Therapeutic Potential of Targeting Prokineticin Receptors in Diseases.

The prokineticins (PKs) were discovered approximately 20 years ago as small peptides inducing gut contractility. Today, they are established as angiogenic, anorectic, and proinflammatory cytokines, chemokines, hormones, and neuropeptides involved in variety of physiologic and pathophysiological pathways. Their altered expression or mutations implicated in several diseases make them a potential biomarker. Their G-protein coupled receptors, PKR1 and PKR2, have divergent roles that can be therapeutic target for treatment of cardiovascular, metabolic, and neural diseases as well as pain and cancer. This article reviews and summarizes our current knowledge of PK family functions from development of heart and brain to regulation of homeostasis in health and diseases. Finally, the review summarizes the established roles of the endogenous peptides, synthetic peptides and the selective ligands of PKR1 and PKR2, and nonpeptide orthostatic and allosteric modulator of the receptors in preclinical disease models. The present review emphasizes the ambiguous aspects and gaps in our knowledge of functions of PKR ligands and elucidates future perspectives for PK research. SIGNIFICANCE STATEMENT: This review provides an in-depth view of the prokineticin family and PK receptors that can be active without their endogenous ligand and exhibits "constitutive" activity in diseases. Their non- peptide ligands display promising effects in several preclinical disease models. PKs can be the diagnostic biomarker of several diseases. A thorough understanding of the role of prokineticin family and their receptor types in health and diseases is critical to develop novel therapeutic strategies with safety concerns.

Effects of Prokineticins on Cerebral Cell Function and Blood-Brain Barrier Permeability.

Prokineticins are a family of small proteins with diverse roles in various tissues, including the brain. However, their specific effects on different cerebral cell types and blood-brain barrier (BBB) function remain unclear. The aim of this study was to investigate the effects of PROK1 and PROK2 on murine cerebral cell lines, bEnd.3, C8.D30, and N2a, corresponding to microvascular endothelial cells, astrocytes and neurons, respectively, and on an established BBB co-culture model. Western blot analysis showed that prokineticin receptors (PROKR1 and PROKR2) were differentially expressed in the considered cell lines. The effect of PROK1 and PROK2 on cell proliferation and migration were assessed using time-lapse microscopy. PROK1 decreased neural cells' proliferation, while it had no effect on the proliferation of endothelial cells and astrocytes. In contrast, PROK2 reduced the proliferation of all cell lines tested. Both PROK1 and PROK2 increased the migration of all cell lines. Blocking PROKRs with the PROKR1 antagonist (PC7) and the PROKR2 antagonist (PKR-A) inhibited astrocyte PROK2-mediated migration. Using the insert co-culture model of BBB, we demonstrated that PROKs increased BBB permeability, which could be prevented by PROKRs' antagonists.

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.

The Deletion of TRPC6 Channels Perturbs Iron and Zinc Homeostasis and Pregnancy Outcome in Mice.

BACKGROUND/AIMS: Transient receptor potential canonical 6 (TRPC6) protein is a nonselective cation channel permitting the uptake of essential elements such as iron (Fe) and zinc (Zn). TRPC6 is found throughout the body with high expression levels in the placenta. However, its role in this organ is still to be determined. To further advance our understanding of the physiological relevance of TRPC6, we have studied the placental histology, pregnancy outcome and the Fe and Zn status of organs (placenta, brain, kidney, liver and lung) collected from TRPC6 deficient (TRPC6-/-) mice and sex and age-matched C57Bl6/J and B6129SF2/J mice. METHODS: Metal content was quantified by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Quantitative reverse transcriptase PCR (qRT-PCR) and Western Blottings (WB) were performed to analyze the expression of placental markers and TRPC6. RESULTS: Our data show that TRPC6-/- mice displayed reduced litter sizes, structural changes of the placenta, along with altered mRNA levels of CD31 and Gcm1, two markers of placental development. Furthermore, immunoblots revealed elevated amounts of TRPC6 proteins in placentas from women diagnosed with preeclampsia, a common gestational disease. When compared to C57Bl6/J and B6129SF2/J, TRPC6-/- mice had elevated Zn levels in placenta, liver and kidney during embryonic development and postnatally, but not at adulthood. High amounts of Fe were found in the adult brain and liver of TRPC6-/- mice. The lung was however not affected by the deletion of TRPC6, indicating that this mouse strain developed organ and age-dependent perturbations in their Zn and Fe status. CONCLUSION: This work indicates that TRPC6 exerts critical pathophysiological functions in placenta, and provides further evidence for a role of this channel in the homeostasis of cations like Zn and Fe.

