l-Citrulline supplementation during pregnancy improves perinatal and postpartum maternal vascular function in a mouse model of preeclampsia.

Preeclampsia is a spontaneously occurring pregnancy complication diagnosed by new-onset hypertension and end-organ dysfunction with or without proteinuria. This pregnancy-specific syndrome contributes to maternal morbidity and mortality and can have detrimental effects on fetal outcomes. Preeclampsia is also linked to increased risk of maternal cardiovascular disease throughout life. Despite intense investigation of this disorder, few treatment options are available. The aim of this study was to investigate the potential therapeutic effects of maternal l-citrulline supplementation on pregnancy-specific vascular dysfunction in the male C57BL/6J × female C57BL/6J C1q-/- preeclampsia-like mouse model. l-Citrulline is a nonessential amino acid that is converted to l-arginine to promote smooth muscle and blood vessel relaxation and improve nitric oxide (NO)-mediated vascular function. To model a preeclampsia-like pregnancy, female C57BL/6J mice were mated to C1q-/- male mice, and a subset of dams was supplemented with l-citrulline throughout pregnancy. Blood pressure, systemic vascular glycocalyx, and ex vivo vascular function were investigated in late pregnancy, and postpartum at 6 and 10 mo of age. Main findings show that l-citrulline reduced blood pressure, increased vascular glycocalyx volume, and rescued ex-vivo vascular function at gestation day 17.5 in this preeclampsia-like model. The vascular benefit of l-citrulline also extended postpartum, with improved vascular function and glycocalyx measures at 6 and 10 mo of age. l-Citrulline-mediated vascular improvements appear, in part, attributable to NO pathway signaling. Taken together, l-citrulline supplementation during pregnancy appears to have beneficial effects on maternal vascular health, which may have translational implications for improved maternal cardiovascular health.

Paternal deficiency of complement component C1q leads to a preeclampsia-like pregnancy in wild-type female mice and vascular adaptations postpartum.

Preeclampsia is a spontaneously occurring, pregnancy-specific syndrome that is clinically diagnosed by new onset hypertension and proteinuria. Epidemiological evidence describes an association between a history of preeclampsia and increased risk for cardiovascular disease in later life; however, the mechanism(s) driving this relationship are unclear. Our study aims to leverage a novel preeclampsia-like mouse model, the C1q-/- model, to help elucidate the acute and persistent vascular changes during and following a preeclampsia-like pregnancy. Female C57BL/6J mice were mated to C1q-/- male mice to model a preeclampsia-like pregnancy ("PE-like"), and the maternal cardiovascular phenotype (blood pressure, renal function, systemic glycocalyx, and ex vivo vascular function) was assessed in late pregnancy and postpartum at 6 and 10 mo of age. Uncomplicated, normotensive pregnancies (female C57BL/6J bred to male C57BL/6J mice) served as age-matched controls. In pregnancy, PE-like dams exhibited increased systolic and diastolic pressure during mid- and late gestation, renal dysfunction, fetal growth restriction, and reduced placental efficiency. Ex vivo wire myography studies of mesenteric arteries revealed severe pregnancy-specific endothelial-dependent and -independent vascular dysfunction. At 3 and 7 mo postpartum (6 and 10 mo old, respectively), hypertension resolved in PE-like dams, whereas mild vascular dysfunction persisted at 3 mo postpartum. In conclusion, the female C57BL/6J-by-male C57BL/6J C1q-/- model recapitulates many aspects of the human preeclampsia syndrome in a low-risk, wild-type female mouse. The pregnancy-specific phenotype results in systemic maternal endothelial-dependent and -independent vascular dysfunction that persists postpartum.

Urinary cortisol and depression in early pregnancy: role of adiposity and race.

