Imbalances in circulating angiogenic factors in the pathophysiology of preeclampsia and related disorders.

Preeclampsia is a devastating medical complication of pregnancy that can lead to significant maternal and fetal morbidity and mortality. It is currently believed that there is abnormal placentation in as early as the first trimester in women destined to develop preeclampsia. Although the etiology of the abnormal placentation is being debated, numerous epidemiologic and experimental studies suggest that imbalances in circulating angiogenic factors released from the placenta are responsible for the maternal signs and symptoms of preeclampsia. In particular, circulating levels of soluble fms-like tyrosine kinase 1, an antiangiogenic factor, are markedly increased in women with preeclampsia, whereas free levels of its ligand, placental, growth factor are markedly diminished. Alterations in these angiogenic factors precede the onset of clinical signs of preeclampsia and correlate with disease severity. Recently, the availability of automated assays for the measurement of angiogenic biomarkers in the plasma, serum, and urine has helped investigators worldwide to demonstrate a key role for these factors in the clinical diagnosis and prediction of preeclampsia. Numerous studies have reported that circulating angiogenic biomarkers have a very high negative predictive value to rule out clinical disease among women with suspected preeclampsia. These blood-based biomarkers have provided a valuable tool to clinicians to accelerate the time to clinical diagnosis and minimize maternal adverse outcomes in women with preeclampsia. Angiogenic biomarkers have also been useful to elucidate the pathogenesis of related disorders of abnormal placentation such as intrauterine growth restriction, intrauterine fetal death, twin-to-twin transfusion syndrome, and fetal hydrops. In summary, the discovery and characterization of angiogenic proteins of placental origin have provided clinicians a noninvasive blood-based tool to monitor placental function and health and for early detection of disorders of placentation. Uncovering the mechanisms of altered angiogenic factors in preeclampsia and related disorders of placentation may provide insights into novel preventive and therapeutic options.

Fine-Tuning Lipid Metabolism by Targeting Mitochondria-Associated Acetyl-CoA-Carboxylase 2 in BRAFV600E Papillary Thyroid Carcinoma.

Background: BRAFV600E acts as an ATP-dependent cytosolic kinase. BRAFV600E inhibitors are widely available, but resistance to them is widely reported in the clinic. Lipid metabolism (fatty acids) is fundamental for energy and to control cell stress. Whether and how BRAFV600E impacts lipid metabolism regulation in papillary thyroid carcinoma (PTC) is still unknown. Acetyl-CoA carboxylase (ACC) is a rate-limiting enzyme for de novo lipid synthesis and inhibition of fatty acid oxidation (FAO). ACC1 and ACC2 genes encode distinct isoforms of ACC. The aim of our study was to determine the relationship between BRAFV600E and ACC in PTC. Methods: We performed RNA-seq and DNA copy number analyses in PTC and normal thyroid (NT) in The Cancer Genome Atlas samples. Validations were performed by using assays on PTC-derived cell lines of differing BRAF status and a xenograft mouse model derived from a heterozygous BRAFWT/V600E PTC-derived cell line with knockdown (sh) of ACC1 or ACC2. Results:ACC2 mRNA expression was significantly downregulated in BRAFV600E-PTC vs. BRAFWT-PTC or NT clinical samples. ACC2 protein levels were downregulated in BRAFV600E-PTC cell lines vs. the BRAFWT/WT PTC cell line. Vemurafenib increased ACC2 (and to a lesser extent ACC1) mRNA levels in PTC-derived cell lines in a BRAFV600E allelic dose-dependent manner. BRAFV600E inhibition increased de novo lipid synthesis rates, and decreased FAO due to oxygen consumption rate (OCR), and extracellular acidification rate (ECAR), after addition of palmitate. Only shACC2 significantly increased OCR rates due to FAO, while it decreased ECAR in BRAFV600E PTC-derived cells vs. controls. BRAFV600E inhibition synergized with shACC2 to increase intracellular reactive oxygen species production, leading to increased cell proliferation and, ultimately, vemurafenib resistance. Mice implanted with a BRAFWT/V600E PTC-derived cell line with shACC2 showed significantly increased tumor growth after vemurafenib treatment, while vehicle-treated controls, or shGFP control cells treated with vemurafenib showed stable tumor growth. Conclusions: These findings suggest a potential link between BRAFV600E and lipid metabolism regulation in PTC. BRAFV600E downregulates ACC2 levels, which deregulates de novo lipid synthesis, FAO due to OCR, and ECAR rates. ShACC2 may contribute to vemurafenib resistance and increased tumor growth. ACC2 rescue may represent a novel molecular strategy for overcoming resistance to BRAFV600E inhibitors in refractory PTC.

