- Maternal and Fetal Medicine
Director of Perinatal Biology, Stanford University School of Medicine (2014 - Present)
PhD Training:University of Rochester School of Medicine (1994)
Board Certification: Maternal and Fetal Medicine, American Board of Obstetrics and Gynecology (2009)
Board Certification: Obstetrics and Gynecology, American Board of Obstetrics and Gynecology (2005)
Fellowship:UCSF (2003) CA
Residency:UCSF (2000) CA
Medical Education:University of Rochester School of Medicine (1996) NY
Independent Studies (7)
- Directed Reading in Obstetrics and Gynecology
OBGYN 299 (Win, Spr)
- Early Clinical Experience in Obstetrics and Gynecology
OBGYN 280 (Win, Spr)
- Graduate Research in Reproductive Biology
OBGYN 399 (Win, Spr)
HUMBIO 194 (Spr)
- Medical Scholars Research
OBGYN 370 (Win, Spr)
- Research in Human Biology
HUMBIO 193 (Aut, Win)
- Undergraduate Research in Reproductive Biology
OBGYN 199 (Aut, Win, Spr)
- Directed Reading in Obstetrics and Gynecology
Graduate and Fellowship Programs
- Maternal Height and Risk of Preeclampsia among Race/Ethnic Groups AMERICAN JOURNAL OF PERINATOLOGY 2019; 36 (8): 864–71
- Differential Dynamics of the Maternal Immune System in Healthy Pregnancy and Preeclampsia FRONTIERS IN IMMUNOLOGY 2019; 10
Impact of Assisted Reproduction on Maternal Vascular Health in Pregnancy and Postpartum.
SAGE PUBLICATIONS INC. 2019: 281A–282A
View details for Web of Science ID 000459610400647
Differential Dynamics of the Maternal Immune System in Healthy Pregnancy and Preeclampsia.
SAGE PUBLICATIONS INC. 2019: 271A
View details for Web of Science ID 000459610400616
Data-Driven Queries between Medications and Spontaneous Preterm Birth among 2.5 Million Pregnancies: Association with Genital Herpes and Antiviral Drugs.
SAGE PUBLICATIONS INC. 2019: 389A
View details for Web of Science ID 000459610400965
- Increased Preeclampsia Risk and Reduced Aortic Compliance With In Vitro Fertilization Cycles in the Absence of a Corpus Luteum HYPERTENSION 2019; 73 (3): 640–49
- Absent or Excessive Corpus Luteum Number Is Associated With Altered Maternal Vascular Health in Early Pregnancy HYPERTENSION 2019; 73 (3): 680–90
- Murine trophoblast-derived and pregnancy-associated exosome-enriched extracellular vesicle microRNAs: Implications for placenta driven effects on maternal physiology PLOS ONE 2019; 14 (2)
Absent or Excessive Corpus Luteum Number Is Associated With Altered Maternal Vascular Health in Early Pregnancy.
Hypertension (Dallas, Tex. : 1979)
Identifying modifiable factors that contribute to preeclampsia risk associated with assisted reproduction can improve maternal health. Vascular dysfunction predates clinical presentation of preeclampsia. Therefore, we examined if a nonphysiological hormonal milieu, a modifiable state, affects maternal vascular health in early pregnancy. Blood pressure, endothelial function, circulating endothelial progenitor cell numbers, lipid levels, and corpus luteum (CL) hormones were compared in a prospective cohort of women with infertility history based on number of CL: 0 CL (programmed frozen embryo transfer [FET], N=18); 1 CL (spontaneous conception [N=16] and natural cycle FET [N=12]); or >3 CL associated with in vitro fertilization [N=11]. Women with 0 or >3 CL lacked the drop in mean arterial blood pressure compared with those with 1 CL (both P=0.05). Reactive hyperemia index was impaired in women with 0 CL compared with 1 CL ( P=0.04) while baseline pulse wave amplitude was higher with > 3 CL compared with 1 CL ( P=0.01) or 0 CL ( P=0.01). Comparing only FET cycles, a lower reactive hyperemia index and a higher augmentation index is noted in FETs with suppressed CL compared with FETs in a natural cycle (both P=0.03). The number of angiogenic and nonangiogenic circulating endothelial progenitor cell numbers was lower in the absence of a CL in FETs ( P=0.01 and P=0.03). Vascular health in early pregnancy is altered in women with aberrant numbers of CL (0 or >3) and might represent insufficient cardiovascular adaptation contributing to an increased risk of preeclampsia.
View details for PubMedID 30636549
Increased Preeclampsia Risk and Reduced Aortic Compliance With In Vitro Fertilization Cycles in the Absence of a Corpus Luteum.
Hypertension (Dallas, Tex. : 1979)
In vitro fertilization involving frozen embryo transfer and donor oocytes increases preeclampsia risk. These in vitro fertilization protocols typically yield pregnancies without a corpus luteum (CL), which secretes vasoactive hormones. We investigated whether in vitro fertilization pregnancies without a CL disrupt maternal circulatory adaptations and increase preeclampsia risk. Women with 0 (n=26), 1 (n=23), or >1 (n=22) CL were serially evaluated before, during, and after pregnancy. Because increasing arterial compliance is a major physiological adaptation in pregnancy, we assessed carotid-femoral pulse wave velocity and transit time. In a parallel prospective cohort study, obstetric outcomes for singleton livebirths achieved with autologous oocytes were compared between groups by CL number (n=683). The expected decline in carotid-femoral pulse wave velocity and rise in carotid-femoral transit time during the first trimester were attenuated in the 0-CL compared with combined single/multiple-CL cohorts, which were similar (group-time interaction: P=0.06 and 0.03, respectively). The blunted changes of carotid-femoral pulse wave velocity and carotid-femoral transit time from prepregnancy in the 0-CL cohort were most striking at 10 to 12 weeks of gestation ( P=0.01 and 0.006, respectively, versus 1 and >1 CL). Zero CL was predictive of preeclampsia (adjusted odds ratio, 2.73; 95% CI, 1.14-6.49) and preeclampsia with severe features (6.45; 95% CI, 1.94-25.09) compared with 1 CL. Programmed frozen embryo transfer cycles (0 CL) were associated with higher rates of preeclampsia (12.8% versus 3.9%; P=0.02) and preeclampsia with severe features (9.6% versus 0.8%; P=0.002) compared with modified natural frozen embryo transfer cycles (1 CL). In common in vitro fertilization protocols, absence of the CL perturbed the maternal circulation in early pregnancy and increased the incidence of preeclampsia.
View details for PubMedID 30636552
- Multiomics modeling of the immunome, transcriptome, microbiome, proteome and metabolome adaptations during human pregnancy BIOINFORMATICS 2019; 35 (1): 95–103
Data-driven queries between medications and spontaneous preterm birth among 2.5 million pregnancies.
