Regulation of pregnancy-associated plasma protein A2 (PAPPA2) in a human placental trophoblast cell line (BeWo)

<p>Abstract</p> <p>Background</p> <p>Pregnancy-associated plasma protein A2 (PAPPA2) is an insulin-like growth factor-binding protein (IGFBP) protease expressed at high levels in the placenta and upregulated in pregnancies complicated by preeclampsia and HELLP (Hemolytic anemia, Elevated Liver enzymes, and Low Platelet count) syndrome. However, it is unclear whether elevated PAPPA2 expression causes abnormal placental development, or whether upregulation compensates for placental pathology. In the present study, we investigate whether PAPPA2 expression is affected by hypoxia, oxidative stress, syncytialization factors or substances known to affect the expression of PAPPA2's paralogue, PAPPA.</p> <p>Methods</p> <p>BeWo cells, a model of placental trophoblasts, were treated with one of the following: hypoxia (2% O2), oxidative stress (20 microM hydrogen peroxide), forskolin (10 microM and 100 microM), TGF-beta (10 and 50 ng/mL), TNF-alpha (100 ng/mL), IL-1beta (100 ng/mL) or PGE2 (1 microM). We used quantitative RT-PCR (qRT-PCR) to quantify the mRNA levels of PAPPA2, as well as those of PAPPA and ADAM12 since these proteases have similar substrates and are also highly expressed in the placenta. Where we observed significant effects on PAPPA2 mRNA levels, we tested for effects at the protein level using an in-cell Western assay.</p> <p>Results</p> <p>Hypoxia, but not oxidative stress, caused a 47-fold increase in PAPPA2 mRNA expression, while TNF-alpha resulted in a 6-fold increase, and both of these effects were confirmed at the protein level. PGE2 resulted in a 14-fold upregulation of PAPPA2 mRNA but this was not reflected at the protein level. Forskolin, TGF-beta and IL-1beta had no significant effect on PAPPA2 mRNA expression. We observed no effects of any treatment on PAPPA or ADAM12 expression.</p> <p>Conclusion</p> <p>Our study demonstrates that factors previously known to be highly expressed in preeclamptic placentae (PGE2 and TNF-alpha), contribute to the upregulation of PAPPA2. Hypoxia, known to occur in preeclamptic placentae, also increased PAPPA2 expression. These results are consistent with the hypothesis that PAPPA2 is upregulated as a consequence of placental pathology, rather than elevated PAPPA2 levels being a cause of preeclampsia.</p

Pregnancy Complications Recur Independently of Maternal Vascular Malperfusion Lesions

Background Spontaneous abortions, intrauterine growth restriction, and preeclampsia are thought to be caused by defective placentation and are associated with increased risk of adverse outcomes in subsequent pregnancies. However, it is not known whether the recurrence of adverse outcomes is associated with the recurrence of placental pathology. We hypothesized that recurrent maternal vascular malperfusion (MVM) underlies the recurrence of adverse outcomes. Methods Using data from the National Collaborative Perinatal Project, we assessed the recurrence of pregnancy complications and MVM lesions (N = 3865), associations between a history of spontaneous abortions and MVM lesions or adverse outcomes in subsequent pregnancies (N = 8312), and whether the recurrence of pregnancy complications occurred independently of the presence of MVM lesions. Results The odds of an MVM lesion were higher for a woman who had had an MVM lesion in a previous pregnancy (aOR = 1.6; 95% CI 1.3–1.9), although this was marginally non-significant after adjusting for covariates such as gestational age, race and BMI. The odds of preeclampsia, a small-for-gestational-age infant, premature delivery and early pregnancy loss were 2.7–5.0 times higher if there had been that same adverse outcome in a previous pregnancy. A history of spontaneous abortions was associated with higher risk of a small-for-gestational-age baby (aOR = 2.4; 95% CI 1.7–3.4) and prematurity (aOR = 5.1; 95% CI 2.3–11.5 for extremely preterm), but not preeclampsia. The recurrence of adverse outcomes was significant when restricting analyses to women without MVM lesions. Similarly, associations between adverse outcomes and previous spontaneous abortions were significant when statistically controlling for the presence of MVM lesions, or excluding pregnancies with MVM lesions. Conclusions Women with adverse outcomes in one pregnancy are at higher risk of complications in subsequent pregnancies. However, there is significant recurrence of adverse outcomes even in the absence of MVM

Associations Between Imprinted Gene Expression in the Placenta, Human Fetal Growth and Preeclampsia