A mouse model of placenta accreta spectrum.

INTRODUCTION: Placenta Accreta Spectrum (PAS) disorder is one of the leading causes of maternal morbidity and mortality due to uncontrollable hemorrhage. The greatest risk factor for development of PAS is prior uterine surgery, frequently cesarean delivery. Despite considerable clinical knowledge, animal models of PAS are lacking. To address this, we used two surgical approaches to create uterine scarring in peripartum and non-pregnant CD-1 mice. Il10-/- mice, with a pro-inflammatory phenotype were also studied. METHODS: In peripartum mice, a hysterotomy was performed to simulate a cesarean section. The second approach utilized endometrial curettage in non-pregnant mice. Sham-operated mice served as control. Following recovery, females were mated. On gestation day 16, pregnant females were euthanized, and the uterus was excised. Tissue was fixed, sectioned, and stained with H&E or cytokeratin immunohistochemistry. The cytokeratin-positive area extending beyond the trophoblast giant cells was measured by quantitative image analysis. Disruption of the circular (inner myometrium) smooth muscle was scored semi-quantitatively. RESULTS: In surgically scarred mice, trophoblast invasion was deeper relative to control mice, regardless of surgical method. The myometrium in experimental mice showed significant disruption compared to sham controls. Results from CD-1 and Il10-/- mice were similar, with the latter showing more severe pathology. DISCUSSION: While further refinement of surgical method is required, our data indicate that surgical uterine scarring in mice represents a promising model of PAS.

PAD4 Deficiency Decreases Inflammation and Susceptibility to Pregnancy Loss in a Mouse Model.

Inflammation is thought to play a critical role in the pathogenesis of placentation disorders such as recurrent miscarriages, growth restriction, and preeclampsia. Recently, neutrophil extracellular traps (NETs) have emerged as a potential mechanism for promoting inflammation in both infectious and noninfectious disorders. To investigate a pathogenic role for NETs in placentation disorders, we studied a model of antiangiogenic factor-mediated pregnancy loss in wild-type (WT) mice and in mice deficient in peptidylarginine deiminase 4 (Padi4-/-) that are unable to form NETs. Overexpression of soluble fms-like tyrosine kinase 1 (sFlt-1), an antiangiogenic protein that is pathogenically linked with abnormal placentation disorders during early gestation, resulted in pregnancy loss and large accumulation of neutrophils and NETs in WT placentas. Interestingly, sFlt-1 overexpression in Padi4-/- mice resulted in dramatically lower inflammatory and thrombotic response, which was accompanied by significant reduction in pregnancy losses. Inhibition of NETosis may serve as a novel target in disorders of impaired placentation.

Gelsolin is an endogenous inhibitor of syncytiotrophoblast extracellular vesicle shedding in pregnancy.

