Abstract
Women represent the cornerstone of a family’s overall health. Therefore, supporting women’s health, particularly in pregnancy, is important to promote public health. Emerging data highlight ...the contribution of social determinants of health (SDOH) on pregnancy outcomes in understudied, underrepresented, and underreported (U3) populations. Importantly, women are uniquely affected by and more vulnerable to adverse outcomes associated with SDOH. The maternal mortality rate has also increased significantly in the United States, especially among U3 individuals. Factors such as access to safe food, housing and environment, access to education and emergency/health services, and stressors such as interpersonal racism, poverty, unemployment, residential segregation, and domestic violence may make women from U3 populations more vulnerable to adverse reproductive health outcomes. Despite progress in promoting women’s health, eliminating social and health disparities in pregnant individuals remains an elusive goal in U3 populations. Moreover, chronic exposure to excessive social/cultural stressors may have a physiologic cost leading to pregnancy complications such as miscarriages, preterm birth, and preeclampsia. Thus, the identification of SDOH-related factors that drive differences in pregnancy-related complications and deaths and the implementation of prevention strategies to address them could reduce disparities in pregnancy-related mortality in U3 populations.
Preterm labor caused by uterine contractions is a major contributor to neonatal morbidity and mortality. Treatment intended to reduce uterine contractions include tocolytic agents, such as ...indomethacin. Unfortunately, clinically used tocolytics are frequently inefficient and cross the placenta causing fetal side effects. Here we show for the first time in obstetrics the use of a targeted nanoparticle directed to the pregnant uterus and loaded with a tocolytic for reducing its placental passage and sustaining its efficacy. Nanoliposomes encapsulating indomethacin and decorated with clinically used oxytocin receptor antagonist were designed and evaluated in-vitro, ex-vivo and in-vivo. The proposed approach resulted in targeting uterine cells in-vitro, inhibiting uterine contractions ex-vivo, while doubling uterine drug concentration, decreasing fetal levels, and maintaining the preterm birth rate in vivo in a pregnant mouse model. This promising approach opens new horizons for drug development in obstetrics that could greatly impact preterm birth, which currently has no successful treatments.
Objective It has been shown that the level of soluble fms-like tyrosine kinase–1 (sFlt-1) is elevated in pregnant women who are destined to have preeclampsia, and a role for sFlt-1 in its ...pathogenesis has been suggested. Our objective was to determine the effect of the over-expression of sFlt-1 on blood pressure and the occurrence of other manifestations of preeclampsia in pregnant mice. Study Design At day 8 of gestation CD-1 mice were allocated randomly to an injection of an adenovirus carrying sFlt-1 (109 plaque-forming units; sFlt-1 group), adenovirus carrying the murine immunoglobulin G2α Fc fragment (109 plaque-forming units; mFc group used as a control for the virus) or saline solution (100 μL; saline group). At day 10 of gestation, blood pressure catheters were inserted through the left carotid artery into the aortic arch and tunneled to a telemetric transmitter. Blood pressure was monitored continuously in the conscious unrestrained animals until day 18. Blood was collected from the pregnant mice at different gestational times, and plasma sFlt-1 was measured by enzyme-linked immunosorbent assay. Pups and placentae were weighed, and maternal platelet counts were determined at death on day 18. Results Plasma levels of sFlt-1 increased significantly in the sFlt-1 mice and were significantly higher than the 2 control groups. The mean blood pressure in the sFlt-1 mice was significantly higher on days 17 and 18 of gestation, compared with the mFc and saline solution groups. The time-course of blood pressure rise mirrored that of the sFlt-1 levels. The average pup weight, placental weight, and maternal platelet counts were significantly lower in the sFlt-1 group, compared with the controls. Conclusion SFlt-1 induces hypertension and fetal growth restriction in pregnant mice, which supports its hypothesized role in the pathogenesis of preeclampsia. This animal model minimizes the need for manipulation or the administration of various compounds to induce the condition.
