Hypoxia triggers a proangiogenic pathway involving cancer cell microvesicles and PAR-2–mediated heparin-binding EGF signaling in endothelial cells

PubMed Central

Svensson, Katrin J.; Kucharzewska, Paulina; Christianson, Helena C.; Sköld, Stefan; Löfstedt, Tobias; Johansson, Maria C.; Mörgelin, Matthias; Bengzon, Johan; Ruf, Wolfram; Belting, Mattias

2011-01-01

Highly malignant tumors, such as glioblastomas, are characterized by hypoxia, endothelial cell (EC) hyperplasia, and hypercoagulation. However, how these phenomena of the tumor microenvironment may be linked at the molecular level during tumor development remains ill-defined. Here, we provide evidence that hypoxia up-regulates protease-activated receptor 2 (PAR-2), i.e., a G-protein–coupled receptor of coagulation-dependent signaling, in ECs. Hypoxic induction of PAR-2 was found to elicit an angiogenic EC phenotype and to specifically up-regulate heparin-binding EGF-like growth factor (HB-EGF). Inhibition of HB-EGF by antibody neutralization or heparin treatment efficiently counteracted PAR-2–mediated activation of hypoxic ECs. We show that PAR-2–dependent HB-EGF induction was associated with increased phosphorylation of ERK1/2, and inhibition of ERK1/2 phosphorylation attenuated PAR-2–dependent HB-EGF induction as well as EC activation. Tissue factor (TF), i.e., the major initiator of coagulation-dependent PAR signaling, was substantially induced by hypoxia in several types of cancer cells, including glioblastoma; however, TF was undetectable in ECs even at prolonged hypoxia, which precludes cell-autonomous PAR-2 activation through TF. Interestingly, hypoxic cancer cells were shown to release substantial amounts of TF that was mainly associated with secreted microvesicles with exosome-like characteristics. Vesicles derived from glioblastoma cells were found to trigger TF/VIIa–dependent activation of hypoxic ECs in a paracrine manner. We provide evidence of a hypoxia-induced signaling axis that links coagulation activation in cancer cells to PAR-2–mediated activation of ECs. The identified pathway may constitute an interesting target for the development of additional strategies to treat aggressive brain tumors. PMID:21788507

NHERF-1 regulation of EGF and neurotensin signalling in HT-29 epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruger, Wade A.; Monteith, Gregory R.; Poronnik, Philip, E-mail: philip.poronnik@sydney.edu.au

2013-03-22

Highlights: ► NHERF-1 expression was abundant throughout HT-29 cells consistent with a cancerous phenotype. ► Knockdown of NHERF-1 lead to a significant reduction in cell proliferation. ► EGF and neurotensin-mediated proliferation was inhibited by knockdown of NHERF-1. ► Neurotensin-mediated Ca{sup 2+} response was abolished by knockdown of NHERF-1. -- Abstract: Neurotensin receptors (NT-R) and the epidermal growth factor receptors (EGF-R) are commonly overexpressed in many epithelial origin tumours. In addition to their role as mitogenic mediators through specific cell signalling, recent studies indicate that the activity/expression of scaffold proteins responsible for the assembly and coordination of the signalling complexes maymore » also have central roles in epithelial transformation. In particular, the “epithelial” PSD-95/Dlg/Zo-1 (PDZ) scaffold/adapter protein, Na{sup +}/H{sup +} exchanger regulatory factor isoform one (NHERF-1), has been identified as a potential regulator of cellular transformation. NHERF-1 is a known regulator of EGF-R function and plays numerous roles in G-protein-coupled receptor signalling. Because of the synergistic signalling between these two potent mitogens, we investigated a potential role for NHERF-1 in the molecular mechanism linking the aberrant proliferative phenotype initiated by some G-Protein-coupled receptor activators in the colon adenocarcinoma HT-29 cell line. Knockdown (80%) of endogenous NHERF-1 leads to significant reduction in proliferation rate; an effect that could not be recovered by exogenous application of either NT or EGF. Inhibition of the EGF-R with AG1487 also inhibited proliferation and this effect could not be recovered with NT. Knockdown of NHERF-1 significantly altered the expression of the EGF-R, and almost completely abolished the NT-mediated increases in intracellular free Ca{sup 2+}. Knockdown of NHERF-1 also attenuated UTP-mediated purinergic Ca{sup 2+} signalling. Taken together

The effects of EGF and IGF-1 on FSH-mediated in vitro maturation of domestic cat oocytes derived from follicular and luteal stages.

PubMed

Yıldırım, Koray; Vural, M Rıfat; Küplülü, Sükrü; Ozcan, Ziya; Polat, I Mert

2014-04-01

The objective of this study was to evaluate the influence of epidermal growth factor (EGF) and insulin like growth factor-I (IGF-1) on the in vitro maturation of cat oocytes recovered from follicular and luteal stage ovaries. Oocytes from follicular (n=580) and luteal (n=209) stages were harvested and divided into four groups, which were cultured in FSH-mediated maturation medium supplemented with: (1) EGF alone (25ng/mL); (2) IGF-1 alone (100ng/mL); (3) EGF+IGF-1 (25ng/mL EGF+100ng/mL IGF-I); or (4) no growth factor (control). The proportion of follicular stage oocytes reaching the metaphase II stage was significantly higher than that of oocytes obtained at the luteal stage in both control and study groups (p<0.001). The percentages of oocytes reaching the metaphase II stage during the follicular period were 62.6% in control; 70.9% in EGF; 72.8% in IGF-1, and 78.1% in EGF+IGF-1 groups, whereas the respective values for gametes collected from luteal stage ovaries were 12.5%, 17.5%, 12.5%, and 16.9%. Additionally, the differences between the study and control groups were significant in the case of follicular stage oocytes. Finally, supplementing the maturation medium with EGF and/or IGF-1 significantly enhanced the meiotic maturation of oocytes recovered from follicular stage ovaries. The present study also demonstrated that the combination of EGF and IGF-I provides an additional or synergic effect on meiotic maturation of oocytes recovered from the follicular stage. Copyright © 2014 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Anti-tumor activity of staurosporine in the tumor microenvironment of cervical cancer: An in vitro study.

PubMed

Yadav, Suresh Singh; Prasad, Chandra Bhushan; Prasad, Shyam Babu; Pandey, Lakshmi Kant; Singh, Sunita; Pradhan, Satyajit; Narayan, Gopeshwar

2015-07-15

The fundamental events for cancer progression and metastases include loss of cell adhesion, cell proliferation, anchorage-independent cell growth (evading anoikis), cell migration and cell invasion. All these events leading to cancer progression happen in a favorable nurturing tumor microenvironment. This study was designed to explore the anti-tumor activity of staurosporine (a nonspecific protein kinase inhibitor) in the tumor microenvironment of cervical cancer. The anti-tumor activity of staurosporine was investigated by cell adhesion assay, colony formation assay, apoptosis assay and quantitative real-time polymerase chain reaction (PCR) in cervical cancer cell lines. The cell adhesion assay showed that staurosporine induces adhesion of cervical cancer cells to the extracellular matrix (ECM) protein fibronectin. The soft agar colony formation assay showed that staurosporine inhibits both the number and size of colony formation in a dose dependent manner and also induces adherent tendency in the cancer cells. Staurosporine also induces prominent apoptosis in single cell suspensions compared to adherent cells. Stroma cell induced transcription of matrix metalloprotease 1 (MMP1) and matrix metalloprotease 2 (MMP2) in cervical cancer cells was inhibited by staurosporine. Our results indicate that staurosporine induces anti-tumor response in the cervical tumor microenvironment by inhibiting the fundamental events for cancer progression and metastases. The present study represents an attractive area for further research and opens up new avenues towards the understanding of cervical cancer therapeutics. Copyright © 2015 Elsevier Inc. All rights reserved.

EGF stimulates the activation of EGF receptors and the selective activation of major signaling pathways during mitosis.

PubMed

Wee, Ping; Shi, Huaiping; Jiang, Jennifer; Wang, Yuluan; Wang, Zhixiang

2015-03-01

Mitosis and epidermal growth factor (EGF) receptor (EGFR) are both targets for cancer therapy. The role of EGFR signaling in mitosis has been rarely studied and poorly understood. The limited studies indicate that the activation of EGFR and downstream signaling pathways is mostly inhibited during mitosis. However, we recently showed that EGFR is phosphorylated in response to EGF stimulation in mitosis. Here we studied EGF-induced EGFR activation and the activation of major signaling pathways downstream of EGFR during mitosis. We showed that EGFR was strongly activated by EGF during mitosis as all the five major tyrosine residues including Y992, Y1045, Y1068, Y1086, and Y1173 were phosphorylated to a level similar to that in the interphase. We further showed that the activated EGFR is able to selectively activate some downstream signaling pathways while avoiding others. Activated EGFR is able to activate PI3K and AKT2, but not AKT1, which may be responsible for the observed effects of EGF against nocodazole-induced cell death. Activated EGFR is also able to activate c-Src, c-Cbl and PLC-γ1 during mitosis. However, activated EGFR is unable to activate ERK1/2 and their downstream substrates RSK and Elk-1. While it activated Ras, EGFR failed to fully activate Raf-1 in mitosis due to the lack of phosphorylation at Y341 and the lack of dephosphorylation at pS259. We conclude that contrary to the dogma, EGFR is activated by EGF during mitosis. Moreover, EGFR-mediated cell signaling is regulated differently from the interphase to specifically serve the needs of the cell in mitosis. Copyright © 2015 Elsevier Inc. All rights reserved.

EGF stimulates Mg{sup 2+} influx in mammary epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trapani, Valentina; Arduini, Daniela; Luongo, Francesca

2014-11-28

Highlights: • EGF stimulation potentiates Mg{sup 2+} influx into epithelial cells. • EGF-induced Mg{sup 2+} influx does not depend on the concomitantly induced Ca{sup 2+} signal. • EGF-induced Ca{sup 2+} signal is dependent on the presence of extracellular Mg{sup 2+}. • New players in EGF-mediated signaling might be exploited as therapeutic targets. - Abstract: Magnesium is well established as a fundamental factor that regulates cell proliferation. However, the molecular mechanisms linking mitogenic signals, extracellular magnesium availability and intracellular effectors are still largely unknown. In the present study we sought to determine whether EGF regulates magnesium homeostasis in normal HC11 mammarymore » epithelial cells. To this end, we measured Mg{sup 2+} and Ca{sup 2+} fluxes by confocal imaging in live cells loaded with specific fluorescent ion indicators (Mag-Fluo-4 and Fluo-4, respectively). EGF stimulation induces a rapid and sustained increase in intracellular Mg{sup 2+}, concomitantly with a rise in intracellular calcium. The increase in intracellular Mg{sup 2+} derives from an influx from the extracellular compartment, and does not depend on Ca{sup 2+}. On the contrary, the increase in intracellular Ca{sup 2+} derives from intracellular stores, and is impaired in the absence of extracellular magnesium. Inhibition of the EGF receptor tyrosine kinase by Tyrphostin AG1478 markedly inhibits EGF-induced Mg{sup 2+} and Ca{sup 2+} signals. These findings demonstrate that not only does Mg{sup 2+} influx represent an important step in the physiological response of epithelial cells to EGF, but unexpectedly the EGF-induced Mg{sup 2+} influx is essential for the Ca{sup 2+} signal to occur.« less

Staurosporines decrease ORMDL proteins and enhance sphingomyelin synthesis resulting in depletion of plasmalemmal phosphatidylserine.

PubMed

Maekawa, Masashi; Lee, Minhyoung; Wei, Kuiru; Ridgway, Neale D; Fairn, Gregory D

2016-11-02

Accumulation of phosphatidylserine in the inner leaflet of the plasma membrane is a hallmark of eukaryotes. Sublethal levels of staurosporine and related compounds deplete phosphatidylserine from the plasma membrane and abrogate K-Ras signaling. Here, we report that low-dose staurosporine and related compounds increase sphingomyelin mass. Mass-spectrometry and metabolic tracer analysis revealed an increase in both the levels and rate of synthesis of sphingomyelin in response to sublethal staurosporine. Mechanistically, it was determined that the abundance of the ORMDL proteins, which negatively regulate serine-palmitoyltransferase, are decreased by low-dose staurosporine. Finally, inhibition of ceramide synthesis, and thus sphingomyelin, prevented the displacement of phosphatidylserine and cholesterol from the inner leaflet of the plasma membrane. The results establish that an optimal level of sphingomyelin is required to maintain the distribution of phosphatidylserine and cholesterol in the plasma membrane and further demonstrate a complex relationship between the trafficking of phosphatidylserine and sphingomyelin.

Lysosome trafficking is necessary for EGF-driven invasion and is regulated by p38 MAPK and Na+/H+ exchangers.

PubMed

Dykes, Samantha S; Steffan, Joshua J; Cardelli, James A

2017-10-04

Tumor invasion through a basement membrane is one of the earliest steps in metastasis, and growth factors, such as Epidermal Growth Factor (EGF) and Hepatocyte Growth Factor (HGF), stimulate this process in a majority of solid tumors. Basement membrane breakdown is one of the hallmarks of invasion; therefore, tumor cells secrete a variety of proteases to aid in this process, including lysosomal proteases. Previous studies demonstrated that peripheral lysosome distribution coincides with the release of lysosomal cathepsins. Immunofluorescence microscopy, western blot, and 2D and 3D cell culture techniques were performed to evaluate the effects of EGF on lysosome trafficking and cell motility and invasion. EGF-mediated lysosome trafficking, protease secretion, and invasion is regulated by the activity of p38 mitogen activated protein kinase (MAPK) and sodium hydrogen exchangers (NHEs). Interestingly, EGF stimulates anterograde lysosome trafficking through a different mechanism than previously reported for HGF, suggesting that there are redundant signaling pathways that control lysosome positioning and trafficking in tumor cells. These data suggest that EGF stimulation induces peripheral (anterograde) lysosome trafficking, which is critical for EGF-mediated invasion and protease release, through the activation of p38 MAPK and NHEs. Taken together, this report demonstrates that anterograde lysosome trafficking is necessary for EGF-mediated tumor invasion and begins to characterize the molecular mechanisms required for EGF-stimulated lysosome trafficking.

Involvement of mitochondrial proteins in calcium signaling and cell death induced by staurosporine in Neurospora crassa.

PubMed

Gonçalves, A Pedro; Cordeiro, J Miguel; Monteiro, João; Lucchi, Chiara; Correia-de-Sá, Paulo; Videira, Arnaldo

2015-10-01

Staurosporine-induced cell death in Neurospora crassa includes a well defined sequence of alterations in cytosolic calcium levels, comprising extracellular Ca(2+) influx and mobilization of Ca(2+) from internal stores. Here, we show that cells undergoing respiratory stress due to the lack of certain components of the mitochondrial complex I (like the 51kDa and 14kDa subunits) or the Ca(2+)-binding alternative NADPH dehydrogenase NDE-1 are hypersensitive to staurosporine and incapable of setting up a proper intracellular Ca(2+) response. Cells expressing mutant forms of NUO51 that mimic human metabolic diseases also presented Ca(2+) signaling deficiencies. Accumulation of reactive oxygen species is increased in cells lacking NDE-1 and seems to be required for Ca(2+) oscillations in response to staurosporine. Measurement of the mitochondrial levels of Ca(2+) further supported the involvement of these organelles in staurosporine-induced Ca(2+) signaling. In summary, our data indicate that staurosporine-induced fungal cell death involves a sophisticated response linking Ca(2+) dynamics and bioenergetics. Copyright © 2015 Elsevier B.V. All rights reserved.

Heparin-binding EGF-like growth factor and enteric neural stem cell transplantation in the prevention of experimental necrotizing enterocolitis in mice.

PubMed

Wei, Jia; Zhou, Yu; Besner, Gail E

2015-07-01

Necrotizing enterocolitis (NEC) is associated with loss of neurons and glial cells in the enteric nervous system (ENS). Our goal was to determine whether enteric neural stem cell (NSC) transplantation, in conjunction with heparin-binding epidermal growth factor-like growth factor (HB-EGF), could protect against experimental NEC. In vitro, HB-EGF on NSC proliferation and migration, and the effects of receptors utilized by HB-EGF to exert these effects, were determined. In vivo, mouse pups were exposed to experimental NEC and treated with NSC alone, HB-EGF alone, NSC+HB-EGF, or HB-EGF overexpressing NSC. NSC engraftment and differentiation into neurons in the ENS, intestinal injury, intestinal permeability, and intestinal motility were determined. HB-EGF promoted NSC proliferation via ErbB-1 receptors and enhanced NSC migration via ErbB-1, ErbB-4, and Nardilysin receptors. HB-EGF significantly enhanced the engraftment of transplanted NSC into the ENS during NEC. NSC transplantation significantly reduced NEC incidence and improved gut barrier function and intestinal motility, and these effects were augmented by simultaneous administration of HB-EGF or by transplantation of HB-EGF overexpressing NSC. HB-EGF promotes NSC proliferation and migration. HB-EGF and NSC reduce intestinal injury and improve gut barrier function and intestinal motility in experimental NEC. Combined HB-EGF and NSC transplantation may represent a potential future therapy to prevent NEC.

HB-EGF embedded in PGA/PLLA scaffolds via subcritical CO2 augments the production of tissue engineered intestine.

PubMed

Liu, Yanchun; Nelson, Tyler; Cromeens, Barrett; Rager, Terrence; Lannutti, John; Johnson, Jed; Besner, Gail E

2016-10-01

The ability to deliver sustained-release, biologically active growth factors through custom designed tissue engineering scaffolds at sites of tissue regeneration offers great therapeutic opportunity. Due to the short in vivo half-lives of most growth factors, it is challenging to deliver these proteins to sites of interest where they may be used before being degraded. The application of subcritical CO2 uses gas-phase CO2 at subcritical pressures ranging from 41 to 62 bar (595-913 PSI) which avoids foaming by reducing the amount of CO2 dissolved in the polymer and maintains completely reversible plasticization. In the current study, heparin-binding EGF-like growth factor (HB-EGF) was embedded into polyglycolic acid (PGA)/Poly-l-latic acid (PLLA) scaffolds via subcritical CO2 exposure for the production of tissue engineered intestine (TEI). PGA fiber morphology after subcritical CO2 exposure was examined by scanning electron microscopy (SEM) and the distribution of HB-EGF embedded in the scaffold fibers was detected by HB-EGF immunofluorescent staining. In vivo implantation of HB-EGF-embedded scaffolds confirmed significantly improved TEI structure as a result of local delivery of the trophic growth factor. These findings may be critical for the production of TEI in the treatment of patients with short bowel syndrome in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magmas Overexpression Inhibits Staurosporine Induced Apoptosis in Rat Pituitary Adenoma Cell Lines

PubMed Central

Gentilin, Erica; Minoia, Mariella; Molè, Daniela; delgi Uberti, Ettore C.; Zatelli, Maria Chiara

2013-01-01

Magmas is a nuclear gene that encodes for the mitochondrial import inner membrane translocase subunit Tim16. Magmas is overexpressed in the majority of human pituitary adenomas and in a mouse ACTH-secreting pituitary adenoma cell line. Here we report that Magmas is highly expressed in two out of four rat pituitary adenoma cell lines and its expression levels inversely correlate to the extent of cellular response to staurosporine in terms of apoptosis activation and cell viability. Magmas over-expression in rat GH/PRL-secreting pituitary adenoma GH4C1 cells leads to an increase in cell viability and to a reduction in staurosporine-induced apoptosis and DNA fragmentation, in parallel with the increase in Magmas protein expression. These results indicate that Magmas plays a pivotal role in response to pro-apoptotic stimuli and confirm and extend the finding that Magmas protects pituitary cells from staurosporine-induced apoptosis, suggesting its possible involvement in pituitary adenoma development. PMID:24069394

MicroRNA-132 targets HB-EGF upon IgE-mediated activation in murine and human mast cells.

PubMed

Molnár, Viktor; Érsek, Barbara; Wiener, Zoltán; Tömböl, Zsófia; Szabó, Péter M; Igaz, Péter; Falus, András

2012-03-01

MicroRNAs provide an additional layer in the regulation of gene expression acting as repressors with several targets at the posttranscriptional level. This study describes microRNA expression patterns during differentiation and activation of mast cells. The expression levels of 567 different mouse miRNAs were compared by microarray between c-Kit+ committed progenitors, mucosal mast cells, resting and IgE-crosslinked BMMCs in vitro. The strongest upregulation of miR-132 upon IgE-mediated activation was validated in human cord blood-derived mast cells as well. HB-EGF growth factor also upregulated upon activation and was ranked high by more prediction algorithms. Co-transfection of miR-132 mimicking precursor and the 3'UTR of human Hbegf-containing luciferase vector proves that the predicted binding site is functional. In line with this, neutralization of miR-132 by anti-miR inhibitor leads to sustained production of HB-EGF protein in activated mast cells. Our data provide a novel example for negative regulation of a growth factor by an upregulated miRNA. © Springer Basel AG 2011

Coordinated Regulation Among Progesterone, Prostaglandins, and EGF-Like Factors in Human Ovulatory Follicles.

PubMed

Choi, Yohan; Wilson, Kalin; Hannon, Patrick R; Rosewell, Katherine L; Brännström, Mats; Akin, James W; Curry, Thomas E; Jo, Misung

2017-06-01

In animal models, the luteinizing hormone surge increases progesterone (P4) and progesterone receptor (PGR), prostaglandins (PTGs), and epidermal growth factor (EGF)-like factors that play essential roles in ovulation. However, little is known about the expression, regulation, and function of these key ovulatory mediators in humans. To determine when and how these key ovulatory mediators are induced after the luteinizing hormone surge in human ovaries. Timed periovulatory follicles were obtained from cycling women. Granulosa/lutein cells were collected from in vitro fertilization patients. The in vivo and in vitro expression of PGR, PTG synthases and transporters, and EGF-like factors were examined at the level of messenger RNA and protein. PGR binding to specific genes was assessed. P4 and PTGs in conditioned media were measured. PGR, PTGS2, and AREG expressions dramatically increased in ovulatory follicles at 12 to 18 hours after human chorionic gonadotropin (hCG). In human granulosa/lutein cell cultures, hCG increased P4 and PTG production and the expression of PGR, specific PTG synthases and transporters, and EGF-like factors, mimicking in vivo expression patterns. Inhibitors for P4/PGR and EGF-signaling pathways reduced hCG-induced increases in PTG production and the expression of EGF-like factors. PGR bound to the PTGS2, PTGES, and SLCO2A1 genes. This report demonstrated the time-dependent induction of PGR, AREG, and PTGS2 in human periovulatory follicles. In vitro studies indicated that collaborative actions of P4/PGR and EGF signaling are required for hCG-induced increases in PTG production and potentiation of EGF signaling in human periovulatory granulosa cells. Copyright © 2017 Endocrine Society

A single cell observation of staurosporine effect on the Ca2+ signals in rat basophilic leukemia cells.

PubMed

Teshima, R; Ikebuchi, H; Terao, T; Miyagawa, T; Arata, Y; Nakanishi, M

1990-09-17

A digital imaging fluorescence microscope was used to study the effect of a protein kinase inhibitor staurosporine on the antigen-dependent calcium signals in an individual rat basophilic leukemia cell (RBL-2H3). Although dose dependency of staurosporine was different from one cell to another, staurosporine inhibited, at low concentration, the calcium influx from the external medium into RBL-2H3 cells. At high concentration, however, it inhibited both the removal of calcium ion from internal stores and the calcium influx from the external medium. These results indicated that staurosporine is necessary for the inhibition of the calcium influx from the external medium and that a protein kinase (possibly protein kinase C) is involved in the calcium influx from the external medium into the cytoplasm.

In brown adipocytes, adrenergically induced β{sub 1}-/β{sub 3}-(G{sub s})-, α{sub 2}-(G{sub i})- and α{sub 1}-(G{sub q})-signalling to Erk1/2 activation is not mediated via EGF receptor transactivation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yanling; Fälting, Johanna M.; Mattsson, Charlotte L.

2013-10-15

Brown adipose tissue is unusual in that the neurotransmitter norepinephrine influences cell destiny in ways generally associated with effects of classical growth factors: regulation of cell proliferation, of apoptosis, and progression of differentiation. The norepinephrine effects are mediated through G-protein-coupled receptors; further mediation of such stimulation to e.g. Erk1/2 activation is in cell biology in general accepted to occur through transactivation of the EGF receptor (by external or internal pathways). We have examined here the significance of such transactivation in brown adipocytes. Stimulation of mature brown adipocytes with cirazoline (α{sub 1}-adrenoceptor coupled via G{sub q}), clonidine (α{sub 2} via G{submore » i}) or CL316243 (β{sub 3} via G{sub s}) or via β{sub 1}-receptors significantly activated Erk1/2. Pretreatment with the EGF receptor kinase inhibitor AG1478 had, remarkably, no significant effect on Erk1/2 activation induced by any of these adrenergic agonists (although it fully abolished EGF-induced Erk1/2 activation), demonstrating absence of EGF receptor-mediated transactivation. Results with brown preadipocytes (cells in more proliferative states) were not qualitatively different. Joint stimulation of all adrenoceptors with norepinephrine did not result in synergism on Erk1/2 activation. AG1478 action on EGF-stimulated Erk1/2 phosphorylation showed a sharp concentration–response relationship (IC{sub 50} 0.3 µM); a minor apparent effect of AG1478 on norepinephrine-stimulated Erk1/2 phosphorylation showed nonspecific kinetics, implying caution in interpretation of partial effects of AG1478 as reported in other systems. Transactivation of the EGF receptor is clearly not a universal prerequisite for coupling of G-protein coupled receptors to Erk1/2 signalling cascades. - Highlights: • In brown adipocytes, norepinephrine regulates proliferation, apoptosis, differentiation. • EGF receptor transactivation is supposed to

Protein-protein interactions between SWCNT/chitosan/EGF and EGF receptor: a model of drug delivery system.

PubMed

Rungnim, Chompoonut; Rungrotmongkol, Thanyada; Kungwan, Nawee; Hannongbua, Supot

2016-09-01

Epidermal growth factor (EGF) was used as the targeting ligand to enhance the specificity of a cancer drug delivery system (DDS) via its specific interaction with the EGF receptor (EGFR) that is overexpressed on the surface of some cancer cells. To investigate the intermolecular interaction and binding affinity between the EGF-conjugated DDS and the EGFR, 50 ns molecular dynamics simulations were performed on the complex of tethered EGFR and EGF linked to single-wall carbon nanotube (SWCNT) through a biopolymer chitosan wrapping the tube outer surface (EGFR·EGF-CS-SWCNT-Drug complex), and compared to the EGFR·EGF complex and free EGFR. The binding pattern of the EGF-CS-SWCNT-Drug complex to the EGFR was broadly comparable to that for EGF, but the binding affinity of the EGF-CS-SWCNT-Drug complex was predicted to be somewhat better than that for EGF alone. Additionally, the chitosan chain could prevent undesired interactions of SWCNT at the binding pocket region. Therefore, EGF connected to SWCNT via a chitosan linker is a seemingly good formulation for developing a smart DDS served as part of an alternative cancer therapy.

Coordinated Regulation Among Progesterone, Prostaglandins, and EGF-Like Factors in Human Ovulatory Follicles

PubMed Central

Choi, Yohan; Wilson, Kalin; Hannon, Patrick R.; Rosewell, Katherine L.; Brännström, Mats; Akin, James W.; Curry, Thomas E.

2017-01-01

Context: In animal models, the luteinizing hormone surge increases progesterone (P4) and progesterone receptor (PGR), prostaglandins (PTGs), and epidermal growth factor (EGF)–like factors that play essential roles in ovulation. However, little is known about the expression, regulation, and function of these key ovulatory mediators in humans. Objective: To determine when and how these key ovulatory mediators are induced after the luteinizing hormone surge in human ovaries. Design and Participants: Timed periovulatory follicles were obtained from cycling women. Granulosa/lutein cells were collected from in vitro fertilization patients. Main Outcome Measures: The in vivo and in vitro expression of PGR, PTG synthases and transporters, and EGF-like factors were examined at the level of messenger RNA and protein. PGR binding to specific genes was assessed. P4 and PTGs in conditioned media were measured. Results: PGR, PTGS2, and AREG expressions dramatically increased in ovulatory follicles at 12 to 18 hours after human chorionic gonadotropin (hCG). In human granulosa/lutein cell cultures, hCG increased P4 and PTG production and the expression of PGR, specific PTG synthases and transporters, and EGF-like factors, mimicking in vivo expression patterns. Inhibitors for P4/PGR and EGF-signaling pathways reduced hCG-induced increases in PTG production and the expression of EGF-like factors. PGR bound to the PTGS2, PTGES, and SLCO2A1 genes. Conclusions: This report demonstrated the time-dependent induction of PGR, AREG, and PTGS2 in human periovulatory follicles. In vitro studies indicated that collaborative actions of P4/PGR and EGF signaling are required for hCG-induced increases in PTG production and potentiation of EGF signaling in human periovulatory granulosa cells. PMID:28323945

GPR30: a seven-transmembrane-spanning estrogen receptor that triggers EGF release.

PubMed

Filardo, Edward J; Thomas, Peter

2005-10-01

Heterotrimeric G proteins and seven-transmembrane-spanning (7TM) receptors are implicated in rapid estrogen signaling. The orphan 7TM receptor GPR30 is linked to estrogen-mediated activation of adenylyl cyclase, release of epidermal growth factor (EGF)-related ligands, and specific estrogen binding. GPR30 acts independently of estrogen receptors, ERalpha and ERbeta, and probably functions as a heptahelical ER. 7TM receptors elicit signals that stimulate second messengers, and convey intracellular signals via EGF receptors. Identification of GPR30 as a Gs-coupled 7TM receptor that triggers release of heparin-binding EGF establishes its role in cell signaling cascades initiated by estrogens, and explains their capacity to activate second messengers and promote EGF-like effects. Thus, estrogen can signal by the same mechanism as various other hormones, through a specific 7TM receptor.

Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hye-Lim; Park, Hyun-Jung; Kwon, Arang

2014-05-01

It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression,more » which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation. - Highlights: • EGF increases the expression level of Smurf1 in mesenchymal precursor cells. • EGF reduces the protein levels and transcriptional activity of Runx2 and Smad1. • EGF suppresses BMP2-induced osteogenic differentiation, which is rescued by Smurf1 knockdown.« less

Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor

PubMed Central

Armant, D. Randall; Kilburn, Brian A.; Petkova, Anelia; Edwin, Samuel S.; Duniec-Dmuchowski, Zophia M.; Edwards, Holly J.; Romero, Roberto; Leach, Richard E.

2006-01-01

Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is downregulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O2 (∼2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O2 upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O2, signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O2 and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O2 rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts. PMID:16407398

Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor.

PubMed

Armant, D Randall; Kilburn, Brian A; Petkova, Anelia; Edwin, Samuel S; Duniec-Dmuchowski, Zophia M; Edwards, Holly J; Romero, Roberto; Leach, Richard E

2006-02-01

Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is down regulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O(2) ( approximately 2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O(2) upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O(2), signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O(2) and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O(2) rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

Comparative experimental/theoretical studies on the EGFR dimerization under the effect of EGF/EGF analogues binding: Highlighting the importance of EGF/EGFR interactions at site III interface.

PubMed

Mehrabi, Masomeh; Mahdiuni, Hamid; Rasouli, Hassan; Mansouri, Kamran; Shahlaei, Mohsen; Khodarahmi, Reza

2018-04-14

Epidermal growth factor receptors (EGFRs) and their cytoplasmic tyrosine kinases play significant roles in cell proliferation and signaling. All the members of the EGFR/ErbB family are primary goals for cancer therapy, particularly for tumors of breast, cervix, ovaries, kidney, esophagus, prostate and non-small-cell lung carcinoma and head and neck tumors. However, the therapeutic ability of accessible anti-ErbB agents is limited. Therefore, recognizing EGF analogues or small organic molecules with high affinity for the extracellular domain of the EGFR is a critical target on cancer research. An effective EGF analogue should have a comparable binding affinity for EGFR in order to create an effective ligand competitive inhibition against circulating wild EGF while fails to transduce appropriate downstream signaling into the cancer cell. In our earlier study we have developed a mutant form of human EGF (mEGF, lacking the four critical amino acid residues; Gln 43 , Tyr 44 , Arg 45 and Asp 46 at the C-terminal of the protein) and its binding properties and mitogenic activity were assessed. The mEGF showed high affinity for EGFR binding domains but caused poor EGFR dimerization and phosphorylation and especially, mEGF induced EGFR internalization. However, underlying mechanism of action of EGF analogues is still unclear and thus considered to be worthwhile for further study. With regard to different effects of the EGF analogue on EGFR activating process, computational analysis of wild EGF/EGFR and mEGF/EGFR complexes (along with EGFt/EGFR complex) were done. Results of the protein dissection identified several interactions within "ligand/EGFR" that are common among EGF and EGFt/mEGF. These results disclose that while several interactions are conserved within EGF/EGFR interfaces, EGF/EGFR interactions on site III interface controls the affinity, EGFR dimerization and subsequent downstream signaling through a heterogeneous set of non-covalent interactions. These findings

Cross-talk between EGF and BMP9 signalling pathways regulates the osteogenic differentiation of mesenchymal stem cells

PubMed Central

Liu, Xing; Qin, Jiaqiang; Luo, Qing; Bi, Yang; Zhu, Gaohui; Jiang, Wei; Kim, Stephanie H; Li, Mi; Su, Yuxi; Nan, Guoxin; Cui, Jing; Zhang, Wenwen; Li, Ruidong; Chen, Xiang; Kong, Yuhan; Zhang, Jiye; Wang, Jinhua; Rogers, Mary Rose; Zhang, Hongyu; Shui, Wei; Zhao, Chen; Wang, Ning; Liang, Xi; Wu, Ningning; He, Yunfeng; Luu, Hue H; Haydon, Rex C; Shi, Lewis L; Li, Tingyu; He, Tong-Chuan; Li, Ming

2013-01-01

Mesenchymal stem cells (MSCs) are multipotent progenitors, which give rise to several lineages, including bone, cartilage and fat. Epidermal growth factor (EGF) stimulates cell growth, proliferation and differentiation. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein tyrosine kinase activity of its receptor, which initiates a signal transduction cascade causing a variety of biochemical changes within the cell and regulating cell proliferation and differentiation. We have identified BMP9 as one of the most osteogenic BMPs in MSCs. In this study, we investigate if EGF signalling cross-talks with BMP9 and regulates BMP9-induced osteogenic differentiation. We find that EGF potentiates BMP9-induced early and late osteogenic markers of MSCs in vitro, which can be effectively blunted by EGFR inhibitors Gefitinib and Erlotinib or receptor tyrosine kinase inhibitors AG-1478 and AG-494 in a dose- and time-dependent manner. Furthermore, EGF significantly augments BMP9-induced bone formation in the cultured mouse foetal limb explants. In vivo stem cell implantation experiment reveals that exogenous expression of EGF in MSCs can effectively potentiate BMP9-induced ectopic bone formation, yielding larger and more mature bone masses. Interestingly, we find that, while EGF can induce BMP9 expression in MSCs, EGFR expression is directly up-regulated by BMP9 through Smad1/5/8 signalling pathway. Thus, the cross-talk between EGF and BMP9 signalling pathways in MSCs may underline their important roles in regulating osteogenic differentiation. Harnessing the synergy between BMP9 and EGF should be beneficial for enhancing osteogenesis in regenerative medicine. PMID:23844832

EGF-mediated EGFR/ERK signaling pathway promotes germinative cell proliferation in Echinococcus multilocularis that contributes to larval growth and development.

PubMed

Cheng, Zhe; Liu, Fan; Li, Xiu; Dai, Mengya; Wu, Jianjian; Guo, Xinrui; Tian, Huimin; Heng, Zhijie; Lu, Ying; Chai, Xiaoli; Wang, Yanhai

2017-02-01

Larvae of the tapeworm E. multilocularis cause alveolar echinococcosis (AE), one of the most lethal helminthic infections in humans. A population of stem cell-like cells, the germinative cells, is considered to drive the larval growth and development within the host. The molecular mechanisms controlling the behavior of germinative cells are largely unknown. Using in vitro cultivation systems we show here that the EGFR/ERK signaling in the parasite can promote germinative cell proliferation in response to addition of human EGF, resulting in stimulated growth and development of the metacestode larvae. Inhibition of the signaling by either the EGFR inhibitors CI-1033 and BIBW2992 or the MEK/ERK inhibitor U0126 impairs germinative cell proliferation and larval growth. These data demonstrate the contribution of EGF-mediated EGFR/ERK signaling to the regulation of germinative cells in E. multilocularis, and suggest the EGFR/ERK signaling as a potential therapeutic target for AE and perhaps other human cestodiasis.

EGF-mediated EGFR/ERK signaling pathway promotes germinative cell proliferation in Echinococcus multilocularis that contributes to larval growth and development

PubMed Central

Li, Xiu; Dai, Mengya; Wu, Jianjian; Guo, Xinrui; Tian, Huimin; Heng, Zhijie; Lu, Ying; Chai, Xiaoli

2017-01-01

Background Larvae of the tapeworm E. multilocularis cause alveolar echinococcosis (AE), one of the most lethal helminthic infections in humans. A population of stem cell-like cells, the germinative cells, is considered to drive the larval growth and development within the host. The molecular mechanisms controlling the behavior of germinative cells are largely unknown. Methodology/Principal findings Using in vitro cultivation systems we show here that the EGFR/ERK signaling in the parasite can promote germinative cell proliferation in response to addition of human EGF, resulting in stimulated growth and development of the metacestode larvae. Inhibition of the signaling by either the EGFR inhibitors CI-1033 and BIBW2992 or the MEK/ERK inhibitor U0126 impairs germinative cell proliferation and larval growth. Conclusions/Significance These data demonstrate the contribution of EGF-mediated EGFR/ERK signaling to the regulation of germinative cells in E. multilocularis, and suggest the EGFR/ERK signaling as a potential therapeutic target for AE and perhaps other human cestodiasis. PMID:28241017

Chemical biology of natural indolocarbazole products: 30 years since the discovery of staurosporine.

PubMed

Nakano, Hirofumi; Omura, Satoshi

2009-01-01

Staurosporine was discovered at the Kitasato Institute in 1977 while screening for microbial alkaloids using chemical detection methods. It was during the same era that protein kinase C was discovered and oncogene v-src was shown to have protein kinase activity. Staurosporine was first isolated from a culture of Actinomyces that originated in a soil sample collected in Mizusawa City, Japan. Thereafter, indolocarbazole compounds have been isolated from a variety of organisms. The biosynthesis of staurosporine and related indolocarbazoles was finally elucidated during the past decade through genetic and biochemical studies. Subsequently, several novel indolocarbazoles have been produced using combinatorial biosynthesis. In 1986, 9 years since its discovery, staurosporine and related indolocarbazoles were shown to be nanomolar inhibitors of protein kinases. They can thus be viewed as forerunners of today's crop of novel anticancer drugs. The finding led many pharmaceutical companies to search for selective protein kinase inhibitors by screening natural products and through chemical synthesis. In the 1990s, imatinib, a Bcr-Abl tyrosine kinase inhibitor, was synthesized and, following human clinical trials for chronic myelogenous leukemia, it was approved for use in the USA in 2001. In 1992, mammalian topoisomerases were shown to be targets for indolocarbazoles. This opened up new possibilities in that indolocarbazole compounds could selectively interact with ATP-binding sites of not only protein kinases but also other proteins that had slight differences in ATP-binding sites. ABCG2, an ATP-binding cassette transporter, was recently identified as an important new target for indolocarbazoles.

Protein-tyrosine-phosphatase-mediated epidermal growth factor (EGF) receptor transinactivation and EGF receptor-independent stimulation of mitogen-activated protein kinase by bradykinin in A431 cells.

PubMed Central

Graness, A; Hanke, S; Boehmer, F D; Presek, P; Liebmann, C

2000-01-01

Transactivation of the epidermal growth factor (EGF) receptor (EGFR) has been proposed to represent an essential link between G-protein-coupled receptors and the mitogen-activated protein kinase (MAPK) pathway in various cell types. In the present work we report, in contrast, that in A431 cells bradykinin transinactivates the EGFR and stimulates MAPK activity independently of EGFR tyrosine phosphorylation. Both effects of bradykinin are mediated by a pertussis-toxin-insensitive G-protein. Three lines of evidence suggest the activation of a protein tyrosine phosphatase (PTP) by bradykinin: (i) treatment of A431 cells with bradykinin decreases both basal and EGF-induced EGFR tyrosine phosphorylation, (ii) this effect of bradykinin can be blocked by two different PTP inhibitors, and (iii) bradykinin significantly increased the PTP activity in total A431 cell lysates when measured in vitro. The transmembrane receptor PTP sigma was identified as a putative mediator of bradykinin-induced downregulation of EGFR autophosphorylation. Activation of MAPK in response to bradykinin was insensitive towards AG 1478, a specific inhibitor of EGFR tyrosine kinase, but was blocked by wortmannin or bisindolylmaleimide, inhibitors of phosphatidylinositol 3-kinase (PI3-K) and protein kinase C (PKC) respectively. These results also suggest that the bradykinin-induced activation of MAPK is independent of EGFR and indicate a pathway involving PI3-K and PKC. In addition, bradykinin evokes a rapid and transient increase in Src kinase activity. Although Src does not participate in bradykinin-induced stimulation of PTP activity, inhibition of Src by 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo(3,4-d)pyrimidine leads to an increase in MAPK activation by bradykinin. Our results suggest that in A431 cells the G(q/11)-protein-coupled bradykinin B(2) receptor may stimulate PTP activity and thereby transinactivate the EGFR, and may simultaneously activate MAPK by an alternative signalling pathway

A potent anti-HB-EGF monoclonal antibody inhibits cancer cell proliferation and multiple angiogenic activities of HB-EGF.

PubMed

Sato, Shuji; Drake, Andrew W; Tsuji, Isamu; Fan, Jinhong

2012-01-01

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the epidermal growth factor family and has a variety of physiological and pathological functions. Modulation of HB-EGF activity might have a therapeutic potential in the oncology area. We explored the therapeutic possibilities by characterizing the in vitro biological activity of anti-HB-EGF monoclonal antibody Y-142. EGF receptor (EGFR) ligand and species specificities of Y-142 were tested. Neutralizing activities of Y-142 against HB-EGF were evaluated in EGFR and ERBB4 signaling. Biological activities of Y-142 were assessed in cancer cell proliferation and angiogenesis assays and compared with the anti-EGFR antibody cetuximab, the HB-EGF inhibitor CRM197, and the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab. The binding epitope was determined with alanine scanning. Y-142 recognized HB-EGF as well as the EGFR ligand amphiregulin, and bound specifically to human HB-EGF, but not to rodent HB-EGF. In addition, Y-142 neutralized HB-EGF-induced phosphorylation of EGFR and ERBB4, and blocked their downstream ERK1/2 and AKT signaling. We also found that Y-142 inhibited HB-EGF-induced cancer cell proliferation, endothelial cell proliferation, tube formation, and VEGF production more effectively than cetuximab and CRM197 and that Y-142 was superior to bevacizumab in the inhibition of HB-EGF-induced tube formation. Six amino acids in the EGF-like domain were identified as the Y-142 binding epitope. Among the six amino acids, the combination of F115 and Y123 determined the amphiregulin cross-reactivity and that F115 accounted for the species selectivity. Furthermore, it was suggested that the potent neutralizing activity of Y-142 was derived from its recognition of R142 and Y123 and its high affinity to HB-EGF. Y-142 has a potent HB-EGF neutralizing activity that modulates multiple biological activities of HB-EGF including cancer cell proliferation and angiogenic

Cross-talk between EGF and BMP9 signalling pathways regulates the osteogenic differentiation of mesenchymal stem cells.

PubMed

Liu, Xing; Qin, Jiaqiang; Luo, Qing; Bi, Yang; Zhu, Gaohui; Jiang, Wei; Kim, Stephanie H; Li, Mi; Su, Yuxi; Nan, Guoxin; Cui, Jing; Zhang, Wenwen; Li, Ruidong; Chen, Xiang; Kong, Yuhan; Zhang, Jiye; Wang, Jinhua; Rogers, Mary Rose; Zhang, Hongyu; Shui, Wei; Zhao, Chen; Wang, Ning; Liang, Xi; Wu, Ningning; He, Yunfeng; Luu, Hue H; Haydon, Rex C; Shi, Lewis L; Li, Tingyu; He, Tong-Chuan; Li, Ming

2013-09-01

Mesenchymal stem cells (MSCs) are multipotent progenitors, which give rise to several lineages, including bone, cartilage and fat. Epidermal growth factor (EGF) stimulates cell growth, proliferation and differentiation. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein tyrosine kinase activity of its receptor, which initiates a signal transduction cascade causing a variety of biochemical changes within the cell and regulating cell proliferation and differentiation. We have identified BMP9 as one of the most osteogenic BMPs in MSCs. In this study, we investigate if EGF signalling cross-talks with BMP9 and regulates BMP9-induced osteogenic differentiation. We find that EGF potentiates BMP9-induced early and late osteogenic markers of MSCs in vitro, which can be effectively blunted by EGFR inhibitors Gefitinib and Erlotinib or receptor tyrosine kinase inhibitors AG-1478 and AG-494 in a dose- and time-dependent manner. Furthermore, EGF significantly augments BMP9-induced bone formation in the cultured mouse foetal limb explants. In vivo stem cell implantation experiment reveals that exogenous expression of EGF in MSCs can effectively potentiate BMP9-induced ectopic bone formation, yielding larger and more mature bone masses. Interestingly, we find that, while EGF can induce BMP9 expression in MSCs, EGFR expression is directly up-regulated by BMP9 through Smad1/5/8 signalling pathway. Thus, the cross-talk between EGF and BMP9 signalling pathways in MSCs may underline their important roles in regulating osteogenic differentiation. Harnessing the synergy between BMP9 and EGF should be beneficial for enhancing osteogenesis in regenerative medicine. © 2013 The Authors. Journal of Cellular and Molecular Medicine Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Vasopressin up-regulates the expression of growth-related immediate-early genes via two distinct EGF receptor transactivation pathways

PubMed Central

Fuentes, Lida Q.; Reyes, Carlos E.; Sarmiento, José M.; Villanueva, Carolina I.; Figueroa, Carlos D.; Navarro, Javier; González, Carlos B.

2008-01-01

Activation of V1a receptor triggers the expression of growth-related immediate-early genes (IEGs), including c-Fos and Egr-1. Here we found that pre-treatment of rat vascular smooth muscle A-10 cell line with the EGF receptor inhibitor AG1478 or the over-expression of an EGFR dominant negative mutant (HEBCD533) blocked the vasopressin-induced expression of IEGs, suggesting that activation of these early genes mediated by V1a receptor is via transactivation of the EGF receptor. Importantly, the inhibition of the metalloproteinases, which catalyzed the shedding of the EGF receptor agonist HB-EGF, selectively blocked the vasopressin-induced expression c-Fos. On the other hand, the inhibition of c-Src selectively blocked the vasopressin-induced expression of Egr-1. Interestingly, in contrast to the expression of c-Fos, the expression of Egr-1 was mediated via the Ras/MEK/MAPK-dependent signalling pathway. Vasopressin-triggered expression of both genes required the release of intracellular calcium, activation of PKC and β-arrestin 2. These findings demonstrated that vasopressin up-regulated the expression of c-Fos and Erg-1 via transactivation of two distinct EGF receptor-dependent signalling pathways. PMID:18571897

EGF domain of coagulation factor IX is conducive to exposure of phosphatidylserine.

PubMed

Hidai, Chiaki; Fujiwara, Yusuke; Kokubun, Shinichiro; Kitano, Hisataka

2017-04-01

Lipid rafts are an initiation site for many different signals. Recently, we reported that an EGF domain in activated coagulation factor IX (EGF-F9) increases lipid raft formation and accelerates cell migration. However, the detailed mechanism is not well understood. This study aimed to evaluate the effects of EGF-F9 on the cell membrane. A431 cells (derived from human squamous cell carcinoma) were treated with recombinant EGF-F9. Cells were immunocytochemically stained with probes for lipid rafts or phosphatidylserine (PS). After 3 min of treatment with EGF-F9, cholera toxin subunit B (CTxB) binding domains emerged at the adhesive tips of filopodia. Subsequently, CTxB staining was observed on the filopodial shaft. Finally, large clusters of CTxB domains were observed at the edge of cell bodies. Markers for lipid rafts, such as caveolin-1 and a GPI anchored protein, co-localized with CTxB. Staining with annexin V and XII revealed that PS was exposed at the tips of filopodia, translocated on filopodial shafts, and co-localized with CTxB at the rafts. Immunocytochemistry showed that scramblase-1 protein was present at the filopodial tips. Our data indicates that EGF-F9 accelerates PS exposure around the filopodial adhesion complex and induces clustering of lipid rafts in the cell body. PS exposure is thought to occur on cells undergoing apoptosis. Further study of the function of the EGF-F9 motif in mediating signal transduction is necessary because it is shared by a number of proteins. © 2017 International Federation for Cell Biology.

Differential regulation of betacellulin and heparin-binding EGF-like growth factor in cultured zebrafish ovarian follicle cells by EGF family ligands.

PubMed

Tse, Anna Chung-Kwan; Ge, Wei

2009-05-01

Recently the roles of epidermal growth factor (EGF) family ligands in vertebrate ovaries have received increasing attention, including betacellulin (BTC), amphiregulin (AR), heparin-binding EGF-like growth factor (HB-EGF), transforming growth factor alpha (TGFalpha), epiregulin, and EGF itself. In the zebrafish (Danio rerio), four members of EGF family have been identified by either molecular cloning or genome sequencing, which are EGF, TGFalpha, BTC, and HB-EGF. Although they are mostly expressed in the oocytes in the ovary, the present study demonstrated the expression of all the four EGF family ligands (egf, btc, tgfa, and hbegf) in cultured zebrafish follicle cells albeit at very low levels. Treatment of the cultured follicle cells with EGF, BTC, and HB-EGF demonstrated differential effects of these ligands on the expression of themselves. While the expression of egf was rather non-responsive to EGF, BTC, and HB-EGF, the expression of btc was consistently down-regulated by all the three molecules. In contrast, hbegf increased its expression in response to these molecules. These results suggest that there is an EGF signaling network in the zebrafish ovarian follicle, and the functionality of this network is self-regulated by its own members.

ROLES OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF-A) IN MEDIATION OF DIOXIN (TCDD)-INDUCED DELAYS IN DEVELOPMENT OF THE MOUSE MAMMARY GLAND

EPA Science Inventory

Roles of Epidermal Growth Factor (EGF) and Transforming Growth Factor-alpha (TGF-a) in Mediation of Dioxin (TCDD)-Induced Delays in Development of the Mouse Mammary Gland.
Suzanne E. Fenton, Barbara Abbott, Lamont Bryant, and Angela Buckalew. U.S. EPA, NHEERL, Reproductive Tox...

TGFβ loss activates ADAMTS-1-mediated EGF-dependent invasion in a model of esophageal cell invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le Bras, Grégoire F.; Taylor, Chase; Koumangoye, Rainelli B.

2015-01-01

invasion of esophageal keratinocytes. • Collective cell invasion is protease dependent and ADAMTS-1 is upregulated. • Inhibition of TGFβ signaling promotes EGF-mediated invasion. • Loss of TGFβ signaling promotes collagen binding and induces alterations in integrin expression. • The TGFβ target ROBO1 is downregulated in cell invasion implying mechanisms of chemorepulsion.« less

EGF receptor ligands: recent advances.

PubMed

Singh, Bhuminder; Carpenter, Graham; Coffey, Robert J

2016-01-01

Seven ligands bind to and activate the mammalian epidermal growth factor (EGF) receptor (EGFR/ERBB1/HER1): EGF, transforming growth factor-alpha (TGFA), heparin-binding EGF-like growth factor (HBEGF), betacellulin (BTC), amphiregulin (AREG), epiregulin (EREG), and epigen (EPGN). Of these, EGF, TGFA, HBEGF, and BTC are thought to be high-affinity ligands, whereas AREG, EREG, and EPGN constitute low-affinity ligands. This focused review is meant to highlight recent studies related to actions of the individual EGFR ligands, the interesting biology that has been uncovered, and relevant advances related to ligand interactions with the EGFR.

EGF receptor ligands: recent advances

PubMed Central

Singh, Bhuminder; Carpenter, Graham; Coffey, Robert J.

2016-01-01

Seven ligands bind to and activate the mammalian epidermal growth factor (EGF) receptor (EGFR/ERBB1/HER1): EGF, transforming growth factor-alpha (TGFA), heparin-binding EGF-like growth factor (HBEGF), betacellulin (BTC), amphiregulin (AREG), epiregulin (EREG), and epigen (EPGN). Of these, EGF, TGFA, HBEGF, and BTC are thought to be high-affinity ligands, whereas AREG, EREG, and EPGN constitute low-affinity ligands. This focused review is meant to highlight recent studies related to actions of the individual EGFR ligands, the interesting biology that has been uncovered, and relevant advances related to ligand interactions with the EGFR. PMID:27635238

beta-Adrenoceptor blockers protect against staurosporine-induced apoptosis in SH-SY5Y neuroblastoma cells.

PubMed

Mikami, Maya; Goubaeva, Farida; Song, Joseph H; Lee, H T; Yang, Jay

2008-07-28

The beta-adrenoceptor blockers exhibit a well-characterized anti-apoptotic property in the heart and kidney while less is known about the effect of this class of drugs on neuronal apoptosis. We studied the effects of three beta-adrenoceptor blockers propranolol (1-(isoproplyamino)-3-(naphthalene-1-yloxy)propan-2-ol), atenolol (2-[4-[2-hydroxy-3-(1-methylethylamino)propoxyl]phenyl]ehanamide), and ICI 118551 (1-[2,3-(dihydro-7-methyl-1H-iden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol), against staurosporine-induced apoptosis in SH-SY5Y human neuroblastoma cells. Staurosporine increased caspase 3-like activity, DNA fragmentation, PARP cleavage, and the number of TUNEL positive cells consistent with the induction of apoptosis. Propranolol and ICI 118551, but not atenolol, demonstrated a concentration-dependent inhibition of caspase 3-like activity. Propranolol and ICI 118551 directly inhibited the enzymatic activity of recombinant caspase 9 while atenolol did not; however, none of the beta-adrenoceptor blockers that were examined directly blocked caspases 2 or 3 activity. In isolated mitochondria, propranolol and ICI 118551 inhibited staurosporine-induced cytochrome c release while atenolol did not. We conclude that propranolol and ICI 118551 protect SH-SY5Y cells against staurosporine-induced apoptosis through a dual action on the mitochondria and on caspase 9 in a cell type and an apoptotic paradigm where the conventional inhibitors of mitochondrial permeability transition such as cyclosporin A and bongkrekic acid demonstrate no protection.

Negative Cooperativity in the EGF Receptor

PubMed Central

Pike, Linda J.

2012-01-01

Scatchard analyses of the binding of EGF to its receptor yield concave up Scatchard plots, indicative of some type of heterogenity in ligand binding affinity. This was typically interpreted as being due to the presence of two independent binding site–one of high affinity representing ≤10% of the receptor population and one of low affinity making up the bulk of the receptors. However, the concept of two independent binding sites is difficult to reconcile with the X-ray structures of the dimerized EGF receptor that show symmetric binding of the two ligands. A new approach to the analysis of 125I-EGF binding data combined with the structure of the singly-occupied Drosophila EGF receptor have now shown that this heterogeneity is due to the presence of negative cooperativity in the EGF receptor. Concerns that negative cooperativity precludes ligand-induced dimerization of the EGF receptor confuse the concepts of linkage cooperativity. Linkage refers to the effect of ligand on the assembly of dimers while cooperativity refers to the effect of ligand binding to one subunit on ligand binding to the other subunit within a preassembled dimer. Binding of EGF to its receptor is positively linked with dimer assembly but shows negative cooperativity within the dimer. PMID:22260659

Silencing of cytosolic NADP(+)-dependent isocitrate dehydrogenase by small interfering RNA enhances the sensitivity of HeLa cells toward staurosporine.

PubMed

Lee, Su-Min; Park, Sin Young; Shin, Seoung Woo; Kil, In Sup; Yang, Eun Sun; Park, Jeen-Woo

2009-02-01

Staurosporine induces the production of reactive oxygen species, which play an important causative role in apoptotic cell death. Recently, it was demonstrated that the control of cellular redox balance and the defense against oxidative damage is one of the primary functions of cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) by supplying NADPH for antioxidant systems. The present report shows that silencing of IDPc expression in HeLa cells greatly enhances apoptosis induced by staurosporine. Transfection of HeLa cells with an IDPc small interfering RNA (siRNA) markedly decreased activity of IDPc, enhancing the susceptibility of staurosporine-induced apoptosis reflected by DNA fragmentation, cellular redox status and the modulation of apoptotic marker proteins. These results indicate that IDPc may play an important role in regulating the apoptosis induced by staurosporine and the sensitizing effect of IDPc siRNA on the apoptotic cell death of HeLa cells offers the possibility of developing a modifier of cancer chemotherapy.

EGF receptor lysosomal degradation is delayed in the cells stimulated with EGF-Quantum dot bioconjugate but earlier key events of endocytic degradative pathway are similar to that of native EGF

PubMed Central

Leontieva, Ekaterina A.; Kornilova, Elena S.

2017-01-01

Quantum dots (QDs) complexed to ligands recognizing surface receptors undergoing internalization are an attractive tool for live cell imaging of ligand-receptor complexes behavior and for specific tracking of the cells of interest. However, conjugation of quasi-multivalent large QD-particle to monovalent small growth factors like EGF that bound their tyrosine-kinase receptors may affect key endocytic events tightly bound to signaling. Here, by means of confocal microscopy we have addressed the key endocytic events of lysosomal degradative pathway stimulated by native EGF or EGF-QD bioconjugate. We have demonstrated that the decrease in endosome number, increase in mean endosome integrated density and the pattern of EEA1 co-localization with EGF-EGFR complexes at early stages of endocytosis were similar for the both native and QD-conjugated ligands. In both cases enlarged hollow endosomes appeared after wortmannin treatment. This indicates that early endosomal fusions and their maturation proceed similar for both ligands. EGF-QD and native EGF similarly accumulated in juxtanuclear region, and live cell imaging of endosome motion revealed the behavior described elsewhere for microtubule-facilitated motility. Finally, EGF-QD and the receptor were found in lysosomes. However, degradation of receptor part of QD-EGF-EGFR-complex was delayed compared to native EGF, but not inhibited, while QDs fluorescence was detected in lysosomes even after 24 hours. Importantly, in HeLa and A549 cells the both ligands behaved similarly. We conclude that during endocytosis EGF-QD behaves as a neutral marker for degradative pathway up to lysosomal stage and can also be used as a long-term cell marker. PMID:28574831

Role of extracellular matrix in regulation of staurosporine-induced apoptosis in breast cancer cells.

PubMed

Vasaturo, F; Malacrino, C; Sallusti, E; Coppotelli, G; Birarelli, P; Giuffrida, A; Albonici, L; Simonelli, L; Modesti, A; Modesti, M; Scarpa, S

2005-04-01

Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.

Novel nanofibrous dressings containing rhEGF and Aloe vera for wound healing applications.

PubMed

Garcia-Orue, Itxaso; Gainza, Garazi; Gutierrez, Franciso Borja; Aguirre, Jose Javier; Evora, Carmen; Pedraz, Jose Luis; Hernandez, Rosa Maria; Delgado, Araceli; Igartua, Manoli

2017-05-25

Nanofibrous membranes produced by electrospinning possess a large surface area-to-volume ratio, which mimics the three-dimensional structure of the extracellular matrix. Thus, nanofibrous dressings are a promising alternative for chronic wound healing, since they can replace the natural ECM until it is repaired. Therefore, in this study we have developed a PLGA nanofibrous membrane that contains recombinant human Epidermal Growth Factor (rhEGF) and Aloe vera (AV) extract. Both of them promote wound healing, as EGF is a wound healing mediator and AV stimulates the proliferation and activity of fibroblast. The obtained membranes were composed of uniform and randomly oriented fibers with an average diameter of 356.03±112.05nm, they presented a porosity of 87.92±11.96% and the amount of rhEGF was 9.76±1.75μg/mg. The in vitro viability assay demonstrated that the membranes containing rhEGF and AV improved fibroblast proliferation, revealing the beneficial effect of the combination. Furthermore, these membranes accelerated significantly wound closure and reepithelisation in an in vivo full thickness wound healing assay carried out in db/db mice. Overall, these findings demonstrated the potential of PLGA nanofibers containing rhEGF and AV for the treatment of chronic wounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Gab1 is essential for membrane translocation, activity and integrity of mTORCs after EGF stimulation in urothelial cell carcinoma

PubMed Central

Chang, Chi-Hao; Chan, Po-Chao; Li, Jian-Ri; Chen, Chun-Jung; Shieh, Jeng-Jer; Fu, Yun-Ching; Chen, Hong-Chen; Wu, Ming-Ju

2015-01-01

Urothelial carcinoma is the most common type of malignancy in long-term dialysis patients and kidney transplant recipients in Taiwan. mTORCs (mammalian target of rapamycin complexes) and EGF are important in urothelial carcinoma. To identify the regulation of mTORCs upon EGF stimulation is necessary. mTOR integrates signals from growth factors via mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2). The mechanism of mTORC1 action has been widely studied; however, the regulation of mTORC2 has not been well studied. Here, we demonstrate that Gab1 is an important upstream regulator in EGF-mediated activation of mTORCs. In our study, we confirm that mTORCs translocate from the cytoplasm to the plasma membrane via the PH domain of Gab1 upon EGF stimulation. Moreover, Gab1 associates with mTORCs. This association stabilizes the integrity of mTORCs and induces mTORC activity. Compared to normal bladder tissue, the expression of Gab1 and activity of mTORCs are elevated in urothelial carcinoma. Collectively, our results suggest that Gab1 is an essential regulator of the EGF-mediated mTORC pathways and may potentially be used as a biomarker for urothelial carcinoma to predict diagnosis and drug response. PMID:25596749

Context-Dependent Sensitivity to Mutations Disrupting the Structural Integrity of Individual EGF Repeats in the Mouse Notch Ligand DLL1

PubMed Central

Schuster-Gossler, Karin; Cordes, Ralf; Müller, Julia; Geffers, Insa; Delany-Heiken, Patricia; Taft, Manuel; Preller, Matthias; Gossler, Achim

2016-01-01

The highly conserved Notch-signaling pathway mediates cell-to-cell communication and is pivotal for multiple developmental processes and tissue homeostasis in adult organisms. Notch receptors and their ligands are transmembrane proteins with multiple epidermal-growth-factor-like (EGF) repeats in their extracellular domains. In vitro the EGF repeats of mammalian ligands that are essential for Notch activation have been defined. However, in vivo the significance of the structural integrity of each EGF repeat in the ligand ectodomain for ligand function is still unclear. Here, we analyzed the mouse Notch ligand DLL1. We expressed DLL1 proteins with mutations disrupting disulfide bridges in each individual EGF repeat from single-copy transgenes in the HPRT locus of embryonic stem cells. In Notch transactivation assays all mutations impinged on DLL1 function and affected both NOTCH1 and NOTCH2 receptors similarly. An allelic series in mice that carried the same point mutations in endogenous Dll1, generated using a mini-gene strategy, showed that early developmental processes depending on DLL1-mediated NOTCH activation were differently sensitive to mutation of individual EGF repeats in DLL1. Notably, some mutations affected only somite patterning and resulted in vertebral column defects resembling spondylocostal dysostosis. In conclusion, the structural integrity of each individual EGF repeat in the extracellular domain of DLL1 is necessary for full DLL1 activity, and certain mutations in Dll1 might contribute to spondylocostal dysostosis in humans. PMID:26801181

Staurosporine potentiates platelet activating factor stimulated phospholipase C activity in rabbit platelets but does not block desensitization by platelet activating factor.

PubMed

Morrison, W J; Dhar, A; Shukla, S D

1989-01-01

The possible involvement of protein kinase C activation in regulating PAF-stimulated PLC activity was studied in rabbit platelets. PAF (100 nM for 5 seconds) stimulated incorporation of 32P into proteins and caused [3H]InsP3 levels to increase about 260% of control. These responses were compared after platelets were pretreated with either PAF, phorbol 12-myristate 13-acetate (PMA) or staurosporine and also after pretreatments with staurosporine followed by PAF or PMA. Pretreating platelets with staurosporine potentiated PAF-stimulated [3H]InsP3 levels by 54% and blocked protein phosphorylation. Pretreatments with PAF and PMA caused PAF-stimulated [3H]InsP3 levels to decrease to 115 and 136%, respectively. Staurosporine pretreatment blocked the decrease caused by the PMA pretreatment but not that by PAF. This study demonstrates that PAF-stimulated PLC activity is negatively affected by protein kinase C (PKC) activation and that inhibition of PKC activity did not prevent desensitization of PLC by PAF.

Improved expression of recombinant plant-made hEGF.

PubMed

Thomas, David Rhys; Walmsley, Amanda Maree

2014-11-01

The yield of recombinant hEGF was increased approximately tenfold through a range of optimisations. Further, the recombinant protein was found to have biological activity comparable to commercial hEGF. Human epidermal growth factor (hEGF) is a powerful mitogen that can enhance the healing of a wide range of injuries, including burns, cuts, diabetic ulcers and gastric ulcers. However, despite its clinical value, hEGF is only consistently used for the treatment of chronic diabetic ulcers due to its high cost. In this study, hEGF was transiently expressed in Nicotiana benthamiana plants and targeted to the apoplast, ER and vacuole. Several other approaches were also included in a stepwise fashion to identify the optimal conditions for the expression of recombinant hEGF. Expression was found to be highest in the vacuole, while targeting hEGF to the ER caused a decrease in total soluble protein (TSP). Using a codon optimised sequence was found to increase vacuolar targeted hEGF yield by ~34 %, while it was unable to increase the yield of ER targeted hEGF. The use of the P19 silencing inhibitor was able to further increase expression by over threefold, and using 5-week-old plants significantly increased expression compared to 4- or 6-week-old-plants. The combined effect of these optimisations increased expression tenfold over the initial apoplast targeted construct to an average yield of 6.24 % of TSP. The plant-made hEGF was then shown to be equivalent to commercial E. coli derived hEGF in its ability to promote the proliferation of mouse keratinocytes. This study supports the potential for plants to be used for the commercial production of hEGF, and identifies a potential limitation for the further improvement of recombinant protein yields.

Staurosporine, but not Ro 31-8220, induces interleukin 2 production and synergizes with interleukin 1alpha in EL4 thymoma cells.

PubMed

Mahon, T M; Matthews, J S; O'Neill, L A

1997-07-01

Protein kinase C (PKC) has been implicated in interleukin 1 (IL1) signal transduction in a number of cellular systems, either as a key event in IL1 action or as a negative regulator. Here we have examined the effects of two PKC inhibitors, staurosporine and the more selective agent Ro 31-8220, on IL1 responses in the murine thymoma line EL4.NOB-1. A 1 h pulse of staurosporine was found to strongly potentiate the induction of IL2 by IL1alpha in these cells. In contrast, neither a pulse nor prolonged incubation with Ro 31-8220 affected the response to IL1alpha. Both agents blocked the response to PMA, however. A 1 h pulse of staurosporine was also found to induce IL2 production on its own, activate the transcription factor nuclear factor kappaB (NFkappaB) and increase the expression of a NFkappaB-linked reporter gene. It synergized with IL1alpha in all of these responses. Ro 31-8220 was again without effect, although both staurosporine and Ro 31-8220 blocked the activation of NFkappaB by PMA. Finally, staurosporine caused the translocation of PKC-alpha and -epsilon, and to a lesser extent PKC-beta, but not PKC-θ or -zeta, from the cytosol to the membrane, although a similar effect was observed with Ro 31-8220. The results suggest that PKC is not involved in IL1alpha signalling in EL4 cells. Furthermore, the potentiating effect of staurosporine on IL1alpha action does not involve PKC inhibition, and is likely to be at the level of NFkappaB activation.

Egr-1 is a critical regulator of EGF-receptor-mediated expansion of subventricular zone neural stem cells and progenitors during recovery from hypoxia–hypoglycemia

PubMed Central

Alagappan, Dhivyaa; Balan, Murugabaskar; Jiang, Yuhui; Cohen, Rachel B.; Kotenko, Sergei V.; Levison, Steven W.

2013-01-01

We recently established that the EGF-R (epidermal growth factor receptor) (EGF-R) is an essential regulator of the reactive expansion of SVZ (subventricular zone) NPs (neural precursors) that occurs during recovery from hypoxic-ischemic brain injury. The purpose of the current studies was to identify the conditions and the transcription factor (s) responsible for inducing the EGF-R. Here, we show that the increase in EGF-R expression and the more rapid division of the NPs can be recapitulated in in vitro by exposing SVZ NPs to hypoxia and hypoglycemia simultaneously, but not separately. The EGF-R promoter has binding sites for multiple transcription factors that includes the zinc finger transcription factor, Egr-1. We show that Egr-1 expression increases in NPs, but not astrocytes, following hypoxia and hypoglycemia where it accumulates in the nucleus. To determine whether Egr-1 is necessary for EGF-R expression, we used SiRNAs (small interfering RNA) specific for Egr-1 to decrease Egr-1 expression. Knocking-down Egr-1 decreased basal levels of EGF-R and it abolished the stress-induced increase in EGF-R expression. By contrast, HIF-1 accumulation did not contribute to EGF-R expression and FGF-2 only modestly induced EGF-R. These studies establish a new role for Egr-1 in regulating the expression of the mitogenic EGF-R. They also provide new information into mechanisms that promote NP expansion and provide insights into strategies for amplifying the numbers of stem cells for CNS (central nervous system) regeneration. PMID:23763269

TGF{beta} induces proHB-EGF shedding and EGFR transactivation through ADAM activation in gastric cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebi, Masahide; Kataoka, Hiromi, E-mail: hkataoka@med.nagoya-cu.ac.jp; Shimura, Takaya

2010-11-19

translocate to the nucleus. ADAM inhibitors blocked this nuclear translocation. TGF{beta} enhanced gastric cancer cell growth and ADAM inhibitors suppressed this effect. EGFR phosphorylation, HB-EGF-CTF nuclear translocation, and cell growth were suppressed in ADAM17 knockdown cells. Conclusion: HB-EGF-CTF nuclear translocation and EGFR transactivation from proHB-EGF shedding mediated by ADAM17 activated by TGF{beta} might be an important pathway of gastric cancer cell proliferation by TGF{beta}.« less

Egf Signaling Directs Neoblast Repopulation by Regulating Asymmetric Cell Division in Planarians.

PubMed

Lei, Kai; Thi-Kim Vu, Hanh; Mohan, Ryan D; McKinney, Sean A; Seidel, Chris W; Alexander, Richard; Gotting, Kirsten; Workman, Jerry L; Sánchez Alvarado, Alejandro

2016-08-22

A large population of proliferative stem cells (neoblasts) is required for physiological tissue homeostasis and post-injury regeneration in planarians. Recent studies indicate that survival of a few neoblasts after sublethal irradiation results in the clonal expansion of the surviving stem cells and the eventual restoration of tissue homeostasis and regenerative capacity. However, the precise mechanisms regulating the population dynamics of neoblasts remain largely unknown. Here, we uncovered a central role for epidermal growth factor (EGF) signaling during in vivo neoblast expansion mediated by Smed-egfr-3 (egfr-3) and its putative ligand Smed-neuregulin-7 (nrg-7). Furthermore, the EGF receptor-3 protein localizes asymmetrically on the cytoplasmic membrane of neoblasts, and the ratio of asymmetric to symmetric cell divisions decreases significantly in egfr-3(RNAi) worms. Our results not only provide the first molecular evidence of asymmetric stem cell divisions in planarians, but also demonstrate that EGF signaling likely functions as an essential regulator of neoblast clonal expansion. Copyright © 2016 Elsevier Inc. All rights reserved.

EGF does not induce Msx-1 and Msx-2 in dental mesenchyme.

PubMed

Wang, Y H; Kollar, E J; Upholt, W B; Mina, M

1998-01-01

Previous heterospecific tissue recombinations indicate that mandibular epithelium exerts the first known inductive signal for odontogenesis in mouse embryos. BMP-4 and EGF are two growth factors implicated as signaling molecules mediating the initial inductive epithelial-mesenchymal interactions during odontogenesis. The purpose of the present study was to examine and compare the effects of these growth factors and mouse mandibular epithelium on expression of Msx-1 and Msx-2 genes in molar-forming mesenchyme. Agarose beads soaked in growth factors or pieces of mouse mandibular epithelium (E11) were placed in contact with E11 molar-forming mesenchyme and cultured for 24 h. Whole-mount in situ hybridization analysis revealed that, in contrast to mouse mandibular epithelium and BMP-4-releasing beads, EGF-releasing beads did not induce the expression of Msx-1 and Msx-2 in E11 molar-forming mesenchyme. These observations suggest that whereas BMP-4 may be involved in activation of Msx-1 and Msx-2 in the underlying mesenchyme, EGF may regulate events involved in the formation of dental lamina.

EGF Functionalized Polymer-Coated Gold Nanoparticles Promote EGF Photostability and EGFR Internalization for Photothermal Therapy

PubMed Central

Silva, Catarina Oliveira; Petersen, Steffen B.; Reis, Catarina Pinto; Rijo, Patrícia; Molpeceres, Jesús; Fernandes, Ana Sofia; Gonçalves, Odete; Gomes, Andreia C.; Correia, Isabel; Vorum, Henrik; Neves-Petersen, Maria Teresa

2016-01-01

The application of functionalized nanocarriers on photothermal therapy for cancer ablation has wide interest. The success of this application depends on the therapeutic efficiency and biocompatibility of the system, but also on the stability and biorecognition of the conjugated protein. This study aims at investigating the hypothesis that EGF functionalized polymer-coated gold nanoparticles promote EGF photostability and EGFR internalization, making these conjugated particles suitable for photothermal therapy. The conjugated gold nanoparticles (100–200 nm) showed a plasmon absorption band located within the near-infrared range (650–900 nm), optimal for photothermal therapy applications. The effects of temperature, of polymer-coated gold nanoparticles and of UVB light (295nm) on the fluorescence properties of EGF have been investigated with steady-state and time-resolved fluorescence spectroscopy. The fluorescence properties of EGF, including the formation of Trp and Tyr photoproducts, is modulated by temperature and by the intensity of the excitation light. The presence of polymeric-coated gold nanoparticles reduced or even avoided the formation of Trp and Tyr photoproducts when EGF is exposed to UVB light, protecting this way the structure and function of EGF. Cytotoxicity studies of conjugated nanoparticles carried out in normal-like human keratinocytes showed small, concentration dependent decreases in cell viability (0–25%). Moreover, conjugated nanoparticles could activate and induce the internalization of overexpressed Epidermal Growth Factor Receptor in human lung carcinoma cells. In conclusion, the gold nanoparticles conjugated with Epidermal Growth Factor and coated with biopolymers developed in this work, show a potential application for near infrared photothermal therapy, which may efficiently destroy solid tumours, reducing the damage of the healthy tissue. PMID:27788212

Single molecule force spectroscopy for in-situ probing oridonin inhibited ROS-mediated EGF-EGFR interactions in living KYSE-150 cells.

