Sandra A. Founds

Altered Global Gene Expression in First Trimester Placentas of Women Destined to Develop Preeclampsia

BACKGROUND Preeclampsia is a pregnancy-specific disorder that remains a leading cause of maternal, fetal and neonatal morbidity and mortality, and is associated with risk for future cardiovascular disease. There are no reliable predictors, specific preventative measures or treatments other than delivery. A widely held view is that the antecedents of preeclampsia lie with impaired placentation in early pregnancy. Accordingly, we hypothesized dysregulation of global gene expression in first trimester placentas of women who later manifested preeclampsia. METHODS Surplus chorionic villus sampling (CVS) tissues were collected at 10-12 weeks gestation in 160 patients with singleton fetuses. Four patients developed preeclampsia, and their banked CVS specimens were matched to 8 control samples from patients with unaffected pregnancies. Affymetrix HG-U133 Plus 2.0 GeneChips were utilized for microarray analysis. Naïve Bayes prediction modeling and pathway analysis were conducted. qRT-PCR examined three of the dysregulated genes. RESULTS Thirty-six differentially expressed genes were identified in the preeclampsia placentas. qRT-PCR verified the microarray analysis. Thirty-one genes were down-regulated. Many were related to inflammation/immunoregulation and cell motility. Decidual gene dysregulation was prominent. No evidence was found for alterations in hypoxia and oxidative stress regulated genes. CONCLUSIONS To our knowledge, this is the first study to show dysregulation of gene expression in the early placentas of women approximately 6 months before developing preeclampsia, thereby reinforcing a placental origin of the disorder. We hypothesize that placentation in preeclampsia is compromised in the first trimester by maternal and fetal immune dysregulation, abnormal decidualization, or both, thereby impairing trophoblast invasion. Several of the genes provide potential targets for the development of clinical biomarkers in maternal blood during the first trimester. Supplementary materials are available for this article via the publishers online edition.

Genome-wide expression profile of first trimester villous and extravillous human trophoblast cells

We have examined the transcriptional changes associated with differentiation from villous to extravillous trophoblast using a whole genome microarray. Villous trophoblast (VT) is in contact with maternal blood and mediates nutrient exchange whereas extravillous trophoblast (EVT) invades the decidua and remodels uterine arteries. Using highly purified first trimester trophoblast we identified over 3000 transcripts that are differentially expressed. Many of these transcripts represent novel functions and pathways that show co-ordinated up-regulation in VT or EVT. In addition we identify new players in established functions such as migration, immune modulation and cytokine or angiogenic factor secretion by EVT. The transition from VT to EVT is also characterised by alterations in transcription factors such as STAT4 and IRF9, which may co-ordinate these changes. Transcripts encoding several members of the immunoglobulin-superfamily, which are normally expressed on leukocytes, were highly transcribed in EVT but not expressed as protein, indicating specific control of translation in EVT. Interactions of trophoblast with decidual leukocytes are involved in regulating EVT invasion. We show that decidual T-cells, macrophages and NK cells express the inhibitory collagen receptor LAIR-1 and that EVT secrete LAIR-2, which can block this interaction. This represents a new mechanism by which EVT can modulate leukocyte function in the decidua. Since LAIR-2 is detectable in the urine of pregnant, but not non-pregnant women, trophoblast-derived LAIR-2 may also have systemic effects during pregnancy.

A Comparison of Circulating TNF Alpha in Obese and Lean Women With and Without Preeclampsia

Objectives: We hypothesized that TNF-α would be higher in obese versus lean women with preeclampsia. Methods: Total plasma TNF-α was measured in a nested case-control study of 123 nulliparous lean and obese control women and women with preeclampsia. Results: Adjusted mean TNF-α concentrations were 0.97 ± 0.11 (pg/mL ± SEM) in lean controls, 1.01 ± 0.10 in obese controls, 1.43 ± 0.11 in lean women with preeclampsia and 1.16 ± 0.11 in obese women with preeclampsia. Pregnancy outcome was the single predictor of TNF-α concentration in the general linear regression model (p = 0.04). Conclusion: TNF-α concentration was higher in preeclampsia compared with control subjects. Obesity was not associated with higher TNF-α concentrations in either preeclampsia or control subjects.

