Fibroblast growth factor-10 and fibroblast growth factor receptors 1-4: expression and peptide localization in human decidua and placenta

Association of Fibroblast Growth Factor-1 Promoter Polymorphism and its Serum Concentrations with Repeated Implantation Failure after In vitro Fertilisation: A Cross-sectional Study

Background

Fibroblast growth factors (FGFs) play a key role in embryo implantation and support endometrial trophoblastic interaction.

Aim

The aim of the study was to evaluate the association between FGF-1 (rs34011) gene variety and its serum concentration with repeated implantation failure (RIF).

Setting and Design

The design of the study was a cross-sectional study.

Materials and Methods

Four hundred infertile women with a history of RIF and 400 healthy women undergoing the first in vitro fertilisation-embryo transfer attempt with successful delivery (controls) were enrolled in the study. Genomic DNA was extracted from peripheral blood leucocytes and genotyped by Tetra-Primer Amplification Refractory Mutation System-Polymerase Chain Reaction. Serum FGF-1 concentration was evaluated with enzyme-linked immunosorbent assay.

Statistical Analysis Used

The ANOVA test was used to analyse the difference between the means of the groups.

Results

In RIF group, the genotype frequencies of the GG, GA and AA were 59%, 33.5% and 7.5%, respectively, whereas in controls were 72.5%, 24% and 3.5%, respectively. The G and A allele frequencies in the RIF group were 75.75% and 24.25%, while in controls were 84.5% and 15.5%, respectively (P < 0.0001). We have also shown that serum FGF-1 concentration in RIF and control groups was 17 ± 3.55 and 23.62 ± 4.91 pg/mL, respectively (P = 0.008). We have also shown that AA genotype is significantly associated with decreased serum FGF-1 concentration in RIF (AA, GA and GG serum levels were 9.55 ± 2.65, 14 ± 3.35 and 22.55 ± 7.26 pg/mL, and in controls were 12.22 ± 2.27, 18.44 ± 5.98 and 26.66 ± 8.29 pg/mL, respectively).

Conclusion

The current study suggests that a significant association between FGF-1 (rs34011) promoter polymorphism and its serum concentration with RIF. The study also suggests that AA genotype is linked to lower FGF-1 serum levels and may play a risk factor for RIF.

Genomic Signatures Associated with Transitions to Viviparity in Cyprinodontiformes

The transition from oviparity to viviparity has occurred independently over 150 times across vertebrates, presenting one of the most compelling cases of phenotypic convergence. However, whether the repeated, independent evolution of viviparity is driven by redeployment of similar genetic mechanisms and whether these leave a common signature in genomic divergence remains largely unknown. Although recent investigations into the evolution of viviparity have demonstrated striking similarity among the genes and molecular pathways involved across disparate vertebrate groups, quantitative tests for genome-wide convergent have provided ambivalent answers. Here, we investigate the potential role of molecular convergence during independent transitions to viviparity across an order of ray-finned freshwater fish (Cyprinodontiformes). We assembled de novo genomes and utilized publicly available genomes of viviparous and oviparous species to test for molecular convergence across both coding and noncoding regions. We found no evidence for an excess of molecular convergence in amino acid substitutions and in rates of sequence divergence, implying independent genetic changes are associated with these transitions. However, both statistical power and biological confounds could constrain our ability to detect significant correlated evolution. We therefore identified candidate genes with potential signatures of molecular convergence in viviparous Cyprinodontiformes lineages. Motif enrichment and gene ontology analyses suggest transcriptional changes associated with early morphogenesis, brain development, and immunity occurred alongside the evolution of viviparity. Overall, however, our findings indicate that independent transitions to viviparity in these fish are not strongly associated with an excess of molecular convergence, but a few genes show convincing evidence of convergent evolution.

MAP3K4 promotes fetal and placental growth by controlling the receptor tyrosine kinases IGF1R/IR and Akt signaling pathway†

Disruption of fetal growth results in severe consequences to human health, including increased fetal and neonatal morbidity and mortality, as well as potential lifelong health problems. Molecular mechanisms promoting fetal growth represent potential therapeutic strategies to treat and/or prevent fetal growth restriction (FGR). Here, we identify a previously unknown role for the mitogen-activated protein kinase kinase kinase 4 (MAP3K4) in promoting fetal and placental growth. We demonstrate that inactivation of MAP3K4 kinase activity causes FGR due in part to placental insufficiency. Significantly, MAP3K4 kinase–inactive mice display highly penetrant lethality prior to weaning and persistent growth reduction of surviving adults. Additionally, we elucidate molecular mechanisms by which MAP3K4 promotes growth through control of the insulin-like growth factor 1 receptor (IGF1R), insulin receptor (IR), and Akt signaling pathway. Specifically, MAP3K4 kinase inactivation in trophoblast stem (TS) cells results in reduced IGF1R and IR expression and decreased Akt activation. We observe these changes in TS cells also occur in differentiated trophoblasts created through in vitro differentiation of cultured TS cells and in vivo in placental tissues formed by TS cells. Furthermore, we show that MAP3K4 controls this pathway by promoting Igf1r transcript expression in TS cells through activation of CREB-binding protein (CBP). In the MAP3K4 kinase–inactive TS cells, Igf1r transcripts are repressed because of reduced CBP activity and increased histone deacetylase 6 expression and activity. Together, these data demonstrate a critical role for MAP3K4 in promoting fetal and placental growth by controlling the activity of the IGF1R/IR and Akt signaling pathway.