PubMed

Pi, Jiang; Jin, Hua; Jiang, Jinhuan; Yang, Fen; Cai, Huaihong; Yang, Peihui; Cai, Jiye; Chen, Zheng W

2017-05-01

As the active anticancer component of Rabdosia Rubescens, oridonin has been proved to show strong anticancer activity in cancer cells, which is also found to be closely related to its specific inhibition effects on the EGFR tyrosine kinase activity. In this study, atomic force microscopy based single molecule force spectroscopy (AFM-SMFS) was used for real-time and in-situ detection of EGF-EGFR interactions in living esophageal cancer KYSE-150 cells to evaluate the anticancer activity of oridonin for the first time. Oridonin was found to induce apoptosis and also reduce EGFR expression in KYSE-150 cells. AFM-SMFS results demonstrated that oridonin could inhibit the binding between EGF and EGFR in KYSE-150 cells by decreasing the unbinding force and binding probability for EGF-EGFR complexes, which was further proved to be closely associated with the intracellular ROS level. More precise mechanism studies based on AFM-SMFS demonstrated that oridonin treatment could decrease the energy barrier width, increase the dissociation off rate constant and decrease the activation energy of EGF-EGFR complexes in ROS dependent way, suggesting oridonin as a strong anticancer agent targeting EGF-EGFR interactions in cancer cells through ROS dependent mechanism. Our results not only suggested oridonin as a strong anticancer agent targeting EGF-EGFR interactions in ROS dependent mechanism, but also highlighted AFM-SMFS as a powerful technique for pharmacodynamic studies by detecting ligand-receptor interactions, which was also expected to be developed into a promising tool for the screening and mechanism studies of drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

EGF receptor uses SOS1 to drive constitutive activation of NFκB in cancer cells

PubMed Central

De, Sarmishtha; Dermawan, Josephine Kam Tai; Stark, George R.

2014-01-01

Activation of nuclear factor κB (NFκB) is a central event in the responses of normal cells to inflammatory signals, and the abnormal constitutive activation of NFκB is important for the survival of most cancer cells. In nonmalignant human cells, EGF stimulates robust activation of NFκB. The kinase activity of the EGF receptor (EGFR) is required, because the potent and specific inhibitor erlotinib blocks the response. Down-regulating EGFR expression or inhibiting EGFR with erlotinib impairs constitutive NFκB activation in several different types of cancer cells and, conversely, increased activation of NFκB leads to erlotinib resistance in these cells. We conclude that EGF is an important mediator of NFκB activation in cancer cells. To explore the mechanism, we selected an erlotinib-resistant cell line in which the guanine nucleotide exchange factor Son of Sevenless 1 (SOS1), well known to be important for EGF-dependent signaling to MAP kinases, is overexpressed. Increased expression of SOS1 increases NFκB activation in several different types of cancer cells, and ablation of SOS1 inhibits EGF-induced NFκB activation in these cells, indicating that SOS1 is a functional component of the pathway connecting EGFR to NFκB activation. Importantly, the guanine nucleotide exchange activity of SOS1 is not required for NFκB activation. PMID:25071181

Role of binding ligand in toxic hybrid proteins: a comparison of EGF-ricin, EGF-ricin A-chain, and ricin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herschman, H.R.

1984-10-30

To analyze the influence of ricin B-chain on (i) the toxicity of hybrid-protein conjugates, (ii) the rate of cellular uptake of conjugates, and (iii) the rate at which ricin A-chain (RTA) is delivered to the cytoplasm, toxic hybrid proteins have been constructed consisting of epidermal growth factor (EGF) coupled in disulfide linkage either to ricin or to RTA. EGF-ricin is no more toxic on A431 cells than EGF-RTA. The two conjugates demonstrate similar kinetics of cellular uptake (defined as antibody irreversible toxicity). EGF-RTA and EGF-ricin, like ricin, required a 2-2 1/2 hour period at 37/sup 0/ before the onset ofmore » protein synthesis inhibition occurred. Results suggest that (i) RTA determines the processes which carry it, either in conjugate or toxin, from the plasma membrane binding site to the cytoplasm following endocytosis, and (ii) the ricin B chain is not required for these processes.« less

The Intracellular Juxtamembrane Domain of the Epidermal Growth Factor (EGF) Receptor Is Responsible for the Allosteric Regulation of EGF Binding*S⃞♦

PubMed Central

Macdonald-Obermann, Jennifer L.; Pike, Linda J.

2009-01-01

We have previously shown that the binding of epidermal growth factor (EGF) to its receptor can best be described by a model that involves negative cooperativity in an aggregating system (Macdonald, J. L., and Pike, L. J. (2008) Proc. Natl. Acad. Sci. U. S. A. 105, 112–117). However, despite the fact that biochemical analyses indicate that EGF induces dimerization of its receptor, the binding data provided no evidence for positive linkage between EGF binding and dimer assembly. By analyzing the binding of EGF to a number of receptor mutants, we now report that in naive, unphosphorylated EGF receptors, ligand binding is positively linked to receptor dimerization but the linkage is abolished upon autophosphorylation of the receptor. Both phosphorylated and unphosphorylated EGF receptors exhibit negative cooperativity, indicating that mechanistically, cooperativity is distinct from the phenomenon of linkage. Nonetheless, both the positive linkage and the negative cooperativity observed in EGF binding require the presence of the intracellular juxtamembrane domain. This indicates the existence of inside-out signaling in the EGF receptor system. The intracellular juxtamembrane domain has previously been shown to be required for the activation of the EGF receptor tyrosine kinase (Thiel, K. W., and Carpenter, G. (2007) Proc. Natl. Acad. Sci. U. S. A. 104, 19238–19243). Our experiments expand the role of this domain to include the allosteric control of ligand binding by the extracellular domain. PMID:19336395

Overcoming acquired drug resistance in colorectal cancer cells by targeted delivery of 5-FU with EGF grafted hollow mesoporous silica nanoparticles

NASA Astrophysics Data System (ADS)

Chen, Lijue; She, Xiaodong; Wang, Tao; He, Li; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

2015-08-01

Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The effect and mechanism of 5-FU loaded EGF grafted HMSNs (EGF-HMSNs-5-FU) in overcoming acquired drug resistance in SW480/ADR cells were studied. The EGF-HMSNs were demonstrated to be specifically internalized in EGFR overexpressed SW480/ADR cells via a receptor-mediated endocytosis and can escape from endo-lysosomes. The EGF-HMSNs-5-FU exhibited much higher cytotoxicity on SW480/ADR cells than HMSNs-5-FU and free 5-FU while the plain HMSNs did not show significant cytotoxicity. The mechanism of EGF-HMSNs-5-FU in overcoming drug resistance in SW480/ADR cells could be attributed to the specific internalization of EGF-HMSNs-5-FU in EGFR overexpressed cells which can lead to high intracellular drug accumulation and cause cell death through S phase arrest.Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The

Developmental defects in zebrafish for classification of EGF pathway inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim

2014-01-15

One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairmentmore » of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors.« less

Heparin-binding EGF-like growth factor and miR-1192 exert opposite effect on Runx2-induced osteogenic differentiation.

PubMed

Yu, S; Geng, Q; Ma, J; Sun, F; Yu, Y; Pan, Q; Hong, A

2013-10-17

Osteoblast differentiation is a pivotal event in bone formation. Runt-related transcription factor-2 (Runx2) is an essential factor required for osteoblast differentiation and bone formation. However, the underlying mechanism of Runx2-regulated osteogenic differentiation is still unclear. Here, we explored the corresponding mechanism using the C2C12/Runx2(Dox) subline, which expresses Runx2 in response to doxycycline (Dox). We found that Runx2-induced osteogenic differentiation of C2C12 cells results in a sustained decrease in the expression of heparin-binding EGF-like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family. Forced expression of HB-EGF or treatment with HB-EGF is capable of reducing the expression of alkaline phosphatase (ALP), a defined marker of early osteoblast differentiation. HB-EGF-mediated inhibition of ALP depends upon activation of the EGFR and the downstream extracellular signal-regulated kinase, c-Jun N-terminal kinase mitogen-activated protein kinase pathways as well as phosphatidylinositol 3-kinase/Akt pathway. Runx2 specifically binds to the Hbegf promoter, suggesting that Hbegf transcription is directly inhibited by Runx2. Runx2 can upregulate miR-1192, which enhances Runx2-induced osteogenic differentiation. Moreover, miR-1192 directly targets Hbegf through translational inhibition, suggesting enhancement of Runx2-induced osteogenic differentiation by miR-1192 through the downregulation of HB-EGF. Taken together, our results suggest that Runx2 induces osteogenic differentiation of C2C12 cells by inactivating HB-EGF-EGFR signaling through the downregulation of HB-EGF via both transcriptional and post-transcriptional mechanisms.

Spatial localization of EGF family ligands and receptors in the zebrafish ovarian follicle and their expression profiles during folliculogenesis.

PubMed

Tse, Anna Chung-Kwan; Ge, Wei

2010-07-01

The roles of epidermal growth factor (EGF) family in the ovary have received increasing attention recently. Despite this, the production sites of EGF family members in the ovarian follicle still remain controversial. Using zebrafish as the model, the present study investigated spatial distribution of several EGF family ligands and receptors in the follicle as well as their temporal expression profiles during folliculogenesis. RT-PCR analysis on the somatic follicle layer and oocyte revealed that all EGF family ligands examined (egf, tgfa, btc and hbegf) were mostly or exclusively expressed in the oocyte. In contrast, their common receptor (egfr) was expressed exclusively in the follicle layer. By comparison, members of activin family showed an opposite pattern of distribution. Activin subunits (inhbaa and inhbb) were both expressed exclusively in the follicle layer whereas activin receptors and follistatin were abundantly present in the oocyte. During folliculogenesis, egf, tgfa and hbegf increased their expression together with egfr in the fast secondary growth phase. The developmental profiles of EGF family during embryogenesis appeared to argue for an important role for EGF family in folliculogenesis rather than embryogenesis as maternal molecules. The present study provided clear evidence for the existence of two paracrine pathways in the follicle, the oocyte-derived EGF family ligands and follicle cell-derived activins, which may mediate oocyte-to-follicle cell and follicle cell-to-oocyte communications, respectively. The functional relationship between these two signaling systems in the follicle is suggested by the observation that all four EGFR ligands examined significantly stimulated activin subunit expression in cultured follicle cells. (c) 2009 Elsevier Inc. All rights reserved.

Heparin-binding EGF-like growth factor and miR-1192 exert opposite effect on Runx2-induced osteogenic differentiation

PubMed Central

Yu, S; Geng, Q; Ma, J; Sun, F; Yu, Y; Pan, Q; Hong, A

2013-01-01

Osteoblast differentiation is a pivotal event in bone formation. Runt-related transcription factor-2 (Runx2) is an essential factor required for osteoblast differentiation and bone formation. However, the underlying mechanism of Runx2-regulated osteogenic differentiation is still unclear. Here, we explored the corresponding mechanism using the C2C12/Runx2Dox subline, which expresses Runx2 in response to doxycycline (Dox). We found that Runx2-induced osteogenic differentiation of C2C12 cells results in a sustained decrease in the expression of heparin-binding EGF-like growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family. Forced expression of HB-EGF or treatment with HB-EGF is capable of reducing the expression of alkaline phosphatase (ALP), a defined marker of early osteoblast differentiation. HB-EGF-mediated inhibition of ALP depends upon activation of the EGFR and the downstream extracellular signal-regulated kinase, c-Jun N-terminal kinase mitogen-activated protein kinase pathways as well as phosphatidylinositol 3-kinase/Akt pathway. Runx2 specifically binds to the Hbegf promoter, suggesting that Hbegf transcription is directly inhibited by Runx2. Runx2 can upregulate miR-1192, which enhances Runx2-induced osteogenic differentiation. Moreover, miR-1192 directly targets Hbegf through translational inhibition, suggesting enhancement of Runx2-induced osteogenic differentiation by miR-1192 through the downregulation of HB-EGF. Taken together, our results suggest that Runx2 induces osteogenic differentiation of C2C12 cells by inactivating HB-EGF-EGFR signaling through the downregulation of HB-EGF via both transcriptional and post-transcriptional mechanisms. PMID:24136232

Epidermal growth factor (EGF) receptor-ligand based molecular staging predicts prognosis in head and neck squamous cell carcinoma partly due to deregulated EGF- induced amphiregulin expression.

PubMed

Gao, Jian; Ulekleiv, Camilla H; Halstensen, Trond S

2016-09-26

Increased expression of epidermal growth factor receptor (EGFR) and its ligands is associated with poor prognosis and chemoresistance in many carcinoma types, but its role in head and neck squamous cell carcinoma (HNSCC) is unclear. Our aim was to clarify whether mRNA expression of EGFR-ligands was linked to prognosis and cisplatin resistance, and if so, which ligand was most important and how was the expression regulated. To examine the prognostic effect of EGFR-ligand expression, we analyzed tumorous mRNA expression in 399 HNSCC patients. The intracellular signaling pathways controlling epidermal growth factor (EGF)-induced amphiregulin (AREG) expression were examined in three oral squamous cell carcinoma (OSCC) cell lines. Effect of AREG on cisplatin resistance was examined by viability assays in four-, and by association in 11 OSCC cell lines. The patients were divided into five groups according to the median mRNA expression levels of four EGFR ligands, i.e. AREG, EGF, heparin-binding EGF-like growth factor (HBEGF) and beta-cellulin (BTC). The number of increased-expressed EGFR-ligands were progressively correlated to five-year survival, even in advanced TNM-stage IV patients, where five-year mortality increased from 26 % if tumor expressed none to one EGFR-ligand, to 45 % in three to four ligand expressing tumors. Thus, staging the tumor according to these EGFR-ligand mRNA expression pattern completely out performed TNM staging in predicting prognosis. Multivariate analysis identified AREG as the dominating predictor, and AREG was overexpressed in OSCC compared to tumors from other sites. Both EGF and HBEGF stimulation induced strong AREG increase in OSCC cell lines, which was partially mediated by the extracellular signal-regulated kinase 1/2 pathway, and negatively regulated by p38, c-Jun N-terminal kinase, and phosphoinositide-3 kinase. Although increased AREG mRNA expression predicted unfavorable prognosis in platinum treated HNSCC patients, AREG did

An EGFR wild type-EGFRvIII-HB-EGF feed forward loop regulates the activation of EGFRvIII

PubMed Central

Li, Li; Chakraborty, Sharmistha; Yang, Chin-Rang; Hatanpaa, Kimmo J.; Cipher, Daisha J.; Puliyappadamba, Vineshkumar Thidil; Rehman, Alizeh; Jiwani, Ameena J.; Mickey, Bruce; Madden, Christopher; Raisanen, Jack; Burma, Sandeep; Saha, Debabrata; Wang, Zhixiang; Pingle, Sandeep C.; Kesari, Santosh; Boothman, David A.; Habib, Amyn A.

2014-01-01

EGFRvIII is a key oncogene in glioblastoma (GBM). EGFRvIII results from an in frame deletion in the extracellular domain of EGFR, does not bind ligand, and is thought to be constitutively active. While EGFRvIII dimerization is known to activate EGFRvIII, the factors that drive EGFRvIII dimerization and activation are not well understood. Here we present a new model of EGFRvIII activation and propose that oncogenic activation of EGFRvIII in glioma cells is driven by co-expressed activated EGFR wild type (EGFRwt). Increasing EGFRwt leads to a striking increase in EGFRvIII tyrosine phosphorylation and activation while silencing EGFRwt inhibits EGFRvIII activation. Both the dimerization arm and the kinase activity of EGFRwt are required for EGFRvIII activation. EGFRwt activates EGFRvIII by facilitating EGFRvIII dimerization. We have previously identified HB-EGF, a ligand for EGFRwt, as a gene induced specifically by EGFRvIII. In this study we show that HB-EGF, is induced by EGFRvIII only when EGFRwt is present. Remarkably, altering HB-EGF recapitulates the effect of EGFRwt on EGFRvIII activation. Thus, increasing HB-EGF leads to a striking increase in EGFRvIII tyrosine phosphorylation while silencing HB-EGF attenuates EGFRvIII phosphorylation, suggesting that an EGFRvIII-HB-EGF-EGFRwt feed forward loop regulates EGFRvIII activation. Silencing EGFRwt or HB-EGF leads to a striking inhibition of EGFRvIII induced tumorigenicity, while increasing EGFRwt or HB-EGF levels resulted in accelerated EGFRvIII mediated oncogenicity in an orthotopic mouse model. Furthermore, we demonstrate the existence of this loop in human GBM. Thus, our data demonstrate that oncogenic activation of EGFRvIII in GBM is likely maintained by a continuous EGFRwt-EGFRvIII-HBEGF loop, potentially an attractive target for therapeutic intervention. PMID:24077285

Maternal heparin-binding-EGF deficiency limits pregnancy success in mice

PubMed Central

Xie, Huirong; Wang, Haibin; Tranguch, Susanne; Iwamoto, Ryo; Mekada, Eisuke; DeMayo, Francesco J.; Lydon, John P.; Das, Sanjoy K.; Dey, Sudhansu K.

2007-01-01

An intimate discourse between the blastocyst and uterus is essential for successful implantation. However, the molecular basis of this interaction is not clearly understood. Exploiting genomic Hbegf mutant mice, we show here that maternal deficiency of heparin-binding EGF-like growth factor (HB-EGF) defers on-time implantation, leading to compromised pregnancy outcome. We also demonstrate that amphiregulin, but not epiregulin, partially compensates for the loss of HB-EGF during implantation. In search of the mechanism of this compensation, we found that reduced preimplantation estrogen secretion from ovarian HB-EGF deficiency is a cause of sustained expression of uterine amphiregulin before the initiation of implantation. To explore the significance specifically of uterine HB-EGF in implantation, we examined this event in mice with conditional deletion of uterine HB-EGF and found that this specific loss of HB-EGF in the uterus still defers on-time implantation without altering preimplantation ovarian estrogen secretion. The observation of normal induction of uterine amphiregulin surrounding the blastocyst at the time of attachment in these conditional mutant mice suggests a compensatory role of amphiregulin for uterine loss of HB-EGF, preventing complete failure of pregnancy. Our study provides genetic evidence that HB-EGF is critical for normal implantation. This finding has high clinical relevance, because HB-EGF signaling is known to be important for human implantation. PMID:17986609

Maternal heparin-binding-EGF deficiency limits pregnancy success in mice.

PubMed

Xie, Huirong; Wang, Haibin; Tranguch, Susanne; Iwamoto, Ryo; Mekada, Eisuke; Demayo, Francesco J; Lydon, John P; Das, Sanjoy K; Dey, Sudhansu K

2007-11-13

An intimate discourse between the blastocyst and uterus is essential for successful implantation. However, the molecular basis of this interaction is not clearly understood. Exploiting genomic Hbegf mutant mice, we show here that maternal deficiency of heparin-binding EGF-like growth factor (HB-EGF) defers on-time implantation, leading to compromised pregnancy outcome. We also demonstrate that amphiregulin, but not epiregulin, partially compensates for the loss of HB-EGF during implantation. In search of the mechanism of this compensation, we found that reduced preimplantation estrogen secretion from ovarian HB-EGF deficiency is a cause of sustained expression of uterine amphiregulin before the initiation of implantation. To explore the significance specifically of uterine HB-EGF in implantation, we examined this event in mice with conditional deletion of uterine HB-EGF and found that this specific loss of HB-EGF in the uterus still defers on-time implantation without altering preimplantation ovarian estrogen secretion. The observation of normal induction of uterine amphiregulin surrounding the blastocyst at the time of attachment in these conditional mutant mice suggests a compensatory role of amphiregulin for uterine loss of HB-EGF, preventing complete failure of pregnancy. Our study provides genetic evidence that HB-EGF is critical for normal implantation. This finding has high clinical relevance, because HB-EGF signaling is known to be important for human implantation.

Nuclear translocation of the cytoplasmic domain of HB-EGF induces gastric cancer invasion.

PubMed

Shimura, Takaya; Yoshida, Michihiro; Fukuda, Shinji; Ebi, Masahide; Hirata, Yoshikazu; Mizoshita, Tsutomu; Tanida, Satoshi; Kataoka, Hiromi; Kamiya, Takeshi; Higashiyama, Shigeki; Joh, Takashi

2012-05-30

Membrane-anchored heparin-binding epidermal growth factor-like growth factor (proHB-EGF) yields soluble HB-EGF, which is an epidermal growth factor receptor (EGFR) ligand, and a carboxy-terminal fragment of HB-EGF (HB-EGF-CTF) after ectodomain shedding. We previously reported that HB-EGF-CTF and unshed proHB-EGF which has the cytoplasmic domain of proHB-EGF (HB-EGF-C), translocate from the plasma membrane to the nucleus and regulate cell cycle after shedding stimuli. However, the significance of nuclear exported HB-EGF-C in human gastric cancer is unclear. We investigated the relationship between intracellular localization of HB-EGF-C and clinical outcome in 96 gastric cancer patients treated with gastrectomy. Moreover, we established stable gastric cancer cell lines overexpressing wild-type HB-EGF (wt-HB-EGF) and mutated HB-EGF (HB-EGF-mC), which prevented HB-EGF-C nuclear translocation after shedding. Cell motility between these 2 gastric cancer cell lines was investigated using a transwell invasion assay and a wound healing assay. Of the 96 gastric cancer cases, HB-EGF-C immunoreactivity was detected in both the nucleus and cytoplasm in 19 cases (19.8 %) and in the cytoplasm only in 25 cases (26.0 %). The nuclear immunoreactivity of HB-EGF-C was significantly increased in stage pT3/4 tumors compared with pT1/2 tumors (T1/2 vs. T3/4: 11.1 % vs. 36.4 %, P < 0.01). The growth of wt-HB-EGF- and HB-EGF-mC-expressing cells significantly increased compared with control cells, but the growth of HB-EGF-mC-expressing cells was significantly decreased compared with wt-HB-EGF-expressing cells. Gastric cancer cell invasion obviously increased in wt-HB-EGF-expressing cells, but invasion in HB-EGF-mC-expressing cells showed a slight increase compared with control cells. Moreover, wt-HB-EGF overexpression increased the effectiveness of wound healing, but had no significant effect in HB-EGF-mC-expressing cells. Both the function of HB-EGF as an EGFR ligand and a novel signal for

Staurosporine Induces Necroptotic Cell Death under Caspase-Compromised Conditions in U937 Cells

PubMed Central

Dunai, Zsuzsanna A.; Imre, Gergely; Barna, Gabor; Korcsmaros, Tamas; Petak, Istvan; Bauer, Pal I.; Mihalik, Rudolf

2012-01-01

For a long time necrosis was thought to be an uncontrolled process but evidences recently have revealed that necrosis can also occur in a regulated manner. Necroptosis, a type of programmed necrosis is defined as a death receptor-initiated process under caspase-compromised conditions. The process requires the kinase activity of receptor-interacting protein kinase 1 and 3 (RIPK1 and RIPK3) and mixed lineage kinase domain-like protein (MLKL), as a substrate of RIPK3. The further downstream events remain elusive. We applied known inhibitors to characterize the contributing enzymes in necroptosis and their effect on cell viability and different cellular functions were detected mainly by flow cytometry. Here we report that staurosporine, the classical inducer of intrinsic apoptotic pathway can induce necroptosis under caspase-compromised conditions in U937 cell line. This process could be hampered at least partially by the RIPK1 inhibitor necrotstin-1 and by the heat shock protein 90 kDa inhibitor geldanamycin. Moreover both the staurosporine-triggered and the classical death ligand-induced necroptotic pathway can be effectively arrested by a lysosomal enzyme inhibitor CA-074-OMe and the recently discovered MLKL inhibitor necrosulfonamide. We also confirmed that the enzymatic role of poly(ADP-ribose)polymerase (PARP) is dispensable in necroptosis but it contributes to membrane disruption in secondary necrosis. In conclusion, we identified a novel way of necroptosis induction that can facilitate our understanding of the molecular mechanisms of necroptosis. Our results shed light on alternative application of staurosporine, as a possible anticancer therapeutic agent. Furthermore, we showed that the CA-074-OMe has a target in the signaling pathway leading to necroptosis. Finally, we could differentiate necroptotic and secondary necrotic processes based on participation of PARP enzyme. PMID:22860037

Gallic acid-capped gold nanoparticles inhibit EGF-induced MMP-9 expression through suppression of p300 stabilization and NFκB/c-Jun activation in breast cancer MDA-MB-231 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ying-Jung; Lee, Yuan-Chin; Huang, Chia-Hui

Triple-negative breast cancers (TNBCs) are highly invasive and have a higher rate of distant metastasis. Matrix metalloproteinase-9 (MMP-9) plays a crucial role in EGF/EGFR-mediated malignant progression and metastasis of TNBCs. Various studies have revealed that treatment with gallic acid down-regulates MMP-9 expression in cancer cells, and that conjugation of phytochemical compounds with gold nanoparticles (AuNPs) increases the anti-tumor activity of the phytochemical compounds. Thus, the effect of gallic acid-capped AuNPs (GA-AuNPs) on MMP-9 expression in EGF-treated TNBC MDA-MB-231 cells was analyzed in the present study. The so-called green synthesis of AuNPs by means of gallic acid was performed at pHmore » 10, and the resulting GA-AuNPs had spherical shape with an average diameter of approximately 50 nm. GA-AuNPs notably suppressed migration and invasion of EGF-treated cells, and inhibited EGF-induced MMP-9 up-regulation. GA-AuNPs abrogated EGF-induced Akt/p65 and ERK/c-Jun phosphorylation, leading to down-regulation of MMP-9 mRNA and protein expression in EGF-treated cells. Meanwhile, EGF-induced p300 stabilization was found to be involved in MMP-9 expression, whereas GA-AuNPs inhibited the EGF-promoted stability of the p300 protein. Although GA-AuNPs and gallic acid suppressed EGF-induced MMP-9 up-regulation via the same signaling pathway, the effective concentration of gallic acid was approximately 100-fold higher than that of GA-AuNPs for inhibition of MMP-9 expression in EGF-treated cells to a similar extent. Collectively, our data indicate that, in comparison with gallic acid, GA-AuNPs have a superior ability to inhibit EGF/EGFR-mediated MMP-9 expression in TNBC MDA-MB-231 cells. Our findings also point to a way to improve the anti-tumor activity of gallic acid. - Highlights: • Gallic acid-capped gold nanoparticles inhibit EGF-induced MMP-9 expression. • EGF-induced MMP-9 expression via p300 stabilization and NFκB/c-Jun activation. • Gallic

SNP analyses of growth factor genes EGF, TGF{beta}-1, and HGF reveal haplotypic association of EGF with autism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toyoda, Takao; Thanseem, Ismail; Kawai, Masayoshi

Autism is a pervasive neurodevelopmental disorder diagnosed in early childhood. Growth factors have been found to play a key role in the cellular differentiation and proliferation of the central and peripheral nervous systems. Epidermal growth factor (EGF) is detected in several regions of the developing and adult brain, where, it enhances the differentiation, maturation, and survival of a variety of neurons. Transforming growth factor-{beta} (TGF{beta}) isoforms play an important role in neuronal survival, and the hepatocyte growth factor (HGF) has been shown to exhibit neurotrophic activity. We examined the association of EGF, TGF{beta}1, and HGF genes with autism, in amore » trio association study, using DNA samples from families recruited to the Autism Genetic Resource Exchange; 252 trios with a male offspring scored for autism were selected for the study. Transmission disequilibrium test revealed significant haplotypic association of EGF with autism. No significant SNP or haplotypic associations were observed for TGF{beta}1 or HGF. Given the role of EGF in brain and neuronal development, we suggest a possible role of EGF in the pathogenesis of autism.« less

Conformational stability of the epidermal growth factor (EGF) receptor as influenced by glycosylation, dimerization and EGF hormone binding.

PubMed

Taylor, Eric S; Pol-Fachin, Laercio; Lins, Roberto D; Lower, Steven K

2017-04-01

The epidermal growth factor receptor (EGFR) is an important transmembrane glycoprotein kinase involved the initiation or perpetuation of signal transduction cascades within cells. These processes occur after EGFR binds to a ligand [epidermal growth factor (EGF)], thus inducing its dimerization and tyrosine autophosphorylation. Previous publications have highlighted the importance of glycosylation and dimerization for promoting proper function of the receptor and conformation in membranes; however, the effects of these associations on the protein conformational stability have not yet been described. Molecular dynamics simulations were performed to characterize the conformational preferences of the monomeric and dimeric forms of the EGFR extracellular domain upon binding to EGF in the presence and absence of N-glycan moieties. Structural stability analyses revealed that EGF provides the most conformational stability to EGFR, followed by glycosylation and dimerization, respectively. The findings also support that EGF-EGFR binding takes place through a large-scale induced-fitting mechanism. Proteins 2017; 85:561-570. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

EGF-dependent re-routing of vesicular recycling switches spontaneous phosphorylation suppression to EGFR signaling

PubMed Central

Baumdick, Martin; Brüggemann, Yannick; Schmick, Malte; Xouri, Georgia; Sabet, Ola; Davis, Lloyd; Chin, Jason W; Bastiaens, Philippe IH

2015-01-01

Autocatalytic activation of epidermal growth factor receptor (EGFR) coupled to dephosphorylating activity of protein tyrosine phosphatases (PTPs) ensures robust yet diverse responses to extracellular stimuli. The inevitable tradeoff of this plasticity is spontaneous receptor activation and spurious signaling. We show that a ligand-mediated switch in EGFR trafficking enables suppression of spontaneous activation while maintaining EGFR’s capacity to transduce extracellular signals. Autocatalytic phosphorylation of tyrosine 845 on unliganded EGFR monomers is suppressed by vesicular recycling through perinuclear areas with high PTP1B activity. Ligand-binding results in phosphorylation of the c-Cbl docking tyrosine and ubiquitination of the receptor. This secondary signal relies on EGF-induced EGFR self-association and switches suppressive recycling to directional trafficking. The re-routing regulates EGFR signaling response by the transit-time to late endosomes where it is switched-off by high PTP1B activity. This ubiquitin-mediated switch in EGFR trafficking is a uniquely suited solution to suppress spontaneous activation while maintaining responsiveness to EGF. DOI: http://dx.doi.org/10.7554/eLife.12223.001 PMID:26609808

Mobility of tethering factor EEA1 on endosomes is decreased upon stimulation of EGF receptor endocytosis in HeLa cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kosheverova, Vera V., E-mail: kosheverova_vera@incras.ru; Kamentseva, Rimma S., E-mail: rkamentseva@yandex.ru; St. Petersburg State University, 7-9, Universitetskaya nab, St. Petersburg, 199034

Tethering factor EEA1, mediating homotypic fusion of early endosomes, was shown to be localized in membrane-bound state both in serum-deprived and stimulated for EGF receptor endocytosis cells. However, it is not known whether dynamics behavior of EEA1 is affected by EGF stimulation. We investigated EEA1 cytosol-to-membrane exchange rate in interphase HeLa cells by FRAP analysis. The data obtained fitted two-states binding model, with the bulk of membrane-associated EEA1 protein represented by the mobile fraction both in serum-starved and EGF-stimulated cells. Fast recovery state had similar half-times in the two cases: about 1.6 s and 2.8 s, respectively. However, the recovery half-time ofmore » slowly cycled EEA1 fraction significantly increased in EGF-stimulated comparing to serum-starved cells (from 21 to 99 s). We suppose that the retardation of EEA1 fluorescence recovery upon EGF-stimulation may be due to the increase of activated Rab5 on endosomal membranes, the growth of the number of tethering events between EEA1-positive vesicles and their clustering. - Highlights: • EEA1 mobility was compared in serum-starved and EGF-stimulated interphase HeLa cells. • FRAP analysis revealed fast and slow components of EEA1 recovery in both cases. • Stimulation of EGFR endocytosis did not affect fast EEA1 turnover. • EGF stimulation significantly increased half-time of slowly exchanged EEA1 fraction.« less

Epidermal growth factor (EGF) in the gastroprotective and ulcer healing actions of colloidal bismuth subcitrate (De-Nol) in rats.

PubMed Central

Konturek, S J; Dembinski, A; Warzecha, Z; Bielanski, W; Brzozowski, T; Drozdowicz, D

1988-01-01

Colloidal bismuth subcitrate (CBS; De-Nol) exhibits gastroprotective properties in experimental animals and enhances the healing of chronic gastroduodenal ulcers, but the mechanisms of these actions have not been entirely elucidated. The present study was designed to determine whether epidermal growth factor (EGF), which also has gastroprotective and ulcer healing properties, contributes to the action of De-Nol on the stomach in rats. It was found that De-Nol protects the gastric mucosa against ethanol damage and that this is accompanied by increased mucosal generation of prostaglandins (PG). Removal of the endogenous source of EGF (sialoadenectomy) did not significantly decrease the protective and PG stimulating effects of De-Nol. Pretreatment with exogenous EGF partially protected the stomach against ethanol injury, but did not influence the protective action of De-Nol in sialoadenectomised animals. De-Nol, like EGF given orally, enhanced the healing of chronic gastric and duodenal ulcers induced by serosal acetic acid. De-Nol was found to bind EGF in a pH-dependent manner and to accumulate it in ulcer area. Thus the peptide is available locally in high concentrations to accelerate the re-epithelialisation and tissue repair of the ulcerated mucosa. These ulcer healing effects of De-Nol were reduced by sialoadenectomy and restored in part by oral administration of EGF. We conclude that salivary glands in rats are not essential for the gastroprotection induced by De-Nol, but seem to play an important role in the ulcer healing action of this drug possibly via an EGF mediated mechanism. PMID:3260885

Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis.

PubMed

Phuc, Le Thi Minh; Taniguchi, Akiyoshi

2017-06-19

The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF) on the uptake efficiency of polystyrene nanoparticles (PS NPs) by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs) indicated that cellular uptake of PS NPs is related to the binding of EGF-EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications.

[Construction and expression of the targeting super-antigen EGF-SEA fusion gene].

PubMed

Xie, Yang; Peng, Shaoping; Liao, Zhiying; Liu, Jiafeng; Liu, Xuemei; Chen, Weifeng

2014-05-01

To construct expression vector for the SEA-EGF fusion gene. Clone the SEA gene and the EGF gene segment with PCR and RT-PCR independently, and connect this two genes by the bridge PCR. Insert the fusion gene EGF-SEA into the expression vector PET-44. Induced the secretion of the fusion protein SEA-EGF by the antileptic. The gene fragment encoding EGF and SEA mature peptide was successfully cloned. The fusion gene EGF-SEA was successfully constructed and was inserted into expression vector. The new recombinant expression vector for fusion gene EGF-SEA is specific for head and neck cancer, laid the foundation for the further study of fusion protein SEA-EGF targeting immune therapy in head and neck tumors.

Repeated dose intramuscular injection of the CIMAvax-EGF vaccine in Sprague Dawley rats induces local and systemic toxicity.

PubMed

Mancebo, A; Casacó, A; González, B; Ledón, N; Sorlozabal, J; León, A; Gómez, D; González, Y; Bada, A M; González, C; Arteaga, M E; Ramírez, H; Fuentes, D

2012-05-09

mediated by the oil-based adjuvant Montanide ISA 51, probably enhanced by the immunological properties of the antigen. This study showed evidences that intramuscular administration during 26 weeks of CIMAvax-EGF at doses up to 15× human total dose is well tolerated in rats and it has a clinical importance since this long lasting study in relevant species allows to treat cancer patients with tumors during long periods with relative weight safety margin. Copyright © 2012 Elsevier Ltd. All rights reserved.

Gallic acid-capped gold nanoparticles inhibit EGF-induced MMP-9 expression through suppression of p300 stabilization and NFκB/c-Jun activation in breast cancer MDA-MB-231 cells.

PubMed

Chen, Ying-Jung; Lee, Yuan-Chin; Huang, Chia-Hui; Chang, Long-Sen

2016-11-01

Triple-negative breast cancers (TNBCs) are highly invasive and have a higher rate of distant metastasis. Matrix metalloproteinase-9 (MMP-9) plays a crucial role in EGF/EGFR-mediated malignant progression and metastasis of TNBCs. Various studies have revealed that treatment with gallic acid down-regulates MMP-9 expression in cancer cells, and that conjugation of phytochemical compounds with gold nanoparticles (AuNPs) increases the anti-tumor activity of the phytochemical compounds. Thus, the effect of gallic acid-capped AuNPs (GA-AuNPs) on MMP-9 expression in EGF-treated TNBC MDA-MB-231 cells was analyzed in the present study. The so-called green synthesis of AuNPs by means of gallic acid was performed at pH10, and the resulting GA-AuNPs had spherical shape with an average diameter of approximately 50nm. GA-AuNPs notably suppressed migration and invasion of EGF-treated cells, and inhibited EGF-induced MMP-9 up-regulation. GA-AuNPs abrogated EGF-induced Akt/p65 and ERK/c-Jun phosphorylation, leading to down-regulation of MMP-9 mRNA and protein expression in EGF-treated cells. Meanwhile, EGF-induced p300 stabilization was found to be involved in MMP-9 expression, whereas GA-AuNPs inhibited the EGF-promoted stability of the p300 protein. Although GA-AuNPs and gallic acid suppressed EGF-induced MMP-9 up-regulation via the same signaling pathway, the effective concentration of gallic acid was approximately 100-fold higher than that of GA-AuNPs for inhibition of MMP-9 expression in EGF-treated cells to a similar extent. Collectively, our data indicate that, in comparison with gallic acid, GA-AuNPs have a superior ability to inhibit EGF/EGFR-mediated MMP-9 expression in TNBC MDA-MB-231 cells. Our findings also point to a way to improve the anti-tumor activity of gallic acid. Copyright © 2016 Elsevier Inc. All rights reserved.

Extracellular calcium triggers unique transcriptional programs and modulates staurosporine-induced cell death in Neurospora crassa

PubMed Central

Gonçalves, A. P.; Monteiro, João; Lucchi, Chiara; Kowbel, David J.; Cordeiro, J. M.; Correia-de-Sá, Paulo; Rigden, Daniel J.; Glass, N. L.; Videira, Arnaldo

2014-01-01

Alterations in the intracellular levels of calcium are a common response to cell death stimuli in animals and fungi and, particularly, in the Neurospora crassa response to staurosporine. We highlight the importance of the extracellular availability of Ca2+ for this response. Limitation of the ion in the culture medium further sensitizes cells to the drug and results in increased accumulation of reactive oxygen species (ROS). Conversely, an approximately 30-fold excess of external Ca2+ leads to increased drug tolerance and lower ROS generation. In line with this, distinct staurosporine-induced cytosolic Ca2+ signaling profiles were observed in the absence or presence of excessive external Ca2+. High-throughput RNA sequencing revealed that different concentrations of extracellular Ca2+ define distinct transcriptional programs. Our transcriptional profiling also pointed to two putative novel Ca2+-binding proteins, encoded by the NCU08524 and NCU06607 genes, and provides a reference dataset for future investigations on the role of Ca2+ in fungal biology. PMID:28357255

Phosphorylation of TNF-alpha converting enzyme by gastrin-releasing peptide induces amphiregulin release and EGF receptor activation.

PubMed

Zhang, Qing; Thomas, Sufi M; Lui, Vivian Wai Yan; Xi, Sichuan; Siegfried, Jill M; Fan, Huizhou; Smithgall, Thomas E; Mills, Gordon B; Grandis, Jennifer Rubin

2006-05-02

G protein-coupled receptors induce EGF receptor (EGFR) signaling, leading to the proliferation and invasion of cancer cells. Elucidation of the mechanism of EGFR activation by G protein-coupled receptors may identify new signaling paradigms. A gastrin-releasing peptide (GRP)/GRP receptor-mediated autocrine pathway was previously described in squamous cell carcinoma of head and neck. In the present study, we demonstrate that TNF-alpha converting enzyme (TACE), a disintegrin and metalloproteinse-17, undergoes a Src-dependent phosphorylation that regulates release of the EGFR ligand amphiregulin upon GRP treatment. Further investigation reveals the phosphatidylinositol 3-kinase (PI3-K) as the intermediate of c-Src and TACE, contributing to their association and TACE phosphorylation. Phosphoinositide-dependent kinase 1 (PDK1), a downstream target of PI3-K, has been identified as the previously undescribed kinase to directly phosphorylate TACE upon GRP treatment. These findings suggest a signaling cascade of GRP-Src-PI3-K-PDK1-TACE-amphiregulin-EGFR with multiple points of interaction, translocation, and phosphorylation. Furthermore, knockdown of PDK1 augmented the antitumor effects of the EGFR inhibitor erlotinib, indicating PDK1 as a therapeutic target to improve the clinical response to EGFR inhibitors.

Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis

PubMed Central

Phuc, Le Thi Minh; Taniguchi, Akiyoshi

2017-01-01

The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF) on the uptake efficiency of polystyrene nanoparticles (PS NPs) by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs) indicated that cellular uptake of PS NPs is related to the binding of EGF–EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications. PMID:28629179

AUGMENTATION OF LIMB PERFUSION AND REVERSAL OF TISSUE ISCHEMIA PRODUCED BY ULTRASOUND-MEDIATED MICROBUBBLE CAVITATION

PubMed Central

Belcik, J. Todd; Mott, Brian H.; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J.; Ammi, Azzdine; Linden, Joel M.; Lindner, Jonathan R.

2015-01-01

Background Ultrasound can increase tissue blood flow in part through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation, and sought to characterize the biologic mediators. Methods and Results Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in non-ischemic mice after unilateral 10 min exposure to intermittent ultrasound alone (mechanical index [MI] 0.6 or 1.3) or ultrasound with lipid microbubbles (2×108 I.V.). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (p<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3-fold and 10-fold higher than control for MI 0.6 and 1.3, respectively; p<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase (eNOS) attenuated flow augmentation produced by ultrasound and microbubbles by 70% (p<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide (NO) production and muscle phospho-eNOS increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40–50% reduction in flow), ultrasound (MI 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control non-ischemic limb. Conclusions Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of eNOS. PMID:25834183

Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation.

PubMed

Belcik, J Todd; Mott, Brian H; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J; Ammi, Azzdine; Linden, Joel M; Lindner, Jonathan R

2015-04-01

Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in nonischemic mice after unilateral 10-minute exposure to intermittent ultrasound alone (mechanical index, 0.6 or 1.3) or ultrasound with lipid microbubbles (2×10(8) IV). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (P<0.05) in muscle perfusion regardless of ultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3- and 10-fold higher than control for mechanical index 0.6 and 1.3, respectively; P<0.05), as was femoral artery dilation. Inhibition of endothelial nitric oxide synthase attenuated flow augmentation produced by ultrasound and microbubbles by 70% (P<0.01), whereas inhibition of adenosine-A2a receptors and epoxyeicosatrienoic acids had minimal effect. Limb nitric oxide production and muscle phospho-endothelial nitric oxide synthase increased in a stepwise fashion by ultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40%-50% reduction in flow), ultrasound (mechanical index, 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control nonischemic limb. Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of endothelial nitric oxide synthase. © 2015 American Heart

Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji

2014-08-01

Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermalmore » growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and

Old dance with a new partner: EGF receptor as the phenobarbital receptor mediating Cyp2B expression.

PubMed

Meyer, Sharon A; Jirtle, Randy L

2013-05-07

The decades-long quest for the phenobarbital (PhB) receptor that mediates activation of Cyp2B would appear fulfilled with the discovery by Mutoh et al., who found that PhB binds with pharmacological affinity to the epidermal growth factor receptor (EGFR). This finding provides a molecular basis for the suppression of hepatocyte EGFR signaling observed with PhB treatment, as previously noted in the context of tumor promotion. Although the PhB-mediated induction of Cyp2B expression through the association of a canonical nuclear receptor with the 5'-enhancer PBREM of Cyp2B is well known, direct binding of PhB to constitutive active androstane receptor (CAR, also known as NR1I3) typical of other xenobiotic-activated nuclear receptors has eluded detection. One EGF-activated pathway affected by the PhB-EGFR interaction is the loss of tyrosine phosphorylation of the scaffold protein RACK1. Dephosphorylated RACK1 provides the mechanistic link between the binding of PhB to EGFR and its effects on CAR by facilitating the interaction of serine/threonine phosphatase PP2A with inactive phosphorylated CAR. The dephosphorylation of CAR enables its translocation to the nucleus and activation of Cyp2B expression. Because EGFR and transducers RACK1, PP2A, and other partners are highly networked in numerous cellular pathways, this newly discovered partnership will surely reveal new fundamental roles for PhB beyond the regulation of drug metabolism.

[99mTc] HYNIC-hEGF, a potential agent for imaging of EGF receptors in vivo: preparation and pre-clinical evaluation.

PubMed

Babaei, Mohammad Hossein; Almqvist, Ylva; Orlova, Anna; Shafii, Mohammad; Kairemo, Kalevi; Tolmachev, Vladimir

2005-06-01

Expression of epidermal growth factor receptors (EGFR) has prognostic and predictive value in many kinds of tumors. Imaging of expression of EGFR in vivo may give valuable diagnostic information. The epidermal growth factor (EGF), a natural ligand, is a possible candidate for the targeting of EGFR. The present study describes a method for preparation of (99m)Tc-EGF via the hydrazinopyridine-3-carboxylic acid (HYNIC) conjugation using tricine and ethylenediamine-N,N'-diacetic acid (EDDA) as co-ligands. Both conjugates bound EGFR expressing cells with nanomolar affinity, and demonstrated good intracellular retention. The complex with EDDA demonstrated much higher stability in blood serum and during cysteine challenge. Biodistribution of (99m)Tc-EDDA-HYNIC-EGF in normal mice demonstrated fast blood clearance of conjugate, and its ability to bind EGFR in vivo. (99m)Tc-EDDA-HYNIC-EGF is a promising candidate for visualization of EGFR expression in vivo.

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors.

PubMed Central

Xiao, J H; Feng, X; Di, W; Peng, Z H; Li, L A; Chambon, P; Voorhees, J J

1999-01-01

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing. PMID:10075925

The effect of hydrostatic pressure on staurosporine-induced neural differentiation in mouse bone marrow‑derived mesenchymal stem cells.

PubMed

Javanmard, F; Azadbakht, M; Pourmoradi, M

2016-01-01

In this study, the role of hydrostatic pressure on staurosporine-induced neural differentiation in mouse bone marrow mesenchymal stem cells were investigated. The cells were cultured in treatment medium containing 100 nM of staurosporine for 4 hours; then the cells were affected by hydrostatic pressure (0, 25,50, 100 mmHg). The percentage of cell viability by trypan blue staining and the percentage of cell death by Hoechst/PI differential staining were assessed. We obtained the total neurite length. Expression of β-tubulin III and GFAP (Glial fibrillary acidic protein) proteins were also analyzed by immunocytochemistry. The percentage of cell viability in treatments decreased relative to the increase in hydrostatic pressure and time (p Keywords: bone marrow mesenchymal stem cell, hydrostatic pressure, immunocytochemistry, neural differentiation, neurite length, cell differentiation.

Resveratrol modulates MED28 (Magicin/EG-1) expression and inhibits epidermal growth factor (EGF)-induced migration in MDA-MB-231 human breast cancer cells.

PubMed

Lee, Ming-Fen; Pan, Min-Hsiung; Chiou, Yi-Siou; Cheng, An-Chin; Huang, Han

2011-11-09

Resveratrol and pterostilbene exhibit diverse biological activities. MED28, a subunit of the mammalian Mediator complex for transcription, was also identified as magicin, an actin cytoskeleton Grb2-associated protein, and as endothelial-derived gene (EG-1). Several tumors exhibit aberrant MED28 expression, whereas the underlying mechanism is unclear. Triple-negative breast cancers, often expressing epidermal growth factor (EGF) receptor (EGFR), are associated with metastasis and poor survival. The objective of this study is to compare the effect of resveratrol and pterostilbene and to investigate the role of MED28 in EGFR-overexpressing MDA-MB-231 breast cancer cells. Pretreatment of resveratrol, but not pterostlbene, suppressed EGF-mediated migration and expression of MED28 and matrix metalloproteinase (MMP)-9 in MDA-MB-231 cells. Moreover, overexpression of MED28 increased migration, and the addition of EGF further enhanced migration. Our data indicate that resveratrol modulates the effect of MED28 on cellular migration, presumably through the EGFR/phosphatidylinositol 3-kinase (PI3K) signaling pathway, in breast cancer cells.

The cannabinoid receptor inverse agonist AM251 regulates the expression of the EGF receptor and its ligands via destabilization of oestrogen-related receptor α protein

PubMed Central

Fiori, JL; Sanghvi, M; O'Connell, MP; Krzysik-Walker, SM; Moaddel, R; Bernier, M

2011-01-01

BACKGROUND AND PURPOSE AM251 is an inverse agonist of the cannabinoid 1 receptor (CB1R) that can exert ‘off-target’ effects in vitro and in CB1R knock-out mice. AM251 is also potent at modulating tumour cell growth, suggesting that growth factor-mediated oncogenic signalling could be regulated by AM251. Since dysregulation of the EGF receptor has been associated with carcinogenesis, we examined AM251 regulation of EGF receptor (EGFR) expression and function. EXPERIMENTAL APPROACH The various biological functions of AM251 were measured in CB1R-negative human cancer cells. Pharmacological and genetic approaches were used to validate the data. KEY RESULTS The mRNA levels for EGFR and its associated ligands, including HB-EGF, were induced several fold in PANC-1 and HCT116 cells in response to AM251. This event was associated with enhanced expression of EGFR on the cell surface with concomitant increase in EGF-induced cellular responses in AM251-treated cells. Exposure to XCT790, a synthetic inverse agonist of the orphan nuclear oestrogen-related receptor α (ERRα), also induced EGFR and HB-EGF expression to the same extent as AM251, whereas pretreatment with the ERRα-selective agonist, biochanin A, blunted AM251 actions. AM251 promoted the degradation of ERRα protein without loss of the corresponding mRNA. Knock-down of ERRα by siRNA-based approach led to constitutive induction of EGFR and HB-EGF levels, and eliminated the biological responses of AM251 and XCT790. Finally, AM251 displaced diethylstilbestrol prebound to the ligand-binding domain of ERRα. CONCLUSIONS AND IMPLICATIONS AM251 up-regulates EGFR expression and signalling via a novel non-CB1R-mediated pathway involving destabilization of ERRα protein in selected cancer cell lines. PMID:21449913

TCDD AND EGF AFFECT MAPK PATHWAY ACTIVATION IN MURINE EMBRYONIC PALATE

EPA Science Inventory

Palatal fusion occurs on GD 14-15 in the mouse, accompanied by a decrease in EGF receptor (EGFR) at the medial edge of the palatal shelves. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate and maintains EGF and EGF receptor (EGFR) expression levels in the medial ed...

HB-EGF function in cardiac valve development requires interaction with heparan sulfate proteoglycans.

PubMed

Iwamoto, Ryo; Mine, Naoki; Kawaguchi, Taichiro; Minami, Seigo; Saeki, Kazuko; Mekada, Eisuke

2010-07-01

HB-EGF, a member of the EGF family of growth factors, plays an important role in cardiac valve development by suppressing mesenchymal cell proliferation. Here, we show that HB-EGF must interact with heparan sulfate proteoglycans (HSPGs) to properly function in this process. In developing valves, HB-EGF is synthesized in endocardial cells but accumulates in the mesenchyme by interacting with HSPGs. Disrupting the interaction between HB-EGF and HSPGs in an ex vivo model of endocardial cushion explants resulted in increased mesenchymal cell proliferation. Moreover, homozygous knock-in mice (HB(Delta)(hb/)(Delta)(hb)) expressing a mutant HB-EGF that cannot bind to HSPGs developed enlarged cardiac valves with hyperproliferation of mesenchymal cells; this resulted in a phenotype that resembled that of Hbegf-null mice. Interestingly, although Hbegf-null mice had abnormal heart chambers and lung alveoli, HB(Delta)(hb/)(Delta)(hb) mice did not exhibit these defects. These results indicate that interactions with HSPGs are essential for the function of HB-EGF, especially in cardiac valve development, in which HB-EGF suppresses mesenchymal cell proliferation.

Capacity of tumor necrosis factor to augment lymphocyte-mediated tumor cell lysis of malignant mesothelioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, R.V.; Manning, L.S.; Davis, M.R.

1991-01-01

Recombinant human tumor necrosis factor (rHuTNF) was evaluated both for direct anti-tumor action against human malignant mesothelioma and for its capacity to augment the generation and lytic phases of lymphocyte-mediated cytotoxicity against this tumor. rHuTNF was directly toxic by MTT assay to one of two mesothelioma cell lines evaluated, but had no effect on susceptibility to subsequent lymphocyte-mediated lysis of either line. TNF alone was incapable of generating anti-mesothelioma lymphokine-activated killer cell (LAK) activity. Furthermore, it did not augment the degree or LAK activity produced by submaximal interleukin-2 (IL-2) concentrations nor did it augment lysis of mesothelioma cells by naturalmore » killer (NK) or LAK effector cells during the 4-hr 51chromium release cytolytic reaction. The studies also suggest that mesothelioma targets are less responsive to TNF plus submaximal IL-2 concentrations than the standard LAK sensitive target Daudi, raising the possibility that intermediate LAK sensitive tumors such as mesothelioma may require separate and specific evaluation in immunomodulation studies. This in vitro study indicates that use of low-dose rHuTNF and IL-2 is unlikely to be an effective substitute for high-dose IL-2 in generation and maintenance of LAK activity in adoptive immunotherapy for mesothelioma.« less

Staurosporine scaffold-based rational discovery of the wild-type sparing reversible inhibitors of EGFR T790M gatekeeper mutant in lung cancer with analog-sensitive kinase technology.

PubMed

Song, Xiaoyun; Liu, Xingcai; Ding, Xi

2017-04-01

The human epidermal growth factor receptor (EGFR) has been established as an attractive target for lung cancer therapy. However, an acquired EGFR T790M gatekeeper mutation is frequently observed in patients treated with first-line anticancer agents such as gefitinib and erlotinib to cause drug resistance, largely limiting the application of small-molecule kinase inhibitors in EGFR-targeted chemotherapy. Previously, the reversible pan-kinase inhibitor staurosporine and its several analogs such as Gö6976 and K252a have been reported to selectively inhibit the EGFR T790M mutant (EGFR T790M ) over wild-type kinase (EGFR WT ), suggesting that the staurosporine scaffold is potentially to develop the wild-type sparing reversible inhibitors of EGFR T790M . Here, we systematically evaluated the inhibitor response of 28 staurosporine scaffold-based compounds to EGFR T790M mutation at structural, energetic, and molecular levels by using an integrated in silico-in vitro analog-sensitive (AS) kinase technology. With the strategy, we were able to identify 4 novel wild-type sparing inhibitors UCN-01, UCN-02, AFN941, and SB-218078 with high or moderate selectivity of 30-, 45-, 5-, and 8-fold for EGFR T790M over EGFR WT , respectively, which are comparable with or even better than that of the parent compound staurosporine (24-fold). Molecular modeling and structural analysis revealed that van der Waals contacts and hydrophobic forces can form between the side chain of mutated residue Met790 and the pyrrolidinone moiety of inhibitor ligand UCN-02, which may simultaneously improve the favorable interaction energy between the kinase and inhibitor, and reduce the unfavorable desolvation penalty upon the kinase-inhibitor binding. A hydroxyl group of UCN-02 additional to staurosporine locates at the pyrrolidinone moiety, which can largely alter the electronic distribution of pyrrolidinone moiety and thus promote the intermolecular interaction with Met790 residue. This can well explain

Increased Endothelin Activity Mediates Augmented Distal Nephron Acidification Induced by Dietary Protein

PubMed Central

Khanna, Apurv; Simoni, Jan; Hacker, Callenda; Duran, Marie-Josée; Wesson, Donald E

2005-01-01

We tested the hypothesis that increased dietary protein augments distal nephron acidification through an endothelin-dependent mechanism. Munich-Wistar rats ate minimum electrolyte diets of 50% (HiPro) and 20% (CON) casein-provided protein, the latter comparable to standard chow. HiPro vs. CON had higher distal nephron H+ secretion (41.3 ± 4.0 vs. 23.0 ± 2.1 pmol/mm.min, p < 0.002) mediated by augmented Na+/H+ exchange and H+-ATPase activity. Renal cortex of HiPro vs. CON had higher ET-1 addition to microdialysate and higher ET-1 mRNA, consistent with increased renal ET-1 production. Bosentan, an endothelin A/B receptor antagonist, decreased HiPro distal nephron H+ secretion (28.4 ± 2.4 vs. 41.3 ± 4.0 pmol/mm.min, p < 0.016) through decreased Na+/H+ exchange and decreased H+-ATPase activity. Increased dietary protein augments distal nephron acidification through an endothelin-sensitive increase in Na+/H+ exchange and H+-ATPase activity, supporting an endothelin role in the distal nephron response to this common challenge to acid-base status. PMID:16555618

3-D individual cell based computational modeling of tumor cell–macrophage paracrine signaling mediated by EGF and CSF-1 gradients†

PubMed Central

Knutsdottir, Hildur; Condeelis, John S.; Palsson, Eirikur

2016-01-01

High density of macrophages in mammary tumors has been associated with a higher risk of metastasis and thus increased mortality in women. The EGF/CSF-1 paracrine signaling increases the number of invasive tumor cells by both recruiting tumor cells further away and manipulating the macrophages’ innate ability to open up a passage into blood vessels thus promoting intravasation and finally metastasis. A 3-D individual-cell-based model is introduced, to better understand the tumor cell–macrophage interactions, and to explore how changing parameters of the paracrine signaling system affects the number of invasive tumor cells. The simulation data and videos of the cell movements correlated well with findings from both in vitro and in vivo experimental results. The model demonstrated how paracrine signaling is necessary to achieve co-migration of tumor cells and macrophages towards a specific signaling source. We showed how the paracrine signaling enhances the number of both invasive tumor cells and macrophages. The simulations revealed that for the in vitro experiments the imposed no-flux boundary condition might be affecting the results, and that changing the setup might lead to different experimental findings. In our simulations, the 3 : 1 tumor cell/macrophage ratio, observed in vivo, was robust for many parameters but sensitive to EGF signal strength and fraction of macrophages in the tumor. The model can be used to identify new agents for targeted therapy and we suggest that a successful strategy to prevent or limit invasion of tumor cells would be to block the tumor cell–macrophage paracrine signaling. This can be achieved by either blocking the EGF or CSF-1 receptors or supressing the EGF or CSF-1 signal. PMID:26686751

Early changes in staurosporine-induced differentiated RGC-5 cells indicate cellular injury response to nonlethal blue light exposure.

PubMed

Zhang, Pei; Huang, Chen; Wang, Wei; Wang, Minshu

2015-06-01

Blue light has been previously demonstrated to induce injury of retinal cells. The cellular responses to nonlethal blue light exposure for each type of retinal cell are of particular interest but remain undetermined. Based on the doses of blue light reported in previous research to be nonlethal to retinal pigment epithelial cells, here we investigated whether and to what extent such doses of blue light are cytotoxic to staurosporine-differentiated RGC-5 cells. RGC-5 cells were differentiated for 24 hours using 200 nM staurosporine. The resulting cells were cultured and exposed to blue light at three different energy levels (1, 10, and 50 J cm(-2)). Cellular morphologies were investigated with an inverted microscope and cell viability was assessed with a Cell Counting Kit-8 (CCK-8) assay. The generation of intracellular reactive oxygen species (ROS) was evaluated by H2DCFDA. After loading of MitoTracker Green FM dye, the mitochondrial contents were analyzed using flow cytometry. The lactate dehydrogenase (LDH) activities in the media were also measured. The level of lipid peroxidation was determined by measuring the amount of malondialdehyde (MDA). Treatment of the cells for 24 hours with 200 nM staurosporine successfully induced the differentiation of RGC-5 cells. No morphological changes were observed in the ssdRGC-5 cells exposed to blue light at 50 J cm(-2), which was the highest energy level tested. Exposure of the ssdRGC-5 cells to this energy level of blue light did, however, decrease their numbers by approximately 72.1% compared to the numbers of such cells found after being left in the dark. Remarkably, the levels of ROS generation and mitochondrial contents were, respectively, increased to 142% and 118% of those of the control by a 10 J cm(-2) exposure of blue light. The LDH activities and MDA levels exhibited no obvious changes in the blue light-exposed ssdRGC-5 cells compared to the control cells. In vitro nonlethal blue light exposure led to cellular

Gallic acid abolishes the EGFR/Src/Akt/Erk-mediated expression of matrix metalloproteinase-9 in MCF-7 breast cancer cells.

PubMed

Chen, Ying-Jung; Lin, Ku-Nan; Jhang, Li-Mei; Huang, Chia-Hui; Lee, Yuan-Chin; Chang, Long-Sen

2016-05-25

Several studies have revealed that natural compounds are valuable resources to develop novel agents against dysregulation of the EGF/EGFR-mediated matrix metalloproteinase-9 (MMP-9) expression in cancer cells. In view of the findings that EGF/EGFR-mediated MMP-9 expression is closely related to invasion and metastasis of breast cancer. To determine the beneficial effects of gallic acid on the suppression of breast cancer metastasis, we explored the effect of gallic acid on MMP-9 expression in EGF-treated MCF-7 breast cancer cells. Treatment with EGF up-regulated MMP-9 mRNA and protein levels in MCF-7 cells. EGF treatment induced phosphorylation of EGFR and elicited Src activation, subsequently promoting Akt/NFκB (p65) and ERK/c-Jun phosphorylation in MCF-7 cells. Activation of Akt/p65 and ERK/c-Jun was responsible for the MMP-9 up-regulation in EGF-treated cells. Gallic acid repressed the EGF-induced activation of EGFR and Src; furthermore, inactivation of Akt/p65 and ERK/c-Jun was a result of the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. Over-expression of constitutively active Akt and MEK1 or over-expression of constitutively active Src eradicated the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. A chromosome conformation capture assay showed that EGF induced a chromosomal loop formation in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun activation. Treatment with gallic acid, EGFR inhibitor, or Src inhibitor reduced DNA looping. Taken together, our data suggest that gallic acid inhibits the activation of EGFR/Src-mediated Akt and ERK, leading to reduced levels of p65/c-Jun-mediated DNA looping and thus inhibiting MMP-9 expression in EGF-treated MCF-7 cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Heparin-binding EGF-like growth factor is present in human amniotic fluid and breast milk.

PubMed

Michalsky, M P; Lara-Marquez, M; Chun, L; Besner, G E

2002-01-01

Heparin-binding EGF-like growth factor (HB-EGF) is a member of the epidermal growth factor (EGF) family that has been implicated in the healing of various organ injuries. Endogenous HB-EGF production is upregulated in response to injury to the kidney, liver, brain, skin, and intestine. Exogenous administration of HB-EGF protects against intestinal epithelial cell apoptosis and necrosis and intestinal ischemia/reperfusion (I/R) injury. This study examines the presence of endogenous HB-EGF in human amniotic fluid and breast milk, fluids that are in intimate contact with the developing and neonatal gastrointestinal tract. Breast milk samples were collected from lactating women and amniotic fluid was gathered from full-term uteri (cesarian sections) or preterm uteri (amniocentesis). Crude and partially purified breast milk and amniotic fluid samples were analyzed for HB-EGF levels using an HB-EGF-specific enzyme-linked immunosorbent assay (ELISA). Analysis results showed detectable HB-EGF levels in human amniotic fluid and breast milk, ranging from 0.2 to 230 pg/mL. Breast milk and amniotic fluid subjected to heparin affinity or HB-EGF-affinity column chromatography showed bioactivity eluting at positions consistent with those known for native HB-EGF. This study represents the first report of detectable HB-EGF in human amniotic fluid and breast milk. The presence of HB-EGF in these fluids may serve a role in the development of the gastrointestinal tract in utero, and in protection against gut mucosal injury after birth. Copyright 2002 by W.B. Saunders Company.

Lefty Blocks a Subset of TGFβ Signals by Antagonizing EGF-CFC Coreceptors

PubMed Central

Cheng, Simon K; Olale, Felix; Brivanlou, Ali H

2004-01-01

Members of the EGF-CFC family play essential roles in embryonic development and have been implicated in tumorigenesis. The TGFβ signals Nodal and Vg1/GDF1, but not Activin, require EGF-CFC coreceptors to activate Activin receptors. We report that the TGFβ signaling antagonist Lefty also acts through an EGF-CFC-dependent mechanism. Lefty inhibits Nodal and Vg1 signaling, but not Activin signaling. Lefty genetically interacts with EGF-CFC proteins and competes with Nodal for binding to these coreceptors. Chimeras between Activin and Nodal or Vg1 identify a 14 amino acid region that confers independence from EGF-CFC coreceptors and resistance to Lefty. These results indicate that coreceptors are targets for both TGFβ agonists and antagonists and suggest that subtle sequence variations in TGFβ signals result in greater ligand diversity. PMID:14966532

Epidermal Growth Factor-Dependent Transformation by a Human EGF Receptor Proto-Oncogene

NASA Astrophysics Data System (ADS)

Velu, Thierry J.; Beguinot, Laura; Vass, William C.; Willingham, Mark C.; Merlino, Glenn T.; Pastan, Ira; Lowy, Douglas R.

1987-12-01

The epidermal growth factor (EGF) receptor gene EGFR has been placed in a retrovirus vector to examine the growth properties of cells that experimentally overproduce a full-length EGF receptor. NIH 3T3 cells transfected with the viral DNA or infected with the corresponding rescued retrovirus developed a fully transformed phenotype in vitro that required both functional EGFR expression and the presence of EGF in the growth medium. Cells expressing 4 × 105 EGF receptors formed tumors in nude mice, while control cells did not. Therefore, the EGFR retrovirus, which had a titer on NIH 3T3 cells that was greater than 107 focus-forming units per milliliter, can efficiently transfer and express this gene, and increased numbers of EGF receptors can contribute to the transformed phenotype.

Donor B cells in Transplants Augment Clonal Expansion and Survival of Pathogenic CD4+ T cells That Mediate Autoimmune-like Chronic GVHD

PubMed Central

Young, James S; Wu, Tao; Chen, Yuhong; Zhao, Dongchang; Liu, Hongjun; Yi, Tangsheng; Johnston, Heather; Racine, Jeremy; Li, Xiaofan; Wang, Audrey; Todorov, Ivan; Zeng, Defu

2013-01-01

We reported that both donor CD4+ T and B cells in transplants were required for induction of an autoimmune-like chronic graft versus host disease (cGVHD) in a murine model of DBA/2 donor to BALB/c recipient, but mechanisms whereby donor B cells augment cGVHD pathogenesis remain unknown. Here, we report that, although donor B cells have little impact on acute GVHD (aGVHD) severity, they play an important role in augmenting the persistence of tissue damage in the acute and chronic GVHD overlapping target organs (i.e. skin and lung); they also markedly augment damage in a prototypical cGVHD target organ- the salivary gland. During cGVHD pathogenesis, donor B cells are activated by donor CD4+ T cells to upregulate MHC II and co-stimulatory molecules. Acting as efficient APCs, donor B cells augment donor CD4+ T clonal expansion, autoreactivity, IL-7Rα expression, and survival. These qualitative changes markedly augment donor CD4+ T cells' capacity in mediating autoimmune-like cGVHD, so that they mediate disease in the absence of donor B cells in secondary recipients. Therefore, a major mechanism whereby donor B cells augment cGVHD is through augmenting the clonal expansion, differentiation and survival of pathogenic CD4+ T cells. PMID:22649197

CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation

PubMed Central

Ravasi, Saula; Citro, Simona; Viviani, Barbara; Capra, Valérie; Rovati, G Enrico

2006-01-01

Background Cysteine-containing leukotrienes (cysteinyl-LTs) are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC) proliferation. We used human ASMC (HASMC) to identify the signal transduction pathway(s) of the leukotriene D4 (LTD4)-induced DNA synthesis. Methods Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R) and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS) was estimated by measuring dichlorodihydrofluorescein (DCF) oxidation. Results We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX) and phosphoinositide 3-kinase (PI3K) inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC) abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Conclusion Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF-R through the

Arf6 regulates EGF-induced internalization of E-cadherin in breast cancer cells.

PubMed

Xu, Rui; Zhang, Yujie; Gu, Luo; Zheng, Jianchao; Cui, Jie; Dong, Jing; Du, Jun

2015-01-01

E-cadherin internalization facilitates dissolution of adherens junctions and promotes tumor cell epithelial-mesenchymal transition (EMT) and migration. Our previous results have shown that Arf6 exerts pro-migratory action in breast cancer cells after EGF stimulation. Despite the fact that EGF signaling stimulates EMT of breast cancer cells, the effect of Arf6 on internalization of E-cadherin of breast cancer cells under EGF treatment remains to be determined. Here, we showed that EGF dose-dependently stimulated E-cadherin internalization by MCF-7 cells with the maximal effect at 50 ng/ml. Meanwhile, EGF treatment markedly increased Arf6 activation. Arf6 was involved in complexes of E-cadherin, and more E-cadherin was pulled down with Arf6 when the activity of the latter was increased. Immunoblotting and immunofluorescence assays showed that transfection breast cancer cells with Arf6-T27N or Arf6 siRNA suppressed EGF-induced E-cadherin internalization. Taken together, our study demonstrated that Arf6 activation plays a potential role in EGF-induced E-cadherin internalization, providing new mechanism underlying the effect of Arf6 on promoting breast cancer cell metastasis.

The first EGF domain of coagulation factor IX attenuates cell adhesion and induces apoptosis.

PubMed

Ishikawa, Tomomi; Kitano, Hisataka; Mamiya, Atsushi; Kokubun, Shinichiro; Hidai, Chiaki

2016-07-01

Coagulation factor IX (FIX) is an essential plasma protein for blood coagulation. The first epidermal growth factor (EGF) motif of FIX (EGF-F9) has been reported to attenuate cell adhesion to the extracellular matrix (ECM). The purpose of the present study was to determine the effects of this motif on cell adhesion and apoptosis. Treatment with a recombinant EGF-F9 attenuated cell adhesion to the ECM within 10 min. De-adhesion assays with native FIX recombinant FIX deletion mutant proteins suggested that the de-adhesion activity of EGF-F9 requires the same process of FIX activation as that which occurs for coagulation activity. The recombinant EGF-F9 increased lactate dehydrogenase (LDH) activity release into the medium and increased the number of cells stained with annexin V and activated caspase-3, by 8.8- and 2.7-fold respectively, indicating that EGF-F9 induced apoptosis. Activated caspase-3 increased very rapidly after only 5 min of administration of recombinant EGF-F9. Treatment with EGF-F9 increased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK), but not that of phosphorylated MAPK 44/42 or c-Jun N-terminal kinase (JNK). Inhibitors of caspase-3 suppressed the release of LDH. Caspase-3 inhibitors also suppressed the attenuation of cell adhesion and phosphorylation of p38 MAPK by EGF-F9. Our data indicated that EGF-F9 activated signals for apoptosis and induced de-adhesion in a caspase-3 dependent manner. © 2016 The Author(s).

Development of Cu-64 labeled EGF for In Vivo PET Imaging of EGFR Expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Backer, Joseph M.

2009-07-12

In this project we proposed to establish feasibility of the development of targeted tracers for radionuclide imaging of epidermal growth factor receptors (EGFR) in cancer patients. The significance and impact of the proposed radiotracers are determined by the crucial role that EGFR plays in many cancers and by the rapid entrance of EGFR-inhibiting drugs into clinic. Clinical experience, however, revealed that only 10-25% of patients that are defined as EGFR-positive by immunohistochemical analysis respond to EGFR-directed therapeutics and there is poor correlation between EGFR immunohistochemistry and treatment. Therefore, for more efficacious use of EGFR-targeting therapeutics, there is a need formore » information about EGFR activity in patients. We hypothesized that radionuclide imaging of functionally active EGFR will provide such information and would allow for 1) rational patient stratification, 2) rapid monitoring of responses to therapy, and 3) development of personalized treatment regimens. We hypothesized that tracers based epidermal growth factor (EGF), a natural EGFR ligand, as a targeting vector would be particularly advantageous. First, only functionally active and therefore critical for disease progression EGFRs will bind and internalize an EGF-based tracer. Second, continuous internalization of EGF-based tracers by recyclable EGFR would lead to intracellular accumulation of radionuclide and improved signal-to-background ratio. Third, small size of EGF relative to antibodies would facilitate tumor penetration with vastly better non-specific soft tissue and blood clearance rates. Fourth, as a human protein, EGF is not expected to be immunogenic. Finally, at the beginning of this project, we have already engineered and expressed functionally active EGF with an N-terminal Cys-tag for site-specific conjugation of various payloads, including radionuclide chelators. In the Phase I of this project, in collaboration with Dr. Blankenberg’s group at

Alkyl isothiocyanates suppress epidermal growth factor receptor kinase activity but augment tyrosine kinase activity.

PubMed

Nomura, Takahiro; Uehara, Yoshimasa; Kawajiri, Hiroo; Ryoyama, Kazuo; Yamori, Takao; Fuke, Yoko

2009-10-01

We have reported the in vitro and in vivo anticancer activities of 6-(methylsulfinyl)hexyl isothiocyanate (6-MITC) derived from a Japanese spice, wasabi. In order to obtain some clues about the mechanism of the anticancer activity, we have studied the effect of alkyl isothiocyanates (MITCs) on protein kinase activities. The anti-autophosphorylation activity of MITCs with respect to the epidermal growth factor (EGF)-stimulated receptor kinase of A431 epidermoid carcinoma cells was examined by incorporation of radioactive ATP into an acid-insoluble fraction. Their anti-phosphorylation activity with respect to the non-receptor protein kinase was analyzed by a standard SDS-PAGE method. All the tested MITCs interfered with the EGF-stimulated receptor kinase activity in a dose-dependent manner, although their effects were less than 1/10 of that of erbstatin in microg/ml. On the other hand, the MITCs did not interfere with non-receptor kinases (kinase A, kinase C, tyrosine kinase and calmodulin dependent kinase III), but enhanced non-receptor tyrosine kinase. A possible anticancer mechanism of MITCs may involve the suppression of EGF receptor kinase activity and augmentation of non-receptor PTK.