BACKGROUND: Depression before and during pregnancy is associated with adverse birth outcomes including low birth weight and preterm birth. Abnormal maternal cortisol has been hypothesized as one mediator between depression and adverse birth outcomes. The relationship between cortisol and depression in pregnancy is exhibited most strongly in the African American population, and most studies have focused either on circulating or placental levels of cortisol. The utility of urinary cortisol in early pregnancy related to depression and adiposity has not been investigated. METHODS: Twenty-five pregnant African American women identified by the Edinburgh Depression Scale as having depression were investigated and matched by body mass index (BMI), age, race, and infant birth weight centile to non-depressed subjects. Maternal urine and plasma cortisol in early pregnancy were quantified and investigated in relation to depression and adiposity. RESULTS: Morning urine cortisol levels tracked positively with plasma cortisol (r(2) = 0.25, p < 0.001). However, no differences were observed in either urinary or plasma cortisol between depressed and non-depressed pregnant women. Plasma cortisol was significantly negatively associated with several measures of maternal adiposity including percent body fat (r(2) = -0.10, p < 0.05), however this relationship was present only in the non-depressed women. In a post-hoc analysis, non-depressed non-obese women were found to have significantly higher cortisol levels compared to women with depression, obesity or both (p < 0.05). CONCLUSIONS: Depressed pregnant women and non-depressed obese pregnant women evidence atypical cortisol levels compared to non-depressed non-obese pregnant women. Plasma cortisol in early pregnancy is negatively associated with measures of maternal adiposity. Atypical low circulating maternal cortisol among depressed (lean and obese) and non-depressed obese pregnant African American women may indicate hypothalamic-pituitary axis dysfunction in early pregnancy.

Pre-pregnancy stress induces maternal vascular dysfunction during pregnancy and postpartum.

An estimated 20% of women suffer from a stress-related mood disorder including depression and anxiety during and after pregnancy, making these disorders among the most common complications of pregnancy. These stress-related disorders are associated with adverse pregnancy outcomes including gestational hypertension and preeclampsia, which are associated with poor cardiometabolic health postpartum. Despite these associations, the direct impact of stress and related disorders on maternal vascular health, and contributing mechanisms, remain understudied. The aim of this study was to investigate the effect of pre-pregnancy stress on maternal vascular outcomes in a BALB/c mouse model of chronic unpredictable stress. Maternal blood pressure and ex-vivo vascular function were investigated during pregnancy and postpartum. Offspring characteristics were assessed at the end of pregnancy and postpartum. Main findings show that pre-pregnancy stress exposure increased blood pressure during mid and late pregnancy and impaired ex vivo vascular function at the end of pregnancy. These effects persisted into the postpartum period, suggesting a long-term effect of stress on maternal vascular health, which appear to be partially attributable to disruptions in nitric oxide (NO) pathway signaling. These data suggest exposure to stress and related disorders, even prior to pregnancy, can contribute to vascular complications during pregnancy and postpartum.

An exploratory factor analysis of nutritional biomarkers associated with major depression in pregnancy.

OBJECTIVE: Major depressive disorder (MDD) during pregnancy increases the risk of adverse maternal and infant outcomes. Maternal nutritional status may be a modifiable risk factor for antenatal depression. We evaluated the association between patterns in mid-pregnancy nutritional biomarkers and MDD. DESIGN: Prospective cohort study. SETTING: Pittsburgh, Pennsylvania, USA. SUBJECTS: Women who enrolled at ≤20 weeks' gestation and had a diagnosis of MDD made with the Structured Clinical Interview for DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) at 20-, 30- and 36-week study visits. A total of 135 women contributed 345 person-visits. Non-fasting blood drawn at enrolment was assayed for red cell essential fatty acids, plasma folate, homocysteine and ascorbic acid; serum 25-hydroxyvitamin D, retinol, vitamin E, carotenoids, ferritin and soluble transferrin receptors. Nutritional biomarkers were entered into principal components analysis. RESULTS: Three factors emerged: Factor 1, Essential Fatty Acids; Factor 2, Micronutrients; and Factor 3, Carotenoids. MDD was prevalent in 21·5 % of women. In longitudinal multivariable logistic models, there was no association between the Essential Fatty Acids or Micronutrients pattern and MDD either before or after adjustment for employment, education or pre-pregnancy BMI. In unadjusted analysis, women with factor scores for Carotenoids in the middle and upper tertiles were 60 % less likely than women in the bottom tertile to have MDD during pregnancy, but after adjustment for confounders the associations were no longer statistically significant. CONCLUSIONS: While meaningful patterns were derived using nutritional biomarkers, significant associations with MDD were not observed in multivariable adjusted analyses. Larger, more diverse samples are needed to understand nutrition-depression relationships during pregnancy.