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.

Formyl peptide receptor-2 is decreased in foetal growth restriction and contributes to placental dysfunction.

STUDY QUESTION: What is the association between placental formyl peptide receptor 2 (FPR2) and trophoblast and endothelial functions in pregnancies affected by foetal growth restriction (FGR)? SUMMARY ANSWER: Reduced FPR2 placental expression in idiopathic FGR results in significantly altered trophoblast differentiation and endothelial function in vitro. WHAT IS KNOWN ALREADY: FGR is associated with placental insufficiency, where defective trophoblast and endothelial functions contribute to reduced feto-placental growth. STUDY DESIGN, SIZE, DURATION: The expression of FPR2 in placental tissues from human pregnancies complicated with FGR was compared to that in gestation-matched uncomplicated control pregnancies (n = 25 from each group). Fpr2 expression was also determined in placental tissues obtained from a murine model of FGR (n = 4). The functional role of FPR2 in primary trophoblasts and endothelial cells in vitro was assessed in diverse assays in a time-dependent manner. PARTICIPANTS/MATERIALS, SETTING, METHODS: Placentae from third-trimester pregnancies complicated by idiopathic FGR (n = 25) and those from gestation-matched pregnancies with appropriately grown infants as controls (n = 25) were collected at gestation 27-40 weeks. Placental tissues were also collected from a spontaneous CBA/CaH × DBA/2 J murine model of FGR. Placental FPR2/Fpr2 mRNA expression was determined by real-time PCR, while protein expression was examined by immunoblotting and immunohistochemistry. siRNA transfection was used to silence FPR2 expression in primary trophoblasts and in human umbilical vein endothelial cells (HUVEC), and the quantitation of cytokines, chemokines and apoptosis was performed following a cDNA array analyses. Functional effects of trophoblast differentiation were measured using HCGB/ß-hCG and syncytin-2 expression as well as markers of apoptosis, tumour protein 53 (TP53), caspase 8, B cell lymphoma 2 (BCL2) and BCL associated X (BAX). Endothelial function was assessed by proliferation, network formation and permeability assays. MAIN RESULTS AND THE ROLE OF CHANCE: Placental FPR2/Fpr2 expression was significantly decreased in FGR placentae (n = 25, P < 0.05) as well as in murine FGR placentae compared to controls (n = 4, P < 0.05). FPR2 siRNA (siFPR2) in term trophoblasts significantly increased differentiation markers, HCGB and syncytin-2; cytokines, interleukin (IL)-6, CXCL8; and apoptotic markers, TP53, caspase 8 and BAX, but significantly reduced the expression of the chemokines CXCL12 and its receptors CXCR4 and CXCR7; CXCL16 and its receptor, CXCR6; and cytokine, IL-10, compared with control siRNA (siCONT). Treatment of HUVECs with siFPR2 significantly reduced proliferation and endothelial tube formation, but significantly increased permeability of HUVECs. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Reduced expression of placental FPR2/Fpr2 was observed in the third trimester at delivery after development of FGR, suggesting that FPR2 is associated with FGR pregnancies. However, there is a possibility that the decreased placental FPR2 observed in FGR may be a consequence rather than a cause of FGR, although our in vitro functional analyses using primary trophoblasts and endothelial cells suggest that FPR2 may have a direct or indirect regulatory role on trophoblast differentiation and endothelial function in FGR. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study linking placental FPR2 expression with changes in the trophoblast and endothelial functions that may explain the placental insufficiency observed in FGR. STUDY FUNDING/COMPETING INTERESTS: P.M. and P.R.E. received funding from the Australian Institute of Musculoskeletal Science, Western Health, St. Albans, Victoria 3021, Australia. M.L. is supported by a Career Development Fellowship from the National Health and Medical Research Council (NHMRC; Grant no. 1047025). Monash Health is supported by the Victorian Government's Operational Infrastructure Support Programme. The authors declare that there is no conflict of interest in publishing this work.

