Uterine injury during diestrus leads to placental and embryonic defects in future pregnancies in mice†.

Uterine injury from procedures such as Cesarean sections (C-sections) often have severe consequences on subsequent pregnancy outcomes, leading to disorders such as placenta previa, placenta accreta, and infertility. With rates of C-section at ~30% of deliveries in the USA and projected to continue to climb, a deeper understanding of the mechanisms by which these pregnancy disorders arise and opportunities for intervention are needed. Here we describe a rodent model of uterine injury on subsequent in utero outcomes. We observed three distinct phenotypes: increased rates of resorption and death, embryo spacing defects, and placenta accreta-like features of reduced decidua and expansion of invasive trophoblasts. We show that the appearance of embryo spacing defects depends entirely on the phase of estrous cycle at the time of injury. Using RNA-seq, we identified perturbations in the expression of components of the COX/prostaglandin pathway after recovery from injury, a pathway that has previously been demonstrated to play an important role in embryo spacing. Therefore, we demonstrate that uterine damage in this mouse model causes morphological and molecular changes that ultimately lead to placental and embryonic developmental defects.

Clotting factor genes are associated with preeclampsia in high-altitude pregnant women in the Peruvian Andes.

Preeclampsia is a multi-organ complication of pregnancy characterized by sudden hypertension and proteinuria that is among the leading causes of preterm delivery and maternal morbidity and mortality worldwide. The heterogeneity of preeclampsia poses a challenge for understanding its etiology and molecular basis. Intriguingly, risk for the condition increases in high-altitude regions such as the Peruvian Andes. To investigate the genetic basis of preeclampsia in a population living at high altitude, we characterized genome-wide variation in a cohort of preeclamptic and healthy Andean families (n = 883) from Puno, Peru, a city located above 3,800 meters of altitude. Our study collected genomic DNA and medical records from case-control trios and duos in local hospital settings. We generated genotype data for 439,314 SNPs, determined global ancestry patterns, and mapped associations between genetic variants and preeclampsia phenotypes. A transmission disequilibrium test (TDT) revealed variants near genes of biological importance for placental and blood vessel function. The top candidate region was found on chromosome 13 of the fetal genome and contains clotting factor genes PROZ, F7, and F10. These findings provide supporting evidence that common genetic variants within coagulation genes play an important role in preeclampsia. A selection scan revealed a potential adaptive signal around the ADAM12 locus on chromosome 10, implicated in pregnancy disorders. Our discovery of an association in a functional pathway relevant to pregnancy physiology in an understudied population of Native American origin demonstrates the increased power of family-based study design and underscores the importance of conducting genetic research in diverse populations.

PRG2 and AQPEP are misexpressed in fetal membranes in placenta previa and percreta†.

The obstetrical conditions placenta accreta spectrum (PAS) and placenta previa are a significant source of pregnancy-associated morbidity and mortality, yet the specific molecular and cellular underpinnings of these conditions are not known. In this study, we identified misregulated gene expression patterns in tissues from placenta previa and percreta (the most extreme form of PAS) compared with control cases. By comparing this gene set with existing placental single-cell and bulk RNA-Seq datasets, we show that the upregulated genes predominantly mark extravillous trophoblasts. We performed immunofluorescence on several candidate molecules and found that PRG2 and AQPEP protein levels are upregulated in both the fetal membranes and the placental disk in both conditions. While this increased AQPEP expression remains restricted to trophoblasts, PRG2 is mislocalized and is found throughout the fetal membranes. Using a larger patient cohort with a diverse set of gestationally aged-matched controls, we validated PRG2 as a marker for both previa and PAS and AQPEP as a marker for only previa in the fetal membranes. Our findings suggest that the extraembryonic tissues surrounding the conceptus, including both the fetal membranes and the placental disk, harbor a signature of previa and PAS that is characteristic of EVTs and that may reflect increased trophoblast invasiveness.

Molecular Signatures of Placentation and Secretion Uncovered in Poeciliopsis Maternal Follicles.

