WorldWideScience

Sample records for factor receptor evidence

  1. Evidence that the modulator of the glucocorticoid-receptor complex is the endogenous molybdate factor.

    OpenAIRE

    Bodine, P V; Litwack, G

    1988-01-01

    We have recently purified the modulator of the glucocorticoid-receptor complex from rat liver. Purified modulator inhibits glucocorticoid-receptor complex activation and stabilizes the steroid-binding ability of the unoccupied glucocorticoid receptor. Since these activities are shared by exogenous sodium molybdate, modulator appears to be the endogenous factor that sodium molybdate mimics. In this report, we present additional evidence for the mechanism of action of purified modulator. (i) Mo...

  2. Association between cadmium and breast cancer risk according to estrogen receptor and human epidermal growth factor receptor 2: epidemiological evidence.

    Science.gov (United States)

    Strumylaite, Loreta; Kregzdyte, Rima; Bogusevicius, Algirdas; Poskiene, Lina; Baranauskiene, Dale; Pranys, Darius

    2014-05-01

    The study aimed to examine the association between cadmium (Cd) and the risk of breast cancer according to estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). A hospital-based case-control study was carried out in 585 cases and 1,170 controls. Information on possible risk factors was collected via a structured questionnaire. Urinary Cd was determined by atomic absorption spectrometry. The ER and HER2 levels in tumor tissue were analyzed by immunohistochemistry. Logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs) for breast cancer by creatinine-adjusted urinary Cd. Women with greater creatinine-adjusted urine Cd (3rd quartile: 0.241-0.399 μg/g and 4th quartile: ≥ 0.4 μg/g) experienced 1.6 times higher risk of breast cancer compared with those having Cd concentration lower than 0.147 μg/g (1st quartile) [OR = 1.6, (95 % CI 1.19, 2.17) and OR = 1.62 (95 % CI 1.19, 2.21), respectively, P trend = 0.001] after adjustment for age and other confounders. Both ER+ and HER2- cases from the highest quartile of urine Cd exhibited approximately twice the breast cancer risk of those in the lowest quartile [OR = 1.9, (95 % CI 1.31, 2.74) and OR = 1.87, (95 % CI 1.33, 2.62), respectively, P trend cadmium as a risk factor for breast cancer, especially for both ER+ and HER2- cancer patients.

  3. Cloning and expression of a cDNA coding for the human platelet-derived growth factor receptor: evidence for more than one receptor class.

    OpenAIRE

    Gronwald, R G; Grant, F J; Haldeman, B A; Hart, C E; O'Hara, P J; Hagen, F S; Ross, R.; Bowen-Pope, D F; Murray, M. J.

    1988-01-01

    The complete nucleotide sequence of a cDNA encoding the human platelet-derived growth factor (PDGF) receptor is presented. The cDNA contains an open reading frame that codes for a protein of 1106 amino acids. Comparison to the mouse PDGF receptor reveals an overall amino acid sequence identity of 86%. This sequence identity rises to 98% in the cytoplasmic split tyrosine kinase domain. RNA blot hybridization analysis of poly(A)+ RNA from human dermal fibroblasts detects a major (approximately ...

  4. Exisulind in combination with celecoxib modulates epidermal growth factor receptor, cyclooxygenase-2, and cyclin D1 against prostate carcinogenesis: in vivo evidence.

    Science.gov (United States)

    Narayanan, Bhagavathi A; Reddy, Bandaru S; Bosland, Maarten C; Nargi, Dominick; Horton, Lori; Randolph, Carla; Narayanan, Narayanan K

    2007-10-01

    Nonsteroidal anti-inflammatory drugs mediate anticancer effects by modulating cyclooxygenase-2 (COX-2)-dependent and/or COX-2-independent mechanism(s); however, the toxicity issue is a concern with single agents at higher doses. In this study, we determined the combined effect of celecoxib, a COX-2 inhibitor, along with exisulind (sulindac sulfone/Aptosyn) at low doses in prostate cancer. We used a sequential regimen of N-methyl-N-nitrosourea + testosterone to induce prostate cancer in Wistar-Unilever rats. Following carcinogen treatment, celecoxib and exisulind individually and their combination at low doses were given in NIH-07 diet for 52 weeks. We determined the incidence of prostatic intraepithelial neoplasia, adenocarcinomas, rate of tumor cell proliferation, and apoptosis. Immunohistochemical and Western blot analysis were done to determine COX-2, epidermal growth factor receptor (EGFR), Akt, androgen receptor, and cyclin D1 expression. Serum prostaglandin E2 and tumor necrosis factor-alpha levels were determined using enzyme immunoassay/ELISA assays. The rats that received celecoxib in combination with exisulind at low doses showed a significant decrease in prostatic intraepithelial neoplasia and adenocarcinomas as well as an enhanced rate of apoptosis. An overall decrease in COX-2, EGFR, Akt, androgen receptor, and cyclin D1 expression was found associated with tumor growth inhibition. Reduced serum levels of COX-2 protein, prostaglandin E2, and tumor necrosis factor-alpha indicated anti-inflammatory effects. A strong inhibition of total and phosphorylated form of EGFR (Tyr(992) and Tyr(845)) and Akt (Ser(473)) was significant in rats given with these agents in combination. In this study, we show for the first time that the combination of celecoxib with exisulind at low doses could prevent prostate carcinogenesis by altering key molecular events.

  5. Analysis of the fibroblast growth factor receptor (FGFR) signalling network with heparin as coreceptor: evidence for the expansion of the core FGFR signalling network.

    Science.gov (United States)

    Xu, Ruoyan; Rudd, Timothy R; Hughes, Ashley J; Siligardi, Giuliano; Fernig, David G; Yates, Edwin A

    2013-05-01

    The evolution of the fibroblast growth factor (FGF)-FGF receptor (FGFR) signalling system has closely followed that of multicellular organisms. The abilities of nine FGFs (FGF-1 to FGF-9; examples of FGF subfamilies 1, 4, 7, 8, and 9) and seven FGFRs or isoforms (FGFR1b, FGFR1c, FGFR2b, FGFR2c, FGFR3b, FGFR3c, and FGFR4) to support signalling in the presence of heparin, a proxy for the cellular heparan sulfate coreceptor, were assembled into a network. A connection between two FGFRs was defined as their mutual ability to signal with a particular FGF. The network contained a core of four receptors (FGFR1c, FGFR2c, FGFR3c, and FGFR4) with complete connectivity and high redundancy. Analysis of the wider network indicated that neither FGF-3 nor FGF-7 was well connected to this core of four receptors, and that divergence of a precursor of FGF subgroups 1, 4 and 9 from FGF subgroup 8 may have allowed expansion from a three-member FGFR core signalling system to the four-member core network. This increases by four-fold the number of possible signalling combinations. Synchrotron radiation CD spectra of the FGFs with heparin revealed no overall common structural change, suggesting the existence of distinct heparin-binding sites throughout the FGFs. The approach provides a potential method of identifying agents capable of influencing particular FGF-FGFR combinations, or areas of the signalling network, for experimental or therapeutic purposes.

  6. ShcA regulates neurite outgrowth stimulated by neural cell adhesion molecule but not by fibroblast growth factor 2: evidence for a distinct fibroblast growth factor receptor response to neural cell adhesion molecule activation

    DEFF Research Database (Denmark)

    Hinsby, Anders M; Lundfald, Line; Ditlevsen, Dorte K;

    2004-01-01

    by two principal routes of signaling: NCAM/Fyn and NCAM/fibroblast growth factor receptor (FGFR), respectively. Previous studies have shown that activation of mitogen-activated protein kinases is a pivotal point of convergence in NCAM signaling, but the mechanisms behind this activation are not clear....... Here, we investigated the involvement of adaptor proteins in NCAM and fibroblast growth factor 2 (FGF2)-mediated neurite outgrowth in the PC12-E2 cell line. We found that both FGFR substrate-2 and Grb2 play important roles in NCAM as well as in FGF2-stimulated events. In contrast, the docking protein...... ShcA was pivotal to neurite outgrowth induced by NCAM, but not by FGF2, in PC12 cells. Moreover, in rat cerebellar granule neurons, phosphorylation of ShcA was stimulated by an NCAM mimicking peptide, but not by FGF2. This activation was blocked by inhibitors of both FGFR and Fyn, indicating that NCAM...

  7. Evidence of paired M2 muscarinic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Potter, L.T.; Ballesteros, L.A.; Bichajian, L.H.; Ferrendelli, C.A.; Fisher, A.; Hanchett, H.E.; Zhang, R. (Univ. of Miami School of Medicine, FL (USA))

    1991-02-01

    Binding assays involving various antagonists, including N-(3H) methylscopolamine, (3H)quinuclidinyl benzilate, AFDX-116, pirenzepine, and propylbenzilylcholine mustard, disclosed only a single population of M2 muscarinic receptors in membranes from the rat brainstem (medulla, pons, and colliculi). However, competition curves between N-(3H)methylscopolamine and various agonists, including oxotremorine, cis-dioxolane, and acetylethylcholine mustard, showed approximately equal numbers of guanine nucleotide-sensitive high affinity (H) sites and guanine nucleotide-insensitive low affinity (L) sites. This 50% H phenomenon persisted in different buffers, at different temperatures, after the number of receptors was halved (and, thus, the remaining receptor to guanine nucleotide-binding protein ratio was doubled), after membrane solubilization with digitonin, and when rabbit cardiac membranes were used instead of rat brainstem membranes. Preferential occupation of H sites with acetylethylcholine mustard, and of L sites with quinuclidinyl benzilate or either mustard, yielded residual free receptor populations showing predominantly L and H sites, respectively. Low concentrations of (3H)-oxotremorine-M labeled only H sites, and the Bmax for these sites was 49% of the Bmax found with (3H)quinuclidinyl benzilate plus guanine nucleotide. These and other results are most consistent with the idea that H and L receptor sites exist on separate but dimeric receptor molecules and with the hypothesis that only the H receptors cycle between high and low affinity, depending upon interactions between this receptor molecule and a guanine nucleotide-binding protein.

  8. Cell and molecular biology of epidermal growth factor receptor.

    Science.gov (United States)

    Ceresa, Brian P; Peterson, Joanne L

    2014-01-01

    The epidermal growth factor receptor (EGFR) has been one of the most intensely studied cell surface receptors due to its well-established roles in developmental biology, tissue homeostasis, and cancer biology. The EGFR has been critical for creating paradigms for numerous aspects of cell biology, such as ligand binding, signal transduction, and membrane trafficking. Despite this history of discovery, there is a continual stream of evidence that only the surface has been scratched. New ways of receptor regulation continue to be identified, each of which is a potential molecular target for manipulating EGFR signaling and the resultant changes in cell and tissue biology. This chapter is an update on EGFR-mediated signaling, and describes some recent developments in the regulation of receptor biology.

  9. Guidelines, evidence, and cultural factors.

    NARCIS (Netherlands)

    Christiaens, T.; Backer, D. de; Burgers, J.S.; Baerheim, A.

    2004-01-01

    OBJECTIVE: To compare four recent guidelines on uncomplicated cystitis and to examine how cultural factors may have affected recommendations. DESIGN: Descriptive study with a qualitative analysis of authors' reasons for recommendations. MATERIAL: Guidelines for general practitioners published

  10. Endothelial atypical cannabinoid receptor: do we have enough evidence?

    Science.gov (United States)

    Bondarenko, Alexander I

    2014-12-01

    Cannabinoids and their synthetic analogues affect a broad range of physiological functions, including cardiovascular variables. Although direct evidence is still missing, the relaxation of a vast range of vascular beds induced by cannabinoids is believed to involve a still unidentified non-CB1 , non-CB2 Gi/o protein-coupled receptor located on endothelial cells, the so called endothelial cannabinoid receptor (eCB receptor). Evidence for the presence of an eCB receptor comes mainly from vascular relaxation studies, which commonly employ pertussis toxin as an indicator for GPCR-mediated signalling. In addition, a pharmacological approach is widely used to attribute the relaxation to eCB receptors. Recent findings have indicated a number of GPCR-independent targets for both agonists and antagonists of the presumed eCB receptor, warranting further investigations and cautious interpretation of the vascular relaxation studies. This review will provide a brief historical overview on the proposed novel eCB receptor, drawing attention to the discrepancies between the studies on the pharmacological profile of the eCB receptor and highlighting the Gi/o protein-independent actions of the eCB receptor inhibitors widely used as selective compounds. As the eCB receptor represents an attractive pharmacological target for a number of cardiovascular abnormalities, defining its molecular identity and the extent of its regulation of vascular function will have important implications for drug discovery. This review highlights the need to re-evaluate this subject in a thoughtful and rigorous fashion. More studies are needed to differentiate Gi/o protein-dependent endothelial cannabinoid signalling from that involving the classical CB1 and CB2 receptors as well as its relevance for pathophysiological conditions. © 2014 The British Pharmacological Society.

  11. Parkinson's disease: evidence for environmental risk factors.

    Science.gov (United States)

    Kieburtz, Karl; Wunderle, Kathryn B

    2013-01-01

    Parkinson's disease (PD) has no known cause. Although recent research has focused particularly on genetic causes of PD, environmental causes also play a role in developing the disease. This article reviews environmental factors that may increase the risk of PD, as well as the evidence behind those factors. Enough evidence exists to suggest that age has a causal relationship to PD. Significant evidence exists that gender, tobacco use, and caffeine consumption are also associated with the development of PD. Other environmental factors (pesticide exposure, occupation, blood urate levels, NSAID use, brain injury, and exercise) have limited or conflicting evidence of a relationship to PD. Future research must not neglect the impact of these environmental factors on the development of PD, especially with respect to potential gene-environment interactions.

  12. Epidermal Growth Factor Receptor in Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira-Cunha, Melissa, E-mail: melissacunha@doctors.org.uk [Hepatobiliary Surgery Unit, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL (United Kingdom); Newman, William G. [Genetic Medicine, MAHSC, University of Manchester, St Mary' s Hospital, Oxford Road, Manchester, M13 9WL (United Kingdom); Siriwardena, Ajith K. [Hepatobiliary Surgery Unit, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL (United Kingdom)

    2011-03-24

    Pancreatic cancer is the fourth leading cause of cancer related death. The difficulty in detecting pancreatic cancer at an early stage, aggressiveness and the lack of effective therapy all contribute to the high mortality. Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein, which is expressed in normal human tissues. It is a member of the tyrosine kinase family of growth factors receptors and is encoded by proto-oncogenes. Several studies have demonstrated that EGFR is over-expressed in pancreatic cancer. Over-expression correlates with more advanced disease, poor survival and the presence of metastases. Therefore, inhibition of the EGFR signaling pathway is an attractive therapeutic target. Although several combinations of EGFR inhibitors with chemotherapy demonstrate inhibition of tumor-induced angiogenesis, tumor cell apoptosis and regression in xenograft models, these benefits remain to be confirmed. Multimodality treatment incorporating EGFR-inhibition is emerging as a novel strategy in the treatment of pancreatic cancer.

  13. Cellular signaling by fibroblast growth factor receptors.

    Science.gov (United States)

    Eswarakumar, V P; Lax, I; Schlessinger, J

    2005-04-01

    The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. A variety of human skeletal dysplasias have been linked to specific point mutations in FGFR1, FGFR2 and FGFR3 leading to severe impairment in cranial, digital and skeletal development. Gain of function mutations in FGFRs were also identified in a variety of human cancers such as myeloproliferative syndromes, lymphomas, prostate and breast cancers as well as other malignant diseases. The binding of FGF and HSPG to the extracellular ligand domain of FGFR induces receptor dimerization, activation and autophosphorylation of multiple tyrosine residues in the cytoplasmic domain of the receptor molecule. A variety of signaling proteins are phosphorylated in response to FGF stimulation including Shc, phospholipase-Cgamma, STAT1, Gab1 and FRS2alpha leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape. The docking proteins FRS2alpha and FRS2beta are major mediators of the Ras/MAPK and PI-3 kinase/Akt signaling pathways as well as negative feedback mechanisms that fine-tune the signal that is initiated at the cell surface following FGFR stimulation.

  14. Hierarchical classification strategy for Phenotype extraction from epidermal growth factor receptor endocytosis screening

    NARCIS (Netherlands)

    L. Cao (Lu); M. Graauw (Marjo de); K. Yan (Kuan); L.C.J. Winkel (Leah C.J.); F.J. Verbeek (Fons)

    2016-01-01

    textabstractBackground: Endocytosis is regarded as a mechanism of attenuating the epidermal growth factor receptor (EGFR) signaling and of receptor degradation. There is increasing evidence becoming available showing that breast cancer progression is associated with a defect in EGFR endocytosis. In

  15. Fibroblast growth factor 23 and its receptors.

    Science.gov (United States)

    Yu, Xijie; White, Kenneth E

    2005-08-01

    Fibroblast growth factor 23 (FGF23) is a circulating factor that plays critical roles in phosphate and vitamin D metabolism, as evidenced by the fact that FGF23 missense mutations cause autosomal dominant hypophosphatemic rickets (ADHR). Autosomal dominant hypophosphatemic rickets is characterized by hypophosphatemia with inappropriately normal 1,25-dihydroxyvitamin D concentrations, as well as bone pain, fracture and rickets. This phenotype parallels that of patients with tumor induced osteomalacia (TIO), X-linked hypophosphatemic rickets (XLH), and fibrous dysplasia (FD), in whom elevated serum FGF23 levels are often observed. The fibroblast growth factor receptors (FGFR1-4) play key roles in skeletal development, as well as in normal metabolic processes. Several FGFR isoforms that potentially mediate the activity of FGF23 have been implicated. In the short term, these findings will lead to further understanding of FGF23 function, and potentially in the long term, to targeted therapies in disorders of hypo- and hyperphosphatemia that involve FGF23.

  16. Evidence for Alpha Receptors in the Human Ureter

    Science.gov (United States)

    Madeb, Ralph; Knopf, Joy; Golijanin, Dragan; Bourne, Patricia; Erturk, Erdal

    2007-04-01

    An immunohistochemical and western blot expression analysis of human ureters was performed in order to characterize the alpha-1-adrenergic receptor distribution along the length of the human ureteral wall. Mapping the distribution will assist in understanding the potential role alpha -1-adrenergic receptors and their subtype density might have in the pathophysiology of ureteral colic and stone passage. Patients diagnosed with renal cancer or bladder cancer undergoing nephrectomy, nephroureterectomy, or cystectomy had ureteral specimens taken from the proximal, mid, distal and tunneled ureter. Tissues were processed for fresh frozen examination and fixed in formalin. None of the ureteral specimens were involved with cancer. Serial histologic sections and immunohistochemical studies were performed using antibodies specific for alpha-1-adrenergic receptor subtypes (alpha 1a, alpha 1b, alpha 1d). The sections were examined under a light microscope and scored as positive or negative. In order to validate and quantify the alpha receptor subtypes along the human ureter. Western blotting techniques were applied. Human ureter stained positively for alpha -1-adrenergic receptors. Immunostaining appeared red, with intense reaction in the smooth muscle of the ureter and endothelium of the neighboring blood vessels. There was differential expression between all the receptors with the highest staining for alpha-1D subtype. The highest protein expression for all three subtypes was in the renal pelvis and decreased with advancement along the ureter to the distal ureter. At the distal ureter, there was marked increase in expression as one progressed towards the ureteral orifice. The same pattern of protein expression was exhibited for all three alpha -1-adrenergic receptor subtypes. We provide preliminary evidence for the ability to detect and quantify the alpha-1-receptor subtypes along the human ureter which to the best of our knowledge has never been done with

  17. Isoforms of receptors of fibroblast growth factors.

    Science.gov (United States)

    Gong, Siew-Ging

    2014-12-01

    The breadth and scope of Fibroblast Growth Factor signaling is immense, with documentation of its role in almost every organism and system studied so far. FGF ligands signal through a family of four distinct tyrosine kinase receptors, the FGF receptors (FGFRs). One contribution to the diversity of function and signaling of FGFs and their receptors arises from the numerous alternative splicing variants that have been documented in the FGFR literature. The present review discusses the types and roles of alternatively spliced variants of the FGFR family members and the significant impact of alternative splicing on the physiological functions of five broad classes of FGFR isoforms. Some characterized known regulatory mechanisms of alternative splicing and future directions in studies of FGFR alternative splicing are also discussed. Presence, absence, and/or the combination of specific exons within each FGFR protein impart upon each individual isoform its unique function and expression pattern during normal function and in diseased states (e.g., in cancers and birth defects). A better understanding of the diversity of FGF signaling in different developmental contexts and diseased states can be achieved through increased knowledge of the presence of specific FGFR isoforms and their impact on downstream signaling and functions. Modern high-throughput techniques afford an opportunity to explore the distribution and function of isoforms of FGFR during development and in diseases.

  18. Nuclear transportation of exogenous epidermal growth factor receptor and androgen receptor via extracellular vesicles.

    Science.gov (United States)

    Read, Jolene; Ingram, Alistair; Al Saleh, Hassan A; Platko, Khrystyna; Gabriel, Kathleen; Kapoor, Anil; Pinthus, Jehonathan; Majeed, Fadwa; Qureshi, Talha; Al-Nedawi, Khalid

    2017-01-01

    Epidermal growth factor receptor (EGFR) plays a central role in the progression of several human malignancies. Although EGFR is a membrane receptor, it undergoes nuclear translocation, where it has a distinct signalling pathway. Herein, we report a novel mechanism by which cancer cells can directly transport EGFR to the nucleus of other cells via extracellular vesicles (EVs). The transported receptor is active and stimulates the nuclear EGFR pathways. Interestingly, the translocation of EGFR via EVs occurs independently of the nuclear localisation sequence that is required for nuclear translocation of endogenous EGFR. Also, we found that the mutant receptor EGFRvIII could be transported to the nucleus of other cells via EVs. To assess the role of EVs in the regulation of an actual nuclear receptor, we studied the regulation of androgen receptor (AR). We found that full-length AR and mutant variant ARv7 are secreted in EVs derived from prostate cancer cell lines and could be transported to the nucleus of AR-null cells. The EV-derived AR was able to bind the androgen-responsive promoter region of prostate specific antigen, and recruit RNA Pol II, an indication of active transcription. The nuclear-translocated AR via EVs enhanced the proliferation of acceptor cells in the absence of androgen. Finally, we provide evidence that nuclear localisation of AR could occur in vivo via orthotopically-injected EVs in male SCID mice prostate glands. To our knowledge, this is the first study showing the nuclear translocation of nuclear receptors via EVs, which significantly extends the role of EVs as paracrine transcriptional regulators.

  19. Soluble and cell surface receptors for tumor necrosis factor

    DEFF Research Database (Denmark)

    Wallach, D; Engelmann, H; Nophar, Y

    1991-01-01

    Tumor necrosis factor (TNF) initiates its multiple effects on cell function by binding at a high affinity to specific cell surface receptors. Two different molecular species of these receptors, which are expressed differentially in different cells, have been identified. The cDNAs of both receptor...... have recently been cloned. Antibodies to one of these receptor species (the p55, type I receptor) can trigger a variety of TNF like effects by cross-linking of the receptor molecules. Thus, it is not TNF itself but its receptors that provide the signal for the response to this cytokine...... in certain pathological situations. Release of the soluble receptors from the cells seems to occur by proteolytic cleavage of the cell surface forms and appears to be a way of down-regulating the cell response to TNF. Because of their ability to bind TNF, the soluble receptors exert an inhibitory effect...

  20. Cardiovascular risk factors regulate the expression of vascular endothelin receptors

    DEFF Research Database (Denmark)

    Xu, Cang-Bao; Sun, Yang; Edvinsson, Lars

    2010-01-01

    , cigarette smoking and hypertension (both strongly related to arterial wall injury), inflammation and atherosclerosis. The vascular endothelin receptors are a protein family that belongs to the larger family of G-protein coupled receptors. They mediate vascular smooth muscle contraction, proliferation......-activated protein kinase pathways and downstream transcription factors such as nuclear factor-kappaB. Understanding the mechanisms involved in vascular endothelin receptor upregulation during cardiovascular disease may provide novel therapeutic approaches....

  1. Pattern of hormone receptors and human epidermal growth factor ...

    African Journals Online (AJOL)

    2015-02-05

    Feb 5, 2015 ... Key words: Breast cancer, human epidermal growth factor receptor 2/neu, immunohistochemistry, ... therapy.[6‑8] Of all these prognostic and predictive factors, ... one of the biggest private medical laboratories in Nigeria.

  2. Circulating levels of tumor necrosis factor-alpha receptor 2 are increased in heart failure with preserved ejection fraction relative to heart failure with reduced ejection fraction: evidence for a divergence in pathophysiology.

    Directory of Open Access Journals (Sweden)

    Brendan N Putko

    Full Text Available BACKGROUND: Various pathways have been implicated in the pathogenesis of heart failure (HF with preserved ejection fraction (HFPEF. Inflammation in response to comorbid conditions, such as hypertension and diabetes, may play a proportionally larger role in HFPEF as compared to HF with reduced ejection fraction (HFREF. METHODS AND RESULTS: This study investigated inflammation mediated by the tumor necrosis factor-alpha (TNFα axis in community-based cohorts of HFPEF patients (n = 100, HFREF patients (n = 100 and healthy controls (n = 50. Enzyme-linked immunosorbent assays were used to investigate levels of TNFα, its two receptors (TNFR1 and TNFR2, and a non-TNFα cytokine, interleukin-6 (IL-6, in plasma derived from peripheral blood samples. Plasma levels of TNFα and TNFR1 were significantly elevated in HFPEF relative to controls, while levels of TNFR2 were significantly higher in HFPEF than both controls and HFREF. TNFα, TNFR1 and TNFR2 were each significantly associated with at least two of the following: age, estimated glomerular filtration rate, hypertension, diabetes, smoking, peripheral vascular disease or history of atrial fibrillation. TNFR2 levels were also significantly associated with increasing grade of diastolic dysfunction and severity of symptoms in HFPEF. CONCLUSIONS: Inflammation mediated through TNFα and its receptors, TNFR1 and TNFR2, may represent an important component of a comorbidity-induced inflammatory response that partially drives the pathophysiology of HFPEF.

  3. Troglitazone inhibits cell proliferation by attenuation of epidermal growth factor receptor signaling independent of peroxisome proliferator-activated receptor γ

    Institute of Scientific and Technical Information of China (English)

    Xiaoqi Li; Xuanming Yang; Youli Xu; Xuejun Jiang; Xin Li; Fajun Nan; Hong Tang

    2009-01-01

    Peroxisome proliferator-activated receptors (PPAR) belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone (TGZ), can inhibit cell proliferation and promote cell differentiation independent of PPARγ. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by target-ing the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinase-signaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro-liferation by promoting EGFR degradation and attenuating Akt phosphorylation.

  4. Corticotropin-releasing factor receptors and stress-related alterations of gut motor function.

    OpenAIRE

    2007-01-01

    International audience; Over the past few decades, corticotropin-releasing factor (CRF) signaling pathways have been shown to be the main coordinators of the endocrine, behavioral, and immune responses to stress. Emerging evidence also links the activation of CRF receptors type 1 and type 2 with stress-related alterations of gut motor function. Here, we review the role of CRF receptors in both the brain and the gut as part of key mechanisms through which various stressors impact propulsive ac...

  5. Interferon gamma-dependent transactivation of epidermal growth factor receptor.

    Science.gov (United States)

    Burova, Elena; Vassilenko, Konstantin; Dorosh, Victoria; Gonchar, Ilya; Nikolsky, Nikolai

    2007-04-03

    The present report provides evidence that, in A431 cells, interferon gamma (IFNgamma) induces the rapid (within 5 min), and reversible, tyrosine phosphorylation of the epidermal growth factor receptor (EGFR). IFNgamma-induced EGFR transactivation requires EGFR kinase activity, as well as activity of the Src-family tyrosine kinases and JAK2. Here, we show that IFNgamma-induced STAT1 activation in A431 and HeLa cells partially depends on the kinase activity of both EGFR and Src. Furthermore, in these cells, EGFR kinase activity is essential for IFNgamma-induced ERK1,2 activation. This study is the first to demonstrate that EGFR is implicated in IFNgamma-dependent signaling pathways.

  6. Clinical Evidence for the Cardiovascular Benefits of Angiotensin Receptor Blockers

    Directory of Open Access Journals (Sweden)

    Georg Nickenig

    2006-03-01

    Full Text Available Targeting the renin-angiotensin-aldosterone system (RAAS, specifically the effector peptide angiotensin II (Ang II, represents a major opportunity for slowing the progression of cardiovascular disease (CVD and, in turn, reducing the risk of morbidity and mortality. Inhibition of angiotensin-converting enzyme (ACE and selective blockade of Ang II AT1 receptors are two approaches through which the pathophysiological effects of Ang II can be targeted. Numerous clinical studies have established the benefits of ACE inhibitors P, (ACE-Is in lessening the morbidity and mortality burden of CVD. There are, however, tolerability concerns associated with ACE-Is, such as angioedema and dry cough. By blocking Ang II at the AT1 receptor level, Ang II receptor blockers (ARBs provide a more specific and complete blockade of the deleterious effects of Ang II and tend to have more favourable tolerability. A number of clinical trials have shown that ARBs are not only associated with positive outcomes across the CVD continuum but may also have a role in the prevention or delay of diabetes (a major cardiovascular risk factor. Ongoing trials are aiming to define the place of such agents in lessening morbidity and mortality from CVD.

  7. Down regulation of epidermal growth factor receptors: direct demonstration of receptor degradation in human fibroblasts

    OpenAIRE

    1984-01-01

    The metabolism of the receptor for epidermal growth factor (EGF) has been measured by labeling the receptor in vivo with radioactive amino acid precursors and then determining, by immunoprecipitation with specific anti-EGF receptor antisera, the rate of degradation of the receptor when the cells are placed in a nonradioactive medium. In human fibroblasts the rate of EGF receptor degradation (t1/2 = 10.1 h) was faster than the rate of degradation of total cell protein. When EGF was added to th...

  8. the significance of epidermal growth factor receptor and survivin ...

    African Journals Online (AJOL)

    2013-01-01

    Jan 1, 2013 ... SURVIVIN EXPRESSION IN BLADDER CANCER TISSUE AND URINE ... Objective: To assess whether epidermal growth factor receptor (EGFR) and survivin ..... lung cancer by the FDA in 2003 (28) and is currently.

  9. Activation of 5-HT7 receptors increases neuronal platelet-derived growth factor β receptor expression.

    Science.gov (United States)

    Vasefi, Maryam S; Kruk, Jeff S; Liu, Hui; Heikkila, John J; Beazely, Michael A

    2012-03-09

    Several antipsychotics have a high affinity for 5-HT7 receptors yet despite intense interest in the 5-HT7 receptor as a potential drug target to treat psychosis, the function and signaling properties of 5-HT7 receptors in neurons remain largely uncharacterized. In primary mouse hippocampal and cortical neurons, as well as in the SH-SY5Y cell line, incubation with 5-HT, 5-carboxamidotryptamine (5-CT), or 5-HT7 receptor-selective agonists increases the expression of platelet-derived growth factor (PDGF)β receptors. The increased PDGFβ receptor expression is cyclic AMP-dependent protein kinase (PKA)-dependent, suggesting that 5-HT7 receptors couple to Gα(s) in primary neurons. Interestingly, up-regulated PDGFβ receptors display an increased basal phosphorylation state at the phospholipase Cγ-activating tyrosine 1021. This novel linkage between the 5-HT7 receptor and the PDGF system may be an important GPCR-neurotrophic factor signaling pathway in neurons.

  10. Oncogenic fingerprint of epidermal growth factor receptor pathway and emerging epidermal growth factor receptor blockade resistance in colorectal cancer

    Science.gov (United States)

    Sobani, Zain A; Sawant, Ashwin; Jafri, Mikram; Correa, Amit Keith; Sahin, Ibrahim Halil

    2016-01-01

    Epidermal growth factor receptor (EGFR) has been an attractive target for treatment of epithelial cancers, including colorectal cancer (CRC). Evidence from clinical trials indicates that cetuximab and panitumumab (anti-EGFR monoclonal antibodies) have clinical activity in patients with metastatic CRC. The discovery of intrinsic EGFR blockade resistance in Kirsten RAS (KRAS)-mutant patients led to the restriction of anti-EGFR antibodies to KRAS wild-type patients by Food and Drug Administration and European Medicine Agency. Studies have since focused on the evaluation of biomarkers to identify appropriate patient populations that may benefit from EGFR blockade. Accumulating evidence suggests that patients with mutations in EGFR downstream signaling pathways including KRAS, BRAF, PIK3CA and PTEN could be intrinsically resistant to EGFR blockade. Recent whole genome studies also suggest that dynamic alterations in signaling pathways downstream of EGFR leads to distinct oncogenic signatures and subclones which might have some impact on emerging resistance in KRAS wild-type patients. While anti-EGFR monoclonal antibodies have a clear potential in the management of a subset of patients with metastatic CRC, further studies are warranted to uncover exact mechanisms related to acquired resistance to EGFR blockade. PMID:27777877

  11. Neural stem cells express melatonin receptors and neurotrophic factors: colocalization of the MT1 receptor with neuronal and glial markers

    Directory of Open Access Journals (Sweden)

    McMillan Catherine R

    2004-10-01

    Full Text Available Abstract Background In order to optimize the potential benefits of neural stem cell (NSC transplantation for the treatment of neurodegenerative disorders, it is necessary to understand their biological characteristics. Although neurotrophin transduction strategies are promising, alternative approaches such as the modulation of intrinsic neurotrophin expression by NSCs, could also be beneficial. Therefore, utilizing the C17.2 neural stem cell line, we have examined the expression of selected neurotrophic factors under different in vitro conditions. In view of recent evidence suggesting a role for the pineal hormone melatonin in vertebrate development, it was also of interest to determine whether its G protein-coupled MT1 and MT2 receptors are expressed in NSCs. Results RT-PCR analysis revealed robust expression of glial cell-line derived neurotrophic factor (GDNF, brain-derived neurotrophic factor (BDNF and nerve growth factor (NGF in undifferentiated cells maintained for two days in culture. After one week, differentiating cells continued to exhibit high expression of BDNF and NGF, but GDNF expression was lower or absent, depending on the culture conditions utilized. Melatonin MT1 receptor mRNA was detected in NSCs maintained for two days in culture, but the MT2 receptor was not seen. An immature MT1 receptor of about 30 kDa was detected by western blotting in NSCs cultured for two days, whereas a mature receptor of about 40 – 45 kDa was present in cells maintained for longer periods. Immunocytochemical studies demonstrated that the MT1 receptor is expressed in both neural (β-tubulin III positive and glial (GFAP positive progenitor cells. An examination of the effects of melatonin on neurotrophin expression revealed that low physiological concentrations of this hormone caused a significant induction of GDNF mRNA expression in NSCs following treatment for 24 hours. Conclusions The phenotypic characteristics of C17.2 cells suggest that they are

  12. Genomic and epigenetic evidence for oxytocin receptor deficiency in autism

    Directory of Open Access Journals (Sweden)

    Worley Gordon

    2009-10-01

    Full Text Available Abstract Background Autism comprises a spectrum of behavioral and cognitive disturbances of childhood development and is known to be highly heritable. Although numerous approaches have been used to identify genes implicated in the development of autism, less than 10% of autism cases have been attributed to single gene disorders. Methods We describe the use of high-resolution genome-wide tilepath microarrays and comparative genomic hybridization to identify copy number variants within 119 probands from multiplex autism families. We next carried out DNA methylation analysis by bisulfite sequencing in a proband and his family, expanding this analysis to methylation analysis of peripheral blood and temporal cortex DNA of autism cases and matched controls from independent datasets. We also assessed oxytocin receptor (OXTR gene expression within the temporal cortex tissue by quantitative real-time polymerase chain reaction (PCR. Results Our analysis revealed a genomic deletion containing the oxytocin receptor gene, OXTR (MIM accession no.: 167055, previously implicated in autism, was present in an autism proband and his mother who exhibits symptoms of obsessive-compulsive disorder. The proband's affected sibling did not harbor this deletion but instead may exhibit epigenetic misregulation of this gene through aberrant gene silencing by DNA methylation. Further DNA methylation analysis of the CpG island known to regulate OXTR expression identified several CpG dinucleotides that show independent statistically significant increases in the DNA methylation status in the peripheral blood cells and temporal cortex in independent datasets of individuals with autism as compared to control samples. Associated with the increase in methylation of these CpG dinucleotides is our finding that OXTR mRNA showed decreased expression in the temporal cortex tissue of autism cases matched for age and sex compared to controls. Conclusion Together, these data provide

  13. Modulation of the NMDA Receptor Through Secreted Soluble Factors.

    Science.gov (United States)

    Cerpa, Waldo; Ramos-Fernández, Eva; Inestrosa, Nibaldo C

    2016-01-01

    Synaptic activity is a critical determinant in the formation and development of excitatory synapses in the central nervous system (CNS). The excitatory current is produced and regulated by several ionotropic receptors, including those that respond to glutamate. These channels are in turn regulated through several secreted factors that function as synaptic organizers. Specifically, Wnt, brain-derived neurotrophic factor (BDNF), fibroblast growth factor (FGF), and transforming growth factor (TGF) particularly regulate the N-methyl-D-aspartate receptor (NMDAR) glutamatergic channel. These factors likely regulate early embryonic development and directly control key proteins in the function of important glutamatergic channels. Here, we review the secreted molecules that participate in synaptic organization and discuss the cell signaling behind of this fine regulation. Additionally, we discuss how these factors are dysregulated in some neuropathologies associated with glutamatergic synaptic transmission in the CNS.

  14. Neurosteroid dehydroepiandrosterone interacts with nerve growth factor (NGF receptors, preventing neuronal apoptosis.

    Directory of Open Access Journals (Sweden)

    Iakovos Lazaridis

    2011-04-01

    Full Text Available The neurosteroid dehydroepiandrosterone (DHEA, produced by neurons and glia, affects multiple processes in the brain, including neuronal survival and neurogenesis during development and in aging. We provide evidence that DHEA interacts with pro-survival TrkA and pro-death p75(NTR membrane receptors of neurotrophin nerve growth factor (NGF, acting as a neurotrophic factor: (1 the anti-apoptotic effects of DHEA were reversed by siRNA against TrkA or by a specific TrkA inhibitor; (2 [(3H]-DHEA binding assays showed that it bound to membranes isolated from HEK293 cells transfected with the cDNAs of TrkA and p75(NTR receptors (K(D: 7.4 ± 1.75 nM and 5.6 ± 0.55 nM, respectively; (3 immobilized DHEA pulled down recombinant and naturally expressed TrkA and p75(NTR receptors; (4 DHEA induced TrkA phosphorylation and NGF receptor-mediated signaling; Shc, Akt, and ERK1/2 kinases down-stream to TrkA receptors and TRAF6, RIP2, and RhoGDI interactors of p75(NTR receptors; and (5 DHEA rescued from apoptosis TrkA receptor positive sensory neurons of dorsal root ganglia in NGF null embryos and compensated NGF in rescuing from apoptosis NGF receptor positive sympathetic neurons of embryonic superior cervical ganglia. Phylogenetic findings on the evolution of neurotrophins, their receptors, and CYP17, the enzyme responsible for DHEA biosynthesis, combined with our data support the hypothesis that DHEA served as a phylogenetically ancient neurotrophic factor.

  15. Evidence against dopamine D1/D2 receptor heteromers

    Science.gov (United States)

    Frederick, Aliya L.; Yano, Hideaki; Trifilieff, Pierre; Vishwasrao, Harshad D.; Biezonski, Dominik; Mészáros, József; Sibley, David R.; Kellendonk, Christoph; Sonntag, Kai C.; Graham, Devon L.; Colbran, Roger J.; Stanwood, Gregg D.; Javitch, Jonathan A.

    2014-01-01

    Hetero-oligomers of G-protein-coupled receptors have become the subject of intense investigation because their purported potential to manifest signaling and pharmacological properties that differ from the component receptors makes them highly attractive for the development of more selective pharmacological treatments. In particular, dopamine D1 and D2 receptors have been proposed to form hetero-oligomers that couple to Gαq proteins, and SKF83959 has been proposed to act as a biased agonist that selectively engages these receptor complexes to activate Gαq and thus phospholipase C. D1/D2 heteromers have been proposed as relevant to the pathophysiology and treatment of depression and schizophrenia. We used in vitro bioluminescence resonance energy transfer (BRET), ex vivo analyses of receptor localization and proximity in brain slices, and behavioral assays in mice to characterize signaling from these putative dimers/oligomers. We were unable to detect Gαq or Gα11 protein coupling to homomers or heteromers of D1 or D2 receptors using a variety of biosensors. SKF83959-induced locomotor and grooming behaviors were eliminated in D1 receptor knockout mice, verifying a key role for D1-like receptor activation. In contrast, SKF83959-induced motor responses were intact in D2 receptor and Gαq knockout mice, as well as in knock-in mice expressing a mutant Ala286-CaMKIIα, that cannot autophosphorylate to become active. Moreover, we found that in the shell of the nucleus accumbens, even in neurons in which D1 and D2 receptor promoters are both active, the receptor proteins are segregated and do not form complexes. These data are not compatible with SKF83959 signaling through Gαq or through a D1–D2 heteromer and challenge the existence of such a signaling complex in the adult animals that we used for our studies. PMID:25560761

  16. Placental growth factor and vascular endothelial growth factor receptor-2 in human lung development.

    Science.gov (United States)

    Janér, Joakim; Andersson, Sture; Haglund, Caj; Karikoski, Riitta; Lassus, Patrik

    2008-08-01

    We examined the pulmonary expression of 2 proangiogenic factors, namely, placental growth factor and vascular endothelial growth factor receptor-2, during lung development and acute and chronic lung injury in newborn infants. Six groups were included in an immunohistochemical study of placental growth factor and vascular endothelial growth factor receptor-2, that is, 9 fetuses, 4 preterm and 8 term infants without lung injury who died soon after birth, 5 preterm infants with respiratory distress syndrome of 10 days, and 6 with bronchopulmonary dysplasia. Placental growth factor concentrations in tracheal aspirate fluid were measured in 70 samples from 20 preterm infants during the first postnatal week. In immunohistochemical analyses, placental growth factor staining was seen in bronchial epithelium and macrophages in all groups. Distal airway epithelium positivity was observed mostly in fetuses and in preterm infants who died soon after birth. Vascular endothelial growth factor receptor-2 staining was seen in vascular endothelium in all groups and also in lymphatic endothelium in fetuses. Vascular endothelial growth factor receptor-2 staining in arterial endothelium was associated with higher and staining in venous endothelium with lower gestational age. In capillaries, less vascular endothelial growth factor receptor-2 staining was seen in bronchopulmonary dysplasia. The mean placental growth factor protein concentration in tracheal aspirate fluid during the first postnatal week was 0.64 +/- 0.42 pg/mL per IgA-secretory component unit. Concentrations during the first postnatal week were stable. Lower placental growth factor concentrations correlated with chorioamnionitis and lactosyl ceramide positivity. The vascular endothelial growth factor receptor-2 staining pattern seems to reflect ongoing differentiation and activity of different endothelia. Lower vascular endothelial growth factor receptor-2 expression in capillary endothelium in bronchopulmonary dysplasia

  17. Evidence for pharmacologically distinct subsets of GABAB receptors.

    Science.gov (United States)

    Scherer, R W; Ferkany, J W; Enna, S J

    1988-09-01

    Activation of GABAB receptors augments neurotransmitter-stimulated cyclic AMP accumulation while inhibiting forskolin-mediated second messenger production. Previous studies have revealed that GABAB receptors are associated with a pertussis toxin sensitive G protein, such as Gi. While such a linkage is consistent with the finding that GABAB receptor activation inhibits forskolin-mediated second messenger accumulation, it fails to explain how GABAB agonists are capable of augmenting receptor-mediated cyclic AMP production. The present experiments were undertaken to explore the possible existence of pharmacologically distinct GABAB receptors in an attempt to explain this apparent discrepancy. For the study, a variety of agents were examined for their ability to inhibit GABAB binding to brain membranes and to modify isoproterenol- or forskolin-stimulated second messenger production in rat brain slices. Of the compounds studied, only 3-aminopropylphosphonic acid and 4-aminobutylphosphonic acid were found to inhibit GABAB binding. However, 4-aminobutylphosphonic acid failed to influence either isoproterenol- or forskolin-stimulated cyclic AMP production. On the other hand, while 3-aminopropylphosphonic acid also failed to affect isoproterenol-stimulated second messenger accumulation, it inhibited the forskolin-mediated response. Given this finding, and the fact that some of the agents tested are known to influence GABAB receptor function in other systems, the results indicate a multiplicity of pharmacologically distinct GABAB receptor recognition sites. This discovery paves the way for the development of more selective GABAB receptor agonists and antagonists possessing different therapeutic potentials.

  18. Corticotropin-releasing factor receptors and stress-related alterations of gut motor function.

    Science.gov (United States)

    Taché, Yvette; Bonaz, Bruno

    2007-01-01

    Over the past few decades, corticotropin-releasing factor (CRF) signaling pathways have been shown to be the main coordinators of the endocrine, behavioral, and immune responses to stress. Emerging evidence also links the activation of CRF receptors type 1 and type 2 with stress-related alterations of gut motor function. Here, we review the role of CRF receptors in both the brain and the gut as part of key mechanisms through which various stressors impact propulsive activity of the gastrointestinal system. We also examine how these mechanisms translate into the development of new approaches for irritable bowel syndrome, a multifactorial disorder for which stress has been implicated in the pathophysiology.

  19. Nerve growth factor receptor molecules in rat brain

    Energy Technology Data Exchange (ETDEWEB)

    Taniuchi, M.; Schweitzer, J.B.; Johnson, E.M. Jr.

    1986-03-01

    The authors have developed a method to immunoprecipitate rat nerve growth factor (NGF) receptor proteins and have applied the method to detect NGF receptor molecules in the rat brain. Crosslinking /sup 125/I-labeled NGF to either PC12 cells or cultured rat sympathetic neurons yielded two radiolabeled molecules (90 kDa and 220 kDa) that were immunoprecipitated by monoclonal antibody 192-IgG. Further, 192-IgG precipitated two radiolabeled proteins, with the expected sizes (80 kDa and 210 kDa) of noncrosslinked NGF receptor components, from among numerous surface-iodinated PC12 cell proteins. These results demonstrate the specific immunoprecipitation of NGF receptor molecules by 192-IgG. They applied the /sup 125/I-NGF crosslinking and 192-IgG-mediated immunoprecipitation procedures to plasma membrane preparations of rat brain: NGF receptor molecules of the same molecular masses as the peripheral receptor components were consistently detected in all regions and in preparations from whole brains. Removal of the peripheral sympathetic innervation of the brain did not eliminate these NGF receptor proteins, indicating that the receptor is endogenous to central nervous system tissues. They also observed retrograde transport of /sup 125/I-labeled 192-IgG from the parietal cortex to the nucleus basalis and from the hippocampus to the nucleus of the diagonal band of Broca and the medial septal nucleus. These findings demonstrate the presence in brain of NGF receptor molecules indistinguishable from those of the peripheral nervous system.

  20. Expression of the epidermal growth factor receptor in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M;

    1992-01-01

    Epidermal growth factor (EGF) receptor expression was evaluated in a panel of 21 small cell lung cancer cell lines with radioreceptor assay, affinity labeling, and Northern blotting. We found high-affinity receptors to be expressed in 10 cell lines. Scatchard analysis of the binding data...... demonstrated that the cells bound between 3 and 52 fmol/mg protein with a KD ranging from 0.5 x 10(-10) to 2.7 x 10(-10) M. EGF binding to the receptor was confirmed by affinity-labeling EGF to the EGF receptor. The cross-linked complex had a M(r) of 170,000-180,000. Northern blotting showed the expression...... of EGF receptor mRNA in all 10 cell lines that were found to be EGF receptor-positive and in one cell line that was found to be EGF receptor-negative in the radioreceptor assay and affinity labeling. Our results provide, for the first time, evidence that a large proportion of a broad panel of small cell...

  1. Advances in Variations of Estrogen Receptor, Progesterone Receptor and Human Epidermal Growth Factor Receptor-2 Status in Metastatic Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    Yuan Yuan; Zhang Lili

    2013-01-01

    Chemotherapy, endocrine therapy and molecular targeted therapy are vital means in the treatment of metastatic breast cancer (MBC), whose reasonable and standard applications are of great importance to prolong patients’ survival and improve the quality of life. The expressions of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2) present signiifcant differences between primary and metastatic breast cancer. However, these differences may affect the selection of MBC patients for therapeutic strategies and judgment on the prognosis. Hence, the relevant researches on variations of hormone receptors and HER-2 in primary and metastatic breast cancer, discordant causes of ER, PR and HER-2 expression in primary and metastatic lesions and clinical value of biopsy to the metastases are reviewed in the study.

  2. Signal transduction by growth factor receptors: signaling in an instant

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy;

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds...

  3. The epidermal growth factor receptor pathway in chronic kidney diseases

    NARCIS (Netherlands)

    Harskamp, Laura R.; Gansevoort, Ron T.; Goor, van Harry; Meijer, Esther

    2016-01-01

    The epidermal growth factor receptor (EGFR) pathway has a critical role in renal development, tissue repair and electrolyte handling. Numerous studies have reported an association between dysregulation of this pathway and the initiation and progression of various chronic kidney diseases such as diab

  4. Epidermal growth factor receptor: Target for delivery and silencing

    NARCIS (Netherlands)

    Santos Oliveira, S.

    2008-01-01

    Epidermal growth factor receptor in cancer therapy Recently, cancer research has been able to identify molecular targets that are specific for (or highly expressed by) cancer cells. These molecular targets serve as models for the development of rationally designed anticancer drugs that target import

  5. Fibroblast growth factor receptors, developmental corruption and malignant disease.

    Science.gov (United States)

    Kelleher, Fergal C; O'Sullivan, Hazel; Smyth, Elizabeth; McDermott, Ray; Viterbo, Antonella

    2013-10-01

    Fibroblast growth factors (FGF) are a family of ligands that bind to four different types of cell surface receptor entitled, FGFR1, FGFR2, FGFR3 and FGFR4. These receptors differ in their ligand binding affinity and tissue distribution. The prototypical receptor structure is that of an extracellular region comprising three immunoglobulin (Ig)-like domains, a hydrophobic transmembrane segment and a split intracellular tyrosine kinase domain. Alternative gene splicing affecting the extracellular third Ig loop also creates different receptor isoforms entitled FGFRIIIb and FGFRIIIc. Somatic fibroblast growth factor receptor (FGFR) mutations are implicated in different types of cancer and germline FGFR mutations occur in developmental syndromes particularly those in which craniosynostosis is a feature. The mutations found in both conditions are often identical. Many somatic FGFR mutations in cancer are gain-of-function mutations of established preclinical oncogenic potential. Gene amplification can also occur with 19-22% of squamous cell lung cancers for example having amplification of FGFR1. Ontologic comparators can be informative such as aberrant spermatogenesis being implicated in both spermatocytic seminomas and Apert syndrome. The former arises from somatic FGFR3 mutations and Apert syndrome arises from germline FGFR2 mutations. Finally, therapeutics directed at inhibiting the FGF/FGFR interaction are a promising subject for clinical trials.

  6. Targeting the epidermal growth factor receptor in solid tumor malignancies

    DEFF Research Database (Denmark)

    Nedergaard, Mette K; Hedegaard, Chris J; Poulsen, Hans S

    2012-01-01

    The epidermal growth factor receptor (EGFR) is over-expressed, as well as mutated, in many types of cancers. In particular, the EGFR variant type III mutant (EGFRvIII) has attracted much attention as it is frequently and exclusively found on many tumor cells, and hence both EGFR and EGFRvIII have...... been proposed as valid targets in many cancer therapy settings. Different strategies have been developed in order to either inhibit EGFR/EGFRvIII activity or to ablate EGFR/EGFRvIII-positive tumor cells. Drugs that inhibit these receptors include monoclonal antibodies (mAbs) that bind...

  7. ENTREPRENEURS' MOTIVATIONAL FACTORS: EMPIRICAL EVIDENCE FROM SERBIA

    Directory of Open Access Journals (Sweden)

    Sloboda Prokić

    2011-03-01

    Full Text Available Entrepreneurs are playing a major role in the economy of each country on the planet. Theycontribute to national economies by starting up and running small and medium sized enterprises(SMEs, which make more than 95% of the total number of enterprises and which are providing jobsto more than 60% of all employees within each country. The significance of entrepreneurship foreconomic development oblige goverments and all other relevant institutions within each country tocontinue to facilitate its growth by all means necessary. In order to do this, these institutions need tobe familiar with motives of entrepreneurs to start their own business. In this paper, results ofempirical research concerning motivational factors of entrepreneurs in Serbia are presented. Thisresearch presents a continuation of serie of research on this topic which were conducted in severalcountries, by using the same methodological approach.

  8. Prostaglandin E2 regulates angiogenesis via activation of fibroblast growth factor receptor-1.

    Science.gov (United States)

    Finetti, Federica; Solito, Raffaella; Morbidelli, Lucia; Giachetti, Antonio; Ziche, Marina; Donnini, Sandra

    2008-01-25

    Prostaglandin E(2) (PGE(2)) behaves as a mitogen in epithelial tumor cells as well as in many other cell types. We investigated the actions of PGE(2) on microvascular endothelial cells (capillary venular endothelial cells) with the purpose of delineating the signaling pathway leading to the acquisition of the angiogenic phenotype and to new vessel formation. PGE(2) (100 nM) produced activation of the fibroblast growth factor receptor 1 (FGFR-1), as measured by its phosphorylation, but not of vascular endothelial growth factor receptor 2. PGE(2) stimulated the EP3 subtype receptor, as deduced by abrogation of EP3 Galpha(i) subunit activity through pertussis toxin. Consistent with this result, in human umbilical venular endothelial cells missing the EP3 receptor, PGE(2) did not phosphorylate FGFR-1. Upon binding to its receptor, PGE(2) initiated an autocrine/paracrine signaling cascade involving the intracellular activation of c-Src, activation of matrix metalloproteinase (predominantly MMP2), which in turn caused the mobilization of membrane-anchored fibroblast growth factor-2 (FGF-2). In fact, in cells unable to release FGF-2 the transfection with both FGFR-1 and EP3 did not result in FGFR-1 phosphorylation in response to PGE(2). Relevance for the FGF2-FGFR-1 system was highlighted by confocal analysis, showing receptor internalization after cell exposure to the prostanoid. ERK1/2 appeared to be the distal signal involved, its phosphorylation being sensitive to either cSrc inhibitor or FGFR-1 blocker. Finally, PGE(2) stimulated cell migration and capillary formation in aortic rings, which were severely reduced by inhibitors of signaling molecules or by receptor antagonist. In conclusion, this study provides evidence for the involvement of FGFR-1 through FGF2 in eliciting PGE(2) angiogenic responses. This signaling pattern is similar to the autocrine-paracrine mechanism which operates in endothelial cells to support neovascular growth.

  9. Evidence for adaptation of porcine Toll-like receptors

    NARCIS (Netherlands)

    Darfour-Oduro, Kwame A.; Megens, Hendrik Jan; Roca, Alfred; Groenen, Martien A.M.; Schook, Lawrence B.

    2016-01-01

    Naturally endemic infectious diseases provide selective pressures for pig populations. Toll-like receptors (TLRs) represent the first line of immune defense against pathogens and are likely to play a crucial adaptive role for pig populations. This study was done to determine whether wild and dome

  10. Epidermal growth factor receptor expression in urinary bladder cancer

    Directory of Open Access Journals (Sweden)

    Dayalu S.L. Naik

    2011-01-01

    Full Text Available Objective : To evaluate the expression pattern of epidermal growth factor receptor (EGFR in urinary bladder cancer and its association with human epidermal growth factor receptor 2 (HER2, epidermal growth factor (EGF, interleukin-6 (IL-6, and high risk human papilloma virus (HPV types 16 and 18. Materials and Methods : Thirty cases of urothelial carcinoma were analyzed. EGFR, HER2, EGF, and IL-6 expressions in the tissue were evaluated by immunohistochemical staining. For HPV, DNA from tissue samples was extracted and detection of HPV was done by PCR technique. Furthermore, evaluation of different intracellular molecules associated with EGFR signaling pathways was performed by the western blot method using lysates from various cells and tissues. Results : In this study, the frequencies of immunopositivity for EGFR, HER2, EGF, and IL-6 were 23%, 60%, 47%, and 80%, respectively. No cases were positive for HPV-18, whereas HPV-16 was detected in 10% cases. Overall, expression of EGFR did not show any statistically significant association with the studied parameters. However, among male patients, a significant association was found only between EGFR and HER2. Conclusions : Overexpression of EGFR and/or HER2, two important members of the same family of growth factor receptors, was observed in a considerable proportion of cases. Precise knowledge in this subject would be helpful to formulate a rational treatment strategy in patients with urinary bladder cancer.

  11. New weighting factors assignment of evidence theory based on evidence distance

    Institute of Scientific and Technical Information of China (English)

    Chen Liangzhou; Shi Wenkang; Du Feng

    2005-01-01

    Evidence theory has been widely used in the information fusion for its effectiveness of the uncertainty reasoning. However, the classical DS evidence theory involves counter-intuitive behaviors when the high conflict information exists. Based on the analysis of some modified methods, Assigning the weighting factors according to the intrinsic characteristics of the existing evidence sources is proposed, which is determined on the evidence distance theory. From the numerical examples, the proposed method provides a reasonable result with good convergence efficiency. In addition, the new rule retrieves to the Yager's formula when all the evidence sources contradict to each other completely.

  12. Evidence for Heterodimerization and Functional Interaction of the Angiotensin Type 2 Receptor and the Receptor MAS

    DEFF Research Database (Denmark)

    Leonhardt, Julia; Steckelings, Ulrike Muscha

    2017-01-01

    The angiotensin type 2 receptor (AT2R) and the receptor MAS are receptors of the protective arm of the renin-angiotensin system. They mediate strikingly similar actions. Moreover, in various studies, AT2R antagonists blocked the effects of MAS agonists and vice versa. Such cross-inhibition may...... indicate heterodimerization of these receptors. Therefore, this study investigated the molecular and functional interplay between MAS and the AT2R. Molecular interactions were assessed by fluorescence resonance energy transfer and by cross correlation spectroscopy in human embryonic kidney-293 cells...... transfected with vectors encoding fluorophore-tagged MAS or AT2R. Functional interaction of AT2R and MAS was studied in astrocytes with CX3C chemokine receptor-1 messenger RNA expression as readout. Coexpression of fluorophore-tagged AT2R and MAS resulted in a fluorescence resonance energy transfer efficiency...

  13. Evidence for leptin receptor isoforms heteromerization at the cell surface.

    Science.gov (United States)

    Bacart, Johan; Leloire, Audrey; Levoye, Angélique; Froguel, Philippe; Jockers, Ralf; Couturier, Cyril

    2010-06-01

    Leptin mediates its metabolic effects through several leptin receptor (LEP-R) isoforms. In humans, long (LEPRb) and short (LEPRa,c,d) isoforms are generated by alternative splicing. Most of leptin's effects are believed to be mediated by the OB-Rb isoform. However, the role of short LEPR isoforms and the possible existence of heteromers between different isoforms are poorly understood. Using BRET1 and optimized co-immunoprecipitation, we observed LEPRa/b and LEPRb/c heteromers located at the plasma membrane and stabilized by leptin. Given the widespread coexpression of LEPRa and LEPRb, our results suggest that LEPRa/b heteromers may represent a major receptor species in most tissues.

  14. Basic evidence for class A G-protein-coupled receptor heteromerization

    Directory of Open Access Journals (Sweden)

    Rafael eFranco

    2016-03-01

    Full Text Available Cell membrane receptors rarely work on isolation, often they form oligomeric complexes with other receptor molecules and they may directly interact with different proteins of the signal transduction machinery. For a variety of reasons, rhodopsin-like class A G-protein-coupled receptors (GPCRs seem an exception to the general rule of receptor-receptor direct interaction. In fact, controversy surrounds their potential to form homo- hetero-dimers/oligomers with other class A GPCRs; in a sense, the field is going backwards instead of forward. This review focuses on the convergent, complementary and telling evidence showing that homo- and heteromers of class A GPCRs exist in transfected cells and, more importantly, in natural sources. It is time to decide between questioning the occurrence of heteromers or, alternatively, facing the vast scientific and technical challenges that class A receptor-dimer/oligomer existence pose to Pharmacology and to Drug Discovery.

  15. Decreased expression of serum and microvascular vascular endothelial growth factor receptor-2 in meningococcal sepsis*.

    NARCIS (Netherlands)

    Flier, M. van der; Baerveldt, E.M.; Miedema, A.; Hartwig, N.G.; Hazelzet, J.A.; Emonts, M.; Groot, R. de; Prens, E.P.; Vught, A.J. van; Jansen, N.J.

    2013-01-01

    OBJECTIVES: To determine the skin microvessel expression of vascular endothelial growth factor receptor 2 and serum-soluble vascular endothelial growth factor receptor 2 levels in children with meningococcal sepsis. DESIGN: Observational study. SETTING: Two tertiary academic children hospital PICUs.

  16. Targeting Extracellular Domains D4 and D7 of Vascular Endothelial Growth Factor Receptor 2 Reveals Allosteric Receptor Regulatory Sites

    OpenAIRE

    Hyde, Caroline A. C.; Giese, Alexandra; Stuttfeld, Edward; Abram Saliba, Johan; Villemagne, Denis; Schleier, Thomas; Binz, H. Kaspar; Ballmer-Hofer, Kurt

    2012-01-01

    Vascular endothelial growth factors (VEGFs) activate three receptor tyrosine kinases, VEGFR-1, -2, and -3, which regulate angiogenic and lymphangiogenic signaling. VEGFR-2 is the most prominent receptor in angiogenic signaling by VEGF ligands. The extracellular part of VEGF receptors consists of seven immunoglobulin homology domains (Ig domains). Earlier studies showed that domains 2 and 3 (D23) mediate ligand binding, while structural analysis of dimeric ligand/receptor complexes by electron...

  17. Evidence for Heterodimerization and Functional Interaction of the Angiotensin Type 2 Receptor and the Receptor MAS.

    Science.gov (United States)

    Leonhardt, Julia; Villela, Daniel C; Teichmann, Anke; Münter, Lisa-Marie; Mayer, Magnus C; Mardahl, Maibritt; Kirsch, Sebastian; Namsolleck, Pawel; Lucht, Kristin; Benz, Verena; Alenina, Natalia; Daniell, Nicholas; Horiuchi, Masatsugu; Iwai, Masaru; Multhaup, Gerhard; Schülein, Ralf; Bader, Michael; Santos, Robson A; Unger, Thomas; Steckelings, Ulrike Muscha

    2017-06-01

    The angiotensin type 2 receptor (AT2R) and the receptor MAS are receptors of the protective arm of the renin-angiotensin system. They mediate strikingly similar actions. Moreover, in various studies, AT2R antagonists blocked the effects of MAS agonists and vice versa. Such cross-inhibition may indicate heterodimerization of these receptors. Therefore, this study investigated the molecular and functional interplay between MAS and the AT2R. Molecular interactions were assessed by fluorescence resonance energy transfer and by cross correlation spectroscopy in human embryonic kidney-293 cells transfected with vectors encoding fluorophore-tagged MAS or AT2R. Functional interaction of AT2R and MAS was studied in astrocytes with CX3C chemokine receptor-1 messenger RNA expression as readout. Coexpression of fluorophore-tagged AT2R and MAS resulted in a fluorescence resonance energy transfer efficiency of 10.8 ± 0.8%, indicating that AT2R and MAS are capable to form heterodimers. Heterodimerization was verified by competition experiments using untagged AT2R and MAS. Specificity of dimerization of AT2R and MAS was supported by lack of dimerization with the transient receptor potential cation channel, subfamily C-member 6. Dimerization of the AT2R was abolished when it was mutated at cysteine residue 35. AT2R and MAS stimulation with the respective agonists, Compound 21 or angiotensin-(1-7), significantly induced CX3C chemokine receptor-1 messenger RNA expression. Effects of each agonist were blocked by an AT2R antagonist (PD123319) and also by a MAS antagonist (A-779). Knockout of a single of these receptors made astrocytes unresponsive for both agonists. Our results suggest that MAS and the AT2R form heterodimers and that-at least in astrocytes-both receptors functionally depend on each other. © 2017 American Heart Association, Inc.

  18. Beclin 1 regulates growth factor receptor signaling in breast cancer.

    Science.gov (United States)

    Rohatgi, R A; Janusis, J; Leonard, D; Bellvé, K D; Fogarty, K E; Baehrecke, E H; Corvera, S; Shaw, L M

    2015-10-16

    Beclin 1 is a haploinsufficient tumor suppressor that is decreased in many human tumors. The function of beclin 1 in cancer has been attributed primarily to its role in the degradative process of macroautophagy. However, beclin 1 is a core component of the vacuolar protein sorting 34 (Vps34)/class III phosphatidylinositoI-3 kinase (PI3KC3) and Vps15/p150 complex that regulates multiple membrane-trafficking events. In the current study, we describe an alternative mechanism of action for beclin 1 in breast cancer involving its control of growth factor receptor signaling. We identify a specific stage of early endosome maturation that is regulated by beclin 1, the transition of APPL1-containing phosphatidyIinositol 3-phosphate-negative (PI3P(-)) endosomes to PI3P(+) endosomes. Beclin 1 regulates PI3P production in response to growth factor stimulation to control the residency time of growth factor receptors in the PI3P(-)/APPL(+)-signaling-competent compartment. As a result, suppression of BECN1 sustains growth factor-stimulated AKT and ERK activation resulting in increased breast carcinoma cell invasion. In human breast tumors, beclin 1 expression is inversely correlated with AKT and ERK phosphorylation. Our data identify a novel role for beclin 1 in regulating growth factor signaling and reveal a mechanism by which loss of beclin 1 expression would enhance breast cancer progression.

  19. Cheiradone: a vascular endothelial cell growth factor receptor antagonist

    Directory of Open Access Journals (Sweden)

    Ahmed Nessar

    2008-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with physiological (for example wound healing and pathological conditions (tumour development. Vascular endothelial growth factor (VEGF, fibroblast growth factor-2 (FGF-2 and epidermal growth factor (EGF are the major angiogenic regulators. We have identified a natural product (cheiradone isolated from a Euphorbia species which inhibited in vivo and in vitro VEGF- stimulated angiogenesis but had no effect on FGF-2 or EGF activity. Two primary cultures, bovine aortic and human dermal endothelial cells were used in in vitro (proliferation, wound healing, invasion in Matrigel and tube formation and in vivo (the chick chorioallantoic membrane models of angiogenesis in the presence of growth factors and cheiradone. In all cases, the concentration of cheiradone which caused 50% inhibition (IC50 was determined. The effect of cheiradone on the binding of growth factors to their receptors was also investigated. Results Cheiradone inhibited all stages of VEGF-induced angiogenesis with IC50 values in the range 5.20–7.50 μM but did not inhibit FGF-2 or EGF-induced angiogenesis. It also inhibited VEGF binding to VEGF receptor-1 and 2 with IC50 values of 2.9 and 0.61 μM respectively. Conclusion Cheiradone inhibited VEGF-induced angiogenesis by binding to VEGF receptors -1 and -2 and may be a useful investigative tool to study the specific contribution of VEGF to angiogenesis and may have therapeutic potential.

  20. Combining a GLP-1 receptor agonist and basal insulin: study evidence and practical considerations.

    Science.gov (United States)

    Carris, Nicholas W; Taylor, James R; Gums, John G

    2014-12-01

    Most patients with diabetes mellitus require multiple medications to achieve glycemic goals. Considering this and the increasing incidence of type 2 diabetes worldwide, the need for effective combination therapy is pressing. Basal insulin and glucagon-like peptide 1 (GLP-1) receptor agonists are frequently used to treat type 2 diabetes. Though both classes of medication are exclusively injectable, which may cause initial hesitation from providers, evidence for their combined use is substantial. This review summarizes the theoretical benefit, supporting evidence, and implementation of a combined basal insulin-GLP-1 receptor agonist regimen. Basal insulin added to a GLP-1 receptor agonist reduces hemoglobin A1c (HbA1c) without weight gain or significantly increased hypoglycemia. A GLP-1 receptor agonist added to basal insulin reduces HbA1c and body weight. Compared with the addition of meal-time insulin to basal insulin, a GLP-1 receptor agonist produces similar or greater reduction in HbA1c, weight loss instead of weight gain, and less hypoglycemia. Gastrointestinal adverse events are common with GLP-1 receptor agonists, especially during initiation and titration. However, combination with basal insulin is not expected to augment expected adverse events that come with using a GLP-1 receptor agonist. Basal insulin can be added to a GLP-1 receptor agonist with a slow titration to target goal fasting plasma glucose. In patients starting a GLP-1 receptor agonist, the dose of basal insulin should be decreased by 20 % in patients with an HbA1c ≤8 %. The evidence from 15 randomized prospective studies supports the combined use of a GLP-1 receptor agonist with basal insulin in a broad range of patients with uncontrolled type 2 diabetes.

  1. Upregulation of epidermal growth factor receptor 4 in ora leukoplakia

    Institute of Scientific and Technical Information of China (English)

    Hiroshi Kobayashi; Kenichi Kumagai; Akito Gotoh; Takanori Eguchi; Hiroyuki Yamada; Yoshiki Hamada; Satsuki Suzuki; Ryuji Suzuki

    2013-01-01

    In the present study, we investigate the expression profile of the epidermal growth factor receptor family, which comprises EGFR/ ErbB 1, HER2/ErbB2, HER3/ErbB3 and HER4/ErbB4 in oral leukoplakia (LP), The expression of four epidermal growth factor receptor (EGFR) family genes and their ligands were measured in LP tissues from 14 patients and compared with levels in 10 patients with oral lichen planus (OLP) and normal oral mucosa (NOM) from 14 healthy donors by real-time polymerase chain reaction (PCR) and immunohistochemistry. Synchronous mRNA coexpression of ErbB1, ErbB2, ErbB3 and ErbB4 was detected in LP lesions. Out of the receptors, only ErbB4 mRNA and protein was more highly expressed in LP compared with NOM tissues. These were strongly expressed by epithelial keratinocytes in LP lesions, as shown by immunohistochemistry. Regarding the ligands, the mRNA of Neuregulin2 and 4 were more highly expressed in OLP compared with NOM tissues. Therefore, enhanced ErbB4 on the keratinocytes and synchronous modulation of EGFR family genes may contribute to the pathogenesis and carcinogenesis of LP.

  2. Multiple autophosphorylation sites of the epidermal growth factor receptor are essential for receptor kinase activity and internalization. Contrasting significance of tyrosine 992 in the native and truncated receptors

    DEFF Research Database (Denmark)

    Sorkin, A; Helin, K; Waters, C M

    1992-01-01

    The role of epidermal growth factor (EGF) receptor autophosphorylation sites in the regulation of receptor functions has been studied using cells transfected with mutant EGF receptors. Simultaneous point mutation of 4 tyrosines (Y1068, Y1086, Y1148, Y1173) to phenylalanine, as well as removal of ...

  3. Topography of human placental receptors for epidermal growth factor.

    Science.gov (United States)

    Rao, C V; Ramani, N; Chegini, N; Stadig, B K; Carman, F R; Woost, P G; Schultz, G S; Cook, C L

    1985-02-10

    These studies were undertaken to determine whether term human placental microvillus plasma membranes, which are exposed to maternal blood, and basolateral plasma membranes, which are in close proximity to fetal blood capillaries, contain receptors for epidermal growth factor (EGF). These two highly purified membranes bound 125I-EGF with similar affinity (apparent dissociation constants, 0.07-0.12 nM, but the total number of available receptors was greater in microvillus (8.2 pmol/mg protein) compared to basolateral (4.9 pmol/mg protein) plasma membranes. Detailed characterization of 125I-EGF binding to these membranes revealed numerous similarities as well as differences. The two membranes contained two major (155 and 140 kDa) and at least three minor (115, 175, and 210 kDa) specific 125I-EGF binding proteins. The 115-kDa protein was only found in basolateral plasma membranes. The 155-kDa protein was predominantly labeled in microvillus, whereas the 140-kDa protein was labeled predominantly in basolateral plasma membranes. The addition of protease inhibitors did not alter the multiple 125I-EGF binding proteins pattern found in these membranes. EGF stimulated phosphorylation of 140- and 155-kDa proteins in both microvillus and basolateral plasma membranes. However, the 155-kDa protein was phosphorylated to a greater extent in microvillus, whereas both 140- and 155-kDa proteins were phosphorylated equally in basolateral plasma membranes. Light and electron microscope autoradiographic studies revealed that 125I-EGF preferentially associated with microvillus plasma membranes. The data demonstrates the presence of EGF receptors in outer cell membranes of syncytiotrophoblasts and suggests that maternal EGF may influence syncytiotrophoblast function by binding to receptors in microvillus plasma membranes, while fetal EGF may also influence syncytiotrophoblast function but via receptors in basolateral plasma membranes.

