Hepatocyte growth factor levels during normal and intra-uterine growth-restricted pregnancies

Hepatocyte growth factor and epidermal growth factor in HIV infected women with preeclampsia

OBJECTIVES

Epidermal growth factor (EGF) and Hepatocyte growth factor (HGF) both have tyrosine kinase receptors (EGFR and c-Met) which upon binding, activates and regulates many important cellular processes such as cell survival, growth, proliferation, differentiation, invasion, repair and so forth via the RAS/MAPK/ERK1/2, PI3K/AKT and JAK STAT3 pathways. These processes are crucial for the development of a placenta and other functions in order for a normal pregnancy to occur. Hence, this study determined the concentrations of HGF and EGF to find the correlation between HIV and preeclampsia (PE).

STUDY DESIGN

A total sample size of n = 80 was used, n = 40 preeclamptic women and n = 40 normotensive women these were further stratified into HIV-positive and HIV-negative women. Analysis of the growth factors were done by using the multiplex Bio-Plex immunoassay method.

RESULTS

Irrespective of HIV status, based on pregnancy type, EGF in PE women displayed an upregulation compared to normotensive women. However, for HGF no variance was found between pregnancy type. Based on HIV status, regardless of pregnancy type, both HGF and EGF levels were significantly increased in HIV-positive women compared to HIV-negative women. Across all groups for HGF, significant difference was found between HIV-negative normotensive women (lower) vs HIV-positive normotensive women (higher). Nevertheless, for EGF across all groups, a statistically significant decrease was found in HIV-negative normotensive women compared to HIV-positive normotensive women, HIV-positive PE women and HIV-negative PE women.

CONCLUSION

The study demonstrates that there is a strong association between HIV and PE and that HGF and EGF are promising biomarkers to use as a diagnostic tool for PE.

Hepatocyte growth factor is elevated in amniotic fluid from obese women and regulates placental glucose and fatty acid metabolism

INTRODUCTION

To evaluate the impact of the pro-inflammatory cytokine hepatocyte growth factor (HGF) on the regulation of glucose and lipid placental metabolism.

METHODS

HGF levels were quantified in amniotic fluid and placenta from control and obese women. 2-deoxy-glucose (2-DOG) uptake, glycolysis, fatty acid oxidation (FAO), fatty acid esterification, de novo fatty acid synthesis, triglyceride levels and carnitine palmitoyltransferase activities (CPT) were measured in placental explants upon addition of pathophysiological HGF levels.

RESULTS

In obese women, total- and -activated-HGF levels in amniotic fluid were elevated ∼24%, and placental HGF levels were ∼3-fold higher than in control women. At a similar dose to that present in amniotic fluid of obese women, HGF (30 ng/mL) increased Glut-1 levels and 2-DOG uptake by ∼25-30% in placental explants. HGF-mediated effect on 2-DOG uptake was dependent on the activation of phosphatidylinositol 3-kinase signaling pathway. In addition, HGF decreased ∼20% FAO, whereas esterification and de novo fatty acid synthesis increased ∼15% and ∼25% respectively, leading to 2-fold triglyceride accumulation in placental explants. In parallel, HGF reduced CPT-I activity ∼70%.

DISCUSSION

HGF is a cytokine elevated in amniotic fluid and placental tissue of obese women, which through its ability to stimulate 2-DOG uptake and metabolism impairs FAO and enhances esterification and de novo fatty acid synthesis, leading to accumulation of placental triglycerides.

Investigating the Relationship between Serum Level of s-Met (Soluble Hepatic Growth Factor Receptor) and Preeclampsia in the First and Second Trimesters of Pregnancy