Genomic imprinting is essential for normal placental and fetal&nbsp;growth. One theory to explain the evolution of imprinting is the kinship&nbsp;theory (KT), which predicts that genes that are paternally expressed will&nbsp;promote fetal growth, whereas maternally expressed genes will suppress&nbsp;growth. We investigated the expression of imprinted genes using microarray&nbsp;measurements of expression in term placentae. Correlations between&nbsp;birthweight and the expression levels of imprinted genes were more&nbsp;significant than for non-imprinted genes, but did not tend to be positive for&nbsp;paternally expressed genes and negative for maternally expressed genes.&nbsp; Imprinted genes were more dysregulated in preeclampsia (a disorder associated&nbsp;with placental insufficiency) than randomly selected genes, and we observed&nbsp;an excess of patterns of dysregulation in preeclampsia that would be expected&nbsp;to reduce nutrient allocation to the fetus, given the predictions of the KT.&nbsp;However, we found no evidence of coordinated regulation among these imprinted&nbsp;genes. A few imprinted genes have previously been shown to be associated with&nbsp;fetal growth and preeclampsia, and our results indicate that this is true for&nbsp;a broader set of imprinted genes

The Response of Kentucky Bluegrass Turf to Varying Nitrogen Sources

The objective of the 2005 nitrogen (N) source study was to compare the turf response and N release rates of various experimental fertilizer products being proposed for marketing to a number of industry standards, such as Milorganite, Sustane, Nature Safe, corn gluten meal, Renaissance, and urea. An untreated control was added for comparison

PAPP-A2 Deficiency Does Not Exacerbate the Phenotype of a Mouse Model of Intrauterine Growth Restriction

BACKGROUND: Pregnancy-associated plasma protein-A2 (PAPP-A2) is consistently upregulated in the placentae of pregnancies complicated by preeclampsia and fetal growth restriction. The causes and significance of this upregulation remain unknown, but it has been hypothesized that it is a compensatory response to improve placental growth and development. We predicted that, if the upregulation of PAPP-A2 in pregnancy complications reflects a compensatory response, then deletion of Pappa2 in mice would exacerbate the effects of a gene deletion previously reported to impair placental development: deficiency of matrix metalloproteinase-9 (MMP9). METHODS: We crossed mice carrying deletions in Pappa2 and Mmp9 to produce pregnancies deficient in one, both, or neither of these genes. We measured pregnancy rates, number of conceptuses, fetal and placental growth, and the histological structure of the placenta. RESULTS: We found no evidence of reduced fertility, increased pregnancy loss, or increased fetal demise in Mmp9&nbsp;-/-&nbsp;females. In pregnancies segregating for Mmp9, Mmp9&nbsp;-/-&nbsp;fetuses were lighter than their siblings with a functional Mmp9 allele. However, deletion of Pappa2 did not exacerbate or reveal any effects of Mmp9 deficiency. We observed some effects of Pappa2 deletion on placental structure that were independent of Mmp9 deficiency, but no effects on fetal growth. At G16, male fetuses were heavier than female fetuses and had heavier placentae with larger junctional zones and smaller labyrinths. CONCLUSIONS: Effects of Mmp9 deficiency were not exacerbated by the deletion of Pappa2. Our results do not provide evidence that upregulation of placental PAPP-A2 represents a mechanism to compensate for impaired fetal growth. &nbsp

What causes the decrease in haematocrit during egg production?

1. Anaemia has been reported in wild animals, typically associated with traumatic events or ill health. However, female birds routinely become \u27anaemic\u27 during egg-laying; we sought to determine the causes of this reduction in haematocrit. 2. Haematocrit in female European Starlings (Sturnus vulgaris Linnaeus) decreased between pre-breeding and egg-laying in 3 out of 4 years (the decrease was marginally non-significant in the fourth year). This was independent of changes in ambient temperature altering the metabolic requirements for thermoregulation. 3. There was a positive relationship between haematocrit and plasma levels of the yolk precursor vitellogenin among egg-laying birds, supporting the hypothesis that the initial reduction in haematocrit is caused by increased blood volume associated with osmoregulatory adjustments to elevated levels of yolk precursors. 4. However, haematocrit did not always recover upon cessation of egg production, remaining low a.t clutch completion (2 of 4 years), incubation (1 of 2 years) and chick rearing (1 of 4 years), suggesting an additional cause of the prolonged reduction in haematocrit. 5. Given the magnitude and prolonged nature of the changes in haematocrit we report, and the interannual variation in haematocrit even during chick-rearing (47-54%), we suggest that \u27anaemia\u27 associated with egg production might have implications for aerobic performance during later stages of breeding

What causes the decrease in haematocrit during egg production?

1. Anaemia has been reported in wild animals, typically associated with traumatic events or ill health. However, female birds routinely become \u27anaemic\u27 during egg-laying; we sought to determine the causes of this reduction in haematocrit. 2. Haematocrit in female European Starlings (Sturnus vulgaris Linnaeus) decreased between pre-breeding and egg-laying in 3 out of 4 years (the decrease was marginally non-significant in the fourth year). This was independent of changes in ambient temperature altering the metabolic requirements for thermoregulation. 3. There was a positive relationship between haematocrit and plasma levels of the yolk precursor vitellogenin among egg-laying birds, supporting the hypothesis that the initial reduction in haematocrit is caused by increased blood volume associated with osmoregulatory adjustments to elevated levels of yolk precursors. 4. However, haematocrit did not always recover upon cessation of egg production, remaining low a.t clutch completion (2 of 4 years), incubation (1 of 2 years) and chick rearing (1 of 4 years), suggesting an additional cause of the prolonged reduction in haematocrit. 5. Given the magnitude and prolonged nature of the changes in haematocrit we report, and the interannual variation in haematocrit even during chick-rearing (47-54%), we suggest that \u27anaemia\u27 associated with egg production might have implications for aerobic performance during later stages of breeding

