RGD-Based Fluorescence to Assess Placental Angiogenesis

Normal fetal growth and placental development depend on active angiogenesis occurring at the fetomaternal interface throughout pregnancy. Nevertheless, reliable in vivo methods to assess placental angiogenesis are still missing. Here, we describe a quantitative and noninvasive in vivo method to specifically measure placental neovascularization in the gravid mouse. This method uses a technique based on the measurement of a fluorescent molecule Angiostamp700 that targets the alpha v beta 3 (αvβ3) integrin, a protein that is highly expressed by endothelial cells during the neovascularization and by trophoblast cells during invasion of the maternal decidua. Due to this noninvasive method, quantification of the fetomaternal angiogenic activity and information regarding the outcome of pregnancy are now possible.

In Vivo Quantitative Assessment of Gestational Choriocarcinoma Development and Progression Using Luminescent Trophoblast Cells

Gestational trophoblastic diseases (GTD) are a group of pregnancy-related disorders representing rare human tumors. Among GTD is the gestational choriocarcinoma (CC), which is a highly malignant gestational trophoblastic tumor that causes high mortality without timely treatment. The incidence of CC is about 1 in 50,000 pregnancies in developed countries and even higher in developing countries. CC developed from molar pregnancies exhibits even higher incidence rates (3-20 in 1000 pregnancies). In the present invention, we developed the first orthotopic animal model of CC. We demonstrate how to mimic the development of this cancer and observe rapid metastasis, which is seen in CC patients, by injecting the luciferase-positive JEG-3 (JEG-3-Luc) cells directly in the placenta of gravid SCID mice. Gravid mice were injected at 7.5 days post coitus (dpc) and followed throughout gestation to assess the parameters of CC development and metastasis. Mice imaged at day 19.5 dpc showed placental tumor development and large sites of metastases in the liver, spleen, lung, and peritoneum. This finding emphasizes the importance of placental vascularization in the rapid dissemination of tumor cells. Morphological analyses and histopathological examinations were performed to confirm JEG-3 cell dissemination in different organs of the gravid mice. This is the first time a CC model was developed by injection of tumor cells within the placenta. This technique offers a new tool to study tumor progression with strong perspectives to test anti-tumor agents in vivo.

Soluble CD146, a biomarker and a target for preventing resistance to anti-angiogenic therapy in glioblastoma

Rationale

Glioblastoma multiforme (GBM) is a primary brain tumor with poor prognosis. The U.S. food and drug administration approved the use of the anti-VEGF antibody bevacizumab in recurrent GBM. However, resistance to this treatment is frequent and fails to enhance the overall survival of patients. In this study, we aimed to identify novel mechanism(s) responsible for bevacizumab-resistance in CD146-positive glioblastoma.

Methods

The study was performed using sera from GBM patients and human GBM cell lines in culture or xenografted in nude mice.

Results

We found that an increase in sCD146 concentration in sera of GBM patients after the first cycle of bevacizumab treatment was significantly associated with poor progression free survival and shorter overall survival. Accordingly, in vitro treatment of CD146-positive glioblastoma cells with bevacizumab led to a high sCD146 secretion, inducing cell invasion. These effects were mediated through integrin αvβ3 and were blocked by mucizumab, a novel humanized anti-sCD146 antibody. In vivo, the combination of bevacizumab with mucizumab impeded CD146 + glioblastoma growth and reduced tumor cell dissemination to an extent significantly higher than that observed with bevacizumab alone.

Conclusion

We propose sCD146 to be 1/ an early biomarker to predict and 2/ a potential target to prevent bevacizumab resistance in patients with glioblastoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40478-022-01451-3.