Introduction. Preeclampsia (PE) is an important cause of mortality and morbidity for mothers, fetuses, and the newborns. Placenta plays a pivotal role in pathogenesis of PE. Hepatic growth factor (HGF) is a cytokine expressed by the mesenchymal stalk of placental villi during pregnancy and assumes a paracrine role in trophoblasts which express its receptor (c-MET). In the present study, we investigate the diagnostic value of s-Met (the soluble form of the receptor) in the first and second trimesters of pregnancy for early diagnosis of preeclampsia. Method and Materials. This is a case-control study conducted on 95 pregnant women. The serum level of s-Met was measured in the first and second trimesters, and the participants were followed until delivery. 44 individuals with preeclampsia (the case group) and 51 individuals without preeclampsia (the control group) were evaluated. Results. Serum level of s-Met in preeclamptic participants was lower than that of the control group in both the first and the second trimesters (P < 0.0001). In addition, serum levels of s-Met were significantly lower during the first and second trimesters in patients with early, severe preeclampsia compared to those with late, mild preeclampsia (P < 0.0001). The sensitivity and specificity of s-Met in the first and second trimesters were, respectively, (83%, 94%) and (77%, 94%) for early preeclampsia and (88%, 92%) and (86%, 98%) for severe preeclampsia. Conclusion. Considering our findings, serum level of s-Met may be used as a predictive factor for early detection of preeclampsia. Further research is required to corroborate the functional and therapeutic value of s-Met in preeclampsia.

Novel biomarkers for predicting intrauterine growth restriction: a systematic review and meta-analysis

BACKGROUND

Several biomarkers for predicting intrauterine growth restriction (IUGR) have been proposed in recent years. However, the predictive performance of these biomarkers has not been systematically evaluated.

OBJECTIVE

To determine the predictive accuracy of novel biomarkers for IUGR in women with singleton gestations.

SEARCH STRATEGY

Electronic databases, reference list checking and conference proceedings.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of novel biomarkers proposed for predicting IUGR.

DATA COLLECTION AND ANALYSIS

Data were extracted on characteristics, quality and predictive accuracy from each study to construct 2×2 tables. Summary receiver operating characteristic curves, sensitivities, specificities and likelihood ratios (LRs) were generated.

MAIN RESULTS

A total of 53 studies, including 39,974 women and evaluating 37 novel biomarkers, fulfilled the inclusion criteria. Overall, the predictive accuracy of angiogenic factors for IUGR was minimal (median pooled positive and negative LRs of 1.7, range 1.0-19.8; and 0.8, range 0.0-1.0, respectively). Two small case-control studies reported high predictive values for placental growth factor and angiopoietin-2 only when IUGR was defined as birthweight centile with clinical or pathological evidence of fetal growth restriction. Biomarkers related to endothelial function/oxidative stress, placental protein/hormone, and others such as serum levels of vitamin D, urinary albumin:creatinine ratio, thyroid function tests and metabolomic profile had low predictive accuracy.

CONCLUSIONS

None of the novel biomarkers evaluated in this review are sufficiently accurate to recommend their use as predictors of IUGR in routine clinical practice. However, the use of biomarkers in combination with biophysical parameters and maternal characteristics could be more useful and merits further research.

Plasma inflammatory and vascular homeostasis biomarkers increase during human pregnancy but are not affected by oily fish intake

The Salmon in Pregnancy Study investigated whether the increased consumption of (n-3) long-chain PUFA (LC-PUFA) from farmed Atlantic salmon affects immune function during pregnancy and atopic disease in neonates compared with a habitual diet low in oily fish. In this context, because the ingestion of (n-3) LC-PUFA may lower the concentrations of inflammatory biomarkers, we investigated whether the consumption of oily fish affects the levels of inflammatory cytokines and vascular adhesion factors during pregnancy. Pregnant women (n = 123) were randomly assigned to continue their habitual diet (control group, n = 61), which was low in oily fish, or to consume two 150-g salmon portions/wk (salmon group, n = 62; providing 3.45 g EPA plus DHA) from 20 wk of gestation until delivery. Plasma inflammatory cytokines and vascular adhesion factors were measured in maternal plasma samples. Inflammatory biomarkers, including IL-8, hepatocyte growth factor, and monocyte chemotactic protein, increased over the course of pregnancy (P < 0.001), whereas plasma matrix metalloproteinase 9, IL-6, TNFα, and nerve growth factor concentrations were not affected. Vascular homeostasis biomarkers soluble E-selectin, soluble vascular adhesion molecule-1, soluble intercellular adhesion molecule (sICAM)-1, and total plasminogen activator inhibitor-1 increased as pregnancy progressed (P < 0.001). The plasma sICAM-1 concentration was greater in the control group than in the salmon group at wk 20 (baseline) and 38 (P = 0.007) but there was no group x time interaction, and when baseline concentration was used as a covariate, the groups did not differ (P = 0.69). The remaining biomarkers analyzed were similar in both groups. Therefore, although some inflammatory and vascular homeostasis biomarkers change during pregnancy, they are not affected by the increased intake of farmed salmon.

