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Sample records for growth factor-2 stimulates

  1. [Fibroblast growth factor-2].

    PubMed

    Faitová, J

    2004-01-01

    Fibroblast growth factor-2 is a member of a large family of proteins that bind heparin and heparan sulfate and modulate the function of a wide range of cell types. FGF-2 occurs in several isoforms resulting from alternative initiations of traslation: an 18 kDa cytoplasmic isoform and four larger molecular weight nuclear isoforms (22, 22.5, 24 and 34 kDa). It acts mainly through a paracrine/autocrine mechanism involving high affinity transmembrane receptors and heparan sulfate proteoglycan low affinity receptors. It is expressed mostly in tissues of mesoderm and neuroectoderm origin, and plays an important role in mesoderm induction, stimulates the growth and development of the new blood vessels (angiogenesis), normal wound healing and tissue development. FGF-2 positively regulates hematopoiesis by acting on various cellular targets: stromal cells, early and committed hematopoietic progenitors and possibly some mature blood cells. FGF-2 is a potent hematopoietic growth factor that is likely to play an important role in physiological and pathological hematopoiesis.

  2. Fibroblast growth factor-2 stimulates adipogenic differentiation of human adipose-derived stem cells

    SciTech Connect

    Kakudo, Natsuko . E-mail: kakudon@takii.kmu.ac.jp; Shimotsuma, Ayuko; Kusumoto, Kenji

    2007-07-27

    Adipose-derived stem cells (ASCs) have demonstrated a capacity for differentiating into a variety of lineages, including bone, cartilage, or fat, depending on the inducing stimuli and specific growth and factors. It is acknowledged that fibroblast growth factor-2 (FGF-2) promotes chondrogenic and inhibits osteogenic differentiation of ASCs, but thorough investigations of its effects on adipogenic differentiation are lacking. In this study, we demonstrate at the cellular and molecular levels the effect of FGF-2 on adipogenic differentiation of ASCs, as induced by an adipogenic hormonal cocktail consisting of 3-isobutyl-1-methylxanthine (IBMX), dexamethasone, insulin, and indomethacin. FGF-2 significantly enhances the adipogenic differentiation of human ASCs. Furthermore, in cultures receiving FGF-2 before adipogenic induction, mRNA expression of peroxisome proliferator-activated receptor {gamma}2 (PPAR{gamma}2), a key transcription factor in adipogenesis, was upregulated. The results of FGF-2 supplementation suggest the potential applications of FGF-2 and ASCs in adipose tissue regeneration.

  3. Down-regulation of hypoxia-inducible factor-2 in PC12 cells by nerve growth factor stimulation.

    PubMed

    Naranjo-Suárez, Salvador; Castellanos, María Carmen; Alvarez-Tejado, Miguel; Vara, Alicia; Landázuri, Manuel O; del Peso, Luis

    2003-08-22

    Cellular responses to low oxygen tension are mediated, at least in part, by the activation of the hypoxia-inducible factors (HIFs). In the presence of oxygen, specific HIF residues become hydroxylated by the action of a recently described group of dioxygenases. These post-translational modifications target HIF for proteosomal degradation and prevent its transcriptional activity. Despite these detailed studies, little is known about the regulation of HIF by stimuli other than hypoxia. Here we report that, in rat pheochromocytoma PC12 cells, nerve growth factor (NGF) stimulation results in a decrease of both basal and hypoxia-induced levels of HIF-2 alpha protein. NGF treatment did not increase HIF-hydroxylase gene expression or activity, and the reduction of the HIF-2 alpha protein level upon stimulation was observed even in the presence of HIF-hydroxylase inhibitors such as deferoxamine or dimethyloxoglutarate. Thus, in contrast to the response to hypoxia, the effect of NGF on HIF-2 alpha protein levels is not mediated by the HIF hydroxilases. Quantitative real time (RT)-PCR showed that NGF stimulation results in a decrease of the HIF-2 alpha mRNA level similar to that found at the protein level. Interestingly, NGF effect was specific for HIF-2 alpha mRNA because it did not affect HIF-1 alpha mRNA levels. NGF treatment reduced HIF-2 alpha mRNA levels even in the presence of actinomycin D, suggesting an effect on mRNA stability. Finally, the effect of NGF on HIF2 alpha correlates with reduction of both basal and hypoxia-induced vascular endothelial growth factor mRNA levels. Reporter assays suggest that the reduced expression of hypoxia-inducible genes upon NGF treatment is related, at least in part, to the reduction of HIF-2 alpha protein. Hence, in PC12 cells the level of HIF-2 alpha protein and its effect on gene expression can be down-regulated by stimuli other than oxygen.

  4. Regulation of pluripotency of inner cell mass and growth and differentiation of trophectoderm of the bovine embryo by colony stimulating factor 2.

    PubMed

    Dobbs, Kyle B; Khan, Firdous A; Sakatani, Miki; Moss, James I; Ozawa, Manabu; Ealy, Alan D; Hansen, Peter J

    2013-12-01

    Colony-stimulating factor 2 (CSF2) enhances competence of the bovine embryo to establish and maintain pregnancy after the embryo is transferred into a recipient. Mechanisms involved could include regulation of lineage commitment, growth, or differentiation of the inner cell mass (ICM) and trophectoderm (TE). Experiments were conducted to evaluate regulation by CSF2 of pluripotency of the ICM and differentiation and growth of the TE. Embryos were cultured with 10 ng/ml recombinant bovine CSF2 or a vehicle control from Days 5 to 7 or 6 to 8 postinsemination. CSF2 increased the number of putative zygotes that developed to blastocysts when the percent of embryos becoming blastocysts in the control group was low but decreased blastocyst yield when blastocyst development in controls was high. ICM isolated from blastocysts by lysing the trophectoderm using antibody and complement via immunosurgery were more likely to survive passage when cultured on mitomycin C-treated fetal fibroblasts if derived from blastocysts treated with CSF2 than if from control blastocysts. There was little effect of CSF2 on characteristics of TE outgrowths from blastocysts. The exception was a decrease in outgrowth size for embryos treated with CSF2 from Days 5 to 7 and an increase in expression of CDX2 when treatment was from Days 6 to 8. Expression of the receptor subunit gene CSF2RA increased from the zygote stage to the 9-16 cell stage before decreasing to the blastocyst stage. In contrast, CSF2RB was undetectable at all stages. In conclusion, CSF2 improves competence of the ICM to survive in a pluripotent state and alters TE outgrowths. Actions of CSF2 occur through a signaling pathway that is likely to be independent of CSF2RB.

  5. Fibroblast Growth Factor-2 Alters the Nature of Extinction

    ERIC Educational Resources Information Center

    Graham, Bronwyn M.; Richardson, Rick

    2011-01-01

    These experiments examined the effects of the NMDA-receptor (NMDAr) antagonist MK801 on reacquisition and re-extinction of a conditioned fear that had been previously extinguished before injection of fibroblast growth factor-2 (FGF2) or vehicle. Recent findings have shown that relearning and re-extinction, unlike initial learning and extinction,…

  6. Fibroblast growth factor-2 promotes keratan sulfate proteoglycan expression by keratocytes in vitro

    NASA Technical Reports Server (NTRS)

    Long, C. J.; Roth, M. R.; Tasheva, E. S.; Funderburgh, M.; Smit, R.; Conrad, G. W.; Funderburgh, J. L.

    2000-01-01

    Keratocytes of the corneal stroma produce a specialized extracellular matrix responsible for corneal transparency. Corneal keratan sulfate proteoglycans (KSPG) are unique products of keratocytes that are down-regulated in corneal wounds and in vitro. This study used cultures of primary bovine keratocytes to define factors affecting KSPG expression in vitro. KSPG metabolically labeled with [(35)S]sulfate decreased during the initial 2-4 days of culture in quiescent cultures with low serum concentrations (0.1%). Addition of fetal bovine serum, fibroblast growth factor-2 (FGF-2), transforming growth factor beta, or platelet derived growth factor all stimulated cell division, but only FGF-2 stimulated KSPG secretion. Combined with serum, FGF-2 also prevented serum-induced KSPG down-regulation. KSPG secretion was lost during serial subculture with or without FGF-2. Expression of KSPG core proteins (lumican, mimecan, and keratocan) was stimulated by FGF-2, and steady state mRNA pools for these proteins, particularly keratocan, were significantly increased by FGF-2 treatment. KSPG expression therefore is supported by exogenous FGF-2 and eliminated by subculture of the cells in presence of serum. FGF-2 stimulates KSPG core protein expression primarily through an increase in mRNA pools.

  7. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1995-05-09

    A device is described for stimulating bone tissue by applying a low level alternating current signal directly to the patient`s skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures. 5 figs.

  8. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, James W.

    1995-01-01

    A device for stimulating bone tissue by applying a low level alternating current signal directly to the patient's skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures.

  9. Increased abundance of aromatase and follicle stimulating hormone receptor mRNA and decreased insulin-like growth factor-2 receptor mRNA in small ovarian follicles of cattle selected for twin births.

    PubMed

    Echternkamp, S E; Aad, P Y; Eborn, D R; Spicer, L J

    2012-07-01

    follicles of Twinners support the hypothesis that increased follicular development and steroidogenesis in Twinner females result from increased extra-ovarian IGF-1 production. Furthermore, a reduction in follicular IGF2R mRNA expression accompanied by a reduction in receptor numbers would increase availability of free IGF-2 and its stimulation of follicular development in Twinners.

  10. Effect of Fibroblast Growth Factor 2 on Equine Synovial Fluid Chondroprogenitor Expansion and Chondrogenesis

    PubMed Central

    Bianchessi, Marta; Chen, Yuwen; Durgam, Sushmitha; Pondenis, Holly; Stewart, Matthew

    2016-01-01

    Mesenchymal stem cells have been identified in the synovial fluid of several species. This study was conducted to characterize chondroprogenitor (CP) cells in equine synovial fluid (SF) and to determine the effect of fibroblast growth factor 2 (FGF-2) on SF-CP monolayer proliferation and subsequent chondrogenesis. We hypothesized that FGF-2 would stimulate SF-CP proliferation and postexpansion chondrogenesis. SF aspirates were collected from adult equine joints. Colony-forming unit (CFU) assays were performed during primary cultures. At first passage, SF-cells were seeded at low density, with or without FGF-2. Following monolayer expansion and serial immunophenotyping, cells were transferred to chondrogenic pellet cultures. Pellets were analyzed for chondrogenic mRNA expression and cartilage matrix secretion. There was a mean of 59.2 CFU/mL of SF. FGF-2 increased the number of population doublings during two monolayer passages and halved the population doubling times. FGF-2 did not alter the immunophenotype of SF-CPs during monolayer expansion, nor did FGF-2 compromise chondrogenesis. Hypertrophic phenotypic markers were not expressed in control or FGF-2 groups. FGF-2 did prevent the development of a “fibroblastic” cell layer around pellet periphery. FGF-2 significantly accelerates in vitro SF-CP expansion, the major hurdle to clinical application of this cell population, without detrimentally affecting subsequent chondrogenic capacity. PMID:26839571

  11. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1993-01-01

    The present invention relates to the electrical treatment of biological tissue. In particular, the present invention discloses a device that produces discrete electrical pulse trains for treating osteoporosis and accelerating bone growth. According to its major aspects and broadly stated, the present invention consists of an electrical circuit configuration capable of generating Bassett-type waveforms shown with alternative signals provide for the treatment of either fractured bones or osteoporosis. The signal generator comprises a quartz clock, an oscillator circuit, a binary divider chain, and a plurality of simple, digital logic gates. Signals are delivered efficiently, with little or no distortion, and uniformly distributed throughout the area of injury. Perferably, power is furnished by widely available and inexpensive radio batteries, needing replacement only once in several days. The present invention can be affixed to a medical cast without a great increase in either weight or bulk. Also, the disclosed stimulator can be used to treat osteoporosis or to strengthen a healing bone after the cast has been removed by attaching the device to the patient`s skin or clothing.

  12. Individual Differences in the Expression of Conditioned Fear Are Associated with Endogenous Fibroblast Growth Factor 2

    ERIC Educational Resources Information Center

    Graham, Bronwyn M.; Richardson, Rick

    2016-01-01

    These experiments examined the relationship between the neurotrophic factor fibroblast growth factor 2 (FGF2) and individual differences in the expression of conditioned fear. Experiments 1 and 2 demonstrated that rats naturally expressing low levels of contextual or cued fear have higher levels of hippocampal FGF2 relative to rats that express…

  13. Biologic Roles of Estrogen Receptor-β and Insulin-Like Growth Factor-2 in Triple-Negative Breast Cancer

    PubMed Central

    Elshimali, Yahya; Garbán, Hermes; Elashoff, David; Vadgama, Jaydutt; Goodglick, Lee

    2015-01-01

    Triple-negative breast cancer (TNBC) occurs in 10–15% of patients yet accounts for almost half of all breast cancer deaths. TNBCs lack expression of estrogen and progesterone receptors and HER-2 overexpression and cannot be treated with current targeted therapies. TNBCs often occur in African American and younger women. Although initially responsive to some chemotherapies, TNBCs tend to relapse and metastasize. Thus, it is critical to find new therapeutic targets. A second ER gene product, termed ERβ, in the absence of ERα may be such a target. Using human TNBC specimens with known clinical outcomes to assess ERβ expression, we find that ERβ1 associates with significantly worse 5-year overall survival. Further, a panel of TNBC cell lines exhibit significant levels of ERβ protein. To assess ERβ effects on proliferation, ERβ expression in TNBC cells was silenced using shRNA, resulting in a significant reduction in TNBC proliferation. ERβ-specific antagonists similarly suppressed TNBC growth. Growth-stimulating effects of ERβ may be due in part to downstream actions that promote VEGF, amphiregulin, and Wnt-10b secretion, other factors associated with tumor promotion. In vivo, insulin-like growth factor-2 (IGF-2), along with ERβ1, is significantly expressed in TNBC and stimulates high ERβ mRNA in TNBC cells. This work may help elucidate the interplay of metabolic and growth factors in TNBC. PMID:25874233

  14. Syndecan-4 proteoliposomes enhance fibroblast growth factor-2 (FGF-2)–induced proliferation, migration, and neovascularization of ischemic muscle

    PubMed Central

    Jang, Eugene; Albadawi, Hassan; Watkins, Michael T.; Edelman, Elazer R.; Baker, Aaron B.

    2012-01-01

    Ischemia of the myocardium and lower limbs is a common consequence of arterial disease and a major source of morbidity and mortality in modernized countries. Inducing neovascularization for the treatment of ischemia is an appealing therapeutic strategy for patients for whom traditional treatment modalities cannot be performed or are ineffective. In the past, the stimulation of blood vessel growth was pursued using direct delivery of growth factors, angiogenic gene therapy, or cellular therapy. Although therapeutic angiogenesis holds great promise for treating patients with ischemia, current methods have not found success in clinical trials. Fibroblast growth factor-2 (FGF-2) was one of the first growth factors to be tested for use in therapeutic angiogenesis. Here, we present a method for improving the biological activity of FGF-2 by codelivering the growth factor with a liposomally embedded coreceptor, syndecan-4. This technique was shown to increase FGF-2 cellular signaling, uptake, and nuclear localization in comparison with FGF-2 alone. Delivery of syndecan-4 proteoliposomes also increased endothelial proliferation, migration, and angiogenic tube formation in response to FGF-2. Using an animal model of limb ischemia, syndecan-4 proteoliposomes markedly improved the neovascularization following femoral artery ligation and recovery of perfusion of the ischemic limb. Taken together, these results support liposomal delivery of syndecan-4 as an effective means to improving the potential of using growth factors to achieve therapeutic neovascularization of ischemic tissue. PMID:22307630

  15. Elevated Fibroblast Growth Factor-2 Increases Tumor Necrosis Factor-α Induced Endothelial Cell Death in High Glucose

    PubMed Central

    Clyne, Alisa Morss; Zhu, Han; Edelman, Elazer R.

    2010-01-01

    Glucose and tumor necrosis factor-α (TNFα) concentrations are elevated in diabetes. Both of these factors correlate with diabetic vasculopathy and endothelial cell apoptosis, yet their combined effects have not been measured. We have previously shown that the angiogenic growth factor fibroblast growth factor-2 (FGF-2), which is generally protective against endothelial cell death, is similarly elevated in high glucose conditions. We therefore investigated the effect of TNFα on endothelial cell death under normal and elevated glucose conditions, with a particular focus on FGF-2. Porcine aortic endothelial cells were cultured in 5 and 30 mM glucose and stimulated with TNFα, together with FGF-2 or a neutralizing FGF-2 antibody. Cell death was measured via cell counts or an annexin apoptotic assay, and cell cycle phase was determined by propidium iodide labeling. TNFα-induced endothelial cell death increased for cells in high glucose, and cell death was enhanced with increasing FGF-2 exposure and negated by a neutralizing FGF-2 antibody. Endothelial cells were most susceptible to TNFα-induced cell death when stimulated with FGF-2 18 h prior to TNFα, corresponding to cell entry into S phase of the proliferative cycle. The FGF-2 associated increase in TNFα-induced cell death was negated by blocking cell entry into S phase. Endothelial cell release of FGF-2 in high glucose leads to cell cycle progression, which makes cells more susceptible to TNFα-induced cell death. These data suggest that growth factor outcomes in high glucose depend on secondary mediators such as cytokines and stimulation cell cycle timing. PMID:18446810

  16. Insulin like growth factor 2 regulation of aryl hydrocarbon receptor in MCF-7 breast cancer cells

    SciTech Connect

    Tomblin, Justin K.; Salisbury, Travis B.

    2014-01-17

    Highlights: •IGF-2 stimulates concurrent increases in AHR and CCND1 expression. •IGF-2 promotes the binding of AHR to the endogenous cyclin D1 promoter. •AHR knockdown inhibits IGF-2 stimulated increases in CCND1 mRNA and protein. •AHR knockdown inhibits IGF-2 stimulated increases in MCF-7 proliferation. -- Abstract: Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancer proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IGF-2 induced an approximately 2-fold increase (P < .001) in the expression of AHR and CCND1. Chromatin immunoprecipitation (ChIP), followed by Q-PCR indicated that IGF-2 promoted (P < .001) a 7-fold increase in AHR binding on the CCND1 promoter. AHR knockdown significantly (P < .001) inhibited IGF-2 stimulated increases in CCND1 mRNA and protein. AHR knockdown cells were less (P < .001) responsive to the proliferative effects of IGF-2 than control cells. Collectively, our findings have revealed a new regulatory mechanism by which IGF-2 induction of AHR promotes the expression of CCND1 and the proliferation of MCF-7 cells. This previously uncharacterized pathway could be important for the proliferation of IGF responsive cancer cells that also express AHR.

  17. Fibroblast growth factor-2 induces osteogenic differentiation through a Runx2 activation in vascular smooth muscle cells

    SciTech Connect

    Nakahara, Takehiro; Sato, Hiroko; Shimizu, Takehisa; Tanaka, Toru; Matsui, Hiroki; Kawai-Kowase, Keiko; Sato, Mahito; Iso, Tatsuya; Arai, Masashi; Kurabayashi, Masahiko

    2010-04-02

    Expression of bone-associated proteins and osteoblastic transcription factor Runx2 in arterial cells has been implicated in the development of vascular calcification. However, the signaling upstream of the Runx2-mediated activation of osteoblastic program in vascular smooth muscle cells (VSMC) is poorly understood. We examined the effects of fibroblast growth factor-2 (FGF-2), an important regulator of bone formation, on osteoblastic differentiation of VSMC. Stimulation of cultured rat aortic SMC (RASMC) with FGF-2 induced the expression of the osteoblastic markers osteopontin (OPN) and osteocalcin. Luciferase assays showed that FGF-2 induced osteocyte-specific element (OSE)-dependent transcription. Downregulation of Runx2 by siRNA repressed the basal and FGF-2-stimulated expression of the OPN gene in RASMC. FGF-2 produced hydrogen peroxide in RASMC, as evaluated by fluorescent probe. Induction of OPN expression by FGF-2 was inhibited not only by PD98059 (MEK1 inhibitor) and PP1 (c-Src inhibitor), but also by an antioxidant, N-acetyl cysteine. Nuclear extracts from FGF-2-treated RASMC exhibited increased DNA-binding of Runx2 to its target sequence. Immunohistochemistry of human coronary atherectomy specimens and calcified aortic tissues showed that expression of FGF receptor-1 and Runx2 was colocalized. In conclusion, these results suggest that FGF-2 plays a role in inducing osteoblastic differentiation of VSMC by activating Runx2 through mitogen-activated protein kinase (MAPK)-dependent- and oxidative stress-sensitive-signaling pathways.

  18. Selection and characterization of a human neutralizing antibody to human fibroblast growth factor-2

    SciTech Connect

    Tao, Jun; Xiang, Jun-Jian; Li, Dan; Deng, Ning; Wang, Hong; Gong, Yi-Ping

    2010-04-09

    Compelling evidences suggest that fibroblast growth factor-2 (FGF-2) plays important roles in tumor growth, angiogenesis and metastasis. Molecules blocking the FGF-2 signaling have been proposed as anticancer agents. Through screening of a human scFv phage display library, we have isolated several human single-chain Fv fragments (scFvs) that bind to human FGF-2. After expression and purification in bacteria, one scFv, named 1A2, binds to FGF-2 with a high affinity and specificity, and completes with FGF-2 binding to its receptor. This 1A2 scFv was then cloned into the pIgG1 vector and expressed in 293T cells. The purified hIgG1-1A2 antibody showed a high binding affinity of 8 x 10{sup -9} M to rhFGF-2. In a set of vitro assays, it inhibited various biological activities of FGF-2 such as the proliferation, migration and tube formation of human umbilical vein endothelial cells. More importantly, hIgG1-1A2 antibody also efficiently blocked the growth while inducing apoptosis of glioma cells. For the first time, we generated a human anti-FGF-2 antibody with proven in vitro anti-tumor activity. It may therefore present a new therapeutic candidate for the treatment of cancers that are dependent on FGF-2 signaling for growth and survival.

  19. Enhanced effect of fibroblast growth factor-2-containing dalteparin/protamine nanoparticles on hair growth

    PubMed Central

    Takabayashi, Yuki; Nambu, Masaki; Ishihara, Masayuki; Kuwabara, Masahiro; Fukuda, Koichi; Nakamura, Shingo; Hattori, Hidemi; Kiyosawa, Tomoharu

    2016-01-01

    Purpose Although treatments for alopecia are in high demand, not all treatments are safe and reliable. Dalteparin/protamine nanoparticles (D/P NPs) can effectively carry growth factors (GFs) such as fibroblast GF (FGF)-2. The purpose of this study was to identify the effects of FGF-2-containing D/P NPs (FGF-2&D/P NPs) on hair growth. Patients and methods In this study, the participants were 12 volunteers with thin hair. One milliliter of FGF-2 (100 ng/mL) and D/P NPs (56 μg/mL) was applied and massaged on the skin of the scalp by the participants twice a day. They were evaluated for 6 months. Participants were photographed using a digital camera for general observation and a hair diagnosis system for measuring hair diameter. Results The mean diameter of the hairs was significantly higher following the application of FGF-2&D/P NPs for 6 months. Objective improvements in thin hair were observed in two cases. Nine participants experienced greater bounce and hair resilience. Conclusion The transdermal application of FGF-2&D/P NPs to the scalp can be used as a new treatment for alopecia. PMID:27274299

  20. Use of fibroblast growth factor 2 for expansion of chondrocytes and tissue engineering

    NASA Technical Reports Server (NTRS)

    Martin, Ivan (Inventor); Freed, Lisa E. (Inventor); Langer, Robert (Inventor); Vunjak-Novakovic, Gordana (Inventor)

    2003-01-01

    The present invention provides an improved method for expanding cells for use in tissue engineering. In particular the method provides specific biochemical factors to supplement cell culture medium during the expansion process in order to reproduce events occurring during embryonic development with the goal of regenerating tissue equivalents that resemble natural tissues both structurally and functionally. These specific biochemical factors improve proliferation of the cells and are capable of de-differentiation mature cells isolated from tissue so that the differentiation potential of the cells is preserved. The bioactive molecules also maintain the responsiveness of the cells to other bioactive molecules. Specifically, the invention provides methods for expanding chondrocytes in the presence of fibroblast growth factor 2 for use in regeneration of cartilage tissue.

  1. Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling

    PubMed Central

    Ramachandra, Rashmi; Namburi, Ramesh B; Ortega-Martinez, Olga; Shi, Xiaofeng; Zaia, Joseph; Dupont, Sam T; Thorndyke, Michael C; Lindahl, Ulf; Spillmann, Dorothe

    2014-01-01

    Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates. PMID:24253764

  2. Improving protein delivery of fibroblast growth factor-2 from bacterial inclusion bodies used as cell culture substrates.

    PubMed

    Seras-Franzoso, Joaquin; Peebo, Karl; García-Fruitós, Elena; Vázquez, Esther; Rinas, Ursula; Villaverde, Antonio

    2014-03-01

    Bacterial inclusion bodies (IBs) have recently been used to generate biocompatible cell culture interfaces, with diverse effects on cultured cells such as cell adhesion enhancement, stimulation of cell growth or induction of mesenchymal stem cell differentiation. Additionally, novel applications of IBs as sustained protein delivery systems with potential applications in regenerative medicine have been successfully explored. In this scenario, with IBs gaining significance in the biomedical field, the fine tuning of this functional biomaterial is crucial. In this work, the effect of temperature on fibroblast growth factor-2 (FGF-2) IB production and performance has been evaluated. FGF-2 was overexpressed in Escherichia coli at 25 and 37 °C, producing IBs with differences in size, particle structure and biological activity. Cell culture topographies made with FGF-2 IBs biofabricated at 25 °C showed higher levels of biological activity as well as a looser supramolecular structure, enabling a higher protein release from the particles. In addition, the controlled use of FGF-2 protein particles enabled the generation of functional topographies with multiple biological activities being effective on diverse cell types.

  3. Chicken stem cell factor enhances primordial germ cell proliferation cooperatively with fibroblast growth factor 2

    PubMed Central

    MIYAHARA, Daichi; OISHI, Isao; MAKINO, Ryuichi; KURUMISAWA, Nozomi; NAKAYA, Ryuma; ONO, Tamao; KAGAMI, Hiroshi; TAGAMI, Takahiro

    2015-01-01

    An in vitro culture system of chicken primordial germ cells (PGCs) has been recently developed, but the growth factor involved in the proliferation of PGCs is largely unknown. In the present study, we investigated the growth effects of chicken stem cell factor (chSCF) on the in vitro proliferation of chicken PGCs. We established two feeder cell lines (buffalo rat liver cells; BRL cells) that stably express the putative secreted form of chSCF (chSCF1-BRL) and membrane bound form of chSCF (chSCF2-BRL). Cultured PGC lines were incubated on chSCF1 or chSCF2-BRL feeder cells with fibroblast growth factor 2 (FGF2), and growth effects of each chSCF isoform were investigated. The in vitro proliferation rate of the PGCs cultured on chSCF2-BRL at 20 days of culture was more than threefold higher than those cultured on chSCF1-BRL cells and more than fivefold higher than those cultured on normal BRL cells. Thus, use of chSCF2-BRL feeder layer was effective for in vitro proliferation of chicken PGCs. However, the acceleration of PGC proliferation on chSCF2-BRL was not observed without FGF2, suggesting that chSCF2 would act as a proliferation co-factor of FGF2. We transferred the PGCs cultured on chSCF2-BRL cells to recipient embryos, generated germline chimeric chickens and assessed the germline competency of cultured PGCs by progeny test. Donor-derived progenies were obtained, and the frequency of germline transmission was 3.39%. The results of this study demonstrate that chSCF2 induces hyperproliferation of chicken PGCs retaining germline competency in vitro in cooperation with FGF2. PMID:26727404

  4. miR-203 facilitates tumor growth and metastasis by targeting fibroblast growth factor 2 in breast cancer

    PubMed Central

    He, Shuqian; Zhang, Guihui; Dong, He; Ma, Maoqiang; Sun, Qing

    2016-01-01

    Breast cancer is the second leading cause of cancer mortality in women worldwide. Molecular therapy is needed to improve the outcome in patients with breast cancer. miR-203 participates in cancer cell proliferation, transformation, and apoptosis. This study showed that miR-203 was upregulated in breast cancer tissues and the MCF-7 cell line. miR-203 knockdown suppressed colony formation and transformation and also limited migration in MCF-7 cells. Fibroblast growth factor 2 (FGF2) was confirmed as a novel target of miR-203, as miR-203 knockdown induced an enhanced expression of FGF2 in MCF-7 cells. Moreover, FGF2 can reverse transforming growth factor-β signal pathway to suppress breast cancer. These findings provide new insights with potential therapeutic applications for the treatment of breast cancer. PMID:27785068

  5. Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog

    PubMed Central

    Momose, Takehito; Miyaji, Hirofumi; Kato, Akihito; Ogawa, Kosuke; Yoshida, Takashi; Nishida, Erika; Murakami, Syusuke; Kosen, Yuta; Sugaya, Tsutomu; Kawanami, Masamitsu

    2016-01-01

    Objective: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. Methods: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. Result: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. Conclusion: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization. PMID:27583044

  6. Nucleo-cytoplasmic translocation and secretion of fibroblast growth factor-2 during avian gastrulation.

    PubMed

    Riese, J; Zeller, R; Dono, R

    1995-01-01

    The expression and distribution of the fibroblast growth factor-2 (FGF-2 or bFGF) proteins during early avian embryogenesis has been analysed in detail. Three FGF-2 protein isoforms of 18.5, 20.0 and 21.5 kDa are expressed during gastrulation of chicken embryos. Using whole mount immunohistochemistry, these proteins were found to be predominantly nuclear in prestreak blastodiscs during mesoderm induction. Distribution of positive cells in the epiblast was mosaic, whereas all cells of the forming hypoblast expressed the FGF-2 proteins. During primitive streak formation, the proteins started to translocate to the cytoplasm in epiblast cells but remained nuclear in the hypoblast. The FGF-2 proteins became predominantly cytoplasmic in all cells during the subsequent developmental stages. Their highest levels were detected in endodermal cells underlying Hensen's node and the newly formed notochord, the dorsal apex of all epiblast cells and, most interestingly, in the extra-cellular basal lamina separating the epiblast from newly formed mesoderm. Heparin and suramin treatment of these advanced embryos (stage 4) revealed a dose-dependent inhibition on the regression of Hensen's node and formation of mesodermal derivatives such as somites. The results are discussed with respect to current models on FGF-mediated functions during vertebrate mesoderm induction and regionalization.

  7. Vascular endothelial growth factor and fibroblast growth factor 2 delivery from spinal cord bridges to enhance angiogenesis following injury.

    PubMed

    De Laporte, Laura; des Rieux, Anne; Tuinstra, Hannah M; Zelivyanskaya, Marina L; De Clerck, Nora M; Postnov, Andrei A; Préat, Véronique; Shea, Lonnie D

    2011-09-01

    The host response to spinal cord injury can lead to an ischemic environment that can induce cell death and limits cell transplantation approaches to promote spinal cord regeneration. Spinal cord bridges that provide a localized and sustained release of vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF-2) were investigated for their ability to promote angiogenesis and nerve growth within the injury. Bridges were fabricated by fusion of poly(lactide-co-glycolide) microspheres using a gas foaming/particulate leaching technique, and proteins were incorporated by encapsulation into the microspheres and/or mixing with the microspheres before foaming. Compared to the mixing method, encapsulation reduced the losses during leaching and had a slower protein release, while VEGF was released more rapidly than FGF-2. In vivo implantation of bridges loaded with VEGF enhanced the levels of VEGF within the injury at 1 week, and bridges releasing VEGF and FGF-2 increased the infiltration of endothelial cells and the formation of blood vessel at 6 weeks postimplantation. Additionally, substantial neurofilament staining was observed within the bridge; however, no significant difference was observed between bridges with or without protein. Bridges releasing angiogenic factors may provide an approach to overcome an ischemic environment that limits regeneration and cell transplantation-based approaches.

  8. The regulation of runt-related transcription factor 2 by fibroblast growth factor-2 and connexin43 requires the inositol polyphosphate/protein kinase Cδ cascade.

    PubMed

    Niger, Corinne; Luciotti, Maria A; Buo, Atum M; Hebert, Carla; Ma, Vy; Stains, Joseph P

    2013-06-01

    Connexin43 (Cx43) plays a critical role in osteoblast function and bone mass accrual, yet the identity of the second messengers communicated by Cx43 gap junctions, the targets of these second messengers and how they regulate osteoblast function remain largely unknown. We have shown that alterations of Cx43 expression in osteoblasts can impact the responsiveness to fibroblast growth factor-2 (FGF2), by modulating the transcriptional activity of runt-related transcription factor 2 (Runx2). In this study, we examined the contribution of the phospholipase Cγ1/inositol polyphosphate/protein kinase C delta (PKCδ) cascade to the Cx43-dependent transcriptional response of MC3T3 osteoblasts to FGF2. Knockdown of expression and/or inhibition of function of phospholipase Cγ1, inositol polyphosphate multikinase, which generates inositol 1,3,4,5-tetrakisphosphate (InsP₄) and InsP₅, and inositol hexakisphosphate kinase 1/2, which generates inositol pyrophosphates, prevented the ability of Cx43 to potentiate FGF2-induced signaling through Runx2. Conversely, overexpression of phospholipase Cγ1 and inositol hexakisphosphate kinase 1/2 enhanced FGF2 activation of Runx2 and the effect of Cx43 overexpression on this response. Disruption of these pathways blocked the nuclear accumulation of PKCδ and the FGF2-dependent interaction of PKCδ and Runx2, reducing Runx2 transcriptional activity. These data reveal that FGF2-signaling involves the inositol polyphosphate cascade, including inositol hexakisphosphate kinase (IP6K), and demonstrate that IP6K regulates Runx2 and osteoblast gene expression. Additionally, these data implicate the water-soluble inositol polyphosphates as mediators of the Cx43-dependent amplification of the osteoblast response to FGF2, and suggest that these low molecular weight second messengers may be biologically relevant mediators of osteoblast function that are communicated by Cx43-gap junctions.

  9. Keratinocyte growth factor-2 inhibits bacterial infection with Pseudomonas aeruginosa pneumonia in a mouse model.

    PubMed

    Feng, Nana; Wang, Qin; Zhou, Jian; Li, Jing; Wen, Xiaoxing; Chen, Shujing; Zhu, Zhenhua; Bai, Chunxue; Song, Yuanlin; Li, Huayin

    2016-01-01

    To determine protective effects of concurrent administration of Keratinocyte growth factor-2 (KGF-2) with Pseudomonas aeruginosa (P. aeruginosa) inoculation on the induced pneumonia. KGF-2 (5 mg/kg) was concurrently administered into the left lobe of 55 mice with P. aeruginosa PAO1 (5 × 10(6) CFU, half-lethal dose); 55 mice in the control group were concurrently administered PBS with the PAO1. We detected and analyzed: body temperature; amount of P. aeruginosa in homogenates; count of total number of nucleated cells and of mononuclear macrophages; protein concentration in bronchoalveolar lavage fluid (BALF); lung wet-to-dry weight ratio; cytokines in BALF and blood; and lung morphology. To study survival rate, concurrent administration of KGF-2 (experimental group) versus PBS (control) with a lethal dose of PAO1 (1 × 10(7) CFU was performed, and survivorship was documented for 7 days post-inoculation. The bacterial CFU in lung homogenates was significantly decreased in the KGF-2 group compared to the control group. There were significantly more mononuclear macrophages in the BALF from the KGF-2 group than from the control group (p < 0.05). KGF-2 increased the surfactant protein and GM-CSF mRNA in lung at 6 h and 72 h after inoculation. Significant reduction of lung injury scores, protein concentrations, lung wet-to-dry weight ratio, and IL-6 and TNF-α levels was noted in the KGF-2 treated rats at 72 h after inoculation (p < 0.05). The 7-day survival rate of the KGF-2 group was significantly higher than that of the control group (p < 0.05). Concurrent administration of KGF-2 facilitates the clearance of P. aeruginosa from the lungs, attenuates P. aeruginosa-induced lung injury, and extends the 7-day survival rate in mice model with P. aeruginosa pneumonia.

  10. Fibroblast growth factor-2 promotes in vitro mitral valve interstitial cell repair through transforming growth factor-β/Smad signaling.

    PubMed

    Han, Li; Gotlieb, Avrum I

    2011-01-01

    Transforming growth factor (TGF)-β and fibroblast growth factor (FGF)-2 both promote repair in valve interstitial cell (VIC) injury models; however, the relationship between TGF-β and FGF-2 in wound repair are not well understood. VIC confluent monolayers were wounded by mechanical injury and incubated separately or in combination with FGF-2, neutralizing antibody to FGF-2, neutralizing antibody to TGF-β, and betaglycan antibody for 24 hours after wounding. Phosphorylated Smad2/3 (pSmad2/3) was localized at the wound edge (WE) and at the monolayer away from the WE. Down-regulation of pSmad2/3 protein expression via small-interfering RNA transfection was performed. The extent of wound closure was monitored for up to 96 hours. FGF-2 incubation resulted in a significant increase in nuclear pSmad2/3 staining at the WE. Neutralizing antibody to TGF-β alone or with FGF-2 present resulted in a similar significant decrease in pSmad2/3. Neutralizing antibody to FGF-2 alone or with FGF-2 present showed a similar significant decrease in pSmad2/3; however, significantly more staining was observed than treatment with neutralizing antibody to TGF-β. Incubation with betaglycan antibody inhibited FGF-2-mediated pSmad2/3 signaling. Wound closure corresponded with pSmad2/3 staining at the WE. Down-regulation of pSmad2/3 via small-interfering RNA transfection significantly reduced the extent to which FGF-2 promoted wound closure. Fibroblast growth factor-2 promotes in vitro VIC wound repair, at least in part, through the TGF-β/Smad2/3 signaling pathway.

  11. A Heparin-Mimicking Block Copolymer Both Stabilizes and Increases the Activity of Fibroblast Growth Factor 2 (FGF2)

    PubMed Central

    2016-01-01

    Fibroblast growth factor 2 (FGF2) is a protein involved in cellular functions in applications such as wound healing and tissue regeneration. Stabilization of this protein is important for its use as a therapeutic since the native protein is unstable during storage and delivery. Additionally, the ability to increase the activity of FGF2 is important for its application, particularly in chronic wound healing and the treatment of various ischemic conditions. Here we report a heparin mimicking block copolymer, poly(styrenesulfonate-co-poly(ethylene glycol) methyl ether methacrylate)-b-vinyl sulfonate) (p(SS-co-PEGMA)-b-VS, that contains a segment that enhances the stability of FGF2 and one that binds to the FGF2 receptor. The FGF2 conjugate retained activity after exposure to refrigeration (4 °C) and room temperature (23 °C) for 7 days, while unmodified FGF2 was inactive after these standard storage conditions. A cell study performed with a cell line lacking native heparan sulfate proteoglycans indicated that the conjugated block copolymer facilitated binding of FGF2 to its receptor similar to the addition of heparin to FGF2. A receptor-based enzyme-linked immunosorbant assay (ELISA) confirmed the results. The conjugate also increased the migration of endothelial cells by 80% compared to FGF2 alone. Additionally, the FGF2-p(SS-co-PEGMA)-b-VS stimulated endothelial cell sprouting 250% better than FGF2 at low concentration. These data verify that this rationally designed protein-block copolymer conjugate enhances receptor binding, cellular processes such as migration and tube-like formation, and stability, and suggest that it may be useful for applications in biomaterials, tissue regeneration, and wound healing. PMID:27580376

  12. The fibroblast growth factor-2 arrests Mycobacterium avium sp. paratuberculosis growth and immunomodulates host response in macrophages.

    PubMed

    Wang, Jianjun; Wang, Zeyou; Yao, Yongliang; Wu, Jianhong; Tang, Xin; Gu, Tao; Li, Guangxin

    2015-07-01

    Mycobacterium tuberculosisis (M. tb) epidemic is one of the most severe health problem worldwide, while mechanisms underlying its pathogenesis and host immune responses remain unclear. Mycobacterium avium (M. avium), a mycobacterial species related to M. tb, shares similarities with M. tb in many ways. In this study, using M. avium infection of macrophages as a model, we systematically studied the effect of fibroblast growth factor-2 (FGF-2) on M. avium infection of macrophages. Our results showed that M. avium infection could increase FGF-2 expression on both mRNA and protein levels. M. avium infection elevated TNF-α and IFN-γ production while the addition of FGF-2 could further increase TNF-α but not IFN-γ level. M. avium infection could increase the expression of oxygen/nitrogen metabolism proteins iNOS and SOD-1, and FGF-2 had additive effect on the expression of these two proteins. M. avium infection had inhibitive effect on actin expression while FGF-2 could partly counteract such inhibition. Moreover, FGF-2 could inhibit M. avium proliferation in macrophages. Our results together indicate that macrophage-secreted FGF-2 upon M. avium infection could suppress M. avium proliferation through various ways including cytokine production, enhancement of phagocytosis as well as oxygen/nitrogen metabolism.

  13. Microfluidic Screening Reveals Heparan Sulfate Enhances Human Mesenchymal Stem Cell Growth by Modulating Fibroblast Growth Factor-2 Transport.

    PubMed

    Titmarsh, Drew M; Tan, Clarissa L L; Glass, Nick R; Nurcombe, Victor; Cooper-White, Justin J; Cool, Simon M

    2017-04-01

    Cost-effective expansion of human mesenchymal stem/stromal cells (hMSCs) remains a key challenge for their widespread clinical deployment. Fibroblast growth factor-2 (FGF-2) is a key hMSC mitogen often supplemented to increase hMSC growth rates. However, hMSCs also produce endogenous FGF-2, which critically interacts with cell surface heparan sulfate (HS). We assessed the interplay of FGF-2 with a heparan sulfate variant (HS8) engineered to bind FGF-2 and potentiate its activity. Bone marrow-derived hMSCs were screened in perfused microbioreactor arrays (MBAs), showing that HS8 (50 μg/ml) increased hMSC proliferation and cell number after 3 days, with an effect equivalent to FGF-2 (50 ng/ml). In combination, the effects of HS8 and FGF-2 were additive. Differential cell responses, from upstream to downstream culture chambers under constant flow of media in the MBA, provided insights into modulation of FGF-2 transport by HS8. HS8 treatment induced proliferation mainly in the downstream chambers, suggesting a requirement for endogenous FGF-2 accumulation, whereas responses to FGF-2 occurred primarily in the upstream chambers. Adding HS8 along with FGF-2, however, maximized the range of FGF-2 effectiveness. Measurements of FGF-2 in static cultures then revealed that this was because HS8 caused increased endogenous FGF-2 production and liberated FGF-2 from the cell surface into the supernatant. HS8 also sustained levels of supplemented FGF-2 available over 3 days. These results suggest HS8 enhances hMSC proliferation and expansion by leveraging endogenous FGF-2 production and maximizing the effect of supplemented FGF-2. This is an exciting strategy for cost-effective expansion of hMSCs. Stem Cells Translational Medicine 2017;6:1178-1190.

  14. High molecular weight fibroblast growth factor-2 in the human heart is a potential target for prevention of cardiac remodeling.

    PubMed

    Santiago, Jon-Jon; McNaughton, Leslie J; Koleini, Navid; Ma, Xin; Bestvater, Brian; Nickel, Barbara E; Fandrich, Robert R; Wigle, Jeffrey T; Freed, Darren H; Arora, Rakesh C; Kardami, Elissavet

    2014-01-01

    Fibroblast growth factor 2 (FGF-2) is a multifunctional protein synthesized as high (Hi-) and low (Lo-) molecular weight isoforms. Studies using rodent models showed that Hi- and Lo-FGF-2 exert distinct biological activities: after myocardial infarction, rat Lo-FGF-2, but not Hi-FGF-2, promoted sustained cardioprotection and angiogenesis, while Hi-FGF-2, but not Lo-FGF-2, promoted myocardial hypertrophy and reduced contractile function. Because there is no information regarding Hi-FGF-2 in human myocardium, we undertook to investigate expression, regulation, secretion and potential tissue remodeling-associated activities of human cardiac (atrial) Hi-FGF-2. Human patient-derived atrial tissue extracts, as well as pericardial fluid, contained Hi-FGF-2 isoforms, comprising, respectively, 53%(±20 SD) and 68% (±25 SD) of total FGF-2, assessed by western blotting. Human atrial tissue-derived primary myofibroblasts (hMFs) expressed and secreted predominantly Hi-FGF-2, at about 80% of total. Angiotensin II (Ang II) up-regulated Hi-FGF-2 in hMFs, via activation of both type 1 and type 2 Ang II receptors; the ERK pathway; and matrix metalloprotease-2. Treatment of hMFs with neutralizing antibodies selective for human Hi-FGF-2 (neu-AbHi-FGF-2) reduced accumulation of proteins associated with fibroblast-to-myofibroblast conversion and fibrosis, including α-smooth muscle actin, extra-domain A fibronectin, and procollagen. Stimulation of hMFs with recombinant human Hi-FGF-2 was significantly more potent than Lo-FGF-2 in upregulating inflammation-associated proteins such as pro-interleukin-1β and plasminogen-activator-inhibitor-1. Culture media conditioned by hMFs promoted cardiomyocyte hypertrophy, an effect that was prevented by neu-AbHi-FGF-2 in vitro. In conclusion, we have documented that Hi-FGF-2 represents a substantial fraction of FGF-2 in human cardiac (atrial) tissue and in pericardial fluid, and have shown that human Hi-FGF-2, unlike Lo-FGF-2, promotes deleterious

  15. Growth hormone stimulation test - series (image)

    MedlinePlus

    The growth hormone (GH) is a protein hormone released from the anterior pituitary gland under the control of the hypothalamus. ... performed on infants and children to identify human growth hormone (hGH) deficiency as a cause of growth retardation. ...

  16. Role of circulating Fibroblast Growth Factor-2 in lipopolysaccharide-induced acute kidney injury in mice

    PubMed Central

    Mattison, Parnell C.; Soler-García, Ángel A.; Das, Jharna R.; Jerebtsova, Marina; Perazzo, Sofia; Tang, Pingtao; Ray, Patricio E.

    2011-01-01

    Background Fibroblast Growth Factor (FGF-2) is an angiogenic growth factor involved in renal growth and regeneration. Previous studies in rodents showed that single intrarenal injections of FGF-2 improved the outcome of acute kidney injury (AKI). Septic children usually show elevated plasma levels of FGF-2, and are at risk of developing AKI. However, the role of circulating FGF-2 in the pathogenesis of AKI is not well understood. Methods Here, we developed a mouse model to determine how FGF-2 released into the circulation modulates the outcome of AKI induced by lipopolysaccharide (LPS). Young FVB/N mice were infected with adenoviruses carrying a secreted form of human FGF-2 or control LacZ vectors. Subsequently, when the circulating levels of FGF-2 were similar to those seen in septic children, mice were injected with a non-lethal dose of LPS or control buffer. Results All mice injected with LPS developed hypotension and AKI, and recovered after five days. FGF-2 did not improve the outcome of AKI, and induced more significant renal proliferative and apoptotic changes during the recovery phase. Conclusions These findings suggest that circulating FGF-2 may not necessarily prevent the development or improve the outcome of AKI. Moreover, the renal accumulation of FGF-2 might cause further renal damage. PMID:21959768

  17. Insulin-like growth factor-2 regulates early neural and cardiovascular system development in zebrafish embryos.

    PubMed

    Hartnett, Lori; Glynn, Catherine; Nolan, Catherine M; Grealy, Maura; Byrnes, Lucy

    2010-01-01

    The insulin-like growth factor (IGF) family is essential for normal embryonic growth and development and it is highly conserved through vertebrate evolution. However, the roles that the individual members of the IGF family play in embryonic development have not been fully elucidated. This study focuses on the role of IGF-2 in zebrafish embryonic development. Two igf-2 genes, igf-2a and igf-2b, are present in the zebrafish genome. Antisense morpholinos were designed to knock down both igf-2 genes. The neural and cardiovascular defects in IGF-2 morphant embryos were then examined further using wholemount in situ hybridisation, TUNEL analysis and O-dianisidine staining. Knockdown of igf-2a or igf-2b resulted in ventralised embryos with reduced growth, reduced eyes, disrupted brain structures and a disrupted cardiovascular system, with igf-2b playing a more significant role in development. During gastrulation, igf-2a and igf-2b are required for development of anterior neural structures and for regulation of genes critical to dorsal-ventral patterning. As development proceeds, igf-2a and igf-2b play anti-apoptotic roles. Gene expression analysis demonstrates that igf-2a and igf-2b play overlapping roles in angiogenesis and cardiac outflow tract development. Igf-2b is specifically required for cardiac valve development and cardiac looping. Injection of a dominant negative IGF-1 receptor led to similar defects in angiogenesis and cardiac valve development, indicating IGF-2 signals through this receptor to regulate cardiovascular development. This is the first study describing two functional igf-2 genes in zebrafish. This work demonstrates that igf-2a and igf-2b are critical to neural and cardiovascular development in zebrafish embryos. The finding that igf-2a and igf-2b do not act exclusively in a redundant manner may explain why both genes have been stably maintained in the genome.

  18. Fibroblast growth factor 2 promotes primitive endoderm development in bovine blastocyst outgrowths.

    PubMed

    Yang, Qi En; Fields, Sarah D; Zhang, Kun; Ozawa, Manabu; Johnson, Sally E; Ealy, Alan D

    2011-11-01

    Primitive endoderm (PE) is the second extraembryonic tissue to form during embryogenesis in mammals. The PE develops from pluripotent cells of the blastocyst inner cell mass. Experimental results described herein provide evidence that FGF2 stimulates PE development during bovine blastocyst development in vitro. Bovine blastocysts were cultured individually on a feeder layer-free, Matrigel-coated surface in the presence or absence of FGF2. A majority of blastocysts cultures formed outgrowths (76.8%) and the rate of outgrowth formation was not affected by FGF2 supplementation. However, supplementation with FGF2 increased the incidence of PE outgrowths on Days 13 and 15 after in vitro fertilization. Presumptive PE cultures contained cells with a phenotype distinct from trophectoderm (TE). Cell identity was validated by expression of GATA4 and GATA6 mRNA and transferrin protein, all markers of the PE lineage. Expression of GATA4 occurred coincident with blastocyst expansion and hatching. These cells did not express IFNT and CDX2 (TE lineage markers). Profiles of FGF receptor (FGFR) isoforms were distinct between PE and TE cultures. Specifically, FGFR1b and FGFR1c were the predominant FGFR transcripts in PE whereas FGFR2b transcripts were abundant in TE. Supplementation with FGF2 increased the mitotic index of PE but not TE. Moreover, FGF signaling appears important for initiation of PE formation in blastocysts, presumably by lineage committal from NANOG-positive epiblast cells, because chemical disruption of FGFR kinase activity with PD173074 reduces GATA4 expression and increases NANOG expression. Collectively, these results indicate that FGF2 and potentially other FGFs specify PE formation and mediate PE proliferation during early pregnancy in cattle.

  19. Fibroblast growth factor 2 is a key determinant of vascular sprouting during bovine luteal angiogenesis.

    PubMed

    Woad, Kathryn J; Hunter, Morag G; Mann, George E; Laird, Mhairi; Hammond, Amanda J; Robinson, Robert S

    2012-01-01

    Fibroblast growth factor (FGF) 2 and vascular endothelial growth factor (VEGF) A are thought to be key controllers of luteal angiogenesis; however, their precise roles in the regulation and coordination of this complex process remain unknown. Thus, the temporal and spatial patterns of endothelial network formation were determined by culturing mixed cell types from early bovine corpora lutea on fibronectin in the presence of FGF2 and VEGFA (6 h to 9 days). Endothelial cells, as determined by von Willebrand factor immunohistochemistry, initially grew in cell islands (days 0-3), before undergoing a period of vascular sprouting to display a more tubule-like appearance (days 3-6), and after 9 days in culture had formed extensive intricate networks. Mixed populations of luteal cells were treated with SU1498 (VEGF receptor 2 inhibitor) or SU5402 (FGF receptor 1 inhibitor) or control on days 0-3, 3-6 or 6-9 to determine the role of FGF2 and VEGFA during these specific windows. The total area of endothelial cells was unaffected by SU1498 treatment during any window. In contrast, SU5402 treatment caused maximal reduction in the total area of endothelial cell networks on days 3-6 vs controls (mean reduction 81%; P<0.001) during the period of tubule initiation. Moreover, SU5402 treatment on days 3-6 dramatically reduced the total number of branch points (P<0.001) and degree of branching per endothelial cell island (P<0.05) in the absence of changes in mean island area. This suggests that FGF2 is a key determinant of vascular sprouting and hence critical to luteal development.

  20. Mitogenic and chondrogenic effects of fibroblast growth factor-2 in adipose-derived mesenchymal cells

    SciTech Connect

    Chiou, Michael; Xu Yue; Longaker, Michael T. . E-mail: Longaker@stanford.edu

    2006-05-05

    Adipose-derived mesenchymal cells (AMCs) have demonstrated a great capacity for differentiating into bone, cartilage, and fat. Studies using bone marrow-derived mesenchymal cells (BMSCs) have shown that fibroblast growth factor (FGF)-2, a potent mitogenic factor, plays an important role in tissue engineering due to its effects in proliferation and differentiation for mesenchymal cells. The aim of this study was to investigate the function of FGF-2 in AMC chondrogenic differentiation and its possible contributions to cell-based therapeutics in skeletal tissue regeneration. Data demonstrated that FGF-2 significantly promoted the proliferation of AMCs and enhanced chondrogenesis in three-dimensional micromass culture. Moreover, priming AMCs with treatment of FGF-2 at 10 ng/ml demonstrated that cells underwent chondrogenic phenotypic differentiation, possibly by inducing N-Cadherin, FGF-receptor 2, and transcription factor Sox9. Our results indicated that FGF-2 potentiates chondrogenesis in AMCs, similar to its functions in BMSCs, suggesting the versatile potential applications of FGF-2 in skeletal regeneration and cartilage repair.

  1. The effects of Ce3+ and Ce4+ on the stability of fibroblast growth factor-2

    NASA Astrophysics Data System (ADS)

    Sun, Liwei; Feng, Hao; Jiang, Rui; Niu, Liping; Song, Yu; Feng, Kai; Qi, Chao

    2010-11-01

    The interaction between tri or tetravalent cerium ions and basic fibroblast growth factor (FGF-2) at 0.1-6: 1 molar ratio under physiological condition was studied by fluorescence and CD spectrum. The different spectra alterations of FGF-2 induced by Ce3+ and Ce4+ showed that Ce3+ and Ce4+ caused different conformational changes of FGF-2 respectively, though both of them destabilized the protein. The instability of FGF-2 in the presence of Ce3+ is involved in the oxidation of its free cystein of protein, but that this treatment nearly does not affect the biological activity. As to Ce4+, it not only induced the conformational changes of protein but also inhibits its activity in a dose-dependent manner, which could be relative to the electrostatic repulsion between Ce4+ and its basic amino acid residues (pI=9.6) or the specific binding of Ce4+ to deprotonated amino acid residues. The interesting results would be helpful to investigate the problem of the stability of proteins.

  2. Fluid flow releases fibroblast growth factor-2 from human aortic smooth muscle cells

    NASA Technical Reports Server (NTRS)

    Rhoads, D. N.; Eskin, S. G.; McIntire, L. V.

    2000-01-01

    This study tested the hypothesis that fluid shear stress regulates the release of fibroblast growth factor (FGF)-2 from human aortic smooth muscle cells. FGF-2 is a potent mitogen that is involved in the response to vascular injury and is expressed in a wide variety of cell types. FGF-2 is found in the cytoplasm of cells and outside cells, where it associates with extracellular proteoglycans. To test the hypothesis that shear stress regulates FGF-2 release, cells were exposed to flow, and FGF-2 amounts were measured from the conditioned medium, pericellular fraction (extracted by heparin treatment), and cell lysate. Results from the present study show that after 15 minutes of shear stress at 25 dyne/cm(2) in a parallel-plate flow system, a small but significant fraction (17%) of the total FGF-2 was released from human aortic smooth muscle cells. FGF-2 levels in the circulating medium increased 10-fold over medium from static controls (P<0.01). A 50% increase in FGF-2 content versus control (P<0.01) was found in the pericellular fraction (extracted by heparin treatment). Furthermore, a significant decrease in FGF-2 was detected in the cell lysate, indicating that FGF-2 was released from inside the cell. Cell permeability studies with fluorescent dextran were performed to examine whether transient membrane disruption caused FGF-2 release. Flow cytometry detected a 50% increase in mean fluorescence of cells exposed to 25 dyne/cm(2) versus control cells. This indicates that the observed FGF-2 release from human aortic smooth muscle cells is likely due to transient membrane disruption on initiation of flow.

  3. RANTES and fibroblast growth factor 2 in jawbone cavitations: triggers for systemic disease?

    PubMed Central

    Lechner, Johann; von Baehr, Volker

    2013-01-01

    Background Jawbone cavitations (JC) are hollow dead spaces in jawbones with dying or dead bone marrow. These areas are defined as fatty degenerative osteonecrosis of the jawbone or neuralgia-inducing cavitational osteonecrosis and may produce facial pain. These afflictions have been linked to the immune system and chronic illnesses. Surgical debridement of JC is reported to lead to an improvement in immunological complaints, such as rheumatic, allergic, and other inflammatory diseases (ID). Little is known about the underlying cause/effect relationship. Objectives JC bone samples were analyzed to assess the expression and quantification of immune modulators that can play a role in the pathogenesis of IDs. The study supports a potential mechanism where JC is a mediating link in IDs. Materials and methods Samples of fatty softened bone taken from JCs were extracted from 31 patients. The specimens were analyzed by bead-based multiplex technology and tested for seven immune messengers. Results Regulated upon activation, normal T-cell expressed, and secreted (RANTES) and fibroblast growth factor (FGF)-2 were found at high levels in the JCs tested. Other cytokines could not be detected at excessive levels. Discussion The study confirms that JC is able to produce inflammatory messengers, primarily RANTES, and, secondarily, FGF-2. Both are implicated in many serious illnesses. The excessive levels of RANTES/FGF-2 in JC patients with amyotrophic lateral sclerosis, multiple sclerosis, rheumatoid arthritis, and breast cancer are compared to levels published in medical journals. Levels detected in JCs are higher than in the serum and cerebrospinal fluid of amyotrophic lateral sclerosis and multiple sclerosis patients and four-fold higher than in breast cancer tissue. Conclusion This study suggests that JC might serve as a fundamental cause of IDs, through RANTES/FGF-2 production. Thus, JC and implicated immune messengers represent an integrative aspect of IDs and serve as a

  4. Effects of the binding of a dextran derivative on fibroblast growth factor 2: secondary structure and receptor-binding studies.

    PubMed

    Bittoun, P; Bagheri-Yarmand, R; Chaubet, F; Crépin, M; Jozefonvicz, J; Fermandjian, S

    1999-06-15

    CMDB (carboxymethyldextran-benzylamide) are dextrans statistically substituted with carboxymethyl and benzylamide groups which can mimick some of the biological properties of heparin. It has previously been shown that CMDB inhibit autocrine growth of breast tumor cells (Bagheri-Yarmand et al., Biochem. Biophys. Res. Commun. 239: 424-428, 1997) and selectively displace fibroblast growth factor 2 (FGF-2) from its receptor. Here, we used circular dichroism and fluorescence anisotropy measurements to show that the conformation of FGF-2 was significantly altered upon its binding to CMDB and to short CMDB fragments prepared within this study. CMDB and fragments formed a stable 1:1 complex with FGF-2, with affinities being estimated as 20+/-10 nM from fluorescence anisotropy analysis. No such a complex was formed with insulin-like growth factor (IGF-1) or epidermal growth factor (EGF). CMDB competed with the FGF-2 receptor for binding to FGF-2 but did not disturb the binding of IGF-1 and EGF to their receptors. Thus, our results highlight the selectivity of CMDB and their fragments towards FGF-2. Heparin, however, competes with CMDB and their fragments for binding to FGF-2. The carboxymethyl and benzylamide groups of these molecules likely interact directly with a heparin-binding region of FGF-2. The resulting change in conformation disturbs the binding of FGF-2 to its receptor and consecutively its mitogenic activity.

  5. The Influence of Platelet-Derived Growth Factor and Fibroblast Growth Factor 2 on Oligodendrocyte Development and Remyelination

    DTIC Science & Technology

    2004-01-01

    AE, Bansal R (1993) The oligodendrocyte and its many cellular processes. Trends Cell Biol 3:191-197. Pluchino S, Quattrini A, Brambilla E, Gritti A...Rosenberg D, Cheung SW, Mobley WC, Fisher S, Genain CP (2000) Human nerve growth factor protects common 141 marmosets against autoimmune

  6. Fibroblast growth factor-2 inhibits mineralization of osteoblast-like Saos-2 cells by inhibiting the functioning of matrix vesicles.

    PubMed

    Liu, Chao; Cui, Yazhou; Luan, Jing; Zhou, Xiaoyan; Liu, Zhenxing; Han, Jinxiang

    2014-02-01

    Fibroblast growth factor-2 (FGF2) inhibits osteoblast mineralization, but the mechanism by which it does so is not fully understood. Matrix vesicles (MVs) play an essential role in the initiation of mineralization, so the current study examined the effect of FGF2 on the functioning of MVs to investigate this mechanism. This study found that FGF2 significantly inhibited differentiation and mineralization of osteoblast-like Saos-2 cells, as indicated by down-regulation of mRNA expression of the osteogenic master regulator runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and collagen 1 alpha 1 (Colla1), and by decreasing the formation of bone nodules. MVs were isolated from Saos-2 cells cultured in osteogenic medium supplemented with and without FGF2 and their presence was verified using electron microscopy and Western blotting. FGF2 markedly reduced the ALP activity of and in vitro mineralization by MVs. These findings suggest that FGF2 inhibits osteoblast mineralization by limiting the capacity of MVs.

  7. Heparin affin regulatory peptide/pleiotrophin mediates fibroblast growth factor 2 stimulatory effects on human prostate cancer cells.

    PubMed

    Hatziapostolou, Maria; Polytarchou, Christos; Katsoris, Panagiotis; Courty, Jose; Papadimitriou, Evangelia

    2006-10-27

    Fibroblast growth factor 2 (FGF2) is a pleiotropic growth factor that has been implicated in prostate cancer formation and progression. In the present study we found that exogenous FGF2 significantly increased human prostate cancer LNCaP cell proliferation and migration. Heparin affin regulatory peptide (HARP) or pleiotrophin seems to be an important mediator of FGF2 stimulatory effects, since the latter had no effect on stably transfected LNCaP cells that did not express HARP. Moreover, FGF2, through FGF receptors (FGFRs), significantly induced HARP expression and secretion by LNCaP cells and increased luciferase activity of a reporter gene vector carrying the full-length promoter of HARP gene. Using a combination of Western blot analyses, as well as genetic and pharmacological inhibitors, we found that activation of FGFR by FGF2 in LNCaP cells leads to NAD(P)H oxidase-dependent hydrogen peroxide production, phosphorylation of ERK1/2 and p38, activation of AP-1, increased expression and secretion of HARP, and, finally, increased cell proliferation and migration. These results establish the role and the mode of activity of FGF2 in LNCaP cells and support an interventional role of HARP in FGF2 effects, providing new insights on the interplay among growth factor pathways within prostate cancer cells.

  8. Effects of fibroblast growth factor 2 on osteoblastic proliferation and differentiation by regulating bone morphogenetic protein receptor expression.

    PubMed

    Park, Jun-Beom

    2011-09-01

    Fibroblast growth factors (FGFs) are known to play a critical role in bone growth and development, affecting both osteogenesis and chondrogenesis. Fibroblast growth factor 2 (FGF-2) is produced intracellularly by osteoblasts and secreted into the surrounding matrix in bone.The dose-dependent effects of FGF-2 were tested to examine the relationship between FGF-2 and osteoblast proliferation and differentiation. Tests used included a cell viability test, an alkaline phosphatase activity test, and a Western blot analysis.Cultures growing in the presence of FGF-2 showed an increased value for 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay and a decreased value for alkaline phosphatase activity. Results of the Western blot analysis showed that the addition of FGF-2 seems to decrease osteocalcin and bone morphogenetic protein receptor IA.These data show that FGF-2 in the tested dosage within MC3T3-E1 cells seems to affect proliferation and differentiation. Results of the Western blot analysis may add some possible mechanisms, and it may be suggested that treatment of FGF-2 may have an influence on the expression of bone morphogenetic protein receptors in osteoprecursor cells. Further elucidation of the mechanisms related to this mechanism within the in vivo model may be necessary to ascertain greater detail.

  9. In vivo injection of fibroblast growth factor-2 into the cisterna magna induces glypican-6 expression in mouse brain tissue.

    PubMed

    Salehi, Zivar

    2009-05-01

    The proteoglycans (PGs) are multifunctional macromolecules composed of a core polypeptide and a variable number of glycosaminoglycan chains. In the nervous system, PGs regulate the structural organization of the extracellular matrix (ECM) and modulate growth factor activities and cell proliferation and migration. Most cortical neurons are generated from neural precursor cells that reside in the ventricular zone of the embryonic brain. The proliferation and differentiation of neural precursor cells are regulated by various growth and neurotrophic factors. Fibroblast growth factor-2 (FGF-2) is an important mitogen for cortical neural precursor cells, and glypicans regulate the action of FGF-2 on neural precursor cells. Glypican-6 is one of the most abundant ECM molecules in the brain. In this study the effects of FGF-2 on glypican-6 expression in brain tissue have been investigated. FGF-2 was injected into the cerebrospinal fluid (CSF) through the cisterna magna of mouse pups. Using Western blotting, it was shown that the expression of glypican-6 is increased in response to infusion of FGF-2 into the CSF. The injection of anti-FGF-2 antibody into the cisterna magna decreased glypican-6 expression in brain tissue. The results from this study suggest that glypican-6 is important in regulating FGF-2 activity during cerebral cortical development.

  10. Triiodothyronine stimulates cartilage growth and maturation by different mechanisms

    SciTech Connect

    Burch, W.M.; Van Wyk, J.J.

    1987-02-01

    The mechanisms by which triiodothyronine (T3) stimulates growth and maturation of growth-plate cartilage in vitro were studied by incubating embryonic chick pelvic cartilages in serum-free medium in the presence and absence of T3 for 3 days. To determine whether T3 might stimulate production of somatomedins by the cartilage, medium from cartilage incubated with and without T3 was assayed for somatomedin C( Sm-C) by radioimmunoassay. No difference in Sm-C content was found. However, cartilage incubated with T3 and increasing amounts of human Sm-C (0.5-20 ng/ml) weighed more and had greater amounts of glycosaminoglycan that cartilage incubated in the same concentrations of Sm-C without T3, suggesting that T3 enhances the growth effect of somatomedin. The authors added a monoclonal antibody to Sm-C (anti-Sm-C) to the organ culture to determine whether T3's stimulatory effect on cartilage growth could be blocked. The anti-Sm-C inhibited growth of cartilage incubated in medium alone and blocked the growth response to T3. They propose two different mechanisms by which T3 affects growth-plate cartilage: (1) T3 promotes cartilage growth primarily through enhancing the effect of somatomedin, and (2) T3 stimulates cartilage maturation possibly by accelerating the normal process of cartilage differentiation from proliferative to hypertrophic chondrocytes.

  11. Electric field stimulated growth of Zn whiskers

    NASA Astrophysics Data System (ADS)

    Niraula, D.; McCulloch, J.; Warrell, G. R.; Irving, R.; Karpov, V. G.; Shvydka, Diana

    2016-07-01

    We have investigated the impact of strong (˜104 V/cm) electric fields on the development of Zn whiskers. The original samples, with considerable whisker infestation were cut from Zn-coated steel floors and then exposed to electric fields stresses for 10-20 hours at room temperature. We used various electric field sources, from charges accumulated in samples irradiated by: (1) the electron beam of a scanning electron microscope (SEM), (2) the electron beam of a medical linear accelerator, and (3) the ion beam of a linear accelerator; we also used (4) the electric field produced by a Van der Graaf generator. In all cases, the exposed samples exhibited a considerable (tens of percent) increase in whiskers concentration compared to the control sample. The acceleration factor defined as the ratio of the measured whisker growth rate over that in zero field, was estimated to approach several hundred. The statistics of lengths of e-beam induced whiskers was found to follow the log-normal distribution known previously for metal whiskers. The observed accelerated whisker growth is attributed to electrostatic effects. These results offer promise for establishing whisker-related accelerated life testing protocols.

  12. Activity and regulation by growth factors of calmodulin-dependent protein kinase III (elongation factor 2-kinase) in human breast cancer

    PubMed Central

    Parmer, T G; Ward, M D; Yurkow, E J; Vyas, V H; Kearney, T J; Hait, W N

    1999-01-01

    Calmodulin-dependent protein kinase III (CaM kinase III, elongation factor-2 kinase) is a unique member of the Ca2+/CaM-dependent protein kinase family. Activation of CaM kinase III leads to the selective phosphorylation of elongation factor 2 (eEF-2) and transient inhibition of protein synthesis. Recent cloning and sequencing of CaM kinase III revealed that this enzyme represents a new superfamily of protein kinases. The activity of CaM kinase III is selectively activated in proliferating cells; inhibition of the kinase blocked cells in G0/G1-S and decreased viability. To determine the significance of CaM kinase III in breast cancer, we measured the activity of the kinase in human breast cancer cell lines as well as in fresh surgical specimens. The specific activity of CaM kinase III in human breast cancer cell lines was equal to or greater than that seen in a variety of cell lines with similar rates of proliferation. The specific activity of CaM kinase III was markedly increased in human breast tumour specimens compared with that of normal adjacent breast tissue. The activity of this enzyme was regulated by breast cancer mitogens. In serum-deprived MDA-MB-231 cells, the combination of insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) stimulated cell proliferation and activated CaM kinase III to activities observed in the presence of 10% serum. Inhibition of enzyme activity blocked cell proliferation induced by growth factors. In MCF-7 cells separated by fluorescence-activated cell sorting, CaM kinase III was increased in S-phase over that of other phases of the cell cycle. In summary, the activity of Ca2+/CaM-dependent protein kinase III is controlled by breast cancer mitogens and appears to be constitutively activated in human breast cancer. These results suggest that CaM kinase III may contribute an important link between growth factor/receptor interactions, protein synthesis and the induction of cellular proliferation in human breast

  13. The characterization of protein release from sericin film in the presence of an enzyme: towards fibroblast growth factor-2 delivery.

    PubMed

    Nishida, Ayumu; Naganuma, Tsuyoshi; Kanazawa, Takanori; Takashima, Yuuki; Yamada, Masaki; Okada, Hiroaki

    2011-07-29

    Aqueous preparations of silk protein (sericin) films were prepared to evaluate their biodegradation properties. In the absence of trypsin, sericin film swelled rapidly, kept its shape, and remained unaltered for 28 days or longer due to form β-sheet structures. In the presence of trypsin, sericin film gradually degraded; since the rate depended on the concentration of trypsin, the films likely underwent enzymatic hydrolysis. Sericin film incorporating the model protein drug fluorescein isothiocyanate-albumin (FA) also gradually degraded in the presence of trypsin and resulted in the sustained release of FA for 2 weeks or longer; in contrast, FA release was quite slow in the absence of trypsin. It is expected that sericin film has potential as a biodegradable and drug-releasing carrier. To evaluate the practical applicability of sericin film for the repair of defective tissues, fibroblast growth factor-2 (FGF-2) was incorporated into sericin films and the films were implanted on skull defects in rats. Whereas FGF-2 release was suppressed in the absence of trypsin in vitro, it appears that FGF-2, immobilized by ionic interactions between sericin and FGF-2, can be sustained-released in vivo from films incorporating 2500 or 250 ng of FGF-2 to support the growth of tissue around wounds.

  14. A Novel Mechanism of Sequestering Fibroblast Growth Factor 2 by Glypican in Lipid Rafts, Allowing Skeletal Muscle Differentiation▿

    PubMed Central

    Gutiérrez, Jaime; Brandan, Enrique

    2010-01-01

    Heparan sulfate proteoglycans (HSPGs) are critical modulators of growth factor activities. Skeletal muscle differentiation is strongly inhibited by fibroblast growth factor 2 (FGF-2). We have shown that HSPGs present at the plasma membrane are expressed in myoblasts and are downregulated during muscle differentiation. An exception is glypican-1, which is present throughout the myogenic process. Myoblasts that do not express glypican-1 exhibit defective differentiation, with an increase in the receptor binding of FGF-2, concomitant with increased signaling. Glypican-1-deficient myoblasts show decreased expression of myogenin, the master gene that controls myogenesis, myosin, and the myoblast fusion index. Reversion of these defects was induced by expression of rat glypican-1. Glypican-1 is the only HSPG localized in lipid raft domains in myoblasts, resulting in the sequestration of FGF-2 away from FGF-2 receptors (FGFRs) located in nonraft domains. A chimeric glypican-1, containing syndecan-1 transmembrane and cytoplasmic domains, is located in nonraft domains interacting with FGFR-IV- and enhanced FGF-2-dependent signaling. Thus, glypican-1 acts as a positive regulator of muscle differentiation by sequestering FGF-2 in lipid rafts and preventing its binding and dependent signaling. PMID:20100867

  15. HULC cooperates with MALAT1 to aggravate liver cancer stem cells growth through telomere repeat-binding factor 2

    PubMed Central

    Wu, Mengying; Lin, Zhuojia; Li, Xiaonan; Xin, Xiaoru; An, Jiahui; Zheng, Qidi; Yang, Yuxin; Lu, Dongdong

    2016-01-01

    The dysregulation of lncRNAs has increasingly been linked to many human diseases, especially in cancers. Our results demonstrate HULC, MALAT1 and TRF2 are highly expressed in human hepatocellular carcinoma tissues, and HULC plus MALAT1 overexpression drastically promotes the growth of liver cancer stem cells. Mechanistically, both HULC and MALAT1 overexpression enhanced RNA polII, P300, CREPT to load on the promoter region of telomere repeat-binding factor 2(TRF2), triggering the overexpression, phosphorylation and SUMOylation of TRF2. Strikingly, the excessive TRF2 interacts with HULC or MALAT1 to form the complex that loads on the telomeric region, replacing the CST/AAF and recruiting POT1, pPOT1, ExoI, SNM1B, HP1 α. Accordingly, the telomere is greatly protected and enlonged. Furthermore, the excessive HULC plus MALAT1 reduced the methylation of the TERC promoter dependent on TRF2, increasing the TERC expression that causes the increase of interplay between TRET and TERC. Ultimately, the interaction between RFC and PCNA or between CDK2 and CyclinE, the telomerase activity and the microsatellite instability (MSI) are significantly increased in the liver cancer stem cells. Our demonstrations suggest that haploinsufficiency of HULC/MALAT1 plays an important role in malignant growth of liver cancer stem cell. PMID:27782152

  16. Angiogenic Capacity of Periodontal Ligament Stem Cells Pretreated with Deferoxamine and/or Fibroblast Growth Factor-2

    PubMed Central

    Ratajczak, Jessica; Hilkens, Petra; Gervois, Pascal; Wolfs, Esther; Jacobs, Reinhilde; Lambrichts, Ivo; Bronckaers, Annelies

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) represent a good source of multipotent cells for cell-based therapies in regenerative medicine. The success rate of these treatments is severely dependent on the establishment of adequate vasculature in order to provide oxygen and nutrients to the transplanted cells. Pharmacological preconditioning of stem cells has been proposed as a promising method to augment their therapeutic efficacy. In this study, the aim was to improve the intrinsic angiogenic properties of PDLSCs by in vitro pretreatment with deferoxamine (DFX; 100μM), fibroblast growth factor-2 (FGF-2; 10ng/mL) or both substances combined. An antibody array revealed the differential expression of several proteins, including vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). ELISA data confirmed a 1.5 to 1.8-fold increase in VEGF for all tested conditions. Moreover, 48 hours after the removal of DFX, VEGF levels remained elevated (1.8-fold) compared to control conditions. FGF-2 and combination treatment resulted in a 5.4 to 13.1-fold increase in PlGF secretion, whereas DFX treatment had no effect. Furthermore, both PDLSCs as pretreated PDLSCs induced endothelial migration. Despite the significant elevated VEGF levels of pretreated PDLSCs, the induced endothelial migration was not higher by pretreated PDLSCs. We find that the observed induced endothelial cell motility was not dependent on VEGF, since blocking the VEGFR1-3 with Axitinib (0.5nM) did not inhibit endothelial motility towards PDLSCs. Taken together, this study provides evidence that preconditioning with DFX and/or FGF-2 significantly improves the angiogenic secretome of PDLSCs, in particular VEGF and PlGF secretion. However, our data suggest that VEGF is not the only player when it comes to influencing endothelial behavior by the PDLSCs. PMID:27936076

  17. Vitamin D3 analogs stimulate hair growth in nude mice.

    PubMed

    Vegesna, Vijaya; O'Kelly, James; Uskokovic, Milan; Said, Jonathan; Lemp, Nathan; Saitoh, Takayuki; Ikezoe, Takayuki; Binderup, Lise; Koeffler, H Phillip

    2002-11-01

    The active form of vitamin D3 can regulate epidermal keratinization by inducing terminal differentiation; and mice lacking the vitamin D receptor display defects leading to postnatal alopecia. These observations implicate the vitamin D3 pathway in regulation of hair growth. We tested the ability of 1,25 dihydroxyvitamin D3 and its synthetic analogs to stimulate hair growth in biege/nude/xid (BNX) nu/nu (nude) mice exhibiting congenital alopecia. Nude mice were treated with different vitamin D3 analogs at doses that we had previously found to be the highest dose without inducing toxicity (hypercalcemia). The mice were monitored for hair growth and were scored according to a defined scale. Skin samples were taken for histological observation of hair follicles and for extraction of RNA and protein. Vitamin D3 analogs dramatically stimulated the hair growth of nude mice, although parental 1,25 dihydroxyvitamin D3 had no effect. Hair growth occurred in a cyclical pattern, accompanied by formation of normal hair follicles and increased expression of certain keratins (Ha7, Ha8, and Hb3). Vitamin D3 analogs seem to act on keratinocytes to initiate hair follicle cycling and stimulate hair growth in mice that otherwise do not grow hair.

  18. Insulin-like Growth Factor 2 Overexpression Induces β-Cell Dysfunction and Increases Beta-cell Susceptibility to Damage*

    PubMed Central

    Casellas, Alba; Mallol, Cristina; Salavert, Ariana; Jimenez, Veronica; Garcia, Miquel; Agudo, Judith; Obach, Mercè; Haurigot, Virginia; Vilà, Laia; Molas, Maria; Lage, Ricardo; Morró, Meritxell; Casana, Estefania; Ruberte, Jesús; Bosch, Fatima

    2015-01-01

    The human insulin-like growth factor 2 (IGF2) and insulin genes are located within the same genomic region. Although human genomic studies have demonstrated associations between diabetes and the insulin/IGF2 locus or the IGF2 mRNA-binding protein 2 (IGF2BP2), the role of IGF2 in diabetes pathogenesis is not fully understood. We previously described that transgenic mice overexpressing IGF2 specifically in β-cells (Tg-IGF2) develop a pre-diabetic state. Here, we characterized the effects of IGF2 on β-cell functionality. Overexpression of IGF2 led to β-cell dedifferentiation and endoplasmic reticulum stress causing islet dysfunction in vivo. Both adenovirus-mediated overexpression of IGF2 and treatment of adult wild-type islets with recombinant IGF2 in vitro further confirmed the direct implication of IGF2 on β-cell dysfunction. Treatment of Tg-IGF2 mice with subdiabetogenic doses of streptozotocin or crossing these mice with a transgenic model of islet lymphocytic infiltration promoted the development of overt diabetes, suggesting that IGF2 makes islets more susceptible to β-cell damage and immune attack. These results indicate that increased local levels of IGF2 in pancreatic islets may predispose to the onset of diabetes. This study unravels an unprecedented role of IGF2 on β-cells function. PMID:25971976

  19. Insulin-like Growth Factor 2 Overexpression Induces β-Cell Dysfunction and Increases Beta-cell Susceptibility to Damage.