Abstract LB566: Class 1 HDAC inhibition induces antitumor immunity by NF-kB-mediated enhanced metabolic fitness and generation of unique effector function enriched memory CD8 T cell subtype

Histone/protein deacetylases (HDACs) are a class of enzymes that regulate gene expression and are involved in regulating the transcription process as well as regulating fundamental cellular processes such as proliferation, differentiation and development. Class I HDACs (which includes HDAC1, 2, 3, and 8) contribute in epigenetic regulations of T cell tolerance. Under anergic T cell condition, HDAC1 and HDAC2 are involved in the histone deacetylation. However, the role of HDACs in CD8 T cell function and differentiation is not well understood. Therefore, we aimed to understand the effect of HDAC inhibition (HDACi) on CD8 T cells phenotype and functionality by using Entinostat (ENT), a class I HDAC (HDAC1 and 3) inhibitor. We found that ENT induces strong immune-mediated anti-tumor effects in TC-1 and B16 tumor-bearing mice. Mechanistically, ENT modulated the tumor microenvironment through an increased infiltration of CD8 T cells, enhanced CD8 T cell antigen-specificity and CD8 T cell functionality represented by interferon gamma (IFN-γ) and granzyme B (GrB) secretion. Our in vitro and in vivo data also indicate that ENT enhances central memory phenotype (CD62L+, CD44+) of CD8 T cells. We also found that ENT-treated CD8 T cells have distinct metabolic phenotype compared to activated CD8 T cells. Specifically, these cells relied more on amino acid metabolism while, unexpectedly, they had lower fatty acid uptake with enhanced mitochondrial potential (TMRM). Interestingly, ENT-induced central memory CD8 T cells also showed increased mitochondrial potential as well as reliance on amino acid metabolism. Therefore, ENT treatment induced memory cells with a unique phenotype different from the classical memory CD8 T cells with enhanced effector functions and reliance on distinct metabolic pathways. Furthermore, ENT-treated CD8 T cells have higher peaks at H3K27Ac site compared to the control. Since these peaks are mostly associated with genes such as IFN-γ, GrB, Pim1, EOMES, and IL-2, the known canonical target genes of NF-κB in CD8 T cells, we further dissected the role of NF-κB in these ENT-mediated effects. First, motif analysis showed that NF-κB binding motif is enriched in differential H3K27Ac sites associated with HDACi. Next, flow cytometry and immunofluorescence analysis showed that although ENT does not increase total NF-κB levels in CD8 T cells, it enhances its binding to the chromatin due to enhanced gene accessibility. This research highlights the significance of epigenetic modulation in enhancing the immune-mediated anti-tumor effects and provide fundamental understanding of the mechanism of action of HDAC inhibition in CD8 T cells.

Citation Format: Nour Shobaki, Pankaj Gaur, Rahul Nadre, Vivek Verma, Peter Ordentlich, Lei Wang, Nazli Jafarzadeh, Wael Traboulsi, Mikayel Mkrtichyan, Seema Gupta, Samir N. Khleif. Class 1 HDAC inhibition induces antitumor immunity by NF-kB-mediated enhanced metabolic fitness and generation of unique effector function enriched memory CD8 T cell subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB566.

Evidence-Based View of Safety and Effectiveness of Prokineticin Receptors Antagonists during Pregnancy

Endocrine gland derived vascular endothelial growth factor (EG-VEGF) is a canonical member of the prokineticin (PROKs) family. It acts via the two G-protein coupled receptors, namely PROKR1 and PROKR2. We have recently demonstrated that EG-VEGF is highly expressed in the human placenta; contributes to placental vascularization and growth and that its aberrant expression is associated with pregnancy pathologies including preeclampsia and fetal growth restriction. These findings strongly suggested that antagonization of its receptors may constitute a potential therapy for the pregnancy pathologies. Two specific antagonists of PROKR1 (PC7) and for PROKR2 (PKRA) were reported to reverse PROKs adverse effects in other systems. In the view of using these antagonists to treat pregnancy pathologies, a proof of concept study was designed to determine the biological significances of PC7 and PKRA in normal pregnancy outcome. PC7 and PKRA were tested independently or in combination in trophoblast cells and during early gestation in the gravid mouse. Both independent and combined treatments uncovered endogenous functions of EG-VEGF. The independent use of antagonists distinctively identified PROKR1 and PROKR2-mediated EG-VEGF signaling on trophoblast differentiation and invasion; thereby enhancing feto-placental growth and pregnancy outcome. Thus, our study provides evidence for the potential safe use of PC7 or PKRA to improve pregnancy outcome.