Placentation evolved many times independently in vertebrates. Although the core functions of all placentas are similar, we know less about how this similarity extends to the molecular level. Here, we study Poeciliopsis, a unique genus of live-bearing fish that have independently evolved complex placental structures at least three times. The maternal follicle is a key component of these structures. It envelops yolk-rich eggs and is morphologically simple in lecithotrophic species but has elaborate villous structures in matrotrophic species. Through sequencing, the follicle transcriptome of a matrotrophic, Poeciliopsis retropinna, and lecithotrophic, P. turrubarensis, species we found genes known to be critical for placenta function expressed in both species despite their difference in complexity. Additionally, when we compare the transcriptome of different river populations of P. retropinna, known to vary in maternal provisioning, we find differential expression of secretory genes expressed specifically in the top layer of villi cells in the maternal follicle. This provides some of the first evidence that the placental structures of Poeciliopsis function using a secretory mechanism rather than direct contact with maternal circulation. Finally, when we look at the expression of placenta proteins at the maternal-fetal interface of a larger sampling of Poeciliopsis species, we find expression of key maternal and fetal placenta proteins in their cognate tissue types of all species, but follicle expression of prolactin is restricted to only matrotrophic species. Taken together, we suggest that all Poeciliopsis follicles are poised for placenta function but require expression of key genes to form secretory villi.

Cardiotoxicity in Hematopoietic Stem Cell Transplant: Keeping the Beat.

INTRODUCTION: The number of hematopoietic stem cell transplants (HSCTs) performed in the United States and worldwide is increasing. Cardiac events have been well described in HSCT, and the incidence and type of cardiac events have not changed over recent decades. PATIENTS AND METHODS: This study adds to the body of evidence in describing the incidence and type of cardiac events experienced by an allogeneic and autologous HSCT population at a single institution from 2012 to 2017. RESULTS: Sixty-five (9.8%) patients experienced cardiac events, including atrial arrhythmia (N = 39), acute heart failure (N = 9), acute coronary syndrome (N = 7), and new onset hypertension (N = 9), with a few instances of bradycardia, ventricular arrhythmia, pericardial effusion, and pericarditis. Our multivariable regression analysis identified age (older), creatinine (higher), and history of coronary artery disease to significantly correlate with risk of cardiac event (P = .005, P = .039, and P = .038, respectively). A subgroup analysis of those patients experiencing a cardiac event found pre-transplant atrial dilation by trans-thoracic echocardiogram to correlate with increased risk of atrial arrhythmia (33.8% vs. 9.7%; P = .03). Patients developing a CE had an increased risk of death within 1 year (11% vs. 32%; P < .001). CONCLUSION: We review our results in context of other important HSCT cardiac studies to illuminate the most relevant factors of medical history, laboratory data, and cardiac measurements that will identify patients at higher risk, allowing for intervention to improve HSCT outcomes.

The Genomes of the Livebearing Fish Species Poeciliopsis retropinna and Poeciliopsis turrubarensis Reflect Their Different Reproductive Strategies.

The evolution of a placenta is predicted to be accompanied by rapid evolution of genes involved in processes that regulate mother-offspring interactions during pregnancy, such as placenta formation, embryonic development, and nutrient transfer to offspring. However, these predictions have only been tested in mammalian species, where only a single instance of placenta evolution has occurred. In this light, the genus Poeciliopsis is a particularly interesting model for placenta evolution, because in this genus a placenta has evolved independently from the mammalian placenta. Here, we present and compare genome assemblies of two species of the livebearing fish genus Poeciliopsis (family Poeciliidae) that differ in their reproductive strategy: Poeciliopsis retropinna which has a well-developed complex placenta and P. turrubarensis which lacks a placenta. We applied different assembly strategies for each species: PacBio sequencing for P. retropinna (622-Mb assembly, scaffold N50 of 21.6 Mb) and 10× Genomics Chromium technology for P. turrubarensis (597-Mb assembly, scaffold N50 of 4.2 Mb). Using the high contiguity of these genome assemblies and near-completeness of gene annotations to our advantage, we searched for gene duplications and performed a genome-wide scan for genes evolving under positive selection. We find rapid evolution in major parts of several molecular pathways involved in parent-offspring interaction in P. retropinna, both in the form of gene duplications as well as positive selection. We conclude that the evolution of the placenta in the genus Poeciliopsis is accompanied by rapid evolution of genes involved in similar genomic pathways as found in mammals.

Siva plays a critical role in mouse embryonic development.

The Siva protein, named after the Hindu God of Destruction, plays important roles in apoptosis in various contexts, including downstream of death receptor activation or p53 tumor suppressor engagement. The function of Siva in organismal development and homeostasis, however, has remained uncharacterized. Here, we generate Siva knockout mice to characterize the physiological function of Siva in vivo. Interestingly, we find that Siva deficiency causes early embryonic lethality accompanied by multiple phenotypes, including developmental delay, abnormal neural tube closure, and defective placenta and yolk sac formation. Examination of Siva expression during embryogenesis shows that Siva is expressed in both embryonic and extra-embryonic tissues, including within the mesoderm, which may explain the vascular defects observed in the placenta and yolk sac. The embryonic phenotypes caused by Siva loss are not rescued by p53 deficiency, nor do they resemble those of p53 null embryos, suggesting that the embryonic function of Siva is not related to the p53 pathway. Moreover, loss of the Ripk3 necroptosis protein does not rescue the observed lethality or developmental defects, suggesting that Siva may play a non-apoptotic role in development. Collectively, these studies reveal a key role for Siva in proper embryonic development.