Birth defects research
Our goal was to develop an approach that can systematically identify potential associations between medication prescribed in pregnancy and spontaneous preterm birth (sPTB) by mining large administrative "claims" databases containing hundreds of medications. One such association that we illustrate emerged with antiviral medications used for herpes treatment.IBM MarketScan® databases (2007-2016) were used. A pregnancy cohort was established using International Classification of Diseases (ICD-9/10) codes. Multiple hypothesis testing and the Benjamini-Hochberg procedure that limited false discovery rate at 5% revealed, among 863 medications, five that showed odds ratios (ORs) <1. The statistically strongest was an association between antivirals and sPTB that we illustrate as a real example of our approach, specifically for treatment of genital herpes (GH). Three groups of women were identified based on diagnosis of GH and treatment during the first 36 weeks of pregnancy: (a) GH without treatment; (b) GH treated with antivirals; (c) no GH or treatment.We identified 2,538,255 deliveries. 0.98% women had a diagnosis of GH. Among them, 60.0% received antiviral treatment. Women with treated GH had OR < 1, (OR [95% CI] = 0.91 [0.85, 0.98]). In contrast, women with untreated GH had a small increased risk of sPTB (OR [95% CI] =1.22 [1.14, 1.32]).Data-driven approaches can effectively generate new hypotheses on associations between medications and sPTB. This analysis led us to examine the association with GH treatment. While unknown confounders may impact these findings, our results indicate that women with untreated GH have a modest increased risk of sPTB.
View details for DOI 10.1002/bdr2.1580
View details for PubMedID 31433567
Maternal Vascular Health in Pregnancy and Postpartum After Assisted Reproduction.
Hypertension (Dallas, Tex. : 1979)
Although most pregnancies after assisted reproduction are associated with a favorable outcome for the mother and infant, reports of abnormal vascular adaptation in early pregnancy and emerging maternal and perinatal pathology warrant further investigations. Herein we extended our previous work and further examined whether perturbations of blood pressure and endothelial function during the first trimester in conceptions with nonphysiological corpus luteum (CL) numbers would persist through the third trimester of pregnancy and into the postpartum period. We investigated both maternal and perinatal outcomes. Participants were grouped according to CL number and method of conception: 0 CL (programmed autologous frozen-thawed embryo transfer, N=10-18); 1 CL (spontaneous conception [N=16] and natural cycle frozen-thawed embryo transfer [N=12]); or >3 CL associated with autologous fresh embryo transfer [N=8-12]. Augmentation index was higher during the third trimester in the absence of a CL compared to 1 CL (P=0.03) and in frozen-thawed embryo transfer in a programmed compared to a natural cycle (P=0.02). Moreover, baseline pulse-wave amplitude was higher in >3 CL conceptions at all time points (all P<0.05). The incidence of preeclampsia and preeclampsia with severe features was significantly higher in the absence of a CL compared to the presence of one or >3 CL (P=0.045 and P=0.03). Infants from conceptions with >3 CL had lower birth weights (P=0.02) and a higher rate of low birth weight offspring (P=0.008). Deficient vascular adaptation during early gestation in conceptions with nonphysiological CL numbers might predispose women to adverse pregnancy outcomes, for example, preeclampsia.
View details for DOI 10.1161/HYPERTENSIONAHA.119.13779
View details for PubMedID 31838910
Murine trophoblast-derived and pregnancy-associated exosome-enriched extracellular vesicle microRNAs: Implications for placenta driven effects on maternal physiology.
2019; 14 (2): e0210675
The role of extracellular vesicles (EVs), specifically exosomes, in intercellular communication likely plays a key role in placental orchestration of pregnancy and maternal immune sensing of the fetus. While murine models are powerful tools to study pregnancy and maternal-fetal immune interactions, in contrast to human placental exosomes, the content of murine placental and pregnancy exosomes remains largely understudied. Using a recently developed in vitro culture technique, murine trophoblast stem cells derived from B6 mice were differentiated into syncytial-like cells. EVs from the conditioned media, as well as from pregnant and non-pregnant sera, were enriched for exosomes. The RNA composition of these murine trophoblast-derived and pregnancy-associated exosome-enriched-EVs (ExoE-EVs) was determined using RNA-sequencing analysis and expression levels confirmed by qRT-PCR. Differentially abundant miRNAs were detected in syncytial differentiated ExoE-EVs, particularly from the X chromosome cluster (mmu-miR-322-3p, mmu-miR-322-5p, mmu-miR-503-5p, mmu-miR-542-3p, and mmu-miR-450a-5p). These were confirmed to be increased in pregnant mouse sera ExoE-EVs by qRT-PCR analysis. Interestingly, fifteen miRNAs were only present within the pregnancy-derived ExoE-EVs compared to non-pregnant controls. Mmu-miR-292-3p and mmu-miR-183-5p were noted to be some of the most abundant miRNAs in syncytial ExoE-EVs and were also present at higher levels in pregnant versus non-pregnant sera ExoE-EVs. The bioinformatics tool, MultiMir, was employed to query publicly available databases of predicted miRNA-target interactions. This analysis reveals that the X-chromosome miRNAs are predicted to target ubiquitin-mediated proteolysis and intracellular signaling pathways. Knowing the cargo of placental and pregnancy-specific ExoE-EVs as well as the predicted biological targets informs studies using murine models to examine not only maternal-fetal immune interactions but also the physiologic consequences of placental-maternal communication.
View details for PubMedID 30730971
Differential Dynamics of the Maternal Immune System in Healthy Pregnancy and Preeclampsia.
Frontiers in immunology
2019; 10: 1305
Preeclampsia is one of the most severe pregnancy complications and a leading cause of maternal death. However, early diagnosis of preeclampsia remains a clinical challenge. Alterations in the normal immune adaptations necessary for the maintenance of a healthy pregnancy are central features of preeclampsia. However, prior analyses primarily focused on the static assessment of select immune cell subsets have provided limited information for the prediction of preeclampsia. Here, we used a high-dimensional mass cytometry immunoassay to characterize the dynamic changes of over 370 immune cell features (including cell distribution and functional responses) in maternal blood during healthy and preeclamptic pregnancies. We found a set of eight cell-specific immune features that accurately identified patients well before the clinical diagnosis of preeclampsia (median area under the curve (AUC) 0.91, interquartile range [0.82-0.92]). Several features recapitulated previously known immune dysfunctions in preeclampsia, such as elevated pro-inflammatory innate immune responses early in pregnancy and impaired regulatory T (Treg) cell signaling. The analysis revealed additional novel immune responses that were strongly associated with, and preceded the onset of preeclampsia, notably abnormal STAT5ab signaling dynamics in CD4+T cell subsets (AUC 0.92, p = 8.0E-5). These results provide a global readout of the dynamics of the maternal immune system early in pregnancy and lay the groundwork for identifying clinically-relevant immune dysfunctions for the prediction and prevention of preeclampsia.