BACKGROUND: Preeclampsia, a pregnancy-specific inflammatory disorder, is characterized by high levels of anti-angiogenic protein, soluble fms-like tyrosine kinase 1 (sFlt1), in the maternal circulation. sFlt1 producing molecular machinery is present in syncytiotrophoblast extracellular vesicles that are released by the placenta into maternal plasma during normal pregnancy, a process greatly accelerated in preeclampsia. We hypothesized that syncytiotrophoblast extracellular vesicles exposes cytoplasmic actin to plasma resulting in depletion of plasma gelsolin (pGSN), an abundant plasma protein that scavenges circulating actin and other pro-inflammatory mediators. OBJECTIVE: To test whether pGSN levels would be lower in preeclampsia and to assess whether recombinant human plasma gelsolin (rhpGSN) may promote placental health by decreasing shedding of syncytiotrophoblast extracellular vesicles. METHODS: We tested pGSN levels in third trimester plasma samples from women with preeclampsia and non-hypertensive pregnancies. We then assessed whether rhpGSN may act as a negative regulator of syncytial shedding in placental explant culture and dynamic mechanical stretch studies. RESULTS: pGSN levels fall in late pregnancy and decline further in preeclampsia patients. Recombinant human pGSN (rhpGSN) at 100µg/ml limits spontaneous syncytiotrophoblast vesicle release and sFlt1 protein dissemination by normal placental explants. Higher rhpGSN doses (500µg/ml) also limit syncytiotrophoblast vesicle and sFlt1 dissemination from preeclamptic placental explants. rhpGSN also mitigates syncytiotrophoblast vesicle during dynamic mechanical stretch. CONCLUSIONS: 1) pGSN, an anti-inflammatory factor of maternal origin is reduced in preeclampsia and may contribute to disease progression and 2) exogenous rhpGSN supplementation can limit the dissemination of toxic syncytiotrophoblast vesicle that characterizes the disease state.

Induced Human Decidual NK-Like Cells Improve Utero-Placental Perfusion in Mice.

Decidual NK (dNK) cells, a distinct type of NK cell, are thought to regulate uterine spiral artery remodeling, a process that allows for increased blood delivery to the fetal-placental unit. Impairment of uterine spiral artery remodeling is associated with decreased placental perfusion, increased uterine artery resistance, and obstetric complications such as preeclampsia and intrauterine growth restriction. Ex vivo manipulation of human peripheral blood NK (pNK) cells by a combination of hypoxia, TGFß-1 and 5-aza-2'-deoxycytidine yields cells with phenotypic and in vitro functional similarities to dNK cells, called idNK cells. Here, gene expression profiling shows that CD56Bright idNK cells derived ex vivo from human pNK cells, and to a lesser extent CD56Dim idNK cells, are enriched in the gene expression signature that distinguishes dNK cells from pNK cells. When injected into immunocompromised pregnant mice with elevated uterine artery resistance, idNK cells homed to the uterus and reduced the uterine artery resistance index, suggesting improved placental perfusion.

Soluble fms-like tyrosine kinase 1 promotes angiotensin II sensitivity in preeclampsia.

Preeclampsia is a hypertensive disorder of pregnancy in which patients develop profound sensitivity to vasopressors, such as angiotensin II, and is associated with substantial morbidity for the mother and fetus. Enhanced vasoconstrictor sensitivity and elevations in soluble fms-like tyrosine kinase 1 (sFLT1), a circulating antiangiogenic protein, precede clinical signs and symptoms of preeclampsia. Here, we report that overexpression of sFlt1 in pregnant mice induced angiotensin II sensitivity and hypertension by impairing endothelial nitric oxide synthase (eNOS) phosphorylation and promoting oxidative stress in the vasculature. Administration of the NOS inhibitor l-NAME to pregnant mice recapitulated the angiotensin sensitivity and oxidative stress observed with sFlt1 overexpression. Sildenafil, an FDA-approved phosphodiesterase 5 inhibitor that enhances NO signaling, reversed sFlt1-induced hypertension and angiotensin II sensitivity in the preeclampsia mouse model. Sildenafil treatment also improved uterine blood flow, decreased uterine vascular resistance, and improved fetal weights in comparison with untreated sFlt1-expressing mice. Finally, sFLT1 protein expression inversely correlated with reductions in eNOS phosphorylation in placental tissue of human preeclampsia patients. These data support the concept that endothelial dysfunction due to high circulating sFLT1 may be the primary event leading to enhanced vasoconstrictor sensitivity that is characteristic of preeclampsia and suggest that targeting sFLT1-induced pathways may be an avenue for treating preeclampsia and improving fetal outcomes.

