Generation and characterization of human Fetal membrane and Decidual cell lines for reproductive biology experiments

Human fetal membrane and maternal decidua parietalis form one of the major feto-maternal interfaces during pregnancy. Studies on this feto-maternal interface is limited as several investigators have limited access to the placenta, and experience difficulties to isolate and maintain primary cells. Many cell lines that are currently available do not have the characteristics or properties of their primary cells of origin. Therefore, we created, characterized the immortalized cells from primary isolates from fetal membrane-derived amnion epithelial cells, amnion and chorion mesenchymal cells, chorion trophoblast cells and maternal decidua parietalis cells. Primary cells were isolated from a healthy full-term, not in labor placenta. Primary cells were immortalized using either a HPV16E6E7 retroviral or a SV40T lentiviral system. The immortalized cells were characterized for the morphology, cell type-specific markers, and cell signalling pathway activation. Genomic stability of these cells was tested using RNA seq, karyotyping, and short tandem repeats DNA analysis. Immortalized cells show their characteristic morphology, and express respective epithelial, mesenchymal and decidual markers similar to that of primary cells. Gene expression of immortalized and primary cells were highly correlated (R = 0.798 to R = 0.974). Short tandem repeats DNA analysis showed in the late passage number (>P30) of cell lines matched 84-100% to the early passage number (<P10) of the cell lines revealing there were no genetic drift over the passages. Karyotyping also revealed no chromosomal anomalies. Creation of these cell lines can standardize experimental approaches, eliminate subject to subject variabilities, and benefit the reproductive biological studies on pregnancies by using these cells.

Innate immune signaling in trophoblast and decidua organoids defines differential antiviral defenses at the maternal-fetal interface

Infections at the maternal-fetal interface can directly harm the developing fetus and compromise the health of the pregnant woman. Innate immune signaling by both fetal-derived placental trophoblasts and the maternal decidua must provide antimicrobial defenses at this critical interface without compromising its integrity. Here, we developed trophoblast and decidua organoids from matched human placentas to define their relative contributions to innate immune defenses at the maternal-fetal interface. We show that trophoblast and decidua organoids recapitulate some, but not all, of the basal cytokine release observed in matched tissue explants. We further show that trophoblast, but not decidua, organoids constitutively release antiviral type III interferons (IFNs) and that fetal and maternal organoids differentially respond to viral infections through the induction of organoid-specific cytokines. These findings define key differences in innate immune signaling generated by fetal-derived trophoblasts and the maternal decidua, which together must protect the fetus from viral infections.

Placenta Accreta: A Review of the Etiology, Diagnosis, and Management

ABSTRACT The incidence of placenta accreta is rising, primarily due to the increase in cesarean section rates. The prenatal diagnosis of placenta accretas has been shown to decrease the amount of blood loss and complications. Real-time ultrasound is helpful for diagnosing placenta accreta, and magnetic resonance imaging (MRI) can increase the sensitivity of prenatal diagnosis. Postpartum hysterectomy for placenta accreta has been the standard of therapy for placenta accreta, but conservative management including uterine artery embolization, and leaving the placenta in situ may be considered in patients who want to preserve their fertility. The etiology of placenta accreta is due to a deficiency of maternal decidua, resulting in placenta invasion into the uterine myometrium. The molecular basis is yet to be elucidated, but it probably involves abnormal paracrine or autocrine signaling between the deficient maternal decidua and the invading placenta trophoblastic tissue. How to cite this article Goh W, Zalud I. Placenta Accreta: A Review of the Etiology, Diagnosis, and Management. Donald School J Ultrasound Obstet Gynecol 2016;10(3):352-363.

C19MC MicroRNAs Regulate the Migration of Human Trophoblasts

Early in pregnancy, trophoblast invasion into the decidua and inner myometrium is essential for establishment of proper implantation, maternal-fetal exchange, and immunological tolerance of the feto-placental allograft. Unlike villous trophoblasts (VTs), extravillous trophoblasts (EVTs) are unique in their capacity to invade the maternal decidua and myometrium. The largest human microRNA (miRNA) gene cluster, the chromosome 19 miRNA cluster (C19MC), is expressed almost exclusively in the placenta and, rarely, in certain tumors and undifferentiated cells. In the work reported here, we found that the expression of C19MC miRNAs is higher in VTs than in EVTs. Using a bacterial artificial chromosome (BAC)-mediated overexpression of C19MC miRNAs in an EVT-derived cell line, which does not naturally express these miRNAs, we found that C19MC miRNAs selectively attenuate cell migration without affecting cell proliferation or apoptosis. A microarray analysis revealed that C19MC miRNAs regulate target transcripts related to cellular movement. Our data also implicated a specific C19MC member, miR-519d, indirectly regulating the EVT invasive phenotype by targeting CXCL6, NR4A2 and FOXL2 transcripts through a 3′UTR miRNA-responsive element. Together, our data suggest a role for C19MC miRNAs in modulating the migration of EVTs.

Noninvasive and Quantitative Assessment ofIn VivoFetomaternal Interface Angiogenesis Using RGD-Based Fluorescence

Angiogenesis is a key process for proper placental development and for the success of pregnancy. Although numerousin vitromethods have been developed for the assessment of this process, relatively few reliablein vivomethods are available to evaluate this activity throughout gestation. Here we report anin vivotechnique that specifically measures placental neovascularization. The technique is based on the measurement of a fluorescent alphavbeta 3 (αvβ3) integrin-targeting molecule called Angiolone-Alexa-Fluor 700. Theαvβ3integrin is highly expressed by endothelial cells during the neovascularization and by trophoblast cells during their invasion of the maternal decidua. Angiolone was injected to gravid mice at 6.5 and 11.5 days post coitus (dpc). The fluorescence was analyzed one day later at 7.5 and 12.5 dpc, respectively. We demonstrated that (i) Angiolone targetsαvβ3protein in the placenta with a strong specificity, (ii) this technique is quantitative as the measurement was correlated to the increase of the placental size observed with increasing gestational age, and (iii) information on the outcome is possible, as abnormal placentation could be detected early on during gestation. In conclusion, we report the validation of a new noninvasive and quantitative method to assess the placental angiogenic activity,in vivo.

Trophoblast Stem Cells: Models for Investigating Trophectoderm Differentiation and Placental Development

The placenta is an ephemeral organ containing diverse populations of trophoblasts that are all derived from the embryonic trophectoderm but have morphological, functional, and molecular diversity within and across species. In hemochorial placentation, these cells play especially important roles, interfacing with and modifying the cells of the maternal decidua. Within the rapidly growing placenta, it has been shown that there are trophoblast stem cells well characterized in the mouse and postulated but not well understood in primates. This review will discuss the characteristics of candidates for human and nonhuman primate trophoblast stem cells, present the diverse methods of their generation, and propose future prospects for experimental systems in which they can shed light on developmental and pathophysiological processes in human pregnancy.