Role of CD146 (MCAM) in Physiological and Pathological Angiogenesis-Contribution of New Antibodies for Therapy

The fundamental role of cell adhesion molecules in mediating various biological processes as angiogenesis has been well-documented. CD146, an adhesion molecule of the immunoglobulin superfamily, and its soluble form, constitute major players in both physiological and pathological angiogenesis. A growing body of evidence shows soluble CD146 to be significantly elevated in the serum or interstitial fluid of patients with pathologies related to deregulated angiogenesis, as autoimmune diseases, obstetric and ocular pathologies, and cancers. To block the undesirable effects of this molecule, therapeutic antibodies have been developed. Herein, we review the multifaceted functions of CD146 in physiological and pathological angiogenesis and summarize the interest of using monoclonal antibodies for therapeutic purposes.

Prokineticin 1 is a new biomarker of human oocyte competence: expression and hormonal regulation throughout late folliculogenesis

CONTEXT

Prokineticin 1 (PROK1) quantification in global follicular fluid (FF) has been recently reported as a predictive biomarker of in vitro fertilization (IVF) outcome. It is now necessary to evaluate its clinical usefulness in individual follicles.

OBJECTIVES

To evaluate the clinical value of PROK1 secretion in individual FF to predict oocyte competence. To determine the impact of follicular size, oocyte maturity, and gonadotropin treatments on PROK1 secretion.

DESIGN AND SETTING

Prospective cohort study from May 2015 to May 2017 at the University Hospital of Grenoble.

PATIENTS

A total of 69 infertile couples underwent IVF.

INTERVENTION(S)

Collection of 298 individual FF from 44 women undergoing IVF; 52 individual cumulus cell (CC) samples and 15 CC primary cultures from 25 women undergoing IVF-intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Oocyte competence was defined as the ability to sustain embryo development to the blastocyst stage. Follicular size was measured by 2D-sonography. PROK1 concentration was quantified by ELISA assay.

RESULTS

PROK1 concentration was correlated to follicular size (r = 0.85, P = 2.2 × 10-16). Normalized PROK1 concentration in FF was predictive of subsequent oocyte competence (AUROC curve = 0.76 [95% CI, 0.69-0.83]; P = 1.7 × 10-9), irrespectively of day-2 embryo morphokinetic parameters. The expression and secretion of PROK1 were increased in FF and CC of mature oocytes (P < 0.01). Follicle Stimulating Hormone and hCG up-regulated PROK1 secretion in CC primary cultures (P < 0.01; P < 0.05), probably through the cAMP pathway (P < 0.01).

CONCLUSIONS

PROK1 quantification in individual FF could constitute a new predictive biomarker of oocyte competence in addition with embryo morphokinetic parameters.

TRIAL REGISTRATION NUMBER

none.

Vascular endothelial growth factor (VEGF) and Endocrine gland-VEGF (EG-VEGF) are down regulated in head and neck cancer

OBJECTIVE

To characterise the role of VEGF, EG-VEGF and its receptors in the development and progression of HNC.

DESIGN

Human serum and tissues samples were collected from healthy, epulis and HNC patients and used for ELISA assays and immunohistochemistry studies, respectively.

SETTING

Ibn Rochd Hospital of Casablanca (Morocco), INSERM and University of Grenoble Alpes (France).

PARTICIPANTS

We used serum from 64 patients with head and neck cancers and from 71 controls without general pathology. Tissues samples were collected from seven patients with OSCC and from seven patients with Epulis.

MAIN OUTCOME MEASURES

We compared circulating VEGF and EG-VEGF in normal and HNC patients and determined the expression, localisation and quantification of VEGF, EG-VEGF and its receptors; PROKR1 and PROKR2 as well as Ki67, CD31 and CD34 in OSCC and Epulis patients.