    PubMed

    Casellas, Alba; Mallol, Cristina; Salavert, Ariana; Jimenez, Veronica; Garcia, Miquel; Agudo, Judith; Obach, Mercè; Haurigot, Virginia; Vilà, Laia; Molas, Maria; Lage, Ricardo; Morró, Meritxell; Casana, Estefania; Ruberte, Jesús; Bosch, Fatima

    2015-07-03

    The human insulin-like growth factor 2 (IGF2) and insulin genes are located within the same genomic region. Although human genomic studies have demonstrated associations between diabetes and the insulin/IGF2 locus or the IGF2 mRNA-binding protein 2 (IGF2BP2), the role of IGF2 in diabetes pathogenesis is not fully understood. We previously described that transgenic mice overexpressing IGF2 specifically in β-cells (Tg-IGF2) develop a pre-diabetic state. Here, we characterized the effects of IGF2 on β-cell functionality. Overexpression of IGF2 led to β-cell dedifferentiation and endoplasmic reticulum stress causing islet dysfunction in vivo. Both adenovirus-mediated overexpression of IGF2 and treatment of adult wild-type islets with recombinant IGF2 in vitro further confirmed the direct implication of IGF2 on β-cell dysfunction. Treatment of Tg-IGF2 mice with subdiabetogenic doses of streptozotocin or crossing these mice with a transgenic model of islet lymphocytic infiltration promoted the development of overt diabetes, suggesting that IGF2 makes islets more susceptible to β-cell damage and immune attack. These results indicate that increased local levels of IGF2 in pancreatic islets may predispose to the onset of diabetes. This study unravels an unprecedented role of IGF2 on β-cells function.

  20. Drosophila imaginal disc growth factor 2 is a trophic factor involved in energy balance, detoxification, and innate immunity

    PubMed Central

    Broz, Vaclav; Kucerova, Lucie; Rouhova, Lenka; Fleischmannova, Jana; Strnad, Hynek; Bryant, Peter J.; Zurovec, Michal

    2017-01-01

    Drosophila imaginal disc growth factor 2 (IDGF2) is a member of chitinase-like protein family (CLPs) able to induce the proliferation of imaginal disc cells in vitro. In this study we characterized physiological concentrations and expression of IDGF2 in vivo as well as its impact on the viability and transcriptional profile of Drosophila cells in vitro. We show that IDGF2 is independent of insulin and protects cells from death caused by serum deprivation, toxicity of xenobiotics or high concentrations of extracellular adenosine (Ado) and deoxyadenosine (dAdo). Transcriptional profiling suggested that such cytoprotection is connected with the induction of genes involved in energy metabolism, detoxification and innate immunity. We also show that IDGF2 is an abundant haemolymph component, which is further induced by injury in larval stages. The highest IDGF2 accumulation was found at garland and pericardial nephrocytes supporting its role in organismal defence and detoxification. Our findings provide evidence that IDGF2 is an important trophic factor promoting cellular and organismal survival. PMID:28230183

  1. A Genome-Inspired DNA Ligand for Affinity Capture of Insulin and Insulin-like Growth Factor-2

    PubMed Central

    Xiao, Junfeng; Carter, Jennifer A.; Frederick, Kimberley A.; McGown, Linda B.

    2009-01-01

    The insulin-linked polymorphic region (ILPR) of the human insulin gene contains tandem repeats of similar G-rich sequences, some of which form intramolecular G-quadruplex structures in vitro. Previous work showed affinity binding of insulin to an intramolecular G-quadruplex formed by ILPR variant a. Here we report on interactions of insulin and the highly homologous insulin-like growth factor 2 (IGF-2) with ILPR variants a, h and i. Circular dichroism indicated intramolecular G-quadruplex formation for variants a and h. Affinity MALDI mass spectrometry and surface plasmon resonance were used to compare protein capture and binding strengths. Insulin and IGF-2 exhibited high binding affinity for variants a and h but not i, indicating the involvement of intramolecular G-quadruplexes. Interaction between insulin and variant a was unique in the appearance of two binding interactions with KD~10−13 M and KD~10−7 M, which was not observed for insulin with variant h (KD~10−8 M) or IGF-2 with either variant (KD’s~10−9 D M). The results provide a basis for design of DNA binding ligands for insulin and IGF-2 and support a new approach to discovery of DNA affinity binding ligands based on genome-inspired sequences rather than the traditional combinatorial selection route to aptamer discovery. PMID:19391177

  2. Overexpression of caudal-related homeobox transcription factor 2 inhibits the growth of transplanted colorectal tumors in nude mice.

    PubMed

    Zheng, Jian-Bao; Qiao, Li-Na; Sun, Xue-Jun; Qi, Jie; Ren, Hai-Liang; Wei, Guang-Bing; Zhou, Pei-Hua; Yao, Jian-Feng; Zhang, Li; Jia, Peng-Bo

    2015-09-01

    Caudal‑related homeobox transcription factor 2 (CDX2) is a transcription factor, which is specifically expressed in the adult intestine. It is essential for the development and homeostasis of the intestinal epithelium and its functions as a tumor suppressor have been demonstrated in the adult colon. The present study aimed to examine the inhibitory effects of the overexpression of CDX2 on subcutaneously‑transplanted tumors, derived from LoVo colon cancer cells, in nude mice, and to provide experimental evidence for the biotherapy of colon cancer. A pEGFP‑C1‑CDX2 eukaryotic expression vector was transfected into the LoVo cells via lipofection, and LoVo cells stably‑expressing CDX2 (pEGFP‑C1‑CDX2 cells) were obtained using G418 selection. A nude mouse subcutaneously‑transplanted tumor model was established by inoculating the nude mice with the pEGFP‑C1‑CDX2 cells, and the effects of overexpression of CDX2 on transplanted tumor growth in the LoVo cells were observed. Western blotting results demonstrated that the protein expression of CDX2 in the LoVo cells was higher in the pEGFP‑C1‑CDX2 cell group, compared with that in the pEGFP‑C1 cell group and the untreated cell group. At 20 days post‑inoculation with either pEGFP‑C1‑CDX2 or pEGFP‑C1, the transplanted tumor masses were significantly lower in the pEGFP‑C1‑CDX2 group, compared with those in the pEGFP‑C1 and untreated groups. Immunohistochemistry revealed that the expression levels of CDX2 and matrix metalloproteinase‑2 (MMP‑2) were detected in each group, and the protein expression of CDX2 was increased in the tumor tissues from the nude mice in the pEGFP‑C1‑CDX2 group. However the expression of MMP‑2 was downregulated in the tumor tissues of the nude mice in the pEGFP‑C1‑CDX2 group. Taken together, these data suggested that pEGFP‑C1‑CDX2 cells exhibited suppressed tumor growth in vivo. Overexpression of CDX2 was observed in transplanted tumors in the p

  3. MicroRNA-29a in Adult Muscle Stem Cells Controls Skeletal Muscle Regeneration During Injury and Exercise Downstream of Fibroblast Growth Factor-2.

    PubMed

    Galimov, Artur; Merry, Troy L; Luca, Edlira; Rushing, Elisabeth J; Mizbani, Amir; Turcekova, Katarina; Hartung, Angelika; Croce, Carlo M; Ristow, Michael; Krützfeldt, Jan

    2016-03-01

    The expansion of myogenic progenitors (MPs) in the adult muscle stem cell niche is critical for the regeneration of skeletal muscle. Activation of quiescent MPs depends on the dismantling of the basement membrane and increased access to growth factors such as fibroblast growth factor-2 (FGF2). Here, we demonstrate using microRNA (miRNA) profiling in mouse and human myoblasts that the capacity of FGF2 to stimulate myoblast proliferation is mediated by miR-29a. FGF2 induces miR-29a expression and inhibition of miR-29a using pharmacological or genetic deletion decreases myoblast proliferation. Next generation RNA sequencing from miR-29a knockout myoblasts (Pax7(CE/+) ; miR-29a(flox/flox) ) identified members of the basement membrane as the most abundant miR-29a targets. Using gain- and loss-of-function experiments, we confirm that miR-29a coordinately regulates Fbn1, Lamc1, Nid2, Col4a1, Hspg2 and Sparc in myoblasts in vitro and in MPs in vivo. Induction of FGF2 and miR-29a and downregulation of its target genes precedes muscle regeneration during cardiotoxin (CTX)-induced muscle injury. Importantly, MP-specific tamoxifen-induced deletion of miR-29a in adult skeletal muscle decreased the proliferation and formation of newly formed myofibers during both CTX-induced muscle injury and after a single bout of eccentric exercise. Our results identify a novel miRNA-based checkpoint of the basement membrane in the adult muscle stem cell niche. Strategies targeting miR-29a might provide useful clinical approaches to maintain muscle mass in disease states such as ageing that involve aberrant FGF2 signaling.

  4. Choline pathways during normal and stimulated renal growth in rats.

    PubMed Central

    Bean, G H; Lowenstein, L M

    1978-01-01

    Cellular membrane synthesis occurs during normal and stimulated renal growth. Choline in the kidney is utilized as a precursor for membrane synthesis via the choline kinase reaction. We investigated choline phosphorylation during normal and stimulated renal growth. Rapidly growing neonatal rat kidneys contained relatively high levels of choline kinase activity (61 pmol phosphorylcholine/min per mg protein). Choline kinase activity and phosphorylcholine production then fell gradually over the 1st mo of life; by 1 mo phosphorylcholine production was 34 pmol phosphorylcholine/min per mg protein. Choline kinase activity increased by 27% (P less than 0.001) in 28-day-old rats when renal growth was stimulated by contralateral nephrectomy; the increase occurred within 2 h after surgery. Thus, changes in the activity of this important enzyme in the initiation of membrane synthesis is associated both with normal renal development and with adaptation to nephron loss. The findings further suggest that the cell membrane may be involved in the initiation of compensatory renal growth. PMID:659614

  5. Insulin-like Growth Factor 2 (IGF-2) Potentiates BMP-9-Induced Osteogenic Differentiation and Bone Formation

    PubMed Central

    Chen, Liang; Jiang, Wei; Huang, Jiayi; He, Bai-Cheng; Zuo, Guo-Wei; Zhang, Wenli; Luo, Qing; Shi, Qiong; Zhang, Bing-Qiang; Wagner, Eric R; Luo, Jinyong; Tang, Min; Wietholt, Christian; Luo, Xiaoji; Bi, Yang; Su, Yuxi; Liu, Bo; Kim, Stephanie H; He, Connie J; Hu, Yawen; Shen, Jikun; Rastegar, Farbod; Huang, Enyi; Gao, Yanhong; Gao, Jian-Li; Zhou, Jian-Zhong; Reid, Russell R; Luu, Hue H; Haydon, Rex C; He, Tong-Chuan; Deng, Zhong-Liang

    2010-01-01

    Efficient osteogenic differentiation and bone formation from mesenchymal stem cells (MSCs) should have clinical applications in treating nonunion fracture healing. MSCs are adherent bone marrow stromal cells that can self-renew and differentiate into osteogenic, chondrogenic, adipogenic, and myogenic lineages. We have identified bone morphogenetic protein 9 (BMP-9) as one of the most osteogenic BMPs. Here we investigate the effect of insulin-like growth factor 2 (IGF-2) on BMP-9-induced bone formation. We have found that endogenous IGF-2 expression is low in MSCs. Expression of IGF-2 can potentiate BMP-9-induced early osteogenic marker alkaline phosphatase (ALP) activity and the expression of later markers. IGF-2 has been shown to augment BMP-9-induced ectopic bone formation in the stem cell implantation assay. In perinatal limb explant culture assay, IGF-2 enhances BMP-9-induced endochondral ossification, whereas IGF-2 itself can promote the expansion of the hypertropic chondrocyte zone of the cultured limb explants. Expression of the IGF antagonists IGFBP3 and IGFBP4 leads to inhibition of the IGF-2 effect on BMP-9-induced ALP activity and matrix mineralization. Mechanistically, IGF-2 is further shown to enhance the BMP-9-induced BMPR-Smad reporter activity and Smad1/5/8 nuclear translocation. PI3-kinase (PI3K) inhibitor LY294002 abolishes the IGF-2 potentiation effect on BMP-9-mediated osteogenic signaling and can directly inhibit BMP-9 activity. These results demonstrate that BMP-9 crosstalks with IGF-2 through PI3K/AKT signaling pathway during osteogenic differentiation of MSCs. Taken together, our findings suggest that a combination of BMP-9 and IGF-2 may be explored as an effective bone-regeneration agent to treat large segmental bony defects, nonunion fracture, and/or osteoporotic fracture. © 2010 American Society for Bone and Mineral Research. PMID:20499340

  6. Fibroblast Growth Factor 2 Dimer with Superagonist In Vitro Activity Improves Granulation Tissue Formation During Wound Healing

    PubMed Central

    Decker, Caitlin G.; Wang, Yu; Paluck, Samantha J.; Shen, Lu; Loo, Joseph A.; Levine, Alex J.; Miller, Lloyd S.; Maynard, Heather D.

    2015-01-01

    Site-specific chemical dimerization of fibroblast growth factor 2 (FGF2) with the optimal linker length resulted in a FGF2 homodimer with improved granulation tissue formation and blood vessel formation at exceptionally low concentrations. Homodimers of FGF2 were synthesized through site-specific linkages to both ends of different molecular weight poly(ethylene glycols) (PEGs). The optimal linker length was determined by screening dimer-induced metabolic activity of human dermal fibroblasts and found to be that closest to the inter-cysteine distance, 70 Å, corresponding to 2 kDa PEG. A straightforward analysis of the kinetics of second ligand binding as a function of tether length showed that, as the polymerization index (the number of monomer repeat units in the polymer, N) of the tether decreases, the mean time for second ligand capture decreases as ~N3/2, leading to an enhancement of the number of doubly bound ligands in steady-state for a given (tethered) ligand concentration. FGF2-PEG2k-FGF2 induced greater fibroblast metabolic activity than FGF2 alone, all other dimers, and all monoconjugates, at each concentration tested, with the greatest difference observed at low (0.1 ng/mL) concentration. FGF2-PEG2k-FGF2 further exhibited superior activity compared to FGF2 for both metabolic activity and migration in human umbilical vein endothelial cells, as well as improved angiogenesis in a coculture model in vitro. Efficacy in an in vivo wound healing model was assessed in diabetic mice. FGF2-PEG2k-FGF2 increased granulation tissue and blood vessel density in the wound bed compared to FGF2. The results suggest that this rationally designed construct may be useful for improving the fibroblast matrix formation and angiogenesis in chronic wound healing. PMID:26731578

  7. Formation of Disulfide Bridges Drives Oligomerization, Membrane Pore Formation, and Translocation of Fibroblast Growth Factor 2 to Cell Surfaces*

    PubMed Central

    Müller, Hans-Michael; Steringer, Julia P.; Wegehingel, Sabine; Bleicken, Stephanie; Münster, Maximilian; Dimou, Eleni; Unger, Sebastian; Weidmann, Georg; Andreas, Helena; García-Sáez, Ana J.; Wild, Klemens; Sinning, Irmgard; Nickel, Walter

    2015-01-01

    Fibroblast growth factor 2 (FGF2) is a key signaling molecule in tumor-induced angiogenesis. FGF2 is secreted by an unconventional secretory mechanism that involves phosphatidylinositol 4,5-bisphosphate-dependent insertion of FGF2 oligomers into the plasma membrane. This process is regulated by Tec kinase-mediated tyrosine phosphorylation of FGF2. Molecular interactions driving FGF2 monomers into membrane-inserted FGF2 oligomers are unknown. Here we identify two surface cysteines that are critical for efficient unconventional secretion of FGF2. They represent unique features of FGF2 as they are absent from all signal-peptide-containing members of the FGF protein family. We show that phosphatidylinositol 4,5-bisphosphate-dependent FGF2 oligomerization concomitant with the generation of membrane pores depends on FGF2 surface cysteines as either chemical alkylation or substitution with alanines impairs these processes. We further demonstrate that the FGF2 variant forms lacking the two surface cysteines are not secreted from cells. These findings were corroborated by experiments redirecting a signal-peptide-containing FGF family member from the endoplasmic reticulum/Golgi-dependent secretory pathway into the unconventional secretory pathway of FGF2. Cis elements known to be required for unconventional secretion of FGF2, including the two surface cysteines, were transplanted into a variant form of FGF4 without signal peptide. The resulting FGF4/2 hybrid protein was secreted by unconventional means. We propose that the formation of disulfide bridges drives membrane insertion of FGF2 oligomers as intermediates in unconventional secretion of FGF2. PMID:25694424

  8. Formation of disulfide bridges drives oligomerization, membrane pore formation, and translocation of fibroblast growth factor 2 to cell surfaces.

    PubMed

    Müller, Hans-Michael; Steringer, Julia P; Wegehingel, Sabine; Bleicken, Stephanie; Münster, Maximilian; Dimou, Eleni; Unger, Sebastian; Weidmann, Georg; Andreas, Helena; García-Sáez, Ana J; Wild, Klemens; Sinning, Irmgard; Nickel, Walter

    2015-04-03

    Fibroblast growth factor 2 (FGF2) is a key signaling molecule in tumor-induced angiogenesis. FGF2 is secreted by an unconventional secretory mechanism that involves phosphatidylinositol 4,5-bisphosphate-dependent insertion of FGF2 oligomers into the plasma membrane. This process is regulated by Tec kinase-mediated tyrosine phosphorylation of FGF2. Molecular interactions driving FGF2 monomers into membrane-inserted FGF2 oligomers are unknown. Here we identify two surface cysteines that are critical for efficient unconventional secretion of FGF2. They represent unique features of FGF2 as they are absent from all signal-peptide-containing members of the FGF protein family. We show that phosphatidylinositol 4,5-bisphosphate-dependent FGF2 oligomerization concomitant with the generation of membrane pores depends on FGF2 surface cysteines as either chemical alkylation or substitution with alanines impairs these processes. We further demonstrate that the FGF2 variant forms lacking the two surface cysteines are not secreted from cells. These findings were corroborated by experiments redirecting a signal-peptide-containing FGF family member from the endoplasmic reticulum/Golgi-dependent secretory pathway into the unconventional secretory pathway of FGF2. Cis elements known to be required for unconventional secretion of FGF2, including the two surface cysteines, were transplanted into a variant form of FGF4 without signal peptide. The resulting FGF4/2 hybrid protein was secreted by unconventional means. We propose that the formation of disulfide bridges drives membrane insertion of FGF2 oligomers as intermediates in unconventional secretion of FGF2.

  9. Exogenous insulin-like growth factor 2 administration enhances memory consolidation and persistence in a time-dependent manner.

    PubMed

    Lee, Younghwan; Lee, Young Woo; Gao, Qingtao; Lee, Younghwa; Lee, Hyung Eun; Ryu, Jong Hoon

    2015-10-05

    Memory consolidation is an important process for the formation of long-term memory. We have previously reported that mature brain-derived neurotrophic factor enhances memory consolidation within 9h after initial learning. Recent studies suggest that insulin-like growth factor 2 (IGF2) significantly enhances memory consolidation and prevents forgetting. Thus, we hypothesized that IGF2 exerts its activity on cognitive performance in a time-dependent manner as observed in our previous study. In the one-trial step-through inhibitory avoidance task, we demonstrate that a bilateral injection of IGF2 into the dorsal hippocampus 6 or 9 h after training significantly enhanced the step-through latencies compared with the vehicle-treated controls in the retention trial, which was conducted 24 h after the acquisition trial. However, 12h post-training, IGF2 injection did not increase the step-through latencies. Intriguingly, in the retention trial at 21 days after the training, hippocampal IGF2 injection 6, 9 or 12 h after the acquisition trial significantly increased the step-through latencies compared with the vehicle-treated controls. IGF2 administration at 9 h and 12 h after the acquisition trial significantly increased discrimination index and exploration time on the novel-located object in the test trial at 24 h and 21 days, respectively, after the acquisition trial in the novel location recognition task. In addition, IGF2-induced an increase in the step-through latencies in the retention trial 24 h or 21 days, respectively, after the initial learning was completely abolished by co-injected anti-IGF2 receptor antibody. These results suggest that IGF2 enhances memory consolidation within 9h after initial learning, and increased IGF2 within the 12 h after the acquisition trial, which represents a delayed consolidation phase, is also critical for memory persistence.

  10. Concentration- and time-dependent response of human gingival fibroblasts to fibroblast growth factor 2 immobilized on titanium dental implants

    PubMed Central

    Ma, Qianli; Wang, Wei; Chu, Paul K; Mei, Shenglin; Ji, Kun; Jin, Lei; Zhang, Yumei

    2012-01-01

    Background Titanium (Ti) implants are widely used clinically, but peri-implantitis remains one of the most common and serious complications. Healthy integration between gingival tissue and the implant surface is critical to long-term success in dental implant therapy. The objective of this study was to investigate how different concentrations of immobilized fibroblast growth factor 2 (FGF2) on the titania nanotubular surface influence the response of human gingival fibroblasts (HGFs). Methods Pure Ti metal was anodized at 20 V to form a vertically organized titanium dioxide nanotube array on which three concentrations of FGF2 (250 ng/mL, 500 ng/mL, or 1000 ng/mL) were immobilized by repeated lyophilization. Surface topography was observed and FGF2 elution was detected using enzyme-linked immunosorbent assay. The bioactivity changes of dissolvable immobilized FGF2 were measured by methyl-thiazolyl-tetrazolium assay. Behavior of HGFs was evaluated using adhesion and methyl-thiazolyl-tetrazolium bromide assays. Results The FGF2 remained for several days on the modified surface on which HGFs were cultured. Over 90% of the dissolvable immobilized FGF2 had been eluted by Day 9, whereas the FGF2 activity was found to diminish gradually from Day 1 to Day 9. The titania nanotubular surface with an optimal preparing concentration (500 ng/mL) of FGF2 immobilization exhibited improved HGF functions such as cellular attachment, proliferation, and extracellular matrix-related gene expression. Moreover, significant bidirectional as well as concentration- and time-dependent bioactivity was observed. Conclusion Synergism of the FGF2-impregnated titanium dioxide nanotubular surface revealed good gingival-implant integration, indicating that these materials might have promising applications in dentistry and other biomedical devices. PMID:22619534

  11. Fibroblast growth factor 2 dimer with superagonist in vitro activity improves granulation tissue formation during wound healing.

    PubMed

    Decker, Caitlin G; Wang, Yu; Paluck, Samantha J; Shen, Lu; Loo, Joseph A; Levine, Alex J; Miller, Lloyd S; Maynard, Heather D

    2016-03-01

    Site-specific chemical dimerization of fibroblast growth factor 2 (FGF2) with the optimal linker length resulted in a FGF2 homodimer with improved granulation tissue formation and blood vessel formation at exceptionally low concentrations. Homodimers of FGF2 were synthesized through site-specific linkages to both ends of different molecular weight poly(ethylene glycols) (PEGs). The optimal linker length was determined by screening dimer-induced metabolic activity of human dermal fibroblasts and found to be that closest to the inter-cysteine distance, 70 Å, corresponding to 2 kDa PEG. A straightforward analysis of the kinetics of second ligand binding as a function of tether length showed that, as the polymerization index (the number of monomer repeat units in the polymer, N) of the tether decreases, the mean time for second ligand capture decreases as ∼N(3/2), leading to an enhancement of the number of doubly bound ligands in steady-state for a given (tethered) ligand concentration. FGF2-PEG2k-FGF2 induced greater fibroblast metabolic activity than FGF2 alone, all other dimers, and all monoconjugates, at each concentration tested, with the greatest difference observed at low (0.1 ng/mL) concentration. FGF2-PEG2k-FGF2 further exhibited superior activity compared to FGF2 for both metabolic activity and migration in human umbilical vein endothelial cells, as well as improved angiogenesis in a coculture model in vitro. Efficacy in an in vivo wound healing model was assessed in diabetic mice. FGF2-PEG2k-FGF2 increased granulation tissue and blood vessel density in the wound bed compared to FGF2. The results suggest that this rationally designed construct may be useful for improving the fibroblast matrix formation and angiogenesis in chronic wound healing.

  12. The Startling Properties of Fibroblast Growth Factor 2: How to Exit Mammalian Cells without a Signal Peptide at Hand*

    PubMed Central

    La Venuta, Giuseppe; Zeitler, Marcel; Steringer, Julia P.; Müller, Hans-Michael; Nickel, Walter

    2015-01-01

    For a long time, protein transport into the extracellular space was believed to strictly depend on signal peptide-mediated translocation into the lumen of the endoplasmic reticulum. More recently, this view has been challenged, and the molecular mechanisms of unconventional secretory processes are beginning to emerge. Here, we focus on unconventional secretion of fibroblast growth factor 2 (FGF2), a secretory mechanism that is based upon direct protein translocation across plasma membranes. Through a combination of genome-wide RNAi screening approaches and biochemical reconstitution experiments, the basic machinery of FGF2 secretion was identified and validated. This includes the integral membrane protein ATP1A1, the phosphoinositide phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2), and Tec kinase, as well as membrane-proximal heparan sulfate proteoglycans on cell surfaces. Hallmarks of unconventional secretion of FGF2 are: (i) sequential molecular interactions with the inner leaflet along with Tec kinase-dependent tyrosine phosphorylation of FGF2, (ii) PI(4,5)P2-dependent oligomerization and membrane pore formation, and (iii) extracellular trapping of FGF2 mediated by heparan sulfate proteoglycans on cell surfaces. Here, we discuss new developments regarding this process including the mechanism of FGF2 oligomerization during membrane pore formation, the functional role of ATP1A1 in FGF2 secretion, and the possibility that other proteins secreted by unconventional means make use of a similar mechanism to reach the extracellular space. Furthermore, given the prominent role of extracellular FGF2 in tumor-induced angiogenesis, we will discuss possibilities to develop highly specific inhibitors of FGF2 secretion, a novel approach that may yield lead compounds with a high potential to develop into anti-cancer drugs. PMID:26416892

  13. Impact of palbociclib combinations on treatment of advanced estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer

    PubMed Central

    Boér, Katalin

    2016-01-01

    Breast cancer is a heterogeneous disease with multiple subgroups based on clinical and molecular characteristics. For the largest subgroup of breast cancers, hormone receptor-positive/human epidermal growth factor 2 (HER2)-negative tumors, hormone treatment is the mainstay of therapy and is likely to result in significant improvement in disease outcomes. However, some of these cancers demonstrate de novo or acquired resistance to endocrine therapy. Despite intensive research to develop new strategies to enhance the efficacy of currently available treatment options for hormone receptor-positive breast cancer, progress has been slow, and there were few advances for a period of 10 years. In 2012, a new molecularly targeted therapeutic strategy, inhibition of mammalian target of rapamycin with everolimus, was introduced into clinical practice. Everolimus, in combination with a steroidal aromatase inhibitor, exemestane, resulted in an increase in progression-free survival, but not overall survival in patients with estrogen receptor (ER)+ve advanced disease who had progressed on hormone therapy. In 2015, the first cyclin-dependent kinases 4/6 (CDK4/6) inhibitor, palbociclib, received accelerated US Food and Drug Administration approval for use in combination with letrozole for the treatment of postmenopausal ER+ve/HER2−ve advanced breast cancer as initial, endocrine-based therapy. The addition of palbociclib to endocrine therapy resulted in longer progression-free survival than letrozole alone. One year later, palbociclib received a new indication, use in combination with fulvestrant, in both premenopausal and postmenopausal females with advanced breast cancer of the same subtype with disease progression following endocrine therapy. Adding palbociclib to fulvestrant resulted in a significantly increased median progression-free survival compared to fulvestrant monotherapy. These new combination regimens of palbociclib with endocrine agents represent an important

  14. Pharmacokinetics of topically applied recombinant human keratinocyte growth factor-2 in alkali-burned and intact rabbit eye.

    PubMed

    Cai, Jianqiu; Dou, Guifang; Zheng, Long; Yang, Ting; Jia, Xuechao; Tang, Lu; Huang, Yadong; Wu, Wencan; Li, Xiaokun; Wang, Xiaojie

    2015-07-01

    Keratinocyte growth factor-2 (KGF-2), an effective agent in the development of epithelial tissue and regeneration during corneal wound healing, is a potential therapeutic option to treat the corneal diseases with corneal epithelial defects. However the tissue distribution and pharmacokinetics of KGF-2 have not been explored yet in eye upon topical application. Using (125)I-labeled recombinant human KGF-2 ((125)I-rhKGF-2), tissue distribution of rhKGF-2 in alkali-burned and control rabbit eyes was studied. Our results revealed that (125)I-rhKGF-2 was distributed to all eye tissues examined. The highest radioactivity level was found in the cornea, followed by iris, sclera, ciliary body, lens, aqueous humor, vitreous body, and serum in a greatest to least order. The levels of (125)I-rhKGF-2 were higher in corneas of alkali-burned eyes than those in control eyes though without statistical significance. Calculated pharmacokinetic parameters of t1/2, Cmax, and Tmax of rhKGF-2 in the rabbit corneas were 3.4 h, 135.2 ng/ml, and 0.5 h, respectively. In iris, lens, aqueous humor, and tear, t1/2, Cmax, and Tmax values were 6.2, 6.5, 5.2, and 2.5 h; 23.2, 4.5, 24.1, and 29,498.9 ng/ml; and 1.0, 0.5, 0.5, and 1.0 h, respectively. Predominant and rapid accumulation of rhKGF-2 in corneas suggests that therapeutic doses of rhKGF-2 could be delivered by topical application for treatment of corneal diseases.

  15. Action Mechanism of Fibroblast Growth Factor-2 (FGF-2) in the Promotion of Periodontal Regeneration in Beagle Dogs.

    PubMed

    Nagayasu-Tanaka, Toshie; Anzai, Jun; Takaki, Shu; Shiraishi, Noriko; Terashima, Akio; Asano, Taiji; Nozaki, Takenori; Kitamura, Masahiro; Murakami, Shinya

    2015-01-01

    Fibroblast growth factor-2 (FGF-2) enhances the formation of new alveolar bone, cementum, and periodontal ligament (PDL) in periodontal defect models. However, the mechanism through which FGF-2 acts in periodontal regeneration in vivo has not been fully clarified yet. To reveal the action mechanism, the formation of regenerated tissue and gene expression at the early phase were analyzed in a beagle dog 3-wall periodontal defect model. FGF-2 (0.3%) or the vehicle (hydroxypropyl cellulose) only were topically applied to the defect in FGF-2 and control groups, respectively. Then, the amount of regenerated tissues and the number of proliferating cells at 3, 7, 14, and 28 days and the number of blood vessels at 7 days were quantitated histologically. Additionally, the expression of osteogenic genes in the regenerated tissue was evaluated by real-time PCR at 7 and 14 days. Compared with the control, cell proliferation around the existing bone and PDL, connective tissue formation on the root surface, and new bone formation in the defect at 7 days were significantly promoted by FGF-2. Additionally, the number of blood vessels at 7 days was increased by FGF-2 treatment. At 28 days, new cementum and PDL were extended by FGF-2. Moreover, FGF-2 increased the expression of bone morphogenetic protein 2 (BMP-2) and osteoblast differentiation markers (osterix, alkaline phosphatase, and osteocalcin) in the regenerated tissue. We revealed the facilitatory mechanisms of FGF-2 in periodontal regeneration in vivo. First, the proliferation of fibroblastic cells derived from bone marrow and PDL was accelerated and enhanced by FGF-2. Second, angiogenesis was enhanced by FGF-2 treatment. Finally, osteoblastic differentiation and bone formation, at least in part due to BMP-2 production, were rapidly induced by FGF-2. Therefore, these multifaceted effects of FGF-2 promote new tissue formation at the early regeneration phase, leading to enhanced formation of new bone, cementum, and PDL.

  16. Transient Hepatic Overexpression of Insulin-Like Growth Factor 2 Induces Free Cholesterol and Lipid Droplet Formation

    PubMed Central

    Kessler, Sonja M.; Laggai, Stephan; Van Wonterghem, Elien; Gemperlein, Katja; Müller, Rolf; Haybaeck, Johannes; Vandenbroucke, Roosmarijn E.; Ogris, Manfred; Libert, Claude; Kiemer, Alexandra K.

    2016-01-01

    Although insulin-like growth factor 2 (IGF2) has been reported to be overexpressed in steatosis and steatohepatitis, a causal role of IGF2 in steatosis development remains elusive. Aim of our study was to decipher the role of IGF2 in steatosis development. Hydrodynamic gene delivery of an Igf2 plasmid used for transient Igf2 overexpression employing codon-optimized plasmid DNA resulted in a strong induction of hepatic Igf2 expression. The exogenously delivered Igf2 had no influence on endogenous Igf2 expression. The downstream kinase AKT was activated in Igf2 animals. Decreased ALT levels mirrored the cytoprotective effect of IGF2. Serum cholesterol was increased and sulfo-phospho-vanillin colorimetric assay confirmed lipid accumulation in Igf2-livers while no signs of inflammation were observed. Interestingly, hepatic cholesterol and phospholipids, determined by thin layer chromatography, and free cholesterol by filipin staining, were specifically increased. Lipid droplet (LD) size was not changed, but their number was significantly elevated. Furthermore, free cholesterol, which can be stored in LDs and has been reported to be critical for steatosis progression, was elevated in Igf2 overexpressing mice. Accordingly, Hmgcr/HmgCoAR was upregulated. To have a closer look at de novo lipid synthesis we investigated expression of the lipogenic transcription factor SREBF1 and its target genes. SREBF1 was induced and also SREBF1 target genes were slightly upregulated. Interestingly, the expression of Cpt1a, which is responsible for mitochondrial fatty acid oxidation, was induced. Hepatic IGF2 expression induces a fatty liver, characterized by increased cholesterol and phospholipids leading to accumulation of LDs. We therefore suggest a causal role for IGF2 in hepatic lipid accumulation. PMID:27199763

  17. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    PubMed

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  18. Nutritional state modulates growth hormone-stimulated lipolysis.

    PubMed

    Bergan, Heather E; Kittilson, Jeffrey D; Sheridan, Mark A

    2015-01-01

    Growth hormone (GH) regulates several processes in vertebrates, including two metabolically disparate processes: promotion of growth, an anabolic action, and mobilization of stored lipid, a catabolic action. In this study, we used hepatocytes isolated from continuously fed and long-term (4weeks) fasted rainbow trout (Oncorhynchus mykiss) as a model to investigate the mechanistic basis of the anabolic and catabolic actions of GH. Our hypothesis was that nutritional state modulates the lipolytic responsiveness of cells by adjusting the signal transduction pathways to which GH links. GH stimulated lipolysis as measured by increased glycerol release in both a time- and concentration-related manner from cells of fasted fish but not from cells of fed fish. Expression of mRNAs that encode the lipolytic enzyme hormone-sensitive lipase (HSL), HSL1 and HSL2, also was stimulated by GH in cells from fasted fish and not in cells from fed fish. Activation of the signaling pathways that mediate GH action also was studied. In cells from fed fish, GH activated the JAK-STAT, PI3K-Akt, and ERK pathways, whereas in cells from fasted fish, GH activated the PLC/PKC and ERK pathways. In hepatocytes from fasted fish, blockade of PLC/PKC and of the ERK pathway inhibited GH-stimulated lipolysis and GH-stimulated HSL mRNA expression, whereas blockade of JAK-STAT or of the PI3K-Akt pathway had no effect on lipolysis or HSL expression stimulated by GH. These results indicate that during fasting GH activates the PLC/PKC and ERK pathways resulting in lipolysis but during periods of feeding GH activates a different complement of signal elements that do not promote lipolysis. These findings suggest that the responsiveness of cells to GH depends on the signal pathways to which GH links and helps resolve the growth-promoting and lipid catabolic actions of GH.

  19. Cell Injury-Induced Release of Fibroblast Growth Factor 2: Relevance to Intracerebral Mesenchymal Stromal Cell Transplantations

    PubMed Central

    Vinodkumar, Deepti; McGrogan, Michael; Bates, Damien

    2015-01-01

    Beneficial effects of intracerebral transplantation of mesenchymal stromal cells (MSC) and their derivatives are believed to be mediated mostly by factors produced by engrafted cells. However, the mesenchymal cell engraftment rate is low, and the majority of grafted cells disappear within a short post-transplantation period. Here, we hypothesize that dying transplanted cells can affect surrounding tissues by releasing their active intracellular components. To elucidate the type, amounts, and potency of these putative intracellular factors, freeze/thaw extracts of MSC or their derivatives were tested in enzyme-linked immunosorbent assays and bioassays. We found that fibroblast growth factor (FGF)2 and FGF1, but not vascular endothelial growth factor and monocyte chemoattractant protein 1 levels were high in extracts despite being low in conditioned media. Extracts induced concentration-dependent proliferation of rat cortical neural progenitor cells and human umbilical vein endothelial cells; these proliferative responses were specifically blocked by FGF2-neutralizing antibody. In the neuropoiesis assay with rat cortical cells, both MSC extracts and killed cells induced expression of nestin, but not astrocyte differentiation. However, suspensions of killed cells strongly potentiated the astrogenic effects of live MSC. In transplantation-relevant MSC injury models (peripheral blood cell-mediated cytotoxicity and high cell density plating), MSC death coincided with the release of intracellular FGF2. The data showed that MSC contain a major depot of active FGF2 that is released upon cell injury and is capable of acutely stimulating neuropoiesis and angiogenesis. We therefore propose that both dying and surviving grafted MSC contribute to tissue regeneration. PMID:25873141

  20. Rac regulates vascular endothelial growth factor stimulated motility.

    PubMed

    Soga, N; Connolly, J O; Chellaiah, M; Kawamura, J; Hruska, K A

    2001-01-01

    During angiogenesis endothelial cells migrate towards a chemotactic stimulus. Understanding the mechanism of endothelial cell migration is critical to the therapeutic manipulation of angiogenesis and ultimately cancer prevention. Vascular endothelial growth factor (VEGF) is a potent chemotactic stimulus of endothelial cells during angiogenesis. The endothelial cell signal transduction pathway of VEGF represents a potential target for cancer therapy, but the mechanisms of post-receptor signal transduction including the roles of rho family GTPases in regulating the cytoskeletal effects of VEGF in endothelial cells are not understood. Here we analyze the mechanisms of cell migration in the mouse brain endothelial cell line (bEND3). Stable transfectants containing a tetracycline repressible expression vector were used to induce expression of Rac mutants. Endothelial cell haptotaxis was stimulated by constitutively active V12Rac on collagen and vitronectin coated supports, and chemotaxis was further stimulated by VEGF. Osteopontin coated supports were the most stimulatory to bEND3 haptotaxis, but VEGF was not effective in further increasing migration on osteopontin coated supports. Haptotaxis on support coated with collagen, vitronectin, and to a lesser degree osteopontin was inhibited by N17 Rac. N17 Rac expression blocked stimulation of endothelial cell chemotaxis by VEGF. As part of the chemotactic stimulation, VEGF caused a loss of actin organization at areas of cell-cell contact and increased stress fiber expression in endothelial cells which were directed towards pores in the transwell membrane. N17 Rac prevented the stimulation of cell-cell contact disruption and the stress fiber stimulation by VEGF. These data demonstrate two pathways of regulating endothelial cell motility, one in which Rac is activated by matrix/integrin stimulation and is a crucial modulator of endothelial cell haptotaxis. The other pathway, in the presence of osteopontin, is Rac independent

  1. Immunohistochemical expression of fibroblast growth factor-2 in developing human cerebrum and epilepsy-associated malformations of cortical development.

    PubMed

    Ueda, Manami; Sugiura, Chitose; Ohno, Kousaku; Kakita, Akiyoshi; Hori, Akira; Ohama, Eisaku; Vinters, Harry V; Miyata, Hajime

    2011-12-01

    To elucidate the biological significance of fibroblast growth factor-2 (FGF-2) expression in epilepsy-associated malformations of cortical development, immunohistochemical expression of FGF-2 was investigated in the developing human cerebral mantles obtained from 30 autopsy cases of fetuses, stillborn infants and children ranging from 12 weeks gestation to 15 years old, and 70 surgically-resected corticectomy specimens from patients with medically intractable epilepsy, including: group I, 12 tubers of tuberous sclerosis; group II, 24 cases of focal cortical dysplasia (FCD) with balloon cells (BC); group III, 11 FCD without BC; group IV, 23 histologically normal-appearing neocortices from patients with Rasmussen encephalitis, cystic-gliotic encephalopathy, temporal lobe epilepsy; and group V, 14 normal-appearing neocortices adjacent to dysplastic lesions from groups I and II. FGF-2 expression was detected in a population of matrix cells and/or neuroblasts within the ventricular zone in fetuses younger than 19 weeks gestation. Nuclei of glioblasts and immature astrocytes were also positive for FGF-2 in cases older than 18 weeks gestation. FGF-2 expression was not detected in immature cortical plate neurons. Astrocytes and ependymal cells were positive for FGF-2 in the postnatal brains. Choroid plexus epithelium was strongly positive for FGF-2 in all cases examined. Among the corticectomy specimens, the cytoplasms and/or nuclei of dysmorphic neurons (DNs) and BCs in groups I and II were variably positive for FGF-2. The proportions of FGF-2 immunoreactive cells (FGF-2-IR%) was significantly higher in groups I (36.9 ± 9.6) and II (45.1 ± 7.0) than in groups III (21.0 ± 5.7), IV (14.4 ± 4.7) and V (24.3 ± 10.3), and that in group V was higher than in group IV (P<0.01). These results indicate that FGF-2 upregulation in DNs and BCs is an important feature common to groups I and II, and suggest that BCs and DNs in these groups represent disturbed gliogenesis from

  2. Fibroblast growth factor-2 up-regulates the expression of nestin through the Ras–Raf–ERK–Sp1 signaling axis in C6 glioma cells

    SciTech Connect

    Chang, Kai-Wei; Huang, Yuan-Li; Wong, Zong-Ruei; Su, Peng-Han; Huang, Bu-Miin; Ju, Tsai-Kai; Yang, Hsi-Yuan

    2013-05-17

    Highlights: •Nestin expression in C6 glioma cells is induced by FGF-2. •Nestin expression is induced by FGF-2 via de novo RNA and protein synthesis. •The FGFR inhibitor SU5402 blocks the FGF-2-induced nestin expression. •The mRNA of FGFR1 and 3 are detected in C6 glioma cells. •Ras–Raf–ERK–Sp1 signaling pathway is responsibe for FGF-2-induced nestin expression. -- Abstract: Nestin is a 240-kDa intermediate filament protein expressed mainly in neural and myogenic stem cells. Although a substantial number of studies have focused on the expression of nestin during development of the central nervous system, little is known about the factors that induce and regulate its expression. Fibroblast growth factor-2 (FGF-2) is an effective mitogen and stimulates the proliferation and differentiation of a subset of nestin-expressing cells, including neural progenitor cells, glial precursor cells, and smooth muscle cells. To assess whether FGF-2 is a potent factor that induces the expression of nestin, C6 glioma cells were used. The results showed that nestin expression was up-regulated by FGF-2 via de novo RNA and protein synthesis. Our RT-PCR results showed that C6 glioma cells express FGFR1/3, and FGFRs is required for FGF-2-induced nestin expression. Further signaling analysis also revealed that FGF-2-induced nestin expression is mediated through FGFR–MAPK–ERK signaling axis and the transcriptional factor Sp1. These findings provide new insight into the regulation of nestin in glial system and enable the further studies on the function of nestin in glial cells.

  3. Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate.

    PubMed

    Su, Ching-Chuan; Kao, Chia-Tze; Hung, Chi-Jr; Chen, Yi-Jyun; Huang, Tsui-Hsien; Shie, Ming-You

    2014-04-01

    β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials.

  4. Retrograde fibroblast growth factor 22 (FGF22) signaling regulates insulin-like growth factor 2 (IGF2) expression for activity-dependent synapse stabilization in the mammalian brain

    PubMed Central

    Terauchi, Akiko; Johnson-Venkatesh, Erin M; Bullock, Brenna; Lehtinen, Maria K; Umemori, Hisashi

    2016-01-01

    Communication between pre- and postsynaptic cells promotes the initial organization of synaptic specializations, but subsequent synaptic stabilization requires transcriptional regulation. Here we show that fibroblast growth factor 22 (FGF22), a target-derived presynaptic organizer in the mouse hippocampus, induces the expression of insulin-like growth factor 2 (IGF2) for the stabilization of presynaptic terminals. FGF22 is released from CA3 pyramidal neurons and organizes the differentiation of excitatory nerve terminals formed onto them. Local application of FGF22 on the axons of dentate granule cells (DGCs), which are presynaptic to CA3 pyramidal neurons, induces IGF2 in the DGCs. IGF2, in turn, localizes to DGC presynaptic terminals and stabilizes them in an activity-dependent manner. IGF2 application rescues presynaptic defects of Fgf22-/- cultures. IGF2 is dispensable for the initial presynaptic differentiation, but is required for the following presynaptic stabilization both in vitro and in vivo. These results reveal a novel feedback signal that is critical for the activity-dependent stabilization of presynaptic terminals in the mammalian hippocampus. DOI: http://dx.doi.org/10.7554/eLife.12151.001 PMID:27083047

  5. Colony-stimulating Factor 2 Acts from Days 5 to 7 of Development to Modify Programming of the Bovine Conceptus at Day 86 of Gestation.

    PubMed

    Siqueira, L G; Tribulo, P; Chen, Z; Denicol, A C; Ortega, M S; Negrón-Pérez, V M; Kannampuzha-Francis, J; Pohler, K G; Rivera, R M; Hansen, P J

    2017-03-31

    Colony-stimulating factor 2 (CSF2) is an embryokine that improves competence of the embryo to establish pregnancy and which may participate in developmental programming. We tested whether culture of bovine embryos with CSF2 alters fetal development and alleviates abnormalities associated with in vitro production (IVP) of embryos. Pregnancies were established by artificial insemination (AI), transfer of an IVP embryo (IVP) or transfer of an IVP embryo treated with 10 ng/ml CSF2 from day 5 to 7 of development (CSF2). Pregnancies were produced using X-sorted semen from a single sire. Female singleton conceptuses were collected on day 86 of gestation. There were few morphological differences between groups although IVP and CSF2 fetuses were heavier than AI fetuses. Bicarbonate concentration in allantoic fluid was lower for IVP than for AI or CSF2. Expression of 92 genes in liver, placenta, and muscle was determined by RT-qPCR. The general pattern for liver and placenta was for IVP to alter expression and for CSF2 to sometimes reverse this effect. For muscle, CSF2 affected gene expression but did not generally reverse effects of IVP. Levels of methylation for each of the three tissues at 12 loci in the promoter of IGF2 and five in the promoter of GRB10 were unaffected by treatment except for CSF2 effects on two CpG for IGF2 in placenta and muscle. In conclusion, CSF2 can act as a developmental programming agent but alone is not able to abolish the adverse effects of in vitro production on fetal characteristics.

  6. Oral hydration during growth hormone stimulation with clonidine.

    PubMed

    May, Melissa; Rose, Susan R

    2007-10-01

    The arginine-clonidine growth hormone (GH) stimulation test causes hypotension, requiring intravenous fluids to stabilize blood pressure (BP) and delaying departure from clinic. We hypothesized that oral hydration during the stimulation test would decrease need for intravenous fluids and shorten clinic stay. Children drank a diet electrolyte drink (10 ml/kg) on arrival to the test, which was repeated after clonidine. Fifteen children (7 girls) were tested without oral hydration, and 23 (6 girls) were tested with oral hydration (age range, 2-15 years). Compared with no oral hydration, intake of >13 ml/kg rarely required intravenous fluids, improved diastolic BP, and permitted discharge at the end of the GH test, with a higher BP.

  7. Interaction of Fibroblast Growth Factor-2 (FGF-2) with Free Gangliosides: Biochemical Characterization and Biological Consequences in Endothelial Cell Cultures

    PubMed Central

    Rusnati, Marco; Tanghetti, Elena; Urbinati, Chiara; Tulipano, Giovanni; Marchesini, Sergio; Ziche, Marina; Presta, Marco

    1999-01-01

    Exogenous gangliosides affect the angiogenic activity of fibroblast growth factor-2 (FGF-2), but their mechanism of action has not been elucidated. Here, a possible direct interaction of sialo-glycolipids with FGF-2 has been investigated. Size exclusion chromatography demonstrates that native, but not heat-denatured, 125I-FGF-2 binds to micelles formed by gangliosides GT1b, GD1b, or GM1. Also, gangliosides protect native FGF-2 from trypsin digestion at micromolar concentrations, the order of relative potency being GT1b > GD1b > GM1 = GM2 = sulfatide > GM3 = galactosyl-ceramide, whereas asialo-GM1, neuraminic acid, and N-acetylneuramin-lactose were ineffective. Scatchard plot analysis of the binding data of fluorochrome-labeled GM1 to immobilized FGF-2 indicates that FGF–2/GM1 interaction occurs with a Kd equal to 6 μM. This interaction is inhibited by the sialic acid-binding peptide mastoparan and by the synthetic fragments FGF-2(112–129) and, to a lesser extent, FGF-2(130–155), whereas peptides FGF-2(10–33), FGF-2(39–59), FGF-2(86–96), and the basic peptide HIV-1 Tat(41–60) were ineffective. These data identify the COOH terminus of FGF-2 as a putative ganglioside-binding region. Exogenous gangliosides inhibit the binding of 125I-FGF-2 to high-affinity tyrosine-kinase FGF-receptors (FGFRs) of endothelial GM 7373 cells at micromolar concentrations. The order of relative potency was GT1b > GD1b > GM1 > sulfatide a = sialo-GM1. Accordingly, GT1b,GD1b, GM1, and GM2, but not GM3 and asialo-GM1, prevent the binding of 125I-FGF-2 to a soluble, recombinant form of extracellular FGFR-1. Conversely, the soluble receptor and free heparin inhibit the interaction of fluorochrome-labeled GM1 to immobilized FGF-2. In agreement with their FGFR antagonist activity, free gangliosides inhibit the mitogenic activity exerted by FGF-2 on endothelial cells in the same range of concentrations. Also in this case, GT1b was the most effective among the gangliosides tested

  8. Expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins in non-small cell lung cancer.

    PubMed

    Shi, Run; Yu, Xinnian; Wang, Yajing; Sun, Jing; Sun, Qi; Xia, Wenjie; Dong, Gaochao; Wang, Anpeng; Gao, Zhaojia; Jiang, Feng; Xu, Lin

    2017-04-01

    Insulin-like growth factor 2 messenger RNA-binding proteins have been described to associate with malignant process in many cancers. However, the role of insulin-like growth factor 2 messenger RNA-binding protein family has not been thoroughly elucidated in non-small cell lung cancer. This study was to investigate the expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins family in non-small cell lung cancer. The expression levels of IGF2BP1-IGF2BP3 in tumor and adjacent normal tissues were determined, and association with clinicopathological features and overall survival was investigated by analyzing The Cancer Genome Atlas lung cancer database. Proliferation, migration, invasion assays, and flow-cytometry analysis were used to investigate the biological function in vitro. Insulin-like growth factor 2 messenger RNA-binding protein expression levels were significantly increased in non-small cell lung cancer compared to adjacent normal lung tissues. Chi-square test indicated that IGF2BP1 and IGF2BP3 expressions correlated with some meaningful clinical characteristics in non-small cell lung cancer. Kaplan-Meier analysis showed that high-level expression of IGF2BP1 or IGF2BP3 predicted poor overall survival in lung adenocarcinoma patients. Multivariate regression analysis showed that high level of IGF2BP3 was an independent risk factor for poor prognosis in lung adenocarcinoma patients (hazard ratio = 1.616, p = 0.017). In vitro, knockdown of IGF2BP3 inhibited lung adenocarcinoma cell proliferation by inducing cell cycle arrest and apoptosis, and undermined abilities of migration and invasion, and overexpression of IGF2BP3 could promote malignant phenotypes in lung adenocarcinoma cells. Our study revealed that expression of insulin-like growth factor 2 messenger RNA-binding proteins was widely upregulated and correlated with some certain clinicopathological features in non-small cell

  9. Fetal growth restriction and the programming of heart growth and cardiac insulin-like growth factor 2 expression in the lamb

    PubMed Central

    Wang, Kimberley C W; Zhang, Lei; McMillen, I Caroline; Botting, Kimberley J; Duffield, Jaime A; Zhang, Song; Suter, Catherine M; Brooks, Doug A; Morrison, Janna L

    2011-01-01

    Abstract Reduced growth in fetal life together with accelerated growth in childhood, results in a ∼50% greater risk of coronary heart disease in adult life. It is unclear why changes in patterns of body and heart growth in early life can lead to an increased risk of cardiovascular disease in adulthood. We aimed to investigate the role of the insulin-like growth factors in heart growth in the growth-restricted fetus and lamb. Hearts were collected from control and placentally restricted (PR) fetuses at 137–144 days gestation and from average (ABW) and low (LBW) birth weight lambs at 21 days of age. We quantified cardiac mRNA expression of IGF-1, IGF-2 and their receptors, IGF-1R and IGF-2R, using real-time RT-PCR and protein expression of IGF-1R and IGF-2R using Western blotting. Combined bisulphite restriction analysis was used to assess DNA methylation in the differentially methylated region (DMR) of the IGF-2/H19 locus and of the IGF-2R gene. In PR fetal sheep, IGF-2, IGF-1R and IGF-2R mRNA expression was increased in the heart compared to controls. LBW lambs had a greater left ventricle weight relative to body weight as well as increased IGF-2 and IGF-2R mRNA expression in the heart, when compared to ABW lambs. No changes in the percentage of methylation of the DMRs of IGF-2/H19 or IGF-2R were found between PR and LBW when compared to their respective controls. In conclusion, a programmed increased in cardiac gene expression of IGF-2 and IGF-2R may represent an adaptive response to reduced substrate supply (e.g. glucose and/or oxygen) in order to maintain heart growth and may be the underlying cause for increased ventricular hypertrophy and the associated susceptibility of cardiomyocytes to ischaemic damage later in life. PMID:21807611

  10. Marked stimulation of growth and motility of human keratinocytes by hepatocyte growth factor

    SciTech Connect

    Matsumoto, K.; Hashimoto, K.; Yoshikawa, K.; Nakamura, T. )

    1991-09-01

    Effect of hepatocyte growth factor (HGF) on normal human epidermal keratinocytes cultured under conditions of low Ca2+ (0.1 mM, growth-promoting condition) and physiological Ca2+ (1.8 mM, differentiation-promoting condition) was investigated. In low Ca2+, HGF markedly enhanced the migration of keratinocytes while it suppressed cell growth and DNA synthesis in a dose-dependent manner. In contrast, HGF enhanced the migration, cell growth, and DNA synthesis of keratinocytes cultured under conditions of physiological Ca2+. The maximal stimulation of DNA synthesis (2.4-fold stimulation) in physiological Ca2+ was seen at 2.5-5 ng/ml HGF and the stimulatory effect of HGF was suppressed by transforming growth factor-beta 1. Analysis of the HGF receptor using 125I-HGF as a ligand showed that human keratinocytes expressed a single class of specific, saturable receptor for HGF in both low and physiological Ca2+ conditions, exhibiting a Kd = 17.3 pM and approximately 690 binding sites/cell under physiological Ca2+. Thus, HGF is a potent factor which enhances growth and migration of normal human keratinocytes under conditions of physiological Ca2+. HGF may play an important role in epidermal tissue repair as it enhances both the migration and growth of keratinocytes.

  11. Nerve growth factor: stimulation of polymorphonuclear leukocyte chemotaxis in vitro.

    PubMed Central

    Gee, A P; Boyle, M D; Munger, K L; Lawman, M J; Young, M

    1983-01-01

    Topical application of mouse nerve growth factor (NGF) to superficial skin wounds of mice has previously been shown to accelerate the rate of wound contraction. Results of the present study reveal that NGF in the presence of plasma is also chemotactic for human polymorphonuclear leukocytes in vitro, and the concentration of NGF required for this effect is similar to that which stimulates ganglionic neurite outgrowth. This property does not arise from liberation of the C5a fragment of complement, nor does it require the known enzymic activity of NGF. (NGF inactivated with diisopropyl fluorophosphate is equally active.) We conclude that NGF can display biological effects on cells of nonneural origin and function, and this feature might play a role in the early inflammatory response to injury. PMID:6580641

  12. Comparison of bifidogenic growth stimulation activities of fermented whey prototypes.

    PubMed

    Moon, Gi-Seong

    2013-12-01

    Fermented whey solution presenting bifidogenic growth stimulation (BGS) activity was processed as prototypes such as sterilized fermented whey (SFW), spray-dried fermented whey (SDFW), and freeze-dried fermented whey (FDFW) and their BGS activities were compared. In optical density (OD600) test, the BGS activity of three prototypes, which showed similar activities, were significantly different with non-fermented whey solution adjusted to pH 4.5 as a control (P<0.05). In viable cell count test, SDFW had the most positive influence than other prototypes on the BGS activity even though the difference was not significant. However, the activities of all prototypes were significantly different than the negative control (no addition). These results indicate that the processed prototypes of fermented whey solution show BGS activities and might be commercialized, with further evidences, in animal or human studies.

  13. Epidermal growth factor-stimulated protein phosphorylation in rat hepatocytes

    SciTech Connect

    Connelly, P.A.; Sisk, R.B.; Johnson, R.M.; Garrison, J.C.

    1987-05-01

    Epidermal growth factor (EGF) causes a 6-fold increase in the phosphorylation state of a cytosolic protein (pp36, M/sub r/ = 36,000, pI = 5.5) in hepatocytes isolated from fasted, male, Wistar rats. Stimulation of /sup 32/P incorporation is observed as early as 1 min following treatment of hepatocytes with EGF and is still present at 30 min after exposure to the growth factor. The phosphate incorporated into pp36 in response to EGF is located predominantly in serine but not tyrosine residues. Phosphorylation of pp36 does not occur in response to insulin or to agents which specifically activate the cAMP-dependent protein kinase (S/sub p/ -cAMPS), protein kinase C (PMA) or Ca/sup 2 +//calmodulin-dependent protein kinases (A23187) in these cells. Prior treatment of hepatocytes with the cAMP analog, S/sub p/-cAMPS, or ADP-ribosylation of N/sub i/, the inhibitory GTP-binding protein of the adenylate cyclase complex, does not prevent EGF-stimulated phosphorylation of pp36. However, as seen in other cell types, pretreatment of hepatocytes with PMA abolishes all EGF-mediated responses including phosphorylation of pp36. These results suggest that EGP specifically activates an uncharacterized, serine protein kinase in hepatocytes that is distal to the intrinsic EGF receptor tyrosine protein kinase. The rapid activation of this kinase suggests that it may play an important role in the early response of the cell to EGF.

  14. Fibroblast growth factor 2 is required for epithelial recovery, but not for pulmonary fibrosis, in response to bleomycin.

    PubMed

    Guzy, Robert D; Stoilov, Ivan; Elton, Timothy J; Mecham, Robert P; Ornitz, David M

    2015-01-01

    The pathogenesis of pulmonary fibrosis involves lung epithelial injury and aberrant proliferation of fibroblasts, and results in progressive pulmonary scarring and declining lung function. In vitro, fibroblast growth factor (FGF) 2 promotes myofibroblast differentiation and proliferation in cooperation with the profibrotic growth factor, transforming growth factor-β1, but the in vivo requirement for FGF2 in the development of pulmonary fibrosis is not known. The bleomycin model of lung injury and pulmonary fibrosis was applied to Fgf2 knockout (Fgf2(-/-)) and littermate control mice. Weight loss, mortality, pulmonary fibrosis, and histology were analyzed after a single intranasal dose of bleomycin. Inflammation was evaluated in bronchoalveolar lavage (BAL) fluid, and epithelial barrier integrity was assessed by measuring BAL protein and Evans Blue dye permeability. Fgf2 is expressed in mouse and human lung epithelial and inflammatory cells, and, in response to bleomycin, Fgf2(-/-) mice have significantly increased mortality and weight loss. Analysis of BAL fluid and histology show that pulmonary fibrosis is unaltered, but Fgf2(-/-) mice fail to efficiently resolve inflammation, have increased BAL cellularity, and, importantly, deficient recovery of epithelial integrity. Fgf2(-/-) mice similarly have deficient recovery of club cell secretory protein(+) bronchial epithelium in response to naphthalene. We conclude that FGF2 is not required for bleomycin-induced pulmonary fibrosis, but rather is essential for epithelial repair and maintaining epithelial integrity after bleomycin-induced lung injury in mice. These data identify that FGF2 acts as a protective growth factor after lung epithelial injury, and call into question the role of FGF2 as a profibrotic growth factor in vivo.

  15. Stimulation of body weight increase and epiphyseal cartilage growth by insulin like growth factor

    NASA Technical Reports Server (NTRS)

    Ellis, S.

    1981-01-01

    The ability of insulin-like growth factor (IGF) to induce growth in hypophysectomized immature rats was tested by continuous infusion of the partially purified factor at daily doses of 6, 21, and 46 mU for an 8-day period. A dose-dependent growth of the proximal epiphyseal cartilage of the tibia and an associated stimulation of the primary spongiosa were produced by these amounts of IGF. The two highest doses of IGF also resulted in dose-dependent increases of body weight. Gel permeation of the sera at neutrality showed that the large-molecular-weight IGF binding protein was not induced by the infusion of IGF, whereas it ws generated in the sera of hypophysectomized rats that were infused with daily doses of 86 mU of human growth hormone.

  16. Fibroblast growth factor 2 induces the precocious development of endothelial cell networks in bovine luteinising follicular cells.

    PubMed

    Laird, Mhairi; Woad, Kathryn J; Hunter, Morag G; Mann, George E; Robinson, Robert S

    2013-01-01

    The transition from follicle to corpus luteum represents a period of intense angiogenesis; however, the exact roles of angiogenic factors during this time remain to be elucidated. Thus, the roles of vascular endothelial growth factor (VEGF) A, fibroblast growth factor (FGF) 2 and LH in controlling angiogenesis were examined in the present study. A novel serum-free luteinising follicular angiogenesis culture system was developed in which progesterone production increased during the first 5 days and was increased by LH (P<0.01). Blockade of signalling from FGF receptors (SU5402; P<0.001) and, to a lesser extent, VEGF receptors (SU1498; P<0.001) decreased the development of endothelial cell (EC) networks. Conversely, FGF2 dose-dependently (P<0.001) induced the precocious transition of undeveloped EC islands into branched networks associated with a twofold increase in the number of branch points (P<0.001). In contrast, VEGFA had no effect on the area of EC networks or the number of branch points. LH had no effect on the area of EC networks, but it marginally increased the number of branch points (P<0.05) and FGF2 production (P<0.001). Surprisingly, progesterone production was decreased by FGF2 (P<0.01) but only on Day 5 of culture. Progesterone production was increased by SU5402 (P<0.001) and decreased by SU1498 (P<0.001). These results demonstrate that FGF and VEGF receptors play a fundamental role in the formation of luteal EC networks in vitro, which includes a novel role for FGF2 in induction of EC sprouting.

  17. Decreased serum fibroblast growth factor - 2 levels in pre- and post-treatment patients with major depressive disorder.

    PubMed

    He, Shen; Zhang, Tianhong; Hong, Bo; Peng, Daihui; Su, Hui; Lin, Zhiguang; Fang, Yiru; Jiang, Kaida; Liu, Xiaohua; Li, Huafang

    2014-09-05

    Increasing evidence indicates that neurotrophic factor dysfunction might be involved in the pathophysiology and treatment of major depressive disorder (MDD). Fibroblast growth factor (FGF)-2, one of the major neurotrophins, plays an important role in the central nervous system (CNS). The aim of this study was to explore whether the FGF-2 in serum was associated with MDD and to evaluate the effects of antidepressant treatment on serum FGF-2 levels. Serum FGF-2 levels were determined in 28 pre- and post-treatment MDD patients and 30 healthy controls using ELISA. The results of the current study revealed that serum FGF-2 levels in MDD patients were significantly lower than those in healthy controls (p=0.005), and the serum FGF-2 levels decreased significantly but marginally following treatment for 8 weeks (p=0.005). These findings demonstrate that the lower serum FGF-2 levels contribute to the pathophysiology of MDD and that FGF-2 may be used as a peripheral biological marker for MDD.

  18. Epidermal growth factor receptor-dependent stimulation of amphiregulin expression in androgen-stimulated human prostate cancer cells.

    PubMed Central

    Sehgal, I; Bailey, J; Hitzemann, K; Pittelkow, M R; Maihle, N J

    1994-01-01

    Amphiregulin is a heparin-binding epidermal growth factor (EGF)-related peptide that binds to the EGF receptor (EGF-R) with high affinity. In this study, we report a role for amphiregulin in androgen-stimulated regulation of prostate cancer cell growth. Androgen is known to enhance EGF-R expression in the androgen-sensitive LNCaP human prostate carcinoma cell line, and it has been suggested that androgenic stimuli may regulate proliferation, in part, through autocrine mechanisms involving the EGF-R. In this study, we demonstrate that LNCaP cells express amphiregulin mRNA and peptide and that this expression is elevated by androgenic stimulation. We also show that ligand-dependent EGF-R stimulation induces amphiregulin expression and that androgenic effects on amphiregulin synthesis are mediated through this EGF-R pathway. Parallel studies using the estrogen-responsive breast carcinoma cell line, MCF-7, suggest that regulation of amphiregulin by estrogen may also be mediated via an EGF-R pathway. In addition, heparin treatment of LNCaP cells inhibits androgen-stimulated cell growth further suggesting that amphiregulin can mediate androgen-stimulated LNCaP proliferation. Together, these results implicate an androgen-regulated autocrine loop composed of amphiregulin and its receptor in prostate cancer cell growth and suggest that the mechanism of steroid hormone regulation of amphiregulin synthesis may occur through androgen upregulation of the EGF-R and subsequent receptor-dependent pathways. Images PMID:8049525

  19. Modulation of HCV reinfection after orthotopic liver transplantation by fibroblast growth factor-2 and other non-interferon mediators

    PubMed Central

    Van, Nguyen Dinh; Falk, Christine S; Sandmann, Lisa; Vondran, Florian W R; Helfritz, Fabian; Wedemeyer, Heiner; Manns, Michael P; Ciesek, Sandra; von Hahn, Thomas

    2016-01-01

    Objective In HCV infected individuals graft infection occurs shortly after orthotopic liver transplantation (OLT). We aimed to describe the composition of the inflammatory response at this time, how it affects the HCV replication cycle and identify novel proviral and antiviral factors. Design We used a Luminex assay to quantify 50 inflammatory mediators in sera before and shortly after OLT. In vitro grown HCV based on the JFH-1 isolate were used to characterise the effects of patient sera and individual mediators on HCV. Results Although the mediator composition is highly variable between individuals, sera drawn immediately post-OLT significantly enhance HCV infectivity compared with control sera from before OLT in about half of the cases. Among 27 non-interferon inflammatory mediators fibroblast growth factor (FGF)-2 stood out as it enhanced HCV RNA replication and release of infectious particles. The effect was concentration-dependent and detectable in dividing and non-dividing cells. Moreover, pharmacological inhibition of FGF-2 receptor signalling abrogated the enhancing effect of FGF-2 and inhibited HCV replication in the absence of serum FGF-2 suggesting that HCV replication is dependent on basal activation of the FGF-2 triggered signalling pathway. Finally, in individuals with chronic HCV infection with high viral load, serum FGF-2 was significantly higher compared with those with low viral load. Conclusions Although no single mediator may account for this effect, serum shortly post-OLT enhances HCV infection. FGF-2 is a novel endogenous driver of HCV replication and a potential therapeutic target. PMID:25800783

  20. Fibroblast growth factor 2 retargeted adenovirus has redirected cellular tropism: evidence for reduced toxicity and enhanced antitumor activity in mice.

    PubMed

    Gu, D L; Gonzalez, A M; Printz, M A; Doukas, J; Ying, W; D'Andrea, M; Hoganson, D K; Curiel, D T; Douglas, J T; Sosnowski, B A; Baird, A; Aukerman, S L; Pierce, G F

    1999-06-01

    Adenovirus (Ad) have been used as vectors to deliver genes to a wide variety of tissues. Despite achieving high expression levels in vivo, Ad vectors display normal tissue toxicity, transient expression, and antivector immune responses that limit therapeutic potential. To circumvent these problems, several retargeting strategies to abrogate native tropism and redirect Ad uptake through defined receptors have been attempted. Despite success in cell culture, in vivo results have generally not shown sufficient selectivity for target tissues. We have previously identified (C. K. Goldman et al., Cancer Res., 57: 1447-1451, 1997) the fibroblast growth factor (FGF) ligand and receptor families as conferring sufficient specificity and binding affinity to be useful for targeting DNA in vivo. In the present studies, we retargeted Ad using basic FGF (FGF2) as a targeting ligand. Cellular uptake is redirected through high-affinity FGF receptors (FGFRs) and not the more ubiquitous lower-affinity Ad receptors. Initial in vitro experiments demonstrated a 10- to 100-fold increase in gene expression in numerous FGFR positive (FGFR+) cell lines using FGF2-Ad when compared with Ad. To determine whether increased selectivity could be detected in vivo, FGF2-Ad was administered i.v. to normal mice. FGF2-Ad demonstrates markedly decreased hepatic toxicity and liver transgene expression compared with Ad treatment. Importantly, FGF2-Ad encoding the herpes simplex virus thymidine kinase (TK) gene transduces Ad-resistant FGFR+ tumor cells both ex vivo and in vivo, which results in substantially enhanced survival (180-260%) when the prodrug ganciclovir is administered. Because FGFRs are up-regulated on many types of malignant or injured cells, this broadly useful method to redirect native Ad tropism and to increase the potency of gene expression may offer significant therapeutic advantages.

  1. Skeletal muscle–specific eukaryotic translation initiation factor 2α phosphorylation controls amino acid metabolism and fibroblast growth factor 21–mediated non–cell-autonomous energy metabolism

    PubMed Central

    Miyake, Masato; Nomura, Akitoshi; Ogura, Atsushi; Takehana, Kenji; Kitahara, Yoshihiro; Takahara, Kazuna; Tsugawa, Kazue; Miyamoto, Chinobu; Miura, Naoko; Sato, Ryosuke; Kurahashi, Kiyoe; Harding, Heather P.; Oyadomari, Miho; Ron, David; Oyadomari, Seiichi

    2016-01-01

    The eukaryotic translation initiation factor 2α (eIF2α) phosphorylation-dependent integrated stress response (ISR), a component of the unfolded protein response, has long been known to regulate intermediary metabolism, but the details are poorly worked out. We report that profiling of mRNAs of transgenic mice harboring a ligand-activated skeletal muscle–specific derivative of the eIF2α protein kinase R-like ER kinase revealed the expected up-regulation of genes involved in amino acid biosynthesis and transport but also uncovered the induced expression and secretion of a myokine, fibroblast growth factor 21 (FGF21), that stimulates energy consumption and prevents obesity. The link between the ISR and FGF21 expression was further reinforced by the identification of a small-molecule ISR activator that promoted Fgf21 expression in cell-based screens and by implication of the ISR-inducible activating transcription factor 4 in the process. Our findings establish that eIF2α phosphorylation regulates not only cell-autonomous proteostasis and amino acid metabolism, but also affects non–cell-autonomous metabolic regulation by induced expression of a potent myokine.—Miyake, M., Nomura, A., Ogura, A., Takehana, K., Kitahara, Y., Takahara, K., Tsugawa, K., Miyamoto, C., Miura, N., Sato, R., Kurahashi, K., Harding, H. P., Oyadomari, M., Ron, D., Oyadomari, S. Skeletal muscle–specific eukaryotic translation initiation factor 2α phosphorylation controls amino acid metabolism and fibroblast growth factor 21–mediated non–cell-autonomous energy metabolism. PMID:26487695

  2. The growth of cultured human foreskin keratinocytes is not stimulated by a tumor promoter.

    PubMed

    Fischer, S M; Viaje, A; Mills, G D; Wong, E W; Weeks, C E; Slaga, T J

    1984-01-01

    The tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA) does not stimulate the growth of human epidermal cells in foreskin explant cultures; a dose-dependent inhibition is seen at doses higher than 10(-5) micrograms/ml. TPA also inhibits epidermal growth factor-stimulated growth and does not induce ornithine decarboxylase activity or increase polyamine levels. This is not due to the rapid breakdown of TPA, since TPA is not metabolized to any appreciable extent.

  3. Diminished growth hormone secretion in blind males after L-dopa stimulation.

    PubMed

    Fatranská, M; Jurcovicová, J; Németh, S; Vigas, M

    1988-12-01

    Growth hormone secretion after L-dopa administration (1000 mg p.o.) was investigated in young adult normal and blind volunteers. The average increment of plasma growth hormone after L-dopa stimulation in the blind was below the criterion for a positive response (less than 5 ng ml-1). The control volunteers showed normal response. After L-dopa stimulation there was a significantly diminished growth hormone response in the young adult blind compared to control volunteers.

  4. MEAT SCIENCE AND MUSCLE BIOLOGY SYMPOSIUM--mechanism of growth hormone stimulation of skeletal muscle growth in cattle.

    PubMed

    Jiang, H; Ge, X

    2014-01-01

    Growth hormone, also called somatotropin (ST), is a polypeptide hormone produced by the anterior pituitary. The major functions of GH include stimulating bone and skeletal muscle growth, lipolysis, milk production, and expression of the IGF-I gene in the liver. Based on these functions, recombinant bovine ST (bST) and recombinant porcine ST (pST) have been used to improve milk production in dairy cows and lean tissue growth in pigs, respectively. However, despite these applications, the mechanisms of action of GH are not fully understood. Indeed, there has been a lot of controversy over the role of liver-derived circulating IGF-I and locally produced IGF-I in mediating the growth-stimulatory effect of GH during the last 15 yr. It is in this context that we have conducted studies to further understand how GH stimulates skeletal muscle growth in cattle. Our results do not support a role of skeletal muscle-derived IGF-I in GH-stimulated skeletal muscle growth in cattle. Our results indicate that GH stimulates skeletal muscle growth in cattle, in part, by stimulating protein synthesis in muscle through a GH receptor-mediated, IGF-I-independent mechanism. In this review, besides discussing these results, we also argue that liver-derived circulating IGF-I should be still considered as the major mechanism that mediates the growth-stimulatory effect of GH on skeletal muscle in cattle and other domestic animals.

  5. Isolation and identification of a new bifidogenic growth stimulator produced by Propionibacterium freudenreichii ET-3.

    PubMed

    Isawa, Kakuhei; Hojo, Kenichi; Yoda, Nobuo; Kamiyama, Tomonori; Makino, Seiya; Saito, Mizue; Sugano, Hitomi; Mizoguchi, Chinami; Kurama, Saori; Shibasaki, Mika; Endo, Noriko; Sato, Yoshio

    2002-03-01

    We have found a new growth stimulator for bifidobacteria in the culture broth of Propionibacterium freudenreichii ET-3. The bifidogenic growth stimulator (BGS) was purified by Diaion HP-20 column chromatography and preparative HPLC. Spectroscopic methods including 1H-NMR, UV, and LC-ESI-MS experiments indicated that the chemical structure of the bifidogenic growth stimulator was 1,4-dihydroxy-2-naphthoic acid (DHNA). Approximately 10 mg/L of DHNA was found to be produced in the culture broth of P. freudenreichii ET-3.

  6. Translational stimulation by reovirus polypeptide sigma 3: substitution for VAI RNA and inhibition of phosphorylation of the alpha subunit of eukaryotic initiation factor 2.

    PubMed Central

    Lloyd, R M; Shatkin, A J

    1992-01-01

    COS cells transfected with plasmids that activate DAI depend on expression of virus-associated I (VAI) RNA to prevent the inhibitory effects of the alpha subunit of eukaryotic initiation factor 2 (eIF-2 alpha) kinase (DAI) and restore the translation of vector-derived dihydrofolate reductase mRNA. This VAI RNA requirement could be completely replaced by reovirus polypeptide sigma 3, consistent with its double-stranded RNA (dsRNA)-binding activity. S4 gene transfection of 293 cells also partially restored adenovirus protein synthesis after infection with the VAI-negative dl331 mutant. In dl331-infected 293 cells, eIF-2 alpha was present mainly in the acidic, phosphorylated form, and trans complementation with polypeptide sigma 3 or VAI RNA decreased the proportion of eIF-2 alpha (P) from approximately 85 to approximately 30%. Activation of DAI by addition of dsRNA to extracts of S4 DNA-transfected COS cells required 10-fold-higher levels of dsRNA than extracts made from cells that were not producing polypeptide sigma 3. In extracts of reovirus-infected mouse L cells, the concentration of dsRNA needed to activate DAI was dependent on the viral serotype used for the infection. Although the proportion of eIF-2 alpha (P) was greater than that in uninfected cells, most of the factor remained in the unphosphorylated form, even at 16 h after infection, consistent with the partial inhibition of host protein synthesis observed with all three viral serotypes. The results indicate that reovirus polypeptide sigma 3 participates in the regulation of protein synthesis by modulating DAI and eIF-2 alpha phosphorylation. Images PMID:1433498

  7. Effects of Stimulant Medication on Growth Rates across 3 Years in the MTA Follow-up

    ERIC Educational Resources Information Center

    Swanson, James M.; Elliott, Glen R.; Greenhill, Laurence L.; Wigal, Timothy; Arnold, L. Eugene; Vitiello, Benedetto; Hechtman, Lily; Epstein, Jeffery N.; Pelham, William E.; Abikoff, Howard B.; Newcorn, Jeffrey H.; Molina, Brooke S. G.; Hinshaw, Stephen P.; Wells, Karen C.; Hoza, Betsy; Jensen, Peter S.; Gibbons, Robert D.; Hur, Kwan; Stehli, Annamarie; Davies, Mark; March, John S.; Conners, C. Keith; Caron, Mark; Volkow, Nora D.

