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  1. Therapeutic applications of macrophage colony-stimulating factor-1 (CSF-1) and antagonists of CSF-1 receptor (CSF-1R) signaling.

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    Hume, David A; MacDonald, Kelli P A

    2012-02-23

    Macrophage-colony stimulating factor (CSF-1) signaling through its receptor (CSF-1R) promotes the differentiation of myeloid progenitors into heterogeneous populations of monocytes, macrophages, dendritic cells, and bone-resorbing osteoclasts. In the periphery, CSF-1 regulates the migration, proliferation, function, and survival of macrophages, which function at multiple levels within the innate and adaptive immune systems. Macrophage populations elicited by CSF-1 are associated with, and exacerbate, a broad spectrum of pathologies, including cancer, inflammation, and bone disease. Conversely, macrophages can also contribute to immunosuppression, disease resolution, and tissue repair. Recombinant CSF-1, antibodies against the ligand and the receptor, and specific inhibitors of CSF-1R kinase activity have been each been tested in a range of animal models and in some cases, in patients. This review examines the potential clinical uses of modulators of the CSF-1/CSF-1R system. We conclude that CSF-1 promotes a resident-type macrophage phenotype. As a treatment, CSF-1 has therapeutic potential in tissue repair. Conversely, inhibition of CSF-1R is unlikely to be effective in inflammatory disease but may have utility in cancer.

  2. Cloning and expression of porcine Colony Stimulating Factor-1 (CSF-1) and Colony Stimulating Factor-1 Receptor (CSF-1R) and analysis of the species specificity of stimulation by CSF-1 and Interleukin 34.

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    Gow, Deborah J; Garceau, Valerie; Kapetanovic, Ronan; Sester, David P; Fici, Greg J; Shelly, John A; Wilson, Thomas L; Hume, David A

    2012-12-01

    Macrophage Colony Stimulating Factor (CSF-1) controls the survival, differentiation and proliferation of cells of the mononuclear phagocyte system. A second ligand for the CSF-1R, Interleukin 34 (IL-34), has been described, but its physiological role is not yet known. The domestic pig provides an alternative to traditional rodent models for evaluating potential therapeutic applications of CSF-1R agonists and antagonists. To enable such studies, we cloned and expressed active pig CSF-1. To provide a bioassay, pig CSF-1R was expressed in the factor-dependent Ba/F3 cell line. On this transfected cell line, recombinant porcine CSF-1 and human CSF-1 had identical activity. Mouse CSF-1 does not interact with the human CSF-1 receptor but was active on pig. By contrast, porcine CSF-1 was active on mouse, human, cat and dog cells. IL-34 was previously shown to be species-specific, with mouse and human proteins demonstrating limited cross-species activity. The pig CSF-1R was equally responsive to both mouse and human IL-34. Based upon the published crystal structures of CSF-1/CSF-1R and IL34/CSF-1R complexes, we discuss the molecular basis for the species specificity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. cAMP inhibits CSF-1-stimulated tyrosine phosphorylation but augments CSF-1R-mediated macrophage differentiation and ERK activation.

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    Wilson, Nicholas J; Cross, Maddalena; Nguyen, Thao; Hamilton, John A

    2005-08-01

    Macrophage colony stimulating factor (M-CSF) or CSF-1 controls the development of the macrophage lineage through its receptor tyrosine kinase, c-Fms. cAMP has been shown to influence proliferation and differentiation in many cell types, including macrophages. In addition, modulation of cellular ERK activity often occurs when cAMP levels are raised. We have shown previously that agents that increase cellular cAMP inhibited CSF-1-dependent proliferation in murine bone marrow-derived macrophages (BMM) which was associated with an enhanced extracellular signal-regulated kinase (ERK) activity. We report here that increasing cAMP levels, by addition of either 8-bromo cAMP (8BrcAMP) or prostaglandin E(1) (PGE1), can induce macrophage differentiation in M1 myeloid cells engineered to express the CSF-1 receptor (M1/WT cells) and can potentiate CSF-1-induced differentiation in the same cells. The enhanced CSF-1-dependent differentiation induced by raising cAMP levels correlated with enhanced ERK activity. Thus, elevated cAMP can promote either CSF-1-induced differentiation or inhibit CSF-1-induced proliferation depending on the cellular context. The mitogen-activated protein kinase/extracellular signal-related protein kinase kinase (MEK) inhibitor, PD98059, inhibited both the cAMP- and the CSF-1R-dependent macrophage differentiation of M1/WT cells suggesting that ERK activity might be important for differentiation in the M1/WT cells. Surprisingly, addition of 8BrcAMP or PGE1 to either CSF-1-treated M1/WT or BMM cells suppressed the CSF-1R-dependent tyrosine phosphorylation of cellular substrates, including that of the CSF-1R itself. It appears that there are at least two CSF-1-dependent pathway(s), one MEK/ERK dependent pathway and another controlling the bulk of the tyrosine phosphorylation, and that cAMP can modulate signalling through both of these pathways.

  4. Cloning and expression of feline colony stimulating factor receptor (CSF-1R) and analysis of the species specificity of stimulation by colony stimulating factor-1 (CSF-1) and interleukin-34 (IL-34).

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    Gow, Deborah J; Garceau, Valerie; Pridans, Clare; Gow, Adam G; Simpson, Kerry E; Gunn-Moore, Danielle; Hume, David A

    2013-02-01

    Colony stimulating factor (CSF-1) and its receptor, CSF-1R, have been previously well studied in humans and rodents to dissect the role they play in development of cells of the mononuclear phagocyte system. A second ligand for the CSF-1R, IL-34 has been described in several species. In this study, we have cloned and expressed the feline CSF-1R and examined the responsiveness to CSF-1 and IL-34 from a range of species. The results indicate that pig and human CSF-1 and human IL-34 are equally effective in cats, where both mouse CSF-1 and IL-34 are significantly less active. Recombinant human CSF-1 can be used to generate populations of feline bone marrow and monocyte derived macrophages that can be used to further dissect macrophage-specific gene expression in this species, and to compare it to data derived from mouse, human and pig. These results set the scene for therapeutic use of CSF-1 and IL-34 in cats. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. The colony-stimulating factor-1 (CSF-1 receptor sustains ERK1/2 activation and proliferation in breast cancer cell lines.

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    Andrea Morandi

    Full Text Available Breast cancer is the second leading cause of cancer-related deaths in western countries. Colony-Stimulating Factor-1 (CSF-1 and its receptor (CSF-1R regulate macrophage and osteoclast production, trophoblast implantation and mammary gland development. The expression of CSF-1R and/or CSF-1 strongly correlates with poor prognosis in several human epithelial tumors, including breast carcinomas. We demonstrate that CSF-1 and CSF-1R are expressed, although at different levels, in 16/17 breast cancer cell lines tested with no differences among molecular subtypes. The role of CSF-1/CSF-1R in the proliferation of breast cancer cells was then studied in MDAMB468 and SKBR3 cells belonging to different subtypes. CSF-1 administration induced ERK1/2 phosphorylation and enhanced cell proliferation in both cell lines. Furthermore, the inhibition of CSF-1/CSF-1R signaling, by CSF-1R siRNA or imatinib treatment, impaired CSF-1 induced ERK1/2 activation and cell proliferation. We also demonstrate that c-Jun, cyclin D1 and c-Myc, known for their involvement in cell proliferation, are downstream CSF-1R in breast cancer cells. The presence of a proliferative CSF-1/CSF-1R autocrine loop involving ERK1/2 was also found. The wide expression of the CSF-1/CSF-1R pair across breast cancer cell subtypes supports CSF-1/CSF-1R targeting in breast cancer therapy.

  6. Role of the colony-stimulating factor (CSF)/CSF-1 receptor axis in cancer.

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    Achkova, Daniela; Maher, John

    2016-04-15

    Cancer cells employ a variety of mechanisms to evade apoptosis and senescence. Pre-eminent among these is the aberrant co-expression of growth factors and their ligands, forming an autocrine growth loop that promotes tumour formation and progression. One growth loop whose transforming potential has been repeatedly demonstrated is the CSF-1/CSF-1R axis. Expression of CSF-1 and/or CSF-1R has been documented in a number of human malignancies, including breast, prostate and ovarian cancer and classical Hodgkin's lymphoma (cHL). This review summarizes the large body of work undertaken to study the role of this cytokine receptor system in malignant transformation. These studies have attributed a key role to the CSF-1/CSF-1R axis in supporting tumour cell survival, proliferation and enhanced motility. Moreover, increasing evidence implicates paracrine interactions between CSF-1 and its receptor in defining a tumour-permissive and immunosuppressive tumour-associated stroma. Against this background, we briefly consider the prospects for therapeutic targeting of this system in malignant disease. © 2016 Authors; published by Portland Press Limited.

  7. Microglial stimulation of glioblastoma invasion involves epidermal growth factor receptor (EGFR) and colony stimulating factor 1 receptor (CSF-1R) signaling.

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    Coniglio, Salvatore J; Eugenin, Eliseo; Dobrenis, Kostantin; Stanley, E Richard; West, Brian L; Symons, Marc H; Segall, Jeffrey E

    2012-05-09

    Glioblastoma multiforme is a deadly cancer for which current treatment options are limited. The ability of glioblastoma tumor cells to infiltrate the surrounding brain parenchyma critically limits the effectiveness of current treatments. We investigated how microglia, the resident macrophages of the brain, stimulate glioblastoma cell invasion. We first examined the ability of normal microglia from C57Bl/6J mice to stimulate GL261 glioblastoma cell invasion in vitro. We found that microglia stimulate the invasion of GL261 glioblastoma cells by approximately eightfold in an in vitro invasion assay. Pharmacological inhibition of epidermal growth factor receptor (EGFR) strongly inhibited microglia-stimulated invasion. Furthermore, blockade of colony stimulating factor 1 receptor (CSF-1R) signaling using ribonucleic acid (RNA) interference or pharmacological inhibitors completely inhibited microglial enhancement of glioblastoma invasion. GL261 cells were found to constitutively secrete CSF-1, the levels of which were unaffected by epidermal growth factor (EGF) stimulation, EGFR inhibition or coculture with microglia. CSF-1 only stimulated microglia invasion, whereas EGF only stimulated glioblastoma cell migration, demonstrating a synergistic interaction between these two cell types. Finally, using PLX3397 (a CSF-1R inhibitor that can cross the blood-brain barrier) in live animals, we discovered that blockade of CSF-1R signaling in vivo reduced the number of tumor-associated microglia and glioblastoma invasion. These data indicate that glioblastoma and microglia interactions mediated by EGF and CSF-1 can enhance glioblastoma invasion and demonstrate the possibility of inhibiting glioblastoma invasion by targeting glioblastoma-associated microglia via inhibition of the CSF-1R.

  8. Mouse neutrophilic granulocytes express mRNA encoding the macrophage colony-stimulating factor receptor (CSF-1R) as well as many other macrophage-specific transcripts and can transdifferentiate into macrophages in vitro in response to CSF-1.

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    Sasmono, R Tedjo; Ehrnsperger, Achim; Cronau, Stephen L; Ravasi, Timothy; Kandane, Rangi; Hickey, Michael J; Cook, Andrew D; Himes, S Roy; Hamilton, John A; Hume, David A

    2007-07-01

    The differentiation of macrophages from their progenitors is controlled by macrophage colony-stimulating factor (CSF-1), which binds to a receptor (CSF-1R) encoded by the c-fms proto-oncogene. We have previously used the promoter region of the CSF-1R gene to direct expression of an enhanced green fluorescent protein (EGFP) reporter gene to resident macrophage populations in transgenic mice. In this paper, we show that the EGFP reporter is also expressed in all granulocytes detected with the Gr-1 antibody, which binds to Ly-6C and Ly-6G or with a Ly-6G-specific antibody. Transgene expression reflects the presence of CSF-1R mRNA but not CSF-1R protein. The same pattern is observed with the macrophage-specific F4/80 marker. Based on these findings, we performed a comparative array profiling of highly purified granulocytes and macrophages. The patterns of mRNA expression differed predominantly through granulocyte-specific expression of a small subset of transcription factors (Egr1, HoxB7, STAT3), known abundant granulocyte proteins (e.g., S100A8, S100A9, neutrophil elastase), and specific receptors (fMLP, G-CSF). These findings suggested that appropriate stimuli might mediate rapid interconversion of the major myeloid cell types, for example, in inflammation. In keeping with this hypothesis, we showed that purified Ly-6G-positive granulocytes express CSF-1R after overnight culture and can subsequently differentiate to form F4/80-positive macrophages in response to CSF-1.

  9. Macrophage colony-stimulating factor (CSF1) controls monocyte production and maturation and the steady-state size of the liver in pigs.

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    Sauter, Kristin A; Waddell, Lindsey A; Lisowski, Zofia M; Young, Rachel; Lefevre, Lucas; Davis, Gemma M; Clohisey, Sara M; McCulloch, Mary; Magowan, Elizabeth; Mabbott, Neil A; Summers, Kim M; Hume, David A

    2016-09-01

    Macrophage colony-stimulating factor (CSF1) is an essential growth and differentiation factor for cells of the macrophage lineage. To explore the role of CSF1 in steady-state control of monocyte production and differentiation and tissue repair, we previously developed a bioactive protein with a longer half-life in circulation by fusing pig CSF1 with the Fc region of pig IgG1a. CSF1-Fc administration to pigs expanded progenitor pools in the marrow and selectively increased monocyte numbers and their expression of the maturation marker CD163. There was a rapid increase in the size of the liver, and extensive proliferation of hepatocytes associated with increased macrophage infiltration. Despite the large influx of macrophages, there was no evidence of liver injury and no increase in circulating liver enzymes. Microarray expression profiling of livers identified increased expression of macrophage markers, i.e., cytokines such as TNF, IL1, and IL6 known to influence hepatocyte proliferation, alongside cell cycle genes. The analysis also revealed selective enrichment of genes associated with portal, as opposed to centrilobular regions, as seen in hepatic regeneration. Combined with earlier data from the mouse, this study supports the existence of a CSF1-dependent feedback loop, linking macrophages of the liver with bone marrow and blood monocytes, to mediate homeostatic control of the size of the liver. The results also provide evidence of safety and efficacy for possible clinical applications of CSF1-Fc. Copyright © 2016 the American Physiological Society.

  10. CSF-1 receptor-mediated differentiation of a new type of monocytic cell with B cell-stimulating activity: its selective dependence on IL-34

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    Yamane, Fumihiro; Nishikawa, Yumiko; Matsui, Kazue; Asakura, Miki; Iwasaki, Eriko; Watanabe, Koji; Tanimoto, Hikaru; Sano, Hiroki; Fujiwara, Yuki; Stanley, E. Richard; Kanayama, Naoki; Mabbott, Neil A.; Magari, Masaki; Ohmori, Hitoshi

    2014-01-01

    With the use of a mouse FDC line, FL-Y, we have been analyzing roles for FDCs in controlling B cell fate in GCs. Beside these regulatory functions, we fortuitously found that FL-Y cells induced a new type of CD11b+ monocytic cells (F4/80+, Gr-1−, Ly6C−, I-A/E−/lo, CD11c−, CD115+, CXCR4+, CCR2+, CX3CR1−) when cultured with a Lin−c-kit+ population from mouse spleen cells. The developed CD11b+ cells shared a similar gene-expression profile to mononuclear phagocytes and were designated as FDMCs. Here, we describe characteristic immunological functions and the induction mechanism of FDMCs. Proliferation of anti-CD40 antibody-stimulated B cells was markedly accelerated in the presence of FDMCs. In addition, the FDMC-activated B cells efficiently acquired GC B cell-associated markers (Fas and GL-7). We observed an increase of FDMC-like cells in mice after immunization. On the other hand, FL-Y cells were found to produce CSF-1 as well as IL-34, both of which are known to induce development of macrophages and monocytes by binding to the common receptor, CSF-1R, expressed on the progenitors. However, we show that FL-Y-derived IL-34, but not CSF-1, was selectively responsible for FDMC generation using neutralizing antibodies and RNAi. We also confirmed that FDMC generation was strictly dependent on CSF-1R. To our knowledge, a CSF-1R-mediated differentiation process that is intrinsically specific for IL-34 has not been reported. Our results provide new insights into understanding the diversity of IL-34 and CSF-1 signaling pathways through CSF-1R. PMID:24052571

  11. [Expressions of Spinal Macrophage Colony Stimulating Factor and Its Receptor CSF-1R in the Development ofComplicated Regional Pain Symptom I].

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    Liao, Zhi-Min; Tang, Yu-Ying; Zheng, Yang-Chun; Xu, Dan

    2016-09-01

    To study the changes of mechanical allodynia and temperature hyperalgesia, as well as the expression of the spinal macrophage colony stimulating factor (M-CSF) and its receptor CSF-1R during the development of complicated regional pain symptom I(CRPS I). The animal model of CRPS I was established using prolonged ischemia-reperfusion injury of rodent left hindpaw. The mechanical allodynia and temperature hyperalgesia of ipsilateral hindpaw were continuously measured for 14 d after reperfusion, and the expressions of spinal M-CSF and CSF-1R in ipsilateral spinal cord horn were measured with immunofluorescence technique on day 3, day 7 and day 14 after reperfusion. The thresholds of mechanical allodynia and temperature hyperalgesia of ipsilateral hindpaw were significantly decreased (PCSF-1R was primarily distributed on the microglia. The immunofluorescence intensities of M-CSF and CSF-1R in ipsilateral spinal cord horn were significantly increased on day 7 and day 14 after reperfusion (PCSF-1R.

  12. The possible mechanisms of tumor progression via CSF-1/CSF-1R pathway activation.

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    Huang, Li; Xu, Ximing; Hao, Yanrong

    2014-01-01

    CSF-1/CSF-1R (colony-stimulating factor-1/colony-stimulating factor-1 receptor) is the primary growth factor regulating the survival, proliferation, and differentiation of cells of the mononuclear phagocytic lineage. Multiple studies have demonstrated that CSF-1/CSF-1R plays a certain role in tumor tissues. CSF-1 binding to CSF-1R through the class III RTKs leads to a series of signal molecules responding to CSF-1 via various signaling pathway. Through these pathways, all signal molecules would promote development of tumor directly or contribute to progress of various cancers indirectly by increasing tumor-associated macrophages, for instance promoting tumor growth, angiogenesis, extracellular matrix breakdown, invasion, and metastasis. Thus, in this paper, we analysis multiple experimental results comprehensively, making a review about the mechanism of CSF-1/CSF-1R promoting tumor progression.

  13. Autocrine CSF-1 and CSF-1 Receptor Co-expression Promotes Renal Cell Carcinoma Growth

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    Menke, Julia; Kriegsmann, Jörg; Schimanski, Carl Christoph; Schwartz, Melvin M.; Schwarting, Andreas; Kelley, Vicki R.

    2011-01-01

    Renal cell carcinoma is increasing in incidence but the molecular mechanisms regulating its growth remain elusive. Co-expression of the monocytic growth factor CSF-1 and its receptor CSF-1R on renal tubular epithelial cells (TEC) will promote proliferation and anti-apoptosis during regeneration of renal tubules. Here we show that a CSF-1-dependent autocrine pathway is also responsible for the growth of renal cell carcinoma (RCC). CSF-1 and CSF-1R were co-expressed in RCC and TEC proximally adjacent to RCC. CSF-1 engagement of CSF-1R promoted RCC survival and proliferation and reduced apoptosis, in support of the likelihood that CSF-1R effector signals mediate RCC growth. In vivo CSF-1R blockade using a CSF-1R tyrosine kinase inhibitor decreased RCC proliferation and macrophage infiltration in a manner associated with a dramatic reduction in tumor mass. Further mechanistic investigations linked CSF-1 and EGF signaling in RCC. Taken together, our results suggest that budding RCC stimulates the proximal adjacent microenvironment in the kidney to release mediators of CSF-1, CSF-1R and EGF expression in RCC. Further, our findings imply that targeting CSF-1/CSF-1R signaling may be therapeutically effective in RCC. PMID:22052465

  14. Priming of mouse macrophages with the macrophage colony-stimulating factor (CSF-1) induces a variety of pathways that regulate expression of the interleukin 6 (Il6) and granulocyte-macrophage colony-stimulating factor (Csfgm) genes.