Excess placental secreted frizzled-related protein 1 in maternal smokers impairs fetal growth.

Maternal cigarette smoking during pregnancy remains one of the most common and preventable causes of fetal growth restriction (FGR), a condition in which a fetus is unable to achieve its genetically determined potential size. Even though epidemiologic evidence clearly links maternal cigarette smoking with FGR, insight into the molecular mechanisms of cigarette smoke-induced FGR is lacking. Here, we performed transcriptional profiling of placentas obtained from smoking mothers who delivered growth-restricted infants and identified secreted frizzled-related protein 1 (sFRP1), an extracellular antagonist of endogenous WNT signaling, as a candidate molecule. sFRP1 mRNA and protein levels were markedly upregulated (~10-fold) in placentas from smoking mothers compared with those from nonsmokers. In pregnant mice, adenovirus-mediated overexpression of sFRP1 led to FGR, increased karyorrhexis in the junctional zone, and decreased proliferation of labyrinthine trophoblasts. Consistent with our hypothesis that placental WNT signaling is suppressed in maternal smokers, we found that exposure to carbon monoxide analogs led to reduced WNT signaling, increased SFRP1 mRNA expression, and decreased cellular proliferation in a trophoblast cell line. Moreover, administration of carbon monoxide analogs to pregnant mice in late gestation led to FGR. In summary, our results indicate that the increased placental expression of sFRP1 seen in smokers impairs fetal growth by inhibiting WNT signaling and trophoblast proliferation.

Homing receptor expression is deviated on CD56+ blood lymphocytes during pregnancy in Type 1 diabetic women.

Type 1 Diabetes Mellitus (T1DM) is characterized by an augmented pro-inflammatory immune state. This contributes to the increased risk for gestational complications observed in T1DM mothers. In normal pregnancies, critical immunological changes occur, including the massive recruitment of lymphocytes, particularly CD56bright NK cells, into early decidua basalis and a 2nd trimester shift towards Type 2 immunity. Decidual CD56bright NK cells arise at least partly from circulating progenitors expressing adhesion molecules SELL and ITGA4 and the chemokine receptors CXCR3 and CXCR4. In vitro studies show that T1DM reduces interactions between blood CD56+ NK cells and decidual endothelial cells by reducing SELL and ITGA4-based interactions. To address the mechanisms by which specific lymphocyte subsets may be recruited from the circulation during pregnancy and whether these mechanisms are altered in T1DM, flow cytometry was used to examine eight peripheral blood lymphocyte subsets (Type 1 (IL18R1+) and Type 2 (IL1RL1+) CD56bright NK, CD56dim NK, NKT and T cells) from control and T1DM women. Blood was collected serially over pregnancy and postpartum, and lymphocytes were compared for expression of homing receptors SELL, ITGA4, CXCR3, and CXCR4. The decline of Type 1/Type 2 immune cells in normal pregnancy was driven by an increase in Type 2 cells that did not occur in T1DM. CD56bright NK cells from control women had the highest expression of all four receptors with greatest expression in 2nd trimester. At this time, these receptors were expressed at very low levels by CD56bright NK cells from TIDM patients. Type 1/Type 2 NKT cell ratios were not influenced by either pregnancy or TIDM. Our results suggest that T1DM alters immunological balances during pregnancy with its greatest impact on CD56bright NK cells. This implicates CD56bright NK cells in diabetic pregnancy complications.

Exposure to experimental preeclampsia in mice enhances the vascular response to future injury.