    2007-01-01

    Objective: To evaluate the hypothesis of stimulant medication effect on physical growth in the follow-up phase of the Multimodal Treatment Study of Children With ADHD. Method: Naturalistic subgroups were established based on patterns of treatment with stimulant medication at baseline, 14-, 24-, and 36-month assessments: not medicated (n = 65),…

  8. Fibroblast growth factor 2 inhibits up-regulation of bone morphogenic proteins and their receptors during osteoblastic differentiation of human mesenchymal stem cells

    SciTech Connect

    Biver, Emmanuel; Soubrier, Anne-Sophie; Thouverey, Cyril; Cortet, Bernard; Broux, Odile; Caverzasio, Joseph; Hardouin, Pierre

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer FGF modulates BMPs pathway in HMSCs by down-regulating BMP/BMPR expression. Black-Right-Pointing-Pointer This effect is mediated by ERK and JNK MAPKs pathways. Black-Right-Pointing-Pointer Crosstalk between FGF and BMPs must be taken into account in skeletal bioengineering. Black-Right-Pointing-Pointer It must also be considered in the use of recombinant BMPs in orthopedic and spine surgeries. -- Abstract: Understanding the interactions between growth factors and bone morphogenic proteins (BMPs) signaling remains a crucial issue to optimize the use of human mesenchymal stem cells (HMSCs) and BMPs in therapeutic perspectives and bone tissue engineering. BMPs are potent inducers of osteoblastic differentiation. They exert their actions via BMP receptors (BMPR), including BMPR1A, BMPR1B and BMPR2. Fibroblast growth factor 2 (FGF2) is expressed by cells of the osteoblastic lineage, increases their proliferation and is secreted during the healing process of fractures or in surgery bone sites. We hypothesized that FGF2 might influence HMSC osteoblastic differentiation by modulating expressions of BMPs and their receptors. BMP2, BMP4, BMPR1A and mainly BMPR1B expressions were up-regulated during this differentiation. FGF2 inhibited HMSCs osteoblastic differentiation and the up-regulation of BMPs and BMPR. This effect was prevented by inhibiting the ERK or JNK mitogen-activated protein kinases which are known to be activated by FGF2. These data provide a mechanism explaining the inhibitory effect of FGF2 on osteoblastic differentiation of HMSCs. These crosstalks between growth and osteogenic factors should be considered in the use of recombinant BMPs in therapeutic purpose of fracture repair or skeletal bioengineering.

  9. An optimized dosing regimen of cimaglermin (neuregulin 1β3, glial growth factor 2) enhances molecular markers of neuroplasticity and functional recovery after permanent ischemic stroke in rats

    PubMed Central

    Parry, Tom J.; Huang, Zhihong; Pavlopoulos, Elias; Finklestein, Seth P.; Ren, Jingmei; Caggiano, Anthony

    2015-01-01

    Cimaglermin (neuregulin 1β3, glial growth factor 2) is a neuregulin growth factor family member in clinical development for chronic heart failure. Previously, in a permanent middle cerebral artery occlusion (pMCAO) rat stroke model, systemic cimaglermin treatment initiated up to 7 days after ischemia onset promoted recovery without reduced lesion volume. Presented here to extend the evidence are two studies that use a rat stroke model to evaluate the effects of cimaglermin dose level and dose frequency initiated 24 hr after pMCAO. Forelimb‐ and hindlimb‐placing scores (proprioceptive behavioral tests), body‐swing symmetry, and infarct volume were compared between treatment groups (n = 12/group). Possible mechanisms underlying cimaglermin‐mediated neurologic recovery were examined through axonal growth and synapse formation histological markers. Cimaglermin was evaluated over a wider dose range (0.02, 0.1, or 1.0 mg/kg) than doses previously shown to be effective but used the same dosing regimen (2 weeks of daily intravenous administration, then 1 week without treatment). The dose‐frequency study used the dose‐ranging study's most effective dose (1.0 mg/kg) to compare daily, once per week, and twice per week dosing for 3 weeks (then 1 week without treatment). Dose‐ and frequency‐dependent functional improvements were observed with cimaglermin without reduced lesion volume. Cimaglermin treatment significantly increased growth‐associated protein 43 expression in both hemispheres (particularly somatosensory and motor cortices) and also increased synaptophysin expression. These data indicate that cimaglermin enhances recovery after stroke. Immunohistochemical changes were consistent with axonal sprouting and synapse formation but not acute neuroprotection. Cimaglermin represents a potential clinical development candidate for ischemic stroke treatment. © 2015 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc

  10. Fibroblast Growth Factor-2 facilitates the growth and chemo-resistance of leukemia cells in the bone marrow by modulating osteoblast functions

    PubMed Central

    Sugimoto, Keiki; Miyata, Yasuhiko; Nakayama, Takayuki; Saito, Shigeki; Suzuki, Ritsuro; Hayakawa, Fumihiko; Nishiwaki, Satoshi; Mizuno, Hiroki; Takeshita, Kyosuke; Kato, Hidefumi; Ueda, Ryuzo; Takami, Akiyoshi; Naoe, Tomoki

    2016-01-01

    Stromal cells and osteoblasts play major roles in forming and modulating the bone marrow (BM) hematopoietic microenvironment. We have reported that FGF2 compromises stromal cell support of normal hematopoiesis. Here, we examined the effects of FGF2 on the leukemia microenvironment. In vitro, FGF2 significantly decreased the number of stromal-dependent and stromal-independent G0-leukemia cells in the stromal layers. Accordingly, CML cells placed on FGF2-treated stromal layers were more sensitive to imatinib. Conversely, FGF2 increased the proliferation of osteoblasts via FGFR1 IIIc, but its effects on osteoblast support of leukemia cell growth were limited. We next treated a human leukemia mouse model with Ara-C with/without systemic FGF2 administration. BM sections from FGF2-treated mice had thickened bone trabeculae and increased numbers of leukemia cells compared to controls. Leukemia cell density was increased, especially in the endosteal region in FGF2/Ara-C -treated mice compared to mice treated with Ara-C only. Interestingly, FGF2 did not promote leukemia cell survival in Ara-C treated spleen. Microarray analysis showed that FGF2 did not alter expression of many genes linked to hematopoiesis in osteoblasts, but modulated regulatory networks involved in angiogenesis and osteoblastic differentiation. These observations suggest that FGF2 promotes leukemia cell growth in the BM by modulating osteoblast functions. PMID:27481339

  11. Stimulants and growth in children with attention-deficit/hyperactivity disorder.

    PubMed

    Negrao, Bianca Lee; Viljoen, Margaretha

    2011-07-01

    Initial suggestions that suppression of growth may be an intrinsic characteristic of attention-deficit/hyperactivity disorder (ADHD) have now largely been disproven. Although controversy persists regarding the possible negative effect of adrenergic stimulants on growth in children with ADHD, the consensus that appears to be reached in the scientific literature is that stimulant usage may cause a manageable attenuation of growth in these children. Since it is known that stimulants increase the amount of dopamine and noradrenaline in the synapse, this writing suggests that these increases in dopamine and noradrenaline are responsible for the growth attenuation in these children. It appears that increased amounts of dopamine and noradrenaline have the ability to inhibit the secretion of growth hormone and growth-related hormones such as prolactin, thyroid hormones, sex hormones and insulin. Therefore, it would be reasonable to suggest that the increases in dopamine and noradrenaline caused by stimulant usage can disrupt the homeostasis of both growth hormone and growth-related hormones, generating the potential for the suppression of growth.

  12. Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

    SciTech Connect

    Hua Chiaho; Wu Shengjie; Chemaitilly, Wassim; Lukose, Renin C.; Merchant, Thomas E.

    2012-11-15

    Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test {>=}7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

  13. Electrical stimulation promotes sensory neuron regeneration and growth-associated gene expression.

    PubMed

    Geremia, Nicole M; Gordon, Tessa; Brushart, Thomas M; Al-Majed, Abdulhakeem A; Verge, Valerie M K

    2007-06-01

    Brief electrical stimulation enhances the regenerative ability of axotomized motor [Nix, W.A., Hopf, H.C., 1983. Electrical stimulation of regenerating nerve and its effect on motor recovery. Brain Res. 272, 21-25; Al-Majed, A.A., Neumann, C.M., Brushart, T.M., Gordon, T., 2000. Brief electrical stimulation promotes the speed and accuracy of motor axonal regeneration. J. Neurosci. 20, 2602-2608] and sensory [Brushart, T.M., Jari, R., Verge, V., Rohde, C., Gordon, T., 2005. Electrical stimulation restores the specificity of sensory axon regeneration. Exp. Neurol. 194, 221-229] neurons. Here we examined the parameter of duration of stimulation on regenerative capacity, including the intrinsic growth programs, of sensory neurons. The effect of 20 Hz continuous electrical stimulation on the number of DRG sensory neurons that regenerate their axons was evaluated following transection and surgical repair of the femoral nerve trunk. Stimulation was applied proximal to the repair site for 1 h, 3 h, 1 day, 7 days or 14 days at the time of nerve repair. Following a 21-day regeneration period, DRG neurons that regenerated axons into the muscle and cutaneous sensory nerve branches were retrogradely identified. Stimulation of 1 h led to a significant increase in DRG neurons regenerating into cutaneous and muscle branches when compared to 0 h (sham) stimulation or longer periods of stimulation. Stimulation for 1 h also significantly increased the numbers of neurons that regenerated axons beyond the repair site 4 days after lesion and was correlated with a significant increase in expression of growth-associated protein 43 (GAP-43) mRNA in the regenerating neurons at 2 days post-repair. An additional indicator of heightened plasticity following 1 h stimulation was elevated expression of brain-derived neurotrophic factor (BDNF). The effect of brief stimulation on enhancing sensory and motoneuron regeneration holds promise for inducing improved peripheral nerve repair in the

  14. Sulfhydryl angiotensin-converting enzyme inhibitor promotes endothelial cell survival through nitric-oxide synthase, fibroblast growth factor-2, and telomerase cross-talk.

    PubMed

    Donnini, Sandra; Terzuoli, Erika; Ziche, Marina; Morbidelli, Lucia

    2010-03-01

    The protective effect exerted by angiotensin-converting enzyme inhibitors (ACEI) in cardiovascular diseases caused by endothelial injury and aging has been attributed to the restoration of endothelial cell functions. Recently, we demonstrated a central role of the fibroblast growth factor-2 (FGF-2)/FGF receptor-1 system in mediating the acquisition of an angiogenic phenotype in coronary microvascular endothelium exposed to ACEI. Here, we report on the rescuing effect of ACEI on impaired endothelium and the intracellular signaling mechanisms that lead endothelial cells to enter apoptosis and to senesce. Conditions mimicking pathological cell damage (serum deprivation) lead to endothelial apoptosis as evidenced by increased caspase-3 activity. ACEI enhanced cell survival through activation of prosurvival and antiaging signals involving Akt phosphorylation, endothelial nitric-oxide synthase (eNOS) expression and activation, FGF-2 and telomerase catalytic subunit (TERT) up-regulation, and delayed senescence. In microvascular endothelial cells exposed to ACEI, Akt/eNOS pathway-dependent FGF-2 was necessary for gene transcription of TERT. These protective effects were particularly evident for sulfhydryl-containing ACEI (zofenoprilat), which were reported to exhibit potent antioxidant effects. In conclusion, ACEI with antioxidant properties up-regulate eNOS, FGF-2, and TERT mRNA, which favor endothelial cell survival and prolong their lifespan, thus restoring endothelial cell functions after vascular damage. These effects could explain the beneficial effects of these drugs in various cardiovascular diseases associated with endothelial injury and aging.

  15. Storage Stability of Keratinocyte Growth Factor-2 in Lyophilized Formulations: Effects of Formulation Physical Properties and Protein Fraction at the Solid-Air Interface

    PubMed Central

    Devineni, Dilip; Gonschorek, Christoph; Cicerone, Marcus T; Xu, Yemin; Carpenter, John F.; Randolph, Theodore W.

    2014-01-01

    Lyophilized formulations of keratinocyte growth factor-2 (KGF-2) were prepared with a range of disaccharide (sucrose or trehalose) and hydroxyethyl starch (HES) mass ratios. Protein degradation was assessed as a function of time of storage of the dried formulations at 40, 50 and 60 °C. Lyophilized and stored samples were rehydrated, and protein degradation was quantified by measuring loss of monomeric protein with size exclusion chromatography and by determining chemical degradation in the soluble fraction with reverse-phase chromatography. The secondary structure of the protein in the lyophilized formulations was studied with infrared spectroscopy. The magnitudes of degradation were compared the key physical properties of the formulations including retention of protein native secondary structure, glass transition temperature (Tg), inverse mean square displacements −1 for hydrogen atoms (fast β relaxation), and the relaxation time τβ, which correlates with relaxation due to fast Johari-Goldstein motions in the glass[1]. In addition, specific surface areas of the lyophilized formulations were determined by Brunauer-Emmet-Teller analysis of krypton adsorption isotherms and used to estimate the fraction of the KGF-2 molecules residing at the solid-air interface. KGF-2 degradation rates were highest in formulations wherein the protein’s structure was most perturbed, and wherein β relaxations were fastest, but the dominant factor governing KGF-2 degradation in freeze-dried formulations was the fraction of the protein found at the glass solid-air interface. PMID:24859390

  16. Developmental regulation of the effects of fibroblast growth factor-2 and 1-octanol on neuronogenesis: implications for a hypothesis relating to mitogen-antimitogen opposition

    NASA Technical Reports Server (NTRS)

    Goto, T.; Takahashi, T.; Miyama, S.; Nowakowski, R. S.; Bhide, P. G.; Caviness, V. S. Jr

    2002-01-01

    Neocortical neurons arise from a pseudostratified ventricular epithelium (PVE) that lies within the ventricular zone (VZ) at the margins of the embryonic cerebral ventricles. We examined the effects of fibroblast growth factor-2 (FGF-2) and 1-octanol on cell output behavior of the PVE in explants of the embryonic mouse cerebral wall. FGF-2 is mitogenic and 1-octanol antimitogenic in the PVE. Whereas all postmitotic cells migrate out of the VZ in vivo, in the explants some postmitotic cells remain within the VZ. We refer to these cells as the indeterminate or I fraction, because they neither exit from the VZ nor reenter S phase as part of the proliferative (P) fraction. They are considered to be either in an extremely prolonged G(1) phase, unable to pass the G(1)/S transition, or in the G(0) state. The I fate choice is modulated by both FGF-2 and 1-octanol. FGF-2 decreased the I fraction and increased the P fraction. In contrast, 1-octanol increased the I fraction and nearly eliminated the P fraction. The effects of FGF-2 and 1-octanol were developmentally regulated, in that they were observed in the developmentally advanced lateral region of the cerebral wall but not in the medial region. Copyright 2002 Wiley-Liss, Inc.

  17. Resistance to therapy in estrogen receptor positive and human epidermal growth factor 2 positive breast cancers: progress with latest therapeutic strategies.

    PubMed

    Lousberg, Laurence; Collignon, Joëlle; Jerusalem, Guy

    2016-11-01

    In this article, we focus on the subtype of estrogen receptor (ER)-positive, human epidermal growth factor 2 (HER2)-positive breast cancer (BC). Preclinical and clinical data indicate a complex molecular bidirectional crosstalk between the ER and HER2 pathways. This crosstalk probably constitutes one of the key mechanisms of drug resistance in this subclass of BC. Delaying or even reversing drug resistance seems possible by targeting pathways implicated in this crosstalk. High-risk patients currently receive anti-HER2 therapy, chemotherapy and endocrine therapy in the adjuvant setting. In metastatic cases, most patients receive a combination of anti-HER2 therapy and chemotherapy. Only selected patients presenting more indolent disease are candidates for combinations of anti-HER2 therapy and endocrine therapy. However, relative improvements in progression-free survival by chemotherapy-based regimens are usually lower in ER-positive patients than the ER-negative and HER2-positive subgroup. Consequently, new approaches aiming to overcome endocrine therapy resistance by adding targeted therapies to endocrine therapy based regimens are currently explored. In addition, dual blockade of HER2 or the combination of trastuzumab and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOP) inhibitors targeting the downstream pathway are strategies to overcome resistance to trastuzumab. This may lead in the near future to the less frequent use of chemotherapy-based treatment options in ER-positive, HER2-positive BC.

  18. Metastatic human epidermal growth factor 2 (HER2/neu) amplified breast cancer with acute fulminant hepatitis responding to trastuzumab, pertuzumab and carboplatin

    PubMed Central

    Macias, Mariela N; Shin, Daniel Sanghoon; Ledezma, Blanca; Sadeghi, Saeed

    2014-01-01

    A 30-year-old woman presented to an outside hospital with pain in the right upper abdomen. Imaging revealed over 100 liver lesions, the largest measuring 74 mm×71 mm, and multiple lytic bone lesions. An outpatient liver biopsy showed a poorly differentiated adenocarcinoma favouring a breast primary. The tumour was oestrogen and progesterone receptor negative, but human epidermal growth factor 2 (HER2/neu) amplified. In her second clinic visit she had decompensated liver failure manifested by new-onset ascites and jaundice. Initially, the chemotherapy plan was for docetaxel, pertuzumab and trastuzumab, but given her severe liver dysfunction we used a combination of carboplatin, pertuzumab and trastuzumab as an inpatient. She was hospitalised for 14 days and eventually discharged with a marked improvement of her symptoms and liver tests. She subsequently completed five outpatient chemotherapy cycles. We showed that carboplatin is a possible alternative to docetaxel when severe liver dysfunction precludes docetaxel's use in combination with pertuzumab and trastuzumab. PMID:24899001

  19. Metastatic human epidermal growth factor 2 (HER2/neu) amplified breast cancer with acute fulminant hepatitis responding to trastuzumab, pertuzumab and carboplatin.

    PubMed

    Macias, Mariela N; Shin, Daniel Sanghoon; Ledezma, Blanca; Sadeghi, Saeed

    2014-06-04

    A 30-year-old woman presented to an outside hospital with pain in the right upper abdomen. Imaging revealed over 100 liver lesions, the largest measuring 74 mm×71 mm, and multiple lytic bone lesions. An outpatient liver biopsy showed a poorly differentiated adenocarcinoma favouring a breast primary. The tumour was oestrogen and progesterone receptor negative, but human epidermal growth factor 2 (HER2/neu) amplified. In her second clinic visit she had decompensated liver failure manifested by new-onset ascites and jaundice. Initially, the chemotherapy plan was for docetaxel, pertuzumab and trastuzumab, but given her severe liver dysfunction we used a combination of carboplatin, pertuzumab and trastuzumab as an inpatient. She was hospitalised for 14 days and eventually discharged with a marked improvement of her symptoms and liver tests. She subsequently completed five outpatient chemotherapy cycles. We showed that carboplatin is a possible alternative to docetaxel when severe liver dysfunction precludes docetaxel's use in combination with pertuzumab and trastuzumab.

  20. Fibroblast growth factor 2 induces E-cadherin down-regulation via PI3K/Akt/mTOR and MAPK/ERK signaling in ovarian cancer cells.

    PubMed

    Lau, Man-Tat; So, Wai-Kin; Leung, Peter C K

    2013-01-01

    Fibroblast growth factor 2 (FGF2) is produced by ovarian cancer cells and it has been suggested to play an important role in tumor progression. In this study, we report that FGF2 treatment down-regulated E-cadherin by up-regulating its transcriptional repressors, Slug and ZEB1, in human ovarian cancer cells. The pharmacological inhibition of phosphatidylinositol-3-kinase (PI3K), mammalian target of rapamycin (mTOR), and MEK suggests that both PI3K/Akt/mTOR and MAPK/ERK signaling are required for FGF2-induced E-cadherin down-regulation. Moreover, FGF2 up-regulated Slug and ZEB1 expression via the PI3K/Akt/mTOR and MAPK/ERK signaling pathways, respectively. Finally, FGF2-induced cell invasion was abolished by the inhibition of the PI3K/Akt/mTOR and MAPK/ERK pathways, and the forced expression of E-cadherin diminished the intrinsic invasiveness of ovarian cancer cells as well as the FGF2-induced cell invasion. This study demonstrates a novel mechanism in which FGF2 down-regulates E-cadherin expression through the activation of PI3K/Akt/mTOR and MAPK/ERK signaling, and the up-regulation of Slug and ZEB1 in human ovarian cancer cells.

  1. Resistance to therapy in estrogen receptor positive and human epidermal growth factor 2 positive breast cancers: progress with latest therapeutic strategies

    PubMed Central

    Lousberg, Laurence; Collignon, Joëlle; Jerusalem, Guy

    2016-01-01

    In this article, we focus on the subtype of estrogen receptor (ER)-positive, human epidermal growth factor 2 (HER2)-positive breast cancer (BC). Preclinical and clinical data indicate a complex molecular bidirectional crosstalk between the ER and HER2 pathways. This crosstalk probably constitutes one of the key mechanisms of drug resistance in this subclass of BC. Delaying or even reversing drug resistance seems possible by targeting pathways implicated in this crosstalk. High-risk patients currently receive anti-HER2 therapy, chemotherapy and endocrine therapy in the adjuvant setting. In metastatic cases, most patients receive a combination of anti-HER2 therapy and chemotherapy. Only selected patients presenting more indolent disease are candidates for combinations of anti-HER2 therapy and endocrine therapy. However, relative improvements in progression-free survival by chemotherapy-based regimens are usually lower in ER-positive patients than the ER-negative and HER2-positive subgroup. Consequently, new approaches aiming to overcome endocrine therapy resistance by adding targeted therapies to endocrine therapy based regimens are currently explored. In addition, dual blockade of HER2 or the combination of trastuzumab and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOP) inhibitors targeting the downstream pathway are strategies to overcome resistance to trastuzumab. This may lead in the near future to the less frequent use of chemotherapy-based treatment options in ER-positive, HER2-positive BC. PMID:27800032

  2. Fibroblast growth factor-2 (FGF2) augmentation early in life alters hippocampal development and rescues the anxiety phenotype in vulnerable animals.

    PubMed

    Turner, Cortney A; Clinton, Sarah M; Thompson, Robert C; Watson, Stanley J; Akil, Huda

    2011-05-10

    Individuals with mood disorders exhibit alterations in the fibroblast growth factor system, including reduced hippocampal fibroblast growth factor-2 (FGF2). It is difficult, however, to pinpoint whether these alterations are a cause or consequence of the disorder. The present study asks whether FGF2 administered the day after birth has long-lasting effects on hippocampal development and emotionality. We show that early-life FGF2 shifts the pace of neurogenesis, with an early acceleration around weaning followed by a deceleration in adulthood. This, in turn, results in a denser dentate gyrus with more neurons. To assess the impact of early-life FGF2 on emotionality, we use rats selectively bred for differences in locomotor response to novelty. Selectively bred low-responder (bLR) rats show low levels of novelty-induced locomotion and exhibit high levels of anxiety- and depression-like behavior compared with their selectively bred high-responder counterparts. Early-life FGF2 decreased anxiety-like behavior in highly anxious bLRs without altering other behaviors and without affecting high-responder rats. Laser capture microscopy of the dentate gyrus followed by microarray analysis revealed genes that were differentially expressed in bLRs exposed to early-life FGF2 vs. vehicle-treated bLRs. Some of the differentially expressed genes that have been positively associated with anxiety were down-regulated, whereas genes that promote cell survival were up-regulated. Overall, these results show a key role for FGF2 in the developmental trajectory of the hippocampus as well as the modulation of anxiety-like behavior in adulthood, and they point to potential downstream targets for the treatment of anxiety disorders.

  3. Sustained dual release of placental growth factor-2 and bone morphogenic protein-2 from heparin-based nanocomplexes for direct osteogenesis

    PubMed Central

    Liu, Yun; Deng, Li-Zhi; Sun, Hai-Peng; Xu, Jia-Yun; Li, Yi-Ming; Xie, Xin; Zhang, Li-Ming; Deng, Fei-Long

    2016-01-01

    Objective To compare the direct osteogenic effect between placental growth factor-2 (PlGF-2) and bone morphogenic protein-2 (BMP-2). Methods Three groups of PlGF-2/BMP-2-loaded heparin–N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) nanocomplexes were prepared: those with 0.5 μg PlGF-2; with 1.0 μg BMP-2; and with 0.5 μg PlGF-2 combined with 1.0 μg BMP-2. The loading efficiencies and release profiles of these growth factors (GFs) in this nanocomplex system were quantified using enzyme-linked immunosorbent assay, their biological activities were evaluated using cell counting kit-8, cell morphology, and cell number counting assays, and their osteogenic activities were quantified using alkaline phosphatase and Alizarin Red S staining assays. Results The loading efficiencies were more than 99% for the nanocomplexes loaded with just PlGF-2 and for those loaded with both PlGF-2 and BMP-2. For the nanocomplex loaded with just BMP-2, the loading efficiency was more than 97%. About 83%–84% of PlGF-2 and 89%–91% of BMP-2 were stably retained on the nanocomplexes for at least 21 days. In in vitro biological assays, PlGF-2 exhibited osteogenic effects comparable to those of BMP-2 despite its dose in the experiments being lower than that of BMP-2. Moreover, the results implied that heparin-based nanocomplexes encapsulating two GFs have enhanced potential in the enhancement of osteoblast function. Conclusion PlGF-2-loaded heparin–HTCC nanocomplexes may constitute a promising system for bone regeneration. Moreover, the dual delivery of PlGF-2 and BMP-2 appears to have greater potential in bone tissue regeneration than the delivery of either GFs alone. PMID:27042064

  4. Biofilm mode of growth of Streptococcus intermedius favored by a competence-stimulating signaling peptide.

    PubMed

    Petersen, Fernanda C; Pecharki, Daniele; Scheie, Anne A

    2004-09-01

    Gram-positive and gram-negative bacteria use quorum sensing to coordinate population behavior. In several streptococci, quorum sensing mediated by competence-stimulating peptides (CSP) is associated with development of competence for transformation. We show here that a synthetic CSP favored the biofilm mode of growth of Streptococcus intermedius without affecting the rate of culture growth.

  5. 5‑Azacytidine inhibits human rhabdomyosarcoma cell growth by downregulating insulin‑like growth factor 2 expression and reactivating the H19 gene product miR‑675, which negatively affects insulin‑like growth factors and insulin signaling.

    PubMed

    Tarnowski, Maciej; Tkacz, Marta; Czerewaty, Michał; Poniewierska-Baran, Agata; Grymuła, Katarzyna; Ratajczak, Mariusz Z

    2015-05-01

    Insulin-like growth factor 2 (IGF2) and 1 (IGF1) and insulin (INS) promote proliferation of rhabdomyosarcoma (RMS) cells by interacting with the insulin-like growth factor 1 receptor (IGF1R) and the insulin receptor (INSR). Loss of imprinting (LOI) by DNA hypermethylation at the differentially methylated region (DMR) for the IGF2‑H19 locus is commonly observed in RMS cells and results in an increase in the expression of proliferation-promoting IGF2 and downregulation of proliferation-inhibiting non-coding H19 miRNAs. One of these miRNAs, miR‑675, has been reported in murine cells to be a negative regulator of IGF1R expression. To better address the role of IGF2 and 1, as well as INS signaling in the pathogenesis of RMS and the involvement of LOI at the IGF2‑H19 locus, we employed the DNA demethylating agent 5‑azacytidine (AzaC). We observed that AzaC‑mediated demethylation of the DMR at the IGF2‑H19 locus resulted in downregulation of IGF2 and an increase in the expression of H19. This epigenetic change resulted in a decrease in RMS proliferation due to downregulation of IGF2 and, IGF1R expression in an miR‑675‑dependent manner. Interestingly, we observed that miR‑675 not only inhibited the expression of IGF1R in a similar manner in human and murine cells, but we also observed its negative effect on the expression of the INSR. These results confirm the crucial role of LOI at the IGF2‑H19 DMR in the pathogenesis of RMS and are relevant to the development of new treatment strategies.

  6. Stimulant-Related Reductions of Growth Rates in the PATS

    ERIC Educational Resources Information Center

    Swanson, James; Greenhill, Laurence; Wigal, Tim; Kollins, Scott; Stehli, Annamarie; Davies, Mark; Chuang, Shirley; Vitiello, Benedetto; Skrobala, Anne; Posner, Kelly; Abikoff, Howard; Oatis, Melvin; McCracken, James; McGough, James; Riddle, Mark; Ghuman, Jaswinder; Cunningham, Charles; Wigal, Sharon

    2006-01-01

    Objective: To investigate growth of children with attention-deficit/hyperactivity disorder (ADHD) in the Preschool ADHD Treatment Study (PATS) before and after initiation of treatment with methylphenidate at titrated doses (average, 14.2 mg/day) administered three times daily, 7 days/week for approximately equal to 1 year. Method: The heights and…

  7. Gastrointestinal hormones stimulate growth of Foregut Neuroendocrine Tumors by transactivating the EGF receptor.

    PubMed

    Di Florio, Alessia; Sancho, Veronica; Moreno, Paola; Delle Fave, Gianfranco; Jensen, Robert T

    2013-03-01

    Foregut neuroendocrine tumors [NETs] usually pursuit a benign course, but some show aggressive behavior. The treatment of patients with advanced NETs is marginally effective and new approaches are needed. In other tumors, transactivation of the EGF receptor (EGFR) by growth factors, gastrointestinal (GI) hormones and lipids can stimulate growth, which has led to new treatments. Recent studies show a direct correlation between NET malignancy and EGFR expression, EGFR inhibition decreases basal NET growth and an autocrine growth effect exerted by GI hormones, for some NETs. To determine if GI hormones can stimulate NET growth by inducing transactivation of EGFR, we examined the ability of EGF, TGFα and various GI hormones to stimulate growth of the human foregut carcinoid,BON, the somatostatinoma QGP-1 and the rat islet tumor,Rin-14B-cell lines. The EGFR tyrosine-kinase inhibitor, AG1478 strongly inhibited EGF and the GI hormones stimulated cell growth, both in BON and QGP-1 cells. In all the three neuroendocrine cell lines studied, we found EGF, TGFα and the other growth-stimulating GI hormones increased Tyr(1068) EGFR phosphorylation. In BON cells, both the GI hormones neurotensin and a bombesin analogue caused a time- and dose-dependent increase in EGFR phosphorylation, which was strongly inhibited by AG1478. Moreover, we found this stimulated phosphorylation was dependent on Src kinases, PKCs, matrix metalloproteinase activation and the generation of reactive oxygen species. These results raise the possibility that disruption of this signaling cascade by either EGFR inhibition alone or combined with receptor antagonists may be a novel therapeutic approach for treatment of foregut NETs/PETs.

  8. Gastrointestinal hormones stimulate growth of Foregut Neuroendocrine Tumors by transactivating the EGF receptor

    PubMed Central

    Di Florio, Alessia; Sancho, Veronica; Moreno, Paola; Fave, Gianfranco Delle; Jensen, Robert T.

    2012-01-01

    Foregut Neuroendocrine Tumors[NETs] usually pursuit a benign course, but some show aggressive behavior. The treatment of patients with advanced NETs is marginally effective and new approaches are needed. In other tumors, transactivation of the EGF receptor(EGFR) by growth factors, gastrointestinal(GI) hormones and lipids can stimulate growth, which has led to new treatments. Recent studies show a direct correlation between NET malignancy and EGFR expression, EGFR inhibition decreases basal NET growth and an autocrine growth effect exerted by GI hormones, for some NETs. To determine if GI hormones can stimulate NET growth by inducing transactivation of EGFR, we examined the ability of EGF, TGFα and various GI hormones to stimulate growth of the human foregut carcinoid, BON, the somatostatinoma QGP-1 and the rat islet tumor, Rin-14B-cell lines. The EGFR tyrosine-kinase inhibitor, AG1478 strongly inhibited EGF and the GI hormones stimulated cell growth, both in BON and QGP-1 cells. In all the three neuroendocrine cell lines studied, we found EGF, TGFα and the other growth-stimulating GI hormones increased Tyr1068 EGFR phosphorylation. In BON cells, both the GI hormones neurotensin and a bombesin analogue caused a time- and dose-dependent increase in EGFR phosphorylation, which was strongly inhibited by AG1478. Moreover, we found this stimulated phosphorylation was dependent on Src kinases, PKCs, matrix metalloproteinase activation and the generation of reactive oxygen species. These results raise the possibility that disruption of this signaling cascade by either EGFR inhibition alone or combined with receptor antagonists may be a novel therapeutic approach for treatment of foregut NETs/PETs. PMID:23220008

  9. Norgestrel and gestodene stimulate breast cancer cell growth through an oestrogen receptor mediated mechanism.

    PubMed Central

    Catherino, W. H.; Jeng, M. H.; Jordan, V. C.

    1993-01-01

    There is great concern over the long-term influence of oral contraceptives on the development of breast cancer in women. Oestrogens are known to stimulate the growth of human breast cancer cells, and this laboratory has previously reported (Jeng & Jordan, 1991) that the 19-norprogestin norethindrone could stimulate the proliferation of MCF-7 human breast cancer cells. We studied the influence of the 19-norprogestins norgestrel and gestodene compared to a 'non' 19-norprogestin medroxyprogesterone acetate (MPA) on MCF-7 cell proliferation. The 19-norprogestins stimulated proliferation at a concentration of 10(-8) M, while MPA could not stimulate proliferation at concentrations as great as 3 x 10(-6) M. The stimulatory activity of the 19-norprogestins could be blocked by the antioestrogen ICI 164,384, but not by the antiprogestin RU486. Transfection studies with the reporter plasmids containing an oestrogen response element or progesterone response element (vitERE-CAT, pS2ERE-CAT, and PRE15-CAT) were performed to determine the intracellular action of norgestrel and gestodene. The 19-norprogestins stimulated the vitERE-CAT activity maximally at 10(-6) M, and this stimulation was inhibited by the addition of ICI 164,384. MPA did not stimulate vitERE-CAT activity. A single base pair alteration in the palindromic sequence of vitERE (resulting in the pS2ERE) led to a dramatic decrease in CAT expression by the 19-norprogestins, suggesting that the progestin activity required specific response element base sequencing. PRE15-CAT activity was stimulated by norgestrel, gestodene and MPA at concentrations well below growth stimulatory activity. This stimulation could be blocked by RU486. These studies suggest that the 19-norprogestins norgestrel and gestodene stimulate MCF-7 breast cancer cell growth by activating the oestrogen receptor. PMID:8494728

  10. Evidence of plasma fluctuations and their effect on the growth of stimulated Brillouin and stimulated Raman scattering in laser plasmas

    SciTech Connect

    Montgomery, D.S.; Fernandez, J.C.; Cobble, J.A.

    1997-11-01

    The reflectivity levels of stimulated Brillouin scattering (SBS) in recent large scale length laser plasma experiments is much lower than expected for conditions where the convective gain exponent is expected to be large. Long wavelength velocity fluctuations caused during the plasma formation process, or by parametric instabilities themselves, have been proposed as a mechanism to detune SBS in these experiments and reduce its gain. Evidence of large velocity fluctuation levels is found in the time-resolved SBS spectra from these experiments, and correlates with observed changes in the reflectivity of both SBS and stimulated Raman scattering (SRS). The authors present evidence of fluctuations which increase as the plasma density systematically increases, and discuss their effect on the growth of parametric instabilities.

  11. Potassium enrichment stimulates the growth and reproduction of a clone of Daphnia dentifera.

    PubMed

    Civitello, David J; Hite, Jessica L; Hall, Spencer R

    2014-07-01

    Nutrient limitation commonly constrains organisms in natural ecosystems. Typically, ecologists focus on limitation by N and P. However, other nutrients can limit growth or reproduction. Here we focus on K limitation of invertebrate consumers (Daphnia dentifera) and phytoplankton in freshwater lakes. All organisms require K for several metabolic processes. In freshwater, K could limit growth because low external concentrations can increase the energetic costs of accumulating K. Furthermore, in a study linking K to disease, we previously found that K enrichment of water from one low-K lake stimulated the growth and reproduction of Daphnia. Here we test whether K could limit the production of Daphnia and phytoplankton across lakes and years. We repeated a life table experiment using water collected from a low-K lake during a different year. K again stimulated Daphnia reproduction. We also enriched water from 12 lakes with K or P and measured short-term growth of Daphnia and the resident algal community. Both nutrients increased Daphnia growth in five lakes. However, only P enhanced algal production. P stimulation of Daphnia positively correlated with algal quantity and the ratio of C to P in seston. However, K stimulation of Daphnia was not correlated with these factors or the background concentration of K. Thus, this study shows repeatable K-limited animal physiology in nature. Further, we can exclude the hypothesis that K stimulates Daphnia indirectly by enhancing algal production. These patterns call for future physiological studies to uncover the mechanistic basis of K limitation in natural systems.

  12. Expression of delta-like 1 homologue and insulin-like growth factor 2 through epigenetic regulation of the genes during development of mouse molar.

    PubMed

    Khan, Qalb-E-Saleem; Sehic, Amer; Skalleberg, Natalie; Landin, Maria A; Khuu, Cuong; Risnes, Steinar; Osmundsen, Harald

    2012-08-01

    Delta-like 1 homolog (Dlk1) and insulin-like growth factor 2 (Igf2) are two of six well-studied mouse imprinted gene clusters that are paternally expressed. Their expression is also linked to their maternally expressed non-coding RNAs, encoded by Gene trap locus 2 (Gtl2) and Imprinted maternally expressed transcript (H19), co-located as imprinted gene clusters. Using deoxyoligonucleotide microarrays and real-time RT-PCR analysis we showed Dlk1 and Gtl2 to exhibit a time-course of expression during tooth development that was similar to that of Igf2 and H19. Western blot analysis of proteins encoded by Dlk1 and Igf2 suggested that the levels of these proteins reflected those of the corresponding mRNAs. Immunohistochemical studies of DLK1 in murine molars detected the protein in both epithelial and mesenchymal regions, in developing cusp mesenchyme, and in newly synthesized enamel and dentin tubules. IGF2 protein was detected primarily at prenatal stages, suggesting that it may be active before birth. Analysis of methylation of cytosine-phosphate-guanine (CpG) islands in both Dlk1 and Igf2 suggested the presence of an increasing fraction of hypermethylated bases with increasing time of development. The increased levels of hypermethylation coincided both with the diminished levels of expression of Dlk1 and Igf2 and with decreased levels of DLK1 and IGF2 proteins in the tooth germ, suggesting that their expression is regulated via methylation of CpG islands present in these genes.

  13. Fibroblast Growth Factor 2-A Predictor of Outcome for Patients Irradiated for Stage II-III Non-Small-Cell Lung Cancer

    SciTech Connect

    Rades, Dirk; Setter, Cornelia; Dahl, Olav; Schild, Steven E.; Noack, Frank

    2012-01-01

    Purpose: The prognostic value of the tumor cell expression of the fibroblast growth factor 2 (FGF-2) in patients with non-small-cell lung cancer (NSCLC) is unclear. The present study investigated the effect of tumor cell expression of FGF-2 on the outcome of 60 patients irradiated for Stage II-III NSCLC. Methods and Materials: The effect of FGF-2 expression and 13 additional factors on locoregional control (LRC), metastasis-free survival (MFS), and overall survival (OS) were retrospectively evaluated. These additional factors included age, gender, Karnofsky performance status, histologic type, histologic grade, T and N category, American Joint Committee on Cancer stage, surgery, chemotherapy, pack-years, smoking during radiotherapy, and hemoglobin during radiotherapy. Locoregional failure was identified by endoscopy or computed tomography. Univariate analyses were performed with the Kaplan-Meier method and the Wilcoxon test and multivariate analyses with the Cox proportional hazard model. Results: On univariate analysis, improved LRC was associated with surgery (p = .017), greater hemoglobin levels (p = .036), and FGF-2 negativity (p <.001). On multivariate analysis of LRC, surgery (relative risk [RR], 2.44; p = .037), and FGF-2 expression (RR, 5.06; p <.001) maintained significance. On univariate analysis, improved MFS was associated with squamous cell carcinoma (p = .020), greater hemoglobin levels (p = .007), and FGF-2 negativity (p = .001). On multivariate analysis of MFS, the hemoglobin levels (RR, 2.65; p = .019) and FGF-2 expression (RR, 3.05; p = .004) were significant. On univariate analysis, improved OS was associated with a lower N category (p = .048), greater hemoglobin levels (p <.001), and FGF-2 negativity (p <.001). On multivariate analysis of OS, greater hemoglobin levels (RR, 4.62; p = .002) and FGF-2 expression (RR, 3.25; p = .002) maintained significance. Conclusions: Tumor cell expression of FGF-2 appeared to be an independent negative predictor

  14. Translation of CUG- but not AUG-initiated forms of human fibroblast growth factor 2 is activated in transformed and stressed cells

    PubMed Central

    1996-01-01

    Four isoforms of the human fibroblast growth factor 2 (FGF-2), with different intracellular localizations and distinct effects on cell phenotype, result from alternative initiations of translation at three CUG and one AUG start codons. We showed here by Western immunoblotting and immunoprecipitation that the CUG-initiated forms of FGF-2 were synthesized in transformed cells, whereas "normal" cells almost exclusively produced the AUG-initiated form. CUG-initiated FGF-2 was induced in primary skin fibroblasts in response to heat shock and oxidative stress. In transformed cells and in stressed fibroblasts, CUG expression was dependent on cis-elements within the 5' region of FGF-2 mRNA and was not correlated to mRNA level, indicating a translational regulation. UV cross-linking experiments revealed that CUG expression was linked to the binding of several cellular proteins to FGF-2 mRNA 5' region. Since translation of FGF-2 mRNA was previously shown to occur by internal ribosome entry, a nonclassical mechanism already described for picornaviruses, the cross-linking patterns of FGF-2 and picornavirus mRNAs were compared. Comigration of several proteins, including a p60, was observed. However, this p60 was shown to be different from the p57/PTB internal entry factor, suggesting a specificity towards FGF-2 mRNA. We report here a process of translational activation of the FGF-2 CUG-initiated forms in direct relation with trans-acting factors specific to transformed and stressed cells. These data favor a critical role of CUG-initiated FGF-2 in cell transformation and in the stress response. PMID:8947560

  15. [Stimulation of longitudinal growth of long bones through electrical current. Scintigraphic examinations on ribbit tibiae].

    PubMed

    Klems, H; Venohr, H; Weigert, M

    1975-01-01

    Report on szintigraphical examinations using 87-mSr in young rabbits treated by direct current of different intensity varying from 2.5 to 40 micro-Ampère. The current was applicated to one tibia using the other as comparison. Corresponding to the realised growth-increase by electric stimulation there was found an increased uptake of 87m-Sr in the electro-stimulated tibia in all 16 rabbits.

  16. The stimulation of dendrite growth by Sema3A requires integrin engagement and focal adhesion kinase.

    PubMed

    Schlomann, Uwe; Schwamborn, Jens C; Müller, Myriam; Fässler, Reinhard; Püschel, Andreas W

    2009-06-15

    The rate and direction of axon and dendrite growth depend on multiple guidance signals and growth factors. Semaphorin 3A (Sema3A) acts as a repellent for axons and attractant for dendrites. Here, we show that the requirement for integrin engagement distinguishes the response of axons and dendrites to Sema3A in hippocampal neurons. Sema3A promotes the extension of hippocampal dendrites by a pathway that requires focal adhesion kinase (FAK). The stimulation of dendrite growth and FAK phosphorylation by Sema3A depend on integrin engagement. Unlike their function as a target of Sema3A during the collapse of axonal growth cones, integrins facilitate the stimulation of dendrite extension. Conditional inactivation of the genes encoding beta1 integrin or FAK blocks the growth-promoting effect of Sema3A but not the collapse of axonal growth cones. Our results demonstrate that different pathways mediate the stimulation of dendrite growth and the collapse of axonal growth cones by Sema3A.

  17. Stimulation of Growth and Ion Uptake in Bean Leaves by Red and Blue Light 1

    PubMed Central

    Blum, Dale E.; Elzenga, J. Theo M.; Linnemeyer, Paul A.; Van Volkenburgh, Elizabeth

    1992-01-01

    Red and blue light both stimulate growth and ion accumulation in bean (Phaseolus vulgaris L.) leaves, and previous studies showed that the growth response is mediated by phytochrome and a blue-light receptor. Results of this study confirm that there is an additional photosynthetic contribution from the growing cells that supports ion uptake and growth. Disc expansion in the light was enhanced by exogenous K+ and Rb+, but was not specific for anions. Light increased K+ accumulation and the rate of 86Rb+ uptake by discs, over darkness, with no effect of light quality. The photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, inhibited light-driven 86Rb+ uptake by 75%. Light quality caused differences in short-term kinetics of growth and acidification of the leaf surface. At comparable fluence rates (50 μmol m−2 s−1), continuous exposure to blue light increased the growth rate 3-fold after a 2-min lag, whereas red light caused a smaller growth response after a lag of 12 min. In contrast, the acidification of the leaf surface normally associated with growth was stimulated 3-fold by red light but only slightly (1.3-fold) by blue light. This result shows that, in addition to acidification caused by red light, a second mechanism specifically stimulated by blue light is normally functioning in light-driven leaf growth. PMID:16653225

  18. Electrical stimulation: Its role in growth, repair and remodeling of the musculoskeletal system

    SciTech Connect

    Black, J.

    1986-01-01

    This book examines the increasingly popular field of electrical stimulation of lesions of the musculoskeletal system, exploring its use in both research and treatment. The book describes clinical experience with electrical stimulation in orthopedic, neuro- and plastic surgery, biological sources of electrical signals, and electromechanical characterization of tissues. Contents include: growth; remodeling and repair; electricity and magnetism; electrical properties of tissues; natural electrical signals in the musculoskeletal system; methods for stimulating tissues; cell, tissue and organ culture; animal studies; clinical applications; overview and a glossary.

  19. LTB4 stimulates growth of human pancreatic cancer cells via MAPK and PI-3 kinase pathways

    SciTech Connect

    Tong, W.-G.; Ding, X.-Z.; Talamonti, Mark S.; Bell, Richard H.; Adrian, Thomas E. . E-mail: tadrian@northwestern.edu

    2005-09-30

    We have previously shown the importance of LTB4 in human pancreatic cancer. LTB4 receptor antagonists block growth and induce apoptosis in pancreatic cancer cells both in vitro and in vivo. Therefore, we investigated the effect of LTB4 on proliferation of human pancreatic cancer cells and the mechanisms involved. LTB4 stimulated DNA synthesis and proliferation of both PANC-1 and AsPC-1 human pancreatic cancer cells, as measured by thymidine incorporation and cell number. LTB4 stimulated rapid and transient activation of MEK and ERK1/2 kinases. The MEK inhibitors, PD98059 and U0126, blocked LTB4-stimulated ERK1/2 activation and cell proliferation. LTB4 also stimulated phosphorylation of p38 MAPK; however, the p38 MAPK inhibitor, SB203580, failed to block LTB4-stimulated growth. The activity of JNK/SAPK was not affected by LTB4 treatment. Phosphorylation of Akt was also induced by LTB4 and this effect was blocked by the PI-3 kinase inhibitor wortmannin, which also partially blocked LTB4-stimulated cell proliferation. In conclusion, LTB4 stimulates proliferation of human pancreatic cancer cells through MEK/ERK and PI-3 kinase/Akt pathways, while p38 MPAK and JNK/SAPK are not involved.

  20. Exogenous folates stimulate growth and budding of Candida glabrata

    PubMed Central

    Porzoor, Afsaneh; Macreadie, Ian G.

    2015-01-01

    Folate, vitamin B9, is well recognized as being essential for cell growth. The utilization of folate is common to all cells, but the source of it may be quite different. For example, mammalian cells depend on exogenous uptake of folates, while plants and microbes can synthesize them. There has been little consideration of uptake of folate in microbial cells, and studies on the effects of folates in mammalian cells, where conditions are restricted. This study shows that exogenous folates (folic acid or folinic acid), causes Candida glabrata cells suspended in water alone to undergo two cycles of cell division and to form multiple buds. The effect was limited to cells in the stationary phase and more profound in quiescent cells. These data indicate a novel response of yeast to folates that may increase the utility of yeast as a model to study folate transport and signaling. PMID:28357288

  1. Light-stimulated growth of isotropic domains in nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Czajkowski, M.; Bartkiewicz, S.; Mysliwiec, J.

    2012-10-01

    Growth dynamics of single isotropic domains, appearing in liquid crystalline azobenzene derivative during diffraction grating recording has been studied under the polarized microscope. Theoretical approach considering light stimulation as main reason of the growth has been proposed. Growth dynamics of population of the domains has been studied by fitting diffraction efficiency dynamics, using diffraction on rectangular phase grating model. Influence of parameters concerning: material properties, domain growth function and incubation time distribution have been studied by series of simulations. Proposed model explains the local extrema effect on diffraction efficiency curves and can be used for fitting with very good precision.

  2. Platelet-derived growth factor stimulated mechanisms of glucosamine incorporation

    SciTech Connect

    Harrington, M.A.; Pledger, W.J. )

    1987-10-01

    Platelet-derived growth factor (PDGF) treatment of density-arrested BALB/c-3T3 cells results in increased ({sup 3}H)glucosamine (GlcN) incorporation into cellular material. The enhanced GlcN incorporation is not due to a preferential increase in proteoglycan synthesis as measured by ({sup 35}S)H{sub 2}SO{sub 4} incorporation. Approximately 50% of the GlcN incorporated in PDGF or platelet-poor plasma (PPP)-treated cultures enters N-linked glycoproteins. Addition of dolichol-phosphate (dolichol-P), a required intermediate in N-linked glycosylation, did not alter ({sup 3}H)GlcN incorporation in PDGF-treated cells but did increase incorporation in PPP-treated cultures to a level comparable to that observed for PDGF-treated cultures. PDGF-treated cultures contained twofold greater quantities of ({sup 3}H)GlcN dolichol intermediates and lipid-free glycoprotein. Over a 12-h time course 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA reductase) activity was similar in cultures treated with PDGF or PPP. Results of these studies reveal that enhanced protein glycosylation in response to PDGF treatment is not the result of a direct effect on HMG CoA reductase.

  3. Fibroblast growth factor-2 (FGF2) and syndecan-1 (SDC1) are potential biomarkers for putative circulating CD15+/CD30+ cells in poor outcome Hodgkin lymphoma patients

    PubMed Central

    2013-01-01

    Background High risk, unfavorable classical Hodgkin lymphoma (cHL) includes those patients with primary refractory or early relapse, and progressive disease. To improve the availability of biomarkers for this group of patients, we investigated both tumor biopsies and peripheral blood leukocytes (PBL) of untreated (chemo-naïve, CN) Nodular Sclerosis Classic Hodgkin Lymphoma (NS-cHL) patients for consistent biomarkers that can predict the outcome prior to frontline treatment. Methods and materials Bioinformatics data mining was used to generate 151 candidate biomarkers, which were screened against a library of 10 HL cell lines. Expression of FGF2 and SDC1 by CD30+ cells from HL patient samples representing good and poor outcomes were analyzed by qRT-PCR, immunohistochemical (IHC), and immunofluorescence analyses. Results To identify predictive HL-specific biomarkers, potential marker genes selected using bioinformatics approaches were screened against HL cell lines and HL patient samples. Fibroblast Growth Factor-2 (FGF2) and Syndecan-1 (SDC1) were overexpressed in all HL cell lines, and the overexpression was HL-specific when compared to 116 non-Hodgkin lymphoma tissues. In the analysis of stratified NS-cHL patient samples, expression of FGF2 and SDC1 were 245 fold and 91 fold higher, respectively, in the poor outcome (PO) group than in the good outcome (GO) group. The PO group exhibited higher expression of the HL marker CD30, the macrophage marker CD68, and metastatic markers TGFβ1 and MMP9 compared to the GO group. This expression signature was confirmed by qualitative immunohistochemical and immunofluorescent data. A Kaplan-Meier analysis indicated that samples in which the CD30+ cells carried an FGF2+/SDC1+ immunophenotype showed shortened survival. Analysis of chemo-naive HL blood samples suggested that in the PO group a subset of CD30+ HL cells had entered the circulation. These cells significantly overexpressed FGF2 and SDC1 compared to the GO group. The

  4. Administration of granulocyte colony-stimulating factor with radiotherapy promotes tumor growth by stimulating vascularization in tumor-bearing mice.

    PubMed

    Kim, Joong Sun; Son, Yeonghoon; Bae, Min Ji; Lee, Minyoung; Lee, Chang Geun; Jo, Wol Soon; Kim, Sung Dae; Yang, Kwangmo

    2015-07-01

    Although granulocyte-colony stimulating factor (G-CSF) is commonly used to support recovery from radiation-induced side-effects, the precise effects of G-CSF on colon cancer under radiotherapy remain poorly understood. In the present study, to investigate the effects of tumor growth following radiotherapy and G-CSF administration in a murine xenograft model of colon cancer, female BALB/c mice were injected with cells of a colon carcinoma cell line (CT26) with irradiation and G-CSF, alone or in combination. Mice received 2 Gy of focal radiation daily for 5 days and intraperitoneal injection of G-CSF (100 µg/kg/day) after irradiation for 7 days. Changes in the levels of myeloperoxidase (MPO), vascular endothelial growth factor (VEGF), matrix metalloproteinase type 9 (MMP-9) and CD31 were assessed in the mouse cancer induced by injection of colon cancer cells. We observed that G-CSF increased the number of circulating neutrophils, but facilitated tumor growth. However, G-CSF treatment did not affect radiation-induced cytotoxicity and cell viability in CT26 cells in vitro. Increased levels of myeloperoxidase, a neutrophil marker and those of vascular endothelial growth factor were observed in tumors with G-CSF supplementation. In addition, we found that increased levels of CD31 and matrix metalloproteinase-9 were correlated with the enhanced tumor growth after G-CSF treatment. Therefore, these data suggest that G-CSF may contribute to tumor growth and decrease the antitumor effect of radiotherapy, possibly by promoting vascularization in cancer lesions.

  5. Some growth factors stimulate cultured adult rabbit ventricular myocyte hypertrophy in the absence of mechanical loading

    NASA Technical Reports Server (NTRS)

    Decker, R. S.; Cook, M. G.; Behnke-Barclay, M.; Decker, M. L.

    1995-01-01

    Cultured adult rabbit cardiac myocytes treated with recombinant growth factors display enhanced rates of protein accumulation (ie, growth) in response to insulin and insulin-like growth factors (IGFs), but epidermal growth factor, acidic or basic fibroblast growth factor, and platelet-derived growth factor failed to increase contractile protein synthesis or growth of the heart cells. Insulin and IGF-1 increased growth rates by stimulating anabolic while simultaneously inhibiting catabolic pathways, whereas IGF-2 elevated growth modestly by apparently inhibiting lysosomal proteolysis. Neutralizing antibodies directed against either IGF-1 or IGF-2 or IGF binding protein 3 blocked protein accumulation. A monoclonal antibody directed against the IGF-1 receptor also inhibited changes in protein turnover provoked by recombinant human IGF-1 but not IGF-2. Of the other growth factors tested, only transforming growth factor-beta 1 increased the fractional rate of myosin heavy chain (MHC) synthesis, with beta-MHC synthesis being elevated and alpha-MHC synthesis being suppressed. However, the other growth factors were able to modestly stimulate the rate of DNA synthesis in this preparation. Bromodeoxyuridine labeling revealed that these growth factors increased DNA synthesis in myocytes and nonmyocytes alike, but the heart cells displayed neither karyokinesis or cytokinesis. In contrast, cocultures of cardiac myocytes and nonmyocytes and nonmyocyte-conditioned culture medium failed to enhance the rate of cardiac MHC synthesis or its accumulation, implying that quiescent heart cells do not respond to "conditioning" by cardiac nonmyocytes. These findings demonstrated that insulin and the IGFs promote passively loaded cultured adult rabbit heart cells to hypertrophy but suggest that other growth factors tested may be limited in this regard.

  6. Insulin-like growth factor I stimulates erythropoiesis in hypophysectomized rats

    SciTech Connect

    Kurtz, A.; Zapf, J.; Eckardt, K.U.; Clemons, G.; Froesch, E.R.; Bauer, C. )

    1988-10-01

    Stimulation of erythropoiesis during growth is necessary to ensure proportionality between erythrocyte mass and body mass. However, the way by which erythrocyte formation is adapted to body growth is still unknown. Growth arrest in hypophysectomized rats is accompanied by decreased erythropoiesis. The authors have, therefore, examined whether insulin-like growth factor I (IGF-I), the mediator of growth hormone effects on body growth, is able to restore erythropoiesis in these animals. Subcutaneous infusions of 120 {mu}g of recombinant human IGF-I per day in hypophysectomized rats led to increases in body weight, {sup 59}Fe incorporation into erythrocytes, and the number of reticulocytes that were similar to increases caused by infusions of 28 milliunits of human growth hormone per day. Body weight gain and {sup 59}Fe incorporation were linearly correlated. Like growth hormone, IGF-I also caused a significant rise in serum erythropoietin concentrations. However, the stimulatory effect on erythropoiesis occurred before serum erythropoietin levels had risen. These results demonstrate that IGF-I mediates the stimulatory effect of growth hormone on erythropoiesis in vivo and thus further support the somatomedin concept. They also show that IGF-I can stimulate erythropoiesis in an endocrine manner, and they suggest two possible routes of action: a direct one and an indirect one by means of enhanced erythropoietin production.

  7. Investigating Effects of Nano- to Micro-Ampere Alternating Current Stimulation on Trichophyton rubrum Growth

    PubMed Central

    Kwon, Dong Rak; Kwon, Hyunjung; Lee, Woo Ram

    2016-01-01

    Background Fungi are eukaryotic microorganisms including yeast and molds. Many studies have focused on modifying bacterial growth, but few on fungal growth. Microcurrent electricity may stimulate fungal growth. Objective This study aims to investigate effects of microcurrent electric stimulation on Trichophyton rubrum growth. Methods Standard-sized inoculums of T. rubrum derived from a spore suspension were applied to potato dextrose cornmeal agar (PDACC) plates, gently withdrawn with a sterile pipette, and were applied to twelve PDACC plates with a sterile spreader. Twelve Petri dishes were divided into four groups. The given amperage of electric current was 500 nA, 2 µA, and 4 µA in groups A, B, and C, respectively. No electric current was given in group D. Results In the first 48 hours, colonies only appeared in groups A and B (500 nA and 2 µA exposure). Colonies in group A (500 nA) were denser. Group C (4 µA) plates showed a barely visible film of fungus after 96 hours of incubation. Fungal growth became visible after 144 hours in the control group. Conclusion Lower intensities of electric current caused faster fungal growth within the amperage range used in this study. Based on these results, further studies with a larger sample size, various fungal species, and various intensities of electric stimulation should be conducted. PMID:27746636

  8. Augmentation of macrophage growth-stimulating activity of lipids by their peroxidation

    SciTech Connect

    Yui, S.; Yamazaki, M. )

    1990-02-15

    Previously, we reported that some kinds of lipids (cholesterol esters, triglycerides, and some negatively charged phospholipids) that are constituents of lipoproteins or cell membranes induce growth of peripheral macrophages in vitro. In this paper, we examined the effect of peroxidation of lipids on their macrophage growth-stimulating activity because lipid peroxidation is observed in many pathological states such as inflammation. When phosphatidylserine, one of the phospholipids with growth-stimulating activity, was peroxidized by UV irradiation, its macrophage growth-stimulating activity was augmented in proportion to the extent of its peroxidation. The activity of phosphatidylethanolamine was also increased by UV irradiation. On the other hand, phosphatidylcholine or highly unsaturated free fatty acids, such as arachidonic acid and eicosapentaenoic acid, did not induce macrophage growth irrespective of whether they were peroxidized. The augmented activity of UV-irradiated phosphatidylserine was not affected by the coexistence of an antioxidant, vitamin E or BHT. These results suggest that some phospholipids included in damaged cells or denatured lipoproteins which are scavenged by macrophages in vivo may induce growth of peripheral macrophages more effectively when they are peroxidized by local pathological processes.

  9. Imatinib mesylate inhibits platelet derived growth factor stimulated proliferation of rheumatoid synovial fibroblasts

    SciTech Connect

    Sandler, Charlotta; Joutsiniemi, Saima; Lindstedt, Ken A.; Juutilainen, Timo; Kovanen, Petri T.; Eklund, Kari K. . E-mail: kari.eklund@hus.fi

    2006-08-18

    Synovial fibroblast is the key cell type in the growth of the pathological synovial tissue in arthritis. Here, we show that platelet-derived growth factor (PDGF) is a potent mitogen for synovial fibroblasts isolated from patients with rheumatoid arthritis. Inhibition of PDGF-receptor signalling by imatinib mesylate (1 {mu}M) completely abrogated the PDGF-stimulated proliferation and inhibited approximately 70% of serum-stimulated proliferation of synovial fibroblasts. Similar extent of inhibition was observed when PDGF was neutralized with anti-PDGF antibodies, suggesting that imatinib mesylate does not inhibit pathways other than those mediated by PDGF-receptors. No signs of apoptosis were detected in synovial fibroblasts cultured in the presence of imatinib. These results suggest that imatinib mesylate specifically inhibits PDGF-stimulated proliferation of synovial fibroblasts, and that inhibition of PDGF-receptors could represent a feasible target for novel antirheumatic therapies.

  10. Epidermal growth factor (EGF) inhibits stimulated thyroid hormone secretion in the mouse

    SciTech Connect

    Ahren, B.

    1987-07-01

    It is known that epidermal growth factor (EGF) inhibits iodide uptake in the thyroid follicular cells and lowers plasma levels of thyroid hormones upon infusion into sheep and ewes. In this study, the effects of EGF on basal and stimulated thyroid hormone secretion were investigated in the mouse. Mice were pretreated with /sup 125/I and thyroxine; the subsequent release of /sup 125/I is an estimation of thyroid hormone secretion. It was found that basal radioiodine secretion was not altered by intravenous injection of EGF (5 micrograms/animal). However, the radioiodine secretion stimulated by both TSH (120 microU/animal) and vasoactive intestinal peptide (VIP; 5 micrograms/animal) were inhibited by EGF (5 micrograms/animal). At a lower dose level (0.5 microgram/animal), EGF had no influence on stimulated radioiodine secretion. In conclusion, EGF inhibits stimulated thyroid hormone secretion in the mouse.

  11. Heparin stimulates epidermal growth factor receptor-mediated phosphorylation of tyrosine and threonine residues.

    PubMed

    Revis-Gupta, S; Abdel-Ghany, M; Koland, J; Racker, E

    1991-07-15

    We have described previously that in extracts of A431 cells epidermal growth factor (EGF) stimulates the phosphorylation of tyrosine as well as of threonine residues in the EGF receptor and in lipocortin 1. We now report that heparin at low concentrations also stimulates the autophosphorylation of the EGF receptor and of the recombinant 56-kDa domain of the EGF receptor that lacks the EGF binding site. To study the stimulations of phosphorylation of threonine residues, a fusion protein was prepared with glutathione S-transferase (GST) and an EGF receptor fragment, TK8 (residues 647-688), that contains the threonine phosphorylation site but no tyrosine. We show that the phosphorylation of threonine residues in GST-TK8 by extracts of A431 cells is stimulated by heparin but not by EGF. These and other results suggest that heparin acts as a chaperone, a substrate modulator, that enhances the susceptibility of the substrate to phosphorylation by protein kinases.

  12. Does Prolonged Therapy with a Long-Acting Stimulant Suppress Growth in Children with ADHD?

    ERIC Educational Resources Information Center

    Spencer, Thomas J.; Faraone, Stephen V.; Biederman, Joseph; Lerner, Marc; Cooper, Kimberly M.; Zimmerman, Brenda

    2006-01-01

    Objective: To investigate whether prolonged therapy with a long-acting stimulant affects growth in children with attention-deficit/hyperactivity disorder (ADHD). Method: One hundred seventy-eight children ages 6 to 13 years received OROS methylphenidate (OROS MPH, CONCERTA) for at least 21 months. Height and weight were measured monthly during the…

  13. [Stimulating effect of triphenylmethane series dyes on growth of Escherichia coli bacteria].

    PubMed

    Bagramian, K A; Panosian, G A; Trchunian, A A

    1998-01-01

    The stimulating effect of a dye of the triphenylmethane group (fast green) applied at low concentrations (10(-4)%) in the presence of toluene on the specific growth rate of bacteria was found. The cell size did not change during batch cultivation. However, the cell dry weight and zeta-potential increased sharply.

  14. Mechanical forces and their second messengers in stimulating cell growth in vitro

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.

    1992-01-01

    Mechanical forces play an important role in modulating the growth of a number of different tissues including skeletal muscle, smooth muscle, cardiac muscle, bone, endothelium, epithelium, and lung. As interest increases in the molecular mechanisms by which mechanical forces are transduced into growth alterations, model systems are being developed to study these processes in tissue culture. This paper reviews the current methods available for mechanically stimulating tissue cultured cells. It then outlines some of the putative 'mechanogenic' second messengers involved in altering cell growth. Not surprisingly, many mechanogenic second messengers are the same as those involved in growth factor-induced cell growth. It is hypothesized that from an evolutionary standpoint, some second messenger systems may have initially evolved for unicellular organisms to respond to physical forces such as gravity and mechanical perturbation in their environment. As multicellular organisms came into existence, they appropriated these mechanogenic second messenger cascades for cellular regulation by growth factors.

  15. Repeated Microneedle Stimulation Induces Enhanced Hair Growth in a Murine Model

    PubMed Central

    Kim, Yoon Seob; Jeong, Kwan Ho; Kim, Jung Eun; Woo, Young Jun; Kim, Beom Joon

    2016-01-01

    Background Microneedle is a method that creates transdermal microchannels across the stratum corneum barrier layer of skin. No previous study showed a therapeutic effect of microneedle itself on hair growth by wounding. Objective The aim of this study is to investigate the effect of repeated microwound formed by microneedle on hair growth and hair growth-related genes in a murine model. Methods A disk microneedle roller was applied to each group of mice five times a week for three weeks. First, to identify the optimal length and cycle, microneedles of lengths of 0.15 mm, 0.25 mm, 0.5 mm, and 1 mm and cycles of 3, 6, 10, and 13 cycles were applied. Second, the effect of hair growth and hair-growth-related genes such as Wnt3a, β-catenin, vascular endothelial growth factor (VEGF), and Wnt10b was observed using optimized microneedle. Outcomes were observed using visual inspection, real-time polymerase chain reaction, and immunohistochemistry. Results We found that the optimal length and cycle of microneedle treatment on hair growth was 0.25 mm/10 cycles and 0.5 mm/10 cycles. Repeated microneedle stimulation promoted hair growth, and it also induced the enhanced expression of Wnt3a, β-catenin, VEGF, and Wnt10b. Conclusion Our study provides evidence that microneedle stimulation can induce hair growth via activation of the Wnt/β-catenin pathway and VEGF. Combined with the drug delivery effect, we believe that microneedle stimulation could lead to new approaches for alopecia. PMID:27746638

  16. Mechanochemical switching between growth and differentiation during fibroblast growth factor-stimulated angiogenesis in vitro: role of extracellular matrix

    PubMed Central

    1989-01-01

    The angiogenic factor, basic fibroblast growth factor (FGF), either stimulates endothelial cell growth or promotes capillary differentiation depending upon the microenvironment in which it acts. Analysis of various in vitro models of spontaneous angiogenesis, in combination with time-lapse cinematography, demonstrated that capillary tube formation was greatly facilitated by promoting multicellular retraction and cell elevation above the surface of the rigid culture dish or by culturing endothelial cells on malleable extracellular matrix (ECM) substrata. These observations suggested to us that mechanical (i.e., tension-dependent) interactions between endothelial cells and ECM may serve to regulate capillary development. To test this hypothesis, FGF-stimulated endothelial cells were grown in chemically defined medium on bacteriological (nonadhesive) dishes that were precoated with different densities of fibronectin. Extensive cell spreading and growth were promoted by fibronectin coating densities that were highly adhesive (greater than 500 ng/cm2), whereas cell rounding, detachment, and loss of viability were observed on dishes coated with low fibronectin concentrations (less than 100 ng/cm2). Intermediate fibronectin coating densities (100-500 ng/cm2) promoted cell extension, but they could not completely resist cell tractional forces. Partial retraction of multicellular aggregates resulted in cell shortening, cessation of growth, and formation of branching tubular networks within 24-48 h. Multicellular retraction and subsequent tube formation also could be elicited on highly adhesive dishes by overcoming the mechanical resistance of the substratum using higher cell plating numbers. Dishes coated with varying concentrations of type IV collagen or gelatin produced similar results. These results suggest that ECM components may act locally to regulate the growth and pattern- regulating actions of soluble FGF based upon their ability to resist cell-generated mechanical

  17. Evidence of plasma fluctuations and their effect on the growth of stimulated Brillouin and stimulated Raman scattering in laser plasmas

    SciTech Connect

    Montgomery, D.S.; Afeyan, B.B.; Cobble, J.A.; Fernandez, J.C.; Wilke, M.D.; Glenzer, S.H.; Kirkwood, R.K.; MacGowan, B.J.; Moody, J.D.; Lindman, E.L.; Munro, D.H.; Wilde, B.H.; Rose, H.A.; Dubois, D.F.; Bezzerides, B.; Vu, H.X.

    1998-05-01

    The reflectivity levels of stimulated Brillouin scattering (SBS) in recent large scale length laser plasma experiments is much lower than expected for conditions where the convective gain exponent is expected to be large [J. C. Fern{acute a}ndez {ital et al.}, Phys. Plasmas {bold 4}, 1849 (1997)]. Long-wavelength velocity fluctuations caused during the plasma formation process, or by parametric instabilities themselves, have been proposed as a mechanism to detune SBS in these experiments and reduce its gain [W. L. Kruer {ital et al.}, Phys. Plasmas {bold 3}, 382 (1996); H. A. Rose, Phys. Plasmas {bold 4}, 437 (1997)]. Evidence of large-velocity fluctuation levels is found in the time-resolved SBS spectra from these experiments, and correlates with observed changes in the reflectivity of both SBS and stimulated Raman scattering (SRS). Evidence of fluctuations that increase with increasing plasma density is presented, and their effect on the growth of parametric instabilities is discussed. {copyright} {ital 1998 American Institute of Physics.}

  18. Longitudinal growth of skeletal myotubes in vitro in a new horizontal mechanical cell stimulator

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.; Karlisch, Patricia

    1989-01-01

    A tissue-culture model system for growing skeletal-muscle cells under more dynamic conditions than found in normal tissue-culture environments is described. A computerized device presented allows mechanical stimulation of the cell's substratum by 300 to 400 pct in length in the horizontal plane. Cell growth rates and skeletal-muscle organogenesis are stimulated in this in vitro system. It is noted that longitudinal myotube growth observed is accompanied by increased rates of cell proliferation and myoblast fusion. Prestretching the collagen-coated substratum before cell plating is shown to lead to increased cell proliferation, myotube orientation, and longitudinal myotube growth. The effects of substratum stretching on myogenesis in the model system are also assessed and attributed to alterations in the cell's extracellular matrix.

  19. Calcitonin gene-related peptide (CGRP) stimulates purkinje cell dendrite growth in culture.

    PubMed

    D'Antoni, Simona; Zambusi, Laura; Codazzi, Franca; Zacchetti, Daniele; Grohovaz, Fabio; Provini, Luciano; Catania, Maria Vincenza; Morara, Stefano

    2010-12-01

    Previous reports described the transient expression during development of Calcitonin Gene-Related Peptide (CGRP) in rodent cerebellar climbing fibers and CGRP receptor in astrocytes. Here, mixed cerebellar cultures were used to analyze the effects of CGRP on Purkinje cells growth. Our results show that CGRP stimulated Purkinje cell dendrite growth under cell culture conditions mimicking Purkinje cell development in vivo. The stimulation was not blocked by CGRP8-37, a specific antagonist, suggesting the activation of other related receptors. CGRP did not affect survival of Purkinje cells, granule cells or astrocytes. The selective expression of Receptor Component Protein (RCP) (a component of CGRP receptor family) in astrocytes points to a role of these cells as mediators of CGRP effect. Finally, in pure cerebellar astrocyte cultures CGRP induced a transient morphological differentiation from flat, polygonal to stellate form. It is concluded that CGRP influences Purkinje cell dendrite growth in vitro, most likely through the involvement of astrocytes.

  20. Hematological and hepatic effects of vascular epidermal growth factor (VEGF) used to stimulate hair growth in an animal model

    PubMed Central

    2013-01-01

    Background Alopecia areata is the hair loss usually reversible, in sharply defined areas. The treatment of alopecia using growth factors shows interesting activity in promoting hair growth. In this concept, VEGF (vascular endothelial growth factor) is a marker of angiogenesis, stimulating hair growth by facilitating the supply of nutrients to the hair follicle, increasing follicular diameter. The aim of this study was the evaluation of a topical gel enriched with VEGF liposomes on the hair growth stimulation and its toxicological aspects. Methods Mesocricetus auratus were randomly divided into three groups. Control group was treated with Aristoflex® gel, 1% group with the same gel but added 1% VEGF and 3% group with 3% VEGF. Biochemical, hematological and histological analyses were done. Results At the end of the experiment (15th day of VEGF treatment) efficacy was determined macroscopically by hair density dermatoscopy analysis, and microscopically by hair diameter analysis. They both demonstrated that hair of the VEGF group increased faster and thicker than control. On the other hand, biochemical and hematological results had shown that VEGF was not 100% inert. Conclusions VEGF increased hair follicle area, but more studies are necessary to confirm its toxicity. PMID:24168457

  1. Circulating Fibroblast Growth Factor-2, HIV-Tat, and Vascular Endothelial Cell Growth Factor-A in HIV-Infected Children with Renal Disease Activate Rho-A and Src in Cultured Renal Endothelial Cells

    PubMed Central

    Das, Jharna R; Gutkind, J. Silvio; Ray, Patricio E

    2016-01-01

    Renal endothelial cells (REc) are the first target of HIV-1 in the kidney. The integrity of REc is maintained at least partially by heparin binding growth factors that bind to heparan sulfate proteoglycans located on their cell surface. However, previous studies showed that the accumulation of two heparin-binding growth factors, Vascular Endothelial Cell Growth Factor-A (VEGF-A) and Fibroblast Growth Factor-2 (FGF-2), in combination with the viral protein Tat, can precipitate the progression of HIV-renal diseases. Nonetheless, very little is known about how these factors affect the behavior of REc in HIV+ children. We carried out this study to determine how VEGF-A, FGF-2, and HIV-Tat, modulate the cytoskeletal structure and permeability of cultured REc, identify key signaling pathways involved in this process, and develop a functional REc assay to detect HIV+ children affected by these changes. We found that VEGF-A and FGF-2, acting in synergy with HIV-Tat and heparin, affected the cytoskeletal structure and permeability of REc through changes in Rho-A, Src, and Rac-1 activity. Furthermore, urine samples from HIV+ children with renal diseases, showed high levels of VEGF-A and FGF-2, and induced similar changes in cultured REc and podocytes. These findings suggest that FGF-2, VEGF-A, and HIV-Tat, may affect the glomerular filtration barrier in HIV+ children through the induction of synergistic changes in Rho-A and Src activity. Further studies are needed to define the clinical value of the REc assay described in this study to identify HIV+ children exposed to circulating factors that may induce glomerular injury through similar mechanisms. PMID:27097314

  2. Stimulation of peanut seedling development and growth by zero-valent iron nanoparticles at low concentrations.

    PubMed

    Li, Xuan; Yang, Yuechao; Gao, Bin; Zhang, Min

    2015-01-01

    Because of its strong pollutant degradation ability, nanoscale zerovalent iron (NZVI) has been introduced to soils and groundwater for remediation purposes, but its impacts on plants are still not very clear. In this work, the effects of low concentration (10-320 μmol/L) NZVI particles on seed germination and growth of peanut plants were evaluated. The exposure of peanut seeds to NZVI at all the tested concentrations altered the seed germination activity, especially the development of seedlings. In comparison with the deionized water treated controls (CK), all of the NZVI treatments had significantly larger average lengths. Further investigations with transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) suggested that NZVI particles may penetrate the peanut seed coats to increase the water uptake to stimulate seed germination. The growth experiments showed that although NZVI at a relatively high concentration (320 μmol/L) showed phytotoxicity to the peanut plants, the lower concentrations of NZVI particles stimulated the growth and root development of the plants. At certain concentrations (e.g., 40 and 80 μmol/L), the NZVI treated samples were even better than the ethylenediaminetetraacetate-iron (EDTA-Fe) solution, a commonly used iron nutrient solution, in stimulating the plant growth. This positive effect was probably due to the uptake of NZVI by the plants, as indicated in the TEM analyses. Because low concentrations of NZVI particles stimulated both the seedling development and growth of peanut, they might be used to benefit the growth of peanuts in large-scale agricultural settings.

  3. Growth Stimulation by Catecholamines in Plant Tissue/Organ Cultures 1

    PubMed Central

    Protacio, Calixto M.; Dai, Yao-ren; Lewis, Eldrin F.; Flores, Hector E.

    1992-01-01

    Addition of catecholamines at micromolar concentrations caused a dramatic stimulation of growth of tobacco (Nicotiana tabacum) thin cell layers (TCLs) and Acmella oppositifolia “hairy” root cultures. A threefold increase in the rate of ethylene evolution was observed in the catecholamine-treated explants. Aminooxyacetic acid and silver thiosulfate, inhibitors of ethylene biosynthesis and action, respectively, reduced the growth-promoting effect of dopamine. However, these compounds alone could also inhibit the growth of the TCL explants. When ethylene in the culture vessel was depleted by trapping with mercuric perchlorate, dopamine-stimulated growth was still obtained, suggesting that ethylene does not mediate the dopamine effect. Dopamine potentiated the growth of TCLs grown in Murashige and Skoog medium supplemented with indoleacetic acid (IAA) and kinetin. When IAA was replaced by 2,4-dichlorophenoxyacetic acid, dopamine addition showed no growth-promoting effect. Instead, 2,4-dichlorophenoxyacetic acid stimulated the growth of TCL explants to the same extent as that obtained with IAA plus dopamine. Because synthetic auxins do not appear to be substrates for IAA oxidizing enzymes, we hypothesized that catecholamines exert their effect by preventing IAA oxidation. Consistent with this explanation, dopamine (25 micromolar) inhibited IAA oxidase activity by 60 to 100% in crude enzyme extracts from tobacco roots and etiolated corn coleoptiles, but had no effect on peroxidase activity in the same extracts. Furthermore, addition of dopamine to TCL cultures resulted in a fourfold reduction in the oxidative degradation of [1-14C]IAA fed to the explants. Because the growth enhancement by catecholamines is observed in both IAA-requiring and IAA-independent cultures, we suggest that these aromatic amines may have a role in the regulation of IAA levels in vivo. ImagesFigure 2 PMID:16668653

  4. Influence of Sound Wave Stimulation on the Growth of Strawberry in Sunlight Greenhouse

    NASA Astrophysics Data System (ADS)

    Qi, Lirong; Teng, Guanghui; Hou, Tianzhen; Zhu, Baoying; Liu, Xiaona

    In this paper, we adopt the QGWA-03 plant audio apparatus to investigate the sound effects on strawberry in the leaf area, the photosynthetic characteristics and other physiological indexes. It was found that when there were no significant differences between the circumstances of the two sunlight greenhouses, the strawberry after the sound wave stimulation grew stronger than in the control and its leaf were deeper green, and shifted to an earlier time about one week to blossom and bear fruit. It was also found that the resistance of strawberry against disease and insect pest were enhanced. The experiment results show that sound wave stimulation can certainly promote the growth of plants.

  5. Amelioration of iron toxicity: A mechanism for aluminum-induced growth stimulation in tea plants.

    PubMed

    Hajiboland, Roghieh; Barceló, Juan; Poschenrieder, Charlotte; Tolrà, Roser

    2013-11-01

    Tea plants (Camellia sinensis) are well adapted to acid soils with high Al availability. These plants not only accumulate high leaf Al concentrations, but also respond to Al with growth stimulation. Decreased oxidative stress has been associated with this effect. Why tea plants not exposed to Al suffer from oxidative stress has not been clarified. In this study, hydroponically grown tea plants treated with 0 to 300 μM Al were analyzed for growth, Al and Fe accumulation, and Al distribution by means of morin and hematoxylin staining. Roots of control plants stained black with hematoxylin. This indicates the formation of a Fe-hematoxylin complex. Young leaves of controls accumulated more than 1000 mg Fe kg(-1) dry weight. This concentration is above the Fe-toxicity threshold in most species. Supply of Al stimulated growth and reduced Fe uptake and transport. These results indicate that Al-induced growth stimulation might be due to alleviation of a latent Fe toxicity occurring in tea plants without Al supply.