Epidermal growth factor induction of front–rear polarity and migration in keratinocytes is mediated by integrin-linked kinase and ELMO2

PubMed Central

Ho, Ernest; Dagnino, Lina

2012-01-01

Epidermal growth factor (EGF) is a potent chemotactic and mitogenic factor for epidermal keratinocytes, and these properties are central for normal epidermal regeneration after injury. The involvement of mitogen-activated protein kinases as mediators of the proliferative effects of EGF is well established. However, the molecular mechanisms that mediate motogenic responses to this growth factor are not clearly understood. An obligatory step for forward cell migration is the development of front–rear polarity and formation of lamellipodia at the leading edge. We show that stimulation of epidermal keratinocytes with EGF, but not with other growth factors, induces development of front–rear polarity and directional migration through a pathway that requires integrin-linked kinase (ILK), Engulfment and Cell Motility-2 (ELMO2), integrin β1, and Rac1. Furthermore, EGF induction of front–rear polarity and chemotaxis require the tyrosine kinase activity of the EGF receptor and are mediated by complexes containing active RhoG, ELMO2, and ILK. Our findings reveal a novel link between EGF receptor stimulation, ILK-containing complexes, and activation of small Rho GTPases necessary for acquisition of front–rear polarity and forward movement. PMID:22160594

Epidermal growth factor induction of front-rear polarity and migration in keratinocytes is mediated by integrin-linked kinase and ELMO2.

PubMed

Ho, Ernest; Dagnino, Lina

2012-02-01

Epidermal growth factor (EGF) is a potent chemotactic and mitogenic factor for epidermal keratinocytes, and these properties are central for normal epidermal regeneration after injury. The involvement of mitogen-activated protein kinases as mediators of the proliferative effects of EGF is well established. However, the molecular mechanisms that mediate motogenic responses to this growth factor are not clearly understood. An obligatory step for forward cell migration is the development of front-rear polarity and formation of lamellipodia at the leading edge. We show that stimulation of epidermal keratinocytes with EGF, but not with other growth factors, induces development of front-rear polarity and directional migration through a pathway that requires integrin-linked kinase (ILK), Engulfment and Cell Motility-2 (ELMO2), integrin β1, and Rac1. Furthermore, EGF induction of front-rear polarity and chemotaxis require the tyrosine kinase activity of the EGF receptor and are mediated by complexes containing active RhoG, ELMO2, and ILK. Our findings reveal a novel link between EGF receptor stimulation, ILK-containing complexes, and activation of small Rho GTPases necessary for acquisition of front-rear polarity and forward movement.

Bcl2-low-expressing MCF7 cells undergo necrosis rather than apoptosis upon staurosporine treatment.

PubMed Central

Poliseno, Laura; Bianchi, Laura; Citti, Lorenzo; Liberatori, Sabrina; Mariani, Laura; Salvetti, Alessandra; Evangelista, Monica; Bini, Luca; Pallini, Vitaliano; Rainaldi, Giuseppe

2004-01-01

We present a ribozyme-based strategy for studying the effects of Bcl2 down-regulation. The anti-bcl2 hammerhead ribozyme Rz-bcl2 was stably transfected into MCF7 cancer cells and the cleavage of Bcl2 mRNA was demonstrated using a new assay for cleavage product detection, while Western blot analysis showed a concomitant depletion of Bcl2 protein. Rz-bcl2-expressing cells were more sensitive to staurosporine than control cells. Moreover, both molecular and cellular read-outs indicated that staurosporine-induced cell death was necrosis rather than apoptosis in these cells. The study of the effects of Bcl2 down-regulation was extended to the global MCF7 protein expression profile, exploiting a proteomic approach. Two reference electro-pherograms of Rz-bcl2-transfected cells, one with the ribozyme in a catalytically active form and the other with the ribozyme in a catalytically inactive form, were obtained. When comparing the two-dimensional maps, 53 differentially expressed spots were found, four of which were identified by MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS as calreticulin, nucleophosmin, phosphoglycerate kinase and pyruvate kinase. How the up-regulation of these proteins might help to explain the modification of Bcl2 activity is discussed. PMID:14748742

Combined immunotherapy of breast cancer with EGF and VEGF vaccines from DNA shuffling in a mouse model.

PubMed

Jin, Dong; Yu, Xin; Chen, Bing; Li, Zhitao; Ding, Jia; Zhao, Xiuyun; Qi, Gaofu

2017-06-01

Development of EGF and VEGF vaccines with high antigenicity for combined immunotherapy of EGF-EGFR signaling-dependent epithelial tumors such as breast cancer. EGF genes from mouse, human and chicken were randomly assembled to chimeric genes by DNA shuffling, then a chimeric EGF was selected out by PCR, SDS-PAGE and immunization for combined immunotherapy of breast cancer with a previously constructed chimeric VEGF vaccine from shuffling. Combined vaccination with chimeric EGF and VEGF from shuffling could induce high titer of antibodies against EGF and VEGF to inhibit tumor growth and angiogenesis, and improve the survival rate of mice with breast cancer. Combined vaccination with EGF and VEGF from shuffling showed better immunotherapy on EGF-EGFR signaling-dependent epithelial tumors such as breast cancer than the single-agent EGF vaccination.

Cigarette smoke induces aberrant EGF receptor activation which mediates lung cancer development and resistance to tyrosine kinase inhibitors

PubMed Central

Filosto, Simone; Becker, Cathleen R.; Goldkorn, Tzipora

2015-01-01

The EGF Receptor (EGFR) and its downstream signaling are implicated in lung cancer development. Therefore, much effort was spent in developing specific tyrosine kinase inhibitors (TKIs) that bind to the EGFR ATP-pocket, blocking EGFR phosphorylation/signaling. Clinical use of TKIs is effective in a subset of lung cancers with mutations in the EGFR kinase domain, rendering the receptor highly susceptible to TKIs. However, these benefits are limited, and emergence of additional EGFR mutations usually results in TKI resistance and disease progression. Previously, we demonstrated one mechanism linking cigarette smoke (CS) to EGFR-driven lung cancer. Specifically, exposure of lung epithelial cells to CS-induced oxidative stress stimulates aberrant EGFR phosphorylation/activation with impaired receptor ubiquitination/degradation. The abnormal stabilization of the activated receptor leads to uncontrolled cell growth and tumorigenesis. Here we describe for the first time a novel post-translational mechanism of EGFR resistance to TKIs. Exposure of airway epithelial cells to CS causes aberrant phosphorylation/activation of EGFR, resulting in a conformation that is different from that induced by the ligand EGF. Unlike EGF-activated EGFR, CS-activated EGFR binds c-Src and caveolin-1 and does not undergo canonical dimerization. Importantly, the CS-activated EGFR is not inhibited by TKIs (AG1478; Erlotinib; Gefitinib); in fact, the CS exposure induces TKI-resistance even in the TKI-sensitive EGFR mutants. Our findings demonstrate that CS exposure stimulates not only aberrant EGFR phosphorylation impairing receptor degradation, but also induces a different EGFR conformation and signaling that are resistant to TKIs. Together, these findings offer new insights into CS-induced lung cancer development and TKI resistance. PMID:22302097

SMOC Binds to Pro-EGF, but Does Not Induce Erk Phosphorylation via the EGFR.

PubMed

Thomas, J Terrig; Chhuy-Hy, Lina; Andrykovich, Kristin R; Moos, Malcolm

2016-01-01

In an attempt to identify the cell-associated protein(s) through which SMOC (Secreted Modular Calcium binding protein) induces mitogen-activated protein kinase (MAPK) signaling, the epidermal growth factor receptor (EGFR) became a candidate. However, although in 32D/EGFR cells, the EGFR was phosphorylated in the presence of a commercially available human SMOC-1 (hSMOC-1), only minimal phosphorylation was observed in the presence of Xenopus SMOC-1 (XSMOC-1) or human SMOC-2. Analysis of the commercial hSMOC-1 product demonstrated the presence of pro-EGF as an impurity. When the pro-EGF was removed, only minimal EGFR activation was observed, indicating that SMOC does not signal primarily through EGFR and its receptor remains unidentified. Investigation of SMOC/pro-EGF binding affinity revealed a strong interaction that does not require the C-terminal extracellular calcium-binding (EC) domain of SMOC or the EGF domain of pro-EGF. SMOC does not appear to potentiate or inhibit MAPK signaling in response to pro-EGF, but the interaction could provide a mechanism for retaining soluble pro-EGF at the cell surface.

Elevated EGF Levels in the Blood Serum of Dogs with Periodontal Diseases and Oral Tumours.

PubMed

Sobczyńska-Rak, Aleksandra; Żylińska, Beata; Polkowska, Izabela; Szponder, Tomasz

2018-01-01

Paradontopathy and neoplasms of the oral cavity represent one of the greatest challenges in human and animal dentistry. EGF plays a key role in maintaining the integrity and proper rate of cell proliferation in normal oral epithelium. The aim of the present study was to study serum levels of EGF in dogs diagnosed with periodontal diseases and oral cavity tumours. The samples comprised of cancerous tissue sections and serum obtained from dogs of various breeds, aged between 5-13 years. Serum EGF concentrations were measured by an immunoenzymatic method. The median for EGF concentration in serum of dogs suffered from severe periodontal diseases was greater when compared to the control group. EGF concentration in dogs with malignant tumours was significantly higher than in those with non-malignant growths. A positive correlation between EGF concentration and tumour size was also observed. EGF level in dogs diagnosed with benign tumours was comparable to the control group. The blood serum level of EGF increases significantly in patients with malignant oral tumours and advanced periodontal disease. In malignant tumours, the high level of EGF correlates with the size and invasiveness of the neoplasm. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

High-level expression and purification of heparin-binding epidermal growth factor (HB-EGF) with SUMO fusion.

PubMed

Lu, Wuguang; Cao, Peng; Lei, Huangzong; Zhang, Shuangquan

2010-03-01

Heparin-binding epidermal growth factor (HB-EGF) can stimulate the division of various cell types and has potential clinical applications that stimulate growth and differentiation. HB-EGF has an EGF-like domain typical of all members of the EGF family. The high expression of active HB-EGF in Escherichia coli has not been successful as the protein contains three intra-molecular disulfide bonds, the same as other members of the EGF super family that are difficult to form correctly in the bacterial intracellular environment. This work fused the non-glycosylated HB-EGF gene with a small ubiquitin-related modifier gene (SUMO) by over-lap PCR. The resulting fusion gene SUMO-HBEGF was highly expressed in BL21(DE3) that the soluble SUMO-HBEGF was up to 30% of the total cellular protein. The fusion protein was purified by Ni-NTA affinity chromatography and cleaved by a SUMO-specific protease Ulp1 to obtain the native HB-EGF, which was further purified by Ni-NTA affinity chromatography. MTT assays indicated the purified HB-EGF, as well as SUMO-HBEGF, had mitogenic activity in a dose-dependent manner.

Saccharomyces boulardii Inhibits EGF Receptor Signaling and Intestinal Tumor Growth in Apcmin Mice

PubMed Central

Chen, Xinhua; Fruehauf, Johannes; Goldsmith, Jeffrey D.; Xu, Hua; Katchar, Kianoosh K; Koon, Hon-Wai; Zhao, Dezheng; Kokkotou, Efi G.; Pothoulakis, Charalabos; Kelly, Ciarán P.

2009-01-01

Saccharomyces boulardii (Sb) is a probiotic yeast with anti-inflammatory and antimicrobial activities and has been used for decades in the prevention and treatment of a variety of human gastrointestinal disorders. We reported previously that Sb modulates host inflammatory responses through down regulation of Erk1/2 MAP kinase activities both in vitro and in vivo. The aim of this study was to identify upstream mediators responsible for Erk1/2 inactivation and to examine the effects of Sb on tumor development in ApcMin mice. We found that the EGF receptor was deactivated upon exposure to Sb leading to inactivation of both the EGFR-Erk and EGFR-Akt pathways. In human colonic cancer cells, Sb prevented EGF induced proliferation, reduced cell colony formation and promoted apoptosis. HER-2, HER-3 and IGF-1R were also found to be inactivated by Sb. Oral intake of Sb reduced intestinal tumor growth and dysplasia in C57BL/6J Min/+ (ApcMin) mice. Thus, in addition to its anti-inflammatory effects, S. boulardii inhibits EGFR and other receptor tyrosine kinase signaling and thereby may also serve a novel therapeutic or prophylactic role in intestinal neoplasia. PMID:19482027

Effect of phorbol derivatives and staurosporine on gravitropic response of primary root of maize

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulkey, T.J.; Kim, S.Y.; Lee, J.S.

1991-05-01

Time-lapse videography and computer-based, video image digitization were used to examine the effects of phorbol derivatives (phorbol 12-myristate 13-acetate, TPA; phorbol 12-myristate 13-acetate 4-O-methyl ether, mTPA) and staurosporine on the kinetics of gravicurvature of primary roots of maize (Zea mays L., Pioneer 3343 and Golden Cross Bantam). Pretreatment of roots with TPA (3 hr, 1 {mu}M) decreases the time lag prior to induction of positive gravicurvature in horizontally-oriented roots by > 60%. The rate of curvature is not significantly different than the rate observed in control roots. Wrongway curvature which is observed in 30-40% of control roots is not observedmore » in TPA-pretreated roots. Oscillatory movements observed in control roots after completion of gravitropic reorientation is completely dampened in TPA-pretreated roots. Pretreatment of roots with mTPA(3hr,1{mu}M), the inactive analog of TPA, does not significantly alter the kinetics of gravicurvature of primary roots of maize. Staurosporine (10{sup {minus}8}M), a microbial alkaloid which has been reported to have antifungal activity and to inhibit phospholipid/Ca{sup ++} dependent protein kinase, completely inhibits TPA-induced alteration of the kinetics of gravitropism. DAG (1-oleoyl-2-acetyl-rac-glycerol), a synthetic diglyceride activator of protein kinase C, exhibits similar activity to TPA. TPA-induced alterations in tissue response to auxin are presented.« less

Increased expression of cyclin B1 mRNA coincides with diminished G{sub 2}-phase arrest in irradiated HeLa cells treated with staurosporine or caffeine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernhard, E.J.; Maity, A.; McKenna, W.G.

1994-12-01

The irradiation of cells results in delayed progression through the G{sub 2} phase of the cell cycle. Treatment of irradiated HeLa cells with caffeine greatly reduces the G{sub 2}-phase delay, while caffeine does not alter progression of cells through the cell cycle in unirradiated cells. In this report we demonstrate that treatment of HeLa cells with the kinase inhibitor staurosporine, but not with the inhibitor H7, also results in a reduction of the G{sub 2}-phase arrest after irradiation. Cell cycle progression in unirradiated cells is unaffected by 4.4 nM (2ng/ml) staurosporine, which releases the radiation-induced G{sub 2}-phase arrest. In HeLamore » cells, the G{sub 2}-phase delay after irradiation in S phase is accompanied by decreased expression of cyclin B1 mRNA. Coincident with the reduction in G{sub 2}-phase delay, we observed an increase in cyclin B1 mRNA accumulation in irradiated, staurosporine-treated cells compared to cells treated with irradiation alone. Caffeine treatment of irradiated HeLa cells also resulted in an elevation in the levels of cyclin B1 message. These results support the hypothesis that diminished cyclin B1 mRNA levels influence G{sub 2}-phase arrest to some degree. The findings that both staurosporine and caffeine treatments reverse the depression in cyclin B1 expression suggest that these two compounds may act on a common pathway of cell cycle control in response to radiation injury. 33 refs., 6 figs.« less

Expression of EGF and EGFR strongly correlates with metastasis of pancreatic ductal carcinoma.

PubMed

Pryczynicz, Anna; Guzińska-Ustymowicz, Katarzyna; Kemona, Andrzej; Czyzewska, Jolanta

2008-01-01

The epidermal growth factor family members: EGF, EGFR and the c-erbB-2(HER-2/neu) gene product have been found to play a role in carcinomas of the stomach, liver, breast, ovary and lungs. Recent reports have indicated that they are also involved in the growth of pancreatic ductal carcinoma, its invasiveness and metastasis. Thirty-six patients with pancreatic ductal carcinoma were analysed with respect to sex, age, histological type, malignancy grade (G), pTN status (pTN), local lymph node involvement and distant metastasis. The tumor levels of EGF, EGFR and c-erbB-2 expression were determined immunohistochemically. Expression of c-erbB-2 was observed in 24/36 cases, EGF in 13/36 cases and EGFR in 18/36 cases. Overexpression of EGF and EGFR was associated with metastasis to lymph nodes and other organs. A correlation was also found between EGF expression and the presence of EGFR in the tumour. The expression of c-erbB-2 protein was not found to correlate with any parameters. EGF and EGFR play a key role in neoplastic spread through lymph node involvement and metastasis to other organs.

A functional EGF+61 polymorphism is associated with severity of obstructive sleep apnea.

PubMed

Ding, Qunli; Cao, Chao; Chen, Zhongbo; Tabusi, Mahebali; Chen, Li; Deng, Zaichun

2015-05-01

Involvement of epidermal growth factor (EGF) is reported in diseases caused by hypoxia. Its functional polymorphism may alter its transcription, affecting EGF expression, contributing to obstructive sleep apnea (OSA). The aim of this study was to investigate associations of EGF+61 polymorphism and risk of OSA. Two hundred two participants were enrolled in this case-control study. DNA was extracted from peripheral blood, and EGF 61A/G polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. No significant association between EGF 61 A/G polymorphism and risk of OSA was observed in any of the gene models tested (AA vs. GG: OR = 0.97, 95% CI = 0.37-2.55; P = 0.95). However, compared with GG genotype, AG genotype associated with decreased risk of severe OSA (AG vs. GG: OR = 0.32, 95% CI = 0.11-0.94). Our study showed that AG genotype has a protective effect on OSA patients against severe disease, although EGF 61A/G polymorphisms have no role on the risk of the disease. Additional large studies should further validate our findings.

The Augmented Cognitive Mediation Model: Examining Antecedents of Factual and Structural Breast Cancer Knowledge Among Singaporean Women.

PubMed

Lee, Edmund W J; Shin, Mincheol; Kawaja, Ariffin; Ho, Shirley S

2016-05-01

As knowledge acquisition is an important component of health communication research, this study examines factors associated with Singaporean women's breast cancer knowledge using an augmented cognitive mediation model. We conducted a nationally representative study that surveyed 802 women between the ages of 30 and 70 using random-digit dialing. The results supported the augmented cognitive mediation model, which proposes the inclusion of risk perception as a motivator of health information seeking and structural knowledge as an additional knowledge dimension. There was adequate support for the hypothesized paths in the model. Risk perception was positively associated with attention to newspaper, television, Internet, and interpersonal communication. Attention to the three media channels was associated with interpersonal communication, but only newspaper and television attention were associated with elaboration. Interpersonal communication was positively associated with structural knowledge, whereas elaboration was associated with both factual and structural knowledge. Differential indirect effects between media attention and knowledge dimensions via interpersonal communication and elaboration were found. Theoretical and practical implications are discussed.

Boca-dependent maturation of β-propeller/EGF modules in low-density lipoprotein receptor proteins

PubMed Central

Culi, Joaquim; Springer, Timothy A; Mann, Richard S

2004-01-01

The extracellular portions of cell surface receptor proteins are often comprised of independently folding protein domains. As they are translated into the endoplasmic reticulum (ER), some of these domains require protein chaperones to assist in their folding. Members of the low-density lipoprotein receptor (LDLR) family require the chaperone called Boca in Drosophila or its ortholog, Mesoderm development, in the mouse. All LDLRs have at least one six-bladed β-propeller domain, which is immediately followed by an epidermal growth factor (EGF) repeat. We show here that Boca is specifically required for the maturation of these β-propeller/EGF modules through the secretory pathway, but is not required for other LDLR domains. Protein interaction data suggest that as LDLRs are translated into the ER, Boca binds to the β-propeller. Subsequently, once the EGF repeat is translated, the β-propeller/EGF module achieves a more mature state that has lower affinity for Boca. We also show that Boca-dependent β-propeller/EGF modules are found not only throughout the LDLR family but also in the precursor to the mammalian EGF ligand. PMID:15014448

Inhibition of the Ras-ERK pathway in mitotic COS7 cells is due to the inability of EGFR/Raf to transduce EGF signaling to downstream proteins.

PubMed

Shi, Huaiping; Zhang, Tianying; Yi, Yongqing; Ma, Yue

2016-06-01

Although previous studies have shown that Ras-ERK signaling in mitosis is closed due to the inhibition of signal transduction, the events involved in the molecular mechanisms are still unclear. In the present study, we investigated the Ras-ERK signaling pathway in mitotic COS7 cells. The results demonstrated that treatment with epidermal growth factor (EGF) failed to increase the endocytosis of EGF-EGFR (EGF receptor) complexes in mitotic COS7 cells, although a large amount of endosomes were found in asynchronous COS7 cells. Clathrin expression levels in mitotic COS7 cells were inhibited whereas caveolin expression levels in mitotic COS7 cells were almost unaffected. Y1068 and Y1086 residues of EGFR in the mitotic COS7 cells were activated. However, Grb2 and Shc in the mitotic COS7 cells did not bind to activated EGFR. Ras activity was inhibited in the mitotic COS7 cells whereas its downstream protein, Raf, was obviously phosphorylated by EGF in mitosis. Treatment with phorbol 12-myristate 13-acetate (PMA) also increased the phosphorylation levels of Raf in the mitotic COS7 cells. Nevertheless, Raf phosphorylation in mitosis was significantly inhibited by AG1478. Lastly, activation of EGF-mediated MEK and ERK in the mitotic COS7 cells was obviously inhibited. In summary, our results suggest that the Ras-ERK pathway is inhibited in mitotic COS7 cells which may be the dual result of the difficulty in the transduction of EGF signaling by EGFR or Raf to downstream proteins.

Decreased Epidermal Growth Factor (EGF) Associated with HMGB1 and Increased Hyperactivity in Children with Autism

PubMed Central

Russo, Anthony J.

2013-01-01

Background Autism spectrum disorders (ASDs), characterized by impaired social interactions and deficits in verbal and nonverbal communication, are thought to affect 1 in 88 children in the United States. There is much support for the role of growth factors in the etiology of autism. Recent research has shown that epithelial growth factor (EGF) is decreased in young autistic children (2–4 years of age). This study was designed to determine plasma levels of EGF in an older group of autistic children (mean age 10.6 years) and to correlate these EGF levels with putative biomarkers HGF, uPA, uPAR, GAD2, MPO GABA, and HMGB1, as well as symptom severity of 19 different symptoms. Subjects and methods Plasma from 38 autistic children, 11 children with pervasive developmental disorder (PDD-NOS) and 40 neurotypical, age and gender similar controls was assessed for EGF concentration using ELISAs. Severity of 19 symptoms (awareness, expressive language, receptive language, (conversational) pragmatic language, focus/attention, hyperactivity, impulsivity, perseveration, fine motor skills, gross motor skills, hypotonia (low muscle tone), tiptoeing, rocking/pacing, stimming, obsessions/fixations, eye contact, sound sensitivity, light sensitivity, and tactile sensitivity) was assessed and then compared to EGF concentrations. Results In this study, we found EGF levels in autistic children and those with PDD-NOS to be significantly lower when compared with neurotypical controls. EGF levels correlated with HMGB1 levels but not the other tested putative biomarkers, and EGF correlated negatively with hyperactivity, gross motor skills, and tiptoeing but not other symptoms. Conclusions These results suggest an association between decreased plasma EGF levels and selected symptom severity. We also found a strong correlation between plasma EGF and HMGB1, suggesting inflammation is associated with decreased EGF. PMID:23645980

Localisation of epidermal growth factor (EGF), its specific receptor (EGF-R) and aromatase at the materno-fetal interface during placentation in the pregnant mare.

PubMed

Allen, W R Twink; Gower, Susan; Wilsher, Sandra

2017-02-01

Implantation and placentation in the mare does not commence until as late as day 40 after ovulation. The reasons for this and the growth factors and/or hormones which drive placentation when it does finally occur are of considerable academic and practical interest. Placental interface tissues recovered from 11 accurately aged and perfused-fixed horse uteri between 20 and 68 days of gestation were stained immunocytochemically for Epidermal Growth Factor (EGF), its specific receptor (EGF-R) and for the steroid hormone enzyme, aromatase. EGF was present in endometrial gland and lumenal epithelia from day 20 but staining intensity increased noticeably for the protein between days 30 and 40, coincidentally with the commencing secretion of equine Chorionic Gonadotrophin (eCG) from the endometrial cups and immediately prior to attachment and commencing interdigitation between the allantochorion and endometrium. EGF-R, on the other hand, was expressed strongly on the cell surface membrane of both non-invasive and invasive trophoblast and it similarly increased in staining intensity between days 30 and 40. Aromatase, the enzyme necessary for conversion of C-19 androgens to C-18 oestrogens, was expressed strongly and constantly from as early as day 12 in the non-invasive trophoblast of the allantochorion, but not the invasive trophoblast of the chorionic girdle, the progenitor tissue of the endometrial cups. The findings support the hypothesis that, in equine pregnancy, the maternal growth factor EGF synergises with maternally and fetally secreted oestrogens to drive the rapid growth and extensive vascularisation of the non-invasive, epitheliochorial, microcotyledonary placenta which results in the birth of the precocious foal after only 11 months gestation. Copyright © 2016 Elsevier Ltd. All rights reserved.

HER1 signaling mediates extravillous trophoblast differentiation in humans.

PubMed

Wright, J K; Dunk, C E; Amsalem, H; Maxwell, C; Keating, S; Lye, S J

2010-12-01

This study examines the role of HER1 signaling in the differentiation of proliferative extravillous trophoblast (EVT) into invasive EVT. Using the JAR choriocarcinoma cell line and placental villous explants as experimental models and immunohistochemical assessment of protein markers of EVT differentiation (downregulation of HER1 and Cx40 and upregulation of HER2 and alpha1 integrin), we show that the ability of decidual conditioned medium (DCM) to induce HER1/2 switching was abrogated in the presence of the HER1 antagonist, AG1478. Similarly, epidermal growth factor (EGF) treatment resulted in the downregulation of HER1 and an upregulation of HER2 expression, whereas co-incubation of EGF with AG1478 inhibited this response. However, EGF did not downregulate Cx40 or induce migration of EVT. In contrast, heparin-binding epidermal-like growth factor (HBEGF) stimulated dose-dependent JAR cell migration, which was inhibited by both AG1478 and AG825 (HER2 antagonist). Western blot analysis of HER1 activation demonstrated that HBEGF-mediated phosphorylation of the HER1 Tyr992 and Tyr1068 sites, while EGF activated the Tyr1045 site. Moreover, HBEGF induced a stronger and more sustained activation of both the mitogen-activated protein kinase and phosphoinositol 3 kinase (PIK3) signaling pathways. Migration assays using a panel of signaling pathway inhibitors demonstrated that the HBEGF-mediated migration was dependent on the PIK3 pathway. These results demonstrate that HBEGF-mediated HER1 signaling through PIK3 is an important component of EVT invasion.

DSE promotes aggressive glioma cell phenotypes by enhancing HB-EGF/ErbB signaling.

PubMed

Liao, Wen-Chieh; Liao, Chih-Kai; Tsai, You-Huan; Tseng, To-Jung; Chuang, Li-Ching; Lan, Chyn-Tair; Chang, Hung-Ming; Liu, Chiung-Hui

2018-01-01

Remodeling of the extracellular matrix (ECM) in the tumor microenvironment promotes glioma progression. Chondroitin sulfate (CS) proteoglycans appear in the ECM and on the cell surface, and can be catalyzed by dermatan sulfate epimerase to form chondroitin sulfate/dermatan sulfate (CS/DS) hybrid chains. Dermatan sulfate epimerase 1 (DSE) is overexpressed in many types of cancer, and CS/DS chains mediate several growth factor signals. However, the role of DSE in gliomas has never been explored. In the present study, we determined the expression of DSE in gliomas by consulting a public database and conducting immunohistochemistry on a tissue array. Our investigation revealed that DSE was upregulated in gliomas compared with normal brain tissue. Furthermore, high DSE expression was associated with advanced tumor grade and poor survival. We found high DSE expression in several glioblastoma cell lines, and DSE expression directly mediated DS chain formation in glioblastoma cells. Knockdown of DSE suppressed the proliferation, migration, and invasion of glioblastoma cells. In contrast, overexpression of DSE in GL261 cells enhanced these malignant phenotypes and in vivo tumor growth. Interestingly, we found that DSE selectively regulated heparin-binding EGF-like growth factor (HB-EGF)-induced signaling in glioblastoma cells. Inhibiting epidermal growth factor receptor (EGFR) and ErbB2 with afatinib suppressed DSE-enhanced malignant phenotypes, establishing the critical role of the ErbB pathway in regulating the effects of DSE expression. This evidence indicates that upregulation of DSE in gliomas contributes to malignant behavior in cancer cells. We provide novel insight into the significance of DS chains in ErbB signaling and glioma pathogenesis.

Both sides of the same coin: Rac1 splicing regulating by EGF signaling.

PubMed

Fu, Xiang-Dong

2017-04-01

EGF, a well-studied mitogen for cancer cells, is revealed to induce an E3 ubiquitin ligase adaptor SPSB1, which recruits the Elongin B/C-Collin complex to trigger ubiquitylation of the negative splicing regulator hnRNP A1. This event is synergized with EGF-activated SR proteins to alter alternative splicing of a key small GTPase Rac1 to enhance cell migration, highlighting converging EGF signals on both negative and positive splicing regulators to jointly promote a key cancer pathway.

Proteomic snapshot of the EGF-induced ubiquitin network

PubMed Central

Argenzio, Elisabetta; Bange, Tanja; Oldrini, Barbara; Bianchi, Fabrizio; Peesari, Raghunath; Mari, Sara; Di Fiore, Pier Paolo; Mann, Matthias; Polo, Simona

2011-01-01

The activity, localization and fate of many cellular proteins are regulated through ubiquitination, a process whereby one or more ubiquitin (Ub) monomers or chains are covalently attached to target proteins. While Ub-conjugated and Ub-associated proteomes have been described, we lack a high-resolution picture of the dynamics of ubiquitination in response to signaling. In this study, we describe the epidermal growth factor (EGF)-regulated Ubiproteome, as obtained by two complementary purification strategies coupled to quantitative proteomics. Our results unveil the complex impact of growth factor signaling on Ub-based intracellular networks to levels that extend well beyond what might have been expected. In addition to endocytic proteins, the EGF-regulated Ubiproteome includes a large number of signaling proteins, ubiquitinating and deubiquitinating enzymes, transporters and proteins involved in translation and transcription. The Ub-based signaling network appears to intersect both housekeeping and regulatory circuitries of cellular physiology. Finally, as proof of principle of the biological relevance of the EGF-Ubiproteome, we demonstrated that EphA2 is a novel, downstream ubiquitinated target of epidermal growth factor receptor (EGFR), critically involved in EGFR biological responses. PMID:21245847

O-GlcNAc on NOTCH1 EGF repeats regulates ligand-induced Notch signaling and vascular development in mammals.

PubMed

Sawaguchi, Shogo; Varshney, Shweta; Ogawa, Mitsutaka; Sakaidani, Yuta; Yagi, Hirokazu; Takeshita, Kyosuke; Murohara, Toyoaki; Kato, Koichi; Sundaram, Subha; Stanley, Pamela; Okajima, Tetsuya

2017-04-11

The glycosyltransferase EOGT transfers O-GlcNAc to a consensus site in epidermal growth factor-like (EGF) repeats of a limited number of secreted and membrane proteins, including Notch receptors. In EOGT-deficient cells, the binding of DLL1 and DLL4, but not JAG1, canonical Notch ligands was reduced, and ligand-induced Notch signaling was impaired. Mutagenesis of O-GlcNAc sites on NOTCH1 also resulted in decreased binding of DLL4. EOGT functions were investigated in retinal angiogenesis that depends on Notch signaling. Global or endothelial cell-specific deletion of Eogt resulted in defective retinal angiogenesis, with a mild phenotype similar to that caused by reduced Notch signaling in retina. Combined deficiency of different Notch1 mutant alleles exacerbated the abnormalities in Eogt -/- retina, and Notch target gene expression was decreased in Eogt -/- endothelial cells. Thus, O-GlcNAc on EGF repeats of Notch receptors mediates ligand-induced Notch signaling required in endothelial cells for optimal vascular development.

Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matt Vaughn Greg Harrington Daniel R Bush

2002-08-06

This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with themore » loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 m

Restoration of CpG Methylation in The Egf Promoter Region during Rat Liver Regeneration.

PubMed

Deming, Li; Ziwei, Li; Xueqiang, Guo; Cunshuan, Xu

2015-01-01

Epidermal growth factor (EGF) is an important factor for healing after tissue damage in diverse experimental models. It plays an important role in liver regeneration (LR). The objective of this experiment is to investigate the methylation variation of 10 CpG sites in the Egf promoter region and their relevance to Egf expression during rat liver regenera- tion. As a follow up of our previous study, rat liver tissue was collected after rat 2/3 partial hepatectomy (PH) during the re-organization phase (from days 14 to days 28). Liver DNA was extracted and modified by sodium bisulfate. The methylation status of 10 CpG sites in Egf promoter region was determined using bisulfite sequencing polymerase chain reaction (PCR), as BSP method. The results showed that 3 (sites 3, 4 and 9) out of 10 CpG sites have strikingly methylation changes during the re-organization phase compared to the regeneration phase (from 2 hours to 168 hours, P=0.002, 0.048 and 0.018, respectively). Our results showed that methylation modification of CpGs in the Egf promoter region could be restored to the status before PH operation and changes of methylation didn't affect Egf mRNA expression during the re-organization phase.

Loss of EGF binding and cation transport response during differentiation of mouse neuroblastoma cells.

PubMed

Mummery, C L; van der Saag, P T; de Laat, S W

1983-01-01

Mouse neuroblastoma cells (clone N1E-115) differentiate in culture upon withdrawal of serum growth factors and acquire the characteristics of neurons. We have shown tht exponentially growing N1E-115 cells possess functional epidermal growth factor (EGF) receptors but that the capacity for binding EGF and for stimulation of DNA synthesis is lost as the cells differentiate. Furthermore, in exponentially growing cells, EGF induces a rapid increase in amiloride-sensitive Na+ influx, followed by stimulation of the (Na+-K+)ATPase, indicating that activation of the Na+/H+ exchange mechanism in N1E-115 cells [1] may be induced by EGF. The ionic response is also lost during differentiation, but we have shown that the stimulation of both Na+ and K+ influx is directly proportional to the number of occupied receptors in all cells whether exponentially growing or differentiating, thus only indirectly dependent on the external EGF concentration. The linearity of the relationships indicates that there is no rate-limiting step between EGF binding and the ionic response. Our data would suggest that as neuroblastoma cells differentiate and acquire neuronal properties, their ability to respond to mitogens, both biologically and in the activation of cation transport processes, progressively decreases owing to the loss of the appropriate receptors.

Restoration of CpG Methylation in The Egf Promoter Region during Rat Liver Regeneration

PubMed Central

Deming, Li; Ziwei, Li; Xueqiang, Guo; Cunshuan, Xu

2015-01-01

Epidermal growth factor (EGF) is an important factor for healing after tissue damage in diverse experimental models. It plays an important role in liver regeneration (LR). The objective of this experiment is to investigate the methylation variation of 10 CpG sites in the Egf promoter region and their relevance to Egf expression during rat liver regenera- tion. As a follow up of our previous study, rat liver tissue was collected after rat 2/3 partial hepatectomy (PH) during the re-organization phase (from days 14 to days 28). Liver DNA was extracted and modified by sodium bisulfate. The methylation status of 10 CpG sites in Egf promoter region was determined using bisulfite sequencing polymerase chain reaction (PCR), as BSP method. The results showed that 3 (sites 3, 4 and 9) out of 10 CpG sites have strikingly methylation changes during the re-organization phase compared to the regeneration phase (from 2 hours to 168 hours, P=0.002, 0.048 and 0.018, respectively). Our results showed that methylation modification of CpGs in the Egf promoter region could be restored to the status before PH operation and changes of methylation didn’t affect Egf mRNA expression during the re-organization phase. PMID:26464832

PRMT1-mediated methylation of the EGF receptor regulates signaling and cetuximab response

PubMed Central

Liao, Hsin-Wei; Hsu, Jung-Mao; Xia, Weiya; Wang, Hung-Ling; Wang, Ying-Nai; Chang, Wei-Chao; Arold, Stefan T.; Chou, Chao-Kai; Tsou, Pei-Hsiang; Yamaguchi, Hirohito; Fang, Yueh-Fu; Lee, Hong-Jen; Lee, Heng-Huan; Tai, Shyh-Kuan; Yang, Mhu-Hwa; Morelli, Maria P.; Sen, Malabika; Ladbury, John E.; Chen, Chung-Hsuan; Grandis, Jennifer R.; Kopetz, Scott; Hung, Mien-Chie

2015-01-01

Posttranslational modifications to the intracellular domain of the EGFR are known to regulate EGFR functions; however, modifications to the extracellular domain and their effects remain relatively unexplored. Here, we determined that methylation at R198 and R200 of the EGFR extracellular domain by protein arginine methyltransferase 1 (PRMT1) enhances binding to EGF and subsequent receptor dimerization and signaling activation. In a mouse orthotopic colorectal cancer xenograft model, expression of a methylation-defective EGFR reduced tumor growth. Moreover, increased EGFR methylation sustained signaling activation and cell proliferation in the presence of the therapeutic EGFR monoclonal antibody cetuximab. In colorectal cancer patients, EGFR methylation level also correlated with a higher recurrence rate after cetuximab treatment and reduced overall survival. Together, these data indicate that R198/R200 methylation of the EGFR plays an important role in regulating EGFR functionality and resistance to cetuximab treatment. PMID:26571401

Chicken adenovirus (CELO virus) particles augment receptor-mediated DNA delivery to mammalian cells and yield exceptional levels of stable transformants.

PubMed Central

Cotten, M; Wagner, E; Zatloukal, K; Birnstiel, M L

1993-01-01

Delivery of genes via receptor-mediated endocytosis is severely limited by the poor exit of endocytosed DNA from the endosome. A large enhancement in delivery efficiency has been obtained by including human adenovirus particles in the delivery system. This enhancement is probably a function of the natural adenovirus entry mechanism, which must include passage through or disruption of the endosomal membrane. In an effort to identify safer virus particles useful in this application, we have tested the chicken adenovirus CELO virus for its ability to augment receptor-mediated gene delivery. We report here that CELO virus possesses pH-dependent, liposome disruption activity similar to that of human adenovirus type 5. Furthermore, the chicken adenovirus can be used to augment receptor-mediated gene delivery to levels comparable to those found for the human adenovirus when it is physically linked to polylysine ligand-condensed DNA particles. The chicken adenovirus has the advantage of being produced inexpensively in embryonated eggs, and the virus is naturally replication defective in mammalian cells, even in the presence of wild-type human adenovirus. Images PMID:8099627

Estradiol attenuates EGF-induced rapid uPAR mobilization and cell migration via the G-protein-coupled receptor 30 in ovarian cancer cells.

PubMed

Henic, Emir; Noskova, Vera; Høyer-Hansen, Gunilla; Hansson, Stefan; Casslén, Bertil

2009-02-01

Epidermal growth factor (EGF) stimulates proliferation and migration in ovarian cancer cells, and high tumor expression of the EGF system correlates with poor prognosis. Epidermal growth factor upregulates urokinase plasminogen activator receptor (uPAR) on the cell surface via 3 distinct mechanisms: rapid mobilization of uPAR from detergent-resistant domains, increased mRNA, and decreased degradation. G-protein-coupled receptor 30 (GPR30) is a newly identified membrane estrogen receptor (ER).The objective of this study was to explore the effects of 17beta-estradiol (E(2)) on uPAR expression and cell migration in ovarian cancer cells and further to identify the ER involved.We used 7 ovarian cancer cell lines, cell migration assay, cellular binding of (125)I-uPA, cellular degradation of (125)I-uPA/PAI-1 complex, enzyme-linked immunosorbent assay for uPAR, solid-phase enzyme immunoassay for ERalpha, and quantitative polymerase chain reaction. Estradiol attenuates the stimulatory effect of EGF on cell migration and uPAR expression. Specifically, E(2) reduces the very rapid increase of detergent extractable uPAR, which occurs within minutes of EGF stimulation and probably represents mobilization of uPAR from detergent-resistant domains such as lipid rafts. Estradiol influenced neither the amount of uPAR mRNA nor the rate of uPAR degradation or solubilization. The nuclear ER antagonists ICI 182780 and tamoxifen, which are GPR30 agonists, as well as the specifically constructed GPR30 agonist G1, mimicked the effect of E(2) on uPAR expression and cell migration. OVCAR-3 cells express mRNA for GPR30.Estradiol attenuates EGF-induced mobilization of ligated uPAR from detergent-resistant domains and subsequent migration in ovarian cancer cells. The response to various ER ligands indicates that this effect is mediated via the membrane ER GPR30.

Rapid Induction of Apoptosis in Gastrulating Mouse Embryos by Ethanol and Its Prevention by HB-EGF

PubMed Central

Kilburn, Brian A.; Chiang, Po Jen; Wang, Jun; Flentke, George R.; Smith, Susan M.; Armant, D. Randall

2006-01-01

Background Ethanol exposure during gastrulation and early neurulation induces apoptosis within certain embryonic cell populations, leading to craniofacial and neurological defects. There is currently little information about the initial kinetics of ethanol-induced apoptosis, and interest in the ability of endogenous survival factors to moderate apoptosis is growing. Ethanol alters intracellular signaling, leading to cell death in chick embryos, suggesting that apoptosis could occur rapidly and that signaling pathways activated by survival factors might reduce apoptosis. Methods Pregnant mice were intubated with 1, 2, or 4 g/kg ethanol on day 7.5 of embryogenesis (E7.5) 1, 3, or 6, hours before harvesting gastrulation-stage embryos. Control animals received maltose/dextran. Blood alcohol concentrations (BAC) were determined by gas chromatography. E7.5 embryos isolated from untreated dams were cultured in vitro for 1 or 3 hr with 0 or 400 mg% ethanol and 0 or 5 nM heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF). Apoptosis was quantified using fluorescence microscopy to detect annexin V binding and DNA fragmentation [terminal deoxynucleotidyl transferase-mediated dUTP-X nick end labeling (TUNEL)] in whole-mount or sectioned embryos. Results Both annexin V binding and TUNEL were elevated (p<0.05) in embryos exposed in utero to 1 g/kg ethanol for 3 hours, increasing linearly with time and ethanol concentration. Apoptosis increased (p<0.05) in all germ cell layers. Mice treated with 4 g/kg sustained BAC of 400 mg% for nearly 3 hours, significantly increasing apoptosis within the first hour. Cultured embryos exposed to 400 mg% ethanol displayed 2- to 3-fold more TUNEL than vehicle-treated embryos (p<0.05); however, exogenous HB-EGF prevented apoptosis. Conclusions Ethanol rapidly produced apoptosis in gastrulation-stage embryos, consistent with induction by intracellular signaling. The ethanol-induced apoptotic pathway was blocked by the

AUGMENTATION OF MUSCLE BLOOD FLOW BY ULTRASOUND CAVITATION IS MEDIATED BY ATP AND PURINERGIC SIGNALING

PubMed Central

Belcik, J. Todd; Davidson, Brian P.; Xie, Aris; Wu, Melinda D.; Yadava, Mrinal; Qi, Yue; Liang, Sherry; Chon, Chae Ryung; Ammi, Azzdine Y.; Field, Joshua; Harmann, Leanne; Chilian, William M.; Linden, Joel; Lindner, Jonathan R.

2017-01-01

Background Augmentation of tissue blood flow by therapeutic ultrasound is thought to rely on convective shear. Microbubble contrast agents that undergo ultrasound-mediated cavitation markedly amplify these effects. We hypothesized that purinergic signalling is responsible for shear-dependent increases in muscle perfusion during therapeutic cavitation. Methods Unilateral exposure of the proximal hindlimb of mice (with or without ischemia produced by iliac ligation) to therapeutic ultrasound (1.3 MHz, mechanical index 1.3) was performed for ten minutes after intravenous injection of 2×108 lipid microbubbles. Microvascular perfusion was evaluated by low-power contrast ultrasound perfusion imaging. In vivo muscle ATP release and in vitro ATP release from endothelial cells or erythrocytes were assessed by a luciferin-luciferase assay. Purinergic signalling pathways were assessed by studying interventions that either (1) accelerated ATP degradation; (2) inhibited P2Y receptors, adenosine receptors, or KATP channels; or (3) inhibited downstream signalling pathways involving endothelial nitric oxide synthase (eNOS) or prostanoid production (indomethacin). Augmentation in muscle perfusion by ultrasound cavitation was assessed in a proof-of-concept clinical trial in 12 subjects with stable sickle cell disease (SCD). Results Therapeutic ultrasound cavitation increased muscle perfusion by 7-fold in normal mice, reversed tissue ischemia for up to 24 hrs in the murine model of peripheral artery disease, and doubled muscle perfusion in patients with SCD. Augmentation in flow extended well beyond the region of ultrasound exposure. Ultrasound cavitation produced a nearly 40-fold focal and sustained increase in ATP, the source of which included both endothelial cells and erythrocytes. Inhibitory studies indicated that ATP was a critical mediator of flow augmentation that acts primarily through either P2Y receptors or through adenosine produced by ectonucleotidase activity. Combined

Augmentation of Muscle Blood Flow by Ultrasound Cavitation Is Mediated by ATP and Purinergic Signaling.

PubMed

Belcik, J Todd; Davidson, Brian P; Xie, Aris; Wu, Melinda D; Yadava, Mrinal; Qi, Yue; Liang, Sherry; Chon, Chae Ryung; Ammi, Azzdine Y; Field, Joshua; Harmann, Leanne; Chilian, William M; Linden, Joel; Lindner, Jonathan R

2017-03-28

Augmentation of tissue blood flow by therapeutic ultrasound is thought to rely on convective shear. Microbubble contrast agents that undergo ultrasound-mediated cavitation markedly amplify these effects. We hypothesized that purinergic signaling is responsible for shear-dependent increases in muscle perfusion during therapeutic cavitation. Unilateral exposure of the proximal hindlimb of mice (with or without ischemia produced by iliac ligation) to therapeutic ultrasound (1.3 MHz, mechanical index 1.3) was performed for 10 minutes after intravenous injection of 2×10 8 lipid microbubbles. Microvascular perfusion was evaluated by low-power contrast ultrasound perfusion imaging. In vivo muscle ATP release and in vitro ATP release from endothelial cells or erythrocytes were assessed by a luciferin-luciferase assay. Purinergic signaling pathways were assessed by studying interventions that (1) accelerated ATP degradation; (2) inhibited P2Y receptors, adenosine receptors, or K ATP channels; or (3) inhibited downstream signaling pathways involving endothelial nitric oxide synthase or prostanoid production (indomethacin). Augmentation in muscle perfusion by ultrasound cavitation was assessed in a proof-of-concept clinical trial in 12 subjects with stable sickle cell disease. Therapeutic ultrasound cavitation increased muscle perfusion by 7-fold in normal mice, reversed tissue ischemia for up to 24 hours in the murine model of peripheral artery disease, and doubled muscle perfusion in patients with sickle cell disease. Augmentation in flow extended well beyond the region of ultrasound exposure. Ultrasound cavitation produced an ≈40-fold focal and sustained increase in ATP, the source of which included both endothelial cells and erythrocytes. Inhibitory studies indicated that ATP was a critical mediator of flow augmentation that acts primarily through either P2Y receptors or adenosine produced by ectonucleotidase activity. Combined indomethacin and inhibition of

Pretreatment with oleic acid accelerates the entrance into the mitotic cycle of EGF-stimulated fibroblasts.

PubMed

Zugaza, J L; Casabiell, X A; Bokser, L; Eiras, A; Beiras, A; Casanueva, F F

1995-07-01

We have previously demonstrated that pretreatment of several cell lines with cis-unsaturated fatty acids, like oleic acid, blocks epidermal growth factor (EGF)-induced early ionic signals, and in particular the [Ca2+]i rise. In the present work we show that this blockade does not alter EGF-stimulated cellular proliferation evaluated by direct cell counting, but induces a powerful enhancement in the pulsed thymidine incorporation assay. The lack of effect of oleic acid on EGF-stimulated cellular proliferation was confirmed by repeated cell counts, cumulative thymidine incorporation, and protein synthesis, but a clear synergistic effect between oleic acid and EGF was again obtained by means of time course experiments with pulsed thymidine. Combined flow cytometry analysis and cell counts at earlier times in EGF-stimulated cells showed that oleic acids accelerates the entrance of cells into the replicative cycle leading to an earlier cell division. Afterward, these oleic acid-pretreated cells became delayed by an unknown compensatory mechanism in such a way that at 48 h post-EGF, the cell count in control and oleic acid-pretreated cells was equal. In conclusion (a) oleic acid accelerates or enhances the EGF mitogenic action and (b) in the long term cells compensate the initial perturbation with respect to untreated cells. As a side observation, the widely employed pulsed thymidine incorporation method as a measure of cell division could be extremely misleading unless experimental conditions are well controlled.

N-methyl-N'-nitro-N-nitrosoguanidine interferes with the epidermal growth factor receptor-mediated signaling pathway.

PubMed

Gao, Zhihua; Yang, Jun; Huang, Yun; Yu, Yingnian

2005-03-01

Many environmental factors, such as ultraviolet (UV) and arsenic, can induce the clustering of cell surface receptors, including epidermal growth factor receptor (EGFR). This is accompanied by the phosphorylation of the receptors and the activation of ensuing cellular signal transduction pathways, which are implicated in the various cellular responses caused by the exposure to these factors. In this study, we have shown that N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), an alkylating agent, also induced the clustering of EGFR in human amnion FL cells, which was similar in morphology to that of epidermal growth factor treatment. However, MNNG treatment did not activate Ras, the downstream mediator in EGFR signaling pathway, as compared to EGF treatment. The autophosphorylation of tyrosine residues Y1068 and Y1173 at the intracellular domain of EGFR, which is related to Ras activation under EGF treatment, was also not observed by MNNG exposure. Interestingly, although MNNG did not affect the binding of EGF to EGFR, MNNG can interfere with EGF function. For instance, pre-incubating FL cells with MNNG inhibited the autophosphorylation of EGFR by EGF treatment, as well as the activation of Ras. In addition, the phosphorylation of Y845 on EGFR by EGF, which is mediated through c-Src or related kinases but not autophosphorylation, was also affected by MNNG. Therefore, MNNG may influence the tyrosine kinase activity as well as the phosphorylation of EGFR through its interaction with EGFR.

Is receptor oligomerization causally linked to activation of the EGF receptor kinase?

NASA Technical Reports Server (NTRS)

Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

1992-01-01

Transduction of a signal from an extracellular peptide hormone to produce an intracellular response is often mediated by a cell surface receptor, which is usually a glycoprotein. The secondary intracellular signal(s) generated after hormone binding to the receptor have been intensively studied. The nature of the primary signal generated by ligand binding to the receptor is understood less well in most cases. The particular case of the epidermal growth factor (EGF) receptor is analyzed, and evidence for or against two dissimilar models of primary signal transduction is reviewed. Evidence for the most widely accepted current model is found to be unconvincing. Evidence for the other model is substantial but indirect; a direct test of this model remains to be done.

Polyurethane foam containing rhEGF as a dressing material for healing diabetic wounds: Synthesis, characterization, in vitro and in vivo studies.

PubMed

Pyun, Do Gi; Choi, Hyun Jun; Yoon, Hyoung Soon; Thambi, Thavasyappan; Lee, Doo Sung

2015-11-01

Diabetic wounds are a major health issue associated with diabetes mellitus. To surmount this issue, we developed polyurethane foams (PUFs) incorporating varying amounts of recombinant human epidermal growth factor (rhEGF) (rhEGF-PUFs) as a wound dressing for diabetic wounds. From electron microscopy images, it was found that the pore size of the rhEGF-PUFs surface (the wound contact layer) was less than 100μm, regardless of rhEGF content. The release of rhEGF from the PUFs was evaluated using an enzyme-linked immunosorbent assay. The result showed that the release of rhEGF was time and concentration dependent, i.e., the amount of released rhEGF significantly increased as the immersion time and the rhEGF content of the PUFs increased. In vitro cytotoxicity testing showed that rhEGF-PUFs increased the viability of HaCaT human keratinocytes and CCD986-sk human fibroblasts, which indicated that the incorporated rhEGF maintained its biological activity. In an in vitro scratch wound healing assay, the wound closure rate was faster in CCD986-sk human fibroblasts than in HaCaT human keratinocytes. Finally, the rhEGF-PUFs were evaluated as an in vivo treatment in a full-thickness wound model in diabetized Sprague-Dawley rats. The result indicated that compared with PUFs, rhEGF-PUFs accelerated wound healing by promoting wound contraction, re-epithelialization, collagen deposition and the formation of a skin appendage. These findings demonstrate that rhEGF-PUFs are a promising dressing for diabetic wounds. Copyright © 2015. Published by Elsevier B.V.

Killing of cultured hepatocytes by conjugates of asialofetuin and EGF linked to the A chains of ricin or diphtheria toxin.

PubMed

Simpson, D L; Cawley, D B; Herschman, H R

1982-06-01

A disulfide-linked conjugate between asialofetuin (ASF) and the toxic A chain (RTA) of ricin is as potent a toxin for cultured rat hepatocytes as our previously described conjugate between ASF and fragment A of diphtheria toxin (DTA). An RTA conjugate of epidermal growth factor (EGF) was a potent toxin for 3T3 cells. In contrast, EGF-DTA was essentially nontoxic for 3T3 cells. We have now examined the toxicity of EGF-RTA and EGF-DTA on cultured hepatocytes. The EGF-DTA conjugate, nontoxic to 3T3 cells, is also a potent toxin for hepatocytes. We also observed a decrease with time of culture in the sensitivity of hepatocytes to the ASF and EGF conjugates. This decrease is not a result of a decrease in EGF or asialoglycoprotein receptors.

Epidermal growth factor regulation of glutathione S-transferase gene expression in the rat is mediated by class Pi glutathione S-transferase enhancer I.

PubMed

Matsumoto, M; Imagawa, M; Aoki, Y

2000-07-01

Using chloramphenicol acetyltransferase assays we showed that epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and 3,3',4,4',5-pentachlorobiphenyl (PenCB) induce class Pi glutathione S-transferase (GSTP1) in primary cultured rat liver parenchymal cells. GSTP1 enhancer I (GPEI), which is required for the stimulation of GSTP1 expression by PenCB, also mediates EGF and TGF alpha stimulation of GSTP1 gene expression. However, hepatocyte growth factor and insulin did not stimulate GPEI-mediated gene expression. On the other hand, the antioxidant reagents butylhydroxyanisole and t-butylhydroquinone, stimulated GPEI-mediated gene expression, but the level of GSTP1 mRNA was not elevated. Our observations suggest that EGF and TGF alpha induce GSTP1 by the same signal transduction pathway as PenCB. Since the sequence of GPEI is similar to that of the antioxidant responsive element (ARE), some factors which bind to ARE might play a role in GPEI-mediated gene expression.

Epidermal growth factor regulation of glutathione S-transferase gene expression in the rat is mediated by class Pi glutathione S-transferase enhancer I.

PubMed Central

Matsumoto, M; Imagawa, M; Aoki, Y

2000-01-01

Using chloramphenicol acetyltransferase assays we showed that epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and 3,3',4,4',5-pentachlorobiphenyl (PenCB) induce class Pi glutathione S-transferase (GSTP1) in primary cultured rat liver parenchymal cells. GSTP1 enhancer I (GPEI), which is required for the stimulation of GSTP1 expression by PenCB, also mediates EGF and TGF alpha stimulation of GSTP1 gene expression. However, hepatocyte growth factor and insulin did not stimulate GPEI-mediated gene expression. On the other hand, the antioxidant reagents butylhydroxyanisole and t-butylhydroquinone, stimulated GPEI-mediated gene expression, but the level of GSTP1 mRNA was not elevated. Our observations suggest that EGF and TGF alpha induce GSTP1 by the same signal transduction pathway as PenCB. Since the sequence of GPEI is similar to that of the antioxidant responsive element (ARE), some factors which bind to ARE might play a role in GPEI-mediated gene expression. PMID:10861232

Targeting autocrine HB-EGF signaling with specific ADAM12 inhibition using recombinant ADAM12 prodomain

NASA Astrophysics Data System (ADS)

Miller, Miles A.; Moss, Marcia L.; Powell, Gary; Petrovich, Robert; Edwards, Lori; Meyer, Aaron S.; Griffith, Linda G.; Lauffenburger, Douglas A.

2015-10-01

Dysregulation of ErbB-family signaling underlies numerous pathologies and has been therapeutically targeted through inhibiting ErbB-receptors themselves or their cognate ligands. For the latter, “decoy” antibodies have been developed to sequester ligands including heparin-binding epidermal growth factor (HB-EGF); however, demonstrating sufficient efficacy has been difficult. Here, we hypothesized that this strategy depends on properties such as ligand-receptor binding affinity, which varies widely across the known ErbB-family ligands. Guided by computational modeling, we found that high-affinity ligands such as HB-EGF are more difficult to target with decoy antibodies compared to low-affinity ligands such as amphiregulin (AREG). To address this issue, we developed an alternative method for inhibiting HB-EGF activity by targeting its cleavage from the cell surface. In a model of the invasive disease endometriosis, we identified A Disintegrin and Metalloproteinase 12 (ADAM12) as a protease implicated in HB-EGF shedding. We designed a specific inhibitor of ADAM12 based on its recombinant prodomain (PA12), which selectively inhibits ADAM12 but not ADAM10 or ADAM17. In endometriotic cells, PA12 significantly reduced HB-EGF shedding and resultant cellular migration. Overall, specific inhibition of ligand shedding represents a possible alternative to decoy antibodies, especially for ligands such as HB-EGF that exhibit high binding affinity and localized signaling.

EGF-CFC proteins are essential coreceptors for the TGF-β signals Vg1 and GDF1

PubMed Central

Cheng, Simon K.; Olale, Felix; Bennett, James T.; Brivanlou, Ali H.; Schier, Alexander F.

2003-01-01

The TGF-β signals Nodal, Activin, GDF1, and Vg1 have been implicated in mesoderm induction and left-right patterning. Nodal and Activin both activate Activin receptors, but only Nodal requires EGF-CFC coreceptors for signaling. We report that Vg1 and GDF1 signaling in zebrafish also depends on EGF-CFC proteins, but not on Nodal signals. Correspondingly, we find that in Xenopus Vg1 and GDF1 bind to and signal through Activin receptors only in the presence of EGF-CFC proteins. These results establish that multiple TGF-β signals converge on Activin receptor/EGF-CFC complexes and suggest a more widespread requirement for coreceptors in TGF-β signaling than anticipated previously. PMID:12514096

Drosophila bunched integrates opposing DPP and EGF signals to set the operculum boundary.

PubMed

Dobens, L L; Peterson, J S; Treisman, J; Raftery, L A

2000-02-01

The Drosophila BMP homolog DPP can function as a morphogen, inducing multiple cell fates across a developmental field. However, it is unknown how graded levels of extracellular DPP are interpreted to organize a sharp boundary between different fates. Here we show that opposing DPP and EGF signals set the boundary for an ovarian follicle cell fate. First, DPP regulates gene expression in the follicle cells that will create the operculum of the eggshell. DPP induces expression of the enhancer trap reporter A359 and represses expression of bunched, which encodes a protein similar to the mammalian transcription factor TSC-22. Second, DPP signaling indirectly regulates A359 expression in these cells by downregulating expression of bunched. Reduced bunched function restores A359 expression in cells that lack the Smad protein MAD; ectopic expression of BUNCHED suppresses A359 expression in this region. Importantly, reduction of bunched function leads to an expansion of the operculum and loss of the collar at its boundary. Third, EGF signaling upregulates expression of bunched. We previously demonstrated that the bunched expression pattern requires the EGF receptor ligand GURKEN. Here we show that activated EGF receptor is sufficient to induce ectopic bunched expression. Thus, the balance of DPP and EGF signals sets the boundary of bunched expression. We propose that the juxtaposition of cells with high and low BUNCHED activity organizes a sharp boundary for the operculum fate.

Effects of structurally stabilized EGF and bFGF on wound healing in type I and type II diabetic mice.

PubMed

Choi, Seong Mi; Lee, Kyoung-Mi; Kim, Hyun Jung; Park, Ik Kyu; Kang, Hwi Ju; Shin, Hang-Cheol; Baek, Dawoon; Choi, Yoorim; Park, Kwang Hwan; Lee, Jin Woo

2018-01-15

Diabetes mellitus comprises a multiple metabolic disorder that affects millions of people worldwide and consequentially poses challenges for clinical treatment. Among the various complications, diabetic ulcer constitutes the most prevalent associated disorder and leads to delayed wound healing. To enhance wound healing capacity, we developed structurally stabilized epidermal growth factor (ST-EGF) and basic fibroblast growth factor (ST-bFGF) to overcome limitations of commercially available EGF (CA-EGF) and bFGF (CA-bFGF), such as short half-life and loss of activity after loading onto a matrix. Neither ST-EGF nor ST-bFGF was toxic, and both were more stable at higher temperatures than CA-EGF and CA-bFGF. We loaded ST-EGF and ST-bFGF onto a hyaluronate-collagen dressing (HCD) matrix, a biocompatible carrier, and tested the effectiveness of this system in promoting wound healing in a mouse model of diabetes. Wounds treated with HCD matrix loaded with 0.3 μg/cm 2 ST-EGF or 1 μg/cm 2 ST-bFGF showed a more rapid rate of tissue repair as compared to the control in type I and II diabetes models. Our results indicate that an HDC matrix loaded with 0.3 μg/cm 2 ST-EGF or 1 μg/cm 2 ST-bFGF can promote wound healing in diabetic ulcers and are suitable for use in wound dressings owing to their stability for long periods at room temperature. Various types of dressing materials loaded with growth factors, such as VEGF, EGF, and bFGF, are widely used to effect wound repair. However, such growth factor-loaded materials have several limitations for use as therapeutic agents in healing-impaired diabetic wounds. To overcome these limitations, we have developed new materials containing structurally stabilized EGF (ST-EGF) and bFGF (ST-bFGF). To confirm the wound healing capacity of newly developed materials (ST-EGF and ST-bFGF-loaded hyaluronate-collagen dressing [HCD] matrix), we applied these matrices in type I and type II diabetic wounds. Notably, these matrices were

Autocrine expression of the epidermal growth factor receptor ligand heparin-binding EGF-like growth factor in cervical cancer.

PubMed

Schrevel, Marlies; Osse, E Michelle; Prins, Frans A; Trimbos, J Baptist M Z; Fleuren, Gert Jan; Gorter, Arko; Jordanova, Ekaterina S

2017-06-01

In cervical cancer, the epidermal growth factor receptor (EGFR) is overexpressed in 70-90% of the cases and has been associated with poor prognosis. EGFR-based therapy is currently being explored in cervical cancer. We investigated which EGFR ligand is primarily expressed in cervical cancer and which cell type functions as the major source of this ligand. We hypothesized that macrophages are the main source of EGFR ligands and that a paracrine loop between tumor cells and macrophages is responsible for ligand expression. mRNA expression analysis was performed on 32 cervical cancer cases to determine the expression of the EGFR ligands amphiregulin, β-cellulin, epidermal growth factor (EGF), epiregulin, heparin-binding EGF-like growth factor (HB‑EGF) and transforming growth factor α (TGFα). Subsequently, protein expression was determined immunohistochemically on 36 additional cases. To assess whether macrophages are the major source of EGFR ligands, immunohistochemical double staining was performed on four representative tissue slides. Expression of the chemokines granulocyte-macrophage colony-stimulating factor (GM-CSF) and C-C motif ligand 2 (CCL2) was determined by mRNA in situ hybridization. Of the known EGFR ligands, HB‑EGF had the highest mRNA expression and HB‑EGF and EGFR protein expression were highly correlated. Tumor specimens with high EGFR expression showed higher numbers of macrophages, and higher expression of GM-CSF and CCL2, but only a small subset (9%) of macrophages was found to be HB‑EGF-positive. Strikingly, 78% of cervical cancer specimens were found to express HB‑EGF. Standardized assessment of staining intensity, using spectral imaging analysis, showed that HB‑EGF expression was higher in the tumor compartment than in the stromal compartment. These results suggest that HB‑EGF is an important EGFR ligand in cervical cancer and that cervical cancer cells are the predominant source of HB‑EGF. Therefore, we propose an autocrine

Threshold levels of ERK activation for chemotactic migration differ for NGF and EGF in rat pheochromocytoma PC12 cells.

PubMed

Ho, W C; Uniyal, S; Zhou, H; Morris, V L; Chan, B M C

2005-03-01

In a previous study, we show that stimulation of chemotaxis in rat pheochromocytoma PC12 cells by nerve growth factor (NGF) and epidermal growth factor (EGF) requires activation of the RAS-ERK signaling pathway. In this study, we compared the threshold levels of ERK activation required for EGF and NGF-stimulated chemotaxis in PC12 cells. The threshold ERK activity required for NGF to stimulate chemotaxis was approximately 30% lower than that for EGF. PD98059 treatment inhibited EGF stimulation of growth and chemotaxis; however, stimulation of chemotaxis required an EGF concentration approximately 10 times higher than for stimulation of PC12 cell growth. Thus, ERK-dependent cellular functions can be differentially elicited by the concentration of EGF. Also, treatment of PC12 cells with the PI3-K inhibitor LY294002 reduced ERK activation by NGF; thus, higher NGF concentrations were required to initiate chemotaxis and to achieve the same maximal chemotactic response seen in untreated PC12 cells. Therefore, the threshold NGF concentration to stimulate chemotaxis could be adjusted by the crosstalk between the ERK and PI3-K pathways, and the contributions of PI3-K and ERK to signal chemotaxis varied with the concentrations of NGF used. In comparison, LY294002 treatment had no effect on ERK activation by EGF, but the chemotactic response was reduced at all the concentrations of EGF tested indicating that NGF and EGF differed in the utilization of ERK and PI3-K to signal chemotaxis in PC12 cells.

N-WASP and cortactin are involved in invadopodium-dependent chemotaxis to EGF in breast tumor cells

PubMed Central

DesMarais, Vera; Yamaguchi, Hideki; Oser, Matthew; Soon, Lilian; Mouneimne, Ghassan; Sarmiento, Corina; Eddy, Robert; Condeelis, John

2009-01-01

Metastatic mammary carcinoma cells, which have previously been observed to form mature, matrix degrading invadopodia on a thick ECM matrix, are able to form invadopodia with similar characteristics on glass without previously applied matrix. They form in response to EGF, and contain the usual invadopodium core proteins N-WASP, Arp2/3, cortactin, cofilin, and F-actin. The study of invadopodia on glass allows for higher resolution analysis including the use of total internal reflection microscopy and analysis of their relationship to other cell motility events, in particular, lamellipodium extension and chemotaxis toward an EGF gradient. Invadopodium formation on glass requires N-WASP and cortactin but not microtubules. In a gradient of EGF more invadopodia form on the side of the cells facing the source of EGF. In addition, depletion of N-WASP or cortactin, which blocks invadopodium fromation, inhibits chemotaxis of cells towards EGF. This appears to be a localized defect in chemotaxis since depletion of N-WASP or cortactin via siRNA had no effect on lamellipodium protrusion or barbed end generation at the lamellipodium's leading edge. Since chemotaxis to EGF by breast tumor cells is involved in metastasis, inhibiting N-WASP activity in breast tumor cells might prevent metastasis of tumor cells while not affecting chemotaxis-dependent innate immunity which depends on WASp function in macrophages. PMID:19373774

Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer.

PubMed

Shetty, Praveenkumar; Patil, Vidya S; Mohan, Rajashekar; D'souza, Leonard Clinton; Bargale, Anil; Patil, Basavaraj R; Dinesh, U S; Haridas, Vikram; Kulkarni, Shrirang P

2017-07-01

Background AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression. Methods Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model. Results Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P < 0.01) and Her-2 positive cases (217.75 ± 60.59 ng/mL, P < 0.0001). In Her-2 negative cases, the HB-EGF concentrations (179.16 ± 118.81 pg/mL) were highly significant compared with normal (14.92 ± 17.33 pg/mL, P < 0.001). IL-6 concentrations were increased significantly in both the breast cancer phenotypes as compared with normal ( P < 0.001). Conclusion The specific expression pattern of annexinA2 and HB-EGF in triple-negative breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

Immuno-modulatory effect of local rhEGF treatment during tissue repair in diabetic ulcers.

PubMed

García-Honduvilla, Natalio; Cifuentes, Alberto; Ortega, Miguel A; Pastor, Marta; Gainza, Garazi; Gainza, Eusebio; Buján, Julia; Álvarez-Mon, Melchor

2018-04-01

Wound healing is a complex process that can be severely impaired due to pathological situations such as diabetes mellitus. Diabetic foot ulcers are a common complication of this pathology and are characterized by an excessive inflammatory response. In this work, the effects of local treatment with recombinant human epidermal growth factor (rhEGF) were studied using a full-thickness wound healing model in streptozotocin-induced diabetic rats. Wound healing process was assessed with different concentrations of rhEGF (0.1, 0.5, 2.0 and 8.0 µg/mL), placebo and both diabetic and non-diabetic controls ( n  = 53). The macroscopic healing observed in treated diabetic rats was affected by rhEGF concentration. Histologically, we also observed an improvement in the epithelialization, granulation tissue formation and maturation in treated groups, finding again the best response at doses of 0.5 and 2.0 µg/mL. Afterwards, the tissue immune response over time was assessed in diabetic rats using the most effective concentrations of rhEGF (0.5 and 2.0 µg/mL), compared to controls. The presence of macrophages, CD4 + T lymphocytes and CD8 + T lymphocytes, in the reparative tissue was quantified, and cytokine expression was measured by quantitative real-time PCR. rhEGF treatment caused a reduction in the number of infiltrating macrophages in the healing tissue of diabetic, as well as diminished activation of these leukocytes. These findings show that local administration of rhEGF improves the healing process of excisional wounds and the quality of the neoformed tissue in a dose-dependent manner. Besides, this treatment reduces the local inflammation associated with diabetic healing, indicating immuno-modulatory properties. © 2018 The authors.

Epidermal growth factor (EGF)-stimulated inositol phosphate formation in hepatocytes is abolished by pertussis toxin and phorbol esters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, R.M.; Garrison, J.C.

1987-05-01

The EGF-stimulated rise in intracellular Ca/sup 2 +/ (Ca/sup 2 +/)/sub i/ and Ca/sup 2 +/-dependent protein phosphorylation events in isolated hepatocytes are blocked by pertussis toxin and phorbol ester pretreatment. The present study characterized the EGF-stimulated formation of inositol 1,4,5-trisphosphate (Ins(1,4,5)P/sub 3/) and inositol 1,3,4-trisphosphate (Ins(1,3,4)P/sub 3/) in hepatocytes using HPLC methodology to separate the InsP/sub 3/ isomers. Both 66 nM EGF and 10 nM angiotensin II (ANG II) caused a rapid increase in the Ins(1,4,5)P/sub 3/ isomer although EGF-stimulated formation was smaller. At a concentration of ANG II (0.1 nM) which gave an equivalent rise in (Ca/sup 2more » +/)/sub i/ as 66 nM EGF, the kinetics and magnitude of Ins(1,4,5)P/sub 3/ formation were similar. EGF or ANG II-stimulated formation of the Ins(1,3,4)P/sub 3/ isomer was more gradual and increased beyond the level of Ins(1,4,5)P/sub 3/ after 60 sec. The initial EGF and ANG II-stimulated increase in both InsP/sub 3/ isomers was not affected by removing external Ca/sup 2 +/ with a 10-fold excess of EGTA. Pretreatment of rats with pertussis toxin for 72 hrs blocked the ability of EGF to increase Ins(1,4,5)P/sub 3/ but did not affect the increase due to ANG II. Three main pretreatment of cells with 1 ..mu..g/ml phorbol 12-myristate-13-acetate (PMA) also inhibited the EGF-stimulated Ins(1,4,5)P/sub 3/ formation. PMA slightly attenuated Ins(1,4,5)P/sub 3/ formation stimulated by 0.1 nM ANG II but not enough to affect the Ca/sup 2 +/ signal. These data suggest that the signal transduction system used by EGF receptors to increase Ins (1,4,5)P/sub 3/ in hepatocytes is somehow different from that used by ANG II receptors.« less

Convection enhanced delivery of boronated EGF as a molecular targeting agent for neutron capture therapy of brain tumors

PubMed Central

Yang, Weilian; Wu, Gong; Huo, Tianyao; Tjarks, Werner; Ciesielski, Michael; Fenstermaker, Robert A.; Ross, Brain D.; Wikstrand, Carol J.; Riley, Kent J.; Binns, Peter J.

2010-01-01

In the present study, we have evaluated a boronated dendrimer-epidermal growth factor (BD-EGF) bioconjugate as a molecular targeting agent for boron neutron capture therapy (BNCT) of the human EGFR gene-transfected F98 rat glioma, designated F98EGFR. EGF was chemically linked to a heavily boronated polyamidoamine dendrimer (BD) by means of the heterobifunctional reagent, mMBS. Biodistribution studies were carried out at 6 h and 24 h following intratumoral (i.t.) injection or intracerebral (i.c.) convection enhanced delivery (CED) of 125I-labeled or unlabeled BD-EGF (40 μg 10B/10 μg EGF) to F98 glioma bearing rats. At 24 h. there was 43% more radioactivity in EGFR(+) tumors following CED compared to i.t. injection, and a doubling of the tumor boron concentration (22.3 μg/g vs. 11.7 μg/g). CED of BD-EGF resulted in a 7.2× increase in the volume of distribution within the infused cerebral hemisphere and a 1.9× increase in tumor uptake of BD-EGF compared with i.t. injection. Based on these favorable bio-distribution data, BNCT was carried out at the Massachusetts Institute of Technology nuclear reactor 14 days following i.c. tumor implantation and 24 h. after CED of BD-EGF. These animals had a MST of 54.1 ± 4.7 days compared to 43.0 ± 2.8 days following i.t. injection. Rats that received BD-EGF by CED in combination with i.v. boronophenylalanine (BPA), which has been used in both experimental and clinical studies, had a MST of 86.0 ± 28.1 days compared to 39.8 ± 1.6 days for i.v. BPA alone (P < 0.01), 30.9 ± 1.4 days for irradiated controls and 25.1 ± 1.0 days for untreated controls (overall P < 0.0001). These data have demonstrated that the efficacy of BNCT was significantly increased (P < 0.006), following i.c CED of BD-EGF compared to i.t injection, and that the survival data were equivalent to those previously reported by us using the boronated anti-human-EGF mAb, C225 (cetuximab). PMID:19588228

A Mena invasion isoform potentiates EGF-induced carcinoma cell invasion and metastasis.

