Placental gene expression of the placental growth factor (PlGF) in intrauterine growth restriction

Objective: We analyzed changes in gene expression of placental growth factor (PIGF) in human placental samples obtained postpartum from pregnancies with IUGR.

Methods: During a twelve-month study period representing the calendar year of 2012 placental samples from 101 pregnancies with IUGR and from 140 normal pregnancies were obtained for analysis of a potential difference in PIGF gene expression.

Results: There was no significant difference in gene activity of the PIGF gene between the IUGR versus normal pregnancy groups (Ln2^α: 0.92; p?α: 0.72; p?=?0.05). Placental PIGF gene activity was significantly lower in fetuses with more severe IUGR versus less severe cases (Ln2^α: ?1.49; p?Conclusion: We found no difference in gene expression of PIGF in placental samples obtained from IUGR pregnancies versus normal pregnancy suggesting the absence of a direct role of PIGF gene activity in the development of defective angiogenesis in IUGR during the later stages of gestation. However, in more severe cases of intrauterine growth restriction PIGF expression does show a significant decrease indicating its potential role in the profound defect in angiogenesis in these cases.     

Placental expression of the angiogenic placental growth factor is stimulated by both aldosterone and simulated starvation

Aldosterone is an important factor supporting placental growth and fetal development. Recently, expression of placental growth factor (PlGF) has been observed in response to aldosterone exposure in different models of atherosclerosis. Thus, we hypothesized that aldosterone up-regulates growth-adaptive angiogenesis in pregnancy, via increased placental PlGF expression.We followed normotensive pregnant women (n = 24) throughout pregnancy and confirmed these results in a second independent first trimester cohort (n = 36). Urinary tetrahydroaldosterone was measured by gas chromatography-mass spectrometry and corrected for creatinine. Circulating PlGF concentrations were determined by ELISA. Additionally, cultured cell lines, adrenocortical H295R and choriocarcinoma BeWo cells, as well as primary human third trimester trophoblasts were tested in vitro. PlGF serum concentrations positively correlated with urinary tetrahydroaldosterone corrected for creatinine in these two independent cohorts. This observation was not due to PlGF, which did not induce aldosterone production in cultured H295R cells. On the other hand, PlGF expression was specifically enhanced by aldosterone in the presence of forskolin (p < 0.01) in trophoblasts. A pronounced stimulation of PlGF expression was observed with reduced glucose concentrations simulating starvation (p < 0.001).In conclusion, aldosterone stimulates placental PlGF production, enhancing its availability during human pregnancy, a response amplified by reduced glucose supply. Given the crucial role of PlGF in maintaining a healthy pregnancy, these data support a key role of aldosterone for a healthy pregnancy outcome.     

Placental dysfunction and fetal programming: the importance of placental size, shape, histopathology, and molecular composition

Normal function of the placenta is pivotal for optimal fetal growth and development. Fetal programming commonly is associated with placental dysfunction that predisposes to obstetric complications and suboptimal fetal outcomes. We consider several clinical phenotypes for placental dysfunction that likely predispose to fetal programming. Some of these reflect abnormal development of the chorioallantoic placenta in size, shape, or histopathology. Others result when exogenous stressors in the maternal environment combine with maladaptation of the placental response to yield small placentas with limited reserve, as typical of early-onset intrauterine growth restriction and preeclampsia. Still others reflect epigenetic changes, including altered expression of imprinted genes, altered enzymatic activity, or altered efficiencies in nutrient transport. Although the human placenta is a transient organ that persists only 9 months, the effects of this organ on the offspring remain for a lifetime.     

基质金属蛋白酶与子痫前期发病关系的研究

目的 探讨基质金属蛋白酶(MMP)2、9在子痫前期患者胎盘绒毛中的表达及其与子痫前期发病的关系.方法 采用免疫组化链霉亲和素-生物素-过氧化物酶复合物(SABC)法检测20例子痫前期患者(病例组)和20例正常孕妇(对照组)胎盘绒毛MMP-2、9的表达,实时荧光定量RT-PCR检测两组孕妇胎盘绒毛MMP-2、9 mRNA的表达水平.因提取后的mRNA部分降解,用于RT-PCR检测的胎盘绒毛病例组13份,对照组10份.采用2-△△Ct相对定量表示PCR结果.结果 对照组孕妇胎盘绒毛MMP-2、9的染色强度均高于病例组,两组比较,差异有统计学意义(P＜0.05);对照组胎盘绒毛MMP-2 mRNA的平均表达水平为7.6±2.8,病例组胎盘绒毛MMP-2 mRNA的平均表达水平为5.6±1.5,两组比较,差异有统计学意义(P＜0.05).对照组胎盘绒毛MMP-9 mRNA的平均表达水平为2.2±2.6,高于病例组的-0.9±2.0,两组比较,差异也有统计学意义(P＜0.05).对照组胎盘绒毛MMP-2的平均表达水平高于MMP-9,两者比较,差异有统计学意义(P＜0.05).结论 MMP-2、9表达降低导致的滋养细胞侵袭能力的下降,可能与子痫前期的发病相关.     

