Embryonic stem cells (ESCs) are pluripotent cells able to grow indefinitely in culture and to differentiate into all cell types of embryo upon specific stimuli. Molecular mechanisms controlling the unique characteristics of ESCs are still largely unknown. We identified Dies1 (Differentiation of ESCs 1), an unpublished gene, which encodes a type I membrane protein. ESCs stably transfected with Dies1 shRNAs failed to properly differentiate toward neural and cardiac cell fate upon appropriate stimuli, and continued to express markers of undifferentiated cells, such as the membrane-associated alkaline phosphatase, and transcription factors, like Oct3/4 and Nanog, when grown under conditions promoting differentiation. Our results demonstrated that Dies1 is required for BMP4/Smad1 signaling cascade: in undifferentiated ESCs Dies1 knockdown did not affect the expression of LIF downstream targets, whereas it resulted in a strong decrease of BMP4 signaling, as demonstrated by the decrease of Id1, 2 and 3 mRNAs, the decreased activity of Id1 gene promoter and the reduced phospho-Smad1 levels. Dies1 KD had no effects in mESCs when the expression of the BMP4 receptor Alk3 was suppressed. The phenotype induced by Dies1 suppression in ESCs is due to the indirect activation Nodal/Activin pathway, that is a consequence of BMP4 pathway inhibition, and that is sufficient to support mESC undifferentiated state in the absence of LIF. less...

CXCR4, CD133, CD44 and ABCG2 are representative transmembrane proteins expressed on the surfaces of normal and/or cancer stem cells. CXCR4 is co-expressed with POU5F1 in endodermal precursors and adult-tissue stem cells. CXCR4 is expressed in a variety of human tumors, such as breast cancer, prostate cancer, pancreatic cancer, and gastric cancer. CXCR4 is a G protein-coupled receptor (GPCR) for CXCL12 (SDF1) chemokine, and the CXCL12-CXCR4 signaling axis is involved in proliferation, survival, migration, and homing of cancer cells. Integrative genomic analyses of CXCR4 gene were carried out to elucidate the mechanisms of CXCR4 expression in stem cells, because CXCR4 is a key molecule occupying the crossroads of oncology, immunology, gerontology and regenerative medicine. Human CXCR4 promoter region with binding sites for HIF1alpha, ETS1, NF-kappaB and GLI was not conserved in mouse and rat Cxcr4 orthologs. Proximal enhancer region with palindromic Smad-binding sites, FOX-binding site, POU-binding site, triple SOX17-binding sites, bHLH-binding site, TCF/LEF-binding site, and double GFI1-binding sites was almost completely conserved among human, chimpanzee, mouse, and rat CXCR4 orthologs. TGFbeta, Nodal, and Activin signals induce CXCR4 upregulation based on Smad2/3 and FOX family members, such as FOXA2, FOXC2, and FOXH1. CXCR4 is expressed in endodermal precursors due to the existence of triple SOX17-binding sites around the POU-binding site instead of the POU5F1-SOX2 joint motif. Because CXCR4 is downregulated by p53-GFI1 signaling axis, p53 mutation in cancer stem cells leads to CXCR4 upregulation. CXCR4 is also upregulated by TGFbeta and Hedgehog signals in tumor cells at the invasion front. Small molecule compound or human antibody targeted to CXCR4 will be applied for cancer therapeutics focusing on cancer stem cells at the primary lesion as well as metastasis or recurrence niches, such as bone marrow and peritoneal cavity. less...