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    Kamdar, S J; Fuller, J A; Nishikawa, S I; Evans, R

    1997-08-25

    Recent data have indicated that resident mouse peritoneal macrophages (PMo) transcribed the interleukin 6 (Il6) and granulocyte-macrophage colony-stimulating factor (Csfgm) genes in response to stimulation with the monocyte-macrophage colony-stimulating factor (CSF-1) but only Il6 mRNA was translated into secreted protein. In this paper, we extend these observations. It is shown that resident PMo incubated with protein kinase (PK)C inhibitors, staurosporine (SP) and its derivative GF109203-X, showed a several fold increase in the levels of Il6 mRNA in control and CSF-1-primed PMo and a parallel release of large amounts of protein. In contrast, SP was shown to have no effect on the release of GM-CSF from control or CSF-1-primed PMo, although it increased by approximately twofold the amount of Csfgm mRNA in CSF-1-primed Mo. When SP was added 4 h after CSF-1 priming to block CSF-1-induced protein kinase pathways, an increased amount of IL-6 release was again seen but without any increase in Il6 mRNA levels. Under these conditions, Csfgm gene expression was relatively unaffected. Activation of PKC by phorbol myristate acetate (PMA) also resulted in increased Il6 gene expression by control and CSF-1-primed PMo. PMA had no apparent effect on Csfgm transcription but appeared to influence translation at a low level, as measured by the release of small amounts of GM-CSF protein. The addition of lipopolysaccharide (LPS) to CSF-1-primed PMo resulted in a synergistic increase in the expression of both genes at the levels of transcription and protein release. The addition of SP to CSF-1-primed Mo before LPS, however, further enhanced IL-6 release but not GM-CSF release from the cells. The data indicate that CSF-1-priming drives a number of pathways involved in the regulation of expression of both genes and renders PMo highly susceptible to appropriate secondary stimulatory agents that transform the PMo into secretory inflammatory cells.

  15. Distinct Roles of CSF-1 Isoforms in Lupus Nephritis

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    Menke, Julia; Iwata, Yasunori; Rabacal, Whitney A.; Basu, Ranu; Stanley, E. Richard

    2011-01-01

    Colony-stimulating factor-1 (CSF-1), the principal growth factor for macrophages, is increased in the kidney, serum, and urine of patients with lupus nephritis, and eliminating CSF-1 suppresses lupus in MRL-Faslpr mice. CSF-1 has three biologically active isoforms: a membrane-spanning cell surface glycoprotein (csCSF-1), a secreted proteoglycan (spCSF-1), and a secreted glycoprotein (sgCSF-1); the role of each isoform in the circulation and kidney in autoimmune disease is not well understood. Here, we constructed mutant MRL-Faslpr mice that only express csCSF-1 or precursors of the spCSF-1 and sgCSF-1 isoforms. Both csCSF-1 and spCSF-1 shifted monocytes toward proinflammatory, activated populations, enhancing their recruitment into the kidney during lupus nephritis. With advancing lupus nephritis, spCSF-1 was the predominant isoform responsible for increasing circulating CSF-1 and, along with the csCSF-1 isoform, for increasing intrarenal CSF-1. Thus, csCSF-1 appears to initiate and promote the local activation of macrophages within the kidney. Intrarenal expression of csCSF-1 and spCSF-1 increases with advancing nephritis, thereby promoting the intrarenal recruitment of monocytes and expansion of Ly6Chi macrophages, which induce apoptosis of the renal parenchyma. Taken together, these data suggest that the three CSF-1 isoforms have distinct biologic properties, suggesting that blocking both circulating and intrarenal CSF-1 may be necessary for therapeutic efficacy. PMID:21885670

  16. CSF-1 Receptor Signaling in Myeloid Cells

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    Stanley, E. Richard; Chitu, Violeta

    2014-01-01

    The CSF-1 receptor (CSF-1R) is activated by the homodimeric growth factors colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34). It plays important roles in development and in innate immunity by regulating the development of most tissue macrophages and osteoclasts, of Langerhans cells of the skin, of Paneth cells of the small intestine, and of brain microglia. It also regulates the differentiation of neural progenitor cells and controls functions of oocytes and trophoblastic cells in the female reproductive tract. Owing to this broad tissue expression pattern, it plays a central role in neoplastic, inflammatory, and neurological diseases. In this review we summarize the evolution, structure, and regulation of expression of the CSF-1R gene. We review, the structures of CSF-1, IL-34, and the CSF-1R and the mechanism of ligand binding to and activation of the receptor. We further describe the pathways regulating macrophage survival, proliferation, differentiation, and chemotaxis downstream from the CSF-1R. PMID:24890514

  17. CSF-1R Inhibitor Development: Current Clinical Status.

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    Peyraud, Florent; Cousin, Sophie; Italiano, Antoine

    2017-09-05

    Colony-stimulating factor 1 receptor (CSF-1R) and its ligands, CSF-1 and interleukin 34 (IL-34), regulate the function and survival of tumor-associated macrophages, which are involved in tumorigenesis and in the suppression of antitumor immunity. Moreover, the CSF-1R/CSF-1 axis has been implicated in the pathogenesis of pigmented villonodular synovitis (PVNS), a benign tumor of the synovium. As advanced or metastatic malignant solid tumors and relapsed/refractory PVNS remain unresolved therapeutic problems, new approaches are needed to improve the outcome of patients with these conditions. In solid tumors, targeting CSF-1R via either small molecules or antibodies has shown interesting results in vitro but limited antitumor activity in vivo. Concerning PVNS, clinical trials assessing CSF-1R inhibitors have revealed promising initial outcomes. Blocking CSF-1/CSF-1R signaling represents a promising immunotherapy approach and several new potential combination therapies for future clinical testing.

  18. [The expressional alterations of CSF-1R after ischemic injury of cerebral cortex].

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    Yu, Dong Hui; Liu, Shuang; Tian, Zeng-Min; Liu, Shu-Hong; Ge, Xue-Ming; Zhou, Chang-Man; Wang, Ya-Qi; Fan, Ming

    2008-02-01

    To observe the expressional alterations of colony stimulating factor-1 receptor (CSF-1R) after ischemic injury of cerebral cortex, and study the function of colony stimulating factor-1 (CSF-1)/CSF-1R signal during the process of ischemic injury and repair of central nervous system (CNS). We examined the distribution and expression of CSF-1R in normal brain tissues and ischemic brain tissues by immunohistology and Western blot analysis. The expression of CSF-1R in neurons could be up-regulated by ischemic injury in CNS. CSF-1/CSF-1R might take part in the process of ischemic injury and repair.

  19. Timing of CSF-1/CSF-1R signaling blockade is critical to improving responses to CTLA-4 based immunotherapy.

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    Holmgaard, Rikke B; Brachfeld, Alexandra; Gasmi, Billel; Jones, David R; Mattar, Marissa; Doman, Thompson; Murphy, Mary; Schaer, David; Wolchok, Jedd D; Merghoub, Taha

    2016-07-01

    Colony stimulating factor-1 (CSF-1) is produced by a variety of cancers and recruits myeloid cells that suppress antitumor immunity, including myeloid-derived suppressor cells (MDSCs.) Here, we show that both CSF-1 and its receptor (CSF-1R) are frequently expressed in tumors from cancer patients, and that this expression correlates with tumor-infiltration of MDSCs. Furthermore, we demonstrate that these tumor-infiltrating MDSCs are highly immunosuppressive but can be reprogrammed toward an antitumor phenotype in vitro upon CSF-1/CSF-1R signaling blockade. Supporting these findings, we show that inhibition of CSF-1/CSF-1R signaling using an anti-CSF-1R antibody can regulate both the number and the function of MDSCs in murine tumors in vivo. We further find that treatment with anti-CSF-1R antibody induces antitumor T-cell responses and tumor regression in multiple tumor models when combined with CTLA-4 blockade therapy. However, this occurs only when administered after or concurrent with CTLA-4 blockade, indicating that timing of each therapeutic intervention is critical for optimal antitumor responses. Importantly, MDSCs present within murine tumors after CTLA-4 blockade showed increased expression of CSF-1R and were capable of suppressing T cell proliferation, and CSF-1/CSF-1R expression in the human tumors was not reduced after treatment with CTLA-4 blockade immunotherapy. Taken together, our findings suggest that CSF-1R-expressing MDSCs can be targeted to modulate the tumor microenvironment and that timing of CSF-1/CSF-1R signaling blockade is critical to improving responses to checkpoint based immunotherapy. Infiltration by immunosuppressive myeloid cells contributes to tumor immune escape and can render patients resistant or less responsive to therapeutic intervention with checkpoint blocking antibodies. Our data demonstrate that blocking CSF-1/CSF-1R signaling using a monoclonal antibody directed to CSF-1R can regulate both the number and function of tumor

  20. Structural basis for the dual recognition of helical cytokines IL-34 and CSF-1 by CSF-1R.

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    Ma, Xiaolei; Lin, Wei Yu; Chen, Yongmei; Stawicki, Scott; Mukhyala, Kiran; Wu, Yan; Martin, Flavius; Bazan, J Fernando; Starovasnik, Melissa A

    2012-04-04

    Lacking any discernible sequence similarity, interleukin-34 (IL-34) and colony stimulating factor 1 (CSF-1) signal through a common receptor CSF-1R on cells of mononuclear phagocyte lineage. Here, the crystal structure of dimeric IL-34 reveals a helical cytokine fold homologous to CSF-1, and we further show that the complex architecture of IL-34 bound to the N-terminal immunoglobulin domains of CSF-1R is similar to the CSF-1/CSF-1R assembly. However, unique conformational adaptations in the receptor domain geometry and intermolecular interface explain the cross-reactivity of CSF-1R for two such distantly related ligands. The docking adaptations of the IL-34 and CSF-1 quaternary complexes, when compared to the stem cell factor assembly, draw a common evolutionary theme for transmembrane signaling. In addition, the structure of IL-34 engaged by a Fab fragment reveals the mechanism of a neutralizing antibody that can help deconvolute IL-34 from CSF-1 biology, with implications for therapeutic intervention in diseases with myeloid pathogenic mechanisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Delivery of CSF-1R to the lumen of macropinosomes promotes its destruction in macrophages.

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    Lou, Jieqiong; Low-Nam, Shalini T; Kerkvliet, Jason G; Hoppe, Adam D

    2014-12-15

    Activation of the macrophage colony stimulating factor-1 receptor (CSF-1R) by CSF-1 stimulates pronounced macropinocytosis and drives proliferation of macrophages. Although the role of macropinocytosis in CSF-1R signaling remains unknown, we show here that, despite internalizing large quantities of plasma membrane, macropinosomes contribute little to the internalization of the CSF-1-CSF-1R complex. Rather, internalization of the CSF-1R in small endocytic vesicles that are sensitive to clathrin disruption, outcompetes macropinosomes for CSF-1R endocytosis. Following internalization, small vesicles carrying the CSF-1R underwent homotypic fusion and then trafficked to newly formed macropinosomes bearing Rab5. As these macropinosomes matured, acquiring Rab7, the CSF-1R was transported into their lumen and degraded. Inhibition of macropinocytosis delayed receptor degradation despite no disruption to CSF-1R endocytosis. These data indicate that CSF-1-stimulated macropinosomes are sites of multivesicular body formation and accelerate CSF-1R degradation. Furthermore, we demonstrate that macropinocytosis and cell growth have a matching dose dependence on CSF-1, suggesting that macropinosomes might be a central mechanism coupling CSF-1R signaling and macrophage growth. © 2014. Published by The Company of Biologists Ltd.

  2. CSF-1/CSF-1R targeting agents in clinical development for cancer therapy.

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    Ries, Carola H; Hoves, Sabine; Cannarile, Michael A; Rüttinger, Dominik

    2015-08-01

    Macrophage infiltration has been identified as an independent poor prognostic factor for several cancer entities. In mouse tumor models macrophages orchestrate various tumor-promoting processes. This observation sparked an interest to therapeutically target these plastic innate immune cells. To date, blockade of colony stimulating factor-1 or its receptor represents the only truly selective approach to manipulate macrophages in cancer patients. Here, we discuss the currently available information on efficacy and safety of various CSF-1/CSF-1R inhibitors in cancer patients and highlight potential combination partners emerging from preclinical studies while considering the differences between mouse and human macrophage biology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. The mechanism of shared but distinct CSF-1R signaling by the non-homologous cytokines IL-34 and CSF-1.

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    Liu, Heli; Leo, Cindy; Chen, Xiaoyan; Wong, Brian R; Williams, Lewis T; Lin, Haishan; He, Xiaolin

    2012-07-01

    Interleukin-34 (IL-34) and colony stimulating factor-1 (CSF-1) both signal through the CSF-1R receptor tyrosine kinase, but they have no sequence homology, and their functions and signaling activities are not identical. We report the crystal structures of mouse IL-34 alone and in complex with the N-terminal three immunoglobulin-like domains (D1-D3) of mouse CSF-1R. IL-34 is structurally related to other helical hematopoietic cytokines, but contains two additional helices integrally associated with the four shared helices. The non-covalently linked IL-34 homodimer recruits two copies of CSF-1R on the sides of the helical bundles, with an overall shape similar to the CSF-1:CSF-1R complex, but the flexible linker between CSF-1R D2 and D3 allows these domains to clamp IL-34 and CSF-1 at different angles. Functional dissection of the IL-34:CSF-1R interface indicates that the hydrophobic interactions, rather than the salt bridge network, dominate the biological activity of IL-34. To degenerately recognize two ligands with completely different surfaces, CSF-1R apparently takes advantage of different subsets of a chemically inert surface that can be tuned to fit different ligand shapes. Differentiated signaling between IL-34 and CSF-1 is likely achieved by the relative thermodynamic independence of IL-34 vs. negative cooperativity of CSF-1 at the receptor-recognition sites, in combination with the difference in hydrophobicity which dictates a more stable IL-34:CSF-1R complex compared to the CSF-1:CSF-1R complex. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Emerging Roles for CSF-1 Receptor and its Ligands in the Nervous System.

    Science.gov (United States)

    Chitu, Violeta; Gokhan, Şölen; Nandi, Sayan; Mehler, Mark F; Stanley, E Richard

    2016-06-01

    The colony-stimulating factor-1 receptor (CSF-1R) kinase regulates tissue macrophage homeostasis, osteoclastogenesis, and Paneth cell development. However, recent studies in mice have revealed that CSF-1R signaling directly controls the development and maintenance of microglia, and cell autonomously regulates neuronal differentiation and survival. While the CSF-1R-cognate ligands, CSF-1 and interleukin-34 (IL-34) compete for binding to the CSF-1R, they are expressed in a largely non-overlapping manner by mature neurons. The recent identification of a dominantly inherited, adult-onset, progressive dementia associated with inactivating mutations in the CSF-1R highlights the importance of CSF-1R signaling in the brain. We review the roles of the CSF-1R and its ligands in microglial and neural development and function, and their relevance to our understanding of neurodegenerative disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Macrophage Proliferation Is Regulated through CSF-1 Receptor Tyrosines 544, 559, and 807*

    Science.gov (United States)

    Yu, Wenfeng; Chen, Jian; Xiong, Ying; Pixley, Fiona J.; Yeung, Yee-Guide; Stanley, E. Richard

    2012-01-01

    Colony-stimulating factor-1 (CSF-1)-stimulated CSF-1 receptor (CSF-1R) tyrosine phosphorylation initiates survival, proliferation, and differentiation signaling pathways in macrophages. Either activation loop Y807F or juxtamembrane domain (JMD) Y559F mutations severely compromise CSF-1-regulated proliferation and differentiation. YEF, a CSF-1R in which all eight tyrosines phosphorylated in the activated receptor were mutated to phenylalanine, lacks in vitro kinase activity and in vivo CSF-1-regulated tyrosine phosphorylation. The addition of Tyr-807 alone to the YEF backbone (Y807AB) led to CSF-1-independent but receptor kinase-dependent proliferation, without detectable activation loop Tyr-807 phosphorylation. The addition of Tyr-559 alone (Y559AB) supported a low level of CSF-1-independent proliferation that was slightly enhanced by CSF-1, indicating that Tyr-559 has a positive Tyr-807-independent effect. Consistent with the postulated autoinhibitory role of the JMD Tyr-559 and its relief by ligand-induced Tyr-559 phosphorylation, the addition of Tyr-559 to the Y807AB background suppressed proliferation in the absence of CSF-1, but restored most of the CSF-1-stimulated proliferation. Full restoration of kinase activation and proliferation required the additional add back of JMD Tyr-544. Inhibitor experiments indicate that the constitutive proliferation of Y807AB macrophages is mediated by the phosphatidylinositol 3-kinase (PI3K) and ERK1/2 pathways, whereas proliferation of WT and Y559,807AB macrophages is, in addition, contributed to by Src family kinase (SFK)-dependent pathways. Thus Tyr-807 confers sufficient kinase activity for strong CSF-1-independent proliferation, whereas Tyr-559 maintains the receptor in an inactive state. Tyr-559 phosphorylation releases this restraint and may also contribute to the CSF-1-regulated proliferative response by activating Src family kinase. PMID:22375015

  6. The promotion of breast cancer metastasis caused by inhibition of CSF-1R/CSF-1 signaling is blocked by targeting the G-CSF receptor.

    Science.gov (United States)

    Swierczak, Agnieszka; Cook, Andrew D; Lenzo, Jason C; Restall, Christina M; Doherty, Judy P; Anderson, Robin L; Hamilton, John A

    2014-08-01

    Treatment options are limited for patients with breast cancer presenting with metastatic disease. Targeting of tumor-associated macrophages through the inhibition of colony-stimulating factor-1 receptor (CSF-1R), a key macrophage signaling pathway, has been reported to reduce tumor growth and metastasis, and these treatments are now in clinical trials. Here, we report that, surprisingly, treatment with neutralizing anti-CSF-1R and anti-CSF-1 antibodies, or with two different small-molecule inhibitors of CSF-1R, could actually increase spontaneous metastasis without altering primary tumor growth in mice bearing two independently derived mammary tumors. The blockade of CSF-1R or CSF-1 led to increased levels of serum G-CSF, increased frequency of neutrophils in the primary tumor and in the metastasis-associated lung, as well as increased numbers of neutrophils and Ly6C(hi) monocytes in the peripheral blood. Neutralizing antibody against the G-CSF receptor, which regulates neutrophil development and function, reduced the enhanced metastasis and neutrophil numbers that resulted from CSF-1R blockade. These results indicate that the role of the CSF-1R/CSF-1 system in breast cancer is far more complex than originally proposed, and requires further investigation as a therapeutic target. ©2014 American Association for Cancer Research.

  7. Regulation of Embryonic and Postnatal Development by the CSF-1 Receptor.

    Science.gov (United States)

    Chitu, Violeta; Stanley, E Richard

    2017-01-01

    Macrophages are found in all tissues and regulate tissue morphogenesis during development through trophic and scavenger functions. The colony stimulating factor-1 (CSF-1) receptor (CSF-1R) is the major regulator of tissue macrophage development and maintenance. In combination with receptor activator of nuclear factor κB (RANK), the CSF-1R also regulates the differentiation of the bone-resorbing osteoclast and controls bone remodeling during embryonic and early postnatal development. CSF-1R-regulated macrophages play trophic and remodeling roles in development. Outside the mononuclear phagocytic system, the CSF-1R directly regulates neuronal survival and differentiation, the development of intestinal Paneth cells and of preimplantation embryos, as well as trophoblast innate immune function. Consistent with the pleiotropic roles of the receptor during development, CSF-1R deficiency in most mouse strains causes embryonic or perinatal death and the surviving mice exhibit multiple developmental and functional deficits. The CSF-1R is activated by two dimeric glycoprotein ligands, CSF-1, and interleukin-34 (IL-34). Homozygous Csf1-null mutations phenocopy most of the deficits of Csf1r-null mice. In contrast, Il34-null mice have no gross phenotype, except for decreased numbers of Langerhans cells and microglia, indicating that CSF-1 plays the major developmental role. Homozygous inactivating mutations of the Csf1r or its ligands have not been reported in man. However, heterozygous inactivating mutations in the Csf1r lead to a dominantly inherited adult-onset progressive dementia, highlighting the importance of CSF-1R signaling in the brain. © 2017 Elsevier Inc. All rights reserved.