  6. Jejunal bypass stimulation of pancreatic growth and cholecystokinin secretion in rats: importance of luminal nutrients.

    PubMed Central

    Levan, V H; Liddle, R A; Green, G M

    1987-01-01

    The effect of jejunal bypass on pancreatic growth and plasma cholecystokinin (CCK) was investigated in rats. Rats underwent bypass of jejunum or sham operation. Rats with jejunal bypass were further divided into three groups; one group received a continuous infusion of a partially hydrolysed liquid diet (Vital) into the bypassed jejunum; a second group received the nutrient solution mixed with trypsin and infused into the bypassed jejunum; the third bypass group did not receive infusion of nutrient or trypsin into the jejunum. Jejunal bypass alone did not significantly stimulate pancreatic growth or DNA content at one or two weeks postoperative. Infusion of nutrient solution into the bypassed jejunum stimulated pancreatic growth and DNA content, with maximal increases of 185% and 181% for pancreatic weight and DNA content, respectively, at two weeks. This coincided with significant increases in postabsorptive plasma CCK concentrations. Infusion of pancreatic proteases into the bypassed jejunum partially reversed the effects of nutrient infusion. These results suggest that exclusion of bile-pancreatic juice or pancreatic proteases from the jejunum does not lead to maximal release of CCK unless the jejunum receives luminal nutrients. It is proposed that CCK release from rat jejunum occurs spontaneously in the absence of pancreatic proteases, and that luminal nutrients in bypassed jejunum increase plasma CCK and stimulate pancreatic growth by maintaining synthesis of CCK. PMID:3692314

  7. Promotion of ovarian follicle growth following mTOR activation: synergistic effects of AKT stimulators.

    PubMed

    Cheng, Yuan; Kim, Jaehong; Li, Xiao Xiao; Hsueh, Aaron J

    2015-01-01

    Mammalian target of rapamycin (mTOR) is a serine/threonine kinase and mTOR signaling is important in regulating cell growth and proliferation. Recent studies using oocyte- and granulosa cell-specific deletion of mTOR inhibitor genes TSC1 or TSC2 demonstrated the important role of mTOR signaling in the promotion of ovarian follicle development. We now report that treatment of ovaries from juvenile mice with an mTOR activator MHY1485 stimulated mTOR, S6K1 and rpS6 phosphorylation. Culturing ovaries for 4 days with MHY1485 increased ovarian explant weights and follicle development. In vivo studies further demonstrated that pre-incubation of these ovaries with MHY1485 for 2 days, followed by allo-grafting into kidney capsules of adult ovariectomized hosts for 5 days, led to marked increases in graft weights and promotion of follicle development. Mature oocytes derived from MHY1485-activated ovarian grafts could be successfully fertilized, leading the delivery of healthy pups. We further treated ovaries with the mTOR activator together with AKT activators (PTEN inhibitor and phosphoinositol-3-kinase stimulator) before grafting and found additive enhancement of follicle growth. Our studies demonstrate the ability of an mTOR activator in promoting follicle growth, leading to a potential strategy to stimulate preantral follicle growth in infertile patients.

  8. Promotion of Ovarian Follicle Growth following mTOR Activation: Synergistic Effects of AKT Stimulators

    PubMed Central

    Cheng, Yuan; Kim, Jaehong; Li, Xiao Xiao; Hsueh, Aaron J.

    2015-01-01

    Mammalian target of rapamycin (mTOR) is a serine/threonine kinase and mTOR signaling is important in regulating cell growth and proliferation. Recent studies using oocyte- and granulosa cell-specific deletion of mTOR inhibitor genes TSC1 or TSC2 demonstrated the important role of mTOR signaling in the promotion of ovarian follicle development. We now report that treatment of ovaries from juvenile mice with an mTOR activator MHY1485 stimulated mTOR, S6K1 and rpS6 phosphorylation. Culturing ovaries for 4 days with MHY1485 increased ovarian explant weights and follicle development. In vivo studies further demonstrated that pre-incubation of these ovaries with MHY1485 for 2 days, followed by allo-grafting into kidney capsules of adult ovariectomized hosts for 5 days, led to marked increases in graft weights and promotion of follicle development. Mature oocytes derived from MHY1485-activated ovarian grafts could be successfully fertilized, leading the delivery of healthy pups. We further treated ovaries with the mTOR activator together with AKT activators (PTEN inhibitor and phosphoinositol-3-kinase stimulator) before grafting and found additive enhancement of follicle growth. Our studies demonstrate the ability of an mTOR activator in promoting follicle growth, leading to a potential strategy to stimulate preantral follicle growth in infertile patients. PMID:25710488

  9. Stimulation of DNA synthesis in cultured primary human mesothelial cells by specific growth factors

    SciTech Connect

    Gabrielson, E.W.; Gerwin, B.I.; Harris, C.C.; Roberts, A.B.; Sporn, M.B.; Lechner, J.F.

    1988-08-01

    Monolayer cultures of human mesothelial cells made quiescent by serum deprivation are induced to undergo one round of DNA synthesis by platelet-derived growth factor (PDGF), epidermal growth factor (EGF), or transforming growth factor type beta 1 (TGF-beta 1). This one-time stimulation is independent of other serum components. The kinetics for induction of DNA synthesis observed for PDGF, EGF, and TGF-beta 1 are all similar to one another, with a peak of DNA synthesis occurring 24-36 h after the addition of the growth factors. Repetitive rounds of DNA synthesis and cell division do not ensue after addition of PDGF, EGF, or TGF-beta 1 alone or in combination; however, in media supplemented with chemically denatured serum, each of these factors is capable of sustaining continuous replication of mesothelial cells. Stimulation of growth by PDGF and TGF-beta 1 is unusual for an epithelial cell type, and indicates that mesothelial cells have growth regulatory properties similar to connective tissue cells.

  10. Proepithelin stimulates growth plate chondrogenesis via nuclear factor-kappaB-p65-dependent mechanisms.

    PubMed

    Wu, Shufang; Zang, Weijin; Li, Xu; Sun, Hongzhi

    2011-07-08

    Proepithelin, a previously unrecognized growth factor in cartilage, has recently emerged as an important regulator for cartilage formation and function. In the present study, we provide several lines of evidences in proepithelin-mediated induction of cell proliferation, differentiation, and apoptosis in the metatarsal growth plate. Proepithelin-mediated stimulation of metatarsal growth and growth plate chondrogenesis was neutralized by pyrrolidine dithiocarbamate, a known NF-κB inhibitor. In rat growth plate chondrocytes, proepithelin induced NF-κB-p65 nuclear translocation, and nuclear NF-κB-p65 initiated its target gene cyclin D1 to regulate chondrocyte functions. The inhibition of NF-κB-p65 expression and activity (by p65 short interfering RNA (siRNA) and pyrrolidine dithiocarbamate, respectively) in chondrocytes reversed the proepithelin-mediated induction of cell proliferation and differentiation and the proepithelin-mediated prevention of cell apoptosis. Moreover, the inhibition of the phosphatidylinositol 3-kinase and Akt abolished the effects of proepithelin on NF-κB activation. Finally, using siRNA and antisense strategies, we demonstrated that endogenously produced proepithelin by chondrocytes is important for chondrocyte growth in serum-deprived conditions. These results support the hypothesis that the induction of NF-κB activity of in growth plate chondrocytes is critical in proepithelin-mediated growth plate chondrogenesis and longitudinal bone growth.

  11. Curcumin suppresses growth of mesothelioma cells in vitro and in vivo, in part, by stimulating apoptosis.

    PubMed

    Wang, Ying; Rishi, Arun K; Wu, Wenjuan; Polin, Lisa; Sharma, Sunita; Levi, Edi; Albelda, Steven; Pass, Harvey I; Wali, Anil

    2011-11-01

    Malignant pleural mesothelioma (MPM) is an aggressive, asbestos-related malignancy of the thoracic pleura. Although, platinum-based agents are the first line of therapy, there is an urgent need for second-line therapies to treat the drug-resistant MPM. Cell cycle as well as apoptosis pathways are frequently altered in MPM and thus remain attractive targets for intervention strategies. Curcumin, the major component in the spice turmeric, alone or in combination with other chemotherapeutics has been under investigation for a number of cancers. In this study, we investigated the biological and molecular responses of MPM cells to curcumin treatments and the mechanisms involved. Flow-cytometric analyses coupled with western immunoblotting and gene-array analyses were conducted to determine mechanisms of curcumin-dependent growth suppression of human (H2373, H2452, H2461, and H226) and murine (AB12) MPM cells. Curcumin inhibited MPM cell growth in a dose- and time-dependent manner while pretreatment of MPM cells with curcumin enhanced cisplatin efficacy. Curcumin activated the stress-activated p38 kinase, caspases 9 and 3, caused elevated levels of proapoptotic proteins Bax, stimulated PARP cleavage, and apoptosis. In addition, curcumin treatments stimulated expression of novel transducers of cell growth suppression such as CARP-1, XAF1, and SULF1 proteins. Oral administration of curcumin inhibited growth of murine MPM cell-derived tumors in vivo in part by stimulating apoptosis. Thus, curcumin targets cell cycle and promotes apoptosis to suppress MPM growth in vitro and in vivo. Our studies provide a proof-of-principle rationale for further in-depth analysis of MPM growth suppression mechanisms and their future exploitation in effective management of resistant MPM.

  12. Phosphoinositide 3-kinase p110δ mediates estrogen- and FSH-stimulated ovarian follicle growth.

    PubMed

    Li, Qian; He, Hui; Zhang, Yin-Li; Li, Xiao-Meng; Guo, Xuejiang; Huo, Ran; Bi, Ye; Li, Jing; Fan, Heng-Yu; Sha, Jiahao

    2013-09-01

    In the mammalian ovary, primordial follicles are generated early in life and remain dormant for prolonged periods. Their growth resumes via primordial follicle activation, and they continue to grow until the preovulatory stage under the regulation of hormones and growth factors, such as estrogen, FSH, and IGF-1. Both FSH and IGF-1 activate the phosphatidylinositol-3 kinase (PI3K)/Akt (acute transforming retrovirus thymoma protein kinase) signaling pathway in granulosa cells (GCs), yet it remains inconclusive whether the PI3K pathway is crucial for follicle growth. In this study, we investigated the p110δ isoform (encoded by the Pik3cd gene) of PI3K catalytic subunit expression in the mouse ovary and its function in fertility. Pik3cd-null females were subfertile, exhibited fewer growing follicles and more atretic antral follicles in the ovary, and responded poorly to exogenous gonadotropins compared with controls. Ovary transplantation showed that Pik3cd-null ovaries responded poorly to FSH stimulation in vitro; this confirmed that the follicle growth defect was intrinsically ovarian. In addition, estradiol (E2)-stimulated follicle growth and GC proliferation in preantral follicles was impaired in Pik3cd-null ovaries. FSH and E2 substantially activated the PI3K/Akt pathway in GCs of control mice but not in those of Pik3cd-null mice. However, primordial follicle activation and oocyte meiotic maturation were not affected by Pik3cd knockout. Taken together, our findings indicate that the p110δ isoform of the PI3K catalytic subunit is a key component of the PI3K pathway for both FSH and E2-stimulated follicle growth in ovarian GCs; however, it is not required for primordial follicle activation and oocyte development.

  13. EFFECT OF POLYAMINE STRUCTURE ON GROWTH STIMULATION AND SPERMINE AND SPERMIDINE CONTENT OF LACTIC ACID BACTERIA

    PubMed Central

    Guirard, Beverly M.; Snell, Esmond E.

    1964-01-01

    Guirard, Beverly M. (University of California, Berkeley), and Esmond E. Snell. Effect of polyamine structure on growth and spermine and spermidine content of lactic acid bacteria. J. Bacteriol. 88:72–80. 1964.—Growth from small inocula of six species of lactobacilli was stimulated by addition of spermine or spermidine to a defined medium; none of four streptococcal species showed this effect. Lactobacillus casei was stimulated to the greatest extent. Several homologues and analogues partially duplicated the growth-promoting effects of spermidine; one inactive homologue, N-(3-aminopropyl)-1,6-hexanediamine, competitively inhibited the growth response to spermidine and spermine, and reduced or eliminated the response to several weakly active compounds. A procedure for separation of spermine and spermidine, and their estimation by bioassay with L. casei, was developed and applied to the estimation of these compounds in bacterial cells. Both compounds are present in lactic acid bacteria in amounts much smaller (1 to 5%) than those found in Escherichia coli. Addition of spermine or spermidine to the growth medium results in large accumulations in the cells, and the two amines show limited interconvertibility. Putrescine does not increase the cell content of either spermine or spermidine. Presence of the inhibitor prevents accumulation of the growth-stimulating amines. The polyamines appear to fill at least two valuable roles in the cell, one relatively nonspecific in its structural requirements, and one filled only by spermine and spermidine or their nearest homologues. N-(3-aminopropyl)-1,6-hexanediamine appears to prevent the latter function by competition for an appropriate cellular receptor. PMID:14197908

  14. Exogenous recombinant bovine growth hormone stimulates growth and hepatic IGF expression in shovelnose sturgeon Scaphirhynchus platorhynchus.

    PubMed

    Fenn, Carlin M; Small, Brian C

    2015-02-01

    Sturgeon are a unique fish for physiological research as they are long-lived, slow-growing, and late-maturing. Furthermore, sturgeon growth hormones appear to share greater structural and molecular similarity with mammalian somatotropins than teleostean somatotropins. In this study, changes in insulin-like growth factor (IGF)-I and IGF-II mRNA expression and corresponding whole-body growth and composition following 6 weeks of bi-weekly recombinant bovine growth hormone (rbGH) administration in shovelnose sturgeon Scaphirhynchus platorhynchus were evaluated. Fish were injected intraperitoneally with 240 μg rbGH/g body weight or a sesame oil sham. Hepatic IGF-I and IGF-II mRNA abundance was significantly higher (P≤0.02) in rbGH-treated fish, as were length (P<0.001) and weight gain (P<0.001). In addition, proximate whole-body analysis demonstrated a significant (P<0.05) increase in protein composition of rbGH-treated fish versus sham-treated fish. There were no significant differences in whole-body moisture, lipid, or ash between the two treatments. These results demonstrate functional roles for GH and IGFs in the promotion of lean growth within this ancient fish species and support the view that the functional effects of GH on hepatic IGF-I expression and somatic growth are conserved from chondostrean to teleostean fishes.

  15. Growth characteristics of different heart cells on novel nanopatch substrate during electrical stimulation.

    PubMed

    Stout, David A; Raimondo, Emilia; Marostica, Giuliano; Webster, Thomas J

    2014-01-01

    During a heart attack, the heart's oxygen supply is cut off, and cardiomyocytes perish. Unfortunately, once these tissues are lost, they cannot be replaced and results in cardiovascular disease-the leading cause of deaths worldwide. Advancements in medical research have been targeted to understand and combat the death of these cardiomyocytes. For example, new research (in vitro) has demonstrated that one can expand cardiomyocyte adhesion and proliferation using polylactic-co-glycolic acid (PLGA) (50:50 (weight percent)) supplemented with carbon nanofibers (CNFs) to create a cardiovascular patch. However, the examination of other cardiovascular cell types has not been investigated. Therefore, the purpose of this present in vitro study was to determine cell growth characteristics of three different important cardiovascular cell types (aortic endothelial, fibroblast and cardiomyocyte) onto the substrate. Cells were seeded onto different PLGA:CNF ratio composites to determine if CNF density has an effect on cell growth, both in static and electrically stimulated environments. During continuous electrical stimulation (rectangle, 2 nm, 5 V/cm, 1 Hz), cardiomyocyte cell density increased in comparison to its static counterparts after 24, 72 and 120 hours. A minor rise in Troponin I excretion in electrical stimulation compared to static conditions indicated nominal cardiomyocyte cell function during cell experiments. Endothelial and fibroblast cell growth experiments indicated the material hindered or stalled proliferation during both static and electrical stimulation experiments, thus supporting the growth of cardiomyocytes onto the dead tissue zone. Furthermore, the results specified that CNF density did have an effect on PLGA:CNF composite cytocompatibility properties with the best results coming from the 50:50 [PLGA:CNF (weight percent:weight percent)] composite. Therefore, this study provides further evidence that a conductive scaffold using nanotechnology should be

  16. Stimulation of DNA and Collagen Synthesis by Autologous Growth Factor in Cultured Fetal Rat Calvaria

    NASA Astrophysics Data System (ADS)

    Canalis, Ernesto; Peck, William A.; Raisz, Lawrence G.

    1980-11-01

    Conditioned medium derived from organ or cell cultures prepared from 19- to 21-day fetal rat calvaria stimulated the incorporation of [3H]proline into collagen and of [3H]thymidine into DNA in organ cultures of the same tissue. Addition of cortisol enhanced the effect on collagen but not on DNA synthesis. These effects appeared to be due to a nondialyzable and heat-stable growth factor.

  17. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    SciTech Connect

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  18. Acute stimulation of transplanted neurons improves motoneuron survival, axon growth, and muscle reinnervation.

    PubMed

    Grumbles, Robert M; Liu, Yang; Thomas, Christie M; Wood, Patrick M; Thomas, Christine K

    2013-06-15

    Few options exist for treatment of pervasive motoneuron death after spinal cord injury or in neurodegenerative diseases such as amyotrophic lateral sclerosis. Local transplantation of embryonic motoneurons into an axotomized peripheral nerve is a promising approach to arrest the atrophy of denervated muscles; however, muscle reinnervation is limited by poor motoneuron survival. The aim of the present study was to test whether acute electrical stimulation of transplanted embryonic neurons promotes motoneuron survival, axon growth, and muscle reinnervation. The sciatic nerve of adult Fischer rats was transected to mimic the widespread denervation seen after disease or injury. Acutely dissociated rat embryonic ventral spinal cord cells were transplanted into the distal tibial nerve stump as a neuron source for muscle reinnervation. Immediately post-transplantation, the cells were stimulated at 20 Hz for 1 h. Other groups were used to control for the cell transplantation and stimulation. When neurons were stimulated acutely, there were significantly more neurons, including cholinergic neurons, 10 weeks after transplantation. This led to enhanced numbers of myelinated axons, reinnervation of more muscle fibers, and more medial and lateral gastrocnemius muscles were functionally connected to the transplant. Reinnervation reduced muscle atrophy significantly. These data support the concept that electrical stimulation rescues transplanted motoneurons and facilitates muscle reinnervation.

  19. GROWTH REGULATING FACTOR5 stimulates Arabidopsis chloroplast division, photosynthesis, and leaf longevity.

    PubMed

    Vercruyssen, Liesbeth; Tognetti, Vanesa B; Gonzalez, Nathalie; Van Dingenen, Judith; De Milde, Liesbeth; Bielach, Agnieszka; De Rycke, Riet; Van Breusegem, Frank; Inzé, Dirk

    2015-03-01

    Arabidopsis (Arabidopsis thaliana) leaf development relies on subsequent phases of cell proliferation and cell expansion. During the proliferation phase, chloroplasts need to divide extensively, and during the transition from cell proliferation to expansion, they differentiate into photosynthetically active chloroplasts, providing the plant with energy. The transcription factor GROWTH REGULATING FACTOR5 (GRF5) promotes the duration of the cell proliferation period during leaf development. Here, it is shown that GRF5 also stimulates chloroplast division, resulting in a higher chloroplast number per cell with a concomitant increase in chlorophyll levels in 35S:GRF5 leaves, which can sustain higher rates of photosynthesis. Moreover, 35S:GRF5 plants show delayed leaf senescence and are more tolerant for growth on nitrogen-depleted medium. Cytokinins also stimulate leaf growth in part by extending the cell proliferation phase, simultaneously delaying the onset of the cell expansion phase. In addition, cytokinins are known to be involved in chloroplast development, nitrogen signaling, and senescence. Evidence is provided that GRF5 and cytokinins synergistically enhance cell division and chlorophyll retention after dark-induced senescence, which suggests that they also cooperate to stimulate chloroplast division and nitrogen assimilation. Taken together with the increased leaf size, ectopic expression of GRF5 has great potential to improve plant productivity.

  20. The structure of granulocyte-colony-stimulating factor and its relationship to other growth factors.

    PubMed Central

    Hill, C P; Osslund, T D; Eisenberg, D

    1993-01-01

    We have determined the three-dimensional structure of recombinant human granulocyte-colony-stimulating factor by x-ray crystallography. Phases were initially obtained at 3.0-A resolution by multiple isomorphous replacement and were refined by solvent flattening and by averaging of the electron density of the three molecules in the asymmetric unit. The current R factor is 21.5% for all data between 6.0- and 2.2-A resolution. The structure is predominantly helical, with 104 of the 175 residues forming a four-alpha-helix bundle. The only other secondary structure is also helical. In the loop between the first two long helices a four-residue 3(10)-helix is immediately followed by a 6-residue alpha-helix. Three residues in the short connection between the second and third bundle helices form almost one turn of left-handed helix. The up-up-down-down connectivity with two long crossover connections has been reported previously for five other proteins, which like granulocyte-colony-stimulating factor are all signaling ligands: growth hormone, granulocyte/macrophage-colony-stimulating factor, interferon beta, interleukin 2, and interleukin 4. Structural similarity among these growth factors occurs despite the absence of similarity in their amino acid sequences. Conservation of this tertiary structure suggests that these different growth factors might all bind to their respective sequence-related receptors in an equivalent manner. Images Fig. 2 PMID:7685117

  1. THE MODE OF ACTION OF ANTIBIOTICS IN STIMULATING GROWTH OF CHICKS

    PubMed Central

    Eyssen, H.; de Somer, P.

    1963-01-01

    A study was made of the effect of antibiotics on growth of chicks and on intestinal absorption of fats and carbohydrates. Around the 8th day of life, chicks fed an antibiotic-free casein-sucrose diet developed a transitory syndrome of malabsorption of fats and carbohydrates, associated with disturbance of the efficiency of feed utilization and poor weight increase. Administration of virginiamycin, at a level of 20 ppm, suppressed this period of malabsorption and resulted in improved feed conversion and increased weight gain. The temporary growth depression and malabsorption were not observed in disinfected rooms in new quarters. Under these conditions virginiamycin did not stimulate growth nor was the efficiency of feed utilization improved by the antibiotic. However, the growth-depressing flora could be introduced to the new quarters by feeding each bird 50 mg of fresh feces collected from chicks in old quarters. Both the intestinal absorption and the growth-promoting effect of virginiamycin were influenced by the type of carbohydrate in the basal diet, and have been found to be most pronounced when sucrose was fed as the sole source of carbohydrate. The malabsorption was less obvious when cornstarch was substituted for sucrose. In this case virginiamycin had only a limited effect on growth and on feed conversion. The present investigations suggest that antibiotics stimulate growth of chicks by their antibacterial action against Gram-positive microorganisms which interfere with the absorption of nutrients. Furthermore, the growth-promoting effect seems to be most pronounced during a limited period of a few days around the 8th day of life. PMID:19867220

  2. Colony-stimulating factor 2 enhances the developmental competence of yak (Poephagus grunniens) preimplantation embryos by modulating the expression of heat shock protein 70 kDa 1A.

    PubMed

    Wen, Zexing; Pan, Yangyang; Cui, Yan; Peng, Xiumei; Chen, Ping; Fan, Jiangfeng; Li, Guyue; Zhao, Tian; Zhang, Jian; Qin, Shujian; Yu, Sijiu

    2017-04-15

    Colony-stimulating factor 2 (CSF2) is known to promote the development and survival of rodents and ruminants preimplantation embryos; however, the effect of CSF2 on yak embryos has not been reported. The objective of this study was to investigate the effects of CSF2 on the developmental competence of yak embryos cultured in vitro in modified synthetic oviduct fluid (mSOF) medium and on the expression pattern of heat shock protein 70 kDa 1A (HSPA1A). In each experiment, cumulus-oocyte complexes (COCs) were matured in vitro and fertilized with frozen-thawed semen. Zygotes were treated with varying concentrations of CSF2 (0, 10, 50, 100 ng/mL) until day 8 after fertilization. Embryo development was calculated as the percentage of oocytes that formed embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula and blastocyst stages. The total cell numbers (TCN) per blastocyst and their allocation to the inner cell mass (ICM) and trophectoderm (TE) lineages were determined using differential CDX2 staining. The expression of HSPA1A was examined by quantitative real-time PCR (qRT-PCR) and immunochemistry to determine the mRNA and protein levels. The results showed that treatment with 50 ng/mL CSF2 significantly (P < 0.05) increased the rate of blastocyst formation (19.01% versus 9.93%) and the TCN per blastocyst (96.94 versus 81.41) compared to the control group. However, no significant differences were observed in the other stages of development. qRT-PCR analysis confirmed that treatment with 50 ng/mL CSF2 significantly (P < 0.05) inhibited the expression of HSPA1A mRNA in blastocysts cultured in vitro relative to the control group, but there were no significant differences between the other treatment groups. Immunocytochemical analysis confirmed that HSPA1A protein accumulation was gradually reduced in yak blastocysts cultured in 0, 10, 100 or 50 ng/mL CSF2, however, no significant differences were observed between the 10 and 100 ng/mL treatments (P > 0.05). In

  3. Overexpression of a metacaspase gene stimulates cell growth and stress response in Schizosaccharomyces pombe.

    PubMed

    Lim, Hye-Won; Kim, Su-Jung; Park, Eun-Hee; Lim, Chang-Jin

    2007-08-01

    A unique gene named pca1(+), encoding a metacaspase, was cloned from the fission yeast Schizosaccharomyces pombe and was used to create a recombinant plasmid, pPMC. The metacaspase mRNA level was markedly elevated in the fission yeast cells harboring the plasmid pPMC. Overexpressed Pca1(+) appeared to stimulate the growth of the fission yeast cells instead of arresting their growth. Its expression was enhanced by stress-inducing agents such as H(2)O(2), sodium nitroprusside, and CdCl(2), and it conferred cytoprotection, especially against CdCl(2). However, such protection was not reproducible in the budding yeast Saccharomyces cerevisiae harboring pPMC. Taken together, these results propose that Pca1(+) may be involved in the growth and stress response of the fission yeast.

  4. Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

    NASA Technical Reports Server (NTRS)

    Grindeland, Richard E.; Roy, R. R.; Edgerton, V. R.; Gosselink, K. L.; Grossman, E. J.; Sawchenko, P. E.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    Growth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.

  5. Stimulation of myofibrillar protein synthesis in hindlimb suspended rats by resistance exercise and growth hormone.

    PubMed

    Linderman, J K; Whittall, J B; Gosselink, K L; Wang, T J; Mukku, V R; Booth, F W; Grindeland, R E

    1995-01-01

    The objective of this study was to determine the ability of a single bout of resistance exercise alone or in combination with recombinant human growth hormone (rhGH) to stimulate myofibrillar protein synthesis (Ks) in hindlimb suspended (HLS) adult female rats. Plantar flexor muscles were stimulated with resistance exercise, consisting of 10 repetitions of ladder climbing on a 1 m grid (85 degrees), carrying an additional 50% of their body weight attached to their tails. Saline or rhGH (1 mg/kg) was administered 30' prior to exercise, and Ks was determined with a constant infusion of 3H-Leucine at 15', 60', 180', and 360' following exercise. Three days of HLS depressed Ks approximately 65% and 30-40% in the soleus and gastrocnemius muscles, respectively (p < or = 0.05). Exercise increased soleus Ks in saline-treated rats 149% 60' following exercise (p < or = 0.05), decaying to that of non-exercised animals during the next 5 hours. Relative to suspended, non-exercised rats rhGH+exercise increased soleus Ks 84%, 108%, and 72% at 15', 60' and 360' following exercise (p < or = 0.05). Gastrocnemius Ks was not significantly increased by exercise or the combination of rhGH and exercise up to 360' post-exercise. Results from this study indicate that resistance exercise stimulated Ks 60' post-exercise in the soleus of HLS rats, with no apparent effect of rhGH to enhance or prolong exercise-induced stimulation. Results suggests that exercise frequency may be important to maintenance of the slow-twitch soleus during non-weightbearing, but that the ability of resistance exercise to maintain myofibrillar protein content in the gastrocnemius of hindlimb suspended rats cannot be explained by acute stimulation of synthesis.

  6. Stimulation of Myofibrillar Protein Synthesis in Hindlimb Suspended Rats by Resistance Exercise and Growth Hormone

    NASA Technical Reports Server (NTRS)

    Linderman, Jon K.; Whittall, Justen B.; Gosselink, Kristin L.; Wang, Tommy J.; Mukku, Venkat R.; Booth, Frank W.; Grindeland, Richard E.

    1995-01-01

    The objective of this study was to determine the ability of a single bout of resistance exercise alone or in combination with recombinant human growth hormone (rhGH) to stimulate myofibrillar protein synthesis (Ks) in hindlimb suspended (HLS) adult female rats. Plantar flexor muscles were stimulated with resistance exercise, consisting of 10 repetitions of ladder climbing on a 1 m grid (85 deg.), carrying an additional 50% of their body weight attached to their tails. Saline or rhGH (1 mg/kg) was administered 30' prior to exercise, and Ks was determined with a constant infusion of H-3-Leucine at 15', 60', 180', and 360' following exercise. Three days of HLS depressed Ks is approx. equal to 65% and 30-40% in the soleus and gastrocnemius muscles, respectively (p is less than or equal to 0.05). Exercise increased soleus Ks in saline-treated rats 149% 60' following exercise (p less than or equal to 0.05), decaying to that of non-exercised animals during the next 5 hours. Relative to suspended, non-exercised rats rhGH + exercise increased soleus Ks 84%, 108%, and 72% at 15', 60' and 360' following exercise (p is less than or equal to 0.05). Gastrocnemius Ks was not significantly increased by exercise or the combination of rhGH and exercise up to 360' post-exercise. Results from this study indicate that resistance exercise stimulated Ks 60' post-exercise in the soleus of HLS rats, with no apparent effect of rhGH to enhance or prolong exercise-induced stimulation. Results suggests that exercise frequency may be important to maintenance of the slow-twitch soleus during non-weightbearing, but that the ability of resistance exercise to maintain myofibrillar protein content in the gastrocnemius of hindlimb suspended rats cannot be explained by acute stimulation of synthesis.

  7. Nerve growth factor and epidermal growth factor stimulate clusterin gene expression in PC12 cells.

    PubMed Central

    Gutacker, C; Klock, G; Diel, P; Koch-Brandt, C

    1999-01-01

    Clusterin (apolipoprotein J) is an extracellular glycoprotein that might exert functions in development, cell death and lipid transport. Clusterin gene expression is elevated at sites of tissue remodelling, such as differentiation and apoptosis; however, the signals responsible for this regulation have not been identified. We use here the clusterin gene as a model system to examine expression in PC12 cells under the control of differentiation and proliferation signals produced by nerve growth factor (NGF) and by epidermal growth factor (EGF) respectively. NGF induced clusterin mRNA, which preceded neurite outgrowth typical of neuronal differentiation. EGF also activated the clusterin mRNA, demonstrating that both proliferation and differentiation signals regulate the gene. To localize NGF- and EGF-responsive elements we isolated the clusterin promoter and tested it in PC12 cell transfections. A 2.5 kb promoter fragment and two 1.5 and 0.3 kb deletion mutants were inducible by NGF and EGF. The contribution to this response of a conserved activator protein 1 (AP-1) motif located in the 0.3 kb fragment was analysed by mutagenesis. The mutant promoter was not inducible by NGF or EGF, which identifies the AP-1 motif as an element responding to both factors. Binding studies with PC12 nuclear extracts showed that AP-1 binds to this sequence in the clusterin promoter. These findings suggest that NGF and EGF, which give differential gene regulation in PC12 cells, resulting in neuronal differentiation and proliferation respectively, use the common Ras/extracellular signal-regulated kinase/AP-1 signalling pathway to activate clusterin expression. PMID:10215617

  8. Lysosomal acid lipase in mesenchymal stem cell stimulation of tumor growth and metastasis

    PubMed Central

    Zhao, Ting; Yan, Cong; Du, Hong

    2016-01-01

    Bone marrow mesenchymal stem cells (MSCs) are an important participant in the tumor microenvironment, in which they promote tumor growth and progression. Here we report for the first time that depletion of lysosomal acid lipase (LAL) in MSCs impairs their abilities to stimulate tumor growth and metastasis both in allogeneic and syngeneic mouse models. Reduced cell viability was observed in LAL-deficient (lal−/−) MSCs, which was a result of both increased apoptosis and decreased proliferation due to cell cycle arrest. The synthesis and secretion of cytokines and chemokines that are known to mediate MSCs' tumor-stimulating and immunosuppressive effects, i.e., IL-6, MCP-1 and IL-10, were down-regulated in lal−/− MSCs. When tumor cells were treated with the conditioned medium from lal−/− MSCs, decreased proliferation was observed, accompanied by reduced activation of oncogenic intracellular signaling molecules in tumor cells. Co-injection of lal−/− MSCs and B16 melanoma cells into wild type mice not only induced CD8+ cytotoxic T cells, but also decreased accumulation of tumor-promoting Ly6G+CD11b+ myeloid-derived suppressor cells (MDSCs), which may synergistically contribute to the impairment of tumor progression. Furthermore, lal−/− MSCs showed impaired differentiation towards tumor-associated fibroblasts. In addition, MDSCs facilitated MSC proliferation, which was mediated by MDSC-secreted cytokines and chemokines. Our results indicate that LAL plays a critical role in regulating MSCs' ability to stimulate tumor growth and metastasis, which provides a mechanistic basis for targeting LAL in MSCs to reduce the risk of cancer metastasis. PMID:27531897

  9. Modulation of cultured porcine granulosa cell responsiveness to follicle stimulating hormone and epidermal growth factor

    SciTech Connect

    Buck, P.A.

    1986-01-01

    Ovarian follicular development is dependent upon the coordinated growth and differentiation of the granulosa cells which line the follicle. Follicle stimulating hormone (FSH) induces granulosa cell differentiation both in vivo and in vitro. Epidermal growth factor (EGF) stimulates granulosa cell proliferation in vitro. The interaction of these two effectors upon selected parameters of growth and differentiation was examined in monolayer cultures of porcine granulose cells. Analysis of the EGF receptor by /sup 125/I-EGF binding revealed that the receptor was of high affinity with an apparent dissociation constant of 4-6 x 10/sup -10/ M. The average number of receptors per cell varied with the state of differentiation both in vivo and in vitro; highly differentiated cells bound two-fold less /sup 125/I-EGF and this effect was at least partially induced by FSH in vitro. EGF receptor function was examined by assessing EGF effects on cell number and /sup 3/H-thymidine incorporation. EGF stimulated thymidine incorporation in both serum-free and serum-supplemented culture, but only in serum-supplemented conditions was cell number increased. EGF receptor function was inversely related to the state of differentiation and was attenuated by FSH. The FSH receptor was examined by /sup 125/I-FSH binding. EGF increased FSH receptor number, and lowered the affinity of the receptor. The function of these receptors was assessed by /sup 125/I-hCG binding and progesterone radioimmunoassay. If EGF was present continuously in the cultures. FSH receptor function was attenuated regardless of FSH receptor number. A preliminary effort to examine the mechanism of this interaction was performed by analyzing hormonally controlled protein synthesis with /sup 35/S-methionine labeling, SDS polyacrylamide gel electrophoresis and fluorography. FSH promoted the expression of a 27,000 dalton protein. This effect was attenuated by EGF.

  10. Evaluation of Masticatory Stimulation Effect on the Maxillary Transversal Growth in Ectodermal Dysplasia Children

    PubMed Central

    Nahass, Mona G; Mourad, Ayman

    2017-01-01

    Aims Severe oligodontia is one of the most important symptoms in children with hypohidrotic ectodermal dysplasia (HED). The growth of the maxilla is a key consideration in restoring their mouth. The aim of this study was to evaluate the transversal maxillary sutural growth, after passive masticatory stimulation, in HED children. We also thought to assess the efficiency and functional outcome of the proposed propriocep-tive passive expansion (PPE) prosthetic device. Materials and methods We studied 13 children (age 6-11 years) suffering from HED with severe oligodontia. Their maxilla was restored by a PPE device formed from two parts and joined by a passive slide system. Distance between the two parts was noted at the anterior and posterior regions at each control visit over an average of 23 months. We also conducted and filled a satisfaction questionnaire over the same period. We tested the hypothesis that the posterior expansion is greater than the anterior expansion (one-tailed Student’s t-test with p-value <0.05). Best-fit linear and quadratic models were used to explore the relationship between age, duration of observation, and the rate of growth. Results The average opening of the device was 2.27 mm in the anterior region and 2.96 mm in the posterior region. The questionnaire response was positive for all children. There are no significant linear or quadratic relationships between the data at the 5% significance level. The posterior expansion is greater than the anterior expansion at the 5% significance level (p-value 0.000394). Limitations Further studies are mandatory to assess the reliability of our particular intervention and treatment modalities for these cases. Conclusion The PPE device, we propose, assures function and esthetics in the long- term. It enhances stimulation by a passive way that leads to physiological growth of the palatal suture. Clinical significance Using this PPE device to restore the maxilla in children with HED promotes

  11. Humic acid-like material from sewage sludge stimulates culture growth of ectomycorrhizal fungi in vitro.

    PubMed

    Hrselová, H; Soukupová, L; Gryndler, M

    2007-01-01

    Significant effects of humic acid-like material (HALM) extracted from sewage sludge on dry matter production of cultures of ectomycorrhizal basidiomycetes were found in vitro. Mycelial growth of the majority of isolates tended to increase in the presence of the HALM and this effect was significant for 6 isolates. Strongest stimulation was observed in the case of Amanita muscaria, Leccinum aurantiacum and Lactarius deterrimus. The results suggest that the HALM can be used as an additive to media for cultivation of ectomycorrhizal basidiomycetes.

  12. Mycelium growth stimulation of the desert truffle Terfezia claveryi chatin by β-cyclodextrin.

    PubMed

    López-Nicolás, José Manuel; Pérez-Gilabert, Manuela; García-Carmona, Francisco; Lozano-Carrillo, María Cecilia; Morte, Asunción

    2013-01-01

    The commercial value of Terfezia claveryi, an edible desert truffle with important gastronomic, nutritional, and antioxidant properties, has led to growing interest in its cultivation. The erratic and slow growth of T. claveryi mycelium in vitro represents an impairment to obtain mycorrhizal plants, and it makes necessary to find a new culture medium able to overcome these drawbacks. In this work, we analyze the effect of cyclodextrins (CDs) on the growth of T. claveryi mycelium. Different parameters, including colony diameter, growth rate, and colony fresh weight, were evaluated, both in the presence and absence of these encapsulant agents. The results obtained confirm the ability of CDs to stimulate the growth of T. claveryi mycelium when present in the culture medium. A similar effect was observed when CDs were added to the culture medium of Tuber melanosporum. Three natural (α-, β-, and γ) and two modified (hydroxypropil-β and methyl-β) CDs were assayed. The best results were obtained with β-cyclodextrin, but no improvement was observed with its chemically modified derivatives. CDs complex the different compounds present in the culture medium which impair mycelial growth.

  13. The role of lactic acid in autocrine B-cell growth stimulation.

    PubMed Central

    Pike, S E; Markey, S P; Ijames, C; Jones, K D; Tosato, G

    1991-01-01

    Growth and survival of Epstein-Barr virus (EBV)-immortalized B lymphocytes cultured at low cell densities require autocrine soluble factors. In this study, we have purified a low molecular weight autocrine soluble factor that promotes growth of EBV-immortalized B cells in serum-free conditions and identified it as lactic acid (LA). Synthetic LA stimulated growth in EBV-immortalized B cells at 1-10 mM, a concentration of LA measured in the culture supernatant of EBV-immortalized cell lines. LA alone was found to account for greater than 70% of the autocrine growth factor activity in serum-free supernatants of EBV-immortalized B cells. Aminooxyacetate, a glutamate-oxaloacetate transaminase inhibitor, specifically inhibited B-cell growth induced by LA, suggesting that this process requires mitochondrial-cytosol transfers. Thus, LA is an autocrine stimulatory molecule that in serum-free conditions is essential for the continuous proliferation of EBV-immortalized B cells. This represents an unexpected function for LA. PMID:1662382

  14. Triiodothyronine stimulates specifically growth hormone mRNA in rat pituitary tumor cells.

    PubMed

    Seo, H; Vassart, G; Brocas, H; Refetoff, S

    1977-05-01

    In a cell-free protein-synthesizing system from a rabbit reticulocyte lysate, total RNA extracted from cultured rat pituitary tumor (GH3) cells directed, in a dose-related manner, the synthesis of proteins that were precipitated by antisera specific to rat growth hormone (somatotropin) and rat prolactin. A marked decrease in growth hormone secretion and growth hormone mRNA activity was observed when cells were grown in a medium deficient in thyroid hormone. Addition of triiodothyronine in physiologic amounts both prevented and completely reversed this effect within 48 hr. Thyroid hormone had no effect on prolactin secretion or prolactin mRNA activity. These data suggest that thyroid hormone may stimulate synthesis of growth hormone through induction of transcriptional activity. The possibility of an additional effect at the posttranscriptional level has not been excluded. Although thyroid hormone is believed to have a general effect on a variety of metabolic processes, some effects, at the molecular level, may be quite selective, as indicated by the observed changes in growth hormone but not prolactin mRNA activity. The GH3 cell model is useful in the study of triiodothyronine action because of independence from secondary hormonal effects caused by hypothyroidism and because simultaneous measurement of prolactin mRNA activity serves as a unique internal control.

  15. Sphere formation of adipose stem cell engineered by poly-2-hydroxyethyl methacrylate induces in vitro angiogenesis through fibroblast growth factor 2.

    PubMed

    Kim, Jong-Ho; Lim, I-Rang; Joo, Hyung Joon; Choi, Seung-Cheol; Choi, Ji-Hyun; Cui, Long-Hui; Im, Lisa; Hong, Soon Jun; Lim, Do-Sun

    A number of researchers have been reporting a wide range of in vitro and in vivo studies of cell engraftment to enhance angiogenesis using stem cells. Despite these efforts, studies involving three-dimensional (3D) culture method that mimics in vivo environment have not reached its peak yet. In this study, we investigated the change and effects on cellular angiogenic growth factors through sphere formation of adipose stem cell (ASC) which is engineered by poly-2-hydroxyethyl methacrylate (Poly-HEMA). First of all, we successfully induced sphere formation of ASC (sph-ASC) on Poly-HEMA coated plates. sph-ASC represented significantly higher expression levels of anti-apoptotic and hypoxic factors compared to monolayer adherent ASC (adh-ASC). Interestingly, sph-ASC showed higher mRNA levels of the following genes; CD31, CD144, vWF, IGF-2, MCP-1, PDGF-A, VEGF-A, VEGF-C, and FGF-2. In addition, mRNA expressions of angiogenic growth factor receptors such as Flk1, FGFR1, FGFR2, and Tie2 were elevated in sph-ASC. In protein level, Cytokine/Chemokines antibody array revealed a significant increase of FGF-2 in sph-ASC (3.17-fold) compared to adh-ASC. To investigate the effects of FGF-2 on sph-ASC, Matrigel angiogenic invasion assay showed significant reduced level of FGF-2 in FGF-2 siRNA transfected sph-ASC (2.27-fold) compared to negative control siRNA transfected sph-ASC. These findings suggest that Poly-HEMA coated plates induce sphere formation of ASC which has significantly higher expression of FGF-2, and plays a critical role as a major regulating growth factor of in vitro angiogenesis.

  16. Vascular endothelial growth factor stimulates osteoblastic differentiation of cultured human periosteal-derived cells expressing vascular endothelial growth factor receptors.

    PubMed

    Hah, Young-Sool; Jun, Jin-Su; Lee, Seong-Gyun; Park, Bong-Wook; Kim, Deok Ryong; Kim, Uk-Kyu; Kim, Jong-Ryoul; Byun, June-Ho

    2011-02-01

    Angiogenesis plays an important role in bone development and postnatal bone fracture repair. Vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) are primarily involved in angiogenesis. This study investigated the expression of VEGF isoforms, VEGFR-1, and VEGFR-2 during the osteoblastic differentiation of cultured human periosteal-derived cells. In addition, the effect of exogenous VEGF on the osteoblastic differentiation of cultured human periosteal-derived cells was also examined. The expression of the VEGF isoforms (VEGF(121), VEGF(165), VEGF(189), and VEGF(206)), VEGFR-1, and VEGFR-2 was observed in the periosteal-derived cells. Administration of KRN633, a VEGFR-1 and VEGFR-2 inhibitor, decreased the alkaline phosphatase (ALP) activity during the osteoblastic differentiation of cultured human periosteal-derived cells. However, the administration of VEGFR2 Kinase Inhibitor IV, a VEGFR-2 inhibitor, did not affect the ALP activity. The addition of recombinant human VEGF(165) elevated the ALP activity and increased the calcium content in the periosteal-derived cells. Treating the periosteal-derived cells with recombinant human VEGF(165) resulted in an increase in Runx2 transactivation in the periosteal-derived cells. These results suggest that exogenous VEGF stimulates the osteoblastic differentiation of cultured human periosteal-derived cells and VEGF might act as an autocrine growth factor for the osteoblastic differentiation of cultured human periosteal-derived cells.

  17. The mycorrhizal fungus Tricholoma matsutake stimulates Pinus densiflora seedling growth in vitro.

    PubMed

    Guerin-Laguette, Alexis; Shindo, Katsumi; Matsushita, Norihisa; Suzuki, Kazuo; Lapeyrie, Frédéric

    2004-12-01

    While it has been suggested that Matsutake mycorrhizae might not be functional and that Matsutake may behave as a saprobic fungus in soil or even have some pathogenic activity on seedlings, we investigated the consequences of Matsutake inoculation on Pinus densiflora growth. Seventy-five days after inoculation, hyphae were anchored on short roots and well-developed Hartig net palmettis were observed. Compared to both control treatments--seedlings treated with distilled water and seedlings treated with autoclaved mycelium--inoculation significantly stimulated seedling total dry weight by 70.9% and 98.0%, respectively. These findings attest that some type of symbiotic relationship must be functional and favour host growth, ruling out claims of pathogenicity under the sterile conditions used here.

  18. Bio-Nano-Magnetic Materials for Localized Mechanochemical Stimulation of Cell Growth and Death.

    PubMed

    Kilinc, Devrim; Dennis, Cindi L; Lee, Gil U

    2016-07-01

    Magnetic nanoparticles are promising new tools for therapeutic applications, such as magnetic nanoparticle hyperthermia therapy and targeted drug delivery. Recent in vitro studies have demonstrated that a force application with magnetic tweezers can also affect cell fate, suggesting a therapeutic potential for magnetically modulated mechanical stimulation. The magnetic properties of nanoparticles that induce physical responses and the subtle responses that result from mechanically induced membrane damage and/or intracellular signaling are evaluated. Magnetic particles with various physical, geometric, and magnetic properties and specific functionalization can now be used to apply mechanical force to specific regions of cells, which permit the modulation of cellular behavior through the use of spatially and time controlled magnetic fields. On one hand, mechanochemical stimulation has been used to direct the outgrowth on neuronal growth cones, indicating a therapeutic potential for neural repair. On the other hand, it has been used to kill cancer cells that preferentially express specific receptors. Advances made in the synthesis and characterization of magnetic nanomaterials and a better understanding of cellular mechanotransduction mechanisms may support the translation of mechanochemical stimulation into the clinic as an emerging therapeutic approach.

  19. Platelet-derived growth factor (PDGF) stimulates glycogen synthase activity in 3T3 cells

    SciTech Connect

    Chan, C.P.; Bowen-Pope, D.F.; Ross, R.; Krebs, E.G.

    1986-05-01

    Hormonal regulation of glycogen synthase, an enzyme that can be phosphorylated on multiple sites, is often associated with changes in its phosphorylation state. Enzyme activation is conventionally monitored by determining the synthase activity ratio ((activity in the absence of glucose 6-P)/(activity in the presence of glucose 6-P)). Insulin causes an activation of glycogen synthase with a concomitant decrease in its phosphate content. In a previous report, the authors showed that epidermal growth factor (EGF) increases the glycogen synthase activity ratio in Swiss 3T3 cells. The time and dose-dependency of this response was similar to that of insulin. Their recent results indicate that PDGF also stimulates glycogen synthase activity. Enzyme activation was maximal after 30 min. of incubation with PDGF; the time course observed was very similar to that with insulin and EGF. At 1 ng/ml (0.03nM), PDGF caused a maximal stimulation of 4-fold in synthase activity ratio. Half-maximal stimulation was observed at 0.2 ng/ml (6 pM). The time course of changes in enzyme activity ratio closely followed that of /sup 125/I-PDGF binding. The authors data suggest that PDGF, as well as EFG and insulin, may be important in regulating glycogen synthesis through phosphorylation/dephosphorylation mechanisms.

  20. Insulin-like growth factor I stimulates elastin synthesis by bovine pulmonary arterial smooth muscle cells.

    PubMed

    Badesch, D B; Lee, P D; Parks, W C; Stenmark, K R

    1989-04-14

    Insulin-like growth factor I stimulates mitogenesis in smooth muscle cells, and upregulates elastin synthesis in embryonic aortic tissue. Increased smooth muscle elastin synthesis may play an important role in vascular remodeling in chronic pulmonary hypertension. Therefore, we studied the effect of IGF-I on elastin and total protein synthesis by pulmonary arterial smooth muscle cells in vitro. Tropoelastin synthesis was measured by enzyme immunoassay, and total protein synthesis was measured by [3H]-leucine incorporation. In addition, the steady-state levels of tropoelastin mRNA were determined by slot blot hybridization. Incubation of confluent cultures with various concentrations of IGF-I resulted in a dose-dependent stimulation of elastin synthesis, with a 2.4-fold increase over control levels at 1000 ng/ml of IGF. The increase in elastin synthesis was reflected by a stimulation of the steady-state levels of tropoelastin mRNA. We conclude that IGF-I has potent elastogenic effects on vascular smooth muscle cells, and speculate that it may contribute to vascular wall remodeling in chronic hypertension.

  1. Clinical features of congenital adrenal insufficiency including growth patterns and significance of ACTH stimulation test.

    PubMed

    Koh, Ji Won; Kim, Gu Hwan; Yoo, Han Wook; Yu, Jeesuk

    2013-11-01

    Congenital adrenal insufficiency is caused by specific genetic mutations. Early suspicion and definite diagnosis are crucial because the disease can precipitate a life-threatening hypovolemic shock without prompt treatment. This study was designed to understand the clinical manifestations including growth patterns and to find the usefulness of ACTH stimulation test. Sixteen patients with confirmed genotyping were subdivided into three groups according to the genetic study results: congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH, n=11), congenital lipoid adrenal hyperplasia (n=3) and X-linked adrenal hypoplasia congenita (n=2). Bone age advancement was prominent in patients with CAH especially after 60 months of chronologic age (n=6, 67%). They were diagnosed in older ages in group with bone age advancement (P<0.05). Comorbid conditions such as obesity, mental retardation, and central precocious puberty were also prominent in this group. In conclusion, this study showed the importance of understanding the clinical symptoms as well as genetic analysis for early diagnosis and management of congenital adrenal insufficiency. ACTH stimulation test played an important role to support the diagnosis and serum 17-hydroxyprogesterone levels were significantly elevated in all of the CAH patients. The test will be important for monitoring growth and puberty during follow up of patients with congenital adrenal insufficiency.

  2. Clinical Features of Congenital Adrenal Insufficiency Including Growth Patterns and Significance of ACTH Stimulation Test

    PubMed Central

    Koh, Ji Won; Kim, Gu Hwan; Yoo, Han Wook

    2013-01-01

    Congenital adrenal insufficiency is caused by specific genetic mutations. Early suspicion and definite diagnosis are crucial because the disease can precipitate a life-threatening hypovolemic shock without prompt treatment. This study was designed to understand the clinical manifestations including growth patterns and to find the usefulness of ACTH stimulation test. Sixteen patients with confirmed genotyping were subdivided into three groups according to the genetic study results: congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH, n=11), congenital lipoid adrenal hyperplasia (n=3) and X-linked adrenal hypoplasia congenita (n=2). Bone age advancement was prominent in patients with CAH especially after 60 months of chronologic age (n=6, 67%). They were diagnosed in older ages in group with bone age advancement (P<0.05). Comorbid conditions such as obesity, mental retardation, and central precocious puberty were also prominent in this group. In conclusion, this study showed the importance of understanding the clinical symptoms as well as genetic analysis for early diagnosis and management of congenital adrenal insufficiency. ACTH stimulation test played an important role to support the diagnosis and serum 17-hydroxyprogesterone levels were significantly elevated in all of the CAH patients. The test will be important for monitoring growth and puberty during follow up of patients with congenital adrenal insufficiency. PMID:24265530

  3. Cyclic mechanical deformation stimulates human lung fibroblast proliferation and autocrine growth factor activity.

    PubMed

    Bishop, J E; Mitchell, J J; Absher, P M; Baldor, L; Geller, H A; Woodcock-Mitchell, J; Hamblin, M J; Vacek, P; Low, R B

    1993-08-01

    Cellular hypertrophy and hyperplasia and increased extracellular matrix deposition are features of tissue hypertrophy resulting from increased work load. It is known, for example, that mechanical forces play a critical role in lung development, cardiovascular remodeling following pressure overload, and skeletal muscle growth. The mechanisms involved in these processes, however, remain unclear. Here we examined the effect of mechanical deformation on fibroblast function in vitro. IMR-90 human fetal lung fibroblasts grown on collagen-coated silastic membranes were subjected to cyclical mechanical deformation (10% increase in culture surface area; 1 Hz) for up to 5 days. Cell number was increased by 39% after 2 days of deformation (1.43 +/- .01 x 10(5) cells/membrane compared with control, 1.03 +/- 0.02 x 10(5) cells; mean +/- SEM; P < 0.02) increasing to 163% above control by 4 days (2.16 +/- 0.16 x 10(5) cells compared with 0.82 +/- 0.03 x 10(5) cells; P < 0.001). The medium from mechanically deformed cells was mitogenic for IMR-90 cells, with maximal activity in the medium from cells mechanically deformed for 2 days (stimulating cell replication by 35% compared with media control; P < 0.002). These data suggest that mechanical deformation stimulates human lung fibroblast replication and that this effect is mediated by the release of autocrine growth factors.

  4. Transforming growth factor Beta 1 stimulates profibrotic activities of luteal fibroblasts in cows.

    PubMed

    Maroni, Dulce; Davis, John S

    2012-11-01

    Luteolysis is characterized by angioregression, luteal cell apoptosis, and remodeling of the extracellular matrix characterized by deposition of collagen 1. Transforming growth factor beta 1 (TGFB1) is a potent mediator of wound healing and fibrotic processes through stimulation of the synthesis of extracellular matrix components. We hypothesized that TGFB1 stimulates profibrotic activities of luteal fibroblasts. We examined the actions of TGFB1 on luteal fibroblast proliferation, extracellular matrix production, floating gel contraction, and chemotaxis. Fibroblasts were isolated from the bovine corpus luteum. Western blot analysis showed that luteal fibroblasts expressed collagen 1 and prolyl 4-hydroxylase but did not express markers of endothelial or steroidogenic cells. Treatment of fibroblasts with TGFB1 stimulated the phosphorylation of SMAD2 and SMAD3. [(3)H]thymidine incorporation studies showed that TGFB1 caused concentration-dependent reductions in DNA synthesis in luteal fibroblasts and significantly (P < 0.05) reduced the proliferative effect of FGF2 and fetal calf serum. However, TGFB1 did not reduce the viability of luteal fibroblasts. Treatment of luteal fibroblasts with TGFB1 induced the expression of laminin, collagen 1, and matrix metalloproteinase 1 as determined by Western blot analysis and gelatin zymography of conditioned medium. TGFB1 increased the chemotaxis of luteal fibroblasts toward fibronectin in a transwell system. Furthermore, TGFB1 increased the fibroblast-mediated contraction of floating bovine collagen 1 gels. These results suggest that TGFB1 contributes to the structural regression of the corpus luteum by stimulating luteal fibroblasts to remodel and contract the extracellular matrix.

  5. Alleviating versus stimulating effects of bicarbonate on the growth of Vallisneria natans under ammonia stress.

    PubMed

    Dou, Yanyan; Wang, Baozhong; Chen, Liangyan; Yin, Daqiang

    2013-08-01

    Bicarbonate plays a crucial role in limiting the growth of submersed aquatic macrophytes in eutrophic lakes, and high ammonia is often toxic to macrophytes. In order to evaluate the combined effect of HCO3 (-) and total ammonia (i.e., the total of NH3 and NH4 (+)) on submersed macrophytes Vallisneria natans, the growth and physiological response of V. natans in the presence of HCO3 (-) and ammonia were studied. The results showed that with the increase of ammonia, morphological parameters of V. natans declined. In contrast, increased HCO3 (-) concentration stimulated the growth of V. natans, especially when the NH4 (+)-N/NO3 (-)-N ratio was 1:7. High ammonia concentration induced excess free amino acids (FAA) accumulation and soluble carbohydrates (SC) depletion in plant tissues. However, the elevated HCO3 (-) promoted the synthesis of SC and rendered the decrease of FAA/SC ratio. The results also suggested that HCO3 (-) could partially alleviate the stress of ammonia, as evidenced by the decrease of FAA/SC ratio and the growth enhancement of V. natans when the ammonia concentration was 0.58 mg L(-1). Given the fact that HCO3 (-) is probably the dominant available carbon source in most eutrophic lakes, the ability of V. natans to use HCO3 (-) for SC synthesis may explain the alleviating effect of HCO3 (-) on V. natans under ammonia stress.

  6. Enhancement of osteoblastic differentiation of mesenchymal stromal cells cultured by selective combination of bone morphogenetic protein-2 (BMP-2) and fibroblast growth factor-2 (FGF-2).

    PubMed

    Maegawa, Naoki; Kawamura, Kenji; Hirose, Motohiro; Yajima, Hiroshi; Takakura, Yoshinori; Ohgushi, Hajime

    2007-01-01

    It is well known that bone marrow contains mesenchymal stromal cells (MSCs), which can show osteoblastic differentiation when cultured in osteogenic medium containing ascorbic acid, beta-glycerophosphate and dexamethasone. The differentiation results in the appearance of osteoblasts, together with the formation of bone matrix; thus, in vitro cultured bone (osteoblasts/bone matrix) could be fabricated by MSC culture. This type of cultured bone has already been used in clinical cases involving orthopaedic problems. To improve the therapeutic effect of the cultured bone, we investigated the culture conditions that contributed to extensive osteoblastic differentiation. Rat bone marrow was primarily cultured to expand the number of MSCs and further cultured in osteogenic medium for 12 days. The culture was also conducted in a medium supplemented with either bone morphogenetic protein-2 (BMP-2) or fibroblast growth factor (FGF-2), or with sequential combinations of both supplements. Among them, the sequential supplementation of FGF-2 followed by BMP-2 showed high alkaline phosphatase activity, sufficient bone-specific osteocalcein expression and abundant bone matrix formation of the MSC culture. These data implied that the number of responding cells or immature osteoblasts was increased by the supplementation of FGF-2 in the early phase of the culture and that these cells can show osteoblastic differentiation, of which capability was augmented by BMP-2 in the late phase. The sequential supplementation of these cytokines into MSC culture might be suitable for the fabrication of ideal cultured bone for use in bone tissue engineering.

  7. Expansion of murine periosteal progenitor cells with fibroblast growth factor 2 reveals an intrinsic endochondral ossification program mediated by bone morphogenetic protein 2.

    PubMed

    van Gastel, Nick; Stegen, Steve; Stockmans, Ingrid; Moermans, Karen; Schrooten, Jan; Graf, Daniel; Luyten, Frank P; Carmeliet, Geert

    2014-09-01

    The preservation of the bone-forming potential of skeletal progenitor cells during their ex vivo expansion remains one of the major challenges for cell-based bone regeneration strategies. We report that expansion of murine periosteal cells in the presence of FGF2, a signal present during the early stages of fracture healing, is necessary and sufficient to maintain their ability to organize in vivo into a cartilage template which gives rise to mature bone. Implantation of FGF2-primed cells in a large bone defect in mice resulted in complete healing, demonstrating the feasibility of using this approach for bone tissue engineering purposes. Mechanistically, the enhanced endochondral ossification potential of FGF2-expanded periosteal cells is predominantly driven by an increased production of BMP2 and is additionally linked to an improved preservation of skeletal progenitor cells in the cultures. This characteristic is unique for periosteal cells, as FGF2-primed bone marrow stromal cells formed significantly less bone and progressed exclusively through the intramembranous pathway, revealing essential differences between both cell pools. Taken together, our findings provide insight in the molecular regulation of fracture repair by identifying a unique interaction between periosteal cells and FGF2. These insights may promote the development of cell-based therapeutic strategies for bone regeneration which are independent of the in vivo use of growth factors, thus limiting undesired side effects.

  8. Molecular and clinical significance of fibroblast growth factor 2 (FGF2 /bFGF) in malignancies of solid and hematological cancers for personalized therapies

    PubMed Central

    Akl, Mohamed R.; Nagpal, Poonam; Ayoub, Nehad M.; Tai, Betty; Prabhu, Sathyen A.; Capac, Catherine M.; Gliksman, Matthew; Goy, Andre; Suh, K. Stephen

    2016-01-01

    Fibroblast growth factor (FGF) signaling is essential for normal and cancer biology. Mammalian FGF family members participate in multiple signaling pathways by binding to heparan sulfate and FGF receptors (FGFR) with varying affinities. FGF2 is the prototype member of the FGF family and interacts with its receptor to mediate receptor dimerization, phosphorylation, and activation of signaling pathways, such as Ras-MAPK and PI3K pathways. Excessive mitogenic signaling through the FGF/FGFR axis may induce carcinogenic effects by promoting cancer progression and increasing the angiogenic potential, which can lead to metastatic tumor phenotypes. Dysregulated FGF/FGFR signaling is associated with aggressive cancer phenotypes, enhanced chemotherapy resistance and poor clinical outcomes. In vitro experimental settings have indicated that extracellular FGF2 affects proliferation, drug sensitivity, and apoptosis of cancer cells. Therapeutically targeting FGF2 and FGFR has been extensively assessed in multiple preclinical studies and numerous drugs and treatment options have been tested in clinical trials. Diagnostic assays are used to quantify FGF2, FGFRs, and downstream signaling molecules to better select a target patient population for higher efficacy of cancer therapies. This review focuses on the prognostic significance of FGF2 in cancer with emphasis on therapeutic intervention strategies for solid and hematological malignancies. PMID:27007053

  9. Fibroblast growth factor 2-retargeted adenoviral vectors exhibit a modified biolocalization pattern and display reduced toxicity relative to native adenoviral vectors.

    PubMed

    Printz, M A; Gonzalez, A M; Cunningham, M; Gu, D L; Ong, M; Pierce, G F; Aukerman, S L

    2000-01-01

    Targeted vectors provide a number of advantages for systemic and local gene delivery strategies. Several groups have investigated the utility of using various ligands to alter the tropism of adenovirus (Ad) vectors. We have previously demonstrated that fibroblast growth factor (FGF) ligands can specifically target DNA transfection and Ad transduction through high-affinity FGF receptors (FGFRs). FGFRs are overexpressed in abnormally proliferating tissues, such as malignancies. The present studies explore the effects of retargeting with FGF2 on the tissue localization pattern and the systemic toxicity of Ad in mice. Results of semiquantitative PCR analyses indicate that the distribution of FGF2-Ad vector genome sequences after intravenous administration in mice is altered. Markedly lower amounts (10- to 20-fold) of FGF2-Ad localize to the liver when compared with native Ad. This decrease in liver deposition translates into a significant reduction in subsequent toxicity as measured by serum transaminases and histopathology in mice injected with FGF2-AdHSV-thymidine kinase with and without ganciclovir administration. In an intraperitoneal model of ovarian cancer, FGF2-Ad generates increased transgene expression in tumor tissue when compared with Ad. Taken together, these results indicate that the retargeting of Ad with FGF2 results in a more efficient vector system for systemic and regional gene therapy applications, with concomitant lower levels of systemic toxicity.

  10. Exploration of Teaching Strategies That Stimulate the Growth of Academic Skills of Children with ASD in Special Education School

    ERIC Educational Resources Information Center

    Manti, Eirini; Scholte, Evert M.; Van Berckelaer-Onnes, Ina A.

    2013-01-01

    The cognitive growth of children with developmental disorders, like autism, can be seriously impaired due to the disorder. If so, in the Netherlands, these children can attend special schools where they are treated to ameliorate disorder symptoms and to stimulate cognitive growth. The aim of this paper was to identify teaching strategies that…

  11. Induction of synapse associated protein 102 expression in cyclosporin A-stimulated hair growth.

    PubMed

    Kim, Chang Deok; Lee, Min-Ho; Sohn, Kyung-Cheol; Kim, Jin-Man; Li, Sheng Jin; Rang, Moon-Jeong; Roh, Seok-Seon; Oh, Young-Seon; Yoon, Tae-Jin; Im, Myung; Seo, Young-Joon; Lee, Jeung-Hoon; Park, Jang-Kyu

    2008-08-01

    Cyclosporin A (CsA) has been used as a potent immunosuppressive agent for inhibiting the graft rejection after organ transplantation. However, CsA provokes lots of side effects including hirsutism, the phenomenon of abnormal hair growth in the body. In the present study, we investigated the hair growth stimulating effect of CsA using in vivo and in vitro test models. When topically applied on the back skin of mice, CsA induced fast telogen to anagen transition. In contrast, CsA had no effect on the growth of human hair follicle tissues cultured in vitro, indicating that it might not have the mitogenic effect on hair follicles. To identify the genes related with CsA-induced hair growth, we performed differential display RT-PCR. Among the genes obtained, the expression of synapse associated protein 102 (SAP102) was verified using competitive RT-PCR. The result showed that the expression of SAP102 was significantly induced by CsA treatment in the back skin of C57BL/6 mice. However, the increase of SAP102 mRNA was also seen in spontaneous anagen mice, suggesting that induction of SAP102 is one event of the anagen hair growth response regardless of how the growth state was induced. SAP102 was not expressed in cultured human hair outer root sheath and dermal papilla cells. Immunohistochemistry analysis showed that CsA induced the expression of SAP102 in perifollicular region of mouse anagen hair. Together, these results suggest that SAP102 is one of hair-cycle-dependent genes, whose expression is related with the anagen progression.

  12. Purification and identification of a growth-stimulating peptide for Bifidobacterium bifidum from natural rubber serum powder.

    PubMed

    Etoh, S; Asamura, K; Obu, A; Sonomoto, K; Ishizaki, A

    2000-10-01

    Natural rubber serum powder, which is a by-product obtained in the production of latex rubber, has a strong growth-stimulating activity for Bifidobacterium bifidum JCM 1254. The retained fraction obtained by ultrafiltration (molecular weight cutoff 1000) showed a growth-stimulating activity in a dose-dependent manner on B12 assay medium with ammonium sulfate. One of the growth stimulators was purified from the retained fraction by acetone precipitation, solid-phase extraction with a hydrophobic pretreatment column, and multistage reversed-phase HPLC. An increase of 53-fold in the specific activity, and a recovery of 1.3% were obtained. The amino acid composition and N-terminal sequence analysis of this growth stimulator provided the structure of Ala-Thr-Pro-Glu-Lys-Glu-Glu-Pro-Thr-Ala. The molecular mass was 1075 by MALDI-TOF MS analysis. These results showed that this growth stimulator was a decapeptide with the sequence shown above. This is the first report that clarified the structure of an active peptide for the growth of Bifidobacterium.

  13. Transforming growth factor type beta specifically stimulates synthesis of proteoglycan in human adult arterial smooth muscle cells.

    PubMed Central

    Chen, J K; Hoshi, H; McKeehan, W L

    1987-01-01

    Myo-intimal proteoglycan metabolism is thought to be important in blood vessel homeostasis, blood clotting, atherogenesis, and atherosclerosis. Human platelet-derived transforming growth factor type beta (TGF-beta) specifically stimulated synthesis of at least two types of chondroitin sulfate proteoglycans in nonproliferating human adult arterial smooth muscle cells in culture. Stimulation of smooth muscle cell proteoglycan synthesis by smooth muscle cell growth promoters (epidermal growth factor, platelet-derived growth factor, and heparin-binding growth factors) was less than 20% of that elicited by TGF-beta. TGF-beta neither significantly stimulated proliferation of quiescent smooth muscle cells nor inhibited proliferating cells. The extent of TGF-beta stimulation of smooth muscle cell proteoglycan synthesis was similar in both nonproliferating and growth-stimulated cells. TGF-beta, which is a reversible inhibitor of endothelial cell proliferation, had no comparable effect on endothelial cell proteoglycan synthesis. These results are consistent with the hypothesis that TGF-beta is a cell-type-specific regulator of proteoglycan synthesis in human blood vessels and may contribute to the myo-intimal accumulation of proteoglycan in atherosclerotic lesions. Images PMID:3474655

  14. Basic Fibroblast Growth Factor-2/beta3 Integrin Expression Profile: Signature of Local Progression After Chemoradiotherapy for Patients With Locally Advanced Non-Small-Cell Lung Cancer

    SciTech Connect

    Massabeau, Carole; Rouquette, Isabelle; Lauwers-Cances, Valerie; Mazieres, Julien; Bachaud, Jean-Marc; Armand, Jean-Pierre; Delisle, Marie-Bernadette; Favre, Gilles; Toulas, Christine; Cohen-Jonathan-Moyal, Elizabeth

    2009-11-01

    Purpose: No biologic signature of chemoradiotherapy sensitivity has been reported for patients with locally advanced non-small-cell lung cancer (NSCLC). We have previously demonstrated that basic fibroblast growth factor (FGF-2) and alphavbeta3 integrin pathways control tumor radioresistance. We investigated whether the expression of the proteins involved in these pathways might be associated with the response to treatment and, therefore, the clinical outcome. Methods and Materials: FGF-2, beta3 integrin, angiopoietin-2, and syndecan-1 expression was studied using immunohistochemistry performed on biopsies obtained, before any treatment, from 65 patients exclusively treated with chemoradiotherapy for locally advanced NSCLC. The response to treatment was evaluated according to the Response Evaluation Criteria in Solid Tumors criteria using computed tomography at least 6 weeks after the end of the chemoradiotherapy. Local progression-free survival, metastasis-free survival, and disease-free survival were studied using the log-rank test and Cox proportional hazard analysis. Results: Among this NSCLC biopsy population, 43.7% overexpressed beta3 integrin (beta3{sup +}), 43% FGF-2 (FGF-2{sup +}), 41.5% syndecan-1, and 59.4% angiopoietin-2. Our results showed a strong association between FGF-2 and beta3 integrin expression (p = .001). The adjusted hazard ratio of local recurrence for FGF-2{sup +}/beta3{sup +} tumors compared with FGF-2{sup -}/beta3{sup -} tumors was 6.1 (95% confidence interval, 2.6-14.6, p = .005). However, the risk of local recurrence was not increased when tumors overexpressed beta3 integrin or FGF-2 alone. Moreover, the co-expression of these two proteins was marginally associated with the response to chemoradiotherapy and metastasis-free survival. Conclusion: The results of this study have identified the combined profile FGF-2/beta3 integrin expression as a signature of local control in patients treated with chemoradiotherapy for locally advanced

  15. Multiple Growth Factors, But Not VEGF, Stimulate Glycosaminoglycan Hyperelongation in Retinal Choroidal Endothelial Cells

    PubMed Central

    Al Gwairi, Othman; Osman, Narin; Getachew, Robel; Zheng, Wenhua; Liang, X-L.; Kamato, Danielle; Thach, Lyna; Little, Peter J.

    2016-01-01

    A major feature of early age-related macular degeneration (AMD) is the thickening of Bruch's membrane in the retina and an alteration in its composition with increased lipid deposition. In certain pathological conditions proteoglycans are responsible for lipid retention in tissues. Growth factors are known to increase the length of glycosaminoglycan chains and this can lead to a large increase in the interaction between proteoglycans and lipids. Using choroidal endothelial cells, we investigated the effects of a number of AMD relevant growth factors TGFβ, thrombin, PDGF, IGF and VEGF on proteoglycan synthesis. Cells were characterized as of endothelial origin using the specific cell markers endothelial nitric oxide synthesis and von Willebrand factor and imaged using confocal microscopy. Cells were treated with growth factors in the presence and absence of the appropriate inhibitors and were radiolabeled with [35S]-SO4. Proteoglycans were isolated by ion exchange chromatography and sized using SDS-PAGE. Radiosulfate incorporation was determined by the cetylpyridinium chloride (CPC) precipitation technique. To measure cellular glycosaminoglycan synthesizing capacity we added xyloside and assessed the xyloside-GAGs by SDS-PAGE. TGFβ, thrombin, PDGF & IGF dose-dependently stimulated radiosulfate incorporation and GAG elongation as well as xyloside-GAG synthesis, however VEGF treatment did not stimulate any changes in proteoglycan synthesis. VEGF did not increase pAKT but caused a large increase in pERK relative to the response to PDGF. Thus, AMD relevant agonists cause glycosaminoglycan hyperelongation of proteoglycans synthesised and secreted by retinal choroidal endothelial cells. The absence of a response to VEGF is intriguing and identifies proteoglycans as a novel potential target in AMD. Future studies will examine the relevance of these changes to enhanced lipid binding and the development of AMD. PMID:27570478

  16. Human-Friendly Light-Emitting Diode Source Stimulates Broiler Growth

    PubMed Central

    Yang, Bo; Dai, Wenhua; Yu, Yonghua

    2015-01-01

    Previous study and our laboratory have reported that short-wavelength (blue and green) light and combination stimulate broiler growth. However, short-wavelength stimuli could have negative effects on poultry husbandry workers. The present study was conducted to evaluate the effects of human-friendly yellow LED light, which is acceptable to humans and close to green light, on broiler growth. We also aimed to investigate the potential quantitative relationship between the wavelengths of light used for artificial illumination and growth parameters in broilers. After hatching, 360 female chicks (“Meihuang” were evenly divided into six lighting treatment groups: white LED strips (400–700 nm, WL); red LED strips (620 nm, RL); yellow LED strips (580 nm, YL); green LED strips (514 nm, GL); blue LED strips (455 nm, BL); and fluorescent strips (400–700 nm, FL). From 30 to 72 days of age, broilers reared under YL and GL were heavier than broilers treated with FL (P < 0.05). Broilers reared under YL obtained the similar growth parameters with the broilers reared under GL and BL (P > 0.05). Moreover, YL significantly improved feeding efficiency when compared with GL and BL at 45 and 60 days of age (P < 0.05). In addition, we found an age-dependent effect of light spectra on broiler growth and a quantitative relationship between LED light spectra (455 to 620 nm) and the live body weights of broilers. The wavelength of light (455 to 620 nm) was found to be negatively related (R2 = 0.876) to live body weight at an early stage of development, whereas the wavelength of light (455 to 620 nm) was found to be positively correlated with live body weight (R2 = 0.925) in older chickens. Our results demonstrated that human-friendly yellow LED light (YL), which is friendly to the human, can be applied to the broilers production. PMID:26270988

  17. Bioengineered sequential growth factor delivery stimulates brain tissue regeneration after stroke.

    PubMed

    Wang, Yuanfei; Cooke, Michael J; Sachewsky, Nadia; Morshead, Cindi M; Shoichet, Molly S

    2013-11-28

    Stroke is a leading cause of disability with no effective regenerative treatment. One promising strategy for achieving tissue repair involves the stimulation of endogenous neural stem/progenitor cells through sequential delivery of epidermal growth factor (EGF) followed by erythropoietin (EPO). Yet currently available delivery strategies such as intracerebroventricular (ICV) infusion cause significant tissue damage. We designed a novel delivery system that circumvents the blood brain barrier and directly releases growth factors to the brain. Sequential release of the two growth factors is a key in eliciting tissue repair. To control release, we encapsulate pegylated EGF (EGF-PEG) in poly(lactic-co-glycolic acid) (PLGA) nanoparticles and EPO in biphasic microparticles comprised of a PLGA core and a poly(sebacic acid) coating. EGF-PEG and EPO polymeric particles are dispersed in a hyaluronan methylcellulose (HAMC) hydrogel which spatially confines the particles and attenuates the inflammatory response of brain tissue. Our composite-mediated, sequential delivery of EGF-PEG and EPO leads to tissue repair in a mouse stroke model and minimizes damage compared to ICV infusion.

  18. Free bone graft reconstruction of irradiated facial tissue: Experimental effects of basic fibroblast growth factor stimulation

    SciTech Connect

    Eppley, B.L.; Connolly, D.T.; Winkelmann, T.; Sadove, A.M.; Heuvelman, D.; Feder, J. )

    1991-07-01

    A study was undertaken to evaluate the potential utility of basic fibroblast growth factor in the induction of angiogenesis and osseous healing in bone previously exposed to high doses of irradiation. Thirty New Zealand rabbits were evaluated by introducing basic fibroblast growth factor into irradiated mandibular resection sites either prior to or simultaneous with reconstruction by corticocancellous autografts harvested from the ilium. The fate of the free bone grafts was then evaluated at 90 days postoperatively by microangiographic, histologic, and fluorochrome bone-labeling techniques. Sequestration, necrosis, and failure to heal to recipient osseous margins was observed both clinically and histologically in all nontreated irradiated graft sites as well as those receiving simultaneous angiogenic stimulation at the time of graft placement. No fluorescent activity was seen in these graft groups. In the recipient sites pretreated with basic fibroblast growth factor prior to placement of the graft, healing and reestablishment of mandibular contour occurred in nearly 50 percent of the animals. Active bone formation was evident at cortical margins adjacent to the recipient sites but was absent in the more central cancellous regions of the grafts.

  19. Colony-Stimulating Factor-1 Promotes Kidney Growth and Repair via Alteration of Macrophage Responses

    PubMed Central

    Alikhan, Maliha A.; Jones, Christina V.; Williams, Timothy M.; Beckhouse, Anthony G.; Fletcher, Anne L.; Kett, Michelle M.; Sakkal, Samy; Samuel, Chrishan S.; Ramsay, Robert G.; Deane, James A.; Wells, Christine A.; Little, Melissa H.; Hume, David A.; Ricardo, Sharon D.