RESULTS

Both EG-VEGF and VEGF circulating levels were significantly decreased in the HNC (P < .01). OSCC patients expressed less EG-VEGF and VEGF proteins, higher PROKR1 and PROKR2 with no change in CD31 and CD34 levels. A significant increase in Ki67 was observed in OSCC.

CONCLUSIONS

We demonstrated that circulating VEGF and EG-VEGF are downregulated in HNC patients and in OSCC tissue. EG-VEGF receptors were increased in OSCC, along with a stabilisation of two key markers of angiogenesis. These findings strongly suggest that downregulation of angiogenesis in HNC might explain its moderate metastatic feature.

Therapeutic targeting of soluble CD146/MCAM with the M2J-1 monoclonal antibody prevents metastasis development and procoagulant activity in CD146-positive invasive tumors

Initially discovered in human melanoma, CD146/MCAM is expressed on many tumors and is correlated with cancer progression and metastasis. However, targeting CD146 remains challenging since it is also expressed on other cell types, as vessel cells, where it displays important physiological functions. We previously demonstrated that CD146 is shed as a soluble form (sCD146) that vectorizes the effects of membrane CD146 on tumor angiogenesis, growth and survival. We thus generated a novel monoclonal antibody, the M2J-1 mAb, which specifically targets sCD146, but not membrane CD146, and counteracts these effects. In our study, we analyzed the effects of sCD146 on the dissemination and the associated procoagulant phenotype in two highly invasive human CD146-positive cancer cell lines (ovarian and melanoma). Results show that sCD146 induced epithelial to mesenchymal transition, favored the generation of cancer stem cells and increased the membrane expression of tissue factor. Treatment of cancer cells with sCD146 in two experimental models (subcutaneous xenografting and intracardiac injection of cancer cells in nude mice) led to increased tumor dissemination and procoagulant activity. The M2J-1 mAb drastically reduced metastasis but also procoagulant activity, in particular by decreasing the number of circulating tumor microparticles, and blocked the relevant signaling pathways as demonstrated by RNA expression profiling experiments. Thus, our findings demonstrate that sCD146 mediates important pro-metastatic and procoagulant effects in two CD146-positive tumors. Targeting sCD146 with the newly generated M2J-1 mAb could constitute an innovative strategy for preventing dissemination and thromboembolism in many CD146-positive tumors.

NLRP7 is increased in human idiopathic fetal growth restriction and plays a critical role in trophoblast differentiation

Fetal growth restriction (FGR) the leading cause of perinatal mortality and morbidity is highly related to abnormal placental development, and placentas from FGR pregnancies are often characterized by increased inflammation. However, the mechanisms of FGR-associated inflammation are far from being understood. NLRP7, a member of a family of receptors involved in the innate immune responses, has been shown to be associated with gestational trophoblastic diseases. Here, we characterized the expression and the functional role of NLRP7 in the placenta and investigated its involvement in the pathogenesis of FGR. We used primary trophoblasts and placental explants that were collected during early pregnancy, and established trophoblast-derived cell lines, human placental villi, and serum samples from early pregnancy (n = 38) and from FGR (n = 40) and age-matched controls (n = 32). Our results show that NLRP7 (i) is predominantly expressed in the trophoblasts during the hypoxic period of placental development and its expression is upregulated by hypoxia and (ii) increases trophoblast proliferation ([³H]-thymidine) and controls the precocious differentiation of trophoblasts towards syncytium (syncytin 1 and 2 and β-hCG production and xCELLigence analysis) and towards invasive extravillous trophoblast (2D and 3D cultures). We have also demonstrated that NLRP7 inflammasome activation in trophoblast cells increases IL-1β, but not IL-18 secretion. In relation to the FGR, we demonstrated that major components of NLRP7 inflammasome machinery are increased and that IL-1β but not IL-18 circulating levels are increased in FGR. Altogether, our results identified NLRP7 as a critical placental factor and provided evidence for its deregulation in FGR. NLRP7 inflammasome is abundantly expressed by trophoblast cells. It is regulated by a key parameter of placental development, hypoxia. It controls trophoblast proliferation, migration, and invasion and exhibits anti-apoptotic role. NLRP7 machinery is deregulated in FGR pregnancies. KEY MESSAGES: NLRP7 inflammasome is abundantly expressed by trophoblast cells. It is regulated by a key parameter of placental development, hypoxia. It controls trophoblast proliferation, migration, and invasion and exhibits anti-apoptotic role. NLRP7 machinery is deregulated in FGR pregnancies.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) and its receptor PROKR2 are associated to human colorectal cancer progression and peritoneal carcinomatosis

