Huaizhi Yin

Effects of pravastatin on angiogenic and placental hypoxic imbalance in a mouse model 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.

Maternal hypercholesterolemia leads to activation of endogenous cholesterol synthesis in the offspring.

OBJECTIVE The purpose of this study was to determine the effect of maternal hypercholesterolemia on hepatic cholesterol metabolism in the offspring in a mouse model. STUDY DESIGN Male and female wild type and apoE(-/-KO) (knockout for the apoprotein E [apoE]) gene) mice were crossbred to obtain all 4 possible genetic offspring types. The litters were maintained on regular chow and sacrificed at 8 months of age. Liver samples were collected and the mRNA expression levels for SCAP, SREBP-1a, SREBP-2, HMGCR, and LDLR determined using real-time RT-PCR. RESULTS We found a significant activation of the transcriptional activity of genes involved in endogenous cholesterol synthesis, as well as LDLR, in the liver of adult mice born to hypercholesterolemic dams. CONCLUSION Reprogramming of hepatic cholesterol homeostasis may be the basis for an increased predisposition to hypercholesterolemia and atherosclerosis found in offspring of mice exposed to a high cholesterol environment during early life.

THE EXPRESSION OF ANTIOXIDANT ENZYMES IN A MOUSE MODEL OF FETAL ALCOHOL SYNDROME

OBJECTIVE Superoxide dismutase, glutathione peroxidase, and catalase prevent cellular damage produced by free radicals. Our objective was to evaluate if prenatal alcohol exposure decreased the expression of antioxidant enzymes in the brain, liver, or placenta of fetal mice. STUDY DESIGN Timed, pregnant C57BL6/J mice were treated on gestational day 8 with intraperitoneal injection of alcohol (0.03 mL/g) or saline (control). Fetuses were harvested on gestational day 18. Fetal brain, liver, and placenta were analyzed for mRNA expression of superoxide dismutase, glutathione peroxidase, and catalase by real-time polymerase chain reaction, with 18S RNA used as reference. RESULTS Superoxide dismutase, glutathione peroxidase, and catalase expression was lower in fetal brains exposed to alcohol with no differences detected in the liver or placenta between the 2 groups. CONCLUSION Maternal alcohol consumption causes a decrease in superoxide dismutase, glutathione peroxidase, and catalase expression in the fetal brain. This may explain the long-term neurologic findings in fetal alcohol syndrome.

The role of NADPH oxidase in a mouse model of fetal alcohol syndrome

OBJECTIVE Fetal alcohol syndrome (FAS) is the most common cause of nongenetic mental retardation. Oxidative stress is one of the purported mechanisms. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) is an enzyme involved in the production of reactive oxygen species. Our objective was to evaluate NOX in the fetal brain of a well-validated mouse model of FAS. STUDY DESIGN Timed, pregnant C57BL/6J mice were injected intraperitoneally with 0.03 mL/g of either 25% ethyl alcohol or saline. Fetal brain, liver, and placenta were harvested on gestational day 18. The unit of analysis was the litter; tissue from 6-8 litters in the alcohol and control group was isolated. Evaluation of messenger ribonucleic acid (mRNA) expression of NOX subunits (DUOX1, DUOX2, NOX1, NOX2, NOX3, NOX4, NOXA1, NOXO1, RAC1, p22phox, and p67phox) was performed using quantitative real-time polymerase chain reaction; alcohol vs placebo groups were compared using a Student t test or a Mann-Whitney test (P < .05). RESULTS Alcohol exposed fetal brains showed significant up-regulation in subunits DUOX2 (1.61 ± 0.28 vs 0.84 ± 0.09; P = .03), NOXA1 (1.75 ± 0.27 vs 1.09 ± 0.06; P = .04), and NOXO1 (1.59 ± 0.10 vs 1.28 ± 0.05; P = .02). Differences in mRNA expression in the placenta were not significant; p67phox was significantly up-regulated in alcohol-exposed livers. CONCLUSION Various NOX subunits are up-regulated in fetal brains exposed to alcohol. This effect was not observed in the fetal liver or placenta. Given the available evidence, the NOX system may be involved in the causation of FAS through the generation of reactive oxygen species and may be a potential target for preventative treatment in FAS.

Single-nucleotide polymorphisms in genes involved in placental function and unexplained stillbirth

OBJECTIVE The purpose of this study was to evaluate the association between unexplained stillbirth (SB) and single-nucleotide polymorphisms (SNPs) in genes involved in placental function using a well-characterized cohort. STUDY DESIGN Placentas were obtained from 50 unexplained SB and 46 live birth controls. Classification of stillbirth was by Wigglesworth criteria. SBs were stratified by weight: appropriate (AGA-SB) and small for gestational age (SGA-SB, less than the 10th percentile) and gestational age: before 32 and after 32 weeks. Placental DNA was extracted and various SNPs in the endothelial nitric oxide synthase (eNOS), Klotho, hypoxic inducible factor-1α, and and tumor necrosis factor-α genes were evaluated. RESULTS None of the SNPs were associated with SB overall. Significantly different genotype distribution emerged for eNOS-SNP rs1800783 when comparing AGA-SB with SGA-SB and control (P = .004). Its allele-A was more frequent in AGA-SB compared with both controls (P = .03) and SGA-SB (P = .001). No differences were seen accordingly to gestational age. CONCLUSION Unexplained stillbirth in the setting of adequate growth is associated with carrier of allele A of rs1800783 eNOS gene in the placenta.

Effect of Normal Pregnancy Followed by Lactation on Long-Term Maternal Health in a Mouse Model

Although it has been widely accepted that pregnancies with complications are associated with increased maternal cardiovascular risk later in life, there is no consensus if noncomplicated pregnancy followed by lactation plays a protective role or is a risk factor. The objective of this study was to investigate the effects of normal pregnancy and lactation on long-term maternal health in a mouse model. CD-1 mice were allocated to breeding (primigravid [PG]) and nonbreeding (nulligravid [NG]) groups. The PG group proceeded through normal pregnancy and delivery. Using a telemetry system, blood pressure (BP) was analyzed in the PG group at 6 months postpartum and in age-matched NG mice. Serum analytes, gene expressions, and protein levels were determined using appropriate analysis methods. Primigravid mice had significantly lower systolic and diastolic BP and fasting glucose levels. Circulating oxytocin (OXT) levels were significantly higher in PG mice. Oxt gene expression was significantly higher in the heart and aorta and lower in visceral adipose tissue (VAT) from PG mice. The oxytocin receptor (Oxtr) gene expression was significantly higher in the heart, aorta, and VAT from PG animals. The level of Oxtr DNA hypermethylation and the expression of mmu-miR-29a were significantly lower in the hearts of PG mice. In PG VAT, glucose transporter-4 expression was significantly higher. Our study demonstrates that a history of normal pregnancy followed by lactation was associated with lower maternal cardiovascular risk factors later in life in female mouse.

225: Developmental programming of adult disease: the role of DNA methylation in genes responsible for antioxidant enzymes

gain, fetal weights, placental weights or number of pups between the RV and control groups. Treatment with RV had no significant effect on baseline myometrial contractility nor on contractility after indomethacin or nifedipine treatment. CONCLUSION: Unlike its effect on vascular smooth muscle, resveratrol does not seem to affect myometrial contractility nor potentiate the effect of tocolytics in pregnant mice.