Placental telomere length and risk of placental abruption

Objective: To investigate the associations of placental telomere length with placental abruption (PA) risk and interactions between placental telomere length and placental mitochondrial DNA (mtDNA) copy number on PA risk.

Materials and methods: Relative telomere length and mtDNA copy number in placental samples collected from 105 cases and 73 controls were measured in two batches using qRT-PCR. Mean differences in relative telomere length between PA cases and controls were examined. After creating batch-specific median cutoffs for relative telomere length (84.92 and 102.53) and mtDNA copy number (2.32 and 1.42), interaction between the two variables was examined using stratified logistic regression models.

Results: Adjusted mean difference in relative telomere length between PA cases and controls was ?0.07 (p?>?0.05). Among participants with low mtDNA copy number, participants with short relative telomere length had a 3.07-fold higher odds (95% CI: 1.13–8.38) of PA as compared with participants with long relative telomere length (the reference group). Among participants with high mtDNA copy number, participants with short relative telomere length had a 0.71-fold lower odds (95% CI: 0.28–1.83) of PA as compared with the reference group (interaction p values?=?0.03). Conclusion: Findings suggest complex relationships between placental telomere length, mtDNA copy number and PA risk which warrant further larger studies.     

Placental thromboxane and prostacyclin in the regulation of placental blood flow

To study the significance of placental thromboxane A2 and prostacyclin in the regulation of placental blood flow, intervillous blood flow was measured using a 133Xenon method from 39 women zero to two days before delivery and compared it with the placental production of thromboxane A2 and prostacyclin as measured with a superfusion method postpartum. The placental production of thromboxane B2 (a metabolite of thromboxane A2; 4.5 +/- 1.3 ng/minute per gram dry weight of tissue; mean +/- SD) and that of 6-keto-prostaglandin F1 alpha (a metabolite of prostacyclin; 0.64 +/- 0.27 ng/minute per gram) did not correlate significantly with intervillous blood flow (153.1 +/- 108.0 mL/minute per 100 mL; r = -0.308 and 0.245, respectively), whereas the thromboxane B2/6-keto-prostaglandin F1 alpha ratio (8.53 +/- 4.3) was inversely related to intervillous blood flow (r = -0.419; P less than .01). In the women with intervillous blood flow below the normal mean (less than 130 mL/minute per 100 mL; N = 20) placental thromboxane B2 production (5.1 + 1.2 ng/minute per gram) was higher (P less than .005) and that of 6-keto-prostaglandin F1 alpha (0.54 +/- 0.23 ng/minute per gram) lower (P less than .02) than those in women with intervillous blood flow above 130 mL/minute per 100 mL (thromboxane B2 4.01 +/- 1.0 and 6-keto-prostaglandin F1 alpha 0.75 +/- 0.27 ng/minute per gram; N = 19). These results suggest that placental thromboxane A2 and prostacyclin may be factors in the regulation of intervillous blood flow and that their balance of production is more important than the presence of either agent alone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Placental expression of VEGF, PlGF and their receptors in a model of placental insufficiency-intrauterine growth restriction (PI-IUGR)

Placental development requires adequate and organized interaction of vascular growth factors and their receptors, including vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). Both VEGF and PlGF, acting through the tyrosine kinase receptors VEGFR-1 and VEGFR-2, have been implicated in playing a role in ovine placental vascular development. The present studies describe the placental expression of components of the VEGF family at two maturational time points (55 and 90 days post coitus, dpc) in a hyperthermic-induced ovine model of placental insufficiency-intrauterine growth restriction (PI-IUGR). Both caruncular and cotyledonary VEGF and PlGF mRNA concentration increased with gestational age (P< 0.05), whereas only cotyledonary VEGF and PlGF protein concentration increased over gestation (P< 0.002). At 55 dpc, VEGF mRNA concentration was elevated in hyperthermic (HT) ewes, compared to control thermoneutral (TN) animals (TN; 0.52+/-0.08 vs HT; 1.27+/-0.17 VEGF/GAPDH, P< 0.001). At 90 dpc, expression of PlGF and VEGF mRNA was not altered by the HT treatment. Both TN cotyledonary VEGFR-1 and VEGFR-2 mRNA expression levels rose significantly over the period studied (P< 0.05 and P< 0.01 respectively). Receptor mRNA concentration in HT cotyledonary tissue was significantly reduced at 90 dpc (VEGFR-1; TN 0.21+/-0.02 vs HT 0.11+/-0.01 VEGFR-1/actin, P< 0.05, VEGFR-2; TN 0.18+/-0.05 vs HT 0.07+/-0.01 VEGFR-2/actin, P< 0.01). Soluble VEGFR-1 (sVEGFR-1) mRNA was not detected in these tissues. These alterations in growth factor and growth factor receptor mRNA expression, as a result of environmental heat stress early in placental development, could impair normal placental vascular development. Furthermore, alterations in VEGF, VEGFR-1 and VEGFR-2 mRNA expression, during the period of maximal placental growth, may contribute to the development of placental insufficiency, and ultimately intrauterine growth restriction.     