  4. Epidermal Growth Factor Receptor (EGFR) Crosstalks in Liver Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Berasain, Carmen, E-mail: cberasain@unav.es; Latasa, María Ujue; Urtasun, Raquel; Goñi, Saioa; Elizalde, María; Garcia-Irigoyen, Oihane; Azcona, María [Division of Hepatology and Gene Therapy, CIMA, University of Navarra, Pamplona 31008 (Spain); Prieto, Jesús [Division of Hepatology and Gene Therapy, CIMA, University of Navarra, Pamplona 31008 (Spain); CIBERehd, University Clinic, University of Navarra, Pamplona 31080 (Spain); Ávila, Matías A. [Division of Hepatology and Gene Therapy, CIMA, University of Navarra, Pamplona 31008 (Spain)

    2011-05-18

    Hepatocarcinogenesis is a complex multistep process in which many different molecular pathways have been implicated. Hepatocellular carcinoma (HCC) is refractory to conventional chemotherapeutic agents, and the new targeted therapies are meeting with limited success. Interreceptor crosstalk and the positive feedback between different signaling systems are emerging as mechanisms of targeted therapy resistance. The identification of such interactions is therefore of particular relevance to improve therapeutic efficacy. Among the different signaling pathways activated in hepatocarcinogenesis the epidermal growth factor receptor (EGFR) system plays a prominent role, being recognized as a “signaling hub” where different extracellular growth and survival signals converge. EGFR can be transactivated in response to multiple heterologous ligands through the physical interaction with multiple receptors, the activity of intracellular kinases or the shedding of EGFR-ligands. In this article we review the crosstalk between the EGFR and other signaling pathways that could be relevant to liver cancer development and treatment.

  5. Redox-dependent regulation of epidermal growth factor receptor signaling

    Directory of Open Access Journals (Sweden)

    David E. Heppner

    2016-08-01

    Full Text Available Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR, a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway.

  6. Evidence that adiponectin receptor 1 activation exacerbates ischemic neuronal death

    Directory of Open Access Journals (Sweden)

    Thundyil John

    2010-08-01

    Full Text Available Abstract Background- Adiponectin is a hormone produced in and released from adipose cells, which has been shown to have anti-diabetic and anti-inflammatory actions in peripheral cells. Two cell surface adiponectin receptors (ADRs mediate the majority of the known biological actions of adiponectin. Thus far, ADR expression in the brain has been demonstrated in the arcuate and the paraventricular nucleus of hypothalamus, where its activation affects food intake. Recent findings suggest that levels of circulating adiponectin increase after an ischemic stroke, but the role of adiponectin receptor activation in stroke pathogenesis and its functional outcome is unclear. Methods- Ischemic stroke was induced in C57BL/6 mice by middle cerebral artery occlusion (MCAO for 1 h, followed by reperfusion. Primary cortical neuronal cultures were established from individual embryonic neocortex. For glucose deprivation (GD, cultured neurons were incubated in glucose-free Locke's medium for 6, 12 or 24 h. For combined oxygen and glucose deprivation (OGD, neurons were incubated in glucose-free Locke's medium in an oxygen-free chamber with 95% N2/5% CO2 atmosphere for either 3, 6, 9, 12 or 24 h. Primary neurons and brain tissues were analysed for Adiponectin and ADRs using reverse transcriptase polymerase chain reaction (RT-PCR, immunoblot and immunochemistry methods. Results- Cortical neurons express ADR1 and ADR2, and that the levels of ADR1 are increased in neurons in response to in vitro or in vivo ischemic conditions. Neurons treated with either globular or trimeric adiponectin exhibited increased vulnerability to oxygen and glucose deprivation which was associated with increased activation of a pro-apoptotic signaling cascade involving p38 mitogen-activated protein kinase (p38MAPK and AMP-activated protein kinase (AMPK. Conclusions- This study reveals a novel pathogenic role for adiponectin and adiponectin receptor activation in ischemic stroke. We show that

  7. STUDIES ON THE HDL RECEPTORS I:EVIDENCE FOR THE EXISTENCE OF HDL RECEPTORS IN BEIJING DUCK LIVER

    Institute of Scientific and Technical Information of China (English)

    武须军; 王克勤

    1994-01-01

    It hab been found that Beijing ducks (BD)have a high level of HDL(70%),high LCAT but very low CETP activity and will not develop atheroscletosis on an atherogenic diet,suggesting that cholesterol ester is mainly carried by HDL and metabolized through an HDL receptor pathway in the liver.However,evidence of this recep-tor′s existence in the liver is not yet complete.In this paper,the HDL receptor in BD liver has been studied.Our experiments showed:1)ApoE-free 125I-HDL could bind specifically to duck hepatic cell membrane with high affinity (Kd=9.6 μg/ml)and was saturable(Bmax=8.9μg/mg cell membrane protein)at room temperature.2)Competitive inhibition studies with unlabelled duck,human,rat and chick HDL and duck apo AI and its lipo-somes formed with PC or DMPC could inhibit the binding of 125I-HDL to duck hepatic cell membranes,but LDL,apo Eand their liposomes with PC or DMPC could not with the exception of duck LDL.3)The receptor could rec-ognize apo AI but not apo B or E.4)Both phosphorase A2 and pronase could inhibit the binding activity.The above results give strong evidence for the existence of a specific HLD receptor pathway in the duck liver,support-ing our hypothesis that CE in Beijing ducks is metabolized directly through the hepatic HDL receptor instead of be-ing transfered back to VLDL and LDL,then through the LDL receptor pathway.This unique way of metabolizing CE may be behind the Beijing duck′s antiatherogenicity.

  8. Bayes factor design analysis: Planning for compelling evidence.

    Science.gov (United States)

    Schönbrodt, Felix D; Wagenmakers, Eric-Jan

    2017-03-01

    A sizeable literature exists on the use of frequentist power analysis in the null-hypothesis significance testing (NHST) paradigm to facilitate the design of informative experiments. In contrast, there is almost no literature that discusses the design of experiments when Bayes factors (BFs) are used as a measure of evidence. Here we explore Bayes Factor Design Analysis (BFDA) as a useful tool to design studies for maximum efficiency and informativeness. We elaborate on three possible BF designs, (a) a fixed-n design, (b) an open-ended Sequential Bayes Factor (SBF) design, where researchers can test after each participant and can stop data collection whenever there is strong evidence for either [Formula: see text] or [Formula: see text], and (c) a modified SBF design that defines a maximal sample size where data collection is stopped regardless of the current state of evidence. We demonstrate how the properties of each design (i.e., expected strength of evidence, expected sample size, expected probability of misleading evidence, expected probability of weak evidence) can be evaluated using Monte Carlo simulations and equip researchers with the necessary information to compute their own Bayesian design analyses.

  9. Basic Pharmacological and Structural Evidence for Class A G-Protein-Coupled Receptor Heteromerization

    Science.gov (United States)

    Franco, Rafael; Martínez-Pinilla, Eva; Lanciego, José L.; Navarro, Gemma

    2016-01-01

    Cell membrane receptors rarely work on isolation, often they form oligomeric complexes with other receptor molecules and they may directly interact with different proteins of the signal transduction machinery. For a variety of reasons, rhodopsin-like class A G-protein-coupled receptors (GPCRs) seem an exception to the general rule of receptor–receptor direct interaction. In fact, controversy surrounds their potential to form homo- hetero-dimers/oligomers with other class A GPCRs; in a sense, the field is going backward instead of forward. This review focuses on the convergent, complementary and telling evidence showing that homo- and heteromers of class A GPCRs exist in transfected cells and, more importantly, in natural sources. It is time to decide between questioning the occurrence of heteromers or, alternatively, facing the vast scientific and technical challenges that class A receptor-dimer/oligomer existence pose to Pharmacology and to Drug Discovery. PMID:27065866

  10. Histamine homologues discriminating between two functional H3 receptor assays. Evidence for H3 receptor heterogeneity?.

    Science.gov (United States)

    Leurs, R; Kathmann, M; Vollinga, R C; Menge, W M; Schlicker, E; Timmerman, H

    1996-03-01

    We studied several histamine homologues as potential ligands for the histamine H3 receptor in two binding assays ([125l]iodophenpropit and N alpha-[3H]methylhistamine binding to rat brain cortex membranes) and two functional H3 receptor models (inhibition of the neurogenic contraction in the guinea pig jejunum and of [3H]noradrenaline release in mouse brain cortex slices). The histamine homologues acted all as competitive H3 antagonists at the guinea pig jejunum. The potency in this model and/or the affinity for N alpha-[3H]methylhistamine binding was higher for the butylene (pA2 = 7.7; pKi = 9.4) and pentylene homologue (impentamine, pA2 = 8.4; pKi = 9.1) than for the propylene, hexylene and octylene homologues (pA2 = 5.9-7.8; pKi = 6.1-7.6). In the mouse brain cortex the propylene, butylene and pentylene homologues acted as partial agonists (alpha = 0.3-0.6) and the hexylene and octylene homologues acted as antagonists. [125I]Iodophenpropit binding was displaced monophasically by the propylene, hexylene and octylene homologues and biphasically by the butylene and pentylene homologues. Biphasic displacement curves were converted to monophasic ones by 10 microM guanosine-5'-O-(3-thiotriphosphate. In conclusion, the homologue of histamine with five methylene groups is a more potent H3 receptor antagonist in the guinea pig jejunum than the other homologues tested. Furthermore, the propylene, butylene and pentylene homologues can discriminate between the two functional H3 receptor models in the guinea pig jejunum and mouse brain. These data are discussed in relation to the efficiency of receptor coupling and receptor heterogeneity.

  11. EXPRESSION OF GROWTH-FACTORS AND GROWTH-FACTOR RECEPTORS IN NORMAL AND TUMOROUS HUMAN THYROID TISSUES

    NARCIS (Netherlands)

    van der Laan, B.F.A.M.; FREEMAN, JL; ASA, SL

    1995-01-01

    A number of growth factors have been implicated as stimuli of thyroid cell proliferation; overexpression of these growth factors and/or their receptors may play a role in the growth of thyroid tumors. To determine if immunohistochemical detection of growth factors and/or their receptors correlates w

  12. Augmentation of radiation response by motesanib, a multikinase inhibitor that targets vascular endothelial growth factor receptors.

    NARCIS (Netherlands)

    Kruser, T.J.; Wheeler, D.L.; Armstrong, E.A.; Iida, M.; Kozak, K.R.; Kogel, A.J. van der; Bussink, J.; Coxon, A.; Polverino, A.; Harari, P.M.

    2010-01-01

    BACKGROUND: Motesanib is a potent inhibitor of vascular endothelial growth factor receptors (VEGFR) 1, 2, and 3, platelet-derived growth factor receptor, and Kit receptors. In this report we examine the interaction between motesanib and radiation in vitro and in head and neck squamous cell carcinoma

  13. Regulation of growth factor receptor degradation by ADP-ribosylation factor domain protein (ARD) 1.

    Science.gov (United States)

    Meza-Carmen, Victor; Pacheco-Rodriguez, Gustavo; Kang, Gi Soo; Kato, Jiro; Donati, Chiara; Zhang, Chun-Yi; Vichi, Alessandro; Payne, D Michael; El-Chemaly, Souheil; Stylianou, Mario; Moss, Joel; Vaughan, Martha

    2011-06-28

    ADP-ribosylation factor domain protein 1 (ARD1) is a 64-kDa protein containing a functional ADP-ribosylation factor (GTP hydrolase, GTPase), GTPase-activating protein, and E3 ubiquitin ligase domains. ARD1 activation by the guanine nucleotide-exchange factor cytohesin-1 was known. GTPase and E3 ligase activities of ARD1 suggest roles in protein transport and turnover. To explore this hypothesis, we used mouse embryo fibroblasts (MEFs) from ARD1-/- mice stably transfected with plasmids for inducible expression of wild-type ARD1 protein (KO-WT), or ARD1 protein with inactivating mutations in E3 ligase domain (KO-E3), or containing persistently active GTP-bound (KO-GTP), or inactive GDP-bound (KO-GDP) GTPase domains. Inhibition of proteasomal proteases in mifepristone-induced KO-WT, KO-GDP, or KO-GTP MEFs resulted in accumulation of these ARD1 proteins, whereas KO-E3 accumulated without inhibitors. All data were consistent with the conclusion that ARD1 regulates its own steady-state levels in cells by autoubiquitination. Based on reported growth factor receptor-cytohesin interactions, EGF receptor (EGFR) was investigated in induced MEFs. Amounts of cell-surface and total EGFR were higher in KO-GDP and lower in KO-GTP than in KO-WT MEFs, with levels in both mutants greater (p = 0.001) after proteasomal inhibition. Significant differences among MEF lines in content of TGF-β receptor III were similar to those in EGFR, albeit not as large. Differences in amounts of insulin receptor mirrored those in EGFR, but did not reach statistical significance. Overall, the capacity of ARD1 GTPase to cycle between active and inactive forms and its autoubiquitination both appear to be necessary for the appropriate turnover of EGFR and perhaps additional growth factor receptors.

  14. A genome-wide association study of emotion dysregulation: Evidence for interleukin 2 receptor alpha.

    Science.gov (United States)

    Powers, Abigail; Almli, Lynn; Smith, Alicia; Lori, Adriana; Leveille, Jen; Ressler, Kerry J; Jovanovic, Tanja; Bradley, Bekh

    2016-12-01

    Emotion dysregulation has been implicated as a risk factor for many psychiatric conditions. Therefore, examining genetic risk associated with emotion dysregulation could help inform cross-disorder risk more generally. A genome-wide association study (GWAS) of emotion dysregulation using single nucleotide polymorphism (SNP) array technology was conducted in a highly traumatized, minority, urban sample (N = 2600, males = 774). Post-hoc analyses examined associations between SNPs identified in the GWAS and current depression, posttraumatic stress disorder (PTSD), and history of suicide attempt. Methylation quantitative trait loci were identified and gene set enrichment analyses were used to broadly determine biological processes involved with these SNPs. Among males, SNP rs6602398, located within the interleukin receptor 2A gene, IL2RA, was significantly associated with emotion dysregulation (p = 1.1 × 10(-8)). Logistic regression analyses revealed this SNP was significantly associated with depression (Exp(B) = 2.67, p < 0.001) and PTSD (Exp(B) = 2.07, p < 0.01). This SNP was associated with differential DNA methylation (p < 0.05) suggesting it may be functionally active. Finally, through gene set enrichment analyses, ten psychiatric disease pathways (adjusted p < 0.01) and the calcium signaling pathway (adjusted p = 0.008) were significantly associated with emotion dysregulation. We found initial evidence for an association between emotion dysregulation and genetic risk loci that have already been implicated in medical disorders that have high comorbidity with psychiatric disorders. Our results provide further evidence that emotion dysregulation can be understood as a potential psychiatric cross-disorder risk factor, and that sex differences across these phenotypes may be critical. Continued research into genetic and biological risk associated with emotion dysregulation is needed.

  15. Implication of platelet-derived growth factor receptor alpha in prostate cancer skeletal metastasis

    Institute of Scientific and Technical Information of China (English)

    Qingxin Liu; Danielle Jernigan; Yun Zhang; Alessandro Fatatis

    2011-01-01

    Metastasis represents by far the most feared complication of prostate carcinoma and is the main cause of death for patients.The skeleton is frequently targeted by disseminated cancer cells andrepresents the sole site of spread in more than 80% of prostate cancer cases.Compatibility between select malignant phenotypes and the microenvironment of colonized tissues is broadly recognized as the culprit for the organ-tropism of cancer cells.Here,we review our recent studies showing that the expression of platelet-derived growth factor receptor alpha (PDGFRα) supports the survival and growth of prostate cancer cells in the skeleton and that the soluble fraction of bone marrow activates PDGFRα in a ligand-independent fashion.Finally,we offer pre-clinical evidence that this receptor is a viable target for therapy.

  16. Polychlorinated Biphenyls Disrupt Hepatic Epidermal Growth Factor Receptor Signaling.

    Science.gov (United States)

    Hardesty, Josiah E; Wahlang, Banrida; Falkner, K Cameron; Clair, Heather B; Clark, Barbara J; Ceresa, Brian P; Prough, Russell A; Cave, Matthew C

    2016-07-26

    1. Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that disrupt hepatic xenobiotic and intermediary metabolism, leading to metabolic syndrome and nonalcoholic steatohepatitis (NASH). 2. Since phenobarbital indirectly activates Constitutive Androstane Receptor (CAR) by antagonizing growth factor binding to the epidermal growth factor receptor (EGFR), we hypothesised that PCBs may also diminish EGFR signaling. 3. The effects of the PCB mixture Aroclor 1260 on the protein phosphorylation cascade triggered by EGFR activation were determined in murine (in vitro and in vivo) and human models (in vitro). EGFR tyrosine residue phosphorylation was decreased by PCBs in all models tested. 4. The IC50 values for Aroclor 1260 concentrations that decreased Y1173 phosphorylation of EGFR were similar in murine AML-12 and human HepG2 cells (∼2-4 μg/mL). Both dioxin and non-dioxin-like PCB congeners decreased EGFR phosphorylation in cell culture. 5. PCB treatment reduced phosphorylation of downstream EGFR effectors including Akt and mTOR, as well as other phosphoprotein targets including STAT3 and c-RAF in vivo. 6. PCBs diminish EGFR signaling in human and murine hepatocyte models and may dysregulate critical phosphoprotein regulators of energy metabolism and nutrition, providing a new mechanism of action in environmental diseases.

  17. Factors that influence effective evidence-based medicine instruction.

    Science.gov (United States)

    Mi, Misa

    2013-01-01

    Evidence-based medicine (EBM) as a health care practice is being incorporated into education programs across the spectrum of medical education to develop lifelong learning skills and to enhance the practice of evidence-based health care. Since improving the quality of patient care is the ultimate goal of EBM, EBM learning must be integrated with clinical application, and resulted outcomes must be reflected in learning transfer (or EBM practice) within the context of solving patient problems. Different factors may constitute the context or environment in which EBM is learned, practiced, and sustained. However, these contextual factors are seldom considered and examined in the development, implementation, and evaluation of EBM instruction for learners at different levels. This article will introduce several contextual factors as tips and strategies that affect EBM learning and transfer. Also included in the article are recommended practices for designing effective EBM instruction that would contribute to a sustainable change in learner behavior.

  18. Fibroblast Growth Factor 10-Fibroblast Growth Factor Receptor 2b Mediated Signaling Is Not Required for Adult Glandular Stomach Homeostasis

    Science.gov (United States)

    Sala, Frederic G.; Ford, Henri R.; Bellusci, Saverio; Grikscheit, Tracy C.

    2012-01-01

    The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10) and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b), in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22) except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis. PMID:23133671

  19. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Directory of Open Access Journals (Sweden)

    Allison L Speer

    Full Text Available The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10 and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b, in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22 except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  20. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Science.gov (United States)

    Speer, Allison L; Al Alam, Denise; Sala, Frederic G; Ford, Henri R; Bellusci, Saverio; Grikscheit, Tracy C

    2012-01-01

    The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10) and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b), in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22) except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  1. Exchange factors directly activated by cAMP mediate melanocortin 4 receptor-induced gene expression

    Science.gov (United States)

    Glas, Evi; Mückter, Harald; Gudermann, Thomas; Breit, Andreas

    2016-01-01

    Gs protein-coupled receptors regulate many vital body functions by activation of cAMP response elements (CRE) via cAMP-dependent kinase A (PKA)-mediated phosphorylation of the CRE binding protein (CREB). Melanocortin 4 receptors (MC4R) are prototypical Gs-coupled receptors that orchestrate the hypothalamic control of food-intake and metabolism. Remarkably, the significance of PKA for MC4R-induced CRE-dependent transcription in hypothalamic cells has not been rigorously interrogated yet. In two hypothalamic cell lines, we observed that blocking PKA activity had only weak or no effects on reporter gene expression. In contrast, inhibitors of exchange factors directly activated by cAMP-1/2 (EPAC-1/2) mitigated MC4R-induced CRE reporter activation and mRNA induction of the CREB-dependent genes c-fos and thyrotropin-releasing hormone. Furthermore, we provide first evidence that extracellular-regulated kinases-1/2 (ERK-1/2) activated by EPACs and not PKA are the elusive CREB kinases responsible for MC4R-induced CREB/CRE activation in hypothalamic cells. Overall, these data emphasize the pivotal role of EPACs rather than PKA in hypothalamic gene expression elicited by a prototypical Gs-coupled receptor. PMID:27612207

  2. Evidence for functional P2X4/P2X7 heteromeric receptors.

    Science.gov (United States)

    Guo, Chang; Masin, Marianela; Qureshi, Omar S; Murrell-Lagnado, Ruth D

    2007-12-01

    The cytolytic ionotropic ATP receptor P2X7 has several important roles in immune cell regulation, such as cytokine release, apoptosis, and microbial killing. Although P2X7 receptors are frequently coexpressed with another subtype of P2X receptor, P2X4, they are believed not to form heteromeric assemblies but to function only as homomers. Both receptors play a role in neuropathic pain; therefore, understanding how they coordinate the cellular response to ATP is important for the development of effective pain therapies. Here, we provide biochemical and electrophysiological evidence for an association between P2X4 and P2X7 that increases the diversity of receptor currents mediated via these two subtypes. The heterologously expressed receptors were coimmunoprecipitated from human embryonic kidney (HEK) 293 cells, and the endogenous P2X4 and P2X7 receptors were similarly coimmunoprecipitated from bone marrow-derived macrophages. In HEK293 cells, the fraction of P2X4 receptors biotinylated at the plasma membrane increased 2-fold in the presence of P2X7 although there was no change in overall expression. Coexpression of a dominant-negative P2X4 mutant (C353W) with P2X7, inhibited P2X7 receptor mediated currents by greater than 2-fold, whereas a nonfunctional but non-dominant-negative mutant (S341W) did not. Coexpression of P2X4S341W with P2X7 produced a current that was potentiated by ivermectin and inhibited by 2',3'-O-(2,4,6-trinitrophenyl) adenosine 5-triphosphate (TNP-ATP), whereas expression of P2X7 alone produced a current that was insensitive to both of these compounds at the concentrations used. These results demonstrate a structural and functional interaction between P2X4 and P2X7, which suggests that they associate to form heteromeric receptors.

  3. Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor

    DEFF Research Database (Denmark)

    Kristensen, T; Moestrup, Søren Kragh; Gliemann, Jørgen;

    1990-01-01

    these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J......The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from...

  4. Evidence for expression of melanocortin-1 receptor in human sebocytes in vitro and in situ.

    Science.gov (United States)

    Böhm, Markus; Schiller, Meinhard; Ständer, Sonja; Seltmann, Holger; Li, Zhuo; Brzoska, Thomas; Metze, Dieter; Schiöth, Helgi B; Skottner, Anna; Seiffert, Kristina; Zouboulis, Christos C; Luger, Thomas A

    2002-03-01

    Many lines of evidence indicate that the activity of sebaceous glands can be modulated by neuropeptides. Direct evidence in man, however, is still missing. We show that SZ95 sebocytes, an immortalized human sebaceous gland cell line, express receptors for alpha-melanocyte-stimulating hormone. Reverse transcription polymerase chain reaction with primers against the five melanocortin receptors and immunofluorescence studies using an antibody directed against a peptide corresponding to the amino acids 2-18 of the human melanocortin-1 receptor disclosed specific transcripts and immunoreactivity for melanocortin-1 receptor in these cells. Melanocortin-1 receptor expression was confirmed in sebocytes of normal human skin by immunohistochemistry. In contrast, no immunostaining for the melanocortin-5 receptor could be detected in sebocytes in situ, in accordance with the lack of specific transcripts for this melanocortin receptor in SZ95 sebocytes. As cytokines play an important role in the recruitment of inflammatory cells in acne and related disorders and alpha-melanocyte-stimulating hormone exerts immunomodulatory effects in many other cell types, we investigated the effect of alpha-melanocyte-stimulating hormone on interleukin-8 secretion by SZ95 sebocytes. Treatment with interleukin-1beta resulted in a marked increase in interleukin-8 release that was partially blocked by coincubation with alpha-melanocyte-stimulating hormone in a dose-dependent manner. Taken together, we show here that the melanocortin-1 receptor is expressed in vitro and in situ in human sebocytes. By modulating interleukin-8 secretion, alpha-melanocyte-stimulating hormone may act as a modulator of inflammatory responses in the pilosebaceous unit.

  5. 2013 Nutrition Risk Evidence Review Panel. Evidence Review for: The Risk Factor of Inadequate Nutrition

    Science.gov (United States)

    2014-01-01

    The 2013 Nutrition Risk Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on November 20 - 21, 2013. The SRP reviewed the new Evidence Report for the Risk Factor of Inadequate Nutrition (from here on referred to as the 2013 Nutrition Evidence Report), as well as the Research Plan for this Risk. Overall, the SRP thinks the well-qualified research team has compiled an excellent summary of background information in the 2013 Nutrition Evidence Report. The SRP would like to commend the authors in general and particularly note that while the 2013 Nutrition Evidence Report has been written using a single nutrient approach, the research plan takes a much more integrated and physiologically based approach.

  6. Thyroid hormones regulate fibroblast growth factor receptor signaling during chondrogenesis.

    Science.gov (United States)

    Barnard, Joanna C; Williams, Allan J; Rabier, Bénédicte; Chassande, Olivier; Samarut, Jacques; Cheng, Sheue-Yann; Bassett, J H Duncan; Williams, Graham R

    2005-12-01

    Childhood hypothyroidism causes growth arrest with delayed ossification and growth-plate dysgenesis, whereas thyrotoxicosis accelerates ossification and growth. Thyroid hormone (T(3)) regulates chondrocyte proliferation and is essential for hypertrophic differentiation. Fibroblast growth factors (FGFs) are also important regulators of chondrocyte proliferation and differentiation, and activating mutations of FGF receptor-3 (FGFR3) cause achondroplasia. We investigated the hypothesis that T(3) regulates chondrogenesis via FGFR3 in ATDC5 cells, which undergo a defined program of chondrogenesis. ATDC5 cells expressed two FGFR1, four FGFR2, and one FGFR3 mRNA splice variants throughout chondrogenesis, and expression of each isoform was stimulated by T(3) during the first 6-12 d of culture, when T(3) inhibited proliferation by 50%. FGFR3 expression was also increased in cells treated with T(3) for 21 d, when T(3) induced an earlier onset of hypertrophic differentiation and collagen X expression. FGFR3 expression was reduced in growth plates from T(3) receptor alpha-null mice, which exhibit skeletal hypothyroidism, but was increased in T(3) receptor beta(PV/PV) mice, which display skeletal thyrotoxicosis. These findings indicate that FGFR3 is a T(3)-target gene in chondrocytes. In further experiments, T(3) enhanced FGF2 and FGF18 activation of the MAPK-signaling pathway but inhibited their activation of signal transducer and activator of transcription-1. FGF9 did not activate MAPK or signal transducer and activator of transcription-1 pathways in the absence or presence of T(3). Thus, T(3) exerted differing effects on FGFR activation during chondrogenesis depending on which FGF ligand stimulated the FGFR and which downstream signaling pathway was activated. These studies identify novel interactions between T(3) and FGFs that regulate chondrocyte proliferation and differentiation during chondrogenesis.

  7. Epidermal Growth Factor Receptor Cell Survival Signaling Requires Phosphatidylcholine Biosynthesis

    Directory of Open Access Journals (Sweden)

    Matt Crook

    2016-11-01

    Full Text Available Identification of pro-cell survival signaling pathways has implications for cancer, cardiovascular, and neurodegenerative disease. We show that the Caenorhabditis elegans epidermal growth factor receptor LET-23 (LET-23 EGFR has a prosurvival function in counteracting excitotoxicity, and we identify novel molecular players required for this prosurvival signaling. uv1 sensory cells in the C. elegans uterus undergo excitotoxic death in response to activation of the OSM-9/OCR-4 TRPV channel by the endogenous agonist nicotinamide. Activation of LET-23 EGFR can effectively prevent this excitotoxic death. We investigate the roles of signaling pathways known to act downstream of LET-23 EGFR in C. elegans and find that the LET-60 Ras/MAPK pathway, but not the IP3 receptor pathway, is required for efficient LET-23 EGFR activity in its prosurvival function. However, activation of LET-60 Ras/MAPK pathway does not appear to be sufficient to fully mimic LET-23 EGFR activity. We screen for genes that are required for EGFR prosurvival function and uncover a role for phosphatidylcholine biosynthetic enzymes in EGFR prosurvival function. Finally, we show that exogenous application of phosphatidylcholine is sufficient to prevent some deaths in this excitotoxicity model. Our work implicates regulation of lipid synthesis downstream of EGFR in cell survival and death decisions.

  8. Epidermal Growth Factor Receptor in Prostate Cancer Derived Exosomes.

    Directory of Open Access Journals (Sweden)

    Geetanjali Kharmate

    Full Text Available Exosomes proteins and microRNAs have gained much attention as diagnostic tools and biomarker potential in various malignancies including prostate cancer (PCa. However, the role of exosomes and membrane-associated receptors, particularly epidermal growth factor receptor (EGFR as mediators of cell proliferation and invasion in PCa progression remains unexplored. EGFR is frequently overexpressed and has been associated with aggressive forms of PCa. While PCa cells and tissues express EGFR, it is unknown whether exosomes derived from PCa cells or PCa patient serum contains EGFR. The aim of this study was to detect and characterize EGFR in exosomes derived from PCa cells, LNCaP xenograft and PCa patient serum. Exosomes were isolated from conditioned media of different PCa cell lines; LNCaP xenograft serum as well as patient plasma/serum by differential centrifugation and ultracentrifugation on a sucrose density gradient. Exosomes were confirmed by electron microscopy, expression of exosomal markers and NanoSight™ analysis. EGFR expression was determined by western blot analysis and ELISA. This study demonstrates that exosomes may easily be derived from PCa cell lines, serum obtained from PCa xenograft bearing mice and clinical samples derived from PCa patients. Presence of exosomal EGFR in PCa patient exosomes may present a novel approach for measuring of the disease state. Our work will allow to build on this finding for future understanding of PCa exosomes and their potential role in PCa progression and as minimal invasive biomarkers for PCa.

  9. Glucocorticoids and atrial natriuretic factor receptors on vascular smooth muscle.

    Science.gov (United States)

    Yasunari, K; Kohno, M; Murakawa, K; Yokokawa, K; Takeda, T

    1990-11-01

    The effect of glucocorticoids on the atrial natriuretic factor (ANF)-mediated formation of cyclic guanosine monophosphate (cGMP) by intact vascular smooth muscle cells (VSMC) was studied in rats. Cultured VSMC were obtained from the renal arteries of 14-week-old Wistar rats by the explant method. Micromolar concentrations of dexamethasone, given as pretreatment for 48 hours, suppressed the ANF-mediated response. The dexamethasone-induced suppression was detectable at 6 hours and reached a maximum 24 hours after administration in a dose-dependent manner. Inhibitors of protein synthesis blocked this effect of the glucocorticoid. The basal activity of guanylate cyclase in the dexamethasone-treated cells was lower than in the control cells. Other steroids having glucocorticoid action mimicked this suppression of the ANF-mediated response. This suppression was blocked by a glucocorticoid receptor antagonist. The results suggest that glucocorticoids suppress ANF-mediated cGMP formation by VSMC through glucocorticoid type II receptors and the induction of protein synthesis. Suppression of the ANF-mediated response may play a role in glucocorticoid-induced hypertension.

  10. Unbanked Households: Evidence of Supply-Side Factors

    OpenAIRE

    Matray , Adrien; Celerier , Claire

    2014-01-01

    This paper provides evidence that supply-side factors significantly drive the high share of unbanked households. Using interstate branching deregulation in the U.S. after 1994 as an exogenous shock, the authors show that an increase in bank competition is associated with a large drop in the share of unbanked households. The authors find that the effect is even stronger for populations that are more likely to be rationed by banks, such as black households living in "high racial bias'' states. ...

  11. Expression of epidermal growth factor receptors in human endometrial carcinoma

    DEFF Research Database (Denmark)

    Nyholm, H C; Nielsen, Anette Lynge; Ottesen, B

    1993-01-01

    Little data exist on the expression of epidermal growth factor receptors (EGF-Rs) in human endometrial cancer. EGF-R status was studied in 65 patients with endometrial carcinomas and in 26 women with nonmalignant postmenopausal endometria, either inactive/atrophic endometrium or adenomatous...... hyperplasia. EGF-R was identified on frozen tissue sections by means of an indirect immunoperoxidase technique with a monoclonal antibody against the external domain of the EGF-R. Seventy-one percent of the carcinomas expressed positive EGF-R immunoreactivity. In general, staining was most prominent....../inactive endometria and seven of 13 (54%) endometria with adenomatous hyperplasia were EGF-R positive, with an immunostaining pattern rather similar to that of the carcinomas....

  12. Cannabinoids go nuclear: evidence for activation of peroxisome proliferator-activated receptors

    Science.gov (United States)

    O'Sullivan, S E

    2007-01-01

    Cannabinoids act at two classical cannabinoid receptors (CB1 and CB2), a 7TM orphan receptor and the transmitter-gated channel transient receptor potential vanilloid type-1 receptor. Recent evidence also points to cannabinoids acting at members of the nuclear receptor family, peroxisome proliferator-activated receptors (PPARs, with three subtypes α, β (δ) and γ), which regulate cell differentiation and lipid metabolism. Much evidence now suggests that endocannabinoids are natural activators of PPARα. Oleoylethanolamide regulates feeding and body weight, stimulates fat utilization and has neuroprotective effects mediated through activation of PPARα. Similarly, palmitoylethanolamide regulates feeding and lipid metabolism and has anti-inflammatory properties mediated by PPARα. Other endocannabinoids that activate PPARα include anandamide, virodhamine and noladin. Some (but not all) endocannabinoids also activate PPARγ; anandamide and 2-arachidonoylglycerol have anti-inflammatory properties mediated by PPARγ. Similarly, ajulemic acid, a structural analogue of a metabolite of Δ9-tetrahydrocannabinol (THC), causes anti-inflammatory effects in vivo through PPARγ. THC also activates PPARγ, leading to a time-dependent vasorelaxation in isolated arteries. Other cannabinoids which activate PPARγ include N-arachidonoyl-dopamine, HU210, WIN55212-2 and CP55940. In contrast, little research has been carried out on the effects of cannabinoids at PPARδ. In this newly emerging area, a number of research questions remain unanswered; for example, why do cannabinoids activate some isoforms and not others? How much of the chronic effects of cannabinoids are through activation of nuclear receptors? And importantly, do cannabinoids confer the same neuro- and cardioprotective benefits as other PPARα and PPARγ agonists? This review will summarize the published literature implicating cannabinoid-mediated PPAR effects and discuss the implications thereof. PMID:17704824

  13. Nod factor receptors form heteromeric complexes and are essential for intracellular infection in Medicago nodules

    NARCIS (Netherlands)

    Moling, S.; Pietraszewska-Bogiel, A.; Postma, M.; Fedorova, E.E.; Hink, M.A.; Limpens, E.H.M.; Gadella, T.W.J.; Bisseling, T.

    2014-01-01

    Rhizobial Nod factors are the key signaling molecules in the legume-rhizobium nodule symbiosis. In this study, the role of the Nod factor receptors NOD FACTOR PERCEPTION (NFP) and LYSIN MOTIF RECEPTOR-LIKE KINASE3 (LYK3) in establishing the symbiotic interface in root nodules was investigated. It wa

  14. Nod factor receptors form heteromeric complexes and are essential for intracellular infection in medicago nodules

    NARCIS (Netherlands)

    Moling, S.; Pietraszewska-Bogiel, A.; Postma, M.; Fedorova, E.; Hink, M.A.; Limpens, E.; Gadella, T.W.J.; Bisseling, T.

    2014-01-01

    Rhizobial Nod factors are the key signaling molecules in the legume-rhizobium nodule symbiosis. In this study, the role of the Nod factor receptors NOD FACTOR PERCEPTION (NFP) and LYSIN MOTIF RECEPTOR-LIKE KINASE3 (LYK3) in establishing the symbiotic interface in root nodules was investigated. It wa

  15. Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

    Science.gov (United States)

    Zhang, Mingdi; Cai, Shizhong; Zuo, Bin; Gong, Wei; Tang, Zhaohui; Zhou, Di; Weng, Mingzhe; Qin, Yiyu; Wang, Shouhua; Liu, Jun; Ma, Fei; Quan, Zhiwei

    2017-05-01

    Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

  16. Nuclear functions and subcellular trafficking mechanisms of the epidermal growth factor receptor family

    Science.gov (United States)

    2012-01-01

    Accumulating evidence suggests that various diseases, including many types of cancer, result from alteration of subcellular protein localization and compartmentalization. Therefore, it is worthwhile to expand our knowledge in subcellular trafficking of proteins, such as epidermal growth factor receptor (EGFR) and ErbB-2 of the receptor tyrosine kinases, which are highly expressed and activated in human malignancies and frequently correlated with poor prognosis. The well-characterized trafficking of cell surface EGFR is routed, via endocytosis and endosomal sorting, to either the lysosomes for degradation or back to the plasma membrane for recycling. A novel nuclear mode of EGFR signaling pathway has been gradually deciphered in which EGFR is shuttled from the cell surface to the nucleus after endocytosis, and there, it acts as a transcriptional regulator, transmits signals, and is involved in multiple biological functions, including cell proliferation, tumor progression, DNA repair and replication, and chemo- and radio-resistance. Internalized EGFR can also be transported from the cell surface to several intracellular compartments, such as the Golgi apparatus, the endoplasmic reticulum, and the mitochondria, in addition to the nucleus. In this review, we will summarize the functions of nuclear EGFR family and the potential pathways by which EGFR is trafficked from the cell surface to a variety of cellular organelles. A better understanding of the molecular mechanism of EGFR trafficking will shed light on both the receptor biology and potential therapeutic targets of anti-EGFR therapies for clinical application. PMID:22520625

  17. Stabilization of the bioactivity of tumor necrosis factor by its soluble receptors

    DEFF Research Database (Denmark)

    Aderka, D; Engelmann, H; Maor, Y;

    1992-01-01

    activity; at high concentrations, the sTNF-Rs indeed inhibit TNF effects. However, we report here that in the presence of low concentrations of the sTNF-Rs, effects of TNF whose induction depend on prolonged treatment with this cytokine are augmented, reflecting an attenuation by the sTNF-Rs of spontaneous......The receptors for tumor necrosis factor (TNF) exist in cell-associated as well as soluble forms, both binding specifically to TNF. Since the soluble forms of TNF receptors (sTNF-Rs) can compete with the cell-associated TNF receptors for TNF, it was suggested that they function as inhibitors of TNF...... TNF activity decay. Evidence that this stabilization of TNF activity by the sTNF-Rs follows from stabilization of TNF structure within the complexes that TNF forms with the sTNF-Rs is presented here, suggesting that the sTNF-Rs can affect TNF activity not only by interfering with its binding to cells...

  18. Orexin-corticotropin-releasing factor receptor heteromers in the ventral tegmental area as targets for cocaine.

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I; Ferré, Sergi; McCormick, Peter J

    2015-04-29

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R-OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R-OX1R heteromer. Cocaine binding to the σ1R-CRF1R-OX1R complex promotes a long-term disruption of the orexin-A-CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking.

  19. Nuclear functions and subcellular trafficking mechanisms of the epidermal growth factor receptor family

    Directory of Open Access Journals (Sweden)

    Wang Ying-Nai

    2012-04-01

    Full Text Available Abstract Accumulating evidence suggests that various diseases, including many types of cancer, result from alteration of subcellular protein localization and compartmentalization. Therefore, it is worthwhile to expand our knowledge in subcellular trafficking of proteins, such as epidermal growth factor receptor (EGFR and ErbB-2 of the receptor tyrosine kinases, which are highly expressed and activated in human malignancies and frequently correlated with poor prognosis. The well-characterized trafficking of cell surface EGFR is routed, via endocytosis and endosomal sorting, to either the lysosomes for degradation or back to the plasma membrane for recycling. A novel nuclear mode of EGFR signaling pathway has been gradually deciphered in which EGFR is shuttled from the cell surface to the nucleus after endocytosis, and there, it acts as a transcriptional regulator, transmits signals, and is involved in multiple biological functions, including cell proliferation, tumor progression, DNA repair and replication, and chemo- and radio-resistance. Internalized EGFR can also be transported from the cell surface to several intracellular compartments, such as the Golgi apparatus, the endoplasmic reticulum, and the mitochondria, in addition to the nucleus. In this review, we will summarize the functions of nuclear EGFR family and the potential pathways by which EGFR is trafficked from the cell surface to a variety of cellular organelles. A better understanding of the molecular mechanism of EGFR trafficking will shed light on both the receptor biology and potential therapeutic targets of anti-EGFR therapies for clinical application.

  20. Cloning the promoter for transforming growth factor-beta type III receptor. Basal and conditional expression in fetal rat osteoblasts

    Science.gov (United States)

    Ji, C.; Chen, Y.; McCarthy, T. L.; Centrella, M.

    1999-01-01

    Transforming growth factor-beta binds to three high affinity cell surface molecules that directly or indirectly regulate its biological effects. The type III receptor (TRIII) is a proteoglycan that lacks significant intracellular signaling or enzymatic motifs but may facilitate transforming growth factor-beta binding to other receptors, stabilize multimeric receptor complexes, or segregate growth factor from activating receptors. Because various agents or events that regulate osteoblast function rapidly modulate TRIII expression, we cloned the 5' region of the rat TRIII gene to assess possible control elements. DNA fragments from this region directed high reporter gene expression in osteoblasts. Sequencing showed no consensus TATA or CCAAT boxes, whereas several nuclear factors binding sequences within the 3' region of the promoter co-mapped with multiple transcription initiation sites, DNase I footprints, gel mobility shift analysis, or loss of activity by deletion or mutation. An upstream enhancer was evident 5' proximal to nucleotide -979, and a silencer region occurred between nucleotides -2014 and -2194. Glucocorticoid sensitivity mapped between nucleotides -687 and -253, whereas bone morphogenetic protein 2 sensitivity co-mapped within the silencer region. Thus, the TRIII promoter contains cooperative basal elements and dispersed growth factor- and hormone-sensitive regulatory regions that can control TRIII expression by osteoblasts.

  1. LysM domain receptor kinases regulating rhizobial Nod factor-induced infection

    NARCIS (Netherlands)

    Limpens, E.H.M.; Franken, C.L.; Smit, P.E.J.; Willemse, J.J.; Bisseling, T.; Geurts, R.

    2003-01-01

    The rhizobial infection of legumes has the most stringent demand toward Nod factor structure of all host responses, and therefore a specific Nod factor entry receptor has been proposed. The SYM2 gene identfied in certain ecotypes of pea (Pisum sativum) is a good candidate for such an entry receptor.

  2. Fibroblast growth factor receptor 3 protein is overexpressed in oral and oropharyngeal squamous cell carcinoma

    NARCIS (Netherlands)

    Koole, Koos; van Kempen, Pauline M W; Swartz, Justin E; Peeters, Ton; van Diest, Paul J; Koole, Ron; van Es, Robert J. J.; Willems, Stefan M

    Fibroblast growth factor receptor 3 (FGFR3) is a member of the fibroblast growth factor receptor tyrosine kinase family. It has been identified as a promising therapeutic target in multiple types of cancer. We have investigated FGFR3 protein expression and FGFR3 gene copy-numbers in a single

  3. Epidermal growth factor receptor-targeted antibody therapy - Mechanisms of action and modulators of therapeutic efficacy

    NARCIS (Netherlands)

    Lammerts van Bueren, Jeroen Jilles

    2008-01-01

    Cancer is an increasing disease in the world population, and in recent years there has been substantial interest in the development of novel therapeutic agents specifically targeting growth factor receptors on tumor cells. The epidermal growth factor receptor (EGFR) represents a tyrosine kinase cell

  4. Analysis of receptor signaling pathways by mass spectrometry: identification of vav-2 as a substrate of the epidermal and platelet-derived growth factor receptors

    DEFF Research Database (Denmark)

    Pandey, A; Podtelejnikov, A V; Blagoev, B;

    2000-01-01

    Oligomerization of receptor protein tyrosine kinases such as the epidermal growth factor receptor (EGFR) by their cognate ligands leads to activation of the receptor. Transphosphorylation of the receptor subunits is followed by the recruitment of signaling molecules containing src homology 2 (SH2...

  5. Expression of epidermal growth factor receptors in human brain tumors.

    Science.gov (United States)

    Libermann, T A; Razon, N; Bartal, A D; Yarden, Y; Schlessinger, J; Soreq, H

    1984-02-01

    The expression of receptors for epidermal growth factor (EGF-R) was determined in 29 samples of brain tumors from 22 patients. Primary gliogenous tumors, of various degrees of cancer, five meningiomas, and two neuroblastomas were examined. Tissue samples were frozen in liquid nitrogen immediately after the operation and stored at -70 degrees until use. Cerebral tissue samples from 11 patients who died from diseases not related to the central nervous system served as controls. Immunoprecipitation of functional EGF-R-kinase complexes revealed high levels of EGF-R in all of the brain tumors of nonneuronal origin that were examined. The level of EGF-R varied between tumors from different patients and also between specimens prelevated from different areas of the same tumor. In contrast, the levels of EGF-R from control specimens were invariably low. The biochemical properties of EGF-R in brain tumor specimens were found to be indistinguishable from those of the well-characterized EGF-R from the A-431 cell line, derived from human epidermoid carcinomas. Human brain EGF-R displays a molecular weight of 170,000 by polyacrylamide-sodium dodecyl sulfate gel electrophoresis. It is phosphorylated mainly in tyrosine residues and shows a 2-dimensional phosphopeptide map similar to that obtained with the phosphorylated EGF-R from membranes of A-431 cells. Our observations suggest that induction of EGF-R expression may accompany the malignant transformation of human brain cells of nonneuronal origin.

  6. Indoxyl Sulfate Downregulates Mas Receptor via Aryl Hydrocarbon Receptor/Nuclear Factor-kappa B, and Induces Cell Proliferation and Tissue Factor Expression in Vascular Smooth Muscle Cells.

    Science.gov (United States)

    Ng, Hwee-Yeong; Bolati, Wulaer; Lee, Chien-Te; Chien, Yu-Shu; Yisireyili, Maimaiti; Saito, Shinichi; Pei, Sung-Nan; Nishijima, Fuyuhiko; Niwa, Toshimitsu

    2016-01-01

    Angiotensin converting enzyme-related carboxypeptidase 2/angiotensin (Ang)-(1-7)/Mas receptor axis is protective in the development of chronic kidney disease and cardiovascular disease. This study is aimed at investigating whether indoxyl sulfate (IS) affects Mas receptor expression, cell proliferation and tissue factor expression in vascular smooth muscle cells, and if Ang-(1-7), an activator of Mas receptor, counteracts the IS-induced effects. IS was administered to normotensive and hypertensive rats. Human aortic smooth muscle cells (HASMCs) were cultured with IS. IS reduced the expression of Mas receptor in the aorta of normotensive and hypertensive rats. IS downregulated the Mas receptor expression in a time- and dose-dependent manner in HASMCs. Knockdown of aryl hydrocarbon receptor (AhR) and nuclear factor-kappa B (NF-x03BA;B) inhibited IS-induced downregulation of Mas receptor. Further, IS stimulated cell proliferation and tissue factor expression in HASMCs. Ang-(1-7) attenuated IS-induced cell proliferation and tissue factor expression in HASMCs. Ang-(1-7) suppressed phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and NF-x03BA;B in HASMCs. IS downregulated the expression of Mas receptor via AhR/NF-x03BA;B, and induced cell proliferation and tissue factor expression in HASMCs. Ang-(1-7) inhibited IS-induced cell proliferation and tissue factor expression by suppressing the phosphorylation of ERK1/2 and NF-x03BA;B p65. © 2016 S. Karger AG, Basel.

  7. Specific antibodies and sensitive immunoassays for the human epidermal growth factor receptors (HER2, HER3, and HER4).

    Science.gov (United States)

    Broughton, Marianne Nordlund; Westgaard, Arne; Paus, Elisabeth; Øijordsbakken, Miriam; Henanger, Karoline J; Naume, Bjørn; Bjøro, Trine

    2017-06-01

    The use of trastuzumab in patients with breast cancer that overexpresses human epidermal growth factor receptor 2 has significantly improved treatment outcomes. However, a substantial proportion of this patient group still experiences progression of the disease after receiving the drug. Evaluation of the changes in expression of the human epidermal growth factor receptors could be of interest. Monoclonal antibodies against the extracellular domain of the human growth factor receptors, 2, 3, and 4, have been raised, and specific and sensitive immunoassays have been established. Sera from healthy individuals (Nordic Reference Interval Project and Database) were analyzed in the human epidermal growth factor receptor 2 assay (N = 805) and the human epidermal growth factor receptor 3 and 4 assays (N = 114), and reference limits were calculated. In addition, sera from 208 individual patients with breast cancer were tested in all three assays. Finally, the human epidermal growth factor receptor 2 assay was compared with a chemiluminescent immunoassay for serum human epidermal growth factor receptor 2/neu. Reference values were as follows: human epidermal growth factor receptor 2, human epidermal growth factor receptor 3, human epidermal growth factor receptor 4, human epidermal growth factor receptor 2 and human epidermal growth factor receptor 3 serum levels between the patients with tissue human epidermal growth factor receptor 2-positive and tissue human epidermal growth factor receptor 2-negative ( p = 0.0026, p = 0.000011) tumors, but not in the serum levels of human epidermal growth factor receptor 4 ( p = 0.054). There was good agreement between the in-house human epidermal growth factor receptor 2 assay and the chemiluminescent immunoassay. Our new specific antibodies for all the three human epidermal growth factor receptors may prove valuable in the development of novel anti-human epidermal growth factor receptor targeted therapies with

  8. Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor

    DEFF Research Database (Denmark)

    Kristensen, Torsten; Moestrup, Søren Kragh; Gliemann, Jørgen;

    1990-01-01

    The human placental receptor (α2MR) for α2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides covering 536 residues from these polypeptides......, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the α- and β-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J., Hamann, U., Rogne, S......., Myklebost, O., Gausepohl, H. and Stanley, K.K. (1988) EMBO J. 7, 4119-4127; Herz, J., Kowal, R.C., Goldstein, J.L. and Brown, M.S. (1990) EMBO J. 9, 1769-1776). N-terminal sequence analysis of the 40 kDa polypeptide shows that it is of distinct genetic origin. It is suggested that LRP is the functional...

  9. Evidence that the newly cloned low-density-lipoprotein receptor related protein (LRP) is the alpha 2-macroglobulin receptor

    DEFF Research Database (Denmark)

    Kristensen, T; Moestrup, Søren Kragh; Gliemann, Jørgen;

    1990-01-01

    The human placental receptor (alpha 2MR) for alpha 2-macroglobulin-proteinase complexes contains 3 polypeptides of approx. 500 kDa, 85 kDa, and 40 kDa. N-terminal sequence analysis of the 500 kDa and 85 kDa polypeptides, analysis of a random selection of peptides convering 536 residues from...... these polypeptides, and analysis of a 1772 bp cDNA encoding part of the 500 kDa polypeptide provide evidence that the 500 kDa and 85 kDa chains are the alpha- and beta-subunits, respectively, of a recently cloned hepatic membrane protein, termed the low density lipoprotein receptor related protein (LRP) (Herz, J......., Hamann, U., Rogne, S., Myklebost, O., Gausepohl, H. and Stanley, K.K. (1988) EMBO J. 7, 4119-4127; Herz, J., Kowal, R.C., Goldstein, J.L. and Brown, M.S. (1990) EMBO J. 9, 1769-1776). N-terminal sequence analysis of the 40 kDa polypeptide shows that it is of distinct genetic origin. It is suggested...

  10. A Selective Nociceptin Receptor Antagonist to Treat Depression: Evidence from Preclinical and Clinical Studies.

    Science.gov (United States)

    Post, Anke; Smart, Trevor S; Krikke-Workel, Judith; Dawson, Gerard R; Harmer, Catherine J; Browning, Michael; Jackson, Kimberley; Kakar, Rishi; Mohs, Richard; Statnick, Michael; Wafford, Keith; McCarthy, Andrew; Barth, Vanessa; Witkin, Jeffrey M

    2016-06-01

    Nociceptin/Orphanin FQ (N/OFQ) is an endogenous ligand of the N/OFQ peptide (NOP) receptor, which is a G protein-coupled receptor in brain regions associated with mood disorders. We used a novel, potent, and selective orally bioavailable antagonist, LY2940094, to test the hypothesis that blockade of NOP receptors would induce antidepressant effects. In this study we demonstrate that targeting NOP receptors with LY2940094 translates to antidepressant-like effects in rodent models and, importantly, to antidepressant efficacy in patients with major depressive disorder (MDD). The proof-of-concept study (POC) was an 8-week, double-blind, placebo-controlled trial that evaluated LY2940094 as a novel oral medication for the treatment of patients with MDD. Once daily oral dosing of LY2940094 at 40 mg for 8 weeks vs placebo provided some evidence for an antidepressant effect based on the change from baseline to week 8 in the GRID-Hamilton Depression Rating Scale-17 item total score, although the predefined POC efficacy criterion (probability of LY2940094 being better than placebo⩾88%) was not met (82.9%). LY2940094 also had an early effect on the processing of emotional stimuli at Week 1 as shown by an increased recognition of positive relative to negative facial expressions in an emotional test battery. LY2940094 was safe and well tolerated. Overall, these are the first human data providing evidence that the blockade of NOP receptor signaling represents a promising strategy for the treatment of MDD.

  11. Fibroblast Growth Factor Receptor (FGFR): A New Target for Non-small Cell Lung Cancer Therapy.

    Science.gov (United States)

    Biello, Federica; Burrafato, Giovanni; Rijavec, Erika; Genova, Carlo; Barletta, Giulia; Truini, Anna; Coco, Simona; Bello, Maria Giovanna Dal; Alama, Angela; Boccardo, Francesco; Grossi, Francesco

    2016-01-01

    Lung cancer is still the leading cause of cancer related death worldwide. Fibroblast growth factor receptor (FGFR) is a tirosine-kinase receptor that is seen to be amplified or mutated in non-small cell lung cancer (NSCLC) and it plays a crucial role in tumour development and maintenance. The authors analyzed the state of the art of FGFR by reviewing the current literature. Fibroblast growth factor (FGF)-FGFR pathway and their aberrations are described, with the evaluation of their possible prognostic role in NSCLC and in particular in squamous cell carcinomas, in which FGFR is more often amplified. New therapeutic agents targeting FGFR signaling have been developed and are now in clinical evaluation. Dysregulation of FGF signaling in tumour cells is related to FGFR gene amplification or mutation, although it is still uncertain which of these aberrations represents a real predictor of response to specific inhibitors. However, recent evidence has questioned whether FGFR is a real target in squamous cell histology. The effectiveness of FGFR inhibitors is also still unclear since there are no clinical data on selected patients. Moreover, the management of specific side effects related to inhibition of the physiological role of FGF should be more thorough.

  12. Sex, the brain and hypertension: brain oestrogen receptors and high blood pressure risk factors.

    Science.gov (United States)

    Hay, Meredith

    2016-01-01

    Hypertension is a major contributor to worldwide morbidity and mortality rates related to cardiovascular disease. There are important sex differences in the onset and rate of hypertension in humans. Compared with age-matched men, premenopausal women are less likely to develop hypertension. However, after age 60, the incidence of hypertension increases in women and even surpasses that seen in older men. It is thought that changes in levels of circulating ovarian hormones as women age may be involved in the increase in hypertension in older women. One of the key mechanisms involved in the development of hypertension in both men and women is an increase in sympathetic nerve activity (SNA). Brain regions important for the regulation of SNA, such as the subfornical organ, the paraventricular nucleus and the rostral ventral lateral medulla, also express specific subtypes of oestrogen receptors. Each of these brain regions has also been implicated in mechanisms underlying risk factors for hypertension such as obesity, stress and inflammation. The present review brings together evidence that links actions of oestrogen at these receptors to modulate some of the common brain mechanisms involved in the ability of hypertensive risk factors to increase SNA and blood pressure. Understanding the mechanisms by which oestrogen acts at key sites in the brain for the regulation of SNA is important for the development of novel, sex-specific therapies for treating hypertension. © 2016 Authors; published by Portland Press Limited.

  13. Dynamic tracing for epidermal growth factor receptor mutations in urinary circulating DNA in gastric cancer patients.

    Science.gov (United States)

    Shi, Xiu-Qin; Xue, Wen-Hua; Zhao, Song-Feng; Zhang, Xiao-Jian; Sun, Wukong

    2017-02-01

    The mutations of epidermal growth factor receptor are detected in gastric cancer, indicating its suitability as a target for receptor tyrosine kinase inhibitors, as well as a marker for clinical outcome of chemotherapeutic treatments. However, extraction of quality tumor tissue for molecular processes remains challenging. Here, we aimed to examine the clinical relevance of urinary cell-free DNA as an alternative tumor material source used specifically for monitoring epidermal growth factor receptor mutations. Therefore, 120 gastric cancer patients with epidermal growth factor receptor mutations and 100 healthy controls were recruited for the study. The gastric patients also received epidermal growth factor receptor inhibitor treatment for a serial monitoring study. Paired primary tumor specimens were obtained with blood and urine samples, which were taken at a 1-month interval for a duration of 12 months. We found that urinary cell-free DNA yielded a close agreement of 92% on epidermal growth factor receptor mutation status when compared to primary tissue at baseline, and of 99% epidermal growth factor receptor mutation status when compared to plasma samples at different time points. Thus, our data suggest that urinary cell-free DNA may be a reliable source for screening and monitoring epidermal growth factor receptor mutations in the primary gastric cancer.

  14. Potent, selective inhibitors of fibroblast growth factor receptor define fibroblast growth factor dependence in preclinical cancer models.

    Science.gov (United States)

    Squires, Matthew; Ward, George; Saxty, Gordan; Berdini, Valerio; Cleasby, Anne; King, Peter; Angibaud, Patrick; Perera, Tim; Fazal, Lynsey; Ross, Douglas; Jones, Charlotte Griffiths; Madin, Andrew; Benning, Rajdeep K; Vickerstaffe, Emma; O'Brien, Alistair; Frederickson, Martyn; Reader, Michael; Hamlett, Christopher; Batey, Michael A; Rich, Sharna; Carr, Maria; Miller, Darcey; Feltell, Ruth; Thiru, Abarna; Bethell, Susanne; Devine, Lindsay A; Graham, Brent L; Pike, Andrew; Cosme, Jose; Lewis, Edward J; Freyne, Eddy; Lyons, John; Irving, Julie; Murray, Christopher; Newell, David R; Thompson, Neil T

    2011-09-01

    We describe here the identification and characterization of 2 novel inhibitors of the fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases. The compounds exhibit selective inhibition of FGFR over the closely related VEGFR2 receptor in cell lines and in vivo. The pharmacologic profile of these inhibitors was defined using a panel of human tumor cell lines characterized for specific mutations, amplifications, or translocations known to activate one of the four FGFR receptor isoforms. This pharmacology defines a profile for inhibitors that are likely to be of use in clinical settings in disease types where FGFR is shown to play an important role.

  15. Parabens and Human Epidermal Growth Factor Receptor Ligand Cross-Talk in Breast Cancer Cells.

    Science.gov (United States)

    Pan, Shawn; Yuan, Chaoshen; Tagmount, Abderrahmane; Rudel, Ruthann A; Ackerman, Janet M; Yaswen, Paul; Vulpe, Chris D; Leitman, Dale C

    2016-05-01

    Xenoestrogens are synthetic compounds that mimic endogenous estrogens by binding to and activating estrogen receptors. Exposure to estrogens and to some xenoestrogens has been associated with cell proliferation and an increased risk of breast cancer. Despite evidence of estrogenicity, parabens are among the most widely used xenoestrogens in cosmetics and personal-care products and are generally considered safe. However, previous cell-based studies with parabens do not take into account the signaling cross-talk between estrogen receptor α (ERα) and the human epidermal growth factor receptor (HER) family. We investigated the hypothesis that the potency of parabens can be increased with HER ligands, such as heregulin (HRG). The effects of HER ligands on paraben activation of c-Myc expression and cell proliferation were determined by real-time polymerase chain reaction, Western blots, flow cytometry, and chromatin immunoprecipitation assays in ERα- and HER2-positive human BT-474 breast cancer cells. Butylparaben (BP) and HRG produced a synergistic increase in c-Myc mRNA and protein levels in BT-474 cells. Estrogen receptor antagonists blocked the synergistic increase in c-Myc protein levels. The combination of BP and HRG also stimulated proliferation of BT-474 cells compared with the effects of BP alone. HRG decreased the dose required for BP-mediated stimulation of c-Myc mRNA expression and cell proliferation. HRG caused the phosphorylation of serine 167 in ERα. BP and HRG produced a synergistic increase in ERα recruitment to the c-Myc gene. Our results show that HER ligands enhanced the potency of BP to stimulate oncogene expression and breast cancer cell proliferation in vitro via ERα, suggesting that parabens might be active at exposure levels not previously considered toxicologically relevant from studies testing their effects in isolation. Pan S, Yuan C, Tagmount A, Rudel RA, Ackerman JM, Yaswen P, Vulpe CD, Leitman DC. 2016. Parabens and human epidermal

  16. Parabens and Human Epidermal Growth Factor Receptor Ligand Cross-Talk in Breast Cancer Cells

    Science.gov (United States)

    Pan, Shawn; Yuan, Chaoshen; Tagmount, Abderrahmane; Rudel, Ruthann A.; Ackerman, Janet M.; Yaswen, Paul; Vulpe, Chris D.; Leitman, Dale C.

    2015-01-01

    Background: Xenoestrogens are synthetic compounds that mimic endogenous estrogens by binding to and activating estrogen receptors. Exposure to estrogens and to some xenoestrogens has been associated with cell proliferation and an increased risk of breast cancer. Despite evidence of estrogenicity, parabens are among the most widely used xenoestrogens in cosmetics and personal-care products and are generally considered safe. However, previous cell-based studies with parabens do not take into account the signaling cross-talk between estrogen receptor α (ERα) and the human epidermal growth factor receptor (HER) family. Objectives: We investigated the hypothesis that the potency of parabens can be increased with HER ligands, such as heregulin (HRG). Methods: The effects of HER ligands on paraben activation of c-Myc expression and cell proliferation were determined by real-time polymerase chain reaction, Western blots, flow cytometry, and chromatin immunoprecipitation assays in ERα- and HER2-positive human BT-474 breast cancer cells. Results: Butylparaben (BP) and HRG produced a synergistic increase in c-Myc mRNA and protein levels in BT-474 cells. Estrogen receptor antagonists blocked the synergistic increase in c-Myc protein levels. The combination of BP and HRG also stimulated proliferation of BT-474 cells compared with the effects of BP alone. HRG decreased the dose required for BP-mediated stimulation of c-Myc mRNA expression and cell proliferation. HRG caused the phosphorylation of serine 167 in ERα. BP and HRG produced a synergistic increase in ERα recruitment to the c-Myc gene. Conclusion: Our results show that HER ligands enhanced the potency of BP to stimulate oncogene expression and breast cancer cell proliferation in vitro via ERα, suggesting that parabens might be active at exposure levels not previously considered toxicologically relevant from studies testing their effects in isolation. Citation: Pan S, Yuan C, Tagmount A, Rudel RA, Ackerman JM

  17. Basic Fibroblast Growth Factor and Fibroblast Growth Factor Receptor-1in Human Meningiomas

    Institute of Scientific and Technical Information of China (English)

    YI Wei; CHEN Jian; Filimon H. Golwa; XUE Delin

    2005-01-01

    The expression of basic fibroblast growth factor (bFGF) and fibroblast growth factor receptor-1 (FGFR-1) in human meningiomas and the relationships between their expression and the tumors' histological features and angiogenesis were investigated by means of immunohistochemical technique. The expression of bFGF and FGFR-1 was detected by antibody of bFGF or FGFR-1.The tumors' angiogenesis was evaluated by microvascular density (MVD) and, which was observed by use of CD34-antibody immunohistochemically. The results showed that there were varied degrees of the expression of bFGF and FGFR-1 proteins in meningiomas. The expression was correlated with the tumors' histological characters and angiogenesis. It was concluded that bFGF and FGFR-1 might play important roles in meningiomas' angiogenesis and proliferation. The expression positive rate of bFGF and FGFR-1 may provide an indication of evaluating the histological and malignant degree of the tumor.

  18. The intrinsic factor-vitamin B12 receptor, cubilin, is a high-affinity apolipoprotein A-I receptor facilitating endocytosis of high-density lipoprotein.

    Science.gov (United States)

    Kozyraki, R; Fyfe, J; Kristiansen, M; Gerdes, C; Jacobsen, C; Cui, S; Christensen, E I; Aminoff, M; de la Chapelle, A; Krahe, R; Verroust, P J; Moestrup, S K

    1999-06-01

    Cubilin is the intestinal receptor for the endocytosis of intrinsic factor-vitamin B12. However, several lines of evidence, including a high expression in kidney and yolk sac, indicate it may have additional functions. We isolated apolipoprotein A-I (apoA-I), the main protein of high-density lipoprotein (HDL), using cubilin affinity chromatography. Surface plasmon resonance analysis demonstrated a high-affinity binding of apoA-I and HDL to cubilin, and cubilin-expressing yolk sac cells showed efficient 125I-HDL endocytosis that could be inhibited by IgG antibodies against apoA-I and cubilin. The physiological relevance of the cubilin-apoA-I interaction was further emphasized by urinary apoA-I loss in some known cases of functional cubilin deficiency. Therefore, cubilin is a receptor in epithelial apoA-I/HDL metabolism.

  19. Isolation of an additional member of the fibroblast growth factor receptor family, FGFR-3

    Energy Technology Data Exchange (ETDEWEB)

    Keegan, K.; Hayman, M.J. (State Univ. of New York, Stony Brook (United States)); Johnson, D.E.; Williams, L.T. (Univ. of California, San Francisco (United States))

    1991-02-15

    The fibroblast growth factors are a family of polypeptide growth factors involved in a variety of activities including mitogenesis, angiogenesis, and wound healing. Fibroblast growth factor receptors (FGFRs) have previously been identified in chicken, mouse, and human and have been shown to contain an extracellular domain with either two or three immunoglobulin-like domains, a transmembrane domain, and a cytoplasmic tyrosine kinase domain. The authors have isolated a human cDNA for another tyrosine kinase receptor that is highly homologous to the previously described FGFR. Expression of this receptor cDNA in COS cells directs the expression of a 125-kDa glycoprotein. They demonstrate that this cDNA encodes a biologically active receptor by showing that human acidic and basic fibroblast growth factors activate this receptor as measured by {sup 45}Ca{sup 2+} efflux assays. These data establish the existence of an additional member of the FGFR family that they have named FGFR-3.

  20. Phenobarbital indirectly activates the constitutive active androstane receptor (CAR) by inhibition of epidermal growth factor receptor signaling.

    Science.gov (United States)

    Mutoh, Shingo; Sobhany, Mack; Moore, Rick; Perera, Lalith; Pedersen, Lee; Sueyoshi, Tatsuya; Negishi, Masahiko

    2013-05-07

    Phenobarbital is a central nervous system depressant that also indirectly activates nuclear receptor constitutive active androstane receptor (CAR), which promotes drug and energy metabolism, as well as cell growth (and death), in the liver. We found that phenobarbital activated CAR by inhibiting epidermal growth factor receptor (EGFR) signaling. Phenobarbital bound to EGFR and potently inhibited the binding of EGF, which prevented the activation of EGFR. This abrogation of EGFR signaling induced the dephosphorylation of receptor for activated C kinase 1 (RACK1) at Tyr(52), which then promoted the dephosphorylation of CAR at Thr(38) by the catalytic core subunit of protein phosphatase 2A. The findings demonstrated that the phenobarbital-induced mechanism of CAR dephosphorylation and activation is mediated through its direct interaction with and inhibition of EGFR.

  1. Evidence for dual receptor-binding sites in Clostridium difficile toxin A.

    Science.gov (United States)

    Lambert, Gregory S; Baldwin, Michael R

    2016-12-01

    TcdA (308 kDa) and TcdB (270 kDa) disrupt the integrity of the intestinal epithelial barrier and provide an environment favorable for Clostridium difficile colonization. Recent evidence suggests that entry of TcdA into cells is mediated by at least two domains. Here, we report the characterization of a second receptor-binding domain (RBD2) for TcdA. While both the isolated combined repetitive oligopeptides (CROPs) and RBD2 fragments are rapidly internalized into cells under physiologic conditions, only the CROPs domain appreciably accumulates at the cell surface. Once internalized, CROPs and RBD2 are trafficked to late endosomal compartments. An internal deletion of RBD2 from TcdA holotoxin ablated toxicity in HT29 cells. These data are consistent with the recently proposed dual receptor model of cellular entry. © 2016 Federation of European Biochemical Societies.

  2. Evidence of Endogenous Mu Opioid Receptor Regulation by Epigenetic Control of the Promoters▿

    OpenAIRE

    Hwang, Cheol Kyu; Song, Kyu Young; Kim, Chun Sung; Choi, Hack Sun; Guo, Xiao-Hong; Law, Ping-Yee; Wei, Li-Na; Loh, Horace H.

    2007-01-01

    The pharmacological effect of morphine as a painkiller is mediated mainly via the mu opioid receptor (MOR) and is dependent on the number of MORs in the cell surface membrane. While several studies have reported that the MOR gene is regulated by various cis- and trans-acting factors, many questions remain unanswered regarding in vivo regulation. The present study shows that epigenetic silencing and activation of the MOR gene are achieved through coordinated regulation at both the histone and ...

  3. Tumor necrosis factor downregulates granulocyte-colony-stimulating factor receptor expression on human acute myeloid leukemia cells and granulocytes.

    OpenAIRE

    Elbaz, O; Budel, L M; Hoogerbrugge, H; Touw, I P; Delwel, R.; Mahmoud, L A; Löwenberg, B. (Bernward)

    1991-01-01

    Tumor necrosis factor (TNF) inhibits granulocyte-colony-stimulating factor (G-CSF)-induced human acute myeloid leukemia (AML) growth in vitro. Incubation of blasts from three patients with AML in serum-free medium with TNF (10(3) U/ml), and subsequent binding studies using 125I-G-CSF reveal that TNF downregulates the numbers of G-CSF receptors by approximately 70%. G-CSF receptor numbers on purified blood granulocytes are also downmodulated by TNF. Downregulation of G-CSF receptor expression ...

  4. DEPENDENCE OF PPAR LIGAND-INDUCED MAPK SIGNALING ON EPIDERMAL GROWTH FACTOR RECEPTOR TRANSACTIVATION HEPARIN-BINDING EGF CLEAVAGE MEDIATES ZINC-INDUCED EGF RECEPTOR PHOSPHORYLATION

    Science.gov (United States)

    Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that function as ligand-activated transcription factors regulating lipid metabolism and homeostasis. In addition to their ability to regulate PPAR-mediated gene transcription, PPARalpha and gamma li...

  5. Epidermal growth factor receptor transactivation by intracellular prostaglandin E2-activated prostaglandin E2 receptors. Role in retinoic acid receptor-β up-regulation.

    Science.gov (United States)

    Fernández-Martínez, Ana B; Lucio Cazaña, Francisco J

    2013-09-01

    The pharmacological modulation of renoprotective factor vascular endothelial growth factor-A (VEGF-A) in the proximal tubule has therapeutic interest. In human proximal tubular HK-2 cells, treatment with all-trans retinoic acid or prostaglandin E2 (PGE2) triggers the production of VEGF-A. The pathway involves an initial increase in intracellular PGE2, followed by activation of EP receptors (PGE2 receptors, most likely an intracellular subset) and increase in retinoic acid receptor-β (RARβ) expression. RARβ then up-regulates transcription factor hypoxia-inducible factor-1α (HIF-1α), which increases the transcription and production of VEGF-A. Here we studied the role in this pathway of epidermal growth factor receptor (EGFR) transactivation by EP receptors. We found that EGFR inhibitor AG1478 prevented the increase in VEGF-A production induced by PGE2- and all-trans retinoic acid. This effect was due to the inhibition of the transcriptional up-regulation of RARβ, which resulted in loss of the RARβ-dependent transcriptional up-regulation of HIF-1α. PGE2 and all-trans retinoic acid also increased EGFR phosphorylation and this effect was sensitive to antagonists of EP receptors. The role of intracellular PGE2 was indicated by two facts; i) PGE2-induced EGFR phosphorylation was substantially prevented by inhibitor of prostaglandin uptake transporter bromocresol green and ii) all-trans retinoic acid treatment, which enhanced intracellular but not extracellular PGE2, had lower effect on EGFR phosphorylation upon pre-treatment with cyclooxygenase inhibitor diclofenac. Thus, EGFR transactivation by intracellular PGE2-activated EP receptors results in the sequential activation of RARβ and HIF-1α leading to increased production of VEGF-A and it may be a target for the therapeutic modulation of HIF-1α/VEGF-A. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Membrane progesterone receptors: evidence for neuroprotective, neurosteroid signaling and neuroendocrine functions in neuronal cells.

    Science.gov (United States)

    Thomas, Peter; Pang, Yefei

    2012-01-01

    Membrane progesterone receptors (mPRs) are novel G protein-coupled receptors belonging to the progestin and adipoQ receptor family (PAQR) that mediate a variety of rapid cell surface-initiated progesterone actions in the reproductive system involving activation of intracellular signaling pathways (i.e. nonclassical actions). The mPRs are highly expressed in the brain, but research on their neural functions has only been conducted in a single neuronal cell line, GT1-7 cells, which have negligible nuclear progesterone receptor (PR) expression. GT1-7 cells express mPRα and mPRβ on their plasma membranes which is associated with the presence of high-affinity, specific [(3)H]-progesterone receptor binding. The neurosteroid, allopregnanolone, is an effective ligand for recombinant mPRα with a relative binding affinity of 7.6% that of progesterone. Allopregnanolone acts as a potent mPR agonist on GT1-7 cells, mimicking the progesterone-induced decrease in cAMP accumulation and its antiapoptotic actions at low nanomolar concentrations. The decrease in cAMP levels is associated with rapid progesterone-induced downregulation of GnRH pulsatile secretion from perifused GT1-7 cells. The recent suggestion that mPRs are alkaline ceramidases and mediate sphingolipid signaling is not supported by empirical evidence that TNFα does not bind to mPRs overexpressed in human cells and that exogenous sphingomyelinase is ineffective in mimicking progestin actions through mPRs to induce meiotic maturation of fish oocytes. Taken together, these recent studies indicate that mPRs mediate neuroprotective effects of progesterone and allopregnanolone and are also the likely intermediaries in progesterone-induced inhibition of pulsatile GnRH secretion in GT1-7 cells. Copyright © 2012 S. Karger AG, Basel.