View details for DOI 10.3389/fimmu.2019.01305
View details for PubMedID 31263463
View details for PubMedCentralID PMC6584811
Multiomics modeling of the immunome, transcriptome, microbiome, proteome and metabolome adaptations during human pregnancy.
Bioinformatics (Oxford, England)
2019; 35 (1): 95–103
Motivation: Multiple biological clocks govern a healthy pregnancy. These biological mechanisms produce immunologic, metabolomic, proteomic, genomic and microbiomic adaptations during the course of pregnancy. Modeling the chronology of these adaptations during full-term pregnancy provides the frameworks for future studies examining deviations implicated in pregnancy-related pathologies including preterm birth and preeclampsia.Results: We performed a multiomics analysis of 51 samples from 17 pregnant women, delivering at term. The datasets included measurements from the immunome, transcriptome, microbiome, proteome and metabolome of samples obtained simultaneously from the same patients. Multivariate predictive modeling using the Elastic Net (EN) algorithm was used to measure the ability of each dataset to predict gestational age. Using stacked generalization, these datasets were combined into a single model. This model not only significantly increased predictive power by combining all datasets, but also revealed novel interactions between different biological modalities. Future work includes expansion of the cohort to preterm-enriched populations and in vivo analysis of immune-modulating interventions based on the mechanisms identified.Availability and implementation: Datasets and scripts for reproduction of results are available through: https://nalab.stanford.edu/multiomics-pregnancy/.Supplementary information: Supplementary data are available at Bioinformatics online.
View details for PubMedID 30561547
Maternal Height and Risk of Preeclampsia among Race/Ethnic Groups.
American journal of perinatology
OBJECTIVE: Shorter maternal height has been associated with preeclampsia risk in several populations. It has been less evident whether an independent contribution to the risk exists from maternal height consistently across different races/ethnicities. We investigated associations between maternal height and risk of preeclampsia for different races/ethnicities.STUDY DESIGN: California singleton live births from 2007 to 2011 were analyzed. Logistic regression was used to estimate adjusted odds ratios for the association between height and preeclampsia after stratification by race/ethnicity. To determine the contribution of height that is as independent of body composition as possible, we performed one analysis adjusted for body mass index (BMI) and the other for weight. Additional analyses were performed stratified by parity, and the presence of preexisting/gestational diabetes and autoimmune conditions.RESULTS: Among 2,138,012 deliveries, 3.1% preeclampsia/eclampsia cases were observed. The analysis, adjusted for prepregnancy weight, revealed an inverse relation between maternal height and risk of mild and severe preeclampsia/eclampsia. When the analysis was adjusted for BMI, an inverse relation between maternal height was observed for severe preeclampsia/eclampsia. These associations were observed for each race/ethnicity.CONCLUSION: Using a large and diverse cohort, we demonstrated that shorter height, irrespective of prepregnancy weight or BMI, is associated with an increased risk of severe preeclampsia/eclampsia across different races/ethnicities.
View details for PubMedID 30396225
Residential agricultural pesticide exposures and risks of preeclampsia.
2018; 164: 546–55
We investigated risks of preeclampsia phenotypes from potential residential pesticide exposures, including 543 individual chemicals and 69 physicochemical groupings that were applied in the San Joaquin Valley of California during the study period, 1998-2011. The study population was derived from birth certificate data linked with Office of Statewide Health Planning and Development maternal and infant hospital discharge data. The following numbers of women with preeclampsia phenotypes were identified: 1045 with superimposed (pre-existing hypertension with preeclampsia) preeclampsia (265 with gestational weeks 20-31 and 780 with gestational weeks 32-36); 3471 with severe preeclampsia (824 with gestational weeks 20-31 and 2647 with gestational weeks 32-36); and 2780 with mild preeclampsia (207 with gestational weeks 20-31 and 2573 with gestational weeks 32-36). The reference population for these groups was 197,461 women who did not have diabetes (gestational or pre-existing), did not have any hypertensive disorder, and who delivered at 37 weeks or later. The frequency of any exposure was lower or about the same in each preeclampsia case group (further delineated by gestational age), and month time period, relative to the frequency in reference population controls. Nearly all odds ratios were below 1.0 for these any vs no exposure comparisons. This study showed a general lack of increased risks between a range of agriculture pesticide exposures near women's residences and various preeclampsia phenotypes.
View details for PubMedID 29614386
- Residential agricultural pesticide exposures and risks of preeclampsia ENVIRONMENTAL RESEARCH 2018; 164: 546–55
Placental lipoprotein lipase activity is positively associated with newborn adiposity
2018; 64: 53–60
Recent data suggest that in addition to glucose, fetal growth is related to maternal triglycerides (TG). To reach the fetus, TG must be hydrolyzed to free fatty acids (FFA) and transported across the placenta, but regulation is uncertain. Placental lipoprotein lipase (pLPL) hydrolyzes TG, both dietary chylomicron TG (CM-TG) and very-low density lipoprotein TG (VLDL-TG), to FFA. This may promote fetal fat accretion by increasing the available FFA pool for placental uptake. We tested the novel hypothesis that pLPL activity, but not maternal adipose tissue LPL activity, is associated with newborn adiposity and higher maternal TG.Twenty mothers (n = 13 normal-weight; n = 7 obese) were prospectively recruited. Maternal glucose, insulin, TG (total, CM-TG, VLDL-TG), and FFA were measured at 14-16, 26-28, and 36-37 weeks, and adipose tissue LPL was measured at 26-28 weeks. At term delivery, placental villous biopsies were immediately analyzed for pLPL enzymatic activity. Newborn percent body fat (newborn %fat) was assessed by skinfolds.Placental LPL activity was positively correlated with birthweight (r = 0.48;P = 0.03) and newborn %fat (r = 0.59;P = 0.006), further strengthened by correcting for gestational age at delivery (r = 0.75;P = 0.0001), but adipose tissue LPL was not. Maternal TG and BMI were not correlated with pLPL activity. Additionally, pLPL gene expression, while modestly correlated with enzymatic activity (r = 0.53;P < 0.05), was not correlated with newborn adiposity.This is the first study to show a positive correlation between pLPL activity and newborn %fat. Placental lipase regulation and the role of pLPL in pregnancies characterized by nutrient excess and fetal overgrowth warrant further investigation.
