Human embryonic epidermis contains a diverse Langerhans cell precursor pool.

Despite intense efforts, the exact phenotype of the epidermal Langerhans cell (LC) precursors during human ontogeny has not been determined yet. These elusive precursors are believed to migrate into the embryonic skin and to express primitive surface markers, including CD36, but not typical LC markers such as CD1a, CD1c and CD207. The aim of this study was to further characterize the phenotype of LC precursors in human embryonic epidermis and to compare it with that of LCs in healthy adult skin.

Biological and physicochemical characterization of a serum- and xeno-free chemically defined cryopreservation procedure for adult human progenitor cells.

While therapeutic cell transplantations using progenitor cells are increasingly evolving towards phase I and II clinical trials and chemically defined cell culture is established, standardization in biobanking is still in the stage of infancy. In this study, the EU FP6-funded CRYSTAL (CRYo-banking of Stem cells for human Therapeutic AppLication) consortium aimed to validate novel Standard Operating Procedures (SOPs) to perform and validate xeno-free and chemically defined cryopreservation of human progenitor cells and to reduce the amount of the potentially toxic cryoprotectant additive (CPA) dimethyl sulfoxide (DMSO). To achieve this goal, three human adult progenitor and stem cell populations-umbilical cord blood (UCB)-derived erythroid cells (UCB-ECs), UCB-derived endothelial colony forming cells (UCB-ECFCs), and adipose tissue (AT)-derived mesenchymal stromal cells (AT-MSCs)-were cryopreserved in chemically defined medium supplemented with 10% or 5% DMSO.

OCT-4 expression in follicular and luteal phase endometrium: a pilot study.

Background: The stem cell marker Octamer-4 (OCT-4) is expressed in human endometrium. Menstrual cycle-dependency of OCT-4 expression has not been investigated to date.

Methods: In a prospective, single center cohort study of 98 women undergoing hysteroscopy during the follicular (n = 49) and the luteal (n = 40) phases of the menstrual cycle, we obtained endometrial samples.

Immunohistochemical examinations of sex hormone receptors in benign vocal fold lesions.

Background: Acquired benign vocal fold lesions are among the most common causes of voice problems. Since the local impact of estrogen and progesterone receptors in laryngeal tissue is discussed controversially, the presence of sex hormone receptors in benign vocal fold alterations needs to be clarified.

Goal Of The Study: To investigate the expression of estrogen-alpha receptors (ER-alpha), estrogen-beta receptors (ER-beta), progesterone receptors (PR) and androgen receptors (AR) in acquired benign vocal fold alterations.

Polymorphisms of the endothelial nitric oxide synthase gene in premenopausal women with polycystic ovary syndrome.

Objectives: To investigate the association of two common genetic polymorphisms of the gene encoding for endothelial nitric oxide synthase (Nos3), the enzyme catalyzing the production of nitric oxide (NO), with occurrence of the polycystic ovary syndrome (PCOS).

Methods: In a prospective case-control study, we analyzed 2 polymorphisms of the Nos3 gene cluster (Nos 3 exon 7 Glu298Asp and 27-base pair repeat in intron 4 of Nos3) in a series of 210 premenopausal Caucasian women with PCOS and 171 healthy controls using pyrosequencing and PCR, respectively. Women completed a detailed questionnaire and underwent a peripheral venous puncture, ultrasonography, and a standardized oral glucose tolerance test (OGTT).

Igbp1 is part of a positive feedback loop in stem cell factor-dependent, selective mRNA translation initiation inhibiting erythroid differentiation.

Stem cell factor (SCF)-induced activation of phosphoinositide-3-kinase (PI3K) is required for transient amplification of the erythroblast compartment. PI3K stimulates the activation of mTOR (target of rapamycin) and subsequent release of the cap-binding translation initiation factor 4E (eIF4E) from the 4E-binding protein 4EBP, which controls the recruitment of structured mRNAs to polysomes. Enhanced expression of eIF4E renders proliferation of erythroblasts independent of PI3K.

beta-HCG/LH receptor (beta-HCG/LH-R) expression in eutopic endometrium and endometriotic implants: evidence for beta-HCG sensitivity of endometriosis.

Background: Luteinizing hormone (LH) and human chorionic gonadotropin (HCG) target their receptor in gonadal and nongonadal cells to stimulate steroidogenesis and cell growth. The aim of the present study was to investigate the expression of HCG/LH-R in endometriosis to elucidate a possible impact of LH and HCG on this disease.