  7. Regulation of ciliary neurotrophic factor receptor alpha in sciatic motor neurons following axotomy.

    Science.gov (United States)

    MacLennan, A J; Devlin, B K; Neitzel, K L; McLaurin, D L; Anderson, K J; Lee, N

    1999-01-01

    Spinal motor neurons are one of the few classes of neurons capable of regenerating axons following axotomy. Injury-induced expression of neurotrophic factors and corresponding receptors may play an important role in this rare ability. A wide variety of indirect data suggests that ciliary neurotrophic factor receptor alpha may critically contribute to the regeneration of injured spinal motor neurons. We used immunohistochemistry, in situ hybridization and retrograde tracing techniques to study the regulation of ciliary neurotrophic factor receptor alpha in axotomized sciatic motor neurons. Ciliary neurotrophic factor receptor alpha immunoreactivity, detected with two independent antisera, is increased in a subpopulation of caudal sciatic motor neuron soma one, two and six weeks after sciatic nerve transection and reattachment, while no changes are detected at one day and 15 weeks post-lesion. Ciliary neurotrophic factor receptor alpha messenger RNA levels are augmented in the same classes of neurons following an identical lesion, suggesting that increased synthesis contributes, at least in part, to the additional ciliary neurotrophic factor receptor alpha protein. Separating the proximal and distal nerve stumps with a plastic barrier does not noticeably affect the injury-induced change in ciliary neurotrophic factor receptor alpha regulation, thereby indicating that this injury response is not dependent on signals distal to the lesion traveling retrogradely through the nerve or signals generated by axonal growth through the distal nerve. The prolonged increases in ciliary neurotrophic factor receptor alpha protein and messenger RNA found in regenerating sciatic motor neurons contrast with the responses of non-regenerating central neurons, which are reported to display, at most, a short-lived increase in ciliary neurotrophic factor receptor alpha messenger RNA expression following injury. The present data are the first to demonstrate, in vivo, neuronal regulation of

  8. Platelet-derived growth factor receptor beta is critical for zebrafish intersegmental vessel formation.

    Directory of Open Access Journals (Sweden)

    Katie M Wiens

    Full Text Available BACKGROUND: Platelet-derived growth factor receptor beta (PDGFRbeta is a tyrosine kinase receptor known to affect vascular development. The zebrafish is an excellent model to study specific regulators of vascular development, yet the role of PDGF signaling has not been determined in early zebrafish embryos. Furthermore, vascular mural cells, in which PDGFRbeta functions cell autonomously in other systems, have not been identified in zebrafish embryos younger than 72 hours post fertilization. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate the role of PDGFRbeta in zebrafish vascular development, we cloned the highly conserved zebrafish homolog of PDGFRbeta. We found that pdgfrbeta is expressed in the hypochord, a developmental structure that is immediately dorsal to the dorsal aorta and potentially regulates blood vessel development in the zebrafish. Using a PDGFR tyrosine kinase inhibitor, a morpholino oligonucleotide specific to PDGFRbeta, and a dominant negative PDGFRbeta transgenic line, we found that PDGFRbeta is necessary for angiogenesis of the intersegmental vessels. SIGNIFICANCE/CONCLUSION: Our data provide the first evidence that PDGFRbeta signaling is required for zebrafish angiogenesis. We propose a novel mechanism for zebrafish PDGFRbeta signaling that regulates vascular angiogenesis in the absence of mural cells.

  9. LysM domain receptor kinases regulating rhizobial Nod factor-induced infection.

    Science.gov (United States)

    Limpens, Erik; Franken, Carolien; Smit, Patrick; Willemse, Joost; Bisseling, Ton; Geurts, René

    2003-10-24

    The rhizobial infection of legumes has the most stringent demand toward Nod factor structure of all host responses, and therefore a specific Nod factor entry receptor has been proposed. The SYM2 gene identified in certain ecotypes of pea (Pisum sativum) is a good candidate for such an entry receptor. We exploited the close phylogenetic relationship of pea and the model legume Medicago truncatula to identify genes specifically involved in rhizobial infection. The SYM2 orthologous region of M. truncatula contains 15 putative receptor-like genes, of which 7 are LysM domain-containing receptor-like kinases (LYKs). Using reverse genetics in M. truncatula, we show that two LYK genes are specifically involved in infection thread formation. This, as well as the properties of the LysM domains, strongly suggests that they are Nod factor entry receptors.

  10. Estrogen receptor α gene polymorphisms and risk of Alzheimer’s disease: evidence from a meta-analysis

    Science.gov (United States)

    Cheng, Daye; Liang, Bin; Hao, Yiwen; Zhou, Wenling

    2014-01-01

    Objective Human estrogen receptor α (ESR1), a member of the nuclear receptor superfamily of ligand-activated transcription factors, is one of the key mediators of hormonal response in estrogen-sensitive tissues. Accumulating evidence has demonstrated that two of the most widely studied single-nucleotide polymorphisms in ESR1 – PvuII (T/C, rs223493) and Xbal (A/G, rs9340799) – are possibly associated with Alzheimer’s disease (AD). However, individual study results are still controversial. Materials and methods We searched PubMed, Embase, Web of Science, Science Direct, SpringerLink, and the Chinese National Knowledge Infrastructure databases for eligible studies assessing the association of ESR1 polymorphisms and AD risk (last search performed in November 2013). Thereafter, a meta-analysis of 13,192 subjects from 18 individual studies was conducted to evaluate the association between ESR1 polymorphisms and susceptibility to AD. Results The results indicated that a significant association was found between the ESR1 PvuII polymorphism and AD risk in Caucasian populations (CC + CT versus TT, odds ratio [OR] 1.14, 95% confidence interval [CI] 1.02–1.28, P=0.03; CT versus TT, OR 1.16, 95% CI 1.02–1.31, P=0.02), whereas no evidence of association was found in Asian populations. Nevertheless, we did not find any significant association between the ESR1 XbaI polymorphism and AD risk for any model in Caucasian and Asian populations (all P>0.05). Conclusion Based on this meta-analysis, we conclude that the ESR1 PvuII polymorphism might be a risk factor in AD development in Caucasian populations, not in Asian populations. Further confirmation is needed from better-designed and larger studies. PMID:25061285

  11. Splicing factors control C. elegans behavioural learning in a single neuron by producing DAF-2c receptor

    Science.gov (United States)

    Tomioka, Masahiro; Naito, Yasuki; Kuroyanagi, Hidehito; Iino, Yuichi

    2016-01-01

    Alternative splicing generates protein diversity essential for neuronal properties. However, the precise mechanisms underlying this process and its relevance to physiological and behavioural functions are poorly understood. To address these issues, we focused on a cassette exon of the Caenorhabditis elegans insulin receptor gene daf-2, whose proper variant expression in the taste receptor neuron ASER is critical for taste-avoidance learning. We show that inclusion of daf-2 exon 11.5 is restricted to specific neuron types, including ASER, and is controlled by a combinatorial action of evolutionarily conserved alternative splicing factors, RBFOX, CELF and PTB families of proteins. Mutations of these factors cause a learning defect, and this defect is relieved by DAF-2c (exon 11.5+) isoform expression only in a single neuron ASER. Our results provide evidence that alternative splicing regulation of a single critical gene in a single critical neuron is essential for learning ability in an organism. PMID:27198602

  12. Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines

    Directory of Open Access Journals (Sweden)

    Kellermeier Silvia

    2010-06-01

    Full Text Available Abstract Background Cholangiocarcinoma (CC is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro. Methods Expression of EGFR (epithelial growth factor receptor, HGFR (hepatocyte growth factor receptor IGF1R (insulin-like growth factor 1 receptor, IGF2R (insulin-like growth factor 2 receptor and VEGFR1-3 (vascular endothelial growth factor receptor 1-3 were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1. The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations. Results EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml, with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D. HuH28, OZ and TFK-1 lacked KRAS mutation. Conclusion CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab.

  13. Sulindac metabolites inhibit epidermal growth factor receptor activation and expression

    Directory of Open Access Journals (Sweden)

    Pangburn Heather A

    2005-09-01

    Full Text Available Abstract Background Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs is associated with a decreased mortality from colorectal cancer (CRC. NSAIDs induce apoptotic cell death in colon cancer cells in vitro and inhibit growth of neoplastic colonic mucosa in vivo however, the biochemical mechanisms required for these growth inhibitory effects are not well defined. We previously reported that metabolites of the NSAID sulindac downregulate extracellular-signal regulated kinase 1/2 (ERK1/2 signaling and that this effect is both necessary and sufficient for the apoptotic effects of these drugs. The goal of this project was to specifically test the hypothesis that sulindac metabolites block activation and/or expression of the epidermal growth factor (EGF receptor (EGFR. Methods HT29 human colon cancer cells were treated with EGF, alone, or in the presence of sulindac sulfide or sulindac sulfone. Cells lysates were assayed by immunoblotting for phosphorylated EGFR (pEGFR, pY1068, total EGFR, phosphorylated ERK1/2 (pERK1/2, total ERK1/2, activated caspase-3, and α-tubulin. Results EGF treatment rapidly induced phosphorylation of both EGFR and ERK1/2 in HT29 colon cancer cells. Pretreatment with sulindac metabolites for 24 h blocked EGF-induced phosphorylation of both EGFR and ERK1/2 and decreased total EGFR protein expression. Under basal conditions, downregulation of pEGFR and total EGFR was detected as early as 12 h following sulindac sulfide treatment and persisted through at least 48 h. Sulindac sulfone induced downregulation of pEGFR and total EGFR was detected as early as 1 h and 24 h, respectively, following drug treatment, and persisted through at least 72 h. EGFR downregulation by sulindac metabolites was observed in three different CRC cell lines, occurred prior to the observed downregulation of pERK1/2 and induction of apoptosis by these drugs, and was not dependent of caspase activation. Conclusion These results suggest that

  14. Expression and purification of Nod factor receptors - Initial characterization of ligand binding

    DEFF Research Database (Denmark)

    Broghammer, Angelique

    . Lipochitooligosaccharides also serve as signals in the mutually beneficial interactions between arbuscular mycorrhiza (AM) and most land plants. In the model legume Lotus japonicus the Nod factor receptors, LjNFR1 and LjNFR5, two LysM receptor like kinases (LysM-RLK), are responsible for perceiving the rhizobial...

  15. Targeting hepatocyte growth factor receptor (Met) positive tumor cells using internalizing nanobody-decorated albumin nanoparticles

    NARCIS (Netherlands)

    Heukers, Raimond|info:eu-repo/dai/nl/325788103; Altintas, Isil|info:eu-repo/dai/nl/341537160; Raghoenath, Smiriti; De Zan, Erica; Pepermans, Richard; Roovers, Rob C.|info:eu-repo/dai/nl/205435599; Haselberg, Rob|info:eu-repo/dai/nl/304822647; Hennink, Wim E.|info:eu-repo/dai/nl/070880409; Schiffelers, Raymond M.|info:eu-repo/dai/nl/212909509; Kok, Robbert J.|info:eu-repo/dai/nl/170678326; Van Bergen en Henegouwen, Paul M P|info:eu-repo/dai/nl/071919481

    2014-01-01

    The hepatocyte growth factor receptor (HGFR, c-Met or Met) is a receptor tyrosine kinase that is involved in embryogenesis, tissue regeneration and wound healing. Abnormal activation of this proto-oncogene product is implicated in the development, progression and metastasis of many cancers. Current

  16. Regulation of Epidermal Growth Factor Receptor Trafficking by Lysine Deacetylase HDAC6

    DEFF Research Database (Denmark)

    Lissanu Deribe, Yonathan; Wild, Philipp; Chandrashaker, Akhila;

    2009-01-01

    Binding of epidermal growth factor (EGF) to its receptor leads to receptor dimerization, assembly of protein complexes, and activation of signaling networks that control key cellular responses. Despite their fundamental role in cell biology, little is known about protein complexes associated...

  17. Targeting of the tumor necrosis factor receptor superfamily for cancer immunotherapy

    NARCIS (Netherlands)

    Bremer, Edwin

    2013-01-01

    The tumor necrosis factor (TNF) ligand and cognate TNF receptor superfamilies constitute an important regulatory axis that is pivotal for immune homeostasis and correct execution of immune responses. TNF ligands and receptors are involved in diverse biological processes ranging from the selective in

  18. No evidence for association of dopamine D2 receptor variant (Ser311/Cys311) with major psychosis

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Tsukasa; Macciardi, F.M.; Badri, F. [Clarke Institute of Psychiatry, Ontario (Canada)] [and others

    1996-07-26

    We investigated a variant of the dopamine D2 receptor gene (Ser311/Cys311 substitution) in Caucasian patients with schizophrenia (n = 273), delusional disorder (n = 62), bipolar I affective disorder (n = 63), and controls (n = 255). No evidence for association between the receptor variant and any of the diseases was found, even when patients with younger age-of-onset (<25 years) were compared with controls. Futhermore, in a subgroup of schizophrenia patients whom we assessed for negative symptoms, those with the Cys allele did not differ from the remainder of the group. Also, the bipolar affective disorder patients with psychotic features did not show evidence for association with the receptor variant. Thus, our results do not provide evidence for an association between this D2 receptor variant and schizophrenia, or delusional disorder, or bipolar affective disorder. 11 refs., 1 tab.

  19. Sulindac metabolites induce proteosomal and lysosomal degradation of the epidermal growth factor receptor.

    Science.gov (United States)

    Pangburn, Heather A; Ahnen, Dennis J; Rice, Pamela L

    2010-04-01

    The epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases. In response to ligand, EGFR is internalized and degraded by the ubiquitin-proteasome/lysosome pathway. We previously reported that metabolites of the nonsteroidal anti-inflammatory drug sulindac downregulate the expression of EGFR and inhibit basal and EGF-induced EGFR signaling through extracellular signal-regulated kinase 1/2. We now have evaluated the mechanisms of sulindac metabolite-induced downregulation of EGFR. EGF-induced downregulation of EGFR occurs within 10 minutes and lasts for 24 hours. By contrast, downregulation of EGFR by sulindac sulfide and sulindac sulfone was first evident at 4 and 24 hours, respectively, with maximal downregulation at 72 hours. Pretreatment with either the lysosomal inhibitor chloroquine or the proteosomal inhibitor MG132 blocked sulindac metabolite-induced downregulation of EGFR. Sulindac metabolites also increased the ubiquitination of EGFR. Whereas sulindac metabolites inhibited phosphorylation of EGFR pY1068, they increased phosphorylation of EGFR pY1045, the docking site where c-Cbl binds, thereby enabling receptor ubiquitination and degradation. Immunofluorescence analysis of EGF and EGFR distribution confirmed the biochemical observations that sulindac metabolites alter EGFR localization and EGFR internalization in a manner similar to that seen with EGF treatment. Expression of ErbB family members HER2 and HER3 was also downregulated by sulindac metabolites. We conclude that downregulation of EGFR expression by sulindac metabolites is mediated via lysosomal and proteosomal degradation that may be due to drug-induced phosphorylation at pY1045 with resultant ubiquitination of EGFR. Thus, sulindac metabolite-induced downregulation of EGFR seems to be mediated through mechanism(s) similar, at least in part, to those involved in EGF-induced downregulation of EGFR.

  20. Phosphorylation and lipid raft association of fibroblast growth factor receptor-2 in oligodendrocytes.

    Science.gov (United States)

    Bryant, M R; Marta, C B; Kim, F S; Bansal, R

    2009-07-01

    Fibroblast growth factors (FGFs) and their receptors (FGFRs) initiate diverse cellular responses that contribute to the regulation of oligodendrocyte (OL) function. To understand the mechanisms by which FGFRs elicit these cellular responses, we investigated the phosphorylation of signal transduction proteins and the role of cholesterol-glycosphingolipid-enriched "lipid raft" microdomains in differentiated OLs. Surprisingly, we found that the most abundant tyrosine-phosphorylated protein in OLs was the 120-kd isoform of FGFR2 and that it was phosphorylated even in the absence of FGF2, suggesting a potential ligand-independent function for this receptor. Furthermore, FGFR2, but not FGFR1, was associated with lipid raft microdomains in OLs and myelin (but not in astrocytes). This provides the first evidence for the association of FGFR with TX-100-insoluble lipid raft fractions. FGFR2 phosphorylated the key downstream target, FRS2 in OLs. Raft disruption resulted in loss of phosphorylated FRS2 from lipid rafts, coupled with the loss of Akt but not of Mek or Erk phosphorylation. This suggests that FGFR2-FRS2 signaling in lipid rafts operates via the PI3-Kinase/Akt pathway rather than the Ras/Mek/Erk pathway, emphasizing the importance of microenvironments within the cell membrane. Also present in lipid rafts in OLs and myelin, but not in astrocytes, was a novel 52-kd isoform of FGFR2 that lacked the extracellular ligand-binding region. These results demonstrate that FGFR2 in OLs and myelin possess unique characteristics that are specific both to receptor type and to OLs and provide a novel mechanism to elicit distinct cellular responses that mediate both FGF-dependent and -independent functions.

  1. Targeted cancer therapies based on antibodies directed against epidermal growth factor receptor: status and perspectives

    Institute of Scientific and Technical Information of China (English)

    Zhenping ZHU

    2007-01-01

    Compelling experimental and clinical evidence suggests that epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of a variety of human cancers; thus, providing a strong rationale for the development of receptor antagonists as effective and specific therapeutic strategies for the treatment of EGFR-expressing cancers. Monoclonal antibodies (mAb), owing to their high specificity towards a given target, represent a unique class of novel cancer therapeutics. A number of anti-EGFR mAb are currently being developed in our clinic, including two that have been approved by the United States Food and Drug Administration for the treatment of refractory metastatic colorectal cancer (mCRC) and squamous cell carcinomas of the head and neck (SCCHN). Cetuximab (Erbitux, IMC-C225), an IgG 1 mAb, has demonstrated significant antitumor activity,both as a single agent and in combination with chemotherapeutics and radiation,in patients with refractory mCRC and SCCHN, respectively. Panitumumab(Vectibix), an IgG2 mAb, has been approved as a single agent for the treatment of patients with refractory mCRC. These mAb, via blocking ligand/receptor interactions, exert their biological activity via multiple mechanisms, includinginhibition of cell cycle progression, potentiation of cell apoptosis, inhibition of DNA repair, inhibition of angiogenesis, tumor cell invasion and metastasis and,potentially, induction of immunological effector mechanisms. Anti-EGFR anti-bodies have demonstrated good safety profiles and potent anticancer activity in our clinic and may prove to be efficacious agents in the treatment of a variety of human malignancies.

  2. Dopaminergic 3H-agonist receptors in rat brain: new evidence on localization and pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Bacopoulos, N.G.

    1984-01-23

    Recent methodological advances have allowed the reliable assay of specific dopaminergic 3H-agonist binding sites in rat striatum. Lesions of dopamine(DA) terminals or drugs which deplete DA levels prevent the preincubation-induced increase in binding, and this effect is completely reversible by preincubation with added DA. It is concluded that the evidence supporting the existence of presynaptic D-3 sites is artefactual and that 3H-DA binding sites are more likely related to post-synaptic receptors. 3H-DA binding involves two sites, one of which has pharmacologic properties similar to D-1 receptors, whereas the other resembles D-2 receptors. The affinity of 15 antipsychotic drugs for 3H-haloperidol binding sites was highly correlated (R = 0.94) with their inhibitory potency at a subset of 3H-DA binding sites. However, the inhibition of 3H-DA binding by antipsychotic drugs was noncompetitive. These findings can be explained by an allosteric model, whereby antagonists bind to a site different from but allosterically linked to a high-affinity 3H-DA binding site.

  3. Tumor necrosis factor receptor-associated factor 3 is a positive regulator of pathological cardiac hypertrophy.

    Science.gov (United States)

    Jiang, Xi; Deng, Ke-Qiong; Luo, Yuxuan; Jiang, Ding-Sheng; Gao, Lu; Zhang, Xiao-Fei; Zhang, Peng; Zhao, Guang-Nian; Zhu, Xueyong; Li, Hongliang

    2015-08-01

    Cardiac hypertrophy, a common early symptom of heart failure, is regulated by numerous signaling pathways. Here, we identified tumor necrosis factor receptor-associated factor 3 (TRAF3), an adaptor protein in tumor necrosis factor-related signaling cascades, as a key regulator of cardiac hypertrophy in response to pressure overload. TRAF3 expression was upregulated in hypertrophied mice hearts and failing human hearts. Four weeks after aortic banding, cardiac-specific conditional TRAF3-knockout mice exhibited significantly reduced cardiac hypertrophy, fibrosis, and dysfunction. Conversely, transgenic mice overexpressing TRAF3 in the heart developed exaggerated cardiac hypertrophy in response to pressure overload. TRAF3 also promoted an angiotensin II- or phenylephrine-induced hypertrophic response in isolated cardiomyocytes. Mechanistically, TRAF3 directly bound to TANK-binding kinase 1 (TBK1), causing increased TBK1 phosphorylation in response to hypertrophic stimuli. This interaction between TRAF3 and TBK1 further activated AKT signaling, which ultimately promoted the development of cardiac hypertrophy. Our findings not only reveal a key role of TRAF3 in regulating the hypertrophic response but also uncover TRAF3-TBK1-AKT as a novel signaling pathway in the development of cardiac hypertrophy and heart failure. This pathway may represent a potential therapeutic target for this pathological process.

  4. Confirmatory factor analysis for the Eating Disorder Examination Questionnaire: Evidence supporting a three-factor model.

    Science.gov (United States)

    Barnes, Jennifer; Prescott, Tim; Muncer, Steven

    2012-12-01

    The purpose of this investigation was to compare the goodness-of-fit of a one factor model with the four factor model proposed by Fairburn (2008) and the three factor model proposed by Peterson and colleagues (2007) for the Eating Disorder Examination Questionnaire (EDE-Q 6.0) (Fairburn and Beglin, 1994). Using a cross-sectional design, the EDE-Q was completed by 569 adults recruited from universities and eating disorder charities in the UK. Confirmatory factor analysis (CFA) was carried out for both the student and non-student groups. CFA indicated that Peterson et al.'s (2007) three factor model was the best fit for both groups within the current data sample. Acceptable levels of internal reliability were observed and there was clear evidence for a hierarchical factor of eating disorder. The results of this study provide support for the three factor model of the EDE-Q suggested by Peterson and colleagues (2007) in that this model was appropriate for both the student and non-student sample populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. The aryl hydrocarbon receptor and estrogen receptor alpha differentially modulate nuclear factor erythroid-2-related factor 2 transactivation in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Raymond; Matthews, Jason, E-mail: jason.matthews@utoronto.ca

    2013-07-15

    Nuclear factor erythroid-2-related factor 2 (NRF2; NFE2L2) plays an important role in mediating cellular protection against reactive oxygen species. NRF2 signaling is positively modulated by the aryl hydrocarbon receptor (AHR) but inhibited by estrogen receptor alpha (ERα). In this study we investigated the crosstalk among NRF2, AHR and ERα in MCF-7 breast cancer cells treated with the NRF2 activator sulforaphane (SFN), a dual AHR and ERα activator, 3,3′-diindolylmethane (DIM), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 17β-estradiol (E2). SFN-dependent increases in NADPH-dependent oxidoreductase 1 (NQO1) and heme oxygenase I (HMOX1) mRNA levels were significantly reduced after co-treatment with E2. E2-dependent repression of NQO1 and HMOX1 was associated with increased ERα but reduced p300 recruitment and reduced histone H3 acetylation at both genes. In contrast, DIM + SFN or TCDD + SFN induced NQO1 and HMOX1 mRNA expression to levels higher than SFN alone, which was prevented by RNAi-mediated knockdown of AHR. DIM + SFN but not TCDD + SFN also induced recruitment of ERα to NQO1 and HMOX1. However, the presence of AHR at NQO1 and HMOX1 restored p300 recruitment and histone H3 acetylation, thereby reversing the ERα-dependent repression of NRF2. Taken together, our study provides further evidence of functional interplay among NRF2, AHR and ERα signaling pathways through altered p300 recruitment to NRF2-regulated target genes. - Highlights: • We examined crosstalk among ERα, AHR, and NRF2 in MCF-7 breast cancer cells. • AHR enhanced the mRNA expression levels of two NRF2 target genes – HMOX1 and NQO1. • ERα repressed HMOX1 and NQO1 expression via decreased histone acetylation. • AHR prevented ERα-dependent repression of HMOX1 and NQO1.

  6. Evidence for antimuscarinic acetylcholine receptor antibody-mediated secretory dysfunction in nod mice.

    Science.gov (United States)

    Nguyen, K H; Brayer, J; Cha, S; Diggs, S; Yasunari, U; Hilal, G; Peck, A B; Humphreys-Beher, M G

    2000-10-01

    Antibodies directed against general and specific target-organ autoantigens are present in the sera of human patients and animal models with autoimmune disease. The relevance of these autoantibodies to the disease process remains ambiguous in most cases. In autoimmune exocrinopathy (Sjögren's syndrome), autoantibodies to the intracellular nuclear proteins SSA/Ro and SSB/La, as well as the cell surface muscarinic cholinergic receptor (M3) are observed. To evaluate the potential role of these factors in the loss of secretory function of exocrine tissues, a panel of monoclonal and polyclonal antibodies was developed for passive transfer into the NOD animal model. Monoclonal antibodies to mouse SSB/La, rat M3 receptor, and a rabbit polyclonal antiparotid secretory protein antibody were obtained for this study. These antibody reagents were subsequently infused into NOD-scid mice. Saliva flow rates were subsequently monitored over a 72-hour period. Submandibular gland lysates were examined by Western blotting for alteration of the distribution of the water channel protein aquaporin (AQP). Evaluation of the secretory response indicated that only antibodies directed toward the extracellular domains of the M3 receptor were capable of mediating the exocrine dysfunction aspect of the clinical pathology of the autoimmune disease. In vitro stimulation with a muscarinic agonist of submandibular gland cells isolated from mice treated with anti-M3 antibody, but not saline or the isotype control, failed to translocate AQP to the plasma membrane. These findings define a clear role for the humoral immune response and the targeting of the cell surface M3 signal transduction receptor as primary events in the development of clinical symptoms of autoimmune exocrinopathy. Furthermore, the anti-M3 receptor activity may negatively affect the secretory response through perturbation of normal signal transduction events, leading to translocation of the epithelial cell water channel.

  7. Equine insulin receptor and insulin-like growth factor-1 receptor expression in digital lamellar tissue and insulin target tissues.

    Science.gov (United States)

    Kullmann, A; Weber, P S; Bishop, J B; Roux, T M; Norby, B; Burns, T A; McCutcheon, L J; Belknap, J K; Geor, R J

    2016-09-01

    Hyperinsulinaemia is implicated in the pathogenesis of endocrinopathic laminitis. Insulin can bind to different receptors: two insulin receptor isoforms (InsR-A and InsR-B), insulin-like growth factor-1 receptor (IGF-1R) and InsR/IGF-1R hybrid receptor (Hybrid). Currently, mRNA expression of these receptors in equine tissues and the influence of body type and dietary carbohydrate intake on expression of these receptors is not known. The study objectives were to characterise InsR-A, InsR-B, IGF-1R and Hybrid expression in lamellar tissue (LT) and insulin responsive tissues from horses and examine the effect of dietary nonstructural carbohydrate (NSC) on mRNA expression of these receptors in LT, skeletal muscle, liver and two adipose tissue (AT) depots of lean and obese ponies. In vivo experiment. Lamellar tissue samples were evaluated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) for receptor mRNA expression (n = 8) and immunoblotting for protein expression (n = 3). Archived LT, skeletal muscle, liver and AT from lean and obese mixed-breed ponies fed either a low (~7% NSC as dry matter; 5 lean, 5 obese) or high NSC diet (~42% NSC as dry matter; 6 lean, 6 obese) for 7 days were evaluated by RT-qPCR to determine the effect of body condition and diet on expression of the receptors in different tissues. Significance was set at P≤0.05. Lamellar tissue expresses both InsR isoforms, IGF-1R and Hybrid. LT IGF-1R gene expression was greater than either InsR isoform and InsR-A expression was greater than InsR-B (P≤0.05). Obesity significantly lowered IGF-1R, InsR-A and InsR-B mRNA expression in LT and InsR-A in tailhead AT. High NSC diet lowered expression of all three receptor types in liver; IGF-1R and InsR-A in LT and InsR-A in tailhead AT. Lamellar tissue expresses IGF-1R, InsR isoforms and Hybrids. The functional characteristics of these receptors and their role in endocrinopathic laminitis warrants further investigation. © 2015 EVJ

  8. EXPRESSION OF EPIDERMAL GROWTH FACTOR, TRANSFORMING GROWTH FACTOR-a AND THEIR RECEPTOR IN HUMAN PITUITARY TUMORS

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Long

    2001-01-01

    [1]LIU Xu-wen, FU Pei-yu, GAO Zhi-xian. Expression of epidermal growth factor receptors in human glioma [J]. Chin J Neurosurgery 1998; 14:71.[2]Wong AJ, Ruppert JM, Bigner SH, et al. Structural alterations of the epidermal growth factor receptor gene in human gliomas [J]. Proc Natl Acad Sci USA 1992; 89:4309.[3]Webster J, Ham J, Bevan JS. Preliminary characterization of growth factors secreted by human pituitary tumors [J]. J Clin Endocrinol Metab 1991; 72:687.[4]Klibanski A. Nonsecreting pituitary tumors [J]. Endocrinol Metab Clin North Am 1987; 16:793.[5]LeRiche VK, Asa SL, Ezzat S. Epidermal growth factor and its receptor (EGF-R) in human pituitary adenomas: EGF-R correlates with tumor aggressiveness [J]. J Clin Endocrinol Metab 1996; 81:656.

  9. Characterization of ubiquitination dependent dynamics in growth factor receptor signaling by quantitative proteomics

    DEFF Research Database (Denmark)

    Akimov, Vyacheslav; Rigbolt, Kristoffer T G; Nielsen, Mogens M;

    2011-01-01

    ) for selectively decoding ubiquitination-driven processes involved in the regulation of cellular signaling networks. We applied this approach to characterize the temporal dynamics of ubiquitination events accompanying epidermal growth factor receptor (EGFR) signal transduction. We used recombinant UBDs derived...

  10. New factors influencing G protein coupled receptors’ system ...

    African Journals Online (AJOL)

    Abdelaziz Ghanemi

    2012-11-24

    Nov 24, 2012 ... system functions. Abdelaziz .... systems. Such factors will be added to those already known including ..... crossroad between cell biology and physics. Nat Cell ... classification of receptors for 5-hydroxytryptamine (Serotonin).

  11. Gene expression of growth factors and growth factor receptors for potential targeted therapy of canine hepatocellular carcinoma.

    Science.gov (United States)

    Iida, Gentoku; Asano, Kazushi; Seki, Mamiko; Sakai, Manabu; Kutara, Kenji; Ishigaki, Kumiko; Kagawa, Yumiko; Yoshida, Orie; Teshima, Kenji; Edamura, Kazuya; Watari, Toshihiro

    2014-03-01

    The purpose of this study was to evaluate the gene expression of growth factors and growth factor receptors of primary hepatic masses, including hepatocellular carcinoma (HCC) and nodular hyperplasia (NH), in dogs. Quantitative real-time reverse transcriptase-polymerase chain reaction was performed to measure the expression of 18 genes in 18 HCCs, 10 NHs, 11 surrounding non-cancerous liver tissues and 4 healthy control liver tissues. Platelet-derived growth factor-B (PDGF-B), transforming growth factor-α, epidermal growth factor receptor, epidermal growth factor and hepatocyte growth factor were found to be differentially expressed in HCC compared with NH and the surrounding non-cancerous and healthy control liver tissues. PDGF-B is suggested to have the potential to become a valuable ancillary target for the treatment of canine HCC.

  12. Molecular size of benzodiazepine receptor in rat brain in situ: evidence for a functional dimer?

    Science.gov (United States)

    Doble, A.; Iversen, L. L.

    1982-02-01

    Benzodiazepine tranquillizers such as diazepam and chlordiazepoxide interact with high-affinity binding sites in nervous tissue1,2. The correlation between the affinities of various benzodiazepines for these sites with their clinical potencies and activity in behavioural and electrophysiological tests in animals suggests that the sites represent the functional `receptor' whereby benzodiazepines exert their effects3. The intimate involvement of benzodiazepines with γ-aminobutyric acid (GABA) and chloride channels raised the possibility that the benzodiazepine binding site (BDZ-R) may be a protein in the GABA receptor-effector complex4,5. GABA agonists enhance the affinity of BDZ-R for benzodiazepines6, although BDZ-R is distinct from the GABA receptor itself3. However, electrophysiological evidence suggests that the action of benzodiazepines is chloride channel, rather than receptor, directed7-10. Several attempts have been made to measure the molecular weight (Mr) of BDZ-R after solubilization from brain membranes: treatment with 1% Triton X-100 followed by assay of binding activity in solute fractions separated according to molecular weight suggested11 a value of ~200,000, photoaffinity labelling of BDZ-R with 3H-flunitrazepam (3H-FNZ) followed by more rigorous solubilization and gel chromatography indicated12,13 an apparent Mr of ~55,000 and a third approach14 a value of ~100,000. The measured molecular weight seems to depend critically on the solubilization procedure used. Chang et al.15 recently described the use of radiation inactivation to determine the size of BDZ-R in situ in calf brain membranes, and estimated a Mr, of 216,000. We have also used this approach; the results reported here indicate a Mr of between 90,000 and 100,000, but this is reduced to 60,000-63,000 in membranes pretreated with GABA, suggesting the disaggregation of a normally dimeric form.

  13. Origin of secretin receptor precedes the advent of tetrapoda: evidence on the separated origins of secretin and orexin.

    Directory of Open Access Journals (Sweden)

    Janice K V Tam

    Full Text Available At present, secretin and its receptor have only been identified in mammals, and the origin of this ligand-receptor pair in early vertebrates is unclear. In addition, the elusive similarities of secretin and orexin in terms of both structures and functions suggest a common ancestral origin early in the vertebrate lineage. In this article, with the cloning and functional characterization of secretin receptors from lungfish and X. laevis as well as frog (X. laevis and Rana rugulosa secretins, we provide evidence that the secretin ligand-receptor pair has already diverged and become highly specific by the emergence of tetrapods. The secretin receptor-like sequence cloned from lungfish indicates that the secretin receptor was descended from a VPAC-like receptor prior the advent of sarcopterygians. To clarify the controversial relationship of secretin and orexin, orexin type-2 receptor was cloned from X. laevis. We demonstrated that, in frog, secretin and orexin could activate their mutual receptors, indicating their coordinated complementary role in mediating physiological processes in non-mammalian vertebrates. However, among the peptides in the secretin/glucagon superfamily, secretin was found to be the only peptide that could activate the orexin receptor. We therefore hypothesize that secretin and orexin are of different ancestral origins early in the vertebrate lineage.

  14. Nerve growth factor and receptor expression in rheumatoid arthritis and spondyloarthritis

    NARCIS (Netherlands)

    Barthel, C.; Yeremenko, N.; Jacobs, R.; Schmidt, R.E.; Bernateck, M.; Zeidler, H.; Tak, P.P.; Baeten, D.; Rihl, M.

    2009-01-01

    Introduction We previously described the presence of nerve growth factor receptors in the inflamed synovial compartment. Here we investigated the presence of the corresponding nerve growth factors, with special focus on nerve growth factor (NGF). Methods mRNA expression levels of four ligands (NGF,

  15. Trophic factor-induced excitatory synaptogenesis involves postsynaptic modulation of nicotinic acetylcholine receptors.

    Science.gov (United States)

    Woodin, Melanie A; Munno, David W; Syed, Naweed I

    2002-01-15

    Neurotrophic factors have well established roles in neuronal development, although their precise involvement in synapse formation and plasticity is yet to be fully determined. Using soma-soma synapses between identified Lymnaea neurons, we have shown recently that trophic factors are required for excitatory but not inhibitory synapse formation. However, neither the precise site (presynaptic versus postsynaptic cell) nor the underlying mechanisms have yet been defined. In the present study, synapse formation between the presynaptic cell visceral dorsal 4 (VD4) and its postsynaptic partner right pedal dorsal 1 (RPeD1) was examined to define the cellular mechanisms mediating trophic factor-induced excitatory synaptogenesis in cell culture. When paired in a soma-soma configuration in the presence of defined media (DM, nonproteinacious), mutually inhibitory synapses were appropriately reconstructed between VD4 and RPeD1. However, when cells were paired in the presence of increasing concentrations of Lymnaea brain-conditioned medium (CM), a biphasic synapse (initial excitatory synaptic component followed by inhibition) developed. The CM-induced excitatory synapse formation required trophic factor-mediated activation of receptor tyrosine kinases in the postsynaptic cell, RPeD1, and a concomitant modulation of existing postsynaptic nicotinic acetylcholine receptors (nAChRs). Specifically, when RPeD1 was isolated in DM, exogenously applied ACh induced a hyperpolarizing response that was sensitive to the AChR antagonist methyllycaconitine (MLA). In contrast, a single RPeD1 isolated in CM exhibited a biphasic response to exogenously applied ACh. The initial depolarizing phase of the biphasic response was sensitive to both mecamylamine and hexamethonium chloride, whereas the hyperpolarizing phase was blocked by MLA. In soma-soma-paired neurons, the VD4-induced synaptic responses in RPeD1 were sensitive to the cholinergic antagonists in a concentration range similar to that

  16. Association of coatomer proteins with the beta-receptor for platelet-derived growth factor

    DEFF Research Database (Denmark)

    Hansen, Klaus; Rönnstrand, L; Rorsman, C

    1997-01-01

    of intracellular vesicle transport. In order to explore the functional significance of the interaction between alpha- and beta'-COP and the PDGF receptor, a receptor mutant was made in which the conserved histidine residue 928 was mutated to an alanine residue. The mutant receptor, which was unable to bind alpha......The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we...... noticed that components of 136 and 97 kDa bound to a peptide from this region of the receptor in a phosphorylation-independent manner. These components have now been purified and identified as alpha- and beta'-coatomer proteins (COPs), respectively. COPs are a family of proteins involved in the regulation...

  17. Extended Synaptotagmin Interaction with the Fibroblast Growth Factor Receptor Depends on Receptor Conformation, Not Catalytic Activity.

    Science.gov (United States)

    Tremblay, Michel G; Herdman, Chelsea; Guillou, François; Mishra, Prakash K; Baril, Joëlle; Bellenfant, Sabrina; Moss, Tom

    2015-06-26

    We previously demonstrated that ESyt2 interacts specifically with the activated FGF receptor and is required for a rapid phase of receptor internalization and for functional signaling via the ERK pathway in early Xenopus embryos. ESyt2 is one of the three-member family of Extended Synaptotagmins that were recently shown to be implicated in the formation of endoplasmic reticulum (ER)-plasma membrane (PM) junctions and in the Ca(2+) dependent regulation of these junctions. Here we show that ESyt2 is directed to the ER by its putative transmembrane domain, that the ESyts hetero- and homodimerize, and that ESyt2 homodimerization in vivo requires a TM adjacent sequence but not the SMP domain. ESyt2 and ESyt3, but not ESyt1, selectively interact in vivo with activated FGFR1. In the case of ESyt2, this interaction requires a short TM adjacent sequence and is independent of receptor autophosphorylation, but dependent on receptor conformation. The data show that ESyt2 recognizes a site in the upper kinase lobe of FGFR1 that is revealed by displacement of the kinase domain activation loop during receptor activation.

  18. Epidermal growth factor receptor (EGFR) and EGFR mutations, function and possible role in clinical trials

    DEFF Research Database (Denmark)

    Voldborg, B R; Damstrup, L; Spang-Thomsen, M;

    1997-01-01

    The epidermal growth factor receptor (EGFR) is a growth factor receptor that induces cell differentiation and proliferation upon activation through the binding of one of its ligands. The receptor is located at the cell surface, where the binding of a ligand activates a tyrosine kinase...... in the intracellular region of the receptor. This tyrosine kinase phosphorylates a number of intracellular substrates that activates pathways leading to cell growth, DNA synthesis and the expression of oncogenes such as fos and jun. EGFR is thought to be involved the development of cancer, as the EGFR gene is often...... amplified, and/or mutated in cancer cells. In this review we will focus on: (I) the structure and function of EGFR, (II) implications of receptor/ligand coexpression and EGFR mutations or overexpression, (III) its effect on cancer cells, (IV) the development of the malignant phenotype and (V) the clinical...

  19. Transactivation of Epidermal Growth Factor Receptor by G Protein-Coupled Receptors: Recent Progress, Challenges and Future Research

    Directory of Open Access Journals (Sweden)

    Zhixiang Wang

    2016-01-01

    Full Text Available Both G protein-coupled receptors (GPCRs and receptor-tyrosine kinases (RTKs regulate large signaling networks, control multiple cell functions and are implicated in many diseases including various cancers. Both of them are also the top therapeutic targets for disease treatment. The discovery of the cross-talk between GPCRs and RTKs connects these two vast signaling networks and complicates the already complicated signaling networks that regulate cell signaling and function. In this review, we focus on the transactivation of epidermal growth factor receptor (EGFR, a subfamily of RTKs, by GPCRs. Since the first report of EGFR transactivation by GPCR, significant progress has been made including the elucidation of the mechanisms underlying the transactivation. Here, we first provide a basic picture for GPCR, EGFR and EGFR transactivation by GPCR. We then discuss the progress made in the last five years and finally provided our view of the future challenge and future researches needed to overcome these challenges.

  20. DETERMINATION OF SERUM SOLUBLE MACROPHAGE COLONY- STIMULATING FACTOR RECEPTOR LEVELS IN PATIENTS with hematological diseases

    Institute of Scientific and Technical Information of China (English)

    RAO; Qing

    2001-01-01

    [1]Heaney MK, Golde DW. Soluble receptors in human disease [J]. J Leukoc Biol 1998; 61:135.[2]Fix P, Praloram V. M-CSF: Haematopoietic growth factor or inflammatory cytokine [J]? Cytokine 1998; 10:32.[3]Sherr C. Colony-stimulating factor ? 1 receptor [J]. Blood 1990; 75:1.[4]Downing JR, Roussel MF, Sherr CJ. Ligand and protein kinase C down modulate the colony-stimulating factor 1 receptor by independent mechanisms [J]. Mol Cell Biol 1989; 9:2890.[5]Baker AH, Cachia PG, Tennant GB, et al. A novel CSF-1 binding factor in a patient in complete remission following cytotoxic therapy for lymphoma [J]. Br J Haematol 1995; 89:219.[6]Wu KF, Zheng GG, Rao Q, et al. Cellular macrophage colony-stimulating factor and its role [J]. Hematologica 1999; 84:951.[7]Rao Q, Han JS, Geng YQ, et al. Antigen association of J6-1 cell membrane associated factor receptor with macrophage colony-stimulating factor receptor [J]. Chin J Cancer Res 1999; 11:235.[8]Rao Q, Han JS, Geng YQ, et al. Quantitation of human soluble macrophage colony stimulating factor receptor in human serum by ELISA assay [J]. Exp Hematol 1999; 27:105.[9]Luo SQ, Zheng DX, Liu YX, et al. Analysis of the ligand-binding domain of macrophage colony- stimulating factor receptor [J]. Chin Sci Bull 2000; 45:1191.[10]Wypych J, Bennett LG, Schwartz MG, et al. Soluble Kit receptor in human serum [J]. Blood 1995; 85:66.[11]Tiesman J, Hart CE. Identification of a soluble receptor for platelet-derived growth factor in cell-conditioned medium and human plasma [J]. J Biol Chem 1993; 269:9621.[12]Zhang Q, Xue YP, Song YH, et al. Expression of cellular M-CSF and M-CSFR in hematopoietic cells [J]. Chin J Hematol 1999; 20:249.[13]Tang SS, Liu HZ, Chen GB, et al. Internalization mediated by membrane-bound macrophage colony- stimulating factor and half-life of cell associated macrophage colony-stimulating factor and its receptor [J]. Chin Sci Bull 2000; 45:627.[14]Zeigler ZR

  1. Estrogen receptor α gene polymorphisms and risk of Alzheimer’s disease: evidence from a meta-analysis

    Directory of Open Access Journals (Sweden)

    Cheng D

    2014-06-01

    Full Text Available Daye Cheng,1 Bin Liang,2 Yiwen Hao,1 Wenling Zhou1 1Department of Transfusion, First Hospital of China Medical University, Shenyang, 2Department of Clinical Laboratory, High Vocational Technological College, China Medical University, Shenyang, People’s Republic of China Objective: Human estrogen receptor α (ESR1, a member of the nuclear receptor superfamily of ligand-activated transcription factors, is one of the key mediators of hormonal response in estrogen-sensitive tissues. Accumulating evidence has demonstrated that two of the most widely studied single-nucleotide polymorphisms in ESR1 – PvuII (T/C, rs223493 and Xbal (A/G, rs9340799 – are possibly associated with Alzheimer’s disease (AD. However, individual study results are still controversial.Materials and methods: We searched PubMed, Embase, Web of Science, Science Direct, SpringerLink, and the Chinese National Knowledge Infrastructure databases for eligible studies assessing the association of ESR1 polymorphisms and AD risk (last search performed in November 2013. Thereafter, a meta-analysis of 13,192 subjects from 18 individual studies was conducted to evaluate the association between ESR1 polymorphisms and susceptibility to AD.Results: The results indicated that a significant association was found between the ESR1 PvuII polymorphism and AD risk in Caucasian populations (CC + CT versus TT, odds ratio [OR] 1.14, 95% confidence interval [CI] 1.02–1.28, P=0.03; CT versus TT, OR 1.16, 95% CI 1.02–1.31, P=0.02, whereas no evidence of association was found in Asian populations. Nevertheless, we did not find any significant association between the ESR1 XbaI polymorphism and AD risk for any model in Caucasian and Asian populations (all P>0.05.Conclusion: Based on this meta-analysis, we conclude that the ESR1 PvuII polymorphism might be a risk factor in AD development in Caucasian populations, not in Asian populations. Further confirmation is needed from better-designed and

  2. [Epidermal growth factor receptor expression and epidermal growth factor blood plasma content in simple and complex endometrial hyperplasia].

    Science.gov (United States)

    Dznelashvili, N; Kasradze, D; Tavartkiladze, A; Mariamidze, A

    2014-01-01

    The goal of our study was to concurrently determine the prognostic significance of Epidermal Growth Factor Receptor (EGFR) expression in endometrium and Epidermal Growth Factor (EGF) blood content in simple and complex hyperplasia. In order to detect EGFR expression, immunohistochemical examination of endometrial scarp from 35 patients was done along with HPLC (High performance liquid chromatography) method, for measuring EGF blood plasma content. The numerical data obtained were processed statistically using computer program SPSS-12. According to the results: 1. A significant/marked increase in EGF blood plasma level together with pronounced EGFR expression in simple endometrial hyperplasia (without atypia) suggests that simple hyperplasia is likely to transform into complex form, while unchanged level of EGF against the background of mild EGFR expression is probably indicative of not very bad prognosis. 2. Normal indices of EGF blood plasma level in simple endometrial hyperplasia (without atypia), accompanied by mild EGFR expression is suggestive of good prognosis. 3. A sharp or extremely sharp increase in EGF blood plasma level with pronounced EGFR expression in complex endometrial hyperplasia (without atypia) is likely to indicate poor prognosis that may lead to the transformation into atypical form. However, unchanged EGF blood plasma level against the background of mild EGFR expression in complex endometrial hyperplasia (without atypia) is likely to point to not very bad prognosis. 4. A marked increase in EGF blood plasma level with a pronounced EGFR expression in complex endometrial hyperplasia (without atypia) is likely to indicate poor prognosis that may lead to the transformation into atypical form. Because it is evident that drastic increase in EGF blood plasma level is not necessary, other factor should be suspected to play the major role, i.e the substance that will (or will not) withstand neoplasia.

  3. Asymmetric Receptor Contact is Required for Tyrosine Autophosphorylation of Fibroblast Growth Factor Receptor in Living Cells

    Energy Technology Data Exchange (ETDEWEB)

    Bae, J.; Boggon, T; Tomé, F; Mandiyan, V; Lax, I; Schlessinge, J

    2010-01-01

    Tyrosine autophosphorylation of receptor tyrosine kinases plays a critical role in regulation of kinase activity and in recruitment and activation of intracellular signaling pathways. Autophosphorylation is mediated by a sequential and precisely ordered intermolecular (trans) reaction. In this report we present structural and biochemical experiments demonstrating that formation of an asymmetric dimer between activated FGFR1 kinase domains is required for transphosphorylation of FGFR1 in FGF-stimulated cells. Transphosphorylation is mediated by specific asymmetric contacts between the N-lobe of one kinase molecule, which serves as an active enzyme, and specific docking sites on the C-lobe of a second kinase molecule, which serves a substrate. Pathological loss-of-function mutations or oncogenic activating mutations in this interface may hinder or facilitate asymmetric dimer formation and transphosphorylation, respectively. The experiments presented in this report provide the molecular basis underlying the control of transphosphorylation of FGF receptors and other receptor tyrosine kinases.

  4. The nerve growth factor and its receptors in airway inflammatory diseases.

    Science.gov (United States)

    Freund-Michel, V; Frossard, N

    2008-01-01

    The nerve growth factor (NGF) belongs to the neurotrophin family and induces its effects through activation of 2 distinct receptor types: the tropomyosin-related kinase A (TrkA) receptor, carrying an intrinsic tyrosine kinase activity in its intracellular domain, and the receptor p75 for neurotrophins (p75NTR), belonging to the death receptor family. Through activation of its TrkA receptor, NGF activates signalling pathways, including phospholipase Cgamma (PLCgamma), phosphatidyl-inositol 3-kinase (PI3K), the small G protein Ras, and mitogen-activated protein kinases (MAPK). Through its p75NTR receptor, NGF activates proapoptotic signalling pathways including the MAPK c-Jun N-terminal kinase (JNK), ceramides, and the small G protein Rac, but also activates pathways promoting cell survival through the transcription factor nuclear factor-kappaB (NF-kappaB). NGF was first described by Rita Levi-Montalcini and collaborators as an important factor involved in nerve differentiation and survival. Another role for NGF has since been established in inflammation, in particular of the airways, with increased NGF levels in chronic inflammatory diseases. In this review, we will first describe NGF structure and synthesis and NGF receptors and their signalling pathways. We will then provide information about NGF in the airways, describing its expression and regulation, as well as pointing out its potential role in inflammation, hyperresponsiveness, and remodelling process observed in airway inflammatory diseases, in particular in asthma.

  5. Expression of tumor necrosis factor related apoptosis inducing ligand receptor in glioblastoma

    Institute of Scientific and Technical Information of China (English)

    Dongling Gao; Zhongwei Zhao; Hongxin Zhang; Lan Zhang; Kuisheng Chen; Yunhan Zhang

    2008-01-01

    BACKGROUND: Receptors for tumor necrosis factor related apoptosis inducing ligand (TRAIL) include death receptor 4, death receptor 5, decoy receptor 1, and decoy receptor 2. Activation of death receptor 4 and 5 selectively kills tumor cells.OBJECTIVE: To detect TRAIL receptor expression in glioblastoma by immunohistochemistry and RT-PCR and to compare this expression to that in normal brain tissue.DESIGN: Observational analysis.SETTING: Department of Pathology, the First Affiliated Hospital of Zhengzhou University; Henan Tumor Pathology Key Laboratory.PARTICIPANTS: Twenty-five patients (17 males and 8 females) who received glioblastoma resection were selected from the Fifth Affiliated Hospital of Zhengzhou University, between September 2003 to June 2004. All glioblastoma samples were diagnosed pathologically. Twenty patients (12 males and 8 females) with craniocerebral injury who received normal brain tissue resection were selected in the same time period. There were no significant differences in sex and age between glioblastoma patients or between craniocerebral injury patients (P>0.05). All patients and appropriate relatives provided informed consent, and this study was approved by the local research ethics committee.METHODS: Polyclonal antibody against TRAIL receptors and an immunohistochemical kit (batch number: 200502) were purchased from Boster Company, Wuhan. Immunohistochemistry: Expression of death receptor 4, death receptor 5, decoy receptor 1, and decoy receptor 2 were observed in both glioblastoma and normal brain tissue. The experiment was performed according to the kit instructions, and positive staining was brown-yellow. Assessment: There were no positive signals (-); weakly positive signals, positive cells75% (++++). Evaluation: Expression levels of TRAIL receptors were estimated in both normal brain tissue and glioblastoma. Expression of decoy receptor 1 and decoy receptor 2 mRNA in glioblastoma were detected by reverse transcription polymerase

  6. Epidermal growth factor receptor mutation enhances expression of vascular endothelial growth factor in lung cancer.

    Science.gov (United States)

    Hung, Ming-Szu; Chen, I-Chuan; Lin, Paul-Yann; Lung, Jr-Hau; Li, Ya-Chin; Lin, Yu-Ching; Yang, Cheng-Ta; Tsai, Ying-Huang

    2016-12-01

    Epidermal growth factor receptor (EGFR) activation has been demonstrated to have a critical role in tumor angiogenesis. In the present study, the correlation between EGFR mutations and vascular endothelial growth factor (VEGF) was investigated in lung cancer cell lines and non-small-cell lung cancer (NSCLC) tumor tissues. VEGF levels were significantly increased in culture medium of lung cancer cells and NSCLC tissues with EGFR mutations (H1650 vs. A549, P=0.0399; H1975 vs. A549, Plung cancer cell lines expressing mutant (exon 19 deletion, E746-A750; exon 21 missense mutation, L858R) and wild-type EGFR genes were established. Significantly increased expression of VEGF and stronger inhibitory effects of gefitinib to VEGF expression were observed in exon 19 deletion stable lung cancer cells (exon 19 deletion vs. wild-type EGFR, P=0.0005). The results of the present study may provide an insight into the association of mutant EGFR and VEGF expression in lung cancer, and may assist with further development of targeted therapy for NSCLC in the future.

  7. Study of the interaction of the Ig2 module of the fibroblast growth factor receptor, FGFR Ig2, with the fibroblast growth factor 1, FGF1, by means of NMR spectroscopy

    DEFF Research Database (Denmark)

    Kochoyan, Artur; Poulsen, Flemming M; Berezin, Vladimir;

    2008-01-01

    Fibroblast growth factor (FGF) receptor (FGFR) consists extracellularly of three immunoglobulin (Ig) modules (Ig1-3). Currently, there are two competing models (symmetric and asymmetric) of the FGF-FGFR-heparin complex based on crystal structures. Indirect evidence exists in support of both models...

  8. Increase of tumor necrosis factor receptor 1 expression in women with unexplained early spontaneous abortion

    Institute of Scientific and Technical Information of China (English)

    YAN Chun-fang; YU Xue-wen; JIN Hui; LI Xu

    2004-01-01

    To investigate membrane tumor necrosis factor receptor 1 protein expression level in decidua andconcentration of soluble tumor necrosis factor receptor 1 in serum in women with unexplained early spontaneous abortion,threatened abortion, and compare the levels with healthy pregnant women. Methods: Thirty-seven women with unexplainedearly spontaneous abortion, 27 women with threatened abortion, and 34 healthy pregnant women undergoing artificial abortionof pregnancy at 6 - 10 weeks of gestation were selected. Decidual samples were collected when women were undergoing arti-ficial abortion, and blood samples were collected at the same time. The level of membrane tumor necrosis factor receptor 1 indecidua was detected by flow cytometer, and the concentration of soluble tumor necrosis factor receptor 1 in sera was mea-sured with an enzyme-linked immunosorbent assay. Results: The ercentages of membrane tumor necrosis factor receptor 1positive decidual cells were 16.42 ± 7.10 Mean ± SD for women with unexplained early spontaneous abortion and 13.14 ±6.30 for healthy pregnant women ( P < 0.05). Serum oncentration of soluble tumor necrosis factor receptor 1 was signifi-cantly higher in women with unexplained early spontaneous abortion than in healthy pregnant women and in women withthreatened abortion, and no difference was found between healthy pregnant women and women with threatened abortion.Conclusion: Women with unexplained early spontaneous abortion present significantly higher expression of tumor necrosisfactor receptor 1 than healthy pregnant women, suggesting that over-expression of tumor necrosis factor receptor 1 may cont-ribute to the development of early spontaneous abortion.

  9. The oncogenic epidermal growth factor receptor variant Xiphophorus melanoma receptor kinase induces motility in melanocytes by modulation of focal adhesions.

    Science.gov (United States)

    Meierjohann, Svenja; Wende, Elisabeth; Kraiss, Anita; Wellbrock, Claudia; Schartl, Manfred

    2006-03-15

    One of the most prominent features of malignant melanoma is the fast generation of metastasizing cells, resulting in the poor prognosis of patients with this tumor type. For this process, cells must gain the ability to migrate. The oncogenic receptor Xmrk (Xiphophorus melanoma receptor kinase) from the Xiphophorus melanoma system is a mutationally activated version of the epidermal growth factor receptor that induces the malignant transformation of pigment cells. Here, we show that the activation of Xmrk leads to a clear increase of pigment cell motility in a fyn-dependent manner. Stimulation of Xmrk induces its interaction with the focal adhesion kinase (FAK) and the interaction of active, receptor-bound fyn with FAK. This results in changes in FAK activity and induces the modulation of stress fibers and focal adhesions. Overexpression of dominant-negative FAK shows that the activity of innate FAK and a receptor-induced focal adhesion turnover are a prerequisite for pigment cell migration. Our findings show that in our system, Xmrk is sufficient for the induction of pigment cell motility and underlines a role of the src family protein tyrosine kinase fyn in melanoma development and progression.

  10. Effects of estrogen receptor antagonist on biological behavior and expression of growth factors in the prolactinoma MMQ cell line.

    Science.gov (United States)

    Lv, Hongtao; Li, Chuzhong; Gui, Songbai; Sun, Meizhen; Li, Dan; Zhang, Yazhuo

    2011-04-01

    The relationship between estrogen and pituitary prolactinoma is well documented. The biological effects of estrogen are mainly mediated by estrogen receptor α (ERα). Several lines of evidence demonstrate that growth factors such as pituitary tumor transforming gene (PTTG), basic fibroblast growth factor (bFGF), transforming growth factor β1 (TGFβ1), transforming growth factor β3 (TGFβ3), and transforming growth factor β receptor type II (TGFβRII) play an important role in prolactinoma pathogenesis induced by estrogen, but the relationship between ERα and such growth factors is still unclear. The aims of this study are to investigate the functional role of ERα in proliferation, prolactin (PRL) secretion, and expression of the above-mentioned growth factors in MMQ cells in the absence of estrogen and to discuss the feasibility of using an estrogen receptor antagonist to treat prolactinoma. Fulvestrant, a "pure" antiestrogen without any estrogen-like activity, was used to block expression of ERα in the MMQ cell line. Proliferation and PRL secretion of MMQ cells were measured using CellTiter 96(®) AQueous One Solution Cell Proliferation Assay (MTS) and the enzyme-linked immunosorbent assay (ELISA) method. Levels of ERα, PTTG, bFGF, TGFβ1, TGFβ3, and TGFβRII were analyzed by real-time polymerase chain reaction (PCR) and Western blot. Fulvestrant significantly inhibited cell proliferation (up to 60.80%) and PRL secretion (up to 77.95%), and changed expression of TGFβ3 and TGFβRII in the absence of estrogen. In conclusion, ERα plays an important functional role in proliferation and PRL secretion of pituitary prolactinomas and also can change expression of some growth factors even under the condition of no estrogen. Fulvestrant could potentially be an effective therapy for treating such tumors.

  11. [Dependence of EGF receptor and STAT factor activation on redox of A431 cells].

    Science.gov (United States)

    Gonchar, I V; Burova, E B; Dorosh, V N; Gamaleĭ, I A; Nikol'skiĭ, N N

    2003-01-01

    Reactive oxygen species (ROS) were established to play an important role in cellular signaling as second messengers by integrating different pathways. Recently, we showed that EGF initiated a rapid tyrosine phosphorylation of both EGF-receptor and STAT factors with simultaneous increase in the intracellular ROS level. Now, we have investigated the effect of intracellular red-ox state on EGF- and H2O2-induced activation of EGF receptor, STAT1 and STAT3. We demonstrated that the pretreatment of A431 cells with antioxidant N-acetyl-L-cysteine (NAC) partly reduced the level of EGF-induced phosphorylation of proteins under investigation. Besides, H2O2-induced activation of EGF receptor, and STAT factors was fully prevented by NAC pretreatment. The inhibition of ROS generation by DPI declined EGF-dependent activation of EGF receptor and STAT factors to basal level. Our results demonstrate the essential role of cellular red-ox status in the modulation of EGF-mediated activation of receptor and STAT factors. We have postulated that EGF-induced ROS generation is a very important initial event promoting physiological activation of EGF receptor and subsequent STAT factor activation.

  12. Evidence that the angiotensin at 2-receptor agonist compound 21 is also a low affinity thromboxane TXA2-receptor antagonist

    DEFF Research Database (Denmark)

    Fredgart, M.; Leurgans, T.; Stenelo, M.;

    2015-01-01

    Objective: The objective of this study was to test whether Compound 21 (C21), a high-affinity, non-peptide angiotensinAT2-receptor agonist, is also an antagonist of thromboxane A2 (TXA2) receptors thus reducing both vasoconstriction and platelet aggregation. Design and method: Binding of C21 to t...

  13. Blocking transforming growth factor- receptor signaling down-regulates transforming growth factor-β1 autoproduction in keloid fibroblasts

    Institute of Scientific and Technical Information of China (English)

    刘伟; 蔡泽浩; 王丹茹; 武小莉; 崔磊; 商庆新; 钱云良; 曹谊林

    2002-01-01

    Objective: To study transforming growth factor-β1(TGF-β1) autoproduction in keloid fibroblasts and theregulation effect of blocking TGF-β intracellular signalingon rhTGF-β1 autoproduction.Methods: Keloid fibroblasts cultured in vitro weretreated with either rhTGF-β1 (5 ng/ml ) or recombinantadenovirus containing a truncated type II TGF-β receptorgene (50 pfu/cell ). Their effects of regulating geneexpression of TGF-β1 and its receptor I and II wereobserved with Northern blot.Results: rhTGF-β1 up-regulated the gene expressionof TGF-β1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated thegene expression of TGF-β1 and its receptor I, but notreceptor II.Conclusions: TGF-β1 autoproduction was observed inkeloid fibroblasts. Over-expression of the truncated TGF-βreceptor H decreased TGF-β1 autoproduction via blockingTGF-β receptor signaling.

  14. Evidence that the EphA2 receptor exacerbates ischemic brain injury.

    Directory of Open Access Journals (Sweden)

    John Thundyil

    Full Text Available Ephrin (Eph signaling within the central nervous system is known to modulate axon guidance, synaptic plasticity, and to promote long-term potentiation. We investigated the potential involvement of EphA2 receptors in ischemic stroke-induced brain inflammation in a mouse model of focal stroke. Cerebral ischemia was induced in male C57Bl6/J wild-type (WT and EphA2-deficient (EphA2(-/- mice by middle cerebral artery occlusion (MCAO; 60 min, followed by reperfusion (24 or 72 h. Brain infarction was measured using triphenyltetrazolium chloride staining. Neurological deficit scores and brain infarct volumes were significantly less in EphA2(-/- mice compared with WT controls. This protection by EphA2 deletion was associated with a comparative decrease in brain edema, blood-brain barrier damage, MMP-9 expression and leukocyte infiltration, and higher expression levels of the tight junction protein, zona occludens-1. Moreover, EphA2(-/- brains had significantly lower levels of the pro-apoptotic proteins, cleaved caspase-3 and BAX, and higher levels of the anti-apoptotic protein, Bcl-2 as compared to WT group. We confirmed that isolated WT cortical neurons express the EphA2 receptor and its ligands (ephrin-A1-A3. Furthermore, expression of all four proteins was increased in WT primary cortical neurons following 24 h of glucose deprivation, and in the brains of WT mice following stroke. Glucose deprivation induced less cell death in primary neurons from EphA2(-/- compared with WT mice. In conclusion, our data provide the first evidence that the EphA2 receptor directly contributes to blood-brain barrier damage and neuronal death following ischemic stroke.

  15. Crystallographic Identification and Functional Characterization of Phospholipids as Ligands for the Orphan Nuclear Receptor Steroidogenic Factor-1

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yong; Choi, Mihwa; Cavey, Greg; Daugherty, Jennifer; Suino, Kelly; Kovach, Amanda; Bingham, Nathan C.; Kliewer, Steven A.; Xu, H.Eric (Van Andel); (U. of Texas-SMED)

    2010-11-10

    The orphan nuclear receptor steroidogenic factor 1 (SF-1) regulates the differentiation and function of endocrine glands. Although SF-1 is constitutively active in cell-based assays, it is not known whether this transcriptional activity is modulated by ligands. Here, we describe the 1.5 {angstrom} crystal structure of the SF-1 ligand binding domain in complex with an LXXLL motif from a coregulator protein. The structure reveals the presence of a phospholipid ligand in a surprisingly large pocket ({approx}1600 {angstrom}{sup 3}), with the receptor adopting the canonical active conformation. The bound phospholipid is readily exchanged and modulates SF-1 interactions with coactivators. Mutations designed to reduce the size of the SF-1 pocket or to disrupt hydrogen bonds with the phospholipid abolish SF-1/coactivator interactions and significantly reduce SF-1 transcriptional activity. These findings provide evidence that SF-1 is regulated by endogenous ligands and suggest an unexpected relationship between phospholipids and endocrine development and function.

  16. Sperm-Egg Interaction: Evidence for Boar Sperm Plasma Membrane Receptors for Porcine Zona Pellucida

    Science.gov (United States)

    Peterson, Rudolph N.; Russell, Lonnie; Bundman, Donna; Freund, Matthew

    1980-01-01

    Freshly ejaculated, noncapacitated boar sperm bind rapidly and in large numbers to pig egg zona pellucida in vitro. In the present study, the number of sperm bound decreased sharply when sperm motility was lowered by energy poisons or by reducing the temperature. Highly motile sperm from humans, guinea pigs, and rats, added at concentrations ten times higher than control sperm, did not bind to the porcine zona. At the same high concentration, a small number of hamster and bull sperm bound to the zona. Binding of boar sperm to the zona pellucida was blocked almost completely by diluted whole antiserum to sperm plasma membranes and by univalent (Fab) antibody to these membranes. When antibody to sperm plasma membrane was first absorbed with plasma membrane vesicles, sperm binding was not inhibited. These results provide direct evidence for the existence of sperm plasma membrane receptors for the zona pellucida of the pig.

  17. Evidence for loss of synaptic AMPA receptors in anterior piriform cortex of aged mice.

    Science.gov (United States)

    Gocel, James; Larson, John

    2013-01-01

    It has been suggested that age-related impairments in learning and memory may be due to age-related deficits in long-term potentiation of glutamatergic synaptic transmission. For example, olfactory discrimination learning is significantly affected by aging in mice and this may be due, in part, to diminished synaptic plasticity in piriform cortex. In the present study, we tested for alterations in electrophysiological properties and synaptic transmission in this simple cortical network. Whole-cell recordings were made from principal neurons in slices of anterior piriform cortex from young (3-6 months old) and old (24-28 months) C57Bl/6 mice. Miniature excitatory postsynaptic currents (mEPSCs) mediated by AMPA receptors were collected from cells in presence of tetrodotoxin (TTX) and held at -80 mV in voltage-clamp. Amplitudes of mEPSCs were significantly reduced in aged mice, suggesting that synaptic AMPA receptor expression is decreased during aging. In a second set of experiments, spontaneous excitatory postsynaptic currents (s/mEPSCs) were recorded in slices from different cohorts of young and old mice, in the absence of TTX. These currents resembled mEPSCs and were similarly reduced in amplitude in old mice. The results represent the first electrophysiological evidence for age-related declines in glutamatergic synaptic function in the mammalian olfactory system.

  18. Internalization mechanisms of the epidermal growth factor receptor after activation with different ligands.

    Directory of Open Access Journals (Sweden)

    Lasse Henriksen

    Full Text Available The epidermal growth factor receptor (EGFR regulates normal growth and differentiation, but dysregulation of the receptor or one of the EGFR ligands is involved in the pathogenesis of many cancers. There are eight ligands for EGFR, however most of the research into trafficking of the receptor after ligand activation focuses on the effect of epidermal growth factor (EGF and transforming growth factor-α (TGF-α. For a long time it was believed that clathrin-mediated endocytosis was the major pathway for internalization of the receptor, but recent work suggests that different pathways exist. Here we show that clathrin ablation completely inhibits internalization of EGF- and TGF-α-stimulated receptor, however the inhibition of receptor internalization in cells treated with heparin-binding EGF-like growth factor (HB-EGF or betacellulin (BTC was only partial. In contrast, clathrin knockdown fully inhibits EGFR degradation after all ligands tested. Furthermore, inhibition of dynamin function blocked EGFR internalization after stimulation with all ligands. Knocking out a number of clathrin-independent dynamin-dependent pathways of internalization had no effect on the ligand-induced endocytosis of the EGFR. We suggest that EGF and TGF-α lead to EGFR endocytosis mainly via the clathrin-mediated pathway. Furthermore, we suggest that HB-EGF and BTC also lead to EGFR endocytosis via a clathrin-mediated pathway, but can additionally use an unidentified internalization pathway or better recruit the small amount of clathrin remaining after clathrin knockdown.

  19. Insulin-like growth factor II: complexity of biosynthesis and receptor binding

    DEFF Research Database (Denmark)

    Gammeltoft, S; Christiansen, Jan; Nielsen, F C

    1991-01-01

    , Man-6-P induces cellular responses. We have studied rat brain neuronal precursor cells where Man-6-P acted as a mitogen suggesting that phosphomannosylated proteins may act as growth factors via the Man-6-P/IGF-II receptor. In conclusion, the gene expression and mechanism of action of IGF-II is very...... and the mannose-6-phosphate (Man-6-P)/IGF-II receptor. There is consensus that the cellular effects of IGF-II are mediated by the IGF-I receptor via activation of its intrinsic tyrosine kinase. The Man-6-P/IGF-II receptor is involved in endocytosis of lysosomal enzymes and IGF-II. In selected cell types, however...... complex suggesting that its biological actions can be regulated at different levels including the transcription, translation, posttranslational processing, receptor binding and intracellular signalling....

  20. Evidence for a General Factor Model of ADHD in Adults

    Science.gov (United States)

    Gibbins, Christopher; Toplak, Maggie E.; Flora, David B.; Weiss, Margaret D.; Tannock, Rosemary

    2012-01-01

    Objective: To examine factor structures of "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.) symptoms of ADHD in adults. Method: Two sets of models were tested: (a) models with inattention and hyperactivity/impulsivity as separate but correlated latent constructs and (b) hierarchical general factor models with a general factor for…

  1. Evidence for Integrin – Venus Kinase Receptor 1 Alliance in the Ovary of Schistosoma mansoni Females Controlling Cell Survival

    Science.gov (United States)

    Gelmedin, Verena; Morel, Marion; Hahnel, Steffen; Cailliau, Katia; Dissous, Colette; Grevelding, Christoph G.

    2017-01-01

    In metazoan integrin signaling is an important process of mediating extracellular and intracellular communication processes. This can be achieved by cooperation of integrins with growth factor receptors (GFRs). Schistosoma mansoni is a helminth parasite inducing schistosomiasis, an infectious disease of worldwide significance for humans and animals. First studies on schistosome integrins revealed their role in reproductive processes, being involved in spermatogenesis and oogenesis. With respect to the roles of eggs for maintaining the parasite´s life cycle and for inducing the pathology of schistosomiasis, elucidating reproductive processes is of high importance. Here we studied the interaction of the integrin receptor Smβ-Int1 with the venus kinase receptor SmVKR1 in S. mansoni. To this end we cloned and characterized SmILK, SmPINCH, and SmNck2, three putative bridging molecules for their role in mediating Smβ-Int1/SmVKR1 cooperation. Phylogenetic analyses showed that these molecules form clusters that are specific for parasitic platyhelminths as it was shown for integrins before. Transcripts of all genes colocalized in the ovary. In Xenopus oocytes germinal vesicle breakdown (GVBD) was only induced if all members were simultaneously expressed. Coimmunoprecipitation results suggest that a Smβ-Int1-SmILK-SmPINCH-SmNck2-SmVKR1 complex can be formed leading to the phosphorylation and activation of SmVKR1. These results indicate that SmVKR1 can be activated in a ligand-independent manner by receptor-complex interaction. RNAi and inhibitor studies to knock-down SmILK as a representative complex member concurrently revealed effects on the extracellular matrix surrounding the ovary and oocyte localization within the ovary, oocyte survival, and egg production. By TUNEL assays, confocal laser scanning microscopy (CLSM), Caspase-3 assay, and transcript profiling of the pro-apoptotic BCL-2 family members BAK/BAX we obtained first evidence for roles of this signaling

  2. A search for presynaptic inhibitory histamine receptors in guinea-pig tissues: Further H3 receptors but no evidence for H4 receptors.