View details for DOI 10.1016/j.placenta.2018.03.001
View details for Web of Science ID 000429556800007
View details for PubMedID 29626981
Occurrence of Selected Structural Birth Defects Among Women With Preeclampsia and Other Hypertensive Disorders
AMERICAN JOURNAL OF EPIDEMIOLOGY
2018; 187 (4): 668–76
To explore a potential association between preeclampsia and selected birth defects, we examined the prevalence of certain birth defects among women with hypertensive disorders including preeclampsia. We analyzed data from 2,499,536 singleton live births in California from 2007 to 2011, including maternal and infant demographics from birth certificates as well as clinical details from delivery hospitalization records. We examined defect groups that were recognizable at birth (e.g., spina bifida and cleft lip). Hypertensive disorders included preexisting hypertension, gestational hypertension, mild preeclampsia, severe preeclampsia/eclampsia, and preeclampsia superimposed on preexisting hypertension. Relative risk values with 95% confidence intervals for each birth defect were calculated by hypertensive group, as well as independent and joint associations of hypertensive and diabetic disorders. Risks of each type of birth defect were higher among offspring of women with hypertensive disorders compared with those without. The risks of birth defects among offspring of women with only a hypertensive disorder were significantly higher than that among women with neither hypertensive nor diabetic disorders (relative risks ranged from 1.37 to 2.77). Risks of birth defects were highest among those born to women with both hypertensive and diabetic disorders compared with those with neither (relative risks ranged from 1.80 to 6.22). These findings support the existence of an association between preeclampsia and certain birth defects and suggest that diabetes may be a contributing factor.
View details for PubMedID 29020134
Maternal Height and Risk of Preeclampsia.
SAGE PUBLICATIONS INC. 2018: 207A–208A
View details for Web of Science ID 000429928200458
- An immune clock of human pregnancy SCIENCE IMMUNOLOGY 2017; 2 (15)
A Proteomic Clock of Human Pregnancy.
American journal of obstetrics and gynecology
Early detection of maladaptive processes underlying pregnancy-related pathologies is desirable, as it will enable targeted interventions ahead of clinical manifestations. The quantitative analysis of plasma proteins features prominently among molecular approaches used to detect deviations from normal pregnancy. However, derivation of proteomic signatures sufficiently predictive of pregnancy-related outcomes has been challenging. An important obstacle hindering such efforts were limitations in assay technology, which prevented the broad examination of the plasma proteome.The recent availability of a highly-multiplexed platform affording the simultaneous measurement of 1,310 plasma proteins opens the door for a more explorative approach. The major aim of this study was to examine whether analysis of plasma collected during gestation of term pregnancy would allow identifying a set of proteins that tightly track gestational age. Establishing precisely-timed plasma proteomic changes during term pregnancy is a critical step in identifying deviations from regular patterns due to fetal and maternal maladaptations. A second aim was to gain insight into functional attributes of identified proteins, and link such attributes to relevant immunological changes.Pregnant women participated in this longitudinal study. In two subsequent subsets of 21 (training cohort) and 10 (validation cohort) women, specific blood specimens were collected during the first (7-14 wks), second (15-20 wks), and third (24-32 wks) trimesters, and 6 wks post-partum for analysis with a highly-multiplexed aptamer-based platform. An elastic net algorithm was applied to infer a proteomic model predicting gestational age. A bootstrapping procedure and piece-wise regression analysis was used to extract the minimum number of proteins required for predicting gestational age without compromising predictive power. Gene ontology analysis was applied to infer enrichment of molecular functions among proteins included in the proteomic model. Changes in abundance of proteins with such functions were linked to immune features predictive of gestational age at the time of sampling in pregnancies delivering at term.An independently validated model consisting of 74 proteins strongly predicted gestational age (p = 3.8x10-14, R = 0.97). The model could be reduced to eight proteins without losing its predictive power (p = 1.7x10-3, R = 0.91). The three top ranked proteins were glypican 3, chorionic somatomammotropin hormone, and granulins. Proteins activating the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathway were enriched in the proteomic model, chorionic somatomammotropin hormone being the top ranked protein. Abundance of chorionic somatomammotropin hormone strongly correlated with STAT5 signaling activity in CD4 T cells, the endogenous cell-signaling event most predictive of gestational age.Results indicate that precisely timed changes in the plasma proteome during term pregnancy mirror a "proteomic clock". Importantly, the combined use of several plasma proteins was required for accurate prediction. The exciting promise of such a "clock" is that deviations from its regular chronological profile may assist in the early diagnoses of pregnancy-relate pathologies and point to underlying pathophysiology. Functional analysis of the proteomic model generated the novel hypothesis that somatomammotropin hormone may critically regulate T-cell function during pregnancy.
View details for PubMedID 29277631
An immune clock of human pregnancy.
2017; 2 (15)
The maintenance of pregnancy relies on finely tuned immune adaptations. We demonstrate that these adaptations are precisely timed, reflecting an immune clock of pregnancy in women delivering at term. Using mass cytometry, the abundance and functional responses of all major immune cell subsets were quantified in serial blood samples collected throughout pregnancy. Cell signaling-based Elastic Net, a regularized regression method adapted from the elastic net algorithm, was developed to infer and prospectively validate a predictive model of interrelated immune events that accurately captures the chronology of pregnancy. Model components highlighted existing knowledge and revealed previously unreported biology, including a critical role for the interleukin-2-dependent STAT5ab signaling pathway in modulating T cell function during pregnancy. These findings unravel the precise timing of immunological events occurring during a term pregnancy and provide the analytical framework to identify immunological deviations implicated in pregnancy-related pathologies.
View details for PubMedID 28864494
A novel quantitative microarray antibody capture (Q-MAC) assay identifies an extremely high HDV prevalence amongst HBV infected Mongolians.
Hepatitis delta virus (HDV) causes the most severe form of human viral hepatitis. HDV requires a hepatitis B virus (HBV) co-infection to provide HDV with HBV surface antigen envelope proteins. The net effect of HDV is to make the underlying HBV disease worse, including higher rates of hepatocellular carcinoma (HCC). Accurate assessments of current HDV prevalence have been hampered by the lack of readily available and reliable quantitative assays, combined with the absence of an FDA-approved therapy. We sought to develop a convenient assay for accurately screening populations and to use this assay to determine HDV prevalence in a population with abnormally high rates of HCC. We developed a high throughput quantitative microarray antibody capture (Q-MAC) assay for anti-HDV IgG wherein recombinant HDV delta antigen is printed by microarray on slides coated with a noncontinuous, nanostructured plasmonic gold film, enabling quantitative fluorescent detection of anti-HDV antibody in small aliquots of patient serum. This assay was then used to screen all HBV-infected patients identified in a large randomly selected cohort designed to represent the Mongolian population. We identified two quantitative thresholds of captured antibody that were 100% predictive of the sample either being positive on standard western blot, or harboring HDV RNA detectable by qPCR, respectively. Subsequent screening of the HBV-positive cohort revealed that a remarkable 57% were RNA positive and an additional 4% were positive on western blot alone.The Q-MAC assay's unique performance characteristics make it ideal for population screening. Its application to the Mongolian HBsAg+ population reveals an apparent ∼60% prevalence of HDV co-infection amongst these HBV-infected Mongolian subjects, which may help explain the extraordinarily high rate of HCC in Mongolia. This article is protected by copyright. All rights reserved.
View details for DOI 10.1002/hep.28957
View details for PubMedID 27880976
Mapping the Fetomaternal Peripheral Immune System at Term Pregnancy.