Angiogenic factors measured in aspirated placental tissue between the 10 + 6 and 18 + 3 weeks of gestation

This study was designed to determine the level of vascular endothelial growth factor-A (VEGF-A), basic fibroblast growth factor (bFGF) and endothelial nitric oxide synthase (eNOS) in chorionic villi during in first and second trimester, and their association with nuchal translucency (NT) measured by ultrasound. Seventy-five singleton healthy pregnancies with no detected congenital malformation were collected for NT measurements and chorionic villus sampling (CVS). Concentrations of angiogenic factors were assayed in chorionic villi sampled between 10 + 6 and 18 + 3 weeks of gestation. ENOS level was steady during this gestational period, while the concentrations of VEGF-A and bFGF significantly decreased. Placental concentrations of VEGF-A and bFGF correlated positively with each other (semi-partial correlation in multivariable linear regression (r): 0.90) and both correlated negatively with the eNOS level (r: -0.64 and r: -0.83, respectively). NT was positively correlated with eNOS concentration and negatively correlated with bFGF levels (r: 0.85 and r: -0.78, respectively). Inverse correlation was found between gestational age and VEGF-A and bFGF concentrations (r: -0.57 and r: 0.73, respectively). Alterations of angiogenic factors in chorionic villi might be an adjunct modality to NT and foetal growth as sonographic markers.

STAU1 selectively regulates the expression of inflammatory and immune response genes and alternative splicing of the nerve growth factor receptor signaling pathway

Double‑stranded RNA‑binding protein Staufen homolog 1 (STAU1) is a highly conserved multifunctional double‑stranded RNA‑binding protein, and is a key factor in neuronal differentiation. RNA sequencing was used to analyze the overall transcriptional levels of the upregulated cells by STAU1 and control cells, and select alternative splicing (AS). It was determined that the high expression of STAU1 led to changes in the expression levels of a variety of inflammatory and immune response genes, including IFIT2, IFIT3, OASL, and CCL2. Furthermore, STAU1 was revealed to exert a significant regulatory effect on the AS of genes related to the 'nerve growth factor receptor signaling pathway'. This is of significant importance for neuronal survival, differentiation, growth, post‑damage repair, and regeneration. In conclusion, overexpression of STAU1 was associated with immune response and regulated AS of pathways related to neuronal growth and repair. In the present study, the whole transcriptome of STAU1 expression was first analyzed, which laid a foundation for further understanding the key functions of STAU1.

Exploring the role of Luman/CREB3 in regulating decidualization of mice endometrial stromal cells by comparative transcriptomics

Background

Luman is a member of CREB3 (cAMP responsive element-binding) subfamily of the basic leucine-zipper (bZIP) transcription factors. It may play an important regulatory role during the decidualization process since Luman was highly expressed in the decidual cells. However, the exact molecular mechanisms of how Luman regulating decidualization is unknown.

Results

Using an in vitro model, we prove that Luman knockdown significantly affects the decidualization process of mice endometrial stromal cells (ESCs) as the expression of two decidual markers PRL8a2 and PRL3c1 were repressed. We employed massively parallel RNA sequencing (RNA-Seq) to understand the changes in the transcriptional landscape associated with knockdown of Luman in ESCs during in vitro decidualization. We found significant dysregulation of genes related to protein processing in the endoplasmic reticulum (ER). Several genes involved in decidualization including bone morphogenetic proteins (e.g. BMP1, BMP4, BMP8A, BMP2, and BMP8B), growth factor-related genes (e.g. VEGFB, FGF10, and FGFR2), and transcription factors (IF4E, IF4A2, WNT4, WNT9A, ETS1, NOTCH1, IRX1, IDB1, IDB2, and IDB3), show altered expression. We also found that the knockdown of Luman is associated with increased expression of cell cycle-related genes including cycA1, cycB1, cycB2, CDK1, CDK2, and PLPK1, which resulted in an increased proportion of ESCs in the G1 phase. Differentially expressed genes (DEGs) were highly enriched on ECM-receptor interaction signaling, endoplasmic reticulum protein processing, focal adhesion, and PI3K-Akt signaling pathways.

Conclusions

Luman knockdown results in widespread gene dysregulation during decidualization of ESCs. Genes involved in protein processing in ER, bone morphogenetic protein, growth factor, and cell cycle progression were identified as particularly important for explaining the decidual deficiency observed in this in vitro model. Therefore, this study provides clues as to the underlying mechanisms that may expand our understanding of gene regulation during decidualization.

Expression and functional role of fibroblast growth factors (FGF) in placenta during different stages of pregnancy in water buffalo (Bubalus bubalis)

The present study documented the expression and functional role of Fibroblast growth factors (FGFs) family and their receptors (Fibroblast growth factor receptor, FGFRs) in placenta (Cotyledon; COT, Caruncle; CAR) during different stages of pregnancy in water buffalo. Samples were collected from Early pregnancy 1 (EP1); Early pregnancy 2 (EP2); Mid pregnancy (MP) and Late pregnancy (LP) while diestrus stage of oestrus cycle (NP) was taken as control. In addition, modulatory role of FGF2 on mRNA expression of von Willebrand factor (vWF), Proliferating cell nuclear antigen (PCNA), steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), 3β-hydroxysteroid dehydrogenase (3βHSD) and BCL2 Associated X (BAX) were studied in cultured trophoblast cells (TCC), obtained from EP2. Real-time PCR (qPCR), Western blot, and immunohistochemistry were applied to investigate mRNA and protein expressions, and the localization of examined factors whereas, P4 secretion was assessed by RIA. The mRNA and protein expression of FGFs and its receptors were maximum (P < 0.05) during EP (EP1 and EP2) in COT. However, FGFR1 and FGFR4 were upregulated (P < 0.05) during EP2 and MP in COT. Similarly, the mRNA and protein expression of FGFs and its receptors were upregulated (P < 0.05) during all stages of pregnancy in CAR. FGF family members were localized in the cytoplasm of trophoblast cells as well as in fetal blood vessels. At 100 ng/ml dosage, FGF2 stimulated the transcript of vWF maximally (P < 0.05). P4 secretion in trophoblast cells treated with FGF2 was maximum with the highest dose at 72 h. These findings corroborate that FGF acts locally in the trophoblast cells to modulate steroid hormone viz. progesterone synthesis, promote angiogenesis and favors cell survivability indicating that this factor may play an essential role in the regulation of placental formation and function in buffalo.