  8. CSF-1 receptor-dependent colon development, homeostasis and inflammatory stress response.

    Directory of Open Access Journals (Sweden)

    Duy Huynh

    Full Text Available The colony stimulating factor-1 (CSF-1 receptor (CSF-1R directly regulates the development of Paneth cells (PC and influences proliferation and cell fate in the small intestine (SI. In the present study, we have examined the role of CSF-1 and the CSF-1R in the large intestine, which lacks PC, in the steady state and in response to acute inflammation induced by dextran sulfate sodium (DSS. As previously shown in mouse, immunohistochemical (IHC analysis of CSF-1R expression showed that the receptor is baso-laterally expressed on epithelial cells of human colonic crypts, indicating that this expression pattern is shared between species. Colons from Csf1r null and Csf1(op/op mice were isolated and sectioned for IHC identification of enterocytes, enteroendocrine cells, goblet cells and proliferating cells. Both Csf1r(-/- and Csf1(op/op mice were found to have colon defects in enterocytes and enteroendocrine cell fate, with excessive goblet cell staining and reduced cell proliferation. In addition, the gene expression profiles of the cell cycle genes, cyclinD1, c-myc, c-fos, and c-myb were suppressed in Csf1r(-/- colonic crypt, compared with those of WT mice and the expression of the stem cell marker gene Lgr5 was markedly reduced. However, analysis of the proliferative responses of immortalized mouse colon epithelial cells (lines; Immorto-5 and YAMC indicated that CSF-1R is not a major regulator of colonocyte proliferation and that its effects on proliferation are indirect. In an examination of the acute inflammatory response, Csf1r(+/- male mice were protected from the adverse affects of DSS-induced colitis compared with WT mice, while Csf1r(+/- female mice were significantly less protected. These data indicate that CSF-1R signaling plays an important role in colon homeostasis and stem cell gene expression but that the receptor exacerbates the response to inflammatory challenge in male mice.

  9. Chromatin-associated CSF-1R binds to the promoter of proliferation-related genes in breast cancer cells.

    Science.gov (United States)

    Barbetti, V; Morandi, A; Tusa, I; Digiacomo, G; Riverso, M; Marzi, I; Cipolleschi, M G; Bessi, S; Giannini, A; Di Leo, A; Dello Sbarba, P; Rovida, E

    2014-08-21

    The colony-stimulating factor-1 (CSF-1) and its receptor CSF-1R physiologically regulate the monocyte/macrophage system, trophoblast implantation and breast development. An abnormal CSF-1R expression has been documented in several human epithelial tumors, including breast carcinomas. We recently demonstrated that CSF-1/CSF-1R signaling drives proliferation of breast cancer cells via 'classical' receptor tyrosine kinase signaling, including activation of the extracellular signal-regulated kinase 1/2. In this paper, we show that CSF-1R can also localize within the nucleus of breast cancer cells, either cell lines or tissue specimens, irrespectively of their intrinsic molecular subtype. We found that the majority of nuclear CSF-1R is located in the chromatin-bound subcellular compartment. Chromatin immunoprecipitation revealed that CSF-1R, once in the nucleus, binds to the promoters of the proliferation-related genes CCND1, c-JUN and c-MYC. CSF-1R also binds the promoter of its ligand CSF-1 and positively regulates CSF-1 expression. The existence of such a receptor/ligand regulatory loop is a novel aspect of CSF-1R signaling. Moreover, our results provided the first evidence of a novel localization site of CSF-1R in breast cancer cells, suggesting that CSF-1R could act as a transcriptional regulator on proliferation-related genes.

  10. Development and characterisation of monoclonal antibodies reactive with porcine CSF1R (CD115).

    Science.gov (United States)

    Moffat, L; Rothwell, L; Garcia-Morales, C; Sauter, K A; Kapetanovic, R; Gow, D J; Hume, D A

    2014-11-01

    Macrophage colony-stimulating factor (CSF1) controls the proliferation and differentiation of cells of the mononuclear phagocyte system. CSF1, alongside a second ligand, interleukin-34 (IL-34), acts by binding to a cell surface receptor (CSF1R). We previously cloned and expressed pig CSF1 and IL-34. Here we produced a pig CSF1R-Ig+pFUSE Fc fusion protein and used it as an immunogen to produce three monoclonal antibodies (ROS8G11, ROS3A5 and ROS3B10) targeted against porcine CSF1R. Specific binding of each monoclonal antibody was confirmed by ELISA, Western blot, flow cytometry and immunocytochemistry. The antibodies did not block CSF1 signalling. The surface expression of CSF1R in pig peripheral blood was restricted to CD14-positive monocytes and was also detected on lung macrophages. These antibodies provided an opportunity to investigate the increase of available CSF1R during pig BMDM differentiation. The new monoclonal antibodies provide useful reagents to support the study of monocyte and macrophage biology in the pig. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  11. Expression of CSF-1 and its receptor CSF-1R in non-hematopoietic neoplasms.

    Science.gov (United States)

    Kascinski, Barry

    2002-01-01

    CSF-1 and its receptor appear to be important in the physiology of several different neoplasms including those of the breast and female reproductive tract. Levels of CSF-1 and CSF-1R expression appear to correlate with tumor cell invasiveness and an adverse clinical prognosis and may be modulated by hormones involved in normal lactogenic differentiation. Also, it appears that CSF-1R activates several different signal transduction pathways but only some of these appear to have direct bearing on tumor cell phenotypes and the activation of pathways in specific cell types may depend on factors above and beyond the receptor itself.

  12. Fibronectin induces macrophage migration through a SFK-FAK/CSF-1R pathway

    National Research Council Canada - National Science Library

    Digiacomo, Graziana; Tusa, Ignazia; Bacci, Marina; Cipolleschi, Maria Grazia; Dello Sbarba, Persio; Rovida, Elisabetta

    .... The Colony-Stimulating Factor-1 Receptor (CSF-1R) is a RTK that supports the survival, proliferation, and motility of monocytes/macrophages, which are essential components of innate immunity and cancer development...

  13. Inhibition of CSF-1R supports T-cell mediated melanoma therapy.

    Directory of Open Access Journals (Sweden)

    Marjolein Sluijter

    Full Text Available Tumor associated macrophages (TAM can promote angiogenesis, invasiveness and immunosuppression. The cytokine CSF-1 (or M-CSF is an important factor of TAM recruitment and differentiation and several pharmacological agents targeting the CSF-1 receptor (CSF-1R have been developed to regulate TAM in solid cancers. We show that the kinase inhibitor PLX3397 strongly dampened the systemic and local accumulation of macrophages driven by B16F10 melanomas, without affecting Gr-1(+ myeloid derived suppressor cells. Removal of intratumoral macrophages was remarkably efficient and a modest, but statistically significant, delay in melanoma outgrowth was observed. Importantly, CSF-1R inhibition strongly enhanced tumor control by immunotherapy using tumor-specific CD8 T cells. Elevated IFNγ production by T cells was observed in mice treated with the combination of PLX3397 and immunotherapy. These results support the combined use of CSF-1R inhibition with CD8 T cell immunotherapy, especially for macrophage-stimulating tumors.

  14. The tumor microenvironment underlies acquired resistance to CSF1R inhibition in gliomas

    Science.gov (United States)

    Quail, Daniela F.; Bowman, Robert L.; Akkari, Leila; Quick, Marsha L.; Schuhmacher, Alberto J.; Huse, Jason T.; Holland, Eric C.; Sutton, James C.; Joyce, Johanna A.

    2017-01-01

    Macrophages accumulate with glioblastoma multiforme (GBM) progression, and can be targeted via inhibition of colony stimulating factor-1 receptor (CSF-1R) to regress high-grade tumors in animal models of this cancer. However, whether and how resistance emerges in response to sustained CSF-1R blockade is unknown. We show that while overall survival is significantly prolonged, tumors recur in >50% of mice. Gliomas re-establish sensitivity to CSF-1R inhibition upon transplantation, indicating that resistance is tumor microenvironment-driven. Phosphatidylinositol 3-kinase (PI3K) pathway activity was elevated in recurrent GBM, driven by macrophage-derived insulin-like growth factor (IGF-1) and tumor cell IGF-1 receptor (IGF-1R). Combining IGF-1R or PI3K blockade with CSF-1R inhibition in recurrent tumors significantly prolonged overall survival. Our findings thus reveal a potential therapeutic approach for treating resistance to CSF-1R inhibitors. PMID:27199435

  15. Inhibition of CSF-1R supports T-cell mediated melanoma therapy.

    Science.gov (United States)

    Sluijter, Marjolein; van der Sluis, Tetje C; van der Velden, Pieter A; Versluis, Mieke; West, Brian L; van der Burg, Sjoerd H; van Hall, Thorbald

    2014-01-01

    Tumor associated macrophages (TAM) can promote angiogenesis, invasiveness and immunosuppression. The cytokine CSF-1 (or M-CSF) is an important factor of TAM recruitment and differentiation and several pharmacological agents targeting the CSF-1 receptor (CSF-1R) have been developed to regulate TAM in solid cancers. We show that the kinase inhibitor PLX3397 strongly dampened the systemic and local accumulation of macrophages driven by B16F10 melanomas, without affecting Gr-1(+) myeloid derived suppressor cells. Removal of intratumoral macrophages was remarkably efficient and a modest, but statistically significant, delay in melanoma outgrowth was observed. Importantly, CSF-1R inhibition strongly enhanced tumor control by immunotherapy using tumor-specific CD8 T cells. Elevated IFNγ production by T cells was observed in mice treated with the combination of PLX3397 and immunotherapy. These results support the combined use of CSF-1R inhibition with CD8 T cell immunotherapy, especially for macrophage-stimulating tumors.

  16. A CSF-1 Receptor Phosphotyrosine 559 Signaling Pathway Regulates Receptor Ubiquitination and Tyrosine Phosphorylation*

    Science.gov (United States)

    Xiong, Ying; Song, Da; Cai, Yunfei; Yu, Wenfeng; Yeung, Yee-Guide; Stanley, E. Richard

    2011-01-01

    Receptor tyrosine kinase (RTK) activation involves ligand-induced receptor dimerization and transphosphorylation on tyrosine residues. Colony-stimulating factor-1 (CSF-1)-induced CSF-1 receptor (CSF-1R) tyrosine phosphorylation and ubiquitination were studied in mouse macrophages. Phosphorylation of CSF-1R Tyr-559, required for the binding of Src family kinases (SFKs), was both necessary and sufficient for these responses and for c-Cbl tyrosine phosphorylation and all three responses were inhibited by SFK inhibitors. In c-Cbl-deficient macrophages, CSF-1R ubiquitination and tyrosine phosphorylation were substantially inhibited. Reconstitution with wild-type, but not ubiquitin ligase-defective C381A c-Cbl rescued these responses, while expression of C381A c-Cbl in wild-type macrophages suppressed them. Analysis of site-directed mutations in the CSF-1R further suggests that activated c-Cbl-mediated CSF-1R ubiquitination is required for a conformational change in the major kinase domain that allows amplification of receptor tyrosine phosphorylation and full receptor activation. Thus the results indicate that CSF-1-mediated receptor dimerization leads to a Tyr-559/SFK/c-Cbl pathway resulting in receptor ubiquitination that permits full receptor tyrosine phosphorylation of this class III RTK in macrophages. PMID:21041311

  17. CSF-1R signaling in health and disease: a focus on the mammary gland.

    Science.gov (United States)

    Sullivan, Amy Renee; Pixley, Fiona Jane

    2014-07-01

    Colony-stimulating factor-1 (CSF-1), also known as macrophage-colony stimulating factor (M-CSF), is the primary growth factor regulating survival, proliferation and differentiation of macrophages. It is also a potent chemokine for macrophages and monocytes. Signaling via the CSF-1 receptor (CSF-1R) is necessary for the production of almost all tissue resident macrophage populations and these macrophages participate, via trophic mechanisms, in the normal development and homeostasis of tissues and organs in which they reside, including the mammary gland. The drawback of this close interaction between macrophages and parenchymal cells is that dysregulation of macrophage trophic functions assists in the development and progression of many cancers, including breast cancer. Furthermore, tumour cells secrete CSF-1 to attract more macrophages to the tumour microenvironment where CSF-1R signaling frequently drives the behaviour of these tumour-associated macrophages (TAMs) to promote tumour progression and metastasis. Evidence is mounting that treated tumours secrete more CSF-1 and the increased recruitment of TAMs limits treatment efficacy. Thus, therapeutic targeting of the CSF-1R to inhibit TAM function is likely to enhance tumour response and improve patient outcomes in the treatment of cancer, including breast cancer.

  18. Overexpression of CSF-1R in nasopharyngeal carcinoma.

    Science.gov (United States)

    Huang, Li; Xu, Ximing; Hao, Yanrong; Chen, Jiaxin; Li, Lei; Cheng, Junping; Chen, Zhaohong; Liang, Wuqing; Yang, Jiao; Ao, Wen; Hao, Xin; Gao, Weiwei

    2015-01-01

    Tumor-associated macrophages play a significant role in tumor progression. CSF-1/CSF-1R is one of the most primary regulators of macrophage physiology in immune system. The expression of CSF-1/CSF-1R in nasopharyngeal carcinoma is unclear. The aim of this study was to compare the expression of CSF-1R in nasopharyngeal carcinoma to nasopharyngitis for assessing the role CSF-1/CSF-1R in nasopharyngeal carcinoma. Diagnostic tissues from 56 nasopharyngeal carcinoma patients and 32 nasopharyngitis patients were evaluated retrospectively by immunohistochemical analysis for the expression of CSF-1R. Significant differences of CSF-1R expression exists between nasopharyngeal carcinoma patients and nasopharyngitis patients (pCSF-1R and worse survival.

  19. Autocrine CSF-1R activation promotes Src-dependent disruption of mammary epithelial architecture.

    Science.gov (United States)

    Wrobel, Carolyn N; Debnath, Jayanta; Lin, Eva; Beausoleil, Sean; Roussel, Martine F; Brugge, Joan S

    2004-04-26

    Elevated coexpression of colony-stimulating factor receptor (CSF-1R) and its ligand, CSF-1, correlates with invasiveness and poor prognosis of a variety of epithelial tumors (Kacinski, B.M. 1995. Ann. Med. 27:79-85). Apart from recruitment of macrophages to the tumor site, the mechanisms by which CSF-1 may potentiate invasion are poorly understood. We show that autocrine CSF-1R activation induces hyperproliferation and a profound, progressive disruption of junctional integrity in acinar structures formed by human mammary epithelial cells in three-dimensional culture. Acini coexpressing receptor and ligand exhibit a dramatic relocalization of E-cadherin from the plasma membrane to punctate intracellular vesicles, accompanied by its loss from the Triton-insoluble fraction. Interfering with Src kinase activity, either by pharmacological inhibition or mutation of the Y561 docking site on CSF-1R, prevents E-cadherin translocation, suggesting that CSF-1R disrupts cell adhesion by uncoupling adherens junction complexes from the cytoskeleton and promoting cadherin internalization through a Src-dependent mechanism. These findings provide a mechanistic basis whereby CSF-1R could contribute to invasive progression in epithelial cancers.

  20. Targeting tumor-associated macrophages with anti-CSF-1R antibody reveals a strategy for cancer therapy.

    Science.gov (United States)

    Ries, Carola H; Cannarile, Michael A; Hoves, Sabine; Benz, Jörg; Wartha, Katharina; Runza, Valeria; Rey-Giraud, Flora; Pradel, Leon P; Feuerhake, Friedrich; Klaman, Irina; Jones, Tobin; Jucknischke, Ute; Scheiblich, Stefan; Kaluza, Klaus; Gorr, Ingo H; Walz, Antje; Abiraj, Keelara; Cassier, Philippe A; Sica, Antonio; Gomez-Roca, Carlos; de Visser, Karin E; Italiano, Antoine; Le Tourneau, Christophe; Delord, Jean-Pierre; Levitsky, Hyam; Blay, Jean-Yves; Rüttinger, Dominik

    2014-06-16

    Macrophage infiltration has been identified as an independent poor prognostic factor in several cancer types. The major survival factor for these macrophages is macrophage colony-stimulating factor 1 (CSF-1). We generated a monoclonal antibody (RG7155) that inhibits CSF-1 receptor (CSF-1R) activation. In vitro RG7155 treatment results in cell death of CSF-1-differentiated macrophages. In animal models, CSF-1R inhibition strongly reduces F4/80(+) tumor-associated macrophages accompanied by an increase of the CD8(+)/CD4(+) T cell ratio. Administration of RG7155 to patients led to striking reductions of CSF-1R(+)CD163(+) macrophages in tumor tissues, which translated into clinical objective responses in diffuse-type giant cell tumor (Dt-GCT) patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Autocrine CSF-1R signaling drives mesothelioma chemoresistance via AKT activation.

    Science.gov (United States)

    Cioce, M; Canino, C; Goparaju, C; Yang, H; Carbone, M; Pass, H I

    2014-04-10

    Clinical management of malignant pleural mesothelioma (MPM) is very challenging because of the uncommon resistance of this tumor to chemotherapy. We report here increased expression of macrophage colony-stimulating-factor-1-receptor (M-CSF/CSF-1R) mRNA in mesothelioma versus normal tissue specimens and demonstrate that CSF-1R expression identifies chemoresistant cells of mesothelial nature in both primary cultures and mesothelioma cell lines. By using RNAi or ligand trapping, we demonstrate that the chemoresistance properties of those cells depend on autocrine CSF-1R signaling. At the single-cell level, the isolated CSF-1R(pos) cells exhibit a complex repertoire of pluripotency, epithelial-mesenchymal transition and detoxifying factors, which define a clonogenic, chemoresistant, precursor-like cell sub-population. The simple activation of CSF-1R in untransformed mesothelial cells is sufficient to confer clonogenicity and resistance to pemetrexed, hallmarks of mesothelioma. In addition, this induced a gene expression profile highly mimicking that observed in the MPM cells endogenously expressing the receptor and the ligands, suggesting that CSF-1R expression is mainly responsible for the phenotype of the identified cell sub-populations. The survival of CSF1R(pos) cells requires active AKT (v-akt murine thymoma viral oncogene homolog 1) signaling, which contributed to increased levels of nuclear, transcriptionally competent β-catenin. Inhibition of AKT reduced the transcriptional activity of β-catenin-dependent reporters and sensitized the cells to senescence-induced clonogenic death after pemetrexed treatment. This work expands what is known on the non-macrophage functions of CSF-1R and its role in solid tumors, and suggests that CSF-1R signaling may have a critical pathogenic role in a prototypical, inflammation-related cancer such as MPM and therefore may represent a promising target for therapeutic intervention.

  2. CSF1R Protein Expression in Reactive Lymphoid Tissues and Lymphoma: Its Relevance in Classical Hodgkin Lymphoma.

    Science.gov (United States)

    Martín-Moreno, Ana M; Roncador, Giovanna; Maestre, Lorena; Mata, Elena; Jiménez, Scherezade; Martínez-Torrecuadrada, Jorge L; Reyes-García, Ana I; Rubio, Carmen; Tomás, José F; Estévez, Mónica; Pulford, Karen; Piris, Miguel A; García, Juan F

    2015-01-01

    Tumour-associated macrophages (TAMs) have been associated with survival in classic Hodgkin lymphoma (cHL) and other lymphoma types. The maturation and differentiation of tissue macrophages depends upon interactions between colony-stimulating factor 1 receptor (CSF1R) and its ligands. There remains, however, a lack of consistent information on CSF1R expression in TAMs. A new monoclonal antibody, FER216, was generated to investigate CSF1R protein distribution in formalin fixed tissue samples from 24 reactive lymphoid tissues and 187 different lymphoma types. We also analysed the distribution of CSF1R+, CD68+ and CD163+ macrophages by double immunostaining, and studied the relationship between CSF1R expression and survival in an independent series of 249 cHL patients. CSF1R+ TAMs were less frequent in B-cell lymphocytic leukaemia and lymphoblastic B-cell lymphoma than in diffuse large B-cell lymphoma, peripheral T-cell lymphoma, angioimmunoblastic T-cell lymphoma and cHL. HRS cells in cHL and, with the exception of three cases of anaplastic large cell lymphoma, the neoplastic cells in NHLs, lacked detectable CSF1R protein. A CSF1R+ enriched microenvironment in cHL was associated with shorter survival in an independent series of 249 cHL patients. CSF1R pathway activation was evident in the cHL and inactivation of this pathway could be a potential therapeutic target in cHL cases.