Materials And Methods: Analysis of HCG/LH-R protein expression in 23 paired samples of ectopic and eutopic tissue of cycling women with endometriosis and in endometrial samples from 22 healthy controls was conducted via immunofluorescence.

A polymorphism of the CYP17 gene related to sex steroid metabolism is associated with female-to-male but not male-to-female transsexualism.

Objective: To assess the association between transsexualism and allele and genotype frequencies of the common cytochrome P450 (CYP) 17 -34 T>C single nucleotide polymorphism (SNP).

Design: Case-control study.

Setting: Academic research institution.

Differential regulation of Foxo3a target genes in erythropoiesis.

The cooperation of stem cell factor (SCF) and erythropoietin (Epo) is required to induce renewal divisions in erythroid progenitors, whereas differentiation to mature erythrocytes requires the presence of Epo only. Epo and SCF activate common signaling pathways such as the activation of protein kinase B (PKB) and the subsequent phosphorylation and inactivation of Foxo3a. In contrast, only Epo activates Stat5.

Estrogen receptor-beta is the predominant estrogen receptor subtype in normal human synovia.

Objective: Joint pain increases after menopause with more than 50% of woman suffering from arthralgies. Since pain and inflammation of joints originate from synovial tissue, we aimed to discover whether estrogen receptors are present in the human synovia.

Methods: This in vitro study was performed on samples of human synovial tissue, obtained from pre- (n = 8) and postmenopausal woman (n = 11) and men (n = 5) following surgery due to traumatic lesions.

Interleukin-1 alpha but not interleukin-1 beta gene polymorphism is associated with polycystic ovary syndrome.

Interleukin-1 (IL1) is a multifunctional cytokine and IL1-mediated inflammatory processes have been proposed to influence the processes of ovulation, fertilization and implantation. All these parameters are also affected in women with polycystic ovary syndrome (PCOS). This study investigated the association of common polymorphisms of the interleukin-1 genes (IL1A and IL1B) with the occurrence and clinical characteristics of PCOS.

ERK and beyond: insights from B-Raf and Raf-1 conditional knockouts.

The Raf/MEK/ERK cascade is a highly conserved signal transduction module whose activation reportedly results in a plethora of physiological outcomes. Depending on the cell type or the stimulus used, the pathway has been implicated in proliferation, differentiation, survival, and migration. Their wide range of activities renders the component of the Raf/MEK/ERK pathway prime candidates for molecule-targeted therapies, in particular, but not exclusively, in the context of cancer.

A polymorphism of the interleukin 1 receptor antagonist is not associated with polycystic ovary syndrome in Caucasian women.

In a prospective case-control study we investigated the association of a common polymorphism of the interleukin 1 receptor antagonist gene (IL-1 RA) with the occurrence and the clinical characteristics of polycystic ovary syndrome (PCOS). Allele frequencies did not vary statistically significantly among women with PCOS and healthy controls or within the PCOS group with respect to their clinical characteristics.

Towards the expression of sex hormone receptors in the human vocal fold.

Background: The human larynx is assumed to be a steroid receptor target organ. There are only very limited data on the evidence of steroid receptors in the vocal folds, although voice alterations due to hormonal influence and treatment have been found.

Goal Of The Study: To investigate the expression of estrogen alpha, progesterone, and androgen receptors in human vocal folds (vocalis muscle, glands, lamina propria, epithelium).

A balance between Raf-1 and Fas expression sets the pace of erythroid differentiation.

Normal erythropoiesis critically depends on the balance between the renewal of precursor cells and their differentiation. If the renewal phase is shortened, the decrease in the precursor pool results in anemia; conversely, impaired differentiation increases the number of proliferating progenitors and the potential risk of leukemic transformation. Using gene ablation, we have discovered 2 self-sustaining signal transduction loops that antagonize each other and regulate erythroid progenitor proliferation and differentiation, respectively.

A polymorphism of the plasminogen activator inhibitor-1 gene promoter and the polycystic ovary syndrome.

Objective: To investigate the association of a common 5G/4G polymorphism of the plasminogen activator inhibitor-1 gene (PAI1) with occurrence and clinical characteristics of the polycystic ovary syndrome (PCOS).