Journal of immunology
Preterm labor and infections are the leading causes of neonatal deaths worldwide. During pregnancy, immunological cross talk between the mother and her fetus is critical for the maintenance of pregnancy and the delivery of an immunocompetent neonate. A precise understanding of healthy fetomaternal immunity is the important first step to identifying dysregulated immune mechanisms driving adverse maternal or neonatal outcomes. This study combined single-cell mass cytometry of paired peripheral and umbilical cord blood samples from mothers and their neonates with a graphical approach developed for the visualization of high-dimensional data to provide a high-resolution reference map of the cellular composition and functional organization of the healthy fetal and maternal immune systems at birth. The approach enabled mapping of known phenotypical and functional characteristics of fetal immunity (including the functional hyperresponsiveness of CD4(+) and CD8(+) T cells and the global blunting of innate immune responses). It also allowed discovery of new properties that distinguish the fetal and maternal immune systems. For example, examination of paired samples revealed differences in endogenous signaling tone that are unique to a mother and her offspring, including increased ERK1/2, MAPK-activated protein kinase 2, rpS6, and CREB phosphorylation in fetal Tbet(+)CD4(+) T cells, CD8(+) T cells, B cells, and CD56(lo)CD16(+) NK cells and decreased ERK1/2, MAPK-activated protein kinase 2, and STAT1 phosphorylation in fetal intermediate and nonclassical monocytes. This highly interactive functional map of healthy fetomaternal immunity builds the core reference for a growing data repository that will allow inferring deviations from normal associated with adverse maternal and neonatal outcomes.
View details for PubMedID 27793998
Preeclampsia Associated with Functional Changes in Cord Blood Endothelial Progenitor Cells.
SAGE PUBLICATIONS INC. 2016: 63A–64A
View details for Web of Science ID 000372879200036
Differential expression of human placental PAPP-A2 over gestation and in preeclampsia.
2016; 37: 19-25
Pregnancy Associated Plasma Protein A2 (PAPP-A2) is a pregnancy related insulin-like growth factor binding protein-5 (IGFBP-5) protease, known to be elevated in preeclampsia. As the insulin-like growth factors are important in human implantation and placentation, we sought to determine the expression pattern of PAPP-A2 over human gestation in normal and preeclamptic pregnancies to evaluate its role in placental development and the pathogenesis of preeclampsia.Placental basal plate and chorionic villi samples, maternal and fetal cord blood sera were obtained from preeclamptic and control pregnancies. Formalin-fixed tissue sections from across gestation were stained for cytokeratin-7, HLA-G, and PAPP-A2. PAPP-A2 immunoblot analysis was also performed on protein lysates and sera.PAPP-A2 expression is predominately expressed by differentiated trophoblasts and fetal endothelium. Chorionic villi show strong expression in the first trimester, followed by a progressive decrease in the second trimester, which returns in the third trimester. PAPP-A2 expression is not impacted by labor. PAPP-A2 is increased in the basal plate, chorionic villi and maternal sera in preeclampsia compared to controls, but is not detectable in cord blood.PAPP-A2 is differentially expressed in different trophoblast populations and shows strong down regulation in the mid second trimester in chorionic villous samples. Both maternal sera and placental tissue from pregnancies complicated by preeclampsia show increased levels of PAPP-A2. PAPP-A2 levels are not altered by labor. Additionally, PAPP-A2 cannot be detected in cord blood demonstrating that the alterations in maternal and placental PAPP-A2 are not recapitulated in the fetal circulation.
View details for DOI 10.1016/j.placenta.2015.11.004
View details for PubMedID 26748159
Umbilical Cord Blood Circulating Progenitor Cells and Endothelial Colony-Forming Cells Are Decreased in Preeclampsia.
Preeclampsia (PE) is a pregnancy-specific disease characterized by the new onset of hypertension and proteinuria. Mothers with PE are known to develop endothelial dysfunction, but its effect on infants has been understudied, as newborns are often asymptomatic. Recent studies indicate that infants born from preeclamptic pregnancies develop endothelial dysfunction including higher blood pressure during childhood and an increased risk of stroke later in life. We hypothesize that PE reduces the number and function of fetal angiogenic progenitor cells and may contribute to this increased risk. We quantified 2 distinct types of angiogenic progenitors, pro-angiogenic circulating progenitor cells (CPCs) and endothelial colony-forming cells (ECFCs), from the umbilical cord blood of preeclamptic pregnancies and normotensive controls. Pro-angiogenic and nonangiogenic CPCs were enumerated via flow cytometry and ECFCs by cell culture. Additionally, we studied the growth, migration, and tube formation of ECFCs from PE and gestational age-matched normotensive control pregnancies. We found that PE resulted in decreased cord blood pro-angiogenic CPCs and ECFCs. Nonangiogenic CPCs were also decreased. Preeclamptic ECFCs demonstrated decreased growth and migration but formed tube-like structures in vitro similar to controls. Our results suggest that the preeclamptic environment alters the number and function of angiogenic progenitor cells and may increase the risk of later vascular disease.
View details for DOI 10.1177/1933719116678692
View details for PubMedID 27879452
Characterization of choline transporters in the human placenta over gestation
2015; 36 (12): 1362-1369
The developing fetus relies on the maternal blood supply to provide the choline it requires for making membrane lipids, synthesizing acetylcholine, and performing important methylation reactions. It is vital, therefore, that the placenta is efficient at transporting choline from the maternal to the fetal circulation. Although choline transporters have been found in term placenta samples, little is known about what cell types express specific choline transporters and how expression of the transporters may change over gestation. The objective of this study was to characterize choline transporter expression levels and localization in the human placenta throughout placental development.We analyzed CTL1 and -2 expression over gestation in human placental biopsies from 6 to 40 weeks gestation (n = 6-10 per gestational window) by immunoblot analysis. To determine the cellular expression pattern of the choline transporters throughout gestation, immunofluorescence analysis was then performed.Both CTL1 and CTL2 were expressed in the chorionic villi from 6 weeks gestation to term. Labor did not alter expression levels of either transporter. CTL1 localized to the syncytial trophoblasts and the endothelium of the fetal vasculature within the chorionic villous structure. CTL2 localized mainly to the stroma early in gestation and by the second trimester co-localized with CTL1 at the fetal vasculature.The differential expression pattern of CTL1 and CTL2 suggests that CTL1 is the key transporter involved in choline transport from maternal circulation and both transporters are likely involved in stromal and endothelial cell choline transport.
View details for DOI 10.1016/j.placenta.2015.10.001
View details for Web of Science ID 000366950500004
View details for PubMedID 26601765
View details for PubMedCentralID PMC4801320
Hepatitis C Virus Sensing by Human Trophoblasts Induces Innate Immune Responses and Recruitment of Maternal NK Cells: Potential Implications for Limiting Vertical Transmission.