  3. CSF-1R inhibition alters macrophage polarization and blocks glioma progression.

    Science.gov (United States)

    Pyonteck, Stephanie M; Akkari, Leila; Schuhmacher, Alberto J; Bowman, Robert L; Sevenich, Lisa; Quail, Daniela F; Olson, Oakley C; Quick, Marsha L; Huse, Jason T; Teijeiro, Virginia; Setty, Manu; Leslie, Christina S; Oei, Yoko; Pedraza, Alicia; Zhang, Jianan; Brennan, Cameron W; Sutton, James C; Holland, Eric C; Daniel, Dylan; Joyce, Johanna A

    2013-10-01

    Glioblastoma multiforme (GBM) comprises several molecular subtypes, including proneural GBM. Most therapeutic approaches targeting glioma cells have failed. An alternative strategy is to target cells in the glioma microenvironment, such as tumor-associated macrophages and microglia (TAMs). Macrophages depend on colony stimulating factor-1 (CSF-1) for differentiation and survival. We used an inhibitor of the CSF-1 receptor (CSF-1R) to target TAMs in a mouse proneural GBM model, which significantly increased survival and regressed established tumors. CSF-1R blockade additionally slowed intracranial growth of patient-derived glioma xenografts. Surprisingly, TAMs were not depleted in treated mice. Instead, glioma-secreted factors, including granulocyte-macrophage CSF (GM-CSF) and interferon-γ (IFN-γ), facilitated TAM survival in the context of CSF-1R inhibition. Expression of alternatively activated M2 markers decreased in surviving TAMs, which is consistent with impaired tumor-promoting functions. These gene signatures were associated with enhanced survival in patients with proneural GBM. Our results identify TAMs as a promising therapeutic target for proneural gliomas and establish the translational potential of CSF-1R inhibition for GBM.

  4. Haploinsufficiency of CSF-1R and clinicopathologic characterization in patients with HDLS.

    Science.gov (United States)

    Konno, Takuya; Tada, Masayoshi; Tada, Mari; Koyama, Akihide; Nozaki, Hiroaki; Harigaya, Yasuo; Nishimiya, Jin; Matsunaga, Akiko; Yoshikura, Nobuaki; Ishihara, Kenji; Arakawa, Musashi; Isami, Aiko; Okazaki, Kenichi; Yokoo, Hideaki; Itoh, Kyoko; Yoneda, Makoto; Kawamura, Mitsuru; Inuzuka, Takashi; Takahashi, Hitoshi; Nishizawa, Masatoyo; Onodera, Osamu; Kakita, Akiyoshi; Ikeuchi, Takeshi

    2014-01-14

    To clarify the genetic, clinicopathologic, and neuroimaging characteristics of patients with hereditary diffuse leukoencephalopathy with spheroids (HDLS) with the colony stimulating factor 1 receptor (CSF-1R) mutation. We performed molecular genetic analysis of CSF-1R in patients with HDLS. Detailed clinical and neuroimaging findings were retrospectively investigated. Five patients were examined neuropathologically. We found 6 different CSF-1R mutations in 7 index patients from unrelated Japanese families. The CSF-1R mutations included 3 novel mutations and 1 known missense mutation at evolutionarily conserved amino acids, and 1 novel splice-site mutation. We identified a novel frameshift mutation. Reverse transcription PCR analysis revealed that the frameshift mutation causes nonsense-mediated mRNA decay by generating a premature stop codon, suggesting that haploinsufficiency of CSF-1R is sufficient to cause HDLS. Western blot analysis revealed that the expression level of CSF-1R in the brain from the patients was lower than from control subjects. The characteristic MRI findings were the involvement of the white matter and thinning of the corpus callosum with signal alteration, and sequential analysis revealed that the white matter lesions and cerebral atrophy relentlessly progressed with disease duration. Spotty calcifications in the white matter were frequently observed by CT. Neuropathologic analysis revealed that microglia in the brains of the patients demonstrated distinct morphology and distribution. These findings suggest that patients with HDLS, irrespective of mutation type in CSF-1R, show characteristic clinical and neuroimaging features, and that perturbation of CSF-1R signaling by haploinsufficiency may play a role in microglial dysfunction leading to the pathogenesis of HDLS.

  5. The c.1085A>G Genetic Variant of CSF1R Gene Regulates Tumor Immunity by Altering the Proliferation, Polarization, and Function of Macrophages.

    Science.gov (United States)

    Yeh, Yu-Min; Hsu, Shan-Ju; Lin, Peng-Chan; Hsu, Keng-Fu; Wu, Pei-Ying; Su, Wu-Chou; Chang, Jang-Yang; Shen, Meng-Ru

    2017-10-15

    Purpose: Targeting tumor-associated macrophages with colony-stimulating factor 1 receptor (CSF-1R) inhibition reveals a strategy for cancer therapy. Here, we studied the impact of CSF1R germline genetic variant on CSF-1R signaling and the susceptibility to CSF-1R inhibitors.Experimental designs:CSF1R germline genetic variants were studied in 140 cancer patients. CSF-1R phosphorylation, endocytosis, and macrophage polarization were measured as the response to CSF-1 stimulation. Tumor-associated macrophages in surgical specimens and sensitivity to CSF-1R inhibitors were used to determine macrophage function.Results: A CSF1R c.1085A>G genetic variant causing the change of histidine to arginine in the domain of receptor dimerization was identified as a high allele frequency in Eastern Asian population. Cancer patients with this variant allele had less M2-like tumor-associated macrophages accompanied by low VEGF expression in tumor tissues. Importantly, CSF1R genetic variant was significantly associated with disease-free survival in colorectal, endometrial, and ovarian cancer. In terms of differentiation, macrophages with CSF1R c.1085A>G genetic variant displayed a refractory response to CSF-1 stimulation and macrophage survival was sensitive to CSF-1R inhibitors with IC50 of 0.1 to 1 nmol/L range. On contrast, CSF-1 induced a prominent phosphorylation and rapid endocytosis of CSF-1R, leading to an M2-like dominant polarization in macrophages with CSF1R c.1085 genotype A_A, in which CSF-1R inhibitors of PLX3397, BLZ945, and GW2580 inhibited macrophage survival with IC50 of 10 to 100 nmol/L range.Conclusions: The CSF1R c.1085A>G genetic variant regulates tumor immunity by altering the polarization and function of macrophages. This genetic variant confers the sensitivity to CSF-1R inhibitors, implying as a biomarker in targeting CSF-1R signaling for cancer treatment. Clin Cancer Res; 23(20); 6021-30. ©2017 AACR. ©2017 American Association for Cancer Research.

  6. Specific inhibition of PI3K p110δ inhibits CSF-1-induced macrophage spreading and invasive capacity.

    Science.gov (United States)

    Mouchemore, Kellie A; Sampaio, Natalia G; Murrey, Michael W; Stanley, E Richard; Lannutti, Brian J; Pixley, Fiona J

    2013-11-01

    Colony stimulating factor-1 (CSF-1) stimulates mononuclear phagocytic cell survival, growth and differentiation into macrophages through activation and autophosphorylation of the CSF-1 receptor (CSF-1R). We have previously demonstrated that CSF-1-induced phosphorylation of Y721 (pY721) in the receptor kinase insert triggers its association with the p85 regulatory subunit of phosphoinositide 3'-kinase (PI3K). Binding of p85 PI3K to the CSF-1R pY721 motif activates the associated p110 PI3K catalytic subunit and stimulates spreading and motility in macrophages and enhancement of tumor cell invasion. Here we show that pY721-based signaling is necessary for CSF-1-stimulated PtdIns(3,4,5)P production. While primary bone marrow-derived macrophages and the immortalized bone marrow-derived macrophage cell line M-/-.WT express all three class IA PI3K isoforms, p110δ predominates in the cell line. Treatment with p110δ-specific inhibitors demonstrates that the hematopoietically enriched isoform, p110δ, mediates CSF-1-regulated spreading and invasion in macrophages. Thus GS-1101, a potent and selective p110δ inhibitor, may have therapeutic potential by targeting the infiltrative capacity of tumor-associated macrophages that is critical for their enhancement of tumor invasion and metastasis. © 2013 FEBS.

  7. CSF-1 receptor signalling is governed by pre-requisite EHD1 mediated receptor display on the macrophage cell surface.

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    Cypher, Luke R; Bielecki, Timothy Alan; Huang, Lu; An, Wei; Iseka, Fany; Tom, Eric; Storck, Matthew D; Hoppe, Adam D; Band, Vimla; Band, Hamid

    2016-09-01

    Colony stimulating factor-1 receptor (CSF-1R), a receptor tyrosine kinase (RTK), is the master regulator of macrophage biology. CSF-1 can bind CSF-1R resulting in receptor activation and signalling essential for macrophage functions such as proliferation, differentiation, survival, polarization, phagocytosis, cytokine secretion, and motility. CSF-1R activation can only occur after the receptor is presented on the macrophage cell surface. This process is reliant upon the underlying macrophage receptor trafficking machinery. However, the mechanistic details governing this process are incompletely understood. C-terminal Eps15 Homology Domain-containing (EHD) proteins have recently emerged as key regulators of receptor trafficking but have not yet been studied in the context of macrophage CSF-1R signalling. In this manuscript, we utilize primary bone-marrow derived macrophages (BMDMs) to reveal a novel function of EHD1 as a regulator of CSF-1R abundance on the cell surface. We report that EHD1-knockout (EHD1-KO) macrophages cell surface and total CSF-1R levels are significantly decreased. The decline in CSF-1R levels corresponds with reduced downstream macrophage functions such as cell proliferation, migration, and spreading. In EHD1-KO macrophages, transport of newly synthesized CSF-1R to the macrophage cell surface was reduced and was associated with the shunting of the receptor to the lysosome, which resulted in receptor degradation. These findings reveal a novel and functionally important role for EHD1 in governing CSF-1R signalling via regulation of anterograde transport of CSF-1R to the macrophage cell surface. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Diabetic Csf1op/op Mice Lacking Macrophages Are Protected Against the Development of Delayed Gastric EmptyingSummary

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    Gianluca Cipriani

    2016-01-01

    Full Text Available Background & Aims: Diabetic gastroparesis is associated with changes in interstitial cells of Cajal (ICC, neurons, and smooth muscle cells in both animal models and humans. Macrophages appear to be critical to the development of cellular damage that leads to delayed gastric emptying (GE, but the mechanisms involved are not well understood. Csf1op/op (Op/Op mice lack biologically active Csf1 (macrophage colony stimulating factor, resulting in the absence of Csf1-dependent tissue macrophages. We used Csf1op/op mice to determine the role of macrophages in the development of delayed GE. Methods: Animals were injected with streptozotocin to make them diabetic. GE was determined weekly. Immunohistochemistry was used to identify macrophages and ICC networks in the gastric muscular layers. Oxidative stress was measured by serum malondialdehyde (MDA levels. Quantitative reverse-transcription polymerase chain reaction was used to measure levels of mRNA. Results: Csf1op/op mice had normal ICC. With onset of diabetes both Csf1op/op and wild-type Csf1+/+ mice developed increased levels of oxidative stress (75.8 ± 9.1 and 41.2 ± 13.6 nmol/mL MDA, respectively. Wild-type Csf1+/+ mice developed delayed GE after the onset of diabetes (4 of 13 whereas no diabetic Csf1op/op mouse developed delayed GE (0 of 15, P = .035. The ICC were disrupted in diabetic wild-type Csf1+/+ mice with delayed GE but remained normal in diabetic Csf1op/op mice. Conclusions: Cellular injury and development of delayed GE in diabetes requires the presence of muscle layer macrophages. Targeting macrophages may be an effective therapeutic option to prevent cellular damage and development of delayed GE in diabetes. Keywords: Diabetic Complications, Gastroparesis, Interstitial Cells of Cajal

  9. The role of atypical protein kinase C in CSF-1-dependent Erk activation and proliferation in myeloid progenitors and macrophages.

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    Angel W Lee

    Full Text Available Colony stimulating factor-1 (CSF-1 or M-CSF is the major physiological regulator of the proliferation, differentiation and survival of cells of the mononuclear phagocyte lineage. CSF-1 binds to a receptor tyrosine kinase, the CSF-1 receptor (CSF-1R. Multiple pathways are activated downstream of the CSF-1R; however, it is not clear which pathways regulate proliferation and survival. Here, we investigated the role of atypical protein kinase Cs (PKCζ in a myeloid progenitor cell line that expressed CSF-1R (32D.R and in primary murine bone marrow derived macrophages (BMMs. In 32D.R cells, CSF-1 induced the phosphorylation of PKCζ and increased its kinase activity. PKC inhibitors and transfections with mutant PKCs showed that optimal CSF-1-dependent Erk activation and proliferation depended on the activity of PKCζ. We previously reported that CSF-1 activated the Erk pathway through an A-Raf-dependent and an A-Raf independent pathway (Lee and States, Mol. Cell. Biol.18, 6779. PKC inhibitors did not affect CSF-1 induced Ras and A-Raf activity but markedly reduced MEK and Erk activity, implying that PKCζ regulated the CSF-1-Erk pathway at the level of MEK. PKCζ has been implicated in activating the NF-κB pathway. However, CSF-1 promoted proliferation in an NF-κB independent manner. We established stable 32D.R cell lines that overexpressed PKCζ. Overexpression of PKCζ increased the intensity and duration of CSF-1 induced Erk activity and rendered cells more responsive to CSF-1 mediated proliferation. In contrast to 32D.R cells, PKCζ inhibition in BMMs had only a modest effect on proliferation. Moreover, PKCζ -specific and pan-PKC inhibitors induced a paradoxical increase in MEK-Erk phosphorylation suggesting that PKCs targeted a common negative regulatory step upstream of MEK. Our results demonstrated that CSF-1 dependent Erk activation and proliferation are regulated differentially in progenitors and differentiated cells.

  10. IL-3 and CSF-1 interact to promote generation of CD11c+ IL-10-producing macrophages.

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    Kuo-Ching Sheng

    Full Text Available Unraveling the mechanisms of hematopoiesis regulated by multiple cytokines remains a challenge in hematology. IL-3 is an allergic cytokine with the multilineage potential, while CSF-1 is produced in the steady state with restricted lineage coverage. Here, we uncovered an instructive role of CSF-1 in IL-3-mediated hematopoiesis. CSF-1 significantly promoted IL-3-driven CD11c+ cell expansion and dampened basophil and mast cell generation from C57BL/6 bone marrow. Further studies indicated that the CSF-1/CSF-1R axis contributed significantly to IL-3-induced CD11c+ cell generation through enhancing c-Fos-associated monopoiesis. CD11c+ cells induced by IL-3 or IL-3/CSF-1 were competent in cellular maturation and endocytosis. Both IL-3 and IL-3/CSF-1 cells lacked classical dendritic cell appearance and resembled macrophages in morphology. Both populations produced a high level of IL-10, in addition to IL-1, IL-6 and TNFα, in response to LPS, and were relatively poor T cell stimulators. Collectively, these findings reveal a role for CSF-1 in mediating the IL-3 hematopoietic pathway through monopoiesis, which regulates expansion of CD11c+ macrophages.

  11. Changes in local cerebral glucose utilization during rewarding brain stimulation.

    OpenAIRE

    Esposito, R U; Porrino, L J; Seeger, T F; Crane, A M; Everist, H D; Pert, A

    1984-01-01

    The quantitative 2-deoxy[14C]glucose method was used to determine local cerebral glucose utilization in unrestrained rats responding (lever-press) for rewarding electrical stimulation to area A10 (ventral tegmental area) and in similarly implanted inactive controls. Self-stimulation was associated with significant increases in metabolic activity, highly circumscribed in the ventral tegmental area, that continued rostrally within a rather compact zone of activity through the medial forebrain b...

  12. Fibronectin induces macrophage migration through a SFK-FAK/CSF-1R pathway.

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    Digiacomo, Graziana; Tusa, Ignazia; Bacci, Marina; Cipolleschi, Maria Grazia; Dello Sbarba, Persio; Rovida, Elisabetta

    2017-07-04

    Integrins, following binding to proteins of the extracellular matrix (ECM) including collagen, laminin and fibronectin (FN), are able to transduce molecular signals inside the cells and to regulate several biological functions such as migration, proliferation and differentiation. Besides activation of adaptor molecules and kinases, integrins transactivate Receptor Tyrosine Kinases (RTK). In particular, adhesion to the ECM may promote RTK activation in the absence of growth factors. The Colony-Stimulating Factor-1 Receptor (CSF-1R) is a RTK that supports the survival, proliferation, and motility of monocytes/macrophages, which are essential components of innate immunity and cancer development. Macrophage interaction with FN is recognized as an important aspect of host defense and wound repair. The aim of the present study was to investigate on a possible cross-talk between FN-elicited signals and CSF-1R in macrophages. FN induced migration in BAC1.2F5 and J774 murine macrophage cell lines and in human primary macrophages. Adhesion to FN determined phosphorylation of the Focal Adhesion Kinase (FAK) and Src Family Kinases (SFK) and activation of the SFK/FAK complex, as witnessed by paxillin phosphorylation. SFK activity was necessary for FAK activation and macrophage migration. Moreover, FN-induced migration was dependent on FAK in either murine macrophage cell lines or human primary macrophages. FN also induced FAK-dependent/ligand-independent CSF-1R phosphorylation, as well as the interaction between CSF-1R and β1. CSF-1R activity was necessary for FN-induced macrophage migration. Indeed, genetic or pharmacological inhibition of CSF-1R prevented FN-induced macrophage migration. Our results identified a new SFK-FAK/CSF-1R signaling pathway that mediates FN-induced migration of macrophages.

  13. The tumor microenvironment underlies acquired resistance to CSF-1R inhibition in gliomas.

    Science.gov (United States)

    Quail, Daniela F; Bowman, Robert L; Akkari, Leila; Quick, Marsha L; Schuhmacher, Alberto J; Huse, Jason T; Holland, Eric C; Sutton, James C; Joyce, Johanna A

    2016-05-20

    Macrophages accumulate with glioblastoma multiforme (GBM) progression and can be targeted via inhibition of colony-stimulating factor-1 receptor (CSF-1R) to regress high-grade tumors in animal models of this cancer. However, whether and how resistance emerges in response to sustained CSF-1R blockade is unknown. We show that although overall survival is significantly prolonged, tumors recur in >50% of mice. Gliomas reestablish sensitivity to CSF-1R inhibition upon transplantation, indicating that resistance is tumor microenvironment-driven. Phosphatidylinositol 3-kinase (PI3K) pathway activity was elevated in recurrent GBM, driven by macrophage-derived insulin-like growth factor-1 (IGF-1) and tumor cell IGF-1 receptor (IGF-1R). Combining IGF-1R or PI3K blockade with CSF-1R inhibition in recurrent tumors significantly prolonged overall survival. Our findings thus reveal a potential therapeutic approach for treating resistance to CSF-1R inhibitors. Copyright © 2016, American Association for the Advancement of Science.

  14. CSF-1R as an inhibitor of apoptosis and promoter of proliferation, migration and invasion of canine mammary cancer cells.