Involvement of the heterodimeric interface region of the nucleotide binding domain-2 (NBD2) in the CFTR quaternary structure and membrane stability.

The cystic fibrosis transmembrane conductance regulator (CFTR) is the only member of the ATP-binding cassette (ABC) superfamily that functions as a chloride channel. The predicted structure of CFTR protein contains two membrane-spanning domains (MSDs), each followed by a nucleotide binding domain (NBD1 and NBD2). The opening of the Cl- channel is directly linked to ATP-driven tight dimerization of CFTR's NBD1 and NBD2 domains. The presence of a heterodimeric interfaces (HI) region in NBD1 and NBD2 generated a head to tail orientation necessary for channel activity. This process was also suggested to promote important conformational changes in the associated transmembrane domains of CFTR, which may impact the CFTR plasma membrane stability. To better understand the role of the individual HI region in this process, we generated recombinant CFTR protein with suppressed HI-NBD1 and HI-NBD2. Our results indicate that HI-NBD2 deletion leads to the loss of the dimerization profile of CFTR that affect its plasma membrane stability. We conclude that, in addition to its role in Cl- transport, HI-NBD2 domain confers membrane stability of CFTR by consolidating its quaternary structure through interactions with HI-NBD1 region.

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.

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.

An EG-VEGF-Dependent Decrease in Homeobox Gene NKX3.1 Contributes to Cytotrophoblast Dysfunction: A Possible Mechanism in Human Fetal Growth Restriction.

Idiopathic fetal growth restriction (FGR) is frequently associated with placental insufficiency. Previous reports have provided evidence that endocrine gland-derived vascular endothelial growth factor (EG-VEGF), a placental secreted protein, is expressed during the first trimester of pregnancy, controls both trophoblast proliferation and invasion, and its increased expression is associated with human FGR. In this study, we hypothesize that EG-VEGF-dependent changes in placental homeobox gene expressions contribute to trophoblast dysfunction in idiopathic FGR. The changes in EG-VEGF-dependent homeobox gene expressions were determined using a homeobox gene cDNA array on placental explants of 8-12 wks gestation after stimulation with EG-VEGF in vitro for 24 h. The homeobox gene array identified a greater-than-five-fold increase in HOXA9, HOXC8, HOXC10, HOXD1, HOXD8, HOXD9 and HOXD11, while NKX 3.1 showed a greater-than-two-fold decrease in mRNA expression compared with untreated controls. Homeobox gene NKX3.1 was selected as a candidate because it is a downstream target of EG-VEGF and its expression and functional roles are largely unknown in control and idiopathic FGR-affected placentae. Real-time PCR and immunoblotting showed a significant decrease in NKX3.1 mRNA and protein levels, respectively, in placentae from FGR compared with control pregnancies. Gene inactivation in vitro using short-interference RNA specific for NKX3.1 demonstrated an increase in BeWo cell differentiation and a decrease in HTR-8/SVneo proliferation. We conclude that the decreased expression of homeobox gene NKX3.1 downstream of EG-VEGF may contribute to the trophoblast dysfunction associated with idiopathic FGR pregnancies.

Adverse effects of perinatal nicotine exposure on reproductive outcomes.