Molecular and cellular underpinnings of normal and abnormal human placental blood flows

Abnormal placental function is well-established as a major cause for poor pregnancy outcome. Placental blood flow within the maternal uteroplacental compartment, the fetoplacental circulation or both is a vital factor in mediating placental function. Impairment in flow in either or both vasculatures is a significant risk factor for adverse pregnancy outcome, potentially impacting maternal well-being, affecting immediate neonatal health and even influencing the long-term health of the infant. Much remains unknown regarding the mechanistic underpinnings of proper placental blood flow. This review highlights the currently recognized molecular and cellular mechanisms in the development of normal uteroplacental and fetoplacental blood flows. Utilizing the entities of preeclampsia and fetal growth restriction as clinical phenotypes that are often evident downstream of abnormal placental blood flow, mechanisms underlying impaired uteroplacental and fetoplacental blood flows are also discussed. Deficiencies in knowledge, which limit the efficacy of clinical care, are also highlighted, underscoring the need for continued research on normal and abnormal placental blood flows.

The fibroblast growth factor 8 family in the female reproductive tract

Several growth factor families have been shown to be involved in the function of the female reproductive tract. One subfamily of the fibroblast growth factor (FGF) superfamily, namely the FGF8 subfamily (including FGF17 and FGF18), has become important as Fgf8 has been described as an oocyte-derived factor essential for glycolysis in mouse cumulus cells and aberrant expression ofFGF18has been described in ovarian and endometrial cancers. In this review, we describe the pattern of expression of these factors in normal ovaries and uteri in rodents, ruminants and humans, as well as the expression of their receptors and intracellular negative feedback regulators. Expression of these molecules in gynaecological cancers is also reviewed. The role of FGF8 and FGF18 in ovarian and uterine function is described, and potential differences between rodents and ruminants have been highlighted especially with respect to FGF18 signalling within the ovarian follicle. Finally, we identify major questions about the reproductive biology of FGFs that remain to be answered, including (1) the physiological concentrations within the ovary and uterus, (2) which cell types within the endometrial stroma and theca layer express FGFs and (3) which receptors are activated by FGF8 subfamily members in reproductive tissues.

Antihypertensive therapy in pre-eclampsia: effects of plasma from nonresponsive patients on endothelial gene expression

Aim: Over 40% of patients with pre-eclampsia are nonresponsive to antihypertensive therapy, but the underlying mechanisms are unknown. We examined the effects of plasma from nonresponsive and responsive patients on endothelial gene expression. Patients & methods: PCR array was performed in human umbilical vein endothelial cells (HUVEC) incubated with plasma from nonresponsive (n = 4) and responsive (n = 4) patients. Gene networks and interactions with antihypertensive drugs used in pre-eclampsia were identified by Ingenuity Pathway Analysis. Results: Nifedipine and hydralazine act by upregulate or downregulate genes found to be downregulated or upregulated in HUVEC incubated with plasma from nonresponsive patients. Conclusion: Our novel findings suggest that plasma from nonresponsive and responsive patients evoke different responses in HUVEC, and might advance the pharmacogenomics research in pre-eclampsia.

Progesterone administration for luteal phase deficiency in human reproduction: an old or new issue?

Luteal phase deficiency (LPD) is described as a condition of insufficient progesterone exposure to maintain a regular secretory endometrium and allow for normal embryo implantation and growth. Recently, scientific focus is turning to understand the physiology of implantation, in particular the several molecular markers of endometrial competence, through the recent transcriptomic approaches and microarray technology. In spite of the wide availability of clinical and instrumental methods for assessing endometrial competence, reproducible and reliable diagnostic tests for LPD are currently lacking, so no type-IA evidence has been proposed by the main scientific societies for assessing endometrial competence in infertile couples. Nevertheless, LPD is a very common condition that may occur during a series of clinical conditions, and during controlled ovarian stimulation (COS) and hyperstimulation (COH) programs. In many cases, the correct approach to treat LPD is the identification and correction of any underlying condition while, in case of no underlying dysfunction, the treatment becomes empiric. To date, no direct data is available regarding the efficacy of luteal phase support for improving fertility in spontaneous cycles or in non-gonadotropin induced ovulatory cycles. On the contrary, in gonadotropin in vitro fertilization (IVF) and non-IVF cycles, LPD is always present and progesterone exerts a significant positive effect on reproductive outcomes. The scientific debate still remains open regarding progesterone administration protocols, specially on routes of administration, dose and timing and the potential association with other drugs, and further research is still needed.

Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila

High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain-containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades.

The endocrine function of human placenta: an overview

During pregnancy, several tightly coordinated and regulated processes take place to enable proper fetal development and gestational success. The formation and development of the placenta is one of these critical pregnancy events. This organ plays essential roles during gestation, including fetal nourishment, support and protection, gas exchange and production of several hormones and other mediators. Placental hormones are mainly secreted by the syncytiotrophoblast, in a highly and tightly regulated way. These hormones are important for pregnancy establishment and maintenance, exerting autocrine and paracrine effects that regulate decidualization, placental development, angiogenesis, endometrial receptivity, embryo implantation, immunotolerance and fetal development. In addition, because they are released into maternal circulation, the profile of their blood levels throughout pregnancy has been the target of intense research towards finding potential robust and reliable biomarkers to predict and diagnose pregnancy-associated complications. In fact, altered levels of these hormones have been associated with some pathologies, such as chromosomal anomalies or pre-eclampsia. This review proposes to revise and update the main pregnancy-related hormones, addressing their major characteristics, molecular targets, function throughout pregnancy, regulators of their expression and their potential clinical interest.