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    Król, Magdalena; Majchrzak, Kinga; Mucha, Joanna; Homa, Agata; Bulkowska, Małgorzata; Jakubowska, Arleta; Karwicka, Malwina; Pawłowski, Karol M; Motyl, Tomasz

    2013-04-05

    Tumor-associated macrophages (TAMs) have high impact on the cancer development because they can facilitate matrix invasion, angiogenesis, and tumor cell motility. It gives cancer cells the capacity to invade normal tissues and metastasize. The signaling of colony-stimulating factor-1 receptor (CSF-1R) which is an important regulator of proliferation and differentiation of monocytes and macrophages regulates most of the tissue macrophages. However, CSF-1R is expressed also in breast epithelial tissue during some physiological stages i.g.: pregnancy and lactation. Its expression has been also detected in various cancers. Our previous study has showed the expression of CSF-1R in all examined canine mammary tumors. Moreover, it strongly correlated with grade of malignancy and ability to metastasis. This study was therefore designed to characterize the role of CSF-1R in canine mammary cancer cells proliferation, apoptosis, migration, and invasion. As far as we know, the study presented hereby is a pioneering experiment in this field of veterinary medicine. We showed that csf-1r silencing significantly increased apoptosis (Annexin V test), decreased proliferation (measured as Ki67 expression) and decreased migration ("wound healing" assay) of canine mammary cancer cells. Treatment of these cells with CSF-1 caused opposite effect. Moreover, csf-1r knock-down changed growth characteristics of highly invasive cell lines on Matrigel matrix, and significantly decreased the ability of these cells to invade matrix. CSF-1 treatment increased invasion of cancer cells. The evidence of the expression and functional role of the CSF-1R in canine mammary cancer cells indicate that CSF-1R targeting may be a good therapeutic approach.

  15. Chronicity following ischaemia-reperfusion injury depends on tubular-macrophage crosstalk involving two tubular cell-derived CSF-1R activators: CSF-1 and IL-34.

    Science.gov (United States)

    Sanchez-Niño, Maria Dolores; Sanz, Ana Belen; Ortiz, Alberto

    2016-09-01

    Two structurally unrelated ligands activate the macrophage colony stimulating factor receptor (CSF-1R, c-fms, CD115): M-CSF/CSF-1 and interleukin-34 (IL-34). Both ligands promote macrophage proliferation, survival and differentiation. IL-34 also activates the protein-tyrosine phosphatase ζ receptor (PTP-ζ, PTPRZ1). Both receptors and cytokines are increased during acute kidney injury. While tubular cell-derived CSF-1 is required for kidney repair, Baek et al (J Clin Invest 2015; 125: 3198-3214) have now identified tubular epithelial cell-derived IL-34 as a promoter of kidney neutrophil and macrophage infiltration and tubular cell destruction during experimental kidney ischaemia-reperfusion, leading to chronic injury. IL-34 promoted proliferation of both intrarenal macrophages and bone marrow cells, increasing circulating neutrophils and monocytes and their kidney recruitment. Thus, injured tubular cells release two CSF-1R activators, one (CSF-1) that promotes tubular cell survival and kidney repair and another (IL-34) that promotes chronic kidney damage. These results hold promise for the development of IL-34-targeting strategies to prevent ischaemia-reperfusion kidney injury in contexts such as kidney transplantation. However, careful consideration should be given to the recent characterization by Bezie et al. (J Clin Invest 2015; 125: 3952-3964) of IL-34 as a T regulatory cell (Treg) cytokine that modulates macrophage responses so that IL-34-primed macrophages potentiate the immune suppressive capacity of Tregs and promote graft tolerance. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  16. Regulation of Saccharomyces cerevisiae maltose fermentation by cold temperature and CSF1 Regulação da fermentação de maltose em Saccharomyces cerevisiae por baixas temperaturas e CSF1

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    Claudia Hollatz

    2003-11-01

    Full Text Available We studied the influence of cold temperature (10ºC on the fermentation of maltose by a S. cerevisiae wild-type strain, and a csf1delta mutant impaired in glucose and leucine uptake at low temperatures. Cold temperature affected the fermentation kinetics by decreasing the growth rate and the final cell yield, with almost no ethanol been produced from maltose by the wild-type cells at 10ºC. The csf1delta strain did not grew on maltose when cultured at 10ºC, indicating that the CSF1 gene is also required for maltose consumption at low temperatures. However, this mutant also showed increased inhibition of glucose and maltose fermentation under salt stress, indicating that CSF1 is probably involved in the regulation of other physiological processes, including ion homeostasis.Foi estudado o efeito da baixa temperatura (10ºC na fermentação de maltose por uma cepa de S. cerevisiae selvagem, e uma cepa csf1delta mutante incapaz de transportar glicose e leucina a baixas temperaturas. A baixa temperatura afeta a cinética da fermentação por diminuir a velocidade de crescimento e rendimento celular final, com quase nenhum etanol produzido a partir de maltose pelas células selvagems a 10ºC. A cepa csf1delta foi incapaz de crescer em maltose a 10ºC, indicando que o gene CSF1 é também necessário para a utilização de maltose a baixas temperaturas. Entretanto, o mutante também mostrou inibição acentuada da fermentação de glicose e maltose por estresse salino, indicando que CSF1 também estaria envolvido na regulação de outros processos fisiológicos, incluindo a homeostase iónica.

  17. CSF-1R expression in tumor-associated macrophages is associated with worse prognosis in classical Hodgkin lymphoma.

    Science.gov (United States)

    Koh, Young Wha; Park, Chansik; Yoon, Dok Hyun; Suh, Cheolwon; Huh, Jooryung

    2014-04-01

    The aim of this study was to determine the prognostic relevance of colony-stimulating 1 receptor (CSF-1R) expression in both Hodgkin/Reed-Sternberg (HRS) cells and the surrounding cells (non-HRS cells) in patients with classical Hodgkin lymphoma (CHL) . Diagnostic tissues from 112 patients with CHL treated with doxorubicin, bleomycin, vinblastine, and dacarbazine were evaluated retrospectively by immunohistochemical analysis for CSF-1R and CD68 and CD163 for tissue-associated macrophages. High numbers (≥30%) of non-HRS cells expressing CSF-1R conferred inferior event-free survival and overall survival in univariate and multivariate analysis. High numbers of non-HRS cells expressing CSF-1R were significantly associated with a high number of tumor-associated macrophages as detected by CD163 expression (P CSF-1R and CD163 was associated with a worse survival outcome than either CSF-1R or CD163 expression alone or no expression. Our data demonstrate that a high number of non-HRS cells expressing CSF-1R are correlated with an increased tumor macrophage content and worse survival.

  18. Teleost soluble CSF-1R modulates cytokine profiles at an inflammatory site, and inhibits neutrophil chemotaxis, phagocytosis, and bacterial killing.

    Science.gov (United States)

    Rieger, Aja M; Havixbeck, Jeffrey J; Belosevic, Miodrag; Barreda, Daniel R

    2015-04-01

    Soluble colony stimulating factor-1 receptor (sCSF-1R) is a novel bony fish protein that contributes to the regulation of macrophage proliferation. We recently showed that this soluble receptor is highly upregulated by teleost macrophages in the presence of apoptotic cells. Further, recombinant sCSF-1R inhibited leukocyte infiltration into a challenge site in vivo. Herein, we characterized the mechanisms underlying these changes as a platform to better understand the evolutionary origins of the CSF-1 immune-regulatory axis and inflammation control in teleosts. Using an in vivo model of self-resolving peritonitis, we show that sCSF-1R downregulates chemokine expression and inhibits neutrophil chemotaxis. Soluble CSF-1R also inhibited gene expression of several pro-inflammatory cytokines and promoted the expression of an anti-inflammatory mediator, IL-10. Finally, the phenotype of infiltrating neutrophils changed significantly in the presence of sCSF-1R. Both a reduced capacity for phagocytosis and pathogen killing were observed. Overall, our results implicate sCSF-1R as an important regulator of neutrophil responses in teleosts. It remains unclear whether this represents an inflammation regulatory factor that is unique to this animal group or one that may be evolutionarily conserved and continues to contribute to the regulation of antimicrobial processes at inflammatory sites in higher vertebrates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. SREBP-1c regulates glucose-stimulated hepatic clusterin expression

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    Kim, Gukhan [Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Geun Hyang; Oh, Gyun-Sik; Yoon, Jin [Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Hae Won [Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Min-Seon [Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Seung-Whan, E-mail: swkim7@amc.seoul.kr [Department of Pharmacology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of)

    2011-05-20

    Highlights: {yields} This is the first report to show nutrient-regulated clusterin expression. {yields} Clusterin expression in hepatocytes was increased by high glucose concentration. {yields} SREBP-1c is directly involved in the transcriptional activation of clusterin by glucose. {yields} This glucose-stimulated activation process is mediated through tandem E-box motifs. -- Abstract: Clusterin is a stress-response protein that is involved in diverse biological processes, including cell proliferation, apoptosis, tissue differentiation, inflammation, and lipid transport. Its expression is upregulated in a broad spectrum of diverse pathological states. Clusterin was recently reported to be associated with diabetes, metabolic syndrome, and their sequelae. However, the regulation of clusterin expression by metabolic signals was not addressed. In this study we evaluated the effects of glucose on hepatic clusterin expression. Interestingly, high glucose concentrations significantly increased clusterin expression in primary hepatocytes and hepatoma cell lines, but the conventional promoter region of the clusterin gene did not respond to glucose stimulation. In contrast, the first intronic region was transcriptionally activated by high glucose concentrations. We then defined a glucose response element (GlRE) of the clusterin gene, showing that it consists of two E-box motifs separated by five nucleotides and resembles carbohydrate response element (ChoRE). Unexpectedly, however, these E-box motifs were not activated by ChoRE binding protein (ChREBP), but were activated by sterol regulatory element binding protein-1c (SREBP-1c). Furthermore, we found that glucose induced recruitment of SREBP-1c to the E-box of the clusterin gene intronic region. Taken together, these results suggest that clusterin expression is increased by glucose stimulation, and SREBP-1c plays a crucial role in the metabolic regulation of clusterin.

  20. Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells.

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    Jianhui Liu

    Full Text Available Glucose-stimulated insulin secretion (GSIS is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM. Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells.

  1. Therapeutic Antibodies Targeting CSF1 Impede Macrophage Recruitment in a Xenograft Model of Tenosynovial Giant Cell Tumor

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    Hongwei Cheng

    2010-01-01

    Full Text Available Tenosynovial giant cell tumor is a neoplastic disease of joints that can cause severe morbidity. Recurrences are common following local therapy, and no effective medical therapy currently exists. Recent work has demonstrated that all cases overexpress macrophage colony-stimulating factor (CSF1, usually as a consequence of an activating gene translocation, resulting in an influx of macrophages that form the bulk of the tumor. New anti-CSF1 drugs have been developed; however there are no preclinical models suitable for evaluation of drug benefits in this disease. In this paper, we describe a novel renal subcapsular xenograft model of tenosynovial giant cell tumor. Using this model, we demonstrate that an anti-CSF1 monoclonal antibody significantly inhibits host macrophage infiltration into this tumor. The results from this model support clinical trials of equivalent humanized agents and anti-CSF1R small molecule drugs in cases of tenosynovial giant cell tumor refractory to conventional local therapy.

  2. A subcellular model of glucose-stimulated pancreatic insulin secretion.

    Science.gov (United States)

    Pedersen, Morten Gram; Corradin, Alberto; Toffolo, Gianna M; Cobelli, Claudio

    2008-10-13

    When glucose is raised from a basal to stimulating level, the pancreatic islets respond with a typical biphasic insulin secretion pattern. Moreover, the pancreas is able to recognize the rate of change of the glucose concentration. We present a relatively simple model of insulin secretion from pancreatic beta-cells, yet founded on solid physiological grounds and capable of reproducing a series of secretion patterns from perfused pancreases as well as from stimulated islets. The model includes the notion of distinct pools of granules as well as mechanisms such as mobilization, priming, exocytosis and kiss-and-run. Based on experimental data, we suggest that the individual beta-cells activate at different glucose concentrations. The model reproduces most of the data it was tested against very well, and can therefore serve as a general model of glucose-stimulated insulin secretion. Simulations predict that the effect of an increased frequency of kiss-and-run exocytotic events is a reduction in insulin secretion without modification of the qualitative pattern. Our model also appears to be the first physiology-based one to reproduce the staircase experiment, which underlies 'derivative control', i.e. the pancreatic capacity of measuring the rate of change of the glucose concentration.

  3. Molecular cloning, pathologically-correlated expression and functional characterization of the colonystimulating factor 1 receptor (CSF-1R) gene from a teleost, Plecoglossus altivelis.

    Science.gov (United States)

    Chen, Qiang; Lu, Xin-Jiang; Li, Ming-Yun; Chen, Jiong

    2016-03-18

    Colony-stimulating factor 1 receptor (CSF-1R) is an important regulator of monocytes/macrophages (MO/MΦ). Although several CSF-1R genes have been identified in teleosts, the precise role of CSF- 1R in ayu (Plecoglossus altivelis) remains unclear. In this study, we characterized the CSF-1R homologue from P. altivelis, and named it PaCSF-1R. Multiple sequence alignment and phylogenetic tree analysis showed that PaCSF-1R was most closely related to that of Japanese ricefish (Oryzias latipes). Tissue distribution and expression analysis showed that the PaCSF-1R transcript was mainly expressed in the head kidney-derived MO/MΦ, spleen, and head kidney, and its expression was significantly altered in various tissues upon Vibrio anguillarum infection. After PaCSF-1R neutralization for 48 h, the phagocytic activity of MO/MΦ was significantly decreased, suggesting that PaCSF-1R plays a role in regulating the phagocytic function of ayu MO/MΦ.

  4. Corticotropin releasing hormone can selectively stimulate glucose uptake in corticotropinoma via glucose transporter 1.

    Science.gov (United States)

    Lu, Jie; Montgomery, Blake K; Chatain, Grégoire P; Bugarini, Alejandro; Zhang, Qi; Wang, Xiang; Edwards, Nancy A; Ray-Chaudhury, Abhik; Merrill, Marsha J; Lonser, Russell R; Chittiboina, Prashant

    2017-10-03

    Pre-operative detection of corticotropin (ACTH) secreting microadenomas causing Cushing's disease (CD) improves surgical outcomes. Current best magnetic resonance imaging fails to detect up to 40% of these microadenomas. 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) is specific, but not sensitive in detecting corticotropinomas. Theoretically, secretagogue stimulation with corticotropin releasing hormone (CRH) could improve detection of adenomas with 18 F-FDG PET. Previous attempts with simultaneous CRH stimulation have failed to demonstrate increased 18 F-FDG uptake in corticotropinomas. We hypothesized that CRH stimulation leads to a delayed elevation in glucose uptake in corticotropinomas. Clinical data was analyzed for efficacy of CRH in improving 18 FDG-PET detection of corticotropinomas in CD. Glucose transporter 1 (GLUT1) immunoreactivity was performed on surgical specimens. Ex-vivo, viable cells from these tumors were tested for secretagogue effects (colorimetric glucose uptake), and for fate of intracellular glucose (glycolysis stress analysis). Validation of ex-vivo findings was performed with AtT-20 cells. CRH increased glucose uptake in human-derived corticotroph tumor cells and AtT-20, but not in normal murine or human corticotrophs (p fasentin suppressed baseline (p < 0.0001) and CRH-mediated glucose uptake. Expectedly, intra-operatively collected corticotropinomas demonstrated GLUT1 overexpression. Lastly, human derived corticotroph tumor cells demonstrated increased glycolysis and low glucose oxidation. Increased and delayed CRH-mediated glucose uptake differentially occurs in adenomatous corticotrophs. Delayed secretagogue-stimulated 18 F-FDG PET could improve microadenoma detection. Copyright © 2017. Published by Elsevier B.V.

  5. Normalization of periodontal tissues in osteopetrotic mib mutant rats, treated with CSF-1

    Science.gov (United States)

    Wojtowicz, A.; Yamauchi, M.; Sotowski, R.; Ostrowski, K.

    1998-01-01

    The osteopetrotic mib mutation in rats causes defects in the skeletal bone tissue in young animals. These defects, i.e. slow bone remodelling, changes in both crystallinity and mineral content, are transient and undergo normalization, even without any treatment in 6-wk-old animals. Treatment with CSF-1 (colony stimulating factor-1) accelerates the normalization process in skeletal bones. The periodontal tissues around the apices of incisors show abnormalities caused by the slow remodelling process of the mandible bone tissue, the deficiency of osteoclasts and their abnormal morphology, as well as the disorganization of periodontal ligament fibres. In contrast to the skeletal tissues, these abnormalities would not undergo spontaneous normalization. Under treatment with colony stimulating factor 1 (CSF-1), the primitive bone trabeculae of mandible are resorbed and the normalization of the number of osteoclasts and their cytology occurs. The organization of the periodontal ligament fibres is partially restored, resembling the histological structure of the normal one.

  6. CSF-1R up-regulation is associated with response to pharmacotherapy targeting tyrosine kinase activity in AML cell lines.

    Science.gov (United States)

    Kogan, Michael; Fischer-Smith, Tracy; Kaminsky, Rafal; Lehmicke, Gabrielle; Rappaport, Jay

    2012-03-01

    The oncogenic potential of colony stimulating factor 1 receptor (CSF-1R) has been well described, while its relevance for human acute myelogenous leukemia (AML) is still undetermined. In a recent clinical trial for AML, sunitinib was found to hold potential therapeutic benefit, however, the mechanism for this remains unknown. In this study, we treated three myeloid cell lines, Mono-Mac 1, THP-1, and U937, with sunitinib, and a small-molecule CSF-1R inhibitor (cFMS-I) to test the anticancer effect of such treatment. Mono-Mac 1 cells had inhibited proliferation and extracellular-signal regulated kinase activity as a result of CSF-1R inhibition and a dose-dependent increase in CSF-1R expression with both sunitinib and cFMS-I. Our results suggest potential for CSF-1R as an important target of sunitinib or other similar drugs. Future study of CSF-1R may produce more targeted therapeutic approaches and aid in the development of personalized medicine for AML.

  7. Profiling Y561-dependent and -independent substrates of CSF-1R in epithelial cells.

    Science.gov (United States)

    Knowlton, Melodie L; Selfors, Laura M; Wrobel, Carolyn N; Gu, Ting-Lei; Ballif, Bryan A; Gygi, Steven P; Polakiewicz, Roberto; Brugge, Joan S

    2010-10-26

    Receptor tyrosine kinases (RTKs) activate multiple downstream cytosolic tyrosine kinases following ligand stimulation. SRC family kinases (SFKs), which are recruited to activated RTKs through SH2 domain interactions with RTK autophosphorylation sites, are targets of many subfamilies of RTKs. To date, there has not been a systematic analysis of the downstream substrates of such receptor-activated SFKs. Here, we conducted quantitative mass spectrometry utilizing stable isotope labeling (SILAC) analysis to profile candidate SRC-substrates induced by the CSF-1R tyrosine kinase by comparing the phosphotyrosine-containing peptides from cells expressing either CSF-1R or a mutant form of this RTK that is unable to bind to SFKs. This analysis identified previously uncharacterized changes in tyrosine phosphorylation induced by CSF-1R in mammary epithelial cells as well as a set of candidate substrates dependent on SRC recruitment to CSF-1R. Many of these candidates may be direct SRC targets as the amino acids flanking the phosphorylation sites in these proteins are similar to known SRC kinase phosphorylation motifs. The putative SRC-dependent proteins include known SRC substrates as well as previously unrecognized SRC targets. The collection of substrates includes proteins involved in multiple cellular processes including cell-cell adhesion, endocytosis, and signal transduction. Analyses of phosphoproteomic data from breast and lung cancer patient samples identified a subset of the SRC-dependent phosphorylation sites as being strongly correlated with SRC activation, which represent candidate markers of SRC activation downstream of receptor tyrosine kinases in human tumors. In summary, our data reveal quantitative site-specific changes in tyrosine phosphorylation induced by CSF-1R activation in epithelial cells and identify many candidate SRC-dependent substrates phosphorylated downstream of an RTK.