Nicotine exposure during pregnancy through cigarette smoking, nicotine replacement therapies or e-cigarette use continues to be a widespread public health problem, impacting both fetal and postnatal health. Yet, at this time, there remains limited data regarding the safety and efficacy in using these nicotine products during pregnancy. Notably, reports assessing the effect of nicotine exposure on postnatal health outcomes in humans, including reproductive health, are severely lacking. Our current understanding regarding the consequences of nicotine exposure during pregnancy is limited to a few animal studies, which do not comprehensively address the underlying cellular mechanisms involved. This paper aims to critically review the current knowledge from human and animal studies regarding the direct and indirect effects (e.g. obesity) of maternal nicotine exposure, regardless of its source, on reproductive outcomes in pregnancy and postnatal life. Furthermore, this review highlights several key cellular mechanisms involved in these adverse reproductive deficits including oxidative stress, inflammation, and endoplasmic reticulum (ER) stress. By understanding the interplay of the cellular mechanisms involved, further strategies could be developed to prevent the reproductive abnormalities resulting from exposure to nicotine in utero and influence informed clinical guidelines for pregnant women.

[Prokineticins: new regulatory peptides in human reproduction]. / Prokinéticines - De nouveaux peptides régulateurs de la reproduction humaine.

During the last decade, there has been growing evidence for the involvement of prokineticins and their receptors (PROK/PROKR) in human reproduction, with multiple roles in the female and male reproductive systems. The PROK/PROKR signalling complex has been reported as a new actor in ovary, uterus, placenta, and testis physiology, with marked dysfunction in various pathological conditions such as polycystic ovary syndrome, recurrent pregnancy loss, preeclampsia, and ectopic pregnancy. Altogether, the results strongly suggest the involvement of prokineticins in spermatogenesis, oocyte competence, embryo implantation, pregnancy, and delivery, and argue for the clinical relevance of these cytokines and their receptors as diagnostic markers for several reproductive diseases.

Associations between synthetic phenols, phthalates, and placental growth/function: a longitudinal cohort with exposure assessment in early pregnancy.

