Placental alkaline phosphatase (PLAP): Is it exclusively placental?

Background: Adverse pregnancies outcomes present a clinical dilemma in Perinatal medicine. This is partly due to lack of accuracy of current biomarkers to predict high-risk pregnancies at an earlier stage. The placental alkaline phosphatase (PLAP) carrying extracellular vesicles (EVs), and their cargo have been reported as a source of biomarkers for placental health and an indication of pre-eclampsia progression.

Chorionic trophoblast cells demonstrate functionally different phenotypes from placental trophoblasts.

Chorionic trophoblast cells (CTCs) are one of the principal components of the fetal membrane and join with the decidua to form a feto-maternal interface. Recent success in isolating CTCs dealt with two separate questions: (1) The necessity of highly enriched and defined media with inhibitors of oxidative stress and cell transition and their impact on growth and trophoblast phenotype, (2) The functional differences between CTCs and other placental trophoblast lineages of cells (placental cytotrophoblast cells [PTC], and extravillous trophoblast [EVT]). CTCs were cultured either in defined media with various inhibitors or in media from which inhibitors were removed individually.

Placental Trophoblast Cell Isolation from the Term Placenta.

Multiple cell lines have been utilized over time in studying placental biology. Still, most of them rely on choriocarcinoma cells or immortalized trophoblast cells that may not be entirely comparable with actual human placental trophoblast cells. Term placentas can be a source of primary villous trophoblasts.

Establishment and comparison of human term placenta-derived trophoblast cells†.

Research on the biology of fetal-maternal barriers has been limited by access to physiologically relevant cells, including trophoblast cells. In this study, we describe the development of a human term placenta-derived cytotrophoblast immortalized cell line (hPTCCTB) derived from the basal plate. Human-term placenta-derived cytotrophoblast immortalized cell line cells are comparable to their primary cells of origin in terms of morphology, marker expression, and functional responses.

mRNA and Protein Expression in Human Fetal Membrane Cells: Potential Biomarkers for Preterm Prelabor Rupture of the Fetal Membranes?

Clinically, unique markers in fetal membrane cells may contribute to the search for biomarkers for preterm prelabor rupture of the fetal membranes (pPROM) in maternal blood. pPROM is associated with overwhelming inflammation and premature cellular senescence causing "biological microfractures" of the fetal membranes. We hypothesize that these pathological processes are associated with the shedding of fetal membrane cells into the maternal circulation.

Amplification of microbial DNA from bacterial extracellular vesicles from human placenta.

Introduction: The placenta is essential for fetal growth and survival and maintaining a successful pregnancy. The sterility of the placenta has been challenged recently; however, the presence of a placental microbiome has been controversial. We tested the hypothesis that the bacterial extracellular vesicles (BEVs) from Gram-negative bacteria as an alternate source of microbial DNA, regardless of the existence of a microbial community in the placenta.

Development of oxidative stress-associated disease models using feto-maternal interface organ-on-a-chip.

Oxidative stress (OS) and inflammation arising from cellular derangements at the fetal membrane-decidual interface (feto-maternal interface [FMi]) is a major antecedent to preterm birth (PTB). However, it is impractical to study OS-associated FMi disease state during human pregnancy, and thus it is difficult to develop strategies to reduce the incidences of PTB. A microfluidic organ-on-chip model (FMi-OOC) that mimics the in vivo structure and functions of FMi in vitro was developed to address this challenge.

A Microphysiological Device to Model the Choriodecidual Interface Immune Status during Pregnancy.

During human pregnancy the chorion (fetal) lines decidua (maternal) creating the feto-maternal interface. Despite their proximity, resident decidual immune cells remain quiescent during gestation and do not invade the chorion. Infection and infiltration of activated immune cells toward the chorion are often associated with preterm birth.

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.

Extracellular vesicles from maternal uterine cells exposed to risk factors cause fetal inflammatory response.

Background: Fetal cell-derived exosomes (extracellular vesicles, 40-160 nm) are communication channels that can signal parturition by inducing inflammatory changes in maternal decidua and myometrium. Little is known about maternal cell-derived exosomes and their functional roles on the fetal side. This study isolated and characterized exosomes from decidual and myometrial cells grown under normal and inflammatory/oxidative stress conditions and determined their impact on fetal membrane cells.

Extracellular vesicle mediated feto-maternal HMGB1 signaling induces preterm birth.

Preterm birth (PTB; <37 weeks of gestation) impacts ∼11% of all pregnancies and contributes to 1 million neonatal deaths worldwide annually. An understanding of the feto-maternal (F-M) signals that initiate birthing (parturition) at term is critical to design strategies to prevent their premature activation, resulting in PTB. Although endocrine and immune cell signaling are well-reported, fetal-derived paracrine signals capable of transitioning quiescent uterus to an active state of labor are poorly studied.

Characterizing the immune cell population in the human fetal membrane.

Problem: This study localized CD45 immune cells and compared changes in their numbers between term, not in labor (TNIL) and term, labor (TL) human fetal membranes.