  8. Profiling Y561-dependent and -independent substrates of CSF-1R in epithelial cells.

    Directory of Open Access Journals (Sweden)

    Melodie L Knowlton

    Full Text Available Receptor tyrosine kinases (RTKs activate multiple downstream cytosolic tyrosine kinases following ligand stimulation. SRC family kinases (SFKs, which are recruited to activated RTKs through SH2 domain interactions with RTK autophosphorylation sites, are targets of many subfamilies of RTKs. To date, there has not been a systematic analysis of the downstream substrates of such receptor-activated SFKs. Here, we conducted quantitative mass spectrometry utilizing stable isotope labeling (SILAC analysis to profile candidate SRC-substrates induced by the CSF-1R tyrosine kinase by comparing the phosphotyrosine-containing peptides from cells expressing either CSF-1R or a mutant form of this RTK that is unable to bind to SFKs. This analysis identified previously uncharacterized changes in tyrosine phosphorylation induced by CSF-1R in mammary epithelial cells as well as a set of candidate substrates dependent on SRC recruitment to CSF-1R. Many of these candidates may be direct SRC targets as the amino acids flanking the phosphorylation sites in these proteins are similar to known SRC kinase phosphorylation motifs. The putative SRC-dependent proteins include known SRC substrates as well as previously unrecognized SRC targets. The collection of substrates includes proteins involved in multiple cellular processes including cell-cell adhesion, endocytosis, and signal transduction. Analyses of phosphoproteomic data from breast and lung cancer patient samples identified a subset of the SRC-dependent phosphorylation sites as being strongly correlated with SRC activation, which represent candidate markers of SRC activation downstream of receptor tyrosine kinases in human tumors. In summary, our data reveal quantitative site-specific changes in tyrosine phosphorylation induced by CSF-1R activation in epithelial cells and identify many candidate SRC-dependent substrates phosphorylated downstream of an RTK.

  9. Expression of M-CSF and CSF-1R is correlated with histological grade in soft tissue tumors.

    Science.gov (United States)

    Richardsen, Elin; Sørbye, Sveinung Wergeland; Crowe, John Phil; Yang, Jia-Lin; Busund, Lill-Tove

    2009-10-01

    Macrophage colony stimulating factor (M-CSF) binds to colony-stimulating factor-1 receptor (CSF-1R) and thereby stimulates the proliferation, differentiation and behaviour of monocytes, macrophages and their bone marrow progenitors. Previous studies have suggested that high expression of these markers is correlated with poor prognosis. M-CSF, CSF-1R and CD68 protein expression was examined by immunohistochemistry in paraffin embedded sections of soft tissue tumor specimens from 46 patients. The proportion of positive cells and the expression intensity of M-CSF, CSF-1R and CD68 in both the tumor cell areas and the adjacent stromal areas were correlated to the histological grade. In the high grade tumors M-CSF and CSF-1R were more highly expressed than in the low grade tumors. This was seen in both the tumor cell areas and the adjacent stromal areas. No differences in CD68 expression between the high and low grade tumors were found either in the tumor cell areas or the stromal areas. The expression of M-CSF and CSF-1R in tumor cell areas and adjacent stromal areas correlate with the histological grade of soft tissue tumors.

  10. The CSF-1 receptor ligands IL-34 and CSF-1 exhibit distinct developmental brain expression patterns and regulate neural progenitor cell maintenance and maturation

    Science.gov (United States)

    Nandi, Sayan; Gokhan, Solen; Dai, Xu-Ming; Wei, Suwen; Enikolopov, Grigori; Lin, Haishan; Mehler, Mark F.; Stanley, E. Richard

    2012-01-01

    The CSF-1 receptor (CSF-1R) regulates CNS microglial development. However, the localization and developmental roles of this receptor and its ligands, IL-34 and CSF-1, in the brain are poorly understood. Here we show that compared to wild type mice, CSF-1R-deficient (Csf1r−/−) mice have smaller brains of greater mass. They further exhibit an expansion of lateral ventricle size, an atrophy of the olfactory bulb and a failure of midline crossing of callosal axons. In brain, IL-34 exhibited a broader regional expression than CSF-1, mostly without overlap. Expression of IL-34, CSF-1 and the CSF-1R were maximal during early postnatal development. However, in contrast to the expression of its ligands, CSF-1R expression was very low in adult brain. Postnatal neocortical expression showed that CSF-1 was expressed in layer VI, whereas IL-34 was expressed in the meninges and layers II–V. The broader expression of IL-34 is consistent with its previously implicated role in microglial development. The differential expression of CSF-1R ligands, with respect to CSF-1R expression, could reflect their CSF-1R-independent signaling. Csf1r−/− mice displayed increased proliferation and apoptosis of neocortical progenitors and reduced differentiation of specific excitatory neuronal subtypes. Indeed, addition of CSF-1 or IL-34 to microglia-free, CSF-1R-expressing dorsal forebrain clonal cultures, suppressed progenitor self-renewal and enhanced neuronal differentiation. Consistent with a neural developmental role for the CSF-1R, ablation of the Csf1r gene in Nestin-positive neural progenitors led to a smaller brain size, an expanded neural progenitor pool and elevated cellular apoptosis in cortical forebrain. Thus our results also indicate novel roles for the CSF-1R in the regulation of corticogenesis. PMID:22542597

  11. Phosphorylation of CSF-1R Y721 mediates its association with PI3K to regulate macrophage motility and enhancement of tumor cell invasion.

    Science.gov (United States)

    Sampaio, Natalia G; Yu, Wenfeng; Cox, Dianne; Wyckoff, Jeffrey; Condeelis, John; Stanley, E Richard; Pixley, Fiona J

    2011-06-15

    Colony stimulating factor-1 (CSF-1) regulates macrophage morphology and motility, as well as mononuclear phagocytic cell proliferation and differentiation. The CSF-1 receptor (CSF-1R) transduces these pleiotropic signals through autophosphorylation of eight intracellular tyrosine residues. We have used a novel bone-marrow-derived macrophage cell line system to examine specific signaling pathways activated by tyrosine-phosphorylated CSF-1R in macrophages. Screening of macrophages expressing a single species of CSF-1R with individual tyrosine-to-phenylalanine residue mutations revealed striking morphological alterations upon mutation of Y721. M⁻/⁻.Y721F cells were apolar and ruffled poorly in response to CSF-1. Y721-P-mediated CSF-1R signaling regulated adhesion and actin polymerization to control macrophage spreading and motility. Moreover, the reduced motility of M⁻/⁻.Y721F macrophages was associated with their reduced capacity to enhance carcinoma cell invasion. Y721 phosphorylation mediated the direct association of the p85 subunit of phosphoinositide 3-kinase (PI3K) with the CSF-1R, but not that of phospholipase C (PLC) γ2, and induced polarized PtdIns(3,4,5)P₃ production at the putative leading edge, implicating PI3K as a major regulator of CSF-1-induced macrophage motility. The Y721-P-motif-based motility signaling was at least partially independent of both Akt and increased Rac and Cdc42 activation but mediated the rapid and transient association of an unidentified ~170 kDa phosphorylated protein with either Rac-GTP or Cdc42-GTP. These studies identify CSF-1R-Y721-P-PI3K signaling as a major pathway in CSF-1-regulated macrophage motility and provide a starting point for the discovery of the immediate downstream signaling events.

  12. Interleukin 6 stimulates hepatic glucose release from prelabeled glycogen pools

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, D.G. (Shriners Burns Institute, Galveston, TX (USA))

    1990-01-01

    Cytokines, derived from a wide variety of cell types, are now believed to initiate many of the physiological responses accompanying the inflammatory phase that follows either Gram-negative septicemia or thermal injury. Because hypoglycemia (after endotoxic challenge) and hyperglycemia (after thermal injury) represent well-characterized responses to these injuries, we sought to determine whether hepatic glycogen metabolism could be altered by specific cytokines. Cultured adult rat hepatocytes were prelabeled with ({sup 14}C)glucose for 24 h, a procedure that resulted in the labeling of hepatic glycogen pools that subsequently could be depleted (with concomitant ({sup 14}C)glucose release) by either glucagon or norepinephrine. After the addition of a highly concentrated human monocyte-conditioned medium (MCM) or various cytokines to these prelabeled cells, ({sup 14}C)glucose release was stimulated by MCM and recombinant human interleukin 6 (IL-6) but was not stimulated by other cytokines tested. Furthermore, only antisera to IL-6 were capable of reducing the glucose-releasing factor activity found in MCM. These data therefore suggest a novel glucoregulatory role for IL-6.

  13. Macrophage Migration and Its Regulation by CSF-1

    Directory of Open Access Journals (Sweden)

    Fiona J. Pixley

    2012-01-01

    Full Text Available Macrophages are terminally differentiated cells of the mononuclear phagocytic lineage and develop under the stimulus of their primary growth and differentiation factor, CSF-1. Although they differentiate into heterogeneous populations, depending upon their tissue of residence, motility is an important aspect of their function. To facilitate their migration through tissues, macrophages express a unique range of adhesion and cytoskeletal proteins. Notably, macrophages do not form large, stable adhesions or actin stress fibers but rely on small, short lived point contacts, focal complexes and podosomes for traction. Thus, macrophages are built to respond rapidly to migratory stimuli. As well as triggering growth and differentiation, CSF-1 is also a chemokine that regulates macrophage migration via activation the CSF-1 receptor tyrosine kinase. CSF-1R autophosphorylation of several intracellular tyrosine residues leads to association and activation of many downstream signaling molecules. However, phosphorylation of just one residue, Y721, mediates association of PI3K with the receptor to activate the major motility signaling pathways in macrophages. Dissection of these pathways will identify drug targets for the inhibition of diseases in which macrophages contribute to adverse outcomes.

  14. The function of the conserved regulatory element within the second intron of the mammalian Csf1r locus.

    Science.gov (United States)

    Sauter, Kristin A; Bouhlel, M Amine; O'Neal, Julie; Sester, David P; Tagoh, Hiromi; Ingram, Richard M; Pridans, Clare; Bonifer, Constanze; Hume, David A

    2013-01-01

    The gene encoding the receptor for macrophage colony-stimulating factor (CSF-1R) is expressed exclusively in cells of the myeloid lineages as well as trophoblasts. A conserved element in the second intron, Fms-Intronic Regulatory Element (FIRE), is essential for macrophage-specific transcription of the gene. However, the molecular details of how FIRE activity is regulated and how it impacts the Csf1r promoter have not been characterised. Here we show that agents that down-modulate Csf1r mRNA transcription regulated promoter activity altered the occupancy of key FIRE cis-acting elements including RUNX1, AP1, and Sp1 binding sites. We demonstrate that FIRE acts as an anti-sense promoter in macrophages and reversal of FIRE orientation within its native context greatly reduced enhancer activity in macrophages. Mutation of transcription initiation sites within FIRE also reduced transcription. These results demonstrate that FIRE is an orientation-specific transcribed enhancer element.

  15. The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity

    DEFF Research Database (Denmark)

    Kelly, Karen R; Brooks, Latina M; Solomon, Thomas

    2009-01-01

    to ingested glucose, 2) GIP may mediate the attenuated glucose-stimulated insulin response after exercise/diet interventions, and 3) the increased PYY(3-36) response represents an improved capacity to regulate satiety and potentially body weight in older, obese, insulin-resistant adults.......Aging and obesity are characterized by decreased beta-cell sensitivity and defects in the potentiation of nutrient-stimulated insulin secretion by GIP. Exercise and diet are known to improve glucose metabolism and the pancreatic insulin response to glucose, and this effect may be mediated through...... to glucose in older (66.8 +/- 1.5 yr), obese (34.4 +/- 1.7 kg/m(2)) adults with impaired glucose tolerance. In addition to GIP, plasma PYY(3-36), insulin, and glucose responses were measured during a 3-h, 75-g oral glucose tolerance test. Both interventions led to a significant improvement in Vo(2 max) (P

  16. Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes

    DEFF Research Database (Denmark)

    Che, Brita Ngum; Oksbjerg, Niels; Hellgren, Lars

    2013-01-01

    stimulated glucose uptake nor glycogen synthesis in insulin-resistant myotubes generated by excess glucose exposure. CONCLUSIONS: Primary porcine myotubes were established as a model of skeletal muscles for measuring glucose uptake and glycogen synthesis, and we showed that PA can play a role in stimulating...

  17. Ghrelin's second life: From appetite stimulator to glucose regulator

    Science.gov (United States)

    Verhulst, Pieter-Jan; Depoortere, Inge

    2012-01-01

    Ghrelin, a 28 amino acid peptide hormone produced by the stomach, was the first orexigenic hormone to be discovered from the periphery. The octanoyl modification at Ser3, mediated by ghrelin O-acyltransferase (GOAT), is essential for ghrelin’s biological activity. Ghrelin stimulates food intake through binding to its receptor (GRLN-R) on neurons in the arcuate nucleus of the hypothalamus. Ghrelin is widely expressed throughout the body; accordingly, it is implicated in several other physiological functions, which include growth hormone release, gastric emptying, and body weight regulation. Ghrelin and GRLN-R expression are also found in the pancreas, suggesting a local physiological role. Accordingly, several recent studies now point towards an important role for ghrelin and its receptor in the regulation of blood glucose homeostasis, which is the main focus of this review. Several mechanisms of this regulation by ghrelin have been proposed, and one possibility is through the regulation of insulin secretion. Despite some controversy, most studies suggest that ghrelin exerts an inhibitory effect on insulin secretion, resulting in increased circulating glucose levels. Ghrelin may thus be a diabetogenic factor. Obesity-related type 2 diabetes has become an increasingly important health problem, almost reaching epidemic proportions in the world; therefore, antagonists of the ghrelin-GOAT signaling pathway, which will tackle both energy- and glucose homeostasis, may be considered as promising new therapies for this disease. PMID:22783041

  18. Molecular Mechanisms of Glucose-Stimulated GLP-1 Secretion From Perfused Rat Small Intestine

    DEFF Research Database (Denmark)

    Kuhre, Rune E.; Frost, Charlotte R.; Svendsen, Berit

    2015-01-01

    not stimulate a response. Luminal glucose-stimulated GLP-1 secretion was also sensitive to luminal GLUT2 inhibition (phloretin), but in contrast to SGLT1 inhibition, phloretin did not eliminate the response, and luminal glucose (20%) stimulated larger GLP-1 responses than luminal α-MGP in matched concentrations...

  19. Rac1- a novel regulator of contraction-stimulated glucose uptake in skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian

    2014-01-01

    Muscle contraction stimulates muscle glucose uptake by facilitating translocation of the glucose transporter 4 from intracellular locations to the cell surface, which allows for diffusion of glucose into the myofibers. However, the intracellular mechanisms regulating this process are not well...... understood. The GTPase, Rac1 has, until recently, only been investigated with regards to its involvement in insulin-stimulated glucose uptake. However, we recently found that Rac1 is activated during muscle contraction and exercise in mice and humans. Remarkably, Rac1 seems to be necessary for exercise....../contraction-stimulated glucose uptake in skeletal muscle, since muscle-specific Rac1 knockout mice display reduced ex vivo contraction- and in vivo exercise-stimulated glucose uptake in skeletal muscle. The molecular mechanisms by which Rac1 regulate glucose uptake is presently unknown. However, recent studies link Rac1...

  20. DMPD: CSF-1 and cell cycle control in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 8981359 CSF-1 and cell cycle control in macrophages. Hamilton JA. Mol Reprod Dev. 1...D 8981359 Title CSF-1 and cell cycle control in macrophages. Authors Hamilton JA. Publication Mol Reprod Dev

  1. Derepression of an endogenous long terminal repeat activates the CSF1R proto-oncogene in human lymphoma.

    Science.gov (United States)

    Lamprecht, Björn; Walter, Korden; Kreher, Stephan; Kumar, Raman; Hummel, Michael; Lenze, Dido; Köchert, Karl; Bouhlel, Mohamed Amine; Richter, Julia; Soler, Eric; Stadhouders, Ralph; Jöhrens, Korinna; Wurster, Kathrin D; Callen, David F; Harte, Michael F; Giefing, Maciej; Barlow, Rachael; Stein, Harald; Anagnostopoulos, Ioannis; Janz, Martin; Cockerill, Peter N; Siebert, Reiner; Dörken, Bernd; Bonifer, Constanze; Mathas, Stephan

    2010-05-01

    Mammalian genomes contain many repetitive elements, including long terminal repeats (LTRs), which have long been suspected to have a role in tumorigenesis. Here we present evidence that aberrant LTR activation contributes to lineage-inappropriate gene expression in transformed human cells and that such gene expression is central for tumor cell survival. We show that B cell-derived Hodgkin's lymphoma cells depend on the activity of the non-B, myeloid-specific proto-oncogene colony-stimulating factor 1 receptor (CSF1R). In these cells, CSF1R transcription initiates at an aberrantly activated endogenous LTR of the MaLR family (THE1B). Derepression of the THE1 subfamily of MaLR LTRs is widespread in the genome of Hodgkin's lymphoma cells and is associated with impaired epigenetic control due to loss of expression of the corepressor CBFA2T3. Furthermore, we detect LTR-driven CSF1R transcripts in anaplastic large cell lymphoma, in which CSF1R is known to be expressed aberrantly. We conclude that LTR derepression is involved in the pathogenesis of human lymphomas, a finding that might have diagnostic, prognostic and therapeutic implications.

  2. Palmitate stimulates glucose transport in rat adipocytes by a mechanism involving translocation of the insulin sensitive glucose transporter (GLUT4)

    Science.gov (United States)

    Hardy, R. W.; Ladenson, J. H.; Henriksen, E. J.; Holloszy, J. O.; McDonald, J. M.

    1991-01-01

    In rat adipocytes, palmitate: a) increases basal 2-deoxyglucose transport 129 +/- 27% (p less than 0.02), b) decreases the insulin sensitive glucose transporter (GLUT4) in low density microsomes and increases GLUT4 in plasma membranes and c) increases the activity of the insulin receptor tyrosine kinase. Palmitate-stimulated glucose transport is not additive with the effect of insulin and is not inhibited by the protein kinase C inhibitors staurosporine and sphingosine. In rat muscle, palmitate: a) does not affect basal glucose transport in either the soleus or epitrochlearis and b) inhibits insulin-stimulated glucose transport by 28% (p less than 0.005) in soleus but not in epitrochlearis muscle. These studies demonstrate a potentially important differential role for fatty acids in the regulation of glucose transport in different insulin target tissues.

  3. Intra-articular administration of an antibody against CSF-1 receptor reduces pain-related behaviors and inflammation in CFA-induced knee arthritis.

    Science.gov (United States)

    Alvarado-Vazquez, P A; Morado-Urbina, C E; Castañeda-Corral, G; Acosta-Gonzalez, R I; Kitaura, H; Kimura, K; Takano-Yamamoto, T; Jiménez-Andrade, J M

    2015-01-01

    Several studies have shown that blockade of colony stimulating factor-1 (CSF-1) or its receptor (CSF-1R) inhibits disease progression in rodent models of rheumatoid arthritis (RA); however, the role of the CSF-1/CSF-1R pathway in RA-induced pain and functional deficits has not been studied. Thus, we examined the effect of chronic intra-articular administration of a monoclonal anti-CSF-1R antibody (AFS98) on spontaneous pain, knee edema and functional disabilities in mice with arthritis. Unilateral arthritis was produced by multiple injections of complete Freund's adjuvant (CFA) into the right knee joint of adult male ICR mice. CFA-injected mice were then treated twice weekly from day 10 until day 25 with anti-CSF-1R antibody (3 and 10 μg/5 μL per joint), isotype control (rat IgG 10 μg/5 μL per joint) or PBS (5 μl/joint). Knee edema, spontaneous flinching, vertical rearing and horizontal exploratory activity were assessed at different days. Additionally, counts of peripheral leukocytes and body weight were measured to evaluate general health status. Intra-articular treatment with anti-CSF-1R antibody significantly increased horizontal exploratory activity and vertical rearing as well as reduced spontaneous flinching behavior and knee edema as compared to CFA-induced arthritis mice treated with PBS. Treatment with this antibody neither significantly affect mouse body weight nor the number of peripheral leukocytes. These results suggest that blockade of CSF-1R at the initial injury site (joint) could represent a therapeutic alternative for improving the functional disabilities and attenuating pain and inflammation in patients with RA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Lysosomal drug sequestration as a mechanism of drug resistance in vascular sarcoma cells marked by high CSF-1R expression.