Microarray Technology Applied to the Complex Disorder of Preeclampsia

Preeclampsia is a life-threatening perinatal complication with unknown etiology. Microarray technology has characterized global gene expression in complex disorders such as preeclampsia. Nursing research and future practice may incorporate findings from microarray analyses to identify susceptibility to and prevent disease, to diagnose early, and to design and monitor personalized therapies. This overview of microarray technology, with emphasis on how it can inform genomics of preeclampsia, may provide concepts to improve future maternal-neonatal nursing care.

Gene Expression in First Trimester Preeclampsia Placenta

Background. The goal of this study was to further validate eight candidate genes identified in a microarray analysis of first trimester placentas in preeclampsia. Material and method. Surplus chorionic villus sampling (CVS) specimens of 4 women subsequently diagnosed with preeclampsia (PE) and 8 control women (C) without preeclampsia analyzed previously by microarray and 24 independent additional control samples (AS) were submitted for confirmatory studies by quantitative real-time polymerase chain reaction (qRT-PCR). Results. Downregulation was significant in FSTL3 in PE as compared to C and AS (p = .04). PAEP was downregulated, but the difference was only significant between C and AS (p = .002) rather than between PE and either of the control groups. Expression levels for CFH, EPAS1, IGFBP1, MMP12, and SEMA3C were not statistically different among groups, but trends were consistent with microarray results; there was no anti-correlation. S100A8 was not measurable in all samples, probably because different probes and primers were needed. Conclusions. This study corroborates reduced FSTL3 expression in the first trimester of preeclampsia. Nonsignificant trends in the other genes may require follow-up in studies powered for medium or medium/large effect sizes. qRT-PCR verification of the prior microarray of CVS may support the placental origins of preeclampsia hypothesis. Replication is needed for the candidate genes as potential biomarkers of susceptibility, early detection, and/or individualized care of maternal—infant preeclampsia.

Development of high-fidelity simulated clinical experiences for baccalaureate nursing students.

High-fidelity simulators offer a teaching tool for nurse educators to provide lifelike simulated clinical experiences for baccalaureate nursing students. A group of faculty teaching a variety of clinical courses followed similar steps within frameworks of the American Association of Colleges of Nursing essentials and education theories to create case scenarios. The benefits of simulation experiences for students are discussed and a template for the nurse educator is provided to help develop simulations. This system is illustrated by an example from a high-risk antepartum obstetric scenario.

LAIR2 localizes specifically to sites of extravillous trophoblast invasion

PURPOSE A global gene expression microarray analysis of surplus chorionic villus sampling (CVS) tissues identified leukocyte-associated immunoglobulin-like receptor 2 (LAIR2) as down-regulated in the first trimester of pregnancies destined for preeclampsia. Neither the localization nor the function of LAIR2 has been examined in the placenta. Localization studies were conducted in placental tissues to determine the precise sites of LAIR2 mRNA production and protein binding. RESULTS Quantitative real time polymerase chain reaction (qRT-PCR) indicated LAIR2 expression in CVS, but none in breast, lymph node, kidney, skin, uterus, or third trimester placentas. In situ hybridization (ISH) revealed a highly restricted LAIR2 localization. LAIR2 mRNA was found only in the more distal portions of trophoblast anchoring cell columns, adjacent to the invading extravillous trophoblast (EVT). Immunohistochemistry (IHC) detected intracellular LAIR2 staining in these same cells. Extracellular staining of this soluble receptor was found in the acellular material between invasive EVT cells distal to the anchoring cell columns. CONCLUSIONS ISH and IHC staining for LAIR2 detected specific, highly localized expression at the leading edge of EVT anchoring cell columns in first trimester placentas. This staining likely identifies the site of production for this soluble receptor. Following secretion, the receptor appears to bind extracellular material among the invasive EVT. The precise restriction of this protein only to the sites of EVT invasion strongly suggests that it functions to regulate this invasion. The decreased LAIR2 expression noted in first trimester placentas that ultimately developed preeclampsia further suggests that alterations in LAIR2 may play an etiologic role in preeclampsia.