    Science.gov (United States)

    Petri, Doris; Schlicker, Eberhard

    2016-07-01

    The histamine H4 receptor is coupled to Gi/o proteins and expressed on inflammatory cells and lymphoid tissues; it was suggested that this receptor also occurs in the brain or on peripheral neurones. Since many Gi/o protein-coupled receptors, including the H3 receptor, serve as presynaptic inhibitory receptors, we studied whether the sympathetic neurones supplying four peripheral tissues and the cholinergic neurones in the hippocampus from the guinea-pig are equipped with release-modulating H4 and H3 receptors. For this purpose, we preincubated tissue pieces from the aorta, atrium, renal cortex and vas deferens with (3)H-noradrenaline and hippocampal slices with (3)H-choline and determined the electrically evoked tritium overflow. The stimulation-evoked overflow in the five superfused tissues was inhibited by the muscarinic receptor agonist oxotremorine, which served as a positive control, but not affected by the H4 receptor agonist 4-methylhistamine. The H3 receptor agonist R-α-methylhistamine inhibited noradrenaline release in the peripheral tissues without affecting acetylcholine release in the hippocampal slices. Thioperamide shifted the concentration-response curve of histamine in the aorta and the renal cortex to the right, yielding apparent pA2 values of 8.0 and 8.1, respectively, which are close to its affinity at other H3 receptors but higher by one log unit than its pKi at the H4 receptor of the guinea-pig. In conclusion, histamine H4 receptors could not be identified in five experimental models of the guinea-pig that are suited for the detection of presynaptic inhibitory receptors whereas H3 receptors could be shown in the peripheral tissues but not in the hippocampus. This article is part of the Special Issue entitled 'Histamine Receptors'.

  3. The specificity protein factor Sp1 mediates transcriptional regulation of P2X7 receptors in the nervous system.

    Science.gov (United States)

    García-Huerta, Paula; Díaz-Hernandez, Miguel; Delicado, Esmerilda G; Pimentel-Santillana, María; Miras-Portugal, M Teresa; Gómez-Villafuertes, Rosa

    2012-12-28

    P2X7 receptors are involved not only in physiological functions but also in pathological brain processes. Although an increasing number of findings indicate that altered receptor expression has a causative role in neurodegenerative diseases and cancer, little is known about how expression of P2rx7 gene is controlled. Here we reported the first molecular and functional evidence that Specificity protein 1 (Sp1) transcription factor plays a pivotal role in the transcriptional regulation of P2X7 receptor. We delimited a minimal region in the murine P2rx7 promoter containing four SP1 sites, two of them being highly conserved in mammals. The functionality of these SP1 sites was confirmed by site-directed mutagenesis and Sp1 overexpression/down-regulation in neuroblastoma cells. Inhibition of Sp1-mediated transcriptional activation by mithramycin A reduced endogenous P2X7 receptor levels in primary cultures of cortical neurons and astrocytes. Using P2rx7-EGFP transgenic mice that express enhanced green fluorescent protein under the control of P2rx7 promoter, we found a high correlation between reporter expression and Sp1 levels in the brain, demonstrating that Sp1 is a key element in the transcriptional regulation of P2X7 receptor in the nervous system. Finally, we found that Sp1 mediates P2X7 receptor up-regulation in neuroblastoma cells cultured in the absence of serum, a condition that enhances chromatin accessibility and facilitates the exposure of SP1 binding sites.

  4. Piglet saphenous vein contains multiple relaxatory prostanoid receptors: evidence for EP4, EP2, DP and IP receptor subtypes

    OpenAIRE

    Wilson, Richard J; Giles, Heather

    2005-01-01

    Prostaglandin E2 produced endothelium-independent relaxation of phenylephrine- and 5-HT-contracted piglet saphenous vein (PSV; pEC50=8.6±0.2; n=6).The prostanoid EP4 receptor antagonist GW627368X (30–300 nM) produced parallel rightward displacement of PGE2 concentration–effect (E/[A]) curves (pKb=9.2±0.2; slope=1). Higher concentrations of GW627368X did not produce further rightward shifts, revealing the presence of non-EP4 prostanoid receptors.In all, 18 other prostanoid receptor agonists re...

  5. Glucocorticoid receptor and nuclear factor kappa-b affect three-dimensional chromatin organization

    NARCIS (Netherlands)

    Kuznetsova, T.; Wang, S.Y.; Rao, N.A.; Mandoli, A.; Martens, J.H.; Rother, N; Aartse, A.; Groh, L.; Janssen-Megens, E.M.; Li, G.; Ruan, Y.; Logie, C.; Stunnenberg, H.G.

    2015-01-01

    BACKGROUND: The impact of signal-dependent transcription factors, such as glucocorticoid receptor and nuclear factor kappa-b, on the three-dimensional organization of chromatin remains a topic of discussion. The possible scenarios range from remodeling of higher order chromatin architecture by activ

  6. The transforming growth factor-beta receptor genes and the risk of intracranial aneurysms

    NARCIS (Netherlands)

    Ruigrok, Ynte M.; Baas, Annette F.; Medic, Jelena; Wijmenga, Cisca; Rinkel, Gabriel J. E.

    2012-01-01

    Background Mutations in the receptor genes of the transforming growth factor beta pathway, TGFBR1 and TGFBR2, cause syndromes with thoracic aortic aneurysms, while genetic variants in TGFBR1 and TGFBR2 are associated with abdominal aortic aneurysms. The transforming growth factor-beta pathway may be

  7. Glucocorticoid receptor and nuclear factor kappa-b affect three-dimensional chromatin organization

    NARCIS (Netherlands)

    Kuznetsova, T.; Wang, S.Y.; Rao, N.A.; Mandoli, A.; Martens, J.H.; Rother, N; Aartse, A.; Groh, L.; Janssen-Megens, E.M.; Li, G.; Ruan, Y.; Logie, C.; Stunnenberg, H.G.

    2015-01-01

    BACKGROUND: The impact of signal-dependent transcription factors, such as glucocorticoid receptor and nuclear factor kappa-b, on the three-dimensional organization of chromatin remains a topic of discussion. The possible scenarios range from remodeling of higher order chromatin architecture by

  8. Epidermal growth factor receptor signalling contributes to house dust mite-induced epithelial barrier dysfunction

    NARCIS (Netherlands)

    Heijink, I H; van Oosterhout, A; Kapus, A

    2010-01-01

    Impaired airway epithelial barrier function has emerged as a key factor in the pathogenesis of allergic asthma. We aimed to discern the involvement of the epidermal growth factor receptor (EGFR) in allergen-induced epithelial barrier impairment, as we previously observed that house dust mite (HDM) s

  9. Requirement for Tumor Necrosis Factor Receptor 2 Expression on Vascular Cells To Induce Experimental Cerebral Malaria

    OpenAIRE

    Stoelcker, Benjamin; Hehlgans, Thomas; Weigl, Karin; Bluethmann, Horst; Grau, Georges E.; Männel, Daniela N

    2002-01-01

    Using tumor necrosis factor receptor type 2 (TNFR2)-deficient mice and generating bone marrow chimeras which express TNFR2 on either hematopoietic or nonhematopoietic cells, we demonstrated the requirement for TNFR2 expression on tissue cells to induce lethal cerebral malaria. Thus, TNFR2 on the brain vasculature mediates tumor necrosis factor-induced neurovascular lesions in experimental cerebral malaria.

  10. Pharmacological targeting of the KIT growth factor receptor: a therapeutic consideration for mast cell disorders

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Akin, C; Gilfillan, A M

    2008-01-01

    KIT is a member of the tyrosine kinase family of growth factor receptors which is expressed on a variety of haematopoietic cells including mast cells. Stem cell factor (SCF)-dependent activation of KIT is critical for mast cell homeostasis and function. However, when KIT is inappropriately activa...

  11. Presenilin 1 regulates epidermal growth factor receptor turnover and signaling in the endosomal-lysosomal pathway.

    Science.gov (United States)

    Repetto, Emanuela; Yoon, Il-Sang; Zheng, Hui; Kang, David E

    2007-10-26

    Mutations in the gene encoding presenilin 1 (PS1) cause the most aggressive form of early-onset familial Alzheimer disease. In addition to its well established role in Abeta production and Notch proteolysis, PS1 has been shown to mediate other physiological activities, such as regulation of the Wnt/beta-catenin signaling pathway, modulation of phosphatidylinositol 3-kinase/Akt and MEK/ERK signaling, and trafficking of select membrane proteins and/or intracellular vesicles. In this study, we present evidence that PS1 is a critical regulator of a key signaling receptor tyrosine kinase, epidermal growth factor receptor (EGFR). Specifically, EGFR levels were robustly increased in fibroblasts deficient in both PS1 and PS2 (PS(-/-)) due to delayed turnover of EGFR protein. Stable transfection of wild-type PS1 but not PS2 corrected EGFR to levels comparable to PS(+/+) cells, while FAD PS1 mutations showed partial loss of activity. The C-terminal fragment of PS1 was sufficient to fully reduce EGFR levels. In addition, the rapid ligand-induced degradation of EGFR was markedly delayed in PS(-/-) cells, resulting in prolonged signal activation. Despite the defective turnover of EGFR, ligand-induced autophosphorylation, ubiquitination, and endocytosis of EGFR were not affected by the lack of PS1. Instead, the trafficking of EGFR from early endosomes to lysosomes was severely delayed by PS1 deficiency. Elevation of EGFR was also seen in brains of adult mice conditionally ablated in PS1 and in skin tumors associated with the loss of PS1. These findings demonstrate a critical role of PS1 in the trafficking and turnover of EGFR and suggest potential pathogenic effects of elevated EGFR as well as perturbed endosomal-lysosomal trafficking in cell cycle control and Alzheimer disease.

  12. Changes of expression of estrogen and progestrone receptors, human epithelial growth factor receptor 2 and Ki-67 after neoadjuvant chemotherapy in the treatment of breast cancer.

    Science.gov (United States)

    Li, M L; Dong, Y; Luan, S L; Zhao, Z H; Ning, F L

    2016-01-01

    Recent studies suggest that the development and prognosis of breast cancer is in close correlation to molecular subtype of breast cancer. Neoadjuvant chemotherapy has been extensively applied in the treatment of local breast cancer in advanced stage. In order to verify the correlation between expression changes of estrogen receptor, progestrone receptor, human epithelial growth factor receptor 2 and Ki-67 after neoadjuvant chemotherapy and neoadjuvant chemotherapy, we studied 120 patients with stage IIAIIIC breast cancer who underwent neoadjuvant chemotherapy in Binzhou Medical University Hospital, Shandong, China from February 2011 to February 2015. Clinical characteristics were retrospectively analyzed. The expression of estrogen receptor, progesterone receptor, human epithelial growth factor receptor 2 and Ki-67 of patients were detected using the immunohistochemical method before and after neoadjuvant chemotherapy. The results suggest that the overall remission rate of neoadjuvant chemotherapy was 76.7% (92/120) of which 16.7% (20/120) of cases had complete remission, 60% (72/120) had partial remission and 23.3% (28/120) were stable. There were no cases of progressive disease. The property of estrogen receptor and the expression of Ki-67 of primary tumor were correlated to the remission rate of neoadjuvant chemotherapy (P less than 0.05). The expression of Ki-67 had a significant decline after neoadjuvant chemotherapy, and the difference had statistical significance (P less than 0.05). The difference in expression of estrogen receptor, progesterone receptor and human epithelial growth factor receptor 2 before and after neoadjuvant chemotherapy had statistical significance (P > 0.05). Hence, it can be concluded that breast cancer patients with negative estrogen receptor expression and high Ki-67 expression before neoadjuvant chemotherapy can achieve better curative effects. Neoadjuvant chemotherapy cannot change the expression states of estrogen receptor

  13. Fraud Risk Factors and Audit Programme Modifications: Evidence from Jordan

    Directory of Open Access Journals (Sweden)

    Modar Abdullatif

    2013-03-01

    Full Text Available This study explores how audit firms in Jordan deal with the presence of fraud risk factors in audit clients. In doing so, the study seeks to explore which fraud risk factors are more important to Jordanianauditors, and how Jordanian auditors consider modifying their audit programmes when fraud risk factors are present in clients. The study uses a structured questionnaire that was administered to seniorlevel auditors in the largest Jordanian audit firms. The findings show that almost all of the 20 fraud risk factors included in the questionnaire were only slightly important (if not unimportant, a finding that is arguably alarming. The perceived importance of modifying the audit programme in the presence of each fraud risk factor was related to the perceived importance of the fraud risk factor itself. However, changes in the nature and extent of audit procedures were more important than changes in the timing of the procedures or the members of the audit team. The most important fraud risk factors were related to the characteristics of management and its attitude towards the audit, while the least important fraud risk factors were related to the difficulties in the client’s financial performance. Factor analysis found that the fraud risk factors could be classified into four separate groups. Possible interpretations of the findings were discussed, such as considering the Jordanian business environment characteristics, and the findings were compared to those of extant international studies.

  14. Stabilization of the bioactivity of tumor necrosis factor by its soluble receptors

    OpenAIRE

    1992-01-01

    The receptors for tumor necrosis factor (TNF) exist in cell-associated as well as soluble forms, both binding specifically to TNF. Since the soluble forms of TNF receptors (sTNF-Rs) can compete with the cell- associated TNF receptors for TNF, it was suggested that they function as inhibitors of TNF activity; at high concentrations, the sTNF-Rs indeed inhibit TNF effects. However, we report here that in the presence of low concentrations of the sTNF-Rs, effects of TNF whose induction depend on...

  15. Fibroblast growth factor receptor signaling is essential for lens fiber cell differentiation

    OpenAIRE

    Zhao, Haotian; Yang, Tianyu; Madakashira, Bhavani P.; Thiels, Cornelius A.; Bechtle, Chad A.; Garcia, Claudia M.; Zhang, Huiming; Yu, Kai; Ornitz, David M.; Beebe, David C.; Robinson, Michael L.

    2008-01-01

    The vertebrate lens provides an excellent model to study the mechanisms that regulate terminal differentiation. Although fibroblast growth factors (FGFs) are thought to be important for lens cell differentiation, it is unclear which FGF receptors mediate these processes during different stages of lens development. Deletion of three FGF receptors (Fgfr1-3) early in lens development demonstrated that expression of only a single allele of Fgfr2 or Fgfr3 was sufficient for grossly normal lens dev...

  16. A receptor model for urban aerosols based on oblique factor analysis

    DEFF Research Database (Denmark)

    Keiding, Kristian; Sørensen, Morten S.; Pind, Niels

    1987-01-01

    A procedure is outlined for the construction of receptor models of urban aerosols, based on factor analysis. The advantage of the procedure is that the covariation of source impacts is included in the construction of the models. The results are compared with results obtained by other receptor-modelling...... procedures. It was found that procedures based on correlating sources were physically sound as well as in mutual agreement. Procedures based on non-correlating sources were found to generate physically obscure models....

  17. Colony stimulating factor 1 receptor inhibition eliminates microglia and attenuates brain injury after intracerebral hemorrhage.

    Science.gov (United States)

    Li, Minshu; Li, Zhiguo; Ren, Honglei; Jin, Wei-Na; Wood, Kristofer; Liu, Qiang; Sheth, Kevin N; Shi, Fu-Dong

    2017-07-01

    Microglia are the first responders to intracerebral hemorrhage, but their precise role in intracerebral hemorrhage remains to be defined. Microglia are the only type of brain cells expressing the colony-stimulating factor 1 receptor, a key regulator for myeloid lineage cells. Here, we determined the effects of a colony-stimulating factor 1 receptor inhibitor (PLX3397) on microglia and the outcome in the context of experimental mouse intracerebral hemorrhage. We show that PLX3397 effectively depleted microglia, and the depletion of microglia was sustained after intracerebral hemorrhage. Importantly, colony-stimulating factor 1 receptor inhibition attenuated neurodeficits and brain edema in two experimental models of intracerebral hemorrhage induced by injection of collagenase or autologous blood. The benefit of colony-stimulating factor 1 receptor inhibition was associated with reduced leukocyte infiltration in the brain and improved blood-brain barrier integrity after intracerebral hemorrhage, and each observation was independent of lesion size or hematoma volume. These results demonstrate that suppression of colony-stimulating factor 1 receptor signaling ablates microglia and confers protection after intracerebral hemorrhage.

  18. Epidermal growth factor induces changes of interaction between epidermal growth factor receptor and actin in intact cells

    Institute of Scientific and Technical Information of China (English)

    Wei Song; Haixing Xuan; Qishui Lin

    2008-01-01

    The epidermal growth factor receptor (EGFR) is a cyto-skeleton-binding protein. Although purified EGFR can interact with actins in vitro and normally at least 10% of EGFR exist in the insoluble cytoskeleton fraction of A431 cells, interaction of cytosolic EGFR with actin can only be visualized by fluorescence resonance energy transfer when epidermal growth factor presents in the cell medium. Results indicate that the correct orientation between EGFR and actin is important in the signal transduction process.

  19. Aberrant expression of leukemia inhibitory factor receptor (LIFR) and leukemia inhibitory factor (LIF) is associated with tubal pregnancy occurrence

    OpenAIRE

    Li, Yong; Sun, Lizhou; ZHAO, Denmei; Ouyang, Jun; Xiang, Mei

    2015-01-01

    Tubal pregnancy is a major cause of maternal death in the first trimester and exploration of its underlying molecular mechanism is of great importance. This study aimed to explore the association of tubal pregnancy with leukemia inhibitory factor (LIF) and leukemia inhibitory factor receptor (LIFR) expression in oviduct tissues. Materials and methods: Immunohistochemistry was performed to probe the differential expression of LIF and LIFR in oviduct tissues among a control group (including NP...

  20. The diminished expression of proangiogenic growth factors and their receptors in gastric ulcers of cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Jiing-Chyuan Luo

    Full Text Available OBJECTIVES: The pathogenesis of the higher occurrence of peptic ulcer disease in cirrhotic patients is complex. Platelets can stimulate angiogenesis and promote gastric ulcer healing. We compared the expressions of proangiogenic growth factors and their receptors in the gastric ulcer margin between cirrhotic patients with thrombocytopenia and those of non-cirrhotic patients to elucidate possible mechanisms. METHODS: Eligible cirrhotic patients (n = 55 and non-cirrhotic patients (n = 55 who had gastric ulcers were enrolled. Mucosa from the gastric ulcer margin and non-ulcer areas were sampled and the mRNA expressions of the proangiogenic growth factors (vascular endothelial growth factor [VEGF], platelet derived growth factor [PDGF], basic fibroblast growth factor [bFGF] and their receptors (VEGFR1, VEGFR2, PDGFRA, PDGFRB, FGFR1, FGFR2 were measured and compared. Platelet count and the expressions of these growth factors and their receptors were correlated with each other. RESULTS: The two groups were comparable in terms of gender, ulcer size and infection rate of Helicobacter pylori. However, the cirrhotic group were younger in age, had a lower platelet count than those in the non-cirrhotic group (p0.5, p<0.001. CONCLUSIONS: Our findings implied that diminished activity of proangiogenic factors and their receptors may contribute to the pathogenesis of gastric ulcers in cirrhotic patients.

  1. Inhibition of corneal neovascularization with new Tyrosine Kinase Inhibitors targeting vascular endothelial growth factor receptors: Sunitinib malate and Sorafenib

    Directory of Open Access Journals (Sweden)

    Delnia Arshadi

    2007-06-01

    Full Text Available Corneal neovascularization (NV is a significant, sight-threatening, complication of many ocular surface disorders. Presence of new vessels in cornea can compromise clarity and thus vision. The data supporting a causal role for vascular endothelial growth factor (VEGF in corneal NV are extensive. Inhibition of VEGF remains as a main strategy for treating corneal NV. There is a growing body of evidence that corneal NV can be reduced by using anti-VEGF agents. Sunitinib malate and Sorafenib are new orally bio-available anti-angiogenic agents undergoing tests of efficacy in the treatment of various types of cancers. The main mechanism of these drugs is inhibiting angiogenesis by diminishing signaling through VEGF receptor1 (VEGFR1, VEGFR2, and platelet-derived growth factor receptors. Since VEGF exerts its angiogenic effects through tyrosine kinase receptors in cornea, any mechanisms which reduce VEGF signaling may inhibit corneal NV or at least attenuate it. Based on this fact we herein hypothesize that Sunitinib malate and Sorafenib can be prepared in topical form and be used in corneal neovascularization states. These approaches offer new hope for the successful treatment of corneal NV. Further investigations in animal models are needed to place these two drugs alongside corneal NV therapeutics.

  2. Down-regulation of rat kidney calcitonin receptors by salmon calcitonin infusion evidence by autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Bouizar, Z.; Rostene, W.H.; Milhaud, G.

    1987-08-01

    In treating age-related osteoporosis and Paget disease of bone, it is of major importance to avoid an escape phenomenon that would reduce effectiveness of the treatment. The factors involved in the loss of therapeutic efficacy with administration of large pharmacological doses of the hormone require special consideration. Down-regulation of the hormone receptors could account for the escape phenomenon. Specific binding sites for salmon calcitonin (sCT) were characterized and localized by autoradiography on rat kidney sections incubated with /sup 125/I-labeled sCT. Autoradiograms demonstrated a heterogeneous distribution of /sup 125/I-labeled sCT binding sites in the kidney, with high densities in both the superficial layer of the cortex and the outer medulla. Infusion of different doses of unlabeled sCT by means of Alzet minipumps for 7 days produced rapid changes in plasma calcium, phosphate, and magnesium levels, which were no longer observed after 2 or 6 days of treatment. Besides, infusion of high doses of sCT induced down-regulation of renal sCT binding sites located mainly in the medulla, where calcitonin (CT) has been shown to exert it physiological effects on water and ion reabsorption. These data suggest that the resistance to high doses of sCT often observed during long-term treatment of patients may be the consequence of not only bone-cell desensitization but also down-regulation of CT-sensitive kidney receptor sites.

  3. Vascular endothelial growth factor A and vascular endothelial growth factor receptor 2 expression in non-small cell lung cancer patients: relation to prognosis

    DEFF Research Database (Denmark)

    Bonnesen, Barbara; Pappot, Helle; Holmstav, Julie;

    2009-01-01

    elements in neoplastic cells and their microenvironment have recently been and are continuously developed including drugs inhibiting the angiogenic system. Angiogenic factor vascular endothelial growth factor (VEGF) and its receptor vascular endothelial growth factor receptor 2 (VEGFR2) seem to play key...

  4. Deregulation of Flk-1/vascular endothelial growth factor receptor-2 in fibroblast growth factor receptor-1-deficient vascular stem cell development.

    Science.gov (United States)

    Magnusson, Peetra; Rolny, Charlotte; Jakobsson, Lars; Wikner, Charlotte; Wu, Yan; Hicklin, Daniel J; Claesson-Welsh, Lena

    2004-03-15

    We have employed embryoid bodies derived from murine embryonal stem cells to study effects on vascular development induced by fibroblast growth factor (FGF)-2 and FGF receptor-1, in comparison to the established angiogenic factor vascular endothelial growth factor (VEGF)-A and its receptor VEGF receptor-2. Exogenous FGF-2 promoted formation of morphologically distinct, long slender vessels in the embryoid bodies, whereas VEGF-A-treated bodies displayed a compact plexus of capillaries. FGF-2 stimulation of embryonal stem cells under conditions where VEGF-A/VEGFR-2 function was blocked, led to formation of endothelial cell clusters, which failed to develop into vessels. FGFR-1(-/-) embryoid bodies responded to VEGF-A by establishment of the characteristic vascular plexus, but FGF-2 had no effect on vascular development in the absence of FGFR-1. The FGFR-1(-/-) embryoid bodies displayed considerably increased basal level of vessel formation, detected by immunohistochemical staining for platelet-endothelial cell adhesion molecule (PECAM)/CD31. This basal vascularization was blocked by neutralizing antibodies against VEGFR-2 or VEGF-A and biochemical analyses indicated changes in regulation of VEGFR-2 in the absence of FGFR-1 expression. We conclude that VEGF-A/VEGFR-2-dependent vessel formation occurs in the absence of FGF-2/FGFR-1, which, however, serve to modulate vascular development.

  5. Evidence that deletion at FCGR3B is a risk factor for systemic sclerosis

    NARCIS (Netherlands)

    McKinney, C.; Broen, J.C.A.; Vonk, M.C.; Beretta, L.; Hesselstrand, R.; Hunzelmann, N.; Riemekasten, G.; Scorza, R.; Simeon, C.P.; Fonollosa, V.; Carreira, P.E.; Ortego-Centeno, N.; Gonzalez-Gay, M.A.; Airo, P.; Coenen, M.J.; Martin, J.; Radstake, T.R.D.J.; Merriman, T.R.

    2012-01-01

    There is increasing evidence that gene copy number (CN) variation influences clinical phenotype. The low-affinity Fc receptor 3B (FCGR3B) located in the FCGR gene cluster is a CN polymorphic gene involved in the recruitment of polymorphonuclear neutrophils to sites of inflammation and their activati

  6. Interactions between Type III receptor tyrosine phosphatases and growth factor receptor tyrosine kinases regulate tracheal tube formation in Drosophila

    Directory of Open Access Journals (Sweden)

    Mili Jeon

    2012-04-01

    The respiratory (tracheal system of the Drosophila melanogaster larva is an intricate branched network of air-filled tubes. Its developmental logic is similar in some ways to that of the vertebrate vascular system. We previously described a unique embryonic tracheal tubulogenesis phenotype caused by loss of both of the Type III receptor tyrosine phosphatases (RPTPs, Ptp4E and Ptp10D. In Ptp4E Ptp10D double mutants, the linear tubes in unicellular and terminal tracheal branches are converted into bubble-like cysts that incorporate apical cell surface markers. This tube geometry phenotype is modulated by changes in the activity or expression of the epidermal growth factor receptor (Egfr tyrosine kinase (TK. Ptp10D physically interacts with Egfr. Here we demonstrate that the Ptp4E Ptp10D phenotype is the consequence of the loss of negative regulation by the RPTPs of three growth factor receptor TKs: Egfr, Breathless and Pvr. Reducing the activity of any of the three kinases by tracheal expression of dominant-negative mutants suppresses cyst formation. By competing dominant-negative and constitutively active kinase mutants against each other, we show that the three RTKs have partially interchangeable activities, so that increasing the activity of one kinase can compensate for the effects of reducing the activity of another. This implies that SH2-domain downstream effectors that are required for the phenotype are likely to be able to interact with phosphotyrosine sites on all three receptor TKs. We also show that the phenotype involves increases in signaling through the MAP kinase and Rho GTPase pathways.

  7. Pertuzumab in human epidermal growth-factor receptor 2-positive breast cancer: clinical and economic considerations

    Directory of Open Access Journals (Sweden)

    Lamond NW

    2014-05-01

    Full Text Available Nathan WD Lamond, Tallal YounisDepartment of Medicine, Dalhousie University at the Queen Elizabeth II Health Sciences Centre, Halifax, NS, CanadaAbstract: In the absence of specific therapy, the 15%–20% of breast cancers demonstrating human epidermal growth-factor receptor 2 (HER2 protein overexpression and/or gene amplification are characterized by a more aggressive phenotype and poorer prognosis compared to their HER2-negative counterparts. Trastuzumab (Herceptin, the first anti-HER2-targeted therapy, has been associated with improved survival outcomes in HER2-positive breast cancer. However, many patients with early stage disease continue to relapse, and metastatic disease remains incurable. In order to further improve these outcomes, several novel HER2-targeted agents have recently been developed. Pertuzumab (Perjeta, a monoclonal antibody against the HER2 dimerization domain, has also been associated with improved patient outcomes in clinical trials, and has recently been approved in combination with chemotherapy and trastuzumab for neoadjuvant therapy of early stage, HER2-positive breast cancer and first-line treatment of metastatic disease. This review briefly summarizes pertuzumab's clinical development as well as the published evidence supporting its use, and highlights some of the currently unanswered questions that will influence pertuzumab’s incorporation into clinical practice.Keywords: HER2/neu, clinical trials, drug development, novel therapies, targeted anticancer therapy

  8. Differential gene expression profiling of human epidermal growth factor receptor 2-overexpressing mammary tumor

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Haining Peng; Yingli Zhong; Daiqiang Li; Mi Tang; Xiaofeng Ding; Jian Zhang

    2008-01-01

    Human epidermal growth factor receptor 2 (HER2) is highly expressed in approximately 30% of breast cancer patients,and substantial evidence supports the relationship between HER2 overexpression and poor overall survival. However,the biological function of HER2 signaltransduction pathways is not entirely clear. To investigate gene activation within the pathways, we screened differentially expressed genes in HER2-positive mouse mammary tumor using two-directional suppression subtractive hybridization combined with reverse dot-blotting analysis. Forty genes and expressed sequence tags related to transduction, cell proliferation/growth/apoptosis and secreted/extracellular matrix proteins were differentially expressed in HER2-positive mammary tumor tissue. Among these, 19 were already reported to be differentially expressed in mammary tumor, 11 were first identified to be differentially expressed in mammary tumor in this study but were already reported in other tumors, and 10 correlated with other cancers. These genes can facilitate the understanding of the role of HER2 signaling in breast cancer.

  9. The role of epidermal growth factor receptor (EGFR) signaling in SARS coronavirus-induced pulmonary fibrosis.

    Science.gov (United States)

    Venkataraman, Thiagarajan; Frieman, Matthew B

    2017-07-01

    Many survivors of the 2003 outbreak of severe acute respiratory syndrome (SARS) developed residual pulmonary fibrosis with increased severity seen in older patients. Autopsies of patients that died from SARS also showed fibrosis to varying extents. Pulmonary fibrosis can be occasionally seen as a consequence to several respiratory viral infections but is much more common after a SARS coronavirus (SARS-CoV) infection. Given the threat of future outbreaks of severe coronavirus disease, including Middle East respiratory syndrome (MERS), it is important to understand the mechanisms responsible for pulmonary fibrosis, so as to support the development of therapeutic countermeasures and mitigate sequelae of infection. In this article, we summarize pulmonary fibrotic changes observed after a SARS-CoV infection, discuss the extent to which other respiratory viruses induce fibrosis, describe available animal models to study the development of SARS-CoV induced fibrosis and review evidence that pulmonary fibrosis is caused by a hyperactive host response to lung injury mediated by epidermal growth factor receptor (EGFR) signaling. We summarize work from our group and others indicating that inhibiting EGFR signaling may prevent an excessive fibrotic response to SARS-CoV and other respiratory viral infections and propose directions for future research. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. ERG Cooperates with Androgen Receptor in Regulating Trefoil Factor 3 in Prostate Cancer Disease Progression

    Directory of Open Access Journals (Sweden)

    David S. Rickman

    2010-12-01

    Full Text Available To elucidate the role of ETS gene fusions in castration-resistant prostate cancer (CRPC, we characterized the transcriptome of 54 CRPC tumor samples from men with locally advanced or metastatic disease. Trefoil factor 3 (TFF3 emerged as the most highly differentially regulated gene with respect to ERG rearrangement status and resistance to hormone ablation therapy. Conventional chromatin immunoprecipitation (ChIP-polymerase chain reaction and ChIP followed by DNA sequencing (ChIP-seq revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG-rearranged prostate cancer cell lines. These results were confirmed in ERG-rearranged hormone-naive prostate cancer (HNPC and CRPC tissue samples. Functional studies demonstrated that ERG has an inhibitory effect on TFF3 expression in hormone-naive cancer but not in the castration-resistant state. In addition, we provide evidence suggesting an effect of androgen receptor signaling on ERG-regulated TFF3 expression. Furthermore, TFF3 overexpression enhances ERG-mediated cell invasion in CRPC prostate cancer cells. Taken together, our findings reveal a novel mechanism for enhanced tumor cell aggressiveness resulting from ERG rearrangement in the castration-resistant setting through TFF3 gene expression.

  11. ERG cooperates with androgen receptor in regulating trefoil factor 3 in prostate cancer disease progression.

    Science.gov (United States)

    Rickman, David S; Chen, Ying-Bei; Banerjee, Samprit; Pan, Yihang; Yu, Jindan; Vuong, Terry; Perner, Sven; Lafargue, Christopher J; Mertz, Kirsten D; Setlur, Sunita R; Sircar, Kanishka; Chinnaiyan, Arul M; Bismar, Tarek A; Rubin, Mark A; Demichelis, Francesca

    2010-12-01

    To elucidate the role of ETS gene fusions in castration-resistant prostate cancer (CRPC), we characterized the transcriptome of 54 CRPC tumor samples from men with locally advanced or metastatic disease. Trefoil factor 3 (TFF3) emerged as the most highly differentially regulated gene with respect to ERG rearrangement status and resistance to hormone ablation therapy. Conventional chromatin immunoprecipitation (ChIP)-polymerase chain reaction and ChIP followed by DNA sequencing (ChIP-seq) revealed direct binding of ERG to ETS binding sites in the TFF3 promoter in ERG-rearranged prostate cancer cell lines. These results were confirmed in ERG-rearranged hormone-naive prostate cancer (HNPC) and CRPC tissue samples. Functional studies demonstrated that ERG has an inhibitory effect on TFF3 expression in hormone-naive cancer but not in the castration-resistant state. In addition, we provide evidence suggesting an effect of androgen receptor signaling on ERG-regulated TFF3 expression. Furthermore, TFF3 overexpression enhances ERG-mediated cell invasion in CRPC prostate cancer cells. Taken together, our findings reveal a novel mechanism for enhanced tumor cell aggressiveness resulting from ERG rearrangement in the castration-resistant setting through TFF3 gene expression.

  12. Dual silencing of insulin-like growth factor-I receptor and epidermal growth factor receptor in colorectal cancer cells is associated with decreased proliferation and enhanced apoptosis.

    Science.gov (United States)

    Kaulfuss, Silke; Burfeind, Peter; Gaedcke, Jochen; Scharf, Jens-Gerd

    2009-04-01

    Overexpression and activation of tyrosine kinase receptors are common features of colorectal cancer. Using the human colorectal cancer cell lines DLD-1 and Caco-2, we evaluated the role of the insulin-like growth factor-I (IGF-I) receptor (IGF-IR) and epidermal growth factor receptor (EGFR) in cellular functions of these cells. We used the small interfering RNA (siRNA) technology to specifically down-regulate IGF-IR and EGFR expression. Knockdown of IGF-IR and EGFR resulted in inhibition of cell proliferation of DLD-1 and Caco-2 cells. An increased rate of apoptosis was associated with siRNA-mediated silencing of IGF-IR and EGFR as assessed by activation of caspase-3/caspase-7. The combined knockdown of both EGFR and IGF-IR decreased cell proliferation and induced cell apoptosis more effectively than did silencing of either receptor alone. Comparable effects on cell proliferation and apoptosis were observed after single and combinational treatment of cells by the IGF-IR tyrosine kinase inhibitor NVP-AEW541 and/or the EGFR tyrosine kinase inhibitor erlotinib. Combined IGF-IR and EGFR silencing by either siRNAs or tyrosine kinase inhibitors diminished the phosphorylation of downstream signaling pathways AKT and extracellular signal-regulated kinase (ERK)-1/2 more effectively than did the single receptor knockdown. Single IGF-IR knockdown inhibited IGF-I-dependent phosphorylation of AKT but had no effect on IGF-I- or EGF-dependent phosphorylation of ERK1/2, indicating a role of EGFR in ligand-dependent ERK1/2 phosphorylation. The present data show that inhibition of the IGF-IR transduction cascade augments the antipoliferative and proapoptotic effects of EGFR inhibition in colorectal cancer cells. A clinical application of combination therapy targeting both EGFR and IGF-IR could be a promising therapeutic strategy.

  13. An Integrated Model of Epidermal Growth Factor Receptor Trafficking and Signal Transduction

    Energy Technology Data Exchange (ETDEWEB)

    Resat, Haluk; Ewald, Jonathan A.; Dixon, David A.; Wiley, H. S.

    2003-08-01

    Endocytic trafficking of many types of receptors can have profound effects on subsequent signaling events. Quantitative models of these processes, however, have usually considered trafficking and signaling independently. Here, we present an integrated model of both the trafficking and signaling pathway of the epidermal growth factor receptor (EGFR) using a probability weighted-dynamic Monte Carlo simulation. Our model consists of hundreds of distinct endocytic compartments and about 13,000 reactions/events that occur over a broad spatio-temporal range. By using a realistic multi-compartment model, we can investigate the distribution of the receptors among cellular compartments as well as their potential signal transduction characteristics. Our new model also allows the incorporation of physio-chemical aspects of ligand-receptor interactions, such as pH-dependent binding in different endosomal compartments. To determine the utility of this approach, we simulated the differential activation of the EGFR by two of its ligands, epidermal growth factor (EGF) and transforming growth factor- alpha (TGF-a). Our simulations predict that when EGFR is activated with TGF-a, receptor activation is biased toward the cell surface whereas EGF produces a signaling bias towards the endosomal compartment. Experiments confirm these predictions from our model and simulations. Our model accurately predicts the kinetics and extent of receptor down-regulation induced by either EGF or TGF-a. Our results suggest that receptor trafficking controls the compartmental bias of signal transduction, rather than simply modulating signal magnitude. Our model provides a new approach to evaluating the complex effect of receptor trafficking on signal transduction. Importantly, the stochastic and compartmental nature of the simulation allows these models to be directly tested by high-throughput approaches, such as quantitative image analysis.

  14. Growth factor receptors and related signalling pathways as targets for novel treatment strategies of hepatocellular cancer

    Institute of Scientific and Technical Information of China (English)

    Michael Hopfner; Detlef Schuppan; Hans Scherübl

    2008-01-01

    Growth factors and their corresponding receptors are commonly overexpressed and/or dysregulated in many cancers including hepatocellular cancer (HCC). Clinical trials indicate that growth factor receptors and their related signalling pathways play important roles in HCC cancer etiology and progression, thus providing rational targets for innovative cancer therapies. A number of strategies including monoclonal antibodies, tyrosine kinase inhibitors ("small molecule inhibitors") and antisense oligonucleotides have already been evaluated for their potency to inhibit the activity and downstream signalling cascades of these receptors in HCC. First clinical trials have also shown that multi-kinase inhibition is an effective novel treatment strategy in HCC. In this respect sorafenib, an inhibitor of Raf-, VEGF- and PDGF-signalling, is the first multi-kinase inhibitor that has been approved by the FDA for the treatment of advanced HCC. Moreover, the serine-threonine kinase of mammalian target of rapamycin (mTOR) upon which the signalling of several growth factor receptors converge plays a central role in cancer cell proliferation, mTOR inhibition of HCC is currently also being studied in preclinical trials. As HCCs represent hypervascularized neoplasms, inhibition of tumour vessel formation via interfering with the VEGF/VEGFR system is another promising approach in HCC treatment. This review will summarize the current status of the various growth factor receptor-based treatment strategies and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.

  15. GATA Factor-G-Protein-Coupled Receptor Circuit Suppresses Hematopoiesis

    Directory of Open Access Journals (Sweden)

    Xin Gao

    2016-03-01

    Full Text Available Hematopoietic stem cells (HSCs originate from hemogenic endothelium within the aorta-gonad-mesonephros (AGM region of the mammalian embryo. The relationship between genetic circuits controlling stem cell genesis and multi-potency is not understood. A Gata2 cis element (+9.5 enhances Gata2 expression in the AGM and induces the endothelial to HSC transition. We demonstrated that GATA-2 rescued hematopoiesis in +9.5−/− AGMs. As G-protein-coupled receptors (GPCRs are the most common targets for FDA-approved drugs, we analyzed the GPCR gene ensemble to identify GATA-2-regulated GPCRs. Of the 20 GATA-2-activated GPCR genes, four were GATA-1-activated, and only Gpr65 expression resembled Gata2. Contrasting with the paradigm in which GATA-2-activated genes promote hematopoietic stem and progenitor cell genesis/function, our mouse and zebrafish studies indicated that GPR65 suppressed hematopoiesis. GPR65 established repressive chromatin at the +9.5 site, restricted occupancy by the activator Scl/TAL1, and repressed Gata2 transcription. Thus, a Gata2 cis element creates a GATA-2-GPCR circuit that limits positive regulators that promote hematopoiesis.

  16. Effect of glucocorticoid on epidermal growth factor receptor in human salivary gland adenocarcinoma cell line HSG.

    Science.gov (United States)

    Kyakumoto, S; Kurokawa, R; Ota, M

    1990-07-12

    Human salivary gland adenocarcinoma (HSG) cells treated with 10(-6) M triamcinolone acetonide for 48 h exhibited a 1.7- to 2.0-fold increase in [125I]human epidermal growth factor (hEGF) binding capacity as compared with untreated HSG cells. Scatchard analysis of [125I]EGF binding data revealed that the number of binding sites was 83,700 (+/- 29,200) receptors/cell in untreated cells and 160,500 (+/- 35,500) receptors/cell in treated cells. No substantial change in receptor affinity was detected. The dissociation constant of the EGF receptor was 0.78 (+/- 0.26).10(-9) M for untreated cells, whereas it was 0.93 (+/- 0.31).10(-9)M for treated cells. The triamcinolone acetonide-induced increase in [125I]EGF binding capacity was dose-dependent between 10(-9) and 10(-6)M, and maximal binding was observed at 10(-6)M. EGF receptors on HSG cells were affinity-labeled with [125I]EGF by use of the cross-linking reagent disuccinimidyl suberate (DSS). The cross-linked [125I]EGF was 3-4% of the total [125I]EGF bound to HSG cells. The affinity-labeled EGF receptor was detected as a specific 170 kDa band in the autoradiograph after SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis revealed that triamcinolone acetonide amplified the intensity of this band 2.0-fold over that of the band of untreated cells. EGF receptor synthesis was also measured by immunoprecipitation of [3H]leucine-labeled EGF receptor protein with anti-hEGF receptor monoclonal antibody. Receptor synthesis was increased 1.7- to 1.8-fold when HSG cells were treated with 10(-8)-10(-6)M triamcinolone acetonide for 48 h. When the immunoprecipitated, [35S]methionine-pulse-labeled EGF receptor was analyzed by SDS-PAGE and fluorography, the newly synthesized EGF receptor was detected at the position of 170 kDa; and treatment of HSG cells with triamcinolone acetonide resulted in a 2.0-fold amplification of this 170 kDa band. There was no significant difference in turnover rate of EGF receptor

  17. Effects of (-)-Epigallocatechin gallate on some protein factors involved in the epidermal growth factor receptor signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Yinjiu Huang; Ruiqing Xu; Baoan Song; Song Yang; Li Zhao; Shouwei Wua

    2009-01-01

    (-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulates growth, survival, proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.

  18. Induction of cyclooxygenase-2 expression by prostaglandin E2 stimulation of the prostanoid EP4 receptor via coupling to Gαi and transactivation of the epidermal growth factor receptor in HCA-7 human colon cancer cells.

    Science.gov (United States)

    Yoshida, Kenji; Fujino, Hiromichi; Otake, Sho; Seira, Naofumi; Regan, John W; Murayama, Toshihiko

    2013-10-15

    Increased expressions of cyclooxygenase-2 (COX-2) and its downstream metabolite, prostaglandin E2 (PGE2), are well documented events in the development of colorectal cancer. Interestingly, PGE2 itself can induce the expression of COX-2 thereby creating the potential for positive feedback. Although evidence for such a positive feedback has been previously described, the specific E-type prostanoid (EP) receptor subtype that mediates this response, as well as the relevant signaling pathways, remain unclear. We now report that the PGE2 stimulated induction of COX-2 expression in human colon cancer HCA-7 cells is mediated by activation of the prostanoid EP4 receptor subtype and is followed by coupling of the receptor to Gαi and the activation of phosphatidylinositol 3-kinase. Subsequent activation of metalloproteinases releases membrane bound heparin-binding epidermal growth factor-like growth factor resulting in the transactivation of epidermal growth factor receptors and the activation of the extracellular signal-regulated kinases and induction of COX-2 expression. This induction of COX-2 expression by PGE2 stimulation of the prostanoid EP4 receptor may underlie the upregulation of COX-2 during colorectal cancer and appears to be an early event in the process of tumorigenesis. © 2013 Elsevier B.V. All rights reserved.

  19. Receptors for T cell-replacing factor/interleukin 5. Specificity, quantitation, and its implication

    OpenAIRE

    1988-01-01

    T cell-replacing factor (TRF)/IL-5 is a glycosylated polypeptide that acts as a key factor for B cell growth and differentiation. Since IL-5 action is probably mediated by specific cell surface receptor(s), we have characterized the binding of IL-5 to cells using biosynthetically [35S]methionine-labeled IL-5 and 125I-IL-5 that had been prepared using Bolton-Hunter reagent. The radiolabeled IL-5 binds specifically to BCL1- B20 (in vitro line) (a murine chronic B cell leukemic cell line previou...

  20. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.; (UPENN-MED)

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  1. Developmentally Regulated Expression of the Nerve Growth Factor Receptor Gene in the Periphery and Brain

    Science.gov (United States)

    Buck, C. R.; Martinez, Humberto J.; Black, Ira B.; Chao, Moses V.

    1987-05-01

    Nerve growth factor (NGF) regulates development and maintenance of function of peripheral sympathetic and sensory neurons. A potential role for the trophic factor in brain has been detected only recently. The ability of a cell to respond to NGF is due, in part, to expression of specific receptors on the cell surface. To study tissue-specific expression of the NGF receptor gene, we have used sensitive cRNA probes for detection of NGF receptor mRNA. Our studies indicate that the receptor gene is selectively and specifically expressed in sympathetic (superior cervical) and sensory (dorsal root) ganglia in the periphery, and by the septum-basal forebrain centrally, in the neonatal rat in vivo. Moreover, examination of tissues from neonatal and adult rats reveals a marked reduction in steady-state NGF receptor mRNA levels in sensory ganglia. In contrast, a 2- to 4-fold increase was observed in the basal forebrain and in the sympathetic ganglia over the same time period. Our observations suggest that NGF receptor mRNA expression is developmentally regulated in specific areas of the nervous system in a differential fashion.

  2. Ric-8A, a Gα protein guanine nucleotide exchange factor potentiates taste receptor signaling

    Directory of Open Access Journals (Sweden)

    Claire J Fenech

    2009-10-01

    Full Text Available Taste receptors for sweet, bitter and umami tastants are G-protein coupled receptors (GPCRs. While much effort has been devoted to understanding G-protein-receptor interactions and identifying the components of the signalling cascade downstream of these receptors, at the level of the G-protein the modulation of receptor signal transduction remains relatively unexplored. In this regard a taste-specific regulator of G-protein signaling (RGS, RGS21, has recently been identified. To study whether guanine nucleotide exchange factors (GEFs are involved in the transduction of the signal downstream of the taste GPCRs we investigated the expression of Ric-8A and Ric-8B in mouse taste cells and their interaction with G-protein subunits found in taste buds. Mammalian Ric-8 proteins were initially identified as potent GEFs for a range of Gα subunits and Ric-8B has recently been shown to amplify olfactory signal transduction. We find that both Ric-8A and Ric-8B are expressed in a large portion of taste bud cells and that most of these cells contain IP3R-3 a marker for sweet, umami and bitter taste receptor cells. Ric-8A interacts with Gα-gustducin and Gαi2 through which it amplifies the signal transduction of hTas2R16, a receptor for bitter compounds. Overall, these findings are consistent with a role for Ric-8 in mammalian taste signal transduction.

  3. Expression of vascular endothelial growth factor and its two receptors in normal human endometrium

    Institute of Scientific and Technical Information of China (English)

    王海燕; 陈贵安

    2003-01-01

    Objectives: We try to demonstrate the expression of vascular endothelial growthfactor (VEGF) and its receptors, flt-1 and KDR, in normal human emdometrium duringthe menstrual cycle.Methods: Immunohistochemical method was used to observe the expression ofVEGF and its two receptors in emdometrium throughout the normal menstrual cyclemeanwhile the isoforms of VEGF were also detected by Western blot analysis. The en-dothelial cells of micro-vessels were marked with Ⅷ factor antibody.Results: VEGF and its receptors existed in endometrial glandular, stromal and vas-cular endothelial cells of human endometrium. Their expressions were higher in the mid-secretory phase of menstrual cycle and highest at menstruation. VEGF121 and VEGF165were the predominant isoforms in normal human endometrium.Conclusion: The expression of VEGF and its two receptors showed cycle-dependentin human endometrium, probably involved in embryonic implantation and endometrialproliferation and differentiation.

  4. Evidence for a heritable unidimensional symptom factor underlying obsessionality.

    Science.gov (United States)

    Mathews, Carol A; Greenwood, Tiffany; Wessel, Jennifer; Azzam, Amin; Garrido, Helena; Chavira, Denise A; Chandavarkar, Uma; Bagnarello, Monica; Stein, Murray; Schork, Nicholas J

    2008-09-05

    The division of obsessive-compulsive symptoms (OCS) into specific factors is now widely accepted. However, the utility of these categories for genetic studies remains unclear, as studies examining their heritability have been inconsistent. Less attention has been paid to the possibility that clinically significant obsessionality is primarily determined by a "core" group of OCS that crosses the boundaries between symptom subgroups. The aim of this study is to determine whether such a core group exists, and to compare its heritability to that of the more traditionally derived symptom factors. We examined the properties and heritability of obsessive-compulsive symptoms in college students, medical students, and obsessive-compulsive disorder (OCD) families using the Leyton Obsessional Inventory. In each of the three samples, we identified a core group of symptoms that comprised a single unique construct and accounted for over 90% of the variation of the four more traditional symptom factors. This core construct was highly correlated with OCD in our families and had a heritability estimate of 0.19 when OCD was not included as a covariate and 0.49 when OCD was included as a covariate. In contrast, the four symptom factors were not heritable. There appears to be an underlying unidimensional component to obsessionality, both in non-clinical and clinical samples. This component, which is heritable, accounts for the majority of the variation of the more traditionally derived symptom factors in our sample, and is composed of OCS that are not specific to any of the symptom subgroups.

  5. Expression of leptin, leptin receptor, and connective tissue growth factor in degenerative disk lesions in the wrist.

    Science.gov (United States)

    Unglaub, Frank; Wolf, Maya B; Kroeber, Markus W; Dragu, Adrian; Schwarz, Stephan; Mittlmeier, Thomas; Kloeters, Oliver; Horch, Raymund E

    2011-06-01

    The purpose of this study was to identify whether leptin and connective tissue growth factor (CTGF) occur in the degenerative fibrocartilage disk and whether cartilage cells express leptin receptors. The study included 23 patients diagnosed with degenerative articular disk tears of the triangular fibrocartilage (TFC) (Palmer type 2C). Patients were divided into 2 groups based on ulna length: 1 group consisted of patients with an ulna-positive variance (group A), and the other group included patients with ulna-negative or -neutral variance (group B). After arthroscopic debridement of the TFC, histologic sections of biopsy specimens were prepared. The biopsy specimens were immunohistochemically analyzed, and the quantity of leptin-, CTGF-, and leptin receptor-positive cells was assessed. Cells positive for leptin, leptin receptor, and CTGF were found. The number of cells positive for leptin was significantly increased in specimens of patients with an ulna-negative variance (group B). In contrast, no significant difference was found for leptin receptor and CTGF in biopsy specimens of patients with ulna-positive or ulna-negative/neutral variance. The inner, middle, and outer zones of the disk do not express significantly different quantities of marker-positive cells. Degenerative fibrocartilage disk tissue cells exhibit leptin receptors and are exposed to the markers leptin and CTGF, providing evidence of a local paracrine system and regenerative processes. Cells of disks from patients with an ulna-neutral/negative length express significantly higher numbers of leptin-positive cells. Level II, diagnostic study. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  6. Cross-talk between the calcium-sensing receptor and the epidermal growth factor receptor in Rat-1 fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Tomlins, Scott A.; Bollinger, Nikki; Creim, Jeffrey A.; Rodland, Karin D.

    2005-08-15

    The calcium-sensing receptor (CaR) is a G-protein coupled receptor that is activated by extracellular calcium (Ca2+o). Rat-1 fibroblasts have been shown to proliferate and increase ERK activity in response to elevation of [Ca2+]o, and these responses are dependent on functional CaR expression. In this report, we examined the role of cross-talk between the CaR and the epidermal growth factor receptor (EGFR) in mediating these responses in Rat-1 cells. This report shows that AG1478, a specific inhibitor of the EGFR kinase, significantly inhibits the increase in proliferation induced by elevated Ca2+o. Further, we show that AG1478 acts downstream or separately from G-protein subunit activation of phospholipase C. AG1478 significantly inhibits Ca2+o-stimulated ERK phosphorylation and in vitro kinase activity. A similar inhibition of ERK phosphorylation was observed in response to the inhibitor AG494. In addition, treatment with inhibitors of metalloproteases involved in shedding of membrane anchored EGF family ligands substantially inhibited the increase in ERK activation in response to elevated Ca2+o. This is consistent with the known expression of TGFa by Rat-1 cells. These results indicate that EGFR transactivation is an important component of the CaR mediated response to increased Ca2+o in Rat-1 fibroblasts, and most likely involves CaR-mediated induction of regulated proteolysis and ligand shedding.

  7. Foreign Direct Investment Location Choice Factors: Some Evidence for Brazil

    Directory of Open Access Journals (Sweden)

    Romana KOREZ-VIDE

    2014-12-01

    Full Text Available Due to the liberalization and transformation of emerging markets economies, the attractiveness of these countries for foreign direct investors has been rising in the last decades. This paper explores foreign direct investment (FDI location choice factors of German and Austrian companies in Brazilian regions. We perform a quantitative analysis, based on the Multinomial Nested Logit Model and supplement its findings by the qualitative analysis, based on the semi-structured experts’ interview. The analyses show that investor-nation specific agglomeration, industry specialization, workforce qualification and physical infrastructure were important FDI location choice factors for German and Austrian companies in Brazil. Suggestions for future research of the FDI location choice factors are discussed.

  8. Dermatologic infections in cancer patients treated with epidermal growth factor receptor inhibitor therapy.

    Science.gov (United States)

    Eilers, R E; Gandhi, M; Patel, J D; Mulcahy, M F; Agulnik, M; Hensing, T; Lacouture, Mario E

    2010-01-06

    Patients treated with epidermal growth factor receptor inhibitors (EGFRIs) frequently experience dermatologic toxic effects. Whereas the impact of these effects on quality of life and EGFRI dosing has been described, their impact on physical health has not been ascertained. We examined the prevalence of infections that complicate dermatologic toxic effects of EGFRIs. We used retrospective chart review methods to analyze 221 patients who were treated in the Skin and Eye Reactions to Inhibitors of EGFR and Kinases clinic, a referral clinic for dermatologic toxic effects of cancer therapies. We reviewed results of bacterial cultures, histopathologic assessment of biopsy samples, and immunohistochemical staining of skin specimens for viral pathogens that were recorded in the patients' medical records. Associations between patient demographic and treatment characteristics and the development of infections were examined using the Fisher exact test. All statistical tests were two-sided. Eighty-four (38%) of the 221 patients showed evidence of infection at sites of dermatologic toxic effect. Fifty (22.6%) of the 221 patients had cultures positive for Staphylococcus aureus, and 12 (5.4%) of the 221 patients cultured positive for methicillin-resistant S aureus. Less frequent infections included herpes simplex (3.2%), herpes zoster (1.8%), and dermatophytes (10.4%). The seborrheic region was the most prevalent site of infection, and patients with leukopenia had higher risk for infection than patients who did not have leukopenia (P = .005). Demographic factors and associated treatments were not associated with the occurrence of a dermatologic infection (P > or = .05). Patients with dermatologic toxic effects following treatment with EGFRIs have a high prevalence of cutaneous infections. Most notably, bacterial infections developed at sites previously affected by dermatologic toxic effects, with leukopenic patients being at greater risk.

  9. Epidermal Growth Factor Receptor Expression in Triple Negative and Nontriple Negative Breast Carcinomas.

    Science.gov (United States)

    Changavi, Arathi A; Shashikala, Arundhathi; Ramji, Ashwini S

    2015-01-01

    The panel of markers used for molecular classification include estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptor (HER)-2/neu, p53, Bcl-2 and basal markers like cytokeratin 5/6 or epidermal growth factor receptor (EGFR). Among these, EGFR plays an important role and is associated with bad prognosis. To study EGFR expression in triple negative breast carcinoma (TNBC) and non-TNBCs (NTNBCs). Fifty cases of breast carcinomas were classified and graded according to World Health Organization and Nottingham modification of Scarff-Bloom-Richardson (SBR) system, respectively. The age of the patients ranged from 28 to 69 years. Histological features such as necrosis, pushing borders, lymphocytic infiltrate and periductal elastosis were noted. The panel of markers used in our study included ER, PR, HER-2/neu and EGFR. EGFR expression was assessed based on membrane staining. Chi-square test was applied for statistical analysis to compare EGFR expression with hormonal status and prognostic factors. P triple negative and strongly expressed EGFR. EGFR expression was inversely associated with ER status and showed strong association with necrosis and lymphocytic infiltrate, but not with pushing border and periductal elastosis. EGFR is an important marker to stratify patients with breast cancer according to molecular classification. Its expression correlated positively with young age, higher SBR grade, necrosis, lymphocytic infiltrate and inversely with hormonal receptor expression.

  10. Evidence of BrdU-positive retinal neurons after application of an Alpha7 nicotinic acetylcholine receptor agonist.

    Science.gov (United States)

    Webster, Mark K; Cooley-Themm, Cynthia A; Barnett, Joseph D; Bach, Harrison B; Vainner, Jessica M; Webster, Sarah E; Linn, Cindy L

    2017-03-27

    Irreversible vision loss due to disease or age is responsible for a reduced quality of life. The experiments in this study test the hypothesis that the α7 nicotinic acetylcholine receptor agonist, PNU-282987, leads to the generation of retinal neurons in an adult mammalian retina in the absence of retinal injury or exogenous growth factors. Using antibodies against BrdU, retinal ganglion cells, progenitor cells and Müller glia, the results of this study demonstrate that multiple types of retinal cells and neurons are generated after eye drop application of PNU-282987 in adult Long Evans rats in a dose-dependent manner. The results of this study provide evidence that progenitor cells, derived from Müller glia after treatment with PNU-282987, differentiate and migrate to the photoreceptor and retinal ganglion cell layers. If retinas were treated with the alpha7 nAChR antagonist, methyllycaconitine, before agonist treatment, BrdU-positive cells were significantly reduced. As adult mammalian neurons do not typically regenerate or proliferate, these results have implications for reversing vision loss due to neurodegenerative disease or the aging process to improve the quality of life for millions of patients. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Characterization of rabbit ileal receptors for Clostridium difficile toxin A. Evidence for a receptor-coupled G protein

    Energy Technology Data Exchange (ETDEWEB)

    Pothoulakis, C.; LaMont, J.T.; Eglow, R.; Gao, N.; Rubins, J.B.; Theoharides, T.C.; Dickey, B.F. (Boston Univ. School of Medicine, MA (USA))

    1991-07-01

    The purpose of this study was to characterize the surface receptor for toxin A, the enterotoxin from Clostridium difficile, on rabbit intestinal brush borders (BB) and on rat basophilic leukemia (RBL) cells. Purified toxin A was radiolabeled using a modified Bolton-Hunter method to sp act 2 microCi/micrograms, with retention of full biologic activity. 3H-Toxin A bound specifically to a single class of receptors on rabbit BB and on RBL cells with dissociation constants of 5.4 x 10(-8) and 3.5 x 10(-8) M, respectively. RBL cells were highly sensitive to toxin A (cell rounding) and had 180,000 specific binding sites per cell, whereas IMR-90 fibroblasts were far less sensitive to toxin A and lacked detectable specific binding sites. Exposure of BB to trypsin or chymotrypsin significantly reduced 3H-toxin A specific binding. Preincubation of BB with Bandeirea simplicifolia (BS-1) lectin also reduced specific binding, and CHAPS-solubilized receptors could be immobilized with WGA-agarose. The addition of 100 nM toxin A accelerated the association of 35S-GTP gamma S with rabbit ileal BB, and preincubation of BB with the GTP analogues GTP gamma S or Gpp(NH)p, significantly reduced 3H-toxin A specific binding. Our data indicate that the membrane receptor for toxin A is a galactose and N-acetyl-glucosamine-containing glycoprotein which appears to be coupled to a G protein.

  12. Central phencyclidine (PCP) receptor binding is glutamate dependent: evidence for a PCP/excitatory amino acid receptor (EAAR) complex

    Energy Technology Data Exchange (ETDEWEB)

    Loo, P.; Braunwalder, A.; Lehmann, J.; Williams, M.

    1986-03-01

    PCP and other dissociative anesthetica block the increase in neuronal firing rate evoked by the EAAR agonist, N-methyl-Daspartate. NMDA and other EAAs such as glutamate (glu) have not been previously shown to affect PCP ligand binding. In the present study, using once washed rat forebrain membranes, 10 ..mu..M-glu was found to increase the binding of (/sup 3/H)TCP, a PCP analog, to defined PCP recognition sites by 20%. Removal of glu and aspartate (asp) by extensive washing decreased TCP binding by 75-90%. In these membranes, 10 ..mu..M L-glu increased TCP binding 3-fold. This effect was stereospecific and evoked by other EAAs with the order of activity, L-glu > D-asp > L- asp > NMDA > D-glu > quisqualate. Kainate, GABA, NE, DA, 5-HT, 2-chloroadenosine, oxotremorine and histamine had no effect on TCP binding at concentrations up to 100 ..mu..M. The effects of L-glu were attenuated by the NMDA-type receptor antagonist, 2-amino-7--phosphonoheptanoate (AP7; 10 ..mu..M-1 mM). These findings indicate that EAAS facilitate TCP binding, possibly through NMDA-type receptors. The observed interaction between the PCP receptor and EAARs may reflect the existence of a macromolecular receptor complex similar to that demonstrated for the benzodiazepines and GABA.

  13. Identification of a truncated splice variant of IL-18 receptor alpha in the human and rat, with evidence of wider evolutionary conservation

    Directory of Open Access Journals (Sweden)

    Chris S. Booker

    2014-09-01

    Full Text Available Interleukin-18 (IL-18 is a pro-inflammatory cytokine which stimulates activation of the nuclear factor kappa beta (NF-κB pathway via interaction with the IL-18 receptor. The receptor itself is formed from a dimer of two subunits, with the ligand-binding IL-18Rα subunit being encoded by the IL18R1 gene. A splice variant of murine IL18r1, which has been previously described, is formed by transcription of an unspliced intron (forming a ‘type II’ IL18r1 transcript and is predicted to encode a receptor with a truncated intracellular domain lacking the capacity to generate downstream signalling. In order to examine the relevance of this finding to human IL-18 function, we assessed the presence of a homologous transcript by reverse transcription-polymerase chain reaction (RT-PCR in the human and rat as another common laboratory animal. We present evidence for type II IL18R1 transcripts in both species. While the mouse and rat transcripts are predicted to encode a truncated receptor with a novel 5 amino acid C-terminal domain, the human sequence is predicted to encode a truncated protein with a novel 22 amino acid sequence bearing resemblance to the ‘Box 1’ motif of the Toll/interleukin-1 receptor (TIR domain, in a similar fashion to the inhibitory interleukin-1 receptor 2. Given that transcripts from these three species are all formed by inclusion of homologous unspliced intronic regions, an analysis of homologous introns across a wider array of 33 species with available IL18R1 gene records was performed, which suggests similar transcripts may encode truncated type II IL-18Rα subunits in other species. This splice variant may represent a conserved evolutionary mechanism for regulating IL-18 activity.

  14. Expression of type 1 corticotropin-releasing factor receptor in the guinea pig enteric nervous system.

    Science.gov (United States)

    Liu, Sumei; Gao, Xiang; Gao, Na; Wang, Xiyu; Fang, Xiucai; Hu, Hong-Zhen; Wang, Guo-Du; Xia, Yun; Wood, Jackie D

    2005-01-17

    Reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiological recording, and intraneuronal injection of the neuronal tracer biocytin were integrated in a study of the functional expression of corticotropin-releasing factor (CRF) receptors in the guinea pig enteric nervous system. RT-PCR revealed expression of CRF1 receptor mRNA, but not CRF2, in both myenteric and submucosal plexuses. Immunoreactivity for the CRF1 receptor was distributed widely in the myenteric plexus of the stomach and small and large intestine and in the submucosal plexus of the small and large intestine. CRF1 receptor immunoreactivity was coexpressed with calbindin, choline acetyltransferase, and substance P in the myenteric plexus. In the submucosal plexus, CRF1 receptor immunoreactivity was found in neurons that expressed calbindin, substance P, choline acetyltransferase, or neuropeptide Y. Application of CRF evoked slowly activating depolarizing responses associated with elevated excitability in both myenteric and submucosal neurons. Histological analysis of biocytin-filled neurons revealed that both uniaxonal neurons with S-type electrophysiological behavior and neurons with AH-type electrophysiological behavior and Dogiel II morphology responded to CRF. The CRF-evoked depolarizing responses were suppressed by the CRF1/CRF2 receptor antagonist astressin and the selective CRF1 receptor antagonist NBI27914 and were unaffected by the selective CRF2 receptor antagonist antisauvagine-30. The findings support the hypothesis that the CRF1 receptor mediates the excitatory actions of CRF on neurons in the enteric nervous system. Actions on enteric neurons might underlie the neural mechanisms by which stress-related release of CRF in the periphery alters intestinal propulsive motor function, mucosal secretion, and barrier functions.

  15. Platelet-derived growth factor receptor-β in myocyte was upregulated by angiotensin II

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To observe the regulation of platelet-derived growth factor (PDGF) receptor-βin myocyte stimulated by angiotensin II (AngII) at both integrated and cellular levels and reveal the signal transduction mechanism in cell, two kidneys, one clip (2K1C) renal hypertension were performed by placing a sliver clip around the left renal artery. Blood pressure and the ratio of left ventricular weight to body weight were measured at 4 and 8 weeks after operation. The content of AngII in heart was detected by radioimmunology assay; the protein level of PDGF receptor-βin heart was measured by Western blot analysis. The alteration of PDGF receptor-βstimulated by AngII and several inhibitors was observed on cultured neonatal rat ventricular myocyte (NRVM). The content of AngII in heart of 2K1C renal hypertensive rat at 4 and 8 weeks after operation was increased. Compared with sham group, 4 and 8 weeks after operation, PDGF receptor-βin heart of 2K1C group was upregulated by 100.3% and 127.1% (P < 0.05), respectively. This upregulation could be inhibited by captopril. For cultured myocyte, PDGF receptor-βwas increased by 47.1% after being stimulated by AngII and this upregulation could be inhibited by losartan which was an inhibitor of AT1 receptor. PLC inhibitor (U73122) and MEK inhibitor (PD98059) could partly inhibit PDGF receptor-βupregulation induced by AngII. These results suggested that AngII could upregulate PDGF receptor-βin myocyte by its AT1 receptor and this effect was at least partly dependent on PLC and extracellular signal-regulated kinase (ERK).

  16. Factors Contributing to Child Scrambling: Evidence from Ukrainian

    Science.gov (United States)

    Mykhaylyk, Roksolana

    2012-01-01

    This study examines the word order phenomenon of optional scrambling in Ukrainian. It aims to test factors such as semantic features and object type that have been shown to affect scrambling in other languages. Forty-one children between 2 ; 7 and 6 ; 0, and twenty adult speakers participated in an elicited production experiment. The picture…

  17. Social Networks and Factor Markets: Panel Data Evidence from Ethiopia

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya; Kahsay, Goytom Abraha; Berhane, Guush

    2017-01-01

    We investigate the role of an indigenous social network in Ethiopia, the iddir, in facilitating factor market transactions among smallholder farmers. We use detailed longitudinal household survey data and employ fixed effects estimation approaches to identify the effect of iddir membership...... credit source. These results suggest that non-market institutions can play crucial roles in facilitating market transactions....

  18. Kinetics of the Attachment of Intrinsic Factor-Bound Cobamides to Ileal Receptors

    Science.gov (United States)

    Mathan, V. I.; Babior, Bernard M.; Donaldson, Robert M.

    1974-01-01

    To determine whether the molecular configuration of vitamin B12 influences the attachment of intrinsic factor-vitamin B12 complex to ileal microvillous membrane receptor sites, we have examined the kinetics of uptake of intrinsic factor-bound cyanocobalamin by brush borders and microvillous membranes isolated from guinea pig ileum, and have compared this uptake with that of intrinsic factor alone and with that of intrinsic factor complexed with various analogs of cyanocobalamin. We first studied the kinetics of binding of cyanocobalamin and other cobamides to human gastric intrinsic factor. The binding of cyanocobalamin showed saturation kinetics and, at relatively high concentrations of cyanocobalamin, a Scatchard plot of binding was linear. The dissociation constant for the intrinsic factor-cyanocobalamin complex was 0.066 nM. When the binding of various vitamin B12 analogs to intrinsic factor was determined by competition experiments, the analogs could be separated into two categories: those with affinities similar to that of cyanocobalamin and those with affinities much lower than that of cyanocobalamin. The affinity of cyanocobalamin for intrinsic factor was not altered by various substitutions at the -CN position, while removal of a single amido group on the corrin ring of substitution of the dimethylbenzimidazole base greatly reduced affinity. Removal of the base totally abolished binding. These findings, confirming those reported by others, are consistent with the concept that the cyanocobalamin molecule fits into a “pocket” in the intrinsic factor molecule, with the nucleotide base facing inward and the -CN side of the planar corrin ring facing outward. We then investigated the attachment of intrinsic factor-bound cyanocobalamin to ileal receptor. Attachment to microvillous membranes showed saturation kinetics with a dissociation constant of 0.25 nM. Attachment was rapid and was 70% complete within 5 min; the second-order rate constant for attachment

  19. Differential requirement of the epidermal growth factor receptor for G protein-mediated activation of transcription factors by lysophosphatidic acid

    Directory of Open Access Journals (Sweden)

    Dent Paul

    2010-01-01

    Full Text Available Abstract Background The role of the epidermal growth factor receptor (EGFR and other receptor tyrosine kinases (RTKs in provoking biological actions of G protein-coupled receptors (GPCRs has been one of the most disputed subjects in the field of GPCR signal transduction. The purpose of the current study is to identify EGFR-mediated mechanisms involved in activation of G protein cascades and the downstream transcription factors by lysophosphatidic acid (LPA. Results In ovarian cancer cells highly responsive to LPA, activation of AP-1 by LPA was suppressed by inhibition of EGFR, an effect that could be reversed by co-stimulation of another receptor tyrosine kinase c-Met with hepatocyte growth factor, indicating that LPA-mediated activation of AP-1 requires activity of a RTK, not necessarily EGFR. Induction of AP-1 components by LPA lied downstream of Gi, G12/13, and Gq. Activation of the effectors of Gi, but not Gq or G12/13 was sensitive to inhibition of EGFR. In contrast, LPA stimulated another prominent transcription factor NF-κB via the Gq-PKC pathway in an EGFR-independent manner. Consistent with the importance of Gi-elicited signals in a plethora of biological processes, LPA-induced cytokine production, cell proliferation, migration and invasion require intact EGFR. Conclusions An RTK activity is required for activation of the AP-1 transcription factor and other Gi-dependent cellular responses to LPA. In contrast, activation of G12/13, Gq and Gq-elicited NF-κB by LPA is independent of such an input. These results provide a novel insight into the role of RTK in GPCR signal transduction and biological functions.

  20. The heparan sulfate co-receptor and the concentration of fibroblast growth factor-2 independently elicit different signalling patterns from the fibroblast growth factor receptor

    Directory of Open Access Journals (Sweden)

    Duchesne Laurence

    2010-06-01

    Full Text Available Abstract Background The fibroblast growth factor receptor (FGFR interprets concentration gradients of FGF ligands and structural changes in the heparan sulfate (HS co-receptor to generate different cellular responses. However, whether the FGFR generates different signals is not known. Results We have previously shown in rat mammary fibroblasts that in cells deficient in sulfation, and so in HS co-receptor, FGF-2 can only stimulate a transient phosphorylation of p42/44 MAPK and so cannot stimulate DNA synthesis. Here we demonstrate that this is because in the absence of HS, FGF-2 fails to stimulate the phosphorylation of the adaptor FGFR substrate 2 (FRS2. In cells possessing the HS co-receptor, FGF-2 elicits a bell-shaped dose response: optimal concentrations stimulate DNA synthesis, but supramaximal concentrations (≥ 100 ng/mL have little effect. At optimal concentrations (300 pg/mL FGF-2 stimulates a sustained dual phosphorylation of p42/44 MAPK and tyrosine phosphorylation of FRS2. In contrast, 100 ng/mL FGF-2 only stimulates a transient early peak of p42/44 MAPK phosphorylation and fails to stimulate appreciably the phosphorylation of FRS2 on tyrosine. Conclusions These results suggest that the nature of the FGFR signal produced is determined by a combination of the HS co-receptor and the concentration of FGF ligand. Both the phosphorylation of the adaptor FRS2, the kinetics (sustained or transient of phosphorylation of p42/44(MAPK are varied, and so differing cellular responses are produced.

  1. Current Evidence of Chinese Herbal Constituents with Effects on NMDA Receptor Blockade

    Directory of Open Access Journals (Sweden)

    David T. Yew

    2013-08-01

    Full Text Available NMDA receptor (NMDA-R is an important molecular entity governing a wide range of functions in the central nervous system. For example, the NMDA-R is involved in memory and cognition, and impairment of both (as in Alzheimer’s Disease is attributed to NMDA-mediated neurotoxicity. With greater understanding of the NMDA-R structure, antagonists with varying degrees of binding-site and subtype selectivity have been developed and put into clinical use. Discovery of target-specific Chinese herbs have also been made in parallel. This article provides an overview of the known active sites on the NMDA-R, followed by a discussion of the relevant herbs and their constituents. Experimental evidence supporting the inhibitory role of the herbal compounds on the NMDA-R is highlighted. For some of the compounds, potential research directions are also proposed to further elucidate the underlying mechanisms of the herbs. It is envisaged that future investigations based on the present data will allow more clinically relevant herbs to be identified.