    2011-01-01

    Colony-stimulating factor (CSF)-1 controls the survival, proliferation, and differentiation of macrophages, which are recognized as scavengers and agents of the innate and the acquired immune systems. Because of their plasticity, macrophages are endowed with many other essential roles during development and tissue homeostasis. We present evidence that CSF-1 plays an important trophic role in postnatal organ growth and kidney repair. Notably, the injection of CSF-1 postnatally enhanced kidney weight and volume and was associated with increased numbers of tissue macrophages. Moreover, CSF-1 promotes postnatal renal repair in mice after ischemia-reperfusion injury by recruiting and influencing macrophages toward a reparative state. CSF-1 treatment rapidly accelerated renal repair with tubular epithelial cell replacement, attenuation of interstitial fibrosis, and functional recovery. Analysis of macrophages from CSF-1-treated kidneys showed increased expression of insulin-like growth factor-1 and anti-inflammatory genes that are known CSF-1 targets. Taken together, these data suggest that CSF-1 is important in kidney growth and the promotion of endogenous repair and resolution of inflammatory injury. PMID:21762674

  20. Colony-stimulating factor-1 promotes kidney growth and repair via alteration of macrophage responses.

    PubMed

    Alikhan, Maliha A; Jones, Christina V; Williams, Timothy M; Beckhouse, Anthony G; Fletcher, Anne L; Kett, Michelle M; Sakkal, Samy; Samuel, Chrishan S; Ramsay, Robert G; Deane, James A; Wells, Christine A; Little, Melissa H; Hume, David A; Ricardo, Sharon D

    2011-09-01

    Colony-stimulating factor (CSF)-1 controls the survival, proliferation, and differentiation of macrophages, which are recognized as scavengers and agents of the innate and the acquired immune systems. Because of their plasticity, macrophages are endowed with many other essential roles during development and tissue homeostasis. We present evidence that CSF-1 plays an important trophic role in postnatal organ growth and kidney repair. Notably, the injection of CSF-1 postnatally enhanced kidney weight and volume and was associated with increased numbers of tissue macrophages. Moreover, CSF-1 promotes postnatal renal repair in mice after ischemia-reperfusion injury by recruiting and influencing macrophages toward a reparative state. CSF-1 treatment rapidly accelerated renal repair with tubular epithelial cell replacement, attenuation of interstitial fibrosis, and functional recovery. Analysis of macrophages from CSF-1-treated kidneys showed increased expression of insulin-like growth factor-1 and anti-inflammatory genes that are known CSF-1 targets. Taken together, these data suggest that CSF-1 is important in kidney growth and the promotion of endogenous repair and resolution of inflammatory injury.

  1. Electric field stimulation through a biodegradable polypyrrole-co-polycaprolactone substrate enhances neural cell growth

    PubMed Central

    Nguyen, Hieu T; Wei, Claudia; Chow, Jacqueline K; Nguyen, Alvin; Coursen, Jeff; Sapp, Shawn; Luebben, Silvia; Chang, Emily; Ross, Robert; Schmidt, Christine E

    2014-01-01

    Nerve guidance conduits (NGCs) are FDA-approved devices used to bridge gaps across severed nerve cables and help direct axons sprouting from the proximal end toward the distal stump. In this paper we present the development of a novel electrically conductive, biodegradable NGC made from a polypyrrole-block-polycaprolactone (PPy-PCL) copolymer material laminated with poly(lactic-co-glycolic acid) (PLGA). The PPy-PCL has a bulk conductivity ranging 10–20 S/cm and loses 40 wt% after 7 months under physiologic conditions. Dorsal root ganglia (DRG) grown on flat PPy-PCL/PLGA material exposed to direct current electric fields (EF) of 100 mV/cm for 2 h increased axon growth by 13% (± 2%) towards either electrode of a 2-electrode setup, compared to control grown on identical substrates without EF exposure. Alternating current increased axon growth by 21% (± 3%) without an observable directional preference, compared to the same control group. The results from this study demonstrate PLGA-coated PPy-PCL is a unique biodegradable material that can deliver substrate EF stimulation to improve axon growth for peripheral nerve repair. PMID:23964001

  2. Electric field stimulation through a biodegradable polypyrrole-co-polycaprolactone substrate enhances neural cell growth.

    PubMed

    Nguyen, Hieu T; Sapp, Shawn; Wei, Claudia; Chow, Jacqueline K; Nguyen, Alvin; Coursen, Jeff; Luebben, Silvia; Chang, Emily; Ross, Robert; Schmidt, Christine E

    2014-08-01

    Nerve guidance conduits (NGCs) are FDA-approved devices used to bridge gaps across severed nerve cables and help direct axons sprouting from the proximal end toward the distal stump. In this article, we present the development of a novel electrically conductive, biodegradable NGC made from a polypyrrole-block-polycaprolactone (PPy-PCL) copolymer material laminated with poly(lactic-co-glycolic acid) (PLGA). The PPy-PCL has a bulk conductivity ranging 10-20 S/cm and loses 40 wt % after 7 months under physiologic conditions. Dorsal root ganglia (DRG) grown on flat PPy-PCL/PLGA material exposed to direct current electric fields (EF) of 100 mV/cm for 2 h increased axon growth by 13% (± 2%) toward either electrode of a 2-electrode setup, compared with control grown on identical substrates without EF exposure. Alternating current increased axon growth by 21% (±3%) without an observable directional preference, compared with the same control group. The results from this study demonstrate PLGA-coated PPy-PCL is a unique biodegradable material that can deliver substrate EF stimulation to improve axon growth for peripheral nerve repair.

  3. Growth hormone stimulates protein synthesis in bovine skeletal muscle cells without altering insulin-like growth factor-I mRNA expression.

    PubMed

    Ge, X; Yu, J; Jiang, H

    2012-04-01

    Growth hormone is a major stimulator of skeletal muscle growth in animals, including cattle. In this study, we determined whether GH stimulates skeletal muscle growth in cattle by direct stimulation of proliferation or fusion of myoblasts, by direct stimulation of protein synthesis, or by direct inhibition of protein degradation in myotubes. We also determined whether these direct effects of GH are mediated by IGF-I produced by myoblasts or myotubes. Satellite cells were isolated from cattle skeletal muscle and were allowed to proliferate as myoblasts or induced to fuse into myotubes in culture. Growth hormone at 10 and 100 ng/mL increased protein synthesis in myotubes (P < 0.05), but had no effect on protein degradation in myotubes or proliferation of myoblasts (P > 0.05). Insulin-like growth factor-I at 50 and 500 ng/mL stimulated protein synthesis (P < 0.01), and this effect of IGF-I was much greater than that of GH (P < 0.05). Besides stimulating protein synthesis, IGF-I at 50 and 500 ng/mL also inhibited protein degradation in myotubes (P < 0.01), and IGF-I at 500 ng/mL stimulated proliferation of myoblasts (P < 0.05). Neither GH nor IGF-I had effects on fusion of myoblasts into myotubes (P > 0.1). These data indicate that GH and IGF-I have largely different direct effects on bovine muscle cells. Growth hormone at 10 and 100 ng/mL had no effect on IGF-I mRNA expression in either myoblasts or myotubes (P > 0.1). This lack of effect was not because the cultured myoblasts or myotubes were not responsive to GH; GH receptor mRNA was detectable in them and the expression of the cytokine-inducible SH2-containing protein (CISH) gene, a well-established GH target gene, was increased by GH in bovine myoblasts (P < 0.05). Overall, the data suggest that GH stimulates skeletal muscle growth in cattle in part through stimulation of protein synthesis in the muscle and that this stimulation is not mediated through increased IGF-I mRNA expression in the muscle.

  4. Significant plant growth stimulation by composted as opposed to untreated Biochar

    NASA Astrophysics Data System (ADS)

    Kammann, Claudia; Messerschmidt, Nicole; Müller, Christoph; Steffens, Diedrich; Schmidt, Hans-Peter; Koyro, Hans-Werner

    2013-04-01

    The application of production-fresh, untreated biochar does not always result in yield improvements, in particular in temperate or boreal soils. Therefore the use of biochar for soil C sequestration, although desirable from a global change mitigation point of view, may never be implemented without proven and economically feasible pathways for biochar effects in agriculture. To investigate earlier reports of the beneficial effects of composting biochar (e.g. Fischer & Glaser, 2012) we conducted a fully replicated (n=3, +/- biochar) large-scale composting study at the Delinat Institute in Arbaz, Switzerland. The materials were manures (bovine, horse and chicken), straw, stone meal and composting was performed with our without +20 vol.% of a woody biochar (German Charcoal GmbH). Interestingly, the rotting temperature was significantly higher in the biochar-compost while C and N were retained to a certain extent. To investigate the effect of composting ("ageing") on biochar effects, a completely randomized full-factorial pot study was carried out in the greenhouse using the pseudo-cereal Chenopodium quinoa. The three factors used in the study were (I) type of biochar addition ("aged", "fresh", or zero BC), (II) addition of compost and (III) low and high application rates of a full NPK-fertilizer (equivalent to 28 and 140 kg N ha-1, NPK + micronutrients) in several doses. The growth medium was a poor loamy sand. Biochars and compost were all added at a rate of 2% (w/w) to the soil. From the start there was a considerable difference between the growth of Quinoa with the fresh compared to the aged biochar. The fresh biochar produced the well-known reduction in plant growth compared to the unamended control. This reduction was alleviated to a certain extent by the addition of either compost and/or increased fertilization. In contrast the co-composted biochar always resulted in a highly significant stimulation of the Quinoa yield (roots, shoots, inflorescences). This

  5. Phosphorylation and Activation of RhoA by ERK in Response to Epidermal Growth Factor Stimulation

    PubMed Central

    Tong, Junfeng; Li, Laiji; Ballermann, Barbara; Wang, Zhixiang

    2016-01-01

    The small GTPase RhoA has been implicated in various cellular activities, including the formation of stress fibers, cell motility, and cytokinesis. In addition to the canonical GTPase cycle, recent findings have suggested that phosphorylation further contributes to the tight regulation of Rho GTPases. Indeed, RhoA is phosphorylated on serine 188 (188S) by a number of protein kinases. We have recently reported that Rac1 is phosphorylated on threonine 108 (108T) by extracellular signal-regulated kinases (ERK) in response to epidermal growth factor (EGF) stimulation. Here, we provide evidence that RhoA is phosphorylated by ERK on 88S and 100T in response to EGF stimulation. We show that ERK interacts with RhoA and that this interaction is dependent on the ERK docking site (D-site) at the C-terminus of RhoA. EGF stimulation enhanced the activation of the endogenous RhoA. The phosphomimetic mutant, GFP-RhoA S88E/T100E, when transiently expressed in COS-7 cells, displayed higher GTP-binding than wild type RhoA. Moreover, the expression of GFP-RhoA S88E/T100E increased actin stress fiber formation in COS-7 cells, which is consistent with its higher activity. In contrast to Rac1, phosphorylation of RhoA by ERK does not target RhoA to the nucleus. Finally, we show that regardless of the phosphorylation status of RhoA and Rac1, substitution of the RhoA PBR with the Rac1 PBR targets RhoA to the nucleus and substitution of Rac1 PBR with RhoA PBR significantly reduces the nuclear localization of Rac1. In conclusion, ERK phosphorylates RhoA on 88S and 100T in response to EGF, which upregulates RhoA activity. PMID:26816343

  6. Testosterone inhibition of growth hormone release stimulated by a growth hormone secretagogue: studies in the rat and dog.

    PubMed

    Rigamonti, Antonello E; Cella, Silvano G; Giordani, Claudio; Bonomo, Sara M; Giunta, Marialuisa; Sartorio, Alessandro; Muller, Eugenio

    2006-01-01

    Anabolic steroids are frequently taken by athletes and bodybuilders together with recombinant human GH (rhGH), though there is some scientific evidence that the use of anabolic steroids reverses the rhGH-induced effects. Recently, we have shown that treatment with rhGH (0.2 IU/kg s.c., daily x 12 days) in the dog markedly reduced the canine GH (cGH) responses stimulated by EP51216, a GH secretagogue (GHS), evaluated after 3 and 5 daily rhGH injections, and that the inhibition was still present a few days after rhGH discontinuation. The aim of the present study was to evaluate in the dog the GH response to EP51216 (125 mug/kg i.v.) in a condition of enhanced androgenic function (i.e. acute injection or 15-day treatment with testosterone at the dose of 2 mg/kg i.m. on alternate days), and in the hypophysectomized rat the hypothalamic and hippocampal expression of ghrelin, the receptor of GHSs (GHS-R), GH-releasing hormone (GHRH) and somatostatin (SS) after specific hormonal replacement therapies (testosterone, 1 mg/kg/day s.c.; hydrocortisone, 500 mug/kg/day s.c.; rhGH, 400 mug/kg/day s.c.; 0.9% saline 0.1 ml/kg/day s.c.; x11 days). In the dog experiments, under baseline conditions, a single injection of EP51216 elicited an abrupt rise of plasma cGH. Twenty-four hours from the acute bolus injection of testosterone, C(max) and AUC(0-90) of the GHS-stimulated cGH response were significantly lower than baseline cGH response; 5 days later, there was still a significant decrease of either parameter versus the original values. Short-term treatment with testosterone markedly reduced the GHS-stimulated cGH responses evaluated during (5th bolus) and at the end (8th bolus) of testosterone treatment. Four and 8 days after testosterone withdrawal, the EP51216-stimulated cGH response was still significantly reduced when compared with that under baseline conditions. Plasma concentrations of insulin-like growth factor 1 (IGF-1) were stable until the 5th bolus of testosterone and

  7. Growth stimulation and proteomic studies of halococci from Permo-Triassic rock salt

    NASA Astrophysics Data System (ADS)

    Legat, A.; Gruber, C.; Stan-Lotter, H.

    2003-04-01

    Viable extremely halophilic archaebacteria were isolated from Austrian Permo-Triassic rock salt and identified as Halococcus species. Growth of these isolates was greatly stimulated by addition of sea salts, Alpine rock salt and rock salt from a Permian deposit in Carrickfergus, Northern Ireland (IS). One-dimensional whole cell protein patterns of strains Hcc. salifodinae and Hcc. dombrowskii were different whether cells were grown in the presence or absence of IS, which suggested influences by unknown components in the rock salt on halobacterial metabolism. Studies of the halococcal proteomes by two-dimensional gel electrophoresis (isoelectric focusing and sodium dodecylsulfate polyacrylamide gele electrophoresis) were begun and revealed differences in the fractions of higher and lower molecular weight components.

  8. High environmental iron concentrations stimulate adhesion and invasive growth of Schizosaccharomyces pombe.

    PubMed

    Prevorovský, Martin; Stanurová, Jana; Půta, Frantisek; Folk, Petr

    2009-04-01

    We have found that a high iron concentration in solid complete cultivation medium potentiates cell-cell and cell-surface adhesion of the fission yeast Schizosaccharomyces pombe. Spotted giant colonies grown on iron-rich media were found to be more compact and more resistant to washing than those grown on plates with a standard iron content. Furthermore, we have documented that excess environmental iron stimulates the invasive growth of S. pombe (and Saccharomyces cerevisiae). Three-dimensional, branched, washing-resistant structures composed mostly of elongated, but separate fission yeast cells, were formed within the solid agar medium. The degree of both adhesion and invasion displayed a specific, iron concentration-dependent response. Our results suggest a novel link between iron availability and the intensively studied and important fungal virulence factors, adhesion and invasion.

  9. Wnt7b stimulates embryonic lung growth by coordinately increasing the replication of epithelium and mesenchyme.

    PubMed

    Rajagopal, Jayaraj; Carroll, Thomas J; Guseh, J Sawalla; Bores, Sam A; Blank, Leah J; Anderson, William J; Yu, Jing; Zhou, Qiao; McMahon, Andrew P; Melton, Douglas A

    2008-05-01

    The effects of Wnt7b on lung development were examined using a conditional Wnt7b-null mouse. Wnt7b-null lungs are markedly hypoplastic, yet display largely normal patterning and cell differentiation. In contrast to findings in prior hypomorphic Wnt7b models, we find decreased replication of both developing epithelium and mesenchyme, without abnormalities of vascular smooth muscle development. We further demonstrate that Wnt7b signals to neighboring cells to activate both autocrine and paracrine canonical Wnt signaling cascades. In contrast to results from hypomorphic models, we show that Wnt7b modulates several important signaling pathways in the lung. Together, these cascades result in the coordinated proliferation of adjacent epithelial and mesenchymal cells to stimulate organ growth with few alterations in differentiation and patterning.

  10. Peripheral Nerve Regeneration Strategies: Electrically Stimulating Polymer Based Nerve Growth Conduits

    PubMed Central

    Anderson, Matthew; Shelke, Namdev B.; Manoukian, Ohan S.; Yu, Xiaojun; McCullough, Louise D.; Kumbar, Sangamesh G.

    2017-01-01

    Treatment of large peripheral nerve damages ranges from the use of an autologous nerve graft to a synthetic nerve growth conduit. Biological grafts, in spite of many merits, show several limitations in terms of availability and donor site morbidity, and outcomes are suboptimal due to fascicle mismatch, scarring, and fibrosis. Tissue engineered nerve graft substitutes utilize polymeric conduits in conjunction with cues both chemical and physical, cells alone and or in combination. The chemical and physical cues delivered through polymeric conduits play an important role and drive tissue regeneration. Electrical stimulation (ES) has been applied toward the repair and regeneration of various tissues such as muscle, tendon, nerve, and articular tissue both in laboratory and clinical settings. The underlying mechanisms that regulate cellular activities such as cell adhesion, proliferation, cell migration, protein production, and tissue regeneration following ES is not fully understood. Polymeric constructs that can carry the electrical stimulation along the length of the scaffold have been developed and characterized for possible nerve regeneration applications. We discuss the use of electrically conductive polymers and associated cell interaction, biocompatibility, tissue regeneration, and recent basic research for nerve regeneration. In conclusion, a multifunctional combinatorial device comprised of biomaterial, structural, functional, cellular, and molecular aspects may be the best way forward for effective peripheral nerve regeneration. PMID:27278739

  11. Sediment burial stimulates the growth and propagule production of Spartina alterniflora Loisel.

    NASA Astrophysics Data System (ADS)

    Deng, Zifa; An, Shuqing; Zhao, Congjiao; Chen, Lin; Zhou, Changfang; Zhi, Yingbiao; Li, Hongli

    2008-03-01

    positive feedback relationship between sedimentation and the growth of S. alterniflora. Thus, moderate sedimentation may stimulate the invasion of exotic species, S. alterniflora in coastal China.

  12. Phosphatidylinositol 4,5-Bisphosphate (PI(4,5)P2)-dependent Oligomerization of Fibroblast Growth Factor 2 (FGF2) Triggers the Formation of a Lipidic Membrane Pore Implicated in Unconventional Secretion*

    PubMed Central

    Steringer, Julia P.; Bleicken, Stephanie; Andreas, Helena; Zacherl, Sonja; Laussmann, Mareike; Temmerman, Koen; Contreras, F. Xabier; Bharat, Tanmay A. M.; Lechner, Johannes; Müller, Hans-Michael; Briggs, John A. G.; García-Sáez, Ana J.; Nickel, Walter

    2012-01-01

    Fibroblast growth factor 2 (FGF2) is a critical mitogen with a central role in specific steps of tumor-induced angiogenesis. It is known to be secreted by unconventional means bypassing the endoplasmic reticulum/Golgi-dependent secretory pathway. However, the mechanism of FGF2 membrane translocation into the extracellular space has remained elusive. Here, we show that phosphatidylinositol 4,5-bisphosphate-dependent membrane recruitment causes FGF2 to oligomerize, which in turn triggers the formation of a lipidic membrane pore with a putative toroidal structure. This process is strongly up-regulated by tyrosine phosphorylation of FGF2. Our findings explain key requirements of FGF2 secretion from living cells and suggest a novel self-sustained mechanism of protein translocation across membranes with a lipidic membrane pore being a transient translocation intermediate. PMID:22730382

  13. Thapsigargin induces rapid, transient growth inhibition and c-fos expression followed by sustained growth stimulation in mouse keratinocyte cultures.

    PubMed

    Harmon, C S; Ducote, J; Xiong, Y

    1996-08-01

    Although the sesquiterpene lactone thapsigargin has been shown to possess hyperplastic and tumor-promoting activities when applied topically to mouse skin in vivo, the cellular mechanism(s) which underlie these effects are unclear. We show here that thapsigargin treatment of Primary mouse epidermal keratinocytes increased intracellular free Ca2+ concentration (Cai) in a concentration-dependent manner. Thapsigargin induced a rapid, transient elevation in keratinocyte Cai, in part due to the release of Ca2+ from intracellular stores. This response was followed by a sustained elevation in Ca2+, resulting entirely from calcium influx. Thapsigargin elicited a biphasic effect on keratinocyte DNA synthesis: a rapid inhibitory effect (50-60% inhibition at 4-8 h), followed by a very marked and sustained elevation. Prolonged treatment of keratinocytes with thapsigargin at relatively high concentrations resulted in cytotoxicity (inhibition of neutral red uptake). The rapid antiproliferative effect of thapsigargin was not associated with cytotoxicity, as determined by either neutral red uptake or by trypan blue exclusion, and was not blocked by pretreatment with Ro 31-7349, a selective inhibitor of protein kinase C. The rapid antiproliferative effect of thapsigargin was associated with rapid, transient activation of keratinocyte c-fos expression and rapid inhibition of total protein synthesis. Taken together, these findings raise the possibility that the hyperplastic and tumor-promoting activities of thapsigargin on epidermis in vivo result from direct keratinocyte growth stimulation as a consequence of a prolonged elevation in levels of Cai.

  14. The multiple sclerosis drug fingolimod (FTY720) stimulates neuronal gene expression, axonal growth and regeneration.

    PubMed

    Anastasiadou, Sofia; Knöll, Bernd

    2016-05-01

    Fingolimod (FTY720) is a new generation oral treatment for multiple sclerosis (MS). So far, FTY720 was mainly considered to target trafficking of immune cells but not brain cells such as neurons. Herein, we analyzed FTY720's potential to directly alter neuronal function. In CNS neurons, we identified a FTY720 governed gene expression response. FTY720 upregulated immediate early genes (IEGs) encoding for neuronal activity associated transcription factors such as c-Fos, FosB, Egr1 and Egr2 and induced actin cytoskeleton associated genes (actin isoforms, tropomyosin, calponin). Stimulation of primary neurons with FTY720 enhanced neurite growth and altered growth cone morphology. In accordance, FTY720 enhanced axon regeneration in mice upon facial nerve axotomy. We identified components of a FTY720 engaged signaling cascade including S1P receptors, G12/13G-proteins, RhoA-GTPases and the transcription factors SRF/MRTF. In summary, we uncovered a broader cellular and therapeutic operation mode of FTY720, suggesting beneficial FTY720 effects also on CNS neurons during MS therapy and for treatment of other neurodegenerative diseases requiring neuroprotective and neurorestorative processes.

  15. BMP-2 Grafted nHA/PLGA Hybrid Nanofiber Scaffold Stimulates Osteoblastic Cells Growth

    PubMed Central

    Haider, Adnan; Kim, Sukyoung; Huh, Man-Woo; Kang, Inn-Kyu

    2015-01-01

    Biomaterials play a pivotal role in regenerative medicine, which aims to regenerate and replace lost/degenerated tissues or organs. Natural bone is a hierarchical structure, comprised of various cells having specific functions that are regulated by sophisticated mechanisms. However, the regulation of the normal functions in damaged or injured cells is disrupted. In order to address this problem, we attempted to artificially generate a scaffold for mimicking the characteristics of the extracellular matrix at the nanoscale level to trigger osteoblastic cell growth. For this purpose, we have chemically grafted bone morphogenetic protein (BMP-2) onto the surface of L-glutamic acid modified hydroxyapatite incorporated into the PLGA nanofiber matrix. After extensive characterization using various spectroscopic techniques, the BMP-g-nHA/PLGA hybrid nanofiber scaffolds were subjected to various in vitro cytocompatibility tests. The results indicated that BMP-2 on BMP-g-nHA/PLGA hybrid nanofiber scaffolds greatly stimulated osteoblastic cells growth, contrary to the nHA/PLGA and pristine PLGA nanofiber scaffold, which are used as control. These results suggest that BMP-g-nHA/PLGA hybrid nanofiber scaffold can be used as a nanodrug carrier for the controlled and targeted delivery of BMP-2, which will open new possibilities for enhancing bone tissue regeneration and will help in the treatment of various bone-related diseases in the future. PMID:26539477

  16. Stimulation of prostaglandin E/sub 2/ production by phorbol esters and epidermal growth factor in porcine thyroid cells

    SciTech Connect

    Kasai, K.; Hiraiwa, M.; Emoto, T.; Akimoto, K.; Takaoka, T.; Shimoda, S.I.

    1987-07-13

    Effects of phorbol esters and epidermal growth factor (EGF) on prostaglandin E/sub 2/ production by cultured porcine thyroid cells were examined. Both phorbol 12-myristate 13-acetate (PMA) and EGF stimulated prostaglandin E/sub 2/ production by the cells in dose related fashion. PMA stimulated prostaglandin E/sub 2/ production over fifty-fold with the dose of 10/sup -7/ M compared with control. EGF (10/sup -7/ M) also stimulated it about ten-fold. The ED/sub 50/ values of PMA and EGF were respectively around 1 x 10/sup -9/ M and 5 x 10/sup -10/ M. Thyroid stimulating hormone (TSH), however, did not stimulate prostaglandin E/sub 2/ production from 1 to 24-h incubation. The release of radioactivity from (/sup 3/H)-arachidonic acid prelabeled cells was also stimulated by PMA and EGF, but not by TSH. These results indicate that both PMA and EGF are potent stimulators of prostaglandin E/sub 2/ production, associated with the activity to stimulate arachidonic acid release in porcine thyroid cells. 36 references, 2 figures, 1 table.

  17. Transforming growth factor-beta stimulates the expression of fibronectin by human keratinocytes.

    PubMed

    Wikner, N E; Persichitte, K A; Baskin, J B; Nielsen, L D; Clark, R A

    1988-09-01

    Transforming growth factor beta (TGF-beta) is a 25-kD protein which has regulatory activity over a variety of cell types. It is distinct from epidermal growth factor (EGF) and EGF analogs, and exerts its action via a distinct receptor. Its effect on proliferation or differentiation can be positive or negative depending on the cell type and the presence of other growth factors. It also modulates the expression of cellular products. TGF-beta causes fibroblasts to increase their production of the extracellular matrix components, fibronectin and collagen. Human keratinocytes (HK) are known to have TGF-beta receptors. We wished to study the effect of TGF-beta on the production of extracellular matrix proteins by human keratinocytes in culture. Human keratinocytes were grown in serum-free defined medium (MCDB-153) to about 70% confluence. Following a 16-h incubation in medium lacking EGF and TGF-beta, cells were incubated for 12 h in medium containing varying concentrations of EGF and TGF-beta. Cells were then labeled with 35S-methionine for 10 h in the same conditions. Labeled proteins from the medium were analyzed by SDS-PAGE and autoradiography. TGF-beta at 10 ng/ml induced a sixfold increase in the secretion of fibronectin, as well as an unidentified 50-kD protein. Thrombospondin production was also increased, but not over a generalized twofold increase in the production of all other proteins. EGF, at 10 ng/ml, caused a smaller additive effect. TGF-beta may be an important stimulator of extracellular matrix production by human keratinocytes.

  18. Stimulation of growth by proteorhodopsin phototrophy involves regulation of central metabolic pathways in marine planktonic bacteria

    PubMed Central

    Palovaara, Joakim; Akram, Neelam; Baltar, Federico; Bunse, Carina; Forsberg, Jeremy; Pedrós-Alió, Carlos; González, José M.; Pinhassi, Jarone

    2014-01-01

    Proteorhodopsin (PR) is present in half of surface ocean bacterioplankton, where its light-driven proton pumping provides energy to cells. Indeed, PR promotes growth or survival in different bacteria. However, the metabolic pathways mediating the light responses remain unknown. We analyzed growth of the PR-containing Dokdonia sp. MED134 (where light-stimulated growth had been found) in seawater with low concentrations of mixed [yeast extract and peptone (YEP)] or single (alanine, Ala) carbon compounds as models for rich and poor environments. We discovered changes in gene expression revealing a tightly regulated shift in central metabolic pathways between light and dark conditions. Bacteria showed relatively stronger light responses in Ala compared with YEP. Notably, carbon acquisition pathways shifted toward anaplerotic CO2 fixation in the light, contributing 31 ± 8% and 24 ± 6% of the carbon incorporated into biomass in Ala and YEP, respectively. Thus, MED134 was a facultative double mixotroph, i.e., photo- and chemotrophic for its energy source and using both bicarbonate and organic matter as carbon sources. Unexpectedly, relative expression of the glyoxylate shunt genes (isocitrate lyase and malate synthase) was >300-fold higher in the light—but only in Ala—contributing a more efficient use of carbon from organic compounds. We explored these findings in metagenomes and metatranscriptomes and observed similar prevalence of the glyoxylate shunt compared with PR genes and highest expression of the isocitrate lyase gene coinciding with highest solar irradiance. Thus, regulatory interactions between dissolved organic carbon quality and central metabolic pathways critically determine the fitness of surface ocean bacteria engaging in PR phototrophy. PMID:25136122

  19. Lactam formation increases receptor binding, adenylyl cyclase stimulation and bone growth stimulation by human parathyroid hormone (hPTH)(1-28)NH2.

    PubMed

    Whitfield, J F; Morley, P; Willick, G E; Isaacs, R J; MacLean, S; Ross, V; Barbier, J R; Divieti, P; Bringhurst, F R

    2000-05-01

    Human parathyroid hormone (1-28)NH2 [hPTH(1-28)NH2] is the smallest of the PTH fragments that can fully stimulate adenylyl cyclase in ROS 17/2 rat osteoblast-like osteosarcoma cells. This fragment has an IC50 of 110 nM for displacing 125I-[Nle8,18,Tyr34]bovine PTH(1-34)NH2 from HKRK B7 porcine kidney cells, which stably express 950,000 human type 1 PTH/PTH-related protein (PTHrP) receptors (PTH1Rs) per cell. It also has an EC50 of 23.9 nM for stimulating adenylyl cyclase in ROS 17/2 cells. Increasing the amphiphilicity of the alpha-helix in the residue 17-28 region by replacing Lys27 with Leu and stabilizing the helix by forming a lactam between Glu22 and Lys26 to produce the [Leu27]cyclo(Glu22-Lys26)hPTH(1-28)NH2 analog dramatically reduced the IC50 for displacing 125I-[Nle8,18,Tyr34]bPTH(1-34)NH2 from hPTH1Rs from 110 to 6 nM and dropped the EC50 for adenylyl cyclase stimulation in ROS 17/2 cells from 23.9 to 9.6 nM. These modifications also increased the osteogenic potency of hPTH(1-28)NH2. Thus, hPTH(1-28)NH2 did not significantly stimulate either femoral or vertebral trabecular bone growth in rats when injected daily at a dose of 5 nmol/100 g body weight for 6 weeks, beginning 2 weeks after ovariectomy (OVX), but it strongly stimulated the growth of trabeculae in the cancellous bone of the distal femurs and L5 vertebrae when injected at 25 nmol/100 g body weight. By contrast [Leu27]cyclo(Glu22-Lys26)hPTH(1-28)NH2 significantly stimulated trabecular bone growth when injected at 5 nmol/100 g of body weight. Thus, these modifications have brought the bone anabolic potency of hPTH(1-28)NH2 considerably closer to the potencies of the larger PTH peptides and analogs.

  20. No evidence for consistent long-term growth stimulation of 13 tropical tree species: results from tree-ring analysis.

    PubMed

    Groenendijk, Peter; van der Sleen, Peter; Vlam, Mart; Bunyavejchewin, Sarayudh; Bongers, Frans; Zuidema, Pieter A

    2015-10-01

    The important role of tropical forests in the global carbon cycle makes it imperative to assess changes in their carbon dynamics for accurate projections of future climate-vegetation feedbacks. Forest monitoring studies conducted over the past decades have found evidence for both increasing and decreasing growth rates of tropical forest trees. The limited duration of these studies restrained analyses to decadal scales, and it is still unclear whether growth changes occurred over longer time scales, as would be expected if CO2 -fertilization stimulated tree growth. Furthermore, studies have so far dealt with changes in biomass gain at forest-stand level, but insights into species-specific growth changes - that ultimately determine community-level responses - are lacking. Here, we analyse species-specific growth changes on a centennial scale, using growth data from tree-ring analysis for 13 tree species (~1300 trees), from three sites distributed across the tropics. We used an established (regional curve standardization) and a new (size-class isolation) growth-trend detection method and explicitly assessed the influence of biases on the trend detection. In addition, we assessed whether aggregated trends were present within and across study sites. We found evidence for decreasing growth rates over time for 8-10 species, whereas increases were noted for two species and one showed no trend. Additionally, we found evidence for weak aggregated growth decreases at the site in Thailand and when analysing all sites simultaneously. The observed growth reductions suggest deteriorating growth conditions, perhaps due to warming. However, other causes cannot be excluded, such as recovery from large-scale disturbances or changing forest dynamics. Our findings contrast growth patterns that would be expected if elevated CO2 would stimulate tree growth. These results suggest that commonly assumed growth increases of tropical forests may not occur, which could lead to erroneous

  1. Involvement of Connective Tissue Growth Factor (CTGF) in Insulin-like Growth Factor-I (IGF1) Stimulation of Proliferation of a Bovine Mammary Epithelial Cell Line

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insulin-like growth factor I (IGF1) plays an important role in mammary gland development and lactation in part by stimulating proliferation of the milk-producing epithelial cells. In this study, we used the bovine mammary epithelial cell line MAC-T cells as a model to understand the mechanism by whi...

  2. Growth Inhibition and Stimulation of Shewanella oneidensis MR-1 by Surfactants and Calcium Polysulfide

    SciTech Connect

    Bailey, Kathryn L.; Tilton, Fred A.; Jansik, Danielle P.; Ergas, Sarina J.; Marshall, Matthew J.; Miracle, Ann L.; Wellman, Dawn M.

    2012-06-14

    Foam delivery technology (FDT) uses surfactant based foam to immobilize subsurface contaminants in situ. Where traditional approaches are impractical, FDT has the potential to overcome many of the technical challenges facing the remediation of contaminated deep vadose zone environments. However, little is known about the effects these reactive chemicals may have on microorganisms inhabiting the contaminated subsurface. In addition, there are currently no standard assays to assess microbial responses to subsurface remedial treatments while these agents are under development. The objective of this study was to develop a rapid laboratory assay to assess the potential growth inhibition and/or stimulation of microorganisms following exposure to candidate FDT components. Calcium polysulfide (CPS) and several surfactants (i.e. sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (CAPB) and NINOL40-CO) have diverse chemistries and are candidate components of FDT. Shewanella oneidensis MR-1 cultures were exposed to a range of concentrations of these chemicals to determine the minimum bactericidal concentration (MBC) and the growth and viability potential of these components. Concentrations of SDS higher than 700 {micro}M were toxic to S. oneidensis MR-1 growth over the course of four days of exposure. The relative acute toxicity order for these compounds was SDS>>CPS>>NINOL40-CO>SLES-CAPB. Dose dependent growth decreases (20 to 100 mM) were observed in the CAPB and SLES treated cultures and both CPS and NINOL 40-CO were toxic at all concentrations tested (1.45 to 7.25 mM CPS). Both SLES (20 to 100 mM) and SDS at lower concentrations (20 to 500 {micro}M) were stimulatory to S. oneidensis MR-1 indicating a capacity to be used as a carbon source. These studies also identified potentially key component characteristics, such as precipitate formation and oxygen availability, which may prove valuable in assessing the response of subsurface

  3. Protein kinase C activators suppress stimulation of capillary endothelial cell growth by angiogenic endothelial mitogens

    PubMed Central

    1987-01-01

    The intracellular events regulating endothelial cell proliferation and organization into formalized capillaries are not known. We report that the protein kinase C activator beta-phorbol 12,13-dibutyrate (PDBu) suppresses bovine capillary endothelial (BCE) cell proliferation (K50 = 6 +/- 4 nM) and DNA synthesis in response to human hepatoma-derived growth factor, an angiogenic endothelial mitogen. In contrast, PDBu has no effect on the proliferation of bovine aortic endothelial cells and is mitogenic for bovine aortic smooth muscle and BALB/c 3T3 cells. Several observations indicate that the inhibition of human hepatoma- derived growth factor-stimulated BCE cell growth by PDBu is mediated through protein kinase C. Different phorbol compounds inhibit BCE cell growth according to their potencies as protein kinase C activators (12- O-tetradecanoylphorbol 13-acetate greater than PDBu much greater than beta-phorbol 12,13-diacetate much much greater than beta-phorbol; alpha- phorbol 12,13-dibutyrate; alpha-phorbol 12,13-didecanoate). PDBu binds to a single class of specific, saturable sites on the BCE cell with an apparent Kd of 8 nM, in agreement with reported affinities of PDBu for protein kinase C in other systems. Specific binding of PDBu to BCE cells is displaced by sn-1,2-dioctanoylglycerol, a protein kinase C activator and an analog of the putative second messenger activating this kinase in vivo. The weak protein kinase C activator, sn-1,2- dibutyrylglycerol, does not affect PDBu binding. A cytosolic extract from BCE cells contains a calcium/phosphatidylserine-dependent protein kinase that is activated by sn-1,2-dioctanoylglycerol and PDBu, but not by beta-phorbol. These findings indicate that protein kinase C activation can cause capillary endothelial cells to become desensitized to angiogenic endothelial mitogens. This intracellular regulatory mechanism might be invoked during certain phases of angiogenesis, for example when proliferating endothelial cells become

  4. Growth inhibition and stimulation of Shewanella oneidensis MR-1 by surfactants and calcium polysulfide.

    PubMed

    Bailey, Kathryn L; Tilton, Fred; Jansik, Danielle P; Ergas, Sarina J; Marshall, Matthew J; Miracle, Ann L; Wellman, Dawn M

    2012-06-01

    Foam delivery technology (FDT) uses surfactant based foam to immobilize subsurface contaminants in situ. Where traditional approaches are impractical, FDT has the potential to overcome many of the technical challenges facing the remediation of contaminated deep vadose zone environments. However, little is known about the effects these reactive chemicals may have on microorganisms inhabiting the contaminated subsurface. In addition, there are currently no standard assays to assess microbial responses to subsurface remedial treatments while these agents are under development. The objective of this study was to develop a rapid laboratory assay to assess the potential growth inhibition and/or stimulation of microorganisms following exposure to candidate FDT components. Calcium polysulfide (CPS) and several surfactants (i.e. sodium laureth sulfate (SLES), sodium dodecyl sulfate (SDS), cocamidopropyl betaine (CAPB) and NINOL40-CO) have diverse chemistries and are candidate components of FDT. Shewanella oneidensis MR-1 cultures were exposed to a range of concentrations of these chemicals to determine the minimum bactericidal concentration (MBC) and the growth and viability potential of these components. Concentrations of SDS higher than 700 μM were toxic to S. oneidensis MR-1 growth over the course of four days of exposure. The relative acute toxicity order for these compounds was SDS > CPS > NINOL 40-CO>SLES≥CAPB. Dose dependent growth decreases (20-100mM) were observed in the CAPB and SLES treated cultures and both CPS and NINOL 40-CO were toxic at all concentrations tested (1.45-7.25 mM CPS). Both SLES (20-100mM) and SDS at lower concentrations (20-500 μM) were stimulatory to S. oneidensis MR-1 indicating a capacity to be used as a carbon source. These studies also identified potentially key component characteristics, such as precipitate formation and oxygen availability, which may prove valuable in assessing the response of subsurface microorganisms. This benchtop

  5. [Stimulation and inhibition of Escherichia coli cell growth during cultivation in the catholyte and anolyte of culture medium].

    PubMed

    Muroshnikov, A I

    2002-01-01

    The effect of pretreatment of growth medium M-9 with direct electric current in the cathode and the anode compartments of a diaphragm electrolyzer on the growth of Escherichia coli cells was studied. The cells were cultured separately in the catholyte and the anolyte of the growth medium. The cell growth was registered as a change in optical density of the culture suspension by the method of turbidimetry. It was found that cells grown in the catholyte at a temperature of 37 degrees C yielded a 20-30% increase in amount as compared to the control. No cell growth was observed in the anolyte, and a part of the initial cells were lysed. Possible mechanisms of stimulation and inhibition of cell growth and the reasons of discrepancies in the earlier published data are discussed.

  6. Growth in Coculture Stimulates Metabolism of the Phenylurea Herbicide Isoproturon by Sphingomonas sp. Strain SRS2

    PubMed Central

    Sørensen, Sebastian R.; Ronen, Zeev; Aamand, Jens

    2002-01-01

    Metabolism of the phenylurea herbicide isoproturon by Sphingomonas sp. strain SRS2 was significantly enhanced when the strain was grown in coculture with a soil bacterium (designated strain SRS1). Both members of this consortium were isolated from a highly enriched isoproturon-degrading culture derived from an agricultural soil previously treated regularly with the herbicide. Based on analysis of the 16S rRNA gene, strain SRS1 was assigned to the β-subdivision of the proteobacteria and probably represents a new genus. Strain SRS1 was unable to degrade either isoproturon or its known metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, or 4-isopropyl-aniline. Pure culture studies indicate that Sphingomonas sp. SRS2 is auxotrophic and requires components supplied by association with other soil bacteria. A specific mixture of amino acids appeared to meet these requirements, and it was shown that methionine was essential for Sphingomonas sp. SRS2. This suggests that strain SRS1 supplies amino acids to Sphingomonas sp. SRS2, thereby leading to rapid metabolism of 14C-labeled isoproturon to 14CO2 and corresponding growth of strain SRS2. Proliferation of strain SRS1 suggests that isoproturon metabolism by Sphingomonas sp. SRS2 provides unknown metabolites or cell debris that supports growth of strain SRS1. The role of strain SRS1 in the consortium was not ubiquitous among soil bacteria; however, the indigenous soil microflora and some strains from culture collections also stimulate isoproturon metabolism by Sphingomonas sp. strain SRS2 to a similar extent. PMID:12089031

  7. Vascular endothelial growth factor directly stimulates tumour cell proliferation in non-small cell lung cancer.

    PubMed

    Devery, Aoife M; Wadekar, Rekha; Bokobza, Sivan M; Weber, Anika M; Jiang, Yanyan; Ryan, Anderson J

    2015-09-01

    Vascular endothelial growth factor (VEGF) is a key stimulator of physiological and pathological angiogenesis. VEGF signals primarily through VEGF receptor 2 (VEGFR2), a receptor tyrosine kinase whose expression is found predominantly on endothelial cells. The purpose of this study was to determine the role of VEGFR2 expression in NSCLC cells. NSCLC cells and tissue sections were stained for VEGFR2 expression by immunohistochemistry (IHC). Immunoblotting and ELISA were used to determine the activation and inhibition of VEGFR2 and its downstream signalling pathways. Five-day proliferation assays were carried out in the presence or absence of VEGF. IHC analysis of NSCLC demonstrated tumour cell VEGFR2 expression in 20% of samples. Immunoblot analysis showed expression of VEGFR2 protein in 3/8 NSCLC cell lines that correlated with VEGFR2 mRNA expression levels. VEGF-dependent VEGFR2 activation was apparent in NSCLC cells, and was associated with increased tumor cell proliferation. Cediranib treatment or siRNA against VEGFR2 inhibited VEGF-dependent increases in cell proliferation. Inhibition of VEGFR2 tyrosine kinase activity using cediranib was more effective than inhibition of AKT (MK2206) or MEK (AZD6244) for overcoming VEGFR2-driven cell proliferation. VEGF treatment did not affect cell survival following treatment with radiation, cisplatin, docetaxel or gemcitabine. Our data suggest that a subset of NSCLC tumour cells express functional VEGFR2 which can act to promote VEGF-dependent tumour cell growth. In this tumour subset, therapies targeting VEGFR2 signalling, such as cediranib, have the potential to inhibit both tumour cell proliferation and angiogenesis.

  8. Immunocytochemical localization of latent transforming growth factor-beta1 activation by stimulated macrophages

    NASA Technical Reports Server (NTRS)

    Chong, H.; Vodovotz, Y.; Cox, G. W.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1999-01-01

    Transforming growth factor-beta1 (TGF-beta) is secreted in a latent form consisting of mature TGF-beta noncovalently associated with its amino-terminal propeptide, which is called latency associated peptide (LAP). Biological activity depends upon the release of TGF-beta from the latent complex following extracellular activation, which appears to be the key regulatory mechanism controlling TGF-beta action. We have identified two events associated with latent TGF-beta (LTGF-beta) activation in vivo: increased immunoreactivity of certain antibodies that specifically detect TGF-beta concomitant with decreased immunoreactivity of antibodies to LAP. Macrophages stimulated in vitro with interferon-gamma and lipopolysaccharide reportedly activate LTGF-beta via cell membrane-bound protease activity. We show through dual immunostaining of paraformaldehyde-fixed macrophages that such physiological TGF-beta activation is accompanied by a loss of LAP immunoreactivity with concomitant revelation of TGF-beta epitopes. The induction of TGF-beta immunoreactivity colocalized with immunoreactive betaglycan/RIII in activated macrophages, suggesting that LTGF-beta activation occurs on the cell surface. Confocal microscopy of metabolically active macrophages incubated with antibodies to TGF-beta and betaglycan/RIII prior to fixation supported the localization of activation to the cell surface. The ability to specifically detect and localize LTGF-beta activation provides an important tool for studies of its regulation.

  9. Arecoline-stimulated connective tissue growth factor production in human buccal mucosal fibroblasts: Modulation by curcumin.

    PubMed

    Deng, Yi-Ting; Chen, Hsin-Ming; Cheng, Shih-Jung; Chiang, Chun-Pin; Kuo, Mark Yen-Ping

    2009-09-01

    Connective tissue growth factor (CTGF) is associated with the onset and progression of fibrosis in many human tissues. Areca nut (AN) chewing is the most important etiological factor in the pathogenesis of oral submucous fibrosis (OSF). We immunohistochemically examined the expression of CTGF protein in 20 cases of OSF and found positive CTGF staining in fibroblasts and endothelial cells in all cases. Western blot analysis showed that arecoline, a main alkaloid found in AN, stimulated CTGF synthesis in a dose- and time-dependent manner in buccal mucosal fibroblasts. Constitutive overexpression of CTGF during AN chewing may enhance the fibrotic activity in OSF and play a role in the pathogenesis of OSF. Pretreatment with NF-kappaB inhibitor Bay 11-7082, JNK inhibitor SP600125, p38 MAPK inhibitor SB203580 and antioxidant N-acetyl-l-cysteine, but not ERK inhibitor PD98059, significantly reduced arecoline-induced CTGF synthesis. Furthermore, curcumin completely inhibited arecoline-induced CTGF synthesis and the inhibition is dose-dependent. These results indicated that arecoline-induced CTGF synthesis was mediated by ROS, NF-kappaB, JNK, P38 MAPK pathways and curcumin could be a useful agent in controlling OSF.

  10. Electrical stimulation drives chondrogenesis of mesenchymal stem cells in the absence of exogenous growth factors

    PubMed Central

    Kwon, Hyuck Joon; Lee, Gyu Seok; Chun, Honggu

    2016-01-01

    Electrical stimulation (ES) is known to guide the development and regeneration of many tissues. However, although preclinical and clinical studies have demonstrated superior effects of ES on cartilage repair, the effects of ES on chondrogenesis remain elusive. Since mesenchyme stem cells (MSCs) have high therapeutic potential for cartilage regeneration, we investigated the actions of ES during chondrogenesis of MSCs. Herein, we demonstrate for the first time that ES enhances expression levels of chondrogenic markers, such as type II collagen, aggrecan, and Sox9, and decreases type I collagen levels, thereby inducing differentiation of MSCs into hyaline chondrogenic cells without the addition of exogenous growth factors. ES also induced MSC condensation and subsequent chondrogenesis by driving Ca2+/ATP oscillations, which are known to be essential for prechondrogenic condensation. In subsequent experiments, the effects of ES on ATP oscillations and chondrogenesis were dependent on extracellular ATP signaling via P2X4 receptors, and ES induced significant increases in TGF-β1 and BMP2 expression. However, the inhibition of TGF-β signaling blocked ES-driven condensation, whereas the inhibition of BMP signaling did not, indicating that TGF-β signaling but not BMP signaling mediates ES-driven condensation. These findings may contribute to the development of electrotherapeutic strategies for cartilage repair using MSCs. PMID:28004813

  11. FINE STRUCTURAL ALTERATIONS OF INTERPHASE NUCLEI OF LYMPHOCYTES STIMULATED TO GROWTH ACTIVITY IN VITRO

    PubMed Central

    Tokuyasu, K.; Madden, S. C.; Zeldis, L. J.

    1968-01-01

    This report describes fine structural changes of interphase nuclei of human peripheral blood lymphocytes stimulated to growth by short-term culture with phytohemagglutinin. Chromatin is found highly labile, its changes accompanying the sequential increases of RNA and DNA synthesis which are known to occur in lymphocyte cultures. In "resting" lymphocytes, abundant condensed chromatin appears as a network of large and small aggregates. Early in the response to phytohemagglutinin, small aggregates disappear during increase of diffuse chromatin regions. Small aggregates soon reappear, probably resulting from disaggregation of large masses of condensed chromatin. Loosened and highly dispersed forms then appear prior to the formation of prophase chromosomes. The loosened state is found by radioautography to be most active in DNA synthesis. Small nucleoli of resting lymphocytes have concentric agranular, fibrillar, and granular zones with small amounts of intranucleolar chromatin. Enlarging interphase nucleoli change chiefly (1) by increase in amount of intranucleolar chromatin and alteration of its state of aggregation and (2) by increase in granular components in close association with fibrillar components. PMID:5699935

  12. Reappraisal of bovril as a source of arginine in the arginine stimulation test for growth hormone deficiency.

    PubMed

    Loh, H H; Norlela, S; Nor Azmi, K

    2015-06-01

    The purpose of this case study is to report the use of oral Bovril (a food supplement which contains arginine) as an alternative test for growth hormone stimulation test. We performed oral Bovril test in 3 patients -- one with suspected growth hormone deficiency in whom insulin tolerance test could not be performed (subject A), one sex-matched control (subject B), and one with confirmed growth hormone deficiency (subject C). 14g/m(2) of oral Bovril was mixed with 150ml of warm water and was given to all three subjects. Blood for growth hormone was taken at baseline, and every 30 minutes till 150 minutes after ingestion of oral Bovril. The ingestion of oral Bovril showed a positive response in subjects A and B, with highest growth hormone levels of 28.4mIU/L and 42.0mIU/L respectively at 150 minutes. Subject C had suppressed growth hormone throughout the test. Oral Bovril is readily available and is a safe alternative for standard growth hormone stimulation test.

  13. Lysophosphatidic acid-induced ADAM12 expression mediates human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth.

    PubMed

    Do, Eun Kyoung; Kim, Young Mi; Heo, Soon Chul; Kwon, Yang Woo; Shin, Sang Hun; Suh, Dong-Soo; Kim, Ki-Hyung; Yoon, Man-Soo; Kim, Jae Ho

    2012-11-01

    Lysophosphatidic acid (LPA) is involved in mesenchymal stem cell-stimulated tumor growth in vivo. However, the molecular mechanism by which mesenchymal stem cells promote tumorigenesis remains elusive. In the present study, we demonstrate that conditioned medium from A549 human lung adenocarcinoma cells (A549 CM) induced the expression of ADAM12, a disintegrin and metalloproteases family member, in human adipose tissue-derived mesenchymal stem cells (hASCs). A549 CM-stimulated ADAM12 expression was abrogated by pretreatment of hASCs with the LPA receptor 1 inhibitor Ki16425 or by small interfering RNA-mediated silencing of LPA receptor 1, suggesting a key role for the LPA-LPA receptor 1 signaling axis in A549 CM-stimulated ADAM12 expression. Silencing of ADAM12 expression using small interfering RNA or short hairpin RNA abrogated LPA-induced expression of both α-smooth muscle actin, a marker of carcinoma-associated fibroblasts, and ADAM12 in hASCs. Using a xenograft transplantation model of A549 cells, we demonstrated that silencing of ADAM12 inhibited the hASC-stimulated in vivo growth of A549 xenograft tumors and the differentiation of transplanted hASCs to α-smooth muscle actin-positive carcinoma-associated fibroblasts. LPA-conditioned medium from hASCs induced the adhesion of A549 cells and silencing of ADAM12 inhibited LPA-induced expression of extracellular matrix proteins, periostin and βig-h3, in hASCs and LPA-conditioned medium-stimulated adhesion of A549 cells. These results suggest a pivotal role for LPA-stimulated ADAM12 expression in tumor growth and the differentiation of hASCs to carcinoma-associated fibroblasts expressing α-smooth muscle actin, periostin, and βig-h3.

  14. Angiotensin III stimulates ERK1/2 mitogen-activated protein kinases and astrocyte growth in cultured rat astrocytes.

    PubMed

    Clark, Michelle A; Tran, Hsieu; Nguyen, Chinh

    2011-10-01

    Angiotensin (Ang) III is a biologically active metabolite of Ang II with similar effects and receptor binding properties as Ang II. Most Ang III studies delineate physiological effects of the peptide but, the intracellular pathways leading to the actions are unknown and are a focus of these studies. We investigated in cultured brainstem and cerebellum rat astrocytes whether Ang III stimulates ERK1/2 mitogen activated protein (MAP) kinases and astrocyte growth. Ang III significantly stimulated ERK1/2 MAP kinases in a dose- and time-dependent manner. The maximal stimulation occurred with 100 nM Ang III (2.8±0.3 and 2.3±0.1-fold over basal, in brainstem and cerebellum astrocytes, respectively). This stimulation occurred as early as 1 min, and was sustained for at least 15 min. Moreover, inhibition of the ERK1/2 MAP kinase pathway by 10 μM PD98059 attenuated Ang III-induced ERK1/2 phosphorylation. Ang III induction of ERK1/2 occurred via stimulation of the Ang AT(1) receptor since pretreatment with 10 μM Losartan, a selective AT(1) receptor blocker, prevented Ang III-induced ERK1/2 phosphorylation. The selective AT(2) Ang receptor blocker PD123319 was ineffective. Comparable to Ang II, Ang III also stimulated astrocyte growth in a concentration-dependent manner, an effect that occurred via activation of the AT(1) receptor as well. These findings suggest that Ang III has similar effects as Ang II in astrocytes since it rapidly stimulates the phosphorylation of the ERK1/2 MAP kinases and induces astrocyte proliferation through activation of the AT(1) receptor. These studies are important in establishing signaling pathways for Ang III and provide validation of the central role of Ang III.

  15. Integrin α6β4 Promotes Autocrine Epidermal Growth Factor Receptor (EGFR) Signaling to Stimulate Migration and Invasion toward Hepatocyte Growth Factor (HGF).

    PubMed

    Carpenter, Brittany L; Chen, Min; Knifley, Teresa; Davis, Kelley A; Harrison, Susan M W; Stewart, Rachel L; O'Connor, Kathleen L

    2015-11-06

    Integrin α6β4 is up-regulated in pancreatic adenocarcinomas where it contributes to carcinoma cell invasion by altering the transcriptome. In this study, we found that integrin α6β4 up-regulates several genes in the epidermal growth factor receptor (EGFR) pathway, including amphiregulin (AREG), epiregulin (EREG), and ectodomain cleavage protease MMP1, which is mediated by promoter demethylation and NFAT5. The correlation of these genes with integrin α6β4 was confirmed in The Cancer Genome Atlas Pancreatic Cancer Database. Based on previous observations that integrin α6β4 cooperates with c-Met in pancreatic cancers, we examined the impact of EGFR signaling on hepatocyte growth factor (HGF)-stimulated migration and invasion. We found that AREG and EREG were required for autocrine EGFR signaling, as knocking down either ligand inhibited HGF-mediated migration and invasion. We further determined that HGF induced secretion of AREG, which is dependent on integrin-growth factor signaling pathways, including MAPK, PI3K, and PKC. Moreover, matrix metalloproteinase activity and integrin α6β4 signaling were required for AREG secretion. Blocking EGFR signaling with EGFR-specific antibodies or an EGFR tyrosine kinase inhibitor hindered HGF-stimulated pancreatic carcinoma cell chemotaxis and invasive growth in three-dimensional culture. Finally, we found that EGFR was phosphorylated in response to HGF stimulation that is dependent on EGFR kinase activity; however, c-Met phosphorylation in response to HGF was unaffected by EGFR signaling. Taken together, these data illustrate that integrin α6β4 stimulates invasion by promoting autocrine EGFR signaling through transcriptional up-regulation of key EGFR family members and by facilitating HGF-stimulated EGFR ligand secretion. These signaling events, in turn, promote pancreatic carcinoma migration and invasion.

  16. Epidermal growth factor stimulates Rac activation through Src and phosphatidylinositol 3-kinase to promote colonic epithelial cell migration.

    PubMed

    Dise, Rebecca S; Frey, Mark R; Whitehead, Robert H; Polk, D Brent

    2008-01-01

    Regulated intestinal epithelial cell migration plays a key role in wound healing and maintenance of a healthy gastrointestinal tract. Epidermal growth factor (EGF) stimulates cell migration and wound closure in intestinal epithelial cells through incompletely understood mechanisms. In this study we investigated the role of the small GTPase Rac in EGF-induced cell migration using an in vitro wound-healing assay. In mouse colonic epithelial (MCE) cell lines, EGF-stimulated wound closure was accompanied by a doubling of the number of cells containing lamellipodial extensions at the wound margin, increased Rac membrane translocation in cells at the wound margin, and rapid Rac activation. Either Rac1 small interfering (si)RNA or a Rac1 inhibitor completely blocked EGF-stimulated wound closure. Whereas EGF failed to activate Rac in colon cells from EGF receptor (EGFR) knockout mice, stable expression of wild-type EGFR restored EGF-stimulated Rac activation and migration. Pharmacological inhibition of either phosphatidylinositol 3-kinase (PI3K) or Src family kinases reduced EGF-stimulated Rac activation. Cotreatment of cells with both inhibitors completely blocked EGF-stimulated Rac activation and localization to the leading edge of cells and lamellipodial extension. Our results present a novel mechanism by which the PI3K and Src signaling cascades cooperate to activate Rac and promote intestinal epithelial cell migration downstream of EGFR.

  17. Metal: ATP characteristics of insulin- and epidermal growth factor-stimulated phosphorylation in detergent extracts of rat liver plasma membranes.

    PubMed

    Uhing, R J; Exton, J H

    1986-09-01

    The metal: ATP characteristics of insulin- and epidermal growth factor-(EGF)-stimulated protein kinase activities were examined in Nonidet P40 extracts of rat liver plasma membranes. The two kinase activities were capable of utilizing either manganese or magnesium, although differences were observed. Insulin-stimulated 32P incorporation into an Mr 95 000 protein exhibited a higher affinity for ATP in the presence of manganese compared to magnesium. At 200 microM ATP, insulin stimulated 32P incorporation into the Mr 95 000 protein 3- to 5-fold after 5 min in the presence of either metal. At 1 mM ATP, insulin-stimulated 32P incorporation was significantly greater in the presence of magnesium. In contrast, EGF-stimulated 32P incorporation into an Mr 170 000 protein exhibited similar ATP dependencies in the presence of magnesium or manganese. Basal phosphorylation of the Mr 170 000 protein was 2- to 3-fold higher in the presence of manganese, however. Since the higher basal phosphorylation persisted after chromatography on wheat germ lectin-Sepharose, it may represent an inherent activity of the receptor kinase. In the presence of magnesium: ATP, low concentrations of manganese enhanced both insulin- and EGF-stimulated phosphorylation of angiotensin II suggesting involvement of a second metal binding site which regulates the kinase activity. The results presented show major differences in the metal: ATP properties of the two major hormonally regulated protein kinase activities observed in detergent-extracted liver membranes.

  18. Epigenetic inhibition of miR-663b by long non-coding RNA HOTAIR promotes pancreatic cancer cell proliferation via up-regulation of insulin-like growth factor 2

    PubMed Central

    Chen, Xuemin; Sun, Donglin; Chen, Tongbing; Peng, Yan; Zhu, Feng; Jiang, Yong; He, Xiaozhou

    2016-01-01

    Pancreatic cancer is one of the most deadly cancers with a poor prognosis. Although microRNAs are involving in the carcinogenesis and development of pancreatic cancer, little information is known regarding the role of miR-663b in pancreatic cancer. In this study, the expression of miR-663b in pancreatic cancer cells was down-regulated by hypermethylation in its putative promoter region, and overexpression of miR-663b repressed cell proliferation, invasion and migration, and induced apoptosis in pancreatic cancer cells. Bioinformatics analysis, luciferase report assay and rescue experiments showed that insulin-like growth factor 2 (IGF2) was a direct target of miR-663b. Results from clinical samples showed that the expression level of miR-663b correlated with the pathological grading, and the expression of miR-663b was down-regulated and was inversely correlated with IGF2 expression level in pancreatic cancer tissues. More importantly, the long non-coding RNA, HOX transcript antisense RNA (HOTAIR), was up-regulated in both pancreatic cancer cells and tissues, and HOTAIR suppressed the expression of miR-663b in pancreatic cancer by histone modification on H3K4me3 and H3K27me3 on miR-663b promoter. Further in vivo studies demonstrated that the stable overexpression of miR-663b or knock-down of HOTAIR inhibited tumor growth and was associated with IGF2 expression. In summary, our studies demonstrated that miR-663b is epigenetically repressed by HOTAIR and exerts its tumor-suppressive function via targeting IGF2 in pancreatic cancer. PMID:27895308

  19. No growth stimulation of tropical trees by 150 years of CO2 fertilization but water-use efficiency increased

    NASA Astrophysics Data System (ADS)

    van der Sleen, Peter; Groenendijk, Peter; Vlam, Mart; Anten, Niels P. R.; Boom, Arnoud; Bongers, Frans; Pons, Thijs L.; Terburg, Gideon; Zuidema, Pieter A.

    2015-01-01

    The biomass of undisturbed tropical forests has likely increased in the past few decades, probably as a result of accelerated tree growth. Higher CO2 levels are expected to raise plant photosynthetic rates and enhance water-use efficiency, that is, the ratio of carbon assimilation through photosynthesis to water loss through transpiration. However, there is no evidence that these physiological responses do indeed stimulate tree growth in tropical forests. Here we present measurements of stable carbon isotopes and growth rings in the wood of 1,100 trees from Bolivia, Cameroon and Thailand. Measurements of carbon isotope fractions in the wood indicate that intrinsic water-use efficiency in both understorey and canopy trees increased by 30-35% over the past 150 years as atmospheric CO2 concentrations increased. However, we found no evidence for the suggested concurrent acceleration of individual tree growth when analysing the width of growth rings. We conclude that the widespread assumption of a CO2-induced stimulation of tropical tree growth may not be valid.

  20. Vasodilator-Stimulated Phosphoprotein Activity Is Required for Coxiella burnetii Growth in Human Macrophages

    PubMed Central

    Colonne, Punsiri M.; Winchell, Caylin G.; Graham, Joseph G.; Onyilagha, Frances I.; MacDonald, Laura J.; Doeppler, Heike R.; Storz, Peter; Kurten, Richard C.; Beare, Paul A.; Voth, Daniel E.

    2016-01-01

    Coxiella burnetii is an intracellular bacterial pathogen that causes human Q fever, an acute flu-like illness that can progress to chronic endocarditis and liver and bone infections. Humans are typically infected by aerosol-mediated transmission, and C. burnetii initially targets alveolar macrophages wherein the pathogen replicates in a phagolysosome-like niche known as the parasitophorous vacuole (PV). C. burnetii manipulates host cAMP-dependent protein kinase (PKA) signaling to promote PV formation, cell survival, and bacterial replication. In this study, we identified the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) as a PKA substrate that is increasingly phosphorylated at S157 and S239 during C. burnetii infection. Avirulent and virulent C. burnetii triggered increased levels of phosphorylated VASP in macrophage-like THP-1 cells and primary human alveolar macrophages, and this event required the Cα subunit of PKA. VASP phosphorylation also required bacterial protein synthesis and secretion of effector proteins via a type IV secretion system, indicating the pathogen actively triggers prolonged VASP phosphorylation. Optimal PV formation and intracellular bacterial replication required VASP activity, as siRNA-mediated depletion of VASP reduced PV size and bacterial growth. Interestingly, ectopic expression of a phospho-mimetic VASP (S239E) mutant protein prevented optimal PV formation, whereas VASP (S157E) mutant expression had no effect. VASP (S239E) expression also prevented trafficking of bead-containing phagosomes to the PV, indicating proper VASP activity is critical for heterotypic fusion events that control PV expansion in macrophages. Finally, expression of dominant negative VASP (S157A) in C. burnetii-infected cells impaired PV formation, confirming importance of the protein for proper infection. This study provides the first evidence of VASP manipulation by an intravacuolar bacterial pathogen via activation of PKA in human

  1. Sulfated gastrin stimulates ghrelin and growth hormone release but inhibits insulin secretion in cattle.

    PubMed

    Zhao, Hongqiong; Yannaing, Swe; Thanthan, Sint; Kuwayama, Hideto

    2011-11-01

    This study was designed to determine the effects of gastrin on the circulating levels of ghrelin, growth hormone (GH), insulin, glucagon and glucose in ruminants. Two experiments were done in eight Holstein steers. Animals were randomly assigned to receive intravenous bolus injections: (1) 0.1% bovine serum albumin in saline as vehicle, 0.8, 4.0 and 20.0 μg/kg body weight (BW) of bovine sulfated gastrin-34; (2) vehicle, 0.53 μg/kg BW of bovine sulfated gastrin-17 alone or combined with 20.0 μg/kg BW of [D-Lys(3)]-GHRP-6, the selective antagonist of GHS-R1a. Blood samples were collected from -10 to 150 min relative to injection time. Concentrations of acyl and total ghrelin in response to gastrin-34 injection were significantly increased in a dose-dependent manner. Concentrations of GH were also markedly elevated by gastrin-34 injection; however, the effect of 20.0 μg/kg was weaker than that of 4.0 μg/kg. The three doses of gastrin-34 equally decreased insulin levels within 15 min and maintained the level until the time of last sampling. Gastrin-34 had no effect (P > 0.05) on the levels of glucagon and glucose. Levels of acyl ghrelin increased after administration of gastrin-17 alone or combined with [D-Lys(3)]-GHRP-6; however, [D-Lys(3)]-GHRP-6 did not block the elevation of GH by gastrin-17. The present results indicate that sulfated gastrin stimulates both ghrelin and GH release, but the GHS-R1a may not contribute to the release of GH by gastrin. Moreover, sulfated gastrin seems to indirectly maintain the homeostasis of blood glucose through the down-regulation of insulin in ruminants.

  2. Triennial growth symposium: Leucine acts as a nutrient signal to stimulate protein synthesis in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The postprandial increases in AA and insulin independently stimulate protein synthesis in skeletal muscle of piglets. Leucine is an important mediator of the response to AA. We have shown that the postprandial increase in leucine, but not isoleucine or valine, acutely stimulates muscle protein synth...

  3. Light-stimulated cell expansion in bean (Phaseolus vulgaris L.) leaves. I. Growth can occur without photosynthesis

    NASA Technical Reports Server (NTRS)

    Van Volkenburgh, E.; Cleland, R. E.

    1990-01-01

    Cell expansion in dicotyledonous leaves is strongly stimulated by bright white light (WL), at least in part as a result of light-induced acidification of the cell walls. It has been proposed that photosynthetic reactions are required for light-stimulated transport processes across plasma membranes of leaf cells, including proton excretion. The involvement of photosynthesis in growth and wall acidification of primary leaves of bean has been tested by inhibiting photosynthesis in two ways: by reducing chlorophyll content of intact plants with tentoxin (TX) and by treating leaf discs with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Exposure to bright WL stimulated growth of intact leaves of TX-treated plants. Discs excised from green as well as from TX-or DCMU-treated leaves also responded by growing faster in WL, as long as exogenous sucrose was supplied to the photosynthetically inhibited tissues. The WL caused acidification of the epidermal surface of intact TX-leaves, but acidification of the incubation medium by mesophyll cells only occurred when photosynthesis was not inhibited. It is concluded that light-stimulated cell enlargement of bean leaves, and the necessary acidification of epidermal cell walls, are mediated by a pigment other than chlorophyll. Light-induced proton excretion by mesophyll cells, on the other hand, may require both a photosynthetic product (or exogenous sugars) and a non-photosynthetic light effect.

  4. Epidermal growth factor-stimulated intestinal epithelial cell migration requires Src family kinase-dependent p38 MAPK signaling.

    PubMed

    Frey, Mark R; Golovin, Anastasia; Polk, D Brent

    2004-10-22

    Members of the epidermal growth factor (EGF) family of ligands and their receptors regulate migration and growth of intestinal epithelial cells. However, our understanding of the signal transduction pathways determining these responses is incomplete. In this study we tested the hypothesis that p38 is required for EGF-stimulated intestinal epithelial monolayer restitution. EGF-stimulated migration in a wound closure model required continuous presence of ligand for several hours for maximal response, suggesting a requirement for sustained signal transduction pathway activation. In this regard, prolonged exposure of cells to EGF activated p38 for up to 5 h. Furthermore genetic or pharmacological blockade of p38 signaling inhibited the ability of EGF to accelerate wound closure. Interestingly p38 inhibition was associated with increased EGF-stimulated ERK1/ERK2 phosphorylation and cell proliferation, suggesting that p38 regulates the balance of proliferation/migration signaling in response to EGF receptor activity. Activation of p38 in intestinal epithelial cells through EGF receptor was abolished by blockade of Src family tyrosine kinase signaling but not inhibition of phosphatidylinositol 3-kinase or protein kinase C. Taken together, these data suggest that Src family kinase-dependent p38 activation is a key component of a signaling switch routing EGF-stimulated responses to epithelial cell migration/restitution rather than proliferation during wound closure.

  5. Insulin-like growth factor I stimulates lipid oxidation, reduces protein oxidation, and enhances insulin sensitivity in humans.

    PubMed Central

    Hussain, M A; Schmitz, O; Mengel, A; Keller, A; Christiansen, J S; Zapf, J; Froesch, E R

    1993-01-01

    To elucidate the effects of insulin-like growth factor I (IGF-I) on fuel oxidation and insulin sensitivity, eight healthy subjects were treated with saline and recombinant human (IGF-I (10 micrograms/kg.h) during 5 d in a crossover, randomized fashion, while receiving an isocaloric diet (30 kcal/kg.d) throughout the study period. On the third and fourth treatment days, respectively, an L-arginine stimulation test and an intravenous glucose tolerance test were performed. A euglycemic, hyperinsulinemic clamp combined with indirect calorimetry and a glucose tracer infusion were performed on the fifth treatment day. IGF-I treatment led to reduced fasting and stimulated (glucose and/or L-arginine) insulin and growth hormone secretion. Basal and stimulated glucagon secretion remained unchanged. Intravenous glucose tolerance was unaltered despite reduced insulin secretion. Resting energy expenditure and lipid oxidation were both elevated, while protein oxidation was reduced, and glucose turnover rates were unaltered on the fifth treatment day with IGF-I as compared to the control period. Enhanced lipolysis was reflected by elevated circulating free fatty acids. Moreover, insulin-stimulated oxidative and nonoxidative glucose disposal (i.e., insulin sensitivity) were enhanced during IGF-I treatment. Thus, IGF-I treatment leads to marked changes in lipid and protein oxidation, whereas, at the dose used, carbohydrate metabolism remains unaltered in the face of reduced insulin levels and enhanced insulin sensitivity. Images PMID:8227340

  6. Stimulation of hybrid poplar growth in petroleum-contaminated soils through oxygen addition and soil nutrient amendments.

    PubMed

    Rentz, Jeremy A; Chapman, Brad; Alvarez, Pedro J J; Schnoor, Jerald L

    2003-01-01

    Hybrid poplar trees (Populus deltoides x nigra DN34) were grown in a green-house using hydrocarbon-contaminated soil from a phytoremediation demonstration site in Health, Ohio. Two independent experiments investigated the effect of nutrient addition on poplar growth and the importance of oxygen addition to root development and plant growth. Biomass measurements, poplar height, and leaf color were used as indicators of plant health in the selection of a 10/5/5 NPK fertilizer applied at 1121 kg/ha (112 kg-N, 24.4 kg-P, 46.5 kg-K per ha) to enhance hybrid poplar growth at the Health site. Five passive methods of oxygen delivery were examined, including aeration tubes, gravel addition, and an Oxygen Release Compound (ORC). When ORC was placed in coffee filters above hydrocarbon-contaminated soil, a statistically significant increase of 145% was observed in poplar biomass growth, relative to unamended controls. The ORC in filters also stimulated significant increases in root density. A 15.2-cm interval of soil directly below ORC addition exhibited an increase from 2.6 +/- 1.0 mg/cm3 to 4.8 +/- 1.0 mg/cm3, showing stimulation of root growth in hydrocarbon-stained soil. The positive response of hybrid poplars to oxygen amendments suggests that overcoming oxygen limitation to plants should be considered in phytoremediation projects when soil contamination exerts a high biochemical oxygen demand, such as in former refinery sites.

  7. Cartilage–Specific Over-Expression of CCN Family Member 2/Connective Tissue Growth Factor (CCN2/CTGF) Stimulates Insulin-Like Growth Factor Expression and Bone Growth

    PubMed Central

    Tomita, Nao; Hattori, Takako; Itoh, Shinsuke; Aoyama, Eriko; Yao, Mayumi; Yamashiro, Takashi; Takigawa, Masaharu

    2013-01-01

    Previously we showed that CCN family member 2/connective tissue growth factor (CCN2) promotes the proliferation, differentiation, and maturation of growth cartilage cells in vitro. To elucidate the specific role and molecular mechanism of CCN2 in cartilage development in vivo, in the present study we generated transgenic mice overexpressing CCN2 and analyzed them with respect to cartilage and bone development. Transgenic mice were generated expressing a ccn2/lacZ fusion gene in cartilage under the control of the 6 kb-Col2a1-enhancer/promoter. Changes in cartilage and bone development were analyzed histologically and immunohistologically and also by micro CT. Primary chondrocytes as well as limb bud mesenchymal cells were cultured and analyzed for changes in expression of cartilage–related genes, and non-transgenic chondrocytes were treated in culture with recombinant CCN2. Newborn transgenic mice showed extended length of their long bones, increased content of proteoglycans and collagen II accumulation. Micro-CT analysis of transgenic bones indicated increases in bone thickness and mineral density. Chondrocyte proliferation was enhanced in the transgenic cartilage. In in vitro short-term cultures of transgenic chondrocytes, the expression of col2a1, aggrecan and ccn2 genes was substantially enhanced; and in long-term cultures the expression levels of these genes were further enhanced. Also, in vitro chondrogenesis was strongly enhanced. IGF-I and IGF-II mRNA levels were elevated in transgenic chondrocytes, and treatment of non-transgenic chondrocytes with recombinant CCN2 stimulated the expression of these mRNA. The addition of CCN2 to non-transgenic chondrocytes induced the phosphorylation of IGFR, and ccn2-overexpressing chondrocytes showed enhanced phosphorylation of IGFR. Our data indicates that the observed effects of CCN2 may be mediated in part by CCN2-induced overexpression of IGF-I and IGF-II. These findings indicate that CCN2-overexpression in

  8. Symbiosis revisited: phosphorus and acid buffering stimulate N2 fixation but not Sphagnum growth

    NASA Astrophysics Data System (ADS)

    van den Elzen, Eva; Kox, Martine A. R.; Harpenslager, Sarah F.; Hensgens, Geert; Fritz, Christian; Jetten, Mike S. M.; Ettwig, Katharina F.; Lamers, Leon P. M.

    2017-03-01

    In pristine Sphagnum-dominated peatlands, (di)nitrogen (N2) fixing (diazotrophic) microbial communities associated with Sphagnum mosses contribute substantially to the total nitrogen input, increasing carbon sequestration. The rates of symbiotic nitrogen fixation reported for Sphagnum peatlands, are, however, highly variable, and experimental work on regulating factors that can mechanistically explain this variation is largely lacking. For two common fen species (Sphagnum palustre and S. squarrosum) from a high nitrogen deposition area (25 kg N ha-1 yr-1), we found that diazotrophic activity (as measured by 15 - 15N2 labeling) was still present at a rate of 40 nmol N gDW-1 h-1. This was surprising, given that nitrogen fixation is a costly process. We tested the effects of phosphorus availability and buffering capacity by bicarbonate-rich water, mimicking a field situation in fens with stronger groundwater or surface water influence, as potential regulators of nitrogen fixation rates and Sphagnum performance. We expected that the addition of phosphorus, being a limiting nutrient, would stimulate both diazotrophic activity and Sphagnum growth. We indeed found that nitrogen fixation rates were doubled. Plant performance, in contrast, did not increase. Raised bicarbonate levels also enhanced nitrogen fixation, but had a strong negative impact on Sphagnum performance. These results explain the higher nitrogen fixation rates reported for minerotrophic and more nutrient-rich peatlands. In addition, nitrogen fixation was found to strongly depend on light, with rates 10 times higher in light conditions suggesting high reliance on phototrophic organisms for carbon. The contrasting effects of phosphorus and bicarbonate on Sphagnum spp. and their diazotrophic communities reveal strong differences in the optimal niche for both partners with respect to conditions and resources. This suggests a trade-off for the symbiosis of nitrogen fixing microorganisms with their Sphagnum

  9. Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

    SciTech Connect

    Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

    2015-03-01

    Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. - Highlights: • Pro-inflammatory cytokines induced VEGF production in normal human

  10. Growth differentiation factor-9 stimulates progesterone synthesis in granulosa cells via a prostaglandin E2/EP2 receptor pathway.

    PubMed

    Elvin, J A; Yan, C; Matzuk, M M

    2000-08-29

    Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor beta superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin E(2) (PGE(2)) receptor (EP2; Ptgerep2) are required for fertility in female but not male mice. To define the interrelationship of these factors, we used a preovulatory granulosa cell culture system in which we added recombinant GDF-9, prostaglandins, prostaglandin receptor agonists, or cyclooxygenase inhibitors. GDF-9 stimulated Cox2 mRNA within 2 h, and PGE(2) within 6 h; however, progesterone was not increased until 12 h after addition of GDF-9. This suggested that Cox2 is a direct downstream target of GDF-9 but that progesterone synthesis required an intermediate. To determine whether prostaglandin synthesis was required for progesterone production, we analyzed the effects of PGE(2) and cyclooxygenase inhibitors on this process. PGE(2) can stimulate progesterone synthesis by itself, although less effectively than GDF-9 (3-fold vs. 6-fold increase over 24 h, respectively). Furthermore, indomethacin or NS-398, inhibitors of Cox2, block basal and GDF-9-stimulated progesterone synthesis. However, addition of PGE(2) to cultures containing both GDF-9 and NS-398 overrides the NS-398 block in progesterone synthesis. To further define the PGE(2)-dependent pathway, we show that butaprost, a specific EP2 agonist, stimulates progesterone synthesis and overrides the NS-398 block. In addition, GDF-9 stimulates EP2 mRNA synthesis by a prostaglandin- and progesterone-independent pathway. Thus, GDF-9 induces an EP2 signal transduction pathway which appears to be required for progesterone synthesis in cumulus granulosa cells. These studies further demonstrate the importance of oocyte-somatic cell interactions in female reproduction.

  11. RhoC Mediates Epidermal Growth Factor-Stimulated Migration and Invasion in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Tumur, Zohra; Katebzadeh, Shahbaz; Guerra, Carlos; Bhushan, Lokesh; Alkam, Tursun; Henson, Bradley S.

    2015-01-01

    Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinoma (HNSCC) where it has been shown to promote tumor cell invasion upon phosphorylation. One mechanism by which EGFR promotes tumor progression is by activating signal cascades that lead to loss of E-cadherin, a transmembrane glycoprotein of the cell-cell adherence junctions; however mediators of these signaling cascades are not fully understood. One such mediator, RhoC, is activated upon a number of external stimuli, such as epidermal growth factor (EGF), but its role as a mediator of EGF-stimulated migration and invasion has not been elucidated in HNSCC. In the present study, we investigate the role of RhoC as a mediator of EGF-stimulated migration and invasion in HNSCC. We show that upon EGF stimulation, EGFR and RhoC were strongly activated in HNSCC. This resulted in activation of the phosphatidylinositol 3-Kinase Akt pathway (PI3K-Akt), phosphorylation of GSK-3β at the Ser9 residue, and subsequent down regulation of E-cadherin cell surface expression resulting in increased tumor cell invasion. Knockdown of RhoC restored E-cadherin expression and inhibited EGF-stimulated migration and invasion. This is the first report in HNSCC demonstrating the role RhoC plays in mediating EGF-stimulated migration and invasion by down-regulating the PI3K-Akt pathway and E-cadherin expression. RhoC may serve as a treatment target for HNSCC. PMID:25622907

  12. Novel degradable co-polymers of polypyrrole support cell proliferation and enhance neurite out-growth with electrical stimulation.