Temporal regulation of fibroblast growth factors and their receptors in the endometrium and conceptus during the pre-implantation period of pregnancy in cattle

We hypothesised that the expression pattern of members of the fibroblast growth factor (FGF) family would be altered in the endometrium as the oestrous cycle/early pregnancy progressed associated with changes in the expression pattern of their receptors in the developing embryo/conceptus. Expression of FGF1 and FGF10 transcript variants 1 and 2 increased significantly as the oestrous cycle/early pregnancy progressed. Neither progesterone (P4) supplementation nor pregnancy status significantly affected the expression of any of the FGF ligands studied. However, there was a significant interaction between day, pregnancy and P4 status on FGF2 expression (P<0.05) and a significant interaction between P4 status and day on FGF10_tv2 expression. FGF10 protein was localised in the luminal and glandular epithelium as well as the stroma but was not detected in the myometrium. By RNA sequencing, the expression of FGF ligands in the developing embryo/conceptus was found to be minimal. The expression of FGF receptor 1 (FGFR1), FGFR2, FGFR3, FGFR4, FGFRL1 and FRS3 was significantly affected by the stage of conceptus development. Interestingly, the expression of FGFR1 and FGFR4 was higher during early embryo development (days 7–13, P<0.05) but decreased on day 16 (P<0.05) while FGFR2 (P<0.001) expression was similar from day 7 through to day 13, with a significant increase by day 16 (P<0.05) that was maintained until day 19 (P>0.05). In conclusion, these data demonstrate that FGF ligands are primarily expressed by the endometrium and their modulation throughout the luteal phase of the oestrous cycle/early pregnancy are associated with alterations in the expression of their receptors in the embryo/conceptus.

Fibroblast growth factor-2 expression in the preimplantation equine conceptus and endometrium of pregnant and cyclic mares

Uterine-derived growth factors and cytokines play essential roles in regulating preimplantation conceptus development. In several species, fibroblast growth factor-2 (FGF2) promotes embryogenesis, trophoblast cell migration, and adhesion. This study investigated mRNA expression for FGF2, its receptors (FGFR1-4), the activating factor FGF binding protein (FGF-BP) in equine endometrium and trophectoderm during early pregnancy and the estrous cycle, and localized FGF2 protein in both endometrium and conceptus tissues. FGF2, FGFRs1-4, and FGFBP mRNAs were expressed in endometrium throughout the estrous cycle and early pregnancy, and in days 14 to 28 conceptus membranes. FGF2 transcription was higher during estrus than on days 7 or 14 of diestrus, suggesting estrogen dependency. Endometrial expression of FGF2 mRNA and protein increased as pregnancy progressed from days 21 and day 28; FGF2 protein was localized predominantly in the luminal and glandular epithelium. FGF2 mRNA was detectable in trophectoderm from as early as day 14, and transcription and translation increased in day 21 and 28 allantochorion. FGF2 protein was localized mainly in the trophectoderm up to day 21 but was present in both trophectoderm and endoderm of day 28 allantochorion. FGFR1 mRNA was down-regulated in the endometrium at day 7 of diestrus but increased again by day 14. Gene expression for all of the FGFR2 splice variants, including FGFR2IIIc, was up-regulated during estrus. During early pregnancy, endometrial FGFR1 expression decreased, whereas FGFR2IIIc expression did not change. Conceptus mRNA expression for all FGFRs increased as pregnancy progressed. FGFBP expression remained unchanged in endometrium, but increased in the conceptus between days 14 and 28, suggesting a role in regulating FGF2 activity in the developing conceptus. We conclude that during weeks 3 and 4 of pregnancy, the equine endometrial epithelium produces FGF2, which may play a role in trophoblast development and adhesion.

The unique expression and function of miR-424 in human placental trophoblasts

Placental hypoperfusion causes cellular hypoxia and is associated with fetal growth restriction and preeclampsia. In response to hypoxia, the repertoire of genes expressed in placental trophoblasts changes, which influences key cellular processes such as differentiation and fusion. Diverse miRNAs were recently found to modulate the cellular response to hypoxia. Here we show that miR-424, which was previously shown to be upregulated by hypoxia in nontrophoblastic cell types, is uniquely downregulated in primary human trophoblasts by hypoxia or chemicals known to hinder cell differentiation. We also identify FGFR1 as a direct target of miR-424 in human trophoblasts. This effect is unique to miR-424 and is not seen with other members of this miRNA family that are expressed in trophoblasts, such as miR-15 and miR-16. Our findings establish a unique role for miR-424 during differentiation of human trophoblasts.

Analysis of human embryos from zygote to blastocyst reveals distinct gene expression patterns relative to the mouse

Early mammalian embryogenesis is controlled by mechanisms governing the balance between pluripotency and differentiation. The expression of early lineage-specific genes can vary significantly between species, with implications for developmental control and stem cell derivation. However, the mechanisms involved in patterning the human embryo are still unclear. We analyzed the appearance and localization of lineage-specific transcription factors in staged preimplantation human embryos from the zygote until the blastocyst. We observed that the pluripotency-associated transcription factor OCT4 was initially expressed in 8-cell embryos at 3 days post-fertilization (dpf), and restricted to the inner cell mass (ICM) in 128-256 cell blastocysts (6dpf), approximately 2 days later than the mouse. The trophectoderm (TE)-associated transcription factor CDX2 was upregulated in 5dpf blastocysts and initially coincident with OCT4, indicating a lag in CDX2 initiation in the TE lineage, relative to the mouse. Once established, the TE expressed intracellular and cell-surface proteins cytokeratin-7 (CK7) and fibroblast growth factor receptor-1 (FGFR1), which are thought to be specific to post-implantation human trophoblast progenitor cells. The primitive endoderm (PE)-associated transcription factor SOX17 was initially heterogeneously expressed in the ICM where it co-localized with a sub-set of OCT4 expressing cells at 4-5dpf. SOX17 was progressively restricted to the PE adjacent to the blastocoel cavity together with the transcription factor GATA6 by 6dpf. We observed low levels of Laminin expression in the human PE, though this basement membrane component is thought to play an important role in mouse PE cell sorting, suggesting divergence in differentiation mechanisms between species. Additionally, while stem cell lines representing the three distinct cell types that comprise a mouse blastocyst have been established, the identity of cell types that emerge during early human embryonic stem cell derivation is unclear. We observed that derivation from plating intact human blastocysts resulted predominantly in the outgrowth of TE-like cells, which impairs human embryonic stem cell derivation. Altogether, our findings provide important insight into developmental patterning of preimplantation human embryos with potential consequences for stem cell derivation.