PubMed

Philippar, Ulrike; Roussos, Evanthia T; Oser, Matthew; Yamaguchi, Hideki; Kim, Hyung-Do; Giampieri, Silvia; Wang, Yarong; Goswami, Sumanta; Wyckoff, Jeffrey B; Lauffenburger, Douglas A; Sahai, Erik; Condeelis, John S; Gertler, Frank B

2008-12-01

The spread of cancer during metastatic disease requires that tumor cells subvert normal regulatory networks governing cell motility to invade surrounding tissues and migrate toward blood and lymphatic vessels. Enabled (Ena)/vasodilator-stimulated phosphoprotein (VASP) proteins regulate cell motility by controlling the geometry of assembling actin networks. Mena, an Ena/VASP protein, is upregulated in the invasive subpopulation of breast cancer cells. In addition, Mena is alternately spliced to produce an invasion isoform, Mena(INV). Here we show that Mena and Mena(INV) promote carcinoma cell motility and invasiveness in vivo and in vitro, and increase lung metastasis. Mena and Mena(INV) potentiate epidermal growth factor (EGF)-induced membrane protrusion and increase the matrix degradation activity of tumor cells. Interestingly, Mena(INV) is significantly more effective than Mena in driving metastases and sensitizing cells to EGF-dependent invasion and protrusion. Upregulation of Mena(INV) could therefore enable tumor cells to invade in response to otherwise benign EGF stimulus levels.

Temperature-induced unfolding of epidermal growth factor (EGF): insight from molecular dynamics simulation

PubMed Central

Yan, Chunli; Pattani, Varun; Tunnell, James W.; Ren, Pengyu

2010-01-01

Thermal disruption of protein structure and function is a potentially powerful therapeutic vehicle. With the emerging nanoparticle-targeting and femtosecond laser technology, it is possible to deliver heating locally to specific molecules. It is therefore important to understand how fast a protein can unfold or lose its function at high temperatures, such as near the water boiling point. In this study, the thermal damage of EGF was investigated by combining the replica exchange (136 replicas) and conventional molecular dynamics simulations. The REMD simulation was employed to rigorously explore the free energy landscape of EGF unfolding. Interestingly, besides the native and unfolded states, we also observed a distinct molten globule (MG) state that retained substantial amount of native contacts. Based on the understanding that which the unfolding of EGF is a three-state process, we have examined the unfolding kinetics of EGF (N→ MG→h multiple 20-ns conventional MD simulations. The Arrhenius prefactors and activation energy barriers determined from the simulation are within the range of previously studied proteins. In contrast to the thermal damage of cells and tissues which take place on the time scale of seconds to hours at relatively low temperatures, the denaturation of proteins occur in nanoseconds when the temperature of heat bath approaches the boiling point. PMID:20466569

EGFP-EGF1-Conjugated PLGA Nanoparticles for Targeted Delivery of siRNA into Injured Brain Microvascular Endothelial Cells for Efficient RNA Interference

PubMed Central

Chen, Chen; Mei, Heng; Shi, Wei; Deng, Jun; Zhang, Bo; Guo, Tao; Wang, Huafang; Hu, Yu

2013-01-01

Injured endothelium is an important target for drug and/or gene therapy because brain microvascular endothelial cells (BMECs) play critical roles in various pathophysiological conditions. RNA-mediated gene silencing presents a new therapeutic approach for treating such diseases, but major challenge is to ensure minimal toxicity and target delivery of siRNA to injured BMECs. Injured BMECs overexpress tissue factor (TF), which the fusion protein EGFP-EGF1 could be targeted to. In this study, TNF alpha (TNF-α) was chosen as a stimulus for primary BMECs to produce injured endothelium in vitro. The EGFP-EGF1-PLGA nanoparticles (ENPs) with loaded TF-siRNA were used as a new carrier for targeted delivery to the injured BMECs. The nanoparticles then produced intracellular RNA interference against TF. We compared ENP-based transfections with NP-mediated transfections, and our studies show that the ENP-based transfections result in a more efficient downregulation of TF. Our findings also show that the TF siRNA-loaded ENPs had minimal toxicity, with almost 96% of the cells viable 24 h after transfection while Lipofectamine-based transfections resulted in only 75% of the cells. Therefore, ENP-based transfection could be used for efficient siRNA transfection to injured BMECs and for efficient RNA interference (RNAi). This transfection could serve as a potential treatment for diseases, such as stroke, atherosclerosis and cancer. PMID:23593330

Lineage-specific co-evolution of the Egf receptor/ligand signaling system.

PubMed

Laisney, Juliette A G C; Braasch, Ingo; Walter, Ronald B; Meierjohann, Svenja; Schartl, Manfred

2010-01-27

The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed with different subsets of Egfr

Lineage-specific co-evolution of the Egf receptor/ligand signaling system

PubMed Central

2010-01-01

Background The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. Results We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Conclusions Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed

Anti-MUC1 antibody inhibits EGF receptor signaling in cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hisatsune, Akinori, E-mail: hisatsun@kumamoto-u.ac.jp; Nakayama, Hideki; Kawasaki, Mitsuru

2011-02-18

Research highlights: {yields} We identified changes in the expression and function of EGFR by anti-MUC1 antibody. {yields} An anti-MUC1 antibody GP1.4 decreased EGFR from cell surface by internalization. {yields} GP1.4 specifically inhibited ERK signaling triggered EGF-EGFR signaling pathway. {yields} Internalization of EGFR was dependent on the presence of MUC1 on cell surface. {yields} GP1.4 significantly inhibited EGF-dependent cancer cell proliferation and migration. -- Abstract: MUC1 is a type I transmembrane glycoprotein aberrantly overexpressed in various cancer cells. High expression of MUC1 is closely associated with cancer progression and metastasis, leading to poor prognosis. We previously reported that MUC1 is internalizedmore » by the binding of the anti-MUC1 antibody, from the cell surface to the intracellular region via the macropinocytotic pathway. Since MUC1 is closely associated with ErbBs, such as EGF receptor (EGFR) in cancer cells, we examined the effect of the anti-MUC1 antibody on EGFR trafficking. Our results show that: (1) anti-MUC1 antibody GP1.4, but not another anti-MUC1 antibody C595, triggered the internalization of EGFR in pancreatic cancer cells; (2) internalization of EGFR by GP1.4 resulted in the inhibition of ERK phosphorylation by EGF stimulation, in a MUC1 dependent manner; (3) inhibition of ERK phosphorylation by GP1.4 resulted in the suppression of proliferation and migration of pancreatic cancer cells. We conclude that the internalization of EGFR by anti-MUC1 antibody GP1.4 inhibits the progression of cancer cells via the inhibition of EGFR signaling.« less

Protective Effects of Bacopa Monnieri on Hydrogen Peroxide and Staurosporine: Induced Damage of Human Neuroblastoma SH-SY5Y Cells.

PubMed

Łojewski, Maciej; Pomierny, Bartosz; Muszyńska, Bożena; Krzyżanowska, Weronika; Budziszewska, Bogusława; Szewczyk, Agnieszka

2016-02-01

Many herbs, and recently their biomass from in vitro cultures, are essential for the treatment of diseases. The aim of this study was to determine the optimal growth of Bacopa monnieri (water hyssop) in an in vitro culture and to examine if extracts of the B. monnieri biomass from the in vitro culture would affect hydrogen peroxide- and staurosporine-induced injury of the human neuroblastoma SH-SY5Y cell line. It has been found that B. monnieri at concentrations of 25, 50, and 100 µg/mL inhibited both hydrogen peroxide-induced efflux of lactate dehydrogenase from damaged cells to culture medium and increased cell viability determined by an MTT assay. Moreover, B. monnieri at concentrations of 10, 25, and 50 µg/mL decreased staurosporine-induced activity of an executive apoptotic enzyme-caspase-3 and protected mitochondrial membrane potential. The obtained data indicate that the biomass from the in vitro culture of B. monnieri prevented SH-SY5Y cell damage related to oxidative stress and had the ability to inhibit the apoptotic process. Thus, this study supports the traditional use of B. monnieri as a neuroprotective therapy, and further in vivo studies on the effects of this preparation on morphology and function of nerve cells could lead to its wider application. Georg Thieme Verlag KG Stuttgart · New York.

A potencial theranostic agent for EGF-R expression tumors: (177)Lu-DOTA-nimotuzumab.

PubMed

Calzada, Victoria; Zhang, Xiuli; Fernandez, Marcelo; Diaz-Miqueli, Arlhee; Iznaga-Escobar, Normando; Deutscher, Susan L; Balter, Henia; Quinn, Thomas P; Cabral, Pablo

2012-10-01

In this work Nimotuzumab (monoclonal antibody, recognizes the EGF-R) was radiolabeled with (177)Lu as a potential cancer therapy radiopharmaceutical. In-vitro cell binding studies and in-vivo biodistribution and imaging studies were performed to determine the radiochemical stability, targeting specificity and pharmacokinetics of the (177)Lu-labeled antibody. Nimotuzumab was derivatized with DOTA-NHS at room temperature for 2 hours. DOTA-Nimotuzumab was radiolabeled with (177)LuCl3 (15 MBq/mg) at 37°C for 1 h. The radiochemical purity was assessed by ITLC, silica gel and by RP-HPLC. Binding specificity studies were performed with EGF-R positive A431 human epithelial carcinoma and EGF-R negative MDA-MB-435 breast carcinoma cells. Biodistribution studies were performed in healthy female CD-1 mice at 1 h, 4 h, 24 h, and A431 xenografted nude mice at 10 min, 1 h, 4 h, 24 h, 48 h, and 96 h. SPECT-CT imaging studies were performed in A431 xenografted mice at 24 h post injection. DOTA-Nimotuzumab was efficiently labeled with (177) LuCl(3) at 37°C. The in vitro stability of labeled product was optimal over 24 h in buffered saline and mouse serum. Specific recognition of EGF-R by (177)Lu-DOTA-Nimotuzumab was observed in A431 cell binding studies. Biodistribution studies demonstrated increasing tumor uptake of (177)Lu-DOTA-Nimotuzumab over time, with tumor to muscle ratios of 6.26, 10.68, and 18.82 at 4 h, 24 h, and 96 h post injection. Imaging of A431 xenografted mice showed high uptake in the tumor. (177)Lu-DOTA-Nimotuzumab has the potential to be a promising therapy agent, which may be useful in the treatment of patients with EGF-R positive cancer.

EFFECTS OF EPIDERMAL GROWTH FACTOR (EGF), TRANSFORMING GROWTH FACTOR- (TGF), AND 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN ON FUSION OF EMBRYONIC PALATES IN SERUM-FREE ORGAN CULTURE USING WILD-TYPE, EGF KNOCKOUT, AND TGF KNOCKOUT MOUSE STRAINS

EPA Science Inventory

Backround: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is teratogenic in mice, producing cleft palate (CP). TCDD exposure disrupts expression of epidermal growth factor (EGF) receptor, EGF, and transforming growth factor- (TGF) in the palate and affects proliferation and different...

ROLE OF RAS IN METAL-INDUCED EGF RECEPTOR AND NFKB SIGNALING IN HUMAN AIRWAY EPITHELIAL CELLS

EPA Science Inventory

We have shown previously that EGF receptor signaling is triggered by some metals associated with ambient air particles. Western blot using phospho-specific antibodies showed that As, Zn and V activated EGF receptor tyrosine kinase and the downstream kinases, MEK1/2 and ERK1/2. Us...

EGF and hydrocortisone as critical factors for the co-culture of adipogenic differentiated ASCs and endothelial cells.

PubMed

Volz, Ann-Cathrin; Huber, Birgit; Schwandt, Alina Maria; Kluger, Petra Juliane

In vitro composed vascularized adipose tissue is and will continue to be in great demand e.g. for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Up to date, the lack of adequate culture conditions, mainly a culture medium, decelerates further achievements. In our study, we evaluated the influence of epidermal growth factor (EGF) and hydrocortisone (HC), often supplemented in endothelial cell (EC) specific media, on the co-culture of adipogenic differentiated adipose-derived stem cells (ASCs) and microvascular endothelial cells (mvECs). In ASCs, EGF and HC are thought to inhibit adipogenic differentiation and have lipolytic activities. Our results showed that in indirect co-culture for 14 days, adipogenic differentiated ASCs further incorporated lipids and partly gained an univacuolar morphology when kept in media with low levels of EGF and HC. In media with high EGF and HC levels, cells did not incorporate further lipids, on the contrary, cells without lipid droplets appeared. Glycerol release, to measure lipolysis, also increased with elevated amounts of EGF and HC in the culture medium. Adipogenic differentiated ASCs were able to release leptin in all setups. MvECs were functional and expressed the cell specific markers, CD31 and von Willebrand factor (vWF), independent of the EGF and HC content as long as further EC specific factors were present. Taken together, our study demonstrates that adipogenic differentiated ASCs can be successfully co-cultured with mvECs in a culture medium containing low or no amounts of EGF and HC, as long as further endothelial cell and adipocyte specific factors are available. Copyright © 2017 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

ERK1/2 mediates sperm acrosome reaction through elevation of intracellular calcium concentration.

PubMed

Jaldety, Yael; Breitbart, Haim

2015-10-01

Mammalian sperm acquire fertilization capacity after residing in the female reproductive tract for a few hours in a process called capacitation. Only capacitated sperm can bind the zona pellucida (ZP) of the egg and undergo the acrosome reaction, a process that allows penetration and fertilization. Extracellular signal regulated kinase (ERK1/2) mediates signalling in many cell types, however its role in sperm function is largely unknown. Here we show that ERK1/2 is highly phosphorylated/activated after a short incubation of mouse sperm under capacitation conditions and that this phosphorylation is reduced after longer incubation. Further phosphorylation was observed upon addition of crude extract of egg ZP or epidermal growth factor (EGF). The mitogen-activated ERK-kinase (MEK) inhibitor U0126 abolished ERK1/2 phosphorylation, in vitro fertilization rate and the acrosome reaction induced by ZP or EGF but not by the Ca2+-ionophore A23187. Moreover, inhibition of ERK1/2 along the capacitation process diminished almost completely the sperm's ability to go through the acrosome reaction, while inhibition at the end of capacitation attenuated the acrosome reaction rate by only 45%. The fact that the acrosome reaction, induced by the Ca2+ -ionophore A23187, was not inhibited by U0126 suggests that ERK1/2 mediates the acrosome reaction by activating Ca2+ transport into the cell. Direct determination of intracellular [Ca2+] revealed that Ca2+ influx induced by EGF or ZP was completely blocked by U0126. Thus, it has been established that the increase in ERK1/2 phosphorylation/activation in response to ZP or by activation of the EGF receptor (EGFR) by EGF, is a key event for intracellular Ca2+ elevation and the subsequent occurrence of the acrosome reaction.

Ezrin/NF-kB activation regulates epithelial- mesenchymal transition induced by EGF and promotes metastasis of colorectal cancer.

PubMed

Li, Yingru; Lin, Zhaoyu; Chen, Bin; Chen, Shuang; Jiang, Zhipeng; Zhou, Taicheng; Hou, Zehui; Wang, Youyuan

2017-08-01

There is growing evidence that epithelial mesenchymal-transition (EMT) plays significant roles in terms of tumor metastasis. There are a lot of cytokines inducing EMT of tumor cells, EGF is one of the important cytokines.Ezrin is a connexin between the cytoskeleton and the cell membrane, which is closely related to the morphological movement and metastasis of tumor cells.EGF can activate Ezrin and affects cell motility. In recent years, many studies have shown that NF-kB acts as an important transcription factor, involving in the process of EMT. However, does Ezrin participate in the regulation of EGF-induced EMT through the NF-kB pathway? This question needs us to discuss.In the present study, we found that EGF could induce colorectal cancer cells to develop EMT,enhance their ability to invade and migrate and promotes phosphorylation of Ezrin Tyr353.On the other hand, inhibition of Ezrin could reverse EGF-induced EMT and inhibit NF-kB P65 translocating into the nucleus. Finally, knockout of Ezrin inhibited EGF-induced lung metastasis of colorectal cancer xenografts and abnormal activation of Ezrin and NF-kB were related with colorectal cancer metastasis and poor prognosis. Our present results suggest that Ezrin/NF-kB pathway may provide experimental evidence for new targeted drugs for colorectal cancer metastasis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Acute Ethanol Exposure Prevents PMA-mediated Augmentation of N-methyl-d-aspartate Receptor Function in Primary Cultured Cerebellar Granule Cells

PubMed Central

Reneau, Jason; Reyland, Mary E.; Popp, R. Lisa

2011-01-01

Many intracellular proteins and signaling cascades contribute to the ethanol sensitivity of native N-methyl-d-aspartate receptors (NMDARs). One putative protein is the serine / threonine kinase, Protein kinase C (PKC). The purpose of this study was to assess if PKC modulates the ethanol sensitivity of native NMDARs expressed in primary cultured cerebellar granule cells (CGCs). With the whole-cell patch-clamp technique, we assessed if ethanol inhibition of NMDA-induced currents (INMDA) (100 μM NMDA plus 10 μM glycine) were altered in CGCs in which the novel and classical PKC isoforms were activated by phorbol-12-myristate-13-acetate (PMA). Percent inhibition by 10, 50 or 100 mM ethanol of NMDA-induced steady-state (ISS) or peak current amplitudes (IPk) of NMDARs expressed in CGCs in which PKC was activated by a 12.5 min, 100 nM PMA exposure at 37° C did not differ from currents obtained from receptors contained in control cells. However, PMA-mediated augmentation of IPk in the absence of ethanol was abolished after brief applications of 10 or 1 mM ethanol co-applied with agonists, and this suppression of enhanced receptor function was observed for up to eight minutes post-ethanol exposure. Because we had previously shown that PMA-mediated augmentation of INMDA of NMDARs expressed in these cells is by activation of PKCα, we assessed the effect of ethanol (1, 10, 50 and 100 mM) on PKCα activity. Ethanol decreased PKCα activity by 18% for 1 mM ethanol and activity decreased with increasing ethanol concentrations with a 50% inhibition observed with 100 mM ethanol. The data suggest that ethanol disruption of PMA-mediated augmentation of INMDA may be due to a decrease in PKCα activity by ethanol. However, given the incomplete blockade of PKCα activity and the low concentration of ethanol at which this phenomenon is observed, other ethanol-sensitive signaling cascades must also be involved. PMID:21624785

Lack of TXNIP protects against mitochondria-mediated apoptosis but not against fatty acid-induced ER stress-mediated beta-cell death.

PubMed

Chen, Junqin; Fontes, Ghislaine; Saxena, Geetu; Poitout, Vincent; Shalev, Anath

2010-02-01

We have previously shown that lack of thioredoxin-interacting protein (TXNIP) protects against diabetes and glucotoxicity-induced beta-cell apoptosis. Because the role of TXNIP in lipotoxicity is unknown, the goal of the present study was to determine whether TXNIP expression is regulated by fatty acids and whether TXNIP deficiency also protects beta-cells against lipoapoptosis. RESARCH DESIGN AND METHODS: To determine the effects of fatty acids on beta-cell TXNIP expression, INS-1 cells and isolated islets were incubated with/without palmitate and rats underwent cyclic infusions of glucose and/or Intralipid prior to islet isolation and analysis by quantitative real-time RT-PCR and immunoblotting. Using primary wild-type and TXNIP-deficient islets, we then assessed the effects of palmitate on apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]), mitochondrial death pathway (cytochrome c release), and endoplasmic reticulum (ER) stress (binding protein [BiP], C/EBP homologous protein [CHOP]). Effects of TXNIP deficiency were also tested in the context of staurosporine (mitochondrial damage) or thapsigargin (ER stress). Glucose elicited a dramatic increase in islet TXNIP expression both in vitro and in vivo, whereas fatty acids had no such effect and, when combined with glucose, even abolished the glucose effect. We also found that TXNIP deficiency does not effectively protect against palmitate or thapsigargin-induced beta-cell apoptosis, but specifically prevents staurosporine- or glucose-induced toxicity. Our results demonstrate that unlike glucose, fatty acids do not induce beta-cell expression of proapoptotic TXNIP. They further reveal that TXNIP deficiency specifically inhibits the mitochondrial death pathway underlying beta-cell glucotoxicity, whereas it has very few protective effects against ER stress-mediated lipoapoptosis.

Regulation of EGF receptor signaling by the MARVEL domain-containing protein CKLFSF8.

PubMed

Jin, Caining; Ding, Peiguo; Wang, Ying; Ma, Dalong

2005-11-21

It is known that chemokine-like factor superfamily 8 (CKLFSF8), a member of the CKLF superfamily, has four putative transmembrane regions and a MARVEL domain. Its structure is similar to TM4SF11 (plasmolipin) and widely distributed in normal tissue. However, its function is not yet known. We show here that CKLFSF8 is associated with the epidermal growth factor receptor (EGFR) and that ectopic expression of CKLFSF8 in several cell lines suppresses EGF-induced cell proliferation, whereas knockdown of CKLFSF8 by siRNA promotes cell proliferation. In cells overexpressing CKLFSF8, the initial activation of EGFR was not affected, but subsequent desensitization of EGF-induced signaling occurred rapidly. This attenuation was correlated with an increased rate of receptor endocytosis. In contrast, knockdown of CKLFSF8 by siCKLFSF8 delayed EGFR endocytosis. These results identify CKLFSF8 as a novel regulator of EGF-induced signaling and indicate that the association of EGFR with four transmembrane proteins is critical for EGFR desensitization.

The epidermal growth factor receptor (EGF-R) is present on the basolateral, but not the apical, surface of enterocytes in the human gastrointestinal tract.

PubMed Central

Playford, R J; Hanby, A M; Gschmeissner, S; Peiffer, L P; Wright, N A; McGarrity, T

1996-01-01

BACKGROUND: While it is clear that luminal epidermal growth factor (EGF) stimulates repair of the damaged bowel, its significance in maintaining normal gut growth remains uncertain. If EGF is important in maintaining normal gut growth, the EGF receptor (EGF-R) should be present on the apical (luminal) surface in addition to the basolateral surface. AIMS/SUBJECTS/METHODS: This study examined the distribution of the EGF-R in the epithelium throughout the human gastro-intestinal tract using immunohistochemistry, electron microscopy, and western blotting of brush border preparations. RESULTS: Immunostaining of the oesophagus showed circumferential EGF-R positivity in the cells of the basal portions of the stratified squamous epithelium but surface cells were EGF-R negative. In the normal stomach, small intestine, and colon, immunostaining localised the receptor to the basolateral surface with the apical membranes being consistently negative. EGF-R positivity within the small intestine appeared to be almost entirely restricted to the proliferative (crypt) region. Western blotting demonstrated a 170 kDa protein in whole tissue homogenates but not in the brush border vesicle preparations. CONCLUSIONS: As the EGF-R is located only on the basolateral surfaces in the normal adult gastrointestinal tract, the major role of luminal EGF is probably to stimulate repair rather than to maintain normal gut growth. Images Figure 1 Figure 2 Figure 3 PMID:8977341

Insulin Signaling Augments eIF4E-Dependent Nonsense-Mediated mRNA Decay in Mammalian Cells.

PubMed

Park, Jungyun; Ahn, Seyoung; Jayabalan, Aravinth K; Ohn, Takbum; Koh, Hyun Chul; Hwang, Jungwook

2016-07-01

Nonsense-mediated mRNA decay (NMD) modulates the level of mRNA harboring a premature termination codon (PTC) in a translation-dependent manner. Inhibition of translation is known to impair NMD; however, few studies have investigated the correlation between enhanced translation and increased NMD. Here, we demonstrate that insulin signaling events increase translation, leading to an increase in NMD of eIF4E-bound transcripts. We provide evidence that (i) insulin-mediated enhancement of translation augments NMD and rapamycin abrogates this enhancement; (ii) an increase in AKT phosphorylation due to inhibition of PTEN facilitates NMD; (iii) insulin stimulation increases the binding of up-frameshift factor 1 (UPF1), most likely to eIF4E-bound PTC-containing transcripts; and (iv) insulin stimulation induces the colocalization of UPF1 and eIF4E in processing bodies. These results illustrate how extracellular signaling promotes the removal of eIF4E-bound NMD targets. Copyright © 2015 Elsevier B.V. All rights reserved.

The expression of epidermal growth factor (EGF) and its receptor (EGFR) during post-natal testes development in the yak.

PubMed

Pan, Y; Cui, Y; Yu, S; Zhang, Q; Fan, J; Abdul Rasheed, B; Yang, K

2014-12-01

Growth factors play critical role in cell proliferation, regulate tissue differentiation and modulate organogenesis. Several growth factors have been identified in the testes of various mammalian species in last few years. In present investigation, the objective was to determine the expression of epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in yak testicular tissue by relative quantitative real time polymerase chain reaction (RT-PCR), Western blot (WB) and immunohistochemistry (IHC) from mRNA and protein levels. The testicular tissues were collected from male yak at 6 and 24 months old. Results of RT-PCR and WB showed that the expression quantity of EGF and EGFR at 24 months of age was higher than at 6 months, and the increase rate of EGFR on mRNA and protein levels was higher than the increase rate EGF during post-natal testes development. Positive staining for EGF and EGFR was very low and mainly localized to Leydig cells testes at 6 months of age with immunohistochemistry, and seminiferous tubules were not observed. At 24 month of age, both the EGF and EGFR could be detected in Leydig cells, peritubular myoid cells, sertoli cells and germ cells of the yak testes. However, EGF and EGFR were localized to preferential adluminal compartment and basal compartment in the seminiferous tubules, respectively. In conclusion, the findings in present studies suggest that EGF and EGFR as important paracrine and/or autocrine regulators in yak testes development and spermatogenesis. © 2014 Blackwell Verlag GmbH.

Batch and fed-batch cultivation for excretive production of human epidermal growth factor (hEGF) with recombinant E. Coli K12 system.

PubMed

Wang, J; Chen, J; Xu, R; Xu, Z

2008-01-01

Batch and fed-batch production of recombinant human epidermal growth factor (hEGF) was studied in an E. coli secretary expression system. By using MMBL medium containing 5 g/L glucose, controlling the temperature at 32 degrees C and maintaining the dissolved oxgen level over 20% saturation, a high yield of hEGF (32 mg/L) was obtained after an 18 hr batch cultivation with 0.2 mM IPTG induction at mid-log phase. Three different glucose feeding strategies were employed to further improve hEGF productivity in a bench top fermentor. Compared with the batch results, hEGF yield was improved up to 25.5% or 28.1%, respectively by intermittent or pH-stat glucose feeding, and up to 150% improvement of hEGF production was achieved by constant feeding of 200 g/L glucose solution at a rate of 0.11 mL/min. The effects of further combined feeding with other medium components and inducer on hEGF yield were also examined in the benchtop fermentor. This work is very helpful to further improve the productivity of extracellular hEGF in the recombinant E. coli system.

EGFR trans-activation mediates pleiotrophin-induced activation of Akt and Erk in cultured osteoblasts.

PubMed

Fan, Jian-Bo; Liu, Wei; Yuan, Kun; Zhu, Xin-Hui; Xu, Da-Wei; Chen, Jia-Jia; Cui, Zhi-Ming

2014-05-09

Pleiotrophin (Ptn) plays an important role in bone growth through regulating osteoblasts' functions. The underlying signaling mechanisms are not fully understood. In the current study, we found that Ptn induced heparin-binding epidermal growth factor (HB-EGF) release to trans-activate EGF-receptor (EGFR) in both primary osteoblasts and osteoblast-like MC3T3-E1 cells. Meanwhile, Ptn activated Akt and Erk signalings in cultured osteoblasts. The EGFR inhibitor AG1478 as well as the monoclonal antibody against HB-EGF (anti-HB-EGF) significantly inhibited Ptn-induced EGFR activation and Akt and Erk phosphorylations in MC3T3-E1 cells and primary osteoblasts. Further, EGFR siRNA depletion or dominant negative mutation suppressed also Akt and Erk activation in MC3T3-E1 cells. Finally, we observed that Ptn increased alkaline phosphatase (ALP) activity and inhibited dexamethasone (Dex)-induced cell death in both MC3T3-E1 cells and primary osteoblasts, such effects were alleviated by AG1478 or anti-HB-EGF. Together, these results suggest that Ptn-induced Akt/Erk activation and some of its pleiotropic functions are mediated by EGFR trans-activation in cultured osteoblasts. Copyright © 2014 Elsevier Inc. All rights reserved.

Different Epidermal Growth Factor (EGF) Receptor Ligands Show Distinct Kinetics and Biased or Partial Agonism for Homodimer and Heterodimer Formation*

PubMed Central

Macdonald-Obermann, Jennifer L.; Pike, Linda J.

2014-01-01

The EGF receptor has seven different cognate ligands. Previous work has shown that these different ligands are capable of inducing different biological effects, even in the same cell. To begin to understand the molecular basis for this variation, we used luciferase fragment complementation to measure ligand-induced dimer formation and radioligand binding to study the effect of the ligands on subunit-subunit interactions in EGF receptor (EGFR) homodimers and EGFR/ErbB2 heterodimers. In luciferase fragment complementation imaging studies, amphiregulin (AREG) functioned as a partial agonist, inducing only about half as much total dimerization as the other three ligands. However, unlike the other ligands, AREG showed biphasic kinetics for dimer formation, suggesting that its path for EGF receptor activation involves binding to both monomers and preformed dimers. EGF, TGFα, and betacellulin (BTC) appear to mainly stimulate receptor activation through binding to and dimerization of receptor monomers. In radioligand binding assays, EGF and TGFα exhibited increased affinity for EGFR/ErbB2 heterodimers compared with EGFR homodimers. By contrast, BTC and AREG showed a similar affinity for both dimers. Thus, EGF and TGFα are biased agonists, whereas BTC and AREG are balanced agonists with respect to selectivity of dimer formation. These data suggest that the differences in biological response to different EGF receptor ligands may result from partial agonism for dimer formation, differences in the kinetic pathway utilized to generate activated receptor dimers, and biases in the formation of heterodimers versus homodimers. PMID:25086039

Essential oil of clove (Eugenia caryophyllata) augments the humoral immune response but decreases cell mediated immunity.

PubMed

Halder, Sumita; Mehta, Ashish K; Mediratta, Pramod K; Sharma, Krishna K

2011-08-01

The present study was undertaken to explore the effect of the essential oil isolated from the buds of Eugenia caryophyllata on some immunological parameters. Humoral immunity was assessed by measuring the hemagglutination titre to sheep red blood cells and delayed type hypersensitivity was assessed by measuring foot pad thickness. Clove oil administration produced a significant increase in the primary as well as secondary humoral immune response. In addition, it also produced a significant decrease in foot pad thickness compared with the control group. Thus, these results suggest that clove oil can modulate the immune response by augmenting humoral immunity and decreasing cell mediated immunity. Copyright © 2011 John Wiley & Sons, Ltd.

Active G protein-coupled receptors (GPCR), matrix metalloproteinases 2/9 (MMP2/9), heparin-binding epidermal growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) are necessary for trenbolone acetate-induced alterations in protein turnover rate of fused bovine satellite cell cultures.

PubMed

Thornton, K J; Kamanga-Sollo, E; White, M E; Dayton, W R

2016-06-01

Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R). We hypothesized that TBA activates GPCR, resulting in activation of MMP2/9 that releases hbEGF, which activates the EGFR and/or erbB2. To determine whether the proposed nongenomic pathway is involved in TBA-mediated alterations in protein turnover, fused BSC cultures were treated with TBA in the presence or absence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R, and resultant protein synthesis and degradation rates were analyzed. Assays were replicated at least 9 times for each inhibitor experiment utilizing BSC cultures obtained from at least 3 different steers that had no previous exposure to steroid compounds. As expected, fused BSC cultures treated with 10 n TBA exhibited increased ( < 0.05) protein synthesis rates and decreased ( < 0.05) protein degradation rates when compared to control cultures. Treatment of fused BSC cultures with 10 n TBA in the presence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( < 0.05) TBA-mediated increases in protein synthesis rate. Alternatively, inhibition of GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( < 0.05) ability of TBA to decrease protein degradation rate. Additionally, fused BSC cultures treated with 10 n

A Phase III Clinical Trial of the Epidermal Growth Factor Vaccine CIMAvax-EGF as Switch Maintenance Therapy in Advanced Non-Small Cell Lung Cancer Patients.

PubMed

Rodriguez, Pedro C; Popa, Xitllaly; Martínez, Odeth; Mendoza, Silvia; Santiesteban, Eduardo; Crespo, Tatiana; Amador, Rosa M; Fleytas, Ricardo; Acosta, Soraida C; Otero, Yanine; Romero, Gala N; de la Torre, Ana; Cala, Mireysi; Arzuaga, Lina; Vello, Loisel; Reyes, Delmairis; Futiel, Niurka; Sabates, Teresa; Catala, Mauricio; Flores, Yoanna I; Garcia, Beatriz; Viada, Carmen; Lorenzo-Luaces, Patricia; Marrero, Maria A; Alonso, Liuba; Parra, Jenelin; Aguilera, Nadia; Pomares, Yaisel; Sierra, Patricia; Rodríguez, Gryssell; Mazorra, Zaima; Lage, Agustin; Crombet, Tania; Neninger, Elia

2016-08-01

EGFR is a well-validated target for patients with non-small cell lung cancer (NSCLC). CIMAvax-EGF is a therapeutic cancer vaccine composed of human recombinant EGF conjugated to a carrier protein and Montanide ISA51 as adjuvant. The vaccine is intended to induce antibodies against self EGFs that block EGF-EGFR interaction. To evaluate overall survival, safety, immunogenicity, and EGF concentration in serum after CIMAvax-EGF, a randomized phase III trial was done in patients with advanced NSCLC. Four to 6 weeks after first-line chemotherapy, 405 patients with stage IIIB/IV NSCLC were randomly assigned to a vaccine group, which received CIMAvax-EGF or a control group, treated with best supportive care. Long-term vaccination was very safe. Most frequent adverse reactions were grade 1 or 2 injection-site pain, fever, vomiting, and headache. Vaccination induced anti-EGF antibodies and decreased serum EGF concentration. In the safety population, median survival time (MST) was 10.83 months in the vaccine arm versus 8.86 months in the control arm. These differences were not significant according the standard log rank (HR, 0.82; P = 0.100), but according a weighted log rank (P = 0.04) that was applied once the nonproportionality of the HR was verified. Survival benefit was significant (HR, 0.77; P = 0.036) in the per-protocol setting (patients receiving at least four vaccine doses): MST was 12.43 months for the vaccine arm versus 9.43 months for the control arm. MST was higher (14.66 months) for vaccinated patients with high EGF concentration at baseline. Switch maintenance with CIMAvax-EGF was well tolerated and significantly increased MST of patients that completed induction vaccination. Baseline EGF concentration predicted survival benefit. Clin Cancer Res; 22(15); 3782-90. ©2016 AACR. ©2016 American Association for Cancer Research.

Ableson Kinases Negatively Regulate Invadopodia Function and Invasion in Head and Neck Squamous Cell Carcinoma by Inhibiting an HB-EGF Autocrine Loop

PubMed Central

Hayes, Karen E.; Walk, Elyse L.; Ammer, Amanda Gatesman; Kelley, Laura C.; Martin, Karen H.; Weed, Scott A.

2014-01-01

Head and neck squamous cell carcinoma (HNSCC) has a proclivity for locoregional invasion. HNSCC mediates invasion in part through invadopodia-based proteolysis of the extracellular matrix (ECM). Activation of Src, Erk1/2, Abl and Arg downstream of epidermal growth factor receptor (EGFR) modulates invadopodia activity through phosphorylation of the actin regulatory protein cortactin. In MDA-MB-231 breast cancer cells, Abl and Arg function downstream of Src to phosphorylate cortactin, promoting invadopodia ECM degradation activity and thus assigning a pro-invasive role for Ableson kinases. We report that Abl kinases have an opposite, negative regulatory role in HNSCC where they suppress invadopodia and tumor invasion. Impairment of Abl expression or Abl kinase activity with imatinib mesylate enhanced HNSCC matrix degradation and 3D collagen invasion, functions that were impaired in MDA-MB-231. HNSCC lines with elevated EGFR and Src activation did not contain increased Abl or Arg kinase activity, suggesting Src could bypass Abl/Arg to phosphorylate cortactin and promote invadopodia ECM degradation. Src transformed Abl−/−/Arg−/− fibroblasts produced ECM degrading invadopodia containing pY421 cortactin, indicating that Abl/Arg are dispensable for invadopodia function in this system. Imatinib treated HNSCC cells had increased EGFR, Erk1/2 and Src activation, enhancing cortactin pY421 and pS405/418 required for invadopodia function. Imatinib stimulated shedding of the EGFR ligand heparin-binding EGF-like growth factor (HB-EGF) from HNSCC cells, where soluble HB-EGF enhanced invadopodia ECM degradation in HNSCC but not in MDA-MB-231. HNSCC cells treated with inhibitors of the EGFR invadopodia pathway indicated that EGFR and Src are required for invadopodia function. Collectively our results indicate that Abl kinases negatively regulate HNSCC invasive processes through suppression of an HB-EGF autocrine loop responsible for activating a EGFR-Src-cortactin cascade

Helicobacter pylori potentiates epithelial:mesenchymal transition in gastric cancer: links to soluble HB-EGF, gastrin and matrix metalloproteinase-7

PubMed Central

Yin, Yinfei; Grabowska, Anna M; Clarke, Philip A; Whelband, Elisabeth; Robinson, Karen; Argent, Richard H; Tobias, Amanda; Kumari, Rajendra; Atherton, John C

2010-01-01

Background and aims Helicobacter pylori (H pylori) infection is a major risk factor in the development of distal gastric adenocarcinoma. Development of the invasive phenotype is associated with the phenomenon of epithelial:mesenchymal transition (EMT). Soluble heparin-binding epidermal growth factor (HB-EGF) has been implicated in this process. A study was undertaken to investigate the possibility that matrix metalloproteinase (MMP)-7 is upregulated in H pylori infection as a result of hypergastrinaemia, which may enhance shedding of HB-EGF and contribute towards EMT in gastric adenocarcinoma cell lines. Methods Three gastric epithelial cell lines (AGS, MGLVA1 and ST16) were co-cultured with the pathogenic H pylori strain 60190 and non-pathogenic strain Tx30a in an in vitro infection model. Gene expression was quantified by real-time PCR, HB-EGF shedding by ELISA and protein expression by immunofluorescence or immunohistochemistry. The INS-GAS mouse, a transgenic mouse model of gastric carcinogenesis which overexpresses amidated gastrin, was used to investigate the in vivo relationship between HB-EGF, MMP-7, gastrin and EMT. Results The pathogenic strain of H pylori significantly upregulated EMT-associated genes Snail, Slug and vimentin in all three gastric cell lines to a greater degree than the non-pathogenic strain. Pathogenic H pylori also upregulated HB-EGF shedding, a factor implicated in EMT, which was partially dependent on both gastrin and MMP-7 expression. Gastrin and MMP-7 siRNAs and MMP-7 neutralising antibody significantly reduced upregulation of HB-EGF shedding in H pylori infected gastric cell lines and reduced EMT gene expression. The effect of H pylori on EMT was also reversed by gastrin siRNA. Neutralisation of gastrin in the INS-GAS mouse model reduced expression of MMP-7, HB-EGF and key EMT proteins. Conclusion The upregulation of MMP-7 by pathogenic H pylori is partially dependent on gastrin and may have a role in the development of gastric

Calmodulin-mediated activation of Akt regulates survival of c-Myc-overexpressing mouse mammary carcinoma cells.

PubMed

Deb, Tushar B; Coticchia, Christine M; Dickson, Robert B

2004-09-10

c-Myc-overexpressing mammary epithelial cells are proapoptotic; their survival is strongly promoted by epidermal growth factor (EGF). We now demonstrate that EGF-induced Akt activation and survival in transgenic mouse mammary tumor virus-c-Myc mouse mammary carcinoma cells are both calcium/calmodulin-dependent. Akt activation is abolished by the phospholipase C-gamma inhibitor U-73122, by the intracellular calcium chelator BAPTA-AM, and by the specific calmodulin antagonist W-7. These results implicate calcium/calmodulin in the activation of Akt in these cells. In addition, Akt activation by serum and insulin is also inhibited by W-7. EGF-induced and calcium/calmodulin-mediated Akt activation occurs in both tumorigenic and non-tumorigenic mouse and human mammary epithelial cells, independent of their overexpression of c-Myc. These results imply that calcium/calmodulin may be a common regulator of Akt activation, irrespective of upstream receptor activator, mammalian species, and transformation status in mammary epithelial cells. However, only c-Myc-overexpressing mouse mammary carcinoma cells (but not normal mouse mammary epithelial cells) undergo apoptosis in the presence of the calmodulin antagonist W-7, indicating the vital selective role of calmodulin for survival of these cells. Calcium/calmodulin-regulated Akt activation is mediated directly by neither calmodulin kinases nor phosphatidylinositol 3-kinase (PI-3 kinase). Pharmacological inhibitors of calmodulin kinase kinase and calmodulin kinases II and III do not inhibit EGF-induced Akt activation, and calmodulin antagonist W-7 does not inhibit phosphotyrosine-associated PI-3 kinase activation. Akt is, however, co-immunoprecipitated with calmodulin in an EGF-dependent manner, which is inhibited by calmodulin antagonist W-7. We conclude that calmodulin may serve a vital regulatory function to direct the localization of Akt to the plasma membrane for its activation by PI-3 kinase.

Influence of epidermal growth factor (EGF) and hydrocortisone on the co-culture of mature adipocytes and endothelial cells for vascularized adipose tissue engineering.

PubMed

Huber, Birgit; Czaja, Alina Maria; Kluger, Petra Juliane

2016-05-01

The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used. © 2016 International Federation for Cell Biology.

Dihydrotestosterone activates the MAPK pathway and modulates maximum isometric force through the EGF receptor in isolated intact mouse skeletal muscle fibres.

PubMed

Hamdi, M M; Mutungi, G

2010-02-01

It is generally believed that steroid hormones have both genomic and non-genomic (rapid) actions. Although the latter form an important component of the physiological response of these hormones, little is known about the cellular signalling pathway(s) mediating these effects and their physiological functions in adult mammalian skeletal muscle fibres. Therefore, the primary aim of this study was to investigate the non-genomic actions of dihydrotestosterone (DHT) and their physiological role in isolated intact mammalian skeletal muscle fibre bundles. Our results show that treating the fibre bundles with physiological concentrations of DHT increases both twitch and tetanic contractions in fast twitch fibres. However, it decreases them in slow twitch fibres. These changes in force are accompanied by an increase in the phosphorylation of MAPK/ERK1/2 in both fibre types and that of regulatory myosin light chains in fast twitch fibres. Both effects were insensitive to inhibitors of Src kinase, androgen receptor, insulin-like growth factor 1 receptor and platelet-derived growth factor receptor. However, they were abolished by the MAPK/ERK1/2 kinase inhibitor PD98059 and the epidermal growth factor (EGF) receptor inhibitor tyrphostin AG 1478. In contrast, testosterone had no effect on force and increased the phosphorylation of ERK1/2 in slow twitch fibres only. From these results we conclude that sex steroids have non-genomic actions in isolated intact mammalian skeletal muscle fibres. These are mediated through the EGF receptor and one of their main physiological functions is the enhancement of force production in fast twitch skeletal muscle fibres.

Prostaglandin E2-stimulated prostanoid EP4 receptors induce prolonged de novo prostaglandin E2 synthesis through biphasic phosphorylation of extracellular signal-regulated kinases mediated by activation of protein kinase A in HCA-7 human colon cancer cells.

PubMed

Fujino, Hiromichi; Seira, Naofumi; Kurata, Naoki; Araki, Yumi; Nakamura, Hiroyuki; Regan, John W; Murayama, Toshihiko

2015-12-05

Approximately two decades have passed since E-type prostanoid 4 (EP4) receptors were cloned, and the signaling pathways mediated by these receptors have since been implicated in cancer development through the alliance of Gαi-protein/phosphatidylinositol 3-kinase (PI3K)/extracellular signal-regulated kinases (ERKs) activation. Although prostanoid EP4 receptors were initially identified as Gαs-coupled receptors, the specific/distinctive role(s) of prostanoid EP4 receptor-induced cAMP/protein kinase A (PKA) pathways in cancer development have not yet been elucidated in detail. We previously reported using HCA-7 human colon cancer cells that prostaglandin E2 (PGE2)-stimulated prostanoid EP4 receptors induced cyclooxygenase-2 (COX-2) as an initiating event in development of colon cancer. Moreover, this induction of COX-2 was mediated by transactivation of epidermal growth factor (EGF) receptors. However, direct activation of EGF receptors by EGF also induced similar amounts of COX-2 in this cell line. Thus, the emergence of unique role(s) for prostanoid EP4 receptors is expected by clarifying the different signaling mechanisms between PGE2-stimulated prostanoid EP4 receptors and EGF-stimulated EGF receptors to induce COX-2 and produce PGE2. We here demonstrated that prostanoid EP4 receptor activation by PGE2 in HCA-7 cells led to PKA-dependent re-activation of ERKs, which resulted in prolonged de novo synthesis of PGE2. Although EGF-stimulated EGF receptors in cells also induced COX-2 and the de novo synthesis of PGE2, the activation of this pathway was transient and not mediated by PKA. Therefore, the novel mechanism underlying prolonged de novo synthesis of PGE2 has provided an insight into the importance of prostanoid EP4 receptor-mediated Gαs-protein/cAMP/PKA pathway in development of colon cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of the anti-receptor ligand-blocking 225 monoclonal antibody on EGF receptor endocytosis and sorting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaramillo, Maria L.; Leon, Zully; Grothe, Suzanne

The anti-receptor antibody, 225 mAb, is known to block binding of ligand to the epidermal growth factor receptor (EGFR). However, the effect of this neutralizing antibody on EGFR endocytosis, trafficking and degradation remains unclear. Here, we demonstrate that endocytosis of {sup 125}I-225 mAb occurs, albeit with a slower rate than that of EGF. Using pulse chase assays, we show that internalized {sup 125}I-225 mAb is recycled to the surface much more efficiently than internalized {sup 125}I-EGF. Also, we found that internalization of {sup 125}I-225 mAb, in contrast to that of EGF, is independent of receptor tyrosine kinase activity, as evidencedmore » by its insensitivity to AG1478, a specific EGFR tyrosine kinase inhibitor. Analysis of the levels of cell surface and total EGFR showed that treatment with 225 mAb results in a 30-40% decrease in surface EGFR and a relatively slow downregulation of total EGFR. Taken together, these data indicate that 225 mAb induces internalization and downregulation of EGFR via a mechanism distinct from that underlying EGF-induced EGFR internalization and downregulation.« less

A tissue factor-cascade-targeted strategy to tumor vasculature: a combination of EGFP-EGF1 conjugation nanoparticles with photodynamic therapy.

PubMed

Shi, Wei; Yin, Yanxue; Wang, Yao; Zhang, Bo; Tan, Pei; Jiang, Ting; Mei, Heng; Deng, Jun; Wang, Huafang; Guo, Tao; Pang, Zhiqing; Hu, Yu

2017-05-09

Tumor requires tumor vasculature to supply oxygen and nutrients so as to support its continued growth, as well as provide a main route for metastatic spread. In this study, a TF-cascade-targeted strategy aiming to disrupt tumor blood vessels was developed by combination of TF-targeted HMME-loaded drug delivery system and PDT. PDT is a promising new modality in the treatment of cancers, which employs the interaction between a tumor-localizing photosensitizer and light of an appropriate wavelength to bring about ROS-induced cell death. In vitro results showed that protein EGFP-EGF1modification could significantly contribute to the uptake of nanoparticles by TF over-expressed BCECs. In vivo multispectral fluorescent imaging, the EGFP-EGF1 conjugated nanoparticles showed significantly higher accumulation in tumor tissues than non-conjugated ones. Tumor tissue slides further presented that EGFP-EGF1 conjugated nanoparticles showed significantly higher accumulation in tumor vasculature than non-conjugated ones. In vitro study demonstrated that PDT increased TF expression of BCECs. In vivo imaging, ex vivo imaging and tumor tissue slides showed that PDT further contribute EGFP-EGF1-NP accumulation in tumor. These promising results indicated that PDT enhanced EGFP-EGF1modified PEG-PLGA nanoparticle accumulation in tumor vaculature. Considering that EGFP-EGF1 conjugation enhanced nanoparticles uptake by TF over-expressed endothelium and PDT increased endothelium TF expression. We conclude that PDT triggered a TF cascade targeted effect. A combination of both EGFP-EGF1 modification and PDT provided a positive feed-back target effect to tumor vessels and might have a great potential for tumor therapy.

The EGF and FGF receptors mediate neuroglian function to control growth cone decisions during sensory axon guidance in Drosophila.

PubMed

García-Alonso, L; Romani, S; Jiménez, F

2000-12-01

Cell adhesion molecules (CAMs) implement the process of axon guidance by promoting specific selection and attachment to substrates. We show that, in Drosophila, loss-of-function conditions of either the Neuroglian CAM, the FGF receptor coded by the gene heartless, or the EGF receptor coded by DER display a similar phenotype of abnormal substrate selection and axon guidance by peripheral sensory neurons. Moreover, neuroglian loss-of-function phenotype can be suppressed by the expression of gain-of-function conditions of heartless or DER. The results are consistent with a scenario where the activity of these receptor tyrosine kinases is controlled by Neuroglian at choice points where sensory axons select between alternative substrates for extension.

Non-Ligand-Induced Dimerization is Sufficient to Initiate the Signalling and Endocytosis of EGF Receptor.

PubMed

Kourouniotis, George; Wang, Yi; Pennock, Steven; Chen, Xinmei; Wang, Zhixiang

2016-07-25

The binding of epidermal growth factor (EGF) to EGF receptor (EGFR) stimulates cell mitogenesis and survival through various signalling cascades. EGF also stimulates rapid EGFR endocytosis and its eventual degradation in lysosomes. The immediate events induced by ligand binding include receptor dimerization, activation of intrinsic tyrosine kinase and autophosphorylation. However, in spite of intensified efforts, the results regarding the roles of these events in EGFR signalling and internalization is still very controversial. In this study, we constructed a chimeric EGFR by replacing its extracellular domain with leucine zipper (LZ) and tagged a green fluorescent protein (GFP) at its C-terminus. We showed that the chimeric LZ-EGFR-GFP was constitutively dimerized. The LZ-EGFR-GFP dimer autophosphorylated each of its five well-defined C-terminal tyrosine residues as the ligand-induced EGFR dimer does. Phosphorylated LZ-EGFR-GFP was localized to both the plasma membrane and endosomes, suggesting it is capable of endocytosis. We also showed that LZ-EGFR-GFP activated major signalling proteins including Src homology collagen-like (Shc), extracellular signal-regulated kinase (ERK) and Akt. Moreover, LZ-EGFR-GFP was able to stimulate cell proliferation. These results indicate that non-ligand induced dimerization is sufficient to activate EGFR and initiate cell signalling and EGFR endocytosis. We conclude that receptor dimerization is a critical event in EGF-induced cell signalling and EGFR endocytosis.

ERK2-Mediated Phosphorylation of Transcriptional Coactivator Binding Protein PIMT/NCoA6IP at Ser298 Augments Hepatic Gluconeogenesis

PubMed Central

Parsa, Kishore V. L.; Kain, Vasundhara; Behera, Soma; Suraj, Sashidhara Kaimal; Babu, Phanithi Prakash; Kar, Anand; Panda, Sunanda; Zhu, Yi-jun; Jia, Yuzhi; Thimmapaya, Bayar; Reddy, Janardan K.; Misra, Parimal

2013-01-01

PRIP-Interacting protein with methyl transferase domain (PIMT) serves as a molecular bridge between CREB-binding protein (CBP)/ E1A binding protein p300 (Ep300) -anchored histone acetyl transferase and the Mediator complex sub-unit1 (Med1) and modulates nuclear receptor transcription. Here, we report that ERK2 phosphorylates PIMT at Ser298 and enhances its ability to activate PEPCK promoter. We observed that PIMT is recruited to PEPCK promoter and adenoviral-mediated over-expression of PIMT in rat primary hepatocytes up-regulated expression of gluconeogenic genes including PEPCK. Reporter experiments with phosphomimetic PIMT mutant (PIMTS298D) suggested that conformational change may play an important role in PIMT-dependent PEPCK promoter activity. Overexpression of PIMT and Med1 together augmented hepatic glucose output in an additive manner. Importantly, expression of gluconeogenic genes and hepatic glucose output were suppressed in isolated liver specific PIMT knockout mouse hepatocytes. Furthermore, consistent with reporter experiments, PIMTS298D but not PIMTS298A augmented hepatic glucose output via up-regulating the expression of gluconeogenic genes. Pharmacological blockade of MAPK/ERK pathway using U0126, abolished PIMT/Med1-dependent gluconeogenic program leading to reduced hepatic glucose output. Further, systemic administration of T4 hormone to rats activated ERK1/2 resulting in enhanced PIMT ser298 phosphorylation. Phosphorylation of PIMT led to its increased binding to the PEPCK promoter, increased PEPCK expression and induction of gluconeogenesis in liver. Thus, ERK2-mediated phosphorylation of PIMT at Ser298 is essential in hepatic gluconeogenesis, demonstrating an important role of PIMT in the pathogenesis of hyperglycemia. PMID:24358311

EGF Induced Centrosome Separation Promotes Mitotic Progression and Cell Survival

PubMed Central

Mardin, Balca R.; Isokane, Mayumi; Cosenza, Marco R.; Krämer, Alwin; Ellenberg, Jan; Fry, Andrew M.; Schiebel, Elmar

2014-01-01

Summary Timely and accurate assembly of the mitotic spindle is critical for the faithful segregation of chromosomes and centrosome separation is a key step in this process. The timing of centrosome separation varies dramatically between cell types; however, the mechanisms responsible for these differences and its significance are unclear. Here, we show that activation of epidermal growth factor receptor (EGFR) signaling determines the timing of centrosome separation. Premature separation of centrosomes decreases the requirement for the major mitotic kinesin Eg5 for spindle assembly, accelerates mitosis and decreases the rate of chromosome missegregation. Importantly, EGF stimulation impacts upon centrosome separation and mitotic progression to different degrees in different cell lines. Cells with high EGFR levels fail to arrest in mitosis upon Eg5 inhibition. This has important implications for cancer therapy since cells with high centrosomal response to EGF are more susceptible to combinatorial inhibition of EGFR and Eg5. PMID:23643362

The E3 ubiquitin ligase NEDD4 mediates cell migration signaling of EGFR in lung cancer cells.

PubMed

Shao, Genbao; Wang, Ranran; Sun, Aiqin; Wei, Jing; Peng, Ke; Dai, Qian; Yang, Wannian; Lin, Qiong

2018-02-19

EGFR-dependent cell migration plays an important role in lung cancer progression. Our previous study observed that the HECT E3 ubiquitin ligase NEDD4 is significantly correlated with tumor metastasis and required for migration and invasion signaling of EGFR in gastric cancer cells. However, how NEDD4 promotes the EGFR-dependent lung cancer cell migration is unknown. This study is to elucidate the mechanism by which NEDD4 mediates the EGFR lung cancer migration signaling. Lentiviral vector-loaded NEDD4 shRNA was used to deplete endogenous NEDD4 in lung cancer cell lines. Effects of the NEDD4 knockdown on the EGFR-dependent or independent lung cancer cell migration were determined using the wound-healing and transwell assays. Association of NEDD4 with activated EGFR was assayed by co-immunoprecipitation. Co-expression of NEDD4 with EGFR or PTEN was determined by immunohistochemical (IHC) staining in 63 lung adenocarcinoma tissue samples. Effects of NEDD4 ectopic expression or knockdown on PTEN ubiquitination and down-regulation, AKT activation and lysosomal secretion were examined using the GST-Uba pulldown assay, immunoblotting, immunofluorescent staining and a human cathepsin B ELISA assay respectively. The specific cathepsin B inhibitor CA-074Me was used for assessing the role of cathepsin B in lung cancer cell migration. Knockdown of NEDD4 significantly reduced EGF-stimulated cell migration in non-small cell lung carcinoma (NSCLC) cells. Co-immunoprecipitation assay found that NEDD4 is associated with EGFR complex upon EGF stimulation, and IHC staining indicates that NEDD4 is co-expressed with EGFR in lung adenocarcinoma tumor tissues, suggesting that NEDD4 might mediate lung cancer cell migration by interaction with the EGFR signaling complex. Interestingly, NEDD4 promotes the EGF-induced cathepsin B secretion, possibly through lysosomal exocytosis, as overexpression of the ligase-dead mutant of NEDD4 impedes lysosomal secretion, and knockdown of NEDD4

High glucose promotes pancreatic cancer cell proliferation via the induction of EGF expression and transactivation of EGFR.

PubMed

Han, Liang; Ma, Qingyong; Li, Junhui; Liu, Han; Li, Wei; Ma, Guodong; Xu, Qinhong; Zhou, Shuang; Wu, Erxi

2011-01-01

Multiple lines of evidence suggest that a large portion of pancreatic cancer patients suffer from either hyperglycemia or diabetes, both of which are characterized by high blood glucose level. However, the underlying biological mechanism of this phenomenon is largely unknown. In the present study, we demonstrated that the proliferative ability of two human pancreatic cancer cell lines, BxPC-3 and Panc-1, was upregulated by high glucose in a concentration-dependent manner. Furthermore, the promoting effect of high glucose levels on EGF transcription and secretion but not its receptors in these PC cell lines was detected by using an EGF-neutralizing antibody and RT-PCR. In addition, the EGFR transactivation is induced by high glucose levels in concentration- and time-dependent manners in PC cells in the presence of the EGF-neutralizing antibody. These results suggest that high glucose promotes pancreatic cancer cell proliferation via the induction of EGF expression and transactivation of EGFR. Our findings may provide new insight on the links between high glucose level and PC in terms of the molecular mechanism and reveal a novel therapeutic strategy for PC patients who simultaneously suffer from either diabetes or hyperglycemia.

Modulation of focal adhesion constituents and their down-stream events by EGF: On the cross-talk of integrins and growth factor receptors.

PubMed

Eberwein, Philipp; Laird, Dougal; Schulz, Simon; Reinhard, Thomas; Steinberg, Thorsten; Tomakidi, Pascal

2015-10-01

Within the concept of integrin growth factor receptor (GFR) cross-talk, little is known about the effects of GFRs on focal adhesions (FAs). Therefore, we tested the hypothesis whether EGF can modulate constituents of FAs and subsequent down-stream events. To this end, EGF-treated keratinocytes were subjected to combined fluorescence imaging and western blotting, to quantify expression and/or activation of molecules, involved in integrin GFR cross-talk, and receptor proximal and distal signaling events. Generally, EGF response revealed an amplified redistribution or activation of molecules under study, which will be explained in detail from the plasma membrane to the cell interior. In addition to significant activation of EGF receptor (EGFR) at tyrosine Tyr845, a remarkable redistribution was detectable for the focal adhesion constituents, integrin ß1 and ß3, and zyxin. Increased activation also applied to focal adhesion kinase (FAK) by phosphorylation at Tyr397, Tyr576, and Src at Tyr418, while total FAK remained unchanged. Risen activity was seen as well for the analyzed distal down-stream events, p190RhoGAP and MAP kinases p42/44. Intriguingly, Src-specific inhibitor Herbimycin A abrogated the entire EGF response except FAK Tyr397 phosphorylation, independent of EGF presence. Mechanistically, our results show that EGF modulates adhesion in a dual fashion, by firstly redistributing focal adhesion constituents to adhesion sites, but also by amplifying levels of activated RhoA antagonist p190RhoGAP, important for cell motility. Further, the findings suggest that the observed EGF response underlies an EGFR integrin cross-talk under recruitment of receptor proximal FAK and Src, and MAP kinase and p190RhoGAP as receptor distal events. Copyright © 2015 Elsevier B.V. All rights reserved.

Oleic acid blocks EGF-induced [Ca2+]i release without altering cellular metabolism in fibroblast EGFR T17.

PubMed

Zugaza, J L; Casabiell, X A; Bokser, L; Casanueva, F F

1995-02-06

EGFR-T17 cells were pretreated with oleic acid and 5-10 minutes later stimulated with EGF, to study if early ionic signals are instrumental in inducing metabolic cellular response. Oleic acid blocks EGF-induced [Ca2+]i rise and Ca2+ influx without altering 2-deoxyglucose and 2-aminobutiryc acid uptake nor acute, nor chronically. Oleic acid it is shown, in the first minutes favors the entrance of both molecules to modify the physico-chemical membrane state. On the other hand, oleic acid is unable to block protein synthesis. The results suggest that EGF-induced Ins(1,4,5)P3/Ca2+ pathway does not seem to be decisive in the control of cellular metabolic activity.

TERATOGENICITY OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN MICE LACKING THE EXPRESSION OF EGF AND/OR TGFALPHA

EPA Science Inventory

Abstract
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure produces hydronephrosis and cleft palate in mice. These responses are correlated with disruption of expression of epidermal growth factor (EGF) receptor ligands, primarily EGF and transforming growth factor-alpha ...

Wounding-induced synthesis of hyaluronic acid in organotypic epidermal cultures requires the release of heparin-binding egf and activation of the EGFR.

PubMed

Monslow, James; Sato, Nobuyuki; Mack, Judith A; Maytin, Edward V

2009-08-01

Hyaluronic acid (HA), a glycosaminoglycan located between keratinocytes in the epidermis, accumulates dramatically following skin wounding. To study inductive mechanisms, a rat keratinocyte organotypic culture model that faithfully mimics HA metabolism was used. Organotypic cultures were needle-punctured 100 times, incubated for up to 24 hours, and HA analyzed by histochemical and biochemical methods. Within 15 minutes post-injury, HA levels had elevated two-fold, increasing to four-fold by 24 hours. HA elevations far from the site of injury suggested the possible involvement of a soluble HA-inductive factor. Media transfer experiments (from wounded cultures to unwounded cultures) confirmed the existence of a soluble factor. From earlier evidence, we hypothesized that an EGF-like growth factor might be responsible. This was confirmed as follows: (1) EGFR kinase inhibitor (AG1478) completely prevented wounding-induced HA accumulation. (2) Rapid tyrosine-phosphorylation of EGFR correlated well with the onset of increased HA synthesis. (3) A neutralizing antibody that recognizes heparin binding EGF-like growth factor (HB-EGF) blocked wounding-induced HA synthesis by > or =50%. (4) Western analyses showed that release of activated HB-EGF (but neither amphiregulin nor EGF) occured after wounding. In summary, rapid HA accumulation after epidermal wounding occurs through a mechanism requiring cleavage of HB-EGF and activation of EGFR signaling.

Intercellular adhesion molecule-1 augments myoblast adhesion and fusion through homophilic trans-interactions.

PubMed

Pizza, Francis X; Martin, Ryan A; Springer, Evan M; Leffler, Maxwell S; Woelmer, Bryce R; Recker, Isaac J; Leaman, Douglas W

2017-07-11

The overall objective of the study was to identify mechanisms through which intercellular adhesion molecule-1 (ICAM-1) augments the adhesive and fusogenic properties of myogenic cells. Hypotheses were tested using cultured myoblasts and fibroblasts, which do not constitutively express ICAM-1, and myoblasts and fibroblasts forced to express full length ICAM-1 or a truncated form lacking the cytoplasmic domain of ICAM-1. ICAM-1 mediated myoblast adhesion and fusion were quantified using novel assays and cell mixing experiments. We report that ICAM-1 augments myoblast adhesion to myoblasts and myotubes through homophilic trans-interactions. Such adhesive interactions enhanced levels of active Rac in adherent and fusing myoblasts, as well as triggered lamellipodia, spreading, and fusion of myoblasts through the signaling function of the cytoplasmic domain of ICAM-1. Rac inhibition negated ICAM-1 mediated lamellipodia, spreading, and fusion of myoblasts. The fusogenic property of ICAM-1-ICAM-1 interactions was restricted to myogenic cells, as forced expression of ICAM-1 by fibroblasts did not augment their fusion to ICAM-1+ myoblasts/myotubes. We conclude that ICAM-1 augments myoblast adhesion and fusion through its ability to self-associate and initiate Rac-mediated remodeling of the actin cytoskeleton.

Tas13D inhibits growth of SMMC-7721 cell via suppression VEGF and EGF expression.

PubMed

He, Huai-Zhen; Wang, Nan; Zhang, Jie; Zheng, Lei; Zhang, Yan-Min

2012-01-01

Taspine, isolated from Radix et Rhizoma Leonticis has demosntrated potential proctiective effects against cancer. Tas13D, a novel taspine derivative synthetized by structure-based drug design, have been shown to possess interesting biological and pharmacological activities. The current study was designed to evaluate its antiproliferative activity and underlying mechanisms. Antiproliferative activity of tas13D was evaluated by xenograft in athymic mice in vivo, and by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and cell migration assays with human liver cancer (SMMC-7721) cell lines in vitro. Docking between tas13D and VEGFR and EGFR was studied by with a Sybyl/Surflex module. VEGF and EGF and their receptor expression was determined by ELISA and real-time PCR methods, respectively. Our present study showed that tas13D inhibited SMMC-7721 xenograft tumor growth, bound tightly with the active site of kinase domains of EGFR and VEGFR, and reduced SMMC-7721 cell proliferation (IC=34.7 μmol/L) and migration compared to negative controls. VEGF and EGF mRNAs were significantly reduced by tas13D treatment in a dose-dependent manner, along with VEGF and EGF production. The obtained results suggest that tas13D inhibits tumor growth and cell proliferation by inhibiting cell migration, downregulating mRNA expression of VEGF and EGF, and decreasing angiogenic factor production. Tas13D deserves further consideration as a chemotherapeutic agent.

Positional cloning identifies zebrafish one-eyed pinhead as a permissive EGF-related ligand required during gastrulation.

PubMed

Zhang, J; Talbot, W S; Schier, A F

1998-01-23

The zebrafish one-eyed pinhead (oep) mutation disrupts embryonic development, resulting in cyclopia and defects in endoderm, prechordal plate, and ventral neuroectoderm formation. We report the molecular isolation of oep using a positional cloning approach. The oep gene encodes a novel EGF-related protein with similarity to the EGF-CFC proteins cripto, cryptic, and FRL-1. Wild-type oep protein contains a functional signal sequence and is membrane-associated. Following ubiquitous maternal and zygotic expression, highest levels of oep mRNA are found in the gastrula margin and in axial structures and forebrain. Widespread misexpression of both membrane-attached and secreted forms of oep rescues prechordal plate and forebrain development in mutant embryos but does not lead to the ectopic induction of these cell types in wild-type fish. These results establish an essential but permissive role for an EGF-related ligand during vertebrate gastrulation.

EGF induces epithelial-mesenchymal transition and cancer stem-like cell properties in human oral cancer cells via promoting Warburg effect.

PubMed

Xu, Qilin; Zhang, Qunzhou; Ishida, Yasutaka; Hajjar, Souren; Tang, Xudong; Shi, Haoran; Dang, Chi V; Le, Anh D

2017-02-07

"Warburg effect", the enhanced glycolysis or aerobic glycolysis, confers cancer cells the ability to survive and proliferate even under stressed conditions. In this study, we explored the role of epidermal growth factor (EGF) in orchestrating Warburg effect, the epithelial-mesenchymal transition (EMT) process, and the acquisition of cancer stem-like cell properties in human oral squamous cell carcinoma (OSCC) cells. Our results showed that EGF induces EMT process in OSCC cells, which correlates with the acquisition of cancer stem-like properties, including the enrichment of CD44+/CD24- population of cancer cells and an increased expression of CSC-related genes, aldehyde dehydrogenase-1 (ALDH1) and Bmi-1. We also showed that EGF concomitantly enhanced L-lactate production, while blocking glycolysis by 2-deoxy-D-glucose (2-DG) robustly reversed EGF-induced EMT process and CSC-like properties in OSCC cells. Mechanistically, we demonstrated that EGF promoted EMT process and CSC generation through EGFR/PI3K/HIF-1α axis-orchestrated glycolysis. Using an orthotopic tumor model of human OSCC (UM-SCC1) injected in the tongue of BALB/c nude mice, we showed that treatment with 2-DG in vivo significantly inhibited the metastasis of tumor cells to the regional cervical lymph nodes and reduced the expression of ALDH1 and vimentin in both in situ tumors and tumor cell-invaded regional lymph nodes. Taken together, these findings have unveiled a new mechanism that EGF drives OSCC metastasis through induction of EMT process and CSC generation, which is driven by an enhanced glycolytic metabolic program in OSCC cells.

Exposure to the cytokine EGF leads to abnormal hyperactivity of pallidal GABA neurons: implications for schizophrenia and its modeling.

PubMed

Sotoyama, Hidekazu; Namba, Hisaaki; Chiken, Satomi; Nambu, Atsushi; Nawa, Hiroyuki

2013-08-01

Previous studies on a cytokine model for schizophrenia reveal that the hyperdopaminergic innervation and neurotransmission in the globus pallidus (GP) is involved in its behavioral impairments. Here, we further explored the physiological consequences of the GP abnormality in the indirect pathway, using the same schizophrenia model established by perinatal exposure to epidermal growth factor (EGF). Single-unit recordings revealed that the neural activity from the lateral GP was elevated in EGF-treated rats in vivo and in vitro (i.e., slice preparations), whereas the central area of the GP exhibited no significant differences. The increase in the pallidal activity was normalized by subchronic treatment with risperidone, which is known to ameliorate their behavioral deficits. We also monitored extracellular GABA concentrations in the substantia nigra, one of the targets of pallidal efferents. There was a significant increase in basal GABA levels in EGF-treated rats, whereas high potassium-evoked GABA effluxes and glutamate levels were not affected. A neurotoxic lesion in the GP of EGF-treated rats normalized GABA concentrations to control levels. Corroborating our in vivo results, GABA release from GP slices was elevated in EGF-treated animals. These findings suggest that the hyperactivity and enhanced GABA release of GP neurons represent the key pathophysiological features of this cytokine-exposure model for schizophrenia. © 2013 International Society for Neurochemistry.

SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells.

PubMed

Moz, Stefania; Basso, Daniela; Bozzato, Dania; Galozzi, Paola; Navaglia, Filippo; Negm, Ola H; Arrigoni, Giorgio; Zambon, Carlo-Federico; Padoan, Andrea; Tighe, Paddy; Todd, Ian; Franchin, Cinzia; Pedrazzoli, Sergio; Punzi, Leonardo; Plebani, Mario

2016-10-25

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner.

Hyperinsulinemia fails to augment ET-1 action in the skeletal muscle vascular bed in vivo in humans

PubMed Central

Lteif, Amale A.; Fulford, Angie D.; Considine, Robert V.; Gelfand, Inessa; Baron, Alain D.; Mather, Kieren J.

2008-01-01

Endogenous endothelin action is augmented in human obesity and type 2 diabetes and contributes to endothelial dysfunction and impairs insulin-mediated vasodilation in humans. We hypothesized that insulin resistance-associated hyperinsulinemia could preferentially drive endothelin-mediated vasoconstriction. We applied hyperinsulinemic-euglycemic clamps with higher insulin dosing in obese subjects than lean subjects (30 vs. 10 mU·m−2·min−1, respectively), with the goal of matching insulin's nitric oxide (NO)-mediated vascular effects. We predicted that, under these circumstances, insulin-stimulated endothelin-1 (ET-1) action (assessed with the type A endothelin receptor antagonist BQ-123) would be augmented in proportion to hyperinsulinemia. NO bioactivity was assessed using the nitric oxide synthase inhibitor NG-monomethyl-l-arginine. Insulin-mediated vasodilation and insulin-stimulated NO bioavailability were well matched across groups by this approach. As expected, steady-state insulin levels were approximately threefold higher in obese than lean subjects (109.2 ± 10.2 pmol/l vs. 518.4 ± 84.0, P = 0.03). Despite this, the augmentation of insulin-mediated vasodilation by BQ-123 was not different between groups. ET-1 flux across the leg was not augmented by insulin alone but was increased with the addition of BQ-123 to insulin (P = 0.01 BQ-123 effect, P = not significant comparing groups). Endothelin antagonism augmented insulin-stimulated NO bioavailability and NOx flux, but not differently between groups and not proportional to hyperinsulinemia. These findings do not support the hypothesis that insulin resistance-associated hyperinsulinemia preferentially drives endothelin-mediated vasoconstriction. PMID:18957616

Endogenous bax translocation in SH-SY5Y human neuroblastoma cells and cerebellar granule neurons undergoing apoptosis.

PubMed

McGinnis, K M; Gnegy, M E; Wang, K K

1999-05-01

Changes at the mitochondria are an early, required step in apoptosis in various cell types. We used western blot analysis to demonstrate that the proapoptotic protein Bax translocated from the cytosolic to the mitochondrial fraction in SH-SY5Y human neuroblastoma cells undergoing staurosporine- or EGTA-mediated apoptosis. Levels of mitochondrial Bax increased 15 min after staurosporine treatment. In EGTA-treated cells, increased levels of mitochondrial Bax were seen at 4 h, consistent with a slower onset of apoptosis in EGTA versus staurosporine treatments. We also demonstrate the concomitant translocation of cytochrome c from the mitochondrial to the cytosolic fractions. We correlated these translocations with changes in caspase-3-like activity. An increase in caspase-3-like activity was evident 2 h after staurosporine treatment. Inhibition of the mitochondrial permeability transition had no effect on Bax translocation or caspase-3-like activity in staurosporine-treated SH-SY5Y cells. In primary cultures of cerebellar granule neurons undergoing low K(+)-mediated apoptosis, Bax translocation to the mitochondrial fraction was evident at 3 h. Cytochrome c release into the cytosol was not significant until 8 h after treatment. These data support a model of apoptosis in which Bax acts directly at the mitochondria to allow the release of cytochrome c.

Metalloproteinase-dependent transforming growth factor-alpha release mediates neurotensin-stimulated MAP kinase activation in human colonic epithelial cells.