BACKGROUND

The highest risk factor for mortality among malignant tumors is metastasis. Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an angiogenic factor which biological activity is mediated via two G protein-coupled receptors, prokineticin receptor1 (PROKR1) and PROKR2. Recent studies suggested that EG-VEGF expression is deregulated in multiple cancers including colorectal cancer (CRC).

METHODS

Using distinctive CRC and peritoneal carcinomatosis (PC) cohorts and a corresponding control cohort, we determined the circulating levels of EG-VEGF and its in situ expression, and that of its related receptors.

RESULTS

Circulating EG-VEGF levels were significantly increased in patients with metastatic PC compared to CRC and control patients (p< 0.05). Furthermore, according to clinicopathologic examinations, local EG-VEGF expression correlated with higher tumor and nodal stages (p< 0.001) of CRC. EG-VEGF and PROKR2 were highly expressed in colorectal primary lesions compared to positive controls. PROKR1 expression was lower and did not change in tumor specimens. Also, EG-VEGF and its receptor PROKR2 were differentially expressed in the colorectal primary lesions and in the control groups.

CONCLUSION

Altogether these findings suggest that EG-VEGF/receptors system might be an important actor in the CRC progression into PC and might be involved in the ability of tumor cells to invade other organs. Circulating EG-VEGF could be proposed as a prognostic marker in human CRC and its progression into PC.

Soluble CD146 is a predictive marker of pejorative evolution and of sunitinib efficacy in clear cell renal cell carcinoma

The objective of the study was to use CD146 mRNA to predict the evolution of patients with non-metastatic clear cell renal cell carcinoma (M0 ccRCC) towards metastatic disease, and to use soluble CD146 (sCD146) to anticipate relapses on reference treatments by sunitinib or bevacizumab in patients with metastatic ccRCC (M1).

Methods: A retrospective cohort of M0 patients was used to determine the prognostic role of intra-tumor CD146 mRNA. Prospective multi-center trials were used to define plasmatic sCD146 as a predictive marker of sunitinib or bevacizumab efficacy for M1 patients.

Results: High tumor levels of CD146 mRNA were linked to shorter disease-free survival (DFS) and overall survival (OS). ccRCC patients from prospective cohorts with plasmatic sCD146 variation <120% following the first cycle of sunitinib treatment had a longer progression-free survival (PFS) and OS. The plasmatic sCD146 variation did not correlate with PFS or OS for the bevacizumab-based treatment. In vitro, resistant cells to sunitinib expressed high levels of CD146 mRNA and protein in comparison to sensitive cells. Moreover, recombinant CD146 protected cells from the sunitinib-dependent decrease of cell viability.

Conclusion: CD146/sCD146 produced by tumor cells is a relevant biological marker of ccRCC aggressiveness and relapse on sunitinib treatment.