    PubMed

    Durgam, Hymavathi; Sapp, Shawn; Deister, Curt; Khaing, Zin; Chang, Emily; Luebben, Silvia; Schmidt, Christine E

    2010-01-01

    Synthetic polymers such as polypyrrole (PPy) are gaining significance in neural studies because of their conductive properties. We evaluated two novel biodegradable block co-polymers of PPy with poly(epsilon-caprolactone) (PCL) and poly(ethyl cyanoacrylate) (PECA) for nerve regeneration applications. PPy-PCL and PPy-PECA co-polymers can be processed from solvent-based colloidal dispersions and have essentially the same or greater conductivity (32 S/cm for PPy-PCL, 19 S/cm for PPy-PECA) compared to the PPy homo-polymer (22 S/cm). The PPy portions of the co-polymers permit electrical stimulation whereas the PCL or PECA blocks enable degradation by hydrolysis. For in vitro tests, films were prepared on polycarbonate sheets by air brushing layers of dispersions and pressing the films. We characterized the films for hydrolytic degradation, electrical conductivity, cell proliferation and neurite extension. The co-polymers were sufficient to carry out electrical stimulation of cells without the requirement of a metallic conductor underneath the co-polymer film. In vitro electrical stimulation of PPy-PCL significantly increased the number of PC12 cells bearing neurites compared to unstimulated PPy-PCL. For in vivo experiments, the PPy co-polymers were coated onto the inner walls of nerve guidance channels (NGCs) made of the commercially available non-conducting biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV). The NGCs were implanted in a 10 mm defect made in the sciatic nerve of rats, and harvested after 8 weeks. Histological staining showed axonal growth. The studies indicated that these new conducting degradable biomaterials have good biocompatibility and support proliferation and growth of PC12 cells in vitro (with and without electrical stimulation) and neurons in vivo (without electrical stimulation).

  13. Opposing effects of a ras oncogene on growth factor-stimulated phosphoinositide hydrolysis: desensitization to platelet-derived growth factor and enhanced sensitivity to bradykinin

    SciTech Connect

    Parries, G.; Hoebel, R.; Racker, E.

    1987-05-01

    Expression of a transforming Harvey or Kirsten ras gene caused opposing effects in the ability of platelet-derived growth factor (PDGF) and bradyknin to activate phospholipase C-mediated phosphoinositide hydrolysis. In (/sup 3/H)inositol-labeled rat-1 fibroblasts, PDGF resulted in a 2-fold increase in the level of (/sup 3/H)inositol trisphosphate (InsP/sub 3/) after 2 min and, in the presence of LiCl, a 3- to 8-fold increase in the level of (/sup 3/H)inositol monophosphate (InsP/sub 1/) after 30 min. However, in EJ-ras-transfected rat-1 cells, which exhibit near normal levels of PDGF receptors, PDGF resulted in little or no accumulation of either (/sup 3/H)InsP/sub 3/ or (/sup 3/H)InsP/sub 1/. Similarly, marked stimulations by PDGF were observed in NIH 3T3 cells, as well as in v-src-transformed 3T3 cells, but not in 3T3 cells transformed by Kirsten sarcoma virus or by transfection with v-Ha-ras DNA. This diminished phosphoinositide response in ras-transformed cells was associated with a markedly attenuated mitogenic response to PDGF. On the other hand, both phosphoinositide metabolism and DNA synthesis in ras-transformed fibroblasts were stimulated several-fold by serum. In NIH 3T3 cells carrying a glucocorticoid-inducible v-Ha-ras gene, a close correlation was found between the expression of p21/sup ras/ and the loss of PDGF-stimulated (/sup 3/H)InsP/sub 1/ accumulation. The authors propose that a ras gene product (p21) can, directly or indirectly, influence growth factor-stimulated phosphoinositide hydrolysis, as well as DNA synthesis, via alterations in the properties of specific growth factor receptors.

  14. Effects of low- and high-frequency repetitive magnetic stimulation on neuronal cell proliferation and growth factor expression: A preliminary report.

    PubMed

    Lee, Ji Yong; Park, Hyung Joong; Kim, Ji Hyun; Cho, Byung Pil; Cho, Sung-Rae; Kim, Sung Hoon

    2015-09-14

    Repetitive magnetic stimulation is a neuropsychiatric and neurorehabilitation tool that can be used to investigate the neurobiology of sensory and motor functions. Few studies have examined the effects of repetitive magnetic stimulation on the modulation of neurotrophic/growth factors and neuronal cells in vitro. Therefore, the current study examined the differential effects of repetitive magnetic stimulation on neuronal cell proliferation as well as various growth factor expression. Immortalized mouse neuroblastoma cells were used as the cell model in this study. Dishes of cultured cells were randomly divided into control, sham, low-frequency (0.5Hz, 1Tesla) and high-frequency (10Hz, 1Tesla) groups (n=4 dishes/group) and were stimulated for 3 days. Expression of neurotrophic/growth factors, Akt and Erk was investigated by Western blotting analysis 3 days after repetitive magnetic stimulation. Neuroblastoma cell proliferation was determined with a cell counting assay. There were differences in cell proliferation based on stimulus frequency. Low-frequency stimulation did not alter proliferation relative to the control, while high-frequency stimulation elevated proliferation relative to the control group. The expression levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), neurotrophin-3 (NT-3) and platelet-derived growth factor (PDGF) were elevated in the high-frequency magnetic stimulation group. Akt and Erk expression was also significantly elevated in the high-frequency stimulation group, while low-frequency stimulation decreased the expression of Akt and Erk compared to the control. In conclusion, we determined that different frequency magnetic stimulation had an influence on neuronal cell proliferation via regulation of Akt and ERK signaling pathways and the expression of growth factors such as BDNF, GDNF, NT-3 and PDGF. These findings represent a promising opportunity to gain insight into how different

  15. Cytotoxic activity and absence of tumor growth stimulation of standardized mistletoe extracts in human tumor models in vitro.

    PubMed

    Kelter, Gerhard; Schierholz, Jörg M; Fischer, Imma U; Fiebig, Heinz-Herbert

    2007-01-01

    Mistletoe extracts are widely used in complementary and alternative cancer therapy in Europe. The extracts possess cytotoxic, as well as immunostimulatory effects. However, some investigators have suggested that low doses of mistletoe extracts could also induce tumor growth. The mistletoe extracts Helixor A, Helixor M and Helixor P were investigated for growth inhibitory and stimulatory effects in a panel of 38 human tumor cell lines in vitro. Mistletoe lectin I (ML-1), adriamycin and interleukin-6 (IL-6) were used as reference compounds. All three mistletoe preparations showed cytotoxic activity [T/C (Test/Control) < 30%]: Helixor P was the most potent, followed by Helixor M and Helixor A with IC50 (50% inhibitory concentration) values of 68.4, 114 and 133 microg/ml, respectively. The IC50 values of ML-1 and adriamycin were 0.026 and 0.069 microg/ml. None of the human tumor cell lines in the panel showed growth stimulation (T/C (Test/Control) > 125%) by the mistletoe extracts or ML-1, apart from two exceptions in the colon carcinoma cell line HCC-2998, in which Helixor M and ML-1 showed a marginal stimulation (TIC 128% and 131%, respectively) at one concentration only. Further investigations into the latter effect of Helixor M and ML-1 in the HCC-2998 line using five different proliferation assays, modified cell culture conditions and the identical production charge of mistletoe extract, as well as a new one, did not confirm the previous observation. It was concluded that the marginal stimulation found in the earlier experiments was a statistical coincidence. Helixor mistletoe preparations and ML-1 have cytotoxic activity and do not stimulate tumor cell proliferation in vitro which is in accordance with previous scientifically based observations on aqueous mistletoe extracts.

  16. Transforming growth factor-alpha in vivo stimulates epithelial cell proliferation in digestive tissues of suckling rats.

    PubMed Central

    Hormi, K; Lehy, T

    1996-01-01

    BACKGROUND: The role that exogenous transforming growth factor-alpha (TGF-alpha) may exert on cell proliferation in vivo is poorly understood. AIM: To investigate the effect of rat TGF-alpha on epithelial cell proliferation in all suckling rat digestive tissues and to compare it with that of rat epidermal growth factor (EGF). ANIMAL AND METHODS: TGF-alpha and EGF were given three times daily either subcutaneously (10 or 20 micrograms/kg) or intraperitoneally (100 micrograms/kg) to rats from the ninth postnatal day. Cell proliferation was assessed through 5-bromo- 2-deoxyuridine incorporation and estimation of labelling indices. RESULTS: For both growth factors, the highest dose given for only two days significantly increased stomach and intestinal weights compared with controls (p < 0.05 to p < 0.001). The proliferative responded depended on the dose given, colonic mucosa being the most sensitive whereas oxyntic mucosa remained unresponsive. TGF-alpha was as potent as EGF in stimulating epithelial cell proliferation in antral, duodenal, and colonic mucosae. However, EGF was more active on oesophageal and jejunal cell proliferation whereas TGF-alpha was more active on pancreatic exocrine cell proliferation and the differences between the two growth factor treated groups were significant. CONCLUSIONS: These results prove for the first time the stimulating effect in vivo of exogenous rat TGF-alpha on epithelial cell proliferation in rat digestive tissues during the developmental period and support a functional role for TGF-alpha at that time. PMID:8944561

  17. CONSEQUENCES OF PROTIST-STIMULATED BACTERIAL PRODUCTION FOR ESTIMATING PROTIST GROWTH EFFICIENCIES

    EPA Science Inventory

    The trophic link between bacteria and bacterivorous protists is a complex interaction that involves feedback of inorganic nutrients and growth substrates that are immediately available for prey growth. These interactions were examined in the laboratory and in incubations of conce...

  18. [Trp3, Arg5]-ghrelin(1-5) stimulates growth hormone secretion and food intake via growth hormone secretagogue (GHS) receptor.

    PubMed

    Ohinata, Kousaku; Kobayashi, Kanako; Yoshikawa, Masaaki

    2006-07-01

    Ghrelin, a 28 amino acid peptide identified as an endogenous ligand for growth hormone secretagogue (GHS) receptor, stimulates food intake and growth hormone (GH) secretion. We designed low molecular weight peptides with affinity for the GHS receptor based on the primary structure of ghrelin. We found that [Trp3, Arg5]-ghrelin(1-5) (GSWFR), a novel pentapeptide composed of all L-amino acids, had affinity for the GHS receptor (IC50 = 10 microM). GSWFR stimulated GH secretion after intravenous or oral administration. Centrally administered GSWFR increased food intake in non-fasted mice. The orexigenic action of GSWFR was inhibited by a GHS receptor antagonist, [D-Lys3]-GH-releasing peptide-6, suggesting that GSWFR stimulated food intake through the GHS receptor. The orexigenic action of GSWFR was also inhibited by a neuropeptide Y (NPY) Y1 receptor antagonist, BIBO3304. These results suggest that the GSWFR-induced feeding is mediated by the NPY Y1 receptor.

  19. Effect of steroidal and nonsteroidal antiestrogens on the growth of a tamoxifen-stimulated human endometrial carcinoma (EnCa101) in athymic mice.

    PubMed

    Gottardis, M M; Ricchio, M E; Satyaswaroop, P G; Jordan, V C

    1990-06-01

    Tamoxifen (TAM), a nonsteroidal antiestrogen, is used in the adjuvant treatment of breast cancer. Previous studies, however, have indicated that some human breast and endometrial tumors are stimulated to grow with TAM in the athymic mouse. One such TAM-stimulated tumor is the EnCa101 human endometrial adenocarcinoma. Our aim was to evaluate the ability of different doses of TAM or other nonsteroidal antiestrogens to stimulate the growth of EnCa101 tumors in athymic mice. Additionally we have evaluated less estrogenic antiestrogens (two steroidal antiestrogens, RU 39,411 and ICI 164,384, and two nonsteroidal antiestrogens, keoxifene and MER-25) for their ability to inhibit TAM-stimulated growth. All experiments were done in ovariectomized athymic mice transplanted in the axillary mammary fat with 1-mm3 pieces of EnCa101 tumor. Sustained release preparations (0.5-2.0-cm Silastic capsule or 5-mg TAM cholesterol pellet) of TAM caused similar tumor growth. The growth rate was not altered by an additional daily i.p. injection of 1 mg TAM in 0.1 ml peanut oil. A 3-mg TAM daily dose was toxic. Four weeks of treatment (100-micrograms s.c. injections, every other day) with nonsteroidal antiestrogens, trioxifene mesylate, enclomiphene, or nafoxidine stimulated tumor growth. However, keoxifene stimulated this tumor to a lesser degree than TAM and partially inhibited TAM-stimulated growth. ICI 164,384 showed no stimulatory activity (1-mg s.c. injections every other day) alone compared to controls but inhibited TAM-stimulated (0.25-cm Silastic capsule) growth. In a parallel experiment, RU 39,411 (1-mg s.c. injections every other day) stimulated EnCa101 to grow. In contrast when RU 39,411 was administered in a sustained release preparation (2.0-cm Silastic capsule) there was no stimulatory growth compared to controls. Additionally RU 39,411 inhibited TAM-stimulated growth, but the low-potency antiestrogen, MER-25, was less effective in this regard. These data suggest that less

  20. Potassium uptake supporting plant growth in the absence of AKT1 channel activity: Inhibition by ammonium and stimulation by sodium

    NASA Technical Reports Server (NTRS)

    Spalding, E. P.; Hirsch, R. E.; Lewis, D. R.; Qi, Z.; Sussman, M. R.; Lewis, B. D.

    1999-01-01

    A transferred-DNA insertion mutant of Arabidopsis that lacks AKT1 inward-rectifying K+ channel activity in root cells was obtained previously by a reverse-genetic strategy, enabling a dissection of the K+-uptake apparatus of the root into AKT1 and non-AKT1 components. Membrane potential measurements in root cells demonstrated that the AKT1 component of the wild-type K+ permeability was between 55 and 63% when external [K+] was between 10 and 1,000 microM, and NH4+ was absent. NH4+ specifically inhibited the non-AKT1 component, apparently by competing for K+ binding sites on the transporter(s). This inhibition by NH4+ had significant consequences for akt1 plants: K+ permeability, 86Rb+ fluxes into roots, seed germination, and seedling growth rate of the mutant were each similarly inhibited by NH4+. Wild-type plants were much more resistant to NH4+. Thus, AKT1 channels conduct the K+ influx necessary for the growth of Arabidopsis embryos and seedlings in conditions that block the non-AKT1 mechanism. In contrast to the effects of NH4+, Na+ and H+ significantly stimulated the non-AKT1 portion of the K+ permeability. Stimulation of akt1 growth rate by Na+, a predicted consequence of the previous result, was observed when external [K+] was 10 microM. Collectively, these results indicate that the AKT1 channel is an important component of the K+ uptake apparatus supporting growth, even in the "high-affinity" range of K+ concentrations. In the absence of AKT1 channel activity, an NH4+-sensitive, Na+/H+-stimulated mechanism can suffice.

  1. Insulin-like growth factor-I-stimulated Akt phosphorylation and oligodendrocyte progenitor cell survival require cholesterol-enriched membranes.

    PubMed

    Romanelli, Robert J; Mahajan, Kedar R; Fulmer, Clifton G; Wood, Teresa L

    2009-11-15

    Previously we showed that insulin-like growth factor-I (IGF-I) promotes sustained phosphorylation of Akt in oligodendrocyte progenitor cells (OPCs) and that Akt phosphorylation is required for survival of these cells. The direct mechanisms, however, by which IGF-I promotes Akt phosphorylation are currently undefined. Recently, cholesterol-enriched membranes (CEMs) have been implicated in regulation of growth factor-mediated activation of the PI3K/Akt pathway and survival of mature oligodendrocytes; however, less is know about their role in OPC survival. In the present study, we investigate the role of CEMs in IGF-I-mediated Akt phosphorylation and OPC survival. We report that acute disruption of membrane cholesterol with methyl-beta-cyclodextrin results in altered OPC morphology and inhibition of IGF-I-mediated Akt phosphorylation. We also report that long-term inhibition of cholesterol biosynthesis with 25-hydroxycholesterol blocks IGF-I stimulated Akt phosphorylation and cell survival. Moreover, we show that the PI3K regulatory subunit, p85, Akt, and the IGF-IR are sequestered within cholesterol-enriched fractions in steady-state stimulation of the IGF-IR and that phosphorylated Akt and IGF-IR are present in cholesterol-enriched fractions with IGF-I stimulation. Together, the results of these studies support a role for CEMs or "lipid rafts" in IGF-I-mediated Akt phosphorylation and provide a better understanding of the mechanisms by which IGF-I promotes OPC survival.

  2. Transforming growth factor-beta 1 stimulates synthesis of proteoglycan aggregates in calf articular cartilage organ cultures

    SciTech Connect

    Morales, T.I. )

    1991-04-01

    Previous work showed that transforming growth factor-beta 1 (TGF-beta 1), added alone to bovine cartilage organ cultures, stimulated (35S)sulfate incorporation into macromolecular material but did not investigate the fidelity of the stimulated system to maintain synthesis of cartilage-type proteoglycans. This paper provides evidence that chondrocytes synthesize the appropriate proteoglycan matrix under TGF-beta 1 stimulation: (1) there is a coordinated increase in hyaluronic acid and proteoglycan monomer synthesis, (2) link-stable proteoglycan aggregates are assembled, (3) the hybrid chondroitin sulfate/keratan sulfate monomeric species is synthesized, and (4) there is an increase in protein core synthesis. Some variation in glycosylation patterns was observed when proteoglycans synthesized under TGF-beta 1 stimulation were compared to those synthesized under basal conditions. Thus comparing TGF-beta 1 to basal samples respectively, the monomers were larger (Kav on Sepharose CL-2B = 0.29 vs 0.41), the chondroitin sulfate chains were longer by approximately 3.5 kDa, the percentage of total glycosaminoglycan in keratan sulfate increased slightly from approximately 4% (basal) to approximately 6%, and the unsulfated disaccharide decreased from 28% (basal) to 12%. All of these variations are in the direction of a more anionic proteoglycan. Since the ability of proteoglycans to confer resiliency to the cartilage matrix is directly related to their anionic nature, these changes would presumably have a beneficial effect on tissue function.

  3. Cultured human foreskin fibroblasts produce a factor that stimulates their growth with properties similar to basic fibroblast growth factor

    SciTech Connect

    Story, M.T. )

    1989-05-01

    To determine if fibroblasts could be a source of fibroblast growth factor (FGF) in tissue, cells were initiated in culture from newborn human foreskin. Fibroblast cell lysates promoted radiolabeled thymidine uptake by cultured quiescent fibroblasts. Seventy-nine percent of the growth-promoting activity of lysates was recovered from heparin-Sepharose. The heparin-binding growth factor reacted on immunoblots with antiserum to human placenta-derived basic FGF and competed with iodinated basic FGF for binding to antiserum to (1-24)bFGF synthetic peptide. To confirm that fibroblasts were the source of the growth factor, cell lysates were prepared from cells incubated with radiolabeled methionine. Heparin affinity purified material was immunoprecipitated with basic FGF antiserum and electrophoresed. Radiolabeled material was detected on gel autoradiographs in the same molecular weight region as authentic iodinated basic FGF. The findings are consistant with the notion that cultured fibroblasts express basic FGF. As these cells also respond to the mitogen, it is possible that the regulation of their growth is under autocrine control. Fibroblasts may be an important source of the growth factor in tissue.

  4. Nerve growth factor and brain-derived neurotrophic factor but not granulocyte colony-stimulating factor, nimodipine and dizocilpine, require ATP for neuroprotective activity after oxygen-glucose deprivation of primary neurons.

    PubMed

    Ferenz, Katja B; Gast, Ronald E; Rose, Karsten; Finger, Indra E; Hasche, Anja; Krieglstein, Josef

    2012-04-11

    In previous work, we have demonstrated by radiolabeling, mass spectrometry and site-directed mutagenesis that nerve growth factor (NGF) as well as brain-derived neurotrophic factor (BDNF) and fibroblast growth factor 2 (FGF2) are capable of ATP-binding and that this binding appears to be essential for their neuroprotective activity. In this study, we attempted to shed some light on the question whether ATP is a general prerequisite for neuroprotection. Therefore, we used the non-ATP-binding granulocyte colony-stimulating factor (GCSF), the calcium antagonist nimodipine and the NMDA antagonist dizocilpine to find out whether they need ATP for neuroprotection comparable to NGF and BDNF. However, ATP was not necessary for the neuroprotective effects of GCSF, nimodipine and dizocilpine on primary cultures of rat cortical neurons damaged by oxygen-glucose deprivation whereas neuroprotection was demonstrable for NGF and BDNF only when ATP was present in the culture medium at a concentration higher than ca. 0.4nmol/l. In circular dichroism studies ATP caused changes of the secondary structure of NGF but not of GCSF. Taken together, we suggest that ATP is not a general prerequisite for neuroprotectivity but some growth factors like NGF and BDNF can stimulate their receptors only if they have bound ATP.

  5. Insulin-like growth factor (IGF) 2 stimulates steroidogenesis and mitosis of bovine granulosa cells through the IGF1 receptor: role of follicle-stimulating hormone and IGF2 receptor.

    PubMed

    Spicer, L J; Aad, P Y

    2007-07-01

    Little is known regarding the role of insulin-like growth factor 2 (IGF2) and the regulation of the IGF2 receptor (IGF2R) during follicular development. Granulosa cells were collected from small (1-5 mm) and large (8-22 mm) bovine follicles and were treated with IGF2 for 1-2 days in serum-free medium, and steroid production, cell proliferation, specific (125)I-IGF2 binding, and gene expression were quantified. IGF2 increased both estradiol and progesterone production by granulosa cells, and cells from large follicles were more responsive to the effects of IGF2 than those from small follicles. Abundance of aromatase (CYP19A1) mRNA was stimulated by IGF2 and IGF1. The effective dose (ED(50)) of IGF2 stimulating 50% of the maximal estradiol production was 63 ng/ml for small follicles and 12 ng/ml for large follicles, and these values were not affected by FSH. The ED(50) of IGF2 for progesterone production was 20 ng/ml for both small and large follicles. IGF2 also increased proliferation of granulosa cells by 2- to 3-fold, as determined by increased cell numbers and (3)H-thymidine incorporation into DNA. Treatment with IGF1R antibodies reduced the stimulatory effect of IGF2 and IGF1 on estradiol production and cell proliferation. Specific receptors for (125)I-IGF2 existed in granulosa cells, and 2-day treatment with estradiol, FSH, or cortisol had no significant effect on specific (125)I-IGF2 binding. Also, FSH treatment of small- and large-follicle granulosa cells had no effect on IGF2R mRNA levels, whereas IGF1 decreased IGF2R mRNA and specific (125)I-IGF2 binding. Granulosa cell IGF2R mRNA abundance was 3-fold greater in small than in large follicles. These findings support the hypothesis that both IGF2 and its receptor may play a role in granulosa cell function during follicular development. In particular, increased free IGF1 in developing follicles may decrease synthesis of IGF2R, thereby allowing for more IGF2 to be bioavailable (free) for induction of

  6. Determination of growth stimulating activity of 'Rhizoginin-S' on cell cultures used in virology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have developed a new bioregulator based on phosphoinositol (PI), designated Rhizoginin-S, which stimulates plant cell division very effectively. The invention of Rhizoginin-S was only possible after development of a simple and effective method of preparation PI, U.S. patent (4,977,091). Developme...

  7. Mononuclear cell modulation of connective tissue function: suppression of fibroblast growth by stimulation of endogenous prostaglandin production.

    PubMed Central

    Korn, J H; Halushka, P V; LeRoy, E C

    1980-01-01

    The role of immune cell products in modulating connective tissue metabolism was investigated. Supernates of both unstimulated and phytohemagglutinin-stimulated human mononuclear cell cultures suppressed fibroblast proliferation (up to 90%) and concomintantly stimulated fibroblast prostaglandin E(PGE) synthesis (20- to 70-fold). The growth suppression was, at least in part, a secondary result of the increased fibroblast PGE synthesis; growth suppression (a) paralled the increased fibroblast PGE synthesis, (b) was reversed by addition of inhibitors of prostaglandin synthesis (indomethacin, meclofenamate, and eicostaetraynoic acid), and (c) was reproduced by addition of exogenous PGE2 to fibroblast cultures. The prostaglandin-stimulatory, growth-suppressive activity was a product of non-T-lymphocyte, adherent cells and was present within 6 h of mononuclear cell culture. The activity was heat (56 degrees C) and trypsin sensitive, nondialyzable, and appeared in the 12,000-20,000 mol wt fractions by Sephadex G-100 chromatography. The activity in supernates of mononuclear cell cultures was removed by incubation with fibroblasts but not by similar incubation with peripheral blood mononuclear cells. Mononuclear cells release a factor(s) which modulates fibroblast proliferation by altering prostaglandin metabolism. PMID:7356693

  8. High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions.

    PubMed

    Woo, Ji-Min; Yang, Kyung-Mi; Kim, Sae-Um; Blank, Lars M; Park, Jin-Byung

    2014-07-01

    Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.

  9. Stimulation of food intake and weight gain in mature female rats by bovine prolactin and bovine growth hormone.

    PubMed

    Byatt, J C; Staten, N R; Salsgiver, W J; Kostelc, J G; Collier, R J

    1993-06-01

    Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.

  10. Platelet-rich plasma stimulated by pulse electric fields: Platelet activation, procoagulant markers, growth factor release and cell proliferation.

    PubMed

    Frelinger, A L; Torres, A S; Caiafa, A; Morton, C A; Berny-Lang, M A; Gerrits, A J; Carmichael, S L; Neculaes, V B; Michelson, A D

    2016-01-01

    Therapeutic use of activated platelet-rich plasma (PRP) has been explored for wound healing, hemostasis and antimicrobial wound applications. Pulse electric field (PEF) stimulation may provide more consistent platelet activation and avoid complications associated with the addition of bovine thrombin, the current state of the art ex vivo activator of therapeutic PRP. The aim of this study was to compare the ability of PEF, bovine thrombin and thrombin receptor activating peptide (TRAP) to activate human PRP, release growth factors and induce cell proliferation in vitro. Human PRP was prepared in the Harvest SmartPreP2 System and treated with vehicle, PEF, bovine thrombin, TRAP or Triton X-100. Platelet activation and procoagulant markers and microparticle generation were measured by flow cytometry. Released growth factors were measured by ELISA. The releasates were tested for their ability to stimulate proliferation of human epithelial cells in culture. PEF produced more platelet-derived microparticles, P-selectin-positive particles and procoagulant annexin V-positive particles than bovine thrombin or TRAP. These differences were associated with higher levels of released epidermal growth factor after PEF than after bovine thrombin or TRAP but similar levels of platelet-derived, vascular-endothelial, and basic fibroblast growth factors, and platelet factor 4. Supernatant from PEF-treated platelets significantly increased cell proliferation compared to plasma. In conclusion, PEF treatment of fresh PRP results in generation of microparticles, exposure of prothrombotic platelet surfaces, differential release of growth factors compared to bovine thrombin and TRAP and significant cell proliferation. These results, together with PEF's inherent advantages, suggest that PEF may be a superior alternative to bovine thrombin activation of PRP for therapeutic applications.

  11. Impact of electro-stimulation on denitrifying bacterial growth and analysis of bacterial growth kinetics using a modified Gompertz model in a bio-electrochemical denitrification reactor.

    PubMed

    Liu, Hengyuan; Chen, Nan; Feng, Chuanping; Tong, Shuang; Li, Rui

    2017-05-01

    This study aimed to investigate the effect of electro-stimulation on denitrifying bacterial growth in a bio-electrochemical reactor, and the growth were modeled using modified Gompertz model under different current densities at three C/Ns. It was found that the similar optimum current density of 250mA/m(2) was obtained at C/N=0.75, 1.00 and 1.25, correspondingly the maximum nitrate removal efficiencies were 98.0%, 99.2% and 99.9%. Moreover, ATP content and cell membrane permeability of denitrifying bacteria were significantly increased at optimum current density. Furthermore, modified Gompertz model fitted well with the microbial growth curves, and the highest maximum growth rates (µmax) and shorter lag time were obtained at the optimum current density for all C/Ns. This study demonstrated that the modified Gompertz model could be used for describing microbial growth under different current densities and C/Ns in a bio-electrochemical denitrification reactor, and it provided an alternative for improving the performance of denitrification process.

  12. Cell growth stimulating effect of Ganoderma lucidum spores and their potential application for Chinese hamster ovary K1 cell cultivation.

    PubMed

    Li, Ding; Zhong, Qi; Liu, Tingting; Wang, Jufang

    2016-06-01

    In this work, water-soluble extracts of Ganoderma lucidum spores (Gls), a Chinese medicinal herb that possesses cell growth stimulating function, were found to be an effective growth factor for Chinese hamster ovary (CHO) cell cultivation. The Gls extract was prepared and supplemented to CHO K1 cell culture media with various serum levels. Our results obtained from both the static culture and the spinner-flask suspension culture showed that use of small-amount Gls extract effectively promoted cell growth and suppressed cell apoptosis induced by serum deprivation with normal cell cycle maintained in a low-serum medium. The low-serum medium containing 1 % (v/v) fetal bovine serum (FBS) and 0.01 % (w/v) Gls extract showed a comparable performance on both cell growth and fusion protein productivity with the conventional CHO culture medium containing 10 % (v/v) FBS and a commercial serum-free medium. This is the first study of the potential of Gls extracts for use as an alternative cell growth factor and nutrient for CHO cells. The findings have presented a new approach to economic cultivation of CHO cells for therapeutic protein production.

  13. Glucocorticoids Hijack Runx2 to Stimulate Wif1 for Suppression of Osteoblast Growth and Differentiation.

    PubMed

    Morimoto, Eri; Li, Meng; Khalid, Aysha B; Krum, Susan A; Chimge, Nyam-Osor; Frenkel, Baruch

    2017-01-01

    Inhibition of Runx2 is one of many mechanisms that suppress bone formation in glucocorticoid (GC)-induced osteoporosis (GIO). We profiled mRNA expression in ST2/Rx2(dox) cells after treatment with doxycycline (dox; to induce Runx2) and/or the synthetic GC dexamethasone (dex). As expected, dex typically antagonized Runx2-driven transcription. Select genes, however, were synergistic stimulated and this was confirmed by RT-qPCR. Among the genes synergistically stimulated by GCs and Runx2 was Wnt inhibitory Factor 1 (Wif1), and Wif1 protein was readily detectable in medium conditioned by cultures co-treated with dox and dex, but neither alone. Cooperation between Runx2 and GCs in stimulating Wif1 was also observed in primary preosteoblast cultures. GCs strongly inhibited dox-driven alkaline phosphatase (ALP) activity in control ST2/Rx2(dox) cells, but not in cells in which Wif1 was silenced. Unlike its anti-mitogenic activity in committed osteoblasts, induction of Runx2 transiently increased the percentage of cells in S-phase and accelerated proliferation in the ST2 mesenchymal pluripotent cell culture model. Furthermore, like the inhibition of Runx2-driven ALP activity, dex antagonized the transient mitogenic effect of Runx2 in ST2/Rx2(dox) cultures, and this inhibition eased upon Wif1 silencing. Plausibly, homeostatic feedback loops that rely on Runx2 activation to compensate for bone loss in GIO are thwarted, exacerbating disease progression through stimulation of Wif1. J. Cell. Physiol. 232: 145-153, 2017. © 2016 Wiley Periodicals, Inc.

  14. Plasma concentrations of luteinising hormone, follicle stimulating hormone, androgen, growth hormone, prolactin, thyroxine and triiodothyronine during growth and sexual development in the cockerel.

    PubMed

    Sterling, R J; Sharp, P J; Klandorf, H; Harvey, S; Lea, R W

    1984-07-01

    Changes in concentrations of plasma luteinising hormone (LH), follicle stimulating hormone (FSH), androgen, growth hormone (GH), prolactin (Prl), thyroxine (T4) and triiodothyronine (T3) were measured during growth and sexual maturation in broiler cockerels reared in continuous light to 7 weeks and 14 h light/d thereafter. Concentrations of LH and FSH began to increase between 13 and 15 weeks, while those of androgens increased between 16 and 17 weeks. FSH concentration increased faster than that of LH. Concentrations of GH and Prl were high at 3 weeks; that of GH decreasing progressively between 3 and 14 weeks of age and thereafter remaining low, while that of Prl was low between 5 and 9 weeks, relatively high between 10 and 13 weeks, and then temporarily decreasing before increasing progressively during sexual maturation. Concentrations of T3 and T4 were higher in juvenile than in adult birds.

  15. Leptin stimulates hepatic growth hormone receptor and insulin-like growth factor gene expression in a teleost fish, the hybrid striped bass.

    PubMed

    Won, Eugene T; Douros, Jonathan D; Hurt, David A; Borski, Russell J

    2016-04-01

    Leptin is an anorexigenic peptide hormone that circulates as an indicator of adiposity in mammals, and functions to maintain energy homeostasis by balancing feeding and energy expenditure. In fish, leptin tends to be predominantly expressed in the liver, another important energy storing tissue, rather than in fat depots as it is in mammals. The liver also produces the majority of circulating insulin-like growth factors (IGFs), which comprise the mitogenic component of the growth hormone (GH)-IGF endocrine growth axis. Based on similar regulatory patterns of leptin and IGFs that we have documented in previous studies on hybrid striped bass (HSB: Morone saxatilis×Morone chrysops), and considering the co-localization of these peptides in the liver, we hypothesized that leptin might regulate the endocrine growth axis in a manner that helps coordinate somatic growth with energy availability. Using a HSB hepatocyte culture system to simulate autocrine or paracrine exposure that might occur within the liver, this study examines the potential for leptin to modulate metabolism and growth through regulation of IGF gene expression directly, or indirectly through the regulation of GH receptors (GHR), which mediate GH-induced IGF expression. First, we verified that GH (50nM) has a classical stimulatory effect on IGF-1 and additionally show it stimulates IGF-2 transcription in hepatocytes. Leptin (5 and/or 50nM) directly stimulated in vitro GHR2 gene expression within 8h of exposure, and both GHR1 and GHR2 as well as IGF-1 and IGF-2 gene expression after 24h. Cells were then co-incubated with submaximal concentrations of leptin and GH (25nM each) to test if they had a synergistic effect on IGF gene expression, possibly through increased GH sensitivity following GHR upregulation by leptin. In combination, however, the treatments only had an additive effect on stimulating IGF-1 mRNA despite their capacity to increase GHR mRNA abundance. This suggests that leptin's stimulatory

  16. Ex Vivo Assay of Electrical Stimulation to Rat Sciatic Nerves: Cell Behaviors and Growth Factor Expression.

    PubMed

    Du, Zhiyong; Bondarenko, Olexandr; Wang, Dingkun; Rouabhia, Mahmoud; Zhang, Ze

    2016-06-01

    Neurite outgrowth and axon regeneration are known to benefit from electrical stimulation. However, how neuritis and their surroundings react to electrical field is difficult to replicate by monolayer cell culture. In this work freshly harvested rat sciatic nerves were cultured and exposed to two types of electrical field, after which time the nerve tissues were immunohistologically stained and the expression of neurotrophic factors and cytokines were evaluated. ELISA assay was used to confirm the production of specific proteins. All cell populations survived the 48 h culture with little necrosis. Electrical stimulation was found to accelerate Wallerian degeneration and help Schwann cells to switch into migratory phenotype. Inductive electrical stimulation was shown to upregulate the secretion of multiple neurotrophic factors. Cellular distribution in nerve tissue was altered upon the application of an electrical field. This work thus presents an ex vivo model to study denervated axon in well controlled electrical field, bridging monolayer cell culture and animal experiment. It also demonstrated the critical role of electrical field distribution in regulating cellular activities.

  17. Stimulation of the growth of Jatropha curcas by the plant growth promoting bacterium Enterobacter cancerogenus MSA2.

    PubMed

    Jha, Chaitanya Kumar; Patel, Baldev; Saraf, Meenu

    2012-03-01

    A novel Enterobacter cancerogenus MSA2 is a plant growth promoting gamma-proteobacterium that was isolated from the rhizosphere of Jatropha cucas a potentially important biofuel feed stock plant. Based on phenotypic, physiological, biochemical and phylogenetic studies, strain MSA2 could be classified as a member of E. cancerogenus. However, comparisons of characteristics with other known species of the genus Enterobacter suggested that strain MSA2 could be a novel PGPB strain. In vitro studies were carried for the plant growth promoting attribute of this culture. It tested positive for ACC (1-aminocyclopropane-1-carboxylic acid) deaminase production, phytase, phosphate solubilization, IAA (Indole acetic acid) production, siderophore, and ammonia production. The isolate was then used as a inoculant for the vegetative study of Jatropha curcas plant. Enterobacter cancerogenus MSA2 supplemented with 1% carboxymethylcellulose showed overall plant growth promotion effect resulting in enhanced root length (124.14%), fresh root mass (81%), fresh shoot mass (120.02%), dry root mass (124%), dry shoot mass (105.54%), number of leaf (30.72%), chlorophyll content (50.41%), and biomass (87.20%) over control under the days of experimental observation. This study was designed for 120 days and was in triplicate and the data was collected at every 30 days.

  18. Melanoma Proteoglycan Modifies Gene Expression to Stimulate Tumor Cell Motility, Growth and Epithelial to Mesenchymal Transition

    PubMed Central

    Yang, Jianbo; Price, Matthew A.; Li, GuiYuan; Bar-Eli, Menashe; Salgia, Ravi; Jagedeeswaran, Ramasamy; Carlson, Jennifer H.; Ferrone, Soldano; Turley, Eva A.; McCarthy, James B.

    2009-01-01

    Melanoma chondroitin sulfate proteoglycan (MCSP) is a plasma membrane-associated proteoglycan that facilitates the growth, motility and invasion of tumor cells. MCSP expression in melanoma cells enhances integrin function and constitutive activation of Erk 1,2. The current studies were performed to determine the mechanism by which MCSP expression promotes tumor growth and motility. The results demonstrate that MCSP expression in radial growth phase (RGP), vertical growth phase (VGP) or metastatic cell lines causes sustained activation of Erk 1,2, enhanced growth and motility which all require the cytoplasmic domain of the MCSP core protein. MCSP expression in an RGP cell line also promotes an epithelial to mesenchymal transition (EMT) based on changes in cell morphology and the expression of several EMT markers. Finally MCSP enhances the expression of c-Met and HGF, and inhibiting c-Met expression or activation limits the increased growth and motility of multiple melanoma cell lines. The studies collectively demonstrate an importance for MCSP in promoting progression by an epigenetic mechanism and they indicate that MCSP could be targeted to delay or inhibit tumor progression in patients. PMID:19738072

  19. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

    PubMed Central

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-01-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506] PMID:25644636

  20. Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I.

    PubMed

    Lim, Chae Jin; Jeon, Jung Eun; Jeong, Se Kyoo; Yoon, Seok Jeong; Kwon, Seon Deok; Lim, Jina; Park, Keedon; Kim, Dae Yong; Ahn, Jeong Keun; Kim, Bong-Woo

    2015-09-01

    Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition.

  1. Acemannan stimulates gingival fibroblast proliferation; expressions of keratinocyte growth factor-1, vascular endothelial growth factor, and type I collagen; and wound healing.

    PubMed

    Jettanacheawchankit, Suwimon; Sasithanasate, Siriruk; Sangvanich, Polkit; Banlunara, Wijit; Thunyakitpisal, Pasutha

    2009-04-01

    Aloe vera has long been used as a traditional medicine for inducing wound healing. Gingival fibroblasts (GFs) play an important role in oral wound healing. In this study, we investigated the effects of acemannan, a polysaccharide extracted from Aloe vera gel, on GF proliferation; keratinocyte growth factor-1 (KGF-1), vascular endothelial growth factor (VEGF), and type I collagen production; and oral wound healing in rats. [(3)H]-Thymidine incorporation assay and ELISA were used. Punch biopsy wounds were created at the hard palate of male Sprague Dawley rats. All treatments (normal saline; 0.1% triamcinolone acetonide; plain 1% Carbopol; and Carbopol containing 0.5%, 1%, and 2% acemannan (w/w)) were applied daily. Wounded areas and histological features were observed at day 7 after treatment. From our studies, acemannan at concentrations of 2, 4, 8, and 16 mg/ml significantly induced cell proliferation (P<0.05). Acemannan concentrations between 2 - 16 mg/ml significantly stimulated KGF-1, VEGF, and type I collagen expressions (P<0.05). Wound healing of animals receiving Carbopol containing 0.5% acemannan (w/w) was significantly better than that of the other groups (P<0.05). These findings suggest that acemannan plays a significant role in the oral wound healing process via the induction of fibroblast proliferation and stimulation of KGF-1, VEGF, and type I collagen expressions.

  2. Glucose Stimulation of Transforming Growth Factor-β Bioactivity in Mesangial Cells Is Mediated by Thrombospondin-1

    PubMed Central

    Poczatek, Maria H.; Hugo, Christian; Darley-Usmar, Victor; Murphy-Ullrich, Joanne E.

    2000-01-01

    Glucose is a key factor in the development of diabetic complications, including diabetic nephropathy. The development of diabetic glomerulosclerosis is dependent on the fibrogenic growth factor, transforming growth factor-β (TGF-β). Previously we showed that thrombospondin-1 (TSP-1) activates latent TGF-β both in vitro and in vivo. Activation occurs as the result of specific interactions of latent TGF-β with TSP-1, which potentially alter the conformation of latent TGF-β. As glucose also up-regulates TSP-1 expression, we hypothesized that the increased TGF-β bioactivity observed in rat and human mesangial cells cultured with high glucose concentrations is the result of latent TGF-β activation by autocrine TSP-1. Glucose-induced bioactivity of TGF-β in mesangial cell cultures was reduced to basal levels by peptides from two different sequences that antagonize activation of latent TGF-β by TSP, but not by the plasmin inhibitor, aprotinin. Furthermore, glucose-dependent stimulation of matrix protein synthesis was inhibited by these antagonist peptides. These studies demonstrate that glucose stimulation of TGF-β activity and the resultant matrix protein synthesis are dependent on the action of autocrine TSP-1 to convert latent TGF-β to its biologically active form. These data suggest that antagonists of TSP-dependent TGF-β activation may be the basis of novel therapeutic approaches for ameliorating diabetic renal fibrosis. PMID:11021838

  3. Growth stimulation of Bacillus cereus and Pseudomonas putida using nanostructured ZnO thin film as transducer element

    NASA Astrophysics Data System (ADS)

    Loukanov, Alexandre; Filipov, Chavdar; Valcheva, Violeta; Lecheva, Marta; Emin, Saim

    2015-04-01

    The semiconductor zinc oxide nanomaterial (ZnO or ZnO:H) is widely used in advanced biosensor technology for the design of highly-sensitive detector elements for various applications. In the attempt to evaluate its effect on common microorganisms, two types of nanostructured transducer films have been used (average diameter 600-1000 nm). They have been prepared by using both wet sol-gel method and magnetron sputtering. Their polycrystalline structure and specific surface features have been analyzed by X-ray diffraction (XRD), scanning electron microscope, and atomic force microscope. The assessment of growth stimulation of bacteria was determined using epifluorescent microscope by cell staining with Live/Dead BacLight kit. In our experiments, the growth stimulation of Gram-positive and Gram-negative bacteria on nanostructured ZnO film is demonstrated by Bacillus cereus and Pseudomonas putida. These two bacterial species have been selected, because they are well known and studied in biosensor technologies, with structural difference of their cell walls. These pathogens are easy for with common source in the liquid food or some commercial products. Our data has revealed that the method of transducer film preparation influences strongly bacterial inhibition and division. These results present the transforming signal precisely, when ZnO is used in biosensor applications.

  4. Selective Endothelin-B Receptor Stimulation Increases Vascular Endothelial Growth Factor in the Rat Brain during Postnatal Development.

    PubMed

    Leonard, M G; Prazad, P; Puppala, B; Gulati, A

    2015-11-01

    Endothelin, vascular endothelial growth factor and nerve growth factor play important roles in development of the central nervous system. ET(B) receptors have been shown to promote neurovascular remodeling in the adult ischemic brain through an increase in VEGF and NGF. It is possible that ET(B) receptors may be involved in postnatal development of the brain through VEGF and NGF. In the present study, the brains of male rat pups on postnatal days 1, 7, 14 and 28 were analyzed for expression of ET(B) receptors, VEGF and NGF. In order to determine the effect of ET(B) receptor stimulation, a separate group of pups were administered saline or ET(B) receptor agonist, IRL-1620, on day 21, and their brains were analyzed on day 28. The intensity of ET(B) receptor and VEGF staining in the vasculature as well as the number of blood vessels of normal pups increased with age and was significantly higher on postnatal day 14 compared to day 1 and day 7. In contrast, both ET(B) and NGF staining intensity in the cortex and subventricular zones decreased (P<0.01) at postnatal day 14 compared to earlier time points. Stimulation of ET(B) receptors resulted in a significant increase in VEGF and ET(B) intensity both in the vasculature and the brain (P<0.05), however, IRL-1620 did not produce any change in NGF expression. Results indicate that ET(B) receptors appear to play a role in the development of the CNS and selective stimulation of ET(B) receptors enhances VEGF but not NGF in the postnatal rat brain.

  5. Down-Regulation by Resveratrol of Basic Fibroblast Growth Factor-Stimulated Osteoprotegerin Synthesis through Suppression of Akt in Osteoblasts

    PubMed Central

    Kuroyanagi, Gen; Otsuka, Takanobu; Yamamoto, Naohiro; Matsushima-Nishiwaki, Rie; Nakakami, Akira; Mizutani, Jun; Kozawa, Osamu; Tokuda, Haruhiko

    2014-01-01

    It is firmly established that resveratrol, a natural food compound abundantly found in grape skins and red wine, has beneficial properties for human health. In the present study, we investigated the effect of basic fibroblast growth factor (FGF-2) on osteoprotegerin (OPG) synthesis in osteoblast-like MC3T3-E1 cells and whether resveratrol affects the OPG synthesis. FGF-2 stimulated both the OPG release and the expression of OPG mRNA. Resveratrol significantly suppressed the FGF-2-stimulated OPG release and the mRNA levels of OPG. SRT1720, an activator of SIRT1, reduced the FGF-2-induced OPG release and the OPG mRNA expression. PD98059, an inhibitor of upstream kinase activating p44/p42 mitogen-activated protein (MAP) kinase, had little effect on the FGF-2-stimulated OPG release. On the other hand, SB203580, an inhibitor of p38 MAP kinase, SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and Akt inhibitor suppressed the OPG release induced by FGF-2. Resveratrol failed to affect the FGF-2-induced phosphorylation of p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. The phosphorylation of Akt induced by FGF-2 was significantly suppressed by resveratrol or SRT1720. These findings strongly suggest that resveratrol down-regulates FGF-2-stimulated OPG synthesis through the suppression of the Akt pathway in osteoblasts and that the inhibitory effect of resveratrol is mediated at least in part by SIRT1 activation. PMID:25290095

  6. Protein kinase C and epidermal growth factor stimulation of Raf1 potentiates adenylyl cyclase type 6 activation in intact cells.

    PubMed

    Beazely, Michael A; Alan, Jamie K; Watts, Val J

    2005-01-01

    Adenylyl cyclase type 6 (AC6) activity is inhibited by protein kinase C (PKC) in vitro; however, in intact cells, PKC activation does not inhibit the activity of transiently expressed AC6. To investigate the effects of PKC activation on AC6 activity in intact cells, we constructed human embryonic kidney (HEK) 293 cells that stably express wild-type AC6 (AC6-WT) or an AC6 mutant lacking a PKC and cyclic AMP-dependent protein kinase (PKA) phosphorylation site, Ser674 (AC6-S674A). In contrast to in vitro observations, we observed a PKC-mediated enhancement of forskolin- and isoproterenol-stimulated cyclic AMP accumulation in HEK-AC6 cells. Phorbol 12-myristate 13-acetate also potentiated cyclic AMP accumulation in cells expressing endogenous AC6, including Chinese hamster ovary cells and differentiated Cath.a differentiated cells. In HEK-AC6-S674A cells, the potentiation of AC6 stimulation was significantly greater than in cells expressing AC6-WT. The positive effect of PKC activation on AC6 activity seemed to involve Raf1 kinase because the Raf1 inhibitor 3-(3,5-dibromo-4-hydroxybenzylidene-5-iodo-1,3-dihydro-indol-2-one (GW5074) inhibited the PKC potentiation of AC6 activity. Furthermore, the forskolin-stimulated activity of a recombinant AC6 in which the putative Raf1 regulatory sites have been eliminated was not potentiated by activation of PKC. The ability of Raf1 to regulate AC6 may involve a direct interaction because AC6 and a constitutively active Raf1 construct were coimmunoprecipitated. In addition, we report that epidermal growth factor receptor activation also enhances AC6 signaling in a Raf1-dependent manner. These data suggest that Raf1 potentiates drug-stimulated cyclic AMP accumulation in cells expressing AC6 after activation of multiple signaling pathways.

  7. Relationships among acylation-stimulating protein, insulin resistance, lipometabolism, and fetal growth in gestational diabetes mellitus women.

    PubMed

    Xu, M; Liu, B; Wu, M-F; Chen, H-T; Cianflone, K; Wang, Z-L

    2015-05-01

    The aim of this study was to investigate the potential relationship between acylation-stimulating protein (ASP), insulin resistance, lipometabolism, the intrauterine metabolic environment and fetal growth in well-controlled gestational diabetes mellitus (GDM) women. A total of 55 well-controlled GDM women, 66 pregnant women with normal glucose tolerance (NGT) and their newborns, were included in this study. Fasting maternal and cord blood ASP, serum lipid profiles, glucose level, insulin level, HOMA-IR, in addition to neonatal anthropometry data, were measured. Maternal blood ASP in GDM is higher than that in NGT. In the GDM group, maternal blood ASP has a positive correlation with TG, FFA and HOMA-IR. Maternal and cord blood ASP levels of LGA fetuses correlate with elevated birth weight and SF4. Similarly, cord blood ASP levels of LGA fetuses also correlate with birth weight and SF4 in the NGT group. The maternal blood ASP level of GDM mothers is associated with lipometabolism, insulin resistance and LGA fetal growth. Nevertheless, the cord blood ASP level correlates with FFA of GDM mothers, LGA fetal growth of GDM and NGT mothers. ASP may be a biomarker for evaluating insulin resistance of GDM and LGA fetal growth.

  8. Bacterial exopolysaccharide and biofilm formation stimulate chickpea growth and soil aggregation under salt stress

    PubMed Central

    Qurashi, Aisha Waheed; Sabri, Anjum Nasim

    2012-01-01

    To compensate for stress imposed by salinity, biofilm formation and exopolysaccharide production are significant strategies of salt tolerant bacteria to assist metabolism. We hypothesized that two previously isolated salt-tolerant strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) have an ability to improve plant growth, These strains can form biofilm and accumulate exopolysacharides at increasing salt stress. These results showed that bacteria might be involved in developing microbial communities under salt stress and helpful in colonizing of bacterial strains to plant roots and soil particles. Eventually, it can add to the plant growth and soil structure. We investigated the comparative effect of exopolysacharide and biofilm formation in two bacterial strains Halomonas variabilis (HT1) and Planococcus rifietoensis (RT4) in response to varying salt stress. We found that biofilm formation and exopolysaccharide accumulation increased at higher salinity. To check the effect of bacterial inoculation on the plant (Cicer arietinum Var. CM-98) growth and soil aggregation, pot experiment was conducted by growing seedlings under salt stress. Inoculation of both strains increased plant growth at elevated salt stress. Weight of soil aggregates attached with roots and present in soil were added at higher salt concentrations compared to untreated controls. Soil aggregation was higher at plant roots under salinity. These results suggest the feasibility of using above strains in improving plant growth and soil fertility under salinity. PMID:24031943

  9. Climate change stimulates the growth of the intertidal macroalgae Ascophyllum nodosum near the northern distribution limit.

    PubMed

    Marbà, Núria; Krause-Jensen, Dorte; Olesen, Birgit; Christensen, Peter B; Merzouk, Anissa; Rodrigues, Joao; Wegeberg, Susse; Wilce, Robert T

    2017-02-01

    Ascophyllum nodosum is a foundation macroalgae of the intertidal zone that distributes across latitude 41.3-69.7°N. We tested the hypothesis that growth of A. nodosum near the northern distribution edge increases with warming. We retrospectively quantified the growth of eight A. nodosum populations at West Greenland and North Norway (from 64°N to 69°N). For seven populations, we measured growth rates since 1997-2002 and for one of them we extended the time series back to 1956 using published estimates. Individuals at northern populations elongated between 2.0 and 9.1 cm year(-1) and this variability correlated with temperature and annual ice-free days. A spatial comparison of A. nodosum growth across the species distribution range showed that Northern (and coldest) populations grew at the slowest rates. Our results demonstrate that arctic climate change enhances the growth of A. nodosum populations and suggest that their productivity may increase in response to projected global warming.

  10. Secretion by stimulated murine macrophages of a heparin-binding fibroblast growth activity, distinct from basic FGE and IL-1

    SciTech Connect

    Rappolee, D.A.; Banda, M.J.; Werb, Z.

    1986-03-01

    Wound healing requires granulation and formation of neovascularization tissue. These two events require increases in fibroblasts, vascular endothelial, and smooth muscle cells. Macrophages may produce several growth factors which participate in these would healing events. To test this hypothesis they have partially purified a fibroblast growth promoting activity from a murine macrophage cell line (P388 Dl). The activity causes growth in Balb/c and Swiss 3T3 cells as measured by thymidine uptake, nuclear labeling and increase in cell number. PDGF, Basic FGF, and EGF are also mitogenic by thymidine uptake, but purified human IL-1 and recombinant murine IL-1 are not. The activity is pH 2.5-, freeze/thaw-, and dialysis/lyphilyzation-stable. The activity elutes from heparin-Sepharose at 2.0M, but not 0.15m, 0.5M, or 3.0M NaCl. Basic FGF elutes from the same heparin-Sepharose batch at 3.0M, but not at the other three NaCl concentrations. The growth activity is secreted by viable murine macrophage line cells (P388D1, WEHI-3, RAW 264.7) at a 48 hour peak after activating (LPS) or phagocytic stimuli. Unstimulated P388D1 caused growth 1.7 times control whereas stimulation increases the growth 5.1 to 7.1 times control. The optimal activity concentration fails to complement insulin in an assay in which optimal basic FGF concentration complements insulin. These data suggest that the activity may contain a progression factor.

  11. Growth factor- and cytokine-stimulated endothelial progenitor cells in post-ischemic cerebral neovascularization

    PubMed Central

    Peplow, Philip V.

    2014-01-01

    Endothelial progenitor cells are resident in the bone marrow blood sinusoids and circulate in the peripheral circulation. They mobilize from the bone marrow after vascular injury and home to the site of injury where they differentiate into endothelial cells. Activation and mobilization of endothelial progenitor cells from the bone marrow is induced via the production and release of endothelial progenitor cell-activating factors and includes specific growth factors and cytokines in response to peripheral tissue hypoxia such as after acute ischemic stroke or trauma. Endothelial progenitor cells migrate and home to specific sites following ischemic stroke via growth factor/cytokine gradients. Some growth factors are less stable under acidic conditions of tissue ischemia, and synthetic analogues that are stable at low pH may provide a more effective therapeutic approach for inducing endothelial progenitor cell mobilization and promoting cerebral neovascularization following ischemic stroke. PMID:25317152

  12. Characterization of lymphokines mediating B cell growth and differentiation from monoclonal anti-CD3 antibody-stimulated T cells.

    PubMed

    Sherris, D; Stohl, W; Mayer, L

    1989-04-01

    Addition of anti-CD3 mAb 147 (IgG1), 446 (IgG1), or 454 (IgG2a) to cultures of T plus non-T cells can result in both B cell growth and differentiation. To determine whether lymphokines mediating these activities were similar to those described from conventional mitogen-induced T cell activation, normal peripheral blood T cells were stimulated with anti-CD3 mAb for 48 h. The supernatants were assayed for factors inducing B cell growth or differentiation (BCDF). A marked increase in Ig secretion was observed when either EBV-transformed B cell lines or normal B cells, pre-activated with Staphylococcus aureus Cowan I strain, were cultured in the presence of mAb 446 (anti-CD3) stimulated T cell supernatant whereas no significant increase in Ig secretion was noted with either mAb 454- or 147-induced T cell supernatant despite equivalent T cell proliferative responses to these antibodies. In contrast, IL-2 secretion was detectable in T cell supernatants from T cells stimulated with either mAb 454 or 147 but not 446. Factors promoting B cell proliferation were detected in all antibody-stimulated T cell supernatants but, contrary to BCDF, appear to act only on non-activated B cells. To determine whether these effector activities were due to distinct lymphokines, supernatants were pooled and concentrated by ammonium sulfate precipitation. Superose 12 permeation chromatography revealed BCDF activity with an apparent Mr of approximately 30,000 Da. The growth factor activity eluted over a wider and higher molecular weight range which overlapped the differentiation factor activity. Fractions containing BCDF activity were pooled, dialyzed, applied to a Mono Q anion-exchange column, and eluted with a linear NaCl gradient. The growth factor activity came off in a single-peak while BCDF was found divided into two major areas. The growth factor eluted at an ionic strength between the two BCDF activities. BCDF has an apparent isoelectric point (pI) of 6, in contrast to the reported p

  13. Growth Disorders

    MedlinePlus

    ... gland problem or disease. The pituitary gland makes growth hormone, which stimulates the growth of bone and other ... of it may be very short. Treatment with growth hormone can stimulate growth. People can also have too ...

  14. Stimulation of chick embryo cartilage sulfate and thymidine uptake: comparison of human serum, purified somatomedins, and other growth factors.

    PubMed

    Jennings, J; Buchanan, F; Freeman, D; Garland, J T

    1980-11-01

    We have compared the stimulation of sulfate and thymidine uptake into 10-day-old embryonic chick cartilage by normal human serum, partially purified somatomedins (Sm) A and B, homogeneous insulin-like growth factors (IGFs) I and II, and several other substances. With the exception of epidermal growth factor, all growth factors ((GFs) were assayed in the absence of other protein. Pelvic rudiments were preincubated in buffer for 6 h and then incubated for 24 h with the GF or serum, with labels added for the final 6 h. Human serum enhanced cartilage uptake of both thymidine and sulfate. There was a dose-dependent stimulation of thymidine uptake by Sm A or B (0.05--2 microgram/ml) and IGF I or II (0.5--20 ng/ml). Unlike serum, neither Sms nor IGFs increased SO4 uptake under these conditions. Bovine GH (10--500 ng/ml), albumin (100-1000 ng/ml), fibroblast GF (1--100 ng/ml), and epidermal GF (1--100 ng/ml) were inactive for both thymidine and sulfate. When a shorter incubation was used (7 h), Sm A enhanced SO4 uptake, and discrimination was increased by preincubation of the rudiments in buffer for 24 h. With this procedure, IGF I (0.5 ng/ml) was nearly equipotent to 5% serum. On a weight basis, IGF I was more active than either Sm A or IGF II. The data suggest that assay conditions are crucial for demonstration of Sm activity. Appropriate conditions may be different for isolated GF than for a complex medium such as serum. The results further suggest that with certain protocols, the responsiveness of chick embryo cartilage is qualitatively similar to that of hypophysectomized rat cartilage.

  15. Stimulation of appetite and the growth, stress, and immune axes of weanling pigs by syndyphalin-33

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parameters measuring growth, stress, and immune response in weanling pigs given the opiate tripeptide syndyphalin-33 (SD) were investigated in three separate trials. In the first trial, 8 nursing pigs were given SD (0.5 umol/kg, n = 4) or vehicle (VEH; n = 4) in a single im injection at 13 d of age ...

  16. Increased daylength stimulates plasma growth hormone and gill Na+, K+ and -ATPase Atlantic salmon (Salmo salar )

    USGS Publications Warehouse

    McCormick, S.D.; Bjornsson, Bjorn Thrandur; Sheridan, M.; Eilertson, C.; Carey, J.B.; O'Dea, M.

    1995-01-01

    Atlantic salmon juveniles reared at constant temperature (9–10°C) were exposed to four photoperiod treatment and sampled every 2 weeks from January through May. Fish reared under normal photoperiod exhibited eight-and three fold increases in plasma growth hormone and gill Na+, K+-ATPase activity, respectively, between January and April. Fish exposed to abrupt increases in daylength (LD 15:9) in February or March responded with earlier increases in plasma growth hormone and gill Na+, K+-ATPase activity, and earlier decreases in condition factor relative to fish in the normal photoperiod group. Fish maintained under short daylength (LD 9:15) from January to May exhibited delayed and muted increases in plasma growth hormone and gill Na+, K+-ATPase activity. Plasma thyroxine exhibited a 2.5-fold increase from February to late March in the normal photoperiod group, was generally lower in the LD 9:15 group, but exhibited no obvious response to abrupt increases in daylength. There was an increase in plasma 3,5,3′-triiodo-l-thyronine with time in all groups (43–80%) but no significant response to photoperiod. Plasma levels of somatostatin-25 were highest in the LD 9:15 group, but there was no detectable response to increased daylength in any of the photoperiod treatments. The results indicate that plasma growth hormone is responsive to increased daylength and may be causally related to subsequent increases in gill Na+, K+-ATPase.

  17. Laser Sintered Porous Ti-6Al-4V Implants Stimulate Vertical Bone Growth.

    PubMed

    Cheng, Alice; Cohen, David J; Kahn, Adrian; Clohessy, Ryan M; Sahingur, Kaan; Newton, Joseph B; Hyzy, Sharon L; Boyan, Barbara D; Schwartz, Zvi

    2017-04-13

    The objective of this study was to examine the ability of 3D implants with trabecular-bone-inspired porosity and micro-/nano-rough surfaces to enhance vertical bone ingrowth. Porous Ti-6Al-4V constructs were fabricated via laser-sintering and processed to obtain micro-/nano-rough surfaces. Male and female human osteoblasts were seeded on constructs to analyze cell morphology and response. Implants were then placed on rat calvaria for 10 weeks to assess vertical bone ingrowth, mechanical stability and osseointegration. All osteoblasts showed higher levels of osteocalcin, osteoprotegerin, vascular endothelial growth factor and bone morphogenetic protein 2 on porous constructs compared to solid laser-sintered controls. Porous implants placed in vivo resulted in an average of 3.1 ± 0.6 mm(3) vertical bone growth and osseointegration within implant pores and had significantly higher pull-out strength values than solid implants. New bone formation and pull-out strength was not improved with the addition of demineralized bone matrix putty. Scanning electron images and histological results corroborated vertical bone growth. This study indicates that Ti-6Al-4V implants fabricated by additive manufacturing to have porosity based on trabecular bone and post-build processing to have micro-/nano-surface roughness can support vertical bone growth in vivo, and suggests that these implants may be used clinically to increase osseointegration in challenging patient cases.

  18. Stimulation of the multiplication of Micrococcus luteus by an autocrine growth factor.

    PubMed

    Mukamolova, G V; Kormer, S S; Kell, D B; Kaprelyants, A S

    1999-07-01

    Viable cells of Micrococcus luteus secrete a proteineous growth factor (Rpf) which promotes the resuscitation of dormant, nongrowing cells to yield normal, colony-forming bacteria. When washed M. luteus cells were used as an inoculum, there was a pronounced influence of Rpf on the true lag phase and cell growth on lactate minimal medium. In the absence of Rpf, there was no increase in colony-forming units for up to 10 days. When the inoculum contained less than 10(5) cells ml-1, macroscopically observable M. luteus growth was not obtained in succinate minimal medium unless Rpf was added. Incubation of M. luteus in the stationary phase for 100 h resulted in a failure of the cells to grow in lactate minimal medium from inocula of small size although the viability of these cells was close to 100% as estimated using agar plates made from lactate minimal medium or rich medium. The underestimation of viable cells by the most-probable-number (MPN) method in comparison with colony-forming units was equivalent to the requirement that at least 10(5) cells grown on succinate medium, 10(3) cells from old stationary phase, or approximately 10-500 washed cells are required per millilitre of inoculum for growth to lead to visible turbidity. The addition of Rpf in the MPN dilutions led to an increase of the viable cell numbers estimated to approximately the same levels as those determined by colony-forming units. Thus, a basic principle of microbiology - "one cell-one culture" - may not be applicable in some circumstances in which the metabolic activity of "starter" cells is not sufficient to produce enough autocrine growth factor to support cell multiplication.

  19. c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

    SciTech Connect

    Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh; Hwang, Pyoung-Han; Yi, Ho-Keun; Nam, Sang-Yun; Lee, Dae-Yeol

    2009-07-17

    c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

  20. Stimulated bacterial growth under elevated p CO₂: results from an off-shore mesocosm study.

    PubMed

    Endres, Sonja; Galgani, Luisa; Riebesell, Ulf; Schulz, Kai-Georg; Engel, Anja

    2014-01-01

    Marine bacteria are the main consumers of freshly produced organic matter. Many enzymatic processes involved in the bacterial digestion of organic compounds were shown to be pH sensitive in previous studies. Due to the continuous rise in atmospheric CO2 concentration, seawater pH is presently decreasing at a rate unprecedented during the last 300 million years but the consequences for microbial physiology, organic matter cycling and marine biogeochemistry are still unresolved. We studied the effects of elevated seawater pCO2 on a natural plankton community during a large-scale mesocosm study in a Norwegian fjord. Nine Kiel Off-Shore Mesocosms for Future Ocean Simulations (KOSMOS) were adjusted to different pCO2 levels ranging initially from ca. 280 to 3000 µatm and sampled every second day for 34 days. The first phytoplankton bloom developed around day 5. On day 14, inorganic nutrients were added to the enclosed, nutrient-poor waters to stimulate a second phytoplankton bloom, which occurred around day 20. Our results indicate that marine bacteria benefit directly and indirectly from decreasing seawater pH. During the first phytoplankton bloom, 5-10% more transparent exopolymer particles were formed in the high pCO2 mesocosms. Simultaneously, the efficiency of the protein-degrading enzyme leucine aminopeptidase increased with decreasing pH resulting in up to three times higher values in the highest pCO2/lowest pH mesocosm compared to the controls. In general, total and cell-specific aminopeptidase activities were elevated under low pH conditions. The combination of enhanced enzymatic hydrolysis of organic matter and increased availability of gel particles as substrate supported up to 28% higher bacterial abundance in the high pCO2 treatments. We conclude that ocean acidification has the potential to stimulate the bacterial community and facilitate the microbial recycling of freshly produced organic matter, thus strengthening the role of the microbial loop in the

  1. Catecholamine-Stimulated Growth of Aeromonas hydrophila Requires the TonB2 Energy Transduction System but Is Independent of the Amonabactin Siderophore

    PubMed Central

    Dong, Yuhao; Liu, Jin; Pang, Maoda; Du, Hechao; Wang, Nannan; Awan, Furqan; Lu, Chengping; Liu, Yongjie

    2016-01-01

    The growth-stimulating effects of catecholamine stress hormones have been demonstrated in many pathogens. However, catecholamine-induced growth and its underlying mechanisms remain poorly understood in Aeromonas hydrophila. The present study sought to demonstrate that norepinephrine (NE), epinephrine (Epi), dopamine (Dopa), and L-dopa stimulate the growth of A. hydrophila in iron-restricted media containing serum. NE exhibited the strongest growth stimulation, which could be blocked by adrenergic antagonists. Furthermore, it was demonstrated that NE could sequester iron from transferrin, thereby providing a more accessible iron source for utilization by A. hydrophila. The deletion of the amoA gene associated with amonabactin synthesis revealed that the amonabactin siderophore is not required for NE-stimulated growth. However, the deletion of the TonB2 energy transduction system resulted in the loss of growth promotion by NE, indicating that a specific TonB-dependent outer membrane receptor might be involved in the transport of iron from transferrin. Collectively, our data show that catecholamine sensing promotes the growth of A. hydrophila in a manner that is dependent on the TonB2 energy transduction system. PMID:28018865

  2. Enhancement of plant growth stimulation activity of irradiated alginate by fractionation

    NASA Astrophysics Data System (ADS)

    Luan, Le Quang; Nagasawa, Naotsugu; Ha, Vo Thi Thu; Hien, Nguyen Quoc; Nakanishi, Tomoko M.

    2009-09-01

    Alginate with the weight-average molecular weight ( Mw) approximately 900 kDa and ratio of M (mannuronate)/G (guluronate) about 1.3 was irradiated by gamma Co-60 in aqueous solution at doses up to 200 kGy. The irradiation dose was shown to be a function for reducing Mw and molecular weight distribution of irradiated alginates. The distribution of oligomer fractions in irradiated products was also investigated by separation using ultrafiltration membranes. The irradiated alginate with Mw approximately 14.2 kDa was found to have a positive influence for growing of barley and soybean. The irradiated oligoalginate fraction with Mw ranging from 1 to 3 kDa displayed the strongest effect on the growth and development of the mentioned plants at low concentration (20 ppm). It is suggested that oligoalginate with Mw in the range 1-3 kDa is a trigger for the growth and development of plants.

  3. Flavonols Stimulate Development, Germination, and Tube Growth of Tobacco Pollen 1

    PubMed Central

    Ylstra, Bauke; Touraev, Alisher; Moreno, Rosa Maria Benito; Stöger, Eva; van Tunen, Arjen J.; Vicente, Oscar; Mol, Joseph N. M.; Heberle-Bors, Erwin

    1992-01-01

    The effect of anther-derived substances on pollen function was studied using pollen produced by in vitro culture of immature pollen of tobacco (Nicotiana tabacum L.) and petunia (Petunia hybrida). Addition of conditioned medium consisting of diffusates from in situ matured pollen strongly increased pollen germination frequency and pollen tube growth, as well as seed set after in situ pollination. Thin-layer chromatography and depletion of phenolic substances by Dowex treatment indicated that flavonols are present in the diffusate and may be the active compounds. When added to the germination medium, flavonols (quercetin, kaempferol, myricetin) but not other flavonoids strongly promoted pollen germination frequency and pollen tube growth in vitro. The best results were obtained at very low concentrations of the flavonols (0.15-1.5 μm), indicating a signaling function. The same compounds were also effective when added during pollen development in vitro. Images Figure 1 Figure 5 PMID:16653074

  4. Metabolic remodeling of the tumor microenvironment: migration stimulating factor (MSF) reprograms myofibroblasts toward lactate production, fueling anabolic tumor growth.

    PubMed

    Carito, Valentina; Bonuccelli, Gloria; Martinez-Outschoorn, Ubaldo E; Whitaker-Menezes, Diana; Caroleo, Maria Cristina; Cione, Erika; Howell, Anthony; Pestell, Richard G; Lisanti, Michael P; Sotgia, Federica

    2012-09-15

    Migration stimulating factor (MSF) is a genetically truncated N-terminal isoform of fibronectin that is highly expressed during mammalian development in fetal fibroblasts, and during tumor formation in human cancer-associated myofibroblasts. However, its potential functional role in regulating tumor metabolism remains unexplored. Here, we generated an immortalized fibroblast cell line that recombinantly overexpresses MSF and studied their properties relative to vector-alone control fibroblasts. Our results indicate that overexpression of MSF is sufficient to confer myofibroblastic differentiation, likely via increased TGF-b signaling. In addition, MSF activates the inflammation-associated transcription factor NFκB, resulting in the onset of autophagy/mitophagy, thereby driving glycolytic metabolism (L-lactate production) in the tumor microenvironment. Consistent with the idea that glycolytic fibroblasts fuel tumor growth (via L-lactate, a high-energy mitochondrial fuel), MSF fibroblasts significantly increased tumor growth, by up to 4-fold. Mechanistic dissection of the MSF signaling pathway indicated that Cdc42 lies downstream of MSF and fibroblast activation. In accordance with this notion, Cdc42 overexpression in immortalized fibroblasts was sufficient to drive myofibroblast differentiation, to provoke a shift towards glycolytic metabolism and to promote tumor growth by up to 2-fold. In conclusion, the MSF/Cdc42/NFκB signaling cascade may be a critical druggable target in preventing "Warburg-like" cancer metabolism in tumor-associated fibroblasts. Thus, MSF functions in the metabolic remodeling of the tumor microenvironment by metabolically reprogramming cancer-associated fibroblasts toward glycolytic metabolism.

  5. Indirect effects of UV radiation: Fe{sup 2+} enrichment stimulates picocyanobacterial growth in Clearwater acidic Shield lakes

    SciTech Connect

    Auclair, J.C.

    1995-12-31

    Ozone depletion and associated increases in UVB radiation could increase the photoreduction of iron in Shield lakes of the Boreal forest zone. Since photoreduced iron (I) is more soluble than iron (III), and the re-oxidation rate slower in acidic (pH = 5--6) lakes, phytoplankton growth and/or species composition may be altered where iron is growth limiting. The differential enrichment of UV{sub A+B} transparent herbivore-free (< 65 mu) lakewater enclosures ({approximately}500L) with phosphorus, phosphorus and Fe (II) and phosphorus, ammonium and Fe (II) revealed that the Spring phytoplankton abundance of an oligotrophic Clearwater acidic Canadian Shield lake was limited by herbivore grazing, rather than by a limiting nutrient. However, in the herbivore-free enriched enclosures the addition of Fe{sup 2+} greatly stimulated picocyanobacterial growth and grazing activity by mixotrophic species comprising the microbial food web of this lake. In spite of a 10-fold increase in the mixotrophic chrysophytes, the authors did not discern any strong competitive interactions among the mixotrophic organisms, strongly suggesting that the latter obtain most if not all of their iron quota from their picoplanktonic prey.

  6. IAA stimulates pollen tube growth and mediates the modification of its wall composition and structure in Torenia fournieri

    PubMed Central

    Wu, Juan-Zi; Lin, Yi; Zhang, Xue-Lian; Pang, Dai-Wen; Zhao, Jie

    2008-01-01

    The effects of several hormones on pollen tube growth were compared in Torenia fournieri and it was found that IAA was the most effective, stimulating pollen tube growth and causing the shank part of pollen tubes to be slender and straighter. The role of IAA was investigated by studying the changes in ultrastructure and PM H+-ATPase distribution in the pollen tubes and the modification of the tube wall. Using the fluorescent marker FM4-64, together with transmission electron microscopy, it was shown that secretory vesicles and mitochondria increased in IAA-treated tubes. Immunolocalization and fluorescence labelling, together with Fourier-transform infrared analysis, detected that IAA enhanced the level of PM H+-ATPase and the synthesis of pectins, and reduced the cellulose density in pollen tubes. Importantly, to observe the orientation of cellulose microfibrils in pollen tubes in situ, atomic force microscopy was used to examine the ‘intact’ tube wall. Atomic force microscopy images showed that cellulose microfibrils were parallel to each other in the subapical region of IAA-treated tubes, but disorganized in control tubes. All results provided new insights into the functions of cellulose microfibrils in pollen tube growth and direction, and revealed that the IAA-induced changes of pollen tubes were attributed to the increase in secretory vesicles, mitochondria, and PM H+-ATPase, and the modification of pectin and cellulose microfibrils in the tube wall. PMID:18544613

  7. Increased soil phosphorus availability induced by faba bean root exudation stimulates root growth and phosphorus uptake in neighbouring maize.

    PubMed

    Zhang, Deshan; Zhang, Chaochun; Tang, Xiaoyan; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R; Davies, William J; Shen, Jianbo

    2016-01-01

    Root growth is influenced by soil nutrients and neighbouring plants, but how these two drivers affect root interactions and regulate plant growth dynamics is poorly understood. Here, interactions between the roots of maize (Zea mays) and faba bean (Vicia faba) are characterized. Maize was grown alone (maize) or with maize (maize/maize) or faba bean (maize/faba bean) as competitors under five levels of phosphorus (P) supply, and with homogeneous or heterogeneous P distribution. Maize had longer root length and greater shoot biomass and P content when grown with faba bean than with maize. At each P supply rate, faba bean had a smaller root system than maize but greater exudation of citrate and acid phosphatase, suggesting a greater capacity to mobilize P in the rhizosphere. Heterogeneous P availability enhanced the root-length density of maize but not faba bean. Maize root proliferation in the P-rich patches was associated with increased shoot P uptake. Increased P availability by localized P application or by the presence of faba bean exudation stimulated root morphological plasticity and increased shoot growth in maize in the maize/faba bean mixture, suggesting that root interactions of neighbouring plants can be modified by increased P availability.

  8. Cracking Streptococcus thermophilus to stimulate the growth of the probiotic Lactobacillus casei in co-culture.

    PubMed

    Ma, Chengjie; Ma, Aimin; Gong, Guangyu; Liu, Zhenmin; Wu, Zhengjun; Guo, Benheng; Chen, Zhengjun

    2015-10-01

    Lactobacillus casei, a probiotic, and Streptococcus thermophilus, a fast acidifying lactic acid bacterial strain, are both used in the food industry. The aim of this study was to investigate the interaction between L. casei and S. thermophilus in the presence or absence of S. thermophilus-specific bacteriophage during milk fermentation. The acidification capability of L. casei co-cultured with S. thermophilus was significantly higher than that observed for L. casei or S. thermophilus cultured alone. However, the probiotic content (i.e., L. casei cell viability) was low. The fastest acidification and the highest viable L. casei cell count were observed in co-cultures of L. casei and S. thermophilus with S. thermophilus phage. In these co-cultures, S. thermophilus compensated for the slow acid production of L. casei in the early exponential growth phase. Thereafter, phage-induced lysis of the S. thermophilus cells eliminated the competition for nutrients, allowing L. casei to grow well. Additionally, the ruptured S. thermophilus cells released intracellular factors, which further promoted the growth and function of the probiotic bacteria. Crude cellular extract isolated from S. thermophilus also significantly accelerated the growth and propagation of L. casei, supporting the stimulatory role of the phage on this micro-ecosystem.

  9. Neuropilin-1 stimulates tumor growth by increasing fibronectin fibril assembly in the tumor microenvironment

    PubMed Central

    Yaqoob, Usman; Cao, Sheng; Shergill, Uday; Jagavelu, Kumaravelu; Geng, Zhimin; Yin, Meng; de Assuncao, Thiago M; Cao, Ying; Szabolcs, Anna; Thorgeirsson, Snorri; Schwartz, Martin; Yang, Ju Dong; Ehman, Richard; Roberts, Lewis; Mukhopadhyay, Debabrata; Shah, Vijay H.

    2012-01-01

    The tumor microenvironment, including stromal myofibroblasts and associated matrix proteins, regulates cancer cell invasion and proliferation. Here we report that neuropilin-1 (NRP-1) orchestrates communications between myofibroblasts and soluble fibronectin (FN) that promote α5β1 integrin-dependent FN fibril assembly, matrix stiffness, and tumor growth. Tumor growth and FN fibril assembly was reduced by genetic depletion or antibody neutralization of NRP-1 from stromal myofibroblasts in vivo. Mechanistically, the increase in FN fibril assembly required glycosylation of serine 612 of the extracellular domain of NRP-1, an intact intracellular NRP-1 SEA domain, and intracellular associations between NRP-1, the scaffold protein GIPC, and the nonreceptor tyrosine kinase c-Abl, that augmented α5β1 FN fibril assembly activity. Analysis of human cancer specimens established an association between tumoral NRP-1 levels and clinical outcome. Our findings indicate that NRP-1 activates the tumor microenvironment, thereby promoting tumor growth. These results not only identify new molecular mechanisms of FN fibril assembly but also have important implications for therapeutic targeting of the myofibroblast in the tumor microenvironment. PMID:22738912

  10. The novel growth factor, progranulin, stimulates mouse cholangiocyte proliferation via sirtuin-1-mediated inactivation of FOXO1.