STUDY QUESTION: Is exposure to environmental chemicals associated with modifications of placental morphology and function? SUMMARY ANSWER: Phthalates, a class of ubiquitous chemicals, showed an association with altered placental weight, placental vascular resistance (PVR), and placental efficiency. WHAT IS KNOWN ALREADY: Only a few epidemiological studies have assessed the effects of phenols and phthalates on placental health. Their results were affected by exposure measurement errors linked to the rapid excretion of these compounds and the reliance on a limited number of spot urine samples to assess exposure. STUDY DESIGN SIZE DURATION: A prospective mother-child cohort, with improved exposure assessment for non-persistent chemicals, recruited participants between 2014 and 2017. Sample size ranged between 355 (placental parameters measured at birth: placental weight and placental-to-fetal weight ratio (PFR): a proxy for placental efficiency) and 426 (placental parameters measured during pregnancy: placental thickness and vascular resistance). PARTICIPANTS/MATERIALS SETTING METHODS: Phenols (four parabens, two bisphenols, triclosan, and benzophenone-3), 13 phthalate metabolites, and two non-phthalate plasticizer metabolites were measured in within-subject pools of repeated urine samples collected during the second and third trimesters of pregnancy (median = 21 samples/trimester/woman). Placental thickness and PVR were measured during pregnancy. The placenta was weighed at birth and the PFR was computed. Both adjusted linear regression and Bayesian Kernel Machine Regression were used to evaluate associations between phenols and phthalates (alone or as a mixture) and placental parameters. Effect modification by child sex was also investigated. MAIN RESULTS AND THE ROLE OF CHANCE: Several phthalate metabolites were negatively associated with placental outcomes. Monobenzyl phthalate (MBzP) concentrations, during the second and third trimesters of pregnancy, were associated with a decrease in both placental weight at birth (ß = -20.1 g [95% CI: -37.8; -2.5] and ß = -17.4 g [95% CI: -33.2; -1.6], for second and third trimester, respectively) and PFR (ß = -0.5 [95% CI: -1, -0.1] and ß = -0.5 [95% CI: -0.9, -0.1], for the second and third trimester, respectively). Additionally, MBzP was negatively associated with PVR during the third trimester (ß= -0.9 [95% CI: -1.8; 0.1]). Mono-n-butyl phthalate (MnBP), was negatively associated with PVR in both trimesters (ß = -1.3, 95% CI: [-2.3, -0.2], and ß = -1.2, 95% CI: [-2.4, -0.03], for the second and third trimester, respectively). After stratification for child sex, Σ diisononyl phthalate (DiNP) (either second or third-trimester exposures, depending on the outcomes considered) was associated with decreased PVR in the third trimester, as well as decreased placental weight and PFR in males. No associations were observed for phenol biomarkers. LIMITATIONS REASONS FOR CAUTION: False positives cannot be ruled out. Therefore, chemicals that were associated with multiple outcomes (MnBP and DiNP) or reported in existing literature as associated with placental outcomes (MBzP) should be considered as the main results. WIDER IMPLICATIONS OF THE FINDINGS: Our results are consistent with in vitro studies showing that phthalates target peroxisome proliferator-activated receptor γ, in the family of nuclear receptors involved in key placental development processes such as trophoblast proliferation, migration, and invasion. In addition to placental weight at birth, we studied placental parameters during pregnancy, which could provide a broader view of how environmental chemicals affect maternal-fetal exchanges over the course of pregnancy. Our findings contribute to the increasing evidence indicating adverse impacts of phthalate exposure on placental health. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the French Research Agency-ANR (MEMORI project ANR-21-CE34-0022). The SEPAGES cohort was supported by the European Research Council (N°311765-E-DOHaD), the European Community's Seventh Framework Programme (FP7/2007-206-N°308333-892 HELIX), the European Union's Horizon 2020 research and innovation programme (N° 874583 ATHLETE Project, N°825712 OBERON Project), the French Research Agency-ANR (PAPER project ANR-12-PDOC-0029-01, SHALCOH project ANR-14-CE21-0007, ANR-15-IDEX-02 and ANR-15-IDEX5, GUMME project ANR-18-CE36-005, ETAPE project ANR-18-CE36-0005-EDeN project ANR-19-CE36-0003-01), the French Agency for Food, Environmental and Occupational Health & Safety-ANSES (CNAP project EST-2016-121, PENDORE project EST-2016-121, HyPAxE project EST-2019/1/039, PENDALIRE project EST-2022-169), the Plan Cancer (Canc'Air project), the French Cancer Research Foundation Association de Recherche sur le Cancer-ARC, the French Endowment Fund AGIR for chronic diseases-APMC (projects PRENAPAR, LCI-FOT, DysCard), the French Endowment Fund for Respiratory Health, the French Fund-Fondation de France (CLIMATHES-00081169, SEPAGES 5-00099903, ELEMENTUM-00124527). N.J. was supported by a doctoral fellowship from the University Grenoble Alpes. V.M. was supported by a Sara Borrell postdoctoral research contract (CD22/00176), granted by Instituto de Salud Carlos III (Spain) and NextGenerationEU funds. The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02852499.

Identification of soluble CD146 as a regulator of trophoblast migration: potential role in placental vascular development.

Both vasculogenesis and angiogenesis occur during normal placental vascular development. Additionally, the placenta undergoes a process of vascular mimicry (pseudo-vasculogenesis) where the placental extravillous trophoblast (EVT) that invade the spiral arteries convert from an epithelial to an endothelial phenotype during normal pregnancy. As soluble CD146 (sCD146) constitutes a new physiological factor with angiogenic properties, we hypothesized that it could be involved in the regulation of placental vascular development by acting on EVT. Using placental villous explants, we demonstrated that sCD146 inhibits EVT outgrowth. Consistently, we showed that sCD146 inhibits the ability of EVT cells (HTR8/SVneo) to migrate, invade and form tubes in Matrigel, without affecting their proliferation or apoptosis. The involvement of sCD146 in human pregnancy was investigated by evaluation of sCD146 levels in 50 pregnant women. We observed physiological down-regulation of sCD146 throughout pregnancy. These results prompted us to investigate the effect of prolonged sCD146 administration in a rat model of pregnancy. Repeated systemic sCD146 injections after coupling caused a significant decrease of pregnancy rate and number of embryos. Histological studies performed on placenta evidenced a reduced migration of glycogen cells (analogous to EVT in rat) in sCD146-treated rats. We propose that in human, sCD146 could represent both an attractive biomarker of placental vascular development and a therapeutic target in pregnancy complications associated with pathological angiogenesis.