  2. Neuropeptide S receptor gene -- converging evidence for a role in panic disorder.

    Science.gov (United States)

    Domschke, K; Reif, A; Weber, H; Richter, J; Hohoff, C; Ohrmann, P; Pedersen, A; Bauer, J; Suslow, T; Kugel, H; Heindel, W; Baumann, C; Klauke, B; Jacob, C; Maier, W; Fritze, J; Bandelow, B; Krakowitzky, P; Rothermundt, M; Erhardt, A; Binder, E B; Holsboer, F; Gerlach, A L; Kircher, T; Lang, T; Alpers, G W; Ströhle, A; Fehm, L; Gloster, A T; Wittchen, H-U; Arolt, V; Pauli, P; Hamm, A; Deckert, J

    2011-09-01

    Animal studies have suggested neuropeptide S (NPS) and its receptor (NPSR) to be involved in the pathogenesis of anxiety-related behavior. In this study, a multilevel approach was applied to further elucidate the role of NPS in the etiology of human anxiety. The functional NPSR A/T (Asn¹⁰⁷Ile) variant (rs324981) was investigated for association with (1) panic disorder with and without agoraphobia in two large, independent case-control studies, (2) dimensional anxiety traits, (3) autonomic arousal level during a behavioral avoidance test and (4) brain activation correlates of anxiety-related emotional processing in panic disorder. The more active NPSR rs324981 T allele was found to be associated with panic disorder in the female subgroup of patients in both samples as well as in a meta-analytic approach. The T risk allele was further related to elevated anxiety sensitivity, increased heart rate and higher symptom reports during a behavioral avoidance test as well as decreased activity in the dorsolateral prefrontal, lateral orbitofrontal and anterior cingulate cortex during processing of fearful faces in patients with panic disorder. The present results provide converging evidence for a female-dominant role of NPSR gene variation in panic disorder potentially through heightened autonomic arousal and distorted processing of anxiety-relevant emotional stimuli.

  3. Evidence that genetic variation in the oxytocin receptor (OXTR) gene influences social cognition in ADHD.

    Science.gov (United States)

    Park, J; Willmott, M; Vetuz, G; Toye, C; Kirley, A; Hawi, Z; Brookes, K J; Gill, M; Kent, L

    2010-05-30

    Some children with ADHD also have social and communication difficulties similar to those seen in children with autistic spectrum disorders and this may be due to shared genetic liability. As the oxytocin receptor (OXTR) gene has been implicated in social cognition and autistic spectrum disorders, this study investigated whether OXTR polymorphisms previously implicated in autism were associated with ADHD and whether they influenced OXTR mRNA expression in 27 normal human amygdala brain samples. The family-based association sample consisted of 450 DSM-IV diagnosed ADHD probands and their parents. Although there was no association with the ADHD phenotype, an association with social cognitive impairments in a subset of the ADHD probands (N=112) was found for SNP rs53576 (F=5.24, p=0.007) with post-hoc tests demonstrating that the AA genotype was associated with better social ability compared to the AG genotype. Additionally, significant association was also found for rs13316193 (F=3.09, p=0.05) with post-hoc tests demonstrating that the CC genotype was significantly associated with poorer social ability than the TT genotype. No significant association between genotype and OXTR mRNA expression was found. This study supports previous evidence that the OXTR gene is implicated in social cognition.

  4. Cloning and expression of the mouse histamine H3 receptor: evidence for multiple isoforms.

    Science.gov (United States)

    Rouleau, Agnès; Héron, Anne; Cochois, Véronique; Pillot, Catherine; Schwartz, Jean-Charles; Arrang, Jean-Michel

    2004-09-01

    The existence of mouse H3-receptor isoforms was investigated by PCR analysis and cDNA cloning. Splicing mechanisms previously reported in various species are conserved in the mouse. The retention/deletion of a fragment in the third intracellular loop of the mouse receptor leads to the existence of three isoforms designated mH(3(445)), mH(3(413)) and mH(3(397)) according to the length of their deduced amino acid sequence. PCR analysis showed that mouse H3-receptor isoforms display different expression patterns in the brain. Following expression in Cos-1 cells, [125I]iodoproxyfan binding indicated similar pharmacological profiles of the mH(3(445)), mH(3(413)) and mH(3(397)) isoforms. The pharmacological profile of the mouse H3 receptor is more similar to the rat receptor than to the human receptor, although some differences were also observed between the mouse and rat receptors. For example, the potency of thioperamide and ciproxifan is slightly higher at the mouse receptor than at the rat receptor but 40-100-fold higher than at the human receptor. In situ hybridization histochemistry showed that the distribution of H3-receptor mRNAs in the mouse brain is rather similar to that previously reported in the rat brain. However, the autoradiographic and cellular expression patterns observed in several brain areas such as the thalamus or hippocampus reveal important differences between the two species.

  5. A novel computational approach for the prediction of networked transcription factors of aryl hydrocarbon-receptor-regulated genes.

    Science.gov (United States)

    Kel, Alexander; Reymann, Susanne; Matys, Volker; Nettesheim, Paul; Wingender, Edgar; Borlak, Jürgen

    2004-12-01

    A novel computational method based on a genetic algorithm was developed to study composite structure of promoters of coexpressed genes. Our method enabled an identification of combinations of multiple transcription factor binding sites regulating the concerted expression of genes. In this article, we study genes whose expression is regulated by a ligand-activated transcription factor, aryl hydrocarbon receptor (AhR), that mediates responses to a variety of toxins. AhR-mediated change in expression of AhR target genes was measured by oligonucleotide microarrays and by reverse transcription-polymerase chain reaction in human and rat hepatocytes. Promoters and long-distance regulatory regions (>10 kb) of AhR-responsive genes were analyzed by the genetic algorithm and a variety of other computational methods. Rules were established on the local oligonucleotide context in the flanks of the AhR binding sites, on the occurrence of clusters of AhR recognition elements, and on the presence in the promoters of specific combinations of multiple binding sites for the transcription factors cooperating in the AhR regulatory network. Our rules were applied to search for yet unknown Ah-receptor target genes. Experimental evidence is presented to demonstrate high fidelity of this novel in silico approach.

  6. Modified epidermal growth factor receptor (EGFR-bearing liposomes (MRBLs are sensitive to EGF in solution.

    Directory of Open Access Journals (Sweden)

    Albert Wong

    Full Text Available Cancers often overexpress EGF and other growth factors to promote cell replication and migration. Previous work has not produced targeted drug carriers sensitive to abnormal amounts of growth factors. This work demonstrates that liposomes bearing EGF receptors covalently crosslinked to p-toluic acid or methyl-PEO(4-NHS ester (or, in short, MRBLs exhibit an increased rate of release of encapsulated drug compounds when EGF is present in solution. Furthermore, the modified EGF receptors retain the abilities to form dimers in the presence of EGF and bind specifically to EGF. These results demonstrate that MRBLs are sensitive to EGF in solution and indicate that MRBL-reconstituted modified EGF receptors, in the presence of EGF in solution, form dimers which increase MRBL permeability to encapsulated compounds.

  7. Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligand-independent dimerization in Sf21 microsomal membranes using non-canonical amino acids

    Science.gov (United States)

    Quast, Robert B.; Ballion, Biljana; Stech, Marlitt; Sonnabend, Andrei; Varga, Balázs R.; Wüstenhagen, Doreen A.; Kele, Péter; Schiller, Stefan M.; Kubick, Stefan

    2016-01-01

    Cell-free protein synthesis systems represent versatile tools for the synthesis and modification of human membrane proteins. In particular, eukaryotic cell-free systems provide a promising platform for their structural and functional characterization. Here, we present the cell-free synthesis of functional human epidermal growth factor receptor and its vIII deletion mutant in a microsome-containing system derived from cultured Sf21 cells. We provide evidence for embedment of cell-free synthesized receptors into microsomal membranes and asparagine-linked glycosylation. Using the cricket paralysis virus internal ribosome entry site and a repetitive synthesis approach enrichment of receptors inside the microsomal fractions was facilitated thereby providing analytical amounts of functional protein. Receptor tyrosine kinase activation was demonstrated by monitoring receptor phosphorylation. Furthermore, an orthogonal cell-free translation system that provides the site-directed incorporation of p-azido-L-phenylalanine is characterized and applied to investigate receptor dimerization in the absence of a ligand by photo-affinity cross-linking. Finally, incorporated azides are used to generate stable covalently linked receptor dimers by strain-promoted cycloaddition using a novel linker system. PMID:27670253

  8. In vitro evidence in rainbow trout supporting glucosensing mediated by sweet taste receptor, LXR, and mitochondrial activity in Brockmann bodies, and sweet taste receptor in liver.

    Science.gov (United States)

    Otero-Rodiño, Cristina; Velasco, Cristina; Álvarez-Otero, Rosa; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2016-10-01

    We previously obtained evidence in rainbow trout peripheral tissues such as liver and Brockmann bodies (BB) for the presence and response to changes in circulating levels of glucose (induced by intraperitoneal hypoglycaemic and hyperglycaemic treatments) of glucosensing mechanisms others than that mediated by glucokinase (GK). There were based on mitochondrial production of reactive oxygen species (ROS) leading to increased expression of uncoupling protein 2 (UCP2), and sweet taste receptor in liver and BB, and on liver X receptor (LXR) and sodium/glucose co-transporter 1 (SGLT-1) in BB. We aimed in the present study to obtain further in vitro evidence for the presence and functioning of these systems. In a first experiment, pools of sliced liver and BB were incubated for 6h at 15°C in modified Hanks' medium containing 2, 4, or 8mM d-glucose, and we assessed the response of parameters related to these glucosensing mechanisms. In a second experiment, pools of sliced liver and BB were incubated for 6h at 15°C in modified Hanks' medium with 8mM d-glucose alone (control) or containing 1mM phloridzin (SGLT-1 antagonist), 20μM genipin (UCP2 inhibitor), 1μM trolox (ROS scavenger), 100μM bezafibrate (T1R3 inhibitor), and 50μM geranyl-geranyl pyrophosphate (LXR inhibitor). The results obtained in both experiments support the presence and functioning of glucosensor mechanisms in liver based on sweet taste receptor whereas in BB the evidence support those based on LXR, mitochondrial activity and sweet taste receptor.

  9. Interleukin-10 and soluble tumor necrosis factor receptors in cerebrospinal fluid of children with bacterial meningitis

    NARCIS (Netherlands)

    Kornelisse, R.F.; Savelkoul, H.F.J.; Mulder, P.H.G.; Suur, M.H.; Straaten, van der P.J.C.; Heijden, van der A.J.; Sukhai, R.N.; Hählen, K.; Neijens, H.J.; Groot, de R.

    1996-01-01

    The antiinflammatory mediators interleukin (IL)-10 and soluble tumor necrosis factor (TNF) receptors p55 (sTNFR-55) and sTNFR-75 in cerebrospinal fluid (CSF) from 37 children with bacterial meningitis were studied. CSF concentrations of IL-10, sTNFR-55, and sTNFR-75 and of the proinflammatory cytoki

  10. Amplification of epidermal growth factor receptor gene in renal cell carcinoma

    DEFF Research Database (Denmark)

    Harper, Peter; El-Hariry, Iman; Powles, Thomas;

    2010-01-01

    Expression of epidermal growth factor receptor (EGFR) may be of prognostic value in renal cell cancer (RCC). Gene amplification of EGFR was investigated in a cohort of 315 patients with advanced RCC from a previously reported randomised study. Using fluorescent in situ hybridisation, only 2...

  11. The neural cell adhesion molecule binds to fibroblast growth factor receptor 2

    DEFF Research Database (Denmark)

    Christensen, Claus; Lauridsen, Jes B; Berezin, Vladimir;

    2006-01-01

    The neural cell adhesion molecule (NCAM) can bind to and activate fibroblast growth factor receptor 1 (FGFR1). However, there are four major FGFR isoforms (FGFR1-FGFR4), and it is not known whether NCAM also interacts directly with the other three FGFR isoforms. In this study, we show by surface...

  12. Endoglin structure and function - Determinants of endoglin phosphorylation by transforming growth factor-beta receptors

    NARCIS (Netherlands)

    Koleva, Rositsa I.; Conley, Barbara A.; Romero, Diana; Riley, Kristin S.; Marto, Jarrod A.; Lux, Andreas; Vary, Calvin P. H.

    2006-01-01

    Determination of the functional relationship between the transforming growth factor-beta(TGF beta) receptor proteins endoglin and ALK1 is essential to the understanding of the human vascular disease, hereditary hemorrhagic telangiectasia. TGF beta 1 caused recruitment of ALK1 into a complex with end

  13. The insulin-like growth factor 1 receptor in cancer : Old focus, new future

    NARCIS (Netherlands)

    Hartog, Hermien; Wesseling, Jelle; Boezen, H. Marike; van der Graaf, Winette T. A.

    2007-01-01

    The importance of insulin-like growth factor 1 receptor (IGF-1R) signalling in malignant behaviour of tumour cells is well established. Currently, development of drugs targeting the IGF-1R as anticancer treatment is emerging. Several IGF-1R targeting strategies are being investigated in phases I and

  14. The insulin-like growth factor 1 receptor in cancer : Old focus, new future

    NARCIS (Netherlands)

    Hartog, Hermien; Wesseling, Jelle; Boezen, H. Marike; van der Graaf, Winette T. A.

    2007-01-01

    The importance of insulin-like growth factor 1 receptor (IGF-1R) signalling in malignant behaviour of tumour cells is well established. Currently, development of drugs targeting the IGF-1R as anticancer treatment is emerging. Several IGF-1R targeting strategies are being investigated in phases I and

  15. The insulin-like growth factor 1 receptor in cancer: old focus, new future.

    NARCIS (Netherlands)

    Hartog, H. de; Wesseling, J.; Boezen, H.M.; Graaf, W.T.A. van der

    2007-01-01

    The importance of insulin-like growth factor 1 receptor (IGF-1R) signalling in malignant behaviour of tumour cells is well established. Currently, development of drugs targeting the IGF-1R as anticancer treatment is emerging. Several IGF-1R targeting strategies are being investigated in phases I and

  16. Effect of fluoride on expression of insulinlike growth factor-1 and its receptor of rat osteoblasts

    Institute of Scientific and Technical Information of China (English)

    喻茂娟

    2013-01-01

    Objective To explore the influence of fluorine on mRNA and protein expression of the insulin-like growth factor-1 (IGF-1) and its receptor of rat osteoblasts.Methods Osteoblasts were isolated from rat bone by enzyme digestion.Different fluorine concentration[0 (con-

  17. Changes in epidermal growth factor receptor expression during chemotherapy in non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jakobsen, Jan Nyrop; Santoni-Rugiu, Eric; Sørensen, Jens Benn

    2014-01-01

    BACKGROUND: Antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, may potentially improve outcome in non-small cell lung cancer (NSCLC) patients with high EGFR expression. The EGFR expression may be heterogeneously distributed within tumors, and small biopsies may thus...

  18. Structural basis for receptor recognition of vitamin-B(12)-intrinsic factor complexes

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Madsen, Mette; Storm, Tina;

    2010-01-01

    Cobalamin (Cbl, vitamin B(12)) is a bacterial organic compound and an essential coenzyme in mammals, which take it up from the diet. This occurs by the combined action of the gastric intrinsic factor (IF) and the ileal endocytic cubam receptor formed by the 460-kilodalton (kDa) protein cubilin...

  19. Orphan nuclear receptor TR4 and fibroblast growth factor 1 in metabolism

    NARCIS (Netherlands)

    Liu, Weilin

    2016-01-01

    Metabolic homeostasis is achieved, in part, through the coordinated activities of members of the Nuclear Receptor (NR) family, a superfamily of ligand-modulated transcription factors (TFs) that mediate responses to a wide range of lipophilic signaling molecules including lipids, steroids, retinoids,

  20. Localization and functional roles of corticotropin-releasing factor receptor type 2 in the cerebellum

    NARCIS (Netherlands)

    Gounko, Natalia V.; Gramsbergen, Albert; van der Want, Johannes J. L.

    2008-01-01

    The corticotropin-releasing factor (CRF) type 2 receptor has three splice variants alpha, beta, and gamma. In the rodent brain only CRF-R2 alpha is present. In the cerebellum, CRF-R2 alpha has two different isoforms: a full-length form (fl) and truncated (tr). Both forms CRF-R2 have a unique cellula

  1. Epidermal growth factor receptor expression in pancreatic lesions induced in the rat by azaserine

    NARCIS (Netherlands)

    Visser, C.J.T.; Weger, R.A. de; Blokland, W.T.M. van; Seifert-Bock, I.; Kobrin, M.S.; Korc, M.; Woutersen, R.A.

    1996-01-01

    In the present study, the expression of the epidermal growth factor receptor (EGFR) was investigated in putative preneoplastic and neoplastic acinar cell lesions induced in the rat pancreas by azaserine, using Northern blotting, in situ hybridisation (ISH) and immunohistochemistry. EGFR protein leve

  2. The role of NMDA receptors in human eating behavior: evidence from a case of anti-NMDA receptor encephalitis

    OpenAIRE

    Perogamvros, Lampros; Schnider, Armin; Leemann, Béatrice Anne Valérie

    2012-01-01

    Research in animal models has implicated N-methyl-D-aspartate (NMDA) receptors (NMDARs) in the control of food intake. Until now, these findings have been not replicated in humans. Here we describe a 22-year-old woman with anti-NMDAR encephalitis and no prior neurological or psychiatric history. Her clinical course was marked by successive eating disorders: anorexia followed by hyperphagia. We propose that, much as they do in other animals, NMDARs in humans interact with the neuroendocrine, h...

  3. Targeting Vascular Endothelial Growth Factor Receptor 2 and Protein Kinase D1 Related Pathways by a Multiple Kinase Inhibitor in Angiogenesis and Inflammation Related Processes In Vitro

    OpenAIRE

    Attila Varga; Pál Gyulavári; Zoltán Greff; Krisztina Futosi; Tamás Németh; Laura Simon-Szabó; Krisztina Kerekes; Csaba Szántai-Kis; Diána Brauswetter; Márton Kokas; Gábor Borbély; Anna Erdei; Attila Mócsai; György Kéri; Tibor Vántus

    2015-01-01

    Emerging evidence suggests that the vascular endothelial growth factor receptor 2 (VEGFR2) and protein kinase D1 (PKD1) signaling axis plays a critical role in normal and pathological angiogenesis and inflammation related processes. Despite all efforts, the currently available therapeutic interventions are limited. Prior studies have also proved that a multiple target inhibitor can be more efficient compared to a single target one. Therefore, development of novel inflammatory pathway-specific...

  4. Solubilization of nerve growth factor receptors of rabbit superior cervical ganglia.

    Science.gov (United States)

    Banerjee, S P; Cuatrecasas, P; Snyder, S H

    1976-09-25

    Nerve growth factor (NGF) receptors of rabbit superior cervical ganglia can be solubilized by treatment with detergents and readily assayed in the soluble state. Triton X-100 and deoxycholate reduce specific binding of NGF to ganglia membranes. In membranes treated with Triton X-100 (0.5 to 2.0%) the reduction in NGF binding by membranes is accompanied by a corresponding increase in binding in the supernatant fluid. NGF binding in soluble preparations can be rapidly assayed by precipitating NGF bound to receptors with polyethylene glycol under conditions in which unbound NGF is not precipitated. NGF binding to soluble preparations is saturable whether evaluated by the binding of 125I-NGF or by diluting 125I-NGF with native NGF. Using both techniques, the dissociation constant for NGF binding to soluble receptors is about 0.2 nM, the same as its dissociation constant from receptor sites in intact membranes. NGF binding to soluble receptors displays a high degree of peptide specificity, similar to receptor sites in intact membranes of superior cervical ganglia. A method of labeling NGF with 125I-3(4-hydroxyphenyl) propionic acid N-hydroxysuccinimide ester is described which leads to binding properties that are superior to those obtained with previously described 125I-NGF preparations.

  5. Nerve growth factor receptor from rabbit sympathetic ganglia membranes. Relationship between subforms.

    Science.gov (United States)

    Kouchalakos, R N; Bradshaw, R A

    1986-12-05

    The receptor for nerve growth factor (NGF) was purified from Triton X-100 extracts of sympathetic ganglia membranes by affinity chromatography on NGF-Sepharose. Elution of purified receptor was accomplished at pH 5 in the presence of 1 M NaCl. Sodium dodecyl sulfate gel electrophoresis of the purified iodinated receptor showed three major bands at Mr = 126,000, Mr = 105,000, and Mr = 81,000. Affinity labeling of the purified receptor using 125I-NGF and the photoreactive agent N-hydroxysuccinimidyl-p-azidobenzoate resulted in two major cross-linked complexes corresponding to Mr = 135,000 and Mr = 110,000. This labeling pattern is similar to that observed with sympathetic ganglia membranes (Massague, J., Guillette, B. J., Czech, M. P., Morgan, C. J., and Bradshaw, R. A. (1981) J. Biol. Chem. 256, 9419-9424) and indicates that these two forms do not arise from the cross-linking procedure. Reaction of the photoaffinity labeled NGF receptors with increasing amounts of trypsin resulted in a progressive decrease in the high molecular weight complex with a concomitant increase in the low molecular weight form. When the larger complex was isolated by electroelution from a sodium dodecyl sulfate gel and treated with trypsin, a species corresponding to Mr = 100,000 was generated. These observations are best explained by a precursor-product relationship for the two NGF receptor species of sympathetic neurons.

  6. Factors Affecting Fertility – New Evidence from Malaysia

    Directory of Open Access Journals (Sweden)

    Awad Atif

    2017-06-01

    Full Text Available This research paper investigates long and short term determinants of fertility rates in Malaysia based on basic macroeconomic variables for the period 1980-2014 using Auto Regressive Distributed Lag (ARDL method. The study reveals that over a long term period, all the selected variables (GDP, infant mortality rate, females’ education and employment have had significant and negative impact on total fertility rates. Whilst during the short term period, only the infant mortality rate has had a positive impact. Since population growth is partly determined by fertility rates, efforts to increase population in Malaysia should consider factors that affect those rates.

  7. miR-29a suppresses MCF-7 cell growth by downregulating tumor necrosis factor receptor 1.

    Science.gov (United States)

    Zhao, Yiling; Yang, Fenghua; Li, Wenyuan; Xu, Chunyan; Li, Li; Chen, Lifei; Liu, Yancui; Sun, Ping

    2017-02-01

    Tumor necrosis factor receptor 1 is the main receptor mediating many tumor necrosis factor-alpha-induced cellular events. Some studies have shown that tumor necrosis factor receptor 1 promotes tumorigenesis by activating nuclear factor-kappa B signaling pathway, while other studies have confirmed that tumor necrosis factor receptor 1 plays an inhibitory role in tumors growth by inducing apoptosis in breast cancer. Therefore, the function of tumor necrosis factor receptor 1 in breast cancer requires clarification. In this study, we first found that tumor necrosis factor receptor 1 was significantly increased in human breast cancer tissues and cell lines, and knockdown of tumor necrosis factor receptor 1 by small interfering RNA inhibited cell proliferation by arresting the cell cycle and inducing apoptosis. In addition, miR-29a was predicted as a regulator of tumor necrosis factor receptor 1 by TargetScan and was shown to be inversely correlated with tumor necrosis factor receptor 1 expression in human breast cancer tissues and cell lines. Luciferase reporter assay further confirmed that miR-29a negatively regulated tumor necrosis factor receptor 1 expression by binding to the 3' untranslated region. In our functional study, miR-29a overexpression remarkably suppressed cell proliferation and colony formation, arrested the cell cycle, and induced apoptosis in MCF-7 cell. Furthermore, in combination with tumor necrosis factor receptor 1 transfection, miR-29a significantly reversed the oncogenic role caused by tumor necrosis factor receptor 1 in MCF-7 cell. In addition, we demonstrated that miR-29a suppressed MCF-7 cell growth by inactivating the nuclear factor-kappa B signaling pathway and by decreasing cyclinD1 and Bcl-2/Bax protein levels. Taken together, our results suggest that miR-29a is an important regulator of tumor necrosis factor receptor 1 expression in breast cancer and functions as a tumor suppressor by targeting tumor necrosis factor receptor 1 to

  8. Identification and Functional Characterisation of Nod Factor Receptor (NFR) Paralogs in Lotus japonicus

    DEFF Research Database (Denmark)

    Vestergaard, Gitte; Radutoiu, Elena Simona; Stougaard, Jens

    an important missing link in plant-bacterial communication. This picture changed with the cloning of LysM-domain containing receptor-like kinases (LysM-RLKs) in different legume species. In Lotus japonicus, two LysM-RLKs, Nod Factor Receptor 1 (NFR1) and Nod Factor Receptor 5 (NFR5), are believed to bind Nod...... factor, subsequently initiating a signal cascade leading to symbiotic nodule development. Similar genes have also been identified in other plants: seven LysM-domain containing receptor-like kinases (LYKs) were found in the model legume Medicago truncatula, two of them, LYK3 and LYK4 playing a role...

  9. Roxatidine, an H(2) receptor blocker, is an estrogenic compound--experimental evidence.

    Science.gov (United States)

    Agrawal, Shyam Sundar; Alvin Jose, Manonmani

    2010-08-01

    Roxatidine is an H(2) receptor blocker frequently used in the treatment of peptic ulcers. H(2) receptor blockers are reported to show antifertility activity. To examine the mechanism of antifertility, estrogenic and antiestrogenic activity was studied using an in vitro rat and rabbit uterine receptor binding assay and in vivo using the uterotrophic assay in immature Wistar rats. The results revealed that roxatidine showed mild receptor binding affinity to both rat and rabbit uterine receptors when compared to estradiol. Interstingly, in vivo roxatidine increases the wet uterine weight of immature Wistar rats significantly (Proxatidine treated group was somewhat similar to that of the estradiol treated group. Histopathological results and the structure of the roxatidine support that H(2) receptor blocker roxatidine is an estrogenic compound.

  10. Evidence for a precursor of the high-affinity metastasis-associated murine laminin receptor

    DEFF Research Database (Denmark)

    Rao, C N; Castronovo, V; Schmitt, M C;

    1989-01-01

    The high-affinity cellular receptor for the basement membrane component laminin is differentially expressed during tumor invasion and metastasis. A cDNA clone encoding the murine laminin receptor was isolated and identified on the basis of sequence homology to the human laminin receptor [Wewer et...... al. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 7137-7141]. Primer extension experiments demonstrated that the clone contained the complete 5' sequence of the murine laminin receptor mRNA. RNA blot data demonstrated a single-sized laminin receptor mRNA, approximately 1400 bases long, in human, mouse......, and rat. The nascent laminin receptor predicted from the cDNA sequence is 295 amino acids long, with a molecular weight of 33,000, and contains one intradisulfide bridge, a short putative transmembrane domain, and an extracellular carboxy-terminal region which has abundant glutamic acid residues...

  11. Tumor necrosis factor receptors support murine hematopoietic progenitor function in the early stages of engraftment.

    Science.gov (United States)

    Pearl-Yafe, Michal; Mizrahi, Keren; Stein, Jerry; Yolcu, Esma S; Kaplan, Ofer; Shirwan, Haval; Yaniv, Isaac; Askenasy, Nadir

    2010-07-01

    Tumor necrosis factor (TNF) family receptors/ligands are important participants in hematopoietic homeostasis, in particular as essential negative expansion regulators of differentiated clones. As a prominent injury cytokine, TNF-alpha has been traditionally considered to suppress donor hematopoietic stem and progenitor cell function after transplantation. We monitored the involvement of TNF receptors (TNF-R) 1 and 2 in murine hematopoietic cell engraftment and their inter-relationship with Fas. Transplantation of lineage-negative (lin(-)) bone marrow cells (BMC) from TNF receptor-deficient mice into wild-type recipients showed defective early engraftment and loss of durable hematopoietic contribution upon recovery of host hematopoiesis. Consistently, cells deficient in TNF receptors had reduced competitive capacity as compared to wild-type progenitors. The TNF receptors were acutely upregulated in bone marrow (BM)-homed donor cells (wild-type) early after transplantation, being expressed in 60%-75% of the donor cells after 6 days. Both TNF receptors were detected in fast cycling, early differentiating progenitors, and were ubiquitously expressed in the most primitive progenitors with long-term reconstituting potential (lin(-)c-kit(+) stem cell antigen (SCA)-1(+)). BM-homed donor cells were insensitive to apoptosis induced by TNF-alpha and Fas-ligand and their combination, despite reciprocal inductive cross talk between the TNF and Fas receptors. The engraftment supporting effect of TNF-alpha is attributed to stimulation of progenitors through TNF-R1, which involves activation of the caspase cascade. This stimulatory effect was not observed for TNF-R2, and this receptor did not assume redundant stimulatory function in TNFR1-deficient cells. It is concluded that TNF-alpha plays a tropic role early after transplantation, which is essential to successful progenitor engraftment.

  12. Growth Factor Receptor-Bound Protein 14 Undergoes Light-Dependent Intracellular Translocation in Rod Photoreceptors: Functional Role on Retinal Insulin Receptor Activation

    OpenAIRE

    Rajala, Ammaji; Roger J. Daly; Tanito, Masaki; Allen, Dustin T.; Lowenna J Holt; Lobanova, Ekaterina; Arshavsky, Vadim Y; Rajala, Raju V.S.

    2009-01-01

    Growth factor receptor-bound protein 14 (Grb14) is involved in growth factor receptor tyrosine kinase signaling. Here we report that light causes a major redistribution of Grb14 among the individual subcellular compartments of the retinal rod photoreceptor. Grb14 is localized predominantly to the inner segment, nuclear layer and synapse in dark-adapted rods, whereas in the light-adapted rods, Grb14 redistributed throughout the entire cell, including the outer segment. The translocation of Grb...

  13. Factors affecting the insurance sector development: Evidence from Albania

    Directory of Open Access Journals (Sweden)

    Eglantina Zyka

    2014-03-01

    Full Text Available In this paper we explore factors potentially affecting the size of Albanian insurance market, over the period 1999 to 2009. The results of co- integration regression show that GDP and fraction urban population, both one lagged value, size of population and paid claims, both at contemporary value, have significant positive effect on aggregate insurance premium in Albania while the market share of the largest company in the insurance market, one lagged value, has significant negative effect on aggregate insurance premiums. Granger causality test shows statistically significance contribution of GDP growth to insurance premium growth, GDP drives insurance premium growth but not vice versa. The Albanian insurance market is under development, indicators as: insurance penetration, premium per capita, ect are still at low level and this can justify the insignificant role of the insurance in the economy

  14. Regulation of Steroidogenesis, Development, and Cell Differentiation by Steroidogenic Factor-1 and Liver Receptor Homolog-1.

    Science.gov (United States)

    Yazawa, Takashi; Imamichi, Yoshitaka; Miyamoto, Kaoru; Khan, Md Rafiqul Islam; Uwada, Junsuke; Umezawa, Akihiro; Taniguchi, Takanobu

    2015-08-01

    Steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) belong to the nuclear receptor superfamily and are categorized as orphan receptors. In addition to other nuclear receptors, these play roles in various physiological phenomena by regulating the transcription of target genes. Both factors share very similar structures and exhibit common functions. Of these, the roles of SF-1 and LRH-1 in steroidogenesis are the most important, especially that of SF-1, which was originally discovered and named to reflect such roles. SF-1 and LRH-1 are essential for steroid hormone production in gonads and adrenal glands through the regulation of various steroidogenesis-related genes. As SF-1 is also necessary for the development of gonads and adrenal glands, it is also considered a master regulator of steroidogenesis. Recent studies have clearly demonstrated that LRH-1 also represents another master regulator of steroidogenesis, which similarly to SF-1, can induce differentiation of non-steroidogenic stem cells into steroidogenic cells. Here, we review the functions of both factors in these steroidogenesis-related phenomena.

  15. The role of NMDA receptors in human eating behavior: evidence from a case of anti-NMDA receptor encephalitis.

    Science.gov (United States)

    Perogamvros, Lampros; Schnider, Armin; Leemann, Beatrice

    2012-06-01

    Research in animal models has implicated N-methyl-D-aspartate (NMDA) receptors (NMDARs) in the control of food intake. Until now, these findings have been not replicated in humans. Here we describe a 22-year-old woman with anti-NMDAR encephalitis and no prior neurological or psychiatric history. Her clinical course was marked by successive eating disorders: anorexia followed by hyperphagia. We propose that, much as they do in other animals, NMDARs in humans interact with the neuroendocrine, homeostatic, and reward systems controlling food intake in the central and peripheral nervous system structures related to feeding and satiety.

  16. Glucocorticoid-induced tumor necrosis factor receptor expression in patients with cervical human papillomavirus infection

    Directory of Open Access Journals (Sweden)

    Cacilda Tezelli Junqueira Padovani

    2013-06-01

    Full Text Available Introduction The progression of human papillomavirus (HPV infection in the anogenital tract has been associated with the involvement of cells with regulatory properties. Evidence has shown that glucocorticoid-induced tumor necrosis factor receptor (GITR is an important surface molecule for the characterization of these cells and proposes that GITR ligand may constitute a rational treatment for many cancer types. We aimed to detect the presence of GITR and CD25 in cervical stroma cells with and without pathological changes or HPV infection to better understand the immune response in the infected tissue microenvironment. Methods We subjected 49 paraffin-embedded cervical tissue samples to HPV DNA detection and histopathological analysis, and subsequently immunohistochemistry to detect GITR and CD25 in lymphocytes. Results We observed that 76.9% of all samples with high GITR expression were HPV-positive regardless of histopathological findings. High GITR expression (77.8% was predominant in samples with ≥1,000 RLU/PCB. Of the HPV-positive samples negative for intraepithelial lesion and malignancy, 62.5% had high GITR expression. High GITR expression was observed in both carcinoma and high-grade squamous intraepithelial lesion (HSIL samples (p = 0.16. CD25 was present in great quantities in all samples. Conclusions The predominance of high GITR expression in samples with high viral load that were classified as HSIL and carcinoma suggests that GITR+ cells can exhibit regulatory properties and may contribute to the progression of HPV-induced cervical neoplasia, emphasizing the importance of GITR as a potential target for immune therapy of cervical cancer and as a disease evolution biomarker.

  17. Tumor necrosis factor-alpha inhibits pre-osteoblast differentiation through its type-1 receptor.

    Science.gov (United States)

    Abbas, Sabiha; Zhang, Yan-Hong; Clohisy, John C; Abu-Amer, Yousef

    2003-04-01

    Tumor necrosis factor-alpha (TNF) is a pro-inflammatory cytokine with a profound role in many skeletal diseases. The cytokine has been described as a mediator of bone loss in osteolysis and other inflammatory bone diseases. In addition to its known bone resorptive action, TNF reduces bone formation by inhibiting osteoblast differentiation. Using primary and transformed osteoblastic cells, we first document that TNF inhibits expression of alkaline phosphatase and matrix deposition, both considered markers of osteoblast differentiation. The effects are dose- and time-dependent. Core-binding factor A1 (cbfa1) is a transcription factor critical for osteoblast differentiation, and we show here that it is activated by the osteoblast differentiation agent, beta-glycerophosphate. Therefore, we investigated whether the inhibitory effects of TNF were associated with altered activity of this transcription factor. Using retardation assays, we show that TNF significantly inhibits cbfal activation by beta-glycerophosphate, manifested by reduced DNA-binding activity. Next, we turned to determine the signaling pathway by which TNF inhibits osteoblast differentiation. Utilizing animals lacking individual TNF receptors, we document that TNFr1 is required for transmitting the cytokine's inhibitory effect. In the absence of this receptor, TNF failed to impact all osteoblast differentiation markers tested. In summary, TNF blocks expression of osteoblast differentiation markers and inhibits beta-glycerophosphate-induced activation of the osteoblast differentiation factor cbfa1. Importantly, these effects are mediated via a mechanism requiring the TNF type-1 receptor.

  18. Tumor necrosis factor-α inhibits angiotensin II receptor type 1 expression in dorsal root ganglion neurons via β-catenin signaling.

    Science.gov (United States)

    Yang, Y; Wu, H; Yan, J-Q; Song, Z-B; Guo, Q-L

    2013-09-17

    Both tumor necrosis factor (TNF)-α and the angiotensin (Ang) II/angiotensin II receptor type 1 (AT1) axis play important roles in neuropathic pain and nociception. In the present study, we explored the interaction between the two systems by examining the mutual effects between TNF-α and the Ang II/AT1 receptor axis in dorsal root ganglion (DRG) neurons. Rat DRG neurons were treated with TNF-α in different concentrations for different lengths of time in the presence or absence of transcription inhibitor actinomycin D, TNF receptor 1 (TNFR1) inhibitor SPD304, β-catenin signaling inhibitor CCT031374, or different kinase inhibitors. TNF-α decreased the AT1 receptor mRNA level as well as the AT1a receptor promoter activity in a dose-dependent manner within 30 h, which led to dose-dependent inhibition of Ang II-binding AT1 receptor level on the cell membrane. Actinomycin D (1 mg/ml), SPD304 (50 μM), p38 mitogen-activated protein kinase (MAPK) inhibitor PD169316 (25 μM), and CCT031374 (50 μM) completely abolished the inhibitory effect of TNF-α on AT1 receptor expression. TNF-α dose-dependently increased soluble β-catenin and phosphorylated GSK-3β levels, which was blocked by SPD304 and PD169316. In DRG neurons treated with AT2 receptor agonist CGP421140, or Ang II with or without AT1 receptor antagonist losartan or AT2 receptor antagonist PD123319 for 30 h, we found that Ang II and Ang II+PD123319 significantly decreased TNF-α expression, whereas CPG421140 and Ang II+losartan increased TNF-α expression. In conclusion, we demonstrate that TNF-α inhibits AT1 receptor expression at the transcription level via TNFR1 in rat DRG neurons by increasing the soluble β-catenin level through the p38 MAPK/GSK-3β pathway. In addition, Ang II appears to inhibit and induce TNF-α expression via the AT1 receptor and the AT2 receptor in DRG neurons, respectively. This is the first evidence of crosstalk between TNF-α and the Ang II/AT receptor axis in DRG neurons.

  19. Characterization of a receptor for human monocyte-derived neutrophil chemotactic factor/interleukin-8

    Energy Technology Data Exchange (ETDEWEB)

    Grob, P.M.; David, E.; Warren, T.C.; DeLeon, R.P.; Farina, P.R.; Homon, C.A. (Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT (USA))

    1990-05-15

    Monocyte-derived neutrophil chemotactic factor/interleukin-8 (MDNCF/IL-8) is an 8,000-dalton protein produced by monocytes which exhibits activity as a chemoattractant for neutrophils with maximal activity achieved at a concentration of 50 ng/ml. This polypeptide has been iodinated by chloramine-T methodology (350 Ci/mM), and specific receptors for MDNCF/IL-8 have been detected on human neutrophils, U937 cells, THP-1 cells, and dimethyl sulfoxide-differentiated HL-60 cells. The binding of MDNCF/IL-8 to human neutrophils is not inhibited by interleukin-1 alpha, tumor necrosis factor-alpha, insulin, or epidermal growth factor. In addition, chemoattractants such as C5a, fMet-Leu-Phe, leukotriene B4, and platelet-activating factor fail to inhibit binding, suggesting that MDNCF/IL-8 utilizes a unique receptor. The receptor for MDNCF/IL-8 is apparently glycosylated since ligand binding is inhibited by the presence of wheat germ agglutinin, a lectin with a binding specificity for N-acetylglucosamine and neuraminic acid. Steady state binding experiments indicate Kd values of 4 and 0.5 nM and receptor numbers of 75,000 and 7,400 for human neutrophils and differentiated HL-60 cells, respectively. 125I-MDNCF/IL-8 bound to human neutrophils is rapidly internalized and subsequently released from cells as trichloroacetic acid-soluble radioactivity. Affinity labeling experiments suggest that the human neutrophil MDNCF/IL-8 receptor exhibits a mass of approximately 58,000 daltons.

  20. Growth Factor Receptors and Apoptosis Regulators: Signaling Pathways, Prognosis, Chemosensitivity and Treatment Outcomes of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Siddik Sarkar

    2009-01-01

    Full Text Available Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

  1. Risk factors and stuttering: evaluating the evidence for clinicians.

    Science.gov (United States)

    Ward, David

    2013-06-01

    This paper summarizes and discusses some of the key issues raised in the other four manuscripts in this special edition of Journal of Fluency Disorders. All the four pieces examine risk factors in developmental stuttering from different perspectives and all provide stand-alone contributions to knowledge on the subject. Thus, rather than review, the focus of the present paper is to highlight those matters, which, from a clinical perspective might be seen as either (a) of the greatest contention, (b) of particular relevance to clinicians, or (c) requiring greater emphasis in future research, on the basis of the conclusions from the authors involved. This paper provides an overview of points of particular clinical interest arising from the four contributions to this special edition. Readers will be able to (a) understand arguments for and against whole word repetitions being included as moments of stuttering in the SSI-3 assessment, (b) understand arguments relating to psychological components in early onset stuttering, (c) understand some of the complexities in interpreting data pertaining to recovery from stuttering, (d) understand where future efforts in research into risk of stuttering should be placed. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. H4 histamine receptors mediate cell cycle arrest in growth factor-induced murine and human hematopoietic progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anne-France Petit-Bertron

    Full Text Available The most recently characterized H4 histamine receptor (H4R is expressed preferentially in the bone marrow, raising the question of its role during hematopoiesis. Here we show that both murine and human progenitor cell populations express this receptor subtype on transcriptional and protein levels and respond to its agonists by reduced growth factor-induced cell cycle progression that leads to decreased myeloid, erythroid and lymphoid colony formation. H4R activation prevents the induction of cell cycle genes through a cAMP/PKA-dependent pathway that is not associated with apoptosis. It is mediated specifically through H4R signaling since gene silencing or treatment with selective antagonists restores normal cell cycle progression. The arrest of growth factor-induced G1/S transition protects murine and human progenitor cells from the toxicity of the cell cycle-dependent anticancer drug Ara-C in vitro and reduces aplasia in a murine model of chemotherapy. This first evidence for functional H4R expression in hematopoietic progenitors opens new therapeutic perspectives for alleviating hematotoxic side effects of antineoplastic drugs.

  3. Circulating vascular endothelial growth factor and its soluble receptors in patients with liver cirrhosis: possible association with hepatic function impairment.

    Science.gov (United States)

    Jaroszewicz, Jerzy; Januszkiewicz, Marcin; Flisiak, Robert; Rogalska, Magdalena; Kalinowska, Alicja; Wierzbicka, Iwona

    2008-10-01

    Recent studies provided in vivo evidences of an increased angiogenesis in animal model of portal hypertension and cirrhosis which was linked to increased expression of vascular endothelial growth factor. The aim of study was to evaluate the plasma concentration of VEGF and its receptors in liver cirrhosis and the possible association with the degree of liver insufficiency. Methods. Vascular endothelial growth factor (VEGF) and its soluble receptors: sVEGF-R1, sVEGF-R2 were measured in plasma of 78 patients with liver cirrhosis by ELISA. Results. The significant increase of plasma VEGF and sVEGF-R1 was observed in liver cirrhosis compared to healthy individuals (153.1+/-51.9 vs. 46.8+/-4.1pg/mL, P<0.05; 279.8+/-34.3 vs. 105.1+/-5.9pg/mL, P<0.001, respectively). Plasma VEGF and foremost sVEGF R1 showed significant associations with biochemical indices of liver function. Among clinical parameters, only ascites revealed significant association with plasma VEGR and sVEGF-R1. VEGF and sVEGF-R1 were increased respectively to the degree of liver insufficiency. It was demonstrated through a significant positive correlation with Child-Pugh score and MELD classification. In conclusion, our study suggests that serum VEGF and VEGF-R1 may reflect the hepatic function impairment in liver cirrhosis and seems to be associated with portal hypertension symptoms.

  4. Evidence for a divergence in function between two glucocorticoid receptors from a basal teleost

    Directory of Open Access Journals (Sweden)

    Li Yi

    2012-08-01

    Full Text Available Abstract Background Duplicated glucocorticoid receptors (GR are present in most teleost fish. The evolutionary advantage of retaining two GRs is unclear, as no subtype specific functional traits or physiological roles have been defined. To identify factors driving the retention of duplicate GRs in teleosts, the current study examined GRs in representatives of two basal ray-finned fish taxa that emerged either side of the teleost lineage whole genome duplication event (WGD event, the acipenseriform, Acipenser ruthenus, (pre-WGD and the osteoglossimorph, Pantodon buchholzi, (post-WGD. Results The study identified a single GR in A. ruthenus (ArGR and two GRs in P. buchholzi (PbGR1 and PbGR2. Phylogenetic analyses showed that ArGR formed a distinct branch separate from the teleosts GRs. The teleost GR lineage was subdivded into two sublineages, each of which contained one of the two P. buchholzi GRs. ArGR, PbGR1 and PbGR2 all possess the unique 9 amino acid insert between the zinc-fingers of the DNA-binding domain that is present in one of the teleost GR lineages (GR1, but not the other (GR2. A splice variant of PbGR2 produces an isoform that lacked these 9 amino acids (PbGR2b. Cortisol stimulated transactivation activity of ArGR, PbGR2b and PbGR1 in vitro; with PbGR2b and PbGR1, the glucocorticoid 11-deoxycortisol was a more potent agonist than cortisol. The hormone sensitivity of PbGR2b and PbGR1 differed in the transactivation assay, with PbGR2b having lower EC50 values and greater fold induction. Conclusions The difference in transactivation activity sensitivity between duplicated GRs of P. buchholzi suggests potential functional differences between the paralogs emerged early in the teleost lineage. Given the pleiotropic nature of GR function in vertebrates, this finding is in accordance with the hypothesis that duplicated GRs were potentially retained through subfunctionalisation followed by gene sharing. A 9 amino acid insert in the DNA

  5. Different expression of mu-opiate receptor in chronic and acute wounds and the effect of beta-endorphin on transforming growth factor beta type II receptor and cytokeratin 16 expression.

    Science.gov (United States)

    Bigliardi, P L; Sumanovski, L T; Büchner, S; Rufli, T; Bigliardi-Qi, M

    2003-01-01

    There is evidence that neuropeptides, especially the opiate receptor agonists, are involved in wound healing. We have previously observed that beta-endorphin, the endogenous ligand for the mu-opiate receptor, stimulates the expression of cytokeratin 16 in a dose-dependent manner in human skin organ cultures. Cytokeratin 16 is expressed in hyperproliferative epidermis such as psoriasis and wound healing. Therefore we were interested to study whether epidermal mu-opiate receptor expression is changed at the wound margins in acute and chronic wounds. Using classical and confocal microscopy, we were able to compare the expression level of mu-opiate receptors and the influence of beta-endorphin on transforming growth factor beta type II receptor in organ culture. Our results show indeed a significantly decreased expression of mu-opiate receptors on keratinocytes close to the wound margin of chronic wounds compared to acute wounds. Additionally beta-endorphin upregulates the expression of transforming growth factor beta type II receptor in human skin organ cultures. These results suggest a crucial role of opioid peptides not only in pain control but also in wound healing. Opioid peptides have already been used in animal models in treatment of wounds; they induce fibroblast proliferation and growth of capillaries, and accelerate the maturation of granulation tissue and the epithelization of the defect. Furthermore opioid peptides may fine-tune pain and the inflammatory response while healing takes place. This new knowledge could potentially be used to design new locally applied drugs to improve the healing of painful chronic wounds.

  6. Opioid Receptors Mediate Direct Predictive Fear Learning: Evidence from One-Trial Blocking

    Science.gov (United States)

    Cole, Sindy; McNally, Gavan P.

    2007-01-01

    Pavlovian fear learning depends on predictive error, so that fear learning occurs when the actual outcome of a conditioning trial exceeds the expected outcome. Previous research has shown that opioid receptors, including [mu]-opioid receptors in the ventrolateral quadrant of the midbrain periaqueductal gray (vlPAG), mediate such predictive fear…

  7. Evidence for association of the cloned liver growth hormone receptor with a tyrosine kinase

    DEFF Research Database (Denmark)

    Wang, X; Uhler, M D; Billestrup, N;

    1992-01-01

    The ability of the cloned liver growth hormone (GH) receptor, when expressed in mammalian cell lines, to copurify with tyrosine kinase activity and be tyrosyl phosphorylated was examined. 125I-human growth hormone-GH receptor complexes isolated from COS-7 cells transiently expressing high levels ...

  8. Structural evidence for evolution of shark Ig new antigen receptor variable domain antibodies from a cell-surface receptor.

    Science.gov (United States)

    Streltsov, V A; Varghese, J N; Carmichael, J A; Irving, R A; Hudson, P J; Nuttall, S D

    2004-08-24

    The Ig new antigen receptors (IgNARs) are single-domain antibodies found in the serum of sharks. Here, we report 2.2- and 2.8-A structures of the type 2 IgNAR variable domains 12Y-1 and 12Y-2. Structural features include, first, an Ig superfamily topology transitional between cell adhesion molecules, antibodies, and T cell receptors; and, second, a vestigial complementarity-determining region 2 at the "bottom" of the molecule, apparently discontinuous from the antigen-binding paratope and similar to that observed in cell adhesion molecules. Thus, we suggest that IgNARs originated as cell-surface adhesion molecules coopted to the immune repertoire and represent an evolutionary lineage independent of variable heavy chain/variable light chain type antibodies. Additionally, both 12Y-1 and 12Y-2 form unique crystallographic dimers, predominantly mediated by main-chain framework interactions, which represent a possible model for primordial cell-based interactions. Unusually, the 12Y-2 complementarity-determining region 3 also adopts an extended beta-hairpin structure, suggesting a distinct selective advantage in accessing cryptic antigenic epitopes.

  9. Phenotypic and functional evidence for the expression of CXCR4 receptor during megakaryocytopoiesis.

    Science.gov (United States)

    Rivière, C; Subra, F; Cohen-Solal, K; Cordette-Lagarde, V; Letestu, R; Auclair, C; Vainchenker, W; Louache, F

    1999-03-01

    The identification of stromal cell-derived factor (SDF)-1alpha as a chemoattractant for human progenitor cells suggests that this chemokine and its receptor might represent critical determinants for the homing, retention, and exit of precursor cells from hematopoietic organs. In this study, we investigated the expression profile of CXCR4 receptor and the biological activity of SDF-1alpha during megakaryocytopoiesis. CD34(+) cells from bone marrow and cord blood were purified and induced to differentiate toward the megakaryocyte lineage by a combination of stem-cell factor (SCF) and recombinant human pegylated megakaryocyte growth and development factor (PEG-rhuMGDF). After 6 days of culture, a time where mature and immature megakaryocytes were present, CD41(+) cells were immunopurified and CXCR4mRNA expression was studied. High transcript levels were detected by a RNase protection assay in cultured megakaryocytes derived from cord blood CD34(+) cells as well as in peripheral blood platelets. The transcript levels were about equivalent to that found in activated T cells. By flow cytometry, a large fraction (ranging from 30% to 100%) of CD41(+) cells showed high levels of CXCR4 antigen on their surface, its expression increasing in parallel with the CD41 antigen during megakaryocytic differentiation. CXCR4 protein was also detected on peripheral blood platelets. SDF-1alpha acts on megakaryocytes by inducing intracellular calcium mobilization and actin polymerization. In addition, in in vitro transmigration experiments, a significant proportion of megakaryocytes was observed to respond to this chemokine. This cell migration was inhibited by pertussis toxin, indicating coupling of this signal to heterotrimeric guanine nucleotide binding proteins. Although a close correlation between CD41a and CXCR4 expession was observed, cell surface markers as well as morphological criteria indicate a preferential attraction of immature megakaryocytes (low level of CD41a and CD42a

  10. Mammographic features of calcifications in DCIS: correlation with oestrogen receptor and human epidermal growth factor receptor 2 status

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Min Sun; Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, So Yeon; Won, Jae-Kyung; Jeon, Yoon-Kyung; Park, In Ae [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Moon, Hyeong-Gon; Han, Wonshik [Seoul National University College of Medicine, Department of Surgery, Seoul (Korea, Republic of)

    2013-08-15

    This study investigated the correlation of oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status with the probability of malignancy (POM) of mammographic calcifications in ductal carcinoma in situ (DCIS). A total of 101 women (age range, 27-83 years) with pure DCIS that presented as mammographic calcifications were included. Three radiologists independently reviewed mammograms according to the BI-RADS lexicon and provided 100-point POM scores and a BI-RADS category. ER, HER2 and breast cancer subtypes were determined using immunohistochemistry (IHC) and fluorescence in situ hybridisation. Pairwise correlations between POM and IHC biomarker scores were calculated, and mammographic features were compared between breast cancer subtypes. HER2 level positively correlated with the POM score (P < 0.0001) and BI-RADS category (P < 0.0001), and ER level inversely correlated with the POM score (P < 0.013) and BI-RADS category (P < 0.010). Fine linear branching (P = 0.004) and segmental (P = 0.014) calcifications were significantly associated with HER2-positive cancers, and clustered calcifications were more frequently observed in ER-positive cancers (P = 0.014). HER2 status in DCIS correlated positively with the POM of mammographic calcifications, as determined by radiologists on the basis of the BI-RADS lexicon. (orig.)

  11. Structural requirements for inducible shedding of the p55 tumor necrosis factor receptor

    DEFF Research Database (Denmark)

    Brakebusch, C; Varfolomeev, E E; Batkin, M

    1994-01-01

    Induced shedding of the p55 tumor necrosis factor receptor (p55-R) was previously shown to be independent of the amino acid sequence properties of the intracellular domain of this receptor. We now find it also independent of the sequence properties of the transmembrane domain and of the cysteine......-rich region that constitutes most of the extracellular domain of the receptor. The shedding is shown to depend solely on the sequence properties of a small region within the spacer that links the cysteine-rich region in the extracellular domain to the transmembrane domain. Detailed tests of effects......, however, by some mutations that seem to change the conformation of the spacer region. These findings suggest that a short amino acid sequence in the p55-R is essential and sufficient for its shedding and that the shedding is mediated either by a protease with limited sequence specificity or by several...

  12. The Epidermal Growth Factor Receptor Responsive miR-125a Represses Mesenchymal Morphology in Ovarian Cancer Cells

    Directory of Open Access Journals (Sweden)

    Karen D. Cowden Dahl

    2009-11-01

    Full Text Available The epithelial-to-mesenchymal transition (EMT that occurs during embryonic development is recapitulated during tumor metastasis. Important regulators of this process include growth factors, transcription factors, and adhesion molecules. New evidence suggests that microRNA (miRNA activity contributes to metastatic progression and EMT; however, the mechanisms leading to altered miRNA expression during cancer progression remain poorly understood. Importantly, overexpression of the epidermal growth factor receptor (EGFR in ovarian cancer correlates with poor disease outcome and induces EMT in ovarian cancer cells. We report that EGFR signaling leads to transcriptional repression of the miRNA miR-125a through the ETS family transcription factor PEA3. Overexpression of miR-125a induces conversion of highly invasive ovarian cancer cells from a mesenchymal to an epithelial morphology, suggesting miR-125a is a negative regulator of EMT. We identify AT-rich interactive domain 3B (ARID3B as a target of miR-125a and demonstrate that ARID3B is overexpressed in human ovarian cancer. Repression of miR-125a through growth factor signaling represents a novel mechanism for regulating ovarian cancer invasive behavior.

  13. Oxidative stress effect on progesterone-induced blocking factor (PIBF) binding to PIBF-receptor in lymphocytes.

    Science.gov (United States)

    de la Haba, Carlos; Palacio, José R; Palkovics, Tamas; Szekeres-Barthó, Júlia; Morros, Antoni; Martínez, Paz

    2014-01-01

    Receptor-ligand binding is an essential interaction for biological function. Oxidative stress can modify receptors and/or membrane lipid dynamics, thus altering cell physiological functions. The aim of this study is to analyze how oxidative stress may alter receptor-ligand binding and lipid domain distribution in the case of progesterone-induced blocking factor/progesterone-induced blocking factor-receptor. For membrane fluidity regionalization analysis of MEC-1 lymphocytes, two-photon microscopy was used in individual living cells. Lymphocytes were also double stained with AlexaFluor647/progesterone-induced blocking factor and Laurdan to evaluate -induced blocking factor/progesterone-induced blocking factor-receptor distribution in the different membrane domains, under oxidative stress. A new procedure has been developed which quantitatively analyzes the regionalization of a membrane receptor among the lipid domains of different fluidity in the plasma membrane. We have been able to establish a new tool which detects and evaluates lipid raft clustering from two-photon microscopy images of individual living cells. We show that binding of progesterone-induced blocking factor to progesterone-induced blocking factor-receptor causes a rigidification of plasma membrane which is related to an increase of lipid raft clustering. However, this clustering is inhibited under oxidative stress conditions. In conclusion, oxidative stress decreases membrane fluidity, impairs receptor-ligand binding and reduces lipid raft clustering.

  14. Interleukin-34:A new ligand for Colony-stimulating factor-1Receptor%Interleukin-34: A new ligand for Colony-stimulating factor-1Receptor

    Institute of Scientific and Technical Information of China (English)

    CHEN Yao; Gang-Qing Yao

    2011-01-01

    1 IntroductionColony-stimulating factor-1 ( CSF1 ) is a important hematopoietic growth factor that is involved in the proliferation,differentiation,and survival of monocytes, macrophages, and bone marrow progenitor cells[1].Its receptor (c-Fms) is known as the c-Fmsproto-oncoprotein[2].By far the most definitive studies demonstrating biologic functions for CSF-1 in vivo are those in the op/op mutant mouse.The deficiency results from a single base-pair insertion in the coding region of the gene to product defective CSF-1[3-4].Mice homozygous for this mutation have significant osteopetrosis,low growth rate,low body weight as well as a toothless phenotype because of a severe deficiency of osteoclasts and mononuclear phagocytes[5-6],and are devoid of serum and tissue CSF-1 activity[7].

  15. The Prostaglandin EP3 Receptor Is an Independent Negative Prognostic Factor for Cervical Cancer Patients

    Science.gov (United States)

    Heidegger, Helene; Dietlmeier, Sebastian; Kuhn, Christina; Vattai, Aurelia; Aberl, Caroline; Mahner, Sven; Kost, Bernd

    2017-01-01

    We know that one of the main risk factors for cervical cancer is an infection with high-risk human papillomavirus (HR-HPV). Prostaglandins and their receptors are very important for the tumour growth and tumour-associated angiogenesis. Little is known about the expression of the Prostaglandin E receptor type 3 (EP3) or the Prostaglandin (PG)E2-EP3 signalling in cervical cancer, so the aim of the study was to analyse the expression of the EP3 receptor in cervical cancer and find prognostic factors in relation to survival; EP3 immunohistological staining of 250 cervical cancer slides was performed and analysed with a semi-quantitative score. The statistical evaluation was performed with Statistical Package for the Social Sciences (SPSS) to evaluate the staining results and the survival analyses of the cervical cancer cases. A significant difference was observed in EP3 expression in Fédération Internationale de Gynécologie et d’Obstétrique (FIGO) stadium I versus FIGO stadium II–IV cases. High expression of EP3 (IRS ≥ 1.5) in cervical cancer patients was correlated with poor prognosis in overall survival rates. Survival in adenocarcinoma (AC) of the cervix was lower than in squamous cell carcinoma (SCC). Cox regression analysis shows that EP3 is an independent prognosticator. In this study we could show that the membrane-bound prostaglandin receptor EP3 is an independent prognosticator for cervical cancer patient survival. Targeting the EP3 receptor seems to be an interesting candidate for endocrine therapy. Therefore, more research is needed on the influence of the receptor system and its influence on cervical cancer growth. PMID:28753926

  16. Extrinsic factors regulate partial agonist efficacy of strychnine-sensitive glycine receptors

    Science.gov (United States)

    Farroni, Jeffrey S; McCool, Brian A

    2004-01-01

    the systems examine here, these effects are independent of both absolute expression level and any system-related alterations in the agonist binding site. We conclude that complex interactions between receptor composition and extrinsic factors may play a significant role in determining strychnine-sensitive glycine receptor partial agonist pharmacology. PMID:15301692

  17. Induction of transforming growth factor beta receptors following focal ischemia in the rat brain.

    Directory of Open Access Journals (Sweden)

    Gabriella Pál

    Full Text Available Transforming growth factor-βs (TGF-βs regulate cellular proliferation, differentiation, and survival. TGF-βs bind to type I (TGF-βRI and II receptors (TGF-βRII, which are transmembrane kinase receptors, and an accessory type III receptor (TGF-βRIII. TGF-β may utilize another type I receptor, activin-like kinase receptor (Alk1. TGF-β is neuroprotective in the middle cerebral artery occlusion (MCAO model of stroke. Recently, we reported the expression pattern of TGF-β1-3 after MCAO. To establish how TGF-βs exert their actions following MCAO, the present study describes the induction of TGF-βRI, RII, RIII and Alk1 at 24 h, 72 h and 1 mo after transient 1 h MCAO as well as following 24 h permanent MCAO using in situ hybridization histochemistry. In intact brain, only TGF-βRI had significant expression: neurons in cortical layer IV contained TGF-βRI. At 24 h after the occlusion, no TGF-β receptors showed induction. At 72 h following MCAO, all four types of TGF-β receptors were induced in the infarct area, while TGF-βRI and RII also appeared in the penumbra. Most cells with elevated TGF-βRI mRNA levels were microglia. TGF-βRII co-localized with both microglial and endothelial markers while TGF-βRIII and Alk1 were present predominantly in endothels. All four TGF-β receptors were induced within the lesion 1 mo after the occlusion. In particular, TGF-βRIII was further induced as compared to 72 h after MCAO. At this time point, TGF-βRIII signal was predominantly not associated with blood vessels suggesting its microglial location. These data suggest that TGF-β receptors are induced after MCAO in a timely and spatially regulated fashion. TGF-β receptor expression is preceded by increased TGF-β expression. TGF-βRI and RII are likely to be co-expressed in microglial cells while Alk1, TGF-βRII, and RIII in endothels within the infarct where TGF-β1 may be their ligand. At later time points, TGF-βRIII may also appear in glial cells

  18. Evidence of positive selection at codon sites localized in extracellular domains of mammalian CC motif chemokine receptor proteins

    Directory of Open Access Journals (Sweden)

    Metzger Kelsey J

    2010-05-01

    Full Text Available Abstract Background CC chemokine receptor proteins (CCR1 through CCR10 are seven-transmembrane G-protein coupled receptors whose signaling pathways are known for their important roles coordinating immune system responses through targeted trafficking of white blood cells. In addition, some of these receptors have been identified as fusion proteins for viral pathogens: for example, HIV-1 strains utilize CCR5, CCR2 and CCR3 proteins to obtain cellular entry in humans. The extracellular domains of these receptor proteins are involved in ligand-binding specificity as well as pathogen recognition interactions. In mammals, the majority of chemokine receptor genes are clustered together; in humans, seven of the ten genes are clustered in the 3p21-24 chromosome region. Gene conversion events, or exchange of DNA sequence between genes, have been reported in chemokine receptor paralogs in various mammalian lineages, especially between the cytogenetically closely located pairs CCR2/5 and CCR1/3. Datasets of mammalian orthologs for each gene were analyzed separately to minimize the potential confounding impact of analyzing highly similar sequences resulting from gene conversion events. Molecular evolution approaches and the software package Phylogenetic Analyses by Maximum Likelihood (PAML were utilized to investigate the signature of selection that has acted on the mammalian CC chemokine receptor (CCR gene family. The results of neutral vs. adaptive evolution (positive selection hypothesis testing using Site Models are reported. In general, positive selection is defined by a ratio of nonsynonymous/synonymous nucleotide changes (dN/dS, or ω >1. Results Of the ten mammalian CC motif chemokine receptor sequence datasets analyzed, only CCR2 and CCR3 contain amino acid codon sites that exhibit evidence of positive selection using site based hypothesis testing in PAML. Nineteen of the twenty codon sites putatively indentified as likely to be under positive

  19. Altered Fibroblast Growth Factor Receptor 4 Stability Promotes Prostate Cancer Progression

    Directory of Open Access Journals (Sweden)

    Jianghua Wang

    2008-08-01

    Full Text Available Fibroblast growth factor receptor 4 (FGFR-4 is expressed at significant levels in almost all human prostate cancers, and expression of its ligands is ubiquitous. A common polymorphism of FGFR-4 in which arginine (Arg388 replaces glycine (Gly388 at amino acid 388 is associated with progression in human prostate cancer. We show that the FGFR-4 Arg388 polymorphism, which is present in most prostate cancer patients, results in increased receptor stability and sustained receptor activation. In patients bearing the FGFR-4 Gly388 variant, expression of Huntingtin-interacting protein 1 (HIP1, which occurs in more than half of human prostate cancers, also results in FGFR-4 stabilization. This is associated with enhanced proliferation and anchorage-independent growth in vitro. Our findings indicate that increased receptor stability and sustained FGFR-4 signaling occur in most human prostate cancers due to either the presence of a common genetic polymorphism or the expression of a protein that stabilizes FGFR-4. Both of these alterations are associated with clinical progression in patients with prostate cancer. Thus, FGFR-4 signaling and receptor turnover are important potential therapeutic targets in prostate cancer.

  20. Epidermal growth factor receptors destined for the nucleus are internalized via a clathrin-dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    De Angelis Campos, Ana Carolina; Rodrigues, Michele Angela; Andrade, Carolina de; Miranda de Goes, Alfredo [Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Nathanson, Michael H. [Department of Internal Medicine, Yale University School of Medicine, New Haven, CT (United States); Gomes, Dawidson A., E-mail: dawidson@icb.ufmg.br [Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil)

    2011-08-26

    Highlights: {yields} EGF and its receptor translocates to the nucleus in liver cells. {yields} Real time imaging shows that EGF moves to the nucleus. {yields} EGF moves with its receptor to the nucleus. {yields} Dynamin and clathrin are necessary for EGFR nuclear translocation. -- Abstract: The epidermal growth factor (EGF) transduces its actions via the EGF receptor (EGFR), which can traffic from the plasma membrane to either the cytoplasm or the nucleus. However, the mechanism by which EGFR reaches the nucleus is unclear. To investigate these questions, liver cells were analyzed by immunoblot of cell fractions, confocal immunofluorescence and real time confocal imaging. Cell fractionation studies showed that EGFR was detectable in the nucleus after EGF stimulation with a peak in nuclear receptor after 10 min. Movement of EGFR to the nucleus was confirmed by confocal immunofluorescence and labeled EGF moved with the receptor to the nucleus. Small interference RNA (siRNA) was used to knockdown clathrin in order to assess the first endocytic steps of EGFR nuclear translocation in liver cells. A mutant dynamin (dynamin K44A) was also used to determine the pathways for this traffic. Movement of labeled EGF or EGFR to the nucleus depended upon dynamin and clathrin. This identifies the pathway that mediates the first steps for EGFR nuclear translocation in liver cells.

  1. Inhibition of epidermal growth factor receptor expression by RNA interference in A549 cells

    Institute of Scientific and Technical Information of China (English)

    MinZHANG; XinZHANG; Chun-xueBAI; JieCHEN; MinQWEI

    2004-01-01

    AIM: To investigate the biological features of A549 cells in which epidermal growth factor (EGF) receptors expression were suppressed by RNA interference (RNAi). METHODS: A549 cells were transfected using short small interfering RNAs (siRNAs) formulated with Lipofectamine 2000. The EGF receptor numbers were determined by Western blotting and flowcytometry. The antiproliferative effects of sequence specific double stranded RNA (dsRNA) were assessed using cell count, colony assay and scratch assay. The chemosensitivity of transfected cells to cisplatin was measured by MTT. RESULTS: Sequence specific dsRNA-EGFR down-regulated EGF receptor expression dramatically. Compared with the control group, dsRNA-EGFR reduced the cell number by 85.0 %, decreased the colonies by 63.3 %, inhibited the migration by 87.2 %, and increased the sensitivity of A549 to cisplatin by four-fold. CONCLUSION: Sequence specific dsRNA-EGFR were capable of suppressing EGF receptor expression, hence significantly inhibiting cellular proliferation and motility, and enhancing chemosensitivity of A549 cells to cisplatin. The successful application of dsRNA-EGFR for inhibition of proliferation in EGF receptor overexpressing cells can help extend the list of available therapeutic modalities in the treatment of non-small-cell lung carcinoma (NSCLC).

  2. Further evidence for increased macrophage migration inhibitory factor expression in prostate cancer

    Directory of Open Access Journals (Sweden)

    Iczkowski Kenneth A

    2005-07-01

    Full Text Available Abstract Background Macrophage migration inhibitory factor (MIF is a cytokine associated with prostate cancer, based on histologic evidence and circulating (serum levels. Recent studies from another laboratory failed to document these results. This study's aims were to extend and confirm our previous data, as well as to define possible mechanisms for the discrepant results. Additional aims were to examine MIF expression, as well as the location of MIF's receptor, CD74, in human prostatic adenocarcinoma compared to matched benign prostate. Methods MIF amounts were determined in random serum samples remaining following routine PSA screening by ELISA. Native, denaturing and reducing polyacrylamide gels and Western blot analyses determined the MIF form in serum. Prostate tissue arrays were processed for MIF in situ hybridization and immunohistochemistry for MIF and CD74. MIF released into culture medium from normal epithelial, LNCaP and PC-3 cells was detected by Western blot analysis. Results Median serum MIF amounts were significantly elevated in prostate cancer patients (5.87 ± 3.91 ng/ml; ± interquartile range; n = 115 compared with patients with no documented diagnosis of prostate cancer (2.19 ± 2.65 ng/ml; n = 158. ELISA diluent reagents that included bovine serum albumin (BSA significantly reduced MIF serum detection (p Conclusion Increased serum MIF was associated with prostate cancer. Diluent reagents that included BSA resulted in MIF serum immunoassay interference. In addition, significant amounts of complexed MIF (180 kDa under denaturing conditions by Western blot found in the serum do not bind to the MIF capture antibody. Increased MIF mRNA expression was observed in prostatic adenocarcinoma compared to benign tissue from matched samples, supporting our earlier finding of increased MIF gene expression in prostate cancer.

  3. Cannabinoid receptor-2 selective antagonist negatively regulates receptor activator of nuclear factor kappa B ligand mediated osteoclastogenesis

    Institute of Scientific and Technical Information of China (English)

    GENG De-chun; XU Yao-zeng; YANG Hui-lin; ZHU Guang-ming; WANG Xian-bin; ZHU Xue-song

    2011-01-01

    Background The cannabinoid receptor-2 (CB2) is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist (AM630) on receptor activator of nuclear factor kappa B (RANK) ligand (RANKL)induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7.Methods RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase (TRAP) staining using a commercial kit. Total ribonucleic acid (RNA)was isolated and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was done to examine the expression of RANK, cathepsin K (CPK) and nuclear factor kappa B (NF-κB). The extracellular signal-regulated kinase (ERK),phosphorylation of ERK (P-ERK) and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay.Results AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of >100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB.Conclusion AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.

  4. Combinatorial activation and repression by seven transcription factors specify Drosophila odorant receptor expression.

    Directory of Open Access Journals (Sweden)

    Shadi Jafari

    Full Text Available The mechanism that specifies olfactory sensory neurons to express only one odorant receptor (OR from a large repertoire is critical for odor discrimination but poorly understood. Here, we describe the first comprehensive analysis of OR expression regulation in Drosophila. A systematic, RNAi-mediated knock down of most of the predicted transcription factors identified an essential function of acj6, E93, Fer1, onecut, sim, xbp1, and zf30c in the regulation of more than 30 ORs. These regulatory factors are differentially expressed in antennal sensory neuron classes and specifically required for the adult expression of ORs. A systematic analysis reveals not only that combinations of these seven factors are necessary for receptor gene expression but also a prominent role for transcriptional repression in preventing ectopic receptor expression. Such regulation is supported by bioinformatics and OR promoter analyses, which uncovered a common promoter structure with distal repressive and proximal activating regions. Thus, our data provide insight into how combinatorial activation and repression can allow a small number of transcription factors to specify a large repertoire of neuron classes in the olfactory system.

  5. Transforming growth factor β receptor type 1 is essential for female reproductive tract integrity and function.

    Directory of Open Access Journals (Sweden)

    Qinglei Li

    2011-10-01

    Full Text Available The transforming growth factor β (TGFβ superfamily proteins are principle regulators of numerous biological functions. Although recent studies have gained tremendous insights into this growth factor family in female reproduction, the functions of the receptors in vivo remain poorly defined. TGFβ type 1 receptor (TGFBR1, also known as activin receptor-like kinase 5, is the major type 1 receptor for TGFβ ligands. Tgfbr1 null mice die embryonically, precluding functional characterization of TGFBR1 postnatally. To study TGFBR1-mediated signaling in female reproduction, we generated a mouse model with conditional knockout (cKO of Tgfbr1 in the female reproductive tract using anti-Müllerian hormone receptor type 2 promoter-driven Cre recombinase. We found that Tgfbr1 cKO females are sterile. However, unlike its role in growth differentiation factor 9 (GDF9 signaling in vitro, TGFBR1 seems to be dispensable for GDF9 signaling in vivo. Strikingly, we discovered that the Tgfbr1 cKO females develop oviductal diverticula, which impair embryo development and transit of embryos to the uterus. Molecular analysis further demonstrated the dysregulation of several cell differentiation and migration genes (e.g., Krt12, Ace2, and MyoR that are potentially associated with female reproductive tract development. Moreover, defective smooth muscle development was also revealed in the uteri of the Tgfbr1 cKO mice. Thus, TGFBR1 is required for female reproductive tract integrity and function, and disruption of TGFBR1-mediated signaling leads to catastrophic structural and functional consequences in the oviduct and uterus.