Journal of immunology
2015; 195 (8): 3737-3747
Hepatitis C virus (HCV) is the world's most common blood-borne viral infection for which there is no vaccine. The rates of vertical transmission range between 3 and 6% with odds 90% higher in the presence of HIV coinfection. Prevention of vertical transmission is not possible because of lack of an approved therapy for use in pregnancy or an effective vaccine. Recently, HCV has been identified as an independent risk factor for preterm delivery, perinatal mortality, and other complications. In this study, we characterized the immune responses that contribute to the control of viral infection at the maternal-fetal interface (MFI) in the early gestational stages. In this study, we show that primary human trophoblast cells and an extravillous trophoblast cell line (HTR8), from first and second trimester of pregnancy, express receptors relevant for HCV binding/entry and are permissive for HCV uptake. We found that HCV-RNA sensing by human trophoblast cells induces robust upregulation of type I/III IFNs and secretion of multiple chemokines that elicit recruitment and activation of decidual NK cells. Furthermore, we observed that HCV-RNA transfection induces a proapoptotic response within HTR8 that could affect the morphology of the placenta. To our knowledge, for the first time, we demonstrate that HCV-RNA sensing by human trophoblast cells elicits a strong antiviral response that alters the recruitment and activation of innate immune cells at the MFI. This work provides a paradigm shift in our understanding of HCV-specific immunity at the MFI as well as novel insights into mechanisms that limit vertical transmission but may paradoxically lead to virus-related pregnancy complications.
View details for DOI 10.4049/jimmunol.1500409
View details for PubMedID 26342030
Baseline placental growth factor levels for the prediction of benefit from early aspirin prophylaxis for preeclampsia prevention
PREGNANCY HYPERTENSION-AN INTERNATIONAL JOURNAL OF WOMENS CARDIOVASCULAR HEALTH
2015; 5 (4): 280-286
Placental growth factor (PlGF) levels early in pregnancy are lower in women who ultimately develop preeclampsia. Early initiation of low-dose aspirin reduces preeclampsia risk in some high risk women. We hypothesized that low PlGF levels may identify women at increased risk for preeclampsia who would benefit from aspirin.Secondary analysis of the MFMU High-Risk Aspirin study including singleton pregnancies randomized to aspirin 60mg/d (n=102) or placebo (n=72), with PlGF collected at 13w 0d-16w 6d. Within the placebo group, we estimated the probability of preeclampsia by PlGF level using logistic regression analysis, then determined a potential PlGF threshold for preeclampsia prediction using ROC analysis. We performed logistic regression modeling for potential confounders.ROC analysis indicated 87.71pg/ml as the threshold between high and low PlGF for preeclampsia-prediction. Within the placebo group high PlGF weakly predicted preeclampsia (AUC 0.653, sensitivity/specificity 63%/66%). We noted a 2.6-fold reduction in preeclampsia with aspirin in the high-PlGF group (12.15% aspirin vs 32.14% placebo, p=0.057), but no significant differences in preeclampsia in the low PlGF group (21.74% vs 15.91%, p=0.445).Unlike other studies, we found that high rather than low PlGF levels were associated with an increased preeclampsia risk. Low PlGF neither identified women at increased risk of preeclampsia nor women who benefitted from aspirin. Further research is needed to determine whether aspirin is beneficial in women with high PlGF, and whether the paradigm linking low PlGF and preeclampsia needs to be reevaluated.High-risk women with low baseline PlGF, a risk factor for preeclampsia, did not benefit from early initiation of low-dose aspirin.
View details for DOI 10.1016/j.preghy.2015.06.001
View details for Web of Science ID 000366078600005
View details for PubMedID 26597741
View details for PubMedCentralID PMC4841270
A Hertzian contact mechanics based formulation to improve ultrasound elastography assessment of uterine cervical tissue stiffness
JOURNAL OF BIOMECHANICS
2015; 48 (9): 1524-1532
Clinical practice requires improved techniques to assess human cervical tissue properties, especially at the internal os, or orifice, of the uterine cervix. Ultrasound elastography (UE) holds promise for non-invasively monitoring cervical stiffness throughout pregnancy. However, this technique provides qualitative strain images that cannot be linked to a material property (e.g., Young's modulus) without knowledge of the contact pressure under a rounded transvaginal transducer probe and correction for the resulting non-uniform strain dissipation. One technique to standardize elastogram images incorporates a material of known properties and uses one-dimensional, uniaxial Hooke's law to calculate Young's modulus within the compressed material half-space. However, this method does not account for strain dissipation and the strains that evolve in three-dimensional space. We demonstrate that an analytical approach based on 3D Hertzian contact mechanics provides a reasonable first approximation to correct for UE strain dissipation underneath a round transvaginal transducer probe and thus improves UE-derived estimates of tissue modulus. We validate the proposed analytical solution and evaluate sources of error using a finite element model. As compared to 1D uniaxial Hooke's law, the Hertzian contact-based solution yields significantly improved Young's modulus predictions in three homogeneous gelatin tissue phantoms possessing different moduli. We also demonstrate the feasibility of using this technique to image human cervical tissue, where UE-derived moduli estimations for the uterine cervix anterior lip agreed well with published, experimentally obtained values. Overall, UE with an attached reference standard and a Hertzian contact-based correction holds promise for improving quantitative estimates of cervical tissue modulus.
View details for DOI 10.1016/j.jbiomech.2015.03.032
View details for PubMedID 26003483
Acute Subclinical Maternal Inflammation in Late Pregnancy
SAGE PUBLICATIONS INC. 2015: 89A–90A
View details for Web of Science ID 000351407200104
Inflammatory predictors of neurologic disability after preterm premature rupture of membranes.
American journal of obstetrics and gynecology
2015; 212 (2): 212.e1–9
The maternal-fetal inflammatory response contributes to both preterm premature rupture of membranes (PPROM) and adverse neurological outcomes. Additionally, cytokines associated with fetal placental inflammation can be detrimental to brain development regardless of inciting infection. We investigated whether differential patterns of cytokine markers in maternal and fetal plasma samples reflect subtypes of placental inflammation and neurological outcomes at 6 months in infants born to mothers with PPROM.Within a prospective cohort study of 25 women with PPROM, plasma cytokines (interleukin [IL]-1β, IL-6, IL-8, and tumor necrosis factor-α) were measured by enzyme-linked immunosorbent assay from maternal blood samples at rupture and delivery, and from fetal umbilical cord blood samples. Patterns of cytokine expression were correlated with specific placenta pathologies. Infants underwent cranial ultrasound after birth and standardized neurological examinations at 6 months' corrected gestational age. Predictors of inflammation and adverse neurological outcome were assessed by logistic regression, adjusting for gestational age at birth.Inflammation of the fetal side of the placenta was associated with elevated maternal IL-6 and IL-8 at delivery and fetal IL-1β, IL-6, IL-8, and tumor necrosis factor-α. Worse neurological outcome at 6 months was associated with inflammation of the fetal side of the placenta and shorter duration from rupture of membrane to delivery, independent of gestational age at birth or cranial ultrasound results.Our findings support the connection between fetal inflammation with adverse neurological outcome with PPROM, regardless of cranial ultrasound results. Further longitudinal studies are needed to adequately examine these patterns, and will aid in risk assessment and intervention strategies.