PubMed

Zhao, Dezheng; Zhan, Yanai; Koon, Hon Wai; Zeng, Huiyan; Keates, Sarah; Moyer, Mary P; Pothoulakis, Charalabos

2004-10-15

Expression of the neuropeptide neurotensin (NT) and its high affinity receptor (NTR1) is increased during the course of Clostridium difficile toxin A-induced acute colitis, and NTR1 antagonism attenuates the severity of toxin A-induced inflammation. We recently demonstrated in non-transformed human colonic epithelial NCM460 cells that NT treatment caused activation of a Ras-mediated MAP kinase pathway that significantly contributes to NT-induced interleukin-8 (IL-8) secretion. Here we used NCM460 cells, which normally express low levels of NTR1, and NCM460 cells stably transfected with NTR1 to identify the upstream signaling molecules involved in NT-NTR1-mediated MAP kinase activation. We found that inhibition of the epidermal growth factor receptor (EGFR) by either an EGFR neutralizing antibody or by its specific inhibitor AG1478 (0.2 microm) blocked NT-induced MAP kinase activation. Moreover, NT stimulated tyrosine phosphorylation of the EGFR, and pretreatment with a broad spectrum metalloproteinase inhibitor batimastat reduced NT-induced MAP kinase activation. Using neutralizing antibodies against the EGFR ligands EGF, heparin-binding-EGF, transforming growth factor-alpha (TGFalpha), or amphiregulin we have shown that only the anti-TGFalpha antibody significantly decreases NT-induced phosphorylation of EGFR and MAP kinases. Furthermore, inhibition of the EGF receptor by AG1478 significantly reduced NT-induced IL-8 promoter activity and IL-8 secretion. This is the first report demonstrating that NT binding to NTR1 transactivates the EGFR and that this response is linked to NT-mediated proinflammatory signaling. Our findings indicate that matrix metalloproteinase-mediated release of TGFalpha and subsequent EGFR transactivation triggers a NT-mediated MAP kinase pathway that leads to IL-8 gene expression in human colonic epithelial cells.

SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells

PubMed Central

Moz, Stefania; Basso, Daniela; Bozzato, Dania; Galozzi, Paola; Navaglia, Filippo; Negm, Ola H.; Arrigoni, Giorgio; Zambon, Carlo-Federico; Padoan, Andrea; Tighe, Paddy; Todd, Ian; Franchin, Cinzia; Pedrazzoli, Sergio; Punzi, Leonardo; Plebani, Mario

2016-01-01

Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner. PMID:27655713

The heparin-binding domain of HB-EGF as an efficient cell-penetrating peptide for drug delivery.

PubMed

Luo, Zhao; Cao, Xue-Wei; Li, Chen; Wu, Miao-Dan; Yang, Xu-Zhong; Zhao, Jian; Wang, Fu-Jun

2016-11-01

Cell-penetrating peptides (CPPs) have been shown to be potential drug carriers for cancer therapy. The inherently low immunogenicity and cytotoxicity of human-derived CPPs make them more suitable for intracellular drug delivery compared to other delivery vehicles. In this work, the protein transduction ability of a novel CPP (termed HBP) derived from the heparin-binding domain of HB-EGF was evaluated. Our data shows, for the first time, that HBP possesses similar properties to typical CPPs and is a potent drug delivery vector for improving the antitumor activity of impermeable MAP30. The intrinsic bioactivities of recombinant MAP30-HBP were well preserved compared to those of free MAP30. Furthermore, HBP conjugated to the C-terminus of MAP30 promoted the cellular uptake of recombinant MAP30-HBP. Moreover, the fusion of HBP to MAP30 gave rise to significantly enhanced cytotoxic effects in all of the tumor cell lines tested. In HeLa cells, this cytotoxicity was mainly caused by the induction of cell apoptosis. Further investigation revealed that HBP enhanced MAP30-induced apoptosis through the activation of the mitochondrial- and death receptor-mediated signaling pathways. In addition, the MAP30-HBP fusion protein caused more HeLa cells to become arrested in S phase compared to MAP30 alone. These results highlight the MAP30-HBP fusion protein as a promising drug candidate for cancer therapy and demonstrate HBP, a novel CPP derived from human HB-EGF, as a new potential vector for antitumor drug delivery. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

Expression of renal distal tubule transporters TRPM6 and NCC in a rat model of cyclosporine nephrotoxicity and effect of EGF treatment.

PubMed

Ledeganck, Kristien J; Boulet, Gaëlle A; Horvath, Caroline A; Vinckx, Marleen; Bogers, Johannes J; Van Den Bossche, Rita; Verpooten, Gert A; De Winter, Benedicte Y

2011-09-01

Renal magnesium (Mg(2+)) and sodium (Na(+)) loss are well-known side effects of cyclosporine (CsA) treatment in humans, but the underlying mechanisms still remain unclear. Recently, it was shown that epidermal growth factor (EGF) stimulates Mg(2+) reabsorption in the distal convoluted tubule (DCT) via TRPM6 (Thébault S, Alexander RT, Tiel Groenestege WM, Hoenderop JG, Bindels RJ. J Am Soc Nephrol 20: 78-85, 2009). In the DCT, the final adjustment of renal sodium excretion is regulated by the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which is activated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to gain more insight into the molecular mechanisms of CsA-induced hypomagnesemia and hyponatremia. Therefore, the renal expression of TRPM6, TRPM7, EGF, EGF receptor, claudin-16, claudin-19, and the NCC, and the effect of the RAAS on NCC expression, were analyzed in vivo in a rat model of CsA nephrotoxicity. Also, the effect of EGF administration on these parameters was studied. CsA significantly decreased the renal expression of TRPM6, TRPM7, NCC, and EGF, but not that of claudin-16 and claudin-19. Serum aldosterone was significantly lower in CsA-treated rats. In control rats treated with EGF, an increased renal expression of TRPM6 together with a decreased fractional excretion of Mg(2+) (FE Mg(2+)) was demonstrated. EGF did not show this beneficial effect on TRPM6 and FE Mg(2+) in CsA-treated rats. These data suggest that CsA treatment affects Mg(2+) homeostasis via the downregulation of TRPM6 in the DCT. Furthermore, CsA downregulates the NCC in the DCT, associated with an inactivation of the RAAS, resulting in renal sodium loss.

Activatory and Inhibitory Fcγ Receptors Augment Rituximab-mediated Internalization of CD20 Independent of Signaling via the Cytoplasmic Domain*

PubMed Central

Vaughan, Andrew T.; Chan, Claude H. T.; Klein, Christian; Glennie, Martin J.; Beers, Stephen A.; Cragg, Mark S.

2015-01-01

Type I anti-CD20 mAb such as rituximab and ofatumumab engage with the inhibitory FcγR, FcγRIIb on the surface of B cells, resulting in immunoreceptor tyrosine-based inhibitory motif (ITIM) phosphorylation. Internalization of the CD20·mAb·FcγRIIb complex follows, the rate of which correlates with FcγRIIb expression. In contrast, although type II anti-CD20 mAb such as tositumomab and obinutuzumab also interact with and activate FcγRIIb, this interaction fails to augment the rate of CD20·mAb internalization, raising the question of whether ITIM phosphorylation plays any role in this process. We have assessed the molecular requirements for the internalization process and demonstrate that in contrast to internalization of IgG immune complexes, FcγRIIb-augmented internalization of rituximab-ligated CD20 occurs independently of the FcγRIIb ITIM, indicating that signaling downstream of FcγRIIb is not required. In transfected cells, activatory FcγRI, FcγRIIa, and FcγRIIIa augmented internalization of rituximab-ligated CD20 in a similar manner. However, FcγRIIa mediated a slower rate of internalization than cells expressing equivalent levels of the highly homologous FcγRIIb. The difference was maintained in cells expressing FcγRIIa and FcγRIIb lacking cytoplasmic domains and in which the transmembrane domains had been exchanged. This difference may be due to increased degradation of FcγRIIa, which traffics to lysosomes independently of rituximab. We conclude that the cytoplasmic domain of FcγR is not required for promoting internalization of rituximab-ligated CD20. Instead, we propose that FcγR provides a structural role in augmenting endocytosis that differs from that employed during the endocytosis of immune complexes. PMID:25568316

Effect of epidermal growth factor (EGF) on the phosphorylation of mitogen-activated protein kinase (MAPK) in the bovine oviduct in vitro: Alteration by heat stress.

PubMed

Wijayagunawardane, Missaka P B; Hambruch, Nina; Haeger, Jan-Dirk; Pfarrer, Christiane

2015-01-01

Epidermal growth factor (EGF) has been shown to be involved in control of the oviductal microenvironment. To elucidate the potential mechanisms responsible for the detrimental effect of heat stress and to identify the relation with the endocrine status, the effects of EGF on the level of phosphorylated mitogen-activated-protein kinase (MAPK) and proliferation of bovine oviductal epithelial cells (OECs) exposed to different cyclic ovarian steroidal environments (luteal phase (LP), follicular phase (FP) and postovulatory phase (PO)) and temperatures (mild heat stress (40 C) and severe heat stress (43 C)) were investigated. Western blot was performed to evaluate phosphorylated MAPK, while proliferation was analyzed by MTT assay. Stimulation of OECs with EGF alone or with EGF in the PO and FP environments significantly increased the amount of phosphorylated MAPK, with MAPK 44 phosphorylation being highest during exposure to PO conditions. These effects were not observed in the LP. Heat treatment completely blocked effects of EGF on phosphorylated MAPK. Additionally, severe heat stress led to a significantly lower basal level of phosphorylated MAPK. PD98059 (MAPK inhibitor) completely abolished EGF-stimulated MAPK phosphorylation and OECs proliferation. Overall the results indicate that EGF has the potential to increase the amount of phosphorylated MAPK in OECs and therefore could be involved in regulation of the bovine oviductal microenvironment. However, these regulatory mechanisms may be compromised in the presence of heat stress (high ambient temperature), leading to low fertility rates and impaired embryo survival.

Effect of epidermal growth factor (EGF) on the phosphorylation of mitogen-activated protein kinase (MAPK) in the bovine oviduct in vitro: Alteration by heat stress

PubMed Central

WIJAYAGUNAWARDANE, Missaka P. B.; HAMBRUCH, Nina; HAEGER, Jan-Dirk; PFARRER, Christiane

2015-01-01

Epidermal growth factor (EGF) has been shown to be involved in control of the oviductal microenvironment. To elucidate the potential mechanisms responsible for the detrimental effect of heat stress and to identify the relation with the endocrine status, the effects of EGF on the level of phosphorylated mitogen-activated-protein kinase (MAPK) and proliferation of bovine oviductal epithelial cells (OECs) exposed to different cyclic ovarian steroidal environments (luteal phase (LP), follicular phase (FP) and postovulatory phase (PO)) and temperatures (mild heat stress (40 C) and severe heat stress (43 C)) were investigated. Western blot was performed to evaluate phosphorylated MAPK, while proliferation was analyzed by MTT assay. Stimulation of OECs with EGF alone or with EGF in the PO and FP environments significantly increased the amount of phosphorylated MAPK, with MAPK 44 phosphorylation being highest during exposure to PO conditions. These effects were not observed in the LP. Heat treatment completely blocked effects of EGF on phosphorylated MAPK. Additionally, severe heat stress led to a significantly lower basal level of phosphorylated MAPK. PD98059 (MAPK inhibitor) completely abolished EGF-stimulated MAPK phosphorylation and OECs proliferation. Overall the results indicate that EGF has the potential to increase the amount of phosphorylated MAPK in OECs and therefore could be involved in regulation of the bovine oviductal microenvironment. However, these regulatory mechanisms may be compromised in the presence of heat stress (high ambient temperature), leading to low fertility rates and impaired embryo survival. PMID:26050642

Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study.

PubMed

Cui, Hai; Zhu, Qiong; Gao, Yunhua; Xia, Hongmei; Tan, Kaibin; He, Ying; Liu, Zheng; Xu, Yali

2017-01-01

This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD) assisted sonolysis in both the in vitro and in vivo clots. Therapeutic ultrasound (TUS) and lipid microbubbles (MBs) were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI) and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT) in rabbits. FAT were dyed with H&E. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P < 0.05). Clots had different pathological changes. Recanalization rates and flow scores in TUS + MB group were significantly higher than the control and TUS group. Flow scores and recanalization ratios were grade 0 in 0% of the control group, grade I in 25% of TUS group, and grade II or higher in 87.5% of TUS + MB group after 30 min sonolysis. Both the in vitro and in vivo sonolysis can be significantly augmented by the introduction of MBs without thrombolytic agents, which might be induced by the enhanced cavitation via UMMD.

KGF and EGF signalling block hair follicle induction and promote interfollicular epidermal fate in developing mouse skin

PubMed Central

Richardson, Gavin D.; Bazzi, Hisham; Fantauzzo, Katherine A.; Waters, James M.; Crawford, Heather; Hynd, Phil; Christiano, Angela M.; Jahoda, Colin A. B.

2009-01-01

Summary A key initial event in hair follicle morphogenesis is the localised thickening of the skin epithelium to form a placode, partitioning future hair follicle epithelium from interfollicular epidermis. Although many developmental signalling pathways are implicated in follicle morphogenesis, the role of epidermal growth factor (EGF) and keratinocyte growth factor (KGF, also known as FGF7) receptors are not defined. EGF receptor (EGFR) ligands have previously been shown to inhibit developing hair follicles; however, the underlying mechanisms have not been characterised. Here we show that receptors for EGF and KGF undergo marked downregulation in hair follicle placodes from multiple body sites, whereas the expression of endogenous ligands persist throughout hair follicle initiation. Using embryonic skin organ culture, we show that when skin from the sites of primary pelage and whisker follicle development is exposed to increased levels of two ectopic EGFR ligands (HBEGF and amphiregulin) and the FGFR2(IIIb) receptor ligand KGF, follicle formation is inhibited in a time- and dose-dependent manner. We then used downstream molecular markers and microarray profiling to provide evidence that, in response to KGF and EGF signalling, epidermal differentiation is promoted at the expense of hair follicle fate. We propose that hair follicle initiation in placodes requires downregulation of the two pathways in question, both of which are crucial for the ongoing development of the interfollicular epidermis. We have also uncovered a previously unrecognised role for KGF signalling in the formation of hair follicles in the mouse. PMID:19474150

Oestrogen receptor-alpha activation augments post-exercise myoblast proliferation.

PubMed

Thomas, A; Bunyan, K; Tiidus, P M

2010-01-01

Our laboratory has shown that oestrogen acts to augment myoblast (satellite cell) activation, proliferation and total number and that this may occur through an oestrogen receptor (OR)-mediated mechanism. The purpose of this study was to further investigate the mechanism of oestrogen influence on augmentation of post-exercise myoblast numbers through use of a specific OR-alpha agonist, propyl pyrazole triol (PPT). Ovariectomized rats were used (n = 64) and separated into four groups: sham, oestrogen supplemented, agonist supplemented, and a combined oestrogen and agonist supplemented group. These groups were further subdivided into control (unexercised) and exercise groups. Surgical removal of white vastus and soleus muscles was performed 72 h post-exercise. Muscle samples were immunostained for the myoblast markers Pax7 and MyoD. A significant increase in total (Pax7-positive) and activated (MyoD-positive) myoblasts was found in all groups post-exercise. A further significant augmentation of total and activated myoblasts occurred in oestrogen supplemented, agonist supplemented and the combined oestrogen and agonist supplemented groups post-exercise in white vastus and soleus muscles relative to unsupplemented animals. These results demonstrate that both oestrogen and the specific OR-alpha receptor agonist, PPT, can significantly and to similar degrees augment myoblast number and activation following exercise-induced muscle damage. This suggests that oestrogen acts through an OR-mediated mechanism to stimulate myoblast proliferation following exercise, with OR-alpha playing a primary role.

Synthetic Human NOTCH1 EGF Modules Unraveled Molecular Mechanisms for the Structural and Functional Roles of Calcium Ions and O-Glycans in the Ligand-Binding Region.

PubMed

Hayakawa, Shun; Koide, Ryosuke; Hinou, Hiroshi; Nishimura, Shin-Ichiro

2016-02-09

The Notch signaling pathway is an evolutionarily highly conserved mechanism that operates across multicellular organisms and is critical for cell-fate decisions during development and homeostasis in most tissues. Notch signaling is modified by posttranslational glycosylations of the Notch extracellular EGF-like domain. To evaluate the structural and functional roles of various glycoforms at multiple EGF domains in the human Notch transmembrane receptor, we established a universal method for the construction of NOTCH1 EGF modules displaying the desired O-glycans at the designated glycosylation sites. The versatility of this strategy was demonstrated by the rapid and highly efficient synthesis of NOTCH1 EGF12 concurrently having a β-D-glucopyranose-initiated glycan (Xylα1 → 3Xylα1 → 3Glcβ1 →) at Ser458 and α-L-fucopyranose-initiated glycan (Neu5Acα2 → 3Galβ1 → 4GlcNAcβ1 → 3Fucα1 →) at Thr466. The efficiency of the proper folding of the glycosylated EGF12 was markedly enhanced in the presence of 5 mM CaCl2. A nuclear magnetic resonance study revealed the existence of strong nuclear Overhauser effects between key sugar moieties and neighboring amino acid residues, indicating that both O-glycans contribute independently to the intramolecular stabilization of the antiparallel β-sheet structure in the ligand-binding region of EGF12. A preliminary test using synthetic human NOTCH1 EGF modules showed significant inhibitory effects on the proliferation and adhesiveness of human breast cancer cell line MCF-7 and lung adenocarcinoma epithelial cell line A549, demonstrating for the first time evidence that exogenously applied synthetic EGF modules have the ability to interact with intrinsic Notch ligands on the surface of cancer cells.

Thrombin-induced p38 mitogen-activated protein kinase activation is mediated by epidermal growth factor receptor transactivation pathway

PubMed Central

Kanda, Yasunari; Mizuno, Katsushige; Kuroki, Yasutomi; Watanabe, Yasuhiro

2001-01-01

Thrombin is a potent mitogen for vascular smooth muscle cells (VSMC) and has been implicated its pathogenic role in vascular remodelling. However, the signalling pathways by which thrombin mediates its mitogenic response are not fully understood.We have previously reported that thrombin activates p38 mitogen-activated protein kinase (p38 MAPK) by a tyrosine kinase-dependent mechanism, and that p38 MAPK has a role in thrombin-induced mitogenic response in rat VSMC.In the present study, we examine the involvement of epidermal growth factor (EGF) receptor in thrombin-induced p38 MAPK activation. We found that thrombin induced EGF receptor tyrosine phosphorylation (transactivation) in A10 cells, a clonal VSMC cell line. A selective inhibitor of EGF receptor kinase (AG1478) inhibited the p38 MAPK activation in a dose-dependent manner, whereas it had no effect on the response to platelet-derived growth factor (PDGF). EGF receptor phosphorylation induced by thrombin was inhibited by BAPTA-AM and GF109203X, which suggest a requirement for intracellular Ca2+ increase and protein kinase C.We next examined the effect of AG1478 on thrombin-induced DNA synthesis. AG1478 inhibited thrombin-induced DNA synthesis in a dose-dependent manner. In contrast, PDGF-induced DNA synthesis was not affected by AG1478.In conclusion, these data suggest that the EGF receptor transactivation and subsequent p38 MAPK activation is required for thrombin-induced proliferation of VSMC. PMID:11309236

FACS-based Isolation of Neural and Glioma Stem Cell Populations from Fresh Human Tissues Utilizing EGF Ligand

PubMed Central

Tome-Garcia, Jessica; Doetsch, Fiona; Tsankova, Nadejda M.

2018-01-01

Direct isolation of human neural and glioma stem cells from fresh tissues permits their biological study without prior culture and may capture novel aspects of their molecular phenotype in their native state. Recently, we demonstrated the ability to prospectively isolate stem cell populations from fresh human germinal matrix and glioblastoma samples, exploiting the ability of cells to bind the Epidermal Growth Factor (EGF) ligand in fluorescence-activated cell sorting (FACS). We demonstrated that FACS-isolated EGF-bound neural and glioblastoma populations encompass the sphere-forming colonies in vitro, and are capable of both self-renewal and multilineage differentiation. Here we describe in detail the purification methodology of EGF-bound (i.e., EGFR+) human neural and glioma cells with stem cell properties from fresh postmortem and surgical tissues. The ability to prospectively isolate stem cell populations using native ligand-binding ability opens new doors for understanding both normal and tumor cell biology in uncultured conditions, and is applicable for various downstream molecular sequencing studies at both population and single-cell resolution. PMID:29516026

Troyer Syndrome Protein Spartin Is Mono-Ubiquitinated and Functions in EGF Receptor Trafficking

PubMed Central

Jupille, Henri; Fatheddin, Parvin; Puertollano, Rosa

2007-01-01

Troyer syndrome is an autosomal recessive hereditary spastic paraplegia caused by mutation in the spartin (SPG20) gene, which encodes a widely expressed protein of unknown function. This mutation results in premature protein truncation and thus might signify a loss-of-function disease mechanism. In this study, we have found that spartin is mono-ubiquitinated and functions in degradation of the epidermal growth factor receptor (EGFR). Upon EGF stimulation, spartin translocates from the cytoplasm to the plasma membrane and colocalizes with internalized EGF-Alexa. Knockdown of spartin by small interfering RNA decreases the rate of EGFR degradation and also affects EGFR internalization, recycling, or both. Furthermore, overexpression of spartin results in a prominent decrease in EGFR degradation. Taken together, our data suggest that spartin is involved in the intracellular trafficking of EGFR and that impaired endocytosis may underlie the pathogenesis of Troyer syndrome. PMID:17332501

Areca nut components stimulate ADAM17, IL-1α, PGE2 and 8-isoprostane production in oral keratinocyte: role of reactive oxygen species, EGF and JAK signaling.

PubMed

Chang, Mei-Chi; Chan, Chiu-Po; Chen, Yi-Jane; Hsien, Hsiang-Chi; Chang, Ya-Ching; Yeung, Sin-Yuet; Jeng, Po-Yuan; Cheng, Ru-Hsiu; Hahn, Liang-Jiunn; Jeng, Jiiang-Huei

2016-03-29

Betel quid (BQ) chewing is an etiologic factor of oral submucous fibrosis (OSF) and oral cancer. There are 600 million BQ chewers worldwide. The mechanisms for the toxic and inflammatory responses of BQ are unclear. In this study, both areca nut (AN) extract (ANE) and arecoline stimulated epidermal growth factor (EGF) and interleukin-1α (IL-1α) production of gingival keratinocytes (GKs), whereas only ANE can stimulate a disintegrin and metalloproteinase 17 (ADAM17), prostaglandin E2 (PGE2) and 8-isoprostane production. ANE-induced EGF production was inhibited by catalase. Addition of anti-EGF neutralizing antibody attenuated ANE-induced cyclooxygenase-2 (COX-2), mature ADAM9 expression and PGE2 and 8-isoprostane production. ANE-induced IL-1α production was inhibited by catalase, anti-EGF antibody, PD153035 (EGF receptor antagonist) and U0126 (MEK inhibitor) but not by α-naphthoflavone (cytochrome p450-1A1 inhibitor). ANE-induced ADAM17 production was inhibited by pp2 (Src inhibitor), U0126, α-naphthoflavone and aspirin. AG490 (JAK inhibitor) prevented ANE-stimulated ADAM17, IL-1α, PGE2 production, COX-2 expression, ADAM9 maturation, and the ANE-induced decline in keratin 5 and 14, but showed little effect on cdc2 expression and EGF production. Moreover, ANE-induced 8-isoprostane production by GKs was inhibited by catalase, anti-EGF antibody, AG490, pp2, U0126, α-naphthoflavone, Zinc protoporphyrin (ZnPP) and aspirin. These results indicate that AN components may involve in BQ-induced oral cancer by induction of reactive oxygen species, EGF/EGFR, IL-1α, ADAMs, JAK, Src, MEK/ERK, CYP1A1, and COX signaling pathways, and the aberration of cell cycle and differentiation. Various blockers against ROS, EGF, IL-1α, ADAM, JAK, Src, MEK, CYP1A1, and COX can be used for prevention or treatment of BQ chewing-related diseases.

Comparative study of the Ar and He atmospheric pressure plasmas on E-cadherin protein regulation for plasma-mediated transdermal drug delivery

NASA Astrophysics Data System (ADS)

Lee, Hyun Young; Hae Choi, Jeong; Hong, Jin Woo; Kim, Gyoo Cheon; Lee, Hae June

2018-05-01

The effects of argon plasma (ArP) and helium plasma (HeP) jets on E-cadherin protein function have been tested in order to choose the working gas for a better plasma-mediated transdermal drug delivery. The plasma-mediated changes of the E-cadherin function and the skin penetration efficacies of epidermal growth factor (EGF) were monitored in vitro using HaCaT human keratinocytes and in vivo using hairless mice. The ArP showed higher efficacy for E-cadherin regulation and EGF absorption than HeP under the same applied voltage and the same gas flow rate. The ArP generates higher volume power density, higher discharge current peak, and more reactive species than HeP, especially for OH with the same operating parameters. Moreover, the effect of ArP on E-cadherin function was blocked by the use of a grounded metal mesh. Taken together, this study presents the possibility that the synergetic effect of negative charges with radicals plays an important role in plasma-mediated E-cadherin regulation, which leads to enhanced transdermal drug delivery.

A combination of cytokines EGF and CNTF protects the functional beta cell mass in mice with short-term hyperglycaemia.

PubMed

Lemper, Marie; De Groef, Sofie; Stangé, Geert; Baeyens, Luc; Heimberg, Harry

2016-09-01

When the beta cell mass or function declines beyond a critical point, hyperglycaemia arises. Little is known about the potential pathways involved in beta cell rescue. As two cytokines, epidermal growth factor (EGF) and ciliary neurotrophic factor (CNTF), restored a functional beta cell mass in mice with long-term hyperglycaemia by reprogramming acinar cells that transiently expressed neurogenin 3 (NGN3), the current study assesses the effect of these cytokines on the functional beta cell mass after an acute chemical toxic insult. Glycaemia and insulin levels, pro-endocrine gene expression and beta cell origin, as well as the role of signal transducer and activator of transcription 3 (STAT3) signalling, were assessed in EGF+CNTF-treated mice following acute hyperglycaemia. The mice were hyperglycaemic 1 day following i.v. injection of the beta cell toxin alloxan, when the two cytokines were applied. One week later, 68.6 ± 4.6% of the mice had responded to the cytokine treatment and increased their insulin(+) cell number to 30% that of normoglycaemic control mice, resulting in restoration of euglycaemia. Although insulin(-) NGN3(+) cells appeared following acute EGF+CNTF treatment, genetic lineage tracing showed that the majority of the insulin(+) cells originated from pre-existing beta cells. Beta cell rescue by EGF+CNTF depends on glycaemia rather than on STAT3-induced NGN3 expression in acinar cells. In adult mice, EGF+CNTF allows the rescue of beta cells in distress when treatment is given shortly after the diabetogenic insult. The rescued beta cells restore a functional beta cell mass able to control normal blood glucose levels. These findings may provide new insights into compensatory pathways activated early after beta cell loss.

Activatory and inhibitory Fcγ receptors augment rituximab-mediated internalization of CD20 independent of signaling via the cytoplasmic domain.

PubMed

Vaughan, Andrew T; Chan, Claude H T; Klein, Christian; Glennie, Martin J; Beers, Stephen A; Cragg, Mark S

2015-02-27

Type I anti-CD20 mAb such as rituximab and ofatumumab engage with the inhibitory FcγR, FcγRIIb on the surface of B cells, resulting in immunoreceptor tyrosine-based inhibitory motif (ITIM) phosphorylation. Internalization of the CD20·mAb·FcγRIIb complex follows, the rate of which correlates with FcγRIIb expression. In contrast, although type II anti-CD20 mAb such as tositumomab and obinutuzumab also interact with and activate FcγRIIb, this interaction fails to augment the rate of CD20·mAb internalization, raising the question of whether ITIM phosphorylation plays any role in this process. We have assessed the molecular requirements for the internalization process and demonstrate that in contrast to internalization of IgG immune complexes, FcγRIIb-augmented internalization of rituximab-ligated CD20 occurs independently of the FcγRIIb ITIM, indicating that signaling downstream of FcγRIIb is not required. In transfected cells, activatory FcγRI, FcγRIIa, and FcγRIIIa augmented internalization of rituximab-ligated CD20 in a similar manner. However, FcγRIIa mediated a slower rate of internalization than cells expressing equivalent levels of the highly homologous FcγRIIb. The difference was maintained in cells expressing FcγRIIa and FcγRIIb lacking cytoplasmic domains and in which the transmembrane domains had been exchanged. This difference may be due to increased degradation of FcγRIIa, which traffics to lysosomes independently of rituximab. We conclude that the cytoplasmic domain of FcγR is not required for promoting internalization of rituximab-ligated CD20. Instead, we propose that FcγR provides a structural role in augmenting endocytosis that differs from that employed during the endocytosis of immune complexes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Human Augmentics: augmenting human evolution.

PubMed

Kenyon, Robert V; Leigh, Jason

2011-01-01

Human Augmentics (HA) refers to technologies for expanding the capabilities, and characteristics of humans. One can think of Human Augmentics as the driving force in the non-biological evolution of humans. HA devices will provide technology to compensate for human biological limitations either natural or acquired. The strengths of HA lie in its applicability to all humans. Its interoperability enables the formation of ecosystems whereby augmented humans can draw from other realms such as "the Cloud" and other augmented humans for strength. The exponential growth in new technologies portends such a system but must be designed for interaction through the use of open-standards and open-APIs for system development. We discuss the conditions needed for HA to flourish with an emphasis on devices that provide non-biological rehabilitation.

Square cell packing in the Drosophila embryo through spatiotemporally regulated EGF receptor signaling

PubMed Central

Tamada, Masako; Zallen, Jennifer A.

2015-01-01

Summary Cells display dynamic and diverse morphologies during development, but the strategies by which differentiated tissues achieve precise shapes and patterns are not well understood. Here we identify a developmental program that generates a highly ordered square cell grid in the Drosophila embryo through sequential and spatially regulated cell alignment, oriented cell division, and apicobasal cell elongation. The basic leucine zipper transcriptional regulator Cnc is necessary and sufficient to produce a square cell grid in the presence of a midline signal provided by the EGF receptor ligand, Spitz. Spitz orients cell divisions through a Pins/LGN-dependent spindle positioning mechanism and controls cell shape and alignment through a transcriptional pathway that requires the Pointed ETS domain protein. These results identify a strategy for producing ordered square cell packing configurations in epithelia and reveal a molecular mechanism by which organized tissue structure is generated through spatiotemporally regulated responses to EGF receptor activation. PMID:26506305

Ascofuranone suppresses EGF-induced HIF-1α protein synthesis by inhibition of the Akt/mTOR/p70S6K pathway in MDA-MB-231 breast cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Yun-Jeong; Cho, Hyun-Ji; Magae, Junji

2013-12-15

Hypoxia-inducible factor (HIF)-1 plays an important role in tumor progression, angiogenesis and metastasis. In this study, we investigated the potential molecular mechanisms underlying the anti-angiogenic effect of ascofuranone, an isoprenoid antibiotic from Ascochyta viciae, in epidermal growth factor (EGF)-1 responsive human breast cancer cells. Ascofuranone significantly and selectively suppressed EGF-induced HIF-1α protein accumulation, whereas it did not affect the expression of HIF-1β. Furthermore, ascofuranone inhibited the transcriptional activation of vascular endothelial growth factor (VEGF) by reducing protein HIF-1α. Mechanistically, we found that the inhibitory effects of ascofuranone on HIF-1α protein expression are associated with the inhibition of synthesis HIF-1α throughmore » an EGF-dependent mechanism. In addition, ascofuranone suppressed EGF-induced phosphorylation of Akt/mTOR/p70S6 kinase, but the phosphorylation of ERK/JNK/p38 kinase was not affected by ascofuranone. These results suggest that ascofuranone suppresses EGF-induced HIF-1α protein translation through the inhibition of Akt/mTOR/p70S6 kinase signaling pathways and plays a novel role in the anti-angiogenic action. - Highlights: • Inhibitory effect of ascofuranone on HIF-1α expression is EGF-specific regulation. • Ascofuranone decreases HIF-1α protein synthesis through Akt/mTOR pathways. • Ascofuranone suppresses EGF-induced VEGF production and tumor angiogenesis.« less

Cellular uptake mediated by epidermal growth factor receptor facilitates the intracellular activity of phosphorothioate-modified antisense oligonucleotides

PubMed Central

Wang, Shiyu; Allen, Nickolas; Vickers, Timothy A; Revenko, Alexey S; Sun, Hong; Liang, Xue-hai; Crooke, Stanley T

2018-01-01

Abstract Chemically modified antisense oligonucleotides (ASOs) with phosphorothioate (PS) linkages have been extensively studied as research and therapeutic agents. PS-ASOs can enter the cell and trigger cleavage of complementary RNA by RNase H1 even in the absence of transfection reagent. A number of cell surface proteins have been identified that bind PS-ASOs and mediate their cellular uptake; however, the mechanisms that lead to productive internalization of PS-ASOs are not well understood. Here, we characterized the interaction between PS-ASOs and epidermal growth factor receptor (EGFR). We found that PS-ASOs trafficked together with EGF and EGFR into clathrin-coated pit structures. Their co-localization was also observed at early endosomes and inside enlarged late endosomes. Reduction of EGFR decreased PS-ASO activity without affecting EGF-mediated signaling pathways and overexpression of EGFR increased PS-ASO activity in cells. Furthermore, reduction of EGFR delays PS-ASO trafficking from early to late endosomes. Thus, EGFR binds to PS-ASOs at the cell surface and mediates essential steps for active (productive) cellular uptake of PS-ASOs through its cargo-dependent trafficking processes which migrate PS-ASOs from early to late endosomes. This EGFR-mediated process can also serve as an additional model to better understand the mechanism of intracellular uptake and endosomal release of PS-ASOs. PMID:29514240

A Novel Positive Feedback Loop Mediated by the Docking Protein Gab1 and Phosphatidylinositol 3-Kinase in Epidermal Growth Factor Receptor Signaling

PubMed Central

Rodrigues, Gerard A.; Falasca, Marco; Zhang, Zhongtao; Ong, Siew Hwa; Schlessinger, Joseph

2000-01-01

The Gab1 protein is tyrosine phosphorylated in response to various growth factors and serves as a docking protein that recruits a number of downstream signaling proteins, including phosphatidylinositol 3-kinase (PI-3 kinase). To determine the role of Gab1 in signaling via the epidermal growth factor (EGF) receptor (EGFR) we tested the ability of Gab1 to associate with and modulate signaling by this receptor. We show that Gab1 associates with the EGFR in vivo and in vitro via pTyr sites 1068 and 1086 in the carboxy-terminal tail of the receptor and that overexpression of Gab1 potentiates EGF-induced activation of the mitogen-activated protein kinase and Jun kinase signaling pathways. A mutant of Gab1 unable to bind the p85 subunit of PI-3 kinase is defective in potentiating EGFR signaling, confirming a role for PI-3 kinase as a downstream effector of Gab1. Inhibition of PI-3 kinase by a dominant-interfering mutant of p85 or by Wortmannin treatment similarly impairs Gab1-induced enhancement of signaling via the EGFR. The PH domain of Gab1 was shown to bind specifically to phosphatidylinositol 3,4,5-triphosphate [PtdIns(3,4,5)P3], a product of PI-3 kinase, and is required for activation of Gab1-mediated enhancement of EGFR signaling. Moreover, the PH domain mediates Gab1 translocation to the plasma membrane in response to EGF and is required for efficient tyrosine phosphorylation of Gab1 upon EGF stimulation. In addition, overexpression of Gab1 PH domain blocks Gab1 potentiation of EGFR signaling. Finally, expression of the gene for the lipid phosphatase PTEN, which dephosphorylates PtdIns(3,4,5)P3, inhibits EGF signaling and translocation of Gab1 to the plasma membrane. These results reveal a novel positive feedback loop, modulated by PTEN, in which PI-3 kinase functions as both an upstream regulator and a downstream effector of Gab1 in signaling via the EGFR. PMID:10648629

MET Signaling Mediates Intestinal Crypt-Villus Development, Regeneration, and Adenoma Formation and Is Promoted by Stem Cell CD44 Isoforms.

PubMed

Joosten, Sander P J; Zeilstra, Jurrit; van Andel, Harmen; Mijnals, R Clinton; Zaunbrecher, Joost; Duivenvoorden, Annet A M; van de Wetering, Marc; Clevers, Hans; Spaargaren, Marcel; Pals, Steven T

2017-10-01

/Met fl/fl /LacZ mice. Lgr5 Creert2 /Met fl/fl /LacZ mice had impaired regeneration of MET-deficient ISCs. Adenoma organoids stimulated with EGF or HGF expanded to almost twice the size of nonstimulated organoids. MET-deficient adenoma organoids did not respond to HGF stimulation, but did respond to EGF. ISC-specific disruption of Met (Lgr5 Creert2 /Met fl/fl /Apc fl/fl mice) caused a twofold increase in apoptosis in microadenomas, resulting in an approximately 50% reduction of microadenoma numbers and significantly reduced average adenoma size. Total epithelial disruption of Met (Ah Cre /Met fl/fl /Apc fl/+ mice) resulted in an approximate 50% reduction in (micro)adenoma numbers. Intestinal crypts from Cd44 -/- mice did not expand to the same extent as crypts from Cd44 +/+ mice on stimulation with HGF, but had the same response to EGF. The negative effect on HGF-mediated growth was overcome by expression of CD44v4-10, but not by CD44s. Similarly, HGF-mediated expansion of adenoma organoids required CD44v4-10. In studies of intestinal organoid cultures and mice with inducible deletion of MET, we found HGF receptor signaling to regulate intestinal homeostasis and regeneration, as well as adenoma formation. These activities of MET are promoted by the stem cell CD44 isoform CD44v4-10. Our findings provide rationale for targeting signaling via MET and CD44 during anti-EGF receptor therapy of patients with colorectal cancer or in patients resistant to EGF receptor inhibitors. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

SOX2 plays a critical role in EGFR-mediated self-renewal of human prostate cancer stem-like cells.

PubMed

Rybak, Adrian P; Tang, Damu

2013-12-01

SOX2 is an essential transcription factor for stem cells and plays a role in tumorigenesis, however its role in prostate cancer stem cells (PCSCs) remains unclear. We report here a significant upregulation of SOX2 at both mRNA and protein levels in DU145 PCSCs propagated as suspension spheres in vitro. The expression of SOX2 in DU145 PCSCs is positively regulated by epidermal growth factor receptor (EGFR) signaling. Activation of EGFR signaling, following the addition of epidermal growth factor (EGF) or ectopic expression of a constitutively-active EGFR mutant (EGFRvIII), increased SOX2 expression and the self-renewal of DU145 PCSCs. Conversely, a small molecule EGFR inhibitor (AG1478) blocked EGFR activation, reduced SOX2 expression and inhibited PCSC self-renewal activity, implicating SOX2 in mediating EGFR-dependent self-renewal of PCSCs. In line with this notion, ectopic SOX2 expression enhanced EGF-induced self-renewal of DU145 PCSCs, while SOX2 knockdown reduced PCSC self-renewal with EGF treatment no longer capable of enhancing their propagation. Furthermore, SOX2 knockdown reduced the capacity of DU145 PCSCs to grow under anchorage-independent conditions. Finally, DU145 PCSCs generated xenograft tumors more aggressively with elevated levels of SOX2 expression compared to xenograft tumors derived from non-PCSCs. Collectively, we provide evidence that SOX2 plays a critical role in EGFR-mediated self-renewal of DU145 PCSCs. © 2013.

Activated protein C cofactor function of protein S: a critical role for Asp95 in the EGF1-like domain

PubMed Central

Andersson, Helena M.; Arantes, Márcia J.; Crawley, James T. B.; Luken, Brenda M.; Tran, Sinh; Dahlbäck, Björn; Rezende, Suely M.

2010-01-01

Protein S has an established role in the protein C anticoagulant pathway, where it enhances the factor Va (FVa) and factor VIIIa (FVIIIa) inactivating property of activated protein C (APC). Despite its physiological role and clinical importance, the molecular basis of its action is not fully understood. To clarify the mechanism of the protein S interaction with APC, we have constructed and expressed a library of composite or point variants of human protein S, with residue substitutions introduced into the Gla, thrombin-sensitive region (TSR), epidermal growth factor 1 (EGF1), and EGF2 domains. Cofactor activity for APC was evaluated by calibrated automated thrombography (CAT) using protein S–deficient plasma. Of 27 variants tested initially, only one, protein S D95A (within the EGF1 domain), was largely devoid of functional APC cofactor activity. Protein S D95A was, however, γ-carboxylated and bound phospholipids with an apparent dissociation constant (Kdapp) similar to that of wild-type (WT) protein S. In a purified assay using FVa R506Q/R679Q, purified protein S D95A was shown to have greatly reduced ability to enhance APC-induced cleavage of FVa Arg306. It is concluded that residue Asp95 within EGF1 is critical for APC cofactor function of protein S and could define a principal functional interaction site for APC. PMID:20308596

Towards Pervasive Augmented Reality: Context-Awareness in Augmented Reality.

PubMed

Grubert, Jens; Langlotz, Tobias; Zollmann, Stefanie; Regenbrecht, Holger

2017-06-01

Augmented Reality is a technique that enables users to interact with their physical environment through the overlay of digital information. While being researched for decades, more recently, Augmented Reality moved out of the research labs and into the field. While most of the applications are used sporadically and for one particular task only, current and future scenarios will provide a continuous and multi-purpose user experience. Therefore, in this paper, we present the concept of Pervasive Augmented Reality, aiming to provide such an experience by sensing the user's current context and adapting the AR system based on the changing requirements and constraints. We present a taxonomy for Pervasive Augmented Reality and context-aware Augmented Reality, which classifies context sources and context targets relevant for implementing such a context-aware, continuous Augmented Reality experience. We further summarize existing approaches that contribute towards Pervasive Augmented Reality. Based our taxonomy and survey, we identify challenges for future research directions in Pervasive Augmented Reality.

EGFR ligands drive multipotential stromal cells to produce multiple growth factors and cytokines via early growth response-1.

PubMed

Kerpedjieva, Svetoslava S; Kim, Duk Soo; Barbeau, Dominique J; Tamama, Kenichi

2012-09-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)-EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase-extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands.

[INHIBITORS OF MAP-KINASE PATHWAY U0126 AND PD98059 DIFFERENTLY AFFECT ORGANIZATION OF TUBULIN CYTOSKELETON AFTER STIMULATION OF EGF RECEPTOR ENDOCYTOSIS].

PubMed

Zlobina, M V; Steblyanko, Yu Yu; Shklyaeva, M A; Kharchenko, V V; Salova, A V; Kornilova, E S

2015-01-01

To confirm the hypothesis about the involvement of EGF-stimulated MAP-kinase ERK1/2 in the regulation of microtubule (MT) system, the influence of two widely used ERK1/2 inhibitors, U0126 and PD98059, on the organization of tubulin cytoskeleton in interphase HeLa cells during EGF receptor endocytosis has been investigated. We have found that addition of U0126 or PD98059 to not-stimulated with EGF ells for 30 min has no effect on radially organized MT system. However, in the case of U0126 addition before EGF endocytosis stimulation, the number of MT per cell decreased within 15 min after such stimulation and was followed by complete MT depolymerization by 60-90 min. Stimulation of EGF endocytosis in the presence of PD98059 resulted only in insignificant depolymerization of MT and it could be detected mainly from their minus-ends. At the same time, MT regions close to plasma membrane became stabilized, which was proved by increase in tubulin acetylation level. This situation was characteristic for all period of the experiment. It has been also found that the inhibitors affect endocytosis dynamics of EGF-receptor complexes. Quantitative analysis demonstrated that the stimulation of endocytosis in the presence of U0126 generated a greater number of endosomes compared to control cells, and their number did not change significantly during the experiment. All these endosomes were localized peripherally. Effect of PD98059 resulted in the formation of lower number of endosomes that in control, but they demonstrated very slow clusterization despite the presence of some intact MT. Both inhibitors decreased EGFR colocolization with early endosomal marker EEA1, which indicated a delay in endosome fusions and maturation. The inhibitors were also shown to affect differently phospho-ERK 1 and 2 forms: U0126 completely inhibited phospho-ERK1 and 2, white, in the presence of PD98059, the two ERK forms demonstrated sharp transient activation in 15 min after stimulation, but only

The EGF receptor family as targets for cancer therapy.

PubMed

Mendelsohn, J; Baselga, J

2000-12-27

Human carcinomas frequently express high levels of receptors in the EGF receptor family, and overexpression of at least two of these receptors, the EGF receptor (EGFr) and closely related ErbB2, has been associated with a more aggressive clinical behavior. Further, transfection or activation of high levels of these two receptors in nonmalignant cell lines can lead to a transformed phenotype. For these reasons therapies directed at preventing the function of these receptors have the potential to be useful anti-cancer treatments. In the last two decades monoclonal antibodies (MAbs) which block activation of the EGFr and ErbB2 have been developed. These MAbs have shown promising preclinical activity and 'chimeric' and 'humanized' MAbs have been produced in order to obviate the problem of host immune reactions. Clinical activity with these antibodies has been documented: trastuzumab, a humanized anti-ErbB2 MAb, is active and was recently approved in combination with paclitaxel for the therapy of patients with metastatic ErbB2-overexpressing breast cancer; IMC-C225, a chimeric anti-EGFr MAb, has shown impressive activity when combined with radiation therapy and reverses resistance to chemotherapy. In addition to antibodies, compounds that directly inhibit receptor tyrosine kinases have shown preclinical activity and early clinical activity has been reported. A series of phase III studies with these antibodies and direct tyrosine kinase inhibitors are ongoing or planned, and will further address the role of these active anti-receptor agents in the treatment of patients with cancer.

Protein tyrosine phosphatase-1B (PTP1B) helps regulate EGF-induced stimulation of S-phase entry in human corneal endothelial cells

PubMed Central

Ishino, Yutaka; Zhu, Cheng; Harris, Deshea L.

2008-01-01

Purpose Human corneal endothelial cells (HCEC), particularly from older donors, only proliferate weakly in response to EGF. The protein tyrosine phosphatase, PTP1B, is known to negatively regulate EGF-induced signaling in several cell types by dephosphorylating the epidermal growth factor receptor (EGFR). The current studies were conducted to determine whether PTP1B plays a role in regulating cell cycle entry in HCEC in response to EGF stimulation. Methods Donor corneas were obtained from the National Disease Research Interchange and accepted for study based on established exclusion criteria. PTP1B was localized in the endothelium of ex vivo corneas and in cultured cells by immunocytochemistry. Western blot analysis verified PTP1B protein expression in HCEC and then compared the relative expression of EGFR and PTP1B in HCEC from young (<3 years old) and older donors (>60 years old). The effect of inhibiting the activity of PTP1B on S-phase entry was tested by comparing time-dependent BrdU incorporation in subconfluent HCEC incubated in the presence or absence of the PTP1B inhibitor, CinnGEL 2Me, before EGF stimulation. Results PTP1B was localized in a punctate pattern mainly within the cytoplasm of HCEC in ex vivo corneas and cultured cells. Western blots revealed the presence of three PTP1B-positive bands in HCEC and the control. Further western blot analysis showed no significant age-related difference in expression of EGFR (p=0.444>0.05); however, PTP1B expression was significantly higher in HCEC from older donors (p=0.024<0.05). Pre-incubation of HCEC with the PTP1B inhibitor significantly increased (p=0.019<0.05) the number of BrdU positive cells by 48 h after EGF stimulation. Conclusions Both immunolocalization and western blot studies confirmed that PTP1B is expressed in HCEC. Staining patterns strongly suggest that at least a subset of PTP1B is localized to the cytoplasm and most likely to the endoplasmic reticulum, the known site of EGFR/PTP1B interaction

[Effect of total flavones from Cuscuta chinensis on expression of Fas/FasL, PCNA and HB-EGF in SD rats model with bromocriptine-induced abortion].

PubMed

Ma, Hong-Xia; You, Zhao-Ling; Wang, Xiao-Yun

2008-11-01

To explore the effect of total flavones from cuscuta chinensis (TFCC) on expression of Fas, PCNA and HB-EGF in SD rats model with bromocriptine-induced abortion. The model rats of bromocriptine during 6-8 d of pregnancy induced early abortion was established, adopting respectively herbs in high and low dosage and progesterone affect model rat and after 12 d, Immunohistochemical was applied to determine Fas, HB-EGF and PCNA in deciduas and placenta. Expression of PCNA on trophoblast and deciduas, HB-EGF on trophoblast, PR on deciduas in the model used Semen cuscutae flavonoid, proesterone and normal pregnacy, were significantlly higher than those of the pure model. Expression of Fas on trophoblast and deciduas in above four groups, were significantlly lower than those of the pure model. There were no expression of HB-EGF on deciduas. TFCC regulates the proliferation and apoptosis of the deciduas and cytotrophoblasts and prevents spontaneous abortions.

EGF promotes the shedding of soluble E-cadherin in an ADAM10-dependent manner in prostate epithelial cells.

PubMed

Grabowska, Magdalena M; Sandhu, Brindar; Day, Mark L

2012-02-01

During the progression of prostate cancer, the epithelial adhesion molecule E-cadherin is cleaved from the cell surface by ADAM15 proteolytic processing, generating an extracellular 80kDa fragment referred to as soluble E-cadherin (sE-cad). Contrary to observations in cancer, the generation of sE-cad appears to correlate with ADAM10 activity in benign prostatic epithelium. The ADAM10-specific inhibitor INCB8765 and the ADAM10 prodomain inhibit the generation of sE-cad, as well as downstream signaling and cell proliferation. Addition of EGF or amphiregulin (AREG) to these untransformed cell lines increases the amount of sE-cad shed into the conditioned media, as well as sE-cad bound to EGFR. EGF-associated shedding appears to be mediated by ADAM10 as shRNA knockdown of ADAM10 results in reduced shedding of sE-cad. To examine the physiologic role of sE-cad on benign prostatic epithelium, we treated BPH-1 and large T immortalized prostate epithelial cells (PrEC) with an sE-cad chimera comprised of the human Fc domain of IgG(1), fused to the extracellular domains of E-cadherin (Fc-Ecad). The treatment of untransformed prostate epithelial cells with Fc-Ecad resulted in phosphorylation of EGFR and downstream signaling through ERK and increased cell proliferation. Pre-treating BPH-1 and PrEC cells with cetuximab, a therapeutic monoclonal antibody against EGFR, decreased the ability of Fc-Ecad to induce EGFR phosphorylation, downstream signaling, and proliferation. These data suggest that ADAM10-generated sE-cad may have a role in EGFR signaling independent of traditional EGFR ligands. Copyright © 2011 Elsevier Inc. All rights reserved.

Differential role of EGF and BFGF in human GBM-TIC proliferation: relationship to EGFR-tyrosine kinase inhibitor sensibility.

PubMed

Bajetto, A; Porcile, C; Pattarozzi, A; Scotti, L; Aceto, A; Daga, A; Barbieri, F; Florio, T

2013-01-01

Glioblastoma multiforme (GBM) is among the most devastating human tumors being rapidly fatal despite aggressive surgery, radiation and chemotherapies. It is characterized by extensive dissemination of tumor cells within the brain that hinders complete surgical resection. GBM tumor initiating-cells (TICs) are a rare subpopulation of cells responsible for tumor development, growth, invasiveness and recurrence after chemotherapy. TICs from human GBM can be selected in vitro using the same conditions permissive for the growth of normal neural cells, of which share some features including marker expression, self-renewal capacity, long-term proliferation, and ability to differentiate into neuronal and glial cells. EGFR overexpression and its constitutive activation is one of the most important signaling alteration identified in GBM, and its pharmacological targeting represents an attractive therapeutic goal. We previously demonstrated that human GBM TICs have different sensitivity to the EGFR kinase inhibitors erlotinib and gefitinib, depending on the differential modulation of downstream signaling cascades. In this work we investigated the mechanisms of resistance to erlotinib in two human GBM TIC cultures, analyzing EGF and bFGF individual contribution to proliferation, clonogenicity, and migration. We demonstrated the presence of a small cell subpopulation whose proliferation is supported by EGF and a larger one mainly dependent on bFGF. Thus, insensitivity to EGFR kinase inhibitors as far as TIC proliferation results from a predominant FGFR activation that hides the inhibitory effects induced on EGFR signaling. Conversely, EGF and bFGF induced cell migration with similar efficacy. In addition, unlike neural stem/progenitors cells, the removal of chondroitin sulphate proteoglycans from cell surface was unable to discern EGF- and bFGF-dependent subpopulations in GBM TICs.

A theoretical model for the Gla-TSR-EGF-1 region of the anticoagulant cofactor protein S: From biostructural pathology to specie

NASA Astrophysics Data System (ADS)

Villoutreix, Bruno O.; Teleman, Olle; Dahlbäck, Björn

1997-05-01

Protein S (PS), which functions as a species-specific anticoagulant cofactor to activated protein C (APC), is a mosaic protein that interacts with the phospholipid membrane via its γ-carboxyglutamate-rich (Gla) module. This module is followed by the thrombin-sensitive region (TSR), sensitive to thrombin cleavage, four epidermal growth factor (EGF)-like modules and a last region referred to as the sex hormone binding globulin (SHBG) domain. Of these, the TSR and the first EGF-like regions have been shown to be important for the species-specific interaction with APC. Difficulties in crystallising PS have so far hindered its study at the atomic level. Here, we report theoretical models for the Gla and EGF-1 modules of human PS constructed using prothrombin and factor X experimental structures. The TSR was built interactively. Analysis of the model linked with the large body of biochemical literature on PS and related proteins leads to suggestions that (i) the TSR stabilises the calcium-loaded Gla module through hydrophobic and ionic interactions and its conformation depends on the presence of the Gla module; (ii) the TSR does not form a calcium binding site but is protected from thrombin cleavage in the calcium-loaded form owing to short secondary structure elements and close contact with the Gla module; (iii) the PS missense mutations in this region are consistent with the structural data, except in one case which needs further investigation; and (iv) the two PS `faces' involving regions of residues Arg49-Gln52-Lys97 (TSR-EGF-1) and Thr103-Pro106 (EGF-1) may be involved in species-specific interactions with APC as they are richer in nonconservative substitution when comparing human and bovine protein S. This preliminary model helps to plan future experiments and the resulting data will be used to further validate and optimise the present structure.

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

EPA Science Inventory

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...

The SH2 and SH3 domains of mammalian Grb2 couple the EGF receptor to the Ras activator mSos1.

PubMed

Rozakis-Adcock, M; Fernley, R; Wade, J; Pawson, T; Bowtell, D

1993-05-06

Many tyrosine kinases, including the receptors for hormones such as epidermal growth factor (EGF), nerve growth factor and insulin, transmit intracellular signals through Ras proteins. Ligand binding to such receptors stimulates Ras guanine-nucleotide-exchange activity and increases the level of GTP-bound Ras, suggesting that these tyrosine kinases may activate a guanine-nucleotide releasing protein (GNRP). In Caenorhabditis elegans and Drosophila, genetic studies have shown that Ras activation by tyrosine kinases requires the protein Sem-5/drk, which contains a single Src-homology (SH) 2 domain and two flanking SH3 domains. Sem-5 is homologous to the mammalian protein Grb2, which binds the autophosphorylated EGF receptor and other phosphotyrosine-containing proteins such as Shc through its SH2 domain. Here we show that in rodent fibroblasts, the SH3 domains of Grb2 are bound to the proline-rich carboxy-terminal tail of mSos1, a protein homologous to Drosophila Sos. Sos is required for Ras signalling and contains a central domain related to known Ras-GNRPs. EGF stimulation induces binding of the Grb2-mSos1 complex to the autophosphorylated EGF receptor, and mSos1 phosphorylation. Grb2 therefore appears to link tyrosine kinases to a Ras-GNRP in mammalian cells.

Epidermal Growth Factor and Interleukin-1β Utilize Divergent Signaling Pathways to Synergistically Upregulate Cyclooxygenase-2 Gene Expression in Human Amnion-Derived WISH Cells1

PubMed Central

Ackerman, William E.; Rovin, Brad H.; Kniss, Douglas A.

2006-01-01

In human parturition, uterotonic prostaglandins (PGs) arise predominantly via increased expression of cyclooxygenase-2 (COX-2 [also known as prostaglandin synthase 2]) within intra-uterine tissues. Interleukin-1 (IL-1) and epidermal growth factor (EGF), both inducers of COX-2 transcription, are among numerous factors that accumulate within amniotic fluid with advancing gestation. It was previously demonstrated that EGF could potentiate IL-1β-driven PGE2 production in amnion and amnion-derived (WISH) cells. To define the mechanism for this observation, we hypothesized that EGF and IL-1β might exhibit synergism in regulating COX-2 gene expression. In WISH cells, combined treatment with EGF and IL-1β resulted in a greater-than-additive increase in COX-2 mRNA relative to challenge with either agent independently. Augmentation of IL-1β-induced transactivation by EGF was not observed in cells harboring reporter plasmids bearing nuclear factor-kappa B (NFκB) regulatory elements alone, but was evident when a fragment (−891/+9) of the COX-2 gene 5′-promoter was present. Both agents transiently activated intermediates of multiple signaling pathways potentially involved in the regulation of COX-2 gene expression. The 26 S proteasome inhibitor, MG-132, selectively abrogated IL-1β-driven NFκB activation and COX-2 mRNA expression. Only pharmacologic blockade of the p38 mitogen-activated protein kinase eliminated COX-2 expression following EGF stimulation. We conclude that EGF and IL-1β appear to signal through different signaling cascades leading to COX-2 gene expression. IL-1β employs the NFκB pathway predominantly, while the spectrum of EGF signaling is broader and includes p38 kinase. The synergism observed between IL-1β and EGF does not rely on augmented NFκB function, but rather, occurs through differential use of independent response elements within the COX-2 promoter. PMID:15329330

Acidic environment augments FcεRI-mediated production of IL-6 and IL-13 in mast cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamide, Yosuke, E-mail: m08702012@gunma-u.ac.jp; Clinical Research Center for Allergy and Rheumatology, Sagamihara National Hospital, Sagamihara; Ishizuka, Tamotsu

Although blood pH is maintained in a narrow range of around pH 7.4 in living organisms, inflammatory loci are characterized by acidic conditions. Mast cells tend to reside close to the surface of the body in areas such as the mucosa and skin where they may be exposed to exogenous acids, and they play an important role in immune responses. However, little is known about the effects of extracellular acidification on the functions of mast cell. Here, we found that extracellular acidification increased the dinitrophenyl-conjugated human serum albumin (DNP-HSA)-induced production of interleukin (IL)-6 and IL-13 in MC/9 cells or bonemore » marrow-derived mouse mast cells sensitized with anti-DNP IgE. Extracellular acidification also inhibited migration of MC/9 cells toward DNP-HSA. In addition, acidic pH stimulated antigen-induced activation of p38 mitogen-activated protein kinase (MAPK) and protein kinase B (Akt). These findings suggest that extracellular acidification augmented antigen/IgE-induced and FcεRI-mediated production of IL-6 and IL-13 in mast cells, and that this was associated with the enhancement of p38 MAPK and Akt activation. - Highlights: • Antigen-induced IL-6 and IL-13 production was augmented by acidic pH in mast cells. • Acidic pH-induced actions were associated with activation of p38 MAPK and Akt. • Inhibition of p38 MAPK and Akt attenuated cytokine responses to acidic pH. • Acidic pH effects are not attributable to actions of known proton-sensing GPCRs.« less

Augmented BMP signaling in the neural crest inhibits nasal cartilage morphogenesis by inducing p53-mediated apoptosis.

PubMed

Hayano, Satoru; Komatsu, Yoshihiro; Pan, Haichun; Mishina, Yuji

2015-04-01

Bone morphogenetic protein (BMP) signaling plays many roles in skull morphogenesis. We have previously reported that enhanced BMP signaling through the BMP type IA receptor (BMPR1A) in cranial neural crest cells causes craniosynostosis during postnatal development. Additionally, we observed that 55% of Bmpr1a mutant mice show neonatal lethality characterized by a distended gastrointestinal tract. Here, we show that severely affected mutants exhibit defective nasal cartilage, failure of fusion between the nasal septum and the secondary palate, and higher levels of phosphorylated SMAD1 and SMAD5 in the nasal tissue. TUNEL demonstrated an increase in apoptosis in both condensing mesenchymal tissues and cartilage of the nasal region in mutants. The levels of p53 (TRP53) tumor suppressor protein were also increased in the same tissue. Injection of pifithrin-α, a chemical inhibitor of p53, into pregnant mice prevented neonatal lethality while concomitantly reducing apoptosis in nasal cartilage primordia, suggesting that enhanced BMP signaling induces p53-mediated apoptosis in the nasal cartilage. The expression of Bax and caspase 3, downstream targets of p53, was increased in the mutants; however, the p53 expression level was unchanged. It has been reported that MDM2 interacts with p53 to promote degradation. We found that the amount of MDM2-p53 complex was decreased in all mutants, and the most severely affected mutants had the largest decrease. Our previous finding that the BMP signaling component SMAD1 prevents MDM2-mediated p53 degradation coupled with our new data indicate that augmented BMP signaling induces p53-mediated apoptosis by prevention of p53 degradation in developing nasal cartilage. Thus, an appropriate level of BMP signaling is required for proper craniofacial morphogenesis. © 2015. Published by The Company of Biologists Ltd.

Correlations of EGF G1380A, bFGF C754G and VEGF T460C polymorphisms with malignant melanoma susceptibility and prognosis: A case-control study.

PubMed

Wang, Xin-Hua; Long, Zi-Wen

2017-06-20

This case-control study aims to investigate the correlations of EGF G1380A, bFGF C754G and VEGF T460C polymorphisms with the susceptibility and prognosis of malignant melanoma. A total of 153 patients with multiple primary melanomas were collected as the case group and another 170 healthy individuals were selected as the control group. ELISA and PCR-RFLP were performed to test the serum level of VEGF and to analyze the genotype as well as allele frequencies of VEGF T460C, EGF G1380A, and bFGF C754G, respectively. The patients were assigned into complete remission (CR), partial remission (PR) and non-remission groups after treatment. HE and CD34 staining were conducted in tissue samples of CR and PR patients. Event-free survival (EFS) and overall survival (OS) were measured. AA genotype of EGF G1380A and GG genotype of bFGF C754G had higher frequency distribution in the case group than the control group. Patients with AA genotype of EGF G1380 and GG genotype of bFGF C754G had an elevated VEGF level in comparison to other genotypes. Patients with GA+GG genotypes of EGF G1380A and CG+CC genotypes of bFGF C754G had higher EFS and OS than those with AA genotype and those with GG genotype, respectively. According to the haplotype analysis, the case group had a notably higher frequency of TAG and CAG along with while lower frequency of TGG and CGC compared with the control group. Logistic regression analysis revealed that the polymorphisms of EGF G1380A and bFGF C754G as well as the haploid TAG increased the susceptibility of malignant melanoma. The results indicated that EGF G1380A and bFGF C754G gene polymorphisms were associated with the susceptibility and prognosis of malignant melanoma, and that the polymorphisms of EGF G1380A and bFGF C754G as well as the haploid TAG increased the susceptibility of malignant melanoma. Copyright © 2017 Elsevier B.V. All rights reserved.

Pinoid kinase regulates root gravitropism through modulation of PIN2-dependent basipetal auxin transport in Arabidopsis thaliana

NASA Astrophysics Data System (ADS)

Muday, Gloria; Sukumar, Poornima; Edwards, Karin; Delong, Alison; Rahman, Abidur

Reversible protein phosphorylation is a key regulatory mechanism governing polar auxin transport. We tested the hypothesis that PINOID (PID)-mediated phosphorylation and RCN1- regulated dephosphorylation might antagonistically regulate auxin transport and gravity response in seedling roots. Here we show that basipetal IAA transport and gravitropism are reduced in pid mutant seedlings, while acropetal transport and lateral root development are unchanged. Treatment of wild-type seedlings with the protein kinase inhibitor, staurosporine, phenocopied the reduced auxin transport and gravity response of pid-9 and reduced formation of asymmetric DR5-revGFP expression at the root tip after reorientation relative to gravity. Gravitropism and auxin transport in pid are resistant to further inhibition by staurosporine. Gravity response defects of rcn1 and pid-9 are partially rescued by treatment with staurosporine or the phosphatase inhibitor, cantharidin, respectively, and in the pid-9 rcn1 double mutant. Furthermore, the effect of staurosporine is lost in pin2, and a PIN2::GFP fusion protein accumulates in endomembrane compartments after staurosporine treatment. In the pid-9 mutant, immunological techniques find a similar PIN2 localization. These data suggest that staurosporine inhibits gravitropism and basipetal IAA transport by blocking PID action and altering PIN2 localization and support the model that PID and RCN1 reciprocally regulate root gravitropic curvature.

Analysis of the presence of cell proliferation-related molecules in the Tgf-β3 null mutant mouse palate reveals misexpression of EGF and Msx-1.

PubMed

del Río, A; Barrio, M C; Murillo, J; Maldonado, E; López-Gordillo, Y; Martínez-Sanz, E; Martínez, M L; Martínez-Álvarez, C

2011-01-01

The Tgf-β(3) null mutant mouse palate presents several cellular anomalies that lead to the appearance of cleft palate. One of them concerns the cell proliferation of both the palatal medial edge epithelium and mesenchyme. In this work, our aim was to determine whether there was any variation in the presence/distribution of several cell proliferation-related molecules that could be responsible for the cell proliferation defects observed in these palates. Our results showed no difference in the presence of EGF-R, PDGF-A, TGF-β(2), Bmp-2, and Bmp-4, and differences were minimal for FGF-10 and Shh. However, the expression of EGF and Msx-1 changed substantially. The shift of the EGF protein expression was the one that most correlated with that of cell proliferation. This molecule is regulated by TGF-β(3), and experiments blocking its activity in culture suggest that EGF misexpression in the Tgf-β(3) null mutant mouse palate plays a role in the cell proliferation defect observed. Copyright © 2010 S. Karger AG, Basel.

Cyclosporin a inhibits T cell-mediated augmentation of mouse natural killer activity.

PubMed

Yanagihara, R H; Adler, W H

1982-06-01

Cyclosporin A (CSA) in vitro inhibited the spontaneous cytotoxic activity of mouse spleen cells against YAC target cells in a 4 hr 51Cr release assay. While natural killer (NK) cells were inhibited directly by CSA, these suppressive effects were largely reversible by coculture of effector cells for an optimal period with polyinosinic-polycytidylic acid (Poly I:C) or lipopolysaccharide (LPS). In contrast concanavalin A (Con A), in the presence of CSA, was unable to augment NK activity. The supernatant, however, of mouse spleen cells cultured with Con A was fully able to augment the NK the activity by freshly cultured spleen cells in the presence of CSA. The results indicate that CSA inhibits NK activity by two distinct mechanisms: a) a direct inactivation of NK cells and b) a suppression of production or release of an NK-activating factor from T cells, but not B cells or macrophages.

Learner Presence, Perception, and Learning Achievements in Augmented-Reality-Mediated Learning Environments

ERIC Educational Resources Information Center

Chen, Yu-Hsuan; Wang, Chang-Hwa

2018-01-01

Although research has indicated that augmented reality (AR)-facilitated instruction improves learning performance, further investigation of the usefulness of AR from a psychological perspective has been recommended. Researchers consider presence a major psychological effect when users are immersed in virtual reality environments. However, most…

PDK1-mediated activation of MRCKα regulates directional cell migration and lamellipodia retraction

PubMed Central

Gagliardi, Paolo Armando; di Blasio, Laura; Puliafito, Alberto; Seano, Giorgio; Sessa, Roberto; Chianale, Federica; Leung, Thomas; Bussolino, Federico

2014-01-01

Directional cell migration is of paramount importance in both physiological and pathological processes, such as development, wound healing, immune response, and cancer invasion. Here, we report that 3-phosphoinositide-dependent kinase 1 (PDK1) regulates epithelial directional migration and invasion by binding and activating myotonic dystrophy kinase–related CDC42-binding kinase α (MRCKα). We show that the effect of PDK1 on cell migration does not involve its kinase activity but instead relies on its ability to bind membrane phosphatidylinositol (3,4,5)-trisphosphate. Upon epidermal growth factor (EGF) stimulation, PDK1 and MRCKα colocalize at the cell membrane in lamellipodia. We demonstrate that PDK1 positively modulates MRCKα activity and drives its localization within lamellipodia. Likewise, the retraction phase of lamellipodia is controlled by PDK1 through an MRCKα-dependent mechanism. In summary, we discovered a functional pathway involving PDK1-mediated activation of MRCKα, which links EGF signaling to myosin contraction and directional migration. PMID:25092657

Epidermal growth factor (EGF) stimulated Ca/sup 2 +/ mobilization in hepatocytes is abolished by phorbol esters, pertussis toxin and partial hepatectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, R.M.; Garrison, J.C.

1986-05-01

EGF has been demonstrated to increase free intracellular Ca/sup 2 +/ levels in isolated hepatocytes putatively by generation of the second messenger inositol trisphosphate (IP/sub 3/). Pretreatment of cells with phorbol 12-myristate 13-acetate (PMA) inhibited the EGF (66 nM) stimulated Ca/sup 2 +/ response as measured by quin2. Inhibition by PMA was maximal within 3 min and was concentration dependent (IC/sub 50/ = 13.5 nM). Four other active phorbol ester analogues blocked the Ca/sup 2 +/ response while inactive analogues did not. EGF was unable to increase intracellular Ca/sup 2 +/ levels in hepatocytes isolated from rats treated with pertussismore » toxin for 72 hrs. Neither PMA nor toxin pretreatment was able to inhibit the Ca/sup 2 +/ response to angiotensin II (Ang II). In hepatocytes isolated 24 hrs after partial hepatectomy, the Ca/sup 2 +/ response to EGF (as measured by phosphorylase activity, EC/sub 50/ = 5 nM) was completely abolished and remained attenuated for 7 days post-hepatectomy. The Ca/sup 2 +/ response to Ang II in this model system was also blunted but required 3 days for development of the full effect and within 7 days full activity is nearly restored. The results suggest that fundamental differences exist in the transduction mechanisms used by these two Ca/sup 2 +/-linked hormones to mobilize intracellular Ca/sup 2 +/ (and putatively increase IP/sub 3/ formation).« less

Feedback activation of STAT3 mediates trastuzumab resistance via upregulation of MUC1 and MUC4 expression

PubMed Central

Li, Wei; Fan, Kexing; Qian, Weizhu; Hou, Sheng; Wang, Hao; Dai, Jianxin; Wei, Huafeng; Guo, Yajun

2014-01-01

Although HER2-targeting antibody trastuzumab confers a substantial benefit for patients with HER2-overexpressing breast and gastric cancer, overcoming trastuzumab resistance remains a large unmet need. In this study, we revealed a STAT3-centered positive feedback loop that mediates the resistance of trastuzumab. Mechanistically, chronic exposure of trastuzumab causes the upregulation of fibronection (FN), EGF and IL-6 in parental trastuzumab-sensitive breast and gastric cells and convergently leads to STAT3 hyperactivation. Activated STAT3 enhances the expression of FN, EGF and IL-6, thus constituting a positive feedback loop which amplifies and maintains the STAT3 signal; furthermore, hyperactivated STAT3 signal promotes the expression of MUC1 and MUC4, consequently mediating trastuzumab resistance via maintenance of persistent HER2 activation and masking of trastuzumab binding to HER2 respectively. Genetic or pharmacological inhibition of STAT3 disrupted STAT3-dependent positive feedback loop and recovered the trastuzumab sensitivity partially due to increased apoptosis induction. Combined trastuzumab with STAT3 inhibition synergistically suppressed the growth of the trastuzumab-resistant tumor xenografts in vivo. Taken together, our results suggest that feedback activation of STAT3 constitutes a key node mediating trastuzumab resistance. Combinatorial targeting on both HER2 and STAT3 may enhance the efficacy of trastuzumab or other HER2-targeting agents in HER2-positive breast and gastric cancer. PMID:25327561

Feedback activation of STAT3 mediates trastuzumab resistance via upregulation of MUC1 and MUC4 expression.

PubMed

Li, Guangchao; Zhao, Likun; Li, Wei; Fan, Kexing; Qian, Weizhu; Hou, Sheng; Wang, Hao; Dai, Jianxin; Wei, Huafeng; Guo, Yajun

2014-09-30

Although HER2-targeting antibody trastuzumab confers a substantial benefit for patients with HER2-overexpressing breast and gastric cancer, overcoming trastuzumab resistance remains a large unmet need. In this study, we revealed a STAT3-centered positive feedback loop that mediates the resistance of trastuzumab. Mechanistically, chronic exposure of trastuzumab causes the upregulation of fibronection (FN), EGF and IL-6 in parental trastuzumab-sensitive breast and gastric cells and convergently leads to STAT3 hyperactivation. Activated STAT3 enhances the expression of FN, EGF and IL-6, thus constituting a positive feedback loop which amplifies and maintains the STAT3 signal; furthermore, hyperactivated STAT3 signal promotes the expression of MUC1 and MUC4, consequently mediating trastuzumab resistance via maintenance of persistent HER2 activation and masking of trastuzumab binding to HER2 respectively. Genetic or pharmacological inhibition of STAT3 disrupted STAT3-dependent positive feedback loop and recovered the trastuzumab sensitivity partially due to increased apoptosis induction. Combined trastuzumab with STAT3 inhibition synergistically suppressed the growth of the trastuzumab-resistant tumor xenografts in vivo. Taken together, our results suggest that feedback activation of STAT3 constitutes a key node mediating trastuzumab resistance. Combinatorial targeting on both HER2 and STAT3 may enhance the efficacy of trastuzumab or other HER2-targeting agents in HER2-positive breast and gastric cancer.

Egr-1 and serum response factor are involved in growth factors- and serum-mediated induction of E2-EPF UCP expression that regulates the VHL-HIF pathway.