Maternal leptin concentrations are similar in African Americans and Caucasians in normal pregnancy, preeclampsia and small-for-gestational-age infants.

Leptin concentrations were measured in African American women in order to assess leptin's role in the increased frequency and severity of preeclampsia. In addition, leptin concentrations were measured in women who delivered small-for-gestational-age (SGA) infants. A case-control study of African American and Caucasian women with normal pregnancies, preeclampsia, or SGA infants was done. Plasma leptin was quantitated by radio-immunoassay. The previously recognized pattern of increased leptin concentrations in preeclampsia was replicated. Leptin concentrations did not differ by race in any diagnostic category, and concentrations in women with SGA infants were not higher than those in healthy women. Differences in the frequency and severity of preeclampsia in African Americans cannot be explained by higher leptin concentrations.

Uric acid concentrations in early pregnancy among preeclamptic women with gestational hyperuricemia at delivery.

OBJECTIVE: We investigated changes in serum uric acid across pregnancy in women with gestational hyperuricemia at delivery, with and without preeclampsia, compared with normal pregnant and women with preeclampsia without gestational hyperuricemia. STUDY DESIGN: This was a nested case-control study of 116 controls, 27 women with preeclampsia with predelivery hyperuricemia, 37 women with preeclampsia without predelivery hyperuricemia, and 35 women with gestational hypertension with hyperuricemia at delivery but without proteinuria. Serum uric acid and creatinine was measured across pregnancy. RESULTS: Women with predelivery hyperuricemia, with and without preeclampsia, had increased uric acid concentrations across pregnancy compared with controls, after 25 weeks' gestation compared with women with preeclampsia without predelivery hyperuricemia. Adjusting for differences in glomerular filtration by serum creatinine accounted for part but not all of the increase in serum uric acid among women with preeclampsia and predelivery hyperuricemia. CONCLUSIONS: Among women with hyperuricemia at delivery, elevations in uric acid occur early. Multiple mechanisms may contribute to increased uric acid including changes in renal function.

The -93T/G LPL Promoter Polymorphism Is Associated With Lower Third-Trimester Triglycerides in Pregnant African American Women.

BACKGROUND: Hypertriglyceridemia is a risk factor for cardiovascular disease and several pregnancy complications. Lipoprotein lipase (LPL) genetic variation modulates nonpregnancy plasma triglycerides, but its effects during pregnancy are unknown. The G allele of the LPL -93T/G promoter polymorphism is 16-23 times more prevalent in Blacks than in Whites, contributing to lower triglycerides in nonpregnant African Americans by increasing LPL expression. PURPOSE: This study investigated whether the triglyceride-lowering effect of -93G is observed in African Americans during pregnancy. METHODS: Genotyping was performed on 124 African American women with uncomplicated pregnancies for common functional LPL polymorphisms/mutations (-93T/G, D9N, N291S, and S447X). Third-trimester plasma triglyceride, high- and low-density lipoprotein cholesterol, apolipoprotein B, and free fatty acid concentrations were measured with colorimetric assays. Clinical characteristics and lipid values were compared across the -93T/G genotypes. RESULTS: Triglycerides were significantly lower in women with the -93GG compared to the -93TT genotype, both with (n = 124, p = .02) and without (n = 108, p = .03) inclusion of participants with other LPL variant alleles. Triglyceride differences persisted after adjustment for prepregnancy body mass index, gestational age at delivery, and smoking. There were no significant differences in the other lipids or apolipoprotein B by -93T/G genotype. CONCLUSIONS: Despite the considerable metabolic changes accompanying pregnancy, the triglyceride-lowering effect associated with the -93GG LPL genotype in African Americans persists during late pregnancy. The -93GG genotype might protect against pregnancy complications stemming from hypertriglyceridemia, but the overall increased risk of pregnancy complications in African American women points to complex, multifactorial relationships among risk factors, race, and adverse pregnancy outcomes.