EG-VEGF maternal levels predict spontaneous preterm birth in the second and third trimesters in pregnant women with risk factors for placenta-mediated complications.

Prediction of spontaneous preterm birth in asymptomatic women remains a great challenge for the public health system. The aim of the study was to determine the informational value of EG-VEGF circulating levels for prediction of spontaneous preterm birth in the second and third trimesters in pregnant women at high risk for placenta-mediated complications. A prospective multicenter cohort study including 200 pregnant patients with five-serum sampling per patient. Women with spontaneous preterm birth have higher concentrations of serum EG-VEGF than uncomplicated patients at 24 weeks, 28 weeks and 32 weeks (p = 0.03, 0.02 and < 0.001). The areas under the curve reached 0.9 with 100% sensitivity at 32 weeks for the prediction of spontaneous preterm birth. Serum EG-VEGF concentrations could be considered as a reliable biomarker of spontaneous preterm birth in high-risk for placenta-mediated complications pregnant women.

The Multifaceted Functions of Prion Protein (PrPC) in Cancer.

The cellular prion protein (PrPC) is a glycoprotein anchored to the cell surface by glycosylphosphatidylinositol (GPI). PrPC is expressed both in the brain and in peripheral tissues. Investigations on PrPC's functions revealed its direct involvement in neurodegenerative and prion diseases, as well as in various physiological processes such as anti-oxidative functions, copper homeostasis, trans-membrane signaling, and cell adhesion. Recent findings have revealed the ectopic expression of PrPC in various cancers including gastric, melanoma, breast, colorectal, pancreatic, as well as rare cancers, where PrPC promotes cellular migration and invasion, tumor growth, and metastasis. Through its downstream signaling, PrPC has also been reported to be involved in resistance to chemotherapy and tumor cell apoptosis. This review summarizes the variance of expression of PrPC in different types of cancers and discusses its roles in their development and progression, as well as its use as a potential target to treat such cancers.

NLRP7 Enhances Choriocarcinoma Cell Survival and Camouflage in an Inflammasome Independent Pathway.

BACKGROUND: Gestational choriocarcinoma (GC) is a highly malignant trophoblastic tumor that often develops from a complete hydatidiform mole (HM). NLRP7 is the major gene responsible for recurrent HM and is involved in the innate immune response, inflammation and apoptosis. NLRP7 can function in an inflammasome-dependent or -independent pathway. Recently, we have demonstrated that NLRP7 is highly expressed in GC tumor cells and contributes to their tumorigenesis. However, the underlying mechanisms are still unknown. Here, we investigated the mechanism by which NLRP7 controls these processes in malignant (JEG-3) and non-tumor (HTR8/SVneo) trophoblastic cells. Cell survival, dedifferentiation, camouflage, and aggressiveness were compared between normal JEG-3 cells or knockdown for NLRP7, JEG-3 Sh NLRP7. In addition, HTR8/SVneo cells overexpressing NLRP7 were used to determine the impact of NLRP7 overexpression on non-tumor cells. NLRP7 involvement in tumor cell growth and tolerance was further characterized in vivo using the metastatic mouse model of GC. RESULTS: We demonstrate that NLRP7 (i) functions in an inflammasome-dependent and -independent manners in HTR8/SVneo and JEG-3 cells, respectively; (ii) differentially regulates the activity of NF-κB in tumor and non-tumor cells; (iii) increases malignant cell survival, dedifferentiation, and camouflage; and (iv) facilitates tumor cells colonization of the lungs in the preclinical model of GC. CONCLUSIONS: This study demonstrates for the first time the mechanism by which NLRP7, independently of its inflammasome machinery, contributes to GC growth and tumorigenesis. The clinical relevance of NLRP7 in this rare cancer highlights its potential therapeutic promise as a molecular target to treat resistant GC patients.

Protocadherin-12 cleavage is a regulated process mediated by ADAM10 protein: evidence of shedding up-regulation in pre-eclampsia.