  6. Transforming Growth Factor β Receptor Type 1 Is Essential for Female Reproductive Tract Integrity and Function

    Science.gov (United States)

    Li, Qinglei; Agno, Julio E.; Edson, Mark A.; Nagaraja, Ankur K.; Nagashima, Takashi; Matzuk, Martin M.

    2011-01-01

    The transforming growth factor β (TGFβ) superfamily proteins are principle regulators of numerous biological functions. Although recent studies have gained tremendous insights into this growth factor family in female reproduction, the functions of the receptors in vivo remain poorly defined. TGFβ type 1 receptor (TGFBR1), also known as activin receptor-like kinase 5, is the major type 1 receptor for TGFβ ligands. Tgfbr1 null mice die embryonically, precluding functional characterization of TGFBR1 postnatally. To study TGFBR1–mediated signaling in female reproduction, we generated a mouse model with conditional knockout (cKO) of Tgfbr1 in the female reproductive tract using anti-Müllerian hormone receptor type 2 promoter-driven Cre recombinase. We found that Tgfbr1 cKO females are sterile. However, unlike its role in growth differentiation factor 9 (GDF9) signaling in vitro, TGFBR1 seems to be dispensable for GDF9 signaling in vivo. Strikingly, we discovered that the Tgfbr1 cKO females develop oviductal diverticula, which impair embryo development and transit of embryos to the uterus. Molecular analysis further demonstrated the dysregulation of several cell differentiation and migration genes (e.g., Krt12, Ace2, and MyoR) that are potentially associated with female reproductive tract development. Moreover, defective smooth muscle development was also revealed in the uteri of the Tgfbr1 cKO mice. Thus, TGFBR1 is required for female reproductive tract integrity and function, and disruption of TGFBR1–mediated signaling leads to catastrophic structural and functional consequences in the oviduct and uterus. PMID:22028666

  7. A novel fibroblast growth factor receptor family member promotes neuronal outgrowth and synaptic plasticity in aplysia.

    Science.gov (United States)

    Pollak, Daniela D; Minh, Bui Quang; Cicvaric, Ana; Monje, Francisco J

    2014-11-01

    Fibroblast Growth Factor (FGF) Receptors (FGFRs) regulate essential biological processes, including embryogenesis, angiogenesis, cellular growth and memory-related long-term synaptic plasticity. Whereas canonical FGFRs depend exclusively on extracellular Immunoglobulin (Ig)-like domains for ligand binding, other receptor types, including members of the tropomyosin-receptor-kinase (Trk) family, use either Ig-like or Leucine-Rich Repeat (LRR) motifs, or both. Little is known, however, about the evolutionary events leading to the differential incorporation of LRR domains into Ig-containing tyrosine kinase receptors. Moreover, although FGFRs have been identified in many vertebrate species, few reports describe their existence in invertebrates. Information about the biological relevance of invertebrate FGFRs and evolutionary divergences between them and their vertebrate counterparts is therefore limited. Here, we characterized ApLRRTK, a neuronal cell-surface protein recently identified in Aplysia. We unveiled ApLRRTK as the first member of the FGFRs family deprived of Ig-like domains that instead contains extracellular LRR domains. We describe that ApLRRTK exhibits properties typical of canonical vertebrate FGFRs, including promotion of FGF activity, enhancement of neuritic outgrowth and signaling via MAPK and the transcription factor CREB. ApLRRTK also enhanced the synaptic efficiency of neurons known to mediate in vivo memory-related defensive behaviors. These data reveal a novel molecular regulator of neuronal function in invertebrates, provide the first evolutionary linkage between LRR proteins and FGFRs and unveil an unprecedented mechanism of FGFR gene diversification in primeval central nervous systems.

  8. Type I insulin-like growth factor receptor signaling in skeletal muscle regeneration and hypertrophy.

    Science.gov (United States)

    Philippou, A; Halapas, A; Maridaki, M; Koutsilieris, M

    2007-01-01

    Skeletal muscle is able not only to increase its mass as an adaptation to mechanical loading generated by and imposed upon muscle but also to regenerate after damage, via its intrinsic regulation of gene transcription. Both cellular processes, muscle regeneration and hypertrophy, are mediated by the activation, proliferation and differentiation of muscle satellite cells and appear to be modulated by the mitotic and myogenic activity of locally produced insulin-like growth factor 1 (IGF-1), which functions in an autocrine/paracrine mode. Differentiation of satellite cells into myoblasts involves the regulation of skeletal muscle-specific proteins belonging to the family of myogenic regulatory factors (MRFs). The endocrine, autocrine and paracrine functions of IGF-1 are mediated through binding to the type I IGF receptor (IGF-1.R), which is a ligand-activated receptor tyrosine kinase. The binding of IGF-1 to IGF-1.R induces its autophosphorylation, which recruits specific cytoplasmic molecules containing the Insulin Receptor Substrate Proteins (IRS). The recruitment of IRS proteins by IGF-1/IGF-1.R binding is a critical level at which the proliferative and differentiative actions of IGF-1 diverge. Specific signaling pathways downstream of IGF-1, potentially involved in the mitogenic and myogenic responses and mediating skeletal muscle protein synthesis and hypertrophy following exercise-induced muscle overloading and damage, are discussed. A potential alternative activation of different signaling pathway(s) via a different receptor remains to be demonstrated.

  9. Interaction between γ-aminobutyric acid A receptor genes: new evidence in migraine susceptibility.

    Directory of Open Access Journals (Sweden)

    Marlene Quintas

    Full Text Available Migraine is a common neurological episodic disorder with a female-to-male prevalence 3- to 4-fold higher, suggesting a possible X-linked genetic component. Our aims were to assess the role of common variants of gamma-aminobutyric acid A receptor (GABAAR genes, located in the X-chromosome, in migraine susceptibility and the possible interaction between them. An association study with 188 unrelated cases and 286 migraine-free controls age- and ethnic matched was performed. Twenty-three tagging SNPs were selected in three genes (GABRE, GABRA3 and GABRQ. Allelic, genotypic and haplotypic frequencies were compared between cases and controls. We also focused on gene-gene interactions. The AT genotype of rs3810651 of GABRQ gene was associated with an increased risk for migraine (OR: 4.07; 95% CI: 1.71-9.73, p=0.002, while the CT genotype of rs3902802 (OR: 0.41; 95% CI: 0.21-0.78, p=0.006 and GA genotype of rs2131190 of GABRA3 gene (OR: 0.53; 95% CI: 0.32-0.88, p=0.013 seem to be protective factors. All associations were found in the female group and maintained significance after Bonferroni correction. We also found three nominal associations in the allelic analyses although there were no significant results in the haplotypic analyses. Strikingly, we found strong interactions between six SNPs encoding for different subunits of GABAAR, all significant after permutation correction. To our knowledge, we show for the first time, the putative involvement of polymorphisms in GABAAR genes in migraine susceptibility and more importantly we unraveled a role for novel gene-gene interactions opening new perspectives for the development of more effective treatments.

  10. Evidence of endogenous mu opioid receptor regulation by epigenetic control of the promoters.

    Science.gov (United States)

    Hwang, Cheol Kyu; Song, Kyu Young; Kim, Chun Sung; Choi, Hack Sun; Guo, Xiao-Hong; Law, Ping-Yee; Wei, Li-Na; Loh, Horace H

    2007-07-01

    The pharmacological effect of morphine as a painkiller is mediated mainly via the mu opioid receptor (MOR) and is dependent on the number of MORs in the cell surface membrane. While several studies have reported that the MOR gene is regulated by various cis- and trans-acting factors, many questions remain unanswered regarding in vivo regulation. The present study shows that epigenetic silencing and activation of the MOR gene are achieved through coordinated regulation at both the histone and DNA levels. In P19 mouse embryonal carcinoma cells, expression of the MOR was greatly increased after neuronal differentiation. MOR expression could also be induced by a demethylating agent (5'-aza-2'-deoxycytidine) or histone deacetylase inhibitors in the P19 cells, suggesting involvement of DNA methylation and histone deacetylation for MOR gene silencing. Analysis of CpG DNA methylation revealed that the proximal promoter region was unmethylated in differentiated cells compared to its hypermethylation in undifferentiated cells. In contrast, the methylation of other regions was not changed in either cell type. Similar methylation patterns were observed in the mouse brain. In vitro methylation of the MOR promoters suppressed promoter activity in the reporter assay. Upon differentiation, the in vivo interaction of MeCP2 was reduced in the MOR promoter region, coincident with histone modifications that are relevant to active transcription. When MeCP2 was disrupted using MeCP2 small interfering RNA, the endogenous MOR gene was increased. These data suggest that DNA methylation is closely linked to the MeCP2-mediated chromatin structure of the MOR gene. Here, we propose that an epigenetic mechanism consisting of DNA methylation and chromatin modification underlies the cell stage-specific mechanism of MOR gene expression.

  11. Extracellular Neurotransmitter Receptor Clustering: Think Outside the Box

    Institute of Scientific and Technical Information of China (English)

    Matthias Kneussel

    2010-01-01

    @@ Postsynaptic submembrane scaffolds cluster neurotransmitter receptors through intracellular protein-protein interactions. Growing evidence supports the view that extracellular factors can be almost as important to trigger synaptic receptor aggregation.

  12. A Murine Fibroblast Growth Factor (FGF) Receptor Expressed in CHO Cells is Activated by Basic FGF and Kaposi FGF

    Science.gov (United States)

    Mansukhani, Alka; Moscatelli, David; Talarico, Daniela; Levytska, Vera; Basilico, Claudio

    1990-06-01

    We have cloned a murine cDNA encoding a tyrosine kinase receptor with about 90% similarity to the chicken fibroblast growth factor (FGF) receptor and the human fms-like gene (FLG) tyrosine kinase. This mouse receptor lacks 88 amino acids in the extracellular portion, leaving only two immunoglobulin-like domains compared to three in the chicken FGF receptor. The cDNA was cloned into an expression vector and transfected into receptor-negative CHO cells. We show that cells expressing the receptor can bind both basic FGF and Kaposi FGF. Although the receptor binds basic FGF with a 15- to 20-fold higher affinity, Kaposi FGF is able to induce down-regulation of the receptor to the same extent as basic FGF. The receptor is phosphorylated upon stimulation with both FGFs, DNA synthesis is stimulated, and a proliferative response is produced in cells expressing the receptor, whereas cells expressing the cDNA in the antisense orientation show none of these responses to basic FGF or Kaposi FGF. Thus this receptor can functionally interact with two growth factors of the FGF family.

  13. Toll-like receptor 2/6-dependent stimulation of mesenchymal stem cells promotes angiogenesis by paracrine factors

    Directory of Open Access Journals (Sweden)

    H Kokemüller

    2013-09-01

    Full Text Available Reconstruction of critical size bone defects represents a major challenge in orthopaedic surgery. Insufficient angiogenesis is a limiting factor for engraftment of large-scale tissue transplants. Transplantation or stimulation of local mesenchymal stem cells (MSCs represents a potential solution to enhance angiogenesis. We recently identified angiogenic properties for the Toll-like receptor (TLR 2/6 agonist MALP-2 and now investigated if MALP-2 could be used to stimulate MSCs in order to promote angiogenesis in vitro and in vivo.Human MSCs from the bone marrow of healthy subjects were isolated, cultured and expanded in vitro and were shown to be positive for mesenchymal stem cells markers as well as for the MALP-2 receptors TLR2 and TLR6. MALP-2 directly enhanced migration but not proliferation of human MSCs. Conditioned medium from MALP-2 stimulated MSCs significantly increased proliferation, migration and tube formation of endothelial cells. Analysis of the conditioned medium from MSCs revealed that MALP-2 stimulation enhanced the secretion of several chemokines and growth factors including vascular endothelial growth factors (VEGF and granulocyte-macrophage colony-stimulating factor (GM-CSF. Finally, we studied MALP-2 effects on MSCs in a sheep model of tissue engineering in vivo. Therefore, MSCs were isolated from the iliac crest of black head sheep and co-cultivated with MALP-2 ex vivo. Implantation of autologous MSCs within a scaffold cylinder into the M. latissimus dorsi significantly enhanced vessel density of these constructs after 6 months.We here present the first evidence that TLR2/6-dependent stimulation of MSCs promotes angiogenesis in vitro and in vivo offering a novel strategy for therapeutic angiogenesis, e.g., for tissue engineering of bone.

  14. TTRAP, a novel protein that associates with CD40, tumor necrosis factor (TNF) receptor-75 and TNF receptor-associated factors (TRAFs), and that inhibits nuclear factor-kappa B activation.

    Science.gov (United States)

    Pype, S; Declercq, W; Ibrahimi, A; Michiels, C; Van Rietschoten, J G; Dewulf, N; de Boer, M; Vandenabeele, P; Huylebroeck, D; Remacle, J E

    2000-06-16

    CD40 belongs to the tumor necrosis factor (TNF) receptor family. CD40 signaling involves the recruitment of TNF receptor-associated factors (TRAFs) to its cytoplasmic domain. We have identified a novel intracellular CD40-binding protein termed TRAF and TNF receptor-associated protein (TTRAP) that also interacts with TNF-R75 and CD30. The region of the CD40 cytoplasmic domain that is required for TTRAP association overlaps with the TRAF6 recognition motif. Association of TTRAP with CD40 increases profoundly in response to treatment of cells with CD40L. Interestingly, TTRAP also associates with TRAFs, with the highest affinity for TRAF6. In transfected cells, TTRAP inhibits in a dose-dependent manner the transcriptional activation of a nuclear factor-kappaB (NF-kappaB)-dependent reporter mediated by CD40, TNF-R75 or Phorbol 12-myristate 13-acetate (PMA) and to a lesser extent by TRAF2, TRAF6, TNF-alpha, or interleukin-1beta (IL-1beta). TTRAP does not affect stimulation of NF-kappaB induced by overexpression of the NF-kappaB-inducing kinase (NIK), the IkappaB kinase alpha (IKKalpha), or the NF-kappaB subunit P65/RelA, suggesting it acts upstream of the latter proteins. Our results indicate that we have isolated a novel regulatory factor that is involved in signal transduction by distinct members of the TNF receptor family.

  15. Human epidermal growth factor receptor-2 in oesophageal cancers: An observational study

    Institute of Scientific and Technical Information of China (English)

    Hazem Al-Momani; Rachel Barnes; Ahmed El-Hadi; Rachit Shah; Wyn G Lewis; Paul Edwards

    2012-01-01

    AIM:To determine the incidence of human epidermal growth factor receptor 2 (HER2) over expression in oesophageal cancers.METHODS:A retrospective study,of one hundred consecutive cases of endoscopic histological samples of oesophageal cancers from a single British cancer network were included.Cancer cases were diagnosed between April 2007 and June 2010.HER2 over expression was assessed using immunohistochemistry,those that scored "0" and "+1" were considered "negative"for HER2; those that scored "+3" were considered "Positive".Cases that were scored "+2" on immunohistochemistry further went on to have HER2 gene analysis using the Ventana HER brightfield dual-colour in situ hybridisations (HER B DISH) assay and either came back to be positive or negative for HER2 over expression.Overall survival was measured from date of histological diagnosis until date of death.93% of the cases were followed up till five years or death,and all were followed up till two years.Cases of gastro-oesophageal junctional tumours were excluded.RESULTS:The median age of our sample was 66years (range:38-91 years).Eighty one were male and 19 female.Ninety-one of the cases were adenocarcinoma of the oesophagus and the rest were cases of squamous cell carcinoma.The anatomical distribution of the tumours was; upper oesophagus 2,middle oesophagus 11,and 87 were in the lower oesophagus.Operative resection was completed in 15 cases; seven cases had attempted surgical resections,i.e.,open and close,33 patients received definitive chemo-radiation and 52 had palliative treatment.Twenty-five of the cancers showed evidence of HER2 over expression,all were adenocarcinomas.Of the 25 cases that showed evidence of HER2 over expression,21 (84%) were located in the lower third of the oesophagus.On staging,24 out of the 25 HER2 positive cases were at stage 3or more (13 at stage 3 and 11 at stage 4),For HER2 negative cases 37 were at stage 3 and 32 were staged as stage 4.Seventeen out of twenty five cases

  16. Nanoconjugation prolongs endosomal signaling of the epidermal growth factor receptor and enhances apoptosis

    Science.gov (United States)

    Wu, L.; Xu, F.; Reinhard, B. M.

    2016-07-01

    It is becoming increasingly clear that intracellular signaling can be subject to strict spatial control. As the covalent attachment of a signaling ligand to a nanoparticle (NP) impacts ligand-receptor binding, uptake, and trafficking, nanoconjugation provides new opportunities for manipulating intracellular signaling in a controlled fashion. To establish the effect of nanoconjugation on epidermal growth factor (EGF) mediated signaling, we investigate here the intracellular fate of nanoconjugated EGF (NP-EGF) and its bound receptor (EGFR) by quantitative correlated darkfield/fluorescence microscopy and density-based endosomal fractionation. We demonstrate that nanoconjugation prolongs the dwell time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF mediated apoptosis at effective concentrations that do not induce apoptosis in the case of free EGF. Overall, these findings indicate nanoconjugation as a rational strategy for modifying signaling that acts by modulating the temporo-spatial distribution of the activated EGF-EGFR ligand-receptor complex.It is becoming increasingly clear that intracellular signaling can be subject to strict spatial control. As the covalent attachment of a signaling ligand to a nanoparticle (NP) impacts ligand-receptor binding, uptake, and trafficking, nanoconjugation provides new opportunities for manipulating intracellular signaling in a controlled fashion. To establish the effect of nanoconjugation on epidermal growth factor (EGF) mediated signaling, we investigate here the intracellular fate of nanoconjugated EGF (NP-EGF) and its bound receptor (EGFR) by quantitative correlated darkfield/fluorescence microscopy and density-based endosomal fractionation. We demonstrate that nanoconjugation prolongs the dwell time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF

  17. Antioxidants for Healthy Skin: The Emerging Role of Aryl Hydrocarbon Receptors and Nuclear Factor-Erythroid 2-Related Factor-2.

    Science.gov (United States)

    Furue, Masutaka; Uchi, Hiroshi; Mitoma, Chikage; Hashimoto-Hachiya, Akiko; Chiba, Takahito; Ito, Takamichi; Nakahara, Takeshi; Tsuji, Gaku

    2017-03-03

    Skin is the outermost part of the body and is, thus, inevitably exposed to UV rays and environmental pollutants. Oxidative stress by these hazardous factors accelerates skin aging and induces skin inflammation and carcinogenesis. Aryl hydrocarbon receptors (AHRs) are chemical sensors that are abundantly expressed in epidermal keratinocytes and mediate the production of reactive oxygen species. To neutralize or minimize oxidative stress, the keratinocytes also express nuclear factor-erythroid 2-related factor-2 (NRF2), which is a master switch for antioxidant signaling. Notably, there is fine-tuned crosstalk between AHR and NRF2, which mutually increase or decrease their activation states. Many NRF2-mediated antioxidant phytochemicals are capable of up- and downmodulating AHR signaling. The precise mechanisms by which these phytochemicals differentially affect the AHR and NRF2 system remain largely unknown and warrant future investigation.

  18. Antioxidants for Healthy Skin: The Emerging Role of Aryl Hydrocarbon Receptors and Nuclear Factor-Erythroid 2-Related Factor-2

    Science.gov (United States)

    Furue, Masutaka; Uchi, Hiroshi; Mitoma, Chikage; Hashimoto-Hachiya, Akiko; Chiba, Takahito; Ito, Takamichi; Nakahara, Takeshi; Tsuji, Gaku

    2017-01-01

    Skin is the outermost part of the body and is, thus, inevitably exposed to UV rays and environmental pollutants. Oxidative stress by these hazardous factors accelerates skin aging and induces skin inflammation and carcinogenesis. Aryl hydrocarbon receptors (AHRs) are chemical sensors that are abundantly expressed in epidermal keratinocytes and mediate the production of reactive oxygen species. To neutralize or minimize oxidative stress, the keratinocytes also express nuclear factor-erythroid 2-related factor-2 (NRF2), which is a master switch for antioxidant signaling. Notably, there is fine-tuned crosstalk between AHR and NRF2, which mutually increase or decrease their activation states. Many NRF2-mediated antioxidant phytochemicals are capable of up- and downmodulating AHR signaling. The precise mechanisms by which these phytochemicals differentially affect the AHR and NRF2 system remain largely unknown and warrant future investigation. PMID:28273792

  19. A Structural Investigation into Oct4 Regulation by Orphan Nuclear Receptors, Germ Cell Nuclear Factor (GCNF) and Liver Receptor Homolog-1 (LRH-1).

    Science.gov (United States)

    Weikum, Emily R; Tuntland, Micheal L; Murphy, Michael N; Ortlund, Eric A

    2016-10-27

    Oct4 is a transcription factor required for maintaining pluripotency and self-renewal in stem cells. Prior to differentiation, Oct4 must be silenced to allow for the development of the three germ layers in the developing embryo. This fine-tuning is controlled by the nuclear receptors, liver receptor homolog-1 and germ cell nuclear factor. Liver receptor homolog-1 is responsible for driving the expression of Oct4 where germ cell nuclear factor represses its expression upon differentiation. Both receptors bind to a DR0 motif located within the Oct4 promoter. Here, we present the first structure of mouse germ cell nuclear factor DNA binding domain in complex with the Oct4 DR0. The overall structure revealed two molecules bound in a head-to-tail fashion on opposite sides of the DNA. Additionally, we solved the structure of the human liver receptor homolog-1 DNA binding domain bound to the same element. We explore the structural elements that govern Oct4 recognition by these two nuclear receptors.

  20. Mutations in fibroblast growth factor receptors: Phenotypic consequences during eukaryotic development

    Energy Technology Data Exchange (ETDEWEB)

    Park, W.J.; Bellus, G.A.; Jabs, E.W. [Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States)

    1995-10-01

    Recently, a tremendous amount of excitement and interest has been generated by the rapid succession of discoveries in the human fibroblast growth factor receptor (FGFR) field. In less than a year, mutations in three FGFRs (FGFR1-FGFR3) have been associated with three skeletal dysplasias and four craniosynostotic syndromes. FGFRs are members of the receptor tyrosine kinase family that bind fibroblast growth factors (FGFs). The FGF family consists of structurally related polypeptides that play a key role in numerous aspects of embryogenesis, growth, and homeostasis. FGFs have a potent growth stimulatory and/or differentiation-inducing effect on cells such as those derived from the early-embryonic mesoderm or ectoderm. In addition to mitogenesis and differentiation, FGFs also stimulate chemotaxis, cell survival, and angiogenesis. FGFs mediate cellular responses on binding to and activation of FGFRs. 45 refs., 2 figs., 1 tab.

  1. Anti-epidermal growth factor receptor skin toxicity: a matter of topical hydration.

    Science.gov (United States)

    Ferrari, Daris; Codecà, Carla; Bocci, Barbara; Crepaldi, Francesca; Violati, Martina; Viale, Giulia; Careri, Carmela; Caldiera, Sarah; Bordin, Veronica; Luciani, Andrea; Zonato, Sabrina; Cassinelli, Gabriela; Foa, Paolo

    2016-02-01

    Skin toxicity is a frequent complication of anti-epidermal growth factor receptor therapy, which can be an obstacle in maintaining the dose intensity and may negatively impact on the clinical outcome of cancer patients. Skin lesions depend on the disruption of the keratinocyte development pathways and no treatment is clearly effective in resolving the cutaneous alterations frequently found during anti-epidermal growth factor receptor therapy. Among systemic treatments, oral tetracycline proved to be useful in preventing skin manifestations. We describe the case of a patient affected by metastatic colorectal cancer, for whom a combination of chemotherapy and cetuximab was used as second-line treatment. The patient developed a symptomatic papulopustular skin rash that disappeared completely after a twice-daily application of a hydrating and moisturizing cream, mainly consisting of a mixture of paraffin, silicone compounds, and macrogol. The marked cutaneous amelioration allowed the patient to continue cetuximab without any further symptoms and was associated with a partial radiological response.

  2. Nonsmall Cell Lung Cancer Therapy: Insight into Multitargeted Small-Molecule Growth Factor Receptor Inhibitors

    Directory of Open Access Journals (Sweden)

    Mridul Roy

    2013-01-01

    Full Text Available To date, lung cancer is the leading cause of cancer-related death worldwide, among which nonsmall cell lung cancer (NSCLC comprises about 85%. Taking into account the side effects of surgery, radiation, platinum-based doublet chemotherapy, and the growth self-sufficiency characteristic of cancer cells, drugs have been discovered toward growth factor receptor (GFR to treat NSCLC. As expected, these drugs provide a greater benefit. To increase the efficacy of such growth factor receptor tyrosine kinase inhibitors (RTKIs, coinhibition of GFR signaling pathways and combination of inhibitors along with radiation or chemotherapy have drew intense insight. Although clinical trials about single-agent RTKIs or their combination strategies suggest their increase potency against cancer, they are not beyond adverse effects, and sometimes the effects are more deadly than chemotherapy. Nevertheless the hope for RTKIs may be proved true by further researches and digging deep into cancer therapeutics.

  3. Mactosylceramide Prevents Glial Cell Overgrowth by Inhibiting Insulin and Fibroblast Growth Factor Receptor Signaling

    DEFF Research Database (Denmark)

    Gerdøe-Kristensen, Stine; Lund, Viktor K; Wandall, Hans H

    2017-01-01

    , in which the mannosyltransferase Egghead controls conversion of glucosylceramide (GlcCer) to mactosylceramide (MacCer). Lack of elongated GSL in egghead (egh) mutants causes overgrowth of subperineurial glia (SPG), largely due to aberrant activation of phosphatidylinositol 3-kinase (PI3K). However, to what...... extent this effect involves changes in upstream signaling events is unresolved. We show here that glial overgrowth in egh is strongly linked to increased activation of Insulin and Fibroblast Growth Factor receptors (FGFR). Glial hypertrophy is phenocopied when overexpressing gain-of-function mutants...... hyperactivation is caused by absence of MacCer and not by GlcCer accumulation. We conclude that an early product in GSL biosynthesis, MacCer, prevents inappropriate activation of Insulin and Fibroblast Growth Factor Receptors in Drosophila glia. This article is protected by copyright. All rights reserved....

  4. Evidence for triclosan-induced activation of human and rodent xenobiotic nuclear receptors

    Science.gov (United States)

    The bacteriostat triclosan (2,4,40-trichloro-20-hydroxydiphenylether) (TCS) decreases rat serum thyroxine via putative nuclear receptor (NR) interaction(s) and subsequent transcriptional up-regulation of hepatic catabolism and clearance. However, due to the evolutionary divergenc...

  5. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These

  6. Study of the interaction of the Ig2 module of the fibroblast growth factor receptor, FGFR Ig2, with the fibroblast growth factor 1, FGF1, by means of NMR spectroscopy

    DEFF Research Database (Denmark)

    Kochoyan, Artur; Poulsen, Flemming M; Berezin, Vladimir

    2008-01-01

    Fibroblast growth factor (FGF) receptor (FGFR) consists extracellularly of three immunoglobulin (Ig) modules (Ig1-3). Currently, there are two competing models (symmetric and asymmetric) of the FGF-FGFR-heparin complex based on crystal structures. Indirect evidence exists in support of both models....... However, it is not clear which model is physiologically relevant. Our aim was to obtain direct, non-crystallographic evidence in support of them. We found by nuclear magnetic resonance that Ig2 could bind to FGF1 not only via the primary site (present in both models), but also via the secondary site...

  7. Structural and Molecular Evidence Suggesting Coronavirus-driven Evolution of Mouse Receptor.

    Science.gov (United States)

    Peng, Guiqing; Yang, Yang; Pasquarella, Joseph R; Xu, Liqing; Qian, Zhaohui; Holmes, Kathryn V; Li, Fang

    2017-02-10

    Hosts and pathogens are locked in an evolutionary arms race. To infect mice, mouse hepatitis coronavirus (MHV) has evolved to recognize mouse CEACAM1a (mCEACAM1a) as its receptor. To elude MHV infections, mice may have evolved a variant allele from the Ceacam1a gene, called Ceacam1b, producing mCEACAM1b, which is a much poorer MHV receptor than mCEACAM1a. Previous studies showed that sequence differences between mCEACAM1a and mCEACAM1b in a critical MHV-binding CC' loop partially account for the low receptor activity of mCEACAM1b, but detailed structural and molecular mechanisms for the differential MHV receptor activities of mCEACAM1a and mCEACAM1b remained elusive. Here we have determined the crystal structure of mCEACAM1b and identified the structural differences and additional residue differences between mCEACAM1a and mCEACAM1b that affect MHV binding and entry. These differences include conformational alterations of the CC' loop as well as residue variations in other MHV-binding regions, including β-strands C' and C'' and loop C'C''. Using pseudovirus entry and protein-protein binding assays, we show that substituting the structural and residue features from mCEACAM1b into mCEACAM1a reduced the viral receptor activity of mCEACAM1a, whereas substituting the reverse changes from mCEACAM1a into mCEACAM1b increased the viral receptor activity of mCEACAM1b. These results elucidate the detailed molecular mechanism for how mice may have kept pace in the evolutionary arms race with MHV by undergoing structural and residue changes in the MHV receptor, providing insight into this possible example of pathogen-driven evolution of a host receptor protein.

  8. Cytoplasmic truncation of the p55 tumour necrosis factor (TNF) receptor abolishes signalling, but not induced shedding of the receptor

    DEFF Research Database (Denmark)

    Brakebusch, C; Nophar, Y; Kemper, O;

    1992-01-01

    The mechanistic relationship between the signalling for the TNF effects by the human p55 TNF receptor (hu-p55-TNF-R) and the formation of a soluble form of the receptor, which is inhibitory to these effects, was explored by examining the function of C-terminally truncated mutants of the receptor,...

  9. Cognitive disorder and changes in cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury

    Institute of Scientific and Technical Information of China (English)

    Weiliang Zhao; Dezhi Kang; Yuanxiang Lin

    2008-01-01

    BACKGROUND: Learning and memory damage is one of the most permanent and the severest symptoms of traumatic brain injury; it can seriously influence the normal life and work of patients. Some research has demonstrated that cognitive disorder is closely related to nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor. OBJECTIVE: To summarize the cognitive disorder and changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury. RETRIEVAL STRATEGY: A computer-based online search was conducted in PUBMED for English language publications containing the key words "brain injured, cognitive handicap, acetylcholine, N-methyl-D aspartate receptors, neural cell adhesion molecule, brain-derived neurotrophic factor" from January 2000 to December 2007. There were 44 papers in total. Inclusion criteria: ① articles about changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury; ② articles in the same researching circle published in authoritative journals or recently published. Exclusion criteria: duplicated articles.LITERATURE EVALUATION: References were mainly derived from research on changes in these four factors following brain injury. The 20 included papers were clinical or basic experimental studies. DATA SYNTHESIS: After craniocerebral injury, changes in these four factors in brain were similar to those during recovery from cognitive disorder, to a certain degree. Some data have indicated that activation of nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor could greatly improve cognitive disorder following brain injury. However, there are still a lot of questions remaining; for example, how do these

  10. Rationale for targeting fibroblast growth factor receptor signaling in breast cancer

    OpenAIRE

    André, Fabrice; Cortés, Javier

    2015-01-01

    Fibroblast growth factor receptor (FGFR) signaling is involved in multiple biological processes, including cell proliferation, survival, differentiation, migration, and apoptosis during embryonic development and adult tissue homeostasis. Given its role in the activation of critical signaling pathways, aberrant FGFR signaling has been implicated in multiple cancer types. A comprehensive search of PubMed and congress abstracts was conducted to identify reports on FGFR pathway components in brea...

  11. Optimal Therapeutic Strategy for Non-small Cell Lung Cancer with Mutated Epidermal Growth Factor Receptor

    Directory of Open Access Journals (Sweden)

    Zhong SHI

    2015-02-01

    Full Text Available Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs have been widely used in non-small cell lung cancer (NSCLC patients, it is still controversial about how to combine EGFR-TKI with chemotherapy and other targeted drugs. We have made a summary on the current therapeutic models of EGFR-TKI combined with chemotherapy/bevacizumab in this review and aimed to find the optimal therapeutic strategy for NSCLC patients with EGFR mutation.

  12. Cutaneous adverse events of epidermal growth factor receptor inhibitors: A retrospective review of 99 cases

    Directory of Open Access Journals (Sweden)

    Kumutnart Chanprapaph

    2015-01-01

    Full Text Available Background: Previous reports regarding the cutaneous adverse events of epidermal growth factor receptor inhibitors are mostly limited to small case reports and case series, mainly involving Caucasian patients. Aims: We describe the trends in the clinical presentation of Asian patients who had cutaneous adverse events induced by epidermal growth factor receptor inhibitors and to explore the relationship between skin adverse events and tumor response. Methods: From 2006 to 2010, medical records of Thai patients with non-small cell lung cancer receiving epidermal growth factor receptor inhibitors were retrieved and analyzed. Results: In all, 99 patients were reviewed and analyzed. Erlotinib and gefitinib were commenced in 75 (75.8% and 24 (24.2% patients, respectively. Cutaneous adverse events occurred in 43 (57.3% patients receiving erlotinib and in 15 (62.5% patients receiving gefitinib. The most common adverse event was xerosis (52.5%. Less common adverse events included papulo-pustular eruption (27.3%, erythematous maculopapular rash (11.1%, mucositis (6.7%, paronychia (5.1%, and trichomegaly (2%. Elderly patients had a higher occurrence of xerosis. The presence of cutaneous adverse events was significantly higher in subjects who had a tumor response. Limitations: The limitations of study include its retrospective nature, and the initial screening of cutaneous adverse events was done by non-dermatologists. Conclusions: Cutaneous adverse events due to epidermal growth factor receptor inhibitors are not uncommon in the Asian population. We found a positive correlation between the occurrences of cutaneou adverse events and tumor response supporting the view that they are surrogate markers for therapeutic response.

  13. Novel Mutations and Deletions of the KIT (Steel Factor Receptor) Gene in Human Piebaldism

    OpenAIRE

    Ezoe, Kazuhiko; Holmes, Stuart A.; Ho, Lingling; Bennett, Christopher P.; Bolognia, Jean L.; Brueton, Louise; Burn, John; Falabella, Rafael; Gatto, Emilia M.; Ishii, Norihisa; Moss, Celia; Pittelkow, Mark R.; Thompson, Elizabeth; Ward, K. Anne; Spritz, Richard A.

    1995-01-01

    Piebaldism is an autosomal dominant genetic disorder of pigmentation characterized by white patches of skin and hair. Melanocytes are lacking in these hypopigmented regions, the result of mutations of the KIT gene, which encodes the cell surface receptor for steel factor (SLF). We describe the analysis of 26 unrelated patients with piebaldism-like hypopigmentation—17 typical patients, 5 with atypical clinical features or family histories, and 4 with other disorders that involve white spotting...

  14. Glucocorticoid-induced tumour necrosis factor receptor (GITR) and its ligand (GITRL) in atopic dermatitis

    DEFF Research Database (Denmark)

    Baumgartner-Nielsen, Jane; Vestergaard, Christian; Thestrup-Pedersen, K.

    2006-01-01

    The glucocorticoid-induced tumour necrosis factor receptor-related gene (GITR) is expressed on regulatory T-cells (Treg), which are CD4+CD25+ lymphocytes. Binding of the GITR-ligand (GITRL) leads to downregulation of the regulatory function of Tregs. Patients suffering from a defect in their Treg......-cells are localized in the vicinity of GITRL-expressing cells in atopic dermatitis skin, the GITR/GITRL interaction may serve to perpetuate the inflammation locally....

  15. Evidence for dopamine receptor pruning between adolescence and adulthood in striatum but not nucleus accumbens.

    Science.gov (United States)

    Teicher, M H; Andersen, S L; Hostetter, J C

    1995-11-21

    Postnatal development of dopamine D1 and D2 receptor families in striatum and nucleus accumbens of rats was studied at 25, 35, 40, 60, 80, 100 and 120 days using autoradiography. These ages were selected to test the hypothesis that dopamine receptors were overproduced prior to puberty (day 40), and pruned back to adult levels thereafter. This hypothesis was confirmed in striatum but not nucleus accumbens. D1 receptor Bmax ([3H]SCH-23390) peaked at 40 days, with levels 67 +/- 21% greater than at 25 days. However, Bmax levels were at least 35% lower at 60-120 days than at 40 days. Similarly, D2 receptor numbers ([3H]YM-09151-2) increased 144 +/- 26% between 25 and 40 days, but were reduced by 34-38% between 60-120 days. In contrast, D1 and D2 receptor Bmax increase approximately 150% between 25 and 40 days in nucleus accumbens, levels fell slightly at 60 or 80 days, but were no different at 100 and 120 days then they were at 40 days. These findings suggest that these two major dopamine target regions follow different developmental strategies, and this has implications for etiological theories of schizophrenia that focus on anomalous receptor pruning.

  16. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  17. Design and characteristics of cytotoxic fibroblast growth factor 1 conjugate for fibroblast growth factor receptor-targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    Szlachcic A

    2016-08-01

    Full Text Available Anna Szlachcic, Malgorzata Zakrzewska, Michal Lobocki, Piotr Jakimowicz, Jacek Otlewski Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland Abstract: Fibroblast growth factor receptors (FGFRs are attractive candidate cancer therapy targets as they are overexpressed in multiple types of tumors, such as breast, prostate, bladder, and lung cancer. In this study, a natural ligand of FGFR, an engineered variant of fibroblast growth factor 1 (FGF1V, was conjugated to a potent cytotoxic drug, monomethyl auristatin E (MMAE, and used as a targeting agent for cancer cells overexpressing FGFRs, similar to antibodies in antibody–drug conjugates. The FGF1V–valine–citrulline–MMAE conjugate showed a favorable stability profile, bound FGFRs on the cell surface specifically, and efficiently released the drug (MMAE upon cleavage by the lysosomal protease cathepsin B. Importantly, the conjugate showed a prominent cytotoxic effect toward cell lines expressing FGFR. FGF1V–vcMMAE was highly cytotoxic at concentrations even an order of magnitude lower than those found for free MMAE. This effect was FGFR-specific as cells lacking FGFR did not show any increased mortality. Keywords: fibroblast growth factor 1, FGF receptor, targeted cancer therapy, cytotoxic conjugates, FGFR-dependent cancer, MMAE, auristatin

  18. Impact of epidermal growth factor receptor and transforming growth factor-α on hepatitis C virus-induced hepatocarcinogenesis.

    Science.gov (United States)

    Badawy, Afkar Abdel-Ghany; El-Hindawi, Ali; Hammam, Olfat; Moussa, Mona; Gabal, Samia; Said, Noha

    2015-10-01

    Epidermal growth factor receptor system plays a central hepato-protective and pro-regenerative role in liver. Transforming growth factor-α (TGF-α) is an important autocrine growth regulator of hepatocytes that plays a role in development of hepatocellular carcinoma (HCC) among patients with chronic hepatitis C (CHC). This study was done on 40 core liver biopsies from patients with CHC, 20 liver specimens from HCC cases on top of CHC as well as five normal controls. All were immunohistochemically stained with epidermal growth factor receptor (EGFR) and TGF-α antibodies. Some selected HCC cases were submitted for FISH technique to detect EGFR gene alteration. By immunohistochemistry EGFR and TGF-α were overexpressed in HCC and cirrhotic cases compared to CHC cases without cirrhosis. Also, their expression was stronger in CHC cases with higher grades of activity and stages of fibrosis compared to lower ones. FISH positive results for EGFR were detected in 33.3% of the examined HCC cases. EGFR and TGF-α can be used as predictive markers for activity, fibrosis, and carcinogenesis in CHC patients. Overexpression of EGFR in HCC patients can be promising in selecting those who can get benefit from anti-EGFR target therapy.

  19. The role of tumour necrosis factor alpha and soluble tumour necrosis factor alpha receptors in the symptomatology of schizophrenia.

    Science.gov (United States)

    Turhan, Levent; Batmaz, Sedat; Kocbiyik, Sibel; Soygur, Arif Haldun

    2016-07-01

    Background Immunological mechanisms may be responsible for the development and maintenance of schizophrenia symptoms. Aim The aim of this study is to measure tumour necrosis factor-alpha (TNF-α), soluble tumour necrosis factor-alpha receptor I (sTNF-αRI), and soluble tumour necrosis factor-alpha receptor II (sTNF-αRII) levels in patients with schizophrenia and healthy individuals, and to determine their relationship with the symptoms of schizophrenia. Methods Serum TNF-α, sTNF-αRI and sTNF-αRII levels were measured. The Positive and Negative Syndrome Scale (PANSS) was administered for patients with schizophrenia (n = 35), and the results were compared with healthy controls (n = 30). Hierarchical regression analyses were undertaken to predict the levels of TNF-α, sTNF-αRI and sTNF-αRII. Results No significant difference was observed in TNF-α levels, but sTNF-αRI and sTNF-αRII levels were lower in patients with schizophrenia. Serum sTNF-αRI and sTNF-αRII levels were found to be negatively correlated with the negative subscale score of the PANSS, and sTNF-αRI levels were also negatively correlated with the total score of the PANSS. Smoking, gender, body mass index were not correlated with TNF-α and sTNF-α receptor levels. Conclusions These results suggest that there may be a change in anti-inflammatory response in patients with schizophrenia due to sTNF-αRI and sTNF-αRII levels. The study also supports low levels of TNF activity in schizophrenia patients with negative symptoms.

  20. Tyrosine Kinase Domain Gene Polymorphism of Epidermal Growth Factor Receptor in Gastric Cancer in Northern Iran

    Directory of Open Access Journals (Sweden)

    Jeivad F

    2012-01-01

    Full Text Available Background: Gastric cancer is one of the most common diseases of digestive system with a low 5-year survival rate and metastasis is the main cause of death. Multi-factors, such as changes in molecular pathways and deregulation of cells are involved in the disease development. Epidermal growth factor receptor pathway (EGFR which is associated with cell proliferation and survival can influence cancer development. EGFR function is governed by its genetic polymorphism; thus, we aimed to study the tyrosine kinase domain gene mutations of the receptor in patients with gastric cancer.Methods : In this experimental study, 123 subjects (83 patients with gastric cancer and 40 normal subjects were investigated in north of Iran for EGFR gene polymorphisms during 1 year. Genomic DNA was extracted by DNA extraction kit according to the manufacture's protocol. Polymerase chain reaction single-stranded conformation polymorphism (PCR-SSCP and silver staining were performed for investigating EGFR gene polymorphisms. Results : The participants included 72 men and 44 women. Gene polymorphism in exon 18 was present in 10% of the study population but SSCP pattern in exon 19 did not show different migrate bands neither in patients nor in normal subjects.Conclusion: It seems that screening for tyrosine kinas gene polymorphism of epidermal growth factor receptor in patients with gastric cancer and use of tyrosine kinas inhibitors could be useful in the prevention of disease progress and improvement of treatment process for a better quality of life in these patients.

  1. Therapy for acute pancreatitis with platelet-activating factor receptor antagonists

    Institute of Scientific and Technical Information of China (English)

    Chong Chen; Shi-Hai Xia; Hong Chen; Xiao-Hong Li

    2008-01-01

    Acute pancreatitis (AP) causes release of plateletactivating factor (PAF),which induces systemic effects that contribute to circulatory disturbances and multiple organ failure.PAF is a cell surface secretion of bioactive lipid,which could produce physiological and pathological effects by binding to its cell surface receptor called platelet-activating factor receptor (PAF-R).Studies showed that PAF participates in the occurrence and development of AP and administration of platelet-activating factor receptor antagonists (PAF-RAs) could significantly reduce local and systemic events after AP.PAF has also been implicated as a key mediator in the progression of severe AP,which can lead to complications and unacceptably high mortality rates.Several classes of PAF-RA show PAFRAs significant local and systemic effects on reducing inflammatory changes.As a preventive treatment,PAF-RA could block a series of PAF-mediatedinflammatory injury and thus improve the prognosis of AR This review introduces the important role of PAF-RA in the treatment of AP.

  2. Dopamine receptor activation increases glial cell line-derived neurotrophic factor in experimental stroke.

    Science.gov (United States)

    Kuric, Enida; Wieloch, Tadeusz; Ruscher, Karsten

    2013-09-01

    Treatment with levodopa enhances functional recovery after experimental stroke but its mechanisms of action are elusive. Reactive astrocytes in the ischemic hemisphere are involved in mechanisms promoting recovery and also express dopamine 1 (D1) and dopamine 2 (D2) receptors. Here we investigated if the activation of astrocytic dopamine receptors (D1 and D2) regulates the expression of glial cell line-derived neurotrophic factor (GDNF) after combined in vitro hypoxia/aglycemia (H/A) and studied the expression of GDNF in the ischemic brain after treatment with levodopa/benserazide following transient occlusion of the middle cerebral artery (tMCAO) in the rat. Twenty-four hours after H/A, GDNF levels were upregulated in exposed astrocytes compared to normoxic control cultures and further elevated by the addition of the selective D1 receptor agonist (R)-(+)-SKF-38393 hydrochloride while D1 receptor antagonism by R(+)-SCH-23390 hydrochloride significantly reduced GDNF. No effect on GDNF levels was observed by the application of the D2 receptor agonist R(-)-2,10,11-trihydroxy-N-propyl-noraporphine hydrobromide hydrate or S-(-)-eticlopride hydrochloride (D2 receptor antagonist). After tMCAO, GDNF was upregulated in D1 expressing reactive astrocytes in the peri-infarct area. In addition, treatment with levodopa/benserazide significantly increased GDNF levels in the infarct core and peri-infarct area after tMCAO without affecting the expression of glial fibrillar acidic protein (GFAP), an intermediate filament and marker of reactive gliosis. After stroke, GDNF levels increase in the ischemic hemisphere in rats treated with levodopa, implicating GDNF in the mechanisms of tissue reorganization and plasticity and in l-DOPA enhanced recovery of lost brain function. Our results support levodopa treatment as a potential recovery enhancing therapy in stroke patients.

  3. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanjuan; Zhang, Shaolian; Wen, Qingqing; Huang, Hongxing; Yang, Peihui, E-mail: typh@jnu.edu.cn

    2015-06-30

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 10{sup 6} cells mL{sup −1} with a detection limit of 40 cells mL{sup −1} was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 10{sup 5} with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening.

  4. Metabotropic glutamate receptor 2 and corticotrophin-releasing factor receptor-1 gene expression is differently regulated by BDNF in rat primary cortical neurons

    DEFF Research Database (Denmark)

    Jørgensen, Christinna V; Klein, Anders B; El-Sayed, Mona;

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and plasticity. Incorporation of matured receptor proteins is an integral part of synapse formation. However, whether BDNF increases synthesis and integration of receptors in functional synapses directly is unclear. We...... are particularly interested in the regulation of the 5-hydroxytryptamine receptor 2A (5-HT2A R). This receptor form a functional complex with the metabotropic glutamate receptor 2 (mGluR2) and is recruited to the cell membrane by the corticotrophin-releasing factor receptor 1 (CRF-R1). The effect of BDNF on gene...... expression for all these receptors, as well as a number of immediate-early genes, was pharmacologically characterized in primary neurons from rat frontal cortex. BDNF increased CRF-R1 mRNA levels up to fivefold, whereas mGluR2 mRNA levels were proportionally downregulated. No effect on 5-HT2A R mRNA was seen...

  5. Dynamic changes in the expression of growth factor receptors in the myocardium microvascular endothelium after murine myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-hong; ZHANG Guo-ping; JIN Hui-ming; CHEN Si-feng

    2007-01-01

    Background After myocardial infarction, specific growth factors promote cardiac angiogenisis, leading to a therapeutic effect. Although this effect is mediated by specific receptors in the endothelium of the cardiac microvasculature, few studies have investigated dynamic changes in their expression. We explored this phenomenon in a murine model.Methods We observed the mRNA expression of receptors by specific angiogenesis gene microarray at day 3 and day 7after infarction. The vascular endothelial growth factor (VEGF) receptor Fik-1 was observed at the protein level at day 3and day 7 by immunohistochemistry. The dynamic expression of fibroblast growth factor receptor-1 (FGFR-1) mRNA in the border zone and the noninfarcted zone at day 3, day 7, day 14, and day 42 was investigated by real-time PCR.Statistical significance was analyzed with SPSS 10.0 software using one-way analysis of variance (ANOVA).Results Three days after infarction, 9 receptors in the border zone and 7 receptors in the noninfarcted zone were down-regulated. Two receptors in the infarct edge and 5 receptors in the distant myocardium were up-regulated. However,at day 7, 11 receptors in the border zone were up-regulated, and only one was down-regulated. In the border zone, Fik-1levels decreased at day 3 but increased significantly at day 7. Real-time PCR showed that FGFR-1 mRNA decreased markedly in the border zone at day 3 but increased afterward for at least 6 weeks. In the early stage (3 days) after infarction, the expression of receptors had decreased to some extent. However, at day 7, receptor expression was active and had moved from the distant noninfarcted zone to the border zone as a part of the acute repair process.Conclusion Selecting the proper growth factors to target receptors with protective activity, and determining appropriate therapeutic timing may be important to the success of therapeutic angiogenesis.

  6. The structure and function of vertebrate fibroblast growth factor receptor 1.

    Science.gov (United States)

    Groth, Casper; Lardelli, Michael

    2002-01-01

    The vertebrate fibroblast growth factor receptor 1 (FGFR1) is alternatively spliced generating multiple splice variants that are differentially expressed during embryo development and in the adult body. The restricted expression patterns of FGFR1 isoforms, together with differential expression and binding of specific ligands, leads to activation of common FGFR1 signal transduction pathways, but may result in distinctively different biological responses as a result of differences in cellular context. FGFR1 isoforms are also present in the nucleus in complex with various fibroblast growth factors where they function to regulate transcription of target genes.

  7. Proteinuria, a modifiable risk factor: angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs).

    Science.gov (United States)

    Dykeman-Sharpe, Jennifer

    2003-01-01

    Microalbuminuria and proteinuria have been determined to be modifiable risk factors for the progression of chronic kidney disease as well as risk factors for cardiovascular events. Angiotensin converting enzyme inhibitors and angiotensin II receptor blockers have been demonstrated to decrease proteinuria at all stages and slow the progression of renal disease. Proteinuria can be used as a marker of successful treatment in patients with chronic kidney disease in combination with other established targets. This article discusses the various diagnostic tests used for the detection of microalbuminuria and proteinuria and appropriate pharmaceutical treatment.

  8. Adiponectin and its receptors in the ovary: further evidence for a link between obesity and hyperandrogenism in polycystic ovary syndrome.

    Science.gov (United States)

    Comim, Fabio V; Hardy, Kate; Franks, Stephen

    2013-01-01

    Polycystic ovary syndrome (PCOS), characterized by ovarian androgen excess, is the commonest endocrine disorder in women. Obesity increases androgen synthesis, a phenomenon attributed to the accompanying hyperinsulinemia. Our hypothesis was that adipokines, fat cell-derived hormones, play a direct role in modulating ovarian androgen secretion. Therefore, the aims of this study were to explore the effects of adipokines (in particular, adiponectin) on ovarian steroidogenesis and compare the expression of adiponectin receptors in ovaries from women with and without PCO. Sections of archived human ovaries (nine from women with normal ovaries and 16 with PCOS, classified histologically, with reference to menstrual history and ultrasound) were analysed by quantitative morphometry and the proportion of positive-labelling cells compared. In addition, studies of androgen production in relation to adipokine function in primary bovine theca cell culture were also performed. A significantly lower proportion of theca cells expressed adiponectin receptors 1 and 2 (AdipoR1, AdipoR2) in polycystic ovaries than in normal ovaries. In cultured theca cells, adiponectin suppressed androstenedione production and gene expression of LH receptor and key enzymes in the androgen synthesis pathway. Moreover, knockdown of genes for AdipoR1 and AdipoR2 was associated with increased androstenedione secretion by bovine theca cells. These results provide evidence for a direct link between fat cell metabolism and ovarian steroidogenesis, suggesting that disruption of adiponectin and/or its receptors plays a key role in pathogenesis of hyperandrogenism in PCOS.

  9. Therapeutic targeting of epidermal growth factor receptor in human cancer: successes and limitations%Therapeutic targeting of epidermal growth factor receptor in humancancer: successes and limitations

    Institute of Scientific and Technical Information of China (English)

    Jill Wykosky; Tim Fenton; Frank Furnari; Webster K. Cavenee

    2011-01-01

    Epidermal growth factor receptor (EGFR) is one of the most commonly altered genes in human cancer by way of over-expression, amplification, and mutation. Targeted inhibition of EGFR activity suppresses signal transduction pathways which control tumor cell growth, proliferation, and resistance to apoptosis. Small molecule tyrosine kinase inhibitors and monoclonal antibodies are among the most common EGFR-targeting agents and have been used clinically for treating various malignancies. This review discusses the successes and challenges of targeting EGFR in human cancer. The genetic alterations of EGFR tend to occur more often in some solid tumors than others, as do the mechanisms of resistance to targeted inhibition. The clinical and basic science experiences with these agents thus far have important implications for the future of therapeutic targeting of EGFR.

  10. The Role of Epidermal Growth Factor Receptor Mutations and Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in the Treatment of Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shih-Chieh [Department of Internal Medicine, National Yang-Ming University Hospital, Yilan 260, Taiwan (China); Chang, Cheng-Yu [Department of Chest Medicine, Far Eastern Memorial Hospital, Taipei 220, Taiwan (China); Shih, Jin-Yuan, E-mail: jyshih@ntu.edu.tw [Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei 100, Taiwan (China)

    2011-06-10

    Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) cases comprise approximately 85% of the lung cancer cases. Before the era of target therapy, platinum-based doublet chemotherapy only led to a median survival of 8–9 months and a one-year survival of 30%–40% in patients with advanced NSCLC. In July 2002, gefitinib, a small-molecule epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), was approved for the treatment of patients with advanced NSCLC in Japan. After the widespread use of gefitinib in the treatment of NSCLC, there have been many new studies regarding the association between the clinical anticancer efficacy of gefitinib and the somatic EGFR mutation status in patients with NSCLC. This article summarizes the role of EGFR mutations in lung cancer and the use of EGFR antagonists in the treatment of lung cancer and its associated adverse effects.

  11. Expression of fibroblast growth factor-2 and fibroblast growth factor receptor-1 protein in the hippocampus in rats exhibiting chronic stress-induced depression

    Institute of Scientific and Technical Information of China (English)

    Gonglin Hou; Mingming Tang

    2011-01-01

    There is evidence that the expression of members of the fibroblast growth factor (FGF) protein family is altered in post-mortem brains of humans suffering from major depressive disorder. The present study examined whether the expression of fibroblast growth factor-2 (FGF2) and fibroblast growth factor receptor-1 (FGFR1) protein is altered following chronic stress in an animal model. Rats were exposed to 35 days of chronic unpredictable mild stress, and then tested using open-field and sucrose consumption tests. Compared with the control group, rats in the chronic stress group exhibited obvious depressive-like behaviors, including anhedonia, anxiety and decreased mobility. The results of western blot analysis and immunohistochemical analysis revealed a downregulation of the expression of FGF2 and FGFR1 in the hippocampus of rats, particularly in the CA1, CA3 and dentate gyrus. This decreased expression is in accord with the results of post-mortem studies in humans with major depressive disorder. These findings suggest that FGF2 and FGFR1 proteins participate in the pathophysiology of depressive-like behavior, and may play an important role in the mechanism of chronic stress-induced depression.

  12. Identification of fibroblast growth factor receptor 3 (FGFR3 as a protein receptor for botulinum neurotoxin serotype A (BoNT/A.

    Directory of Open Access Journals (Sweden)

    Birgitte P S Jacky

    Full Text Available Botulinum neurotoxin serotype A (BoNT/A causes transient muscle paralysis by entering motor nerve terminals (MNTs where it cleaves the SNARE protein Synaptosomal-associated protein 25 (SNAP25206 to yield SNAP25197. Cleavage of SNAP25 results in blockage of synaptic vesicle fusion and inhibition of the release of acetylcholine. The specific uptake of BoNT/A into pre-synaptic nerve terminals is a tightly controlled multistep process, involving a combination of high and low affinity receptors. Interestingly, the C-terminal binding domain region of BoNT/A, HC/A, is homologous to fibroblast growth factors (FGFs, making it a possible ligand for Fibroblast Growth Factor Receptors (FGFRs. Here we present data supporting the identification of Fibroblast Growth Factor Receptor 3 (FGFR3 as a high affinity receptor for BoNT/A in neuronal cells. HC/A binds with high affinity to the two extra-cellular loops of FGFR3 and acts similar to an agonist ligand for FGFR3, resulting in phosphorylation of the receptor. Native ligands for FGFR3; FGF1, FGF2, and FGF9 compete for binding to FGFR3 and block BoNT/A cellular uptake. These findings show that FGFR3 plays a pivotal role in the specific uptake of BoNT/A across the cell membrane being part of a larger receptor complex involving ganglioside- and protein-protein interactions.

  13. Identification of fibroblast growth factor receptor 3 (FGFR3 as a protein receptor for botulinum neurotoxin serotype A (BoNT/A.

    Directory of Open Access Journals (Sweden)

    Birgitte P S Jacky

    Full Text Available Botulinum neurotoxin serotype A (BoNT/A causes transient muscle paralysis by entering motor nerve terminals (MNTs where it cleaves the SNARE protein Synaptosomal-associated protein 25 (SNAP25206 to yield SNAP25197. Cleavage of SNAP25 results in blockage of synaptic vesicle fusion and inhibition of the release of acetylcholine. The specific uptake of BoNT/A into pre-synaptic nerve terminals is a tightly controlled multistep process, involving a combination of high and low affinity receptors. Interestingly, the C-terminal binding domain region of BoNT/A, HC/A, is homologous to fibroblast growth factors (FGFs, making it a possible ligand for Fibroblast Growth Factor Receptors (FGFRs. Here we present data supporting the identification of Fibroblast Growth Factor Receptor 3 (FGFR3 as a high affinity receptor for BoNT/A in neuronal cells. HC/A binds with high affinity to the two extra-cellular loops of FGFR3 and acts similar to an agonist ligand for FGFR3, resulting in phosphorylation of the receptor. Native ligands for FGFR3; FGF1, FGF2, and FGF9 compete for binding to FGFR3 and block BoNT/A cellular uptake. These findings show that FGFR3 plays a pivotal role in the specific uptake of BoNT/A across the cell membrane being part of a larger receptor complex involving ganglioside- and protein-protein interactions.

  14. Tissue-specific pioneer factors associate with androgen receptor cistromes and transcription programs

    Science.gov (United States)

    Pihlajamaa, Päivi; Sahu, Biswajyoti; Lyly, Lauri; Aittomäki, Viljami; Hautaniemi, Sampsa; Jänne, Olli A

    2014-01-01

    Androgen receptor (AR) binds male sex steroids and mediates physiological androgen actions in target tissues. ChIP-seq analyses of AR-binding events in murine prostate, kidney and epididymis show that in vivo AR cistromes and their respective androgen-dependent transcription programs are highly tissue specific mediating distinct biological pathways. This high order of tissue specificity is achieved by the use of exclusive collaborating factors in the three androgen-responsive tissues. We find two novel collaborating factors for AR signaling in vivo—Hnf4α (hepatocyte nuclear factor 4α) in mouse kidney and AP-2α (activating enhancer binding protein 2α) in mouse epididymis—that define tissue-specific AR recruitment. In mouse prostate, FoxA1 serves for the same purpose. FoxA1, Hnf4α and AP-2α motifs are over-represented within unique AR-binding loci, and the cistromes of these factors show substantial overlap with AR-binding events distinct to each tissue type. These licensing or pioneering factors are constitutively bound to chromatin and guide AR to specific genomic loci upon hormone exposure. Collectively, liganded receptor and its DNA-response elements are required but not sufficient for establishment of tissue-specific transcription programs. PMID:24451200

  15. Factors influencing the development of evidence-based practice among nurses: a self-report survey

    Directory of Open Access Journals (Sweden)

    Dalheim Anne

    2012-10-01

    Full Text Available Abstract Background Health authorities in several countries have decided that the health care services should be evidence-based. Recent research indicates that evidence-based practice may be more successfully implemented if the interventions overcome identified barriers. Aims The present study aimed to examine factors influencing the implementation of evidence-based practice among nurses in a large Norwegian university hospital. Methods Cross-sectional data was collected from 407 nurses during the period November 8 to December 3, 2010, using the Norwegian version of Developing Evidence-based Practice questionnaire (DEBP. The DEBP included data on various sources of information used for support in practice, on potential barriers for evidence-based practice, and on self-reported skills on managing research-based evidence. The DEBP was translated into Norwegian in accordance with standardized guidelines for translation and cultural adaptation. Results Nurses largely used experienced-based knowledge collected from their own observations, colleagues and other collaborators for support in practice. Evidence from research was seldom used. The greatest barriers were lack of time and lack of skills to find and manage research evidence. The nurse’s age, the number of years of nursing practice, and the number of years since obtaining the last health professional degree influenced the use of sources of knowledge and self-reported barriers. Self-reported skills in finding, reviewing and using different sources of evidence were positively associated with the use of research evidence and inversely related to barriers in use of research evidence. Conclusion Skills in evidence-based practice seem to reduce barriers to using research evidence and to increase use of research evidence in clinical practice.

  16. Platelet-derived growth factors and their receptors in normal and malignant hematopoiesis

    Science.gov (United States)

    Demoulin, Jean-Baptiste; Montano-Almendras, Carmen P.

    2012-01-01

    Platelet-derived growth factors (PDGF) bind to two closely related receptor tyrosine kinases, PDGF receptor α and β, which are encoded by the PDGFRA and PDGFRB genes. Aberrant activation of PDGF receptors occurs in myeloid malignancies associated with hypereosinophilia, due to chromosomal alterations that produce fusion genes, such as ETV6-PDGFRB or FIP1L1-PDGFRA. Most patients are males and respond to low dose imatinib, which is particularly effective against PDGF receptor kinase activity. Recently, activating point mutations in PDGFRA were also described in hypereosinophilia. In addition, autocrine loops have been identified in large granular lymphocyte leukemia and HTLV-transformed lymphocytes, suggesting new possible indications for tyrosine kinase inhibitor therapy. Although PDGF was initially purified from platelets more than 30 years ago, its physiological role in the hematopoietic system remains unclear. Hematopoietic defects in PDGF-deficient mice have been reported but appear to be secondary to cardiovascular and placental abnormalities. Nevertheless, PDGF acts directly on several hematopoietic cell types in vitro, such as megakaryocytes, platelets, activated macrophages and, possibly, certain lymphocyte subsets and eosinophils. The relevance of these observations for normal human hematopoiesis remains to be established. PMID:22432087

  17. Receptor binding sites for atrial natriuretic factor are expressed by brown adipose tissue

    Energy Technology Data Exchange (ETDEWEB)

    Bacay, A.C.; Mantyh, C.R.; Vigna, S.R.; Mantyh, P.W. (Wadsworth VA Medical Center, Los Angeles, CA (USA))

    1988-09-01

    To explore the possibility that atrial natriuretic factor (ANF) is involved in thermoregulation we used quantitative receptor autoradiography and homogenate receptor binding assays to identify ANF bindings sites in neonatal rat and sheep brown adipose tissue, respectively. Using quantitative receptor autoradiography were were able to localize high levels of specific binding sites for {sup 125}I-rat ANF in neonatal rat brown adipose tissue. Homogenate binding assays on sheep brown fat demonstrated that the radioligand was binding to the membrane fraction and that the specific binding was not due to a lipophilic interaction between {sup 125}I-rat ANF and brown fat. Specific binding of {sup 125}I-rat ANF to the membranes of brown fat cells was inhibited by unlabeled rat ANF with a Ki of 8.0 x 10(-9) M, but not by unrelated peptides. These studies demonstrate that brown fat cells express high levels of ANF receptor binding sites in neonatal rat and sheep and suggest that ANF may play a role in thermoregulation.

  18. Fibroblast growth factor receptor signaling is essential for lens fiber cell differentiation.

    Science.gov (United States)

    Zhao, Haotian; Yang, Tianyu; Madakashira, Bhavani P; Thiels, Cornelius A; Bechtle, Chad A; Garcia, Claudia M; Zhang, Huiming; Yu, Kai; Ornitz, David M; Beebe, David C; Robinson, Michael L

    2008-06-15

    The vertebrate lens provides an excellent model to study the mechanisms that regulate terminal differentiation. Although fibroblast growth factors (FGFs) are thought to be important for lens cell differentiation, it is unclear which FGF receptors mediate these processes during different stages of lens development. Deletion of three FGF receptors (Fgfr1-3) early in lens development demonstrated that expression of only a single allele of Fgfr2 or Fgfr3 was sufficient for grossly normal lens development, while mice possessing only a single Fgfr1 allele developed cataracts and microphthalmia. Profound defects were observed in lenses lacking all three Fgfrs. These included lack of fiber cell elongation, abnormal proliferation in prospective lens fiber cells, reduced expression of the cell cycle inhibitors p27(kip1) and p57(kip2), increased apoptosis and aberrant or reduced expression of Prox1, Pax6, c-Maf, E-cadherin and alpha-, beta- and gamma-crystallins. Therefore, while signaling by FGF receptors is essential for lens fiber differentiation, different FGF receptors function redundantly.

  19. Molecular Recognition of Corticotropin releasing Factor by Its G protein-coupled Receptor CRFR1

    Energy Technology Data Exchange (ETDEWEB)

    Pioszak, Augen A.; Parker, Naomi R.; Suino-Powell, Kelly; Xu, H. Eric (Van Andel)

    2009-01-15

    The bimolecular interaction between corticotropin-releasing factor (CRF), a neuropeptide, and its type 1 receptor (CRFR1), a class B G-protein-coupled receptor (GPCR), is crucial for activation of the hypothalamic-pituitary-adrenal axis in response to stress, and has been a target of intense drug design for the treatment of anxiety, depression, and related disorders. As a class B GPCR, CRFR1 contains an N-terminal extracellular domain (ECD) that provides the primary ligand binding determinants. Here we present three crystal structures of the human CRFR1 ECD, one in a ligand-free form and two in distinct CRF-bound states. The CRFR1 ECD adopts the alpha-beta-betaalpha fold observed for other class B GPCR ECDs, but the N-terminal alpha-helix is significantly shorter and does not contact CRF. CRF adopts a continuous alpha-helix that docks in a hydrophobic surface of the ECD that is distinct from the peptide-binding site of other class B GPCRs, thereby providing a basis for the specificity of ligand recognition between CRFR1 and other class B GPCRs. The binding of CRF is accompanied by clamp-like conformational changes of two loops of the receptor that anchor the CRF C terminus, including the C-terminal amide group. These structural studies provide a molecular framework for understanding peptide binding and specificity by the CRF receptors as well as a template for designing potent and selective CRFR1 antagonists for therapeutic applications.

  20. Structural analysis of the receptors for granulocyte colony-stimulating factor on neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    Hanazono, Y.; Hosoi, T.; Kuwaki, T.; Matsuki, S.; Miyazono, K.; Miyagawa, K.; Takaku, F. (Univ. of Tokyo (Japan))

    1990-11-01

    We investigated granulocyte colony-stimulating factor (G-CSF) receptors on neutrophils from three patients with chronic myelogenous leukemia (CML) in the chronic phase, in comparison with four normal volunteers. Because we experienced some difficulties in radioiodinating intact recombinant human G-CSF, we developed a new derivative of human G-CSF termed YPY-G-CSF. It was easy to iodinate this protein using the lactoperoxidase method because of two additional tyrosine residues, and its radioactivity was higher than that previously reported. The biological activity of YPY-G-CSF as G-CSF was fully retained. Scatchard analysis demonstrated that CML neutrophils had a single class of binding sites (1400 +/- 685/cell) with a dissociation constant (Kd) of 245 +/- 66 pM. The number of sites and Kd value of CML neutrophils were not significantly different from those of normal neutrophils (p greater than 0.9). Cross-linking studies revealed two specifically labeled bands of (125I)YPY-G-CSF-receptor complexes with apparent molecular masses of 160 and 110 kd on both normal and CML neutrophils. This is the first report describing two receptor proteins on neutrophils. According to the analyses of the proteolytic process of these cross-linked complexes and proteolytic mapping, we assume that alternative splicing or processing from a single gene may generate two distinct receptor proteins that bind specifically to G-CSF but have different fates in intracellular metabolism.

  1. Identification and characterization of tumor necrosis factor receptor (TNFR)-associated factor 3 from humphead snapper, Lutjanus sanguineus.

    Science.gov (United States)

    Cai, Jia; Xia, Hongli; Huang, Yucong; Tang, Jufen; Jian, Jichang; Wu, Zaohe; Lu, Yishan

    2015-10-01

    Tumor necrosis factor receptor (TNFR)-associated factor 3(TRAF3) is a key regulator in TNFR and Toll-like receptor (TLRs)/RIG-I-like receptors (RLRs) signal pathway. Here, a TRAF3 gene (Ls-TRAF3, GenBank Accession No: KJ789921) is cloned from humphead snapper (Lutjanus sanguineus). The Ls-TRAF3 cDNA contains an open reading frame of 1788 bp, which encodes a polypeptide of 595 amino acids. The deduced amino acid of Ls-TRAF3 possesses a RING finger, two TRAF-type zinc fingers, a coiled-coil and a MATH domain. Ls-TRAF3 protein shares high identities with other known TRAF3 proteins. In healthy fish, Ls-TRAF3 transcripts were broadly expressed in all examined tissues with highest expression levels in spleen, liver and head kidney. Quantitative real-time PCR (qRT-PCR) analysis revealed that Ls-TRAF3 could be induced by bacteria or viral PAMP poly I:C stimulation in vivo. Here, we also showed Ls-TRAF3 that, positively regulated IRF3 and Mx upon poly I:C stimuli, whereas prevented production of proinflammatory cytokine IL-6 after LPS injection. Moreover, over-expression of wide type (WT) Ls-TRAF3 and truncated forms, including ΔZinc finger 1, ΔZinc finger 2 and Δcoiled-coil suppressed NF-κB activity significantly, whereas the inhibitory effect of NF-κB was partially impaired when the RING finger or MATH domain deletion, suggesting the latter was more important for downstream signal transduction. Taken together, these results implicated that Ls-TRAF3 might play regulatory roles in immune response to pathogen invasion.

  2. Evidence for dopamine D-2 receptors on cholinergic interneurons in the rat caudate-putamen

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, V.L.; Dawson, T.M.; Filloux, F.M.; Wamsley, J.K.

    1988-01-01

    The aziridinium ion of ethylcholine (AF64A) is a neurotoxin that has demonstrated selectivity for cholinergic neurons. Unilateral stereotaxic injection of AF64A into the caudate-putamen of rats, resulted in a decrease in dopamine D-2 receptors as evidenced by a decrease in (/sup 3/H)-sulpiride binding. Dopamine D-1 receptors, labeled with (/sup 3/H)-SCH 23390, were unchanged. The efficacy of the lesion was demonstrated by the reduction of Na/sup +/-dependent high affinity choline uptake sites labeled with (/sup 3/H)-hemicholinium-3. These data indicate that a population of D-2 receptors are postsynaptic on cholinergic interneurons within the striatum of rat brain.

  3. No evidence for oncogenic mutations in the adrenocorticotropin receptor gene in human adrenocortical neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Latronico, A.C.; Reincke, M.; Mendonca, B.B. [National Inst. of Child Health and Human Development, Bethesda, MD (United States)] [and others

    1995-03-01

    The mechanism(s) of tumorigenesis for the majority of adrenocortical neoplasms remain unknown. G-Protein-coupled receptors were recently proposed as candidate protooncogenes. That activating mutations of this class of receptors might be important for tumor induction or progression of endocrine neoplasms was strengthened by the recent identification of such mutations in hyperfunctioning thyroid adenomas. To examine whether the ACTH receptor (ACTH-R) gene could be an oncogene in human adrenocortical tumors, we amplified by the polymerase chain reaction and directly sequenced the entire exon of the ACTH-R gene in 25 adrenocortical tumors (17 adenomas and 8 carcinomas) and 2 adrenocortical cancer cell lines. We found no missense point mutations or even silent polymorphisms in any of the tumors and cell lines studied. We conclude that activating mutations of the ACTH-R gene do not represent a frequent mechanism of human adrenocortical tumorigenesis. 15 refs., 2 tabs.

  4. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...

  5. Molecular characterization and functional analysis of tumor necrosis factor receptor-associated factor 2 in the Pacific oyster.

    Science.gov (United States)

    Huang, Baoyu; Zhang, Linlin; Du, Yishuai; Li, Li; Tang, Xueying; Zhang, Guofan

    2016-01-01

    Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) are a family of crucial adaptors, playing vital roles in mediating signal transduction in immune signaling pathways, including RIG-I-like receptor (RLR) signaling pathway. In the present study, a new TRAF family member (CgTRAF2) was identified in the Pacific oyster, Crassostrea gigas. Comparison and phylogenetic analysis revealed that CgTRAF2 could be a new member of the invertebrate TRAF2 family. Quantitative real-time PCR revealed that CgTRAF2 mRNA was highly expressed in the digestive gland, gills, and hemocytes, and it was significantly up-regulated after Vibrio alginolyticus and ostreid herpesvirus 1 (OsHV-1) challenge. The CgTRAF2 mRNA expression profile in different developmental stages of oyster larvae suggested that CgTRAF2 could function in early larval development. CgTRAF2 mRNA expression pattern, after the silence of CgMAVS (Mitochondrial Antiviral Signaling) -like, indicated that CgTRAF2 might function downstream of CgMAVS-like. Moreover, the subcellular localization analysis revealed that CgTRAF2 was localized in cytoplasm, and it may play predominately important roles in signal transduction. Collectively, these results demonstrated that CgTRAF2 might play important roles in the innate immunity and larval development of the Pacific oyster.