Sex-specific differences in placental global gene expression in pregnancies complicated by asthma

Background

Chronic maternal asthma is associated with reduced growth of the female fetus and normal growth of the male fetus. The mechanisms that control the differential effects of maternal asthma on the fetus have not been fully elucidated but alterations in placental function may play a role. In the current study we have used microarray platform to examine fetal sex-specific global changes in placental gene expression in pregnancies complicated by asthma as compared to non-asthmatic subjects.

Methods

Placental RNA was extracted from 11 control subjects and 38 asthmatic subjects. Labeled cDNA was hybridized to an oligonucleotide chip with 1700 double spotted well-characterized human genes. Global gene expression data analysis and visualization were performed using the Binary Tree-Structured Vector Quantization (BTSVQ) software. Functional relationships of differentially expressed genes were assessed using protein-protein interaction database I2D, network analysis and visualization software NAViGaTOR and Ingenuity Pathway Analysis software.

Results

Overall, 65 genes were found to be altered in placentae of pregnancies complicated by asthma. Of these, only 6 genes were altered in male placentae. There were 59 gene changes in female placentae of asthmatic mothers relative to control placentae. Some of the sex-specific genes were associated with growth, inflammation and immune pathways.

Conclusion

There are sex-specific alterations in placental gene expression in the presence of maternal asthma. Given that many of the identified genes in the female placentae were associated with or involved in cellular growth and tissue development, these may contribute to the sexually dimorphic difference in fetal growth in response to maternal asthma.     

Stimulatory effects of extracellular calcium on chorionic gonadotrophin and placental lactogen release by human placental explants

The effects of sudden modifications of extracellular calcium ion concentration on human chorionic gonadotrophin (hCG) and human placental lactogen (hPL) release were investigated using term placental explants incubated in Krebs Ringer solution. The hCG and hPL releases were both stimulated when the extracellular Ca2+ concentration was increased. The hCG and hPL secretions elicited by the addition of extracellular Ca2+ were larger when placental explants were preincubated in alpha-calcium (no added calcium + EGTA) than in normo-calcium (1.5 mM). Removal of extracellular Ca2+ from the medium also elicited an increase in hCG and hPL release. However, this stimulatory effect of Ca2+ omission was partly suppressed by washing the explants prior to incubation in the alpha-calcium medium, and was completely abolished when alpha-calcium medium was supplemented with 1 mM cobalt. Our results indicate that changes in Ca2+ modify hCG and hPL release from term placental explants in a manner concordant with the 'stimulus-secretion coupling' concept.     

Distinct effects of short- and long-term type 1 diabetes to the placental extracellular matrix and fetal development in mice

PurposeWe have previously shown that the development of complications in the early pregnant decidua and myometrium in mice correlates with diabetes progression. In the current study, we investigated the influence of diabetes progression on the placental extracellular matrix (ECM) and on fetal development at the end of pregnancy.MethodsAlloxan-induced type 1 diabetic female mice were bred either 30–50 days after diabetes induction (D) or 90-110D. Fetal and placental weights were registered at the 19th day of pregnancy together with analysis of gene expression, deposition and turnover of the placental ECM.ResultsThe short-term diabetic group (30-50D) showed elevated embryonic losses and underweight fetuses (89%) with normal weight placentas. In contrast, the long-term group (90-110D) had increased malformations/fetal deaths and underweight fetuses (42%) and heavy placentas (50%). Normal-weight fetuses from the long-term group had placentas with either regular weight and fetal/placental weight ratio or increased weight and low fetal/placental weight ratio. Furthermore, the placentas of the short-term group showed alterations in the synthesis and deposition of collagen types I and V and in the activity of MMP2 whereas placentas of the 90-110D group presented alterations in collagen type III and V and MMP9.ConclusionsDiabetes progression promoted distinct outcomes in pregnancy. Modifications of both synthesis and turnover of ECM occurred even before changes of placental weight were detected. Adjustment of fetal/placental weight ratio or placental enlargement restored normal growth in part of the fetuses from the long-term group.