Objective We sought to investigate the mechanisms of action by which pravastatin improves vascular reactivity in a mouse model of preeclampsia induced by overexpression of soluble Fms-like tyrosine ...kinase-1 (sFlt)-1. Study Design Pregnant CD-1 mice were randomly allocated to tail vein injection with adenovirus carrying sFlt-1 or murine immunoglobulin G2 Fc (control), and thereafter to receive pravastatin (5 mg/kg/d) or water. Mice were sacrificed at gestational day 18. Protein expression of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor receptor-1, and hemeoxygenase-1 were assayed by Western blot in aorta, liver, and kidneys. Serum total cholesterol concentrations were measured. Results Pravastatin up-regulated eNOS expression in the aorta of sFlt-1 mice by nearly 2-fold ( P = .005) to levels similar to control mice. Total cholesterol levels, vascular endothelial growth factor receptor-1, and hemeoxygenase-1 protein expression were similar across groups. Conclusion Pravastatin prevents vascular dysfunction in part by up-regulation of eNOS in the vasculature. Our data support a role for statins in preeclampsia prevention.
Objective Preeclampsia alters fetal programming and results in long-term metabolic consequences in the offspring. Pravastatin has been shown to prevent preeclampsia in animal models. Our aim was to ...characterize the effects of preeclampsia on fetal programming of adult growth and metabolic function, and evaluate the role of preventive pravastatin therapy, using a well characterized murine model. Study Design CD-1 mice were injected through the tail vein with adenovirus carrying soluble fms-like tyrosine kinase 1 (sFlt-1) and randomly allocated to pravastatin (5 mg/kg/day; sFlt-1/prav, n = 7) or water (sFlt-1, n = 6) until weaning. A control group was injected with adenovirus carrying the murine immunoglobulin G2α Fc fragment (mFc, n = 8). Male and female offspring (6-8/group) were weighed every month until 6 months of age. Intraperitoneal glucose tolerance testing was performed after 16 hours of fasting at 3 and 6 months of age; glucose and insulin responses were measured. Results sFlt-1 offspring weight was lower than mFc control ( P < .001) until 2 months of age for females and 5 months of age for males ( P < .001). There were no differences in postnatal growth between mFc and sFlt-1/prav offspring. At 3 and 6 months, female sFlt-1 offspring had higher glucose response compared with mFc and sFlt-1/prav. Three-month-old male sFlt-1 had lower insulin response compared with mFc offspring. Conclusion Preeclampsia alters postnatal growth and metabolic function in the adult offspring in this animal model. Maternal therapy with prav prevents some of these alterations in the offspring.
Objective Indomethacin (IND) is a prostaglandin production inhibitor that reduces uterine contractions, but crosses the placenta leading to adverse fetal effects. Liposomes (LIP) are nanoscale ...systems clinically used to preferentially deliver a drug to the tissue of interest and simultaneously prevent distribution to unwanted locations. Our objective was to determine whether LIP could prevent the transfer of IND across the placenta to the fetus while preserving its pharmacological activity. Study Design Multilamellar LIP were designed with a 150- to 200-nm size, fluorescently labeled, and loaded with IND. Timed pregnant CD1 mice (n = 6/group) on gestational day 18 were administered LIP, LIP-IND (1 mg IND/kg), or saline (SAL) via tail vein injection, or IND (1 mg/kg) via oral gavage. After 4 hours, the uterus, placenta, and fetuses were retrieved. LIP levels were visualized using fluorescent microscopy and quantitatively assessed by National Institutes of Health image processing software. LIP brightness values (mean ± SEM) in arbitrary units (AU) were normalized to the autofluorescence of the same tissue (as measured in SAL group). IND and prostaglandin E2 levels were assessed using liquid chromatography-tandem mass spectrometry and enzyme-linked immunosorbent assay, respectively. Results The qualitative analysis of LIP distribution revealed that the system was primarily confined within the uterus, minimally detected within the placenta, and absent in the fetus. LIP fluorescence was greater in the uterus compared to placenta and fetus (uterus 15.3 ± 5.4 AU vs placenta 3.0 ± 3.5 AU vs fetus 4.4 ± 2.5 AU; P = .009). LIP-IND resulted in a 7.6-fold reduction in the IND levels in the fetus compared to IND alone (LIP-IND 10.7 ± 17.1 ng/g vs IND 81.3 ± 24.7 ng/g; P = .041). Prostaglandin E2 levels were significantly reduced in the uterus of animals given LIP-IND and IND compared to LIP and SAL. Conclusion LIP localized within the uterus and did not cross the placenta to the fetus. IND within the fetus was reduced 7.6-fold while encapsulated within the LIP and the pharmacologic effects of IND were maintained. Thus, LIP provide a novel therapeutic approach to correct the primary clinical limitation of IND by reducing placental passage to the fetus.