The expression of fibroblast growth factor receptors during early bovine conceptus development and pharmacological analysis of their actions on trophoblast growth in vitro

The overall aim of this work was to examine the expression profiles for fibroblast growth factor receptors (FGFRs) and describe their biological importance during bovine pre- and peri-implantation conceptus development. FGFR1 and FGFR2 mRNAs were detected at 1-, 2-, 8-cell, morula and blastocyst stages whereas FGFR3 and FGFR4 mRNAs were detected after the 8-cell stage but not earlier. The abundance of FGFR1, FGFR3, and FGFR4 mRNAs increased at the morula and blastocyst stages. Immunofluorescence microscopy detected FGFR2 and FGFR4 exclusively in trophoblast cells whereas FGFR1 and FGFR3 were detected in both trophoblast cells and inner cell mass in blastocysts. Neither transcripts for FGF10 nor its receptor (FGFR2b) were temporally related to interferon τ (IFNT) transcript profile during peri- and postimplantation bovine conceptus development. A series of studies used a chemical inhibitor of FGFR kinase function (PD173074) to examine FGFR activation requirements during bovine embryo development. Exposing embryos to the inhibitor (1 μM) beginning on day 5 post-fertilization did not alter the percentage of embryos that developed into blastocysts or blastocyst cell numbers. The inhibitor did not alter the abundance of CDX2 mRNA but decreased (P<0.05) the relative abundance of IFNT mRNA in blastocysts. Exposing blastocysts to the inhibitor from days 8 to 11 post-fertilization reduced (P<0.05) the percentage of blastocysts that formed outgrowths after transfer to Matrigel-coated plates. In conclusion, each FGFR was detected in bovine embryos, and FGFR activation is needed to maximize IFNT expression and permit outgrowth formation.

The tyrosine phosphatase SHP-1 negatively regulates cytotrophoblast proliferation in first-trimester human placenta by modulating EGFR activation

Insulin-like growth factors (IGFs) influence placental cell (cytotrophoblast) kinetics. We recently reported that the protein tyrosine phosphatase (PTP) SHP-2 positively regulates IGF actions in the placenta. In other systems, the closely related PTP, SHP-1, functions as a negative regulator of signaling events but its role in the placenta is still unknown. We examined the hypothesis that SHP-1 negatively regulates IGF actions in the human placenta. Immunohistochemical (IHC) analysis demonstrated that SHP-1 is abundant in cytotrophoblast. SHP-1 expression was decreased in first-trimester placental explants using siRNA; knockdown did not alter IGF-induced proliferation but it significantly enhanced proliferation in serum-free conditions, revealing that placental growth is endogenously regulated. Candidate regulators were determined by using antibody arrays, Western blotting, and IHC to examine the activation status of multiple receptor tyrosine kinases (RTKs) in SHP-1-depleted explants; amongst the alterations observed was enhanced activation of EGFR, suggesting that SHP-1 may interact with EGFR to inhibit proliferation. The EGFR tyrosine kinase inhibitor PD153035 reversed the elevated proliferation seen in the absence of SHP-1. This study demonstrates a role for SHP-1 in human trophoblast turnover and establishes SHP-1 as a negative regulator of EGFR activation. Targeting placental SHP-1 expression may provide therapeutic benefits in common pregnancy conditions with abnormal trophoblast proliferation.

When genetic load does not correlate with phenotypic spectrum: lessons from the GnRH receptor (GNRHR)

CONTEXT

A broad spectrum of GnRH-deficient phenotypes has been identified in individuals with both mono- and biallelic GNRHR mutations.

OBJECTIVE

The objective of the study was to determine the correlation between the severity of the reproductive phenotype(s) and the number and functional severity of rare sequence variants in GNRHR.

SUBJECTS

Eight hundred sixty-three probands with different forms of GnRH deficiency, 46 family members and 422 controls were screened for GNRHR mutations. The 70 subjects (32 patients and 38 family members) harboring mutations were divided into four groups (G1-G4) based on the functional severity of the mutations (complete or partial loss of function) and the number of affected alleles (monoallelic or biallelic) with mutations, and these classes were mapped on their clinical phenotypes.

RESULTS

The prevalence of heterozygous rare sequence variants in GNRHR was significantly higher in probands vs. controls (P < 0.01). Among the G1-G3 groups (homozygous subjects with successively decreasing severity and number of mutations), the hypogonadotropic phenotype related to their genetic load. In contrast, subjects in G4, with only monoallelic mutations, demonstrated a greater diversity of clinical phenotypes.

CONCLUSIONS

In patients with GnRH deficiency and biallelic mutations in GNRHR, genetic burden defined by severity and dose is associated with clinical phenotype. In contrast, for patients with monoallelic GNRHR mutations this correlation does not hold. Taken together, these data indicate that as-yet-unidentified genetic and/or environmental factors may combine with singly mutated GNRHR alleles to produce reproductive phenotypes.

Preimplantation factor (PIF) promoting role in embryo implantation: increases endometrial integrin-α2β3, amphiregulin and epiregulin while reducing betacellulin expression via MAPK in decidua

BACKGROUND

Viable embryos secrete preimplantation factor (PIF), a peptide that has autocrine effects where levels correlate with cultured embryos development. sPIF (PIF synthetic analog) promotes implantation by regulating decidual-cells immunity, adhesion, apoptosis and enhances trophoblastic cell invasion. Herein sPIF priming effects on non-decidualized endometrium and decidualized-stroma are investigated, assessing elements critical for effective embryo-maternal cross-talk, prior to and at implantation.

METHODS

We tested sPIF effect on human non-pregnant endometrial epithelial and non-decidualized stroma α2β3 integrin expression (IHC and flow cytometry), comparing with scrambled PIF (PIFscr-control). We examined sPIF effect on decidualized non-pregnant human endometrial stromal cells (HESC) determining pro-inflammatory mediators expression and secretion (ELISA) and growth factors (GFs) expression (Affymetrix global gene array). We tested sPIF effect on HESC Phospho-kinases (BioPlex) and isolated kinases activity (FastKinase).