BACKGROUND: Early identification of pregnant women at risk for preeclampsia is a priority to implement preventive measures. Some biochemical and ultrasonographic parameters have shown promising predictive performance, but so far there is no clinically validated screening procedure. CONTENT: Using a series of keywords, we reviewed electronic databases (Medline, Embase, all records to May 2009) reporting the performance of biological and ultrasonographic markers to predict preeclampsia, both single markers and combinations of markers. We analyzed the data according to gestational age and risk levels of the studied populations. We evaluated the methodological quality of included publications using QUADAS (quality assessment of diagnostic accuracy studies). We identified 37 relevant studies that assessed 71 different combinations of biochemical and ultrasonographic markers. Most studies were performed during the second trimester on small-scale high-risk populations with few cases of preeclampsia. Combinations of markers generally led to an increase in sensitivity and/or specificity compared with single markers. In low-risk populations, combinations including placental protein 13 (PP13), pregnancy-associated plasma protein A (PAPP-A), a disintegrin and metalloprotease-12 (ADAM12), activin A, or inhibin A measured in first or early second trimester and uterine artery Doppler in second trimester appear promising (sensitivity 60%-80%, specificity >80%) In high-risk populations, the combination of PP13 and pulsatility index in first trimester showed 90% sensitivity and 90% specificity in a single study limited to severe preeclampsia. SUMMARY: Combinations of biochemical and ultrasonographic markers improved the performance of early prediction of preeclampsia. From a perspective of integrative medicine, large population-based studies evaluating algorithms combining multiple markers are needed, if screening approaches are to be implemented eventually. less...

BACKGROUND: Inhibins and activins are important regulators of the female reproductive system. Recently, a novel inhibin subunit, named betaE, has been identified and shown to be expressed in several human tissues. However, only limited data on the expression of this novel inhibin-betaE subunit in normal and pathological human placenta as well as and human chorionic carcinoma cell lines exist. MATERIALS AND METHODS: Tissue specimens of normal, preeclamptic and HELLP pregnancies (n = 18) were obtained at the course of an cesarean section. Normal and pathological placental tissues as well as chorionic carcinoma cells (BeWo and JEG) were analyzed by using immunohistochemistry and RT-PCR. RESULTS: Expression of the inhibin betaE subunit could be demonstrated at the protein level by means of immunohistochemical evaluation and at the transcriptional level by betaE-specific RT-PCR analysis. The immunoreactive score for inhibin-betaE did not show any significant differences between normal, preeclamptic and HELLP tissue in extravillous trophoblast and syncytiotrophoblast cells. Expression of inhibin betaE could further be demonstrated for the human chorionic carcinoma cell lines JEG and BeWo. DISCUSSION: We demonstrated that inhibin-betaE is expressed in normal and pathological human placenta tissues. Although the precise role of this novel inhibin subunit for human placenta development is quite unclear, similarities with the well-characterized betaA- and betaB-subunits suggest an involvement in autocrine/paracrine signaling pathways, angiogenesis, decidualization and tissue remodeling under normal as well as malignant conditions. Additionally, the human chorionic carcinoma cell lines JEG and BeWo synthesize this subunit and therefore can be used as a cell culture model for further functional analysis of this subunit in human placental tissue. less...

RATIONALE: Activin A receptor type II-like kinase 1 (ACVRL1 also known as ALK1) mutation is a cause of hereditary hemorrhagic telangiectasia (HHT) and/or heritable pulmonary arterial hypertension (PAH). OBJECTIVES: To describe the characteristics of PAH patients carrying an ACVRL1 mutation. METHODS: We reviewed clinical, functional, and hemodynamic characteristics of 32 PAH patients carrying an ACVRL1 mutation corresponding to 9 patients from the French PAH Network and 23 from literature analysis. These cases were compared to 370 patients from the French PAH Network (93 with a BMPR2 mutation and 277 considered as idiopathic cases without identified mutation). Distribution of mutations in ACVRL1 gene in PAH patients was compared to the HHT Mutation Database. MEASUREMENTS AND MAIN RESULTS: At diagnosis, ACVRL1 mutants were significantly younger (21.8+/-16.7 years) than BMPR2 mutation carriers and non-carriers (35.7+/-14.9 and 47.6+/-16.3 years, p<0.0001). In 7 of the 9 patients from the French PAH Network, PAH diagnosis preceded manifestations of HHT. ACVRL1 mutants had a better hemodynamic status at diagnosis, but none responded to acute vasodilator challenge and they had shorter survival when compared to other PAH patients despite similar use of specific therapies. ACVRL1 mutations in exon 10 were more frequently observed in PAH patients, as compared to what was observed in the HHT Mutation Database (33.3% versus 5%, p<0.0001). CONCLUSION: ACVRL1 mutation carriers were characterized by a younger age at PAH diagnosis. Despite less severe initial hemodynamics and similar management, these patients had worse prognosis compared to other PAH patients, suggesting more rapid disease progression. less...