    PubMed

    Frampton, Gabriel; Ueno, Yoshiyuki; Quinn, Matthew; McMillin, Matthew; Pae, Hae Yong; Galindo, Cheryl; Leyva-Illades, Dinorah; DeMorrow, Sharon

    2012-12-01

    Progranulin (PGRN), a secreted growth factor, regulates the proliferation of various epithelial cells. Its mechanism of action is largely unknown. Sirtuin 1 (Sirt1) is a protein deacetylase that is known to regulate the transcriptional activity of the forkhead receptor FOXO1, thereby modulating the balance between proapoptotic and cell cycle-arresting genes. We have shown that PGRN is overexpressed in cholangiocarcinoma and stimulates proliferation. However, its effects on hyperplastic cholangiocyte proliferation are unknown. In the present study, the expression of PGRN and its downstream targets was determined after bile duct ligation (BDL) in mice and in a mouse cholangiocyte cell line after stimulation with PGRN. The effects of PGRN on cholangiocyte proliferation were assessed in sham-operated (sham) and BDL mice treated with PGRN or by specifically knocking down endogenous PGRN expression using Vivo-Morpholinos or short hairpin RNA. PGRN expression and secretion were upregulated in proliferating cholangiocytes isolated after BDL. Treatment of mice with PGRN increased biliary mass and cholangiocyte proliferation in vivo and in vitro and enhanced cholangiocyte proliferation observed after BDL. PGRN treatment decreased Sirt1 expression and increased the acetylation of FOXO1, resulting in the cytoplasmic accumulation of FOXO1 in cholangiocytes. Overexpression of Sirt1 in vitro prevented the proliferative effects of PGRN. Conversely, knocking down PGRN expression in vitro or in vivo inhibited cholangiocyte proliferation. In conclusion, these data suggest that the upregulation of PGRN may be a key feature stimulating cholangiocyte proliferation. Modulating PGRN levels may be a viable technique for regulating the balance between ductal proliferation and ductopenia observed in a variety of cholangiopathies.

  11. Effects of methylmercury on primary cultured rat hepatocytes: Cell injury and inhibition of growth factor stimulated DNA synthesis

    SciTech Connect

    Tanno, Keiichi; Fukazawa, Toshiyuki; Tajima, Shizuko; Fujiki, Motoo )

    1992-08-01

    Many more studies deal with the toxicity of methylmercury on nervous tissue than on its toxicity to the liver. Methylmercury accumulates in the liver in higher concentrations than brain and the liver has the primary function of detoxifying methylmercury. According to recent studies, hepatocyte mitochondrial membranes are destroyed by methylmercury and DNA synthesis is inhibited by methylmercury during hepatocyte regeneration. Methylmercury alters the membrane ion permeability of isolate skate hepatocytes, and inhibits the metal-sensitive alcohol dehydrogenase and glutathione reductase of primary cultured rat hepatocytes. However, little is known about the effect of methylmercury on hepatocyte proliferation in primary cultured rat hepatocytes. We therefore used the primary cultured rat hepatocytes to investigate the effects of methylmercury on cell injury and growth factor stimulate DNA synthesis. The primary effect of methylmercury is to inhibit hepatocyte proliferation rather than to cause direct cell injury. 16 refs., 4 figs.

  12. A Novel Lactobacillus casei LP1 Producing 1,4-Dihydroxy-2-Naphthoic Acid, a Bifidogenic Growth Stimulator.

    PubMed

    Kang, Jo-Eun; Kim, Tae-Jung; Moon, Gi-Seong

    2015-03-01

    1,4-Dihydroxy-2-naphthoic acid (DHNA) is a bifidogenic growth stimulator (BGS) and could be a functional food ingredient since bifidobacteria are beneficial for human health. For that reason, lactic acid bacteria producing DHNA have been screened. A lactic acid bacterium LP1 strain isolated from a natural cheese was confirmed to produce DHNA, analyzed by a HPLC method. The strain was identified as Lactobacillus casei by 16S rRNA gene sequence analysis. The cell-free supernatant of fermented whey produced by L. casei LP1 presented the BGS activity for three bifidobacterial strains such as Bifidobacterium longum subsp. infantis KCTC 3127, Bifidobacterium bifidum KCTC 3202, and Bifidobacterium breve KCTC 3220 which were human-originated. To the best of our knowledge, a L. casei strain which can produce DHNA was firstly identified in this study.

  13. Oral phosphorus supplementation secondarily increases circulating fibroblast growth factor 23 levels at least partially via stimulation of parathyroid hormone secretion.

    PubMed

    Takasugi, Satoshi; Akutsu, Miho; Nagata, Masashi

    2014-01-01

    Oral phosphorus supplementation stimulates fibroblast growth factor 23 (FGF23) secretion; however, the underlying mechanism remains unclear. The aim of this study was to investigate the involvement of parathyroid hormone (PTH) in increased plasma FGF23 levels after oral phosphorus supplementation in rats. Rats received single dose of phosphate with concomitant subcutaneous injection of saline or human PTH (1-34) after treatment with cinacalcet or its vehicle. Cinacalcet is a drug that acts as an allosteric activator of the calcium-sensing receptor and reduces PTH secretion. Plasma phosphorus and PTH levels significantly increased 1 h after oral phosphorus administration and returned to basal levels within 3 h, while plasma FGF23 levels did not change up to 2 h post-treatment, but rather significantly increased at 3 h after administration and maintained higher levels for at least 6 h compared with the 0 time point. Plasma PTH and FGF23 levels were significantly lower in the cinacalcet-treated rats than in the vehicle-treated rats. Plasma phosphorus levels were significantly higher in the cinacalcet-treated rats than in the vehicle-treated rats at 2, 3, 4, and 6 h after oral phosphorus administration. Furthermore, rats treated with cinacalcet+human PTH (1-34) showed transiently but significantly higher plasma FGF23 levels at 3 h after oral phosphorus administration compared with cinacalcet-treated rats. These results suggest that oral phosphorus supplementation secondarily increases circulating FGF23 levels at least partially by stimulation of PTH secretion.

  14. Polysaccharides from Capsosiphon fulvescens stimulate the growth of IEC-6 Cells by activating the MAPK signaling pathway.

    PubMed

    Go, Hiroe; Hwang, Hye-Jung; Nam, Taek-Jeong

    2011-06-01

    Seaweed extracts show diverse bioactivities, such as antioxidant and antitumor activity. Capsosiphon fulvescens is a green alga that is abundant along the southwest coast of South Korea. Although it is consumed for its purported health-enhancing properties, particularly as a treatment for stomach disorders and hangovers, the health effects of dietary C. fulvescens remain unclear. We extracted polysaccharides from C. fulvescens (Cf-PS), investigated their effects on the proliferation of rat small intestinal epithelial IEC-6 cells, and determined the signaling cascade involved. We cultured IEC-6 cells in the presence of Cf-PS, which stimulated cell proliferation in a dose-dependent manner, and analyzed the Wnt and MAPK signaling pathways, which are related to cell proliferation. Cf-PS treatment induced the translocation of β-catenin, an effector of the Wnt signaling pathway, from the cytosol to the nucleus and increased the expression of cyclinD1 and c-myc. Cf-PS also induced ERK1/2 phosphorylation, which is activated by mitogenic and proliferative stimuli such as growth factors, but the phosphorylation of JNK and p38 was not enhanced. Our results show that Cf-PS regulates proliferation via stimulating the nuclear translocation of β-catenin and ERK1/2 activation in intestinal epithelial cells.

  15. An Antagonistic Vascular Endothelial Growth Factor (VEGF) Variant Inhibits VEGF-Stimulated Receptor Autophosphorylation and Proliferation of Human Endothelial Cells

    NASA Astrophysics Data System (ADS)

    Siemeister, Gerhard; Schirner, Michael; Reusch, Petra; Barleon, Bernhard; Marme, Dieter; Martiny-Baron, Georg

    1998-04-01

    Vascular endothelial growth factor (VEGF) is a potent mitogen with a unique specificity for endothelial cells and a key mediator of aberrant endothelial cell proliferation and vascular permeability in a variety of human pathological situations, such as tumor angiogenesis, diabetic retinopathy, rheumatoid arthritis, or psoriasis. VEGF is a symmetric homodimeric molecule with two receptor binding interfaces lying on each pole of the molecule. Herein we report on the construction and recombinant expression of an asymmetric heterodimeric VEGF variant with an intact receptor binding interface at one pole and a mutant receptor binding interface at the second pole of the dimer. This VEGF variant binds to VEGF receptors but fails to induce receptor activation. In competition experiments, the heterodimeric VEGF variant antagonizes VEGF-stimulated receptor autophosphorylation and proliferation of endothelial cells. A 15-fold excess of the heterodimer was sufficient to inhibit VEGF-stimulated endothelial cell proliferation by 50%, and a 100-fold excess resulted in an almost complete inhibition. By using a rational approach that is based on the structure of VEGF, we have shown the feasibility to construct a VEGF variant that acts as an VEGF antagonist.

  16. The Oligo Fucoidan Inhibits Platelet-Derived Growth Factor-Stimulated Proliferation of Airway Smooth Muscle Cells.

    PubMed

    Yang, Chao-Huei; Tsao, Chiung-Fang; Ko, Wang-Sheng; Chiou, Ya-Ling

    2016-01-09

    In the pathogenesis of asthma, the proliferation of airway smooth muscle cells (ASMCs) is a key factor in airway remodeling and causes airway narrowing. In addition, ASMCs are also the effector cells of airway inflammation. Fucoidan extracted from marine brown algae polysaccharides has antiviral, antioxidant, antimicrobial, anticlotting, and anticancer properties; however, its effectiveness for asthma has not been elucidated thus far. Platelet-derived growth factor (PDGF)-treated primary ASMCs were cultured with or without oligo-fucoidan (100, 500, or 1000 µg/mL) to evaluate its effects on cell proliferation, cell cycle, apoptosis, and Akt, ERK1/2 signaling pathway. We found that PDGF (40 ng/mL) increased the proliferation of ASMCs by 2.5-fold after 48 h (p < 0.05). Oligo-fucoidan reduced the proliferation of PDGF-stimulated ASMCs by 75%-99% after 48 h (p < 0.05) and induced G₁/G₀ cell cycle arrest, but did not induce apoptosis. Further, oligo-fucoidan supplementation reduced PDGF-stimulated extracellular signal-regulated kinase (ERK1/2), Akt, and nuclear factor (NF)-κB phosphorylation. Taken together, oligo-fucoidan supplementation might reduce proliferation of PDGF-treated ASMCs through the suppression of ERK1/2 and Akt phosphorylation and NF-κB activation. The results provide basis for future animal experiments and human trials.

  17. The Oligo Fucoidan Inhibits Platelet-Derived Growth Factor-Stimulated Proliferation of Airway Smooth Muscle Cells

    PubMed Central

    Yang, Chao-Huei; Tsao, Chiung-Fang; Ko, Wang-Sheng; Chiou, Ya-Ling

    2016-01-01

    In the pathogenesis of asthma, the proliferation of airway smooth muscle cells (ASMCs) is a key factor in airway remodeling and causes airway narrowing. In addition, ASMCs are also the effector cells of airway inflammation. Fucoidan extracted from marine brown algae polysaccharides has antiviral, antioxidant, antimicrobial, anticlotting, and anticancer properties; however, its effectiveness for asthma has not been elucidated thus far. Platelet-derived growth factor (PDGF)-treated primary ASMCs were cultured with or without oligo-fucoidan (100, 500, or 1000 µg/mL) to evaluate its effects on cell proliferation, cell cycle, apoptosis, and Akt, ERK1/2 signaling pathway. We found that PDGF (40 ng/mL) increased the proliferation of ASMCs by 2.5-fold after 48 h (p < 0.05). Oligo-fucoidan reduced the proliferation of PDGF-stimulated ASMCs by 75%–99% after 48 h (p < 0.05) and induced G1/G0 cell cycle arrest, but did not induce apoptosis. Further, oligo-fucoidan supplementation reduced PDGF-stimulated extracellular signal-regulated kinase (ERK1/2), Akt, and nuclear factor (NF)-κB phosphorylation. Taken together, oligo-fucoidan supplementation might reduce proliferation of PDGF-treated ASMCs through the suppression of ERK1/2 and Akt phosphorylation and NF-κB activation. The results provide basis for future animal experiments and human trials. PMID:26761017

  18. Phage-Antibiotic Synergy (PAS): beta-lactam and quinolone antibiotics stimulate virulent phage growth.

    PubMed

    Comeau, André M; Tétart, Françoise; Trojet, Sabrina N; Prère, Marie-Françoise; Krisch, H M

    2007-08-29

    Although the multiplication of bacteriophages (phages) has a substantial impact on the biosphere, comparatively little is known about how the external environment affects phage production. Here we report that sub-lethal concentrations of certain antibiotics can substantially stimulate the host bacterial cell's production of some virulent phage. For example, a low dosage of cefotaxime, a cephalosporin, increased an uropathogenic Escherichia coli strain's production of the phage PhiMFP by more than 7-fold. We name this phenomenon Phage-Antibiotic Synergy (PAS). A related effect was observed in diverse host-phage systems, including the T4-like phages, with beta-lactam and quinolone antibiotics, as well as mitomycin C. A common characteristic of these antibiotics is that they inhibit bacterial cell division and trigger the SOS system. We therefore examined the PAS effect within the context of the bacterial SOS and filamentation responses. We found that the PAS effect appears SOS-independent and is primarily a consequence of cellular filamentation; it is mimicked by cells that constitutively filament. The fact that completely unrelated phages manifest this phenomenon suggests that it confers an important and general advantage to the phages.

  19. Essiac? and Flor-Essence? herbal tonics stimulate the in vitro growth of human breast cancer cells

    SciTech Connect

    Kulp, K S; Montgomery, J L; McLimans, B; Latham, E R; Shattuck, D L; Klotz, D M; Bennett, L M

    2005-10-07

    People diagnosed with cancer often self-administer complementary and alternative medicines (CAMs) to supplement their conventional treatments, improve health, or prevent recurrence. Flor-Essence{reg_sign} and Essiac{reg_sign} Herbal Tonics are commercially available complex mixtures of herbal extracts sold as dietary supplements and used by cancer patients based on anecdotal evidence that they can treat or prevent disease. In this study, we evaluated Flor-Essence{reg_sign} and Essiac{reg_sign} for their effects on the growth of human tumor cells in culture. The effect of Flor-Essence{reg_sign} and Essiac{reg_sign} herbal tonics on cell proliferation was tested in MCF-7, MDA-MB-436, MDA-MB-231, and T47D cancer cells isolated from human breast tumors. Estrogen receptor (ER) dependent activation of a luciferase reporter construct was tested in MCF-7 cells. Specific binding to the ER was tested using an ICI 182,780 competition assay. Flor-Essence{reg_sign} and Essiac{reg_sign} herbal tonics at 1%, 2%, 4% and 8% stimulated cell proliferation relative to untreated controls and activated ER dependent luciferase activity in MCF-7 cells. A 10{sup -7} M concentration of ICI 870,780 inhibited the induction of ER dependent luciferase activity by Flor-Essence{reg_sign} and Essiac{reg_sign}, but did not affect cell proliferation. Flor-Essence{reg_sign} and Essiac{reg_sign} Herbal Tonics can stimulate the growth of human breast cancer cells through ER mediated as well as ER independent mechanisms of action. Cancer patients and health care providers can use this information to make informed decisions about the use of these CAMs.

  20. Tissue factor expression in human arterial smooth muscle cells. TF is present in three cellular pools after growth factor stimulation.

    PubMed Central

    Schecter, A D; Giesen, P L; Taby, O; Rosenfield, C L; Rossikhina, M; Fyfe, B S; Kohtz, D S; Fallon, J T; Nemerson, Y; Taubman, M B

    1997-01-01

    Tissue factor (TF) is a transmembrane glycoprotein that initiates the coagulation cascade. Because of the potential role of TF in mediating arterial thrombosis, we have examined its expression in human aortic and coronary artery smooth muscle cells (SMC). TF mRNA and protein were induced in SMC by a variety of growth agonists. Exposure to PDGF AA or BB for 30 min provided all of the necessary signals for induction of TF mRNA and protein. This result was consistent with nuclear runoff analyses, demonstrating that PDGF-induced TF transcription occurred within 30 min. A newly developed assay involving binding of digoxigenin-labeled FVIIa (DigVIIa) and digoxigenin-labeled Factor X (DigX) was used to localize cellular TF. By light and confocal microscopy, prominent TF staining was seen in the perinuclear cytoplasm beginning 2 h after agonist treatment and persisting for 10-12 h. Surface TF activity, measured on SMC monolayers under flow conditions, increased transiently, peaking 4-6 h after agonist stimulation and returning to baseline within 16 h. Peak surface TF activity was only approximately 20% of total TF activity measured in cell lysates. Surface TF-blocking experiments demonstrated that the remaining TF was found as encrypted surface TF, and also in an intracellular pool. The relatively short-lived surface expression of TF may be critical for limiting the thrombotic potential of intact SMC exposed to growth factor stimulation. In contrast, the encrypted surface and intracellular pools may provide a rich source of TF under conditions associated with SMC damage, such as during atherosclerotic plaque rupture or balloon arterial injury. PMID:9410905

  1. Effect of epidermal growth factor on follicle-stimulating hormone-induced proliferation of granulosa cells from chicken prehierarchical follicles.

    PubMed

    Lin, Jin-xing; Jia, Yu-dong; Zhang, Cai-qiao

    2011-11-01

    The development of ovarian follicular cells is controlled by multiple circulating and local hormones and factors, including follicle-stimulating hormone (FSH) and epidermal growth factor (EGF). In this study, the stage-specific effect of EGF on FSH-induced proliferation of granulosa cells was evaluated in the ovarian follicles of egg-laying chickens. Results showed that EGF and its receptor (EGFR) mRNAs displayed a high expression in granulosa cells from the prehierarchical follicles, including the large white follicle (LWF) and small yellow follicle (SYF), and thereafter the expression decreased markedly to the stage of the largest preovulatory follicle. SYF represents a turning point of EGF/EGFR mRNA expression during follicle selection. Subsequently the granulosa cells from SYF were cultured to reveal the mediation of EGF in FSH action. Cell proliferation was remarkably increased by treatment with either EGF or FSH (0.1-100 ng/ml). This result was confirmed by elevated proliferating cell nuclear antigen (PCNA) expression and decreased cell apoptosis. Furthermore, EGF-induced cell proliferation was accompanied by increased mRNA expressions of EGFR, FSH receptor, and the cell cycle-regulating genes (cyclins D1 and E1, cyclin-dependent kinases 2 and 6) as well as decreased expression of luteinizing hormone receptor mRNA. However, the EGF or FSH-elicited effect was reversed by simultaneous treatment with an EGFR inhibitor AG1478. In conclusion, EGF and EGFR expressions manifested stage-specific changes during follicular development and EGF mediated FSH-induced cell proliferation and retarded cell differentiation in the prehierarchical follicles. These expressions thus stimulated follicular growth before selection in the egg-laying chicken.

  2. BET bromodomain proteins mediate downstream signaling events following growth factor stimulation in human lung fibroblasts and are involved in bleomycin-induced pulmonary fibrosis.

    PubMed

    Tang, Xiaoyan; Peng, Ruoqi; Ren, Yonglin; Apparsundaram, Subramanium; Deguzman, Jeremy; Bauer, Carla M; Hoffman, Ann F; Hamilton, Shannon; Liang, Zhenmin; Zeng, Hang; Fuentes, Maria E; Demartino, Julie A; Kitson, Christopher; Stevenson, Christopher S; Budd, David C

    2013-01-01

    Epigenetic alterations, such as histone acetylation, regulate the signaling outcomes and phenotypic responses of fibroblasts after growth factor stimulation. The bromodomain and extra-terminal domain-containing proteins (Brd) bind to acetylated histone residues, resulting in recruitment of components of the transcriptional machinery and subsequent gene transcription. Given the central importance of fibroblasts in tissue fibrosis, this study sought to determine the role of Brd proteins in human lung fibroblasts (LFs) after growth factor stimulation and in the murine bleomycin model of lung fibrosis. Using small interfering RNA against human Brd2 and Brd4 and pharmacologic Brd inhibitors, this study found that Brd2 and Brd4 are essential in mediating the phenotypic responses of LFs downstream of multiple growth factor pathways. Growth factor stimulation of LFs causes increased histone acetylation, association of Brd4 with growth factor-responsive genes, and enhanced transcription of these genes that could be attenuated with pharmacologic Brd inhibitors. Of note, lung fibrosis induced after intratracheal bleomycin challenge in mice could be prevented by pretreatment of animals with pharmacologic inhibitors of Brd proteins. This study is the first demonstration of a role for Brd2 and Brd4 proteins in mediating the responses of LFs after growth factor stimulation and in driving the induction of lung fibrosis in mice in response to bleomycin challenge.

  3. MbIDGF, a novel member of the imaginal disc growth factor family in Mamestra brassicae, stimulates cell proliferation in two lepidopteran cell lines without insulin.

    PubMed

    Zhang, Jun; Iwai, Sachio; Tsugehara, Taketo; Takeda, Makio

    2006-07-01

    Imaginal disc growth factor (IDGF) is a soluble polypeptide growth factor that was first identified from the conditioned medium of Drosophilia imaginal disc C1.8+ cells. Working with insulin, IDGF stimulated the growth of cultured imaginal disk cells, which suggested that IDGF might function as a cofactor of Drosophila insulin or insulin like peptide. Here we report a new member of the IDGF family, named MbIDGF, from the cabbage armyworm, Mamestra brassicae. Using a cloned cDNA of MbIDGF, recombinant MbIDGF protein was expressed in baculovirus-infected Sf9 cells and purified. Without insulin, the recombinant MbIDGF protein stimulated cell growth of SES-MaBr-4 and NIAS-MaBr-93 cell lines that were derived from the fat bodies and hemocytes of M. brassicae, in a dose-dependent manner. The saturation of growth stimulation by MbIDGF was attained for the two types of cells at 80 ng/ml (0.8 nM) and 300 ng/ml (6 nM), respectively. The results suggest that MbIDGF may stimulate the growth of lepidopteran cells by a new mechanism without associating with the insulin pathway.

  4. 8-Cl-cAMP antagonizes mitogen-activated protein kinase activation and cell growth stimulation induced by epidermal growth factor

    PubMed Central

    Budillon, A; Gennaro, E Di; Caraglia, M; Barbarulo, D; Abbruzzese, A; Tagliaferri, P

    1999-01-01

    The growth factor-activated mitogenic pathways are often disregulated in tumour cells and, therefore, they can provide specific molecular targets for novel anti-tumour approaches. 8-Chloro-cAMP (8-Cl-cAMP), a synthetic cAMP analogue, is a novel anti-tumour agent that has recently undergone clinical evaluation. We investigated the effects of 8-CI-cAMP on the epidermal growth factor (EGF)/EGF receptor (EGF-R) signalling in human epidermoid cancer KB cells, which are responsive to the mitogenic stimulus of EGF. We found that the growth-promoting activity of EGF was completely abolished when EGF treatment was performed in combination with 8-CI-cAMP. The inhibition of the EGF-induced proliferation by 8-CI-cAMP was paralleled by the blockade of the EGF-stimulated activation of mitogen-activated protein kinases (MAPK), ERK-1 and ERK-2. Conversely, we found an increase of EGF-R expression and EGF-R tyrosine phosphorylation when KB cells were growth inhibited by 8-Cl-cAMP. Moreover, the activity of Raf-1 and MEK-1 protein kinases, the activators upstream MAPK in the phosphorylation cascade induced by EGF, was not modified in 8-Cl-cAMP-treated cells. We concluded that the impairment of KB cell response to EGF, induced by 8-Cl-cAMP, resides in the specific inhibition of MAPK/ERKs activity while the function of the upstream elements in the EGF-R signalling is preserved. © 1999 Cancer Research Campaign PMID:10584873

  5. Recombinant bovine somatotropin stimulates short term increases in growth rate and insulin-like growth factor I (IGF-I) in chickens.

    PubMed

    Buonomo, F C; Baile, C A

    1988-07-01

    Recombinant bovine somatotropin (rbGH) was administered by subcutaneous injection at daily doses of 0.5 or 2.5 mg/kg for a two week period in female broiler chicks between 4 and 6 weeks of age. Half of the chicks received dietary corticosterone at a 1 ppm level. Growth rate was significantly increased 6.1% and 6.9% following one week of treatment with 0.5 or 2.5 mg/kg rbGH respectively. Treatment with the same respective doses of rbGH in the presence of 1 ppm corticosterone, supplied to suppress any possible immune response elicited by the heterologous somatotropin, resulted in an 8.0% and 7.8% increase (P less than .05) in growth rate during the first week of treatment. The rbGH-associated increase in growth rate was accompanied by a significant increase in food intake, higher circulating levels of IGF-I, and lower plasma T4 concentrations, while plasma T3 levels were unchanged. All effects were attenuated during the second week of treatment, concomitant with the development of high antibody titer against rbGH regardless of dietary corticosterone administration. Carcass parameters relating to bone, muscle and fat were not different between rbGH-treated and control chickens at the end of the two week treatment period. Thus rbGH is capable of stimulating a short-term improvement in growth rate, which is related to increased feed consumption and is of limited duration.

  6. Functional characterization of a soybean growth stimulator Bradyrhizobium sp. strain SR-6 showing acylhomoserine lactone production.

    PubMed

    Ali, Amanat; Ayesha; Hameed, Sohail; Imran, Asma; Iqbal, Mazhar; Iqbal, Javed; Oresnik, Ivan J

    2016-09-01

    A soybean nodule endophytic bacterium Bradyrhizobium sp. strain SR-6 was characterized for production of acyl homoserine lactones (AHLs) as quorum sensing molecules. Mass spectrometry analysis of AHLs revealed the presence of C6-HSL, 3OH-C6-HSL, C8-HSL, C10-HSL, 3oxoC10-HSL, 3oxo-C12-HSL and 3OH-C12-HSL which are significantly different from those reported earlier in soybean symbionts. Purified AHL extracts significantly improved wheat and soybean seedling growth and root hair development along with increased soybean nodulation under axenic conditions. A positive correlation was observed among in vivo nitrogenase and catalase enzyme activities of the strain SR-6. Transmission electron microscopic analysis showed the cytochemical localization of catalase activity within the bacteroids, specifically attached to the peribacteroidal membrane. Root and nodule colonization proved rhizosphere competence of SR-6. The inoculation of SR-6 resulted in increased shoot length (13%), plant dry matter (50%), grain weight (16%), seed yield (20%) and N-uptake (14%) as compared to non-inoculated soybean plants. The symbiotic bacterium SR-6 has potential to improve soybean growth and yield in sub-humid climate of Azad Jammu and Kashmir region of Pakistan. The production and mass spectrometric profiling of AHLs as well as in vivo cytochemical localization of catalase enzyme activity in soybean Bradyrhizobium sp. have never been reported earlier elsewhere before our these investigations.

  7. The Probiotic Mixture VSL#3 Accelerates Gastric Ulcer Healing by Stimulating Vascular Endothelial Growth Factor

    PubMed Central

    Dharmani, Poonam; De Simone, Claudio; Chadee, Kris

    2013-01-01

    Studies assessing the effect and mechanism of probiotics on diseases of the upper gastrointestinal tract (GI) including gastric ulcers are limited despite extensive work and promising results of this therapeutic option for other GI diseases. In this study, we investigated the mechanisms by which the probiotic mixture VSL#3 (a mixture of eight probiotic bacteria including Lactobacilli, Bifidobacteria and Streptococcus species) heals acetic acid induced gastric ulcer in rats. VSL#3 was administered orally at low (6×109 bacteria) or high (1.2×1010 bacteria) dosages from day 3 after ulcer induction for 14 consecutive days. VSL#3 treatments significantly enhanced gastric ulcer healing in a dose-dependent manner. To assess the mechanism(s) whereby VSL#3 exerted its protective effects, we quantified the gene expression of several pro-inflammatory cytokines, protein and expression of stomach mucin-Muc5ac, regulatory cytokine-IL-10, COX-2 and various growth factors. Of all the components examined, only expression and protein production of VEGF was increased 332-fold on day 7 in the ulcerated tissues of animals treated with VSL#3. Predictably, animals treated with VEGF neutralizing antibody significantly delayed gastric ulcer healing in VSL#3 treated animals. This is the first report to demonstrate high efficacy of the probiotic mixture VSL#3 in enhancing gastric ulcer healing. Probiotic efficacy was effective at higher concentrations of VSL#3 by specifically increasing the expression and production of angiogenesis promoting growth factors, primarily VEGF. PMID:23484048

  8. Vascular endothelial growth factor stimulates bone repair by promoting angiogenesis and bone turnover.

    PubMed

    Street, John; Bao, Min; deGuzman, Leo; Bunting, Stuart; Peale, Franklin V; Ferrara, Napoleone; Steinmetz, Hope; Hoeffel, John; Cleland, Jeffrey L; Daugherty, Ann; van Bruggen, Nicholas; Redmond, H Paul; Carano, Richard A D; Filvaroff, Ellen H

    2002-07-23

    Several growth factors are expressed in distinct temporal and spatial patterns during fracture repair. Of these, vascular endothelial growth factor, VEGF, is of particular interest because of its ability to induce neovascularization (angiogenesis). To determine whether VEGF is required for bone repair, we inhibited VEGF activity during secondary bone healing via a cartilage intermediate (endochondral ossification) and during direct bone repair (intramembranous ossification) in a novel mouse model. Treatment of mice with a soluble, neutralizing VEGF receptor decreased angiogenesis, bone formation, and callus mineralization in femoral fractures. Inhibition of VEGF also dramatically inhibited healing of a tibial cortical bone defect, consistent with our discovery of a direct autocrine role for VEGF in osteoblast differentiation. In separate experiments, exogenous VEGF enhanced blood vessel formation, ossification, and new bone (callus) maturation in mouse femur fractures, and promoted bony bridging of a rabbit radius segmental gap defect. Our results at specific time points during the course of healing underscore the role of VEGF in endochondral vs. intramembranous ossification, as well as skeletal development vs. bone repair. The responses to exogenous VEGF observed in two distinct model systems and species indicate that a slow-release formulation of VEGF, applied locally at the site of bone damage, may prove to be an effective therapy to promote human bone repair.

  9. Purified human platelet-derived growth factor receptor has ligand-stimulated tyrosine kinase activity.

    PubMed Central

    Bishayee, S; Ross, A H; Womer, R; Scher, C D

    1986-01-01

    The platelet-derived growth factor receptor (PDGF-R), a 180-kDa single-chain polypeptide, was purified from membranes of the human osteogenic sarcoma cell line MG-63. Purification was achieved by treatment of membranes with PDGF and ATP, followed by solubilization with nonionic detergent and successive chromatography on solid-phase anti-phosphotyrosine monoclonal antibody and DEAE-cellulose. The PDGF-R, which was estimated to be 50-80% pure by NaDodSO4/polyacrylamide gel electrophoresis of 32P-labeled preparations, was free of contaminating epidermal growth factor receptor and had no detectable phosphatase activity. It specifically bound 125I-labeled PDGF, a reaction quantified by binding of the ligand-PDGF-R complex to the anti-phosphotyrosine antibody. The purified receptor displayed PDGF-stimulatable tyrosine kinase activity, assayed by autophosphorylation of PDGF-R at tyrosine residues and by phosphorylation of angiotensin II. The Km for ATP in the autophosphorylation reaction was 7.5 microM. Addition of PDGF did not change the Km but increased the Vmax 1.7-fold. Images PMID:3018745

  10. Stimulant medication effects on growth and bone age in children with attention-deficit/hyperactivity disorder: a prospective cohort study.

    PubMed

    Poulton, Alison S; Bui, Quoc; Melzer, Elaine; Evans, Richard

    2016-03-01

    Stimulant medication is known to cause transient weight loss and slowing down of growth, but whether it delays physical maturation is unclear. We studied growth and bone age over the first 3 years of treatment in children with attention-deficit/hyperactivity disorder (patients) compared with healthy siblings (controls). Bone age was estimated blindly by two independent radiologists using Tanner and Whitehouse version 3. Dexamphetamine or methylphenidate was titrated and continued when clinically indicated. Forty out of 73 patients, together with 22 controls, completed the study. There were no significant growth differences between the two groups at baseline. Despite slower growth on treatment [5.1 cm/year, 95% confidence interval (CI): 4.7-5.5, vs. 6.3 cm/year, 95% CI: 5.7-6.8, P=0.002; and 2.7 kg/year, 95% CI: 2.1-3.3, vs. 4.4 kg/year, 95% CI: 3.5-5.3, P=0.005], the patients showed no significant maturational delay (RUS score: 49 U/year, 95% CI: 44-55, vs. 55 U/year, 95% CI: 47-63, P=0.27). A subgroup of patients underwent serial biochemistry and dual-energy X-ray absorptiometry, recording a significant reduction in fat (5.61±3.56-4.22±3.09 kg, P<0.001) and leptin (3.88±2.87-2.57±1.94 ng/ml, P=0.017). The pattern of change in height z-score over time was modified by the dose of medication (P for interaction=0.024). We found no medication effect on the rate of maturation, which was instead predicted by baseline leptin (P=0.035 controlling for age and sex).

  11. Stimulant medication effects on growth and bone age in children with attention-deficit/hyperactivity disorder: a prospective cohort study

    PubMed Central

    Bui, Quoc; Melzer, Elaine; Evans, Richard

    2016-01-01

    Stimulant medication is known to cause transient weight loss and slowing down of growth, but whether it delays physical maturation is unclear. We studied growth and bone age over the first 3 years of treatment in children with attention-deficit/hyperactivity disorder (patients) compared with healthy siblings (controls). Bone age was estimated blindly by two independent radiologists using Tanner and Whitehouse version 3. Dexamphetamine or methylphenidate was titrated and continued when clinically indicated. Forty out of 73 patients, together with 22 controls, completed the study. There were no significant growth differences between the two groups at baseline. Despite slower growth on treatment [5.1 cm/year, 95% confidence interval (CI): 4.7–5.5, vs. 6.3 cm/year, 95% CI: 5.7–6.8, P=0.002; and 2.7 kg/year, 95% CI: 2.1–3.3, vs. 4.4 kg/year, 95% CI: 3.5–5.3, P=0.005], the patients showed no significant maturational delay (RUS score: 49 U/year, 95% CI: 44–55, vs. 55 U/year, 95% CI: 47–63, P=0.27). A subgroup of patients underwent serial biochemistry and dual-energy X-ray absorptiometry, recording a significant reduction in fat (5.61±3.56–4.22±3.09 kg, P<0.001) and leptin (3.88±2.87–2.57±1.94 ng/ml, P=0.017). The pattern of change in height z-score over time was modified by the dose of medication (P for interaction=0.024). We found no medication effect on the rate of maturation, which was instead predicted by baseline leptin (P=0.035 controlling for age and sex). PMID:26544899

  12. Stimulating Neoblast-Like Cell Proliferation in Juvenile Fasciola hepatica Supports Growth and Progression towards the Adult Phenotype In Vitro

    PubMed Central

    Rathinasamy, Vignesh; Toet, Hayley; McCammick, Erin; O’Connor, Anna; Marks, Nikki J.; Mousley, Angela; Brennan, Gerard P.; Halton, David W.; Spithill, Terry W.; Maule, Aaron G.

    2016-01-01

    Fascioliasis (or fasciolosis) is a socioeconomically important parasitic disease caused by liver flukes of the genus Fasciola. Flukicide resistance has exposed the need for new drugs and/or a vaccine for liver fluke control. A rapidly improving ‘molecular toolbox’ for liver fluke encompasses quality genomic/transcriptomic datasets and an RNA interference platform that facilitates functional genomics approaches to drug/vaccine target validation. The exploitation of these resources is undermined by the absence of effective culture/maintenance systems that would support in vitro studies on juvenile fluke development/biology. Here we report markedly improved in vitro maintenance methods for Fasciola hepatica that achieved 65% survival of juvenile fluke after 6 months in standard cell culture medium supplemented with 50% chicken serum. We discovered that this long-term maintenance was dependent upon fluke growth, which was supported by increased proliferation of cells resembling the “neoblast” stem cells described in other flatworms. Growth led to dramatic morphological changes in juveniles, including the development of the digestive tract, reproductive organs and the tegument, towards more adult-like forms. The inhibition of DNA synthesis prevented neoblast-like cell proliferation and inhibited growth/development. Supporting our assertion that we have triggered the development of juveniles towards adult-like fluke, mass spectrometric analyses showed that growing fluke have an excretory/secretory protein profile that is distinct from that of newly-excysted juveniles and more closely resembles that of ex vivo immature and adult fluke. Further, in vitro maintained fluke displayed a transition in their movement from the probing behaviour associated with migrating stage worms to a slower wave-like motility seen in adults. Our ability to stimulate neoblast-like cell proliferation and growth in F. hepatica underpins the first simple platform for their long-term in

  13. Gastric pentadecapeptide BPC 157 accelerates healing of transected rat Achilles tendon and in vitro stimulates tendocytes growth.

    PubMed

    Staresinic, M; Sebecic, B; Patrlj, L; Jadrijevic, S; Suknaic, S; Perovic, D; Aralica, G; Zarkovic, N; Borovic, S; Srdjak, M; Hajdarevic, K; Kopljar, M; Batelja, L; Boban-Blagaic, A; Turcic, I; Anic, T; Seiwerth, S; Sikiric, P

    2003-11-01

    In studies intended to improve healing of transected Achilles tendon, effective was a stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419). Currently in clinical trials for inflammatory bowel disease (PLD-116, PL 14736, Pliva), it ameliorates internal and external wound healing. In rats, the right Achilles tendon transected (5 mm proximal to its calcaneal insertion) presents with a large tendon defect between cut ends. Agents (/kg b.w., i.p., once time daily) (BPC 157 (dissolved in saline, with no carrier addition) (10 microg, 10 ng or 10 pg) or saline (5.0 ml)), were firstly applied at 30 min after surgery, the last application at 24 h before autopsy. Achilles functional index (AFI) was assessed once time daily. Biomechanical, microscopical and macroscopical assessment was on day 1, 4, 7, 10 and 14. Controls generally have severely compromised healing. In comparison, pentadecapeptide BPC 157 fully improves recovery: (i) biomechanically, increased load of failure, load of failure per area and Young's modulus of elasticity; (ii) functionally, significantly higher AFI-values; (iii) microscopically, more mononuclears and less granulocytes, superior formation of fibroblasts, reticulin and collagen; (iv) macroscopically, smaller size and depth of tendon defect, and subsequently the reestablishment of full tendon integrity. Likewise, unlike TGF-beta, pentadecapeptide BPC 157, presenting with no effect on the growth of cultured cell of its own, consistently opposed 4-hydroxynonenal (HNE), a negative modulator of the growth. HNE-effect is opposed in both combinations: BPC 157+HNE (HNE growth inhibiting effect reversed into growth stimulation of cultured tendocytes) and HNE+BPC 157(abolished inhibiting activity of the aldehyde), both in the presence of serum and serum deprived conditions. In conclusion, these findings, particularly, Achilles tendon transection fully recovered in rats, peptide stability suitable delivery, usefully favor gastric

  14. Specific growth stimulation by linoleic acid in hepatoma cell lines transfected with the target protein of a liver carcinogen.

    PubMed Central

    Keler, T; Barker, C S; Sorof, S

    1992-01-01

    The hepatic carcinogen N-2-fluorenylacetamide (2-acetylaminofluorene) was shown previously to interact specifically with its target protein, liver fatty acid binding protein (L-FABP), early during hepatocarcinogenesis in rats. In search of the significance of the interaction, rat L-FABP cDNA in the sense and antisense orientations was transfected into a subline of the rat hepatoma HTC cell line that did not express L-FABP. After the transfections, the basal doubling times of the cells were not significantly different. However, at 10(-5)-10(-7) M, linoleic acid, which is an essential fatty acid, a ligand of L-FABP, and the precursor of many eicosanoids and related lipids, stimulated the incorporation of [3H]thymidine in three randomly isolated and stably transfected cell clones that expressed L-FABP, but virtually did not stimulate the incorporation of [3H]thymidine in three L-FABP-nonexpressing clones transfected with the antisense DNA. Linoleic acid at 10(-6) M increased cell number almost 3-fold (38% vs. 14%; P less than 0.0001) and thymidine incorporation nearly 5-fold (23.2% vs. 4.9%; P less than 0.001) in the L-FABP-expressing cells compared to that in the transfected nonexpressing cells. L-FABP acted specifically and cooperatively with linoleic acid, inasmuch as all the proteins other than L-FABP in the transfected L-FABP nonexpressing cells and four other fatty acids (gamma-linolenic acid, dihomo-gamma-linolenic acid, arachidonic acid, and palmitoleic acid) were unable to effect a significant elevation or difference in the level of DNA synthesis that was attributable to the transfection. Metabolism of the linoleic acid to oxygenated derivatives was apparently necessary, since the cyclooxygenase inhibitor indomethacin partly inhibited and the antioxidant lipoxygenase inhibitors nordihydroguariaretic acid and alpha-tocopherol completely abolished the growth stimulation. The evidence supports the idea that L-FABP, the target protein of the liver carcinogen

  15. Volatile Compounds Emitted by Pseudomonas aeruginosa Stimulate Growth of the Fungal Pathogen Aspergillus fumigatus

    PubMed Central

    Briard, Benoit; Heddergott, Christoph

    2016-01-01

    ABSTRACT Chronic lung infections with opportunistic bacterial and fungal pathogens are a major cause of morbidity and mortality especially in patients with cystic fibrosis. Pseudomonas aeruginosa is the most frequently colonizing bacterium in these patients, and it is often found in association with the filamentous fungus Aspergillus fumigatus. P. aeruginosa is known to inhibit the growth of A. fumigatus in situations of direct contact, suggesting the existence of interspecies communication that may influence disease outcome. Our study shows that the lung pathogens P. aeruginosa and A. fumigatus can interact at a distance via volatile-mediated communication and expands our understanding of interspecific signaling in microbial communities. PMID:26980832

  16. Kick-starting the cell cycle: From growth-factor stimulation to initiation of DNA replication

    NASA Astrophysics Data System (ADS)

    Aguda, Baltazar D.

    2001-03-01

    The essential genes, proteins and associated regulatory networks involved in the entry into the mammalian cell cycle are identified, from activation of growth-factor receptors to intracellular signal transduction pathways that impinge on the cell cycle machinery and ultimately on the initiation of DNA replication. Signaling pathways mediated by the oncoproteins Ras and Myc induce the activation of cyclin-dependent kinases CDK4 and CDK2, and the assembly and firing of pre-replication complexes require a collaboration among E2F, CDK2, and Cdc7 kinase. A proposed core mechanism of the restriction point, the major checkpoint prior to commitment to DNA synthesis, involves cyclin E/CDK2, the phosphatase Cdc25A, and the CDK inhibitor p27Kip1.

  17. In vivo, cAMP stimulates growth and morphogenesis of mouse mammary ducts.

    PubMed

    Silberstein, G B; Strickland, P; Trumpbour, V; Coleman, S; Daniel, C W

    1984-08-01

    In culture, cAMP is known to be mitogenic for mammary cells and several other epithelia, but evidence for a similar role in vivo has been only correlative. We have used plastic implants to cause slow release of cholera toxin and other cAMP-active agents to local areas of mammary glands in ovariectomized mice. Elevated levels of intracellular cAMP around the implants promoted vigorous growth and normal ductal morphogenesis, while distant sites were unaffected. Local effects of cAMP included restoration of normal ductal caliber, formation of new end buds, and reinitiation of DNA synthesis in both epithelium and surrounding stroma. Thus, cAMP is both a mitogenic and a morphogenetic factor in this tissue.

  18. Infergen Stimulated Macrophages Restrict Mycobacterium tuberculosis Growth by Autophagy and Release of Nitric Oxide

    PubMed Central

    Pahari, Susanta; Khan, Nargis; Aqdas, Mohammad; Negi, Shikha; Kaur, Jagdeep; Agrewala, Javed N.

    2016-01-01

    IFN alfacon-1 (Infergen) is a synthetic form of Interferon (IFN)-α2b. Infergen has immunomodulatory activity and is effective against hepatitis C virus. However, the effect of Infergen (IFG) on Mycobacterium tuberculosis (Mtb) has not yet been reported. Therefore, for the first time, we have studied the influence of IFG in constraining the survival of Mtb in human macrophages. We observed that IFG significantly enhanced the maturation and activation of macrophages. Further, it substantially augmented the secretion of IL-6, nitric oxide (NO) and antigen uptake. Moreover, macrophages exhibited remarkably higher bactericidal activity, as evidenced by reduction in the Mtb growth. Infergen-mediated mechanism was different from the type-1 interferons; since it worked through the activation of NF-κB, phosphorylation of STAT-3 and Akt-PI3K that improved the bactericidal activity through autophagy and NO release. In future, IFG immunotherapy can be a novel strategy for treating patients and controlling TB. PMID:28000752

  19. Autocrine epidermal growth factor signaling stimulates directionally persistent mammary epithelial cell migration

    SciTech Connect

    Maheshwari, Gargi; Wiley, H Steven ); Lauffenburger, Douglas A.

    2001-12-24

    Autocrine receptor/ligand signaling loops were first identified in tumor cells, where it was found that transformation of cells resulted in overexpression of certain growth factors leading to unregulated proliferation of the tumor cells (Sporn and Todaro, 1980). However, in the ensuing decades autocrine signaling has been found to operate in numerous physiological situations (Sporn and Roberts, 1992), including wound healing (Tokumaru et al., 2000), angiogenesis (Seghezzi et al., 1998), and tissue organization during development (Wasserman and Freeman, 1998) and reproductive cycles (Xie et al., 1997). Although it is becoming evident that autocrine loops play crucial roles in regulation of cell function within tissue contexts, it is unclear whether their effects on cell responses are different from the effects of the same ligand presented in exogenous or paracrine manner.

  20. Loss of cytochrome cM stimulates cyanobacterial heterotrophic growth in the dark.

    PubMed

    Hiraide, Yuto; Oshima, Kenshiro; Fujisawa, Takatomo; Uesaka, Kazuma; Hirose, Yuu; Tsujimoto, Ryoma; Yamamoto, Haruki; Okamoto, Shinobu; Nakamura, Yasukazu; Terauchi, Kazuki; Omata, Tatsuo; Ihara, Kunio; Hattori, Masahira; Fujita, Yuichi

    2015-02-01

    Although cyanobacteria are photoautotrophs, they have the capability for heterotrophic metabolism that enables them to survive in their natural habitat. However, cyanobacterial species that grow heterotrophically in the dark are rare. It remains largely unknown how cyanobacteria regulate heterotrophic activity. The cyanobacterium Leptolyngbya boryana grows heterotrophically with glucose in the dark. A dark-adapted variant dg5 isolated from the wild type (WT) exhibits enhanced heterotrophic growth in the dark. We sequenced the genomes of dg5 and the WT to identify the mutation(s) of dg5. The WT genome consists of a circular chromosome (6,176,364 bp), a circular plasmid pLBA (77,793 bp) and two linear plasmids pLBX (504,942 bp) and pLBY (44,369 bp). Genome comparison revealed three mutation sites. Phenotype analysis of mutants isolated from the WT by introducing these mutations individually revealed that the relevant mutation is a single adenine insertion causing a frameshift of cytM encoding Cyt c(M). The respiratory oxygen consumption of the cytM-lacking mutant grown in the dark was significantly higher than that of the WT. We isolated a cytM-lacking mutant, ΔcytM, from another cyanobacterium Synechocystis sp. PCC 6803, and ΔcytM grew in the dark with a doubling time of 33 h in contrast to no growth of the WT. The respiratory oxygen consumption of ΔcytM grown in the dark was about 2-fold higher than that of the WT. These results suggest a suppressive role(s) for Cyt cM in regulation of heterotrophic activity.

  1. Early posthatch feeding stimulates satellite cell proliferation and skeletal muscle growth in turkey poults.

    PubMed

    Halevy, Orna; Nadel, Yael; Barak, Miriam; Rozenboim, Israel; Sklan, David

    2003-05-01

    The effect of early posthatch feeding on skeletal muscle growth and satellite cell myogenesis was studied in turkey poults. Poults were either fed immediately posthatch or food-deprived for the first 48 h and then refed for the rest of the experiment. Body and breast muscle weights were lower in the starved poults than in fed controls throughout the experiment (P < 0.05). Cultures of breast muscle satellite cells revealed significantly higher DNA synthesis in the fed group than in the starved group as early as d 1 (P < 0.05). These levels continued to rise, reaching approximately 500-fold those of feed-deprived poults on d 4. In the latter group, thymidine incorporation peaked only on d 6, and then declined. Thereafter, it decreased to the same levels as those in the fed group. Satellite cell number per gram muscle increased until d 4, and was higher in the fed group than in the starved group (P < 0.05). Pax7 levels in cell cultures derived from the fed group were markedly higher than in the starved group on d 2 (P < 0.05). Myogenin levels in both culture and muscle were higher in the fed than in the starved groups until d 4 (P < 0.05). Phosphorylation of the survival factor Akt and cyclin-dependent kinase inhibitor p21 levels were higher in cells derived from the fed group relative to those from the starved group 48 h posthatch (P < 0.05). Similarly, Akt phosphorylation and insulin-like growth factor I (IGF-I) levels were significantly higher in the muscles of the fed group (P < 0.05). Together, these results suggest that immediate posthatch feeding of poults is critical for satellite cell survival and myogenesis probably via IGF-I.

  2. Male pheromone stimulates ovarian follicular development and body growth in juvenile female opossums (Monodelphis domestica).

    PubMed

    Harder, John D; Jackson, Leslie M

    2003-02-11

    Female opossums are induced into estrus by direct exposure to a non-volatile pheromone in male scentmarks. Juvenile females develop this responsiveness by 150 days of age (days), and earlier (130 days) if exposed to male pheromone beginning at 90 days. The goal of this study was to examine the effect of male pheromone on body growth and ovarian follicular development in young opossums. Females (n = 28) were weaned at 56 days and caged individually with ad libitum food and water from 84 days. Body mass was recorded 2-3 times weekly and the onset of estrus was monitored by urogenital sinus cytology. Exposed females were given continuous access to adult male scentmarks from 90 days and randomly selected for necropsy at 105 and 130 days. Unexposed females were isolated from direct contact with males and their scentmarks and randomly selected for necropsy at 90, 105, 130, and 150 days. Exposed females were larger (63.5 +/- 1.1 g) than unexposed females (56.6 +/- 1.1 g) at 130 days, and 4 of 5 had expressed estrus or proestrus. Uterine mass at 130 days was higher (P < 0.05) in exposed (129.8 +/- 28.8 mg) than in unexposed (25.4 +/- 6.7 mg) females, none of which expressed estrus by 150 days. The mean number of developing, antral follicles per female increased from 1.5 +/- 1.5 at 90 days to 17.8 +/- 5.2 at 130 days. Mean diameter of developing antral follicles at 130 days was larger in exposed (534 +/- 54 microm) than in unexposed females (393 +/- 4 microm). The results of this study demonstrate that pheromonal induction of first estrus in juvenile opossums is associated with an increased rate of body growth and follicular development.

  3. Jerusalem artichokes stimulate growth of broiler chickens and protect them against endotoxins and potential cecal pathogens.

    PubMed

    Kleessen, Brigitta; Elsayed, N A A E; Loehren, U; Schroedl, W; Krueger, Monika

    2003-11-01

    Control of intestinal pathogens during the earliest phases of broiler production may be the best strategy for the reduction of human pathogens on processed broiler carcasses. The recent ban on antibiotics in poultry feed has served to focus much attention on alternative methods of controlling the gastrointestinal microflora. A field trial was conducted to evaluate the effect of the fructan-rich Jerusalem artichoke, or topinambur (administered as 0.5% topinambur syrup in drinking water), on cultural numbers of selected cecal bacteria (total aerobes, Enterobacteriaceae, Bdellovibrio spp., and Clostridium perfringens) and levels of bacterial endotoxins as well as on body weights and relative weights of organs (the pancreas and the bursa of Fabricius) of chickens in the first 35 days of life (with weekly investigations being conducted). One-day-old broiler chickens (Ross 308) were randomly assigned to experimental (with topinambur) and control (without topinambur) groups. They were allowed free access to a standard broiler diet without growth-promoting antibiotics. Topinambur treatment resulted in a significant increase (P < 0.01) in cecal counts of B. bacteriovorus, which parasitizes susceptible gram-negative pathogens. Topinambur led to significantly smaller numbers of total aerobes, Enterobacteriaceae, and C. perfringens as well as to reduced levels of endotoxins in the blood compared with those for control birds. Increased body weights resulting from topinambur consumption were observed on day 35 of the trial period (P < 0.05). The relative weights of the pancreas and the bursa of Fabricius, however, were higher (P < 0.05) for topinambur-treated broilers than for control birds at the ages of 14, 21, 28, and 35 days. These results indicate that a small amount of topinambur in broilers' drinking water has a beneficial effect on growth performance, reduces bacterial endotoxin levels, and suppresses potential pathogens in broilers' ceca.

  4. Nitric oxide synthase inhibitors attenuate transforming-growth-factor-beta 1-stimulated capillary organization in vitro.

    PubMed Central

    Papapetropoulos, A.; Desai, K. M.; Rudic, R. D.; Mayer, B.; Zhang, R.; Ruiz-Torres, M. P.; García-Cardeña, G.; Madri, J. A.; Sessa, W. C.

    1997-01-01

    Angiogenesis is a complex process involving endothelial cell (EC) proliferation, migration, differentiation, and organization into patent capillary networks. Nitric oxide (NO), an EC mediator, has been reported to be antigenic as well as proangiogenic in different models of in vivo angiogenesis. Our aim was to investigate the role of NO in capillary organization using rat microvascular ECs (RFCs) grown in three-dimensional (3D) collagen gels. RFCs placed in 3D cultures exhibited extensive tube formation in the presence of transforming growth factor-beta 1. Addition of the NO synthase (NOS) inhibitors L-nitro-arginine methylester (L-NAME, 1 mmol/L) or L-monomethyl-nitro-l-arginine (1 mmol/L) inhibited tube formation and the accumulation of nitrite in the media by approximately 50%. Incubation of the 3D cultures with excess L-arginine reversed the inhibitory effect of L-NAME on tube formation. In contrast to the results obtained in 3D cultures, inhibition of NO synthesis by L-NAME did not influence RFC proliferation in two-dimensional (2D) cultures or antagonize the ability of transforming growth factor-beta 1 to suppress EC proliferation in 2D cultures. Reverse transcriptase-polymerase chain reaction revealed the constitutive expression of all three NOS isoforms, neuronal, inducible, and endothelial NOSs, in 2D and 3D cultures. Moreover, Western blot analysis demonstrated the presence of immunoreactive protein for all NOS isoforms in 3D cultures of RFCs. In addition, in the face of NOS blockade, co-treatment with the NO donor sodium nitroprusside or the stable analog of cGMP, 8-bromo-cGMP, restored capillary tube formation. Thus, the autocrine production of NO and the activation of soluble guanylate cyclase are necessary events in the process of differentiation and in vitro capillary tube organization of RFCs. Images Figure 2 Figure 4 Figure 5 PMID:9137106

  5. Quantitative phosphoproteomics after auxin-stimulated lateral root induction identifies an SNX1 protein phosphorylation site required for growth.

    PubMed

    Zhang, Hongtao; Zhou, Houjiang; Berke, Lidija; Heck, Albert J R; Mohammed, Shabaz; Scheres, Ben; Menke, Frank L H

    2013-05-01

    Protein phosphorylation is instrumental to early signaling events. Studying system-wide phosphorylation in relation to processes under investigation requires a quantitative proteomics approach. In Arabidopsis, auxin application can induce pericycle cell divisions and lateral root formation. Initiation of lateral root formation requires transcriptional reprogramming following auxin-mediated degradation of transcriptional repressors. The immediate early signaling events prior to this derepression are virtually uncharacterized. To identify the signal molecules responding to auxin application, we used a lateral root-inducible system that was previously developed to trigger synchronous division of pericycle cells. To identify and quantify the early signaling events following this induction, we combined (15)N-based metabolic labeling and phosphopeptide enrichment and applied a mass spectrometry-based approach. In total, 3068 phosphopeptides were identified from auxin-treated root tissue. This root proteome dataset contains largely phosphopeptides not previously reported and represents one of the largest quantitative phosphoprotein datasets from Arabidopsis to date. Key proteins responding to auxin treatment included the multidrug resistance-like and PIN2 auxin carriers, auxin response factor2 (ARF2), suppressor of auxin resistance 3 (SAR3), and sorting nexin1 (SNX1). Mutational analysis of serine 16 of SNX1 showed that overexpression of the mutated forms of SNX1 led to retarded growth and reduction of lateral root formation due to the reduced outgrowth of the primordium, showing proof of principle for our approach.

  6. Nitrogen Stimulates the Growth of Subsurface Basalt-associated Microorganisms at the Western Flank of the Mid-Atlantic Ridge

    PubMed Central

    Zhang, Xinxu; Fang, Jing; Bach, Wolfgang; Edwards, Katrina J.; Orcutt, Beth N.; Wang, Fengping

    2016-01-01

    Oceanic crust constitutes the largest aquifer system on Earth, and microbial activity in this environment has been inferred from various geochemical analyses. However, empirical documentation of microbial activity from subsurface basalts is still lacking, particularly in the cool (<25°C) regions of the crust, where are assumed to harbor active iron-oxidizing microbial communities. To test this hypothesis, we report the enrichment and isolation of crust-associated microorganisms from North Pond, a site of relatively young and cold basaltic basement on the western flank of the Mid-Atlantic Ridge that was sampled during Expedition 336 of the Integrated Ocean Drilling Program. Enrichment experiments with different carbon (bicarbonate, acetate, methane) and nitrogen (nitrate and ammonium) sources revealed significant cell growth (one magnitude higher cell abundance), higher intracellular DNA content, and increased Fe3+/ΣFe ratios only when nitrogen substrates were added. Furthermore, a Marinobacter strain with neutrophilic iron-oxidizing capabilities was isolated from the basalt. This work reveals that basalt-associated microorganisms at North Pond had the potential for activity and that microbial growth could be stimulated by in vitro nitrogen addition. Furthermore, iron oxidation is supported as an important process for microbial communities in subsurface basalts from young and cool ridge flank basement. PMID:27199959

  7. Testosterone increases display behaviors but does not stimulate growth of adult plumage in male golden-collared manakins (Manacus vitellinus).

    PubMed

    Day, Lainy B; McBroom, Jennifer T; Schlinger, Barney A

    2006-02-01

    In order to attract females, male golden-collared manakins gather in leks and perform a complex display consisting of acrobatics accompanied by loud "wingsnapping". During this display, males show off their yellow beard and yellow, black, and green plumage that is striking in comparison to the dull green plumage of young males and females. We investigated the role of testosterone (T) in activating the display of manakins and in stimulating the growth of the adult male plumage. T regulates song, copulation, and territorial aggression in temperate species. In tropical species, however, T levels can be relatively low year round, which has raised questions about the involvement of T in courtship display and male aggression in these species. In neither temperate nor tropical species has the role of hormones in the shift from juvenile to adult plumage been well studied. Therefore, we implanted green-plumaged birds and adult males with either a T pellet or an inert pellet (controls) and observed the display behaviors of these birds in the field and in captivity. In captive birds, we also plucked feathers from sexually dimorphic regions and observed color and regeneration rate of new feathers. We found that birds implanted with T increased several display behaviors compared to controls. All plucked feathers grew back the same color as prior to treatment; however, we observed some differences in feather growth rate between T-treated birds and controls.

  8. Nitrogen Stimulates the Growth of Subsurface Basalt-associated Microorganisms at the Western Flank of the Mid-Atlantic Ridge.

    PubMed

    Zhang, Xinxu; Fang, Jing; Bach, Wolfgang; Edwards, Katrina J; Orcutt, Beth N; Wang, Fengping

    2016-01-01

    Oceanic crust constitutes the largest aquifer system on Earth, and microbial activity in this environment has been inferred from various geochemical analyses. However, empirical documentation of microbial activity from subsurface basalts is still lacking, particularly in the cool (<25°C) regions of the crust, where are assumed to harbor active iron-oxidizing microbial communities. To test this hypothesis, we report the enrichment and isolation of crust-associated microorganisms from North Pond, a site of relatively young and cold basaltic basement on the western flank of the Mid-Atlantic Ridge that was sampled during Expedition 336 of the Integrated Ocean Drilling Program. Enrichment experiments with different carbon (bicarbonate, acetate, methane) and nitrogen (nitrate and ammonium) sources revealed significant cell growth (one magnitude higher cell abundance), higher intracellular DNA content, and increased Fe(3+)/ΣFe ratios only when nitrogen substrates were added. Furthermore, a Marinobacter strain with neutrophilic iron-oxidizing capabilities was isolated from the basalt. This work reveals that basalt-associated microorganisms at North Pond had the potential for activity and that microbial growth could be stimulated by in vitro nitrogen addition. Furthermore, iron oxidation is supported as an important process for microbial communities in subsurface basalts from young and cool ridge flank basement.

  9. A novel GH secretagogue, A233, exhibits enhanced growth activity and innate immune system stimulation in teleosts fish.

    PubMed

    Martinez, Rebeca; Ubieta, Kenia; Herrera, Fidel; Forellat, Alina; Morales, Reynold; de la Nuez, Ania; Rodriguez, Rolando; Reyes, Osvaldo; Oliva, Ayme; Estrada, Mario P

    2012-09-01

    In teleosts fish, secretion of GH is regulated by several hypothalamic factors that are influenced by the physiological state of the animal. There is an interaction between immune and endocrine systems through hormones and cytokines. GH in fish is involved in many physiological processes that are not overtly growth related, such as saltwater osmoregulation, antifreeze synthesis, and the regulation of sexual maturation and immune functions. This study was conducted to characterize a decapeptide compound A233 (GKFDLSPEHQ) designed by molecular modeling to evaluate its function as a GH secretagogue (GHS). In pituitary cell culture, the peptide A233 induces GH secretion and it is also able to increase superoxide production in tilapia head-kidney leukocyte cultures. This effect is blocked by preincubation with the GHS receptor antagonist [d-Lys(3)]-GHRP6. Immunoneutralization of GH by addition of anti-tilapia GH monoclonal antibody blocked the stimulatory effect of A233 on superoxide production. These experiments propose a GH-mediated mechanism for the action of A233. The in vivo biological action of the decapeptide was also demonstrated for growth stimulation in goldfish and tilapia larvae (P<0.001). Superoxide dismutase levels, antiprotease activity, and lectin titer were enhanced in tilapia larvae treated with this novel molecule. The decapeptide A233 designed by molecular modeling is able to function as a GHS in teleosts and enhance parameters of the innate immune system in the fish larvae.

  10. Nematode suppression and growth stimulation in corn plants (Zea mays L.) irrigated with domestic effluent.

    PubMed

    Barros, Kenia Kelly; do Nascimento, Clístenes Williams Araújo; Florencio, Lourdinha

    2012-01-01

    Treated wastewater has great potential for agricultural use due to its concentrations of nutrients and organic matter, which are capable of improving soil characteristics. Additionally, effluents can induce suppression of plant diseases caused by soil pathogens. This study evaluates the effect of irrigation with effluent in a UASB reactor on maize (Zea mays L.) development and on suppression of the diseases caused by nematodes of the genus Meloidogyne. Twelve lysimeters of 1 m(3) each were arranged in a completely randomized design, with four treatments and three replicates. The following treatments were used: T1 (W+I), irrigation with water and infestation with nematodes; T2 (W+I+NPK), irrigation with water, infestation with nematodes and fertilization with nitrogen (N), phosphorus (P) and potassium (K); T3 (E+I), irrigation with effluent and infestation with nematodes; and T4 (E+I+P), irrigation with effluent, infestation with nematodes and fertilization with phosphorus. The plants irrigated with the effluent plus the phosphorus fertilizer had better growth and productivity and were more resistant to the disease symptoms caused by the nematodes. The suppression levels may have been due to the higher levels of Zn and NO(3)(-) found in the leaf tissue of the plants irrigated with the effluent and phosphorus fertilizer.

  11. Chronic warming stimulates growth of marsh grasses more than mangroves in a coastal wetland ecotone.

    PubMed

    Coldren, G A; Barreto, C R; Wykoff, D D; Morrissey, E M; Langley, J A; Feller, I C; Chapman, S K

    2016-11-01

    Increasing temperatures and a reduction in the frequency and severity of freezing events have been linked to species distribution shifts. Across the globe, mangrove ranges are expanding toward higher latitudes, likely due to diminishing frequency of freezing events associated with climate change. Continued warming will alter coastal wetland plant dynamics both above- and belowground, potentially altering plant capacity to keep up with sea level rise. We conducted an in situ warming experiment, in northeast Florida, to determine how increased temperature (+2°C) influences co-occurring mangrove and salt marsh plants. Warming was achieved using passive warming with three treatment levels (ambient, shade control, warmed). Avicennia germinans, the black mangrove, exhibited no differences in growth or height due to experimental warming, but displayed a warming-induced increase in leaf production (48%). Surprisingly, Distichlis spicata, the dominant salt marsh grass, increased in biomass (53% in 2013 and 70% in 2014), density (41%) and height (18%) with warming during summer months. Warming decreased plant root mass at depth and changed abundances of anaerobic bacterial taxa. Even while the poleward shift of mangroves is clearly controlled by the occurrences of severe freezes, chronic warming between these freeze events may slow the progression of mangrove dominance within ecotones.

  12. A Novel Pyrimidin-Like Plant Activator Stimulates Plant Disease Resistance and Promotes Growth

    PubMed Central

    Sun, Tie-Jun; Lu, Yun; Narusaka, Mari; Shi, Chao; Yang, Yu-Bing; Wu, Jian-Xin; Zeng, Hong-Yun; Narusaka, Yoshihiro; Yao, Nan

    2015-01-01

    Plant activators are chemicals that induce plant defense responses to a broad spectrum of pathogens. Here, we identified a new potential plant activator, 5-(cyclopropylmethyl)-6-methyl-2-(2-pyridyl)pyrimidin-4-ol, named PPA (pyrimidin-type plant activator). Compared with benzothiadiazole S-methyl ester (BTH), a functional analog of salicylic acid (SA), PPA was fully soluble in water and increased fresh weight of rice (Oryza sativa) and Arabidopsis plants at low concentrations. In addition, PPA also promoted lateral root development. Microarray data and real-time PCR revealed that PPA-treated leaves not challenged with pathogen showed up-regulation of genes related to reactive oxygen species (ROS), defenses and SA. During bacterial infection, Arabidopsis plants pretreated with PPA showed dramatically decreased disease symptoms and an earlier and stronger ROS burst, compared with plants pretreated with BTH. Microscopy revealed that H2O2 accumulated in the cytosol, plasma membrane and cell wall around intracellular bacteria, and also on the bacterial cell wall, indicating that H2O2 was directly involved in killing bacteria. The increase in ROS-related gene expression also supported this observation. Our results indicate that PPA enhances plant defenses against pathogen invasion through the plant redox system, and as a water-soluble compound that can promote plant growth, has broad potential applications in agriculture. PMID:25849038

  13. Epidermal growth factor inhibits radioiodine uptake but stimulates deoxyribonucleic acid synthesis in newborn rat thyroids grown in nude mice

    SciTech Connect

    Ozawa, S.; Spaulding, S.W. )

    1990-08-01

    We have studied the effect of altering the level of circulating epidermal growth factor (EGF) on the function and growth of newborn rat thyroids transplanted into nude mice. Preliminary studies confirmed that sialoadenectomy reduced circulating EGF levels in nude mice (from 0.17 +/- 0.02 to 0.09 +/- 0.02 ng/ml), and that ip injection of 5 micrograms EGF raised EGF levels (the peak level of 91.7 +/- 3.3 ng/ml was achieved at 30 min, with a subsequent half-life of about 1 h). The radioiodine uptake by newborn rat thyroid transplants in the sialoadenectomized and sham-operated animals correlated inversely with the circulating EGF levels determined when the mice were killed (r = -0.99). Low-dose TSH treatment (0.1 microU/day) generally stimulated the radioiodine uptake, but high-dose TSH groups (100 microU/day) were not significantly different from the control group. The 5-day nuclear (3H)thymidine labeling index was 6.8 +/- 0.5% IN newborn rat thyroid transplants grown in sialoadenectomized animals, 13.1 +/- 0.3% in sham-operated animals, and 16.8 +/- 0.5% in nude mice receiving 5 micrograms EGF ip daily. In general, both low-dose and high-dose TSH promoted DNA synthesis under low EGF conditions but were ineffective in the presence of higher levels of EGF. Adult rat thyroid transplants showed no significant responses. Although sialoadenectomy may alter other factors besides EGF, it appears that changes in the levels of circulating EGF within the physiological range affect the function and growth of newborn rat thyroid transplants. Circulating EGF may play a role in thyroid maturation and may also be involved in the regulation of thyroid function throughout life.

  14. Novel bioactive from Lactobacillus brevis DSM17250 to stimulate the growth of Staphylococcus epidermidis: a pilot study.

    PubMed

    Holz, C; Benning, J; Schaudt, M; Heilmann, A; Schultchen, J; Goelling, D; Lang, C

    2017-02-07

    Commensal skin microbiota plays an important role in both influencing the immune response of the skin and acting as a barrier against colonisation of potentially pathogenic microorganisms and overgrowth of opportunistic pathogens. Staphylococcus epidermidis is a key constituent of the normal microbiota on human skin. It balances the inflammatory response after skin injury and produces antimicrobial molecules that selectively inhibit skin pathogens. Here we describe Lactobacillus brevis DSM17250 that was identified among hundreds of Lactobacillus strains to exhibit an anti-inflammatory effect in human keratinocytes in vitro and specific stimulatory impact on the growth of S. epidermidis. The aqueous cell-free extract of L. brevis DSM17250 was used in an ointment formulation and tested in a randomized placebo-controlled double blinded human pilot study. Healthy volunteers with diagnosed dry skin were treated for four weeks. The study data shows that L. brevis DSM17250 extract induces re-colonisation of the skin by protective commensal microorganisms as judged from selective bacterial cultivation of surface-associated skin microorganism of the lower leg. Furthermore, the 4 week administration of the L. brevis DSM17250 extract significantly improved the transepidermal water loss value (TEWL), reduced the xerosis cutis symptoms and stinging. The data shows that daily application of L. brevis DSM17250 extract in a topical product significantly improves the microbial skin microbiota by promoting the growth of species which possess beneficial regulatory and protective properties such as S. epidermidis. Restoring the natural skin microbiota leads to significantly improved skin barrier function (as transepidermal water loss) and decrease of xeroderma (xerosis cutis) symptoms (as measured by dry skin area and severity index, DASI). We propose that improving and stabilizing the natural skin microbiota by specifically stimulating the growth of S. epidermidis is an important and

  15. A fullerene colloidal suspension stimulates the growth and denitrification ability of wastewater treatment sludge-derived bacteria.

    PubMed

    Huang, Fei; Ge, Ling; Zhang, Bo; Wang, Yun; Tian, Hao; Zhao, Liping; He, Yiliang; Zhang, Xiaojun

    2014-08-01

    Fullerene (C60) is a nanoparticle that has been widely studied and applied in numerous commodities. However, there are concerns regarding its potential negative impact on the environment. A fullerene colloidal suspension (nC60) is known for its property of selectively inhibiting the growth of microorganisms. In this study, using denaturing gradient gel electrophoresis fingerprinting technology, we found that fullerene altered the structure of a sludge-derived microbial community. Specifically, the bacteria from Bacillus, Acidovorax and Cloacibacterium genera were enriched in abundance when supplemented with nC60 at pH 6.5 under aerobic conditions. The effects of the fullerene colloidal suspension on a strain of Bacillus isolated from the same microbial community were evaluated to further characterize the growth-stimulating effect of nC60. The biomass of cultures of this strain incubated with nC60 concentrations ranging from 3 mg L(-1) to 7 mg L(-1) was approximately twice that of the control during the stationary phase. The fullerene also induced higher superoxide dismutase activity in Bacillus cereus. Furthermore, the nitrate removal rate of B. cereus increased to nearly 55% in the presence of 5 mg L(-1) nC60, compared to 35% for the control. Meanwhile, the cumulative loading amount of nitrite was reduced from 33 μg mL(-1) to 25 μg mL(-1) by the addition of 5 mg L(-1) nC60. Our results demonstrate that the fullerene colloidal suspension is conditionally capable of promoting the growth and denitrification metabolism of certain bacteria, such as B. cereus. Fullerene might have both inhibitory and stimulatory effects on microorganisms in various environments.

  16. Human platelet lysate versus minoxidil stimulates hair growth by activating anagen promoting signaling pathways.

    PubMed

    Dastan, Maryam; Najafzadeh, Nowruz; Abedelahi, Ali; Sarvi, Mohammadreza; Niapour, Ali

    2016-12-01

    Minoxidil and human platelet lysate (HPL) are commonly used to treat patients with hair loss. However, the roles of HPL versus minoxidil in hair follicle biology largely remain unknown. Here, we hypothesized that bulge and dermal papilla (DP) cells may express specific genes, including Kras, Erk, Akt, Shh and β-catenin after exposure to minoxidil or HPL. The mouse hair follicles were isolated on day 10 after depilation and bulge or DP regions were dissected. The bulge and DP cells were cultured for 14days in DMEM/F12 medium. Then, the cells were treated with 100μM minoxidil and 10% HPL for 10 days. Nuclear morphology was identified using DAPi staining. Reverse transcriptase and real-time polymerase chain reaction (PCR) analysis were also performed to examine the expression of Kras, Erk, Akt, Shh and β-catenin mRNA levels in the treated bulge and DP regions after organ culture. Here, we found that minoxidil influences bulge and DP cell survival (P<0.05). Apoptosis in DP cells was also meaningfully decreased by HPL treatment (P=0.014). In addition, Kras, Akt, Erk, Shh and β-catenin mRNA levels were changed in response to minoxidil treatment in both bulge and DP cells. HPL mediated Erk upregulation in both bulge and DP cells (P<0.05), but Kras and Akt mRNA levels were not considerably different in the HPL-treated cells. β-catenin mRNA level was also significantly increased in the bulge region by HPL. We also found that Shh mRNA level was considerably higher in HPL-treated bulge cells than in minoxidil-treated bulge cells. In contrast, the expression of β-cateinin and Shh in the DP cells was not meaningfully increased after treatment with HPL. Our results suggest that minoxidil and HPL can promote hair growth by activating the main anagen inducing signaling pathways.

  17. Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor.

    PubMed

    Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

    2015-03-01

    Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD.

  18. Characterization of mechanical behavior of an epithelial monolayer in response to epidermal growth factor stimulation

    SciTech Connect

    Yang, Ruiguo; Chen, Jennifer Y.; Xi, Ning; Lai, King Wai Chiu; Qu, Chengeng; Fung, Carmen Kar Man; Penn, Lynn S.; Xi, Jun

    2012-03-10

    Cell signaling often causes changes in cellular mechanical properties. Knowledge of such changes can ultimately lead to insight into the complex network of cell signaling. In the current study, we employed a combination of atomic force microscopy (AFM) and quartz crystal microbalance with dissipation monitoring (QCM-D) to characterize the mechanical behavior of A431 cells in response to epidermal growth factor receptor (EGFR) signaling. From AFM, which probes the upper portion of an individual cell in a monolayer of cells, we observed increases in energy dissipation, Young's modulus, and hysteresivity. Increases in hysteresivity imply a shift toward a more fluid-like mechanical ordering state in the bodies of the cells. From QCM-D, which probes the basal area of the monolayer of cells collectively, we observed decreases in energy dissipation factor. This result suggests a shift toward a more solid-like state in the basal areas of the cells. The comparative analysis of these results indicates a regionally specific mechanical behavior of the cell in response to EGFR signaling and suggests a correlation between the time-dependent mechanical responses and the dynamic process of EGFR signaling. This study also demonstrates that a combination of AFM and QCM-D is able to provide a more complete and refined mechanical profile of the cells during cell signaling. -- Highlights: Black-Right-Pointing-Pointer The EGF-induced cellular mechanical response is regionally specific. Black-Right-Pointing-Pointer The EGF-induced cellular mechanical response is time and dose dependent. Black-Right-Pointing-Pointer A combination of AFM and QCM-D provides a more complete mechanical profile of cells.

  19. Cortisol stimulates growth hormone gene expression in rainbow trout leucocytes in vitro.

    PubMed

    Yada, Takashi; Muto, Kohji; Azuma, Teruo; Hyodo, Susumu; Schreck, Carl B

    2005-05-15

    Extrapituitary expression of the growth hormone (GH) gene has been reported for the immune system of various vertebrates. In the rainbow trout (Oncorhynchus mykiss), GH mRNA could be detected in several lymphoid organs and leucocytes by reverse transcriptase-polymerase chain reaction (RT-PCR). To understand the control of GH expression in the fish immune system, mRNA levels for two distinct GH genes (GH1 and GH2) in trout leucocytes isolated from peripheral blood were quantified using a real-time PCR method. Both GH mRNAs could be detected in trout leucocytes, although their levels were extremely low compared to those in pituitary cells. The levels of GH2 mRNA in leucocytes were several times higher than those of GH1, while no difference was observed between GH1 and GH2 mRNA levels in the pituitary. Administration of dibutyryl cyclic AMP and cortisol produced a significant elevation of GH mRNA levels in trout leucocytes, although the levels were unchanged by T3. GH1 and GH2 mRNA levels showed similarities in responses to those factors. The effect of cortisol on GH mRNA appears biphasic; a dose-depending elevation of GH gene expression was observed in leucocytes treated with cortisol at below 200 nM, however, cortisol had no effect at 2000 nM. Cortisol-treated leucocytes showed no significant change in the mRNA level of beta-actin or proliferative activity during the experiments. Our results thus show that, at the low levels, GH gene expression in trout leucocytes is regulated by cortisol, which has been known as a regulatory factor of GH gene expression in pituitary cells, and suggest a physiological significance of paracrine GH produced in the fish immune system.

  20. Magneto-mechanical bone growth stimulation by actuation of highly porous ferromagnetic fiber arrays

    NASA Astrophysics Data System (ADS)

    Markaki, Athina E.; Clyne, Trevor W.

    2005-02-01

    This work relates to porous material made by bonding together fibres of a magnetic material. When subjected to a magnetic field, the array deforms, with individual fibres becoming magnetised along their length and then tending to line up locally with the direction of the field. An investigation is presented into the concept that this deformation could induce beneficial strains in bone tissue network in the early stages of growth as it grows into the porous fibre array. An analytical model has been developed, based on the deflection of individual fibre segments (between joints) experiencing bending moments as a result of the induced magnetic dipole. The model has been validated via measurements made on simple fibre assemblies and random fibre arrays. Work has also been done on the deformation characteristics of random fibre arrays with a matrix filling the inter-fibre space. This has the effect of reducing the fibre deflections. The extent of this reduction, and an estimate of the maximum strains induced in the space-filling material, can be obtained using a simple force balance approach. Predictions indicate that in-growing bone tissue, with a stiffness of around 0.01-0.1 GPa, could be strained to beneficial levels (~1 millistrain), using magnetic field strengths in current diagnostic use (~1 Tesla), provided the fibre segment aspect ratio is at least about 10. Such material has a low Young"s modulus, but the overall stiffness of a prosthesis could be matched to that of cortical bone by using an integrated design involving a porous magneto-active layer bonded to a dense non-magnetic core.

