的血液循环,是子宫与妊娠母体的终末分支,能提供充足的胎盘血流和养分,满足胚胎的生长发育。滋养细胞的侵袭及其介导的子宫螺旋动脉细胞的凋亡是重铸过程的两个关键环节,若重铸障碍则胎盘灌注量不足,继而胚胎缺血、缺氧,导致一系列病理妊娠。早期研究表明复发性流产患者蜕膜组织中滋养细胞侵袭减少,螺旋动脉重铸障碍,因此对复发性流产这一特征性病理改变产生的研究成为阐明病因的关键。     

蜕膜巨噬细胞与滋养细胞凋亡在子痫前期发病中的潜在作用

子痫前期是产科常见且严重的妊娠并发症，是导致围产儿及孕产妇死亡的重要原因[1]，其确切发病机制至今仍不清楚。其发病机制的假说很多，普遍认为胎盘在其发生与发展中起着重要作用[2]。滋养细胞的增殖、分化及凋亡是胎盘形成过程中必不可少的步骤[3]。蜕膜巨噬细胞作为清除凋亡成分的主要细胞[4]，若其功能异常，必将影响滋养细胞的增殖和分化，妨碍胎盘的形成，最终导致子痫前期的发生。现就蜕膜巨噬细胞和滋养细胞凋亡在子痫前期发病中的潜在作用进行综述。     

母胎界面免疫调节与子痫前期关系的研究进展

子痫前期是妊娠期特发性疾病,可累及全身各器官系统,严重威胁母儿健康,患者远期罹患心血管疾病、肾脏疾病等风险也显著增加,但病因及发病机制尚不明确,因而目前尚无有效的防治措施。现已明确,母胎界面免疫活性细胞及免疫分子的相互作用、免疫调节机制的异常可直接导致滋养细胞的浅着床、螺旋动脉重铸障碍,从而在子痫前期的发病机制中起着重要作用。     

Pathophysiology of placenta creta: the role of decidua and extravillous trophoblast

Placenta creta is associated with massive postpartum hemorrhage and commonly leads to emergency hysterectomy. While the exact pathogenesis of placenta creta is unknown, proposed hypotheses include a primary deficiency of decidua, abnormal maternal vascular remodeling, excessive trophoblastic invasion, or a combination thereof. To assess these changes in placenta creta, we retrospectively reviewed 49 cases of gravid hysterectomy, 38 with and 11 without the diagnosis of creta, gathered clinical data, and evaluated histopathology of extravillous trophoblast. Specifically, we evaluated maternal vessels for remodeling by endovascular trophoblast, as well as the morphology and depth of invasion of interstitial trophoblast at the implantation site. Compared to controls, cases with creta had decreased proportion of remodeled vessels, with many vessels displaying partial physiologic change. Cases with creta also demonstrated vascular remodeling deeper in the myometrium; however, vascular remodeling of large outer myometrial vessels was only demonstrated in increta and percreta cases, and was absent in both non-creta and accreta. As previously reported, interstitial trophoblast invaded the uterine wall to a significantly greater depth in placenta creta; however, there was no significant difference between creta subtypes. Finally, Ki-67 staining was rarely observed in extravillous trophoblast, except in the trophoblast columns of first trimester creta cases. We, therefore, conclude that the pathogenesis of placenta creta is multi-dimensional, involving increased, but incomplete trophoblast invasion in a background of absent decidua. We further propose that placenta increta and percreta are not due to a further invasion of extravillous trophoblast in the uterine wall, rather they likely arise secondary to dehiscence of a scar, leading to the presence of chorionic villi deep within the uterine wall, and thus give extravillous trophoblast greater access to the deep myometrium.     

Apoptosis and its role in the trophoblast

During early placentation the trophoblast of the human placenta differentiates to the villous and extravillous types of trophoblast. Villous trophoblast provides the epithelial cover of the placental villous trees in direct contact to maternal blood. Extravillous trophoblast invades maternal uterine tissues thus directly contacting maternal stromal and immune cells. A subset of extravillous trophoblast, endovascular trophoblast initially occludes the lumen of spiral arteries and comes into direct contact with maternal blood. In recent years apoptosis has been described in both types of trophoblast and the importance of this cascade for the normal function of the trophoblast has become obvious. One feature of serious conditions such as preeclampsia or intrauterine growth restriction is changes in apoptosis regulation in villous and/or extravillous trophoblast resulting in altered trophoblast invasion and/or shedding into the maternal circulation. This review summarizes recent findings on trophoblast apoptosis in normal and pathologic pregnancies.     