Few surface markers are available to monitor lineage differentiation during chondrogenesis. Recently, delta-like1/fetal antigen1 (dlk1/FA1), a transmembrane protein of the Notch/Delta/Serrata family, was shown to be essential for inducing early chondrogenesis. Thus, we investigated the possible use of dlk1/FA1 as a novel surface marker for chondroprogenitor cells during hESC differentiation. We found that, Dlk1/FA1 is expressed specifically in cells undergoing transition from proliferating to prehypertrophic chondrocytes during endochondral ossification of the mouse limb. In hESC cells, dlk1/FA1 was not expressed by undifferentiated hESC, but expressed during in vitro embryoid bodies (hEBs) formation upon down-regulation of undifferentiated markers e.g. Oct 3/4 Similarly, dlk1/FA1 was expressed in chondrocytic cells during in vivo teratoma formation. Interestingly, treatment of hEBs with Activin B, a member of TGF-ss family, markedly increased Dlk1 expression in association with up-regulation of the mesoderm-specific markers (e.g. FOXF1, KDR and VE-cadherin) and SOX9. dlk1/FA1(+) cells isolated by fluorescence activated cell sorting (FACS) were capable of differentiating into chondrocytic cells when cultured as micromass pellets in a xeno-free system containing TGFbeta1. In conclusion, we identified dlk1/FA1 as a novel marker of chondroprogenitor cells that undergo embryonic lineage progression from proliferation to the prehypertrophic stage. Tracking dlk1/FA1 expression as a mesoderm/chondroprogenitor surface marker provides a novel strategy for designing clinically relevant protocols to direct the differentiation of hESC into chondrocytes. less...

Somatostatin and cortistatin are neuromodulators with divergent expression patterns and biological roles. Whereas expression and function of genes encoding somatostatin (PSS1) and the related peptide cortistatin (PSS2) have been studied in detail for the central nervous system (CNS) and immune system, relatively little is known about their expression patterns in the peripheral nervous system (PNS). We compare the expression patterns of PSS1 and PSS2 in chicken embryos. At E14, PSS1 is higher in the CNS versus PNS, whereas PSS2 is higher in the PNS. During early development, PSS1 is transiently expressed in lumbar sympathetic ganglia and is detectable at low levels throughout the development of dorsal root and ciliary ganglia. In contrast, PSS2 expression increases as development progresses in sympathetic and dorsal root ganglia, whereas levels in ciliary ganglia by E8 are more than 100-fold higher than in sympathetic ganglia. Activin, which induces somatostatin-like immunoreactivity in ciliary ganglion neurons in vivo and in vitro, controls PSS2 expression by stabilizing PSS2 but not PSS1 mRNA. We conclude that much of the somatostatin-like immunoreactivity in the developing avian peripheral nervous system is actually cortistatin, the PSS2 product, as opposed to true somatostatin, which is the PSS1 product. The identification of PSS2 as the predominantly expressed somatostatin gene family member in avian autonomic neurons provides a molecular basis for further functional and pharmacological studies. J. Comp. Neurol. 518:839-850, 2010. (c) 2009 Wiley-Liss, Inc. less...