The 677 C-T methylenetetrahydrofolate reductase mutation does not predict increased maternal homocysteine during pregnancy.

OBJECTIVE: To test the hypothesis that, regardless of the presence of the 677 C-T methylenetetrahydrofolate reductase (MTHFR) mutation, maternal homocysteine concentrations will not be significantly different in women who are taking prenatal vitamins containing folic acid, and to test this relationship in preeclampsia because homocysteine concentrations are higher in preeclamptic pregnancies. METHODS: Fifty-seven pregnant white women (control and preeclamptic) with and without the 677 C-T MTHFR mutation were studied. Total plasma homocysteine and plasma folic acid were analyzed. RESULTS: Homocysteine concentrations were not different by MTHFR genotype (wild type 677 CC 8.7 +/- 5.6 microM versus mutant 677 TT 9.0 +/- 5.7 microM, P =.84) in preeclamptic or normal pregnancies. However, mean homocysteine concentrations were significantly increased in preeclamptic pregnancies compared with those in normal pregnancies (10.6 +/- 7.3 microM versus 7.2 +/- 3.0 microM, P <.03) as previously reported. CONCLUSION: The 677 C-T MTHFR polymorphism does not significantly affect maternal homocysteine concentrations in most women taking prenatal vitamins including women with preeclampsia. The increase in plasma folic acid likely affects maternal homocysteine more than the MTHFR genotype. If homocysteine is considered a thrombophilia risk factor, the concentration of the amino acid and not a particular genotype should be determined.

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 HOMA(IR) by pro-inflammatory:anti-inflammatory ratio. Regression stratifying by BMI and preterm birth was conducted. RESULTS: There was no difference in median HOMA(IR) 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.

Plasma levels of inflammatory markers neopterin, sialic acid, and C-reactive protein in pregnancy and preeclampsia.

BACKGROUND: To determine whether the cellular inflammatory marker of activated macrophages and monocytes, neopterin (NEO), and the acute-phase inflammatory markers sialic acid (SA) and C-reactive protein (CRP) are elevated in pregnancy and further elevated in the pregnancy syndrome preeclampsia. METHODS: Maternal plasma concentrations of NEO, SA, and CRP were measured by high-sensitivity enzyme-linked immunosorbent assay (ELISA) or high-performance liquid chromatography in 20 nonpregnant women, 40 women with uncomplicated pregnancies, 50 women with transient hypertension of pregnancy alone, 49 women with small for gestational age (SGA) infants without preeclampsia, and 47 women with preeclampsia. RESULTS: The mean concentration of plasma NEO, SA, and CRP were all significantly elevated in all groups of pregnant women compared to nonpregnant women (P < 0.001 for all). In addition, maternal plasma NEO concentrations were further elevated in women with preeclampsia compared to the other groups of pregnant women (P < 0.01). As expected, the acute-phase inflammatory markers CRP and SA correlated positively with each other. However, CRP was also correlated with the activated macrophage and monocyte marker NEO in women with transient hypertension of pregnancy and with preeclampsia (P < 0.05). CONCLUSIONS: The inflammatory markers NEO, SA, and CRP are all elevated during pregnancy. However, only NEO, a marker of macrophage and monocyte activation, was further elevated in women with preeclampsia. These data suggest that there is a striking increase in inflammation during pregnancy, and cellular immune activation is further elevated during preeclampsia.