Präeklampsie, Pathogenese und Vorhersage

Preeclampsia is one of the most frequent pathologies in pregnancy and is accompanied by substantial morbidity and mortality for both mother and infant. The actual cause remains unknown but there is little doubt that the placenta plays a central role in the pathogenesis. The subtype with early manifestation of disease symptoms is closely linked to an intrinsic defect of trophoblasts. When this defect becomes apparent at an undifferentiated stage of trophoblast development the clinical picture of a combination of preeclampsia and intrauterine growth restriction appears. A defect that is manifested at a later stage may affect the villous or extravillous phenotype of trophoblasts and result in preeclampsia or isolated intrauterine growth restriction. The trophoblast defect may interfere with production of proteins. Serum levels of biomarkers in pregnant women in the first or early second trimester can be used for prediction of the disease. Biochemical markers combined with other biophysical parameters, such as blood pressure, Doppler indices of the blood flow in the uterine artery and clinical risk markers can be used to develop risk algorithms for an early stage prediction of the appearance of disease symptoms later in pregnancy. This opens up the promising possibility for an early intervention with preventive drugs. Preeclampsia with manifestation of the disease late in pregnancy develops in conditions with a large placental mass but fetal growth tends to be undisturbed and the overall prognosis is better than in the early onset type.     

Secretion of cytokines by villous cytotrophoblast and extravillous trophoblast in the first trimester of human pregnancy

Cytokines are proposed to play roles in regulation of trophoblast invasion, spiral artery remodeling and immunoregulation during early pregnancy. Secretion of 12 cytokines (interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p70, IL-13, IFNγ, GM-CSF, MCP-1 and RANTES) by first trimester extravillous trophoblast and villous cytotrophoblast cells was examined using multiplex cytokine array technology. Seven (IL-1β, IL-8, IL-12p70, IL-13, GM-CSF, MCP-1 and RANTES) of the 12 cytokines examined were detectable in the samples studied (n=10 each group). Villous cytotrophoblast production of IL-1β and IL-8 increased with gestational age. Extravillous trophoblast production of IL-8, IL-13 and RANTES increased with gestational age. At 12-14 weeks gestation extravillous trophoblast cells secreted higher levels of IL-8, IL-13 and RANTES than villous cytotrophoblast cells.     

Normal and abnormal transformation of the spiral arteries during pregnancy

This article reviews the anatomy and physiology of the uterine circulation, with emphasis on the remodeling of spiral arteries during normal pregnancy, and the timing and anatomical pathways of trophoblast invasion of the spiral arteries. We review the definitions of the placental bed and basal plate of the placenta, their relevance to the study of the physiologic transformation of the spiral arteries, as well as the methods to obtain and examine placental bed biopsy specimens. We also examine the role of the extravillous trophoblast in normal and abnormal pregnancies, and the criteria used to diagnose failure of physiologic transformation of the spiral arteries. Finally, we comment on the use of uterine artery Doppler velocimetry as a surrogate marker of chronic uteroplacental ischemia.     

Expression Patterns of Two Serine Protease HtrA1 Forms in Human Placentas Complicated by Preeclampsia with and without Intrauterine Growth Restriction

Preeclampsia (PE) and intrauterine growth restriction (IUGR) are pregnancy-specific disorders that have in common abnormal placental implantation, a marked proliferation of villous cytotrophoblastic cells and focal necrosis of the syncytiotrophoblast. Several studies show an ischemic placenta with a high-resistance vasculature, which cannot deliver an adequate blood supply to the feto-placental unit. The cause of PE is a matter of debate, but recently studies in mice suggest that the primary feto-placental lesions are sufficient to initiate the disease.HtrA1, a member of the family of HtrA proteins, is a secreted multidomain protein with serine protease activity. It is expressed in first and third trimester of gestation. In specimens from the first trimester of gestation, immunostaining for HtrA1 is generally found in both layers of villous trophoblast, syncytiotrophoblast and cytotrophoblast. Cytoplasm of extravillous trophoblast and extracellular matrix of cell islands and cell columns are labeled for HtrA1. Specimens from third trimester of gestation show a more intense positivity for HtrA1 in the syncytiotrophoblast than in cytotrophoblast. The extravillous trophoblast and the decidual cells, is positive for HtrA1. The purpose of this study is to investigate the expression pattern of HtrA1 in placentas from PE without IUGR (maternal PE) and with IUGR (fetal PE) by quantitative western blotting and immunohistochemistry. By quantitative western blotting analysis we observed a significant upregulation of ～30 kDa HtrA1 form in PE. Differently, we detected a significant total HtrA1 down-regulation in PE–IUGR. Moreover, immunostaining for HtrA1 was positive in the villous trophoblast, in the syncytial knots and irregularly in the fetal vessel walls in PE placentas while immunostaining for HtrA1was present particularly in the syncytial knots in PE–IUGR placentas. In conclusion, we suggest that the ～30 kDa HtrA1 form can be correlated to maternal PE while that the significant down-regulation of total HtrA1 can be correlated to placental PE. These HtrA1 alterations could be considered as possible markers to discriminate placental PE from maternal PE.     