  6. Follicle-stimulating hormone regulates expression and activity of epidermal growth factor receptor in the murine ovarian follicle.

    Science.gov (United States)

    El-Hayek, Stephany; Demeestere, Isabelle; Clarke, Hugh J

    2014-11-25

    Fertility depends on the precise coordination of multiple events within the ovarian follicle to ensure ovulation of a fertilizable egg. FSH promotes late follicular development, including expression of luteinizing hormone (LH) receptor by the granulosa cells. Expression of its receptor permits the subsequent LH surge to trigger the release of ligands that activate EGF receptors (EGFR) on the granulosa, thereby initiating the ovulatory events. Here we identify a previously unknown role for FSH in this signaling cascade. We show that follicles of Fshb(-/-) mice, which cannot produce FSH, have a severely impaired ability to support two essential EGFR-regulated events: expansion of the cumulus granulosa cell layer that encloses the oocyte and meiotic maturation of the oocyte. These defects are not caused by an inability of Fshb(-/-) oocytes to produce essential oocyte-secreted factors or of Fshb(-/-) cumulus cells to respond. In contrast, although expression of both Egfr and EGFR increases during late folliculogenesis in Fshb(+/-) females, these increases fail to occur in Fshb(-/-) females. Remarkably, supplying a single dose of exogenous FSH activity to Fshb(-/-) females is sufficient to increase Egfr and EGFR expression and to restore EGFR-dependent cumulus expansion and oocyte maturation. These studies show that FSH induces an increase in EGFR expression during late folliculogenesis and provide evidence that the FSH-dependent increase is necessary for EGFR physiological function. Our results demonstrate an unanticipated role for FSH in establishing the signaling axis that coordinates ovulatory events and may contribute to the diagnosis and treatment of some types of human infertility.

  7. Follicle-stimulating hormone regulates expression and activity of epidermal growth factor receptor in the murine ovarian follicle

    Science.gov (United States)

    El-Hayek, Stephany; Demeestere, Isabelle; Clarke, Hugh J.

    2014-01-01

    Fertility depends on the precise coordination of multiple events within the ovarian follicle to ensure ovulation of a fertilizable egg. FSH promotes late follicular development, including expression of luteinizing hormone (LH) receptor by the granulosa cells. Expression of its receptor permits the subsequent LH surge to trigger the release of ligands that activate EGF receptors (EGFR) on the granulosa, thereby initiating the ovulatory events. Here we identify a previously unknown role for FSH in this signaling cascade. We show that follicles of Fshb−/− mice, which cannot produce FSH, have a severely impaired ability to support two essential EGFR-regulated events: expansion of the cumulus granulosa cell layer that encloses the oocyte and meiotic maturation of the oocyte. These defects are not caused by an inability of Fshb−/− oocytes to produce essential oocyte-secreted factors or of Fshb−/− cumulus cells to respond. In contrast, although expression of both Egfr and EGFR increases during late folliculogenesis in Fshb+/− females, these increases fail to occur in Fshb−/− females. Remarkably, supplying a single dose of exogenous FSH activity to Fshb−/− females is sufficient to increase Egfr and EGFR expression and to restore EGFR-dependent cumulus expansion and oocyte maturation. These studies show that FSH induces an increase in EGFR expression during late folliculogenesis and provide evidence that the FSH-dependent increase is necessary for EGFR physiological function. Our results demonstrate an unanticipated role for FSH in establishing the signaling axis that coordinates ovulatory events and may contribute to the diagnosis and treatment of some types of human infertility. PMID:25385589

  8. Imaging evidence for endothelin ETA/ETB receptor heterodimers in isolated rat mesenteric resistance arteries

    DEFF Research Database (Denmark)

    Kapsokalyvas, Dimitrios; Schiffers, Paul M H; Maij, Nathan

    2014-01-01

    to their normal ETA-mediated responses. They were then exposed to 100 nM linear ET-1 (ETB-agonist) labeled with Oregon Green 488 (OG488/L.-ET-1) and/or to 16nM intact ET-1 (ETA/ETB-agonist) labeled with the rhodamine dye TAMRA (TAMRA/ET-1). Two photon laser scanning microscopy (TPLSM) was used...... the occurrence of Fluorescence Resonant Energy Transfer (FRET) and suggests close proximity of the two receptor subtypes within the arterial wall. SIGNIFICANCE: The methodology that is introduced by these new observations may be useful to assess ET-receptor heterodimerization in biopsies from relevant...

  9. Germ cell nuclear factor directly represses the transcription of peroxisome proliferator-activated receptor delta gene

    Institute of Scientific and Technical Information of China (English)

    Chengqiang He; Naizheng Ding; Jie Kang

    2008-01-01

    Germ cell nuclear factor (GCNF) is a transcription factor that can repress gene transcription and plays an important role during spermatogenesis. Peroxisome proliferator-activated receptor delta (PPARδ) is a nuclear hormone receptor belonging to the steroid receptor superfamily.It can activate the expression of many genes,including those involved in lipid metabolism.In this report,we showed that GCNF specifically interacts with PPARδ promoter.Overexpression of GCNF in African green monkey SV40 transformed kidney fibroblast COS7 cells and mouse embryo fibroblast NIH 3T3 cells represses the activity of PPARδ promoter.The mutation of GCNF response element in PPARδ promoter relieves the repression in NIH 3T3 cells and mouse testis.Moreover,we showed that GCNF in nuclear extracts of mouse testis is able to bind to PPARδ promoter directly.We also found that GCNF and PPARδ mRNA were expressed with different patterns in mouse testis by in situ hybridization.These results suggested that GCNF might be a negative regulator of PPARδ gene expression through its direct interaction with PPARδ promoter in mouse testis.

  10. EXPRESSION OF EPIDERMAL GROWTH FACTOR RECEPTOR IN DIFFERENT SALIVARY ADENOID CYSTIC CARCINOMA CELL LINES

    Institute of Scientific and Technical Information of China (English)

    MA Jie; ZONG Zhi-hong; WANG Zhao-yuan

    2005-01-01

    Objective: To investigate the expression of epidermal growth factor receptor, a receptor tyrosine protein kinase, in the subcellular fractions of human salivary adenoid cystic carcinoma cell lines SACC-83 and SACC-LM. Methods: Low metastatic and high metastatic cells of the adenoid cystic carcinoma, SACC-83 and SACC-LM, were cultured. Their subcellular fractions were extracted. The expression of epidermal growth factor receptor was detected with Western blot method, and the results of protein expression were quantitatively analyzed by FluorChem V2.0 software. Results: The results of Western blot analysis indicated that, EGFR expression on the membrane of SACC-83 cells was significantly higher than that of SACC-LM cells, but its expression in cytoplasm was significantly less in the former than the later (P<0.01). In SACC-83 cell line, EGFR was over-expressed in membrane (P<0.01), but in SACC-LM cell line, EGFR was over-expressed in cytoplasm (P<0.01). Conclusion: The results suggest that the obtaining of metastasis ability is related to the high expression of EGFR protein in cytoplasm, so the molecular targeting therapy to EGFR may be an ideal treatment for the invasion and metastasis of salivary adenoid cystic carcinoma.

  11. Airway epithelial platelet-activating factor receptor expression is markedly upregulated in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Shukla SD

    2014-08-01

    Full Text Available Shakti Dhar Shukla,1,* Sukhwinder Singh Sohal,1,* Malik Quasir Mahmood,1 David Reid,2 Hans Konrad Muller,1 Eugene Haydn Walters1 1NHMRC Centre for Research Excellence for Chronic Respiratory Disease and Lung Ageing, School of Medicine, University of Tasmania, Hobart, Tasmania, Australia; 2Queensland Institute of Medical Research, Iron Metabolism Laboratory, Brisbane, Queensland, Australia *Shakti Dhar Shukla and Sukhwinder Singh Sohal are joint first authors Background: We recently published that platelet-activating factor receptor (PAFr is upregulated on the epithelium of the proximal airways of current smokers and also in bronchial epithelial cells exposed to cigarette smoke extract. These treated cells also showed upregulation of Streptococcus pneumoniae adhesion. Bacterial wall phosphorylcholine specifically binds to PAFr expressed on airway epithelium, thus facilitating adherence and tissue invasion, which may be relevant to chronic obstructive pulmonary disease (COPD. Moreover, the use of inhaled corticosteroids (ICS in COPD patients is associated with an increased risk of invasive respiratory pneumococcal infections. Objective: In this study, we have investigated whether PAFr expression is especially upregulated in airway epithelium in COPD patients and whether this expression may be modulated by ICS therapy. Methods: We cross-sectionally evaluated PAFr expression in bronchial biopsies from 15 COPD patients who were current smokers (COPD-smokers and 12 COPD-ex-smokers, and we compared these to biopsies from 16 smokers with normal lung function. We assessed immunostaining with anti-PAFr monoclonal antibody. We also used material from a previous double-blinded randomized placebo-controlled 6-month ICS intervention study in COPD patients to explore the effect of ICS on PAFr expression. We employed computer-aided image analysis to quantify the percentage of epithelium stained for PAFr. Results: Markedly enhanced expression of PAFr was found

  12. Surface proteome analysis identifies platelet derived growth factor receptor-alpha as a critical mediator of transforming growth factor-beta-induced collagen secretion.

    Science.gov (United States)

    Heinzelmann, Katharina; Noskovičová, Nina; Merl-Pham, Juliane; Preissler, Gerhard; Winter, Hauke; Lindner, Michael; Hatz, Rudolf; Hauck, Stefanie M; Behr, Jürgen; Eickelberg, Oliver

    2016-05-01

    Fibroblasts are extracellular matrix-producing cells in the lung. Fibroblast activation by transforming growth factor-beta leads to myofibroblast-differentiation and increased extracellular matrix deposition, a hallmark of pulmonary fibrosis. While fibroblast function with respect to migration, invasion, and extracellular matrix deposition has been well-explored, little is known about the surface proteome of lung fibroblasts in general and its specific response to fibrogenic growth factors, in particular transforming growth factor-beta. We thus performed a cell-surface proteome analysis of primary human lung fibroblasts in presence/absence of transforming growth factor-beta, followed by characterization of our findings using FACS analysis, Western blot, and siRNA-mediated knockdown experiments. We identified 213 surface proteins significantly regulated by transforming growth factor-beta, platelet derived growth factor receptor-alpha being one of the top down-regulated proteins. Transforming growth factor beta-induced downregulation of platelet derived growth factor receptor-alpha induced upregulation of platelet derived growth factor receptor-beta expression and phosphorylation of Akt, a downstream target of platelet derived growth factor signaling. Importantly, collagen type V expression and secretion was strongly increased after forced knockdown of platelet derived growth factor receptor-alpha, an effect that was potentiated by transforming growth factor-beta. We therefore show previously underappreciated cross-talk of transforming growth factor-beta and platelet derived growth factor signaling in human lung fibroblasts, resulting in increased extracellular matrix deposition in a platelet derived growth factor receptor-alpha dependent manner. These findings are of particular importance for the treatment of lung fibrosis patients with high pulmonary transforming growth factor-beta activity.

  13. Effect of liver regeneration after partial hepatectomy and ischemia-reperfusion on expression of growth factor receptors

    Institute of Scientific and Technical Information of China (English)

    P Baier; G Wolf-Vorbeck; S Hempel; UT Hopt; E von Dobschuetz

    2006-01-01

    AIM: To investigate the effects of experimental partial hepatectomy and normothermic ischemia-reperfusion damage on the time course of the expression of four different growth factor receptors in liver regeneration.This is relevant due to the potential therapeutic use of growth factors in stimulating liver regeneration.METHODS: For partial hepatectomy (PH) 80% of the liver mass was resected in Sprague Dawley rats.Ischemia and reperfusion (I/R) were induced by occlusion of the portal vein and the hepatic artery for 15 min. The epidermal growth factor receptor, hepatic growth factor receptor, fibroblast growth factor receptor and tumour necrosis factor receptor-1 were analysed by immunohistochemistry up to 72 h after injury.Quantitative RT-PCR was performed at the time point of minimal receptor expression (24 h).RESULTS: In immunohistochemistry, EGFR, HGFR,FGFR and TNFR1 showed biphasic kinetics after partial hepatectomy with a peak up to 12 h, a nadir after 24 h and another weak increase up to 72 h. During liver regeneration, after ischemia and reperfusion, the receptor expression was lower; the nadir at 24 h after reperfusion was the same. To evaluate whether this nadir was caused by a lack of mRNA transcription, or due to a posttranslational regulation, RT-PCR was performed at 24 h and compared to resting liver. In every probe there was specific mRNA for the receptors. EGFR, FGFR and TNFR1 mRNA expression was equal or lower than in resting liver, HGFR expression after I/R was stronger than in the control.CONCLUSION: At least partially due to a post-transcriptional process, there is a nadir in the expression of the analysed receptors 24 h after liver injury. Therefore,a therapeutic use of growth factors to stimulate liver regeneration 24 h after the damage might be not successful.

  14. Pre- and postsynaptic localization of the 5-HT7 receptor in rat dorsal spinal cord: immunocytochemical evidence.

    Science.gov (United States)

    Doly, Stéphane; Fischer, Jacqueline; Brisorgueil, Marie-Jeanne; Vergé, Daniel; Conrath, Marie

    2005-09-26

    Several lines of evidence indicate that 5-HT7 receptors are involved in pain control at the level of the spinal cord, although their mechanism of action is poorly understood. To provide a morphological basis for understanding the action of 5-HT on this receptor, we performed an immunocytochemical study of 5-HT7 receptor distribution at the lumbar level. 5-HT7 immunolabelling is localized mainly in the two superficial laminae of the dorsal horn and in small and medium-sized dorsal root ganglion cells, which is consistent with a predominant role in nociception. In addition, moderate labelling is found in the lumbar dorsolateral nucleus (Onuf's nucleus), suggesting involvement in the control of pelvic floor muscles. Electron microscopic examination of the dorsal horn revealed three main localizations: 1) a postsynaptic localization on peptidergic cell bodies in laminae I-III and in numerous dendrites; 2) a presynaptic localization on unmyelinated and thin myelinated peptidergic fibers (two types of axon terminals are observed, large ones, presumably of primary afferent origin, and smaller ones partially from intrinsic cells; this presynaptic labelling represents 60% and 22% of total labelling in laminae I and II, respectively); and 3) 16.9% of labelling in lamina I and 19.8% in lamina II are observed in astrocytes. Labeled astrocytes are either intermingled with neuronal elements or make astrocytic "feet" on blood vessels. In dendrites, the labelling is localized on synaptic differentiations, suggesting that 5-HT may act synaptically on the 5-HT7 receptor. This localization is compared with other 5-HT receptor localizations, and their physiological consequences are discussed.

  15. Membrane Progesterone Receptors (mPRs): Evidence for Neuroprotective, Neurosteroid Signaling and Neuroendocrine Functions in Neuronal Cells

    Science.gov (United States)

    Thomas, Peter; Pang, Yefei

    2012-01-01

    Membrane progesterone receptors (mPRs) are novel G protein-coupled receptors belonging to the progestin and adipoQ receptor family (PAQR) that mediate a variety of rapid, cell surface-initiated progesterone actions in the reproductive system involving activation of intracellular signaling pathways (i.e. nonclassical actions). The mPRs are highly expressed in the brain but research on their neural functions has only been conducted in a single neuronal cell line, GT1-7 cells, which have negligible nuclear progesterone receptor (PR) expression. GT1-7 cells express mPRα and mPRβ on their plasma membranes which is associated with the presence of high affinity, specific [3H]-progesterone receptor binding. The neurosteroid, allopregnanolone, is an effective ligand for recombinant mPRα with a relative binding affinity of 7.6% that of progesterone. Allopregnanolone acts as a potent mPR agonist on GT1-7 cells, mimicking the progesterone-induced decrease in cAMP accumulation and its antiapoptotic actions at low nanomolar concentrations.. The decrease in cAMP levels is associated with rapid progesterone-induced down-regulation of GnRH pulsatile secretion from perifused GT1-7 cells. The recent suggestion that mPRs are alkaline ceramidases and mediate sphingolipid signaling is not supported by empirical evidence that TNFα does not bind to mPRs over expressed in human cells and that exogenous sphingomyelinase is ineffective in mimicking progestin actions through mPRs to induce meiotic maturation of fish oocytes. Taken together, these recent studies indicate that mPRs mediate neuroprotective effects of progesterone and allopregnanolone and are also the likely intermediaries in progesterone-induced inhibition of pulsatile GnRH secretion in GT1-7 cells. PMID:22687885

  16. Advanced Research of Fibroblast Growth Factor Receptor 
in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Dan PU

    2013-11-01

    Full Text Available Lung cancer is severely threatening human health. In recent years, the treatment for lung adenocarcinoma has made a great progress, targeted therapy has been widely applied in clinic, and benefits amount of patients. However, in squamous cell lung cancer, the incidence of epidermal growth factor receptor (EGFR gene mutant and ALK fusion gene are low,and targeted therapy like Tarceva and crizotinib, can hardly work. Since the fibroblast growth factors (fibroblast growth factor, FGF pathway is considered to be related to tumor cell proliferation, metastasis and angiogenesis, more and more researches proved the amplification of fibroblast growth factor receptor (FGFR in squamous cell lung cancer. Experiments in vivo and in vitro found that blocking FGF pathway could reduce the proliferation of tumor cells and inhibit metastasis. The FGF pathway might be a new target for treatment of squamous cell lung cancer. This article reviews the effect of FGFR in tumorigenesis,as well as the prospect as a therapeutic target in non-small cell lung cancer.

  17. Receptor Signaling Directs Global Recruitment of Pre-existing Transcription Factors to Inducible Elements

    Science.gov (United States)

    Cockerill, Peter N.

    2016-01-01

    Gene expression programs are largely regulated by the tissue-specific expression of lineage-defining transcription factors or by the inducible expression of transcription factors in response to specific stimuli. Here I will review our own work over the last 20 years to show how specific activation signals also lead to the wide-spread re-distribution of pre-existing constitutive transcription factors to sites undergoing chromatin reorganization. I will summarize studies showing that activation of kinase signaling pathways creates open chromatin regions that recruit pre-existing factors which were previously unable to bind to closed chromatin. As models I will draw upon genes activated or primed by receptor signaling in memory T cells, and genes activated by cytokine receptor mutations in acute myeloid leukemia. I also summarize a hit-and-run model of stable epigenetic reprograming in memory T cells, mediated by transient Activator Protein 1 (AP-1) binding, which enables the accelerated activation of inducible enhancers. PMID:28018147

  18. Oxidatively fragmented phosphatidylcholines activate human neutrophils through the receptor for platelet-activating factor.

    Science.gov (United States)

    Smiley, P L; Stremler, K E; Prescott, S M; Zimmerman, G A; McIntyre, T M

    1991-06-15

    Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) activates neutrophils (polymorphonuclear leukocytes, PMN) through a receptor that specifically recognizes short sn-2 residues. We oxidized synthetic [2-arachidonoyl]phosphatidylcholine to fragment and shorten the sn-2 residue, and then examined the phospholipid products for the ability to stimulate PMN. 1-Palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine was fragmented by ozonolysis to 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine. This phospholipid activated human neutrophils at submicromolar concentrations, and is effects were inhibited by specific PAF receptor antagonists WEB2086, L659,989, and CV3988. 1-Palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine next was fragmented by an uncontrolled free radical-catalyzed reaction: it was treated with soybean lipoxygenase to form its sn-2 15-hydroperoxy derivative (which did not activate neutrophils) and then allowed to oxidize under air. The secondary oxidation resulted in the formation of numerous fragmented phospholipids (Stremler, K. E., Stafforini, D. M., Prescott, S. M., and McIntyre, T. M. (1991) J. Biol. Chem. 266, 11095-11103), some of which activated PMN. Hydrolysis of sn-2 residues with phospholipase A2 destroyed biologic activity, as did hydrolysis with PAF acetylhydrolase. PAF acetylhydrolase is specific for short or intermediate length sn-2 residues and does not hydrolyze the starting material (Stremler, K. E., Stafforini, D. M., Prescott, S. M., and McIntyre, T. M. (1991) J. Biol. Chem. 266, 11095-11103). Neutrophil activation was completely blocked by L659,989, a specific PAF receptor antagonist. We conclude that diacylphosphatidylcholines containing an sn-2 polyunsaturated fatty acyl residue can be oxidatively fragmented to species with sn-2 residues short enough to activate the PAF receptor of neutrophils. This suggests a new mechanism for the appearance of biologically active phospholipids, and shows

  19. Epidermal growth factor receptor in the prawn Macrobrachium rosenbergii: function and putative signaling cascade.

    Science.gov (United States)

    Sharabi, Omri; Ventura, Tomer; Manor, Rivka; Aflalo, Eliahu D; Sagi, Amir

    2013-09-01

    Epidermal growth factor receptors (EGFRs) are highly conserved members of the tyrosine kinase receptor superfamily found in metazoans and plants. In arthropods, EGFRs are vital for the proper development of embryos and of adult limbs, gonads, and eyes as well as affecting body size. In searching for genes involved in the growth and development of our model organism, the decapod crustacean (Macrobrachium rosenbergii), a comprehensive transcript library was established using next-generation sequencing. Using this library, the expression of several genes assigned to the signal transduction pathways mediated by EGFRs was observed, including a transcript encoding M. rosenbergii EGFR (Mr-EGFR), several potential ligands upstream to the receptor, and most of the putative downstream signal transducer genes. The deduced protein encoded by Mr-EGFR, representing the first such receptor reported thus far in crustaceans, shows sequence similarity to other arthropod EGFRs. The M. rosenbergii gene is expressed in most tested tissues. The role of Mr-EGFR was revealed by temporarily silencing the transcript through weekly injections of double-stranded Mr-EGFR RNA. Such treatment resulted in a significant reduction in growth and a delay in the appearance of a male secondary sexual characteristic, namely the appendix masculina. An additional function of Mr-EGFR was revealed with respect to eye development. Although the optic ganglion appeared to have retained its normal morphology, Mr-EGFR-silenced individuals developed abnormal eyes that presented irregular organization of the ommatidia, reflected by unorganized receptor cells occupying large areas of the dioptric portion and by a shortened crystalline tract layer.

  20. Molecular assembly of the ternary granulocyte-macrophage colony-stimulating factor receptor complex.

    Science.gov (United States)

    McClure, Barbara J; Hercus, Timothy R; Cambareri, Bronwyn A; Woodcock, Joanna M; Bagley, Christopher J; Howlett, Geoff J; Lopez, Angel F

    2003-02-15

    Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic cytokine that stimulates the production and functional activity of granulocytes and macrophages, properties that have encouraged its clinical use in bone marrow transplantation and in certain infectious diseases. Despite the importance of GM-CSF in regulating myeloid cell numbers and function, little is known about the exact composition and mechanism of assembly of the GM-CSF receptor complex. We have now produced soluble forms of the GM-CSF receptor alpha chain (sGMRalpha) and beta chain (sbetac) and utilized GM-CSF, the GM-CSF antagonist E21R (Glu21Arg), and the betac-blocking monoclonal antibody BION-1 to define the molecular assembly of the GM-CSF receptor complex. We found that GM-CSF and E21R were able to form low-affinity, binary complexes with sGMRalpha, each having a stoichiometry of 1:1. Importantly, GM-CSF but not E21R formed a ternary complex with sGMRalpha and sbetac, and this complex could be disrupted by E21R. Significantly, size-exclusion chromatography, analytical ultracentrifugation, and radioactive tracer experiments indicated that the ternary complex is composed of one sbetac dimer with a single molecule each of sGMRalpha and of GM-CSF. In addition, a hitherto unrecognized direct interaction between betac and GM-CSF was detected that was absent with E21R and was abolished by BION-1. These results demonstrate a novel mechanism of cytokine receptor assembly likely to apply also to interleukin-3 (IL-3) and IL-5 and have implications for our molecular understanding and potential manipulation of GM-CSF activation of its receptor.

  1. Expression of fibroblast growth factor (FGF)-8 isoforms and FGF receptors in human ovarian tumors.

    Science.gov (United States)

    Valve, E; Martikainen, P; Seppänen, J; Oksjoki, S; Hinkka, S; Anttila, L; Grenman, S; Klemi, P; Härkönen, P

    2000-12-01

    FGF-8 is a mitogenic growth factor, which is widely expressed during embryonic development but only at a very low level in adult tissues. Alternative splicing of the human FGF-8 gene potentially allows coding for 4 protein isoforms (a, b, e, f), which differ in their transforming capacity. The FGF-8 isoforms preferentially activate the receptors FGFR1IIIc, FGFR2IIIc, FGFR3IIIc and FGFR4. FGF-8 is over-expressed in human breast and prostate cancers. Expression has also been found in RT-PCR studies of human ovarian and testicular cancers. The present study was undertaken to examine which FGF-8 isoforms are expressed in ovarian cancer and whether FGF-8 receptors are also expressed. Specimens from 5 normal human ovaries and 51 ovarian tumors (1 benign tumor, 8 borderline malignancies, 42 malignant tumors of different histopathological types) were studied by RT-PCR and immunohistochemistry. FGF-8 isoform b was expressed in all ovarian tumors and in all 7 ovarian-cancer cell lines studied. Isoform a was co-expressed in 9 malignant ovarian tumors. FGF-8 mRNA was not detected by RT-PCR of 3 normal ovary samples. Immunohistochemical staining localized FGF-8 protein to cancer cells. In general, the increased intensity of FGF-8 staining was associated with loss of differentiation within the tumors (Bowker's test, p = 0.37). FGF-8 staining of surface epithelium observed on 2 normal ovaries was very faint. RT-PCR showed that FGFR1IIIc, FGFR2IIIc and FGFR4 were the FGF-8 receptors expressed in normal ovaries and in ovarian tumors. FGF-8 receptor immunoreactivity was preferentially found in normal ovary surface epithelium and tumor cells but also in some stromal cells. Collectively, our results show that ovarian cancers of a wide variety of histological types expressing receptors for FGF-8 have acquired the capacity of expressing FGF-8. This suggests that FGF-8 has an important role in ovarian tumorigenesis.

  2. Epidermal Growth Factor Receptor-Dependent Mutual Amplification between Netrin-1 and the Hepatitis C Virus.

    Directory of Open Access Journals (Sweden)

    Marie-Laure Plissonnier

    2016-03-01

    Full Text Available Hepatitis C virus (HCV is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC. The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+ and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR, a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species.

  3. Transient downregulation of glomerular atrial natriuretic factor receptors in high output heart failure in the rat.

    Science.gov (United States)

    Gauquelin, G; Bonhomme, M C; Garcia, R

    1995-03-01

    The renal response to exogenous atrial natriuretic factor (ANF) is blunted in chronic heart failure. The aim of the present studies was to investigate whether renal ANF receptor regulation in chronic heart failure is a time related event. Glomerular ANF receptors were analysed in radioligand binding experiments at 0, 1, 2, 6, 12, 24, and 48 h, as well as at 1, 2, 4, and 8 weeks after the induction of an aortocaval shunt. Rats with aortocaval shunts had lower packed cell volume and body weight and higher relative heart weight than sham operated controls. Plasma ANF C and N terminal levels were increased in shunt rats as early as 5 min after establishment of the shunt. Right and left atrial ANF concentrations were decreased and ventricular ANF concentration was increased in shunt rats at 6 and 12 h respectively. Competitive inhibition of 125I-ANF binding showed that at 6 h the density (Bmax) of glomerular ANF receptors was significantly lower than in the controls [518(SEM 10) v 759(12) fmol.mg-1 protein] without differences in their affinity (Kd). The low Bmax in shunt animals persisted at 12, 24, and 48 h, even at 1 week [Bmax: 400(29) and 713(28) fmol.mg-1 protein; Kd: 80(2) and 70(4) pM, for AC rats and controls, respectively]. Bmax values were not significantly different at 2, 4, and 8 weeks. In 24 h animals, C-ANF displaced 65% of total binding, with both total and C ANF binding sites being 38% lower in shunt animals. Downregulation of glomerular ANF receptors is a transient event during the development of high output heart failure in the rat. Thus the blunted renal response to ANF during chronic heart failure is not likely to be due to a decrease in renal ANF receptor density or affinity.

  4. Potentiation of nerve growth factor-induced neurite outgrowth by fluvoxamine: role of sigma-1 receptors, IP3 receptors and cellular signaling pathways.

    Directory of Open Access Journals (Sweden)

    Tomoko Nishimura

    Full Text Available BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs have been widely used and are a major therapeutic advance in psychopharmacology. However, their pharmacology is quite heterogeneous. The SSRI fluvoxamine, with sigma-1 receptor agonism, is shown to potentiate nerve-growth factor (NGF-induced neurite outgrowth in PC 12 cells. However, the precise cellular and molecular mechanisms underlying potentiation by fluvoxamine are not fully understood. In this study, we examined the roles of cellular signaling pathways in the potentiation of NGF-induced neurite outgrowth by fluvoxamine and sigma-1 receptor agonists. METHODS AND FINDINGS: The effects of three SSRIs (fluvoxamine, sertraline, paroxetine and three sigma-1 receptor agonists (SA4503, 4-phenyl-1-(4-phenylbutyl piperidine (PPBP, and dehydroepiandrosterone (DHEA-sulfate on NGF-induced neurite outgrowth in PC12 cells were examined. Also examined were the effects of the sigma-1 receptor antagonist NE-100, inositol 1,4,5-triphosphate (IP(3 receptor antagonist, and specific inhibitors of signaling pathways in the potentiation of NGF-induced neurite outgrowth by selective sigma-1 receptor agonist SA4503. Fluvoxamine (but not sertraline or paroxetine and the sigma-1 receptor agonists SA4503, PPBP, and DHEA-sulfate significantly potentiated NGF-induced neurite outgrowth in PC12 cells in a concentration-dependent manner. The potentiation by fluvoxamine and the three sigma-1 receptor agonists was blocked by co-administration of the selective sigma-1 receptor antagonist NE-100, suggesting that sigma-1 receptors play a role in blocking the enhancement of NGF-induced neurite outgrowth. Moreover, the potentiation by SA4503 was blocked by co-administration of the IP(3 receptor antagonist xestospongin C. In addition, the specific inhibitors of phospholipase C (PLC-gamma, phosphatidylinositol 3-kinase (PI3K, p38MAPK, c-Jun N-terminal kinase (JNK, and the Ras/Raf/mitogen-activated protein kinase (MAPK

  5. Anatomical evidence for transsynaptic influences of estrogen on brain-derived neurotrophic factor expression.

    Science.gov (United States)

    Blurton-Jones, M; Kuan, P N; Tuszynski, M H

    2004-01-12

    Several studies have demonstrated that estrogen modulates brain-derived neurotrophic factor (BDNF) mRNA and protein within the adult hippocampus and cortex. However, mechanisms underlying this regulation are unknown. Although an estrogen response element (ERE)-like sequence has been identified within the BDNF gene, such a classical mechanism of estrogen-induced transcriptional activation requires the colocalized expression of estrogen receptors within cells that produce BDNF. Developmental studies have demonstrated such a relationship, but to date no studies have examined colocalization of estrogen receptors and BDNF within the adult brain. By utilizing double-label immunohistochemistry for BDNF, estrogen receptor-alpha (ER-alpha), and estrogen receptor-beta (ER-beta), we found only sparse colocalization between ER-alpha and BDNF in the hypothalamus, amygdala, prelimbic cortex, and ventral hippocampus. Furthermore, ER-beta and BDNF do not colocalize in any brain region. Given the recent finding that cortical ER-beta is almost exclusively localized to parvalbumin-immunoreactive GABAergic neurons, we performed BDNF/parvalbumin double labeling and discovered that axons from cortical ER-beta-expressing inhibitory neurons terminate on BDNF-immunoreactive pyramidal cells. Collectively, these findings support a potential transsynaptic relationship between estrogen state and cortical BDNF: By directly modulating GABAergic interneurons, estrogen may indirectly influence the activity and expression of BDNF-producing cortical neurons.

  6. Immunomodulator CD200 promotes neurotrophic activity by interacting with and activating the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Pankratova, Stanislava; Bjornsdottir, Halla; Christensen, Claus;

    2016-01-01

    in the suppression of microglia activation. We for the first time demonstrated that CD200 can interact with and transduce signaling through activation of the fibroblast growth factor receptor (FGFR), thereby inducing neuritogenesis and promoting neuronal survival in primary neurons. CD200-induced FGFR...... phosphorylation was abrogated by CD200R, whereas FGF2-induced FGFR activation was inhibited by CD200. We also identified a sequence motif located in the first Ig-like module of CD200, likely representing the minimal CD200 binding site for FGFR. The FGFR binding motif overlaps with the CD200R binding site......, suggesting that they can compete for CD200 binding in cells that express both receptors. We propose that CD200 in neurons functions as a ligand of FGFR....

  7. Ramucirumab (IMC-1121B): Monoclonal antibody inhibition of vascular endothelial growth factor receptor-2.

    Science.gov (United States)

    Spratlin, Jennifer

    2011-04-01

    Angiogenesis, a well-recognized characteristic of malignancy, has been exploited more than any other pathway targeted by biologic anti-neoplastic therapies. Vascular endothelial growth factor receptor-2 (VEGFR-2) is the critical receptor involved in malignant angiogenesis with its activation inducing a number of other cellular modifications resulting in tumor growth and metastases. Ramucirumab (IMC-1121B; ImClone Systems Corporation, Branchburg, NJ) is a fully human monoclonal antibody developed to specifically inhibit VEGFR-2. Ramucirumab is currently being investigated in multiple clinical trials across a variety of tumor types. Herein, angiogenesis inhibition in cancer is reviewed and up-to-date information on the clinical development of ramucirumab is presented.

  8. Treatment related changes of the serum epidermal growth factor receptor in advanced colorectal cancer

    DEFF Research Database (Denmark)

    Spindler, K G; Aalund Olsen, Dorte; Brandslund, I

    2009-01-01

    .001), and a correlation between the magnitude of increase and a higher degree of skin toxicity, a well known indicator of clinical benefit to EGFR inhibitors. sEGFR in rectal cancer patients displayed a decreasing tendency during CRT (p...e22096 Background: The epidermal growth factor receptor (EGFR) is an established target for therapy in colorectal cancer. The extracellular domain of the receptor is shed into circulation and detectable by ELISA. We investigated the changes in sEGFR levels during preoperative chemoradiation (CRT......) in rectal cancer patients and third-line treatment with cetuximab and irinotecan (CETIRI) in advanced disease, to elucidate the predictive or prognostic value in these settings. METHODS: We included 126 healthy controls and 118 patients with chemorefractory mCRC treated with cetuximab (initial 400/m(2) mg...

  9. Fibroblast growth factor receptor 2 plays an essential role in telencephalic progenitors.

    Science.gov (United States)

    Ever, Leah; Zhao, Rui-Jing; Eswarakumar, Veraragavan P; Gaiano, Nicholas

    2008-01-01

    We used loss-of-function analysis to determine the role of fibroblast growth factor receptor 2 (FGFR2) in telencephalic progenitors, and also to examine interactions between FGFR and Notch signaling. While the telencephalon of FGFR2 mutants appears grossly normal, mutant telencephalic progenitors exhibit altered proliferative behavior in vivo and in vitro. Based upon our prior finding that Notch1 activation increased neurosphere frequency in FGF2, we tested whether this effect is mediated by FGFR1 or FGFR2. We found that Notch1 activation increased neurosphere frequency in cells mutant for either FGFR1 or FGFR2, but had no effect on the reduced size of neurospheres mutant for those receptors. Additional analyses revealed biochemical changes in the adult neocortex mutant for the IIIc isoform of FGFR2, and essential roles for FGFR2 in nasopharynx, eyelid, and cornea development.

  10. Structural Basis for Negative Cooperativity in Growth Factor Binding to an EGF Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A. (UPENN-MED)

    2010-09-27

    Transmembrane signaling by the epidermal growth factor receptor (EGFR) involves ligand-induced dimerization and allosteric regulation of the intracellular tyrosine kinase domain. Crystallographic studies have shown how ligand binding induces dimerization of the EGFR extracellular region but cannot explain the high-affinity and low-affinity classes of cell-surface EGF-binding sites inferred from curved Scatchard plots. From a series of crystal structures of the Drosophila EGFR extracellular region, we show here how Scatchard plot curvature arises from negatively cooperative ligand binding. The first ligand-binding event induces formation of an asymmetric dimer with only one bound ligand. The unoccupied site in this dimer is structurally restrained, leading to reduced affinity for binding of the second ligand, and thus negative cooperativity. Our results explain the cell-surface binding characteristics of EGF receptors and suggest how individual EGFR ligands might stabilize distinct dimeric species with different signaling properties.

  11. A Premature Termination of Human Epidermal Growth Factor Receptor Transcription in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jihene Elloumi-Mseddi

    2014-01-01

    Full Text Available Our success in producing an active epidermal growth factor receptor (EGFR tyrosine kinase in Escherichia coli encouraged us to express the full-length receptor in the same host. Despite its large size, we were successful at producing the full-length EGFR protein fused to glutathione S-transferase (GST that was detected by Western blot analysis. Moreover, we obtained a majoritarian truncated GST-EGFR form detectable by gel electrophoresis and Western blot. This truncated protein was purified and confirmed by MALDI-TOF/TOF analysis to belong to the N-terminal extracellular region of the EGFR fused to GST. Northern blot analysis showed two transcripts suggesting the occurrence of a transcriptional arrest.

  12. Evidence that the anorexia induced by lipopolysaccharide is mediated by the 5-HT2C receptor.

    Science.gov (United States)

    von Meyenburg, Claudia; Langhans, Wolfgang; Hrupka, Brian J

    2003-01-01

    Rats consistently reduce their food intake following injections of bacterial lipopolysaccharides (LPS). Because inhibition of serotonergic (5-HT) activity by 8-OH-DPAT (5-HT(1A) activation) attenuates LPS-induced anorexia, we conducted a series of studies to examine whether other 5-HT-receptors are involved in the mediation of peripheral LPS-induced anorexia. In all experiments, rats were injected with LPS (100 microg/kg body weight [BW] ip) at lights out (hour 0). Antagonists were administered peripherally at hour 4, shortly after the onset of anorexia, which presumably follows the enhanced cytokine production after LPS. Food intake was then recorded during the subsequent 2 h or longer. 5-HT receptor antagonists cyanopindolol and SB 224289 (5-HT(1B)), ketanserin (5-HT(2A)), RS-102221 (5-HT(2C)), and metoclopramide (5-HT(3)) failed to attenuate LPS-induced anorexia. In contrast, both ritanserin (5-HT(2A/C)-receptor antagonist) (0.5 mg/kg BW) and SB 242084 (5-HT(2C)) (0.3 mg/kg BW) attenuated LPS-induced anorexia at doses that did not alter food intake in non-LPS-treated rats (all Panorexia following peripheral LPS administration is mediated through an enhanced 5-HT-ergic activity and the 5-HT(2C) receptor.

  13. Evidence for non-random distribution of Fc gamma receptor genotype combinations

    NARCIS (Netherlands)

    van der Pol, WL; Jansen, MD; Sluiter, WJ; van de Sluis, B; Leppers-van de Straat, FGJ; Kobayashi, T; Westendorp, RGJ; Huizinga, TWJ; van de Winkel, JGJ

    2003-01-01

    Human IgG receptors (FcgammaR) display considerable heterogeneity, and are crucial immune response modulating molecules. FcgammaRIIA, FcgammaRIIIA, and FcgammaRIIIB display functional biallelic polymorphisms. FcgammaR polymorphisms have been found associated with susceptibility to infectious and aut

  14. NO EVIDENCE FOR A ROLE OF MUSCARINIC M(2) RECEPTORS IN FUNCTIONAL ANTAGONISM IN BOVINE TRACHEA

    NARCIS (Netherlands)

    ROFFEL, AF; MEURS, H; ELZINGA, CRS; ZAAGSMA, J

    1 The functional antagonism between methacholine- or histamine-induced contraction and beta-adrenoceptor-mediated relaxation was evaluated in bovine tracheal smooth muscle in vitro. In addition, the putative contribution of muscarinic M(2) receptors mediating inhibition of beta-adrenoceptor-induced

  15. Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction : integrating evidence into clinical practice

    NARCIS (Netherlands)

    Zannad, Faiez; Stough, Wendy Gattis; Rossignol, Patrick; Bauersachs, Johann; McMurray, John J. V.; Swedberg, Karl; Struthers, Allan D.; Voors, Adriaan A.; Ruilope, Luis M.; Bakris, George L.; O'Connor, Christopher M.; Gheorghiade, Mihai; Mentz, Robert J.; Cohen-Solal, Alain; Maggioni, Aldo P.; Beygui, Farzin; Filippatos, Gerasimos S.; Massy, Ziad A.; Pathak, Atul; Pina, Ileana L.; Sabbah, Hani N.; Sica, Domenic A.; Tavazzi, Luigi; Pitt, Bertram

    2012-01-01

    Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HFREF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These cl

  16. Oxytocin receptor gene methylation : converging multilevel evidence for a role in social anxiety

    NARCIS (Netherlands)

    Ziegler, Christiane; Dannlowski, Udo; Bräuer, David; Stevens, Stephan; Laeger, Inga; Wittmann, Hannah; Kugel, Harald; Dobel, Christian; Hurlemann, René; Reif, Andreas; Lesch, Klaus-Peter; Heindel, Walter; Kirschbaum, Clemens; Arolt, Volker; Gerlach, Alexander L; Hoyer, Jürgen; Deckert, Jürgen; Zwanzger, Peter; Domschke, Katharina

    2015-01-01

    Social anxiety disorder (SAD) is a commonly occurring and highly disabling disorder. The neuropeptide oxytocin and its receptor (OXTR) have been implicated in social cognition and behavior. This study-for the first time applying a multilevel epigenetic approach-investigates the role of OXTR gene met

  17. Evidence for homogeneity of thromboxane A2 receptor using structurally different antagonists.

    Science.gov (United States)

    Swayne, G T; Maguire, J; Dolan, J; Raval, P; Dane, G; Greener, M; Owen, D A

    1988-08-01

    Nine structurally dissimilar thromboxane antagonists (SQ 29548, ICI 185282, AH 23848, BM 13505 (Daltroban), BM 13177 (Sulotroban), SK&F 88046, L-636499, L-640035 and a Bayer compound SK&F 47821) were studied for activity as thromboxane A2 receptor antagonists. The assays used were inhibition of responses induced by the thromboxane mimetic, U46619, on human washed platelet aggregation, rabbit platelet aggregation, rabbit aortic strip contraction, anaesthetised guinea-pig bronchoconstriction, and a radio-labelled ligand (125I-PTA-OH) binding assay as a measure of affinity for the human platelet receptor. The results of the present study, with activities spanning at least four orders of magnitude along with statistically significant correlations (at least P less than 0.01), strongly suggests that between assays, antagonists and species a homogenous population of thromboxane A2 receptors exists. This finding is in contrast to those of a close series of 13-azapinane antagonists studied by other workers which have suggested receptor heterogeneity.

  18. Conservation of lepidopteran ecdysteroid receptor provides evidence for butterfly susceptibility to diacylhydrazine and bisacylhydrazine chemicals

    Science.gov (United States)

    Diacylhydrazine (DAH) and bisacylhydrazine (BAH) chemicals (e.g., methoxyfenozide and tebufenozide, respectively), also known as moulting accelerating compounds, act as agonists of the ecdysteroid receptor (EcR), and have been used as selective insecticides for pests within the o...

  19. Expression of growth factor ligand and receptor genes in the preimplantation bovine embryo.

    Science.gov (United States)

    Watson, A J; Hogan, A; Hahnel, A; Wiemer, K E; Schultz, G A

    1992-02-01

    The sensitive technique of mRNA phenotyping with the reverse transcription-polymerase chain reaction was employed to determine the patterns of gene expression for several growth factor ligand and receptor genes during bovine preimplantation development. Several thousand bovine embryos encompassing a developmental series from one-cell zygotes to hatched blastocysts were produced by the application of in vitro maturation, fertilization, and oviductal epithelial cell embryo coculture methods. Transcripts for transforming growth factor (TGF-alpha) and platelet-derived growth factor (PDGF-A) are detectable in all preimplantation bovine stages as observed in the mouse. Transcripts for TGF-beta 2 and insulin-like growth factor (IGF-II) and the receptors for PDGF-alpha, insulin, IGF-I, and IGF-II are also detectable throughout bovine preimplantation development, suggesting that these mRNAs are products of both the maternal and the embryonic genomes in the cow, whereas in the mouse they are present only following the activation of the embryonic genome at the two-cell stage. In contrast to the mouse embryo, IGF-I mRNA was detected within preimplantation bovine embryos. Basic fibroblast growth factor (bFGF) is a maternal message in the bovine embryo, since it is only detectable up until the eight-cell embryo stage. Bovine trophoblast protein (bTP) mRNA was detectable within day 8 bovine blastocysts. As was observed in the mouse, the transcripts for insulin, epidermal growth factor (EGF), or nerve growth factor (NGF) were not detectable in any bovine embryo stage. Analyses of this type should aid the development of a completely defined culture medium for the more efficient production of preimplantation bovine embryos.

  20. Featured Article: Nuclear export of opioid growth factor receptor is CRM1 dependent.

    Science.gov (United States)

    Kren, Nancy P; Zagon, Ian S; McLaughlin, Patricia J

    2016-02-01

    Opioid growth factor receptor (OGFr) facilitates growth inhibition in the presence of its specific ligand opioid growth factor (OGF), chemically termed [Met(5)]-enkephalin. The function of the OGF-OGFr axis requires the receptor to translocate to the nucleus. However, the mechanism of nuclear export of OGFr is unknown. In this study, endogenous OGFr, as well as exogenously expressed OGFr-EGFP, demonstrated significant nuclear accumulation in response to leptomycin B (LMB), an inhibitor of CRM1-dependent nuclear export, suggesting that OGFr is exported in a CRM1-dependent manner. One consensus sequence for a nuclear export signal (NES) was identified. Mutation of the associated leucines, L217 L220 L223 and L225, to alanine resulted in decreased nuclear accumulation. NES-EGFP responded to LMB, indicating that this sequence is capable of functioning as an export signal in isolation. To determine why the sequence functions differently in isolation than as a full length protein, the localization of subNES was evaluated in the presence and absence of MG132, a potent inhibitor of proteosomal degradation. MG132 had no effect of subNES localization. The role of tandem repeats located at the C-terminus of OGFr was examined for their role in nuclear trafficking. Six of seven tandem repeats were removed to form deltaTR. DeltaTR localized exclusively to the nucleus indicating that the tandem repeats may contribute to the localization of the receptor. Similar to the loss of cellular proliferation activity (i.e. inhibition) recorded with subNES, deltaTR also demonstrated a significant loss of inhibitory activity indicating that the repeats may be integral to receptor function. These experiments reveal that OGFr contains one functional NES, L217 L220 L223 and L225 and can be exported from the nucleus in a CRM1-dependent manner.

  1. Decreased expression of fibroblast and keratinocyte growth factor isoforms and receptors during scarless repair.

    Science.gov (United States)

    Dang, Catherine M; Beanes, Steven R; Soo, Chia; Ting, Kang; Benhaim, Prosper; Hedrick, Marc H; Lorenz, H Peter

    2003-05-01

    Fibroblast growth factors (FGFs) are a family of 21 cytokines with a broad spectrum of activities, including regulation of cell proliferation, differentiation, and migration. The various FGFs bind to one or more of four different tyrosine kinase receptor types. FGFs 1, 2, 5, 7, and 10 are up-regulated during adult cutaneous wound healing. However, the expression of FGFs during fetal skin development and scarless wound healing has not been characterized. It was hypothesized that differential expression of FGF isoforms and receptors occurs during fetal skin development and that this differential expression pattern may regulate the transition from scarless repair to healing with scar formation. Excisional wounds (2 mm) were created on fetal rats at gestational days 16.5 (scarless) (one wound per fetus, n = 36 fetuses) and 19.5 (scarring) (one wound per fetus, n = 36 fetuses). Wounds were harvested at 24, 48, and 72 hours. Survival until wound harvest ranged from 66 to 75 percent for the gestational day 16 fetuses, and from 83 to 92 percent for the gestational day 19 fetuses. Nonwounded fetal skin from littermates (n = 12 fetuses per wound harvest time point) was used as the control. Wounds/skins were pooled by harvest time point, and RNA was isolated from pooled wounds/skins. Reduced-cycle, specific-primer reverse transcriptase-polymerase chain reaction was performed to determine the expression of FGF isoforms 2, 5, 7, 9, and 10 and FGF receptors 1, 2, and 4 in wounds relative to unwounded skin.In unwounded fetal skin, FGF isoform 5 expression more than doubled at birth. FGF 10 expression doubled during the transition period. FGF 7 expression increased more than sevenfold at birth. Expression of FGF isoforms 2 and 9 did not change during late fetal skin development. The expression of FGF receptors 1, 2, and 4 increased at birth. After wounding, expression of FGF isoforms 7 and 10 was down-regulated in scarless wounds, whereas FGF receptor 2 expression decreased in

  2. [Team-based community psychiatry: importance of context factors and transferability of evidence from studies].

    Science.gov (United States)

    Weinmann, S; Gühne, U; Kösters, M; Gaebel, W; Becker, T

    2012-07-01

    The German Society for Psychiatry, Psychotherapy and Neurology (DGPPN) guidelines on psychosocial interventions for people with severe mental illness appraise the transferability of results of trials evaluating community-based mental health services to the German situation. This assessment has to draw on research results on factors determining effectiveness. This must be seen against the background of a lack of high-quality trials in Germany. The article discusses system, context and setting factors related to the transfer of evidence on community-based service models from other countries. These issues are discussed on the basis of evidence concerning the models of case management, assertive community treatment and community mental health teams. International differences in study findings are highlighted and the importance of treatment-as-usual in influencing study results is emphasized. The more control services including elements of community-based care there are and the less the pressure to reduce inpatient treatment (threshold to inpatient care admission), the smaller the relative effect sizes of innovative care models will be.In the absence of direct evidence, careful examination of transferability is required before introducing health care models. Research has revealed solid evidence for several factors influencing the effects of innovative community mental health care. Among key factors in the care of people with severe mental illness, home visits and joint team responsibility for both psychiatric and social care were identified. This evidence can facilitate the adaptation of successful mental health care models in Germany.

  3. Experimental evidence for growth factor treatment and function in certain neurological disorders.

    Science.gov (United States)

    Springer, J E

    1993-11-01

    This issue focuses on the potential utilization or involvement of growth factors in Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and epilepsy. Certainly, the role of growth factors in other neurological disorders associated with stroke, trauma, and neurodegeneration needs to be considered. While there is no direct evidence to indicate that a neurological disorder is associated with the compromised function of a specific growth factor, the use of these molecules as therapeutic agents is justifiable. Undoubtedly, the outcome of current clinical trials will certainly influence future decisions on the use of growth factor therapies.

  4. Mammary tumors that become independent of the type I insulin-like growth factor receptor express elevated levels of platelet-derived growth factor receptors

    Directory of Open Access Journals (Sweden)

    Campbell Craig I

    2011-11-01

    Full Text Available Abstract Background Targeted therapies are becoming an essential part of breast cancer treatment and agents targeting the type I insulin-like growth factor receptor (IGF-IR are currently being investigated in clinical trials. One of the limitations of targeted therapies is the development of resistant variants and these variants typically present with unique gene expression patterns and characteristics compared to the original tumor. Results MTB-IGFIR transgenic mice, with inducible overexpression of the IGF-IR were used to model mammary tumors that develop resistance to IGF-IR targeting agents. IGF-IR independent mammary tumors, previously shown to possess characteristics associated with EMT, were found to express elevated levels of PDGFRα and PDGFRβ. Furthermore, these receptors were shown to be inversely expressed with the IGF-IR in this model. Using cell lines derived from IGF-IR-independent mammary tumors (from MTB-IGFIR mice, it was demonstrated that PDGFRα and to a lesser extent PDGFRβ was important for cell migration and invasion as RNAi knockdown of PDGFRα alone or PDGFRα and PDGFRβ in combination, significantly decreased tumor cell migration in Boyden chamber assays and suppressed cell migration in scratch wound assays. Somewhat surprisingly, concomitant knockdown of PDGFRα and PDGFRβ resulted in a modest increase in cell proliferation and a decrease in apoptosis. Conclusion During IGF-IR independence, PDGFRs are upregulated and function to enhance tumor cell motility. These results demonstrate a novel interaction between the IGF-IR and PDGFRs and highlight an important, therapeutically relevant pathway, for tumor cell migration and invasion.

  5. Integration of estrogen and progesterone receptors with pathological and molecular prognostic factors in breast cancer patients.

    Science.gov (United States)

    Gago, F E; Tello, O M; Diblasi, A M; Ciocca, D R

    1998-12-01

    In this study we have examined biopsies from women with localized primary breast cancer to investigate the prognostic performance of estrogen receptors (ER) and progesterone receptors (PR) for estimating the metastatic probability of the patients, and to explore whether discrimination gets better by combining clinicopathological and other molecular parameters into a score. This prospective study involved 205 patients with a median follow-up of 5 y. Among the evaluated clinicopathological data were: patient's age; tumor size; axillary lymph node involvement; and tumor grade. The most representative tumor samples were derived to a single laboratory for immunohistochemical evaluation of the following molecular markers: ER, PR, proliferating cell nuclear antigen (PCNA), p53 protein product, erbB-2 (HER-2/neu) oncoprotein, and P170 glycoprotein (mdrl gen product). Distant metastases (study endpoint) appeared in 19.5% (40/205) of the patients, most of these patients presented a mixture of poor, regular and good prognostic factors. Disease-free survival analysis procedures (Kaplan-Meier method) identified tumor size, axillary lymph node involvement, tumor grade, receptor status, PCNA, p53, erbB-2 and P170 as useful prognostic factors. Proportional hazard regression analysis (Cox) identified in order of importance erbB-2, tumor size, receptors status, tumor grade and PCNA as useful prognostic factors. To facilitate the evaluation of the prognostic factors, a practical and simple score system was derived. A high pathological score identified 65% of the patients that developed distant metastases, while a high molecular score was obtained in 57% of patients with metastatic disease. There was a significant improvement in the diagnosis of probability of being with distant metastases when the pathological score was combined with the molecular score, 82% of the patients with distant metastases showed an elevated combined score. Validation of this scoring system will need further

  6. Nuclear Factor-κB: Activation and Regulation during Toll-like Receptor Signaling

    Institute of Scientific and Technical Information of China (English)

    Ruaidhrí J. Carmody; Youhai H. Chen

    2007-01-01

    Toll-like receptors (TLRs) recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-κB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-κB activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-κB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-κB.

  7. Revisiting epidermal growth factor receptor in glioblastoma multiforme: Does it play a role in response to therapy?

    Directory of Open Access Journals (Sweden)

    Priyanka Soni

    2014-01-01

    Full Text Available Background and Aim: Glioblastoma multiforme (GBM are the most aggressive class of cancer of central nervous system with hallmark characteristics that include rampant proliferation, necrosis, and endothelial proliferation. Epidermal growth factor receptor (EGFR has been implicated as the primary contributor to glioblastoma initiation and succession. The present study was designed to evaluate EGFR protein expression in GBM as predictor of response to therapy and survival. Materials and Methods: Epidermal growth factor receptor was assessed by immunohistochemistry as a percentage of positive tumor cells in hot spots (10 high-power fields. The study group comprised of 35 cases of GBM. All cases underwent surgical resection and subsequently underwent radiotherapy (n = 17 or radiotherapy with adjuvant temozolomide chemotherapy (n = 18. Immediate response to therapy was assessed at 3 months using World Health Organization response evaluation criteria in solid tumors criteria and cases followed up for survival. Results: Twenty-four cases (68.6% expressed EGFR while 11/35 (31.4% cases were negative. Response to therapy was evident in 21/35 cases (60.0% and 14/35 were (40.0% nonresponders. Mean EGFR protein expression in responders was 37.23 ± 33.70 and in nonresponders was 59.5 ± 39.46 (P = 0.542. The percentage of responders which were EGFR negative was 72.7% and while response in EGFR positive cases was observed in 54.2%. Mean survival in EGFR positive and negative GBM was 394.37 ± 189.11 and 420.54 ± 191.23 days, respectively. Conclusion: The EGFR negative cases appear to respond better to therapy, however, the difference is not statistically significant (P = 0.298. Further, EGFR protein expression does not play a definitive role in predicting survival. This is an original study evaluating EGFR in terms of therapeutic response.

  8. Platelet-Derived Growth Factor (PDGF/PDGF Receptors (PDGFR Axis as Target for Antitumor and Antiangiogenic Therapy

    Directory of Open Access Journals (Sweden)

    Anca Maria Cimpean

    2010-03-01

    Full Text Available Angiogenesis in normal and pathological conditions is a multi-step process governed by positive and negative endogenous regulators. Many growth factors are involved in different steps of angiogenesis, like vascular endothelial growth factors (VEGF, fibroblast growth factor (FGF-2 or platelet-derived growth factors (PDGF. From these, VEGF and FGF-2 were extensively investigated and it was shown that they significantly contribute to the induction and progression of angiogenesis. A lot of evidence has been accumulated in last 10 years that supports the contribution of PDGF/PDGFR axis in developing angiogenesis in both normal and tumoral conditions. The crucial role of PDGF-B and PDGFR-β in angiogenesis has been demonstrated by gene targeting experiments, and their expression correlates with increased vascularity and maturation of the vascular wall. PDGF and their receptors were identified in a large variety of human tumor cells. In experimental models it was shown that inhibition of PDGF reduces interstitial fluid pressure in tumors and enhances the effect of chemotherapy. PDGFR have been involved in the cardiovascular development and their loss leads to a disruption in yolk sac blood vessels development. PDGFRβ expression by pericytes is necessary for their recruitment and integration in the wall of tumor vessels. Endothelial cells of tumor-associated blood vessels can express PDGFR. Based on these data, it was suggested the potential benefit of targeting PDGFR in the treatment of solid tumors. The molecular mechanisms of PDGF/PDGFR-mediated angiogenesis are not fully understood, but it was shown that tyrosine kinase inhibitors reduce tumor growth and angiogenesis in experimental xenograft models, and recent data demonstrated their efficacy in chemoresistant tumors. The in vivo effects of PDGFR inhibitors are more complex, based on the cross-talk with other angiogenic factors. In this review, we summarize data regarding the mechanisms and

  9. Evidence that the positive inotropic effects of the alkylxanthines are not due to adenosine receptor blockade.

    Science.gov (United States)

    Collis, M. G.; Keddie, J. R.; Torr, S. R.

    1984-01-01

    We investigated the possibility that the positive inotropic effects of the alkylxanthines are due to adenosine receptor blockade. The potency of 8-phenyltheophylline, theophylline and enprofylline as adenosine antagonists was assessed in vitro, using the guinea-pig isolated atrium, and in vivo, using the anaesthetized dog. The order of potency of the alkylxanthines as antagonists of the negative inotropic response to 2-chloroadenosine in vitro, and of the hypotensive response to adenosine in vivo was 8-phenyltheophylline greater than theophylline greater than enprofylline. The order of potency of the alkylxanthines as positive inotropic and chronotropic agents in the anaesthetized dog was enprofylline greater than theophylline greater than 8-phenyltheophylline. The results of this study indicate that the inotropic effects of the alkylxanthines in the anaesthetized dog are not due to adenosine receptor blockade. PMID:6322898

  10. Treatment of pancreatic cancer with epidermal growth factor receptor-targeted therapy

    Directory of Open Access Journals (Sweden)

    Bryan A Faller

    2009-09-01

    Full Text Available Bryan A Faller, Barbara BurtnessDepartment of Medical Oncology, Fox Chase Cancer Center, Philadelphia, PA, USAAbstract: Pancreatic adenocarcinoma is a common malignancy that remains refractory to available therapies. Gemcitabine has long been the standard, first-line agent in advanced disease. The epidermal growth factor receptor (EGFR is a commonly expressed target in pancreatic cancer that is involved in tumor proliferation, metastasis, and induction of angiogenesis. The addition of the EGFR inhibitor erlotinib to gemcitabine has recently been demonstrated to provide a small, yet statistically significant, survival benefit in advanced disease. This has prompted further research into the applications of EGFR-targeted therapy in pancreatic cancer, albeit with disappointing results. Resistance to these therapies seems highly prevalent and has been implicated in their limited efficacy. The development of rash is associated with treatment efficacy and suggests that predictive factors may one day be identified to guide appropriate patient selection for these agents. Preclinical research has shown promise that resistance to EGFR-targeted therapies can be overcome through a variety of approaches. Application of this research in clinical trials may ultimately yield an unquestioned role for EGFR-targeted therapy in the management of this disease.Keywords: cetuximab, drug resistance, epidermal growth factor receptor, erlotinib, gemcitabine, pancreatic cancer

  11. Brain-derived neurotrophic factor and its receptors in Bergmann glia cells.

    Science.gov (United States)

    Poblete-Naredo, Irais; Guillem, Alain M; Juárez, Claudia; Zepeda, Rossana C; Ramírez, Leticia; Caba, Mario; Hernández-Kelly, Luisa C; Aguilera, José; López-Bayghen, Esther; Ortega, Arturo

    2011-12-01

    Brain-derived neurotrophic factor is an abundant and widely distributed neurotrophin expressed in the Central Nervous System. It is critically involved in neuronal differentiation and survival. The expression of brain-derived neurotrophic factor and that of its catalytic active cognate receptor (TrkB) has been extensively studied in neuronal cells but their expression and function in glial cells is still controversial. Despite of this fact, brain-derived neurotrophic factor is released from astrocytes upon glutamate stimulation. A suitable model to study glia/neuronal interactions, in the context of glutamatergic synapses, is the well-characterized culture of chick cerebellar Bergmann glia cells. Using, this system, we show here that BDNF and its functional receptor are present in Bergmann glia and that BDNF stimulation is linked to the activation of the phosphatidyl-inositol 3 kinase/protein kinase C/mitogen-activated protein kinase/Activator Protein-1 signaling pathway. Accordingly, reverse transcription-polymerase chain reaction (RT-PCR) experiments predicted the expression of full-length and truncated TrkB isoforms. Our results suggest that Bergmann glia cells are able to express and respond to BDNF stimulation favoring the notion of their pivotal role in neuroprotection. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Pharmacological evidence for the mediation of the panicolytic effect of fluoxetine by dorsal periaqueductal gray matter μ-opioid receptors.

    Science.gov (United States)

    Roncon, Camila Marroni; Almada, Rafael Carvalho; Maraschin, Jhonatan Christian; Audi, Elisabeth Aparecida; Zangrossi, Hélio; Graeff, Frederico Guilherme; Coimbra, Norberto Cysne

    2015-12-01

    Previously reported results have shown that the inhibitory effect of fluoxetine on escape behavior, interpreted as a panicolytic-like effect, is blocked by pretreatment with either the opioid receptor antagonist naloxone or the 5-HT1A receptor (5-HT1A-R) antagonist WAY100635 via injection into the dorsal periaqueductal gray matter (dPAG). Additionally, reported evidence indicates that the μ-opioid receptor (MOR) interacts with the 5-HT1A-R in the dPAG. In the present work, pretreatment of the dPAG with the selective MOR blocker CTOP antagonized the anti-escape effect of chronic fluoxetine (10 mg/kg, i.p., daily, for 21 days), as measured in the elevated T-maze (ETM) test, indicating mediation of this effect by the MOR. In addition, the combined administration of sub-effective doses of the selective MOR agonist DAMGO (intra-dPAG) and sub-effective doses of chronic as well as subchronic (7 days) fluoxetine increased avoidance and escape latencies, suggesting that the activation of MORs may facilitate and accelerate the effects of fluoxetine. The current observation that MORs located in the dPAG mediate the anti-escape effect of fluoxetine may open new perspectives for the development of more efficient and fast-acting panic-alleviating drugs.

  13. GABAB receptor ligands for the treatment of alcohol use disorder: preclinical and clinical evidence

    Directory of Open Access Journals (Sweden)

    Roberta eAgabio

    2014-06-01

    Full Text Available The present paper summarizes the preclinical and clinical studies conducted to define the anti-alcohol pharmacological profile of the prototypic GABAB receptor agonist, baclofen, and its therapeutic potential for treatment of alcohol use disorder (AUD. Numerous studies have reported baclofen-induced suppression of alcohol drinking (including relapse- and binge-like drinking and alcohol reinforcing, motivational, stimulating, and rewarding properties in rodents and monkeys. The majority of clinical surveys conducted to date – including case reports, retrospective chart reviews, and randomized placebo-controlled studies – suggest the ability of baclofen to suppress alcohol consumption, craving for alcohol, and alcohol withdrawal symptomatology in alcohol-dependent patients. The recent identification of a positive allosteric modulatory binding site, together with the synthesis of in vivo effective ligands, represents a novel, and likely more favorable, option for pharmacological manipulations of the GABAB receptor. Accordingly, data collected to date suggest that positive allosteric modulators of the GABAB receptor reproduce several anti-alcohol effects of baclofen and display a higher therapeutic index (with larger separation – in terms of doses – between anti-alcohol effects and sedation.

  14. Validating Antibodies to the Cannabinoid CB2 Receptor: Antibody Sensitivity Is Not Evidence of Antibody Specificity.

    Science.gov (United States)

    Marchalant, Yannick; Brownjohn, Philip W; Bonnet, Amandine; Kleffmann, Torsten; Ashton, John C

    2014-06-01

    Antibody-based methods for the detection and quantification of membrane integral proteins, in particular, the G protein-coupled receptors (GPCRs), have been plagued with issues of primary antibody specificity. In this report, we investigate one of the most commonly utilized commercial antibodies for the cannabinoid CB2 receptor, a GPCR, using immunoblotting in combination with mass spectrometry. In this way, we were able to develop powerful negative and novel positive controls. By doing this, we are able to demonstrate that it is possible for an antibody to be sensitive for a protein of interest-in this case CB2-but still cross-react with other proteins and therefore lack specificity. Specifically, we were able to use western blotting combined with mass spectrometry to unequivocally identify CB2 protein in over-expressing cell lines. This shows that a common practice of validating antibodies with positive controls only is insufficient to ensure antibody reliability. In addition, our work is the first to develop a label-free method of protein detection using mass spectrometry that, with further refinement, could provide unequivocal identification of CB2 receptor protein in native tissues.

  15. Cannabinoid receptors on peripheral leukocytes from patients with schizophrenia: Evidence for defective immunomodulatory mechanisms.

    Science.gov (United States)

    de Campos-Carli, Salvina Maria; Araújo, Marcio Sobreira; de Oliveira Silveira, Amanda Cardoso; de Rezende, Vitor Bortolo; Rocha, Natalia Pessoa; Ferretjans, Rodrigo; Ribeiro-Santos, Rafael; Teixeira-Carvalho, Andrea; Martins-Filho, Olindo Assis; Berk, Michael; Salgado, João Vinícius; Teixeira, Antonio Lucio

    2017-04-01

    to evaluate cannabinoid receptors (CBRs) expression on peripheral immune cells, i.e., blood monocytes, neutrophils, lymphocytes, and NK cells, and their relationship to a wide range of serum cytokine levels in subjects with schizophrenia and controls. A sample of 55 people with chronic schizophrenia and 48 controls were enrolled in the study. The expression of the cannabinoid receptors CB1R and CB2R was evaluated in peripheral blood leukocytes by flow cytometry. Serum levels of cytokines/chemokines were simultaneously analyzed by cytometric bead array. We found higher expression of cannabinoid receptors on cells of the innate immune system in subjects with schizophrenia when compared with controls. Serum levels of interleukin-4 (IL-4), IL-6, IL-10, IL-17, interferon (IFN-γ), and (C-X-C motif) ligand 10/interferon gamma-induced protein 10 (CXCL10/IP10) were decreased, while levels of the chemokine (C-C motif) ligand 2/monocyte chemoattractant protein-1 (CCL2/MCP-1) were increased in the schizophrenia group in comparison with controls. Patients with schizophrenia showed simpler correlation network between cytokines and CBRs expression than controls. Patients with schizophrenia showed increased CBRs expression in cells of the innate immune system and simpler correlation network between cytokines and CBRs expression when compared with controls. These results suggest a defective endocannabinoid system-mediated immunomodulation in patients with schizophrenia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Epidermal growth factor receptor targeted therapy in stages III and IV head and neck cancer.

    Science.gov (United States)

    Cripps, C; Winquist, E; Devries, M C; Stys-Norman, D; Gilbert, R

    2010-06-01

    What are the benefits associated with the use of anti-epidermal growth factor receptor (anti-EGFR) therapies in squamous cell carcinoma of the head and neck (HNSCC)? Anti-EGFR therapies of interest included cetuximab, gefitinib, lapatinib, zalutumumab, erlotinib, and panitumumab. Head-and-neck cancer includes malignant tumours arising from a variety of sites in the upper aerodigestive tract. The most common histologic type is squamous cell carcinoma, and most common sites are the oral cavity, the oropharynx, the hypopharynx, and the larynx. Worldwide, HNSCC is the sixth most common neoplasm, and despite advances in therapy, long-term survival in HNSCC patients is poor. Primary surgery followed by chemoradiation, or primary chemoradiation, are the standard treatment options for patients with locally advanced (stages III-IVB) HNSCC; however, meta-analytic data indicate that the benefit of concurrent platinum-based chemotherapy disappears in patients over the age of 70 years. Cetuximab is a monoclonal antibody approved for use in combination with radiation in the treatment of patients with untreated locally advanced HNSCC and as monotherapy for patients with recurrent or metastatic (stage IVC) HNSCC who have progressed on platinum-based therapy. Given the interest in anti-EGFR agents in advanced HNSCC, the Head and Neck Cancer Disease Site Group (DSG) of Cancer Care Ontario's Program in Evidence-Based Care (PEBC) chose to systematically review the literature pertaining to this topic so as to develop evidence-based recommendations for treatment. Outcomes of interest included overall and progression-free survival, quality of life, tumour response rate and duration, and the toxicity associated with the use of anti-EGFR therapies. The medline, embase, and Cochrane Library databases, the American Society of Clinical Oncology online conference proceedings, the Canadian Medical Association InfoBase, and the National Guidelines Clearinghouse were systematically searched to

  17. Neuritogenic and neuroprotective properties of peptide agonists of the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Li, Shizhong; Bock, Elisabeth Marianne; Berezin, Vladimir

    2010-01-01

    Fibroblast growth factor receptors (FGFRs) interact with their cognate ligands, FGFs, and with a number of cell adhesion molecules (CAMs), such as the neural cell adhesion molecule (NCAM), mediating a wide range of events during the development and maintenance of the nervous system. Determination...... of protein structure, in silico modeling and biological studies have recently resulted in the identification of FGFR binding peptides derived from various FGFs and NCAM mimicking the effects of these molecules with regard to their neuritogenic and neuroprotective properties. This review focuses on recently...... developed functional peptide agonists of FGFR with possible therapeutic potential....

  18. Neuritogenic and Neuroprotective Properties of Peptide Agonists of the Fibroblast Growth Factor Receptor

    Directory of Open Access Journals (Sweden)

    Shizhong Li

    2010-05-01

    Full Text Available Fibroblast growth factor receptors (FGFRs interact with their cognate ligands, FGFs, and with a number of cell adhesion molecules (CAMs, such as the neural cell adhesion molecule (NCAM, mediating a wide range of events during the development and maintenance of the nervous system. Determination of protein structure, in silico modeling and biological studies have recently resulted in the identification of FGFR binding peptides derived from various FGFs and NCAM mimicking the effects of these molecules with regard to their neuritogenic and neuroprotective properties. This review focuses on recently developed functional peptide agonists of FGFR with possible therapeutic potential.

  19. Expression and functional characterization of platelet-derived growth factor receptor-like gene

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To investigate the role of platelet-derived growth factor receptor-like gene(PDGFRL)in the anti-cancer therapy for colorectal cancers(CRC).METHODS:PDGFRL mRNA and protein levels were measured by reverse transcription-polymerase chain reaction(RT-PCR)and immunohistochemistry in CRC and colorectal normal tissues.PDGFRL prokaryotic expression vector was carried out in Escherichia coli(E.coli),and purified by immobilized metal affinity chromatography.The effect of PDGFRL protein on CRC HCT-116 cells was det...

  20. Epidermal Growth Factor Receptor Overexpression as a Target for Auger Electron Radiotherapy of Breast Cancer

    Science.gov (United States)

    2002-08-01

    radiotherapeutic agent for breast cancer. © 2001 Elsevier Science Inc . All rights reserved. Keywords: Breast cancer; Indium-111; Epidermal growth factor receptor... Science Inc . All rights reserved. PII: S0969-8051(01)00262-1 896 .1. Wang et al. / Nuclear Medicine and Biology 28 (2001) 895-902 A NW3 rn- NH, + NHC...raymond.reilly@utoronto.ca (R.M. Reilly). (cDTPAA) with an E-amino group on a lysine residue or the 0969-8051/01/$ - see front matter © 2001 Elsevier

  1. Regulation of tumour necrosis factor (TNF) induced apoptosis by soluble TNF receptors in Helicobacter pylori infection

    OpenAIRE

    Shibata, J; Goto, H.; Arisawa, T.; Niwa, Y.; Hayakawa, T.; Nakayama, A.; Mori, N.