Plasma level of soluble c-Met is tightly associated with the clinical risk of preeclampsia

OBJECTIVE

The objective of the study was to examine the relevance of the soluble form c-Met (sMet) with the clinical risk for severe preeclampsia.

STUDY DESIGN

This prospective case-control study was performed by using plasma derived from 44 preeclamptic and 51 uncomplicated pregnant women. Plasma concentration of sMet was measured with specific enzyme-linked immunosorbent assay, and the predictive values were determined based on the receiver-operating characteristic (ROC) curves analysis.

RESULTS

Plasma s-Met level in normal pregnant women changed in a gestation-dependent manner, peaking at weeks 19-24. In women with severe preeclampsia, the circulating sMet level was significantly lower than that in the gestational stage-matched controls during gestational weeks 15-30. The ROC curve analysis revealed a significant correlation between plasma sMet level and the risk of developing severe preeclampsia.

CONCLUSION

Plasma sMet could serve as a potential biomarker for predicting severe preeclampia at early second trimester of pregnancy.

Maternal obesity and markers of inflammation in pregnancy

OBJECTIVES

To evaluate whether obesity is associated with changes in pro-inflammatory and immunomodulatory cytokines in pregnancy.

METHODS

We performed a cross-sectional study using maternal serum from the early second trimester to examine biomarkers associated with inflammation in relation to maternal body mass index (n=80 total).

RESULTS

Leptin and high sensitivity C-reactive protein were significantly different between groups and increased with increasing body mass index. MCP-1 was significantly increased in the morbidly obese mothers. Interleukin-2 exhibited a U-shaped relationship with body mass index; transforming growth factor-beta1 demonstrated a nonsignificant negative trend with body mass index; and the levels of hepatocyte growth factor and tumor necrosis factor-alpha did not differ appreciably between groups.

CONCLUSIONS

Maternal obesity in pregnancy is associated with changes in cytokines, protein hormones and acute phase proteins in the second trimester, with an increase in MCP-1 in the morbid obesity category, and an increase in Leptin and hsCRP with increasing BMI category.

Changes in plasma levels of hepatocyte growth factor and its associated factors during pregnancy

AIM

Hepatocyte growth factor (HGF) was originally identified as a factor that stimulates the mitogenesis of hepatocyte, and also plays a role in maintaining pregnancy. We conducted this study to evaluate the changes in plasma concentrations of HGF and its associated factors during normal pregnancy.

METHODS

Blood specimens were obtained from 14 healthy non-pregnant and 175 healthy pregnant and post-partum women (189 women in all). The women's plasma concentrations of total HGF, active HGF, active HGF activator (HGFA), HGF activator inhibitor type 1 (HAI-1) and HGF activator inhibitor type 2 (HAI-2) were determined by enzyme-linked immunosorbent assay.

RESULTS

The levels of active HGF and HGF activator were significantly lower in pregnant women compared with those of non-pregnant women. The level of plasma HAI-1 significantly increased as pregnancy progressed, while it fell post-partum. Also, there were no differences in the concentrations of total HGF and HAI-2 in non-pregnant and pregnant women.

CONCLUSION

A high concentration of HAI-1 during pregnancy may decrease the plasma level of active HGFA. This may in turn inhibit the activation of the precursor form of HGF, leading to a decrease in the level of plasma active HGF.

Expression of hepatocyte growth factor/scatter factor receptor in IUGR fetuses' placentas: an immunohistochemical analysis

OBJECTIVE

We aimed to evaluate the expression sta tus of c-met, receptor for the hepatocyte growth factor (HGF), in the placentas of intrauterine growth retardation (IUGR) fetuses.