Cardiovascular disease (CVD) remains the leading killer of women in developed nations. One sex-specific risk factor is preeclampsia, a syndrome of hypertension and proteinuria that complicates 5% of pregnancies. Although preeclampsia resolves after delivery, exposed women are at increased long-term risk of premature CVD and mortality. Pre-existing CVD risk factors are associated with increased risk of developing preeclampsia but whether preeclampsia merely uncovers risk or contributes directly to future CVD remains a critical unanswered question. A mouse preeclampsia model was used to test the hypothesis that preeclampsia causes an enhanced vascular response to future vessel injury. A preeclampsia-like state was induced in pregnant CD1 mice by overexpressing soluble fms-like tyrosine kinase-1, a circulating antiangiogenic protein that induces hypertension and glomerular disease resembling human preeclampsia. Two months postpartum, soluble fms-like tyrosine kinase-1 levels and blood pressure normalized and cardiac size and function by echocardiography and renal histology were indistinguishable in preeclampsia-exposed compared with control mice. Mice were then challenged with unilateral carotid injury. Preeclampsia-exposed mice had significantly enhanced vascular remodeling with increased vascular smooth muscle cell proliferation (180% increase; P<0.01) and vessel fibrosis (216% increase; P<0.001) compared with control pregnancy. In the contralateral uninjured vessel, there was no difference in remodeling after exposure to preeclampsia. These data support a new model in which vessels exposed to preeclampsia retain a persistently enhanced vascular response to injury despite resolution of preeclampsia after delivery. This new paradigm may contribute to the substantially increased risk of CVD in woman exposed to preeclampsia.

Ouabain inhibits placental sFlt1 production by repressing HSP27-dependent HIF-1α pathway.

Up-regulation of placental soluble fms-like tyrosine kinase 1 (sFlt1) contributes to the pathogenesis of preeclampsia. To evaluate novel upstream pathways that regulate placental sFlt1 production, we screened a library of natural compounds (n=502) in human placental cell lines. Here, we report 3 compounds in the cardiac glycoside family, ouabain, gitoxigenin, and digitoxin, that inhibit placental sFlt1 production at nanomolar concentrations in vitro. We further characterized ouabain and demonstrated that it inhibits sFlt1 mRNA and protein expression in human placental cytotrophoblasts and explant cultures in a dose- and time-dependent manner. Ouabain down-regulated sFlt1 production by inhibiting hypoxia-inducible factor 1 (HIF-1α) protein expression in the placenta. Furthermore, we found that phosphorylation of heat-shock protein 27 (HSP27) was necessary for ouabain to inhibit HIF-1α translation. In a rat model of pregnancy-induced hypertension, ouabain reduced mean arterial pressure and enhanced placental HSP27 phosphorylation without any adverse effects on pups. Further studies are needed to explore the usefulness of targeting HIF-1α/HSP27 pathway in preeclampsia.

Hydrogen sulfide attenuates sFlt1-induced hypertension and renal damage by upregulating vascular endothelial growth factor.

Soluble fms-like tyrosine kinase 1 (sFlt1), a circulating antiangiogenic protein, is elevated in kidney diseases and contributes to the development of preeclampsia. Hydrogen sulfide is a vasorelaxant and proangiogenic gas with therapeutic potential in several diseases. Therefore, we evaluated the potential therapeutic effect and mechanisms of action of hydrogen sulfide in an animal model of sFlt1-induced hypertension, proteinuria, and glomerular endotheliosis created by adenovirus-mediated overexpression of sFlt1 in Sprague-Dawley rats. We injected sFlt1-overexpressing animals intraperitoneally with the hydrogen sulfide-donor sodium hydrosulfide (NaHS) (50 µmol/kg, twice daily) or vehicle (n=7 per group). Treatment with NaHS for 8 days significantly reduced sFlt1-induced hypertension, proteinuria, and glomerular endotheliosis. Measurement of plasma protein concentrations with ELISA revealed a reduction of free plasma sFlt1 and an increase of free plasma vascular endothelial growth factor (VEGF) after treatment with NaHS. Renal VEGF-A mRNA expression increased significantly with NaHS treatment. In vitro, NaHS was proangiogenic in an endothelial tube assay and attenuated the antiangiogenic effects of sFlt1. Stimulation of podocytes with NaHS resulted in both short-term VEGF release (120 minutes) and upregulation of VEGF-A mRNA levels (24 hours). Furthermore, pretreatment of mesenteric vessels with a VEGF receptor 2-neutralizing antibody significantly attenuated NaHS-induced vasodilation. These results suggest that hydrogen sulfide ameliorates sFlt1-induced hypertension, proteinuria, and glomerular endotheliosis in rats by increasing VEGF expression. Further studies are warranted to evaluate the role of hydrogen sulfide as a novel therapeutic agent for vascular disorders such as preeclampsia.