    1999-01-01

    BACKGROUND—Tumour necrosis factor (TNF) is a predominant cytokine produced in the gastric mucosa of patients with Helicobacter pylori infection. TNF induces apoptosis in a variety of cells. The soluble TNF receptors (sTNF-Rs) can be divided into sTNF-RI and sTNF-RII, both of which inhibit TNF activity. However, their precise mechanisms remain unclear.
AIM—To investigate the role of sTNF-Rs in H pylori infection.
METHODS—In 40 patients, production of TNF and sTNF-Rs in gastric mucosa was measu...

  2. Fibroblast growth factor (FGF)-21 signals through both FGF receptor-1 and 2

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Fibroblast growth factor (FGF)-21 is a member of the FGF superfamily based on sequence homology. However, unlike most members of this family it does not show any mitogenic activity in all cell types tested. The objective of this study is to identify and characterize receptors for this molecule. Sequencing of the cDNA clones from 3T3-L1 adipocytes indicates that the only isoforms for FGFR-1 and 2 expressed in 3T3-L1 cells are 1IIIc and 2IIIc, respectively, suggesting that FGF-21 regulates glucose metabolism in 3T3-L1 adipocytes through FGFR-1IIIc and FGFR-2IIIc.

  3. Identification of soluble forms of the fibroblast growth factor receptor in blood.

    OpenAIRE

    Hanneken, A; Ying, W; Ling, N; Baird, A.

    1994-01-01

    We have purified three acidic (FGF-1) and basic (FGF-2) fibroblast growth factor binding proteins (FGF-BP1, FGF-BP2, and FGF-BP3) from human plasma and calf serum and demonstrate the presence of these circulating FGF-BPs in blood. Each are truncated forms of the high-affinity FGF receptor (FGFR-1). FGF-BP1 and FGF-BP2 have estimated molecular masses of 70-85 kDa and 55-60 kDa, respectively, and are detected by using 125I-labeled FGF-2 ligand blotting. Immunoblotting with four distinct antibod...

  4. Insulin-like growth factor-I receptor in proliferation and motility of pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Minoru; Tomizawa; Fuminobu; Shinozaki; Takao; Sugiyama; Shigenori; Yamamoto; Makoto; Sueishi; Takanobu; Yoshida

    2010-01-01

    AIM:To develop a molecular therapy for pancreatic cancer, the insulin-like growth factor-I (IGF-I) signaling pathway was analyzed.METHODS: Pancreatic cancer cell lines (MIA-Paca2, NOR-P1, PANC-1, PK-45H, PK-1, PK-59 and KP-4) were cultured in media with 10 mL/L fetal bovine serum. Western blotting analysis was performed to clarify the expression of IGF-I receptor (IGF-IR). Picropodophyllin (PPP), a specific inhibitor of IGF-IR, LY294002, a specific inhibitor of phosphatidylinositol3 kinase (PI3K), and PD980...

  5. The cytokines cardiotrophin-like cytokine/cytokine-like factor-1 (CLC/CLF) and ciliary neurotrophic factor (CNTF) differ in their receptor specificities.

    Science.gov (United States)

    Tormo, Aurélie Jeanne; Letellier, Marie-Claude; Lissilaa, Rami; Batraville, Laurie-Anne; Sharma, Mukut; Ferlin, Walter; Elson, Greg; Crabé, Sandrine; Gauchat, Jean-François

    2012-12-01

    Ciliary neurotrophic factor (CNTF) and cardiotrophin-like cytokine (CLC) are two cytokines with neurotrophic and immunomodulatory activities. CNTF is a cytoplasmic factor believed to be released upon cellular damage, while CLC requires interaction with a soluble cytokine receptor, cytokine-like factor 1 (CLF), to be efficiently secreted. Both cytokines activate a receptor complex comprising the cytokine binding CNTF receptor α (CNTFRα) and two signaling chains namely, leukemia inhibitory factor receptor β (LIFRβ) and gp130. Human CNTF can recruit and activate an alternative receptor in which CNTFRα is substituted by IL-6Rα. As both CNTF and CLC have immune-regulatory activities in mice, we compared their ability to recruit mouse receptors comprising both gp130 and LIFRβ signaling chains and either IL-6Rα or IL-11Rα which, unlike CNTFRα, are expressed by immune cells. Our results indicate that 1) mouse CNTF, like its human homologue, can activate cells expressing gp130/LIFRβ with either CNTFRα or IL-6Rα and, 2) CLC/CLF is more restricted in its specificity in that it activates only the tripartite CNTFR. Several gp130 signaling cytokines influence T helper cell differentiation. We therefore investigated the effect of CNTF on CD4 T cell cytokine production. We observed that CNTF increased the number of IFN-γ producing CD4 T cells. As IFN-γ is considered a mediator of the therapeutic effect of IFN-β in multiple sclerosis, induction of IFN-γ by CNTF may contribute to the beneficial immunomodulatory effect of CNTF in mouse multiple sclerosis models. Together, our results indicate that CNTF activates the same tripartite receptors in mouse and human cells and further validate rodent models for pre-clinical investigation of CNTF and CNTF derivatives. Furthermore, CNTF and CLC/CLF differ in their receptor specificities. The receptor α chain involved in the immunomodulatory effects of CLC/CLF remains to be identified.

  6. Immunotoxin Therapies for the Treatment of Epidermal Growth Factor Receptor-Dependent Cancers

    Directory of Open Access Journals (Sweden)

    Nathan Simon

    2016-05-01

    Full Text Available Many epithelial cancers rely on enhanced expression of the epidermal growth factor receptor (EGFR to drive proliferation and survival pathways. Development of therapeutics to target EGFR signaling has been of high importance, and multiple examples have been approved for human use. However, many of the current small molecule or antibody-based therapeutics are of limited effectiveness due to the inevitable development of resistance and toxicity to normal tissues. Recombinant immunotoxins are therapeutic molecules consisting of an antibody or receptor ligand joined to a protein cytotoxin, combining the specific targeting of a cancer-expressed receptor with the potent cell killing of cytotoxic enzymes. Over the decades, many bacterial- or plant-based immunotoxins have been developed with the goal of targeting the broad range of cancers reliant upon EGFR overexpression. Many examples demonstrate excellent anti-cancer properties in preclinical development, and several EGFR-targeted immunotoxins have progressed to human trials. This review summarizes much of the past and current work in the development of immunotoxins for targeting EGFR-driven cancers.

  7. A chemokine-binding domain in the tumor necrosis factor receptor from variola (smallpox) virus.

    Science.gov (United States)

    Alejo, Alí; Ruiz-Argüello, M Begoña; Ho, Yin; Smith, Vincent P; Saraiva, Margarida; Alcami, Antonio

    2006-04-11

    Variola virus (VaV) is the causative agent of smallpox, one of the most devastating diseases encountered by man, that was eradicated in 1980. The deliberate release of VaV would have catastrophic consequences on global public health. However, the mechanisms that contribute to smallpox pathogenesis are poorly understood at the molecular level. The ability of viruses to evade the host defense mechanisms is an important determinant of viral pathogenesis. Here we show that the tumor necrosis factor receptor (TNFR) homologue CrmB encoded by VaV functions not only as a soluble decoy TNFR but also as a highly specific binding protein for several chemokines that mediate recruitment of immune cells to mucosal surfaces and the skin, sites of virus entry and viral replication at late stages of smallpox. CrmB binds chemokines through its C-terminal domain, which is unrelated to TNFRs, was named smallpox virus-encoded chemokine receptor (SECRET) domain and uncovers a family of poxvirus chemokine inhibitors. An active SECRET domain was found in another viral TNFR (CrmD) and three secreted proteins encoded by orthopoxviruses. These findings identify a previously undescribed chemokine-binding and inhibitory domain unrelated to host chemokine receptors and a mechanism of immune modulation in VaV that may influence smallpox pathogenesis.

  8. Increased expression of receptors for orexigenic factors in nodose ganglion of diet-induced obese rats.

    Science.gov (United States)

    Paulino, Gabriel; Barbier de la Serre, Claire; Knotts, Trina A; Oort, Pieter J; Newman, John W; Adams, Sean H; Raybould, Helen E

    2009-04-01

    The vagal afferent pathway is important in short-term regulation of food intake, and decreased activation of this neural pathway with long-term ingestion of a high-fat diet may contribute to hyperphagic weight gain. We tested the hypothesis that expression of genes encoding receptors for orexigenic factors in vagal afferent neurons are increased by long-term ingestion of a high-fat diet, thus supporting orexigenic signals from the gut. Obesity-prone (DIO-P) rats fed a high-fat diet showed increased body weight and hyperleptinemia compared with low-fat diet-fed controls and high-fat diet-induced obesity-resistant (DIO-R) rats. Expression of the type I cannabinoid receptor and growth hormone secretagogue receptor 1a in the nodose ganglia was increased in DIO-P compared with low-fat diet-fed controls or DIO-R rats. Shifts in the balance between orexigenic and anorexigenic signals within the vagal afferent pathway may influence food intake and body weight gain induced by high fat diets.

  9. Expression of membrane receptor for tumour necrosis factor on human blood lymphocytes.

    Science.gov (United States)

    Zola, H; Flego, L; Weedon, H

    1993-08-01

    Using a monoclonal antibody against the human p75 tumour necrosis factor receptor (TNFR-I) combined with a high-sensitivity immunofluorescence flow cytometric procedure, a proportion of peripheral blood lymphocytes can be shown to express TNFR-I constitutively. Approximately 50% of peripheral blood lymphocytes consisting mostly of CD4 cells and including most CD45R0-positive cells, express TNFR-I. Receptor expression is increased by a variety of activation signals. Only a minority (up to 30%) of tonsil B cells express measurable levels of TNFR-I. The tonsil B cells which express TNFR-I include both cells with a germinal centre cell phenotype and cells with the phenotype of the follicular mantle zone. Activation of B cells with anti-immunoglobulin, alone or in combination with interleukin-4 or interleukin-2, increases receptor expression, particularly in cells with the phenotype of mantle zone cells. The functional significance of constitutive expression of TNFR by blood and tissue lymphocytes is discussed.

  10. Radiotracer Methods for Targeted Imaging of the Epidermal Growth Factor Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kyung Ho; Lee, Kyung Han [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    While indirect targeting strategies using reporter-genes are taking center stage in current molecular imaging research, another vital strategy has long involved direct imaging of specific receptors using radiolabeled ligands. Recently, there is renewal of immense interest in this area with particular attention to the epidermal growth factor receptor (EGFR), a transmembrane glycoprotein critically involved in the regulation of many cellular functions and malignancies. Recently, two novel classes of EGFR-targeting anticancer drugs have entered clinical trials with great expectations. These are monoclonal antibodies such as cetuximab that target the extracellular domain, and small molecule tyrosine kinase inhibitors such as gefitinib (Iressa) and erlotinib (Tarceva) that target the catalytic domain of the receptor. However, early results have showed disappointing survival benefits, disclosing a major challenge for this therapeutic strategy; namely, the need to identify tumors that are most likely to respond to the agents. To address this important clinical issue, several noninvasive imaging techniques are under investigation including radiolabeled probes based on small molecule tyrosine kinase inhibitors, anti-EGFR antibodies, and EGF peptides. This review describes the current status, limitations, and future prospects in the development of radiotracer methods for EGFR imaging.

  11. IDENTIFICATION OF NOVEL FIBROBLAST GROWTH FACTOR RECEPTOR 3 GENE MUTATIONS IN ACTINIC CHEILITIS

    Science.gov (United States)

    Chou, Annie; Dekker, Nusi; Jordan, Richard C.K.

    2009-01-01

    Objective Activating mutations in the fibroblast growth factor receptor 3 (FGFR3) gene are responsible for several craniosynostosis and chondrodysplasia syndromes as well as some human cancers including bladder and cervical carcinoma. Despite a high frequency in some benign skin disorders, FGFR3 mutations have not been reported in cutaneous malignancies. Actinic cheilitis (AC) is a sun-induced premalignancy affecting the lower lip that frequently progresses to squamous cell carcinoma (SCC). The objective of this study was to determine if FGFR3 gene mutations are present in AC and SCC of the lip. Study Design DNA was extracted and purified from micro-dissected, formalin-fixed, paraffin-embedded tissue sections of 20 cases of AC and SCC arising in AC. Exons 7, 15, and 17 were PCR amplified and direct sequenced. Results Four novel somatic mutations in the FGFR3 gene were identified: exon 7 mutation 742C→T (amino acid change R248C), exon 15 mutations 1850A→G (D617G) and 1888G→A (V630M), and exon 17 mutation 2056G→A (E686K). Grade of dysplasia did not correlate with presence of mutations. Conclusion The frequency of FGFR3 receptor mutations suggests a functional role for the FGFR3 receptor in the development of epithelial disorders and perhaps a change may contribute to the pathogenesis of some AC and SCC. PMID:19327639

  12. Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation.

    Science.gov (United States)

    Roth, Lise; Prahst, Claudia; Ruckdeschel, Tina; Savant, Soniya; Weström, Simone; Fantin, Alessandro; Riedel, Maria; Héroult, Mélanie; Ruhrberg, Christiana; Augustin, Hellmut G

    2016-04-26

    Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165-amino acid isoform of vascular endothelial growth factor A (VEGF-A165). NRP1 is also the receptor for the CendR peptides, a class of cell- and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A165, a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation.

  13. All-atom structural models for complexes of insulin-like growth factors IGF1 and IGF2 with their cognate receptor.

    Science.gov (United States)

    Vashisth, Harish; Abrams, Cameron F

    2010-07-16

    Type 1 insulin-like growth factor receptor (IGF1R) is a membrane-spanning glycoprotein of the insulin receptor family that has been implicated in a variety of cancers. The key questions related to molecular mechanisms governing ligand recognition by IGF1R remain unanswered, partly due to the lack of testable structural models of apo or ligand-bound receptor complexes. Using a homology model of the IGF1R ectodomain IGF1RDeltabeta, we present the first experimentally consistent all-atom structural models of IGF1/IGF1RDeltabeta and IGF2/IGF1RDeltabeta complexes. Our explicit-solvent molecular dynamics (MD) simulation of apo-IGF1RDeltabeta shows that it displays asymmetric flexibility mechanisms that result in one of two binding pockets accessible to growth factors IGF1 and IGF2, as demonstrated via an MD-assisted Monte Carlo docking procedure. Our MD-generated ensemble of structures of apo and IGF1-bound IGF1RDeltabeta agrees reasonably well with published small-angle X-ray scattering data. We observe simultaneous contacts of each growth factor with sites 1 and 2 of IGF1R, suggesting cross-linking of receptor subunits. Our models provide direct evidence in favor of suggested electrostatic complementarity between the C-domain (IGF1) and the cysteine-rich domain (IGF1R). Our IGF1/IGF1RDeltabeta model provides structural bases for the observation that a single IGF1 molecule binds to IGF1RDeltabeta at low concentrations in small-angle X-ray scattering studies. We also suggest new possible structural bases for differences in the affinities of insulin, IGF1, and IGF2 for their noncognate receptors.

  14. Fibroblast growth factor receptor 4 regulates tumor invasion by coupling fibroblast growth factor signaling to extracellular matrix degradation

    DEFF Research Database (Denmark)

    Sugiyama, Nami; Varjosalo, Markku; Meller, Pipsa;

    2010-01-01

    Aberrant expression and polymorphism of fibroblast growth factor receptor 4 (FGFR4) has been linked to tumor progression and anticancer drug resistance. We describe here a novel mechanism of tumor progression by matrix degradation involving epithelial-to-mesenchymal transition in response...... to membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14) induction at the edge of tumors expressing the FGFR4-R388 risk variant. Both FGFR4 and MT1-MMP were upregulated in tissue biopsies from several human cancer types including breast adenocarcinomas, where they were partially coexpressed at the tumor....../stroma border and tumor invasion front. The strongest overall coexpression was found in prostate carcinoma. Studies with cultured prostate carcinoma cell lines showed that the FGFR4-R388 variant, which has previously been associated with poor cancer prognosis, increased MT1-MMP-dependent collagen invasion...

  15. Genetic Evidence for Function of the bHLH-PAS Protein Gce/Met As a Juvenile Hormone Receptor.

    Directory of Open Access Journals (Sweden)

    Marek Jindra

    2015-07-01

    Full Text Available Juvenile hormones (JHs play a major role in controlling development and reproduction in insects and other arthropods. Synthetic JH-mimicking compounds such as methoprene are employed as potent insecticides against significant agricultural, household and disease vector pests. However, a receptor mediating effects of JH and its insecticidal mimics has long been the subject of controversy. The bHLH-PAS protein Methoprene-tolerant (Met, along with its Drosophila melanogaster paralog germ cell-expressed (Gce, has emerged as a prime JH receptor candidate, but critical evidence that this protein must bind JH to fulfill its role in normal insect development has been missing. Here, we show that Gce binds a native D. melanogaster JH, its precursor methyl farnesoate, and some synthetic JH mimics. Conditional on this ligand binding, Gce mediates JH-dependent gene expression and the hormone's vital role during development of the fly. Any one of three different single amino acid mutations in the ligand-binding pocket that prevent binding of JH to the protein block these functions. Only transgenic Gce capable of binding JH can restore sensitivity to JH mimics in D. melanogaster Met-null mutants and rescue viability in flies lacking both Gce and Met that would otherwise die at pupation. Similarly, the absence of Gce and Met can be compensated by expression of wild-type but not mutated transgenic D. melanogaster Met protein. This genetic evidence definitively establishes Gce/Met in a JH receptor role, thus resolving a long-standing question in arthropod biology.

  16. Heparan sulfate proteoglycan isoforms of the CD44 hyaluronan receptor induced in human inflammatory macrophages can function as paracrine regulators of fibroblast growth factor action.

    Science.gov (United States)

    Jones, M; Tussey, L; Athanasou, N; Jackson, D G

    2000-03-17

    The CD44 glycoprotein is expressed in multiple isoforms on a variety of cell types where it functions as a receptor for hyaluronan-mediated motility. Recently, interest has centered on CD44 heparan sulfate proteoglycan (HSPG) isoforms because of their potential to sequester heparin-binding growth factors and chemokines. Expression of these isoforms on ectodermal cells has recently been shown to regulate limb morphogenesis via presentation of fibroblast growth factor (FGF) 4/FGF 8 while expression on tumor cells was shown to sequester hepatocyte growth factor and promote tumor dissemination. To date, however, CD44 HSPG expression in tissue macrophages and lymphocytes has not been adequately investigated, despite the fact these cells actively synthesize growth factors and chemokines and indirect evidence that monocyte CD44 sequesters macrophage inflammatory protein-1beta. Here we show primary human monocytes rather than lymphocytes express CD44 HSPGs, but only following in vitro differentiation to macrophages or activation with the proinflammatory cytokine interleukin-1alpha or bacterial lipopolysaccharide. Furthermore, we show these isoforms are preferentially modified with heparan rather than chondroitin sulfate, bind the macrophage-derived growth factors FGF-2, vascular endothelial growth factor, and heparin-binding epidermal growth factor with varying affinities (K(d) 25-330 nM) and in the case of FGF-2, can stimulate productive binding to the high affinity tyrosine kinase FGF receptor 1 (FGFR1). In contrast, we find no evidence for significant binding to C-C chemokines. Last, we confirm by immunofluorescent antibody staining that inflamed synovial membrane macrophages express CD44 HSPGs and that expression is greatest in cells containing high FGF-2 levels. These results suggest a paracrine role for macrophage CD44 HSPG isoforms in the regulation of growth factor action during inflammation.

  17. Scientific reasoning in kindergarten: Cognitive factors in experimentation and evidence evaluation

    NARCIS (Netherlands)

    Graaf, J. van der; Segers, P.C.J.; Verhoeven, L.T.W.

    2016-01-01

    The aim of the present study was to investigate the role of cognitive factors in two core components of scientific reasoning: experimentation and evidence evaluation. Measures of visuospatial and verbal working memory, inhibition, cognitive flexibility, vocabulary, grammatical ability, and spatial v

  18. Scientific reasoning in kindergarten: Cognitive factors in experimentation and evidence evaluation

    NARCIS (Netherlands)

    Graaf, J. van der; Segers, P.C.J.; Verhoeven, L.T.W.

    2016-01-01

    The aim of the present study was to investigate the role of cognitive factors in two core components of scientific reasoning: experimentation and evidence evaluation. Measures of visuospatial and verbal working memory, inhibition, cognitive flexibility, vocabulary, grammatical ability, and spatial v

  19. Clopidogrel inhibits angiogenesis of gastric ulcer healing via downregulation of vascular endothelial growth factor receptor 2.

    Science.gov (United States)

    Luo, Jiing-Chyuan; Peng, Yen-Ling; Chen, Tseng-Shing; Huo, Teh-Ia; Hou, Ming-Chih; Huang, Hui-Chun; Lin, Han-Chieh; Lee, Fa-Yauh

    2016-09-01

    Although clopidogrel does not cause gastric mucosal injury, it does not prevent peptic ulcer recurrence in high-risk patients. We explored whether clopidogrel delays gastric ulcer healing via inhibiting angiogenesis and to elucidate the possible mechanisms. Gastric ulcers were induced in Sprague Dawley rats, and ulcer healing and angiogenesis of ulcer margin were compared between clopidogrel-treated rats and controls. The expressions of the proangiogenic growth factors and their receptors including basic fibroblast growth factor (bFGF), bFGF receptor (FGFR), vascular endothelial growth factor (VEGF), VEGFR1, VEGFR2, platelet-derived growth factor (PDGF)A, PDGFB, PDGFR A, PDGFR B, and phosphorylated form of mitogenic activated protein kinase pathways over the ulcer margin were compared via western blot and reverse transcription polymerase chain reaction. In vitro, human umbilical vein endothelial cells (HUVECs) were used to elucidate how clopidogrel inhibited growth factors-stimulated HUVEC proliferation. The ulcer sizes were significantly larger and the angiogenesis of ulcer margin was significantly diminished in the clopidogrel (2 and 10 mg/kg/d) treated groups. Ulcer induction markedly increased the expression of phosphorylated form of extracellular signal-regulated kinase (pERK), FGFR2, VEGF, VEGFR2, and PDGFRA when compared with those of normal mucosa. Clopidogrel treatment significantly decreased pERK, FGFR2, VEGF, VEGFR2, and PDGFRA expression at the ulcer margin when compared with those of the respective control group. In vitro, clopidogrel (10(-6)M) inhibited VEGF-stimulated (20 ng/mL) HUVEC proliferation, at least, via downregulation of VEGFR2 and pERK. Clopidogrel inhibits the angiogenesis of gastric ulcer healing at least partially by the inhibition of the VEGF-VEGFR2-ERK signal transduction pathway. Copyright © 2015. Published by Elsevier B.V.

  20. Divergent effects of insulin-like growth factor-1 receptor expression on prognosis of estrogen receptor positive versus triple negative invasive ductal breast carcinoma

    NARCIS (Netherlands)

    Hartog, H.; Horlings, H.M.; Vegt, B. van der; Kreike, B.; Ajouaou, A.; Vijver, M.J. van de; Marike Boezen, H.; Bock, G.H. de; Graaf, W.T. van der; Wesseling, J.

    2011-01-01

    The insulin-like growth factor type 1 receptor (IGF1R) is involved in progression of breast cancer and resistance to systemic treatment. Targeting IGF1R signaling may, therefore, be beneficial in systemic treatment. We report the effect of IGF1R expression on prognosis in invasive ductal breast carc

  1. Oligomerization of epidermal growth factor receptors (EGFR) on A431 cells studied by time-resolved fluorescence imaging microscopy: a stereochemical model for tyrosine kinase receptor activation

    NARCIS (Netherlands)

    Gadella, Th.W.J.; Jovin, T.M.

    1995-01-01

    The aggregation states of the epidermal growth factor receptor (EGFR) on single A431 human epidermoid carcinoma cells were assessed with two new techniques for determining fluorescence resonance en- ergy transfer: donor photobleaching fluorescence reso- nance energy transfer (pbFRET) microscopy and

  2. Divergent effects of insulin-like growth factor-1 receptor expression on prognosis of estrogen receptor positive versus triple negative invasive ductal breast carcinoma

    NARCIS (Netherlands)

    Hartog, Hermien; Horlings, Hugo M; van der Vegt, Bert; Kreike, Bas; Ajouaou, Abderrahim; van de Vijver, Marc J; Boezen, Hendrika; de Bock, Geertruida H; van der Graaf, Wilhelmina; Wesseling, Jelle

    2011-01-01

    The insulin-like growth factor type 1 receptor (IGF1R) is involved in progression of breast cancer and resistance to systemic treatment. Targeting IGF1R signaling may, therefore, be beneficial in systemic treatment. We report the effect of IGF1R expression on prognosis in invasive ductal breast carc

  3. Oligomerization of epidermal growth factor receptors (EGFR) on A431 cells studied by time-resolved fluorescence imaging microscopy: a stereochemical model for tyrosine kinase receptor activation

    NARCIS (Netherlands)

    Th.W.J. Gadella; T.M. Jovin

    1995-01-01

    The aggregation states of the epidermal growth factor receptor (EGFR) on single A431 human epidermoid carcinoma cells were assessed with two new techniques for determining fluorescence resonance en- ergy transfer: donor photobleaching fluorescence reso- nance energy transfer (pbFRET) microscopy and

  4. EXPRESSION AND SIGNIFICANCE OF BASIC FIBROBLAST GWOWTH FACTOR AND FIBROBLAST GROWTH FACTOR RECEPTOR-1 IN OVARIAN EPITHELIAL NEOPLASM

    Institute of Scientific and Technical Information of China (English)

    高尚风; 杨蓉; 高博; 刘惠喜

    2003-01-01

    fibroblast growth factor (bFGF), fibroblast growth factor receptor-1 (FGFR-1) and carcinogenesis and progression of ovarian epithelial neoplasm. Methods Ten cases of normal ovarian tissues and 75 cases of ovarian epithelial neoplasm tissues were detected by immunohistochemical methods: S-P for bFGF, FGFR-1,double immunohistochemistry Lab-SA for Ki-67 antigen and bFGF. Results The expression level of bFGF, FGFR-1in ovarian epithelium and ovarian epithelial neoplasm showed a step-wise increase in the following order:normal〈benign〈borderline〈malignant; The expression level and intensity of bFGF and FGFR-1 were increased with the decrease of differentiation degree and increase of clinical stage in ovarian carcinoma; There was no statistical difference between the expression of bFGF, FGFR-1 in serous cystadenocarcinoma and that of mucinous cystadenocarcinoma; The expression of bFGF was correlated with that of FGFR-1 in neoplastic tissues; There were positive expression rates of bFGF and Ki-67 antigen in ovarian epithelial neoplasm. Conclusion As an important proliferative factor, bFGF plays an important role in carcinogenisis and progression of ovarian epithelial neoplasm.

  5. [Functional analysis of transforming growth factor-beta type II dominant negative receptor].

    Science.gov (United States)

    Takarada, M

    1996-06-01

    The transforming growth factor-beta (TGF-beta) is a multifunctional homodimeric protein with an apparent molecular weight of 25 KDa. TGF-beta transduces signals by forming heteromeric complexes of their type-I (T beta R-I) and type-II (T beta R-II) serin/threonine kinase receptors. TGF-beta binds first to T beta R-II receptor, and then the ligand in this complex is recognized by T beta R-I, resulting in formation of a heteromeric receptor complex composed of T beta R-I and T beta R-II. Once received, T beta R-I becomes phosphorylated in the GS domain by the associated constitutively active T beta R-II and transmits the downstream signal. It has been reported that formation of the heteromeric complex is indispensible at least in epithelial cells for growth inhibition and extracellular matrix production induced by TGF-beta. In this study, the functional role of T beta R-II for the TGF-beta-induced signals in osteoblastic cells was investigated by using a dominant negative type of T beta R-II mutant receptors (T beta RIIDNR). ROS 17/2.8 and MG 63 cells were found to express T beta R-I, T beta R-II, and T beta R-III, and their cell growth was inhibited by TGF-beta, whereas alkaline phosphatase activity was stimulated. Cells that were stably transfected with the T beta RIIDNR plasmid showed decreased response to TGF-beta during growth and alkaline phosphatase activity. These results indicate that the intracellular serine/threonine kinase domain of T beta R-II is essential for signal transduction of the TGF-beta-induced alkaline phosphatase activity as well as growth inhibition.

  6. Expression of osteoprotegerin, receptor activator of nuclear factor kappa-B ligand, tumor necrosis factor-related apoptosis-inducing ligand, stromal cell-derived factor-1 and their receptors in epithelial metastatic breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Labovsky Vivian

    2012-06-01

    Full Text Available Abstract Background While breast cancer (BC is the major cause of death among women worldwide, there is no guarantee of better patient survival because many of these patients develop primarily metastases, despite efforts to detect it in its early stages. Bone metastasis is a common complication that occurs in 65-80 % of patients with disseminated disease, but the molecular basis underlying dormancy, dissemination and establishment of metastasis is not understood. Our objective has been to evaluate simultaneously osteoprotegerin (OPG, receptor activator of nuclear factor kappa B ligand (RANKL, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL, stromal cell-derived factor-1 (SDF-1, and their receptors (R in 2 human BC cell lines, MDA-MB-231 and MCF-7. Methods OPG, RANKL, TRAIL and SDF-1 expression and release, in addition to the expression of their receptors has been investigated using immunofluorescence, immunocytochemistry and ELISA analyses. Results MCF-7 cells released higher levels of OPG in conditioned media (CM than MDA-MB-231 cells; 100 % of both types of cell expressed OPG, RANKL, TRAIL and SDF-1. Moreover, 100 % in both lines expressed membrane RANKL and RANK, whereas only 50 % expressed CXCR4. Furthermore, 100 % expressed TRAIL-R1 and R4, 30-50 % TRAIL-R2, and 40-55 % TRAIL-R3. Conclusions MCF-7 and MDA-MB-231 cells not only released OPG, but expressed RANKL, TRAIL and SDF-1. The majority of the cells also expressed RANK, CXCR4 and TRAIL-R. Since these ligands and their receptors are implicated in the regulation of proliferation, survival, migration and future bone metastasis during breast tumor progression, assessment of these molecules in tumor biopsies of BC patients could be useful in identifying patients with more aggressive tumors that are also at risk of bone metastasis, which may thus improve the available options for therapeutic intervention.

  7. Current evidence on whether perinatal risk factors influence coeliac disease is circumstantial.

    Science.gov (United States)

    Mårild, Karl; Ludvigsson, Jonas F; Størdal, Ketil

    2016-04-01

    Coeliac disease is triggered by an interplay of environmental and genetic factors and is one of the most prevalent autoimmune diseases in children, occurring in about 1% of Europeans. Over the last few decades, there has been a growing interest in the role of the perinatal environment in coeliac disease and this review discusses the growing body of literature on coeliac disease and perinatal risk factors. There is still only circumstantial evidence that the perinatal environment influences coeliac disease development. Large-scale cohort studies and emerging scientific concepts, such as epigenetics, may help us establish the role of these environmental factors. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  8. Toxicity profile of epidermal growth factor receptor tyrosine kinase inhibitors in patients with epidermal growth factor receptor gene mutation-positive lung cancer

    Science.gov (United States)

    Takeda, Masayuki; Nakagawa, Kazuhiko

    2017-01-01

    Recent progress in the research on the molecular biology of lung cancer revealed that the clinical response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is associated with the presence of activating EGFR mutations. Three EGFR-TKIs, namely afatinib, erlotinib and gefitinib, are currently available for the treatment of patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC). Due to the dearth of published phase III trials prospectively evaluating the effects of one EGFR-TKI in comparison with another in such patients, the decision-making regarding which agent to recommend to any given patient lies with the treating physician. Given the potential long-term exposure of such patients to EGFR-TKIs, the toxicological properties of these drugs in such patients may differ from those observed in unselected patients. The aim of the present study was to provide an overview of the key adverse events (rash, diarrhea, hepatotoxicity and interstitial lung disease) reported for EGFR-TKIs in clinical trials including patients with advanced NSCLC. PMID:28123721

  9. The Role of Epidermal Growth Factor Receptor Mutations and Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors in the Treatment of Lung Cancer

    Directory of Open Access Journals (Sweden)

    Shih-Chieh Chang

    2011-06-01

    Full Text Available Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC cases comprise approximately 85% of the lung cancer cases. Before the era of target therapy, platinum-based doublet chemotherapy only led to a median survival of 8–9 months and a one-year survival of 30%–40% in patients with advanced NSCLC. In July 2002, gefitinib, a small-molecule epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI, was approved for the treatment of patients with advanced NSCLC in Japan. After the widespread use of gefitinib in the treatment of NSCLC, there have been many new studies regarding the association between the clinical anticancer efficacy of gefitinib and the somatic EGFR mutation status in patients with NSCLC. This article summarizes the role of EGFR mutations in lung cancer and the use of EGFR antagonists in the treatment of lung cancer and its associated adverse effects.

  10. Journal impact factor versus the evidence level of articles published in plastic surgery journals.

    Science.gov (United States)

    Rodrigues, Maria A; Tedesco, Ana C B; Nahas, Fabio X; Ferreira, Lydia M

    2014-06-01

    The aim of this study was to assess the correlation between impact factor and the level of evidence of articles in plastic surgery journals. The four plastic surgery journals with the top impact factors in 2011 were selected. Articles were selected using the PubMed database between January 1 and December 31, 2011. The journal evidence index was calculated by dividing the number of randomized clinical trials by the total number of articles published in the specific journal, multiplied by 100. This index was correlated to the impact factor of the journal and compared with the average of the other journals. Two investigators independently evaluated each journal, followed by a consensus and assessment of the interexaminer concordance. The kappa test was used to evaluate the concordance between the two investigators and Fisher's exact test was used to evaluate which journal presented the highest number of randomized clinical trials. The journal evidence index values were as follows: Plastic and Reconstructive Surgery, 1.70; Journal of Plastic, Reconstructive and Aesthetic Surgery, 0.40; Aesthetic Plastic Surgery, 0.56; and Annals of Plastic Surgery, 0.35. The impact factors of these journals in 2011 were as follows: Plastic and Reconstructive Surgery, 3.382; Journal of Plastic, Reconstructive and Aesthetic Surgery, 1.494; Aesthetic Plastic Surgery, 1.407; and Annals of Plastic Surgery, 1.318. After consensus, the quantity of adequate studies was low and similar between these journals; only the journal Plastic and Reconstructive Surgery showed a higher journal evidence index. The journal Plastic and Reconstructive Surgery exhibited the highest journal evidence index and had the highest impact factor. The number of adequate articles was low in all of the assessed journals.

  11. Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng\\/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5\\'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

  12. A novel unidirectional cross-talk from the insulin-like growth factor-I receptor to leptin receptor in human breast cancer cells.

    Science.gov (United States)

    Ozbay, Tuba; Nahta, Rita

    2008-06-01

    Obesity is a major risk factor for the development and progression of breast cancer. Increased circulating levels of the obesity-associated hormones leptin and insulin-like growth factor-I (IGF-I) and overexpression of the leptin receptor (Ob-R) and IGF-I receptor (IGF-IR) have been detected in a majority of breast cancer cases and during obesity. Due to correlations between increased leptin, Ob-R, IGF-I, and IGF-IR in breast cancer, we hypothesized that molecular interactions may exist between these two signaling pathways. Coimmunoprecipitation and immunoblotting showed that IGF-IR and Ob-R interact in the breast cancer cell lines MDA-MB-231, MCF7, BT474, and SKBR3. Stimulation of cells with IGF-I promoted Ob-R phosphorylation, which was blocked by IGF-IR kinase inhibition. In addition, IGF-I activated downstream signaling molecules in the leptin receptor and IGF-IR pathways. In contrast to IGF-I, leptin did not induce phosphorylation of IGF-IR, indicating that receptor cross-signaling is unidirectional, occurring from IGF-IR to Ob-R. Our results show, for the first time, a novel interaction and cross-talk between the IGF-I and leptin receptors in human breast cancer cells.

  13. Evidence for an A2/Ra adenosine receptor in the guinea-pig trachea

    Science.gov (United States)

    Brown, C.M.; Collis, M.G.

    1982-01-01

    1 An attempt was made to determine whether the extracellular adenosine receptor that mediates relaxation in the guinea-pig trachea is of the A1/Ri or A2/Ra subtype. 2 Dose-response curves to adenosine and a number of 5′- and N6-substituted analogues were constructed for the isolated guinea-pig trachea, contracted with carbachol. 3 The 5′-substituted analogues of adenosine were the most potent compounds tested, the order of potency being 5′-N-cyclopropylcarboxamide adenosine (NCPCA) > 5′-N-ethylcarboxamide adenosine (NECA) > 2-chloroadenosine > L-N6-phenylisopropyladenosine (L-PIA) > adenosine > D-N6-phenylisopropyladenosine (D-PIA). 4 The difference in potency between the stereoisomers D- and L-PIA on the isolated trachea was at the most five fold. 5 Responses to low doses of adenosine and its analogues were attenuated after treatment with either theophylline or 8-phenyltheophylline. The responses to 2-chloroadenosine were affected to a lesser extent than were those to the other purines. 6 Adenosine transport inhibitors, dipyridamole and dilazep, potentiated responses to adenosine, did not affect those to NCPCA, NECA, L-PIA and D-PIA but significantly reduced the responses to high doses of 2-chloroadenosine. 7 Relaxations evoked by 9-β-D-xylofuranosyladenosine which can activate intracellular but not extracellular adenosine receptors, were attenuated by dipyridamole but unaffected by 8-phenyltheophylline. 8 The results support the existence of an extracellular A2/Ra subtype of adenosine receptor and an intracellular purine-sensitive site, both of which mediate relaxation. PMID:6286021

  14. Evidence of balanced diversity at the chicken interleukin 4 receptor alpha chain locus

    Directory of Open Access Journals (Sweden)

    Podisi Baitsi

    2009-06-01

    Full Text Available Abstract Background The comparative analysis of genome sequences emerging for several avian species with the fully sequenced chicken genome enables the genome-wide investigation of selective processes in functionally important chicken genes. In particular, because of pathogenic challenges it is expected that genes involved in the chicken immune system are subject to particularly strong adaptive pressure. Signatures of selection detected by inter-species comparison may then be investigated at the population level in global chicken populations to highlight potentially relevant functional polymorphisms. Results Comparative evolutionary analysis of chicken (Gallus gallus and zebra finch (Taeniopygia guttata genes identified interleukin 4 receptor alpha-chain (IL-4Rα, a key cytokine receptor as a candidate with a significant excess of substitutions at nonsynonymous sites, suggestive of adaptive evolution. Resequencing and detailed population genetic analysis of this gene in diverse village chickens from Asia and Africa, commercial broilers, and in outgroup species red jungle fowl (JF, grey JF, Ceylon JF, green JF, grey francolin and bamboo partridge, suggested elevated and balanced diversity across all populations at this gene, acting to preserve different high-frequency alleles at two nonsynonymous sites. Conclusion Haplotype networks indicate that red JF is the primary contributor of diversity at chicken IL-4Rα: the signature of variation observed here may be due to the effects of domestication, admixture and introgression, which produce high diversity. However, this gene is a key cytokine-binding receptor in the immune system, so balancing selection related to the host response to pathogens cannot be excluded.

  15. Comparison the relationship between the levels of insulin resistance, hs-CRP, percentage of body fat and serum osteoprotegerin/receptor activator of nuclear factor κβ ligand in prediabetic patients.

    Science.gov (United States)

    Bilgir, Oktay; Yavuz, Mehmet; Bilgir, Ferda; Akan, Ozden Y; Bayindir, Aslı G; Calan, Mehmet; Bozkaya, Giray; Yuksel, Arif

    2017-01-31

    BACKGROUND Receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPN) are soluble members of the tumor necrosis factor superfamily. Growing evidence suggest that there is link between inflammation, insulin resistance and OPG, sRANKL. We aimed to ascertain whether OPG and sRANKL levels are altered in prediabetic subjects and there is association between OPG, sRANKL and metabolic parameters.

  16. Neurophysiological evidence for the presence of cannabinoid CB1 receptors in the laterodorsal tegmental nucleus

    DEFF Research Database (Denmark)

    Soni, Neeraj; Satpathy, Shankha; Kohlmeier, Kristi Anne

    2014-01-01

    Marijuana, which acts within the endocannabinoid (eCB) system as an agonist of the cannabinoid type 1 receptor (CB1R), exhibits addictive properties and has powerful actions on the state of arousal of an organism. The laterodorsal tegmental nucleus (LDT), as a component of the reticular activating...... the firing frequency and synaptic activity of neurons in this nucleus. Therefore, endogenous eCB transmission could play a role in processes involving the LDT, such as cortical activation and motivated behaviours and, further, behavioural actions of marijuana are probably mediated, in part, via cellular...

  17. Epidemiological evidence for the role of the haemoglobin receptor, HmbR, in meningococcal virulence

    OpenAIRE

    Harrison, Odile B.; Evans, Nicholas J.; Blair, Jessica M.; Grimes, Holly S.; Tinsley, Colin R.; Nassif, Xavier; Kriz, Paula; Ure, Roisin; Gray, Steve J.; Derrick, Jeremy P.; Maiden, Martin C.J.; Feavers, Ian M.

    2009-01-01

    The distribution of the haemoglobin receptor gene (hmbR) was investigated in disease and carried Neisseria meningitidis isolates revealing that the gene occurred at a significantly higher frequency in disease isolates compared to those obtained from carriage. Where hmbR was absent, the locus was occupied by the cassettes exl2 or exl3, or with a “pseudo hmbR” gene designated exl4. The hmbR locus in published N. meningitidis genomes, as well as N. gonorrhoeae and N. lactamica ST-640, exhibited ...

  18. Epidemiological evidence for the role of the haemoglobin receptor, HmbR, in meningococcal virulence

    Science.gov (United States)

    Harrison, Odile B.; Evans, Nicholas J.; Blair, Jessica M.; Grimes, Holly S.; Tinsley, Colin R.; Nassif, Xavier; Kriz, Paula; Ure, Roisin; Gray, Steve J.; Derrick, Jeremy P.; Maiden, Martin C.J.; Feavers, Ian M.

    2009-01-01

    The distribution of the haemoglobin receptor gene (hmbR) was investigated in disease and carried Neisseria meningitidis isolates revealing that the gene occurred at a significantly higher frequency in disease isolates compared to those obtained from carriage. Where hmbR was absent, the locus was occupied by the cassettes exl2 or exl3, or with a “pseudo hmbR” gene designated exl4. The hmbR locus in published N. meningitidis genomes, as well as N. gonorrhoeae and N. lactamica ST-640, exhibited characteristics of a pathogenicity island. These data are consistent with a role for the hmbR gene in meningococcal disease. PMID:19476432

  19. Soluble tumour necrosis factor receptor release after anti-CD3 monoclonal antibody treatment in mice is independent of tumour necrosis factor-alpha release.

    NARCIS (Netherlands)

    Vossen, A.C.T.M.; Tibbe, G.J.M.; Buurman, W.A.; Benner, R.; Savelkoul, H.F.J.

    1996-01-01

    Soluble tumour necrosis factor receptor release after anti-CD3 monoclonal antibody treatment in mice is independent of tumour necrosis factor-alpha release. Vossen AC, Tibbe GJ, Buurman WA, Benner R, Savelkoul HF. Department of Immunology, Erasmus University, Rotterdam, The Netherlands. The involvem

  20. Flow cytometric detection of growth factor receptors in autografts and analysis of growth factor concentrations in autologous stem cell transplantation: possible significance for platelet recovery

    DEFF Research Database (Denmark)

    Schiødt, I; Jensen, Charlotte Harken; Kjaersgaard, E

    2000-01-01

    In order to improve prediction of hematopoietic recovery, we conducted a pilot study, analyzing the significance of growth factor receptor expression in autografts as well as endogenous growth factor levels in blood before, during and after stem cell transplantation. Three early acting (stem cell...

  1. Grape seed extract inhibits angiogenesis via suppression of the vascular endothelial growth factor receptor signaling pathway.

    Science.gov (United States)

    Wen, Wei; Lu, Jianming; Zhang, Keqiang; Chen, Shiuan

    2008-12-01

    Blockade of angiogenesis is an important approach for cancer treatment and prevention. Vascular endothelial growth factor (VEGF) is one of the most critical factors that induce angiogenesis and has thus become an attractive target for antiangiogenesis treatment. However, most current anti-VEGF agents often cause some side effects when given chronically. Identification of naturally occurring VEGF inhibitors derived from diet would be one alternative approach with an advantage of known safety. Grape seed extract (GSE), a widely used dietary supplement, is known to have antitumor activity. In this study, we have explored the activity of GSE on VEGF receptor and angiogenesis. We found that GSE could directly inhibit the kinase activity of purified VEGF receptor 2, a novel activity of GSE that has not been characterized. GSE could also inhibit the VEGF receptor/mitogen-activated protein kinase-mediated signaling pathway in endothelial cells. As a result, GSE could inhibit VEGF-induced endothelial cell proliferation and migration as well as sprout formation from aorta ring. In vivo assay further showed that GSE could inhibit tumor growth and tumor angiogenesis of MDA-MB-231 breast cancer cells in mice. Consistent with the in vitro data, GSE treatment of tumor-bearing mice led to concomitant reduction of blood vessel density and phosphorylation of mitogen-activated protein kinase. Depletion of polyphenol with polyvinylpyrrolidone abolished the antiangiogenic activity of GSE, suggesting a water-soluble fraction of polyphenol in GSE is responsible for the antiangiogenic activity. Taken together, this study indicates that GSE is a well-tolerated and inexpensive natural VEGF inhibitor and could potentially be useful in cancer prevention or treatment.

  2. Neural cell adhesion molecule differentially interacts with isoforms of the fibroblast growth factor receptor.

    Science.gov (United States)

    Christensen, Claus; Berezin, Vladimir; Bock, Elisabeth

    2011-10-26

    The fibroblast growth factor receptor (FGFR) can be activated through direct interactions with various fibroblast growth factors or through a number of cell adhesion molecules, including the neural cell adhesion molecule (NCAM). We produced recombinant proteins comprising the ligand-binding immunoglobulin-like modules 2 and 3 of FGFR1b, FGFR1c, FGFR2b, FGFR2c, FGFR3b, FGFR3c, and FGFR4, and found that all FGFR isoforms, except for FGFR4, interacted with NCAM. The binding affinity of NCAM-FGFR interactions was considerably higher for splice variant 'b' than for splice variant 'c'. We suggest that the expression pattern of various FGFR isoforms determines the cell context-specific effects of NCAM signaling through FGFR.

  3. The epidermal growth factor receptor is a regulator of epidermal complement component expression and complement activation

    DEFF Research Database (Denmark)

    Abu-Humaidan, Anas H A; Ananthoju, Nageshwar; Mohanty, Tirthankar;

    2014-01-01

    The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin...... wounds in vivo and in cultured keratinocytes after exposure to supernatant from stimulated mononuclear cells. In contrast, the epidermal expression of complement components was downregulated in ex vivo injured skin lacking the stimulation from infiltrating inflammatory cells but with intact injury......-induced epidermal growth factor receptor (EGFR)-mediated growth factor response. In cultured primary keratinocytes, stimulation with the potent EGFR ligand, TGF-α, yielded a significant downregulation of complement component expression. Indeed, EGFR inhibition significantly enhanced the induction of complement...

  4. Epidermal Growth Factor Receptor Inhibitors: A Review of Cutaneous Adverse Events and Management

    Directory of Open Access Journals (Sweden)

    K. Chanprapaph

    2014-01-01

    Full Text Available Epidermal growth factor inhibitors (EGFRI, the first targeted cancer therapy, are currently an essential treatment for many advance-stage epithelial cancers. These agents have the superior ability to target cancers cells and better safety profile compared to conventional chemotherapies. However, cutaneous adverse events are common due to the interference of epidermal growth factor receptor (EGFR signaling in the skin. Cutaneous toxicities lead to poor compliance, drug cessation, and psychosocial discomfort. This paper summarizes the current knowledge concerning the presentation and management of skin toxicity from EGFRI. The common dermatologic adverse events are papulopustules and xerosis. Less common findings are paronychia, regulatory abnormalities of hair growth, maculopapular rash, mucositis, and postinflammatory hyperpigmentation. Radiation enhances EGFRI rash due to synergistic toxicity. There is a positive correlation between the occurrence and severity of cutaneous adverse effects and tumor response. To date, prophylactic systemic tetracycline and tetracycline class antibiotics have proven to be the most effective treatment regime.

  5. Reproductive factors and hormone receptor status among very young (<35 years) breast cancer patients.

    Science.gov (United States)

    Jia, Xiaoqing; Liu, Guangyu; Mo, Miao; Cheng, Jingyi; Shen, Zhenzhou; Shao, Zhimin

    2015-09-15

    The prognosis for breast cancer occurs in young women is usually poor. The impact of different reproductive factors on disease characteristics is still largely unknown. We analyzed 261 patients aged ≤35 years old who were treated at the Cancer Hospital of Fudan University, Shanghai, China. The relationships between certain reproductive factors (age at menarche, parity, number of children, breastfeeding, history of abortion, age at first full-term pregnancy and oral contraceptive (OC) use) and disease characteristics were evaluated. Compared with patients who experienced fewer full-term pregnancies (menarche was ≥15 years exhibited a greater chance of PR-positive tumors (64.8%) (P = 0.036) compared with those whose age of menarche was menarche are more possible to exhibit hormone receptor-positive tumors. Additionally, patients who have taken OCs are more likely to present with advanced disease.

  6. Sex, Receptors and Attachment: A Review of Individual Factors Influencing Response to Oxytocin

    Directory of Open Access Journals (Sweden)

    Kai S Macdonald

    2013-01-01

    Full Text Available As discussed in the larger review in this special issue (MacDonald and Feifel, intranasal oxytocin (IN OT is demonstrating a growing potential as a therapeutic agent in psychiatry. Importantly, research suggests that a variety of individual factors may influence a person’s response to OT. In this mini-review, I provides a review of three: (1 sex and hormonal status; (2 genetic variation in aspects of the OT system (i.e. OT receptors; and (3 attachment history. Each of these factors will be important to monitor as we strive to develop a richer understanding of OT's role in human development, brain-based disease, and the potential for individualized, OT-targeted treatments.

  7. Expression of oestrogen receptors, ERα, ERβ, and ERβ variants, in endometrial cancers and evidence that prostaglandin F may play a role in regulating expression of ERα

    Directory of Open Access Journals (Sweden)

    Jabbour Henry N

    2009-09-01

    Full Text Available Abstract Background Endometrial cancer is the most common gynaecological malignancy; risk factors include exposure to oestrogens and high body mass index. Expression of enzymes involved in biosynthesis of oestrogens and prostaglandins (PG is often higher in endometrial cancers when compared with levels detected in normal endometrium. Oestrogens bind one of two receptors (ERα and ERβ encoded by separate genes. The full-length receptors function as ligand-activated transcription factors; splice variant isoforms of ERβ lacking a ligand-binding domain have also been described. PGs act in an autocrine or paracrine manner by binding to specific G-protein coupled receptors. Methods We compared expression of ERs, progesterone receptor (PR and cyclooxygenase-2 (COX-2 in stage 1 endometrial adenocarcinomas graded as well (G1, moderately (G2 or poorly (G3 differentiated (n ≥ 10 each group using qRTPCR, single and double immunohistochemistry. We used endometrial adenocarcinoma cell lines to investigate the impact of PGF2α on expression of ERs and PR. Results Full length ERβ (ERβ1 and two ERβ variants (ERβ2, ERβ5 were expressed in endometrial cancers regardless of grade and the proteins were immunolocalised to the nuclei of cells in both epithelial and stromal compartments. Immunoexpression of COX-2 was most intense in cells that were ERαneg/low. Expression of PR in endometrial adenocarcinoma (Ishikawa cell lines and tissues broadly paralleled that of ERα. Treatment of adenocarcinoma cells with PGF2α reduced expression of ERα but had no impact on ERβ1. Cells incubated with PGF2α were unable to increase expression of PR mRNA when they were incubated with E2. Conclusion We have demonstrated that ERβ5 protein is expressed in stage 1 endometrial adenocarcinomas. Expression of three ERβ variants, including the full-length protein is not grade-dependent and most cells in poorly differentiated cancers are ERβpos/ERαneg. We found evidence of a

  8. Correlation between Grade in Transitional Cell Carcinoma (TCC and Expression of Epidermal Growth Factor Receptor (EGFR

    Directory of Open Access Journals (Sweden)

    MR Jallali Nadoushan

    2007-08-01

    Full Text Available Background: The present study was undertaken to investigate the correlation of Epidermal Growth Factor Receptor (EGFR expression with grade of Transitional Cell Carcinoma (TCC. Methods: Tumor samples of 75 patients from Mostafa Khomaini Hospital with Transitional Cell Carcinoma of the bladder were analyzed by immunohistochemistry for expression of EGFR. In this context, we assigned the bladder tumors a grade accord¬ing WHO classification. Results analyzed for possible correlation with the expression status of the Epidermal Growth Factor Receptor (EGFR. Results: This cross-sectional study showed that all grades of Transitional Cell Carcinoma expressed EGFR, and 14 cases were LMP (18.9% which 10 cases among them had negative cells according EGFR point of view(71.4% and 4 cases had re¬ported positive (28.6%. Thirty five cases were low grade (46.7% which 18 cases among them had reported negative cells (51.4% and 17 cases had positive cells (48.6%. Twenty six cases were high grade (34.7% that 9 cases among them had reported negative cells (34.6%. Seventeen cases had positive cells (65.4%. Mann-Witney test showed relation between grade and expression of EGFR (P<0.05. Conclusions: This study showed that expression of EGFR is correlated with grade of tumor.

  9. Production of neutralizing monoclonal antibody against human vascular endothelial growth factor receptor

    Institute of Scientific and Technical Information of China (English)

    Rong LI; Dong-sheng XIONG; Xiao-feng SHAO; Jia LIU; Yuan-fu XU; Yuan-sheng XU; Han-zhi LIU; Zhen-ping ZHU; Chun-zheng YANG

    2004-01-01

    AIM: To prepare neutralizing monoclonal antibody (mAb) against extracellular immunoglobulin (Ig)-like domainⅢ of vascular endothelial growth factor receptor KDR and study its biological activity. METHODS: Soluble KDR Ig domain Ⅲ (KDR-Ⅲ) fusion protein was expressed in E Coli and purified from the bacterial periplasmic extracts via an affinity chromatography. Monoclonal antibodies against KDR-Ⅲ were prepared by hybridoma technique. ELISA and FACS analysis were used to identify its specificity. Immunoprecipitation and [3H]-thymidine incorporation assay were also used to detect the activity of anti-KDR mAb blocking the phosphorylation of KDR tyrosine kinase receptor and the influence on vascular endothelial growth factor-induced mitogenesis of human endothelial ceils.RESULTS: A monoclonal antibody, Ycom1D3 (IgG1), was generated from a mouse immunized with the recombinant KDR-Ⅲ protein. Ycom1D3 bound specifically to both the soluble KDR-Ⅲ and the cell-surface expressed KDR. Ycom1D3 effectively blocked VEGF/KDR interaction and inhibited VEGF-stimulated KDR activation in human endothelial cells. Furthermore, the antibody efficiently neutralized VEGF-induced mitogenesis of human endothelial cells. CONCLUSION: Our results suggest that the anti-KDR mAb, Ycom1D3, has potential applications in the treatment of cancer and other diseases where pathological angiogenesis is involved.

  10. Familial clustering of recurrent pericarditis may disclose tumour necrosis factor receptor-associated periodic syndrome.

    Science.gov (United States)

    Cantarini, Luca; Lucherini, Orso Maria; Baldari, Cosima Tatiana; Laghi Pasini, Franco; Galeazzi, Mauro

    2010-01-01

    Although several causes of recurrent pericarditis have been identified, the etiology remains obscure in most cases. The tumour necrosis factor receptor-1 associated periodic syndrome (TRAPS) is the most common autosomal dominant autoinflammatory disorder and is caused by mutations in the TNFRSF1A gene encoding the 55-kD receptor for tumour necrosis factor-(TNF)-alpha. Serosal membrane inflammation is a common feature of TRAPS, usually in the form of polyserositis. In addition, patients affected with recurrent pericarditis as the only clinical manifestation of TRAPS have been recently described. Our aim was to investigate the possible involvement of mutations in the TNFRSF1A gene in a cohort of patients affected with idiopathic recurrent pericarditis. Twenty consecutive patients diagnosed with idiopathic recurrent pericarditis were enrolled. Each patient underwent detailed examinations in order to rule out underlying diseases such as infections, connective tissue disorders and malignancies, and mutations of the TNFRSF1A gene were searched for by amplifying, using polymerase chain reaction (PCR), genomic DNA, and direct sequencing. TNFRSF1A mutations were found in 2 of the 20 patients. They were siblings, and they both carried a heterozygous low-penetrance R92Q mutation in the TNFRSF1A gene. Familial clustering has been recently reported in up to 10% of patients with recurrent pericarditis, thus suggesting in some cases a possible genetic predisposition. Our study suggests that familial clustering may represent a clue for investigating mutations in the TNFRSF1A gene in these patients and eventually disclose TRAPS.

  11. Toll-like receptor and tumour necrosis factor dependent endotoxin-induced acute lung injury

    Science.gov (United States)

    Togbe, Dieudonnée; Schnyder-Candrian, Silvia; Schnyder, Bruno; Doz, Emilie; Noulin, Nicolas; Janot, Laure; Secher, Thomas; Gasse, Pamela; Lima, Carla; Coelho, Fernando Rodrigues; Vasseur, Virginie; Erard, François; Ryffel, Bernhard; Couillin, Isabelle; Moser, Rene

    2007-01-01

    Recent studies on endotoxin/lipopolysaccharide (LPS)-induced acute inflammatory response in the lung are reviewed. The acute airway inflammatory response to inhaled endotoxin is mediated through Toll-like receptor 4 (TLR4) and CD14 signalling as mice deficient for TLR4 or CD14 are unresponsive to endotoxin. Acute bronchoconstriction, tumour necrosis factor (TNF), interleukin (IL)-12 and keratinocyte-derived chemokine (KC) production, protein leak and neutrophil recruitment in the lung are abrogated in mice deficient for the adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/Interleukin-1 receptor (TIR)-domain-containing adaptor protein (TIRAP), but independent of TIR-domain-containing adaptor-inducing interferon-beta (TRIF). In particular, LPS-induced TNF is required for bronchoconstriction, but dispensable for inflammatory cell recruitment. Lipopolysaccharide induces activation of the p38 mitogen-activated protein kinase (MAPK). Inhibition of pulmonary MAPK activity abrogates LPS-induced TNF production, bronchoconstriction, neutrophil recruitment into the lungs and broncho-alveolar space. In conclusion, TLR4-mediated, bronchoconstriction and acute inflammatory lung pathology to inhaled endotoxin are dependent on TLR4/CD14/MD2 expression using the adapter proteins TIRAP and MyD88, while TRIF, IL-1R1 or IL-18R signalling pathways are dispensable. Further downstream in this axis of signalling, TNF blockade reduces only acute bronchoconstriction, while MAPK inhibition abrogates completely endotoxin-induced inflammation. PMID:18039275

  12. Alternative Splicing of Fibroblast Growth Factor Receptor IgIII Loops in Cancer

    Directory of Open Access Journals (Sweden)

    Klaus Holzmann

    2012-01-01

    Full Text Available Alternative splicing of the IgIII loop of fibroblast growth factor receptors (FGFRs 1–3 produces b- and c-variants of the receptors with distinctly different biological impact based on their distinct ligand-binding spectrum. Tissue-specific expression of these splice variants regulates interactions in embryonic development, tissue maintenance and repair, and cancer. Alterations in FGFR2 splicing are involved in epithelial mesenchymal transition that produces invasive, metastatic features during tumor progression. Recent research has elucidated regulatory factors that determine the splice choice both on the level of exogenous signaling events and on the RNA-protein interaction level. Moreover, methodology has been developed that will enable the in depth analysis of splicing events during tumorigenesis and provide further insight on the role of FGFR 1–3 IIIb and IIIc in the pathophysiology of various malignancies. This paper aims to summarize expression patterns in various tumor types and outlines possibilities for further analysis and application.

  13. Fibroblast growth factor receptor 2 IIIc as a therapeutic target for colorectal cancer cells.

    Science.gov (United States)

    Matsuda, Yoko; Hagio, Masahito; Seya, Tomoko; Ishiwata, Toshiyuki

    2012-09-01

    A high percentage of colorectal carcinomas overexpress a lot of growth factors and their receptors, including fibroblast growth factor (FGF) and FGF receptor (FGFR). We previously reported that FGFR2 overexpression was associated with distant metastasis and that FGFR2 inhibition suppressed cell growth, migration, and invasion. The FGFR2 splicing isoform FGFR2IIIb is associated with well-differentiated histologic type, tumor angiogenesis, and adhesion to extracellular matrices. Another isoform, FGFR2IIIc, correlates with the aggressiveness of various types of cancer. In the present study, we examined the expression and roles of FGFR2IIIc in colorectal carcinoma to determine the effectiveness of FGFR2IIIc-targeting therapy. In normal colorectal tissues, FGFR2IIIc expression was weakly detected in superficial colorectal epithelial cells and was not detected in proliferative zone cells. FGFR2IIIc-positive cells were detected by immunohistochemistry in the following lesions, listed in the order of increasing percentage: hyperplastic polyps growth, soft agar colony formation, migration, and invasion, as well as decreased adhesion to extracellular matrices. Furthermore, FGFR2IIIc-transfected colorectal carcinoma cells formed larger tumors in subcutaneous tissues and the cecum of nude mice. Fully human anti-FGFR2IIIc monoclonal antibody inhibited the growth and migration of colorectal carcinoma cells through alterations in cell migration, cell death, and development-related genes. In conclusion, FGFR2IIIc plays an important role in colorectal carcinogenesis and tumor progression. Monoclonal antibody against FGFR2IIIc has promising potential in colorectal carcinoma therapy.

  14. DC electric stimulation upregulates angiogenic factors in endothelial cells through activation of VEGF receptors.

    Science.gov (United States)

    Bai, Huai; Forrester, John V; Zhao, Min

    2011-07-01

    Small direct current (DC) electric fields direct some important angiogenic responses of vascular endothelial cells. Those responses indicate promising use of electric fields to modulate angiogenesis. We sought to determine the regulation of electric fields on transcription and expression of a serial of import angiogenic factors by endothelial cells themselves. Using semi-quantitative PCR and ELISA we found that electric stimulation upregulates the levels of mRNAs and proteins of a number of angiogenic proteins, most importantly VEGF165, VEGF121 and IL-8 in human endothelial cells. The up-regulation of mRNA levels might be specific, as the mRNA encoding bFGF, TGF-beta and eNOS are not affected by DC electric stimulation at 24h time-point. Inhibition of VEGF receptor (VEGFR1 or VEGFR2) signaling significantly decreased VEGF production and completely abolished IL-8 production. DC electric stimulation selectively regulates production of some growth factors and cytokines important for angiogenesis through a feed-back loop mediated by VEGF receptors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Prophylaxis and treatment of dermatologic adverse events from epidermal growth factor receptor inhibitors.

    Science.gov (United States)

    Wu, Peggy A; Balagula, Yevgeniy; Lacouture, Mario E; Anadkat, Milan J

    2011-07-01

    As the number and uses for targeted therapies such as epidermal growth factor receptor inhibitors (EGFRIs) increase, so does the need to recognize and treat the dermatologic side-effects of these agents. Although agents such as gefitinib, erlotinib, cetuximab, lapatinib, and panitumumab have less systemic side-effects than traditional cytotoxic chemotherapy, dermatologic adverse events from EGFRIs are significantly more common. These dermatologic toxicities have previously led to reduction or cessation of therapy and recently have been shown to decrease patients' quality of life. This review provides a symptom-based treatment approach to the common dermatologic adverse effects seen with the epidermal growth factor receptor antagonists: papulopustular rash, xerosis, pruritus as well as hair, nail, and mucosal changes. Each dermatologic toxicity is described; prophylaxis and treatment options, from topical to systemic, are presented based on a review of the current literature with emphasis on new clinical trials results. We also provide specific recommendations based on our practice in a specialty clinic. Although the field continues to evolve, this review presents the most up-to-date information on managing dermatologic adverse effects of EGFRIs. Practitioners should find this article to be a practical resource in approaching patients on EGFRIs with dermatologic toxicities. As we learn how to optimally manage the adverse effects of these agents, we practitioners have the opportunity to increase patients' quality of life and decrease reductions or cessations of life-prolonging therapy.

  16. PhyloScan: identification of transcription factor binding sites using cross-species evidence

    Directory of Open Access Journals (Sweden)

    Newberg Lee A

    2007-01-01

    Full Text Available Abstract Background When transcription factor binding sites are known for a particular transcription factor, it is possible to construct a motif model that can be used to scan sequences for additional sites. However, few statistically significant sites are revealed when a transcription factor binding site motif model is used to scan a genome-scale database. Methods We have developed a scanning algorithm, PhyloScan, which combines evidence from matching sites found in orthologous data from several related species with evidence from multiple sites within an intergenic region, to better detect regulons. The orthologous sequence data may be multiply aligned, unaligned, or a combination of aligned and unaligned. In aligned data, PhyloScan statistically accounts for the phylogenetic dependence of the species contributing data to the alignment and, in unaligned data, the evidence for sites is combined assuming phylogenetic independence of the species. The statistical significance of the gene predictions is calculated directly, without employing training sets. Results In a test of our methodology on synthetic data modeled on seven Enterobacteriales, four Vibrionales, and three Pasteurellales species, PhyloScan produces better sensitivity and specificity than MONKEY, an advanced scanning approach that also searches a genome for transcription factor binding sites using phylogenetic information. The application of the algorithm to real sequence data from seven Enterobacteriales species identifies novel Crp and PurR transcription factor binding sites, thus providing several new potential sites for these transcription factors. These sites enable targeted experimental validation and thus further delineation of the Crp and PurR regulons in E. coli. Conclusion Better sensitivity and specificity can be achieved through a combination of (1 using mixed alignable and non-alignable sequence data and (2 combining evidence from multiple sites within an intergenic

  17. Vascular endothelial growth factor regulates osteoblast survival – evidence for an autocrine feedback mechanism

    Directory of Open Access Journals (Sweden)

    Street John

    2009-06-01

    Full Text Available Abstract Background Apoptosis of osteoblasts and osteoclasts regulates bone homeostasis. Skeletal injury in humans results in 'angiogenic' responses primarily mediated by vascular endothelial growth factor(VEGF, a protein essential for bone repair in animal models. Osteoblasts release VEGF in response to a number of stimuli and express receptors for VEGF in a differentiation dependent manner. This study investigates the putative role of VEGF in regulating the lifespan of primary human osteoblasts(PHOB in vitro. Methods PHOB were examined for VEGF receptors. Cultures were supplemented with VEGF(0–50 ng/mL, a neutralising antibody to VEGF, mAB VEGF(0.3 ug/mL and Placental Growth Factor (PlGF, an Flt-1 receptor-specific VEGF ligand(0–100 ng/mL to examine their effects on mineralised nodule assay, alkaline phosphatase assay and apoptosis.. The role of the VEGF specific antiapoptotic gene target BCl2 in apoptosis was determined. Results PHOB expressed functional VEGF receptors. VEGF 10 and 25 ng/mL increased nodule formation 2.3- and 3.16-fold and alkaline phosphatase release 2.6 and 4.1-fold respectively while 0.3 ug/mL of mAB VEGF resulted in approx 40% reductions in both. PlGF 50 ng/mL had greater effects on alkaline phosphatase release (103% increase than on nodule formation (57% increase. 10 ng/mL of VEGF inhibited spontaneous and pathological apoptosis by 83.6% and 71% respectively, while PlGF had no significant effect. Pretreatment with mAB VEGF, in the absence of exogenous VEGF resulted in a significant increase in apoptosis (14 vs 3%. VEGF 10 ng/mL increased BCl2 expression 4 fold while mAB VEGF decreased it by over 50%. Conclusion VEGF is a potent regulator of osteoblast life-span in vitro. This autocrine feedback regulates survival of these cells, mediated via a non flt-1 receptor mechanism and expression of BCl2 antiapoptotic gene.

  18. MiR-125a TNF receptor-associated factor 6 to inhibit osteoclastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Li-Juan; Liao, Lan [Department of Endocrinology, Xiangya Hospital of Central South University, 87 Xiangya Road, Changsha, Hunan 410008 (China); Yang, Li [Department of Endocrinology, Hunan Province Geriatric Hospital, Changsha, Hunan 410001 (China); Li, Yu [Department of Endocrinology, Xiangya Hospital of Central South University, 87 Xiangya Road, Changsha, Hunan 410008 (China); Jiang, Tie-Jian, E-mail: jiangtiejian@gmail.com [Department of Endocrinology, Xiangya Hospital of Central South University, 87 Xiangya Road, Changsha, Hunan 410008 (China)

    2014-02-15

    MicroRNAs (miRNAs) play important roles in osteoclastogenesis and bone resorption. In the present study, we found that miR-125a was dramatically down-regulated during macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclastogenesis of circulating CD14+ peripheral blood mononuclear cells (PBMCs). Overexpression of miR-125a in CD14+ PBMCs inhibited osteoclastogenesis, while inhibition of miR-125a promoted osteoclastogenesis. TNF receptor-associated factor 6 (TRAF6), a transduction factor for RANKL/RANK/NFATc1 signal, was confirmed to be a target of miR-125a. EMSA and ChIP assays confirmed that NFATc1 bound to the promoter of the miR-125a. Overexpression of NFATc1 inhibited miR-125a transcription, and block of NFATc1 expression attenuated RANKL-regulated miR-125a transcription. Here, we reported that miR-125a played a biological function in osteoclastogenesis through a novel TRAF6/ NFATc1/miR-125a regulatory feedback loop. It suggests that regulation of miR-125a expression may be a potential strategy for ameliorating metabolic disease. - Highlights: • MiR-125a was significantly down-regulated in osteoclastogenesis of CD14+ PBMCs. • MiR-125a inhibited osteoclast differentiation by targeting TRAF6. • NFATc1 inhibited miR-125a transciption by binding to the promoter of miR-125a. • TRAF6/NFATc1 and miR-125a form a regulatory feedback loop in osteoclastogenesis.

  19. Acute phenobarbital administration induces hyperalgesia: pharmacological evidence for the involvement of supraspinal GABA-A receptors

    Directory of Open Access Journals (Sweden)

    C.M. Yokoro

    2001-03-01

    Full Text Available The aim of the present study was to determine if phenobarbital affects the nociception threshold. Systemic (1-20 mg/kg phenobarbital administration dose dependently induced hyperalgesia in the tail-flick, hot-plate and formalin tests in rats and in the abdominal constriction test in mice. Formalin and abdominal constriction tests were the most sensitive procedures for the detection of hyperalgesia in response to phenobarbital compared with the tail-flick and hot-plate tests. The hyperalgesia induced by systemic phenobarbital was blocked by previous administration of 1 mg/kg ip picrotoxin or either 1-2 mg/kg sc or 10 ng icv bicuculline. Intracerebroventricular phenobarbital administration (5 µg induced hyperalgesia in the tail-flick test. In contrast, intrathecal phenobarbital administration (5 µg induced antinociception and blocked systemic-induced hyperalgesia in this test. We suggest that phenobarbital may mediate hyperalgesia through GABA-A receptors at supraspinal levels and antinociception through the same kind of receptors at spinal levels.

  20. Hyperalgesic effect induced by barbiturates, midazolam and ethanol: pharmacological evidence for GABA-A receptor involvement

    Directory of Open Access Journals (Sweden)

    M.A.K.F. Tatsuo

    1997-02-01

    Full Text Available The involvement of GABA-A receptors in the control of nociception was studied using the tail-flick test in rats. Non-hypnotic doses of the barbiturates phenobarbital (5-50 mg/kg, pentobarbital (17-33 mg/kg, and thiopental (7.5-30 mg/kg, of the benzodiazepine midazolam (10 mg/kg or of ethanol (0.4-1.6 g/kg administered by the systemic route reduced the latency for the tail-flick response, thus inducing a 'hyperalgesic' state in the animals. In contrast, non-convulsant doses of the GABA-A antagonist picrotoxin (0.12-1.0 mg/kg administered systemically induced an increase in the latency for the tail-flick response, therefore characterizing an 'antinociceptive' state. Previous picrotoxin (0.12 mg/kg treatment abolished the hyperalgesic state induced by effective doses of the barbiturates, midazolam or ethanol. Since phenobarbital, midazolam and ethanol reproduced the described hyperalgesic effect of GABA-A-specific agonists (muscimol, THIP, which is specifically antagonized by the GABA-A antagonist picrotoxin, our results suggest that GABA-A receptors are tonically involved in the modulation of nociception in the rat central nervous system

  1. Pavlovian conditioning of morphine-induced alterations of immune status: evidence for opioid receptor involvement.

    Science.gov (United States)

    Coussons-Read, M E; Dykstra, L A; Lysle, D T

    1994-12-01

    Prior work in our laboratory has shown that morphine's immunomodulatory effects can become conditioned to environmental stimuli that predict drug administration. These immune alterations include conditioned changes in natural killer cell activity, interleukin-2 production, and mitogen-induced lymphocyte proliferation. The present study examined the involvement of opioid receptor activity in the establishment and expression of conditioned morphine-induced alterations of immune status. During the training phase of the experiment, Lewis rats received two conditioning sessions during which a subcutaneous injection of 15 mg/kg morphine sulfate was paired with exposure to a distinctive environment. On the test day, animals were re-exposed to the distinctive environment alone prior to sacrifice. Saline or naltrexone (0.3, 1.0, 3.0 or 10.0 mg/kg) was administered during either the training or the test session. Administration of naltrexone prior to training antagonized the development of all of the conditioned alterations of immune status including changes in the mitogenic responsiveness of splenocytes, suppression of natural killer cel