PubMed

Lim, Jung Hwa; Jung, Cho-Rok; Lee, Chan-Hee; Im, Dong-Soo

2008-11-01

E2-EPF ubiquitin carrier protein (UCP) has been shown to be highly expressed in common human cancers and target von Hippel-Lindau (VHL) for proteosomal degradation in cells, thereby stabilizing hypoxia-inducible factor (HIF)-1alpha. Here, we investigated cellular factors that regulate the expression of UCP gene. Promoter deletion assay identified binding sites for early growth response-1 (Egr-1) and serum response factor (SRF) in the UCP promoter. Hepatocyte or epidermal growth factor (EGF), or phorbol 12-myristate 13-acetate induced UCP expression following early induction of Egr-1 expression in HeLa cells. Serum increased mRNA and protein levels of SRF and UCP in the cell. By electrophoretic mobility shift and chromatin immunoprecipitation assays, sequence-specific DNA-binding of Egr-1 and SRF to the UCP promoter was detected in nuclear extracts from HeLa cells treated with EGF and serum, respectively. Overexpression of Egr-1 or SRF increased UCP expression. RNA interference-mediated depletion of endogenous Egr-1 or SRF impaired EGF- or serum-mediated induction of UCP expression, which was required for cancer cell proliferation. Systemic delivery of EGF into mice also increased UCP expression following early induction of Egr-1 expression in mouse liver. The induced UCP expression by the growth factors or serum increased HIF-1alpha protein level under non-hypoxic conditions, suggesting that the Egr-1/SRF-UCP-VHL pathway is in part responsible for the increased HIF-1alpha protein level in vitro and in vivo. Thus, growth factors and serum induce expression of Egr-1 and SRF, respectively, which in turn induces UCP expression that positively regulates cancer cell growth.

EGFR Ligands Drive Multipotential Stromal Cells to Produce Multiple Growth Factors and Cytokines via Early Growth Response-1

PubMed Central

Kerpedjieva, Svetoslava S.; Kim, Duk Soo; Barbeau, Dominique J.

2012-01-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)–EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase–extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands. PMID:22316125

ERK2-mediated C-terminal serine phosphorylation of p300 is vital to the regulation of epidermal growth factor-induced keratin 16 gene expression.

PubMed

Chen, Yun-Ju; Wang, Ying-Nai; Chang, Wen-Chang

2007-09-14

We previously reported that the epidermal growth factor (EGF) regulates the gene expression of keratin 16 by activating the extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling which in turn enhances the recruitment of p300 to the keratin 16 promoter. The recruited p300 functionally cooperates with Sp1 and c-Jun to regulate the gene expression of keratin 16. This study investigated in detail the molecular events incurred upon p300 whereby EGF caused an enhanced interaction between p300 and Sp1. EGF apparently induced time- and dose-dependent phosphorylation of p300, both in vitro and in vivo, through the activation of ERK2. The six potential ERK2 phosphorylation sites, including three threonine and three serine residues as revealed by sequential analysis, were first identified in vitro. Confirmation of these six sites in vivo indicated that these three serine residues (Ser-2279, Ser-2315, and Ser-2366) on the C terminus of p300 were the major signaling targets of EGF. Furthermore, the C-terminal serine phosphorylation of p300 stimulated its histone acetyltransferase activity and enhanced its interaction with Sp1. These serine phosphorylation sites on p300 controlled the p300 recruitment to the keratin 16 promoter. When all three serine residues on p300 were replaced by alanine, EGF could no longer induce the gene expression of keratin 16. Taken together, these results strongly suggested that the ERK2-mediated C-terminal serine phosphorylation of p300 was a key event in the regulation of EGF-induced keratin 16 expression. These results also constituted the first report identifying the unique p300 phosphorylation sites induced by ERK2 in vivo.

Polarised Clathrin-Mediated Endocytosis of EGFR During Chemotactic Invasion

PubMed Central

Mutch, Laura Jane; Howden, Jake Davey; Jenner, Emma Poppy Louise; Poulter, Natalie Sarah; Rappoport, Joshua Zachary

2014-01-01

Directed cell migration is critical for numerous physiological processes including development and wound healing. However chemotaxis is also exploited during cancer progression. Recent reports have suggested links between vesicle trafficking pathways and directed cell migration. Very little is known about the potential roles of endocytosis pathways during metastasis. Therefore we performed a series of studies employing a previously characterised model for chemotactic invasion of cancer cells to assess specific hypotheses potentially linking endocytosis to directed cell migration. Our results demonstrate that clathrin-mediated endocytosis is indispensable for epidermal growth factor (EGF) directed chemotactic invasion of MDA-MB-231 cells. Conversely, caveolar endocytosis is not required in this mode of migration. We further found that chemoattractant receptor (EGFR) trafficking occurs by clathrin-mediated endocytosis and is polarised towards the front of migrating cells. However, we found no role for clathrin-mediated endocytosis in focal adhesion disassembly in this migration model. Thus, this study has characterised the role of endocytosis during chemotactic invasion and has identified functions mechanistically linking clathrin-mediated endocytosis to directed cell motility. PMID:24921075

Nanoconjugation prolongs endosomal signaling of the epidermal growth factor receptor and enhances apoptosis

NASA Astrophysics Data System (ADS)

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

aPKCζ affects directed cell migration through the regulation of myosin light chain phosphorylation

PubMed Central

Petrov, Daria; Dahan, Inbal; Cohen-Kfir, Einav; Ravid, Shoshana

2017-01-01

ABSTRACT Cell motility is an essential cellular process for a variety of biological events. It requires cross-talk between the signaling and the cytoskeletal systems. Despite the recognized importance of aPKCζ for cell motility, there is little understanding of the mechanism by which aPKCζ mediates extracellular signals to the cytoskeleton. In the present study, we report that aPKCζ is required for the cellular organization of acto-non-muscle myosin II (NMII) cytoskeleton, for proper cell adhesion and directed cell migration. We show that aPKCζ mediates EGF-dependent RhoA activation and recruitment to the cell membrane. We also show that aPKCζ mediates EGF-dependent myosin light chain (MRLC) phosphorylation that is carried out by Rho-associated protein kinase (ROCK), and that aPKCζ is required for EGF-dependent phosphorylation and inhibition of the myosin phosphatase targeting subunit (MYPT). Finally, we show that aPKCζ mediates the spatial organization of the acto-NMII cytoskeleton in response to EGF stimulation. Our data suggest that aPKCζ is an essential component regulator of acto-NMII cytoskeleton organization leading to directed cell migration, and is a mediator of the EGF signal to the cytoskeleton. PMID:27541056

EGF-receptor phosphorylation and downstream signaling are activated by benzo[a]pyrene 3,6-quinone and benzo[a]pyrene 1,6-quinone in human mammary epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez-Fragoso, Lourdes; Melendez, Karla; Hudson, Laurie G.

2009-03-15

Benzo[a]pyrene (BaP) is activated by xenobiotic-metabolizing enzymes to highly mutagenic and carcinogenic metabolites. Previous studies in this laboratory have shown that benzo[a]pyrene quinones (BPQs), 1,6-BPQ and 3,6-BPQ, are able to induce epidermal growth factor receptor (EGFR) cell signaling through the production of reactive oxygen species. Recently, we have reported that BPQs have the potential to induce the expression of genes involved in numerous pathways associated with cell proliferation and survival in human mammary epithelial cells. In the present study we demonstrated that BPQs not only induced EGFR tyrosine autophosphorylation, but also induced EGFR-dependent tyrosine phosphorylation of phospholipase C-{gamma}1 and severalmore » signal transducers and activators of transcription (STATs). The effects of BPQs were evaluated in a model of EGF withdrawal in MCF10-A cells. We found that BPQs (1 {mu}M), induced EGFR tyrosine phosphorylation at positions Y845, Y992, Y1068, and Y1086. PLC-{gamma}1 phosphorylation correlated with the phosphorylation of tyrosine-Y992, a proposed docking site for PLC-{gamma}1 on the EGFR. Additionally, we found that BPQs induced the activation of STAT-1, STAT-3, STAT-5a and STAT-5b. STAT5 was shown to translocate to the nucleus following 3,6-BPQ and 1,6-BPQ exposures. Although the patterns of phosphorylation at EGFR, PLC-{gamma}1 and STATs were quite similar to those induced by EGF, an important difference between BPQ-mediated signaling of the EGFR was observed. Signaling produced by EGF ligand produced a rapid disappearance of EGFR from the cell surface, whereas BPQ signaling maintained EGFR receptors on the cell membrane. Thus, the results of these studies show that 1,6-BPQ and 3,6-BPQ can produce early events as evidenced by EGFR expression, and a prolonged transactivation of EGFR leading to downstream cell signaling pathways.« less

EGF-Receptor Phosphorylation and Downstream Signaling are Activated by Benzo[a]pyrene 3,6-quinone and Benzo[a]pyrene 1,6-quinone in Human Mammary Epithelial Cells

PubMed Central

Rodríguez-Fragoso, Lourdes; Melendez, Karla; Hudson, Laurie; Lauer, Fredine T.; Burchiel, Scott W.

2013-01-01

Benzo[a]pyrene (BaP) is activated by xenobiotic-metabolizing enzymes to highly mutagenic and carcinogenic metabolites. Previous studies in this laboratory have shown that benzo(a)pyrene quinones (BPQs), 1,6-BPQ and 3,6-BPQ, are able to induce epidermal growth factor receptor (EGFR) cell signaling through the production of reactive oxygen species. Recently, we have reported that BPQs have the potential to induce the expression of genes involved in numerous pathways associated with cell proliferation and survival in human mammary epithelial cells. In the present study we demonstrated that BPQs not only induced EGFR tyrosine autophosphorylation, but also induced EGFR-dependent tyrosine phosphorylation of phospholipase C-γ1 and several signal transducers and activators of transcription (STATs). The effects of BPQs were evaluated in a model of EGF withdrawal in MCF10-A cells. We found that BPQs (1 μM), induced EGFR tyrosine phosphorylation at positions Y845, Y992, Y1068, and Y1086. PLC-γ1 phosphorylation correlated with the phosphorylation of tyrosine-Y992, a proposed docking site for PLC-γ1 on the EGFR. Additionally, we found that BPQs induced the activation of STAT-1, STAT-3, STAT-5a and STAT-5b. STAT5 was shown to translocate to the nucleus following 3,6-BPQ and 1,6-BPQ exposures. Although the pattern of phosphorylation at EGFR, PLC-γ1 and STATs were quite similar to those induced by EGF, an important difference between BPQ-mediated signaling of the EGFR was observed. Signaling produced by EGF ligand produced a rapid disappearance of EGFR from the cell surface, whereas BPQ signaling maintained EGFR receptors on the cell membrane. Thus, the results of these studies show that 1,6-BPQ and 3,6-BPQ can produce early events as evidenced by EGFR expression, and a prolonged transactivation of EGFR leading to downstream cell signaling pathways. PMID:19166869

EGF-receptor phosphorylation and downstream signaling are activated by benzo[a]pyrene 3,6-quinone and benzo[a]pyrene 1,6-quinone in human mammary epithelial cells.

PubMed

Rodríguez-Fragoso, Lourdes; Melendez, Karla; Hudson, Laurie G; Lauer, Fredine T; Burchiel, Scott W

2009-03-15

Benzo[a]pyrene (BaP) is activated by xenobiotic-metabolizing enzymes to highly mutagenic and carcinogenic metabolites. Previous studies in this laboratory have shown that benzo[a]pyrene quinones (BPQs), 1,6-BPQ and 3,6-BPQ, are able to induce epidermal growth factor receptor (EGFR) cell signaling through the production of reactive oxygen species. Recently, we have reported that BPQs have the potential to induce the expression of genes involved in numerous pathways associated with cell proliferation and survival in human mammary epithelial cells. In the present study we demonstrated that BPQs not only induced EGFR tyrosine autophosphorylation, but also induced EGFR-dependent tyrosine phosphorylation of phospholipase C-gamma1 and several signal transducers and activators of transcription (STATs). The effects of BPQs were evaluated in a model of EGF withdrawal in MCF10-A cells. We found that BPQs (1 muM), induced EGFR tyrosine phosphorylation at positions Y845, Y992, Y1068, and Y1086. PLC-gamma1 phosphorylation correlated with the phosphorylation of tyrosine-Y992, a proposed docking site for PLC-gamma1 on the EGFR. Additionally, we found that BPQs induced the activation of STAT-1, STAT-3, STAT-5a and STAT-5b. STAT5 was shown to translocate to the nucleus following 3,6-BPQ and 1,6-BPQ exposures. Although the patterns of phosphorylation at EGFR, PLC-gamma1 and STATs were quite similar to those induced by EGF, an important difference between BPQ-mediated signaling of the EGFR was observed. Signaling produced by EGF ligand produced a rapid disappearance of EGFR from the cell surface, whereas BPQ signaling maintained EGFR receptors on the cell membrane. Thus, the results of these studies show that 1,6-BPQ and 3,6-BPQ can produce early events as evidenced by EGFR expression, and a prolonged transactivation of EGFR leading to downstream cell signaling pathways.

Restraint Stress Inhibits Mouse Implantation: Temporal Window and the Involvement of HB-EGF, Estrogen and Progesterone

PubMed Central

Yuan, Hong-Jie; Liang, Bo; Zheng, Liang-Liang; Liu, Yu-Xiang; Luo, Ming-Jiu; Tan, Jing-He

2013-01-01

It is known that psychological stress affects reproduction in women, but it is unknown whether the effect is by impairing implantation. Although studies suggest that long periods of auditory or restraint stress may inhibit implantation in rats and mice, the exact stage of pregnancy at which stress impairs implantation is unclear. Furthermore, whether stress impairs implantation by decreasing the heparin-binding epidermal growth factor-like growth factor (HB-EGF), estrogen and/or progesterone and whether by acting on embryos or on the uterus need further investigations. In this study, a 24-h restraint stress was initiated at 15:30 of day 3 (regimen 1) or at 07:30 (regimen 2) or 15:30 of day 4 (regimen 3) of pregnancy (vaginal plug  =  day 1) to observe effects of restraint stress applied at different peri-implantation stages on implantation. Among the three regimens, whereas regimens 1 and 3 affected neither term pregnancy nor litter size, regimen 2 reduced both. Further observations indicated that regimen 2 of restraint stress also delayed blastocyst hatching and the attachment reaction, decreased serum concentrations of progesterone and estradiol, and down regulated the expression of HB-EGF in both the endometrium and blastocysts. Taken together, the results suggested that restraint stress inhibited mouse implantation in a temporal window-dependent manner and by impairing blastocyst activation and hatching and uterine receptivity via down-regulating HB-EGF, estrogen and progesterone. Thus, the stress applied within the implantation window impaired implantation by acting on both embryos and the uterus. PMID:24244689

Synthesis and characterization of N-parinaroyl analogs of ganglioside GM3 and de-N-acetyl GM3. Interactions with the EGF receptor kinase

NASA Technical Reports Server (NTRS)

Song, W.; Welti, R.; Hafner-Strauss, S.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

1993-01-01

A specific plasma membrane glycosphingolipid, known as ganglioside GM3, can regulate the intrinsic tyrosyl kinase activity of the epidermal growth factor (EGF) receptor; this modulation is not associated with alterations in hormone binding to the receptor. GM3 inhibits EGF receptor tyrosyl kinase activity in detergent micelles, in plasma membrane vesicles, and in whole cells. In addition, immunoaffinity-purified EGF receptor preparations contain ganglioside GM3 (Hanai et al. (1988) J. Biol. Chem. 263, 10915-10921), implying that the glycosphingolipid is intimately associated with the receptor kinase in cell membranes. Both the nature of this association and the molecular mechanism of kinase inhibition remain to be elucidated. In this report, we describe the synthesis of a fluorescent analog of ganglioside GM3, in which the native fatty acid was replaced with trans-parinaric acid. This glycosphingolipid inhibited the receptor kinase activity in a manner similar to that of the native ganglioside. A modified fluorescent glycosphingolipid, N-trans-parinaroyl de-N-acetyl ganglioside GM3, was also prepared. This analog, like the nonfluorescent de-N-acetyl ganglioside GM3, had no effect on receptor kinase activity. Results from tryptophan fluorescence quenching and steady-state anisotropy measurements in membranes containing these fluorescent probes and the human EGF receptor were consistent with the notion that GM3, but not de-N-acetyl GM3, interacts specifically with the receptor in intact membranes.

64Cu-Labeled Trastuzumab Fab-PEG24-EGF Radioimmunoconjugates Bispecific for HER2 and EGFR: Pharmacokinetics, Biodistribution, and Tumor Imaging by PET in Comparison to Monospecific Agents.

PubMed

Kwon, Luke Yongkyu; Scollard, Deborah A; Reilly, Raymond M

2017-02-06

Heterodimerization of EGFR with HER2 coexpressed in breast cancer (BC) promotes tumor growth, and increased EGFR expression is associated with trastuzumab resistance. Our aim was to construct 64 Cu-labeled bispecific radioimmunoconjugates (bsRIC) composed of trastuzumab Fab, which binds HER2 linked through a polyethylene glycol (PEG 24 ) spacer to EGF, and to compare their pharmacokinetic, biodistribution, and tumor imaging characteristics by positron-emission tomography (PET). bsRICs were generated by linking maleimide modified trastuzumab Fab with thiolated EGF through a thioether bond. HER2 and EGFR binding were assessed in vitro in MDA-MB-231 (EGFR mod /HER2 low ), MDA-MB-468 (EGFR high /HER2 neg ), MDA-MB-231-H2N (EGFR mod /HER2 mod ), and SKOV3 (EGFR low /HER2 high ) cells by competition and saturation cell binding assays to estimate the dissociation constant (K d ). The elimination of the 64 Cu-NOTA-trastuzumab Fab-PEG 24 -EGF bsRICs from the blood of Balb/c mice was compared to monospecific 64 Cu-NOTA-trastuzumab Fab and 64 Cu-NOTA-EGF. MicroPET/CT imaging was performed in NOD/SCID mice bearing subcutaneous MDA-MB-468, MDA-MB-231/H2N, or SKOV3 human BC xenografts at 24 and 48 h postinjection (p.i.) of bsRICs. Tumor and normal tissue uptake were quantified by biodistribution studies and compared to monospecific agents. The binding of bsRICs to MDA-MB-231 cells was decreased to 24.5 ± 5.2% by excess EGF, while the binding of bsRICs to SKOV3 cells was decreased to 38.6 ± 5.4% by excess trastuzumab Fab, demonstrating specific binding to both EGFR and HER2. 64 Cu-labeled bsRICs incorporating the PEG 24 spacer were eliminated more slowly from the blood than 64 Cu-bsRICs without the PEG spacer and were cleared much more slowly than 64 Cu-NOTA-Fab or 64 Cu-NOTA-EGF. All three tumor xenografts were visualized by microPET/CT at 24 and 48 h p.i. of bsRICs. Biodistribution studies at 48 h p.i. in NOD/SCID mice with MDA-MB-231/H2N tumors demonstrated significantly

Regional control of Drosophila gut stem cell proliferation: EGF establishes GSSC proliferative set point & controls emergence from quiescence.

PubMed

Strand, Marie; Micchelli, Craig A

2013-01-01

Adult stem cells vary widely in their rates of proliferation. Some stem cells are constitutively active, while others divide only in response to injury. The mechanism controlling this differential proliferative set point is not well understood. The anterior-posterior (A/P) axis of the adult Drosophila midgut has a segmental organization, displaying physiological compartmentalization and region-specific epithelia. These distinct midgut regions are maintained by defined stem cell populations with unique division schedules, providing an excellent experimental model with which to investigate this question. Here, we focus on the quiescent gastric stem cells (GSSCs) of the acidic copper cell region (CCR), which exhibit the greatest period of latency between divisions of all characterized gut stem cells, to define the molecular basis of differential stem cell activity. Our molecular genetic analysis demonstrates that the mitogenic EGF signaling pathway is a limiting factor controlling GSSC proliferation. We find that under baseline conditions, when GSSCs are largely quiescent, the lowest levels of EGF ligands in the midgut are found in the CCR. However, acute epithelial injury by enteric pathogens leads to an increase in EGF ligand expression in the CCR and rapid expansion of the GSSC lineage. Thus, the unique proliferative set points for gut stem cells residing in physiologically distinct compartments are governed by regional control of niche signals along the A/P axis.

Multiple mechanisms of serotonin 5-HT2 receptor desensitization.

PubMed

Rahman, S; Neuman, R S

1993-07-20

Desensitization of serotonin 5-HT2 receptor-mediated enhancement of the N-methyl-D-aspartate (NMDA) depolarization was studied in rat cortical neurons. Serotonin and (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) induced long term desensitization. Staurosporine, a nonspecific protein kinase C inhibitor, potentiated the serotonin and DOI facilitation, suggesting acute desensitization was operative. In the case of DOI, long term desensitization was prevented by staurosporine. Activators of protein kinase C abolished the serotonin facilitation, an action prevented by staurosporine. Concanavalin A potentiated the facilitation at 100 microM, but not 30 microM serotonin, suggesting these receptors undergo dose dependent internalization. Calmodulin antagonists prevent long term desensitization induced by serotonin. The depolarization induced by NMDA alone was not altered by staurosporine, protein kinase C activators, concanavalin A or calmodulin antagonists. Serotonin at 100 microM, but not 30 microM, induced heterologous desensitization of phenylephrine and carbachol induced facilitation of the NMDA depolarization. We conclude that serotonin 5-HT2 receptors both induce and undergo several forms of desensitization.

Perform light and optic experiments in Augmented Reality

NASA Astrophysics Data System (ADS)

Wozniak, Peter; Vauderwange, Oliver; Curticapean, Dan; Javahiraly, Nicolas; Israel, Kai

2015-10-01

In many scientific studies lens experiments are part of the curriculum. The conducted experiments are meant to give the students a basic understanding for the laws of optics and its applications. Most of the experiments need special hardware like e.g. an optical bench, light sources, apertures and different lens types. Therefore it is not possible for the students to conduct any of the experiments outside of the university's laboratory. Simple optical software simulators enabling the students to virtually perform lens experiments already exist, but are mostly desktop or web browser based. Augmented Reality (AR) is a special case of mediated and mixed reality concepts, where computers are used to add, subtract or modify one's perception of reality. As a result of the success and widespread availability of handheld mobile devices, like e.g. tablet computers and smartphones, mobile augmented reality applications are easy to use. Augmented reality can be easily used to visualize a simulated optical bench. The students can interactively modify properties like e.g. lens type, lens curvature, lens diameter, lens refractive index and the positions of the instruments in space. Light rays can be visualized and promote an additional understanding of the laws of optics. An AR application like this is ideally suited to prepare the actual laboratory sessions and/or recap the teaching content. The authors will present their experience with handheld augmented reality applications and their possibilities for light and optic experiments without the needs for specialized optical hardware.

Proteomic Analysis of the Epidermal Growth Factor Receptor (EGFR) Interactome and Post-translational Modifications Associated with Receptor Endocytosis in Response to EGF and Stress*

PubMed Central

Tong, Jiefei; Taylor, Paul; Moran, Michael F.

2014-01-01

Aberrant expression, activation, and stabilization of epidermal growth factor receptor (EGFR) are causally associated with several human cancers. Post-translational modifications and protein-protein interactions directly modulate the signaling and trafficking of the EGFR. Activated EGFR is internalized by endocytosis and then either recycled back to the cell surface or degraded in the lysosome. EGFR internalization and recycling also occur in response to stresses that activate p38 MAP kinase. Mass spectrometry was applied to comprehensively analyze the phosphorylation, ubiquitination, and protein-protein interactions of wild type and endocytosis-defective EGFR variants before and after internalization in response to EGF ligand and stress. Prior to internalization, EGF-stimulated EGFR accumulated ubiquitin at 7 K residues and phosphorylation at 7 Y sites and at S1104. Following internalization, these modifications diminished and there was an accumulation of S/T phosphorylations. EGFR internalization and many but not all of the EGF-induced S/T phosphorylations were also stimulated by anisomycin-induced cell stress, which was not associated with receptor ubiquitination or elevated Y phosphorylation. EGFR protein interactions were dramatically modulated by ligand, internalization, and stress. In response to EGF, different E3 ubiquitin ligases became maximally associated with EGFR before (CBL, HUWE1, and UBR4) or after (ITCH) internalization, whereas CBLB was distinctively most highly EGFR associated following anisomycin treatment. Adaptin subunits of AP-1 and AP-2 clathrin adaptor complexes also became EGFR associated in response to EGF and anisomycin stress. Mutations preventing EGFR phosphorylation at Y998 or in the S1039 region abolished or greatly reduced EGFR interactions with AP-2 and AP-1, and impaired receptor trafficking. These results provide new insight into spatial, temporal, and mechanistic aspects of EGFR regulation. PMID:24797263

FGF/EGF signaling regulates the renewal of early nephron progenitors during embryonic development.

PubMed

Brown, Aaron C; Adams, Derek; de Caestecker, Mark; Yang, Xuehui; Friesel, Robert; Oxburgh, Leif

2011-12-01

Recent studies indicate that nephron progenitor cells of the embryonic kidney are arranged in a series of compartments of an increasing state of differentiation. The earliest progenitor compartment, distinguished by expression of CITED1, possesses greater capacity for renewal and differentiation than later compartments. Signaling events governing progression of nephron progenitor cells through stages of increasing differentiation are poorly understood, and their elucidation will provide key insights into normal and dysregulated nephrogenesis, as well as into regenerative processes that follow kidney injury. In this study, we found that the mouse CITED1(+) progenitor compartment is maintained in response to receptor tyrosine kinase (RTK) ligands that activate both FGF and EGF receptors. This RTK signaling function is dependent on RAS and PI3K signaling but not ERK. In vivo, RAS inactivation by expression of sprouty 1 (Spry1) in CITED1(+) nephron progenitors results in loss of characteristic molecular marker expression and in increased death of progenitor cells. Lineage tracing shows that surviving Spry1-expressing progenitor cells are impaired in their subsequent epithelial differentiation, infrequently contributing to epithelial structures. These findings demonstrate that the survival and developmental potential of cells in the earliest embryonic nephron progenitor cell compartment are dependent on FGF/EGF signaling through RAS.

Polycystin-1 promotes PKC{alpha}-mediated NF-{kappa}B activation in kidney cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banzi, Manuela; Aguiari, Gianluca; Trimi, Viky

2006-11-17

Polycystin-1 (PC1), the PKD1 gene product, is a membrane receptor which regulates many cell functions, including cell proliferation and apoptosis, both typically increased in cyst lining cells in autosomal dominant polycystic kidney disease. Here we show that PC1 upregulates the NF-{kappa}B signalling pathway in kidney cells to prevent cell death. Human embryonic kidney cell lines (HEK293{sup CTT}), stably expressing a PC1 cytoplasmic terminal tail (CTT), presented increased NF-{kappa}B nuclear levels and NF-{kappa}B-mediated luciferase promoter activity. This, consistently, was reduced in HEK293 cells in which the endogenous PC1 was depleted by RNA interference. CTT-dependent NF-{kappa}B promoter activation was mediated by PKC{alpha}more » because it was blocked by its specific inhibitor Ro-320432. Furthermore, it was observed that apoptosis, which was increased in PC1-depleted cells, was reduced in HEK293{sup CTT} cells and in porcine kidney LtTA cells expressing a doxycycline-regulated CTT. Staurosporine, a PKC inhibitor, and parthenolide, a NF-{kappa}B inhibitor, significantly reduced the CTT-dependent antiapoptotic effect. These data reveal, therefore, a novel pathway by which polycystin-1 activates a PKC{alpha}-mediated NF-{kappa}B signalling and cell survival.« less

Hair growth is promoted by BeauTop via expression of EGF and FGF-7

PubMed Central

Lee, Chien-Ying; Yang, Chi-Yu; Lin, Ching-Che; Yu, Min-Chien; Sheu, Shuenn-Jyi; Kuan, Yu-Hsiang

2018-01-01

Minoxidil and finasteride have been approved to treat hair loss by the Food and Drug Administration. However, the further elucidation of treatments for hair loss, including those using Chinese herbal medicine, remains important clinically. BeauTop (BT) is a health food supplement which contains Ginseng radix, Astragali radix, Radix Angelicae sinensis, Ligustri fructus, Rehmannia glutinosa and Eclipta prostrata (Linn). Susbsequent to oral administration of BT at 0.6 g/kg/day to wax/rosin-induced alopecia in C57BL/6 mice, BT significantly induced hair growth at day 8 compared with control treatment (P<0.05). The expression levels of epidermal growth factor (EGF), and fibroblast growth factor (FGF)-7 were increased compared with control animals on day 8. In contrast, levels of FGF-5 of the BT group were reduced compared with the control on day 12. There were no effects on the expression of insulin-like growth factor 1. The results demonstrated that the mechanism of BT improving alopecia is potentially associated with modulation of EGF and FGF-7 levels. Taken together, it is suggested that BT may have a potential effect of the promotion of hair growth. PMID:29693180

Ribozyme-mediated signal augmentation on a mass-sensitive biosensor.

PubMed

Knudsen, Scott M; Lee, Joonhyung; Ellington, Andrew D; Savran, Cagri A

2006-12-20

Mass-based detection methods such as the quartz crystal microbalance (QCM) offer an attractive option to label-based methods; however the sensitivity is generally lower by comparison. In particular, low-molecular-weight analytes can be difficult to detect based on mass addition alone. In this communication, we present the use of effector-dependent ribozymes (aptazymes) as reagents for augmenting small ligand detection on a mass-sensitive device. Two distinct aptazymes were chosen: an L1-ligase-based aptazyme (L1-Rev), which is activated by a small peptide (MW approximately 2.4 kDa) from the HIV-1 Rev protein, and a hammerhead cleavase-based aptazyme (HH-theo3) activated by theophylline (MW = 180 Da). Aptazyme activity was observed in real time, and low-molecular-weight analyte detection has been successfully demonstrated with both aptazymes.

Stathmin decreases cholangiocarcinoma cell line sensitivity to staurosporine-triggered apoptosis via the induction of ERK and Akt signaling.

PubMed

Wang, Yueqi; Gao, Zhihui; Zhang, Dexiang; Bo, Xiaobo; Wang, Yaojie; Wang, Jiwen; Shen, Sheng; Liu, Han; Suo, Tao; Pan, Hongtao; Ai, Zhilong; Liu, Houbao

2017-02-28

Cholangiocarcinoma is a rare, but highly fatal malignancy. However, the intrinsic mechanism involved in its tumorigenesis remains obscure. An urgent need remains for a promising target for cholangiocarcinoma biological therapies. Based on comparative proteomical technologies, we found 253 and 231 different spots in gallbladder tumor cell lines and cholangiocarcinoma cell lines, respectively, relative to non-malignant cells. Using Mass Spectrometry (MS) and database searching, we chose seven differentially expressed proteins. High Stathmin expression was found in both cholangiocarcinoma and gallbladder carcinoma cells. Stathmin expression was validated using immunohistochemistry and western blot in cholangiocarcinoma tissue samples and peritumoral tissue. It was further revealed that high Stathmin expression was associated with the repression of staurosporine-induced apoptosis in the cholangiocarcinoma cell. Moreover, we found that Stathmin promoted cancer cell proliferation and inhibited its apoptosis through protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) signaling. Integrin, β1 appears to serve as a partner of Stathmin induction of ERK and Akt signaling by inhibiting apoptosis in the cholangiocarcinoma cell. Understanding the regulation of anti-apoptosis effect by Stathmin might provide new insight into how to overcome therapeutic resistance in cholangiocarcinoma.

Secondary Breast Augmentation.

PubMed

Brown, Mitchell H; Somogyi, Ron B; Aggarwal, Shagun

2016-07-01

After studying this article, the participant should be able to: 1. Assess common clinical problems in the secondary breast augmentation patient. 2. Describe a treatment plan to correct the most common complications of breast augmentation. 3. Provide surgical and nonsurgical options for managing complications of breast augmentation. 4. Decrease the incidence of future complications through accurate assessment, preoperative planning, and precise surgical technique. Breast augmentation has been increasing steadily in popularity over the past three decades. Many of these patients present with secondary problems or complications following their primary breast augmentation. Two of the most common complications are capsular contracture and implant malposition. Familiarity and comfort with the assessment and management of these complications is necessary for all plastic surgeons. An up-to-date understanding of current devices and techniques may decrease the need to manage future complications from the current cohort of breast augmentation patients.

Chin augmentation

MedlinePlus

... page: //medlineplus.gov/ency/article/002986.htm Chin augmentation To use the sharing features on this page, please enable JavaScript. Chin augmentation is surgery to reshape or enhance the size ...

Eimeria maxima recombinant Gam82 gametocyte antigen vaccine protects against coccidiosis and augments humoral and cell-mediated immunity.

PubMed

Jang, Seung I; Lillehoj, Hyun S; Lee, Sung Hyen; Lee, Kyung Woo; Park, Myeong Seon; Cha, Sung-Rok; Lillehoj, Erik P; Subramanian, B Mohana; Sriraman, R; Srinivasan, V A

2010-04-09

Intestinal infection with Eimeria, the etiologic agent of avian coccidiosis, stimulates protective immunity to subsequent colonization by the homologous parasite, while cross-protection against heterologous species is poor. As a first step toward the development of a broad specificity Eimeria vaccine, this study was designed to assess a purified recombinant protein from Eimeria maxima gametocytes (Gam82) in stimulating immunity against experimental infection with live parasites. Following Gam82 intramuscular immunization and oral parasite challenge, body weight gain, fecal oocyst output, lesion scores, serum antibody response, and cytokine production were assessed to evaluate vaccination efficacy. Animals vaccinated with Gam82 and challenged with E. maxima showed lower oocyst shedding and reduced intestinal pathology compared with non-vaccinated and parasite-challenged animals. Gam82 vaccination also stimulated the production of antigen-specific serum antibodies and induced greater levels of IL-2 and IL-15 mRNAs compared with non-vaccinated controls. These results demonstrate that the Gam82 recombinant protein protects against E. maxima and augments humoral and cell-mediated immunity. Published by Elsevier Ltd.

ANALYSIS OF ANDROGEN- AND EGF-RECEPTOR EXPRESSION IN THE FETAL RAT PHALLUS AFTER EXPOSURE TO VINCLOZOLIN

EPA Science Inventory

Analysis of Androgen- and EGF-Receptor Expression in the Fetal Rat Phallus After Exposure to Vinclozolin
Cynthia Wolf1,2, Barbara Abbott1, Gerald A. LeBlanc2, and L. Earl Gray, Jr.1
1USEPA, ORD, NHEERL, RTD, RTP, NC 27711, 2NCSU, Environmental and Molecular Toxicology, Ral...

A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study

PubMed Central

2014-01-01

Background This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model. Methods Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar. Results Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group. Conclusions Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and

Endogenous flow-induced superoxide stimulates Na/H exchange activity via PKC in thick ascending limbs

PubMed Central

Garvin, Jeffrey L.

2014-01-01

Luminal flow stimulates Na reabsorption along the nephron and activates protein kinase C (PKC) which enhances endogenous superoxide (O2−) production by thick ascending limbs (TALs). Exogenously-added O2− augments TAL Na reabsorption, a process also dependent on PKC. Luminal Na/H exchange (NHE) mediates NaHCO3 reabsorption. However, whether flow-stimulated, endogenously-produced O2− enhances luminal NHE activity and the signaling pathway involved are unclear. We hypothesized that flow-induced production of endogenous O2− stimulates luminal NHE activity via PKC in TALs. Intracellular pH recovery was measured as an indicator of NHE activity in isolated, perfused rat TALs. Increasing luminal flow from 5 to 20 nl/min enhanced total NHE activity from 0.104 ± 0.031 to 0.167 ± 0.036 pH U/min, 81%. The O2− scavenger tempol decreased total NHE activity by 0.066 ± 0.011 pH U/min at 20 nl/min but had no significant effect at 5 nl/min. With the NHE inhibitor EIPA in the bath to block basolateral NHE, tempol reduced flow-enhanced luminal NHE activity by 0.029 ± 0.010 pH U/min, 30%. When experiments were repeated with staurosporine, a nonselective PKC inhibitor, tempol had no effect. Because PKC could mediate both induction of O2− by flow and the effect of O2− on luminal NHE activity, we used hypoxanthine/xanthine oxidase to elevate O2−. Hypoxanthine/xanthine oxidase increased luminal NHE activity by 0.099 ± 0.020 pH U/min, 137%. Staurosporine and the PKCα/β1-specific inhibitor Gö6976 blunted this effect. We conclude that flow-induced O2− stimulates luminal NHE activity in TALs via PKCα/β1. This accounts for part of flow-stimulated bicarbonate reabsorption by TALs. PMID:25080525

Relaxin augments the inflammatory IL6 response in the choriodecidua

PubMed Central

JS, Horton; SY, Yamamoto; GD, Bryant-Greenwood

2012-01-01

Intrauterine infection frequently leads to preterm birth (PTB), with the pathophysiology involving activation of the innate immune system and its associated inflammatory response. The choriodecidua produces relaxin (RLN) and elevated levels are associated with preterm premature rupture of the fetal membranes. However, it is not increased in bacterially-mediated PTB, but may act as an endogenous sterile inflammatory mediator. Elevated systemic RLN levels from the corpus luteum are also associated with PTB, but the mechanism is unknown. In clinical obstetrics, intrauterine inflammation or infection can coexist with elevated RLN. Therefore, in this study, we further characterized the effects of RLN alone or together with an inflammatory mediator on the production of IL1B, CSF2 (GM-CSF), IL6, IL8 and TNF, from chorionic cytotrophoblasts (CyT), decidual fibroblasts (DF) and stromal cells (DSC), using interleukin-1 beta (IL1B) to mimic sterile inflammation or lipopolysaccharide (LPS) for bacterial infection. Endogenous differences between the cells showed that the CyT expressed more and the RXFP1, its receptor RXFP1 splice variant D. CyT also showed the most robust cAMP response to RLN with increased IL6 secreted after 4 h, preceded by increased transcription at 1 h, likely due to activation of RXFP1 and cAMP. When all cell types were treated with IL1B and RLN, RLN augmented secretion of IL6 and IL8 from CyT and DF, but not DSC. Similarly, RLN augmented LPS-induced IL6 secretion from CyT and DF. Despite the structural similarity between TLR4 and RXFP1, blocking TLR4 in CyT had no effect on RLN-induced IL6 secretion, suggesting specific activation of RXFP1. Thus, we have shown that in the presence of a low level of intrauterine inflammation/infection, elevated RLN could act on the CyT and DF to augment the inflammatory response, contributing to the pathophysiology of PTB. PMID:22386961

Dioscin augments HSV-tk-mediated suicide gene therapy for melanoma by promoting connexin-based intercellular communication

PubMed Central

Li, Bin; Wu, Yingya; Liu, Xijuan; Tan, Yuhui; Du, Biaoyan

2017-01-01

Suicide gene therapy is a promising strategy against melanoma. However, the low efficiency of the gene transfer technique can limit its application. Our preliminary data showed that dioscin, a glucoside saponin, could upregulate the expression of connexins Cx26 and Cx43, major components of gap junctions, in melanoma cells. We hypothesized that dioscin may increase the bystander effect of herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) through increasing the formation of gap junctions. Further analysis showed that dioscin indeed could increase the gap junctional intercellular communication in B16 melanoma cells, resulting in more efficient GCV-induced bystander killing in B16tk cells. By contrast, overexpression of dominant negative Cx43 impaired the cell-cell communication of B16 cells and subsequently weakened the bystander effect of HSV-tk/GCV gene therapy. In vivo, combination treatment with dioscin and GCV of tumor-bearing mice with 30% positive B16tk cells and 70% wild-type B16 cells caused a significant reduction in tumor volume and weight compared to treatment with GCV or dioscin alone. Taken together, these results demonstrated that dioscin could augment the bystander effect of the HSV-tk/GCV system through increasing connexin-mediated gap junction coupling. PMID:27903977

EGF receptor-targeting peptide conjugate incorporating a near-IR fluorescent dye and a novel 1,4,7-triazacyclononane-based (64)Cu(II) chelator assembled via click chemistry.

PubMed

Viehweger, Katrin; Barbaro, Lisa; García, Karina Pombo; Joshi, Tanmaya; Geipel, Gerhard; Steinbach, Jörg; Stephan, Holger; Spiccia, Leone; Graham, Bim

2014-05-21

A new Boc-protected 1,4,7-triazacyclononane (TACN)-based pro-chelator compound featuring a "clickable" azidomethylpyridine pendant has been developed as a building block for the construction of multimodal imaging agents. Conjugation to a model alkyne (propargyl alcohol), followed by deprotection, generates a pentadentate ligand, as confirmed by X-ray crystallographic analysis of the corresponding distorted square-pyramidal Cu(II) complex. The ligand exhibits rapid (64)Cu(II)-binding kinetics (>95% radiochemical yield in <5 min) and a high resistance to demetalation. It may thus prove suitable for use in (64)Cu(II)-based in vivo positron emission tomography (PET). The new chelating building block has been applied to the construction of a bimodal (PET/fluorescence) peptide-based imaging probe targeting the epidermal growth factor (EGF) receptor, which is highly overexpressed on the surface of several types of cancer cells. The probe consists of a hexapeptide sequence, Leu-Ala-Arg-Leu-Leu-Thr (designated "D4"), followed by a Cys-β-Ala-β-Ala spacer, then a β-homopropargylglycine residue with the TACN-based chelator "clicked" to its side chain. A sulfonated near-infrared (NIR) fluorescent cyanine dye (sulfo-Cy5) was introduced at the N-terminus to study the EGF receptor-binding ability of the probe by laser-fluorescence spectroscopy. Binding was also confirmed by coimmunoprecipitation methods, and an apparent dissociation constant (Kd) of ca. 10 nM was determined from radioactivity-based measurements of probe binding to two EGF receptor-expressing cell lines (FaDu and A431). The probe is shown to be a biased or partial allosteric agonist of the EGF receptor, inducing phosphorylation of Thr669 and Tyr992, but not the Tyr845, Tyr998, Tyr1045, Tyr1068, or Tyr1148 residues of the receptor, in the absence of the orthosteric EGF ligand. Additionally, the probe was found to suppress the EGF-stimulated autophosphorylation of these latter residues, indicating that it is also

Epidermal growth factor improves survival and prevents intestinal injury in a murine model of Pseudomonas aeruginosa pneumonia

PubMed Central

Dominguez, Jessica A.; Vithayathil, Paul J.; Khailova, Ludmila; Lawrance, Christopher P.; Samocha, Alexandr J.; Jung, Enjae; Leathersich, Ann M.; Dunne, W. Michael; Coopersmith, Craig M.

2011-01-01

Mortality from pneumonia is mediated, in part, through extrapulmonary causes. Epidermal growth factor (EGF) has broad cytoprotective effects, including potent restorative properties in the injured intestine. The purpose of this study was to determine the efficacy of EGF treatment following Pseudomonas aeruginosa pneumonia. FVB/N mice underwent intratracheal injection of either Pseudomonas aeruginosa or saline and were then randomized to receive either systemic EGF or vehicle beginning immediately or 24 hours after the onset of pneumonia. Systemic EGF decreased seven-day mortality from 65% to 10% when initiated immediately after the onset of pneumonia and to 27% when initiated 24 hours after the onset of pneumonia. Even though injury in pneumonia is initiated in the lungs, the survival advantage conferred by EGF was not associated with improvements in pulmonary pathology. In contrast, EGF prevented intestinal injury by reversing pneumonia-induced increases in intestinal epithelial apoptosis and decreases in intestinal proliferation and villus length. Systemic cytokines, kidney and liver function were unaffected by EGF therapy although EGF decreased pneumonia-induced splenocyte apoptosis. To determine whether the intestine was sufficient to account for extrapulmonary effects induced by EGF, a separate set of experiments were done using transgenic mice with enterocyte-specific overexpression of EGF (IFABP-EGF mice) which were compared to WT mice subjected to pneumonia. IFABP-EGF mice had improved survival compared to WT mice following pneumonia (50% vs. 28% respectively, p<0.05) and were protected from pneumonia-induced intestinal injury. Thus, EGF may be a potential adjunctive therapy for pneumonia, mediated in part by its effects on the intestine. PMID:21701422

G protein-coupled receptor 30 expression is up-regulated by EGF and TGF alpha in estrogen receptor alpha-positive cancer cells.

PubMed

Vivacqua, Adele; Lappano, Rosamaria; De Marco, Paola; Sisci, Diego; Aquila, Saveria; De Amicis, Francesca; Fuqua, Suzanne A W; Andò, Sebastiano; Maggiolini, Marcello

2009-11-01

In the present study, we evaluated the regulation of G protein-coupled receptor (GPR)30 expression in estrogen receptor (ER)-positive endometrial, ovarian, and estrogen-sensitive, as well as tamoxifen-resistant breast cancer cells. We demonstrate that epidermal growth factor (EGF) and TGF alpha transactivate the GPR30 promoter and accordingly up-regulate GPR30 mRNA and protein levels only in endometrial and tamoxifen-resistant breast cancer cells. These effects exerted by EGF and TGF alpha were dependent on EGF receptor (EGFR) expression and activation and involved phosphorylation of the Tyr(1045) and Tyr(1173) EGFR sites. Using gene-silencing experiments and specific pharmacological inhibitors, we have ascertained that EGF and TGF alpha induce GPR30 expression through the EGFR/ERK transduction pathway, and the recruitment of c-fos to the activator protein-1 site located within GPR30 promoter sequence. Interestingly, we show that functional cross talk of GPR30 with both activated EGFR and ER alpha relies on a physical interaction among these receptors, further extending the potential of estrogen to trigger a complex stimulatory signaling network in hormone-sensitive tumors. Given that EGFR/HER2 overexpression is associated with tamoxifen resistance, our data may suggest that ligand-activated EGFR could contribute to the failure of tamoxifen therapy also by up-regulating GPR30, which in turn could facilitates the action of estrogen. In addition, important for resistance is the ability of tamoxifen to bind to and activate GPR30, the expression of which is up-regulated by EGFR activation. Our results emphasize the need for new endocrine agents able to block widespread actions of estrogen without exerting any stimulatory activity on transduction pathways shared by the steroid and growth factor-signaling networks.

Comparative measurement of ghrelin, leptin, adiponectin, EGF and IGF-1 in breast milk of mothers with overweight/obese and normal-weight infants.

PubMed

Khodabakhshi, A; Ghayour-Mobarhan, M; Rooki, H; Vakili, R; Hashemy, S-I; Mirhafez, S R; Shakeri, M-T; Kashanifar, R; Pourbafarani, R; Mirzaei, H; Dahri, M; Mazidi, M; Ferns, G; Safarian, M

2015-05-01

Obese infants are more susceptible to develop adulthood obesity and its related comorbidities. Previous studies have shown the presence of hormones and growth factors in maternal breast milk that may influence infant adiposity. The aim of this study was to investigate differences in concentrations of three hormones and two growth factors in the breast milk of mothers with obese and non-obese infants. In this cross-sectional study, 40 mothers with overweight or obese infants (weight for length percentile >97) and 40 age-matched mothers with normal-weight infant (-10 < weight for length percentile < 85) who were between 2 and 5 months of age were enrolled. Anthropometric indices of infants and mothers were measured by routine methods. Breast milk concentrations of ghrelin and adiponectin, leptin, epithelial growth factor (EGF) and insulin-like growth factor-1 (IGF-1) were measured using enzyme-linked immunosorbent assay methods. The mean breast milk concentration of ghrelin was higher in mothers with normal-weight infants, 137.50 pg/ml, than in mothers with obese infants, 132.00 pg/ml (P=0.001). This was also true regarding the concentration of EGF in mothers with (0/04 ng/ml) and without (0/038 ng/ml) normal-weight infants (P=0.01). No significant differences were observed in concentrations of leptin, adiponectin and IGF-1 between two groups (P > 0.05). There was also a significant positive correlation between EGF and ghrelin in both groups. This study revealed that there was a correlation between ghrelin and EGF level in breast milk of mothers with obese and non-obese infants, suggesting a possible regulatory effect of these two hormones on weight in infants.

Coordinated Pulses of mRNA and of Protein Translation or Degradation Produce EGF-Induced Protein Bursts.

PubMed

Golan-Lavi, Roni; Giacomelli, Chiara; Fuks, Garold; Zeisel, Amit; Sonntag, Johanna; Sinha, Sanchari; Köstler, Wolfgang; Wiemann, Stefan; Korf, Ulrike; Yarden, Yosef; Domany, Eytan

2017-03-28

Protein responses to extracellular cues are governed by gene transcription, mRNA degradation and translation, and protein degradation. In order to understand how these time-dependent processes cooperate to generate dynamic responses, we analyzed the response of human mammary cells to the epidermal growth factor (EGF). Integrating time-dependent transcript and protein data into a mathematical model, we inferred for several proteins their pre-and post-stimulus translation and degradation coefficients and found that they exhibit complex, time-dependent variation. Specifically, we identified strategies of protein production and degradation acting in concert to generate rapid, transient protein bursts in response to EGF. Remarkably, for some proteins, for which the response necessitates rapidly decreased abundance, cells exhibit a transient increase in the corresponding degradation coefficient. Our model and analysis allow inference of the kinetics of mRNA translation and protein degradation, without perturbing cells, and open a way to understanding the fundamental processes governing time-dependent protein abundance profiles. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Hair growth is promoted by BeauTop via expression of EGF and FGF‑7.

PubMed

Lee, Chien-Ying; Yang, Chi-Yu; Lin, Ching-Che; Yu, Min-Chien; Sheu, Shuenn-Jyi; Kuan, Yu-Hsiang

2018-06-01

Minoxidil and finasteride have been approved to treat hair loss by the Food and Drug Administration. However, the further elucidation of treatments for hair loss, including those using Chinese herbal medicine, remains important clinically. BeauTop (BT) is a health food supplement which contains Ginseng radix, Astragali radix, Radix Angelicae sinensis, Ligustri fructus, Rehmannia glutinosa and Eclipta prostrata (Linn). Susbsequent to oral administration of BT at 0.6 g/kg/day to wax/rosin‑induced alopecia in C57BL/6 mice, BT significantly induced hair growth at day 8 compared with control treatment (P<0.05). The expression levels of epidermal growth factor (EGF), and fibroblast growth factor (FGF)‑7 were increased compared with control animals on day 8. In contrast, levels of FGF‑5 of the BT group were reduced compared with the control on day 12. There were no effects on the expression of insulin‑like growth factor 1. The results demonstrated that the mechanism of BT improving alopecia is potentially associated with modulation of EGF and FGF‑7 levels. Taken together, it is suggested that BT may have a potential effect of the promotion of hair growth.

Epidermal growth factor improves survival and prevents intestinal injury in a murine model of pseudomonas aeruginosa pneumonia.

PubMed

Dominguez, Jessica A; Vithayathil, Paul J; Khailova, Ludmila; Lawrance, Christopher P; Samocha, Alexandr J; Jung, Enjae; Leathersich, Ann M; Dunne, W Michael; Coopersmith, Craig M

2011-10-01

Mortality from pneumonia is mediated, in part, through extrapulmonary causes. Epidermal growth factor (EGF) has broad cytoprotective effects, including potent restorative properties in the injured intestine. The purpose of this study was to determine the efficacy of EGF treatment following Pseudomonas aeruginosa pneumonia. FVB/N mice underwent intratracheal injection of either P. aeruginosa or saline and were then randomized to receive either systemic EGF or vehicle beginning immediately or 24 h after the onset of pneumonia. Systemic EGF decreased 7-day mortality from 65% to 10% when initiated immediately after the onset of pneumonia and to 27% when initiated 24 h after the onset of pneumonia. Even though injury in pneumonia is initiated in the lungs, the survival advantage conferred by EGF was not associated with improvements in pulmonary pathology. In contrast, EGF prevented intestinal injury by reversing pneumonia-induced increases in intestinal epithelial apoptosis and decreases in intestinal proliferation and villus length. Systemic cytokines and kidney and liver function were unaffected by EGF therapy, although EGF decreased pneumonia-induced splenocyte apoptosis. To determine whether the intestine was sufficient to account for extrapulmonary effects induced by EGF, a separate set of experiments was done using transgenic mice with enterocyte-specific overexpression of EGF (IFABP-EGF [intestinal fatty acid-binding protein linked to mouse EGF] mice), which were compared with wild-type mice subjected to pneumonia. IFABP-EGF mice had improved survival compared with wild-type mice following pneumonia (50% vs. 28%, respectively, P < 0.05) and were protected from pneumonia-induced intestinal injury. Thus, EGF may be a potential adjunctive therapy for pneumonia, mediated in part by its effects on the intestine.

Overexpression of Heparin-Binding Epidermal Growth Factor-Like Growth Factor Mediates Liver Fibrosis in Transgenic Mice.

PubMed

Guo, Yongze; Ding, Qian; Chen, Lei; Ji, Chenguang; Hao, Huiyao; Wang, Jia; Qi, Wei; Xie, Xiaoli; Ma, Junji; Li, Aidi; Jiang, Xiaoyu; Li, Xiaotian; Jiang, Huiqing

2017-08-01

The role of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in liver fibrosis is not clear and is sometimes even contradictory. To clarify this role, a HB-EGF transgenic (Tg) mouse model was, for the first time, used to evaluate the functions of HB-EGF in liver fibrosis. For the in vivo study, carbon tetrachloride injection and bile duct ligation treatment were used to induce liver fibrosis in HB-EGF Tg mice and wild-type (WT) mice, respectively. Primary hepatic satellite cells (HSCs) were isolated from HB-EGF Tg and WT mice for the in vitro study. Compared with the WT mice, HB-EGF Tg mice were shown to develop more severe liver fibrosis when treated with carbon tetrachloride or bile duct ligation, with increased matrix metalloproteinases 13 activity and enhanced expression of fibrogenic genes including α-smooth muscle actin and collagen I. HB-EGF gene transfer led to an increase in proliferation and a decrease in apoptosis in primary HSCs. The ERK signaling pathway was more highly activated in primary HSCs from HB-EGF Tg mice than in those from WT mice. Our investigation confirmed the profibrotic effect of HB-EGF on the liver using a Tg mouse model. This result may contribute to the elucidation of HB-EGF as a therapeutic target in liver fibrosis. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Vitamin D fails to prevent serum starvation- or staurosporine-induced apoptosis in human and rat osteosarcoma-derived cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witasp, Erika; Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm; Gustafsson, Ann-Catrin

2005-05-13

Previous studies have suggested that 1,25(OH){sub 2}D{sub 3}, the active form of vitamin D{sub 3}, may increase the survival of bone-forming osteoblasts through an inhibition of apoptosis. On the other hand, vitamin D{sub 3} has also been shown to trigger apoptosis in human cancer cells, including osteosarcoma-derived cell lines. In the present study, we show that 1,25(OH){sub 2}D{sub 3} induces a time- and dose-dependent loss of cell viability in the rat osteosarcoma cell line, UMR-106, and the human osteosarcoma cell line, TE-85. We were unable, however, to detect nuclear condensation, phosphatidylserine externalization, or other typical signs of apoptosis in thismore » model. Moreover, 1,25(OH){sub 2}D{sub 3} failed to protect against apoptosis induced by serum starvation or incubation with the protein kinase inhibitor, staurosporine. These in vitro findings are thus at variance with several previous reports in the literature and suggest that induction of or protection against apoptosis of bone-derived cells may not be a primary function of vitamin D{sub 3}.« less

Bi-directional gap junction-mediated soma-germline communication is essential for spermatogenesis.

PubMed

Smendziuk, Christopher M; Messenberg, Anat; Vogl, A Wayne; Tanentzapf, Guy

2015-08-01

Soma-germline interactions play conserved essential roles in regulating cell proliferation, differentiation, patterning and homeostasis in the gonad. In the Drosophila testis, secreted signalling molecules of the JAK-STAT, Hedgehog, BMP and EGF pathways are used to mediate soma-germline communication. Here, we demonstrate that gap junctions may also mediate direct, bi-directional signalling between the soma and germ line. When gap junctions between the soma and germ line are disrupted, germline differentiation is blocked and germline stem cells are not maintained. In the soma, gap junctions are required to regulate proliferation and differentiation. Localization and RNAi-mediated knockdown studies reveal that gap junctions in the fly testis are heterotypic channels containing Zpg (Inx4) and Inx2 on the germ line and the soma side, respectively. Overall, our results show that bi-directional gap junction-mediated signalling is essential to coordinate the soma and germ line to ensure proper spermatogenesis in Drosophila. Moreover, we show that stem cell maintenance and differentiation in the testis are directed by gap junction-derived cues. © 2015. Published by The Company of Biologists Ltd.

Calmodulin kinase II and protein kinase C mediate the effect of increased intracellular calcium to augment late sodium current in rabbit ventricular myocytes.

PubMed

Ma, Jihua; Luo, Antao; Wu, Lin; Wan, Wei; Zhang, Peihua; Ren, Zhiqiang; Zhang, Shuo; Qian, Chunping; Shryock, John C; Belardinelli, Luiz

2012-04-15

An increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) augments late sodium current (I(Na.L)) in cardiomyocytes. This study tests the hypothesis that both Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) and protein kinase C (PKC) mediate the effect of increased [Ca(2+)](i) to increase I(Na.L). Whole cell and open cell-attached patch clamp techniques were used to record I(Na.L) in rabbit ventricular myocytes dialyzed with solutions containing various concentrations of [Ca(2+)](i). Dialysis of cells with [Ca(2+)](i) from 0.1 to 0.3, 0.6, and 1.0 μM increased I(Na.L) in a concentration-dependent manner from 0.221 ± 0.038 to 0.554 ± 0.045 pA/pF (n = 10, P < 0.01) and was associated with an increase in mean Na(+) channel open probability and prolongation of channel mean open-time (n = 7, P < 0.01). In the presence of 0.6 μM [Ca(2+)](i), KN-93 (10 μM) and bisindolylmaleimide (BIM, 2 μM) decreased I(Na.L) by 45.2 and 54.8%, respectively. The effects of KN-93 and autocamtide-2-related inhibitory peptide II (2 μM) were not different. A combination of KN-93 and BIM completely reversed the increase in I(Na.L) as well as the Ca(2+)-induced changes in Na(+) channel mean open probability and mean open-time induced by 0.6 μM [Ca(2+)](i). Phorbol myristoyl acetate increased I(Na.L) in myocytes dialyzed with 0.1 μM [Ca(2+)](i); the effect was abolished by Gö-6976. In summary, both CaMKII and PKC are involved in [Ca(2+)](i)-mediated augmentation of I(Na.L) in ventricular myocytes. Inhibition of CaMKII and/or PKC pathways may be a therapeutic target to reduce myocardial dysfunction and cardiac arrhythmias caused by calcium overload.

The SRC homology 2 domain of Rin1 mediates its binding to the epidermal growth factor receptor and regulates receptor endocytosis.

PubMed

Barbieri, M Alejandro; Kong, Chen; Chen, Pin-I; Horazdovsky, Bruce F; Stahl, Philip D

2003-08-22

Activated epidermal growth factor receptors (EGFRs) recruit intracellular proteins that mediate receptor signaling and endocytic trafficking. Rin1, a multifunctional protein, has been shown to regulate EGFR internalization (1). Here we show that EGF stimulation induces a specific, rapid, and transient membrane recruitment of Rin1 and that recruitment is dependent on the Src homology 2 (SH2) domain of Rin1. Immunoprecipitation of EGFR is accompanied by co-immunoprecipitation of Rin1 in a time- and ligand-dependent manner. Association of Rin1 and specifically the SH2 domain of Rin1 with the EGFR was dependent on tyrosine phosphorylation of the intracellular domain of the EGFR. The recruitment of Rin1, observed by light microscopy, indicated that although initially cytosolic, Rin1 was recruited to both plasma membrane and endosomes following EGF addition. Moreover, the expression of the SH2 domain of Rin1 substantially impaired the internalization of EGF without affecting internalization of transferrin. Finally, we found that Rin1 co-immunoprecipitated with a number of tyrosine kinase receptors but not with cargo endocytic receptors. These results indicate that Rin1 provides a link via its SH2 domain between activated tyrosine kinase receptors and the endocytic pathway through the recruitment and activation of Rab5a.

Epidermal growth factor treatment decreases mortality and is associated with improved gut integrity in sepsis

PubMed Central

Clark, Jessica A.; Clark, Andrew T.; Hotchkiss, Richard S.; Buchman, Timothy G.; Coopersmith, Craig M.

2007-01-01

Epidermal growth factor (EGF) is a cytoprotective peptide that has healing effects on the intestinal mucosa. We sought to determine whether systemic administration of EGF following the onset of sepsis improved intestinal integrity and decreased mortality. FVB/N mice were subjected to either sham laparotomy or 2×23 cecal ligation and puncture (CLP). Septic mice were further randomized to receive intraperitoneal injection of either 150 μg/kg/day EGF or 0.9% saline. Circulating EGF levels were decreased following CLP compared to sham animals but were unaffected by giving exogenous EGF treatment. In contrast, intestinal EGF levels increased following CLP, and were further augmented by exogenous EGF treatment. Intestinal EGF-receptor (EGF-R) was increased following CLP whether assayed by immunohistochemistry, real-time PCR or western blot, and exogenous EGF treatment decreased intestinal EGF-R. Villus length decreased 2-fold between sham and septic animals, and EGF treatment resulted in near total restitution of villus length. Sepsis decreased intestinal proliferation and increased intestinal apoptosis. This was accompanied by increased expression of the pro-apoptotic proteins Bid and FADD, as well as the cyclin-dependent kinase inhibitor p21cip1/waf. EGF treatment after the onset of sepsis restored both proliferation and apoptosis to levels seen in sham animals and normalized expression of Bid, FADD, and p21cip1/waf. To determine whether improvements in gut homeostasis were associated with a decrease in sepsis-induced mortality, septic mice with or without EGF treatment after CLP were followed seven days for survival. Mortality decreased from 60% to 30% in mice treated with EGF after the onset of sepsis (p<0.05). EGF may thus be a potential therapeutic agent for the treatment of sepsis, in part due to its ability to protect intestinal integrity. PMID:18004230

The role of peroxisome proliferator-activated receptor-{beta}/{delta} in epidermal growth factor-induced HaCaT cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang Pengfei; Jiang Bimei; Yang Xinghua

2008-10-15

Epidermal growth factor (EGF) has been shown to be a potent mitogen for epidermal cells both in vitro and in vivo, thus contributing to the development of an organism. It has recently become clear that peroxisome proliferator-activated receptor-{beta}/{delta} (PPAR{beta}/{delta}) expression and activation is involved in the cell proliferation. However, little is known about the role of PPAR{beta}/{delta} in EGF-induced proliferation of HaCaT keratinocytes. In this study, HaCaT cells were cultured in the presence and absence of EGF and we identified that EGF induced an increase of PPAR{beta}/{delta} mRNA and protein level expression in time-dependent and dose-dependent manner, and AG1487, anmore » EGF receptor (EGFR) special inhibitor, caused attenuation of PPAR{beta}/{delta} protein expression. Electrophoretic mobility shift assay (EMSA) revealed that EGF significantly increased PPAR{beta}/{delta} binding activity in HaCaT keratinocytes. Antisense phosphorothioate oligonucleotides (asODNs) against PPAR{beta}/{delta} caused selectively inhibition of PPAR{beta}/{delta} protein content induced by EGF and significantly attenuated EGF-mediated cell proliferation. Treatment of the cells with L165041, a specific synthetic ligand for PPAR{beta}/{delta}, significantly enhanced EGF-mediated cell proliferation. Finally, c-Jun ablation inhibited PPAR{beta}/{delta} up-regulation induced by EGF, and chromatin immunoprecipitation (ChIP) showed that c-Jun bound to the PPAR{beta}/{delta} promoter and the binding increased in EGF-stimulated cells. These results demonstrate that EGF induces PPAR{beta}/{delta} expression in a c-Jun-dependent manner and PPAR{beta}/{delta} plays a vital role in EGF-stimulated proliferation of HaCaT cells.« less

Function-specific intracellular signaling pathways downstream of heparin-binding EGF-like growth factor utilized by human trophoblasts.

PubMed

Jessmon, Philip; Kilburn, Brian A; Romero, Roberto; Leach, Richard E; Armant, D Randall

2010-05-01

Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1-2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation.

Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma.

PubMed

Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Guan, Shan; Woodfield, Sarah E; Vasudevan, Sanjeev A; Tao, Ling; Pang, Jonathan C; Lu, Jiaxiong; Zhang, Huiyuan; Zhang, Fuchun; Yang, Jianhua

2017-01-03

Neuroblastoma is the most common extracranial solid tumor in children. The ErbB family of proteins is a group of receptor tyrosine kinases that promote the progression of various malignant cancers including neuroblastoma. Thus, targeting them with small molecule inhibitors is a promising strategy for neuroblastoma therapy. In this study, we investigated the anti-tumor effect of afatinib, an irreversible inhibitor of members of the ErbB family, on neuroblastoma. We found that afatinib suppressed the proliferation and colony formation ability of neuroblastoma cell lines in a dose-dependent manner. Afatinib also induced apoptosis and blocked EGF-induced activation of PI3K/AKT/mTOR signaling in all neuroblastoma cell lines tested. In addition, afatinib enhanced doxorubicin-induced cytotoxicity in neuroblastoma cells, including the chemoresistant LA-N-6 cell line. Finally, afatinib exhibited antitumor efficacy in vivo by inducing apoptosis in an orthotopic xenograft neuroblastoma mouse model. Taken together, these results show that afatinib inhibits neuroblastoma growth both in vitro and in vivo by suppressing EGFR-mediated PI3K/AKT/mTOR signaling. Our study supports the idea that EGFR is a potential therapeutic target in neuroblastoma. And targeting ErbB family protein kinases with small molecule inhibitors like afatinib alone or in combination with doxorubicin is a viable option for treating neuroblastoma.

Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nanney, L.B.; Stoscheck, C.M.; Magid, M.

1986-03-01

Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normalmore » epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that (/sup 125/I)EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers.« less

TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF)

EPA Science Inventory

TITLE:
TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF). AUTHORS (ALL): Abbott, Barbara D.1; Best, Deborah S.1; Narotsky, Michael G.1. SPONSOR NAME: None INSTITUTIONS (ALL): 1. Repro Tox ...

Augmenting computer networks

NASA Technical Reports Server (NTRS)

Bokhari, S. H.; Raza, A. D.

1984-01-01

Three methods of augmenting computer networks by adding at most one link per processor are discussed: (1) A tree of N nodes may be augmented such that the resulting graph has diameter no greater than 4log sub 2((N+2)/3)-2. Thi O(N(3)) algorithm can be applied to any spanning tree of a connected graph to reduce the diameter of that graph to O(log N); (2) Given a binary tree T and a chain C of N nodes each, C may be augmented to produce C so that T is a subgraph of C. This algorithm is O(N) and may be used to produce augmented chains or rings that have diameter no greater than 2log sub 2((N+2)/3) and are planar; (3) Any rectangular two-dimensional 4 (8) nearest neighbor array of size N = 2(k) may be augmented so that it can emulate a single step shuffle-exchange network of size N/2 in 3(t) time steps.

EGF targeted fluorescence molecular tomography as a predictor of PDT outcomes in pancreas cancer models

NASA Astrophysics Data System (ADS)

Samkoe, Kimberley S.; Davis, Scott C.; Srinivasan, Subhadra; Isabelle, Martin E.; O'Hara, Julia; Hasan, Tayyaba; Pogue, Brian W.

2010-02-01

Verteporfin photodynamic therapy (PDT) is a promising adjuvant therapy for pancreas cancer and investigations for its use are currently underway in both orthotopic xenograft mouse models and in human clinical trials. The mouse models have been studied extensively using magnetic resonance (MR) imaging as a measure of surrogate response to verteporfin PDT and it was found that tumor lines with different levels of aggression respond with varying levels to PDT. MR imaging was successful in determining the necrotic volume caused by PDT but there was difficultly in distinguishing inflamed tissues and regions of surviving tumor. In order to understand the molecular changes within the tumor immediately post-PDT we propose the implementation of MR-guided fluorescence molecular tomography (FMT) in conjunction with an exogenously administered fluorescently labeled epidermal growth factor (EGF-IRDye800CW, LI-COR Biosciences). We have previously shown that MR-guided FMT is feasible in the mouse abdomen when multiple regions of fluorescence are considered from contributing internal organs. In this case the highly aggressive AsPC-1 (+EGFR) orthotopic tumor was implanted in SCID mice, interstitial verteporfin PDT (1mg/kg, 20J/cm) was performed when the tumor reached ~60mm3 and both tumor volume and EGF binding were followed with MR-guided FMT.

Epidermal growth factor treatment decreases mortality and is associated with improved gut integrity in sepsis.

PubMed

Clark, Jessica A; Clark, Andrew T; Hotchkiss, Richard S; Buchman, Timothy G; Coopersmith, Craig M

2008-07-01

Epidermal growth factor (EGF) is a cytoprotective peptide that has healing effects on the intestinal mucosa. We sought to determine whether systemic administration of EGF after the onset of sepsis improved intestinal integrity and decreased mortality. FVB/N mice were subjected to either sham laparotomy or 2 x 23 cecal ligation and puncture (CLP). Septic mice were further randomized to receive injection of either 150 microg kg(-1) d(-1) (i.p.) EGF or 0.9% saline (i.p.). Circulating EGF levels were decreased after CLP compared with sham animals but were unaffected by giving exogenous EGF treatment. In contrast, intestinal EGF levels increased after CLP and were further augmented by exogenous EGF treatment. Intestinal EGF receptor was increased after CLP, whether assayed by immunohistochemistry, real-time polymerase chain reaction, or Western blot, and exogenous EGF treatment decreased intestinal EGF receptor. Villus length decreased 2-fold between sham and septic animals, and EGF treatment resulted in near total restitution of villus length. Sepsis decreased intestinal proliferation and increased intestinal apoptosis. This was accompanied by increased expression of the proapoptotic proteins Bid and Fas-associated death domain, as well as the cyclin-dependent kinase inhibitor p21 cip1/waf Epidermal growth factor treatment after the onset of sepsis restored both proliferation and apoptosis to levels seen in sham animals and normalized expression of Bid, Fas-associated death domain, and p21 cip1/waf . To determine whether improvements in gut homeostasis were associated with a decrease in sepsis-induced mortality, septic mice with or without EGF treatment after CLP were followed 7 days for survival. Mortality decreased from 60% to 30% in mice treated with EGF after the onset of sepsis (P < 0.05). Thus, EGF may be a potential therapeutic agent for the treatment of sepsis in part due to its ability to protect intestinal integrity.

Control of Human Endometrial Stromal Cell Motility by PDGF-BB, HB-EGF and Trophoblast-Secreted Factors

PubMed Central

Schwenke, Maren; Knöfler, Martin; Velicky, Philipp; Weimar, Charlotte H. E.; Kruse, Michelle; Samalecos, Annemarie; Wolf, Anja; Macklon, Nick S.; Bamberger, Ana-Maria; Gellersen, Birgit

2013-01-01

Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of

Function-Specific Intracellular Signaling Pathways Downstream of Heparin-Binding EGF-Like Growth Factor Utilized by Human Trophoblasts1

PubMed Central

Jessmon, Philip; Kilburn, Brian A.; Romero, Roberto; Leach, Richard E.; Armant, D. Randall

2010-01-01

Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1–2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation. PMID:20130271

A role for calcium in the regulation of ATP-binding cassette, sub-family C, member 3 (ABCC3) gene expression in a model of epidermal growth factor-mediated breast cancer epithelial-mesenchymal transition.

PubMed

Stewart, Teneale A; Azimi, Iman; Thompson, Erik W; Roberts-Thomson, Sarah J; Monteith, Gregory R

2015-03-13

Epithelial-mesenchymal transition (EMT), a process implicated in cancer metastasis, is associated with the transcriptional regulation of members of the ATP-binding cassette superfamily of efflux pumps, and drug resistance in breast cancer cells. Epidermal growth factor (EGF)-induced EMT in MDA-MB-468 breast cancer cells is calcium signal dependent. In this study induction of EMT was shown to result in the transcriptional up-regulation of ATP-binding cassette, subfamily C, member 3 (ABCC3), a member of the ABC transporter superfamily, which has a recognized role in multidrug resistance. Buffering of cytosolic free calcium inhibited EGF-mediated ABCC3 increases, indicating a calcium-dependent mode of regulation. Silencing of TRPM7 (an ion channel involved in EMT associated vimentin induction) did not inhibit ABCC3 up-regulation. Silencing of the store operated calcium entry (SOCE) pathway components ORAI1 and STIM1 also did not alter ABCC3 induction by EGF. However, the calcium permeable ion channel transient receptor potential cation channel, subfamily C, member 1 (TRPC1) appears to contribute to the regulation of both basal and EGF-induced ABCC3 mRNA. Improved understanding of the relationship between calcium signaling, EMT and the regulation of genes important in therapeutic resistance may help identify novel therapeutic targets for breast cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

Angiotensin II initiates tyrosine kinase Pyk2-dependent signalings leading to activation of Rac1-mediated c-Jun NH2-terminal kinase.

PubMed

Murasawa, S; Matsubara, H; Mori, Y; Masaki, H; Tsutsumi, Y; Shibasaki, Y; Kitabayashi, I; Tanaka, Y; Fujiyama, S; Koyama, Y; Fujiyama, A; Iba, S; Iwasaka, T

2000-09-01

Ca(2+)-sensitive tyrosine kinase Pyk2 was shown to be involved in angiotensin (Ang) II-mediated activation of extracellular signal-regulated kinase (ERK) via transactivation of epidermal growth factor receptor (EGF-R). In this study, we tested the involvement of Pyk2 and EGF-R in Ang II-induced activation of JNK and c-Jun in cardiac fibroblasts. Ang II markedly stimulated JNK activities, which were abolished by genistein and intracellular Ca(2+) chelators but partially by protein kinase C depletion. Inhibition of EGF-R did not affect Pyk2 and JNK activation by Ang II. Stable transfection with a dominant negative (DN) mutant for Pyk2 (PKM) completely blocked JNK activation by Ang II. DN mutants of Rac1 (DN-Rac1) and MEK kinase (DN-MEKK1) also abolished it, whereas those of Cdc42, RhoA, and Ha-Ras had no effect. Induction of c-Jun gene transcription by Ang II was abolished in PKM, DN-Rac1, and DN-MEKK1, in which Ang II-induced binding of ATF2/c-Jun heterodimer to the activator protein-1 sequence at -190 played a key role. These results suggest that 1) in cardiac fibroblasts activation of JNK and c-Jun by Ang II is initiated by Pyk2-dependent signalings but not by downstream signals of EGF-R or Ras, 2) Rac1 but not Cdc42 is required for JNK activation by Ang II upstream of MEKK1, and 3) ATF-2/c-Jun binding to the activator protein-1 sequence at -190 plays a key role for induction of c-Jun gene by Ang II.

Pilot-optimal augmentation synthesis

NASA Technical Reports Server (NTRS)

Schmidt, D. K.