RESULTS

sPIF up-regulates α2β3 integrin expression in epithelial cells, (P < 0.05) while PIFscr had no effect. In contrast, in stromal cell cultures sPIF had no effect on the same. In HESC, sPIF up-regulates pro-inflammatory cytokines; IL8, IL1β and IL6 expression. The major increase in GRO-α, ICAM-1 and MCP-3 expression is coupled with same ligands secretion (P < 0.05). sPIF modulates in HESC GFs expression: up-regulates amphiregulin and epiregulin- critical for implantation and enhances several fibroblast growth factors (FGF) relevant for decidual function. In contrast, sPIF down-regulates major pro-proliferative ligands, betacellulin and IGF1 expression. sPIF modulatory effect on GFs is exerted by down-regulating pro-proliferative phospho-activated MAPkinases, p-MEK1 and p-ERK (P < 0.01, P < 0.04, respectively). Stress-induced p-38-MAPK (P = 0.04) and c-Jun kinase signaling involved MAPK8IP2 (-2.1 fold) expression decreased which protects against reactive oxygen species. Although pro-inflammatory p-NFkB (P = 0.06) decrease was mild, its promoter TNFRS11 expression markedly (-25-fold) decreased. In contrast, anti-proliferative phosphatases PTPRZ1 and PPP2R2C expression increased.

CONCLUSIONS

sPIF post-fertilization primes endometrial-epithelium, while during implantation creates a beneficial pro-inflammatory milieu. PIF acts by balancing decidual pro-implantation properties while controlling excessive pro-proliferative and inflammatory signals expression. Overall, PIF influences critical peri-implantation events in a sequential coordinated fashion which facilitates embryo implantation.

Caveolin-1 orchestrates fibroblast growth factor 2 signaling control of angiogenesis in placental artery endothelial cell caveolae

Fibroblast growth factor (FGF) receptor 1 (FGFR1) protein was expressed as the long and short as well as some truncated forms in ovine fetoplacental artery ex vivo and in vitro. Upon FGF2 stimulation, both the long and short FGFR1s were tyrosine phosphorylated and the PI3K/AKT1 and ERK1/2 pathways were activated in a concentration- and time- dependent manner in ovine fetoplacental artery endothelial (oFPAE) cells. Blockade of the PI3K/AKT1 pathway attenuated FGF2-stimulated cell proliferation and migration as well as tube formation; blockade of the ERK1/2 pathway abolished FGF2-stimulated tube formation and partially inhibited cell proliferation and did not alter cell migration. Both AKT1 and ERK1/2 were co-fractionated with caveolin-1 and activated by FGF2 in the caveolae. Disruption of caveolae by methyl-β-cyclodextrin inhibited FGF2 activation of AKT1 and ERK1/2. FGFR1 was found in the caveolae where it physically binds to caveolin-1. FGF2 stimulated dissociation of FGFR1 from caveolin-1. Downregulation of caveolin-1 significantly attenuated the FGF2-induced activation of AKT1 and ERK1/2 and inhibited FGF2-induced cell proliferation, migration and tube formation in oFPAE cells. Pretreatment with a caveolin-1 scaffolding domain peptide to mimic caveolin-1 overexpression also inhibited these FGF2-induced angiogenic responses. These data demonstrate that caveolae function as a platform for regulating FGF2-induced angiogenesis through spatiotemporally compartmentalizing FGFR1 and the AKT1 and ERK1/2 signaling modules; the major caveolar structural protein caveolin-1 interacts with FGFR1 and paradoxically regulates FGF2-induced activation of PI3K/AKT1 and ERK1/2 pathways that coordinately regulate placental angiogenesis.

Idiopathic hypogonadotropic hypogonadism in a mother and her monozygotic twins born after a single embryo transfer

OBJECTIVE

To describe a mother with idiopathic hypogonadotropic hypogonadism (IHH) and her monozygotic (MZ) twin boys who all have the same heterozygous fibroblast growth factor receptor-1 (FGFR1) gene mutation.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

A 28-year-old mother with normosmic IHH gave birth to MZ twin boys after a transfer of a single frozen-thawed embryo.

INTERVENTION(S)

Clinical and biochemical evaluation of IHH. Sequence analysis of the 17 coding exons (exons 2-18) and exon-intron boundaries of FGFR1 from polymerase chain reaction-amplified genomic DNA from peripheral blood leukocytes of the subjects.

MAIN OUTCOME MEASURE(S)

Phenotypic features of the subjects.

RESULT(S)

All subjects harbored a previously undescribed heterozygous FGFR1 mutation (c.2049-1 G-->C), leading to the skipping of exon 16 and thus a loss of amino acids 684-726 in the tyrosine kinase domain of the receptor. The absence of exon 16 was verified at the cDNA level. The twins manifested with microphallus, cryptorchidism, and deficient postnatal activation of the hypothalamic-pituitary-gonadal axis, findings consistent with IHH.

CONCLUSION(S)

Our report underlines that assisted reproductive techniques enable the inheritance of gene mutations causing infertility. This is the first report on the phenotypic features of MZ twins with an FGFR1 mutation.

MiR-205 silences MED1 in hypoxic primary human trophoblasts

Acting through degradation of target mRNA or inhibition of translation, microRNAs (miRNAs) regulate development, differentiation, and cellular response to diverse cues. We analyzed changes in miRNA expression in human placental trophoblasts exposed to hypoxia, which may result from hypoperfusion and placental injury. Using an miRNA microarray screen, confirmed by Northern blot analysis, we defined a set of seven miRNAs (miR-93, miR-205, miR-224, miR-335, miR-424, miR-451, and miR-491) that are differentially regulated in primary trophoblasts exposed to hypoxia. We combined in silico prediction of miRNA targets with gene expression profiling data to identify a series of potential targets for the miRNAs, which were further analyzed using luciferase reporter assays. Among experimentally confirmed targets, we found that the transcriptional coactivator MED1, which plays an important role in placental development, is a target for miR-205. Using gain- and loss-of-function assays, we confirmed that miR-205 interacts with a specific target in the 3'-UTR sequence of MED1 and silences MED1 expression in human trophoblasts exposed to hypoxia, suggesting that miR-205 plays a role in trophoblast injury.