MATERIALS AND METHODS

Placentas were obtained during delivery from both third trimester normal and IUGR complicated pregnancies. Ultrasonographic estimation of fetal birth weight has been done and placentas of those under the fifth percentile for their gestational ages were enrolled in the study group. Eighteen fetuses with IUGR and 6 uncomplicated pregnancies were subjected to the study. Histological sections from placentas were immunohistochemically evaluated for the expression status of c-met.

RESULTS

Seventeen of the eighteen patients (94.4%) in the study group were found to have overexpression of the c-met while this figure was only 16.7% (1/6) in the control group (p < 0.0001). There was a strong statistically significant difference between the two groups regarding degree of c-met expression.

CONCLUSION

Our present findings suggest that c-met is an important cell membrane receptor in human placenta. Deregulation of the interaction between HGF and its receptor c-met during placentation may be the cause responsible for the growth retardation of the fetus due to the impaired placental functions.

Trophoblast apoptosis is inhibited by hepatocyte growth factor through the Akt and beta-catenin mediated up-regulation of inducible nitric oxide synthase

Excessive apoptosis of trophoblast cells is thought to be a contributing factor in complications of pregnancy such as pre-eclampsia. Hepatocyte growth factor (HGF) inhibits apoptosis in trophoblasts and we have investigated the signalling pathways through which this anti-apoptotic effect is mediated. Treatment of cells with HGF led to rapid phosphorylation of Akt while an Akt inhibitor blocked the protective effect of HGF. Glycogen synthase kinase-3beta (GSK-3beta) was found to be one of the downstream targets of Akt. HGF treatment inactivated GSK-3beta which in turn led to the activation of the transcription factor beta-catenin. Pharmacological inhibition of GSK-3beta, independently of HGF treatment, strongly increased both beta-catenin activity and cell survival, suggesting that beta-catenin alone has a pronounced anti-apoptotic effect. We also found that both HGF treatment and pharmacological activation of beta-catenin leads to increased expression of inducible nitric oxide synthase (iNOS). We suggest that the Akt mediated activation of beta-catenin leads to inhibition of trophoblast apoptosis following increased expression of iNOS.

Human decidual production of hepatocyte-growth factor is not influenced by trophoblastic invasion in vivo

OBJECTIVE

To evaluate and compare production of hepatocyte growth factor (HGF) from human first-trimester implantation-site decidua (decidua basalis) and nonimplantation site decidua (decidua parietalis), and hence to determine whether human trophoblast invasion in vivo is associated with increased decidual HGF production.

DESIGN

Controlled prospective study.

SETTING

University hospital-based study.

PATIENT(S)

Ten women undergoing first-trimester termination of singleton pregnancy for psychosocial reasons without preexisting medical or gynecologic diseases.

INTERVENTION(S)

Decidual samples surgically excised and processed for paraffin-embedded immunohistochemistry and for reverse transcription-polymerase chain reaction (RT-PCR) studies.

MAIN OUTCOME MEASURE(S)

Protein and mRNA production in decidua basalis and decidua parietalis by immunohistochemistry and RT-PCR, respectively.

RESULT(S)

No statistically significant difference was found between decidua basalis and decidua parietalis in HGF protein or mRNA production. Immunohistochemical analysis (n = 9) showed a mean score of 3.28 +/- 2.37 for decidua basalis and 3.61 +/- 2.66 for decidua parietalis. Semiquantitative analysis of HGF mRNA expression between the two sites showed no statistically significant difference (n = 10)

CONCLUSION(S)

Human decidual production of HGF is not influenced by trophoblastic invasion in vivo.

Aspects of human fetoplacental vasculogenesis and angiogenesis. I. Molecular regulation

Patterns of fetoplacental angiogenesis vary during gestation and in association with certain pregnancy pathologies. In a set of three linked reviews, we provide a survey of current knowledge about the molecular regulation, cellular players, qualitative and quantitative morphological features of the vascularization of human placental villi. Here, an account is given of the role played by hypoxia-inducible factor in mediating the effects of oxygen on production of growth factor ligands and receptors which regulate angiogenesis and vessel maturation. However, it should be noted that, for the human placenta early in gestation, the normal (i.e. physiological) partial pressure of O(2)is low but this does not mean that the tissue is hypoxic. Thus, the mechanisms of regulating angiogenic growth factor production may differ at this time in comparison to those found later in gestation or in other tissues or organs. The vasculature in the placenta is plastic and changes markedly as gestation progresses. This is controlled by the complex interplay between physical factors and chemical factors including oxygen, growth factors and growth inhibitors. The companion reviews describe morphological features of normal and pathological development of the human placenta in the context of the factors discussed here.