Evidence of endothelial dysfunction in preeclampsia and risk of adverse pregnancy outcome.

The purpose of this study is to investigate whether endothelial dysfunction, as assessed by elevated cellular fibronectin (cFN), in women with preeclampsia is associated with an increased risk of preterm and/or small-for-gestational-age (SGA) births. Maternal plasma cFN was measured by enzyme-linked immunosorbent assay in samples collected at admission to delivery in 605 normotensive women, 171 women with transient hypertension, and 187 women with preeclampsia. Logistic regression was used to estimate the risk for preterm delivery, SGA, or both. Elevated cFN in women with preeclampsia was associated with an increased risk of both preterm and SGA births (odds ratio, 3.0; confidence interval [CI], 1.0-8.7) compared with women with preeclampsia without elevated cFN. The risk of preterm birth was 14.7-fold higher (CI, 8.1-26.7) and the risk of SGA was 6.8-fold higher (CI, 3.5-13.1) in women with preeclampsia, hyperuricemia, and elevated cFN compared with normotensive women. Elevated cFN is prevalent among women with preeclampsia and identifies women at increased risk of preterm delivery and SGA.

Preeclampsia risk and angiotensinogen polymorphisms M235T and AGT -217 in African American and Caucasian women.

INTRODUCTION: Genetic variants of the angiotensinogen gene have been linked to both hypertension and preeclampsia. The M235T polymorphism is more common in hypertension and preeclampsia in some populations. A polymorphism in the angiotensinogen basal promoter region of AGT -217 is more common in African Americans with hypertension. The authors investigated the frequency of M235T and AGT -217 in Caucasian and African American women with and without preeclampsia. METHODS: The study was a nested case-control study of primiparous women with singleton pregnancies. Genomic DNA from preeclamptic and control subjects underwent polymerase chain reaction amplification and restriction digestion. RESULTS: The M235T and AGT -217 polymorphisms were both more common in African American women; however, the variants were not more common in preeclampsia. CONCLUSION: The frequency of angiotensinogen polymorphisms M235T and AGT -217 is different by race; however, these polymorphisms are not associated with an increased risk of preeclampsia.

Angiotensin II decreases system A amino acid transporter activity in human placental villous fragments through AT1 receptor activation.

Reduced transport of amino acids from mother to fetus can lead to fetal intrauterine growth restriction (IUGR). The activities of several amino acid transport systems, including system A, are decreased in placental syncytiotrophoblast of IUGR pregnancies. Na(+)-K(+)-ATPase activity provides an essential driving force for Na(+)-coupled system A transport, is decreased in the placenta of IUGR pregnancies, and is decreased by angiotensin II in several tissues. Several reports have shown activation of the fetoplacental renin-angiotensin system (RAS) in IUGR. We investigated the effect of angiotensin II on placental system A transport and Na(+)-K(+)-ATPase activity in placental villi. Placental system A activity in single primary villous fragments was measured as the Na(+)-dependent uptake of alpha-(methylamino)isobutyric acid, and Na(+)/K(+) ATPase activity was measured as ouabain-sensitive uptake of (86)rubidium. Angiotensin II decreased system A activity in a concentration-dependent fashion (10-500 nmol/l). Angiotensin II type 1 receptor (AT1-R) antagonists losartan and AT1-R anti-peptide blocked the angiotensin II effect, but the angiotensin II type 2 receptor antagonist PD-123319 was without effect. System A activity was not altered by preincubation with AT1-R-independent vasoconstrictors, and antioxidants did not prevent the decrease in activity mediated by angiotensin II. Angiotensin II decreased Na(+)-K(+)-ATPase activity by an AT1-R dependent mechanism, and inhibition of Na(+)-K(+)-ATPase activity decreased system A activity in a dose-response fashion. These data suggest that angiotensin II, via AT1-R signaling, decreases system A activity by suppressing Na(+)-K(+)-ATPase in human placental villi, consistent with possible adverse effects of enhanced placental RAS on fetal growth.