Is There Evidence of Separate Inflammatory or Metabolic Forms of Preeclampsia

Objectives. To examine whether high insulin resistance versus high inflammation identifies subtypes of preeclampsia. Methods. A cytokine panel, glucose and insulin were measured in 37 preeclampsia plasma samples. Wilcoxon rank sum assessed median concentration of HOMAIR by pro-inflammatory:anti-inflammatory ratio. Regression stratifying by BMI and preterm birth was conducted. Results. There was no difference in median HOMAIR by the pro-inflammatory:anti-inflammatory ratio (p = 0.16). No subsets scatterplot clusters emerged. A positive correlation between HOMAlog and the ratio was significant (p = 0.04). Conclusions. No dichotomous subsets of preeclampsia by inflammation versus insulin resistance were detected. Contrary to our hypothesis, insulin resistance was higher as inflammation increased in preeclampsia.

Variation in endoglin pathway genes is associated with preeclampsia: a case-control candidate gene association study.

BackgroundPreeclampsia is a hypertensive, multi-system pregnancy disorder whose pathophysiology remains unclear. Elevations in circulating soluble endoglin (sENG) and placental/blood ENG mRNA expression antedate the clinical onset of preeclampsia. This study investigated if endoglin (ENG) pathway genetic variation was also associated with the development of preeclampsia.MethodsWe used a case–control candidate gene association design. Data from 355 white (181 preeclampsia cases/174 controls) and 60 black (30 preeclampsia cases/30 controls) women matched on ancestry, age, and parity were analyzed. Tagging single nucleotide polymorphisms (tSNPs) and potentially functional SNPs in ENG, TGFβ1, TGFβR1, ALK1, and TGFβR2 were genotyped with iPLEX® and TaqMan®. Chi-square or Fisher’s exact tests were used to conduct allele/genotype/haplotype tests in white/black subgroups separately. Odds ratios were computed with binary logistic regression for tSNPs with significant genotype tests.ResultsOf the 49 SNPs evaluated, variation in two ENG tSNPs (rs11792480, rs10121110) and one TGFβR2 tSNP (rs6550005) was associated with preeclampsia in white women (P <0.05, each). In black women, variation in two TGFβ1 tSNPs (rs4803455, rs4803457), one TGFβR1 tSNP (rs10739778), and three TGFβR2 tSNPs (rs6550005, rs1346907, rs877572) was associated with preeclampsia (P <0.05, each). Further evaluation of ENG tSNP rs10121110 revealed that white women inheriting the AA genotype were 2.29 times more likely to develop preeclampsia compared to the GG genotype (P = 0.008, [99% CI: 1.02 to 5.13]). For black women, similar evaluation of TGFβ1 tSNP rs4803457 revealed women inheriting the CT genotype were 7.44 times more likely to develop preeclampsia than those with the CC genotype (P = 0.005, [99% CI: 1.19 to 46.41]).ConclusionsENG pathway genetic variation is associated with preeclampsia. Different ENG pathway genes may be involved in preeclampsia development among white and black women. Additional studies are needed to validate these findings and to determine if genetic variation in ENG pathway genes impacts ENG and sENG levels in preeclampsia.

LAIR2-expressing extravillous trophoblasts associate with maternal spiral arterioles undergoing physiologic conversion

Leukocyte-associated immunoglobulin-like receptor 2 (LAIR2) was identified on a global gene expression microarray analysis of surplus chorionic villus sampling (CVS) tissues as down-regulated in the first trimester of preeclampsia pregnancies. LAIR2 is the soluble receptor counterpart to LAIR1, an inhibitory receptor found on multiple immune cell subsets. In situ and immunohistochemical studies have previously shown that placental expression of LAIR2 expression is highly restricted, confined to the more distal portions of extravillous trophoblast (EVT) cell columns. This study examines LAIR2 expression in deeper layers of trophoblasts in the placental implantation site, maternal decidua and maternal spiral arterioles. Immunohistochemical staining detected LAIR2 expression on a subset of EVT within the implantation site. This trophoblast included the invasive EVT infiltrating the maternal decidual vessels and the EVT forming the endovascular trophoblastic plugs. More specifically, LAIR2-positive EVT showed a striking predilection for maternal decidual arterioles and the immediately surrounding decidua. Moreover, the appearance of EVT expressing LAIR2 in these areas was contemporaneous with the process of spiral arteriole remodeling. Based on these findings, we suggest that LAIR2-expressing EVT may play an important role in the remodeling of maternal spiral arterioles.