Plasma hepatocyte growth factor as a marker for small-for-gestational age fetuses

OBJECTIVE

To study the association between hepatocyte growth factor (HGF) levels and pregnancy outcome.

STUDY DESIGN

Hepatocyte growth factor levels were measured in 42 plasma samples between weeks 14 and 21 of gestation using an enzyme-linked immunosorbent assay (ELISA). Results were correlated to pregnancy outcome and Mann-Whitney U-test applied to study the differences.

RESULTS

Hepatocyte growth factor values in pregnancies that develop preeclampsia (n=12) were not significantly different from unaffected pregnancies (n=21, multiples of the median (MoM)=1.38, P=0.47). However, hepatocyte growth factor values were significantly elevated in pregnancies of small-for-gestational age (SGA) fetuses (n=9) compared to uncomplicated pregnancies (MoM=2.66, P<0.001).

CONCLUSION

Measurement of hepatocyte growth factor in peripheral blood between 14 and 21 weeks gestation may offer new possibilities in the early diagnosis and prediction of fetal birth weight but not of preeclampsia.

Use of transgenic mice model for understanding the placentation: towards clinical applications in human obstetrical pathologies?

The mammalian embryo and fetus are unable to develop without a well-established, functional placenta. This transitory yet indispensable structure attaches the conceptus to the uterus and establishes the vascular connections necessary for nutrient and gaseous exchange between maternal and fetal compartments. Genetic targeting strategy allows the generation of mice lacking a specific gene. Such approaches reveal: (i) the high incidence of mutant embryonic or fetal death in utero, and (ii) the extraembryonic (placental) causes of these deaths. Due to the similarities presented between mouse and human placenta, we propose to use the potential of mouse targeting experiments as a model in order to understand human obstetrical pathologies. In this paper, we first review genes that have been demonstrated to be required in mice for implantation, choriovitelline and chorioallantoic placentation. Using examples (integrins, homeoboxs, hepatocyte growth factor or epidermal growth factor receptor...) we demonstrate the reality and efficiency of such an approach. Other candidate genes (receptor of leukemia inhibitory factor, Wnt2 or retinoic acid receptor alpha...) in order to understand, prevent and treat human obstetrical pathologies.

A role for hepatocyte growth factor during early postimplantation growth of the placental lineage in mice

Hepatocyte growth factor (HGF) is implicated in placental development; hgfr and hgf null mutant embryos develop placental insufficiency and lethality at 11.5 days (E11.5) after fertilization. The function of HGF in placentation at implantation (E4.5) has not been studied. Using reverse transcription-polymerase chain reaction, we detected HGF receptor (HGFR) mRNA in preimplantation embryos and in cultured blastocyst outgrowths. HGFR protein was detected in trophoblast cells in blastocyst outgrowths. HGF mRNA was not detected at these stages but was detected in the uterus at E5.5. Using in situ hybridization, we detected HGF mRNA in the mesometrial uterus, near the embryo, from E6.5 through E8.5. At E8.5, HGFR mRNA was detected in the chorionic placenta, and HGF mRNA was detected in the allantois. The expression for HGF and HGFR suggested a maternal-to-embryonic communication before the development of the allantois. To test this, blastocyst outgrowths were cultured with HGF. HGF stimulated the outgrowth of trophoblasts in a time-dependent manner and stimulated the expression of proliferating cell nuclear antigen, but it did not scatter trophoblasts. HGF stimulated an increase in the trophoblast cell number, but caused a decrease in the total number of terminally differentiated trophoblasts expressing placental lactogen-1 protein. These data suggest that HGF stimulates the cell division, but not the differentiation, of trophoblast cells during implantation.