Antagonism of EG-VEGF Receptors as Targeted Therapy for Choriocarcinoma Progression In Vitro and In Vivo

Purpose: Choriocarcinoma (CC) is the most malignant gestational trophoblastic disease that often develops from complete hydatidiform moles (CHM). Neither the mechanism of CC development nor its progression is yet characterized. We recently identified endocrine gland-derived vascular endothelial growth factor (EG-VEGF) as a novel key placental growth factor that controls trophoblast proliferation and invasion. EG-VEGF acts via two receptors, PROKR1 and PROKR2. Here, we demonstrate that EG-VEGF receptors can be targeted for CC therapy.Experimental Design: Three approaches were used: (i) a clinical investigation comparing circulating EG-VEGF in control (n = 20) and in distinctive CHM (n = 38) and CC (n = 9) cohorts, (ii) an in vitro study investigating EG-VEGF effects on the CC cell line JEG3, and (iii) an in vivo study including the development of a novel CC mouse model, through a direct injection of JEG3-luciferase into the placenta of gravid SCID-mice.Results: Both placental and circulating EG-VEGF levels were increased in CHM and CC (×5) patients. EG-VEGF increased JEG3 proliferation, migration, and invasion in two-dimensional (2D) and three-dimensional (3D) culture systems. JEG3 injection in the placenta caused CC development with large metastases compared with their injection into the uterine horn. Treatment of the animal model with EG-VEGF receptor's antagonists significantly reduced tumor development and progression and preserved pregnancy. Antibody-array and immunohistological analyses further deciphered the mechanism of the antagonist's actions.Conclusions: Our work describes a novel preclinical animal model of CC and presents evidence that EG-VEGF receptors can be targeted for CC therapy. This may provide safe and less toxic therapeutic options compared with the currently used multi-agent chemotherapies. Clin Cancer Res; 23(22); 7130-40. ©2017 AACR.

Prokineticins in central and peripheral control of human reproduction

Prokineticin 1 (PROK1) and (PROK2), are two closely related proteins that were identified as the mammalian homologs of their two amphibian homologs, mamba intestinal toxin (MIT-1) and Bv8. PROKs activate two G-protein linked receptors (prokineticin receptor 1 and 2, PROKR1 and PROKR2). Both PROK1 and PROK2 have been found to regulate a stunning array of biological functions. In particular, PROKs stimulate gastrointestinal motility, thus accounting for their family name "prokineticins". PROK1 acts as a potent angiogenic mitogen, thus earning its other name, endocrine gland-derived vascular endothelial factor. In contrast, PROK2 signaling pathway has been shown to be a critical regulator of olfactory bulb morphogenesis and sexual maturation. During the last decade, strong evidences established the key roles of prokineticins in the control of human central and peripheral reproductive processes. PROKs act as main regulators of the physiological functions of the ovary, uterus, placenta, and testis, with marked dysfunctions in various pathological conditions such as recurrent pregnancy loss, and preeclampsia. PROKs have also been associated to the tumor development of some of these organs. In the central system, prokineticins control the migration of GnRH neurons, a key process that controls reproductive functions. Importantly, mutations in PROK2 and PROKR2 are associated to the development of Kallmann syndrome, with direct consequences on the reproductive system. This review describes the finely tuned actions of prokineticins in the control of the central and peripheral reproductive processes. Also, it discusses future research directions for the use of these cytokines as diagnostic markers for several reproductive diseases.

Inhibition of human placental endothelial cell proliferation and angiogenesis by netrin-4

INTRODUCTION

Netrin-4 is a secreted member of the laminin-related protein family, known to be involved in axonal guidance and endothelial cell survival, proliferation, and migration. We have recently reported the cellular localization of netrin-4 and its receptor neogenin in human first trimester and term placenta. A strong expression of netrin-4 was observed in trophoblast and in endothelial cells, suggesting a potential role of this protein in placental angiogenesis. In relation to human pregnancy, it has been reported that circulating netrin-4 were increased in fetal umbilical cord blood of intrauterine growth restriction IUGR compared to normal pregnancy suggesting an adverse effect of this protein on placental and fetal development. The aim of this study was to determine the role of netrin-4 in placental angiogenesis.

METHODS

The effects of netrin-4 on proliferation, migration, tube-like organization, and spheroid sprouting of human placental microvascular endothelial cells (HPEC) were studied.