Identification and reciprocal introgression of a QTL affecting body mass in mice

The aim of this study was to examine the effects of a QTL in different genetic backgrounds. A QTL affecting body mass on chromosome 6 was identified in an F2 cross between two lines of mice that have been divergently selected for this trait. The effect of the QTL on mass increased between 6 and 10 weeks of age and was not sex-specific. Body composition analysis showed effects on fat-free dry body mass and fat mass. To examine the effect of this QTL in different genetic backgrounds, the high body mass sixth chromosome was introgressed into the low body mass genetic background and vice versa by repeated marker-assisted backcrossing. After three generations of backcrossing, new F2 populations were established within each of the introgression lines by crossing individuals that were heterozygous across the sixth chromosome. The estimated additive effect of the QTL on 10-week body mass was similar in both genetic backgrounds and in the original F2 population (i.e., ~0.4 phenotypic standard deviations); no evidence of epistatic interaction with the genetic background was found. The 95% confidence interval for the location of the QTL was refined to a region of approximately 7 cM between D6Mit268 and D6Mit123

Sex-Dependent Effects of Prenatal Food and Protein Restriction on Offspring Physiology in Rats and Mice: Systematic Review and Meta-Analyses

Background:&nbsp; Males and females may experience different effects of early-life adversity on life-long health. One hypothesis is that male foetuses invest more in foetal growth and relatively less in placental growth, and that this makes them susceptible to poor nutrition in utero, particularly if nutrition is reduced part-way through gestation. Objectives:&nbsp; Our objectives were to examine whether (1) food and/ or protein restriction in rats and mice has consistent sex-dependent effects, (2) sex-dependency differs between types of outcomes, and (3) males are more severely affected when restriction starts part-way through gestation. Data sources:&nbsp; PubMed and Web of Science were searched to identify eligible studies. Study eligibility criteria:&nbsp; Eligible studies described controlled experiments that restricted protein or food during gestation in rats or mice, examined physiological traits in offspring from manipulated pregnancies, and tested whether effects differed between males and females. Results:&nbsp; Our search identified 292 articles, of which the full texts of 72 were assessed, and 65 were included for further synthesis. A majority (50) used Wistar or Sprague-Dawley rats and so these were the primary focus. Among studies in which maternal diet was restricted for the duration of gestation, no type of trait was consistently more severely affected in one particular sex, although blood pressure was generally increased in both sexes. Meta-analysis found no difference between sexes in the effect of protein restriction throughout gestation on blood pressure. Among studies restricting food in the latter half of gestation only, there were again few consistent sex-dependent effects, although three studies found blood pressure was increased in males only. Meta-analysis found that food restriction in the second half of gestation increased adult blood pressure in both sexes, with a significantly greater effect in males. Birthweight was consistently reduced in both sexes, a result confirmed by meta-analysis. Conclusions:&nbsp; We found little support for the hypotheses that males are more affected by food and protein restriction, or that effects are particularly severe if nutrition is reduced part-way through gestation. However, less than half of the studies tested for sex by maternal diet interactions to identify sex-dependent effects. As a result, many reported sex-specific effects may be false positives

A major QTL controls susceptibility to spinal curvature in the curveback guppy

<p>Abstract</p> <p>Background</p> <p>Understanding the genetic basis of heritable spinal curvature would benefit medicine and aquaculture. Heritable spinal curvature among otherwise healthy children (<it>i.e. </it>Idiopathic Scoliosis and Scheuermann kyphosis) accounts for more than 80% of all spinal curvatures and imposes a substantial healthcare cost through bracing, hospitalizations, surgery, and chronic back pain. In aquaculture, the prevalence of heritable spinal curvature can reach as high as 80% of a stock, and thus imposes a substantial cost through production losses. The genetic basis of heritable spinal curvature is unknown and so the objective of this work is to identify quantitative trait loci (QTL) affecting heritable spinal curvature in the <it>curveback </it>guppy. Prior work with <it>curveback </it>has demonstrated phenotypic parallels to human idiopathic-type scoliosis, suggesting shared biological pathways for the deformity.</p> <p>Results</p> <p>A major effect QTL that acts in a recessive manner and accounts for curve susceptibility was detected in an initial mapping cross on LG 14. In a second cross, we confirmed this susceptibility locus and fine mapped it to a 5 cM region that explains 82.6% of the total phenotypic variance.</p> <p>Conclusions</p> <p>We identify a major QTL that controls susceptibility to curvature. This locus contains over 100 genes, including MTNR1B, a candidate gene for human idiopathic scoliosis. The identification of genes associated with heritable spinal curvature in the <it>curveback </it>guppy has the potential to elucidate the biological basis of spinal curvature among humans and economically important teleosts.</p