Thr-114 is an important functional residue of fibroblast growth factor 10 identified by structure-based mutational analysis

Fibroblast growth factor 10 (FGF10) plays important roles in vertebrate limb development, lung branching morphogenesis, and epidermis regeneration. The receptor (FGFR2b) binding specificity is an essential element in regulating the diverse functions of FGF10. Analyzing the FGF10:FGFR2b complex we found that Thr-114 in beta4 of FGF10 could form specific interactions with D3 of FGFR2b. To investigate the role of Thr-114 played on functions of FGF10, two mutants of FGF10 were constructed, named TA (Thr-114-->Ala) and TR (Thr-114-->Arg), respectively. The biological activity assays showed that the receptor-binding affinity, the stimulating growth effect on rat tracheal epithelium (RTE) cells, and the inducing ability in receptor phosphorylation of both mutants were decreased, which were consistent with the interaction analysis of the TA:FGFR2b and TR:FGFR2b complexes. These results suggested that Thr-114 is a crucial functional residue for FGF10, and mutating Thr-114 to Ala or Arg would lead to great decrease in receptor-binding affinity and biological activity of FGF10.

Expression of basic fibroblast growth factor, its receptors and syndecans in bladder cancer

Basic fibroblast growth factor (bFGF) is a heparin-binding cationic protein involved in a variety of pathological conditions including angiogenesis and solid tumour growth. The basic fibroblast growth factor receptor (FGFR) family comprises at least 4 high affinity tyrosine kinase receptors that require syndecans for their function. Mounting evidence indicates that syndecans, that bind both bFGF and their FGFRs, will act as stimulators, whereas syndecans that only bind bFGF will act as inhibitors of signaling by sequestering the growth factor. Recent findings have highlighted the importance of syndecans in urological cancers. The aim of this study is to investigate the expression of bFGF, its receptors (R1 and R2) and syndecans (1-4) in invasive urothelial carcinoma and normal-looking urothelium by Western blotting, RT-PCR, and immunohistochemistry analyses. Interestingly, bFGF, FGFR1 and FGFR2 protein levels statistically increased in bladder cancer tissues. mRNA of FGFR1 and syndecans (1-4), showed a statistically significant increase while an mRNA increase in the other molecules analysed was not significant. bFGF, its receptors and syndecan immunostaining were mainly present in the urothelium both in normal-looking tissues and urothelial neoplastic cells. In conclusion, our data report that the bFGF, FGFR and syndecan expressions are altered in bladder tumours.

Placental expression of insulin-like growth factor-I, fibroblast growth factor-basic, and neural cell adhesion molecule in preeclampsia

OBJECTIVE

To investigate placental expression of insulin-like growth factor-I (IGF-I), fibroblast growth factor-basic (FGF-b), and neural cell adhesion molecule (N-CAM) in preeclampsia.

STUDY DESIGN

An immunohistochemical analysis using IGF-I, FGF-b, and N-CAM antibodies was conducted on 4% paraformaldehyde-fixed placental tissues of preeclamptic patients (N = 14) and normotensive pregnant subjects (N = 10). Immunostaining patterns of chorionic villi and amniochorionic membranes were assessed.

RESULTS

Significantly increased FGF-b and N-CAM immunoreactivities in cytotrophoblasts and increased FGF-b immunoreactivity in capillary endothelium of chorionic villi of preeclamptic subjects were noted. Significantly increased FGF-b and decreased N-CAM immunoreactivities in extravillous trophoblasts and decidual cells of amniochorionic membranes obtained from preeclamptic subjects were demonstrated. Additionally, a significantly increased IGF-I immunoreactivity was shown in decidual cells of preeclamptic cases.

CONCLUSION

Investigation of the regional distribution of IGF-I, FGF-b, and N-CAM at the maternal-fetal interface establishes a better understanding of cell-specific altered growth processes, which may be associated with the pathogenesis of preeclampsia.

Construction and characterization of a high activity mutant of human keratinocyte growth factor-2

Keratinocyte growth factor-2 (KGF-2) plays an important role in vertebrate limb development, lung branching morphogenesis, regeneration and reconstruction of the epidermis. Previous studies have used the wild type factor. Here, we have constructed a double-site mutant of human KGF-2, named STEA. STEA possesses higher receptor binding affinity and promotes better proliferation activity on rat tracheal epithelium (RTE) cells than recombinant human KGF-2. These results suggest that the simultaneous mutation of Ser115 to Thr and Glu117 to Ala improves the biological activity of KGF-2.

Fibroblast growth factor 4 gene therapy for chronic ischemic heart disease

Therapeutic myocardial angiogenesis and arteriogenesis represent a novel treatment strategy for patients with angina refractory to traditional medical and surgical therapies. The fibroblast growth factors are a family of proteins that are known mediators of angio-/arteriogenesis. Based on promising preclinical animal data, a series of four randomized placebo-controlled clinical trials have been conducted to determine the safety and efficacy of local delivery of fibroblast growth factor 4 with the use of adenovirus-vector-mediated gene transfer to induce myocardial angio-/arteriogenesis in patients with stable angina. This review describes the scientific rationale underlying these clinical trials, provides an overview of their results, and discusses the implications for future studies.

Progesterone regulates FGF10, MET, IGFBP1, and IGFBP3 in the endometrium of the ovine uterus

Progesterone (P4) is unequivocally required to maintain a uterine environment conducive to pregnancy. This study investigated the effects of P4 treatment on expression of selected growth factors (fibroblast growth factor 7 [FGF7], FGF10, hepatocyte growth factor [HGF], and insulin-like growth factors [IGF1 and IGF2]), their receptors (MET, FGFR2(IIIB), and IGF1R), and IGF binding proteins (IGFBPs) in the ovine uterus. Ewes received daily injections of corn oil vehicle (CO) or 25 mg of P4 in vehicle from 36 h after mating (Day 0) to hysterectomy on Day 9 or Day 12. Another group received P4 to Day 8 and 75 mg of mifepristone (RU486, a P4 receptor antagonist) from Day 8 through Day 12. Endometrial FGF10 mRNA levels increased between Day 9 and Day 12 and in response to P4 on Day 9 in CO-treated ewes, which had larger blastocysts, and were substantially reduced in P4+RU486-treated ewes, which had no blastocysts on Day 12. Endometrial FGF7 or HGF mRNA levels were not affected by day or reduced by RU486 treatment, but MET mRNA levels were higher in P4-treated ewes on Day 9 and Day 12. Levels of IGF1, IGF2, and IGF1R mRNA in the endometria were not affected by early P4 treatment. Although stromal IGFBPs were unaffected by P4, levels of IGFBP1 and IGFBP3 mRNA in uterine luminal epithelia were increased substantially between Day 9 and Day 12 of pregnancy in CO-treated ewes and on Day 9 in early P4-treated ewes. Therefore, FGF10, MET, IGFBP1, and IGFBP3 are P4-regulated factors within the endometrium of the ovine uterus that have potential effects on endometrial function and peri-implantation blastocyst growth and development.