Cardiac angiogenic imbalance leads to peripartum cardiomyopathy.

Peripartum cardiomyopathy (PPCM) is an often fatal disease that affects pregnant women who are near delivery, and it occurs more frequently in women with pre-eclampsia and/or multiple gestation. The aetiology of PPCM, and why it is associated with pre-eclampsia, remain unknown. Here we show that PPCM is associated with a systemic angiogenic imbalance, accentuated by pre-eclampsia. Mice that lack cardiac PGC-1α, a powerful regulator of angiogenesis, develop profound PPCM. Importantly, the PPCM is entirely rescued by pro-angiogenic therapies. In humans, the placenta in late gestation secretes VEGF inhibitors like soluble FLT1 (sFLT1), and this is accentuated by multiple gestation and pre-eclampsia. This anti-angiogenic environment is accompanied by subclinical cardiac dysfunction, the extent of which correlates with circulating levels of sFLT1. Exogenous sFLT1 alone caused diastolic dysfunction in wild-type mice, and profound systolic dysfunction in mice lacking cardiac PGC-1α. Finally, plasma samples from women with PPCM contained abnormally high levels of sFLT1. These data indicate that PPCM is mainly a vascular disease, caused by excess anti-angiogenic signalling in the peripartum period. The data also explain how late pregnancy poses a threat to cardiac homeostasis, and why pre-eclampsia and multiple gestation are important risk factors for the development of PPCM.

Cardiovascular adaptations of pregnancy in T and B cell-deficient mice.

The pathophysiology of gestational hypertensive disorders is incompletely defined. T lymphocytes are implicated. Both T and natural killer (NK) cells express RAS and, in implantation sites, NK cells are highly enriched. We hypothesized that T cells and/or NK cells contribute to circulatory control during pregnancy. Using radiotelemetry of arterial pressure, heart rate, and activity, mice without T and B cells (genotypes BALB/c-Rag2(-/-) and NOD.scid) were examined at baseline and across pregnancy. These strains differ in NK cell competency, with Rag2(-/-) being normal and NOD.scid impaired. Circulatory features differed between these inbred strains. Rag2(-/-); had blood pressure responses to pregnancy that did not differ from congenic normal mice. NOD.scid had higher midgestational blood pressure compared with normoglycemic NOD mice (3-5 mm Hg greater than NOD; P < 0.004). In comparison to controls, both T and B strains had much higher heart rates after first trimester that did not remit until parturition (>30 bpm greater than control; P < 0.0001). NOD.scid had additional anomalies, including 90% depletion of circulating NK cells and elevated (57%) proliferation of uterine NK cells within implantation sites. These data demonstrate immune control of midgestational heart rate and suggest NK cells contribute to midpregnancy regulation of mean arterial pressure.

Identification of the primary outcomes that result from deficient spiral arterial modification in pregnant mice.

Pre-eclampsia, an acute complication of human pregnancy, is associated within complete physiological modification of decidual spiral arteries. This is thought to promote oxidative stress from perfusion/reperfusion of the placenta and to restrict placental and fetal growth. Alymphoid (genotype Rag2(-/-)/Il2rg(-/-)) mice, sufficient in dendritic and myeloid cell functions, lack spiral arterial modification with individual spiral arteries having ~1.7x the vascular resistance and 0.66x the blood velocity of +/+ mice. Their placentae are measurably hypoxic yet neither placental growth nor fetal survival is impaired and gestational hypertension is not seen. Thus, lymphocytes rather than vascular adaptations appear to be the pivotal contributors to the clinical complications of pre-eclampsia.

Uterine NK cells, spiral artery modification and the regulation of blood pressure during mouse pregnancy.