Evolution of invasive placentation with special reference to non-human primates

It is now possible to view human placentation in an evolutionary context because advances in molecular phylogenetics provide a reliable scenario for the evolution of mammals. Perhaps the most striking finding is the uniqueness of human placenta. The lower primates have non-invasive placentae and even tarsiers and New World monkeys show restricted trophoblast invasion. Moreover, a truly villous placenta occurs only in Old World monkeys and great apes. The two latter groups of haplorhine primates show varying degrees of trophoblast-uterine interaction, including differences in?the extent of decidualization, formation and disintegration of a cytotrophoblastic shell, degree of interstitial trophoblast invasion and depth of trophoblast invasion into spiral arteries. Recently, the occurrence of human-like deep invasion was confirmed in gorillas and chimpanzees. As the still enigmatic disease of pre-eclampsia also occurs in these species, such information may reveal the evolutionary roots of this disease of impaired maternal-fetal interaction.     

Osteopontin expression in gestational trophoblastic diseases: correlation with expression of the adhesion molecule, CEACAM1.

The human placenta is a complex tissue with multiple endocrine and nutritional functions and a unique capacity for rapid proliferation but tightly controlled invasion, differentiating it from malignant tumors. Osteopontin (OPN) is a glycoprotein of the extracellular matrix, which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. OPN also could be implicated in regulating implantation and placentation by promoting cellular migration and invasion in a placenta-specific fashion. We could demonstrate the expression pattern of OPN in the normal human placenta in which it is localized in the extravillous (intermediate) trophoblast and the villous cytotrophoblast. CEACAM1 is an adhesion molecule, which we have recently found to be expressed at the maternal-fetal interface of the normal placenta with a localization to the extravillous (invasive) trophoblast and in gestational trophoblastic disease (GTD) and also to be potentially implicated in trophoblast invasion and tumorigenesis. Both OPN and CEACAM1 have been shown to interact with integrin beta3. The purpose of this study was to investigate the expression pattern of OPN in GTD and to correlate it with the expression of CEACAM1. To analyze the expression of OPN, we performed immunohistochemistry on a total of 27 cases of GTD, including 21 hydatidiform moles and 6 choriocarcinomas, which had previously been characterized with respect to their CEACAM1 expression. Hydatidiform moles showed a positivity for OPN in villous cytotrophoblast and in the trophoblast proliferations on the villous surface. The strongest OPN expression could be observed in the choriocarcinomas with a heterogenous OPN expression pattern. CEACAM1 had shown similar results and was found to be expressed in choriocarcinoma. The expression pattern of osteopontin in gestational trophoblastic diseases indicates that it might play a role in the pathogenesis of GTD (possibly as a functional complex with CEACAM1 and integrin beta3) and might be useful as an additional diagnostic marker for such lesions.     

Implantation and extravillous trophoblast invasion: From rare archival specimens to modern biobanking

Extravillous trophoblast invasion serves to attach the placenta to the uterus and to enable access to nutrients for the embryo throughout pregnancy – secretions of the uterine glands in the first trimester, maternal blood in the second and third trimester. For assessing extravillous trophoblast invasion, histology (in combination with immunohistochemistry) still plays a major role in placental research. This is especially true for the re-assessment of rare archival specimens from early human implantation sites or placenta in utero with the background of recent knowledge which may help to strengthen current hypotheses. This review summarizes the recently expanded picture of extravillous trophoblast invasion, gives an overview about fundamental archival specimens in placental research, presents new images of archival specimens, gives insights into the latest developments in the field of biobanking and provides insight into the current situation on sample usage in the absence of biobanks. Modern techniques allow expanding our hitherto believed concept of extravillous trophoblast invasion, which is not restricted to spiral arteries: Extravillous trophoblasts also invade into uterine glands and uterine veins and thereby connect all these luminal structures with the intervillous space. All biomedical research dramatically depends on the quality of the assessed biological samples. Hence, researchers should be aware that the time between collection of a sample from a body and the beginning of analysis (pre-analytical phase) may have more impact on the outcome of a study than previously assumed.