Method Of Study: Fetal membranes (amniochorion) from normal TNIL and TL subjects were analyzed by immunohistochemistry (IHC), immunofluorescence (IF), and flow cytometry for evidence of total (CD45 ) immune cells as well as innate immune cells (neutrophils, macrophages and NK cells) using specific markers. Fetal origin of immune cells was determined using polymerase chain reaction (PCR) for SRY gene in Y chromosome.

Isolation and characterization human chorion membrane trophoblast and mesenchymal cells.

Introduction: To develop protocols for isolation and culture of human chorionic mesenchymal and trophoblast cells and test their differential responsiveness to oxidative stress.

Methods: Chorion trophoblast cells (CTC) and chorion mesenchymal cells (CMC) were isolated from term fetal membranes by modifying current protocols. Their purity and characteristics were tested using bright field microscopy and after staining for cytokeratin (CK)-7 and vimentin.

Inflammation, but not infection, induces EMT in human amnion epithelial cells.

A non-reversible state of epithelial to mesenchymal transition (EMT) at term accumulates proinflammatory mesenchymal cells and predisposes fetal membrane to weakening prior to delivery at term. We investigated the induction of EMT in amnion epithelial cells (AEC) in response to inflammation and infection associated with spontaneous preterm birth (SPTB). For this, membranes from SPTB were screened for EMT markers.

Stretch, scratch, and stress: Suppressors and supporters of senescence in human fetal membranes.

Introduction: Throughout gestation, amnion membranes undergo mechanical and or physiological stretch, scratch, or stress which is withstood by repairing and remodeling processes to protect the growing fetus. At term, increased oxidative stress (OS) activates p38MAPK, induces senescence, and inflammation contributing to membrane dysfunction to promote labor. However, the signaling initiated by stretch and scratch is still unclear.

Fetal membrane extracellular vesicle profiling reveals distinct pathways induced by infection and inflammation in vitro.

Problem: Fetal inflammatory signals can be propagated to maternal tissues to initiate labor via exosomes (extracellular vesicles; 30-150 nm). We tested the hypothesis that fetal membrane cells exposed to infectious and inflammatory mediators associated with preterm birth (PTB) produce exosomes with distinct protein cargo contents indicative of underlying pathobiology.

Methods Of Study: Fetal membrane explants (FM) as well as primary amnion epithelial (AEC) and mesenchymal cells (AMC), and chorion cells (CC) from term deliveries were maintained in normal conditions (control) or exposed to LPS 100 ng/mL or TNF-α 50 ng/mL for 48 hours.

Oxidative stress-induced downregulation of glycogen synthase kinase 3 beta in fetal membranes promotes cellular senescence†.

Objective: Oxidative stress (OS)-induced stress signaler p38 mitogen-activated protein kinase (p38MAPK) activation and fetal membrane senescence are associated with parturition. This study determined changes in glycogen synthase kinase 3 beta (GSK3β) and its regulation by p38MAPK in effecting senescence to further delineate the molecular mechanism involved in senescence.

Methods: Primary human amnion epithelial cells and amnion mesenchymal cells were treated with cigarette smoke extract (CSE, OS inducer).

Damage-Associated molecular pattern markers HMGB1 and cell-Free fetal telomere fragments in oxidative-Stressed amnion epithelial cell-Derived exosomes.

Term labor in humans is associated with increased oxidative stress (OS) -induced senescence and damages to amnion epithelial cells (AECs). Senescent fetal cells release alarmin high-mobility group box 1 (HMGB1) and cell-free fetal telomere fragments (cffTF) which can be carried by exosomes to other uterine tissues to produce parturition-associated inflammatory changes. This study characterized AEC-derived exosomes under normal and OS conditions and their packaging of HMGB1 and cffTF.

A Screen of FDA-Approved Drugs for Inhibitors of Zika Virus Infection.

Currently there are no approved vaccines or specific therapies to prevent or treat Zika virus (ZIKV) infection. We interrogated a library of FDA-approved drugs for their ability to block infection of human HuH-7 cells by a newly isolated ZIKV strain (ZIKV MEX_I_7). More than 20 out of 774 tested compounds decreased ZIKV infection in our in vitro screening assay.

Amnion-Epithelial-Cell-Derived Exosomes Demonstrate Physiologic State of Cell under Oxidative Stress.

At term, the signals of fetal maturity and feto-placental tissue aging prompt uterine readiness for delivery by transitioning quiescent myometrium to an active stage. It is still unclear how the signals reach the distant myometrium. Exosomes are a specific type of extracellular vesicle (EVs) that transport molecular signals between cells, and are released from a wide range of cells, including the maternal and fetal cells.

Senescence of primary amniotic cells via oxidative DNA damage.

Objective: Oxidative stress is a postulated etiology of spontaneous preterm birth (PTB) and preterm prelabor rupture of the membranes (pPROM); however, the precise mechanistic role of reactive oxygen species (ROS) in these complications is unclear. The objective of this study is to examine impact of a water soluble cigarette smoke extract (wsCSE), a predicted cause of pregnancy complications, on human amnion epithelial cells.

Methods: Amnion cells isolated from fetal membranes were exposed to wsCSE prepared in cell culture medium and changes in ROS levels, DNA base and strand damage was determined by using 2'7'-dichlorodihydro-fluorescein and comet assays as well as Fragment Length Analysis using Repair Enzymes (FLARE) assays, respectively.