    Science.gov (United States)

    Gorden, Brandi H; Saha, Jhuma; Khammanivong, Ali; Schwartz, Gary K; Dickerson, Erin B

    2014-01-01

    Human angiosarcoma and canine hemangiosarcoma are thought to arise from vascular tissue or vascular forming cells based upon their histological appearance. However, recent evidence indicates a hematopoietic or angioblastic cell of origin for these tumors. In support of this idea, we previously identified an endothelial-myeloid progenitor cell population with high expression of endothelial cell markers and the myeloid cell marker, colony stimulating factor 1 receptor (CSF-1R). Here, we further characterized these cells to better understand how their cellular characteristics may impact current therapeutic applications. We performed cell enrichment studies from canine hemangiosarcoma and human angiosarcoma cell lines to generate cell populations with high or low CSF-1R expression. We then utilized flow cytometry, side population and cell viability assays, and fluorescence based approaches to elucidate drug resistance mechanisms and to determine the expression of hematopoietic and endothelial progenitor cell markers. We demonstrated that cells with high CSF-1R expression enriched from hemangiosarcoma and angiosarcoma cell lines are more drug resistant than cells with little or no CSF-1R expression. We determined that the increased drug resistance may be due to increased ABC transporter expression in hemangiosarcoma and increased drug sequestration within cellular lysosomes in both hemangiosarcoma and angiosarcoma. We identified drug sequestration within cellular lysosomes as a shared drug resistance mechanism in human and canine vascular sarcomas marked by high CSF-1R expression. Taken together, our results demonstrate that studies in highly prevalent canine hemangiosarcoma may be especially relevant to understanding and addressing drug resistance mechanisms in both the canine and human forms of this disease.

  5. Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1

    Science.gov (United States)

    Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian; Richter, Erik A; Jensen, Thomas E

    2015-01-01

    An alternative to the canonical insulin signalling pathway for glucose transport is muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle, and passive stretch stimulates muscle glucose transport. However, the signalling mechanism regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1, was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport, however, its role in stretch-stimulated glucose transport and signalling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle-specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton in isolated soleus and extensor digitorum longus muscles. In addition, the role of Rac1 in contraction-stimulated glucose transport during conditions without mechanical load on the muscles was evaluated in loosely hanging muscles and muscles in which cross-bridge formation was blocked by the myosin ATPase inhibitors BTS and Blebbistatin. Knockout as well as pharmacological inhibition of Rac1 reduced stretch-stimulated glucose transport by 30–50% in soleus and extensor digitorum longus muscle. The actin depolymerizing agent latrunculin B similarly decreased glucose transport in response to stretching by 40–50%. Rac1 inhibition reduced contraction-stimulated glucose transport by 30–40% in tension developing muscle but did not affect contraction-stimulated glucose transport in muscles in which force development was prevented. Our findings suggest that Rac1 and the actin cytoskeleton regulate stretch-stimulated glucose transport and that Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle. Key

  6. Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1

    DEFF Research Database (Denmark)

    Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian

    2015-01-01

    Alternatives to the canonical insulin signaling pathway for glucose transport are muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle and passive stretch has been shown to increase muscle glucose transport. However, the signaling mechanism...... regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1 was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport but its role in stretch......-stimulated glucose transport and signaling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton...

  7. Fluctuations of extracellular glucose and lactate in the mouse primary visual cortex during visual stimulation.

    Science.gov (United States)

    Béland-Millar, Alexandria; Messier, Claude

    2018-02-16

    We measured the extracellular glucose and lactate in the primary visual cortex in the CD-1 mouse using electrochemical electrodes. To gain some additional information on brain metabolism, we examined the impact of systemic injections of lactate and fructose on the brain extracellular glucose and lactate changes observed during visual stimulation. We found that simple stimulation using a flashlight produced a decrease in visual cortex extracellular glucose and an increase in extracellular lactate. Similar results were observed following visual stimulation with an animated movie without soundtrack or the presentation of a novel object. Specificity of these observations was confirmed by the absence of extracellular glucose and lactate changes when the mice were presented a second time with the same object. Previous experiments have shown that systemic injections of fructose and lactate lead to an increase in blood lactate but no change in blood glucose while they both increase brain extracellular glucose but they do not increase brain extracellular lactate. When mice were visually stimulated after they had received these injections, we found that lactate, and to a slightly lesser degree fructose, both reduced the amplitude of the changes in extracellular glucose and lactate that accompanied visual stimulation. Thus, neural activation leads to an increase in extracellular lactate and a decrease in extracellular glucose. Novelty, attentional resources and availability of metabolic fuels modulate these fluctuations. The observations are consistent with a modified view of brain metabolism that takes into account the blood and brain glucose availability. Copyright © 2018. Published by Elsevier B.V.

  8. Wortmannin inhibits both insulin- and contraction-stimulated glucose uptake and transport in rat skeletal muscle

    DEFF Research Database (Denmark)

    Wojtaszewski, Jørgen; Hansen, B F; Ursø, Birgitte

    1996-01-01

    stimulation but was unaffected by contractions. In addition, the insulin-stimulated PI 3-kinase activity and muscle glucose uptake and transport in individual muscles were dose-dependently inhibited by wortmannin with one-half maximal inhibition values of approximately 10 nM and total inhibition at 1 micro......The role of phosphatidylinositol (PI) 3-kinase for insulin- and contraction-stimulated muscle glucose transport was investigated in rat skeletal muscle perfused with a cell-free perfusate. The insulin receptor substrate-1-associated PI 3-kinase activity was increased sixfold upon insulin......-stimulated glucose uptake but also decreased the contractility. In conclusion, inhibition of PI 3-kinase with wortmannin in skeletal muscle coincides with inhibition of insulin-stimulated glucose uptake and transport. Furthermore, in contrast to recent findings in incubated muscle, wortmannin also inhibited...

  9. Acute hypoglycemia in healthy humans impairs insulin stimulated glucose uptake and glycogen synthase in skeletal muscle

    DEFF Research Database (Denmark)

    Voss, Thomas S; Vendelbo, Mikkel H; Kampmann, Ulla

    2017-01-01

    and glucose clearance in skeletal muscle were impaired whereas insulin signaling to glucose transport was unaffected by hypoglycemia. Insulin-stimulated glycogen synthase activity was completely ablated during hyperinsulinemic hypoglycemia and catecholamine signaling via PKA as well as phosphorylation......Hypoglycemia is the leading limiting factor in glycemic management of insulin-treated diabetes. Skeletal muscle is the predominant site of insulin-mediated glucose disposal and our study was designed to test to what extent insulin induced hypoglycemia affects glucose uptake in skeletal muscle...... euglycemia (bolus insulin and glucose infusion) and iii) saline control with skeletal muscle biopsies taken just before, 30 min and 75 min after insulin/saline injection.During hypoglycemia glucose levels reached a nadir of ∼2.0mmol/l and epinephrine rose to ∼900pg/ml.Insulin stimulated glucose disposal...

  10. Promotion of Tumor Invasion by Tumor-Associated Macrophages: The Role of CSF-1-Activated Phosphatidylinositol 3 Kinase and Src Family Kinase Motility Signaling

    Directory of Open Access Journals (Sweden)

    Amy R. Dwyer

    2017-06-01

    Full Text Available Macrophages interact with cells in every organ to facilitate tissue development, function and repair. However, the close interaction between macrophages and parenchymal cells can be subverted in disease, particularly cancer. Motility is an essential capacity for macrophages to be able to carry out their various roles. In cancers, the macrophage’s interstitial migratory ability is frequently co-opted by tumor cells to enable escape from the primary tumor and metastatic spread. Macrophage accumulation within and movement through a tumor is often stimulated by tumor cell production of the mononuclear phagocytic growth factor, colony-stimulating factor-1 (CSF-1. CSF-1 also regulates macrophage survival, proliferation and differentiation, and its many effects are transduced by its receptor, the CSF-1R, via phosphotyrosine motif-activated signals. Mutational analysis of CSF-1R signaling indicates that the major mediators of CSF-1-induced motility are phosphatidyl-inositol-3 kinase (PI3K and one or more Src family kinase (SFK, which activate signals to adhesion, actin polymerization, polarization and, ultimately, migration and invasion in macrophages. The macrophage transcriptome, including that of the motility machinery, is very complex and highly responsive to the environment, with selective expression of proteins and splice variants rarely found in other cell types. Thus, their unique motility machinery can be specifically targeted to block macrophage migration, and thereby, inhibit tumor invasion and metastasis.

  11. Promotion of Tumor Invasion by Tumor-Associated Macrophages: The Role of CSF-1-Activated Phosphatidylinositol 3 Kinase and Src Family Kinase Motility Signaling

    Science.gov (United States)

    Dwyer, Amy R.; Greenland, Eloise L.; Pixley, Fiona J.

    2017-01-01

    Macrophages interact with cells in every organ to facilitate tissue development, function and repair. However, the close interaction between macrophages and parenchymal cells can be subverted in disease, particularly cancer. Motility is an essential capacity for macrophages to be able to carry out their various roles. In cancers, the macrophage’s interstitial migratory ability is frequently co-opted by tumor cells to enable escape from the primary tumor and metastatic spread. Macrophage accumulation within and movement through a tumor is often stimulated by tumor cell production of the mononuclear phagocytic growth factor, colony-stimulating factor-1 (CSF-1). CSF-1 also regulates macrophage survival, proliferation and differentiation, and its many effects are transduced by its receptor, the CSF-1R, via phosphotyrosine motif-activated signals. Mutational analysis of CSF-1R signaling indicates that the major mediators of CSF-1-induced motility are phosphatidyl-inositol-3 kinase (PI3K) and one or more Src family kinase (SFK), which activate signals to adhesion, actin polymerization, polarization and, ultimately, migration and invasion in macrophages. The macrophage transcriptome, including that of the motility machinery, is very complex and highly responsive to the environment, with selective expression of proteins and splice variants rarely found in other cell types. Thus, their unique motility machinery can be specifically targeted to block macrophage migration, and thereby, inhibit tumor invasion and metastasis. PMID:28629162

  12. Is contraction-stimulated glucose transport feedforward regulated by Ca2+?

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Angin, Yeliz; Sylow, Lykke

    2014-01-01

    feedforward regulator of the translocation of glucose transporter 4 to the cell surface to facilitate transmembrane glucose transport. This review summarizes the evidence supporting the Ca(2+) feedforward model and its proposed signalling links to regulation of glucose transport in skeletal muscle and other...... cell types. The literature is contrasted against our recent findings suggesting that SR Ca(2+) release is neither essential nor adequate to stimulate glucose transport in muscle. Instead, feedback signals through AMPK and mechanical stress are likely to account for most of contraction......-stimulated glucose transport. A revised working model is proposed, in which muscle glucose transport during contraction is not directly regulated by SR Ca(2+) release but rather responds exclusively to feedback signals activated secondary to cross-bridge cycling and tension development....

  13. Transcription factor complex formation and chromatin fine structure alterations at the murine c-fms (CSF-1 receptor) locus during maturation of myeloid precursor cells

    NARCIS (Netherlands)

    Tagoh, H; Himes, R; Clarke, D; Leenen, PJM; Riggs, AD; Hume, D; Bonifer, C

    2002-01-01

    Expression of the gene for the macrophage colony stimulating factor receptor (CSF-1R), c-fms, has been viewed as a hallmark of the commitment of multipotent precursor cells to macrophages. Lineage-restricted expression of the gene is controlled by conserved elements in the proximal promoter and

  14. The function of the conserved regulatory element within the second intron of the mammalian Csf1r locus.

    Directory of Open Access Journals (Sweden)

    Kristin A Sauter

    Full Text Available The gene encoding the receptor for macrophage colony-stimulating factor (CSF-1R is expressed exclusively in cells of the myeloid lineages as well as trophoblasts. A conserved element in the second intron, Fms-Intronic Regulatory Element (FIRE, is essential for macrophage-specific transcription of the gene. However, the molecular details of how FIRE activity is regulated and how it impacts the Csf1r promoter have not been characterised. Here we show that agents that down-modulate Csf1r mRNA transcription regulated promoter activity altered the occupancy of key FIRE cis-acting elements including RUNX1, AP1, and Sp1 binding sites. We demonstrate that FIRE acts as an anti-sense promoter in macrophages and reversal of FIRE orientation within its native context greatly reduced enhancer activity in macrophages. Mutation of transcription initiation sites within FIRE also reduced transcription. These results demonstrate that FIRE is an orientation-specific transcribed enhancer element.

  15. Pigment Pattern Formation in the Guppy, Poecilia reticulata, Involves the Kita and Csf1ra Receptor Tyrosine Kinases

    Science.gov (United States)

    Kottler, Verena A.; Fadeev, Andrey; Weigel, Detlef; Dreyer, Christine

    2013-01-01

    Males of the guppy (Poecilia reticulata) vary tremendously in their ornamental patterns, which are thought to have evolved in response to a complex interplay between natural and sexual selection. Although the selection pressures acting on the color patterns of the guppy have been extensively studied, little is known about the genes that control their ontogeny. Over 50 years ago, two autosomal color loci, blue and golden, were described, both of which play a decisive role in the formation of the guppy color pattern. Orange pigmentation is absent in the skin of guppies with a lesion in blue, suggesting a defect in xanthophore development. In golden mutants, the development of the melanophore pattern during embryogenesis and after birth is affected. Here, we show that blue and golden correspond to guppy orthologs of colony-stimulating factor 1 receptor a (csf1ra; previously called fms) and kita. Most excitingly, we found that both genes are required for the development of the black ornaments of guppy males, which in the case of csf1ra might be mediated by xanthophore–melanophore interactions. Furthermore, we provide evidence that two temporally and genetically distinct melanophore populations contribute to the adult camouflage pattern expressed in both sexes: one early appearing and kita-dependent and the other late-developing and kita-independent. The identification of csf1ra and kita mutants provides the first molecular insights into pigment pattern formation in this important model species for ecological and evolutionary genetics. PMID:23666934

  16. Insight on Mutation-Induced Resistance from Molecular Dynamics Simulations of the Native and Mutated CSF-1R and KIT.

    Science.gov (United States)

    Da Silva Figueiredo Celestino Gomes, Priscila; Chauvot De Beauchêne, Isaure; Panel, Nicolas; Lopez, Sophie; De Sepulveda, Paulo; Geraldo Pascutti, Pedro; Solary, Eric; Tchertanov, Luba

    2016-01-01

    The receptors tyrosine kinases (RTKs) for the colony stimulating factor-1, CSF-1R, and for the stem cell factor, SCFR or KIT, are important mediators of signal transduction. The abnormal function of these receptors, promoted by gain-of-function mutations, leads to their constitutive activation, associated with cancer or other proliferative diseases. A secondary effect of the mutations is the alteration of receptors' sensitivity to tyrosine kinase inhibitors, compromising effectiveness of these molecules in clinical treatment. In particular, the mutation V560G in KIT increases its sensitivity to Imatinib, while the D816V in KIT, and D802V in CSF-1R, triggers resistance to the drug. We analyzed the Imatinib binding affinity to the native and mutated KIT (mutations V560G, S628N and D816V) and CSF-1R (mutation D802V) by using molecular dynamics simulations and energy calculations of Imatinib•target complexes. Further, we evaluated the sensitivity of the studied KIT receptors to Imatinib by measuring the inhibition of KIT phosphorylation. Our study showed that (i) the binding free energy of Imatinib to the targets is highly correlated with their experimentally measured sensitivity; (ii) the electrostatic interactions are a decisive factor affecting the binding energy; (iii) the most deleterious impact to the Imatinib sensitivity is promoted by D802V (CSF-1R) and D816V (KIT) mutations; (iv) the role of the juxtamembrane region, JMR, in the imatinib binding is accessory. These findings contribute to a better description of the mutation-induced effects alternating the targets sensitivity to Imatinib.

  17. Adrenergic receptor stimulation attenuates insulin-stimulated glucose uptake in 3T3-L1 adipocytes by inhibiting GLUT4 translocation

    NARCIS (Netherlands)

    Mulder, A.; Tack, C.J.J.; Olthaar, A.J.; Smits, P.; Sweep, C.G.J.; Bosch, R.R.

    2005-01-01

    Activation of the sympathetic nervous system inhibits insulin-stimulated glucose uptake. However, the underlying mechanisms are incompletely understood. Therefore, we studied the effects of catecholamines on insulin-stimulated glucose uptake and insulin-stimulated translocation of GLUT4 to the

  18. CSF-1R inhibition attenuates renal and neuropsychiatric disease in murine lupus.

    Science.gov (United States)

    Chalmers, Samantha A; Wen, Jing; Shum, Justine; Doerner, Jessica; Herlitz, Leal; Putterman, Chaim

    2016-08-26

    Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease that can affect multiple end organs. Kidney and brain are two of the organs most commonly involved in SLE. Past studies have suggested the importance of macrophages in the pathogenesis of lupus nephritis (LN). Furthermore, as the immune effectors of the brain, microglia have been implicated in pathways leading to neuropsychiatric SLE (NPSLE). We depleted macrophages and microglia using GW2580, a small colony stimulating factor-1 receptor (CSF-1R) kinase inhibitor, in MRL-lpr/lpr (MRL/lpr) mice, a classic murine lupus model that displays features of both LN and NPSLE. Treatment was initiated before the onset of disease, and mice were followed for the development of LN and neurobehavioral dysfunction throughout the study. Treatment with GW2580 significantly ameliorated kidney disease, as evidenced by decreased proteinuria, BUN, and improved renal histopathology, despite equivalent levels of IgG and C3 deposition in the kidneys of treated and control mice. We were able to confirm macrophage depletion within the kidney via IBA-1 staining. Furthermore, we observed specific improvement in the depression-like behavioral deficit of MRL/lpr mice with GW2580 treatment. Circulating antibody and autoantibody levels were, however, not affected. These results provide additional support for the role of macrophages as a potentially valuable therapeutic target in SLE. Inhibiting CSF-1 receptor signaling would be more targeted than current immunosuppressive therapies, and may hold promise for the treatment of renal and neuropsychiatric end organ disease manifestations. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Effects of AMPK on high glucose stimulated apoptosis of endothelial cells via regulation of calcium influx

    Directory of Open Access Journals (Sweden)

    Ting LU

    2015-11-01

    Full Text Available Objective To investigate the inhibitory effect of adenosine monophosphate (AMP-dependent protein kinase (AMPK on high glucose-stimulated endothelial cell apoptosis and its mechanism. Methods MS-1 endothelial cells were cultured in vitro, and they were treated with AMPK agonist, AMPK inhibitor, 2-APB (a blocker of store operated Ca2+ channel (SOCC and (or high glucose, and a control group without any intervention were set up. TUNEL assay was performed to determine apoptotic cells. Laser scanning confocal microscopy was used to assess the Ca2+ influx into cells, and Western-blotting was performed to determine the expressions of Stim1 and Orai1 of the store operated Ca2+ channel (SOCC proteins. Results Apoptosis of endothelial cells was induced significantly, and the expressions of Stim1 and Orai1 were upregulated in high glucose group compared with that in control group (P<0.05. The rate of apoptosis of high glucose-induced endothelial cell was found to be increased in AMPK inhibitor group and decreased in AMPK agonist group, and the expressions of Stim1 and Orai1 were found to be down-regulated in AMPK agonist group as compared with that in high glucose group (P<0.05. Compared with the control group, high glucose stimulation significantly induced the Ca2+ influx to endothelial cells; compared with high glucose group, 2-APB significantly inhibited high glucose-induced Ca2+ influx to endothelial cells, and blocked the inducing effect of high-glucose on endothelial cell apoptosis. Compared with high glucose group, AMPK agonist significantly inhibited high glucose-induced cell Ca2+ influx. Conclusion By reducing the expressions of Stim1 and Orai1, AMPK may inhibit SOCC-mediated Ca2+ influx, and block the high glucose-stimulated endothelial cell apoptosis, thus play an important protective role in sustaining endothelial cell function. DOI: 10.11855/j.issn.0577-7402.2015.10.01

  20. Glucose-stimulated acrolein production from unsaturated fatty acids.

    Science.gov (United States)

    Medina-Navarro, R; Duran-Reyes, G; Diaz-Flores, M; Hicks, J J; Kumate, J

    2004-02-01

    Glucose auto-oxidation may be a significant source of reactive oxygen species (ROS), and also be important in the lipid peroxidation process, accompanied by the release of toxic reactive products. We wanted to demonstrate that acrolein can be formed directly and actively from free fatty acids in a hyperglycemic environment. A suspension of linoleic and arachidonic acids (2.5 mM) was exposed to different glucose concentrations (5, 10 and 15 mmol/L) in vitro. The samples were extracted with organic solvents, partitioned, followed at 255-267 nm, and analysed using capillary electrophoresis and mass spectroscopy. The total release of aldehydes significantly (P < 0.01) increased from 1.0 to 5.1, 8.3 and 13.1 micromol/L after 6 hours of incubation, proportional to glucose concentrations. It was possible to verify a correlate hydroperoxide formation as well. Among the lipid peroxidation products, acrolein (5% of total) and its condensing product, 4-hydroxy-hexenal, were identified. From the results presented here, it was possible to demonstrate the production of acrolein, probably as a fatty acid product, due to free radicals generated from the glucose auto-oxidation process. The results led us to propose that acrolein, which is one of the most toxic aldehydes, is produced during hyperglycemic states, and may lead to tissue injury, as one of the initial problems to be linked to high levels of glucose in vivo.