OBJECTIVE:To estimate the effects of pravastatin on the altered vascular function in a mouse model of preeclampsia induced by overexpression of soluble fms-like tyrosine kinase-1 (sFlt-1).
...METHODS:Pregnant CD1 mice, at day 8 of gestation, were randomly allocated to injection using the tail vein of the adenovirus carrying sFlt-1 (10 plaque-forming units in 100 microliters; sFlt-1 group) or mFc (10 plaque-forming units) as virus control, and then to receive pravastatin (Pra; 5 mg/kg/d) dissolved in drinking water or control. The mice in four groups (sFlt-1, sFlt-1-pravastatin, mFc, and mFc-pravastatin; n=4–6 per group) were killed at day 18 of gestation and 2-mm segments of carotid artery were used for vascular reactivity studies. Serum sFlt-1 levels were also measured by enzyme-linked immunosorbent assay.
RESULTS:Mice in the sFlt-1 group had the highest responses to phenylephrine. Treatment with pravastatin decreased the contractile responses to phenylephrine (maximal effect mean±standard error of the mean 137.35± 27.70 compared with 42.24±8.76; P=.006) for sFlt-1 compared with sFlt-1-pravastatin, respectively. There were no differences in the contractile responses to thromboxane A2. The vasorelaxant responses to acetylcholine were significantly highest in the mFc-pravastatin group, with a maximal effect of 108.37±5.25 compared with 89.77±3.96 in the mFc group (P=.008), and those with sodium nitroprusside were not different across the four groups. Serum sFlt-1 levels were not different at baseline (day 8) but were significantly lower in sFlt-1-pravastatin compared with sFlt-1 at day 18 (59.42±5.31 compared with 102.59±15.15 ng/mL; P=.01).
CONCLUSION:Pravastatin improved the vascular reactivity in this murine model of preeclampsia by decreasing sFlt-1 levels. Statins should be evaluated for the prevention of the vascular abnormalities of preeclampsia.
In order to determine the effects of pravastatin (Pra) on angiogenic and placental hypoxic imbalance in a model of preeclampsia induced by overexpression of soluble fms-like tyrosine kinase 1 ...(sFlt-1), we randomly allocated pregnant CD1 mice to injection with adenovirus-carrying sFlt-1 or mFc (control). The sFlt-1 group received either Pra (sFlt-1 + Pra) or water (sFlt-1). Mice were sacrificed at day 18, and serum levels of sFlt-1 and soluble endoglin (sEng) were measured. Placental expression of placental (PLGF) and vascular endothelial (VEGF) growth factors and other markers of angiogenesis and hypoxia were assayed. We observed that Pra treatment in sFlt-1 mice reduced sFlt-1 and sEng concentrations at day 18 to levels similar to control group. Placental PLGF and VEGF expression were upregulated, and markers of hypoxia downregulated to levels similar to control group. Hence, Pra prevents the rise in circulating antiangiogenic factors in a mouse model of preeclampsia. Statins may represent a novel approach to prevention of preeclampsia.
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