RESULTS

We demonstrated that netrin-4 inhibits HPEC proliferation, tube-like formation, migration and spheroid sprouting, suggesting a direct role of netrin-4 in the regulation of intra-villus angiogenesis.

DISCUSSION

This is the first report of an anti-angiogenic activity of netrin-4 in human placenta. This study brings new insights into netrin-4 roles in placental angiogenesis and suggests possible involvements of netrin-4 in angiogenesis-related pathologies such as IUGR.

PPARγ controls pregnancy outcome through activation of EG-VEGF: new insights into the mechanism of placental development

PPARγ-deficient mice die at E9.5 due to placental abnormalities. The mechanism by which this occurs is unknown. We demonstrated that the new endocrine factor EG-VEGF controls the same processes as those described for PPARγ, suggesting potential regulation of EG-VEGF by PPARγ. EG-VEGF exerts its functions via prokineticin receptor 1 (PROKR1) and 2 (PROKR2). This study sought to investigate whether EG-VEGF mediates part of PPARγ effects on placental development. Three approaches were used: 1) in vitro, using human primary isolated cytotrophoblasts and the extravillous trophoblast cell line (HTR-8/SVneo); 2) ex vivo, using human placental explants (n = 46 placentas); and 3) in vivo, using gravid wild-type PPARγ(+/-) and PPARγ(-/-) mice. Major processes of placental development that are known to be controlled by PPARγ, such as trophoblast proliferation, migration, and invasion, were assessed in the absence or presence of PROKR1 and PROKR2 antagonists. In both human trophoblast cell and placental explants, we demonstrated that rosiglitazone, a PPARγ agonist, 1) increased EG-VEGF secretion, 2) increased EG-VEGF and its receptors mRNA and protein expression, 3) increased placental vascularization via PROKR1 and PROKR2, and 4) inhibited trophoblast migration and invasion via PROKR2. In the PPARγ(-/-) mouse placentas, EG-VEGF levels were significantly decreased, supporting an in vivo control of EG-VEGF/PROKRs system during pregnancy. The present data reveal EG-VEGF as a new mediator of PPARγ effects during pregnancy and bring new insights into the fine mechanism of trophoblast invasion.

EG-VEGF, BV8, and their receptor expression in human bronchi and their modification in cystic fibrosis: Impact of CFTR mutation (delF508)

Enhanced lung angiogenesis has been reported in cystic fibrosis (CF). Recently, two highly homologous ligands, endocrine gland vascular endothelial growth factor (EG-VEGF) and mammalian Bv8, have been described as new angiogenic factors. Both ligands bind and activate two closely related G protein-coupled receptors, the prokineticin receptor (PROKR) 1 and 2. Yet, the expression, regulation, and potential role of EG-VEGF, BV8, and their receptors in normal and CF lung are still unknown. The expression of the receptors and their ligands was examined using molecular, biochemical, and immunocytochemistry analyses in lungs obtained from CF patients vs. control and in normal and CF bronchial epithelial cells. Cystic fibrosis transmembrane conductance regulator (CFTR) activity was evaluated in relation to both ligands, and concentrations of EG-VEGF were measured by ELISA. At the mRNA level, EG-VEGF, BV8, and PROKR2 gene expression was, respectively, approximately five, four, and two times higher in CF lungs compared with the controls. At the cellular level, both the ligands and their receptors showed elevated expressions in the CF condition. Similar results were observed at the protein level. The EG-VEGF secretion was apical and was approximately two times higher in CF compared with the normal epithelial cells. This secretion was increased following the inhibition of CFTR chloride channel activity. More importantly, EG-VEGF and BV8 increased the intracellular concentration of Ca(2+) and cAMP and stimulated CFTR-chloride channel activity. Altogether, these data suggest local roles for epithelial BV8 and EG-VEGF in the CF airway peribronchial vascular remodeling and highlighted the role of CFTR activity in both ligand biosynthesis and secretion.