Reproductive success in mammals involves coordinated changes in the immune and cardiovascular as well as in the neuroendocrine and reproductive systems. This review addresses studies that identify potential links for NK cells and T cells with the local and systemic cardiovascular adaptations of pregnancy. The studies reviewed have utilized immunohistochemisty and in vivo analyses of vascular parameters by ultrasound, chronic monitoring of hemodynamics via radiotelemetric recording and intravital microscopy. At the uterine level, functional subsets of uterine natural killer cells were identified. These included subsets expressing molecules important for vasoregulation, in addition to those previously identified for angiogenesis. Spiral arteries showed conducted responses that could account for conceptus control of vasoactivity and mouse gestational blood pressure 5-phase pattern. Vascular immunology is an emerging transdisciplinary field, critical for both reproductive immunology and cardiovascular disease.

Spiral arterial remodeling is not essential for normal blood pressure regulation in pregnant mice.

Maternal cardiovascular adaptations occur in normal pregnancy, systemically, and within the uterus. In humans, gestational control of blood pressure is clinically important. Transient structural remodeling of endometrial spiral arteries normally occurs in human and mouse pregnancies. In mice, this depends on uterine natural killer cell function. Using normal and immune-deficient mice, we asked whether spiral artery remodeling critically regulates gestational mean arterial pressure and/or placental growth. Radiotelemetric transmitters were implanted in females and hemodynamic profiles to a dietary salt challenge and to pregnancy were assessed. Implantation sites from noninstrumented females were used for histological morphometry. Both normal and immune-deficient mice had normal sensitivity to salt and showed similar 5-phase gestational patterns of mean arterial pressure correlating with stages of placental development, regardless of spiral artery modification. After implantation, mean arterial pressure declined during the preplacental phase to reach a midgestation nadir. With gestation day 9 opening of placental circulation, pressure rose, reaching baseline before parturition, whereas heart rate dropped. Heart rate stabilized before parturition. Placental sizes deviated during late gestation when growth stopped in normal mice but continued in immune-deficient mice. As an indication of the potential for abnormal hemodynamics, 2 pregnant females delivering dead offspring developed late gestational hypertension. This study characterizes a dynamic pattern of blood pressure over mouse pregnancy that parallels human gestation. Unexpectedly, these data reveal that spiral artery remodeling is not required for normal gestational control of blood pressure or for normal placental growth.

Aberrant endometrial features of pregnancy in diabetic NOD mice.

OBJECTIVE: Pregnant diabetic women are at a 4-12 times higher risk for preeclampsia, an urgent acute-onset complication of mid- to late gestation, than normal pregnant women. Hallmarks of preeclampsia are hypertension, proteinuria, and incomplete modification of endometrial spiral arteries. Transient proangiogenic lymphocytes called uterine natural killer (uNK) cells are implicated in human and rodent spiral artery modification. We studied mid- to late gestations in spontaneously type 1 diabetic NOD mice to investigate whether diabetes alters uNK cell homing and/or function. RESEARCH DESIGN AND METHODS: Normoglycemic, pre-diabetic, and diabetic NOD mice and controls were mated. Lymphocytes and endometrial endothelium and decidua were studied histologically and in functional assays. RESULTS: Conception accelerated progression to overt diabetes in NOD females who had limited spiral artery development, heavier placentas, and lighter fetuses displaying numerous birth defects compared with controls. UNK cell numbers were reduced in the decidua basalis of diabetic females, whereas interferon-gamma production was elevated. In diabetic NOD mice, decidual expression of the mucosal vascular addressin cell adhesion molecule (MAdCAM)-1 was aberrant in position, whereas vascular cell adhesion molecule (VCAM)-1 expression was reduced. Assays of lymphocyte adhesion to tissue sections under shear forces indicated that diabetes compromises the potential homing functions of both endometrial endothelium and peripheral NK cells. CONCLUSIONS: In diabetes, gestational endometrium has immune and vascular defects that likely contribute to murine fetal loss and birth defects. Analogous problems and preeclampsia in diabetic women may involve similar mechanisms.