Placental expression of insulin-like growth factor-I, fibroblast growth factor-basic and neural cell adhesion molecule in pregnancies with small for gestational age fetuses

OBJECTIVE

To investigate placental expression of insulin-like growth factor-I (IGF-I), fibroblast growth factor-basic (FGF-b) and neural cell adhesion molecule (N-CAM) regarding the pathogenesis of pregnancies with small for gestational age (SGA) fetuses.

STUDY DESIGN

An immunohistochemical analysis using anti-IGF-I, anti-FGF-b and anti-N-CAM antibodies was carried out on 4% paraformaldehyde-fixed placental tissues of third trimester pregnancies complicated with SGA fetuses (n=12) and subjects exhibiting appropriately grown fetuses (n=10). Immunostaining patterns of chorionic villi and amniochorionic membranes were assessed.

RESULT

IGF-I, FGF-b and N-CAM immunostainings in chorionic villi demonstrated significantly increased immunoreactivities in cytotrophoblasts of SGA cases, whereas increased IGF-I immunostaining in syncitiotrophoblasts and increased N-CAM immunostaining in capillary endothelium were noted in the same group. IGF-I, FGF-b and N-CAM immunostainings in amniochorionic membranes revealed significantly decreased IGF-I immunoreactivities in extravillous trophoblasts and increased IGF-I immunoreactivities in decidual cells of SGA cases, while significantly decreased N-CAM immunoreactivities in both decidual cells and extravillous trophoblasts were noted. FGF-b immunostaining revealed no significant differences in both extravillous trophoblasts and decidual cells of SGA cases.

CONCLUSION

Increased placental expression of IGF-I, FGF-b and N-CAM may act in an autocrine and/or paracrine manner to restore the impaired trophoblastic proliferation, migration and metabolism at all gestational stages by means of a positive feedback mechanism.

Heparan sulfate proteoglycans and their binding proteins in embryo implantation and placentation

Complex interactions occur among embryonic, placental and maternal tissues during embryo implantation. Many of these interactions are controlled by growth factors, extracellular matrix and cell surface components that share the ability to bind heparan sulfate (HS) polysaccharides. HS is carried by several classes of cell surface and secreted proteins called HS proteoglycan that are expressed in restricted patterns during implantation and placentation. This review will discuss the expression of HS proteoglycans and various HS binding growth factors as well as extracellular matrix components and HS-modifying enzymes that can release HS-bound proteins in the context of implantation and placentation.

FGF 10 and Sprouty 2 modulate trophoblast invasion and branching morphogenesis

Branching morphogenesis (BM) of the chorionic villous tree is a crucial component of early placental formation. Fibroblast growth factors (FGFs), their receptor tyrosine kinase (RTK) and negative regulators like Sprouty (Spry) proteins are pivotal factors in the development of diverse branching organ systems. The aim of this study was to examine the effect of FGF10 and Sprouty 2 on BM of the chorionic villi in vitro. Villous explants of first trimester placentas were cultured and their outgrowths were monitored. The effect of FGF10 was tested on matrigel migration/invasion assay, collagenolytic activity of single cell trophoblasts and on villous explants outgrowths. siRNA of Spry2 was used to reduce its expression and to investigate the role of Sprouty 2 in villous explants outgrowths. Quantitative RT-PCR and immunohistochemistry were performed to determine Sprouty 2 and HLA-G (a marker of invasion) expression. FGF 10 stimulated by 8-fold the migration/invasion of single cell trophoblast enhanced their collagenolytic activity. Reduction of Spry2 expression in villous explants showed a marked increase in villous outgrowths. This was accompanied by enhanced staining for HLA-G and by the reduction of Spry2 expression that was confirmed by immunohistochemistry and by quantitative RT-PCR. We conclude that trophoblast outgrowth and invasion (part of placental villi sprouting) at the fetal maternal interface is in part under delicate control of FGF 10 and Sprouty 2. FGF 10 promotes invasion and outgrowth of trophoblasts. In addition, it increases Spry2 expression, which attenuates trophoblast sprouting.

Human placental Hofbauer cells express sprouty proteins: a possible modulating mechanism of villous branching

The development of the chorionic villous tree into a complex and organized ramified tubular network can be termed branching morphogenesis. Studying the molecular mechanisms involved in this process may contribute to the understanding of pregnancy complications such as preeclampsia. Sprouty (Spry) proteins are important regulators of branching morphogenesis and growth factor signaling. We analyzed the expression of Spry genes in human placenta. RT-PCR and immunohistochemistry were employed to detect placental Spry expression. Quantitative RT-PCR was used to assess the effect of FGF and reduced oxygen fraction on Spry gene expression. Spry 1, 2 and 3 expression was observed in placental tissue from all three trimesters. Our results reveal for the first time that Spry proteins are localized in the stroma of the chorionic villi, adjacent to cytotrophoblasts in areas of villous sprouting. Immunofluorescent double staining with anti-Spry and anti-CD68 confirmed that placental macrophages (Hofbauer cells) express Spry. Reduced oxygen fraction, FGF-4 and FGF-10 stimulated Spry-2 expression. Hofbauer cells also expressed c-Cbl, a protein that interacts with Spry. Placental expression of Spry and c-Cbl implies an important role for Hofbauer cells in placental development, possibly through a mesenchymal-epithelial interaction with trophoblasts. Regulation of Spry-2 expression by FGF-4 and FGF-10 suggests an orchestrated regulatory system that modulates villous branching.