  1. Granulosa cell responsiveness to follicle stimulating hormone during early growth of hen ovarian follicles.

    PubMed

    Johnson, A L; Lee, Jeeyoung

    2016-01-01

    In the laying hen ovary, the cyclic recruitment of a follicle represents a process in which a single follicle is selected to enter the rapid growth phase and undergo final maturation prior to ovulation. Published data support the proposal that final differentiation of the granulosa cell (GC) layer commences at the time of follicle selection. This process is characterized by the enhanced capacity for FSH-induced cell signaling via the protein kinase A/cyclic adenosine monophosphate (cAMP) pathway. One consequence of such signaling within the GC layer is the initial capacity for steroidogenesis (predominantly progesterone production) mediated by increased expression of mRNA encoding steroidogenic acute regulatory protein (STAR) and the cholesterol side-chain cleavage enzyme (CYP11A). Prior to selection, the GC layer remains minimally responsive to a 3 h challenge with FSH (10 ng/mL), in vitro, compared to that from the most recently selected 9- to 12-mm follicle. By comparison, when the duration of the cell culture prior to FSH challenge is increased to 18 h, GCs collected from 1- to 2-mm, 3- to 5-mm, and 6- to 8-mm follicles respond to a 3 h FSH challenge by increasing STAR expression and progesterone production, with the greatest response from GCs collected from 6- to 8-mm follicles. Culture with Bone Morphogenetic Protein 6 (BMP6) enhances both CYP11A expression and FSH responsiveness at each stage of development, with the greatest response again occurring in GCs from 6- to 8-mm follicles. Significantly, factors that activate mitogen activated protein kinase (MAPK) or protein kinase C (PKC) signaling prevent the ability of prolonged culture or culture with BMP6 to induce FSH-responsiveness and the initiation of GC differentiation at each stage of development. Collectively, these results provide further support for the hypothesis that prior to follicle selection, inhibitory cell signaling (e.g., MAPK, PKC) maintains the GC layer in an undifferentiated state in

  2. Neural Growth Factor Stimulates Proliferation of Spinal Cord Derived-Neural Precursor/Stem Cells

    PubMed Central

    Han, Youngmin

    2016-01-01

    Objective Recently, regenerative therapies have been used in clinical trials (heart, cartilage, skeletal). We don't make use of these treatments to spinal cord injury (SCI) patients yet, but regenerative therapies are rising interest in recent study about SCI. Neural precursor/stem cell (NPSC) proliferation is a significant event in functional recovery of the central nervous system (CNS). However, brain NPSCs and spinal cord NPSCs (SC-NPSCs) have many differences including gene expression and proliferation. The purpose of this study was to investigate the influence of neural growth factor (NGF) on the proliferation of SC-NPSCs. Methods NPSCs (2×104) were suspended in 100 µL of neurobasal medium containing NGF-7S (Sigma-Aldrich) and cultured in a 96-well plate for 12 days. NPSC proliferation was analyzed five times for either concentration of NGF (0.02 and 2 ng/mL). Sixteen rats after SCI were randomly allocated into two groups. In group 1 (SCI-vehicle group, n=8), animals received 1.0 mL of the saline vehicle solution. In group 2 (SCI-NGF group, n=8), the animals received single doses of NGF (Sigma-Aldrich). A dose of 0.02 ng/mL of NGF or normal saline as a vehicle control was intra-thecally injected daily at 24 hour intervals for 7 days. For Immunohistochemistry analysis, rats were sacrificed after one week and the spinal cords were obtained. Results The elevation of cell proliferation with 0.02 ng/mL NGF was significant (p<0.05) but was not significant for 2 ng/mL NGF. The optical density was increased in the NGF 0.02 ng/mL group compared to the control group and NGF 2 ng/mL groups. The density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group (p<0.05). High power microscopy revealed that the density of nestin in the SCI-NGF group was significantly increased over the SCI-vehicle group. Conclusion SC-NPSC proliferation is an important pathway in the functional recovery of SCI. NGF enhances SC-NPSC proliferation in vitro and in

  3. A novel action of follicle-stimulating hormone in the ovary promotes estradiol production without inducing excessive follicular growth before puberty

    PubMed Central

    François, Charlotte M.; Petit, Florence; Giton, Frank; Gougeon, Alain; Ravel, Célia; Magre, Solange; Cohen-Tannoudji, Joëlle; Guigon, Céline J.

    2017-01-01

    In cyclic females, FSH stimulates ovarian estradiol (E2) production and follicular growth up to the terminal stage. A transient elevation in circulating FSH and E2 levels occurs shortly after birth. But what could be the action of FSH on the ovary during this period, and in particular how it stimulates ovarian steroidogenesis without supporting terminal follicular maturation is intriguing. By experimentally manipulating FSH levels, we demonstrate in mice that the mid-infantile elevation in FSH is mandatory for E2 production by the immature ovary, but that it does not stimulate follicle growth. Importantly, FSH increases aromatase expression to stimulate E2 synthesis, however it becomes unable to induce cyclin D2, a major driver of granulosa cell proliferation. Besides, although FSH prematurely induces luteinizing hormone (LH) receptor expression in granulosa cells, LH pathway is not functional in these cells to induce their terminal differentiation. In line with these results, supplying infantile mice with a superovulation regimen exacerbates E2 production, but it does not stimulate the growth of follicles and it does not induce ovulation. Overall, our findings unveil a regulation whereby high postnatal FSH concentrations ensure the supply of E2 required for programming adult reproductive function without inducing follicular maturation before puberty.

  4. Upper airway loading induces growth retardation and change in local chondrocyte IGF-I expression is reversed by stimulation of GH release in juvenile rats.

    PubMed

    Segev, Yael; Berdugo-Boura, Nilly; Porati, Orit; Tarasiuk, Ariel

    2008-11-01

    Chronic resistive airway loading (CAL) impairs growth in juvenile rats. The effects of CAL on epiphyseal growth plate (EGP) structure and insulin-like growth factor (IGF)-I gene expression have not been explored. Little is known about whether stimulants of endogenous growth hormone (GH) secretion can normalize this growth impairment. This study explored the effect of CAL on circulating and EGP GH/IGF-I pathway GH and the effect of ritanserin (endogenous GH stimulant) on somatic growth and the GH/IGF-I axis. We hypothesized that CAL would lead to a decrease in body temperature (Tb) and alterations of GH/IGF-I pathways, consequently leading to growth retardation. The tracheae of 22-day-old male rats were obstructed by tracheal banding (38 sham-operated control, 42 CAL). Tibial EGP morphometry, liver and EGP IGF mRNA, and serum GH and IGF-I levels were analyzed with quantitative real-time PCR and ELISA. Tb and locomotion activity (MA) were measured with telemetric transmitters inserted into the abdominal cavity. CAL animals had lower Tb and MA despite preserved food consumption. CAL impaired both tibial and tail length gains. Tail and tibial length gains inversely correlated with tracheal resistance. Circulating GH and IGF-I, liver and EGP IGF-I mRNA, and EGP width were decreased in the CAL group. Ritanserin administration to CAL animals normalized circulating and local EGP GH and IGF-I levels and minimized the longitudinal growth impairment. We conclude that CAL causes growth delay associated with alterations in the GH/IGF-I axis. Stimulation of GH release by ritanserin restored both global and local GH/IGF-I pathways, yet growth parameters were only partially restored.

  5. Basic Fibroblast Growth Factor Stimulates the Proliferation of Bone Marrow Mesenchymal Stem Cells in Giant Panda (Ailuropoda melanoleuca)

    PubMed Central

    Wang, Jun-Jie; Liu, Yu-Liang; Sun, Yuan-Chao; Ge, Wei; Wang, Yong-Yong; Dyce, Paul W.; Hou, Rong; Shen, Wei

    2015-01-01

    It has been widely known that the giant panda (Ailuropoda melanoleuca) is one of the most endangered species in the world. An optimized platform for maintaining the proliferation of giant panda mesenchymal stem cells (MSCs) is very necessary for current giant panda protection strategies. Basic fibroblast growth factor (bFGF), a member of the FGF family, is widely considered as a growth factor and differentiation inducer within the stem cell research field. However, the role of bFGF on promoting the proliferation of MSCs derived from giant panda bone marrow (BM) has not been reported. In this study, we aimed to investigate the role of bFGF on the proliferation of BM-MSCs derived from giant panda. MSCs were cultured for cell proliferation analysis at 24, 48 and 72 hrs following the addition of bFGF. With increasing concentrations of bFGF, cell numbers gradually increased. This was further demonstrated by performing 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) cell proliferation assay, 5-Bromo-2-deoxyUridine (BrdU) labeling and cell cycle testing. Furthermore, the percentage of MSCs that were OCT4 positive increased slightly following treatment with 5 ng/ml bFGF. Moreover, we demonstrated that the extracellular signal-regulated kinase (ERK) signaling pathway may play an important role in the proliferation of panda MSCs stimulated by bFGF. In conclusion, this study suggests that giant panda BM-MSCs have a high proliferative capacity with the addition of 5 ng/ml bFGF in vitro. PMID:26375397

  6. Basic Fibroblast Growth Factor Stimulates the Proliferation of Bone Marrow Mesenchymal Stem Cells in Giant Panda (Ailuropoda melanoleuca).

    PubMed

    Wang, Jun-Jie; Liu, Yu-Liang; Sun, Yuan-Chao; Ge, Wei; Wang, Yong-Yong; Dyce, Paul W; Hou, Rong; Shen, Wei

    2015-01-01

    It has been widely known that the giant panda (Ailuropoda melanoleuca) is one of the most endangered species in the world. An optimized platform for maintaining the proliferation of giant panda mesenchymal stem cells (MSCs) is very necessary for current giant panda protection strategies. Basic fibroblast growth factor (bFGF), a member of the FGF family, is widely considered as a growth factor and differentiation inducer within the stem cell research field. However, the role of bFGF on promoting the proliferation of MSCs derived from giant panda bone marrow (BM) has not been reported. In this study, we aimed to investigate the role of bFGF on the proliferation of BM-MSCs derived from giant panda. MSCs were cultured for cell proliferation analysis at 24, 48 and 72 hrs following the addition of bFGF. With increasing concentrations of bFGF, cell numbers gradually increased. This was further demonstrated by performing 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) cell proliferation assay, 5-Bromo-2-deoxyUridine (BrdU) labeling and cell cycle testing. Furthermore, the percentage of MSCs that were OCT4 positive increased slightly following treatment with 5 ng/ml bFGF. Moreover, we demonstrated that the extracellular signal-regulated kinase (ERK) signaling pathway may play an important role in the proliferation of panda MSCs stimulated by bFGF. In conclusion, this study suggests that giant panda BM-MSCs have a high proliferative capacity with the addition of 5 ng/ml bFGF in vitro.

  7. Transient receptor potential vanilloid 2 activation by focal mechanical stimulation requires interaction with the actin cytoskeleton and enhances growth cone motility.

    PubMed

    Sugio, Shouta; Nagasawa, Masami; Kojima, Itaru; Ishizaki, Yasuki; Shibasaki, Koji

    2016-12-22

    We have previously reported that transient receptor potential vanilloid 2 (TRPV2) can be activated by mechanical stimulation, which enhances axonal outgrowth in developing neurons; however, the molecular mechanisms that govern the contribution of TRPV2 activation to axonal outgrowth remain unclear. In the present study, we examined this mechanism by using PC12 cells as a neuronal model. Overexpression of TRPV2 enhanced axonal outgrowth in a mechanical stimulus-dependent manner. Accumulation of TRPV2 at the cell surface was 4-fold greater in the growth cone compared with the soma. In the growth cone, TRPV2 is not static, but dynamically accumulates (within ∼100 ms) to the site of mechanical stimulation. The dynamic and acute clustering of TRPV2 can enhance very weak mechanical stimuli via focal accumulation of TRPV2. Focal application of mechanical stimuli dramatically increased growth cone motility and caused actin reorganization via activation of TRPV2. We also found that TRPV2 physically interacts with actin and that changes in the actin cytoskeleton are required for its activation. Here, we demonstrated for the first time to our knowledge that TRPV2 clustering is induced by mechanical stimulation generated by axonal outgrowth and that TRPV2 activation is triggered by actin rearrangements that result from mechanical stimulation. Moreover, TRPV2 activation enhances growth cone motility and actin accumulation to promote axonal outgrowth. Sugio, S., Nagasawa, M., Kojima, I., Ishizaki, Y., Shibasaki, K. Transient receptor potential vanilloid 2 activation by focal mechanical stimulation requires interaction with the actin cytoskeleton and enhances growth cone motility.

  8. In vitro stimulation of vascular endothelial growth factor by borate-based glass fibers under dynamic flow conditions.

    PubMed

    Chen, Sisi; Yang, Qingbo; Brow, Richard K; Liu, Kun; Brow, Katherine A; Ma, Yinfa; Shi, Honglan

    2017-04-01

    Bioactive borate glass has been recognized to have both hard and soft tissue repair and regeneration capabilities through stimulating both osteogenesis and angiogenesis. However, the underlying biochemical and cellular mechanisms remain unclear. In this study, dynamic flow culturing modules were designed to simulate the micro-environment near the vascular depletion and hyperplasia area in wound-healing regions, thus to better investigate the mechanisms underlying the biocompatibility and functionality of borate-based glass materials. Glass fibers were dosed either upstream or in contact with the pre-seeded cells in the dynamic flow module. Two types of borate glasses, doped with (1605) or without (13-93B3) CuO and ZnO, were studied along with the silicate-based glass, 45S5. Substantial fiber dissolution in cell culture medium was observed, leading to the release of ions (boron, sodium and potassium) and the deposition of a calcium phosphate phase. Different levels of vascular endothelial growth factor secretion were observed from cells exposed to these three glass fibers, and the copper/zinc containing borate 1605 fibers exhibited the most positive influence. These results indicate that dynamic studies of in vitro bioactivity provide useful information to understand the in vivo response to bioactive borate glasses.

  9. Gene expression regulation in the plant growth promoting Bacillus atrophaeus UCMB-5137 stimulated by maize root exudates.

    PubMed

    Mwita, Liberata; Chan, Wai Yin; Pretorius, Theresa; Lyantagaye, Sylvester L; Lapa, Svitlana V; Avdeeva, Lilia V; Reva, Oleg N

    2016-09-15

    Despite successful use of Plant Growth Promoting Rhizobacteria (PGPR) in agriculture, little is known about specific mechanisms of gene regulation facilitating the effective communication between bacteria and plants during plant colonization. Active PGPR strain Bacillus atrophaeus UCMB-5137 was studied in this research. RNA sequencing profiles were generated in experiments where root exudate stimulations were used to mimic interactions between bacteria and plants. It was found that the gene regulation in B. atrophaeus UCMB-5137 in response to the root exudate stimuli differed from the reported gene regulation at similar conditions in B. amyloliquefaciens FZB42, which was considered as a paradigm PGPR. This difference was explained by hypersensitivity of UCMB-5137 to the root exudate stimuli impelling it to a sessile root colonization behavior through the CcpA-CodY-AbrB regulation. It was found that the transcriptional factor DegU also could play an important role in gene regulations during plant colonization. A significant stress caused by the root exudates on in vitro cultivated B. atrophaeus UCMB-5137 was noticed and discussed. Multiple cases of conflicted gene regulations showed scantiness of our knowledge on the regulatory network in Bacillus. Some of these conflicted regulations could be explained by interference of non-coding RNA (ncRNA). Search through differential expressed intergenic regions revealed 49 putative loci of ncRNA regulated by the root exudate stimuli. Possible target mRNA were predicted and a general regulatory network of B. atrophaeus UCMB-5137 genome was designed.

  10. Terbinafine: effects on platelet-derived growth factor-stimulated smooth muscle cells in vitro and myointimal proliferation in vivo

    SciTech Connect

    McCarthy, L.; Van Halen, R.G.; St. Denny, I.H.; Glinka, K.G.; Handley, D.A.; Stuetz, A.; Nemecek, G.M.

    1987-05-01

    Terbinafine (T; (E)-N-(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthalenemethanamine), an antimycotic agent with antimitogenic activity in fibroblasts, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated aortic smooth muscle cell DNA synthesis in vitro and myointimal proliferation in vivo. Exposure of smooth muscle cells to 1-25 ..mu..M T resulted in a concentration-dependent inhibition of PDGF-induced mitogenesis as determined by (/sup 3/H)thymidine incorporation or cell number. The IC/sub 50/ for T was approximately 5 ..mu..M. The inhibitory effect of terbinafine persisted in the presence of 0.4-8.0 ..mu..g/ml cholesterol or 130 ..mu..g/ml mevalonate. Administration of T to rats for 2 d before and 14 d after balloon catheter carotid injury resulted in a 40% decrease in lesion area. These observations indicate that T is both a potent in vitro antagonist of the smooth muscle cell mitogenic response to PDGF and an effective, well-tolerated, orally active inhibitor of myointimal proliferation in vivo.

  11. Involvement of JAK1, JAK2, and JAK3 in Stimulation of Functional Activity of Mesenchymal Progenitor Cells by Fibroblast Growth Factor.

    PubMed

    Zyuz'kov, G N; Zhdanov, V V; Udut, E V; Miroshnichenko, L A; Simanina, E V; Polyakova, T Yu; Stavrova, L A; Udut, V V; Minakova, M Yu; Dygai, A M

    2016-12-01

    We studied the involvement of individual JAK kinases in the realization of the growth potential of mesenchymal precursors under the effect of fibroblast growth factor. The important role of JAK2 and JAK3 in determining the initial level of mitotic activity of progenitor cells and participation of JAK1 in this process under conditions of cytokine stimulation of progenitor cells were demonstrated. Specific inhibitors of these kinases reduced the yield of fibroblast CFU and the rate of their division. Moreover, blockade of JAK1, JAK2, and JAK3 under the effect of fibroblast growth factor was accompanied by an increase in the intensity of progenitor cell differentiation.

  12. Thrombin-activated platelets induce proliferation of human skin fibroblasts by stimulating autocrine production of insulin-like growth factor-1.

    PubMed

    Giacco, Ferdinando; Perruolo, Giuseppe; D'Agostino, Elio; Fratellanza, Giorgio; Perna, Enzo; Misso, Saverio; Saldalamacchia, Gennaro; Oriente, Francesco; Fiory, Francesca; Miele, Claudia; Formisano, Salvatore; Beguinot, Francesco; Formisano, Pietro

    2006-11-01

    Platelet components have found successful clinical utilization to initiate or to accelerate tissue-repair mechanisms. However, the molecular pathways by which platelet factors contribute to tissue regeneration have not been fully elucidated. We have studied the effect of thrombin-activated platelets (TAPs) on cell growth in vivo and in cultured cell systems. Application of TAPs to ulcerative skin lesions of diabetic patients induced local activation of ERK1/2 and Akt/PKB. Moreover, when applied to cultured human skin fibroblasts, TAPs promoted cell growth and DNA synthesis and activated platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF)-1 receptor tyrosine kinases. PDGF was released by TAPs and rapidly achieved a plateau. At variance, the release of IGF-1 was mainly provided by the TAPs-stimulated fibroblasts and progressively increased up to 48 h. The PDGF-R blocker Ag1296 reduced the activation of Akt/PKB and, at a lesser extent, of ERK1/2. Conversely, inhibition of IGF-1 signaling by Ag1024 and expression of a dominant-negative IGF-1R mutant selectively reduced the stimulation of ERK1/2 by TAPs and fibroblast-released factors, with minor changes of Akt/PKB activity. Thus, platelet factors promote fibroblast growth by acutely activating Akt/PKB and ERK1/2. Sustained activation of ERK1/2, however, requires autocrine production of IGF-1 by TAPs-stimulated fibroblasts.

  13. Increased abundance of aromatase and follicle stimulating hormone receptor mRNA and decreased insulin-like growth factor-2 receptor mRNA in small ovarian follicles of cattle selected for twin births

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle genetically selected for twin ovulations and births (Twinner) exhibit increased ovarian follicular development, increased ovulation rate, and greater blood and follicular fluid IGF 1 concentrations compared with contemporary cattle not selected for twins (Control). Experimental objectives wer...

  14. Growth hormone stimulation test

    MedlinePlus

    Arginine test; Arginine-GHRH test ... of re-inserting the needle each time. The test takes between 2 to 5 hours. The procedure ... eat for 10 to 12 hours before the test. Eating food can change the test results. Some ...

  15. Epidermal growth factor stimulates mouse placental lactogen I but inhibits mouse placental lactogen II secretion in vitro.

    PubMed Central

    Yamaguchi, M; Ogren, L; Endo, H; Thordarson, G; Kensinger, R; Talamantes, F

    1992-01-01

    This study was undertaken to determine whether epidermal growth factor (EGF) regulates the secretion of mouse placental lactogen (mPL)-I and mPL-II. Primary cell cultures were prepared from placentas from days 7, 9, and 11 of pregnancy and cultured for up to 5 days. Addition of EGF (20 ng/ml) to the medium resulted in significant stimulation of mPL-I secretion by the second day of culture in cells from days 7 and 9 of pregnancy and significant inhibition of mPL-II secretion by the third or fourth day of culture in cells from days 7, 9, and 11. Dose-response studies carried out with cells from day 7 of pregnancy demonstrated that the minimum concentration of EGF that stimulated mPL-I secretion and inhibited mPL-II secretion was 1.0 ng/ml. EGF did not affect the DNA content of the cells or cell viability, assessed by trypan blue exclusion, nor did it have a general effect on protein synthesis. There are three types of PL-containing giant cells in mouse placental cell cultures: cells that contain either mPL-I or mPL-II and cells that contain both hormones. Immunocytochemical analysis and the reverse hemolytic plaque assay indicated that EGF treatment was accompanied by a significant increase in the number of cells that produce mPL-I, but among the PL cells that contained mPL-I, there was no change in the fraction of cells that contained only mPL-I or the fraction that contained both mPL-I and mPL-II. In contrast, EGF treatment did affect the distribution of mPL-II among PL cells. In control cultures, about 75% of the cells that contained mPL-II also contained mPL-I, but in EGF-treated cultures, all of the cells that contained mPL-II also contained mPL-I. These data suggest that EGF regulates mPL-I and mPL-II secretion at least partly by regulating PL cell differentiation. PMID:1454826

  16. Electrical stimulation of cerebellar fastigial nucleus promotes the expression of growth arrest and DNA damage inducible gene β and motor function recovery in cerebral ischemia/reperfusion rats.

    PubMed

    Liu, Bin; Li, Jianrui; Li, Longling; Yu, Lehua; Li, Changqing

    2012-06-27

    This study focused on the effects of electrical stimulation of cerebellar fastigial nucleus on the expression of growth arrest and DNA damage inducible gene β (Gadd45β) and on motor function recovery after focal cerebral ischemia/reperfusion (I/R) in rats. Sprague-Dawley (SD) rats were randomly divided into 4 groups: sham I/R (control group), I/R (I/R group), I/R with sham stimulation and I/R with electrical stimulation at 6h, 12h, 24h, 2d and 3d after I/R. Cerebral ischemia and reperfusion was established by nylon monofilament occlusion method. Fastigial nucleus (FN) electrical stimulation was applied at 2h after ischemia for 1h. The changes in the expression of Gadd45β were analyzed by immunohistochemistry, real-time polymerase chain reaction (PCR) and Western-blot respectively. Another group of rats were divided into the same 4 groups. Montoya staircase test score was used to test the motor function of affected forelimb. The levels of Gadd45β were significantly elevated after I/R injury. FN electrical stimulation treatment elevated the expression of Gadd45β further and improved motor function recovery. These results suggest that FN electrical stimulation can promote the expression of Gadd45β and motor function recovery after focal cerebral ischemia.

  17. Regulation by intracellular Ca sup 2+ and cyclic AMP of the growth factor-induced ruffling membrane formation and stimulation of fluid-phase endocytosis and exocytosis

    SciTech Connect

    Miyata, Yoshihiko Tokyo Metropolitan Inst. of Medical Science ); Nishida, Eisuke; Sakai, Hikoichi ); Koyasu, Shigeo; Yahara, Ichiro )

    1989-04-01

    Insulin, insulin-like growth factor-I (IGF-I), and epidermal growth factor (EGF) induce formation of ruffling membranes and stimulate the fluid-phase endocytosis and exocytosis in human epidermoid carcinoma KB cells. An increase in intracellular Ca{sup 2+} concentration by treatment with A23187, a calcium ionophore, or an increase in intracellular cAMP level by treatment with dibutyryl cAMP or forskolin almost completely inhibited the insulin-, IGF-I-, or EGF-induced formation of ruffling membranes. Increases in Ca{sup 2+} or cAMP concentration also inhibited almost completely the stimulation of fluid-phase endocytosis and exocytosis elicited by these growth factors. These results suggest that the growth factor-induced ruffling membrane formation and the stimulation of fluid-phase endocytosis and exocytosis have a common regulatory mechanism involving intracellular concentrations of Ca{sup 2+} and cAMP. {sup 125}I-EGF binding assays and immunoprecipitation experiments with anti-phosphotyrosine antibody revealed that treatment of KB cells with A23187, dibutyryl cAMP, or forskolin did not inhibit the EGF binding to the cells nor subsequent tyrosine autophosphorylation of its receptors. These results indicate that Ca{sup 2+}- and/or cAMP-sensitive intracellular reactions exist downstream from the receptor kinase activation in the process of these early cellular responses.

  18. Fibroblast growth factor stimulates angiotensin converting enzyme expression in vascular smooth muscle cells. Possible mediator of the response to vascular injury.

    PubMed Central

    Fishel, R S; Thourani, V; Eisenberg, S J; Shai, S Y; Corson, M A; Nabel, E G; Bernstein, K E; Berk, B C

    1995-01-01

    Angiotensin converting enzyme (ACE) activity contributes to the vascular response to injury because ACE inhibition limits neointima formation in rat carotid arteries after balloon injury. To investigate the mechanisms by which ACE may contribute to vascular smooth muscle cell (VSMC) proliferation, we studied expression of ACE in vivo after injury and in vitro after growth factor stimulation. ACE activity 14 d after injury was increased 3.6-fold in the injured vessel. ACE expression, measured by immunohistochemistry, became apparent at 7 d in the neointima and at 14 d was primarily in the most luminal neointimal cells. To characterize hormones that induce ACE in vivo, cultured VSMC were exposed to steroids and growth factors. Among steroids, only glucocorticoids stimulated ACE expression with an 8.0 +/- 2.1-fold increase in activity and a 6.5-fold increase in mRNA (30 nM dexamethasone for 72 h). Among growth factors tested, only fibroblast growth factor (FGF) stimulated ACE expression (4.2 +/- 0.7-fold increase in activity and 1.6-fold increase in mRNA in response to 10 ng/ml FGF for 24 h). Dexamethasone and FGF were synergistic at the indicated concentrations inducing 50.6 +/- 12.4-fold and 32.5-fold increases in activity and mRNA expression, respectively. In addition, when porcine iliac arteries were transfected with recombinant FGF-1 (in the absence of injury), ACE expression increased in neointimal VSMC, to the same extent as injured, nontransfected arteries. The data suggest a temporal sequence for the response to injury in which FGF induces ACE, ACE generates angiotensin II, and angiotensin II stimulates VSMC growth in concert with FGF. Images PMID:7814638

  19. Estradiol-stimulated growth of MCF-7 tumors implanted in athymic mice: a model to study the tumoristatic action of tamoxifen.

    PubMed

    Gottardis, M M; Robinson, S P; Jordan, V C

    1988-01-01

    Ovariectomized athymic (nude) mice were inoculated (10(7) cells) with the breast cancer cell line, MCF-7, into the axillary mammary fat pads. Tumors did not grow unless animals were implanted with a 1.7 mg estradiol sustained (8-week)-release cholesterol pellet. Co-implantation with tamoxifen (5 mg, 4-week release) caused an inhibition of estradiol-stimulated growth but did not cause tumor growth when implanted alone. The metabolism of [3H]tamoxifen was determined in the athymic mouse bearing MCF-7 tumors. Metabolites in the liver, uterus and tumor were determined by TLC. The principal metabolite in each of the tissues was 4-hydroxytamoxifen (by comparison of Rfs with authentic standards). Studies with 4-hydroxytamoxifen and N-desmethyltamoxifen (the principal metabolites in patients) showed that each was effective in inhibiting estradiol-stimulated tumor growth. However, tumor growth could be reactivated by treatment with estradiol alone. In a separate experiment, tumor-implanted animals were treated with tamoxifen for 1, 2 and 6 months. Tamoxifen did not cause tumor growth. Nevertheless, tumor growth was reactivated by estradiol on each occasion. These studies confirm the tumoristatic actions of tamoxifen and strongly support the view that therapy must be given indefinitely to patients to control tumor recurrence. The athymic mouse model can be used in the future to determine the efficacy of novel antiestrogens and the development of antiestrogen drug resistance.

  20. Neuroprotective effect of miR-665 against sevoflurane anesthesia-induced cognitive dysfunction in rats through PI3K/Akt signaling pathway by targeting insulin-like growth factor 2

    PubMed Central

    Lu, Xihua; Lv, Shuaiguo; Mi, Yan; Wang, Lei; Wang, Gensheng

    2017-01-01

    The aim of this study was to investigate the in vivo and in vitro effects of miR-665 on sevoflurane anesthesia-induced cognitive dysfunction. SH-SY5Y cells and male SD rats were treated with sevoflurane to simulate anesthesia-induced cognitive dysfunction. The cells and rats both were transfected with a miR-665 mimic, inhibitor, scramble, IGF-2 siRNA, or treated with P13K/Akt inhibitor LY294002. The cell apoptosis, autophagy, growth related proteins, and mRNA levels were measured using different methods. The motor performance was assessed using the Morris water maze (MWM) test. Finally, the differences were statistically analyzed. It was noted that sevoflurane-induced miR-665 downregulation accompanied with the upregulation of IGF-2 in vivo and motor deficits in vitro. Moreover, sevoflurane also induced hippocampal neuroapoptosis; reduced regular autophagy; increased Bax/Bcl-2 ratio; decreased the expression of Beclin 1, PSD95, and p-CREB; and activated P13K/Akt signaling pathway. However, the treatment by miR-665 mimics significantly reversed all the molecular changes and improved motor performance. Our data demonstrate the neuroprotective effect of miR-665 against sevoflurane anesthesia-induced cognitive impairment. This study suggests that miR-665 might be explored as a potential target of therapy for sevoflurane-induced cognitive impairment. PMID:28386360

  1. Partially transformed, anchorage-independent human diploid fibroblasts result from overexpression of the c-sis oncogene: Mitogenic activity of an apparent monomeric platelet-derived growth factor 2 species

    SciTech Connect

    Stevens, C.W.; Brondyk, W.H.; Burgess, J.A.; Manoharan, T.H.; Hane, B.G.; Fahl, W.E.

    1988-05-01

    A human c-sis cDNA in an expression vector was introduced into human diploid fibroblasts by transfection or electroporation. Fibroblast clones showing an aberrant, densely packed colony morphology were isolated and found to overexpress a 3.6-kilobase sis mRNA species and associated immunoprecipitable platelet-derived growth factor (PDGF) 2 proteins. Parallel analyses in cell clones of sis mRNA expression and colony formation in agar indicated that, above a threshold, a linear, positive correlation existed between sis overexpression and acquired anchorage independence. The sis-overexpressing cells formed transient, regressing tumor nodules when injected into nude mice, consistent with the finite life span which they retained. Protein products generated from the transfected c-sis construct in two overexpressing clones were immunoprecipitated with anti-human PDGF antibodies. One clone contained an apparent PDGF dimer of 21 kilodaltons; the second clone contained only on apparent PDGF monomer of 12 kilodaltons, which was shown to account for all of the mitogenic activity present in the cells, essentially all of which was concentrated in the membrane fraction. The results demonstrate a clear link between sis overexpression and acquisition of a partially transformed, anchorage-independent phenotype, and when combined with previous observations of sis overexpression in human tumors, clearly implicate sis overexpression as a genetic mechanism which contributes to human cell transformation.

  2. Recombinant human follicle-stimulating hormone and transforming growth factor-alpha enhance in vitro maturation of porcine oocytes.

    PubMed

    Mito, Tomomi; Yoshioka, Koji; Noguchi, Michiko; Yamashita, Shoko; Hoshi, Hiroyoshi

    2013-07-01

    The biological functions of recombinant human follicle-stimulating hormone (FSH) and transforming growth factor-α (TGF-α) on in vitro maturation of porcine oocytes were investigated. Cumulus-oocyte complexes were matured in defined porcine oocyte medium containing 0-0.1 IU/ml FSH in the presence or absence of 10 ng/ml TGF-α. The percentage of oocytes reaching metaphase II was significantly higher with the addition of 0.01-0.1 IU/ml FSH compared with no addition, and was further enhanced in the presence of TGF-α. The rates of sperm penetration and blastocyst formation were significantly higher with the addition of 0.05-0.1 IU/ml FSH compared with no addition after in vitro fertilization and embryo culture. There was no beneficial effect of FSH and TGF-α on nuclear maturation of denuded oocytes. The specific EGF receptor inhibitor, AG1478, completely inhibited TGF-α-induced meiotic resumption, but did not completely prevent the stimulatory effect of FSH. Addition of both FSH and TGF-α significantly enhanced cumulus expansion compared with no addition. When cumulus expansion-related genes (HAS2, HAPLN1, and VCAN) mRNA expression in COCs was measured during in vitro maturaiton, addition of both of FSH and TGF-α upregulated the expression of HAS2 mRNA after 20 hr culture and HAPLN1 mRNA after 44 hr culture compared with no addition. Expression of VCAN mRNA was significantly higher in the presence of FSH compared with addition of TGF-α alone. These results suggest that FSH and TGF-α synergistically enhance porcine oocyte maturation via cumulus cells, and act through different signaling pathways.

  3. Stimulation of intestinal growth and function with DPP4 inhibition in a mouse short bowel syndrome model.

    PubMed

    Sueyoshi, Ryo; Woods Ignatoski, Kathleen M; Okawada, Manabu; Hartmann, Bolette; Holst, Jens; Teitelbaum, Daniel H

    2014-08-15

    Glucagon-like peptide-2 (GLP-2) has been shown to be effective in patients with short bowel syndrome (SBS), but it is rapidly inactivated by dipeptidyl peptidase IV (DPP4). We used an orally active DPP4 inhibitor (DPP4-I), MK-0626, to determine the efficacy of this approach to promote adaptation after SBS, determined optimal dosing, and identified further functional actions in a mouse model of SBS. Ten-week-old mice underwent a 50% proximal small bowel resection. Dose optimization was determined over a 3-day post-small bowel resection period. The established optimal dose was given for 7, 30, and 90 days and for 7 days followed by a 23-day washout period. Adaptive response was assessed by morphology, intestinal epithelial cell (IEC) proliferation (proliferating cell nuclear antigen), epithelial barrier function (transepithelial resistance), RT-PCR for intestinal transport proteins and GLP-2 receptor, IGF type 1 receptor, and GLP-2 plasma levels. Glucose-stimulated sodium transport was assessed for intestinal absorptive function. Seven days of DPP4-I treatment facilitated an increase in GLP-2 receptor levels, intestinal growth, and IEC proliferation. Treatment led to differential effects over time, with greater absorptive function at early time points and enhanced proliferation at later time points. Interestingly, adaptation continued in the group treated for 7 days followed by a 23-day washout. DPP4-I enhanced IEC proliferative action up to 90 days postresection, but this action seemed to peak by 30 days, as did GLP-2 plasma levels. Thus DPP4-I treatment may prove to be a viable option for accelerating intestinal adaptation with SBS.

  4. Mechanical loading by fluid shear stress of myotube glycocalyx stimulates growth factor expression and nitric oxide production.

    PubMed

    Juffer, Petra; Bakker, Astrid D; Klein-Nulend, Jenneke; Jaspers, Richard T

    2014-07-01

    Skeletal muscle fibers have the ability to increase their size in response to a mechanical overload. Finite element modeling data suggest that mechanically loaded muscles in vivo may experience not only tensile strain but also shear stress. However, whether shear stress affects biological pathways involved in muscle fiber size adaptation in response to mechanical loading is unknown. Therefore, our aim was twofold: (1) to determine whether shear stress affects growth factor expression and nitric oxide (NO) production by myotubes, and (2) to explore the mechanism by which shear stress may affect myotubes in vitro. C2C12 myotubes were subjected to a laminar pulsating fluid flow (PFF; mean shear stress 0.4, 0.7 or 1.4 Pa, 1 Hz) or subjected to uni-axial cyclic strain (CS; 15 % strain, 1 Hz) for 1 h. NO production during 1-h PFF or CS treatment was quantified using Griess reagent. The glycocalyx was degraded using hyaluronidase, and stretch-activated ion channels (SACs) were blocked using GdCl3. Gene expression was analyzed immediately after 1-h PFF (1.4 Pa, 1 Hz) and at 6 h post-PFF treatment. PFF increased IGF-I Ea, MGF, VEGF, IL-6, and COX-2 mRNA, but decreased myostatin mRNA expression. Shear stress enhanced NO production in a dose-dependent manner, while CS induced no quantifiable increase in NO production. Glycocalyx degradation and blocking of SACs ablated the shear stress-stimulated NO production. In conclusion, shear stress activates signaling pathways involved in muscle fiber size adaptation in myotubes, likely via membrane-bound mechanoreceptors. These results suggest that shear stress exerted on myofiber extracellular matrix plays an important role in mechanotransduction in muscle.

  5. Carbon dioxide stimulates the production of amylovorin L by Lactobacillus amylovorus DCE 471, while enhanced aeration causes biphasic kinetics of growth and bacteriocin production.

    PubMed

    Neysens, Patricia; De Vuyst, Luc

    2005-11-25

    The effects of both oxygen and carbon dioxide on growth of and product formation by Lactobacillus amylovorus DCE 471, a promising new sourdough starter culture, were assessed through controlled, in vitro fermentation experiments, using a temperature of 37 degrees C and a constant pH of 5.4. It was seen that aeration affected both cell growth and amylovorin L production. At aeration rates of 1 l min(-1) and more, the bacterial population was subjected to oxidative stress as reflected by biphasic growth patterns. During the first growth phase, the maximum specific growth rate increased with increasing aeration rates stabilizing at the highest oxygen concentrations. The maximum obtainable cell yields decreased. During the second growth phase, the amylovorin L production was stimulated at the highest aeration. However, amylovorin titers were never higher in the presence of oxygen compared with the anaerobic fermentations. Carbon dioxide did not influence cell growth of L. amylovorus DCE 471. The maximum specific growth rate and the biomass concentrations were merely affected. On the other hand, the maximum soluble bacteriocin titers coincided with the highest carbon dioxide flow rates. These results indicate that mild aeration of type II sourdoughs might enhance both cell yield and amylovorin L production by L. amylovorus DCE 471, thereby contributing to the competitiveness of the strain. Growth in an ecosystem together with yeasts producing carbon dioxide might exert a positive effect on the production of amylovorin L as well.

  6. Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 17: bone growth stimulators as an adjunct for lumbar fusion.

    PubMed

    Kaiser, Michael G; Eck, Jason C; Groff, Michael W; Ghogawala, Zoher; Watters, William C; Dailey, Andrew T; Resnick, Daniel K; Choudhri, Tanvir F; Sharan, Alok; Wang, Jeffrey C; Dhall, Sanjay S; Mummaneni, Praveen V

    2014-07-01

    The relationship between the formation of a solid arthrodesis and electrical and electromagnetic energy is well established; most of the information on the topic, however, pertains to the healing of long bone fractures. The use of both invasive and noninvasive means to supply this energy and supplement spinal fusions has been investigated. Three forms of electrical stimulation are routinely used: direct current stimulation (DCS), pulsed electromagnetic field stimulation (PEMFS), and capacitive coupled electrical stimulation (CCES). Only DCS requires the placement of electrodes within the fusion substrate and is inserted at the time of surgery. Since publication of the original guidelines, few studies have investigated the use of bone growth stimulators. Based on the current review, no conflict with the previous recommendations was generated. The use of DCS is recommended as an option for patients younger than 60 years of age, since a positive effect on fusion has been observed. The same, however, cannot be stated for patients over 60, because DCS did not appear to have an impact on fusion rates in this population. No study was reviewed that investigated the use of CCES or the routine use of PEMFS. A single low-level study demonstrated a positive impact of PEMFS on patients undergoing revision surgery for pseudarthrosis, but this single study is insufficient to recommend for or against the use of PEMFS in this patient population.

  7. Effects of recombinant growth hormone (GH) replacement and psychomotor and cognitive stimulation in the neurodevelopment of GH-deficient (GHD) children with cerebral palsy: a pilot study.

    PubMed

    Devesa, Jesús; Alonso, Begoña; Casteleiro, Nerea; Couto, Paula; Castañón, Beatriz; Zas, Eva; Reimunde, Pedro

    2011-01-01

    Cerebral palsy (CP) is the main cause of physical disability in childhood and is an important health issue that has a strong socioeconomic impact. There is no effective treatment for CP and therapeutic approaches report only partial benefits for affected people. In this study we assessed the effects of growth hormone (GH) treatment combined with psychomotor and cognitive stimulation in the neurodevelopment of children with CP and GH deficiency (GHD). The study was carried out in 11 patients (7 boys and 4 girls; 4.12 ± 1.31 years) with GHD and CP who were treated with recombinant GH (rGH) and psychomotor and cognitive stimulation during 2 months. Battelle Developmental Inventory Screening Test (BDIST) was performed 2 months before commencing GH treatment, just before commencing GH administration, and after 2 months of combined treatment involving GH and cognitive stimulation. Psychomotor and cognitive status did not change during the period in which only cognitive stimulation was performed; however, significant improvements in personal and social skills, adaptive behavior, gross motor skills and total psychomotor abilities, receptive and total communication, cognitive skills and in the total score of the test (P < 0.01), and in fine motor skills and expressive communication (P < 0.02) were observed after the combined treatment period. Therefore, GH replacement together with psychomotor and cognitive stimulation seem to be useful for the appropriate neurodevelopment of children with GHD and CP.

  8. Auxofuran, a novel metabolite that stimulates the growth of fly agaric, is produced by the mycorrhiza helper bacterium Streptomyces strain AcH 505.

    PubMed

    Riedlinger, Julia; Schrey, Silvia D; Tarkka, Mika T; Hampp, Rüdiger; Kapur, Manmohan; Fiedler, Hans-Peter

    2006-05-01

    The mycorrhiza helper bacterium Streptomyces strain AcH 505 improves mycelial growth of ectomycorrhizal fungi and formation of ectomycorrhizas between Amanita muscaria and spruce but suppresses the growth of plant-pathogenic fungi, suggesting that it produces both fungal growth-stimulating and -suppressing compounds. The dominant fungal-growth-promoting substance produced by strain AcH 505, auxofuran, was isolated, and its effect on the levels of gene expression of A. muscaria was investigated. Auxofuran and its synthetic analogue 7-dehydroxy-auxofuran were most effective at a concentration of 15 microM, and application of these compounds led to increased lipid metabolism-related gene expression. Cocultivation of strain AcH 505 and A. muscaria stimulated auxofuran production by the streptomycete. The antifungal substances produced by strain AcH 505 were identified as the antibiotics WS-5995 B and C. WS-5995 B completely blocked mycelial growth at a concentration of 60 microM and caused a cell stress-related gene expression response in A. muscaria. Characterization of these compounds provides the foundation for molecular analysis of the fungus-bacterium interaction in the ectomycorrhizal symbiosis between fly agaric and spruce.

  9. Platelet-derived growth factor stimulation of (/sup 3/H)-glucosamine incorporation in density-arrested BALB/c-3T3 cells

    SciTech Connect

    Harrington, M.A.; Wharton, W.; Pledger, W.J.

    1987-01-01

    G/sub 0//G/sub 1/ traverse in density-arrested BALB/c-3T3 cells is controlled by multiple serum-derived growth factors. Platelet-derived growth factor (PDGF) initiates a proliferative response, whereas factors present in plasma facilitate progression through G/sub 0//G/sub 1/. In the absence of competence formation, progression factors are unable to stimulate cell cycle traverse. The authors have identified the stimulation of a biochemical process specific to competence formation in BALB/c-3T3 cells. PDGF treated BALB/c-3T3 cells incorporated 5-10 fold more (/sup 3/H)-glucosamine (GlcN) into acid-insoluble material as compared to platelet-poor plasma (PPP) treated cultures. Increased GlcN incorporation occurred in density-arrested BALB/c-3T3 cells in response to treatment with other competence factors, fibroblast growth factor, and Ca/sub 3/ (PO/sub 4/)/sub 2/ and was not due to cell-cycle traverse. Stimulation of (/sup 3/H)-GlcN incorporation by PDGF was time dependent, and increased incorporation of (/sup 3/H)-GlcN into protein required de novo protein synthesis. Several mechanisms through which PDGF could increase GlcN incorporation into cellular material were examined. Results of these studies suggest an increase in the cellular capacity to glycosylate proteins is a response to or a part of competence formation.

  10. Regulation of mouse thymidylate synthase gene expression in growth-stimulated cells: upstream S phase control elements are indistinguishable from the essential promoter elements.

    PubMed Central

    Ash, J; Liao, W C; Ke, Y; Johnson, L F

    1995-01-01

    Expression of the mammalian thymidylate synthase (TS) gene in growth-stimulated cells is closely coordinated with entry into S phase. Previous studies with transfected TS minigenes have shown that sequences upstream of the coding region as well as an intron in the transcribed region are both necessary for proper regulation of TS mRNA content in growth-stimulated cells. The goal of the present study was to identify the upstream regulatory elements. Minigenes consisting of TS 5' flanking sequences linked to the TS coding region (interrupted by introns 1 and 2) were stably transfected into mouse 3T6 cells. Deletion and site-directed mutagenesis of the 5' flanking region revealed that there is a close correspondence between the upstream sequences that are necessary for S phase regulation and the 30 nucleotide region that is essential for promoter activity. These observations raised the possibility that regulation of the TS gene occurs at the transcriptional level. However, nuclear run-on assays showed that the rate of transcription of the TS gene changed very little during the G1-S phase transition. Furthermore, when the TS promoter was linked to an intron-less luciferase indicator gene, there was no change in expression following growth-stimulation. Therefore it appears that the TS gene is controlled primarily at the posttranscriptional level, and that the TS essential promoter region is necessary (although not sufficient) for proper S phase regulation. Images PMID:8524656

  11. Growth of human hemopoietic colonies in response to recombinant gibbon interleukin 3: comparison with human recombinant granulocyte and granulocyte-macrophage colony-stimulating factor

    SciTech Connect

    Messner, H.A.; Yamasaki, K.; Jamal, N.; Minden, M.M.; Yang, Y.C.; Wong, G.G.; Clark, S.C.

    1987-10-01

    Supernatants of COS-1 cells transfected with gibbon cDNA encoding interleukin 3 (IL-3) with homology to sequences for human IL-3 were tested for ability to promote growth of various human hemopoietic progenitors. The effect of these supernatants as a source of recombinant IL-3 was compared to that of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) as well as to that of medium conditioned by phytohemagglutinin-stimulated leukocytes. The frequency of multilineage colonies, erythroid bursts, and megakaryocyte colonies in cultures containing the COS-1 cell supernatant was equivalent to the frequency observed in the controls and significantly higher than found in cultures plated with recombinant GM-CSF. G-CSF did not support the formation of multilineage colonies, erythroid bursts, and megakaryocyte colonies. In contrast, growth of granulocyte-macrophage colonies was best supported with GM-CSF, while recombinant IL-3 yielded colonies at lower or at best equivalent frequency. The simultaneous addition of higher concentrations of GM-CSF to cultures containing IL-3 in optimal amounts did not enhance the formation of multilineage colonies, erythroid bursts, and megakaryocyte colonies. However, the frequency of such colonies and bursts increased with GM-CSF when cultures were plated with suboptimal concentrations of IL-3. Growth of colonies within the granulocyte-macrophage lineage is optimally supported by GM-CSF and does not increase with further addition of IL-3.

  12. Adipose-derived stem cells stimulate regeneration of peripheral nerves: BDNF secreted by these cells promotes nerve healing and axon growth de novo.

    PubMed

    Lopatina, Tatiana; Kalinina, Natalia; Karagyaur, Maxim; Stambolsky, Dmitry; Rubina, Kseniya; Revischin, Alexander; Pavlova, Galina; Parfyonova, Yelena; Tkachuk, Vsevolod

    2011-03-14

    Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation.

  13. Macimorelin (AEZS-130)-Stimulated Growth Hormone (GH) Test: Validation of a Novel Oral Stimulation Test for the Diagnosis of Adult GH Deficiency

    PubMed Central

    Swerdloff, R.; Wang, C.; Kyle, M.; Kipnes, M.; Biller, B. M. K.; Cook, D.; Yuen, K. C. J.; Bonert, V.; Dobs, A.; Molitch, M. E.; Merriam, G. R.

    2013-01-01

    Context: In the absence of panhypopituitarism and low serum IGF-I levels, the diagnosis of adult GH deficiency (AGHD) requires confirmation with a GH stimulation test. Macimorelin is a novel, orally active ghrelin mimetic that stimulates GH secretion. Objective: The objective of the study was to determine the diagnostic efficacy and safety of macimorelin in AGHD. Design: This was a multicenter open-label study comparing the diagnostic accuracy of oral macimorelin with that of arginine+GHRH in AGHD patients and healthy, matched controls. After 43 AGHD patients and 10 controls were tested, the GHRH analog Geref Diagnostic [GHRH(1–29)NH2] became unavailable in the United States. The study was completed by testing 10 additional AGHD patients and 38 controls with macimorelin alone. Main Outcome Measure: Peak GH area under the receiver operating characteristic curve after macimorelin was measured. Results: Fifty AGHD subjects and 48 controls were evaluated. Peak GH levels in AGHD patients and controls after macimorelin were 2.36 ± 5.69 and 17.71 ± 19.11 ng/mL, respectively (P < .0001). With macimorelin, the receiver operating characteristic analysis yielded an optimal GH cut point of 2.7 ng/mL, with 82% sensitivity, 92% specificity, and 13% misclassification rate. For subjects receiving both tests, macimorelin showed discrimination comparable with arginine+GHRH (area under the receiver operating characteristic curve 0.99 vs 0.94, respectively, P = .29). Obesity (body mass index > 30 kg/m2) was present in 58% of subjects, and peak GH levels were inversely associated with body mass index in controls (r = −0.37, P = .01). Using the separate cut points of 6.8 ng/mL for nonobese and 2.7 for obese subjects reduced the misclassification rate to 11%. Only 1 drug-related serious adverse event, an asymptomatic QT interval prolongation on the electrocardiogram, was reported. Conclusion: Oral macimorelin is safe, convenient, and effective in diagnosing AGHD with accuracy

  14. Wafer-scale crack-free AlGaN on GaN through two-step selective-area growth for optically pumped stimulated emission

    NASA Astrophysics Data System (ADS)

    Ko, Young-Ho; Bae, Sung-Bum; Kim, Sung-Bock; Kim, Dong Churl; Leem, Young Ahn; Cho, Yong-Hoon; Nam, Eun-Soo

    2016-07-01

    Crack-free AlGaN template has been successfully grown over entire 2-in. wafer by using 2-step selective-area growth (SAG). The GaN truncated structure was obtained by vertical growth mode with low growth temperature. AlGaN of second step was grown under lateral growth mode. Low pressure enhanced the relative ratio of lateral to vertical growth rate as well as absolute overall growth rate. High V/III ratio was favorable for lateral growth mode. Crack-free planar AlGaN was obtained under low pressure of 30 Torr and high V/III ratio of 4400. The AlGaN was crack-free over entire 2-in. wafer and had quite uniform Al-mole fraction. The dislocation density of the AlGaN with 20% Al-composition was as low as ~7.6×108 /cm2, measured by cathodoluminescence. GaN/AlGaN multi-quantum well (MQW) with cladding and waveguide layers were grown on the crack-free AlGaN template with low dislocation density. It was confirmed that the MQW on the AlGaN template emitted the stimulated emission at 355.5 nm through optical pumping experiment. The AlGaN obtained by 2-step SAG would provide high crystal quality for highly-efficient optoelectronic devices as well as the ultraviolet laser diode.

  15. Loss of platelet-derived growth factor-stimulated phospholipase activity in NIH-3T3 cells expressing the EJ-ras oncogene

    SciTech Connect

    Benjamin, C.W.; Tarpley, W.G.; Gorman, R.R.

    1987-01-01

    Data indicating that the 21-kDa protein (p21) Harvey-ras gene product shares sequence homology with guanine nucleotide-binding proteins (G proteins) has stimulated research on the influence(s) of p21 on G-protein-regulated systems in vertebrate cells. Previous work demonstrated that NIH-3T3 mouse cells expressing high levels of the cellular ras oncogene isolated from the EJ human bladder carcinoma (EJ-ras) exhibited reduced hormone-stimulated adenylate cyclase activity. The authors now report that in these cells another enzyme system thought to be regulated by G proteins is inhibited, namely phospholipases A/sub 2/ and C. NIH-3T3 cells incubated in plasma-derived serum release significant levels of prostaglandin E/sub 2/ (PGE/sub 2/) as determined by radioimmunoassay when exposed to platelet-derived growth factor (PDGF) at 2 units/ml. The lack of PDGF-stimulated PGE/sub 2/ release from EJ-ras-transfected cells is not due to a defect in the prostaglandin cyclooxygenase enzyme, since incubation of control cells and EJ-ras-transfected cells in 0.33, 3.3, or 33 ..mu..M arachidonate resulted in identical levels of PGE/sub 2/ release. The lack of PDGF-stimulated PGE/sub 2/ release from EJ-ras-transfected cells also does not result from the loss of functional PDGF receptors. EJ-ras-transformed cells bind 70% as much /sup 125/I-labeled PDGF as control cells and are stimulated to incorporate (/sup 3/H)thymidine and to proliferate after exposure to PDGF. Determination of total water-soluble inositolphospholipids and changes in the specific activities of phosphatidylcholine in control and EJ-ras-transfected cells demonstrated that PDGF-stimulated phospholipase C and A/sub 2/ activities are inhibited in the EJ-ras-transfected cells.

  16. Clonidine-stimulated growth hormone concentrations (cut-off values) measured by immunochemiluminescent assay (ICMA) in children and adolescents with short stature

    PubMed Central

    de Fátima Borges, Maria; Teixeira, Flávia Carolina Cândida; Feltrin, Aline Karin; Ribeiro, Karina Alvarenga; Nascentes, Gabriel Antonio Nogueira; Resende, Elisabete Aparecida Mantovani Rodrigues; Ferreira, Beatriz Pires; Silva, Adriana Paula; Palhares, Heloísa Marcelina Cunha

    2016-01-01

    OBJECTIVES: To establish cut-off values for growth hormone concentrations using clonidine as a secretagogue and an immunochemiluminescent assay as the method of measurement and to analyze the response time as well as the influence of gender, nutritional status and pubertal stage. METHODS: A total of 225 tests were performed in 3 patient groups, categorized as group 1 (normal), group 2 (idiopathic short stature) and group 3 (growth hormone deficiency). Among the 199 disease-free individuals, 138 were prepubertal, and 61 were pubertal. Clonidine (0.1 mg/m2) was orally administered, and the growth hormone level was measured by immunochemiluminescent assay. The growth hormone peak and the difference between the growth hormone peak and the baseline level were then analyzed. Statistical analyses were performed using Student's t-test or the Mann-Whitney test and Kruskal-Wallis test followed by Dunn's post hoc test. Cut-off values were determined using a receiver operating characteristic curve. RESULTS: Group 1 and group 2 had no difference in growth hormone peak, gender, body mass index standard deviation score, or pubertal stage. Group 3 exhibited a significantly lower growth hormone peak than the other groups did. The receiver operating characteristic curve demonstrated that growth hormone concentrations ≥ 3.0 ng/mL defined responsiveness to clonidine. In total, 3.02% of individuals in group 1 and group 2 were considered false positive, i.e., these children lacked growth hormone deficiency and had a peak below 3.0 ng/mL. CONCLUSION: Clonidine-stimulated growth hormone concentrations ≥3 ng/mL, as measured by immunochemiluminescent assay, suggest responsiveness to the stimulus regardless of gender, body mass index standard deviation score or pubertal stage. PMID:27166774

  17. Stimulation of the growth of femoral trabecular bone in ovariectomized rats by the novel parathyroid hormone fragment, hPTH-(1-31)NH2 (Ostabolin).

    PubMed

    Whitfield, J F; Morley, P; Willick, G E; Ross, V; Barbier, J R; Isaacs, R J; Ohannessian-Barry, L

    1996-02-01

    The human parathyroid hormone, hPTH-(1-84), and its hPTH-(1-34) fragment are promising anabolic agents for treating osteoporosis because they can strongly stimulate the production of biomechanically effective cortical and trabecular bone in osteopenic ovariectomized (OVX) rats and trabecular bone in osteoporotic postmenopausal humans. The ideal PTH fragment for treating osteoporosis would be the smallest and functionally simplest fragment that activates only one signal mechanism and still strongly stimulates trabecular bone growth. A new PTH fragment, hPTH-(1-31)NH2, which only stimulates adenylyl cyclase instead of stimulating both adenylyl cyclase and phospholipase-C as do hPTH-(1-84) and hPTH-(1-34), is this minimum, high-potency anabolic fragment. hPTH-(1-31)NH2 (which we have named Ostabolin) can greatly thicken trabeculae and increase the dry weight and calcium content of trabecular bone in the distal femurs of osteopenic, young, sexually mature OVX Sprague-Dawley rats when injected subcutaneously each day for 6 weeks at doses between 0.4 and 1.6 nmole/100 g of body weight.

  18. TGF beta induces a sustained c-fos expression associated with stimulation or inhibition of cell growth in EL2 or NIH 3T3 fibroblasts.

    PubMed

    Liboi, E; Di Francesco, P; Gallinari, P; Testa, U; Rossi, G B; Peschle, C

    1988-02-29

    We have previously indicated that epidermal growth factor (EGF) plays a fundamental role in the proliferation control of EL2 rat fibroblast line. It is shown here that transforming growth factor beta (TGF beta) stimulates both DNA synthesis and proliferation of EL2 cells, while exerting an inhibitory effect on the growth of murine NIH-3T3 fibroblasts. We also report the effect of TGF beta and EGF on c-fos expression in EL2 cells, as compared to that of TGF beta in NIH-3T3 fibroblasts. In EL2 cells EGF induces a transient c-fos expression at both mRNA and protein level, as previously observed in NIH-3T3 fibroblasts treated with platelet-derived or fibroblast growth factor (PDGF, FGF). Conversely, TGF beta induces in EL2 cells a sustained expression of fos mRNA and protein, which are still detectable at least 24 and 7 hr after treatment respectively. In NIH-3T3 fibroblasts TGF beta causes a sustained fos RNA expression, which is not associated, however, with detectable fos protein. We conclude that in fibroblasts stimulated by mitogens c-fos expression may be differentially modulated, depending of the growth factor and the cell line. This is seemingly due to differential regulation of fos gene expression, not only at the transcriptional and/or post-transcriptional level (transient or sustained fos RNA induction by EGF or TGF beta in EL2 cells), but also at the translational level (fos protein(s) induction by TGF beta in EL2 but not NIH-3T3 fibroblasts, possibly related to the stimulatory vs inhibitory effect of this factor on the growth of the former vs the latter line).

  19. Des (1-3) IGF-I-stimulated growth of human stromal BPH cells is inhibited by a vitamin D3 analogue.

    PubMed

    Crescioli, C; Villari, D; Forti, G; Ferruzzi, P; Petrone, L; Vannelli, G B; Adorini, L; Salerno, R; Serio, M; Maggi, M

    2002-12-30

    Prostate growth and differentiation is under the control of androgens not only during fetal life and childhood but also in adulthood, and it has been proposed that increased prostatic concentration of androgens, or increased androgen responsiveness, causes benign prostatic hyperplasia (BPH). However, different androgen ablation strategies such as treatment with GnRH agonists and finasteride resulted in a modest decrease of the hyperplastic prostate volume. In the last few years it became evident that both androgen-dependent and androgen-independent growth factors promote prostate enlargement by inducing cell proliferation or reducing apoptosis. Therefore, new therapeutic strategies, aimed at reducing intraprostatic growth factor signaling, are under investigation. In this study, we report further evidence that a non hypercalcemic-analogue of vitamin D(3), analogue (V) decreases growth factor-induced human BPH cell proliferation and survival. We found that Des (1-3) insulin-like growth factor [Des (1-3) IGF-I], an IGF-I analogue, which does not bind to IGF-binding proteins, is a potent mitogen for BPH stromal cells via a dual mechanism: stimulation of cell growth and inhibition of apoptosis. Similar results were previously reported for another growth factor for BPH cells, keratinocyte growth factor (KGF). Accordingly, we speculate that both KGF and IGF might be involved in the pathogenesis of BPH. We also found analogue (V) not only inhibits the mitogenic activity of growth factors on BPH cells, but even decreased the basal expression of bcl-2, and induced apoptosis. Therefore, vitamin D(3) analogues might be considered for the medical treatment of BPH.

  20. PKCθ activation in pancreatic acinar cells by gastrointestinal hormones/neurotransmitters and growth factors is needed for stimulation of numerous important cellular signaling cascades.

    PubMed

    Sancho, Veronica; Berna, Marc J; Thill, Michelle; Jensen, R T

    2011-12-01

    The novel PKCθ isoform is highly expressed in T-cells, brain and skeletal muscle and originally thought to have a restricted distribution. It has been extensively studied in T-cells and shown to be important for apoptosis, T-cell activation and proliferation. Recent studies showed its presence in other tissues and importance in insulin signaling, lung surfactant secretion, intestinal barrier permeability, platelet and mast-cell functions. However, little information is available for PKCθ activation by gastrointestinal (GI) hormones/neurotransmitters and growth factors. In the present study we used rat pancreatic acinar cells to explore their ability to activate PKCθ and the possible interactions with important cellular mediators of their actions. Particular attention was paid to cholecystokinin (CCK), a physiological regulator of pancreatic function and important in pathological processes affecting acinar function, like pancreatitis. PKCθ-protein/mRNA was present in the pancreatic acini, and T538-PKCθ phosphorylation/activation was stimulated only by hormones/neurotransmitters activating phospholipase C. PKCθ was activated in time- and dose-related manner by CCK, mediated 30% by high-affinity CCK(A)-receptor activation. CCK stimulated PKCθ translocation from cytosol to membrane. PKCθ inhibition (by pseudostrate-inhibitor or dominant negative) inhibited CCK- and TPA-stimulation of PKD, Src, RafC, PYK2, p125(FAK) and IKKα/β, but not basal/stimulated enzyme secretion. Also CCK- and TPA-induced PKCθ activation produced an increment in PKCθ's direct association with AKT, RafA, RafC and Lyn. These results show for the first time the PKCθ presence in pancreatic acinar cells, its activation by some GI hormones/neurotransmitters and involvement in important cell signaling pathways mediating physiological responses (enzyme secretion, proliferation, apoptosis, cytokine expression, and pathological responses like pancreatitis and cancer growth).

  1. PKCθ activation in pancreatic acinar cells by gastrointestinal hormones/neurotransmitters and growth factors is needed for stimulation of numerous important cellular signaling cascades

    PubMed Central

    Sancho, Veronica; Berna, Marc J.; Thill, Michelle; Jensen, R. T.

    2011-01-01

    The novel PKCθ isoform is highly expressed in T-cells, brain and skeletal muscle and originally thought to have a restricted distribution. It has been extensively studied in T-cells and shown to be important for apoptosis, T-cell activation and proliferation. Recent studies showed its presence in other tissues and importance in insulin signaling, lung surfactant secretion, intestinal barrier permeability, platelet and mast-cell functions. However, little information is available for PKCθ activation by gastrointestinal(GI) hormones/neurotransmitters and growth factors. In the present study we used rat pancreatic acinar cells to explore their ability to activate PKCθ and the possible interactions with important cellular mediators of their actions. Particular attention was paid to cholecystokinin(CCK), a physiological regulator of pancreatic function and important in pathological processes affecting acinar function, like pancreatitis. PKCθ-protein/mRNA were present in the pancreatic acini, and T538-PKCθ phosphorylation/activation was stimulated only by hormones/neurotransmitters activating phospholipase C. PKCθ was activated in time- and dose-related manner by CCK, mediated 30% by high-affinity CCKA-receptor activation. CCK stimulated PKCθ translocation from cytosol to membrane. PKCθ inhibition (by pseudostrate-inhibitor or dominant negative) inhibited CCK- and TPA-stimulation of PKD, Src, RafC, PYK2, p125FAK and IKKα/β, but not basal/stimulated enzyme secretion. Also CCK- and TPA-induced PKCθ activation produced an increment in PKCθ’s direct association with AKT, RafA, RafC and Lyn. These results show for the first time PKCθ presence in pancreatic acinar cells, its activation by some GI hormones/neurotransmitters and involvement in important cell signaling pathways mediating physiological responses (enzyme secretion, proliferation, apoptosis, cytokine expression, and pathological responses like pancreatitis and cancer growth). PMID:21810446

  2. Murine embryonic stem cells secrete cytokines/growth modulators that enhance cell survival/anti-apoptosis and stimulate colony formation of murine hematopoietic progenitor cells.

    PubMed

    Guo, Ying; Graham-Evans, Barbara; Broxmeyer, Hal E

    2006-04-01

    Stromal cell-derived factor (SDF)-1/CXCL12, released by murine embryonic stem (ES) cells, enhances survival, chemotaxis, and hematopoietic differentiation of murine ES cells. Conditioned medium (CM) from murine ES cells growing in the presence of leukemia inhibitory factor (LIF) was generated while the ES cells were in an undifferentiated Oct-4 expressing state. ES cell-CM enhanced survival of normal murine bone marrow myeloid progenitors (CFU-GM) subjected to delayed growth factor addition in vitro and decreased apoptosis of murine bone marrow c-kit(+)lin- cells. ES CM contained interleukin (IL)-1alpha, IL-10, IL-11, macrophage-colony stimulating factor (CSF), oncostatin M, stem cell factor, vascular endothelial growth factor, as well as a number of chemokines and other proteins, some of which are known to enhance survival/anti-apoptosis of progenitors. Irradiation of ES cells enhanced release of some proteins and decreased release of others. IL-6, FGF-9, and TNF-alpha, not detected prior to irradiation was found after ES cells were irradiated. ES cell CM also stimulated CFU-GM colony formation. Thus, undifferentiated murine ES cells growing in the presence of LIF produce/release a number of biologically active interleukins, CSFs, chemokines, and other growth modulatory proteins, results which may be of physiological and/or practical significance.

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

    SciTech Connect

    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 2 +/)/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.

  4. Effects of Agaricus lilaceps fairy rings on soil aggregation and microbial community structure in relation to growth stimulation of western wheatgrass (Pascopyrum smithii) in Eastern Montana rangeland.

    PubMed

    Caesar-Tonthat, The Can; Espeland, Erin; Caesar, Anthony J; Sainju, Upendra M; Lartey, Robert T; Gaskin, John F

    2013-07-01

    Stimulation of plant productivity caused by Agaricus fairy rings has been reported, but little is known about the effects of these fungi on soil aggregation and the microbial community structure, particularly the communities that can bind soil particles. We studied three concentric zones of Agaricus lilaceps fairy rings in Eastern Montana that stimulate western wheatgrass (Pascopyrum smithii): outside the ring (OUT), inside the ring (IN), and stimulated zone adjacent to the fungal fruiting bodies (SZ) to determine (1) soil aggregate proportion and stability, (2) the microbial community composition and the N-acetyl-β-D-glucosaminidase activity associated with bulk soil at 0-15 cm depth, (3) the predominant culturable bacterial communities that can bind to soil adhering to wheatgrass roots, and (4) the stimulation of wheatgrass production. In bulk soil, macroaggregates (4.75-2.00 and 2.00-0.25 mm) and aggregate stability increased in SZ compared to IN and OUT. The high ratio of fungal to bacteria (fatty acid methyl ester) and N-acetyl-β-D-glucosaminidase activity in SZ compared to IN and OUT suggest high fungal biomass. A soil sedimentation assay performed on the predominant isolates from root-adhering soil indicated more soil-binding bacteria in SZ than IN and OUT; Pseudomonas fluorescens and Stenotrophomonas maltophilia isolates predominated in SZ, whereas Bacillus spp. isolates predominated in IN and OUT. This study suggests that growth stimulation of wheatgrass in A. lilaceps fairy rings may be attributed to the activity of the fungus by enhancing soil aggregation of bulk soil at 0-15 cm depth and influencing the amount and functionality of specific predominant microbial communities in the wheatgrass root-adhering soil.

  5. The paired basic amino acid-cleaving enzyme 4 (PACE4) is involved in the maturation of insulin receptor isoform B: an opportunity to reduce the specific insulin receptor-dependent effects of insulin-like growth factor 2 (IGF2).

    PubMed

    Kara, Imène; Poggi, Marjorie; Bonardo, Bernadette; Govers, Roland; Landrier, Jean-François; Tian, Sun; Leibiger, Ingo; Day, Robert; Creemers, John W M; Peiretti, Franck

    2015-01-30

    Gaining the full activity of the insulin receptor (IR) requires the proteolytic cleavage of its proform by intra-Golgi furin-like activity. In mammalian cells, IR is expressed as two isoforms (IRB and IRA) that are responsible for insulin action. However, only IRA transmits the growth-promoting and mitogenic effects of insulin-like growth factor 2. Here we demonstrate that the two IR isoforms are similarly cleaved by furin, but when this furin-dependent maturation is inefficient, IR proforms move to the cell surface where the proprotein convertase PACE4 selectively supports IRB maturation. Therefore, in situations of impaired furin activity, the proteolytic maturation of IRB is greater than that of IRA, and accordingly, the amount of phosphorylated IRB is also greater than that of IRA. We highlight the ability of a particular proprotein convertase inhibitor to effectively reduce the maturation of IRA and its associated mitogenic signaling without altering the signals emanating from IRB. In conclusion, the selective PACE4-dependent maturation of IRB occurs when furin activity is reduced; accordingly, the pharmacological inhibition of furin reduces IRA maturation and its mitogenic potential without altering the insulin effects.

  6. No growth stimulation of Canada's boreal forest under half-century of combined warming and CO2 fertilization.

    PubMed

    Girardin, Martin P; Bouriaud, Olivier; Hogg, Edward H; Kurz, Werner; Zimmermann, Niklaus E; Metsaranta, Juha M; de Jong, Rogier; Frank, David C; Esper, Jan; Büntgen, Ulf; Guo, Xiao Jing; Bhatti, Jagtar

    2016-12-27

    Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada's boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada's National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO2 concentration.

  7. No growth stimulation of Canada’s boreal forest under half-century of combined warming and CO2 fertilization

    PubMed Central

    Girardin, Martin P.; Hogg, Edward H.; Kurz, Werner; Zimmermann, Niklaus E.; Metsaranta, Juha M.; de Jong, Rogier; Frank, David C.; Esper, Jan; Büntgen, Ulf; Guo, Xiao Jing; Bhatti, Jagtar

    2016-01-01

    Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada’s boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada’s National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significant regional- and species-related trends in growth, but the positive and negative trends compensate each other to yield no strong overall trend in forest growth when averaged across the Canadian boreal forest. The spatial patterns of growth trends identified in our analysis were to some extent coherent with trends estimated by remote sensing, but there are wide areas where remote-sensing information did not match the forest growth trends. Quantifications of tree growth variability as a function of climate factors and atmospheric CO2 concentration reveal strong negative temperature and positive moisture controls on spatial patterns of tree growth rates, emphasizing the ecological sensitivity to regime shifts in the hydrological cycle. An enhanced dependence of forest growth on soil moisture during the late-20th century coincides with a rapid rise in summer temperatures and occurs despite potential compensating effects from increased atmospheric CO2 concentration. PMID:27956624

  8. Gamma-caprolactone stimulates growth of quorum-quenching Rhodococcus populations in a large-scale hydroponic system for culturing Solanum tuberosum.

    PubMed

    Cirou, Amélie; Raffoux, Aurélie; Diallo, Stéphanie; Latour, Xavier; Dessaux, Yves; Faure, Denis

    2011-11-01

    Bacteria degrading quorum sensing (QS) signals have been proposed as biocontrol agents able to quench QS-dependent expression of virulence symptoms caused by Pectobacterium on potato plants. We report here that gamma-caprolactone (GCL) treatment stimulated growth of the native QS-degrading bacterial community in an industrial plant hydroponic system for culturing Solanum tuberosum. Post-GCL treatment, QS-degrading bacteria were mainly identified as Rhodococcus isolates, while Agrobacterium isolates dominated under similar untreated conditions. Most of the assayed Rhodococcus isolates exhibited efficient biocontrol activity for protecting potato tubers. Analytical chemistry approach revealed the rapid degradation of GCL introduced in the plant cultures.

  9. EphA3 Expressed in the Chicken Tectum Stimulates Nasal Retinal Ganglion Cell Axon Growth and Is Required for Retinotectal Topographic Map Formation

    PubMed Central

    Rapacioli, Melina; Salierno, Marcelo; Etchenique, Roberto; Flores, Vladimir; Sanchez, Viviana; Carri, Néstor Gabriel; Scicolone, Gabriel

    2012-01-01

    Background Retinotopic projection onto the tectum/colliculus constitutes the most studied model of topographic mapping and Eph receptors and their ligands, the ephrins, are the best characterized molecular system involved in this process. Ephrin-As, expressed in an increasing rostro-caudal gradient in the tectum/colliculus, repel temporal retinal ganglion cell (RGC) axons from the caudal tectum and inhibit their branching posterior to their termination zones. However, there are conflicting data regarding the nature of the second force that guides nasal axons to invade and branch only in the caudal tectum/colliculus. The predominant model postulates that this second force is produced by a decreasing rostro-caudal gradient of EphA7 which repels nasal optic fibers and prevents their branching in the rostral tectum/colliculus. However, as optic fibers invade the tectum/colliculus growing throughout this gradient, this model cannot explain how the axons grow throughout this repellent molecule. Methodology/Principal Findings By using chicken retinal cultures we showed that EphA3 ectodomain stimulates nasal RGC axon growth in a concentration dependent way. Moreover, we showed that nasal axons choose growing on EphA3-expressing cells and that EphA3 diminishes the density of interstitial filopodia in nasal RGC axons. Accordingly, in vivo EphA3 ectodomain misexpression directs nasal optic fibers toward the caudal tectum preventing their branching in the rostral tectum. Conclusions We demonstrated in vitro and in vivo that EphA3 ectodomain (which is expressed in a decreasing rostro-caudal gradient in the tectum) is necessary for topographic mapping by stimulating the nasal axon growth toward the caudal tectum and inhibiting their branching in the rostral tectum. Furthermore, the ability of EphA3 of stimulating axon growth allows understanding how optic fibers invade the tectum growing throughout this molecular gradient. Therefore, opposing tectal gradients of repellent ephrin

  10. Stimulation of cartilage amino acid uptake by growth hormone-dependent factors in serum. Mediation by adenosine 3':5'-monophosphate.

    PubMed

    Drezner, M K; Eisenbarth, G S; Neelon, F A; Lebovitz, H E

    1975-02-13

    The effects of growth hormone-dependent serum factors on amino acid transport and on cartilage cyclic AMP levels in embryonic chicken cartilage were studied in vitro. Cartilages incubated in medium containing rat serum showed a significantly greater uptake of alpha-amino [1-14C] isobutyrate or [1-14C] cycloleucine than control cartilages incubated in medium alone. Normal rat serum (5%) added to the incubation medium also caused an increase in cartilage cyclic AMP content (from as little as 23% to as much as 109%). The factors in serum which increase cartilage cyclic AMP and amino acid uptake are growth hormone dependent, since neither growth hormone itself nor serum from hypophysectomized rats restores these serum factors. Studies comparing the ability of sera with varying amounts of growth hormone-dependent factors to stimulate amino-aminoisobutyrate transport and to increase cartilage cyclic AMP show a striking linear correlation between the two effects (r=0.977). Theophylline and prostaglandin E1, WHICH RAISE CARTILAGE CYCLIC AMP also increase amino-aminoisobutyrate transport. Exogenous cyclic AMP, N6-monobutyryl cyclic AMP and n6, 02'-dibutyryl cyclic AMP increase cartilage amino-aminoisobutyrate transport. The data are compatible with the thesis that growth hormone-dependent serum factors increase cartilage amino acid transport by elevating cartilage cyclic AMP.

  11. Stimulating seedling growth in early stages of secondary forest succession: a modeling approach to guide tree liberation.

    PubMed

    van Kuijk, Marijke; Anten, Niels P R; Oomen, Roelof J; Schieving, Feike

    2014-01-01

    Excessive growth of non-woody plants and shrubs on degraded lands can strongly hamper tree growth and thus secondary forest succession. A common method to accelerate succession, called liberation, involves opening up the vegetation canopy around young target trees. This can increase growth of target trees by reducing competition for light with neighboring plants. However, liberation has not always had the desired effect, likely due to differences in light requirement between tree species. Here we present a 3D-model, which calculates photosynthetic rate of individual trees in a vegetation stand. It enables us to examine how stature, crown structure, and physiological traits of target trees and characteristics of the surrounding vegetation together determine effects of light on tree growth. The model was applied to a liberation experiment conducted with three pioneer species in a young secondary forest in Vietnam. Species responded differently to the treatment depending on their height, crown structure and their shade-tolerance level. Model simulations revealed practical thresholds over which the tree growth response is heavily influenced by the height and density of surrounding vegetation and gap radius. There were strong correlations between calculated photosynthetic rates and observed growth: the model was well able to predict growth of trees in young forests and the effects of liberation there upon. Thus, our model serves as a useful tool to analyze light competition between young trees and surrounding vegetation and may help assess the potential effect of tree liberation.

  12. Stimulating seedling growth in early stages of secondary forest succession: a modeling approach to guide tree liberation

    PubMed Central

    van Kuijk, Marijke; Anten, Niels P. R.; Oomen, Roelof J.; Schieving, Feike

    2014-01-01

    Excessive growth of non-woody plants and shrubs on degraded lands can strongly hamper tree growth and thus secondary forest succession. A common method to accelerate succession, called liberation, involves opening up the vegetation canopy around young target trees. This can increase growth of target trees by reducing competition for light with neighboring plants. However, liberation has not always had the desired effect, likely due to differences in light requirement between tree species. Here we present a 3D-model, which calculates photosynthetic rate of individual trees in a vegetation stand. It enables us to examine how stature, crown structure, and physiological traits of target trees and characteristics of the surrounding vegetation together determine effects of light on tree growth. The model was applied to a liberation experiment conducted with three pioneer species in a young secondary forest in Vietnam. Species responded differently to the treatment depending on their height, crown structure and their shade-tolerance level. Model simulations revealed practical thresholds over which the tree growth response is heavily influenced by the height and density of surrounding vegetation and gap radius. There were strong correlations between calculated photosynthetic rates and observed growth: the model was well able to predict growth of t