1978-01-01

An augmentation synthesis method usable in the absence of quantitative handling qualities specifications, and yet explicitly including design objectives based on pilot-rating concepts, is presented. The algorithm involves the unique approach of simultaneously solving for the stability augmentation system (SAS) gains, pilot equalization and pilot rating prediction via optimal control techniques. Simultaneous solution is required in this case since the pilot model (gains, etc.) depends upon the augmented plant dynamics, and the augmentation is obviously not a priori known. Another special feature is the use of the pilot's objective function (from which the pilot model evolves) to design the SAS.

Augmenting the access grid using augmented reality

NASA Astrophysics Data System (ADS)

Li, Ying

2012-01-01

The Access Grid (AG) targets an advanced collaboration environment, with which multi-party group of people from remote sites can collaborate over high-performance networks. However, current AG still employs VIC (Video Conferencing Tool) to offer only pure video for remote communication, while most AG users expect to collaboratively refer and manipulate the 3D geometric models of grid services' results in live videos of AG session. Augmented Reality (AR) technique can overcome the deficiencies with its characteristics of combining virtual and real, real-time interaction and 3D registration, so it is necessary for AG to utilize AR to better assist the advanced collaboration environment. This paper introduces an effort to augment the AG by adding support for AR capability, which is encapsulated in the node service infrastructure, named as Augmented Reality Service (ARS). The ARS can merge the 3D geometric models of grid services' results and real video scene of AG into one AR environment, and provide the opportunity for distributed AG users to interactively and collaboratively participate in the AR environment with better experience.

RGS16 inhibits breast cancer cell growth by mitigating phosphatidylinositol 3-kinase signaling.

PubMed

Liang, Genqing; Bansal, Geetanjali; Xie, Zhihui; Druey, Kirk M

2009-08-07

Aberrant activity of the phosphatidylinositol 3-kinase (PI3K) pathway supports growth of many tumors including those of breast, lung, and prostate. Resistance of breast cancer cells to targeted chemotherapies including tyrosine kinase inhibitors (TKI) has been linked to persistent PI3K activity, which may in part be due to increased membrane expression of epidermal growth factor (EGF) receptors (HER2 and HER3). Recently we found that proteins of the RGS (regulator of G protein signaling) family suppress PI3K activity downstream of the receptor by sequestering its p85alpha subunit from signaling complexes. Because a substantial percentage of breast tumors have RGS16 mutations and reduced RGS16 protein expression, we investigated the link between regulation of PI3K activity by RGS16 and breast cancer cell growth. RGS16 overexpression in MCF7 breast cancer cells inhibited EGF-induced proliferation and Akt phosphorylation, whereas shRNA-mediated extinction of RGS16 augmented cell growth and resistance to TKI treatment. Exposure to TKI also reduced RGS16 expression in MCF7 and BT474 cell lines. RGS16 bound the amino-terminal SH2 and inter-SH2 domains of p85alpha and inhibited its interaction with the EGF receptor-associated adapter protein Gab1. These results suggest that the loss of RGS16 in some breast tumors enhances PI3K signaling elicited by growth factors and thereby promotes proliferation and TKI evasion downstream of HER activation.

RETINOIC ACID INDUCTION OF CLEFT PALATE IN EGF AND TGF-ALPHA KNOCKOUT MICE: STAGE SPECIFIC INFLUENCES OF GROWTH FACTOR EXPRESSION

EPA Science Inventory

ABBOTT, B. D., LEFFLER, K.E. AND BUCKALEW, A.R, Reproductive Toxicology Division, NHEERL, ORD, US EPA, Research Triangle Park, North Carolina. Retinoic acid induction of cleft palate (CP) in EGF and TGF knockout mice: Stage specific influences of growth factor expression.
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Enterocyte-specific epidermal growth factor prevents barrier dysfunction and improves mortality in murine peritonitis.

PubMed

Clark, Jessica A; Gan, Heng; Samocha, Alexandr J; Fox, Amy C; Buchman, Timothy G; Coopersmith, Craig M

2009-09-01

Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes (IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.

Novel role of cannabinoid receptor 2 in inhibiting EGF/EGFR and IGF-I/IGF-IR pathways in breast cancer.

PubMed

Elbaz, Mohamad; Ahirwar, Dinesh; Ravi, Janani; Nasser, Mohd W; Ganju, Ramesh K

2017-05-02

Breast cancer is the second leading cause of cancer deaths among women. Cannabinoid receptor 2 (CNR2 or CB2) is an integral part of the endocannabinoid system. Although CNR2 is highly expressed in the breast cancer tissues as well as breast cancer cell lines, its functional role in breast tumorigenesis is not well understood. We observed that estrogen receptor-α negative (ERα-) breast cancer cells highly express epidermal growth factor receptor (EGFR) as well as insulin-like growth factor-I receptor (IGF-IR). We also observed IGF-IR upregulation in ERα+ breast cancer cells. In addition, we found that higher CNR2 expression correlates with better recurrence free survival in ERα- and ERα+ breast cancer patients. Therefore, we analyzed the role of CNR2 specific agonist (JWH-015) on EGF and/or IGF-I-induced tumorigenic events in ERα- and ERα+ breast cancers. Our studies showed that CNR2 activation inhibited EGF and IGF-I-induced migration and invasion of ERα+ and ERα- breast cancer cells. At the molecular level, JWH-015 inhibited EGFR and IGF-IR activation and their downstream targets STAT3, AKT, ERK, NF-kB and matrix metalloproteinases (MMPs). In vivo studies showed that JWH-015 significantly reduced breast cancer growth in ERα+ and ERα- breast cancer mouse models. Furthermore, we found that the tumors derived from JWH-015-treated mice showed reduced activation of EGFR and IGF-IR and their downstream targets. In conclusion, we show that CNR2 activation suppresses breast cancer through novel mechanisms by inhibiting EGF/EGFR and IGF-I/IGF-IR signaling axes.

Brain injury expands the numbers of neural stem cells and progenitors in the SVZ by enhancing their responsiveness to EGF

PubMed Central

Alagappan, Dhivyaa; Lazzarino, Deborah A; Felling, Ryan J; Balan, Murugabaskar; Kotenko, Sergei V; Levison, Steven W

2009-01-01

There is an increase in the numbers of neural precursors in the SVZ (subventricular zone) after moderate ischaemic injuries, but the extent of stem cell expansion and the resultant cell regeneration is modest. Therefore our studies have focused on understanding the signals that regulate these processes towards achieving a more robust amplification of the stem/progenitor cell pool. The goal of the present study was to evaluate the role of the EGFR [EGF (epidermal growth factor) receptor] in the regenerative response of the neonatal SVZ to hypoxic/ischaemic injury. We show that injury recruits quiescent cells in the SVZ to proliferate, that they divide more rapidly and that there is increased EGFR expression on both putative stem cells and progenitors. With the amplification of the precursors in the SVZ after injury there is enhanced sensitivity to EGF, but not to FGF (fibroblast growth factor)-2. EGF-dependent SVZ precursor expansion, as measured using the neurosphere assay, is lost when the EGFR is pharmacologically inhibited, and forced expression of a constitutively active EGFR is sufficient to recapitulate the exaggerated proliferation of the neural stem/progenitors that is induced by hypoxic/ischaemic brain injury. Cumulatively, our results reveal that increased EGFR signalling precedes that increase in the abundance of the putative neural stem cells and our studies implicate the EGFR as a key regulator of the expansion of SVZ precursors in response to brain injury. Thus modulating EGFR signalling represents a potential target for therapies to enhance brain repair from endogenous neural precursors following hypoxic/ischaemic and other brain injuries. PMID:19570028

Radiographic and Histologic Evaluation of a Bone Void that Formed After Recombinant Human Bone Morphogenetic Protein-2-Mediated Sinus Graft Augmentation: A Case Report.

PubMed

Kang, Hyun-Joo; Jun, Choong-Man; Yun, Jeong-Ho

2016-01-01

In the present case report, the authors describe radiographic and histologic observations of a bone void that formed after a sinus augmentation using a graft material that contained recombinant human bone morphogenetic protein-2 (rhBMP-2) and discuss clinical and histologic implications of their findings. Sinus augmentation was performed using a graft material comprising 1 g of hydroxyapatite/β-tricalcium phosphate, which contained 1 mg of rhBMP-2. Radiographic evaluation was conducted with panoramic radiographs and computed tomography images of the augmented maxillary sinus, which were analyzed using a three-dimensional image-reconstruction program. Histologic evaluation was also performed on a biopsy specimen obtained 6 months after the sinus augmentation. The total augmented volume increased from 1,582.2 mm(3) immediately after the sinus augmentation to 3,344.9 mm3 at 6 months after the augmentation because of the formation of a bone void. Twenty-six months after the sinus augmentation, the bone void remained but had reduced in volume, with the total augmented volume reduced to 2,551.7 mm(3). Histologically, new bone was observed to be in contact with the grafted particles, and a fatty marrow-like tissue was present in the area of the bone void. This case report shows that the bone void that had formed after sinus augmentation resolved over time and seemed to be partially replaced with new bone. Furthermore, none of the implants failed, and clinical adverse events were not observed during the follow-up period.

Use of SLAM and PVRL4 and identification of pro-HB-EGF as cell entry receptors for wild type phocine distemper virus.

PubMed

Melia, Mary M; Earle, John Philip; Abdullah, Haniah; Reaney, Katherine; Tangy, Frederic; Cosby, Sara Louise

2014-01-01

Signalling lymphocyte activation molecule (SLAM) has been identified as an immune cell receptor for the morbilliviruses, measles (MV), canine distemper (CDV), rinderpest and peste des petits ruminants (PPRV) viruses, while CD46 is a receptor for vaccine strains of MV. More recently poliovirus like receptor 4 (PVRL4), also known as nectin 4, has been identified as a receptor for MV, CDV and PPRV on the basolateral surface of polarised epithelial cells. PVRL4 is also up-regulated by MV in human brain endothelial cells. Utilisation of PVRL4 as a receptor by phocine distemper virus (PDV) remains to be demonstrated as well as confirmation of use of SLAM. We have observed that unlike wild type (wt) MV or wtCDV, wtPDV strains replicate in African green monkey kidney Vero cells without prior adaptation, suggesting the use of a further receptor. We therefore examined candidate molecules, glycosaminoglycans (GAG) and the tetraspan proteins, integrin β and the membrane bound form of heparin binding epithelial growth factor (proHB-EGF),for receptor usage by wtPDV in Vero cells. We show that wtPDV replicates in Chinese hamster ovary (CHO) cells expressing SLAM and PVRL4. Similar wtPDV titres are produced in Vero and VeroSLAM cells but more limited fusion occurs in the latter. Infection of Vero cells was not inhibited by anti-CD46 antibody. Removal/disruption of GAG decreased fusion but not the titre of virus. Treatment with anti-integrin β antibody increased rather than decreased infection of Vero cells by wtPDV. However, infection was inhibited by antibody to HB-EGF and the virus replicated in CHO-proHB-EGF cells, indicating use of this molecule as a receptor. Common use of SLAM and PVRL4 by morbilliviruses increases the possibility of cross-species infection. Lack of a requirement for wtPDV adaptation to Vero cells raises the possibility of usage of proHB-EGF as a receptor in vivo but requires further investigation.

Type I neuregulin1α is a novel local mediator to suppress hepatic gluconeogenesis in mice

PubMed Central

Arai, Takatomo; Ono, Yumika; Arimura, Yujiro; Sayama, Keimon; Suzuki, Tomohiro; Shinjo, Satoko; Kanai, Mai; Abe, Shin-ichi; Semba, Kentaro; Goda, Nobuhito

2017-01-01

Neuregulin1 is an epidermal growth factor (EGF)-like domain-containing protein that has multiple isoforms and functions as a local mediator in the control of various cellular functions. Here we show that type I isoform of neuregulin1 with an α-type EGF-like domain (Nrg1α) is the major isoform in mouse liver and regulates hepatic glucose production. Forced expression of Nrg1α in mouse liver enhanced systemic glucose disposal and decreased hepatic glucose production with reduced fasting blood glucose levels. Nuclear forkhead box protein O1 (FoxO1) and its downstream targets, PEPCK and G6Pase, were suppressed in liver and isolated hepatocytes by Nrg1α overexpression. In contrast, silencing of Nrg1α enhanced glucose production with increased PEPCK and G6Pase expressions in cAMP/dexamethasone-stimulated hepatocytes. Mechanistically, the recombinant α-type EGF-like domain of NRG1α (rNRG1α) stimulated the ERBB3 signalling pathway in hepatocytes, resulting in decreased nuclear FoxO1 accumulation via activation of both the AKT and ERK pathways. In addition, acute treatment with rNRG1α also suppressed elevation of blood glucose levels after both glucose and pyruvate challenge. Although a liver-specific deletion of Nrg1 gene in mice showed little effect on systemic glucose metabolism, these results suggest that NRG1α have a novel regulatory function in hepatic gluconeogenesis by regulating the ERBB3-AKT/ERK-FoxO1 cascade. PMID:28218289

Cellular senescence of human mammary epithelial cells (HMEC) is associated with an altered MMP-7/HB-EGF signaling and increased formation of elastin-like structures.

PubMed

Bertram, Catharina; Hass, Ralf

2009-10-01

The extracellular matrix (ECM) and a complex interplay of cell-to-cell and cell-to-matrix (ECM) interactions provide important platforms to determine cellular senescence and a potentially tumorigenic transformation of normal human mammary epithelial cells (HMEC). An enhanced formation of extracellular filaments, consisting of elastin-like structures, in senescent post-selection HMEC populations was paralleled by a significantly increased expression of its precursor protein tropoelastin and matched with a markedly elevated activity of the cross-linking enzyme family of lysyl oxidases (LOX). RNAi experiments revealed both the ECM metalloproteinase MMP-7 and the growth factor HB-EGF as potential effectors of an increased tropoelastin expression. Moreover, co-localization of MMP-7 and HB-EGF as well as a concomittant downstream signaling via Fra-1 indicated a possible association between the reduced MMP-7 enzyme activity and an impaired HB-EGF processing, resulting in an enhanced tropoelastin synthesis during senescence of HMEC. In agreement with previous work, these findings suggested an important influence of the extracellular proteinase MMP-7 on the aging process of HMEC, affecting both extracellular remodeling as well as intracellular signaling pathways.

CXCL4 is a novel nickel-binding protein and augments nickel allergy.

PubMed

Kuroishi, T; Bando, K; Tanaka, Y; Shishido, K; Kinbara, M; Ogawa, T; Muramoto, K; Endo, Y; Sugawara, S

2017-08-01

Nickel (Ni) is the most frequent metal allergen and induces a TH 1 -dependent type-IV allergy. Although Ni 2+ is considered to bind to endogenous proteins, it currently remains unclear whether these Ni-binding proteins are involved in Ni allergy in vivo. We previously reported the adjuvant effects of lipopolysaccharide (LPS) in a Ni allergy mouse model. As LPS induces a number of inflammatory mediators, we hypothesized that Ni-binding protein(s) are also induced by LPS. The objective of this study was to purify and identify Ni-binding protein(s) from serum taken from LPS-injected mice (referred as LPS serum) and examined the augmenting effects of these Ni-binding protein(s) on Ni allergy in an in vivo model. BALB/cA mice were sensitized with an i.p. injection of NiCl 2 and LPS. Ten days after sensitization, mice were challenged with NiCl 2 by an i.d. injection into ear pinnae. Ni-binding protein(s) were purified by Ni-affinity column chromatography and gel filtration. Lipopolysaccharide serum, but not serum taken from saline-injected mice, augmented ear swelling induced by Ni-allergic inflammation. Ni-binding, but not non-binding fraction, purified from LPS serum augmented Ni-allergic inflammation. Mass spectrometry and Western blotting detected CXCL4 in the active fraction. A batch analysis with Ni-sepharose and a surface plasmon resonance analysis revealed direct binding between CXCL4 and Ni 2+ . Recombinant CXCL4 augmented Ni-allergic inflammation and exerted adjuvant effects at the sensitization phase. These results indicate that CXCL4 is a novel Ni-binding protein that augments Ni allergy at the elicitation and sensitization phases. This is the first study to demonstrate that the Ni-binding protein augments Ni allergy in vivo. © 2017 John Wiley & Sons Ltd.

In the Age of Breast Augmentation, Breast Reconstruction Provides an Opportunity to Augment the Breast.

PubMed

Zimmerman, Amanda L; Tugertimur, Bugra; Smith, Paul D; Kumar, Ambuj; Dayicioglu, Deniz

2017-01-01

Augmentation mammoplasty remains the most common cosmetic surgery procedure performed. The objective of this article is to evaluate the impact of augmented volume of the reconstructed breast in patients that undergo nipple-sparing mastectomy and patients previously augmented who undergo mastectomy with tissue expander/implant-based reconstruction. Patients undergoing skin-sparing mastectomy, nipple-sparing mastectomy, and mastectomy after previous augmentation followed by tissue expander/implant-based reconstruction between June 2011 and April 2015 by 2 surgeons at the same institution were included. Retrospective chart review of the patients identified using these criteria was performed to record patient characteristics, complications, breast volume, implant volume, and percentage change in volume at the time of reconstruction. Percentage change of breast volume was calculated using the formula (implant breast weight)/(breast weight) for skin-sparing and nipple-sparing mastectomy patients and (final breast implant weight - [breast weight + augmentation breast implant weight])/([breast weight + augmentation breast implant]) for patients undergoing mastectomy following previous augmentation. A total of 293 patients were included in the study with 63 patients who underwent nipple-sparing mastectomy, 166 patients who underwent skin-sparing mastectomy, and 64 patients who underwent previous augmentation with subsequent mastectomy. Mean percentage change in breast volume was 66% in the nipple-sparing mastectomy group, 15% for the right breast and 18% for the left breast in the skin-sparing mastectomy group, and 81% for the right breast and 72% for the left breast in the mastectomy following previous augmentation group. Complication rate for nipple-sparing mastectomy was 27%, mastectomy following previous augmentation was 20.3%, and skin-sparing mastectomy group was 18.7%. Patients who undergo nipple-sparing mastectomy or mastectomy following previous augmentation have

Spatio-temporal imaging of EGF-induced activation of protein kinase A by FRET in living cells

NASA Astrophysics Data System (ADS)

Wang, Jin Jun; Chen, Xiao-Chuan; Xing, Da

2004-07-01

Intracellular molecular interaction is important for the study of cell physiology, yet current relevant methods require fixation or microinjection and lack temporal or spatial resolution. We introduced a new method -- fluorescence resonance energy transfer (FRET) to detect molecular interaction in living cells. On the basis of FRET principle, A-kinase activity reporter (AKAR) protein was designed to consist of the fusions of cyan fluorescent protein (CFP), a phosphoamino acid binding domain, a consensus substrate for protein kinase-A (PKA), and yellow fluorescent protein (YFP). In this study, the designed pAKAR plasmid was used to transfect a human lung cancer cell line (ASTC-a-1). When the AKAR-transfected cells were treated by forskolin (Fsk), we were able to observe the efficient transfer of energy from excited CFP to YFP within the AKAR molecule by fluorescence microcopy, whereas no FRET was detected in the transfected cells without the treatment of Fsk. When the cells were treated by Epidermal growth factor (EGF), the change of FRET was observed at different subcellular locations, reflecting PKA activation inside the cells upon EGF stimulation. The successful design of a fluorescence reporter of PKA activation and its application demonstrated the superiority of this technology in the research of intracellular protein-protein interaction.

Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin.

PubMed

Johnson, Adam S; García, Dana M

2007-12-19

Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the carbachol-receptor interaction activates a Gq-mediated pathway which is commonly linked to Ca2+ mobilization. The purpose of the present study was to test for involvement of calcium and to probe calcium-dependent mediators to reveal their role in carbachol-mediated dispersion. Carbachol-induced pigment granule dispersion was blocked by the calcium chelator BAPTA. In contrast, the calcium channel antagonist verapamil, and incubation in Ca2+-free medium failed to block carbachol-induced dispersion. The calcineurin inhibitor cypermethrin blocked carbachol-induced dispersion; whereas, two protein kinase C inhibitors (staurosporine and bisindolylmaleimide II) failed to block carbachol-induced dispersion, and the protein kinase C activator phorbol 12-myristate 13-acetate failed to elicit dispersion. A rise in intracellular calcium is necessary for carbachol-induced dispersion; however, the Ca2+ requirement is not dependent on extracellular sources, implying that intracellular stores are sufficient to enable pigment granule dispersion to occur. Calcineurin is a likely Ca2+-dependent mediator involved in the signal cascade. Although the pathway leads to the generation of diacylglycerol and calcium (both required for the activation of certain PKC isoforms), our evidence does not support a significant role for PKC.

[Augmentation technique on the proximal humerus].

PubMed

Scola, A; Gebhard, F; Röderer, G

2015-09-01

The treatment of osteoporotic fractures is still a challenge. The advantages of augmentation with respect to primary in vitro stability and the clinical use for the proximal humerus are presented in this article. In this study six paired human humeri were randomized into an augmented and a non-augmented group. Osteosynthesis was performed with a PHILOS plate (Synthes®). In the augmented group the two screws finding purchase in the weakest cancellous bone were augmented. The specimens were tested in a 3-part fracture model in a varus bending test. The augmented PHILOS plates withstood significantly more load cycles until failure. The correlation to bone mineral density (BMD) showed that augmentation could partially compensate for low BMD. The augmentation of the screws in locked plating in a proximal humerus fracture model is effective in improving the primary stability in a cyclic varus bending test. The targeted augmentation of two particular screws in a region of low bone quality within the humeral head was almost as effective as four screws with twice the amount of bone cement. Screw augmentation combined with a knowledge of the local bone quality could be more effective in enhancing the primary stability of a proximal humerus locking plate because the effect of augmentation can be exploited more effectively limiting it to the degree required. The technique of augmentation is simple and can be applied in open and minimally invasive procedures. When the correct procedure is used, complications (cement leakage into the joint) can be avoided.

Advanced intellect-augmentation techniques

NASA Technical Reports Server (NTRS)

Engelbart, D. C.

1972-01-01

User experience in applying our augmentation tools and techniques to various normal working tasks within our center is described so as to convey a subjective impression of what it is like to work in an augmented environment. It is concluded that working-support, computer-aid systems for augmenting individuals and teams, are undoubtedly going to be widely developed and used. A very special role in this development is seen for multi-access computer networks.

Transforming growth factor alpha is a critical mediator of radiation lung injury.

PubMed

Chung, Eun Joo; Hudak, Kathryn; Horton, Jason A; White, Ayla; Scroggins, Bradley T; Vaswani, Shiva; Citrin, Deborah

2014-09-01

Radiation fibrosis of the lung is a late toxicity of thoracic irradiation. Epidermal growth factor (EGF) signaling has previously been implicated in radiation lung injury. We hypothesized that TGF-α, an EGF receptor ligand, plays a key role in radiation-induced fibrosis in lung. Mice deficient in transforming growth factor (TGF-α(-/-)) and control C57Bl/6J (C57-WT) mice were exposed to thoracic irradiation in 5 daily fractions of 6 Gy. Cohorts of mice were followed for survival (n ≥ 5 per group) and tissue collection (n = 3 per strain and time point). Collagen accumulation in irradiated lungs was assessed by Masson's trichrome staining and analysis of hydroxyproline content. Cytokine levels in lung tissue were assessed with ELISA. The effects of TGF-α on pneumocyte and fibroblast proliferation and collagen production were analyzed in vitro. Lysyl oxidase (LOX) expression and activity were measured in vitro and in vivo. Irradiated C57-WT mice had a median survival of 24.4 weeks compared to 48.2 weeks for irradiated TGF-α(-/-) mice (P = 0.001). At 20 weeks after irradiation, hydroxyproline content was markedly increased in C57-WT mice exposed to radiation compared to TGF-α(-/-) mice exposed to radiation or unirradiated C57-WT mice (63.0, 30.5 and 37.6 μg/lung, respectively, P = 0.01). C57-WT mice exposed to radiation had dense foci of subpleural fibrosis at 20 weeks after exposure, whereas the lungs of irradiated TGF-α (-/-) mice were largely devoid of fibrotic foci. Lung tissue concentrations of IL-1β, IL-4, TNF-α, TGF-β and EGF at multiple time points after irradiation were similar in C57-WT and TGF-α(-/-) mice. TGF-α in lung tissue of C57-WT mice rose rapidly after irradiation and remained elevated through 20 weeks. TGF-α(-/-) mice had lower basal LOX expression than C57-WT mice. Both LOX expression and LOX activity were increased after irradiation in all mice but to a lesser degree in TGF-α(-/-) mice. Treatment of NIH-3T3 fibroblasts with TGF

Internalization Mechanisms of the Epidermal Growth Factor Receptor after Activation with Different Ligands

PubMed Central

Henriksen, Lasse; Grandal, Michael Vibo; Knudsen, Stine Louise Jeppe; van Deurs, Bo; Grøvdal, Lene Melsæther

2013-01-01

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. PMID:23472148

Expression of heparin-binding EGF-like growth factor in term chorionic villous explants and its role in trophoblast survival.

PubMed

Imudia, A N; Kilburn, B A; Petkova, A; Edwin, S S; Romero, R; Armant, D R

2008-09-01

Heparin-binding EGF-like growth factor (HBEGF) induces trophoblast extravillous differentiation and prevents apoptosis. These functions are compromised in preeclampsia. Because HBEGF is downregulated in placentas delivered by women with preeclampsia, we have examined its expression and cytoprotective activity in term villous explants. Chorionic villous explants prepared from non-pathological placentas collected by cesarean section at term were cultured at either 20% or 2% O2 and treated with the HBEGF antagonist CRM197 or recombinant HBEGF. Paraffin sections were assayed for trophoblast death, proliferation and HBEGF expression using the TUNEL method, immunohistochemistry for nuclear Ki67 expression and semi-quantitative immunohistochemistry with image analysis, respectively. Trophoblast cell death was increased significantly after 8h of culture with CRM197 or by culture for 2h at 2% O2. Exogenous HBEGF prevented cell death due to hypoxia. Proliferative capacity was not affected by culture at either 20% or 2% O2. Contrary to first trimester placenta, term trophoblasts do not elevate HBEGF expression in response to hypoxia. However, low endogenous levels of HBEGF are required to maintain survival. Therefore, HBEGF-mediated signaling significantly reduces trophoblast cell death at term and its deficiency in preeclampsia could negatively impact trophoblast survival.

Expression of heparin-binding EGF-like growth factor in term chorionic villous explants and its role in trophoblast survival

PubMed Central

Imudia, Anthony N.; Kilburn, Brian A.; Petkova, Anelia; Edwin, Samuel S.; Romero, Roberto; Armant, D. Randall

2008-01-01

Heparin-binding EGF-like growth factor (HBEGF) induces trophoblast extravillous differentiation and prevents apoptosis. These functions are compromised in preeclampsia. Because HBEGF is downregulated in placentas delivered by women with preeclampsia, we have examined its expression and cytoprotective activity in term villous explants. Chorionic villous explants prepared from non-pathological placentas collected by cesarean section at term were cultured at either 20% or 2% O2 and treated with the HBEGF antagonist CRM197 or recombinant HBEGF. Paraffin sections were assayed for trophoblast death, proliferation and HBEGF expression using the TUNEL method, immunohistochemistry for nuclear Ki67 expression and semi-quantitative immunohistochemistry with image analysis, respectively. Trophoblast cell death was increased significantly after 8 h of culture with CRM197 or by culture for 2 h at 2% O2. Exogenous HBEGF prevented cell death due to hypoxia. Proliferative capacity was not affected by culture at either 20% or 2% O2. Contrary to first trimester placenta, term trophoblasts do not elevate HBEGF expression in response to hypoxia. However, low endogenous levels of HBEGF are required to maintain survival. Therefore, HBEGF-mediated signaling significantly reduces trophoblast cell death at term and its deficiency in preeclampsia could negatively impact trophoblast survival. PMID:18691754

Responsiveness of intestinal epithelial cell turnover to TGF-alpha after bowel resection in a rat is correlated with EGF receptor expression along the villus-crypt axis.

PubMed

Sukhotnik, Igor; Mogilner, Jorge G; Shaoul, Ron; Karry, Rahel; Lieber, Michael; Suss-Toby, Edith; Ure, Benno M; Coran, Arnold G

2008-01-01

Recent evidence suggests that transforming growth factor alpha (TGF-alpha) enhances enterocyte proliferation and stimulates intestinal adaptation after massive bowel resection. In the present study, we evaluated the effects of TGF-alpha on enterocyte turnover and correlated it with epidermal-growth factor (EGF) receptor expression along the villus-crypt axis in a rat model of short bowel syndrome (SBS). Male rats were divided into three groups, sham rats underwent bowel transection (group A); SBS rats underwent a 75% bowel resection (group B); and SBS/TGF-alpha rats underwent bowel resection and were treated with TGF-alpha (75 microg/kg) (group C) from the seventh postoperative day. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined on day 15. Villus tips, lateral villi and crypts were separated using laser capture microdissection. EGF receptor expression for each compartment was assessed by quantitative real-time PCR (Taqman). Statistical analysis was performed using one-way ANOVA test, with P < 0.05 considered statistically significant. Treatment with TGF-alpha resulted in a significant increase in all parameters of intestinal adaptation. EGF receptor expression in crypts significantly increased in SBS rats (vs sham rats) (0.035 +/- 0.013 vs 0.010 +/- 0.002 Log ng Total RNA/18 s) and was accompanied by a significant increase in enterocyte proliferation (169 +/- 8 vs 138 +/- 5 BrdU positive cells/per 10 crypts, P < 0.05) and decreased apoptosis following TGF-alpha administration (group C). A significant decrease in EGF receptor expression at the tip of the villus (0.005 +/- 0.002 vs 0.029 +/- 0.014 Log ng Total RNA/18 s) and in the lateral villus (0.003 +/- 0.001 vs 0.028 +/- 0.006 Log ng Total RNA/18 s) in SBS (group B) rats (vs sham, group A) was accompanied by increased cell apoptosis in these compartments following treatment with TGF-alpha (group C). In a rat model of SBS, TGF-alpha increased enterocyte proliferation

Epidermal growth factor and tumor necrosis factor α cooperatively promote the motility of hepatocellular carcinoma cell lines via synergistic induction of fibronectin by NF-κB/p65.

PubMed

Liu, Zong-Cai; Ning, Fen; Wang, Hai-Fang; Chen, Dan-Yang; Cai, Yan-Na; Sheng, Hui-Ying; Lash, Gendie E; Liu, Li; Du, Jun

2017-11-01

The interaction between hepatocellular carcinoma (HCC) cells and their microenvironment plays a fundamental role in tumor metastasis. The HCC microenvironment is rich in epidermal growth factor (EGF) and tumor necrosis factor α (TNFα), which may cooperatively, rather than individually, interact with tumor cells to influence their biological behavior. Immunohistochemistry was performed to study the expression of EGF and TNFα in HCCs. Western blotting, immunofluorescence, qRT-PCR, wound healing scratch and invasion assay, and chromatin immunoprecipitation assays were used to study the combined roles of EGF and TNFα in the motility of HCC cells in vitro. We demonstrated that both EGF and TNFα were highly expressed in HCCs, and HCCs with higher expression of both EGF and TNFα were more frequently rated as high-grade tumors. In vitro, EGF and TNFα cooperatively promoted the motility of HCC cells mainly via synergistic induction of an extracellular matrix glycoprotein fibronectin (FN). Mechanistically, EGF and TNFα jointly increased the nuclear translocation and PKC mediated phosphorylation of NF-κB/p65 which could bind to the -356bp to -259bp fragment of the FN promoter, leading to a markedly increased activity of the FN promoter in HCC cells. HCCs with higher expression of both EGF and TNFα were more frequently rated as high-grade tumors. EGF and TNFα cooperatively promoted the motility of HCC cells mainly through NF-κB/p65 mediated synergistic induction of FN in vitro. These findings highlight the crosstalk between EGF and TNFα in promoting HCC, and provide potential targets for HCC prevention and treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Association of the membrane estrogen receptor, GPR30, with breast tumor metastasis and transactivation of the epidermal growth factor receptor.

PubMed

Filardo, Edward J; Quinn, Jeffrey A; Sabo, Edmond

2008-10-01

The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases function as a common signaling conduit for membrane receptors that lack intrinsic enzymatic activity, such as G-protein coupled receptors and integrins. GPR30, an orphan member of the seven transmembrane receptor (7TMR) superfamily has been linked to specific estrogen binding, rapid estrogen-mediated activation of adenylyl cyclase and the release of membrane-tethered proHB-EGF. More recently, GPR30 expression in primary breast adenocarcinoma has been associated with pathological parameters commonly used to assess breast cancer progression, including the development of extramammary metastases. This newly appreciated mechanism of cross communication between estrogen and EGF is consistent with the observation that 7TMR-mediated transactivation of the EGFR is a recurrent signaling paradigm and may explain prior data reporting the EGF-like effects of estrogen. The molecular details surrounding GPR30-mediated release of proHB-EGF, the involvement of integrin beta1 as a signaling intermediary in estrogen-dependent EGFR action, and the possible implications of these data for breast cancer progression are discussed herein.

Bit-1 Mediates Integrin-dependent Cell Survival through Activation of the NFκB Pathway*

PubMed Central

Griffiths, Genevieve S.; Grundl, Melanie; Leychenko, Anna; Reiter, Silke; Young-Robbins, Shirley S.; Sulzmaier, Florian J.; Caliva, Maisel J.; Ramos, Joe W.; Matter, Michelle L.

2011-01-01

Loss of properly regulated cell death and cell survival pathways can contribute to the development of cancer and cancer metastasis. Cell survival signals are modulated by many different receptors, including integrins. Bit-1 is an effector of anoikis (cell death due to loss of attachment) in suspended cells. The anoikis function of Bit-1 can be counteracted by integrin-mediated cell attachment. Here, we explored integrin regulation of Bit-1 in adherent cells. We show that knockdown of endogenous Bit-1 in adherent cells decreased cell survival and re-expression of Bit-1 abrogated this effect. Furthermore, reduction of Bit-1 promoted both staurosporine and serum-deprivation induced apoptosis. Indeed knockdown of Bit-1 in these cells led to increased apoptosis as determined by caspase-3 activation and positive TUNEL staining. Bit-1 expression protected cells from apoptosis by increasing phospho-IκB levels and subsequently bcl-2 gene transcription. Protection from apoptosis under serum-free conditions correlated with bcl-2 transcription and Bcl-2 protein expression. Finally, Bit-1-mediated regulation of bcl-2 was dependent on focal adhesion kinase, PI3K, and AKT. Thus, we have elucidated an integrin-controlled pathway in which Bit-1 is, in part, responsible for the survival effects of cell-ECM interactions. PMID:21383007

Augmented reality in neurosurgery

PubMed Central

Tagaytayan, Raniel; Kelemen, Arpad

2016-01-01

Neurosurgery is a medical specialty that relies heavily on imaging. The use of computed tomography and magnetic resonance images during preoperative planning and intraoperative surgical navigation is vital to the success of the surgery and positive patient outcome. Augmented reality application in neurosurgery has the potential to revolutionize and change the way neurosurgeons plan and perform surgical procedures in the future. Augmented reality technology is currently commercially available for neurosurgery for simulation and training. However, the use of augmented reality in the clinical setting is still in its infancy. Researchers are now testing augmented reality system prototypes to determine and address the barriers and limitations of the technology before it can be widely accepted and used in the clinical setting. PMID:29765445

Augmented reality in neurosurgery.

PubMed

Tagaytayan, Raniel; Kelemen, Arpad; Sik-Lanyi, Cecilia

2018-04-01

Neurosurgery is a medical specialty that relies heavily on imaging. The use of computed tomography and magnetic resonance images during preoperative planning and intraoperative surgical navigation is vital to the success of the surgery and positive patient outcome. Augmented reality application in neurosurgery has the potential to revolutionize and change the way neurosurgeons plan and perform surgical procedures in the future. Augmented reality technology is currently commercially available for neurosurgery for simulation and training. However, the use of augmented reality in the clinical setting is still in its infancy. Researchers are now testing augmented reality system prototypes to determine and address the barriers and limitations of the technology before it can be widely accepted and used in the clinical setting.

Augmenting brain metabolism to increase macro- and chaperone-mediated autophagy for decreasing neuronal proteotoxicity and aging.

PubMed

Loos, Ben; Klionsky, Daniel J; Wong, Esther

2017-09-01

Accumulation of toxic protein aggregates in the nerve cells is a hallmark of neuronal diseases and brain aging. Mechanisms to enhance neuronal surveillance to improve neuronal proteostasis have a direct impact on promoting neuronal health and forestalling age-related decline in brain function. Autophagy is a lysosomal degradative pathway pivotal for neuronal protein quality control. Different types of autophagic mechanisms participate in protein handling in neurons. Macroautophagy targets misfolded and aggregated proteins in autophagic vesicles to the lysosomes for destruction, while chaperone-mediated autophagy (CMA) degrades specific soluble cytosolic proteins delivered to the lysosomes by chaperones. Dysfunctions in macroautophagy and CMA contribute to proteo- and neuro-toxicity associated with neurodegeneration and aging. Thus, augmenting or preserving both autophagic mechanisms pose significant benefits in delaying physiological and pathological neuronal demises. Recently, life-style interventions that modulate metabolite ketone bodies, energy intake by caloric restriction and energy expenditure by exercise have shown to enhance both autophagy and brain health. However, to what extent these interventions affect neuronal autophagy to promote brain fitness remains largely unclear. Here, we review the functional connections of how macroautophagy and CMA are affected by ketone bodies, caloric restriction and exercise in the context of neurodegeneration. A concomitant assessment of yeast Saccharomyces cerevisiae is performed to reveal the conserved nature of such autophagic responses to substrate perturbations. In doing so, we provide novel insights and integrated evidence for a potential adjuvant therapeutic strategy to intervene in the neuronal decline in neurodegenerative diseases by controlling both macroautophagy and CMA fluxes favorably. Copyright © 2017 Elsevier Ltd. All rights reserved.

Targeting tumor cells via EGF receptors: selective toxicity of an HBEGF-toxin fusion protein.

PubMed

Chandler, L A; Sosnowski, B A; McDonald, J R; Price, J E; Aukerman, S L; Baird, A; Pierce, G F; Houston, L L

1998-09-25

Over-expression of the epidermal growth factor receptor (EGFR) is a hallmark of numerous solid tumors, thus providing a means of selectively targeting therapeutic agents. Heparin-binding epidermal growth factor (HBEGF) binds to EGFRs with high affinity and to heparan sulfate proteoglycans, resulting in increased mitogenic potential compared to other EGF family members. We have investigated the feasibility of using HBEGF to selectively deliver a cytotoxic protein into EGFR-expressing tumor cells. Recombinant fusion proteins consisting of mature human HBEGF fused to the plant ribosome-inactivating protein saporin (SAP) were expressed in Escherichia coli. Purified HBEGF-SAP chimeras inhibited protein synthesis in a cell-free assay and competed with EGF for binding to receptors on intact cells. A construct with a 22-amino-acid flexible linker (L22) between the HBEGF and SAP moieties exhibited an affinity for the EGFR that was comparable to that of HBEGF. The sensitivity to HBEGF-L22-SAP was determined for a variety of human tumor cell lines, including the 60 cell lines comprising the National Cancer Institute Anticancer Drug Screen. HBEGF-L22-SAP was cytotoxic in vitro to a variety of EGFR-bearing cell lines and inhibited growth of EGFR-over-expressing human breast carcinoma cells in vivo. In contrast, the fusion protein had no effect on small-cell lung carcinoma cells, which are EGFR-deficient. Our results demonstrate that fusion proteins composed of HBEGF and SAP exhibit targeting specificity and cytotoxicity that may be of therapeutic value in treating a variety of EGFR-bearing malignancies.

Urine epidermal growth factor, monocyte chemoattractant protein-1 or their ratio as predictors of complete remission in primary glomerulonephritis.

PubMed

Chanrat, Eakkapat; Worawichawong, Supanat; Radinahamed, Piyanuch; Sathirapongsasuti, Nuankanya; Nongnuch, Arkom; Assanatham, Montira; Udomsubpayakul, Umaporn; Kitiyakara, Chagriya

2018-04-01

The balance of several cytokines likely influences the resolution of glomerulonephritis. Monocyte chemoattractant protein-1(MCP-1) is a chemokine that promotes renal inflammation whereas epidermal growth factor (EGF) stimulates protective responses. Previously, high urine MCP-1(MCP-1) and low urine EGF (EGF) levels were found to be associated with tubulointerstitial fibrosis, but there is limited information on the value of these mediators as predictors of therapeutic responses or long term outcome in primary glomerulonephritis. To determine the performance of urine EGF, MCP-1 or their ratio at baseline as biomarkers to predict complete remission, and the relationship of these mediators with subsequent renal function 24 months later in primary glomerulonephritis. This is a prospective study of patients with biopsy-proven primary glomerulonephritis. Baseline urine samples were collected at biopsy before therapy. MCP-1 and EGF were analyzed by enzyme-linked immunosorbent assays and expressed as a ratio to urine creatinine (ng/mgCr) or as EGF/MCP-1 ratio (ng/ng). Proteinuria and estimated glomerular filtration rate (eGRF) were monitored after therapy. Complete remission (CR) was defined as proteinuria ≤ 0.3 g/gCr. Median follow-up was 20 months. Of all patients (n = 74), 38 patients (51.4%) subsequently achieved CR. Baseline urine EGF and EGF/MCP-1 levels were significantly higher in CR compared to Not CR. By contrast, MCP-1 was not different. High EGF (EGF > 75 ng/mgCr) was a significant predictor (OR 2.28) for CR by multivariate analysis after adjusting for proteinuria, blood pressure, baseline eGFR. In patients who completed 24 months follow-up (n = 43), baseline EGF correlated inversely with proteinuria and positively with eGFR at 24 months. High urine EGF level is a promising biomarker of CR. Baseline EGF levels correlated with kidney function at 2 years. EGF/MCP-1 was not superior to EGF alone. Further studies are necessary to

Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) levels in patients with overt and subclinical hyperthyroidism: effects of treatment.

PubMed

Erem, Cihangir; Civan, Nadim; Coskun, Hulya; Mentese, Ahmet; Suleyman, Akile Karacin; Altay, Diler Us; Akgul, Zeynep; Deger, Orhan

2016-06-01

Signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) has been shown to increase in parallel with platelet activation in acute ischaemic and thrombotic diseases. There has been no study evaluating SCUBE1 levels in patients with overt hyperthyroidism (OHyper) and subclinical hyperthyroidism (SHyper), conditions which are known to show impairment of both endothelial and platelet function. This study sought to evaluate SCUBE1 concentrations in patients with SHyper and OHyper, and assessed the effects of antithyroid drug (ATD) therapy on circulating SCUBE1 levels. Forty-five untreated patients with OHyper, 20 untreated patients with SHyper and 30 age- and sex-matched healthy controls were prospectively included in the study. Biochemical and hormonal parameters were evaluated in all patients before and after treatment. Compared with the control subjects, SCUBE1 levels were significantly increased in patients with SHyper and OHyper (P < 0·0001 and P = 0·002, respectively). SCUBE1 levels were not significantly different in patients with OHyper compared with patients with SHyper. There was no significant correlation between serum thyroid hormones and SCUBE1 levels. Plasma SCUBE1 levels decreased significantly in both OHyper and SHyper after ATD treatment (P < 0·05). Increased SCUBE1 levels in both SHyper and OHyper patients may reflect increased platelet activation and possible endothelial dysfunction, which might augment the risk for atherosclerotic and atherothrombotic complications. SCUBE1 may be used as a reliable marker of endothelial damage in hyperthyroidism, especially in the subclinical period. © 2015 John Wiley & Sons Ltd.

Observation of reversible, rapid changes in drug susceptibility of hypoxic tumor cells in a microfluidic device.

PubMed

Germain, Todd; Ansari, Megan; Pappas, Dimitri

2016-09-14

Hypoxia is a major stimulus for increased drug resistance and for survival of tumor cells. Work from our group and others has shown that hypoxia increases resistance to anti-cancer compounds, radiation, and other damage-pathway cytotoxic agents. In this work we utilize a microfluidic culture system capable of rapid switching of local oxygen concentrations to determine changes in drug resistance in prostate cancer cells. We observed rapid adaptation to hypoxia, with drug resistance to 2 μM staurosporine established within 30 min of hypoxia. Annexin-V/Sytox Green apoptosis assays over 9 h showed 78.0% viability, compared to 84.5% viability in control cells (normoxic cells with no staurosporine). Normoxic cells exposed to the same staurosporine concentration had a viability of 48.6% after 9 h. Hypoxia adaptation was rapid and reversible, with Hypoxic cells treated with 20% oxygen for 30 min responding to staurosporine with 51.6% viability after drug treatment for 9 h. Induction of apoptosis through the receptor-mediated pathway, which bypasses anti-apoptosis mechanisms induced by hypoxia, resulted in 39.4 ± 7% cell viability. The rapid reversibility indicates co-treatment of oxygen with anti-cancer compounds may be a potential therapeutic target. Copyright © 2016 Elsevier B.V. All rights reserved.

[Augmentation with PMMA cement].

PubMed

Kühn, K-D; Höntzsch, D

2015-09-01

Cements based on polymethyl methacrylate (PMMA) can be used without any problem in a variety of clinical augmentations. Cement-related complications in surgical procedures involving PMMA cements, such as embolism, thermal necrosis, toxicity and hypersensitivity, are often due to other causes. Knowledge about the properties of the cement helps the user to safely employ PMMA cements in augmentations. High radio-opacity is required in vertebral body augmentations and this is provided in particular by zirconium dioxide. In vertebral body augmentations, a low benzoyl peroxide (BPO) content can considerably prolong the liquid dough phase. In augmentations with cement fillings in the region of a tumor, a high BPO content can specifically increase the peak temperature of the PMMA cement. In osteosynthetic augmentations with PMMA, necrosis is rare because heat development in the presence of metallic implants is low due to heat conduction via the implant. Larger cement fillings where there is no heat conduction via metal implants can exhibit substantially higher peak temperatures. The flow properties of PMMA cements are of particular importance for the user to allow optimum handling of PMMA cements. In patients with hypersensitivity to antibiotics, there is no need to avoid the use of PMMA as there are sufficient PMMA-based alternatives. The PMMA cements are local drug delivery systems and antibiotics, antiseptics, antimycotics and also cytostatics can be mixed with the cement. Attention must be paid to antagonistic and synergistic effects.

Gold nanoparticles as a platform for creating a multivalent poly-SUMO chain inhibitor that also augments ionizing radiation.

PubMed

Li, Yi-Jia; Perkins, Angela L; Su, Yang; Ma, Yuelong; Colson, Loren; Horne, David A; Chen, Yuan

2012-03-13

Protein-protein interactions mediated by ubiquitin-like (Ubl) modifications occur as mono-Ubl or poly-Ubl chains. Proteins that regulate poly-SUMO (small ubiquitin-like modifier) chain conjugates play important roles in cellular response to DNA damage, such as those caused by cancer radiation therapy. Additionally, high atomic number metals, such as gold, preferentially absorb much more X-ray energy than soft tissues, and thus augment the effect of ionizing radiation when delivered to cells. In this study, we demonstrate that conjugation of a weak SUMO-2/3 ligand to gold nanoparticles facilitated selective multivalent interactions with poly-SUMO-2/3 chains leading to efficient inhibition of poly-SUMO-chain-mediated protein-protein interactions. The ligand-gold particle conjugate significantly sensitized cancer cells to radiation but was not toxic to normal cells. This study demonstrates a viable approach for selective targeting of poly-Ubl chains through multivalent interactions created by nanoparticles that can be chosen based on their properties, such as abilities to augment radiation effects.

Augmented reality: a review.

PubMed

Berryman, Donna R

2012-01-01

Augmented reality is a technology that overlays digital information on objects or places in the real world for the purpose of enhancing the user experience. It is not virtual reality, that is, the technology that creates a totally digital or computer created environment. Augmented reality, with its ability to combine reality and digital information, is being studied and implemented in medicine, marketing, museums, fashion, and numerous other areas. This article presents an overview of augmented reality, discussing what it is, how it works, its current implementations, and its potential impact on libraries.

Angiostatic, tumor inflammatory and anti-tumor effects of CXCL4(47-70) and CXCL4L1(47-70) in an EGF-dependent breast cancer model.

PubMed

Van Raemdonck, Katrien; Berghmans, Nele; Vanheule, Vincent; Bugatti, Antonella; Proost, Paul; Opdenakker, Ghislain; Presta, Marco; Van Damme, Jo; Struyf, Sofie

2014-11-15

CXCL4 and CXCL4L1, platelet-derived CXC chemokines, and their carboxy-terminal peptides CXCL4(47-70) and CXCL4L1(47-70) previously displayed angiostatic and anti-tumoral activity in a melanoma model. Here, we found CXCL4(47-70) and CXCL4L1(47-70) to inhibit lymphatic endothelial cell proliferation in vitro. Furthermore, the angiostatic potential of CXCL4(47-70) and CXCL4L1(47-70) was tested against different angiogenic stimuli (FGF1, FGF2, FGF8, EGF and VEGF). Besides reducing FGF2-induced vascular endothelial cell growth, CXCL4(47-70) and CXCL4L1(47-70) efficiently counteracted EGF. Consequently, we considered their anti-tumoral potential in EGF-dependent MDA-MB-231 breast tumors. In tumor-bearing mice, CXCL4(47-70) reduced tumor growth better than CXCL4L1(47-70). In CXCL4(47-70)-treated tumors significantly more intratumoral monocytes/macrophages and dendritic cells were present and higher expression levels of CCL5 and IFN- γ were detected by qPCR on tumor lysates. Because neither peptide was able to specifically bind CXCR3A or CXCR3B, differential glycosaminoglycan binding and direct interaction with cytokines (EGF and CCL5) might explain any differences in anti-tumoral effects. Notably, CCL5-induced monocyte chemotaxis in vitro was increased by addition of CXCL4(47-70) or CXCL4L1(47-70). Finally, CXCL4(47-70) and CXCL4L1(47-70) inhibited proliferation of MDA-MB-231 cells. Our results suggest a tumor type-dependent responsiveness to either CXCL4(47-70) or CXCL4L1(47-70) treatment, defined by anti-proliferative, angiostatic and inflammatory actions, and substantiate their therapeutic potential.

Angiostatic, tumor inflammatory and anti-tumor effects of CXCL447–70 and CXCL4L147–70 in an EGF-dependent breast cancer model

PubMed Central

Van Raemdonck, Katrien; Berghmans, Nele; Vanheule, Vincent; Bugatti, Antonella; Proost, Paul; Opdenakker, Ghislain; Presta, Marco; Van Damme, Jo; Struyf, Sofie

2014-01-01

CXCL4 and CXCL4L1, platelet-derived CXC chemokines, and their carboxy-terminal peptides CXCL447–70 and CXCL4L147–70 previously displayed angiostatic and anti-tumoral activity in a melanoma model. Here, we found CXCL447–70 and CXCL4L147–70 to inhibit lymphatic endothelial cell proliferation in vitro. Furthermore, the angiostatic potential of CXCL447–70 and CXCL4L147–70 was tested against different angiogenic stimuli (FGF1, FGF2, FGF8, EGF and VEGF). Besides reducing FGF2-induced vascular endothelial cell growth, CXCL447–70 and CXCL4L147–70 efficiently counteracted EGF. Consequently, we considered their anti-tumoral potential in EGF-dependent MDA-MB-231 breast tumors. In tumor-bearing mice, CXCL447–70 reduced tumor growth better than CXCL4L147–70. In CXCL447–70-treated tumors significantly more intratumoral monocytes/macrophages and dendritic cells were present and higher expression levels of CCL5 and IFN-γ were detected by qPCR on tumor lysates. Because neither peptide was able to specifically bind CXCR3A or CXCR3B, differential glycosaminoglycan binding and direct interaction with cytokines (EGF and CCL5) might explain any differences in anti-tumoral effects. Notably, CCL5-induced monocyte chemotaxis in vitro was increased by addition of CXCL447–70 or CXCL4L147–70. Finally, CXCL447–70 and CXCL4L147–70 inhibited proliferation of MDA-MB-231 cells. Our results suggest a tumor type-dependent responsiveness to either CXCL447–70 or CXCL4L147–70 treatment, defined by anti-proliferative, angiostatic and inflammatory actions, and substantiate their therapeutic potential. PMID:25373734

The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator

PubMed Central

Grants, Jennifer M.; Goh, Grace Y. S.; Taubert, Stefan

2015-01-01

The Mediator multiprotein complex (‘Mediator’) is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways. PMID:25634893

2-Dimensional changes of the soft tissue profile of augmented and non-augmented human extraction sockets: a randomized pilot study.

PubMed

Flügge, Tabea; Nelson, Katja; Nack, Claudia; Stricker, Andres; Nahles, Susanne

2015-04-01

This study identified the soft tissue changes of the alveolar ridge at different time points within 12 weeks after tooth extraction with and without socket augmentation. In 38 patients with single tooth extractions, 40 sockets were augmented and 39 extraction sockets were not augmented. At 2, 4, 6, 8 and 12 weeks impressions were taken and casts digitized with a laser scanner. The horizontal and vertical changes were compared between augmented and non-augmented sites. A p-value <0.05 was considered statistically significant. The mean changes of augmented sockets were between 0.4 mm (2 weeks) and 0.8 mm (12 weeks). In non-augmented sockets changes of 0.7 mm (2 weeks) and of 1.0 mm (12 weeks) were demonstrated. The mean values differed significantly between the buccal and oral region (p < 0.01). Overall, there were significant differences of the mean dimensional changes regarding time (p < 0.01) and augmentation (p < 0.01). Augmented sockets showed less resorption within 4 weeks after extraction compared to non-augmented sockets. Non-augmented sockets showed a continuous dimensional loss with a great variation over 12 weeks whereas augmented sockets had the highest degree of resorption between 4 and 6 weeks. At 12 weeks a comparable resorption in augmented and non-augmented sockets was observed. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Improvement of Atrophic Acne Scars in Skin of Color Using Topical Synthetic Epidermal Growth Factor (EGF) Serum: A Pilot Study.

PubMed

Stoddard, Marie Alexia; Herrmann, Jennifer; Moy, Lauren; Moy, Ronald

2017-04-01

BACKGROUND: Atrophic scarring in skin of color is a common, permanent, and distressing result of uncontrolled acne vulgaris. Ablative lasers and chemical peels are frequently used to improve the appearance of atrophic scars, primarily through the stimulation of collagen and elastin; however, these treatment modalities are associated with risks, such as dyspigmentation and hypertrophic scarring, especially in patients with darker skin.

OBJECTIVE: We evaluated the efficacy of topically applied synthetic epidermal growth factor (EGF) serum in reducing the appearance of atrophic acne scars in skin of color.

METHODS: A single-center clinical trial was performed on twelve healthy men and women (average age 32.5) with Fitzpatrick Type IV-V skin and evidence of facial grade II-IV atrophic acne scars. Subjects applied topical EGF serum to the full-face twice daily for 12 weeks. Scar improvement was investigated at each visit using an Investigator Global Assessment (IGA), a Goodman grade, clinical photography, and patient self-assessment.

RESULTS: Eleven subjects completed the trial. Compared to baseline, there was an improvement in mean IGA score from 3.36 (SEM = 0.15) to 2.18 (SEM = 0.33). Mean Goodman grade was reduced from 2.73 (SEM = 0.19) to 2.55 (SEM = 0.21). Of the eleven pairs of before and after photographs, nine were correctly chosen as the post-treatment image by a blind investigator. On self-assessment, 81% reported a "good" to "excellent" improvement in their scars compared to baseline (P = 0.004).

CONCLUSION: Topical EGF may improve the appearance of atrophic acne scars in skin of color. Additional, larger studies should be conducted to better characterize improvement.

J Drugs Dermatol. 2017;16(4):322-326.

Augmented Reality for the Improvement of Remote Laboratories: An Augmented Remote Laboratory

ERIC Educational Resources Information Center

Andujar, J. M.; Mejias, A.; Marquez, M. A.

2011-01-01

Augmented reality (AR) provides huge opportunities for online teaching in science and engineering, as these disciplines place emphasis on practical training and unsuited to completely nonclassroom training. This paper proposes a new concept in virtual and remote laboratories: the augmented remote laboratory (ARL). ARL is being tested in the first…

Differentiated thyroid cancer cell invasion is regulated through epidermal growth factor receptor-dependent activation of matrix metalloproteinase (MMP)-2/gelatinase A

PubMed Central

Yeh, Michael W; Rougier, Jean-Philippe; Park, Jin-Woo; Duh, Quan-Yang; Wong, Mariwil; Werb, Zena; Clark, Orlo H

2008-01-01

Mechanisms of invasion in thyroid cancer remain poorly understood. We hypothesized that signaling via the epidermal growth factor receptor (EGFR) stimulates thyroid cancer cell invasion by altering the expression and cleavage of matrix metalloproteinases (MMPs). Papillary and follicular carcinoma cell lines were treated with EGF, the EGFR tyrosine kinase inhibitor AG1478, and the MMP inhibitors GM-6001 and Col-3. Flow cytometry was used to detect EGFR. In vitro invasion assays, gelatin zymography, and quantitative reverse transcription-PCR were used to assess the changes in invasive behavior and MMP expression and activation. All cell lines were found to overexpress functional EGFR. EGF stimulated invasion by thyroid cancer cells up to sevenfold (P<0.0001), a process that was antagonized completely by AG1478 and Col-3, partially by GM-6001, but not by the serine protease inhibitor aprotinin. EGF upregulated expression of MMP-9 (2.64– to 8.89-fold, P<0.0001) and membrane type-1 MMP (MT1-MMP, 1.97- to 2.67-fold, P<0.0001). This effect was blocked completely by AG1478 and partially by Col-3. The activation of MMP-2 paralleled MT1-MMP expression. We demonstrate that MMPs are critical effectors of invasion in the papillary and follicular thyroid cancer cell lines studied. Invasion is regulated by signaling through EGFR, an effect mediated by augmentation of gelatinase expression and activation. MMP inhibitors and growth factor antagonists may be effective tumoristatic agents for the treatment of aggressive thyroid carcinomas. PMID:17158762

Regulation of cell proliferation and estrogen synthesis by ovine LH, IGF-I, and EGF in theca interstitial cells of the domestic hen cultured in defined media.

PubMed

Onagbesan, O M; Peddie, M J; Williams, J

1994-05-01

There is relatively little information on the factors which regulate the proliferation and alterations in the steroidogenic capacity of avian theca cells during follicular maturation. The development of culture conditions for these cells to determine the effects of gonadotrophin (LH) and the growth factors epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) on DNA synthesis and estrogen production is reported. Cultures were established in serum-supplemented (with fetal calf serum or chicken serum) or ITS+ (insulin, transferrin, and selenium plus additives) supplemented serum-free media. Cell replication occurred throughout the 72-hr culture period as indicated by a linear increase in the DNA content of the culture dishes. Aromatase activity of the cells as defined by conversion of androstenedione to estrogen was best maintained in serum-free medium while sera inhibited this activity. Ovine LH enhanced the aromatase activity of cultured cells from medium and small-sized follicles, while IGF-I and EGF inhibited both basal and LH-stimulated aromatase activity. LH, IGF-I, and EGF all stimulated cell proliferation as reflected by increased DNA. The responses of cells to these peptides varied with the size of the follicle, with the greatest effects on cells from F4/5.

Dynamic augmentation restores anterior tibial translation in ACL suture repair: a biomechanical comparison of non-, static and dynamic augmentation techniques.

PubMed

Hoogeslag, Roy A G; Brouwer, Reinoud W; Huis In 't Veld, Rianne; Stephen, Joanna M; Amis, Andrew A

2018-02-03

There is a lack of objective evidence investigating how previous non-augmented ACL suture repair techniques and contemporary augmentation techniques in ACL suture repair restrain anterior tibial translation (ATT) across the arc of flexion, and after cyclic loading of the knee. The purpose of this work was to test the null hypotheses that there would be no statistically significant difference in ATT after non-, static- and dynamic-augmented ACL suture repair, and they will not restore ATT to normal values across the arc of flexion of the knee after cyclic loading. Eleven human cadaveric knees were mounted in a test rig, and knee kinematics from 0° to 90° of flexion were recorded by use of an optical tracking system. Measurements were recorded without load and with 89-N tibial anterior force. The knees were tested in the following states: ACL-intact, ACL-deficient, non-augmented suture repair, static tape augmentation and dynamic augmentation after 10 and 300 loading cycles. Only static tape augmentation and dynamic augmentation restored ATT to values similar to the ACL-intact state directly postoperation, and maintained this after cyclic loading. However, contrary to dynamic augmentation, the ATT after static tape augmentation failed to remain statistically less than for the ACL-deficient state after cyclic loading. Moreover, after cyclic loading, ATT was significantly less with dynamic augmentation when compared to static tape augmentation. In contrast to non-augmented ACL suture repair and static tape augmentation, only dynamic augmentation resulted in restoration of ATT values similar to the ACL-intact knee and decreased ATT values when compared to the ACL-deficient knee immediately post-operation and also after cyclic loading, across the arc of flexion, thus allowing the null hypotheses to be rejected. This may assist healing of the ruptured ACL. Therefore, this study would support further clinical evaluation of dynamic augmentation of ACL repair.

Carbachol-mediated pigment granule dispersion in retinal pigment epithelium requires Ca2+ and calcineurin

PubMed Central

Johnson, Adam S; García, Dana M

2007-01-01

Background Inside bluegill (Lepomis macrochirus) retinal pigment epithelial cells, pigment granules move in response to extracellular signals. During the process of aggregation, pigment motility is directed toward the cell nucleus; in dispersion, pigment is directed away from the nucleus and into long apical processes. A number of different chemicals have been found to initiate dispersion, and carbachol (an acetylcholine analog) is one example. Previous research indicates that the carbachol-receptor interaction activates a Gq-mediated pathway which is commonly linked to Ca2+ mobilization. The purpose of the present study was to test for involvement of calcium and to probe calcium-dependent mediators to reveal their role in carbachol-mediated dispersion. Results Carbachol-induced pigment granule dispersion was blocked by the calcium chelator BAPTA. In contrast, the calcium channel antagonist verapamil, and incubation in Ca2+-free medium failed to block carbachol-induced dispersion. The calcineurin inhibitor cypermethrin blocked carbachol-induced dispersion; whereas, two protein kinase C inhibitors (staurosporine and bisindolylmaleimide II) failed to block carbachol-induced dispersion, and the protein kinase C activator phorbol 12-myristate 13-acetate failed to elicit dispersion. Conclusion A rise in intracellular calcium is necessary for carbachol-induced dispersion; however, the Ca2+ requirement is not dependent on extracellular sources, implying that intracellular stores are sufficient to enable pigment granule dispersion to occur. Calcineurin is a likely Ca2+-dependent mediator involved in the signal cascade. Although the pathway leads to the generation of diacylglycerol and calcium (both required for the activation of certain PKC isoforms), our evidence does not support a significant role for PKC. PMID:18093324

Repeated vertebral augmentation for new vertebral compression fractures of postvertebral augmentation patients: a nationwide cohort study

PubMed Central

Liang, Cheng-Loong; Wang, Hao-Kwan; Syu, Fei-Kai; Wang, Kuo-Wei; Lu, Kang; Liliang, Po-Chou

2015-01-01

Purpose Postvertebral augmentation vertebral compression fractures are common; repeated vertebral augmentation is usually performed for prompt pain relief. This study aimed to evaluate the incidence and risk factors of repeat vertebral augmentation. Methods We performed a retrospective, nationwide, population-based longitudinal observation study, using the National Health Insurance Research Database (NHIRD) of Taiwan. All patients who received vertebral augmentation for vertebral compression fractures were evaluated. The collected data included patient characteristics (demographics, comorbidities, and medication exposure) and repeat vertebral augmentation. Kaplan–Meier and stratified Cox proportional hazard regressions were performed for analyses. Results The overall incidence of repeat vertebral augmentation was 11.3% during the follow-up until 2010. Patients with the following characteristics were at greater risk for repeat vertebral augmentation: female sex (AOR=1.24; 95% confidence interval [CI]: 1.10–2.36), advanced age (AOR=1.60; 95% CI: 1.32–2.08), diabetes mellitus (AOR=4.31; 95% CI: 4.05–5.88), cerebrovascular disease (AOR=4.09; 95% CI: 3.44–5.76), dementia (AOR=1.97; 95% CI: 1.69–2.33), blindness or low vision (AOR=3.72; 95% CI: 2.32–3.95), hypertension (AOR=2.58; 95% CI: 2.35–3.47), and hyperlipidemia (AOR=2.09; 95% CI: 1.67–2.22). Patients taking calcium/vitamin D (AOR=2.98; 95% CI: 1.83–3.93), bisphosphonates (AOR=2.11; 95% CI: 1.26–2.61), or calcitonin (AOR=4.59; 95% CI: 3.40–5.77) were less likely to undergo repeat vertebral augmentation; however, those taking steroids (AOR=7.28; 95% CI: 6.32–8.08), acetaminophen (AOR=3.54; 95% CI: 2.75–4.83), or nonsteroidal anti-inflammatory drugs (NSAIDs) (AOR=6.14; 95% CI: 5.08–7.41) were more likely to undergo repeat vertebral augmentation. Conclusion We conclude that the incidence of repeat vertebral augmentation is rather high. An understanding of risk factors predicting repeat

Reductive Augmentation of the Breast.

PubMed

Chasan, Paul E

2018-06-01

Although breast reduction surgery plays an invaluable role in the correction of macromastia, it almost always results in a breast lacking in upper pole fullness and/or roundness. We present a technique of breast reduction combined with augmentation termed "reductive augmentation" to solve this problem. The technique is also extremely useful for correcting breast asymmetry, as well as revising significant pseudoptosis in the patient who has previously undergone breast augmentation with or without mastopexy. An evolution of techniques has been used to create a breast with more upper pole fullness and anterior projection in those patients desiring a more round, higher-profile appearance. Reductive augmentation is a one-stage procedure in which a breast augmentation is immediately followed by a modified superomedial pedicle breast reduction. Often, the excision of breast tissue is greater than would normally be performed with breast reduction alone. Thirty-five patients underwent reductive augmentation, of which 12 were primary surgeries and 23 were revisions. There was an average tissue removal of 255 and 227 g, respectively, per breast for the primary and revision groups. Six of the reductive augmentations were performed for gross asymmetry. Fourteen patients had a previous mastopexy, and 3 patients had a previous breast reduction. The average follow-up was 26 months. Reductive augmentation is an effective one-stage method for achieving a more round-appearing breast with upper pole fullness both in primary breast reduction candidates and in revisionary breast surgery. This technique can also be applied to those patients with significant asymmetry. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Membrane type 1-matrix metalloproteinase cleaves off the NH2-terminal portion of heparin-binding epidermal growth factor and converts it into a heparin-independent growth factor.

PubMed

Koshikawa, Naohiko; Mizushima, Hiroto; Minegishi, Tomoko; Iwamoto, Ryo; Mekada, Eisuke; Seiki, Motoharu

2010-07-15

Epidermal growth factor (EGF) receptors (ErbB) and EGF family members represent promising targets for cancer therapy. Heparin-binding EGF (HB-EGF) is a member of the EGF family and is an important target for therapy in some types of human cancers. Processing of HB-EGF by proprotein convertases, and successively, by ADAM family proteases, generates a soluble growth factor that requires heparin as a cofactor. Although heparin potentiates HB-EGF activity in vitro, it is not clear how the heparin-binding activity of HB-EGF is regulated. Here, we show that membrane type 1-matrix metalloproteinase (MT1-MMP; MMP14), a potent invasion-promoting protease, markedly enhances HB-EGF-dependent tumor formation in mice. MT1-MMP additionally cleaves HB-EGF and removes the NH(2)-terminal 20 amino acids that are important for binding heparin. Consequently, the processing of HB-EGF by MT1-MMP converts HB-EGF into a heparin-independent growth factor with enhanced mitogenic activity, and thereby, expression of both proteins costimulates tumor cell growth in vitro and in vivo. The ErbB family of receptors expressed in human gastric carcinoma cells play a role in mediating enhanced HB-EGF activity by MT1-MMP during invasive cell growth in collagen. Thus, we shed light on a new mechanism whereby HB-EGF activity is regulated that should be considered when designing HB-EGF-targeted cancer therapy. (c)2010 AACR.

PINOID kinase regulates root gravitropism through modulation of PIN2-dependent basipetal auxin transport in Arabidopsis.

PubMed

Sukumar, Poornima; Edwards, Karin S; Rahman, Abidur; Delong, Alison; Muday, Gloria K

2009-06-01

Reversible protein phosphorylation is a key regulatory mechanism governing polar auxin transport. We characterized the auxin transport and gravitropic phenotypes of the pinoid-9 (pid-9) mutant of Arabidopsis (Arabidopsis thaliana) and tested the hypothesis that phosphorylation mediated by PID kinase and dephosphorylation regulated by the ROOTS CURL IN NAPHTHYLPHTHALAMIC ACID1 (RCN1) protein might antagonistically regulate root auxin transport and gravity response. Basipetal indole-3-acetic acid transport and gravitropism are reduced in pid-9 seedlings, while acropetal transport and lateral root development are unchanged. Treatment of wild-type seedlings with the protein kinase inhibitor staurosporine phenocopies the reduced auxin transport and gravity response of pid-9, while pid-9 is resistant to inhibition by staurosporine. Staurosporine and the phosphatase inhibitor, cantharidin, delay the asymmetric expression of DR5revGFP (green fluorescent protein) at the root tip after gravistimulation. Gravity response defects of rcn1 and pid-9 are partially rescued by treatment with staurosporine and cantharidin, respectively. The pid-9 rcn1 double mutant has a more rapid gravitropic response than rcn1. These data are consistent with a reciprocal regulation of gravitropism by RCN1 and PID. Furthermore, the effect of staurosporine is lost in pinformed2 (pin2). Our data suggest that reduced PID kinase function inhibits gravitropism and basipetal indole-3-acetic acid transport. However, in contrast to PID overexpression studies, we observed wild-type asymmetric membrane distribution of the PIN2 protein in both pid-9 and wild-type root tips, although PIN2 accumulates in endomembrane structures in pid-9 roots. Similarly, staurosporine-treated plants expressing a PIN2GFP fusion exhibit endomembrane accumulation of PIN2GFP, but no changes in membrane asymmetries were detected. Our data suggest that PID plays a limited role in root development; loss of PID activity alters auxin

Augmented assessment as a means to augmented reality.

PubMed

Bergeron, Bryan

2006-01-01

Rigorous scientific assessment of educational technologies typically lags behind the availability of the technologies by years because of the lack of validated instruments and benchmarks. Even when the appropriate assessment instruments are available, they may not be applied because of time and monetary constraints. Work in augmented reality, instrumented mannequins, serious gaming, and similar promising educational technologies that haven't undergone timely, rigorous evaluation, highlights the need for assessment methodologies that address the limitations of traditional approaches. The most promising augmented assessment solutions incorporate elements of rapid prototyping used in the software industry, simulation-based assessment techniques modeled after methods used in bioinformatics, and object-oriented analysis methods borrowed from object oriented programming.

Matrikine and matricellular regulators of EGF Receptor signaling on cancer cell migration and invasion

PubMed Central

Grahovac, Jelena; Wells, Alan

2014-01-01

SYNOPSIS Cancer invasion is a complex process requiring, among other events, extensive remodeling of the extracellular matrix including deposition of pro-migratory and pro-proliferative moieties. In recent years it has been described that while invading through matrices cancer cells can change shape and adapt their migration strategies depending on the microenvironmental context. Although intracellular signaling pathways governing the mesenchymal to amoeboid migration shift and vice versa have been mostly elucidated, the extracellular signals promoting these shifts are largely unknown. In this review we summarize findings that point to matrikines that bind specifically to the EGF receptor as matricellular molecules that enable cancer cell migrational plasticity and promote invasion. PMID:24247562

Dose-related influence of sodium selenite on apoptosis in human thyroid follicles in vitro induced by iodine, EGF, TGF-beta, and H2O2.

PubMed

Lehmann, Petra; Rank, Petra; Hallfeldt, Klaus L J; Krebs, Bjarne; Gärtner, Roland

2006-08-01

Apoptosis of thyroid follicular cells is induced by high doses of iodide, epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), as well as H2O2 and might be attenuated by antioxidants. Therefore, we examined the apoptotic index induced by these substances in selenium-treated vs untreated human thyroid follicular cells. Reconstituted human thyroid follicles were incubated with sodium selenite (10 or 100 nM) for 72 h; controls received none. The follicles were then distributed to 24-well plates and incubated with potassium iodide (5, 10, or 20 nM), EGF (5 ng/mL), TGF-beta (5 ng/mL), or H2O2 (100 muM). Apoptosis was determined by a mitochondrial potential assay and the number of apoptotic cells counted by two independent, experienced technicians and the glutathione peroxidase (GPx) activity was determined. Asignificant increase of apoptic cells was obtained in control thyroid follicles treated with iodine (5, 10, or 20 microM), thyroidstimulating hormone (TSH) 1, or 10 mU/mL in combination with 5 and 10 microM iodine, EGF (5 ng/mL) and TGF-beta (5 ng/mL), or H2O2 (100 microM) (p < 0.001). In contrast, in thyroid follicles preincubated with 10 or 100 nM sodium selenite, the apoptototic index was identical to the basal rate. In H2O2-treated follicles, the apoptotic index was still significantly elevated but 50% lower compared to control cells. The GPx activity increased from 1.4 +/- 0.2 to 2.25 +/- 0.4 mU/microg DNA with 10 nMselenite and 2.6 + 0.4 mU/microg DNA with 100 nM selenite. Sodium selenite might increase the antioxidative potential in human thyroid follicles in vitro and therefore diminish the apoptosis induced by TGF-beta, EGF, iodide, and even H2O2.

EXPRESSION OF EGFR AND ITS LIGANDS IN RESPONSE TO TCDD OR RETINOIC ACID IN EGF AND TGFALPHA KO FETAL MOUSE PALATE

EPA Science Inventory

EXPRESSION OF EGFR AND ITS LIGANDS IN RESPONSE TO TCDD OR RETINOIC ACID IN EGF AND TGF" KO FETAL MOUSE PALATE. Abbott, Barbara D.1; Boyd, Hadiya2; Wood, Carmen1; Held, Gary1. 1.EPA, ORD, NHEERL, RTD, US EPA, Research Triangle Park, NC, USA. 2MARC Program, NCCU, Durham, NC, USA. <...