View details for PubMedID 25223243
Maternal and fetal alternative complement pathway activation in early severe preeclampsia.
American journal of reproductive immunology (New York, N.Y. : 1989)
2014; 71 (1): 55–60
We sought to determine whether alternative complement activation fragment Bb (Bb) levels are elevated in the maternal, fetal, and placental blood in cases of severe preeclampsia (PE) compared with normotensive controls.This was a cross-sectional study of women admitted at ≥24 weeks gestation with or without severe PE. Maternal plasma was collected at the time of enrollment. Umbilical venous cord and intervillous space blood were collected at delivery. Plasma Bb levels were assessed using ELISA. Bb levels were compared between cases and controls.Median Bb levels were higher in the maternal plasma of severe PE subjects (n = 24) than in controls (n = 20), 1.45 ± 1.03 versus 0.65 ± 0.23 μg/mL, P < 0.001. In umbilical venous plasma, Bb levels were higher in severe PE subjects (n = 15) compared with controls (n = 15), 2.48 ± 1.40 versus 1.01 ± 0.57 μg/mL, P = 0.01.Activation fragment Bb is increased in the maternal and umbilical venous blood of cases of severe PE when compared with normotensive controls. These data provide support for alternative complement pathway involvement in the pathogenesis of severe PE and demonstrate that alternative complement activation occurs not only in the maternal but also in the fetal compartment.
View details for PubMedID 24128411
The discovery of a reciprocal relationship between tyrosine-kinase signaling and cullin neddylation.
2013; 8 (10): e75200
While neddylation is known to activate cullin (CUL)-RING ubiquitin ligases (CRLs), its role in regulating T cell signaling is poorly understood. Using the investigational NEDD8 activating enzyme (NAE) inhibitor, MLN4924, we found that neddylation negatively regulates T cell receptor (TCR) signaling, as its inhibition increases IL-2 production, T cell proliferation and Treg development in vitro. We also discovered that loss of CUL neddylation occurs upon TCR signaling, and CRLs negatively regulate IL-2 production. Additionally, we found that tyrosine kinase signaling leads to CUL deneddylation in multiple cell types. These studies indicate that CUL neddylation is a global regulatory mechanism for tyrosine kinase signaling.
View details for PubMedID 24124476
Siglec-6 is expressed in gestational trophoblastic disease and affects proliferation, apoptosis and invasion.
2012; 19 (6): 827–40
Sialic acid immunoglobulin-like lectin (Siglec)-6 is a transmembrane receptor that binds leptin. Leptin is an obesity-associated peptide hormone overexpressed in gestational trophoblastic disease (GTD). GTD encompasses several placental abnormalities that range from benign to malignant. Among GTD, molar placentas are characterized by excess proliferation, whereas gestational trophoblastic neoplasias (GTN) have characteristically aggressive invasion. We hypothesized that in GTD, Siglec-6 expression would increase with disease severity and that Siglec-6 and leptin would promote proliferation, inhibit apoptosis and/or promote invasion. Siglec-6 expression patterns were evaluated with particular attention to the diagnostic utility of Siglec-6 in GTD (controls: normal placentas (n=32), hydropic abortus placentas (n=7), non-GTD reproductive tract cancers (n=2); GTD: partial moles (PM; n=11), complete moles (n=24), GTN (n=6)). In normal placentas, Siglec-6 expression dramatically decreased after 8 weeks gestation. Complete molar placentas had significantly higher Siglec-6 expression than controls, but expression was not significantly different from PM. In GTN, Siglec-6 expression was low. These data suggest that Siglec-6 may have diagnostic utility for distinguishing complete moles from normal and hydropic abortus placentas. Functional studies in choriocarcinoma-derived BeWO cells demonstrated a complex interplay between Siglec-6 expression and leptin exposure. In cells lacking Siglec-6, leptin treatment promoted invasion, likely through interaction with LepR leptin receptor, without affecting proliferation or apoptosis. Siglec-6 expression promoted proliferation in a leptin-dependent manner, but protected cells from apoptosis and promoted invasion in a leptin-independent manner. We propose that Siglec-6 and leptin play a role in the aberrant properties characteristic of GTD, namely excess proliferation and invasion.
View details for PubMedID 23089140
Pandemic influenza A H1N1 2009 infection versus vaccination: a cohort study comparing immune responses in pregnancy.
2012; 7 (3): e33048
With the emergence of H1N1 pandemic (pH1N1) influenza, the CDC recommended that pregnant women be one of five initial target groups to receive the 2009 monovalent H1N1 vaccine, regardless of prior infection with this influenza strain. We sought to compare the immune response of pregnant women to H1N1 infection versus vaccination and to determine the extent of passive immunity conferred to the newborn.During the 2009-2010 influenza season, we enrolled a cohort of women who either had confirmed pH1N1 infection during pregnancy, did not have pH1N1 during pregnancy but were vaccinated against pH1N1, or did not have illness or vaccination. Maternal and umbilical cord venous blood samples were collected at delivery. Hemagglutination inhibition assays (HAI) for pH1N1 were performed. Data were analyzed using linear regression analyses. HAIs were performed for matched maternal/cord blood pairs for 16 women with confirmed pH1N1 infection, 14 women vaccinated against pH1N1, and 10 women without infection or vaccination. We found that pH1N1 vaccination and wild-type infection during pregnancy did not differ with respect to (1) HAI titers at delivery, (2) HAI antibody decay slopes over time, and (3) HAI titers in the cord blood.Vaccination against pH1N1 confers a similar HAI antibody response as compared to pH1N1 infection during pregnancy, both in quantity and quality. Illness or vaccination during pregnancy confers passive immunity to the newborn.
View details for PubMedID 22457731
Pre-eclampsia is associated with elevated CXCL12 levels in placental syncytiotrophoblasts and maternal blood
EUROPEAN JOURNAL OF OBSTETRICS & GYNECOLOGY AND REPRODUCTIVE BIOLOGY
2011; 157 (1): 32–37
Placental derived vasculogenic/angiogenic substances in maternal blood are dysregulated in pre-eclampsia. We hypothesized that CXCL12, a chemokine with vasculogenic actions, is amongst such molecules.CXCL12, CXCL16, CXCR4, and CXCR6 immunolocalization in placental tissue was analyzed in pre-eclampsia (n=8) in comparison to controls (n=8). CXCL12, measured by ELISA in blood, in women diagnosed with pre-eclampsia (n=14) and prior to the development of pre-eclampsia (at 20 weeks' gestation, n=20) was compared with CXCL12 concentrations in gestation-matched, healthy control subjects (n=34).In placental tissue, syncytiotrophoblast staining for CXCL12 was increased in pre-eclampsia. Maternal serum CXCL12 was increased in pre-eclampsia [2000 (SD 402) vs 1484 (SD 261)pg/ml, P=0.01] but not in plasma obtained at 20 weeks of gestation prior to the onset of pre-eclampsia [1183 (SD 336) vs 1036 (SD 144)pg/ml, P=0.09].Our data suggest that the syncytiotrophoblast contributes to a pre-eclampsia-associated increase in CXCL12 levels in maternal blood. These findings support the hypothesis that an imbalance of angiogenic factors contributes to the pathogenesis of pre-eclampsia.