Study Design: In a case-control study, we evaluated a series of 106 Caucasian women with PCOS and 102 healthy controls. Women completed a detailed questionnaire and underwent a peripheral venous puncture, ultrasonography, and a standardized oral glucose tolerance test (OGTT).

The erythroid phenotype of EKLF-null mice: defects in hemoglobin metabolism and membrane stability.

Development of red blood cells requires the correct regulation of cellular processes including changes in cell morphology, globin expression and heme synthesis. Transcription factors such as erythroid Kruppel-like factor EKLF (Klf1) play a critical role in erythropoiesis. Mice lacking EKLF die around embryonic day 14 because of defective definitive erythropoiesis, partly caused by a deficit in beta-globin expression.

Systemic HCG treatment in patients with endometriosis: a new perspective for a painful disease.

Background: Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus. This condition causes painful periods, chronic pelvic pain, subfertility and a profound reduction in quality of life, especially during women's reproductive years. Currently available medical therapies offer comparatively little therapeutic benefit and are often burdened by considerable side effects.

Thyroid hormone T3 acting through the thyroid hormone alpha receptor is necessary for implementation of erythropoiesis in the neonatal spleen environment in the mouse.

Thyroid hormones (THs) mediate many physiological and developmental functions in vertebrates. All these functions are mediated by binding of the active form of the TH T3 to the specific nuclear receptors TRalpha and TRbeta, which are transcription factors. Using mutant mice lacking TRs or deficient for TH production, we show that T3 influences neonatal erythropoiesis through TRalpha.

Expansion and differentiation of immature mouse and human hematopoietic progenitors.

A prerequisite for proper investigation of self-renewal and differentiation of hematopoietic cells is the possibility to obtain large quantities of homogenous primary progenitors under defined conditions, allowing meaningful biochemical and molecular analyses. These cells should show renewal and differentiation characteristics similar to the in vivo situation. The serum-free culture systems delineated in this chapter meet these requirements, employing primary hematopoietic cells derived from murine fetal liver and human umbilical cord blood, which show physiological self-renewal responses to cytokine/hormone combinations, which in vivo are involved in stress hematopoiesis.

FoxO3a regulates erythroid differentiation and induces BTG1, an activator of protein arginine methyl transferase 1.

Erythropoiesis requires tight control of expansion, maturation, and survival of erythroid progenitors. Because activation of phosphatidylinositol-3-kinase (PI3K) is required for erythropoietin/stem cell factor-induced expansion of erythroid progenitors, we examined the role of the PI3K-controlled Forkhead box, class O (FoxO) subfamily of Forkhead transcription factors. FoxO3a expression and nuclear accumulation increased during erythroid differentiation, whereas untimely induction of FoxO3a activity accelerated differentiation of erythroid progenitors to erythrocytes.

Cooperative signaling between cytokine receptors and the glucocorticoid receptor in the expansion of erythroid progenitors: molecular analysis by expression profiling.

Erythroid progenitors undergo renewal (proliferation without apparent differentiation) in response to erythropoietin (Epo), stem cell factor (SCF), and glucocorticoids (dexamethasone) (Dex). SCF and Dex cooperate with Epo to promote proliferation and inhibit differentiation of erythroid progenitors, while Epo alone is required to protect erythroid cells from apoptosis during terminal red cell maturation. To examine the mechanism of the synergistic interactions of Epo, SCF, and Dex, we analyzed gene expression patterns using DNA chip-based large-scale comparative gene profiling using microarrays enriched in hematopoietic transcripts or containing randomly selected genes.

Differential regulation of proteasome-dependent estrogen receptor alpha and beta turnover in cultured human uterine artery endothelial cells.

Estrogen-induced loss of estrogen receptor (ER) alpha expression limits estrogen responsiveness in many target cells. However, whether such a mechanism contributes to changes in vascular endothelial ER alpha and/or ER beta levels is unclear. Using RT-PCR assays, we did not find any regulation of ER alpha or ER beta mRNA expression in human uterine artery endothelial cell (HUAEC) nuclear extracts on stimulation with 17 beta-estradiol for 1 or 2 h.

Raf-1 antagonizes erythroid differentiation by restraining caspase activation.

The Raf kinases are key signal transducers activated by mitogens or oncogenes. The best studied Raf isoform, Raf-1, was identified as an inhibitor of apoptosis by conventional and conditional gene ablation in mice. c-raf-1(-)(/)(-) embryos are growth retarded and anemic, and die at midgestation with anomalies in the placenta and fetal liver.