Metabolism of cholesterol and progesterone is differentially regulated in primary trophoblastic subtypes and might be disturbed in recurrent miscarriages.

During pregnancy, extravillous trophoblasts (EVTs) invade the maternal decidua and remodel the local vasculature to establish blood supply for the growing fetus. Compromised EVT function has been linked to aberrant pregnancy associated with maternal and fetal morbidity and mortality. However, metabolic features of this invasive trophoblast subtype are largely unknown. Using primary human trophoblasts isolated from first trimester placental tissues, we show that cellular cholesterol homeostasis is differentially regulated in EVTs compared with villous cytotrophoblasts. Utilizing RNA-sequencing, gene set-enrichment analysis, and functional validation, we provide evidence that EVTs display increased levels of free and esterified cholesterol. Accordingly, EVTs are characterized by increased expression of the HDL-receptor, scavenger receptor class B type I, and reduced expression of the LXR and its target genes. We further reveal that EVTs express elevated levels of hydroxy-delta-5-steroid dehydrogenase 3 beta- and steroid delta-isomerase 1 (HSD3B1) (a rate-limiting enzyme in progesterone synthesis) and are capable of secreting progesterone. Increasing cholesterol export by LXR activation reduced progesterone secretion in an ABCA1-dependent manner. Importantly, HSD3B1 expression was decreased in EVTs of idiopathic recurrent spontaneous abortions, pointing toward compromised progesterone metabolism in EVTs of early miscarriages. Here, we provide insights into the regulation of cholesterol and progesterone metabolism in trophoblastic subtypes and its putative relevance in human miscarriage.

Orthopaedic nurses' engagement in clinical research; an exploration of ideas, facilitators and challenges.

BACKGROUND: Previous international studies have identified individual and organisational barriers to nurses' research utilisation, but there is little data reporting on nurses' engagement in research design and/or delivery, particularly within the orthopaedic speciality. AIM: To explore orthopaedic nurses' views regarding the research priorities for neuro-musculoskeletal care and the perceived barriers and facilitators associated with their engagement in the research process. METHODS: A single centre mixed methods study (n = 75) employing a survey and 14 focus group discussions. FINDINGS: The current sample of clinical orthopaedic nurses showed little evidence of research engagement. Research priorities focused on: 1) Understanding and improving patient and staff experiences; 2) Improving processes, systems and workload models; an 3) Interventions to improve clinical outcomes. Key themes arising from the focus group discussions were research activity, priorities and motivation, culture and leadership, and resources. CONCLUSION: These findings suggest that significant work is still required to build sufficient research capacity and capability within the nursing workforce. Key to success will be developing effective leaders who can create a positive and supportive research culture across an organisation to strengthen the research voice of nursing and which will drive improvements in future care.

Gene expression across mammalian organ development.

The evolution of gene expression in mammalian organ development remains largely uncharacterized. Here we report the transcriptomes of seven organs (cerebrum, cerebellum, heart, kidney, liver, ovary and testis) across developmental time points from early organogenesis to adulthood for human, rhesus macaque, mouse, rat, rabbit, opossum and chicken. Comparisons of gene expression patterns identified correspondences of developmental stages across species, and differences in the timing of key events during the development of the gonads. We found that the breadth of gene expression and the extent of purifying selection gradually decrease during development, whereas the amount of positive selection and expression of new genes increase. We identified differences in the temporal trajectories of expression of individual genes across species, with brain tissues showing the smallest percentage of trajectory changes, and the liver and testis showing the largest. Our work provides a resource of developmental transcriptomes of seven organs across seven species, and comparative analyses that characterize the development and evolution of mammalian organs.

Genome amplification and cellular senescence are hallmarks of human placenta development.