Protocadherins are a group of transmembrane proteins with homophilic binding activity, members of the cadherin superfamily. Apart from their role in adhesion, the cellular functions of protocadherins are essentially unknown. Protocadherin (PCDH)12 was previously identified in invasive trophoblasts and endothelial and mesangial cells in the mouse. Invalidation studies revealed that the protein was required for optimal placental development. In this article, we show that its human homolog is abundantly expressed in various trophoblast subtypes of the human placenta and at lower levels in endothelial cells. We demonstrate that PCDH12 is shed at high rates in vitro. The shedding mechanism depends on ADAM10 and results in reduced cellular adhesion in a cell migration assay. PCDH12 is subsequently cleaved by the γ-secretase complex, and its cytoplasmic domain is rapidly degraded by the proteasome. PCDH12 shedding is regulated by interlinked intracellular pathways, including those involving protein kinase C, PI3K, and cAMP, that either increase or inhibit cleavage. In endothelial cells, VEGF, prostaglandin E(2), or histamine regulates PCDH12 shedding. The extracellular domain of PCDH12 was also detected in human serum and urine, thus providing evidence of PCDH12 shedding in vivo. Importantly, we observed an increase in circulating PCDH12 in pregnant women who later developed a pre-eclampsia, a frequent pregnancy syndrome and a major cause of maternal and fetal morbidity and mortality. In conclusion, we speculate that, like in mice, PCDH12 may play an important role in human placental development and that proteolytic cleavage in response to external factors, such as cytokines and pathological settings, regulates its activity.

Animal Models of Chorioamnionitis: Considerations for Translational Medicine.

Preterm birth is defined as any birth occurring before 37 completed weeks of gestation by the World Health Organization. Preterm birth is responsible for perinatal mortality and long-term neurological morbidity. Acute chorioamnionitis is observed in 70% of premature labor and is associated with a heavy burden of multiorgan morbidities in the offspring. Unfortunately, chorioamnionitis is still missing effective biomarkers and early placento- as well as feto-protective and curative treatments. This review summarizes recent advances in the understanding of the underlying mechanisms of chorioamnionitis and subsequent impacts on the pregnancy outcome, both during and beyond gestation. This review also describes relevant and current animal models of chorioamnionitis used to decipher associated mechanisms and develop much needed therapies. Improved knowledge of the pathophysiological mechanisms underpinning chorioamnionitis based on preclinical models is a mandatory step to identify early in utero diagnostic biomarkers and design novel anti-inflammatory interventions to improve both maternal and fetal outcomes.

The Placental NLRP3 Inflammasome and Its Downstream Targets, Caspase-1 and Interleukin-6, Are Increased in Human Fetal Growth Restriction: Implications for Aberrant Inflammation-Induced Trophoblast Dysfunction.

Fetal growth restriction (FGR) is commonly associated with placental insufficiency and inflammation. Nonetheless, the role played by inflammasomes in the pathogenesis of FGR is poorly understood. We hypothesised that placental inflammasomes are differentially expressed and contribute to the aberrant trophoblast function. Inflammasome gene expression profiles were characterised by real-time PCR on human placental tissues collected from third trimester FGR and gestation-matched control pregnancies (n = 25/group). The functional significance of a candidate inflammasome was then investigated using lipopolysaccharide (LPS)-induced models of inflammation in human trophoblast organoids, BeWo cells in vitro, and a murine model of FGR in vivo. Placental mRNA expression of NLRP3, caspases 1, 3, and 8, and interleukin 6 increased (>2-fold), while that of the anti-inflammatory cytokine, IL-10, decreased (<2-fold) in FGR compared with control pregnancies. LPS treatment increased NLRP3 and caspase-1 expression (>2-fold) in trophoblast organoids and BeWo cell cultures in vitro, and in the spongiotrophoblast and labyrinth in the murine model of FGR. However, the LPS-induced rise in NLRP3 was attenuated by its siRNA-induced down-regulation in BeWo cell cultures, which correlated with reduced activity of the apoptotic markers, caspase-3 and 8, compared to the control siRNA-treated cells. Our findings support the role of the NLRP3 inflammasome in the inflammation-induced aberrant trophoblast function, which may contribute to FGR.