Quantitative Analysis of Cancer Cell Migration in Gradients Of EGF, HGF, and SDF-alpha Using a Microfluidic Chemotaxis Device

DTIC Science & Technology

2005-01-01

Quantitative Analysis of Cancer Cell Migration in Gradients of EGF, HGF, and SDF-alpha Using a Microfluidic Chemotaxis Device The University of California...allowing for parallel analysis . Additionally, simple methods of localizing gels into microdevices are demonstrated. The device was characterized by...To overcome some of these drawbacks, several approaches have utilized free diffusion to produce gradients in static environ - ments.5-9 However

PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells

PubMed Central

Bazzani, Lorenzo; Donnini, Sandra; Giachetti, Antonio; Christofori, Gerhard; Ziche, Marina

2018-01-01

Prostaglandin E2 (PGE2) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1, PTGS2, MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE2-induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression. PMID:29599917

PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells.

PubMed

Bazzani, Lorenzo; Donnini, Sandra; Giachetti, Antonio; Christofori, Gerhard; Ziche, Marina

2018-03-13

Prostaglandin E 2 (PGE 2 ) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE 2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE 2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE 2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE 2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1 , PTGS2 , MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE 2 -induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression.

The Mediator complex of Caenorhabditis elegans: insights into the developmental and physiological roles of a conserved transcriptional coregulator.

PubMed

Grants, Jennifer M; Goh, Grace Y S; Taubert, Stefan

2015-02-27

The Mediator multiprotein complex ('Mediator') is an important transcriptional coregulator that is evolutionarily conserved throughout eukaryotes. Although some Mediator subunits are essential for the transcription of all protein-coding genes, others influence the expression of only subsets of genes and participate selectively in cellular signaling pathways. Here, we review the current knowledge of Mediator subunit function in the nematode Caenorhabditis elegans, a metazoan in which established and emerging genetic technologies facilitate the study of developmental and physiological regulation in vivo. In this nematode, unbiased genetic screens have revealed critical roles for Mediator components in core developmental pathways such as epidermal growth factor (EGF) and Wnt/β-catenin signaling. More recently, important roles for C. elegans Mediator subunits have emerged in the regulation of lipid metabolism and of systemic stress responses, engaging conserved transcription factors such as nuclear hormone receptors (NHRs). We emphasize instances where similar functions for individual Mediator subunits exist in mammals, highlighting parallels between Mediator subunit action in nematode development and in human cancer biology. We also discuss a parallel between the association of the Mediator subunit MED12 with several human disorders and the role of its C. elegans ortholog mdt-12 as a regulatory hub that interacts with numerous signaling pathways. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Picture Exchange Communication System and Pals: A Peer-Mediated Augmentative and Alternative Communication Intervention for Minimally Verbal Preschoolers With Autism.

PubMed

Thiemann-Bourque, Kathy; Brady, Nancy; McGuff, Sara; Stump, Keenan; Naylor, Amy

2016-10-01

This study was conducted to investigate the effectiveness of a social intervention that integrates peer-mediated approaches and the Picture Exchange Communication System (PECS). Effects were evaluated using a series of A-B designs replicated across 4 children with severe autism and limited verbal skills. Seven peers without disabilities were trained to use PECS and facilitative social skills. Measures of changes included rates of communication behaviors, modes, functions, and engagement. Outcomes revealed an intervention effect for 1 child with autism, and this effect was replicated across 3 other children. All children improved in peer-directed communication, with greater increases for 2 children during snack time. For each child with autism, the primary communication behavior was to initiate with picture symbols to request; the peer's primary communication was to respond. Two children increased communicative functions to comment and to share, and all 4 children showed improved social engagement. All peers increased their communication with the children with autism. These findings add to the limited research on the benefits of teaching typically developing peers to be responsive listeners to preschoolers with autism by learning to use PECS. These results invite further investigation of teaching peers other augmentative and alternative communication approaches and how to increase children's communication with peers for different purposes.

Curcumin Inhibits CD4+ T Cell Activation, but Augments CD69 Expression and TGF-β1-Mediated Generation of Regulatory T Cells at Late Phase

PubMed Central

Kim, Girak; Jang, Mi Seon; Son, Young Min; Seo, Min Ji; Ji, Sang Yun; Han, Seung Hyun; Jung, In Duk; Park, Yeong-Min; Jung, Hyun Jung; Yun, Cheol-Heui

2013-01-01

Background Curcumin is a promising candidate for a natural medicinal agent to treat chronic inflammatory diseases. Although CD4+ T cells have been implicated in the pathogenesis of chronic inflammation, whether curcumin directly regulates CD4+ T cells has not been definitively established. Here, we showed curcumin-mediated regulation of CD2/CD3/CD28-initiated CD4+ T cell activation in vitro. Methodology/Principal Findings Primary human CD4+ T cells were stimulated with anti-CD2/CD3/CD28 antibody-coated beads as an in vitro surrogate system for antigen presenting cell-T cell interaction and treated with curcumin. We found that curcumin suppresses CD2/CD3/CD28-initiated CD4+ T cell activation by inhibiting cell proliferation, differentiation and cytokine production. On the other hand, curcumin attenuated the spontaneous decline of CD69 expression and indirectly increased expression of CCR7, L-selectin and Transforming growth factor-β1 (TGF-β1) at the late phase of CD2/CD3/CD28-initiated T cell activation. Curcumin-mediated up-regulation of CD69 at late phase was associated with ERK1/2 signaling. Furthermore, TGF-β1 was involved in curcumin-mediated regulation of T cell activation and late-phase generation of regulatory T cells. Conclusions/Significance Curcumin not merely blocks, but regulates CD2/CD3/CD28-initiated CD4+ T cell activation by augmenting CD69, CCR7, L-selectin and TGF-β1 expression followed by regulatory T cell generation. These results suggest that curcumin could directly reduce T cell-dependent inflammatory stress by modulating CD4+ T cell activation at multiple levels. PMID:23658623

Epidermal growth factor selectively enhances functional enterocyte adaptation after massive small bowel resection.

PubMed

Dunn, J C; Parungo, C P; Fonkalsrud, E W; McFadden, D W; Ashley, S W

1997-01-01

After massive small bowel resection, the intestine adapts to compensate. In addition to proliferation, enterocytes also undergo selective functional adaptation. In this study we examined the effect of intraperitoneal administration of epidermal growth factor (EGF) on the expression of the brush border dissacharidase sucrase, the sodium glucose cotransporter (SGLT1), and the sodium-potassium ATPase pump (NaK ATPase) by enterocytes in the remnant intestine after massive small bowel resection. Adult Lewis rats underwent either ileal transection or 70% proximal intestinal resection. These animals were subdivided into groups that received either saline or EGF intraperitoneally for 1 week. Ilea from each group were harvested 4 weeks postoperatively. Enterocytes were separated from these segments by calcium chelation. The total protein from the isolated cells was subjected to Western blot analysis. Administration of EGF to animals that underwent transection did not significantly alter the expression of sucrase, SGLT1, or NaK ATPase. After intestinal resection, the expressions of sucrase and SGLT1 were significantly increased. The combination of EGF administration and intestinal resection resulted in a further increase in SGLT1 expression. The intraperitoneal administration of EGF selectively enhanced the expression of SGLT1 by enterocytes after massive small bowel resection. Administration of EGF to sham-operated animals did not have similar effects. These results suggest that EGF augments the adaptive response and may therefore have a therapeutic role in the management of patients with short bowel syndrome.

Pedicle screw cement augmentation. A mechanical pullout study on different cement augmentation techniques.

PubMed

Costa, Francesco; Ortolina, Alessandro; Galbusera, Fabio; Cardia, Andrea; Sala, Giuseppe; Ronchi, Franco; Uccelli, Carlo; Grosso, Rossella; Fornari, Maurizio

2016-02-01

Pedicle screws with polymethyl methacrylate (PMMA) cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques remains unknown. This study aimed to determine the difference in pullout strength between different cement augmentation techniques. Uniform synthetic bones simulating severe osteoporosis were used to provide a platform for each augmentation technique. In all cases a polyaxial screw and acrylic cement (PMMA) at medium viscosity were used. Five groups were analyzed: I) only screw without PMMA (control group); II) retrograde cement pre-filling of the tapped area; III) cannulated and fenestrate screw with cement injection through perforation; IV) injection using a standard trocar of PMMA (vertebroplasty) and retrograde pre-filling of the tapped area; V) injection through a fenestrated trocar and retrograde pre-filling of the tapped area. Standard X-rays were taken in order to visualize cement distribution in each group. Pedicle screws at full insertion were then tested for axial pullout failure using a mechanical testing machine. A total of 30 screws were tested. The results of pullout analysis revealed better results of all groups with respect to the control group. In particular the statistical analysis showed a difference of Group V (p = 0.001) with respect to all other groups. These results confirm that the cement augmentation grants better results in pullout axial forces. Moreover they suggest better load resistance to axial forces when the distribution of the PMMA is along all the screw combining fenestration and pre-filling augmentation technique. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schürpf, Thomas; Chen, Qiang; Liu, Jin-huan

Developmental endothelial cell locus-1 (Del-1) glycoprotein is secreted by endothelial cells and a subset of macrophages. Del-1 plays a regulatory role in vascular remodeling and functions in innate immunity through interaction with integrin {alpha}{sub V}{beta}{sub 3}. Del-1 contains 3 epidermal growth factor (EGF)-like repeats and 2 discoidin-like domains. An Arg-Gly-Asp (RGD) motif in the second EGF domain (EGF2) mediates adhesion by endothelial cells and phagocytes. We report the crystal structure of its 3 EGF domains. The RGD motif of EGF2 forms a type II' {beta} turn at the tip of a long protruding loop, dubbed the RGD finger. Whereas EGF2more » and EGF3 constitute a rigid rod via an interdomain calcium ion binding site, the long linker between EGF1 and EGF2 lends considerable flexibility to EGF1. Two unique O-linked glycans and 1 N-linked glycan locate to the opposite side of EGF2 from the RGD motif. These structural features favor integrin binding of the RGD finger. Mutagenesis data confirm the importance of having the RGD motif at the tip of the RGD finger. A database search for EGF domain sequences shows that this RGD finger is likely an evolutionary insertion and unique to the EGF domain of Del-1 and its homologue milk fat globule-EGF 8. The RGD finger of Del-1 is a unique structural feature critical for integrin binding.« less

EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, Da-min; Lu, Pei-Hua, E-mail: lphty1_1@163.com; Zhang, Ke

In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 throughmore » lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R.« less

Indirubin, an acting component of indigo naturalis, inhibits EGFR activation and EGF-induced CDC25B gene expression in epidermal keratinocytes.

PubMed

Hsieh, Wan-Ling; Lin, Yin-Ku; Tsai, Chi-Neu; Wang, Ta-Min; Chen, Tzu-Ya; Pang, Jong-Hwei S

2012-08-01

Topical indigo naturalis ointment is clinically proved to be an effective therapy for plaque-type psoriasis. Indirubin, as the active component of indigo naturalis, inhibits cell proliferation of epidermal keratinocytes. However, the detailed underlying mechanism is not fully understood. To further investigate the anti-proliferating effects of indigo naturalis and indirubin on epidermal keratinocytes. The decreased expression of CDC25B in indigo naturalis- or indirubin-treated epidermal keratinocytes, as revealed by cDNA microarray analysis, was studied. The CDC25B expression was examined under different serum concentrations and compared between primary and immortalized keratinocytes. The activation of EGFR and the effect of EGF on the cell proliferation and CDC25B expression were also investigated in epidermal keratinocytes. RT/real-time PCR and western blot method were used to analyze the CDC25B expression at the mRNA and protein levels, respectively. Indigo naturalis and indirubin were confirmed to down-regulate CDC25B expression significantly at both the mRNA and protein levels. The growth-dependent expression of CDC25B was demonstrated by the increased expression in serum-stimulated and immortalized keratinocytes. The activation of EGF receptor, known to be highly expressed in psoriatic lesions, was inhibited by indigo naturalis or indirubin. The cell proliferation and CDC25B expression of epidermal keratinocytes were induced by EGF alone and confirmed to be inhibited by indigo naturalis or indirubin. Except being a common therapeutic target in various cancers, CDC25B also plays an important role in the hyper-proliferation of epidermal keratinocytes which can be suppressed by anti-psoriatic drug indigo naturalis and its component, indirubin. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Augmenting Human Performance in Remotely Piloted Aircraft.

PubMed

Gruenwald, Christina M; Middendorf, Matthew S; Hoepf, Michael R; Galster, Scott M

2018-02-01

An experiment in a program of research supporting the sense-assess-augment (SAA) framework is described. The objective is to use physiological measures to assess operator cognitive workload in remotely piloted aircraft (RPA) operations, and provide augmentation to assist the operator in times of high workload. In previous experiments, physiological measures were identified that demonstrate sensitivity to changes in workload. The current research solely focuses on the augmentation component of the SAA paradigm. This line of research uses a realistic RPA simulation with varying levels of workload. Recruited from the Midwest region were 12 individuals (6 women) to participate in the experiment. The subjects were trained to perform a surveillance task and a tracking task using RPAs. There was also a secondary task in which subjects were required to answer cognitive probes. A within subjects factorial design was employed with three factors per task. Subjective workload estimates were acquired using the NASA-TLX. Performance data were calculated using a composite scoring algorithm. Augmentation significantly improved performance and reduced workload in both tasks. In the surveillance task, augmentation increased performance from 573.78 to 679.04. Likewise, augmentation increased performance in the tracking task from 749.39 to 791.81. Augmentation was more beneficial in high workload conditions than low workload conditions. The increase in performance and decrease in workload associated with augmentation is an important and anticipated finding. This suggests that augmentation should only be provided when it is truly needed, especially if the augmentation requires additional assets and/or resources.Gruenwald CM, Middendorf MS, Hoepf MR, Galster SM. Augmenting human performance in remotely piloted aircraft. Aerosp Med Hum Perform. 2018; 89(2):115-121.

Augmentation-related brain plasticity

PubMed Central

Di Pino, Giovanni; Maravita, Angelo; Zollo, Loredana; Guglielmelli, Eugenio; Di Lazzaro, Vincenzo

2014-01-01

Today, the anthropomorphism of the tools and the development of neural interfaces require reconsidering the concept of human-tools interaction in the framework of human augmentation. This review analyses the plastic process that the brain undergoes when it comes into contact with augmenting artificial sensors and effectors and, on the other hand, the changes that the use of external augmenting devices produces in the brain. Hitherto, few studies investigated the neural correlates of augmentation, but clues on it can be borrowed from logically-related paradigms: sensorimotor training, cognitive enhancement, cross-modal plasticity, sensorimotor functional substitution, use and embodiment of tools. Augmentation modifies function and structure of a number of areas, i.e., primary sensory cortices shape their receptive fields to become sensitive to novel inputs. Motor areas adapt the neuroprosthesis representation firing-rate to refine kinematics. As for normal motor outputs, the learning process recruits motor and premotor cortices and the acquisition of proficiency decreases attentional recruitment, focuses the activity on sensorimotor areas and increases the basal ganglia drive on the cortex. Augmentation deeply relies on the frontoparietal network. In particular, premotor cortex is involved in learning the control of an external effector and owns the tool motor representation, while the intraparietal sulcus extracts its visual features. In these areas, multisensory integration neurons enlarge their receptive fields to embody supernumerary limbs. For operating an anthropomorphic neuroprosthesis, the mirror system is required to understand the meaning of the action, the cerebellum for the formation of its internal model and the insula for its interoception. In conclusion, anthropomorphic sensorized devices can provide the critical sensory afferences to evolve the exploitation of tools through their embodiment, reshaping the body representation and the sense of the self

A novel taspine derivative, HMQ1611, inhibits breast cancer cell growth via estrogen receptor α and EGF receptor signaling pathways.

PubMed

Zhan, Yingzhuan; Zhang, Yanmin; Liu, Cuicui; Zhang, Jie; Smith, Wanli W; Wang, Nan; Chen, Yinnan; Zheng, Lei; He, Langchong

2012-06-01

Breast cancer is a common cancer with a leading cause of cancer mortality in women. Currently, the chemotherapy for breast cancer is underdeveloped. Here, we report a novel taspine derivative, HMQ1611, which has anticancer effects using in vitro and in vivo breast cancer models. HMQ1611 reduced cancer cell proliferation in four human breast cancer cell lines including MDA-MB-231, SK-BR-3, ZR-75-30, and MCF-7. HMQ1611 more potently reduced growth of estrogen receptor α (ERα)-positive breast cancer cells (ZR-75-30 and MCF-7) than ERα-negative cells (MDA-MB-231 and SK-BR-3). Moreover, HMQ1611 arrested breast cancer cell cycle at S-phase. In vivo tumor xenograft model, treatment of HMQ1611 significantly reduced tumor size and weight compared with vehicles. We also found that HMQ1611 reduced ERα expression and inhibited membrane ERα-mediated mitogen-activated protein kinase (MAPK) signaling following the stimulation of cells with estrogen. Knockdown of ERα by siRNA transfection in ZR-75-30 cells attenuated HMQ1611 effects. In contrast, overexpression of ERα in MDA-MB-231 cells enhanced HMQ1611 effects, suggesting that ERα pathway mediated HMQ1611's inhibition of breast cancer cell growth in ERα-positive breast cancer. HMQ1611 also reduced phosphorylation of EGF receptor (EGFR) and its downstream signaling players extracellular signal-regulated kinase (ERK)1/2 and AKT activation both in ZR-75-30 and MDA-MB-231 cells. These results showed that the novel compound HMQ1611 had anticancer effects, and partially via ERα and/or EGFR signaling pathways, suggesting that HMQ1611 may be a potential novel candidate for human breast cancer intervention. ©2012 AACR.

Confronting an Augmented Reality

ERIC Educational Resources Information Center

Munnerley, Danny; Bacon, Matt; Wilson, Anna; Steele, James; Hedberg, John; Fitzgerald, Robert

2012-01-01

How can educators make use of augmented reality technologies and practices to enhance learning and why would we want to embrace such technologies anyway? How can an augmented reality help a learner confront, interpret and ultimately comprehend reality itself ? In this article, we seek to initiate a discussion that focuses on these questions, and…

Advanced Intellect-Augmentation Techniques.

ERIC Educational Resources Information Center

Engelbart, D. C.

This progress report covers a two-year project which is part of a program that is exploring the value of computer aids in augmenting human intellectual capability. The background and nature of the program, its resources, and the activities it has undertaken are outlined. User experience in applying augmentation tools and techniques to various…

COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito

2010-09-03

Research highlights: {yields} ARF1 activation is involved in the EGFR transport to the ER and the nucleus. {yields} Assembly of {gamma}-COP coatomer mediates EGFR transport to the ER and the nucleus. {yields} Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored.more » Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH{sub 2}-terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with {gamma}-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.« less

Mitomycin C-treated or irradiated concanavalin A-activated T cells augment the activation of cytotoxic T cells in vivo.

PubMed

Moyers, C; Pottmeyer-Gerber, C; Gerber, M; Buszello, H; Dröge, W

1984-10-01

The activation of cytotoxic T lymphocytes (CTL) in vivo after immunization of normal or cyclophosphamide-treated mice with allogeneic cells was strongly augmented by the administration of mitomycin C-treated or irradiated concanavalin A-activated spleen cells (Con A-spl). This effect of the Con A-spl was abrogated by treatment with Anti-Thy 1 antibody plus complement, and was therefore presumably mediated by activated "helper" T cells. (The term "helper" cell is only operationally defined in this context and indicates that the augmenting irradiation resistant T cells are obviously not CTL precursor cells). These observations indicated (i) that even the cytotoxic response against allogeneic stimulator cells suffers in vivo from insufficient "helper" T cell activity, and (ii) that the injection of Con A-spl may serve as a simple procedure to apply this "helper" activity in vivo. This procedure was at least as effective as the repeated injection of interleukin 2 (IL-2)-containing cell supernatants with up to four 30-unit doses of IL-2 per mouse. IL-2-containing cell supernatants were found to mediate similar effects only if injected into the footpads but not intravenously. This was in line with the reported observation that IL-2 has an extremely short half-life in vivo. The injection of Con A-spl was also found to augment the proliferative response in the regional lymph nodes.

The Augmentation System Framework.

ERIC Educational Resources Information Center

Engelbart, Doug; Hooper, Kristina

1986-01-01

Augmentation systems are composed of things that will add to what the human is genetically endowed with in order to extend the net capabilities that a human or human organization can apply to the problems or goals of human society. A broad brush categorization of the components of an augmentation system includes three distinct though interacting…

Gold nanoparticles as a platform for creating a multivalent poly-SUMO chain inhibitor that also augments ionizing radiation

PubMed Central

Li, Yi-Jia; Perkins, Angela L.; Su, Yang; Ma, Yuelong; Colson, Loren; Horne, David A.; Chen, Yuan

2012-01-01

Protein-protein interactions mediated by ubiquitin-like (Ubl) modifications occur as mono-Ubl or poly-Ubl chains. Proteins that regulate poly-SUMO (small ubiquitin-like modifier) chain conjugates play important roles in cellular response to DNA damage, such as those caused by cancer radiation therapy. Additionally, high atomic number metals, such as gold, preferentially absorb much more X-ray energy than soft tissues, and thus augment the effect of ionizing radiation when delivered to cells. In this study, we demonstrate that conjugation of a weak SUMO-2/3 ligand to gold nanoparticles facilitated selective multivalent interactions with poly-SUMO-2/3 chains leading to efficient inhibition of poly-SUMO-chain-mediated protein-protein interactions. The ligand-gold particle conjugate significantly sensitized cancer cells to radiation but was not toxic to normal cells. This study demonstrates a viable approach for selective targeting of poly-Ubl chains through multivalent interactions created by nanoparticles that can be chosen based on their properties, such as abilities to augment radiation effects. PMID:22388745

ARSC: Augmented Reality Student Card--An Augmented Reality Solution for the Education Field

ERIC Educational Resources Information Center

El Sayed, Neven A. M.; Zayed, Hala H.; Sharawy, Mohamed I.

2011-01-01

Augmented Reality (AR) is the technology of adding virtual objects to real scenes through enabling the addition of missing information in real life. As the lack of resources is a problem that can be solved through AR, this paper presents and explains the usage of AR technology we introduce Augmented Reality Student Card (ARSC) as an application of…

Augmented Reality-Guided Lumbar Facet Joint Injections.

PubMed

Agten, Christoph A; Dennler, Cyrill; Rosskopf, Andrea B; Jaberg, Laurenz; Pfirrmann, Christian W A; Farshad, Mazda

2018-05-08

The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality-guided and 20 computed tomography (CT)-guided facet joint injections each: for each augmented reality-guided injection, the hologram was manually aligned with the phantom container using the ring markers. The radiologists targeted the virtual facet joint and tried to place the needle tip in the holographic joint space. Computed tomography was performed after each needle placement to document final needle tip position. Time needed from grabbing the needle to final needle placement was measured for each simulated injection. An independent radiologist rated images of all needle placements in a randomized order blinded to modality (augmented reality vs CT) and performer as perfect, acceptable, incorrect, or unsafe. Accuracy and time to place needles were compared between augmented reality-guided and CT-guided facet joint injections. In total, 39/40 (97.5%) of augmented reality-guided needle placements were either perfect or acceptable compared with 40/40 (100%) CT-guided needle placements (P = 0.5). One augmented reality-guided injection missed the facet joint space by 2 mm. No unsafe needle placements occurred. Time to final needle placement was substantially faster with augmented reality guidance (mean 14 ± 6 seconds vs 39 ± 15 seconds, P < 0.001 for both readers). Augmented reality-guided facet joint injections are feasible and accurate without potentially harmful needle placement in an experimental setting.

Challenges associated with reentry maxillary sinus augmentation.

PubMed

Mardinger, Ofer; Moses, Ofer; Chaushu, Gavriel; Manor, Yifat; Tulchinsky, Ze'ev; Nissan, Joseph

2010-09-01

This study was a retrospective assessment of reentry sinus augmentation compared with sinus augmentation performed for the first time. There were 38 subjects who required sinus augmentation. The study group (17 patients, 21 sinuses) included subjects following failure of a previous sinus augmentation procedure that required reentry augmentation. The control group (21 patients, 21 sinuses) included subjects in which sinus augmentation was performed for the first time. Patients' medical files were reviewed. A preformed questionnaire was used to collect data regarding demographic parameters, medical and dental health history, habits, and intra- and postoperative data. Operative challenges in the study group included adhesions of the buccal flap to the Schneiderian membrane (62%, 13/21, P<.001), bony fenestration of the lateral wall with adhesions (71%, 15/21, P<.001), limited mobility of a clinical fibrotic Schneiderian membrane (71%, 15/21, P<.001), and increased incidence of membrane perforations (47%, 10/21, versus 9.5%, 2/21, P=.03). In the control group the Schneiderian membrane was thin and flexible. Sinus augmentation succeeded in all cases of both groups. Implant failure was significantly higher in the study group (11% versus 0%, P<.001). Clinical success of reentry sinus augmentation is predictable despite its complexity. Clinicians should be aware of anatomical changes caused by previous failure of this procedure. Patients should be informed about the lower success rate of implants when reentry sinus augmentation is required. Copyright (c) 2010 Mosby, Inc. All rights reserved.

The EGF Repeat-Specific O-GlcNAc-Transferase Eogt Interacts with Notch Signaling and Pyrimidine Metabolism Pathways in Drosophila

PubMed Central

Müller, Reto; Jenny, Andreas; Stanley, Pamela

2013-01-01

The O-GlcNAc transferase Eogt modifies EGF repeats in proteins that transit the secretory pathway, including Dumpy and Notch. In this paper, we show that the Notch ligands Delta and Serrate are also substrates of Eogt, that mutation of a putative UDP-GlcNAc binding DXD motif greatly reduces enzyme activity, and that Eogt and the cytoplasmic O-GlcNAc transferase Ogt have distinct substrates in Drosophila larvae. Loss of Eogt is larval lethal and disrupts Dumpy functions, but does not obviously perturb Notch signaling. To identify novel genetic interactions with eogt, we investigated dominant modification of wing blister formation caused by knock-down of eogt. Unexpectedly, heterozygosity for several members of the canonical Notch signaling pathway suppressed wing blister formation. And importantly, extensive genetic interactions with mutants in pyrimidine metabolism were identified. Removal of pyrimidine synthesis alleles suppressed wing blister formation, while removal of uracil catabolism alleles was synthetic lethal with eogt knock-down. Therefore, Eogt may regulate protein functions by O-GlcNAc modification of their EGF repeats, and cellular metabolism by affecting pyrimidine synthesis and catabolism. We propose that eogt knock-down in the wing leads to metabolic and signaling perturbations that increase cytosolic uracil levels, thereby causing wing blister formation. PMID:23671640

Threat Reappraisal as a Mediator of Symptom Change in Cognitive-Behavioral Treatment of Anxiety Disorders: A Systematic Review

ERIC Educational Resources Information Center

Smits, Jasper A. J.; Julian, Kristin; Rosenfield, David; Powers, Mark B.

2012-01-01

Objective: Identifying mediators of therapeutic change is important to the development of interventions and augmentation strategies. Threat reappraisal is considered a key mediator underlying the effects of cognitive-behavioral therapy (CBT) for anxiety disorders. The present study systematically reviewed the evidence for the threat reappraisal…

Hsp105 family proteins suppress staurosporine-induced apoptosis by inhibiting the translocation of Bax to mitochondria in HeLa cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagishi, Nobuyuki; Ishihara, Keiichi; Saito, Youhei

2006-10-15

Hsp105 (Hsp105{alpha} and Hsp105{beta}), major heat shock proteins in mammalian cells, belong to a subgroup of the HSP70 family, HSP105/110. Previously, we have shown that Hsp105{alpha} has completely different effects on stress-induced apoptosis depending on cell type. However, the molecular mechanisms by which Hsp105{alpha} regulates stress-induced apoptosis are not fully understood. Here, we established HeLa cells that overexpress either Hsp105{alpha} or Hsp105{beta} by removing doxycycline and examined how Hsp105 modifies staurosporine (STS)-induced apoptosis in HeLa cells. Apoptotic features such as the externalization of phosphatidylserine on the plasma membrane and nuclear morphological changes were induced by the treatment with STS, andmore » the STS-induced apoptosis was suppressed by overexpression of Hsp105{alpha} or Hsp105{beta}. In addition, we found that overexpression of Hsp105{alpha} or Hsp105{beta} suppressed the activation of caspase-3 and caspase-9 by preventing the release of cytochrome c from mitochondria. Furthermore, the translocation of Bax to mitochondria, which results in the release of cytochrome c from the mitochondria, was also suppressed by the overexpression of Hsp105{alpha} or Hsp105{beta}. Thus, it is suggested that Hsp105 suppresses the stress-induced apoptosis at its initial step, the translocation of Bax to mitochondria in HeLa cells.« less

α-Lipoic acid inhibits human lung cancer cell proliferation through Grb2-mediated EGFR downregulation.

PubMed

Yang, Lan; Wen, Ya; Lv, Guoqing; Lin, Yuntao; Tang, Junlong; Lu, Jingxiao; Zhang, Manqiao; Liu, Wen; Sun, Xiaojuan

2017-12-09

Alpha lipoic acid (α -LA) is a naturally occurring antioxidant and metabolic enzyme co-factor. Recently, α -LA has been reported to inhibit the growth of various cancer cells, but the precise signaling pathways that mediate the effects of α -LA on non-small cell lung cancer (NSCLC) development remain unclear. The CCK-8 assay was used to assess cell proliferation in NSCLC cell lines after α -LA treatment. The expression of growth factor receptor-bound protein 2 (Grb2), cyclin-dependent kinase (CDK)-2, CDK4, CDK6, Cyclin D3, Cyclin E1, Ras, c-Raf, epidermal growth factor receptor (EGFR), ERK1/2 and activated EGFR and ERK1/2 was evaluated by western blotting. Grb2 levels were restored in α-LA-treated cells by transfection of a plasmid carrying Grb2 and were reduced in NSCLC cells via specific siRNA-mediated knockdown. α -LA dramatically decreased NSCLC cell proliferation by downregulating Grb2; in contrast, Grb2 overexpression significantly prevented α-LA-induced decrease in cell growth in vitro. Western blot analysis indicated that α-LA decreased the levels of phospho-EGFR, CDK2/4/6, Cyclins D3 and E1, which are associated with the inhibition of G1/S-phase transition. Additional experiments indicated that Grb2 inhibition partially abolished EGF-induced phospho-EGFR and phospho-ERK1/2 activity. In addition, α-LA exerted greater inhibitory effects than gefitinib on NSCLC cells by preventing EGF-induced EGFR activation. For the first time, these findings provide the first evidence that α-LA inhibits cell proliferation through Grb2 by suppressing EGFR phosphorylation and that MAPK/ERK is involved in this pathway. Copyright © 2017. Published by Elsevier Inc.

Thrombin-mediated proteoglycan synthesis utilizes both protein-tyrosine kinase and serine/threonine kinase receptor transactivation in vascular smooth muscle cells.

PubMed

Burch, Micah L; Getachew, Robel; Osman, Narin; Febbraio, Mark A; Little, Peter J

2013-03-08

G protein-coupled receptor signaling is mediated by three main mechanisms of action; these are the classical pathway, β-arrestin scaffold signaling, and the transactivation of protein-tyrosine kinase receptors such as those for EGF and PDGF. Recently, it has been demonstrated that G protein-coupled receptors can also mediate signals via transactivation of serine/threonine kinase receptors, most notably the transforming growth factor-β receptor family. Atherosclerosis is characterized by the development of lipid-laden plaques in blood vessel walls. Initiation of plaque development occurs via low density lipoprotein retention in the neointima of vessels due to binding with modified proteoglycans secreted by vascular smooth muscle cells. Here we show that transactivation of protein-tyrosine kinase receptors is mediated by matrix metalloproteinase triple membrane bypass signaling. In contrast, serine/threonine kinase receptor transactivation is mediated by a cytoskeletal rearrangement-Rho kinase-integrin system, and both protein-tyrosine kinase and serine/threonine kinase receptor transactivation concomitantly account for the total proteoglycan synthesis stimulated by thrombin in vascular smooth muscle. This work provides evidence of thrombin-mediated proteoglycan synthesis and paves the way for a potential therapeutic target for plaque development and atherosclerosis.

Vertebral Augmentation can Induce Early Signs of Degeneration in the Adjacent Intervertebral Disc: Evidence from a Rabbit Model.

PubMed

Feng, Zhiyun; Chen, Lunhao; Hu, Xiaojian; Yang, Ge; Wang, Yue; Chen, Zhong

2018-04-11

An experimental study. The aim of this study was to determine the effect of polymethylmethacrylate (PMMA) augmentation on the adjacent disc. Vertebral augmentation with PMMA reportedly may predispose the adjacent vertebra to fracture. The influence of PMMA augmentation on the adjacent disc, however, remains unclear. Using a retroperitoneal approach, PMMA augmentation was performed for 23 rabbits. For each animal, at least one vertebra was augmented with 0.2 to 0.3 mL PMMA. The disc adjacent to the augmented vertebra and a proximal control disc were studied using magnetic resonance (MR) imaging, histological and molecular level evaluation at 1, 3, and 6 months postoperatively. Marrow contact channels in the endplate were quantified in histological slices and number of invalid channels (those without erythrocytes inside) was rated. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) was performed to determine disc cell apoptosis. On MR images, the signal and height of the adjacent disc did not change 6 months after vertebral augmentation. Histological scores of the adjacent disc increased over time, particularly for the nucleus pulposus. The adjacent disc had greater nucleus degeneration score than the control disc at 3 months (5.7 vs. 4.5, P < 0.01) and 6 months (6.9 vs. 4.4, P < 0.001). There were more invalid marrow contact channels in the endplate of augmented vertebra than the control (43.3% vs. 11.1%, P < 0.01). mRNA of ADAMTS-5, MMP-13, HIF-1α, and caspase-3 were significantly upregulated in the adjacent disc at 3 and 6 months (P < 0.05 for all). In addition, there were more TUNEL-positive cells in the adjacent disc than in the control disc (43.4% vs. 24.0%, P < 0.05) at 6 months postoperatively. Vertebral augmentation can induce early degenerative signs in the adjacent disc, which may be due to impaired nutrient supply to the disc. N/A.

Role of peptidylarginine deiminase 2 (PAD2) in mammary carcinoma cell migration.

PubMed

Horibata, Sachi; Rogers, Katherine E; Sadegh, David; Anguish, Lynne J; McElwee, John L; Shah, Pragya; Thompson, Paul R; Coonrod, Scott A

2017-05-26

Penetration of the mammary gland basement membrane by cancer cells is a crucial first step in tumor invasion. Using a mouse model of ductal carcinoma in situ, we previously found that inhibition of peptidylarginine deiminase 2 (PAD2, aka PADI2) activity appears to maintain basement membrane integrity in xenograft tumors. The goal of this investigation was to gain insight into the mechanisms by which PAD2 mediates this process. For our study, we modulated PAD2 activity in mammary ductal carcinoma cells by lentiviral shRNA-mediated depletion, lentiviral-mediated PAD2 overexpression, or PAD inhibition and explored the effects of these treatments on changes in cell migration and cell morphology. We also used these PAD2-modulated cells to test whether PAD2 may be required for EGF-induced cell migration. To determine how PAD2 might promote tumor cell migration in vivo, we tested the effects of PAD2 inhibition on the expression of several cell migration mediators in MCF10DCIS.com xenograft tumors. In addition, we tested the effect of PAD2 inhibition on EGF-induced ductal invasion and elongation in primary mouse mammary organoids. Lastly, using a transgenic mouse model, we investigated the effects of PAD2 overexpression on mammary gland development. Our results indicate that PAD2 depletion or inhibition suppresses cell migration and alters the morphology of MCF10DCIS.com cells. In addition, we found that PAD2 depletion suppresses the expression of the cytoskeletal regulatory proteins RhoA, Rac1, and Cdc42 and also promotes a mesenchymal to epithelial-like transition in tumor cells with an associated increase in the cell adhesion marker, E-cadherin. Our mammary gland organoid study found that inhibition of PAD2 activity suppresses EGF-induced ductal invasion. In vivo, we found that PAD2 overexpression causes hyperbranching in the developing mammary gland. Together, these results suggest that PAD2 plays a critical role in breast cancer cell migration. Our findings that EGF

[Cement augmentation on the spine : Biomechanical considerations].

PubMed

Kolb, J P; Weiser, L; Kueny, R A; Huber, G; Rueger, J M; Lehmann, W

2015-09-01

Vertebral compression fractures are the most common osteoporotic fractures. Since the introduction of vertebroplasty and screw augmentation, the management of osteoporotic fractures has changed significantly. The biomechanical characteristics of the risk of adjacent fractures and novel treatment modalities for osteoporotic vertebral fractures, including pure cement augmentation by vertebroplasty, and cement augmentation of screws for posterior instrumentation, are explored. Eighteen human osteoporotic lumbar spines (L1-5) adjacent to vertebral bodies after vertebroplasty were tested in a servo-hydraulic machine. As augmentation compounds we used standard cement and a modified low-strength cement. Different anchoring pedicle screws were tested with and without cement augmentation in another cohort of human specimens with a simple pull-out test and a fatigue test that better reflects physiological conditions. Cement augmentation in the osteoporotic spine leads to greater biomechanical stability. However, change in vertebral stiffness resulted in alterations with the risk of adjacent fractures. By using a less firm cement compound, the risk of adjacent fractures is significantly reduced. Both screw augmentation techniques resulted in a significant increase in the withdrawal force compared with the group without cement. Augmentation using perforated screws showed the highest stability in the fatigue test. The augmentation of cement leads to a significant change in the biomechanical properties. Differences in the stability of adjacent vertebral bodies increase the risk of adjacent fractures, which could be mitigated by a modified cement compound with reduced strength. Screws that were specifically designed for cement application displayed greatest stability in the fatigue test.

Augmented Reality Comes to Physics

NASA Astrophysics Data System (ADS)

Buesing, Mark; Cook, Michael

2013-04-01

Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as Tagwhat and Star Chart (a must for astronomy class). The yellow line marking first downs in a televised football game2 and the enhanced puck that makes televised hockey easier to follow3 both use augmented reality to do the job.

LACK OF EXPRESSION OF EGF AND TGF-ALPHA IN THE FETAL MOUSE ALTERS FORMATION OF PROSTATIC EPITHELIAL BUDS AND INFLUENCES THE RESPONSE TO TCDD

EPA Science Inventory

Lack of Expression of EGF and TGF in the Fetal Mouse Alters Formation of Prostatic Epithelial Buds and Responsiveness to TCDD-Induced Impairment of Prostatic Bud Formation.

Barbara D. Abbott, Tien-Min Lin, Nathan T. Rasmussen, Robert W. Moore,
Ralph M. Albrecht, Judi...

Accumulation of pro-cancer cytokines in the plasma fraction of stored packed red cells.

PubMed

Benson, Douglas D; Beck, Adam W; Burdine, Marie S; Brekken, Rolf; Silliman, Christopher C; Barnett, Carlton C

2012-03-01

Perioperative blood transfusion has been linked to decreased survival in pancreatic cancer; however, the exact causal mechanism has not been elucidated. Allogeneic transfusions are known to expose patients to foreign cells and lipid mediators. We hypothesize that stored packed red cells (pRBCs) contain pro-cancer cytokines that augment tumor progression. We analyzed the plasma fraction of stored pRBCs for pro-cancer cytokines and evaluated the affect of both storage time and leukocyte reduction on these mediators. Chemiarray™ analysis for pro-cancer cytokines was performed on the acellular plasma fraction of stored leukocyte-reduced (LR) and non-leukocyte-reduced (NLR) pRBCs at day 1 (D.1-fresh) and day 42 (D.42-outdate) of storage. Elevated expression of monocyte chemotactic protein-1 (MCP-1), regulated on activation, normal T cell expressed and secreted (RANTES), angiogenin, tumor necrosis factor-alpha (TNF-α), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) was found. Specific enzyme-linked immunosorbent assay was performed for each of these factors in LR and NLR blood at D.1, day 28, and D.42. Data were analyzed by ANOVA. A p value ≤ 0.05 was considered significant; N ≥ 4 per group. Migration assays were performed using inhibitors of EGF (gefitinib) and PDGF (imatinib) on murine pancreatic adenocarcinoma cells (Pan02) exposed to D.1 and D.42 LR and NLR plasma. Proliferation assays were performed on Pan02 cells to test the inhibition of PDGF. MCP-1 levels increased with storage time in LR blood, 86.3 ± 6.3 pg/ml at D.1 vs. 121.2 ± 6.1 pg/ml at D.42 (p = 0.007), and NLR blood, 78.2 ± 7.3 pg/ml at D.1 vs. 647.8 ± 220.7 pg/ml at D.42 (p = 0.02). RANTES levels are lower in LR compared to NLR stored blood, 3.0 ± 1.9 vs. 15.8 ± 0.7 pg/ml at D.42 (p < 0.001), but similar in D.1 blood, 13.8 ± 1.8 pg/ml in LR vs. 12.0 ± 1.6 pg/ml in NLR. Angiogenin levels were different between LR and NLR blood, 0 pg/ml (undetectable) vs. 44.2 ± 3

Activation of sperm EGFR by light irradiation is mediated by reactive oxygen species.

PubMed

Shahar, Shiran; Hillman, Pnina; Lubart, Rachel; Ickowicz, Debby; Breitbart, Haim

2014-01-01

To acquire fertilization competence, spermatozoa must undergo several biochemical and motility changes in the female reproductive tract, collectively called capacitation. Actin polymerization and the development of hyperactivated motility (HAM) are part of the capacitation process. In a recent study, we showed that irradiation of human sperm with visible light stimulates HAM through a mechanism involving reactive-oxygen-species (ROS), Ca(2+) influx, protein kinases A (PKA), and sarcoma protein kinase (Src). Here, we showed that this effect of light on HAM is mediated by ROS-dependent activation of the epidermal growth factor receptor (EGFR). Interestingly, ROS-mediated HAM even when the EGFR was activated by EGF, the physiological ligand of EGFR. Light irradiation stimulated ROS-dependent actin polymerization, and this effect was abrogated by PBP10, a peptide which activates the actin-severing protein, gelsolin, and causes actin-depolymerization in human sperm. Light-stimulated tyrosine phosphorylation of Src-dependent gelsolin, resulting in enhanced HAM. Thus, light irradiation stimulates HAM through a mechanism involving Src-mediated actin polymerization. Light-stimulated HAM and in vitro-fertilization (IVF) rate in mouse sperm, and these effects were mediated by ROS and EGFR. In conclusion, we show here that irradiation of sperm with visible light, enhances their fertilization capacity via a mechanism requiring ROS, EGFR and HAM. © 2014 The American Society of Photobiology.

The development of augmented video system on postcards

NASA Astrophysics Data System (ADS)

Chen, Chien-Hsu; Chou, Yin-Ju

2013-03-01

This study focuses on development of augmented video system on traditional picture postcards. The system will provide users to print out the augmented reality marker on the sticker to stick on the picture postcard, and it also allows users to record their real time image and video to augment on that stick marker. According dynamic image, users can share travel moods, greeting, and travel experience to their friends. Without changing in the traditional picture postcards, we develop augmented video system on them by augmented reality (AR) technology. It not only keeps the functions of traditional picture postcards, but also enhances user's experience to keep the user's memories and emotional expression by augmented digital media information on them.

Computerized tomography-assisted calculation of sinus augmentation volume.

PubMed

Krennmair, Gerald; Krainhöfner, Martin; Maier, Harald; Weinländer, Michael; Piehslinger, Eva

2006-01-01

This study was intended to calculate the augmentation volume for a sinus lift procedure based on cross-sectional computerized tomography (CT) scans for 2 different augmentation heights. Based on area calculations of cross-sectional CT scans, the volume of additional bone needed was calculated for 44 sinus lift procedures. The amount of bone volume needed to raise the sinus floor to heights of both 12 and 17 mm was calculated. To achieve a sinus floor height of 12 mm, it was necessary to increase the height by a mean of 7.2+/-2.1 mm (range, 3.0 to 10.5 mm), depending on the residual ridge height; to achieve a height of 17 mm, a mean of 12.4+/-2.0 mm (range, 8.5 to 15.5 mm) was required (P < .01). The calculated augmentation volume for an augmentation height of 12 mm was 1.7+/-.9 cm3; for an augmentation height of 17 mm, the volume required was 3.6+/-1.5 cm3. Increasing the height of the sinus lift by 5 mm, ie, from 12 mm to 17 mm augmentation height, increased the augmentation volume by 100%. A significant correlation was found between augmentation height and the calculated sinus lift augmentation volume (r = 0. 78, P < .01). Detailed preoperative knowledge of sinus lift augmentation volume is helpful as a predictive value in deciding on a donor site for harvesting autogenous bone and on the ratio of bone to bone substitute to use. Calculation of the augmentation size can help determine the surgical approach and thus perioperative treatment and the costs of the surgery for both patients and clinicians.

Human IgG2 antibodies against epidermal growth factor receptor effectively trigger antibody-dependent cellular cytotoxicity but, in contrast to IgG1, only by cells of myeloid lineage.

PubMed

Schneider-Merck, Tanja; Lammerts van Bueren, Jeroen J; Berger, Sven; Rossen, Kai; van Berkel, Patrick H C; Derer, Stefanie; Beyer, Thomas; Lohse, Stefan; Bleeker, Wim K; Peipp, Matthias; Parren, Paul W H I; van de Winkel, Jan G J; Valerius, Thomas; Dechant, Michael

2010-01-01

Ab-dependent cellular cytotoxicity (ADCC) is usually considered an important mechanism of action for immunotherapy with human IgG1 but not IgG2 Abs. The epidermal growth factor receptor (EGF-R) Ab panitumumab represents the only human IgG2 Ab approved for immunotherapy and inhibition of EGF-R signaling has been described as its principal mechanism of action. In this study, we investigated effector mechanisms of panitumumab compared with zalutumumab, an EGF-R Ab of the human IgG1 isotype. Notably, panitumumab was as effective as zalutumumab in recruiting ADCC by myeloid effector cells (i.e., neutrophils and monocytes) in contrast to NK cell-mediated ADCC, which was only induced by the IgG1 Ab. Neutrophil-mediated tumor cell killing could be stimulated by myeloid growth factors and was triggered via FcgammaRIIa. Panitumumab-mediated ADCC was significantly affected by the functional FcgammaRIIa-R131H polymorphism and was induced more effectively by neutrophils from FcgammaRIIa-131H homozygous donors than from -131R individuals. This polymorphism did not affect neutrophil ADCC induced by the IgG1 Ab zalutumumab. The in vivo activity of both Abs was assessed in two animal models: a high-dose model, in which signaling inhibition is a dominant mechanism of action, and a low-dose model, in which effector cell recruitment plays a prominent role. Zalutumumab was more effective than panitumumab in the high-dose model, reflecting its stronger ability to induce EGF-R downmodulation and growth inhibition. In the low-dose model, zalutumumab and panitumumab similarly prevented tumor growth. Thus, our results identify myeloid cell-mediated ADCC as a potent and additional mechanism of action for EGF-R-directed immunotherapy.

RMS active damping augmentation

NASA Technical Reports Server (NTRS)

Gilbert, Michael G.; Scott, Michael A.; Demeo, Martha E.

1992-01-01

The topics are presented in viewgraph form and include: RMS active damping augmentation; potential space station assembly benefits to CSI; LaRC/JSC bridge program; control law design process; draper RMS simulator; MIMO acceleration control laws improve damping; potential load reduction benefit; DRS modified to model distributed accelerations; accelerometer location; Space Shuttle aft cockpit simulator; simulated shuttle video displays; SES test goals and objectives; and SES modifications to support RMS active damping augmentation.

Toxic ligand conjugates as tools in the study of receptor-ligand interactions.

PubMed

Herschman, H R; Simpson, D L; Cawley, D B

1982-01-01

We have constructed hybrid proteins in which the toxic A chains of ricin or diptheria toxin have been linked to either asialofetuin, fetuin, or epidermal growth factor (EGF). Both ASF-RTA and ASF-DTA are potent toxins on cultured rat hepatocytes, cells that display the asialoglycoprotein receptor. Toxicity of these two compounds is restricted to hepatocytes and can be blocked by asialoglycoproteins but not the native glycoproteins or asialoagalactoglycoprotein derivatives, indicating that the toxicity of the conjugates is mediated by the hepatic asialoglycoprotein receptor. The EGF-RTA conjugate is an extremely potent toxin on cells that can bind the hormone, but is only poorly effective on cells that are unable to bind EGF. The EGF-DTA conjugate, in contrast, is unable to kill 3T3 cells and is at least two orders of magnitude less effective than EGF-RTA on A431 cells, a cell line with 1-2 X 10(6) EGF receptors per cell. However, when EGF-RTA and EGF-DTA were tested on primary liver hepatocyte cultures, which were susceptible to both ASF-RTA and ASF-DTA, both EGF conjugates were potent toxins. Sensitivity of the hepatocyte cultures to ricin toxicity increases slightly during a 52-hr culture period. In contrast, sensitivity to EGF-RTA and ASF-RTA decline dramatically during this period. Receptors for both ligands remain plentiful on the cell surface during this time.

Transforming growth factor-{alpha} enhances corneal epithelial cell migration by promoting EGFR recycling.

PubMed

McClintock, Jennifer L; Ceresa, Brian P

2010-07-01

PURPOSE. The goal of this study was to determine the molecular mechanism by which transforming growth factor-alpha (TGF-alpha) is a more potent activator of epidermal growth factor receptor (EGFR)-mediated corneal wound healing than epidermal growth factor (EGF). METHODS. Telomerase immortalized human corneal epithelial (hTCEpi) cells and primary human corneal epithelial cells were tested for their ability to migrate in response to EGF and TGF-alpha. In parallel, the endocytic trafficking of the EGFR in response to these same ligands was examined using indirect immunofluorescence, immunoblots, and radioligand binding. RESULTS. TGF-alpha, compared with EGF, is a more potent activator of corneal epithelial cell migration. Although both TGF-alpha and EGF were able to induce EGFR internalization and phosphorylation, only those receptors that were stimulated with EGF progressed to lysosomal degradation. EGFRs stimulated with TGF-alpha recycled back to the plasma membrane, where they could be reactivated with ligand. CONCLUSIONS. This study reveals that EGFR-mediated cell migration is limited by ligand-stimulated downregulation of the EGFR. This limitation can be overcome by treating cells with TGF-alpha because TGF-alpha stimulates EGFR endocytosis, but not degradation. After internalization of the TGF-alpha/EGFR complex, EGFR recycles back to the plasma membrane, where it can be restimulated. This sequence of events provides the receptor multiple opportunities for stimulation. Thus, stimulation with TGF-alpha prolongs EGFR signaling compared with EGF.

A mechanism regulating proteolysis of specific proteins during renal tubular cell growth.

PubMed

Franch, H A; Sooparb, S; Du, J; Brown, N S

2001-06-01

Growth factors suppress the degradation of cellular proteins in lysosomes in renal epithelial cells. Whether this process also involves specific classes of proteins that influence growth processes is unknown. We investigated chaperone-mediated autophagy, a lysosomal import pathway that depends on the 73-kDa heat shock cognate protein and allows the degradation of proteins containing a specific lysosomal import consensus sequence (KFERQ motif). Epidermal growth factor (EGF) or ammonia, but not transforming growth factor beta1, suppresses total protein breakdown in cultured NRK-52E renal epithelial cells. EGF or ammonia prolonged the half-life of glyceraldehyde-3-phosphate dehydrogenase, a classic substrate for chaperone-mediated autophagy, by more than 90%, whereas transforming growth factor beta1 did not. EGF caused a similar increase in the half-life of the KFERQ-containing paired box-related transcription factor, Pax2. The increase in half-life was accompanied by an increased accumulation of proteins with a KFERQ motif including glyceraldehyde-3-phosphate dehydrogenase and Pax2. Ammonia also increased the level of the Pax2 protein. Lysosomal import of KFERQ proteins depends on the abundance of the 96-kDa lysosomal glycoprotein protein (lgp96), and we found that EGF caused a significant decrease in lgp96 in cellular homogenates and associated with lysosomes. We conclude that EGF in cultured renal cells regulates the breakdown of proteins targeted for destruction by chaperone-mediated autophagy. Because suppression of this pathway results in an increase in Pax2, these results suggest a novel mechanism for the regulation of cell growth.

Nonsteady-Flow Thrust Augmenting Ejectors

NASA Technical Reports Server (NTRS)

Foa, J. V.

1979-01-01

Ejector augmenters in which the transfer of mechanical energy from the primary to the secondary flow takes place through the work of interface pressure forces are investigated. Nonsteady flow processes are analyzed from the standpoint of energy transfer efficiency and a comparison of a rotary jet augmenter to an ejector is presented.

PKC/CREB pathway mediates the expressions of GABAA receptor subunits in cultured hippocampal neurons after low-Mg2+ solution treatment.

PubMed

Wu, Guofeng; Yu, Jinpeng; Wang, Likun; Ren, Siying; Zhang, Yixia

2018-02-01

To investigate the potential effects of the PKC/CREB pathway on the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons using a model of epilepsy that employed conditions of low magnesium (Mg 2+ ). A total of 108 embryonic rats at the age of 18 embryonic days (E18)prepared from adult female SD rats were used as experimental subjects. Primary rat hippocampal cultures were prepared from the embryonic 18 days rats. The cultured hippocampal neurons were then treated with artificial cerebrospinal fluid containing low Mg 2+ solutions to generate a low Mg 2+ model of epilepsy. The low Mg 2+ stimulation lasted for 3 h and then returned to in maintenance medium for 20 h. The changes of the GABA A receptor subunit α1, γ2, δ were observed by blocking or activating the function of the CREB. The quantification of the GABA A receptor subunit α1, γ2, δ and the CREB were determined by a qRT-PCR and a Western blot method. After the neurons were exposed to a low-Mg 2+ solution for 3 h, GABA A receptor mRNA expression markedly increased compared to the control, and then gradually decreased. In contrast, CREB mRNA levels exhibited a dramatic down-regulation 3 h after terminating low-Mg 2+ treatment, and then peaked at 9 h. Western blot analyses verified that staurosporine suppressed CREB phosphorylation (p-CREB). The mRNA expression of GABA A receptor subunit α1 increased only in the presence of staurosporine, whereas the expressions of subunits γ2 and δ significantly increased in the presence of either KG-501 or staurosporine. Furthermore, phorbol 12-myristate 13-acetate (PMA) decreased the expressions of GABA A subunits α1, γ2, and δ when administered alone. However, the administration of either KG-501 or staurosporine reversed the inhibitory effects of PMA. The PKC/CREB pathway may negatively regulate the expressions of GABA A receptor subunits α1, γ2, and δ in cultured hippocampal neurons in low Mg 2+ model of

Comparative gene expression profiling of ADAMs, MMPs, TIMPs, EMMPRIN, EGF-R and VEGFA in low grade meningioma.

PubMed

Rooprai, Harcharan K; Martin, Andrew J; King, Andrew; Appadu, Usha D; Jones, Huw; Selway, Richard P; Gullan, Richard W; Pilkington, Geoffrey J

2016-12-01

MMPs (matrix metalloproteinases), ADAMs (a disintegrin and metalloproteinase) and TIMPs (tissue inhibitors of metalloproteinases) are implicated in invasion and angiogenesis: both are tissue remodeling processes involving regulated proteolysis of the extracellular matrix, growth factors and their receptors. The expression of these three groups and their correlations with clinical behaviour has been reported in gliomas but a similar comprehensive study in meningiomas is lacking. In this study, we aimed to evaluate the patterns of expression of 23 MMPs, 4 TIMPs, 8 ADAMs, selective growth factors and their receptors in 17 benign meningiomas using a quantitative real-time polymerase chain reaction (qPCR). Results indicated very high gene expression of 13 proteases, inhibitors and growth factors studied: MMP2 and MMP14, TIMP-1, -2 and -3, ADAM9, 10, 12, 15 and 17, EGF-R, EMMPRIN and VEGF-A, in almost every meningioma. Expression pattern analysis showed several positive correlations between MMPs, ADAMs, TIMPs and growth factors. Furthermore, our findings suggest that expression of MMP14, ADAM9, 10, 12, 15 and 17, TIMP-2, EGF-R and EMMPRIN reflects histological subtype of meningioma such that fibroblastic subtype had the highest mRNA expression, transitional subtype was intermediate and meningothelial type had the lowest expression. In conclusion, this is the first comprehensive study characterizing gene expression of 8 ADAMs in meningiomas. These neoplasms, although by histological definition benign, have invasive potential. Taken together, the selected elevated gene expression pattern may serve to identify targets for therapeutic intervention or indicators of biological progression and recurrence.

Augmentation cystoplasty in neurogenic bladder

PubMed Central

Kocjancic, Ervin; Demirdağ, Çetin

2016-01-01

The aim of this review is to update the indications, contraindications, technique, complications, and the tissue engineering approaches of augmentation cystoplasty (AC) in patients with neurogenic bladder. PubMed/MEDLINE was searched for the keywords "augmentation cystoplasty," "neurogenic bladder," and "bladder augmentation." Additional relevant literature was determined by examining the reference lists of articles identified through the search. The update review of of the indications, contraindications, technique, outcome, complications, and tissue engineering approaches of AC in patients with neurogenic bladder is presented. Although some important progress has been made in tissue engineering AC, conventional AC still has an important role in the surgical treatment of refractory neurogenic lower urinary tract dysfunction. PMID:27617312

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Wooyoung; Bazer, Fuller W.; Song, Gwonhwa, E-mail: ghsong@korea.ac.kr

The low oxygen environment in the uterine environment requires pre-implantation embryos to adapt to oxygen deficiency. Hypoxia-inducible factor (HIF)-1 is a master regulator whereby cells adapt to changes in oxygen concentrations. In addition to hypoxic conditions, non-hypoxic stimuli such as growth factors also activate expression of HIF-1. In this study, the mechanisms underlying low oxygen-dependent and epidermal growth factor (EGF)-dependent expression of HIF-1α were explored using porcine trophectoderm (pTr) cells. The results indicated that expression of HIF-1α and HIF-1β mRNAs was not affected by low concentrations of oxygen; however, hypoxic conditions markedly increased the abundance of HIF-1α protein, especially inmore » nuclei of pTr cells. Even under normoxic conditions, the abundance of HIF-1α protein increased in response to EGF. This EGF-mediated increase in HIF-1α protein was blocked through inhibition of translation by cycloheximide. The inhibitors LY294002 (PI3K-AKT inhibitor), U0126 (inhibitor of ERK1/2) and rapamycin (mTOR inhibitor) also blocked the ability of EGF to increase HIF-1α protein and to phosphorylate AKT, ERK1/2 and mTOR proteins. Both hypoxia and EGF induced proliferation of pTr cells. This ability of EGF to stimulate proliferation of pTr cells was suppressed by EGFR siRNA, but not HIF-1α siRNA, but a significant decrease in EGF-induced HIF-1α protein occurred when pTr cells were transfected with HIF-1α siRNA. The results of the present study suggest that pTr cells adapt to oxygen deficiency and proliferate in response to an oxygen-dependent HIF-1 system, and that EGF at maternal–conceptus interface can increase the abundance of HIF-1α protein via translational regulation through AKT, ERK1/2 and mTOR signaling cascades. - Highlights: • HIF-1α expression is up-regulated in pTr cells under low oxygen concentrations. • EGF induces HIF-1α accumulation in pTr cells. • EGF-induced HIF-1α accumulation is blocked by

Is a synthetic augmentation in medial open wedge high tibial osteotomies superior to no augmentation in terms of bone-healing?

PubMed

Ferner, Felix; Dickschas, Joerg; Ostertag, Helmut; Poske, Ulrich; Schwitulla, Judith; Harrer, Joerg; Strecker, Wolf

2016-01-01

Medial open-wedge high tibial osteotomy (MOWHTO) is an established method to treat unicompartimental osteoarthritis of the knee joint. However, augmentation of the created tibial gap after osteotomy is controversially discussed. We performed a prospective investigation of 49 consecutive cases of MOWHTO at our department. Patients were divided into two groups: group A consisted of 19 patients while group B consisted of 30 patients. In group A, the augmentation of the opening gap after osteotomy was filled with a synthetic bone graft, whereas group B received no augmentation. As an indicator for bone healing we investigated the non-union rate in our study population and compared the non-union-rate between the two groups. The non-union rate was 28% in group A (five of 19 patients had to undergo revision) which received synthetic augmentation, while it was 3.3% in group B (one of 30 patients had to undergo revision) which received no augmentation. The difference between the groups was statistically significant (p-value 0.027). With regard to bone healing after MOWHTO, synthetic augmentation was not superior to no augmentation in terms of non-union rates after surgery. In fact, we registered a significantly higher rate of non-union after augmentation with synthetic bone graft. III. Copyright © 2015 Elsevier B.V. All rights reserved.

Augmented Reality Comes to Physics

ERIC Educational Resources Information Center

Buesing, Mark; Cook, Michael

2013-01-01

Augmented reality (AR) is a technology used on computing devices where processor-generated graphics are rendered over real objects to enhance the sensory experience in real time. In other words, what you are really seeing is augmented by the computer. Many AR games already exist for systems such as Kinect and Nintendo 3DS and mobile apps, such as…

Cytotoxic effects of basic FGF and heparin binding EGF conjugated with cytotoxin saporin on vascular cell cultures.

PubMed

Chen, C; Li, J; Micko, C J; Pierce, G F; Cunningham, M R; Lumsden, A B

1998-02-15

Vascular smooth muscle cell (SMC) proliferation is an integral component of intimal lesion formation. In this study we compared the mitogenic effects of basic fibroblast growth factor (bFGF) and heparin binding epidermal growth factor (HBEGF) and the cytotoxic effects of bFGF and HBEGF conjugated with plant cytotoxin saporin (SAP) on vascular cell cultures. Human vascular SMCs and endothelial cells were cultured and FGF receptor-1 (FGFR-1) and EGF receptor (EGFR) expression were detected by immunohistochemical staining. Cells were grown in 24-well plates. Variable amounts of testing drugs (bFGF, HBEGF, SAP, bFGF-SAP, or HBEGF-SAP) were added to quadruplicate wells after 24 h. Cells without drugs were used as control. The total number of cells was counted at 72 h using a hemocytometer. The cultured human vascular SMCs and endothelial cells expressed both FGFR-1 and EGFR with predominant perinuclear localization. bFGF and HBEGF demonstrated equally potent mitogenic effects on SMC proliferation. SAP alone showed a limited cytotoxic effect on both SMCs and endothelial cells. bFGF had a more potent effect on endothelial cell proliferation than HBEGF. bFGF-SAP was equally cytotoxic for both SMCs and endothelial cells, while HBEGF-SAP had a more selectively cytotoxic effect on SMCs than on endothelial cells. These data suggest that the mitogenic effects of bFGF and HBEGF and the cytotoxic effects of bFGF-SAP and HBEGF-SAP may both be mediated by their corresponding growth factor receptors. Because of its selective cytotoxic effect on SMCs, HBEGF-SAP may become a more attractive agent for controlling intimal lesion formation.

Strategies and Challenges in Simultaneous Augmentation Mastopexy.

PubMed

Spring, Michelle A; Hartmann, Emily C; Stevens, W Grant

2015-10-01

Simultaneous breast augmentation and mastopexy is a common procedure often considered to be one of the most difficult cosmetic breast surgeries. One-stage augmentation mastopexy was initially described more than 50 years ago. The challenge lies in the fact that the surgery has multiple opposing goals: to increasing the volume of a breast, enhance the shape, and simultaneously decrease the skin envelope. Successful outcomes in augmentation can be expected with proper planning, technique, and patient education. This article focuses on common indications for simultaneous augmentation mastopexy, techniques for safe and effective combined procedures, challenges of the procedure, and potential complications. Copyright © 2015 Elsevier Inc. All rights reserved.

Selective regulation of clathrin-mediated epidermal growth factor receptor signaling and endocytosis by phospholipase C and calcium

PubMed Central

Delos Santos, Ralph Christian; Bautista, Stephen; Lucarelli, Stefanie; Bone, Leslie N.; Dayam, Roya M.; Abousawan, John; Botelho, Roberto J.; Antonescu, Costin N.

2017-01-01

Clathrin-mediated endocytosis is a major regulator of cell-surface protein internalization. Clathrin and other proteins assemble into small invaginating structures at the plasma membrane termed clathrin-coated pits (CCPs) that mediate vesicle formation. In addition, epidermal growth factor receptor (EGFR) signaling is regulated by its accumulation within CCPs. Given the diversity of proteins regulated by clathrin-mediated endocytosis, how this process may distinctly regulate specific receptors is a key question. We examined the selective regulation of clathrin-dependent EGFR signaling and endocytosis. We find that perturbations of phospholipase Cγ1 (PLCγ1), Ca2+, or protein kinase C (PKC) impair clathrin-mediated endocytosis of EGFR, the formation of CCPs harboring EGFR, and EGFR signaling. Each of these manipulations was without effect on the clathrin-mediated endocytosis of transferrin receptor (TfR). EGFR and TfR were recruited to largely distinct clathrin structures. In addition to control of initiation and assembly of CCPs, EGF stimulation also elicited a Ca2+- and PKC-dependent reduction in synaptojanin1 recruitment to clathrin structures, indicating broad control of CCP assembly by Ca2+ signals. Hence EGFR elicits PLCγ1-calcium signals to facilitate formation of a subset of CCPs, thus modulating its own signaling and endocytosis. This provides evidence for the versatility of CCPs to control diverse cellular processes. PMID:28814502

The homeobox gene mirror links EGF signalling to embryonic dorso-ventral axis formation through notch activation.

PubMed

Jordan, K C; Clegg, N J; Blasi, J A; Morimoto, A M; Sen, J; Stein, D; McNeill, H; Deng, W M; Tworoger, M; Ruohola-Baker, H

2000-04-01

Recent studies in vertebrates and Drosophila melanogaster have revealed that Fringe-mediated activation of the Notch pathway has a role in patterning cell layers during organogenesis. In these processes, a homeobox-containing transcription factor is responsible for spatially regulating fringe (fng) expression and thus directing activation of the Notch pathway along the fng expression border. Here we show that this may be a general mechanism for patterning epithelial cell layers. At three stages in Drosophila oogenesis, mirror (mirr) and fng have complementary expression patterns in the follicle-cell epithelial layer, and at all three stages loss of mirr enlarges, and ectopic expression of mirr restricts, fng expression, with consequences for follicle-cell patterning. These morphological changes are similar to those caused by Notch mutations. Ectopic expression of mirr in the posterior follicle cells induces a stripe of rhomboid (rho) expression and represses pipe (pip), a gene with a role in the establishment of the dorsal-ventral axis, at a distance. Ectopic Notch activation has a similar long-range effect on pip. Our results suggest that Mirror and Notch induce secretion of diffusible morphogens and we have identified TGF-beta (encoded by dpp) as such a molecule in germarium. We also found that mirr expression in dorsal follicle cells is induced by the EGF-receptor (EGFR) pathway and that mirr then represses pip expression in all but the ventral follicle cells, connecting EGFR activation in the dorsal follicle cells to repression of pip in the dorsal and lateral follicle cells. Our results suggest that the differentiation of ventral follicle cells is not a direct consequence of germline signalling, but depends on long-range signals from dorsal follicle cells, and provide a link between early and late events in Drosophila embryonic dorsal-ventral axis formation.

Amine fluoride gel affects the viability and the generation of superoxide anions in human polymorphonuclear leukocytes: an in vitro study.

PubMed

Knoll-Köhler, Elisabeth; Stiebel, Juliane

2002-08-01

Amine hydrofluorides are widely used to prevent caries. As an acidulated gel, they were also studied for their applicability to reduce pathogenic bacteria in periodontal pockets. We assessed the toxicity of this pharmaceutical amine hydrofluoride preparation on human polymorphonuclear leukocytes in vitro by measuring Trypan blue exclusion and the generation of superoxide anions (O2) by the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) after a 3-min contact with gel. Depending on the experimental conditions, gel dilutions up to 1.3 x 10(4) resulted in an increase in Trypan blue-colored cells and liberation of beta-glucuronidase. Dilutions between 3 x 10(4) and 1 x 10(5) augmented the fMLP-mediated O2- generation, which could be prevented by Ca2+ chelation with BAPTA-AM (1,2'-bis (o-aminophenoxyethane-N.N.N'.N'-tetraacetic acid tetra (acetoxymethyl) ester) and ethyleneglycoltetraacetic acid (EGTA) or inhibition of protein kinase C (PKC) with staurosporine and bisindolylmaleimide I. respectively. Compared with data published on the minimal inhibitory concentration for periodontal pathogenic bacteria, the cytotoxicity of amine hydrofluorides on eukaryotic cells is much greater and thus of consequence for their clinical use.

Predicting self-reported research misconduct and questionable research practices in university students using an augmented Theory of Planned Behavior

PubMed Central

Rajah-Kanagasabai, Camilla J.; Roberts, Lynne D.

2015-01-01

This study examined the utility of the Theory of Planned Behavior model, augmented by descriptive norms and justifications, for predicting self-reported research misconduct and questionable research practices in university students. A convenience sample of 205 research active Western Australian university students (47 male, 158 female, ages 18–53 years, M = 22, SD = 4.78) completed an online survey. There was a low level of engagement in research misconduct, with approximately one in seven students reporting data fabrication and one in eight data falsification. Path analysis and model testing in LISREL supported a parsimonious two step mediation model, providing good fit to the data. After controlling for social desirability, the effect of attitudes, subjective norms, descriptive norms and perceived behavioral control on student engagement in research misconduct and questionable research practices was mediated by justifications and then intention. This revised augmented model accounted for a substantial 40.8% of the variance in student engagement in research misconduct and questionable research practices, demonstrating its predictive utility. The model can be used to target interventions aimed at reducing student engagement in research misconduct and questionable research practices. PMID:25983709

Predicting self-reported research misconduct and questionable research practices in university students using an augmented Theory of Planned Behavior.

PubMed

Rajah-Kanagasabai, Camilla J; Roberts, Lynne D

2015-01-01

This study examined the utility of the Theory of Planned Behavior model, augmented by descriptive norms and justifications, for predicting self-reported research misconduct and questionable research practices in university students. A convenience sample of 205 research active Western Australian university students (47 male, 158 female, ages 18-53 years, M = 22, SD = 4.78) completed an online survey. There was a low level of engagement in research misconduct, with approximately one in seven students reporting data fabrication and one in eight data falsification. Path analysis and model testing in LISREL supported a parsimonious two step mediation model, providing good fit to the data. After controlling for social desirability, the effect of attitudes, subjective norms, descriptive norms and perceived behavioral control on student engagement in research misconduct and questionable research practices was mediated by justifications and then intention. This revised augmented model accounted for a substantial 40.8% of the variance in student engagement in research misconduct and questionable research practices, demonstrating its predictive utility. The model can be used to target interventions aimed at reducing student engagement in research misconduct and questionable research practices.

A lifting surface theory for thrust augmenting ejectors

NASA Technical Reports Server (NTRS)

Bevilaqua, P. M.

1977-01-01

The circulation theory of airfoil lift has been applied to calculate the performance of thrust augmenting ejectors. The ejector shroud is considered to be 'flying' in the secondary velocity field induced by the entrainment of the primary jet, so that the augmenting thrust is viewed as analogous to the lift on an airfoil. Vortex lattice methods are utilized to compute the thrust augmentation from the force on the flaps. The augmentation is shown to be a function of the length and shape of the flaps, as well as their position and orientation. Predictions of this new theory are compared with the results of classical methods of calculating the augmentation by integration of the stream thrust.

Bradykinin-induced growth inhibition of normal rat kidney (NRK) cells is paralleled by a decrease in epidermal-growth-factor receptor expression.

PubMed Central

Van Zoelen, E J; Peters, P H; Afink, G B; Van Genesen, S; De Roos, D G; Van Rotterdam, W; Theuvenet, A P

1994-01-01

Normal rat kidney fibroblasts, grown to density arrest in the presence of epidermal growth factor (EGF), can be induced to undergo phenotypic transformation by treatment with transforming growth factor beta or retinoic acid. Here we show that bradykinin blocks this growth-stimulus-induced loss of density-dependent growth arrest by a specific receptor-mediated mechanism. The effects of bradykinin are specific, and are not mimicked by other phosphoinositide-mobilizing agents such as prostaglandin F2 alpha. Northern-blot analysis and receptor-binding studies demonstrate that bradykinin also inhibits the retinoic acid-induced increase in EGF receptor levels in these cells. These studies provide additional evidence that EGF receptor levels modulate EGF-induced expression of the transformed phenotype in these cells. Images Figure 5 PMID:8135739

High vascular delivery of EGF, but low receptor binding rate is observed in AsPC-1 tumors as compared to normal pancreas.

PubMed

Samkoe, Kimberley S; Sexton, Kristian; Tichauer, Kenneth M; Hextrum, Shannon K; Pardesi, Omar; Davis, Scott C; O'Hara, Julia A; Hoopes, P Jack; Hasan, Tayyaba; Pogue, Brian W

2012-08-01

Cellular receptor targeted imaging agents present the potential to target extracellular molecular expression in cancerous lesions; however, the image contrast in vivo does not reflect the magnitude of overexpression expected from in vitro data. Here, the in vivo delivery and binding kinetics of epidermal growth factor receptor (EGFR) was determined for normal pancreas and AsPC-1 orthotopic pancreatic tumors known to overexpress EGFR. EGFR in orthotopic xenograft AsPC-1 tumors was targeted with epidermal growth factor (EGF) conjugated with IRDye800CW. The transfer rate constants (k(e), K₁₂, k₂₁, k₂₃, and k₃₂) associated with a three-compartment model describing the vascular delivery, leakage rate and binding of targeted agents were determined experimentally. The plasma excretion rate, k (e), was determined from extracted blood plasma samples. K₁₂, k₂₁, and k₃₂ were determined from ex vivo tissue washing studies at time points ≥ 24 h. The measured in vivo uptake of IRDye800CW-EGF and a non-targeted tracer dye, IRDye700DX-carboxylate, injected simultaneously was used to determined k₂₃. The vascular exchange of IRDye800CW-EGF in the orthotopic tumor (K₁₂ and k₂₁) was higher than in the AsPC-1 tumor as compared to normal pancreas, suggesting that more targeted agent can be taken up in tumor tissue. However, the cellular associated (binding) rate constant (k₂₃) was slightly lower for AsPC-1 pancreatic tumor (4.1 × 10(-4) s(-1)) than the normal pancreas (5.5 × 10(-4) s(-1)), implying that less binding is occurring. Higher vascular delivery but low cellular association in the AsPC-1 tumor compared to the normal pancreas may be indicative of low receptor density due to low cellular content. This attribute of the AsPC-1 tumor may indicate one contributing cause of the difficulty in treating pancreatic tumors with cellular targeted agents.