Genome amplification and cellular senescence are commonly associated with pathological processes. While physiological roles for polyploidization and senescence have been described in mouse development, controversy exists over their significance in humans. Here, we describe tetraploidization and senescence as phenomena of normal human placenta development. During pregnancy, placental extravillous trophoblasts (EVTs) invade the pregnant endometrium, termed decidua, to establish an adapted microenvironment required for the developing embryo. This process is critically dependent on continuous cell proliferation and differentiation, which is thought to follow the classical model of cell cycle arrest prior to terminal differentiation. Strikingly, flow cytometry and DNAseq revealed that EVT formation is accompanied with a genome-wide polyploidization, independent of mitotic cycles. DNA replication in these cells was analysed by a fluorescent cell-cycle indicator reporter system, cell cycle marker expression and EdU incorporation. Upon invasion into the decidua, EVTs widely lose their replicative potential and enter a senescent state characterized by high senescence-associated (SA) ß-galactosidase activity, induction of a SA secretory phenotype as well as typical metabolic alterations. Furthermore, we show that the shift from endocycle-dependent genome amplification to growth arrest is disturbed in androgenic complete hydatidiform moles (CHM), a hyperplastic pregnancy disorder associated with increased risk of developing choriocarinoma. Senescence is decreased in CHM-EVTs, accompanied by exacerbated endoreduplication and hyperploidy. We propose induction of cellular senescence as a ploidy-limiting mechanism during normal human placentation and unravel a link between excessive polyploidization and reduced senescence in CHM.

Investigating human placentation and pregnancy using first trimester chorionic villi.

Chorionic villus sampling (CVS), routinely used for prenatal diagnosis of cytogenetic disorders, also possesses great potential for the study of placentation. To better understand villus biology, human placentation, and how these relate to pregnancy outcomes, we examined the morphology and transcriptomes of villi obtained via CVS from 10 to 14 weeks of pregnancy and correlated these with pregnancy attributes and clinical outcomes. First, we established a morphological scoring system based on three main villus features: branching, budding and vascularization. We then tested whether morphology scores were predictive of pregnancy attributes and clinical outcomes. Finally, we used RNA sequencing to assess the transcriptional basis of villus morphology and tested the hypothesis that gene expression may predict pregnancy outcomes. We demonstrate that villus morphology varies tremendously between patients, irrespective of gestational age, and that transcriptional differences are highly predictive of villus morphology. We show that pre-eclampsia markers are associated with villi with low morphology scores. Additionally, we identify SVEP1 as a possible biomarker for defining gestational age. Overall, chorionic villi in the first trimester remain one of the few means to correlate placental function with pregnancy outcome and these samples are a valuable and increasingly rare resource.

Desynchronizing Embryonic Cell Division Waves Reveals the Robustness of Xenopus laevis Development.

The early Xenopus laevis embryo is replete with dynamic spatial waves. One such wave, the cell division wave, emerges from the collective cell division timing of first tens and later hundreds of cells throughout the embryo. Here, we show that cell division waves do not propagate between neighboring cells and do not rely on cell-to-cell coupling to maintain their division timing. Instead, intrinsic variation in division period autonomously and gradually builds these striking patterns of cell division. Disrupting this pattern of division by placing embryos in a temperature gradient resulted in highly asynchronous entry to the midblastula transition and misexpression of the mesodermal marker Xbra. Remarkably, this gene expression defect is corrected during involution, resulting in delayed yet normal Xbra expression and viable embryos. This implies the existence of a previously unknown mechanism for normalizing mesodermal gene expression during involution.

Molecular conservation of marsupial and eutherian placentation and lactation.

Eutherians are often mistakenly termed 'placental mammals', but marsupials also have a placenta to mediate early embryonic development. Lactation is necessary for both infant and fetal development in eutherians and marsupials, although marsupials have a far more complex milk repertoire that facilitates morphogenesis of developmentally immature young. In this study, we demonstrate that the anatomically simple tammar placenta expresses a dynamic molecular program that is reminiscent of eutherian placentation, including both fetal and maternal signals. Further, we provide evidence that genes facilitating fetal development and nutrient transport display convergent co-option by placental and mammary gland cell types to optimize offspring success.

IFPA meeting 2016 workshop report I: Genomic communication, bioinformatics, trophoblast biology and transport systems.

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2016 there were twelve themed workshops, four of which are summarized in this report. These workshops covered innovative technologies applied to new and traditional areas of placental research: 1) genomic communication; 2) bioinformatics; 3) trophoblast biology and pathology; 4) placental transport systems.

Transcriptional dynamics of tail regeneration in Xenopus tropicalis.

In contrast to humans, many amphibians are able to rapidly and completely regenerate complex tissues, including entire appendages. Following tail amputation, Xenopus tropicalis tadpoles quickly regenerate muscle, spinal cord, cartilage, vasculature and skin, all properly patterned in three dimensions. To better understand the molecular basis of this regenerative competence, we performed a transcriptional analysis of the first 72 h of tail regeneration using RNA-Seq. Our analysis refines the windows during which many key biological signaling processes act in regeneration, including embryonic patterning signals, immune responses, bioelectrical signaling and apoptosis. Our work provides a deep database for researchers interested in appendage regeneration, and points to new avenues for further study.