Blood concentrations of hormone-inactive and active sex-steroid metabolites and their precursors were measured, taking into account changes in protein-peptide hormones that control the reproductive axis (in a total of 14 parameters) in men in the 18- to 72-year-old age interval. A significant decrease in the blood concentration of unutilized precursors of active sex steroids (pregnenolone, progesterone, dehydroepiandrosterone, and its sulfate), unbound testosterone, androstenedione (an inactive metabolite of testosterone), and an active metabolite, 5alpha-dihydrotestosterone was determined after the age of 35. However, the level of total testosterone and of estradiol (another active metabolite of testosterone) remained constant. The systems regulating the production of active sex steroids resisted a higher load, causing the luteinizing and follicle-stimulating hypophyseal hormones and activin of steroidogenic glands to increase and correlate positively with age; these hormones correlated negatively with certain sex steroids that realize negative feedback. A decrease in the level of adrenocorticotropic hypophyseal hormone with age suggests a more substantial role for adrenal glands as compared to that of testicles in reducing the blood concentration of active sex steroids. In general, despite the reduced activity of steroidogenic glands in 60- to 70-year-old men, their testosterone and estradiol concentrations remain unchanged, due to coordinated growth in the concentration of luteinizing and follicle-stimulating hypophyseal hormones, and to the activin of steroidogenic glands, which stimulated sex steroid biosynthesis. At the same time, the androgen effect was inhibited as a result of reduced levels of unbound testosterone and 5alpha-dihydrotestosterone. less...

Aims: Fibrodysplasia ossificans progressiva (FOP) is a rare and severely disabling autosomal dominant disorder characterized by congenital malformations of the great toes and progressive postnatal heterotopic ossification A point mutation in the activin receptor IA (ACVR1) gene is the cause of FOP. Most of the reported cases of FOP are sporadic and caused by de novo mutations; however, some rare cases can also result from parental germline mosaicism associated with a greater risk of recurrence in successive pregnancies. Therefore, once the pathogenic mutation has been identified in the proband, it is relative cheaper and important to perform prenatal diagnostic tests to exclude the recurrence risk of FOP in subsequent pregnancies. In this study, we first investigated the mutation in the ACVR1 gene in a Chinese FOP patient and then performed prenatal tests to exclude the risk of recurrence in the patient's unborn sibling. Methods: A couple visited our clinic with their 4-year-old son, who was clinically diagnosed with FOP, for genetic counseling. Genetic testing was performed by amplifying all the nine exons of the ACVR1 gene using the conventional polymerase chain reaction. Further, DNA sequencing was used to determine the mutation based on the results of a mutation screening using denaturing high-performance liquid chromatography. Subsequently, a prenatal test was performed using the same technique as that used for the proband. Results: A recurrent single nucleotide mutation c.617 G>A (R206H) of the ACVR1 gene was identified in the patient; however, both the parents had a normal ACVR1 gene. Prenatal tests showed that the fetus did not carry the pathogenic mutation. Conclusion: The results confirmed that a recurrent single nucleotide mutation c.617 G>A (R206H) was the genetic cause of FOP and explored the utility of prenatal testing in excluding the risk of recurrence in the successive pregnancy. less...

Members of the transforming growth factor beta (TGF-beta) family have been genetically linked to vascular formation during embryogenesis. However, contradictory studies about the role of TGF-beta and other family members with reported vascular functions, such as bone morphogenetic protein (BMP) 9, in physiological and pathological angiogenesis make the need for mechanistic studies apparent We demonstrate, by genetic and pharmacological means, that the TGF-beta and BMP9 receptor activin receptor-like kinase (ALK) 1 represents a new therapeutic target for tumor angiogenesis. Diminution of ALK1 gene dosage or systemic treatment with the ALK1-F(c) fusion protein RAP-041 retarded tumor growth and progression by inhibition of angiogenesis in a transgenic mouse model of multistep tumorigenesis. Furthermore, RAP-041 significantly impaired the in vitro and in vivo angiogenic response toward vascular endothelial growth factor A and basic fibroblast growth factor. In seeking the mechanism for the observed effects, we uncovered an unexpected signaling synergy between TGF-beta and BMP9, through which the combined action of the two factors augmented the endothelial cell response to angiogenic stimuli. We delineate a decisive role for signaling by TGF-beta family members in tumor angiogenesis and offer mechanistic insight for the forthcoming clinical development of drugs blocking ALK1 in oncology. less...