View details for DOI 10.1016/j.ejogrb.2011.02.023
View details for Web of Science ID 000292948100007
View details for PubMedID 21450389
The Impact of Preeclampsia on Gene Expression at the Maternal-Fetal Interface.
2011; 1 (1): 100–108
Preeclampsia (PE) impacts 8 million mother-infant pairs worldwide each year. This human pregnancy-specific disease characterized by hypertension and proteinuria accounts for significant maternal and neonatal morbidity and mortality. The current theory of the pathogenesis of PE as reviewed by Drs. Christopher Redman and Ian Sargent is thought to occur as a 2-stage process with poor placentation in the first half of pregnancy resulting in the maternal response in the second half of pregnancy. Our studies have focused on understanding the placental contribution to this serious disease by examining the gene expression profile of the deciduas basalis or basal plate, the region of the placenta involved in the "poor placentation". In this review we present summaries of our microarray datasets both of normal placentation and those gene expression changes resulting in the context of PE. Additionally, we have taken this opportunity to combine the data sets to provide a more comprehensive view of this region of the placenta. As defects in the basal plate are, in part, at the root of the disease process, we believe that understanding the pathobiology that occurs in this region will increase our ability to alter the development and/or course of PE.
View details for PubMedID 21743843
Severe Preeclampsia-Related Changes in Gene Expression at the Maternal-Fetal Interface Include Sialic Acid-Binding Immunoglobulin-Like Lectin-6 and Pappalysin-2
2009; 150 (1): 452–62
Preeclampsia (PE), which affects 4-8% of human pregnancies, causes significant maternal and neonatal morbidity and mortality. Within the basal plate, placental cytotrophoblasts (CTBs) of fetal origin invade the uterus and extensively remodel the maternal vasculature. In PE, CTB invasion is often shallow, and vascular remodeling is rudimentary. To better understand possible causes, we conducted a global analysis of gene expression at the maternal-fetal interface in placental samples from women with PE (n = 12; 24-36 wk) vs. samples from women who delivered due to preterm labor with no evidence of infection (n = 11; 24-36 wk), a condition that our previous work showed is associated with normal CTB invasion. Using the HG-U133A&B Affymetrix GeneChip platform, and statistical significance set at log odds-ratio of B >0, 55 genes were differentially expressed in PE. They encoded proteins previously associated with PE [e.g. Flt-1 (vascular endothelial growth factor receptor-1), leptin, CRH, and inhibin] and novel molecules [e.g. sialic acid binding Ig-like lectin 6 (Siglec-6), a potential leptin receptor, and pappalysin-2 (PAPP-A2), a protease that cleaves IGF-binding proteins]. We used quantitative PCR to validate the expression patterns of a subset of the genes. At the protein level, we confirmed PE-related changes in the expression of Siglec-6 and PAPP-A2, which localized to invasive CTBs and syncytiotrophoblasts. Notably, Siglec-6 placental expression is uniquely human, as is spontaneous PE. The functional significance of these novel observations may provide new insights into the pathogenesis of PE, and assaying the circulating levels of these proteins could have clinical utility for predicting and/or diagnosing PE.
View details for DOI 10.1210/en.2008-0990
View details for Web of Science ID 000262052300050
View details for PubMedID 18818296
View details for PubMedCentralID PMC2630905
Cytotrophoblast induction of arterial apoptosis and lymphangiogenesis in an in vivo model of human placentation
JOURNAL OF CLINICAL INVESTIGATION
2006; 116 (10): 2643–52
We studied the vascular effects of invasive human cytotrophoblasts in vivo by transplanting placental villi to the fifth mammary fat pads or beneath the kidney capsules of Scid mice. Over 3 weeks, robust cytotrophoblast invasion was observed in both locations. The architecture of the mammary fat pad allowed for detailed analysis of the cells' interactions with resident murine blood vessels, which revealed specific induction of apoptosis in the endothelial cells and smooth muscle walls of the arterioles. This finding, and confirmation of the results in an in vitro coculture model, suggests that a parallel process is important for enabling cytotrophoblast endovascular invasion during human pregnancy. Cytotrophoblast invasion of the kidney parenchyma was accompanied by a robust lymphangiogenic response, while in vitro, the cells stimulated lymphatic endothelial cell migration via the actions of VEGF family members, FGF, and TNF-alpha. Immunolocalization analyses revealed that human pregnancy is associated with lymphangiogenesis in the decidua since lymphatic vessels were not a prominent feature of the nonpregnant endometrium. Thus, the placenta triggers the development of a decidual lymphatic circulation, which we theorize plays an important role in maintaining fluid balance during pregnancy, with possible implications for maternal-fetal immune cell trafficking.
View details for DOI 10.1172/JC127306
View details for Web of Science ID 000240965700014
View details for PubMedID 16998586
View details for PubMedCentralID PMC1570373
Echogenic intracardiac focus - Potential for misdiagnosis
JOURNAL OF ULTRASOUND IN MEDICINE
2003; 22 (11): 1207–14
To assess the potential rate of specular reflectors within the fetal heart producing reflections of sufficient amplitude to be mistaken for echogenic intracardiac foci.Between July 1999 and December 2000, 200 patients were randomly selected from the University of California, San Francisco, perinatal database who met the following criteria: (1) had singleton pregnancy, (2) delivered at University of California, San Francisco, and (3) had obstetric sonography at University of California, San Francisco, between 18 and 22 weeks' gestation. Bright focal reflections within the heart were judged to be either "true" or "false" echogenic intracardiac foci.In this population of patients who underwent routine obstetric sonography at a tertiary care hospital, the rate of true echogenic intracardiac focus cases was 11 per 200 (5.5%). The rate of false echogenic intracardiac focus cases was 34 per 200 (17%). The most common locations for identification of a spurious echogenic intracardiac focus were the endocardial cushion, the moderator band, and the tricuspid valve annulus.A specular reflection from the moderator band was judged the false echogenic intracardiac focus most likely to fool examiners. The rate of specular reflection from the moderator band was 11 per 200 (5.5%). Because it is possible to generate a specular reflection from an interface in the fetal heart in virtually any patient, it is important to exercise caution before diagnosing an echogenic intracardiac focus.
View details for DOI 10.7863/jum.2003.22.11.1207
View details for Web of Science ID 000186284000010
View details for PubMedID 14620892