  1. Insulin-stimulated glucose uptake in healthy and insulin-resistant skeletal muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul S

    2016-01-01

    Skeletal muscle is the largest tissues in the human body and is considered the primary target for insulin-stimulated glucose disposal. In skeletal muscle, binding of the insulin to insulin receptor (IR) initiates a signaling cascade that results in the translocation of the insulin-sensitive glucose...... transporter protein 4 (GLUT4) to the plasma membrane which leads to facilitated diffusion of glucose into the cell. Understanding the precise signaling events guiding insulin-stimulated glucose uptake is pivotal, because impairment in these signaling events leads to development of insulin resistance and type...... 2 diabetes. This review summarizes current understanding of insulin signaling pathways mediating glucose uptake in healthy and insulin-resistant skeletal muscle....

  2. Sweet Taste Receptor Activation in the Gut Is of Limited Importance for Glucose-Stimulated GLP-1 and GIP Secretion

    DEFF Research Database (Denmark)

    Saltiel, Monika Yosifova; Kuhre, Rune Ehrenreich; Christiansen, Charlotte Bayer

    2017-01-01

    Glucose stimulates the secretion of the incretin hormones: glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). It is debated whether the sweet taste receptor (STR) triggers this secretion. We investigated the role of STR activation for glucose-stimulated incretin...

  3. CNC-bZIP protein Nrf1-dependent regulation of glucose-stimulated insulin secretion.

    Science.gov (United States)

    Zheng, Hongzhi; Fu, Jingqi; Xue, Peng; Zhao, Rui; Dong, Jian; Liu, Dianxin; Yamamoto, Masayuki; Tong, Qingchun; Teng, Weiping; Qu, Weidong; Zhang, Qiang; Andersen, Melvin E; Pi, Jingbo

    2015-04-01

    The inability of pancreatic β-cells to secrete sufficient insulin in response to glucose stimulation is a major contributing factor to the development of type 2 diabetes (T2D). We investigated both the in vitro and in vivo effects of deficiency of nuclear factor-erythroid 2-related factor 1 (Nrf1) in β-cells on β-cell function and glucose homeostasis. Silencing of Nrf1 in β-cells leads to a pre-T2D phenotype with disrupted glucose metabolism and impaired insulin secretion. Specifically, MIN6 β-cells with stable knockdown of Nrf1 (Nrf1-KD) and isolated islets from β-cell-specific Nrf1-knockout [Nrf1(b)-KO] mice displayed impaired glucose responsiveness, including elevated basal insulin release and decreased glucose-stimulated insulin secretion (GSIS). Nrf1(b)-KO mice exhibited severe fasting hyperinsulinemia, reduced GSIS, and glucose intolerance. Silencing of Nrf1 in MIN6 cells resulted in oxidative stress and altered glucose metabolism, with increases in both glucose uptake and aerobic glycolysis, which is associated with the elevated basal insulin release and reduced glucose responsiveness. The elevated glycolysis and reduced glucose responsiveness due to Nrf1 silencing likely result from altered expression of glucose metabolic enzymes, with induction of high-affinity hexokinase 1 and suppression of low-affinity glucokinase. Our study demonstrated a novel role of Nrf1 in regulating glucose metabolism and insulin secretion in β-cells and characterized Nrf1 as a key transcription factor that regulates the coupling of glycolysis and mitochondrial metabolism and GSIS. Nrf1 plays critical roles in regulating glucose metabolism, mitochondrial function, and insulin secretion, suggesting that Nrf1 may be a novel target to improve the function of insulin-secreting β-cells.

  4. Impaired insulin-stimulated nonoxidative glucose metabolism in glucose-tolerant women with previous gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Vestergaard, H; Kühl, C

    1996-01-01

    OBJECTIVE: Our purpose was to investigate insulin sensitivity and insulin secretion in women with previous gestational diabetes. STUDY DESIGN: Twelve women with previous gestational diabetes and 11 controls were examined by oral and intravenous glucose tolerance tests and a hyperinsulinemic....... RESULTS: Women with previous gestational diabetes had a decreased glucose disposal rate (p..., and hexokinase were similar in the two groups. The first-phase insulin response to the intravenous glucose tolerance test was, in absolute terms, comparable in the two groups. However, when the decreased insulin sensitivity was taken into account, women with previous gestational diabetes had a relative insulin...

  5. Effect of glycogen synthase overexpression on insulin-stimulated muscle glucose uptake and storage.

    Science.gov (United States)

    Fogt, Donovan L; Pan, Shujia; Lee, Sukho; Ding, Zhenping; Scrimgeour, Angus; Lawrence, John C; Ivy, John L

    2004-03-01

    Insulin-stimulated muscle glucose uptake is inversely associated with the muscle glycogen concentration. To investigate whether this association is a cause and effect relationship, we compared insulin-stimulated muscle glucose uptake in noncontracted and postcontracted muscle of GSL3-transgenic and wild-type mice. GSL3-transgenic mice overexpress a constitutively active form of glycogen synthase, which results in an abundant storage of muscle glycogen. Muscle contraction was elicited by in situ electrical stimulation of the sciatic nerve. Right gastrocnemii from GSL3-transgenic and wild-type mice were subjected to 30 min of electrical stimulation followed by hindlimb perfusion of both hindlimbs. Thirty minutes of contraction significantly reduced muscle glycogen concentration in wild-type (49%) and transgenic (27%) mice, although transgenic mice retained 168.8 +/- 20.5 micromol/g glycogen compared with 17.7 +/- 2.6 micromol/g glycogen for wild-type mice. Muscle of transgenic and wild-type mice demonstrated similar pre- (3.6 +/- 0.3 and 3.9 +/- 0.6 micromol.g(-1).h(-1) for transgenic and wild-type, respectively) and postcontraction (7.9 +/- 0.4 and 7.0 +/- 0.4 micromol.g(-1).h(-1) for transgenic and wild-type, respectively) insulin-stimulated glucose uptakes. However, the [14C]glucose incorporated into glycogen was greater in noncontracted (151%) and postcontracted (157%) transgenic muscle vs. muscle of corresponding wild-type mice. These results indicate that glycogen synthase activity is not rate limiting for insulin-stimulated glucose uptake in skeletal muscle and that the inverse relationship between muscle glycogen and insulin-stimulated glucose uptake is an association, not a cause and effect relationship.

  6. Exercise-stimulated glucose uptake - regulation and implications for glycaemic control

    DEFF Research Database (Denmark)

    Sylow, Lykke; Kleinert, Maximilian; Richter, Erik

    2017-01-01

    Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant...... energy supply during physical activity. Here, we review the molecular mechanisms that regulate the movement of glucose from the capillary bed into the muscle cell and discuss what is known about their integrated regulation during exercise. Novel developments within the field of mass spectrometry...... muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux...

  7. Nutrient responsive nesfatin-1 regulates energy balance and induces glucose-stimulated insulin secretion in rats.

    Science.gov (United States)

    Gonzalez, R; Perry, R L S; Gao, X; Gaidhu, M P; Tsushima, R G; Ceddia, R B; Unniappan, S

    2011-10-01

    Nesfatin-1 is a recently discovered anorexigen, and we first reported nesfatin-like immunoreactivity in the pancreatic β-cells. The aim of this study was to characterize the effects of nesfatin-1 on whole-body energy homeostasis, insulin secretion, and glycemia. The in vivo effects of continuous peripheral delivery of nesfatin-1 using osmotic minipumps on food intake and substrate partitioning were examined in ad libitum-fed male Fischer 344 rats. The effects of nesfatin-1 on glucose-stimulated insulin secretion (GSIS) were examined in isolated pancreatic islets. L6 skeletal muscle cells and isolated rat adipocytes were used to assess the effects of nesfatin-1 on basal and insulin-mediated glucose uptake as well as on major steps of insulin signaling in these cells. Nesfatin-1 reduced cumulative food intake and increased spontaneous physical activity, whole-body fat oxidation, and carnitine palmitoyltransferase I mRNA expression in brown adipose tissue but did not affect uncoupling protein 1 mRNA in the brown adipose tissue. Nesfatin-1 significantly enhanced GSIS in vivo during an oral glucose tolerance test and improved insulin sensitivity. Although insulin-stimulated glucose uptake in L6 muscle cells was inhibited by nesfatin-1 pretreatment, basal and insulin-induced glucose uptake in adipocytes from nesfatin-1-treated rats was significantly increased. In agreement with our in vivo results, nesfatin-1 enhanced GSIS from isolated pancreatic islets at both normal (5.6 mM) and high (16.7 mM), but not at low (2 mM), glucose concentrations. Furthermore, nesfatin-1/nucleobindin 2 release from rat pancreatic islets was stimulated by glucose. Collectively, our data indicate that glucose-responsive nesfatin-1 regulates insulin secretion, glucose homeostasis, and whole-body energy balance in rats.

  8. Variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects

    DEFF Research Database (Denmark)

    Kofoed, Klaus F; Hove, Jens D; Freiberg, Jacob

    2002-01-01

    The aim of this study was to assess regional and global variability of insulin-stimulated myocardial glucose uptake in healthy elderly subjects and to evaluate potentially responsible factors. Twenty men with a mean age of 64 years, no history of cardiovascular disease, and normal blood pressure......, bicycle exercise test, electrocardiogram and echocardiography were studied [ P(coronary artery disease) ... rest and hyperaemic blood flow during dipyridamole infusion were measured with nitrogen-13 ammonia and positron emission tomography in 16 left ventricular myocardial segments. Intra-individual and inter-individual variability of insulin-stimulated myocardial glucose uptake [relative dispersion...

  9. Rac1 is a novel regulator of contraction-stimulated glucose uptake in skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke; Jensen, Thomas Elbenhardt; Kleinert, Maximilian

    2013-01-01

    In skeletal muscle, the actin cytoskeleton-regulating GTPase, Rac1, is necessary for insulin-dependent GLUT4 translocation. Muscle contraction increases glucose transport and represents an alternative signaling pathway to insulin. Whether Rac1 is activated by muscle contraction and regulates...... contraction-induced glucose uptake is unknown. Therefore, we studied the effects of in vivo exercise and ex vivo muscle contractions on Rac1 signaling and its regulatory role in glucose uptake in mice and humans. Muscle Rac1-GTP binding was increased after exercise in mice (~60-100%) and humans (~40......%), and this activation was AMP-activated protein kinase independent. Rac1 inhibition reduced contraction-stimulated glucose uptake in mouse muscle by 55% in soleus and by 20-58% in extensor digitorum longus (EDL; P glucose uptake was decreased by 27% (P = 0...

  10. Exercise-stimulated glucose uptake - regulation and implications for glycaemic control.

    Science.gov (United States)

    Sylow, Lykke; Kleinert, Maximilian; Richter, Erik A; Jensen, Thomas E

    2017-03-01

    Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux through metabolic processes (glycolysis and glucose oxidation). The available data suggest that no single signal transduction pathway can fully account for the regulation of any of these key steps, owing to redundancy in the signalling pathways that mediate glucose uptake to ensure maintenance of muscle energy supply during physical activity. Here, we review the molecular mechanisms that regulate the movement of glucose from the capillary bed into the muscle cell and discuss what is known about their integrated regulation during exercise. Novel developments within the field of mass spectrometry-based proteomics indicate that the known regulators of glucose uptake are only the tip of the iceberg. Consequently, many exciting discoveries clearly lie ahead.

  11. Disassembly of the actin network inhibits insulin-dependent stimulation of glucose transport and prevents recruitment of glucose transporters to the plasma membrane.

    Science.gov (United States)

    Tsakiridis, T; Vranic, M; Klip, A

    1994-11-25

    In muscle and fat tissues, insulin stimulates glucose transport through the translocation of glucose transporter proteins from an intracellular storage pool to the plasma membrane. The mechanism of this translocation is unknown. We have examined the possible role of the actin microfilament network in the stimulation of glucose transport by insulin and on the distribution of glucose transporters, in differentiated L6 rat skeletal muscle cells. Insulin (10(-7) M for 30 min) caused a major reorganization of the actin network of differentiated L6 myotubes. Cytochalasin D, a widely used inhibitor of actin filament formation, caused a dose- and time-dependent disassembly of the actin network, which was associated with an 80% inhibition of the insulin stimulation of glucose transport, without affecting the basal rate of glucose uptake. L6 myotubes express three glucose transporter isoforms, named GLUT1, GLUT3, and GLUT4. Disassembly of the actin network by cytochalasin D did not affect the number of basal glucose transporters in the plasma membrane but reduced the content of all three glucose transporters in intracellular membranes and prevented their appearance at the plasma membrane response to insulin. The inhibitory effect of cytochalasin D treatment on the insulin stimulation of glucose transport occurred downstream of tyrosine phosphorylation of the insulin receptor substrate-1 and of binding of phosphatidylinositol 3-kinase to the insulin receptor substrate-1. Using immunoprecipitation of intact membranes, we detected specific association of the actin-binding protein spectrin with GLUT4 glucose transporter-containing vesicles. We conclude that an intact actin network is required for the correct intracellular localization of glucose transporters, as well as for their incorporation into the plasma membrane in response to insulin. A direct interaction may exist between the actin network and the glucose transporter vesicles which may be mediated through a spectrin

  12. Malonyl coenzyme A affects insulin-stimulated glucose transport in myotubes.

    Science.gov (United States)

    Patil, P B; Minteer, S D; Mielke, A A; Lewis, L R; Casmaer, C A; Barrientos, E J; Ju, J-S; Smith, J L; Fisher, J S

    2007-02-01

    There seems to be an association between increased concentrations of malonyl coenzyme A (malonyl CoA) in skeletal muscle and diabetes and/or insulin resistance. The purpose of the current study was to test the hypothesis that treatments designed to manipulate malonyl CoA concentrations would affect insulin-stimulated glucose transport in cultured C2C12 myotubes. We assessed glucose transport after polyamine-mediated delivery of malonyl CoA to myotubes, after incubation with dichloroacetate (which reportedly increases malonyl CoA levels), or after exposure of myotubes to 2-bromopalmitate, a carnitine palmitoyl transferase I inhibitor. All three of these treatments prevented stimulation of glucose transport by insulin. We also assayed glucose transport after 30 min of inhibition of acetyl coenzyme A carboxylase (ACC), the enzyme which catalyzes the production of malonyl CoA. Three unrelated ACC inhibitors (diclofop, clethodim, and Pfizer CP-640186) all enhanced insulin-stimulated glucose transport. However, none of the treatments designed to manipulate malonyl CoA concentrations altered markers of proximal insulin signaling through Akt. The findings support the hypothesis that acute changes in malonyl CoA concentrations affect insulin action in muscle cells but suggest that the effects do not involve alterations in proximal insulin signaling.

  13. Identification of 3-amido-4-anilinoquinolines as potent and selective inhibitors of CSF-1R kinase.

    Science.gov (United States)

    Scott, David A; Balliet, Carrie L; Cook, Donald J; Davies, Audrey M; Gero, Thomas W; Omer, Charles A; Poondru, Srinivasu; Theoclitou, Maria-Elena; Tyurin, Boris; Zinda, Michael J

    2009-02-01

    3-amido-4-anilinoquinolines are potent and highly selective inhibitors of CSF-1R. Their synthesis and SAR is reported, along with initial efforts to optimize the physical properties and PK through modifications at the quinoline 6- and 7-positions.

  14. Pyridyl and thiazolyl bisamide CSF-1R inhibitors for the treatment of cancer.

    Science.gov (United States)

    Scott, David A; Aquila, Brian M; Bebernitz, Geraldine A; Cook, Donald J; Dakin, Les A; Deegan, Tracy L; Hattersley, Maureen M; Ioannidis, Stephanos; Lyne, Paul D; Omer, Charles A; Ye, Minwei; Zheng, Xiaolan

    2008-09-01

    The bisamide class of kinase inhibitors was identified as being active against CSF-1R. The synthesis and SAR of pyridyl and thiazolyl bisamides are reported, along with the pharmacokinetic properties and in vivo activity of selected examples.

  15. Metformin increases insulin-stimulated glucose transport in insulin-resistant human skeletal muscle.

    Science.gov (United States)

    Galuska, D; Zierath, J; Thörne, A; Sonnenfeld, T; Wallberg-Henriksson, H

    1991-05-01

    The effect of metformin (0.1 mM) on glucose transport was investigated in healthy control and in insulin-resistant human skeletal muscle. Muscle samples (200-400 mg) were obtained from the rectus abdominis muscle (abdominal surgery) or from the vastus lateralis portion of the quadriceps femoris muscle (open biopsy technique) from 8 healthy controls (age 38 +/- 4 yrs, BMI 23 +/- 1) and from 6 insulin-resistant subjects (age 53 +/- 5 yrs, BMI 30 +/- 2). Metformin had no effect on basal or insulin-stimulated (100 microU/ml) 3-0-methylglucose transport in incubated muscle strips from healthy subjects. Muscle tissue from the insulin resistant group did not respond to 100 microU/ml of insulin (0.73 +/- 0.17 for basal and 0.81 +/- 0.22 mumol x ml-1 x h-1 for insulin-stimulation, NS). Basal glucose transport was unaffected by metformin, whereas insulin-stimulated (100 microU/ml) glucose transport was increased by 63% in the insulin-resistant muscles (0.73 +/- 0.17 in the absence vs 1.19 +/- 0.18 mumol x ml-1 x h-1 in the presence of metformin, p less than 0.05). In conclusion, metformin abolishes insulin-resistance in human skeletal muscle by normalizing insulin-stimulated glucose transport accross the muscle cell membrane. The mechanism for this effect remains to be elucidated.

  16. Genetic and pharmacological targeting of CSF-1/CSF-1R inhibits tumor-associated macrophages and impairs BRAF-induced thyroid cancer progression.

    Science.gov (United States)

    Ryder, Mabel; Gild, Matti; Hohl, Tobias M; Pamer, Eric; Knauf, Jeff; Ghossein, Ronald; Joyce, Johanna A; Fagin, James A

    2013-01-01

    Advanced human thyroid cancers are densely infiltrated with tumor-associated macrophages (TAMs) and this correlates with a poor prognosis. We used BRAF-induced papillary thyroid cancer (PTC) mouse models to examine the role of TAMs in PTC progression. Following conditional activation of BRAF(V600E) in murine thyroids there is an increased expression of the TAM chemoattractants Csf-1 and Ccl-2. This is followed by the development of PTCs that are densely infiltrated with TAMs that express Csf-1r and Ccr2. Targeting CCR2-expressing cells during BRAF-induction reduced TAM density and impaired PTC development. This strategy also induced smaller tumors, decreased proliferation and restored a thyroid follicular architecture in established PTCs. In PTCs from mice that lacked CSF-1 or that received a c-FMS/CSF-1R kinase inhibitor, TAM recruitment and PTC progression was impaired, recapitulating the effects of targeting CCR2-expressing cells. Our data demonstrate that TAMs are pro-tumorigenic in advanced PTCs and that they can be targeted pharmacologically, which may be potentially useful for patients with advanced thyroid cancers.

  17. Genetic and pharmacological targeting of CSF-1/CSF-1R inhibits tumor-associated macrophages and impairs BRAF-induced thyroid cancer progression.

    Directory of Open Access Journals (Sweden)

    Mabel Ryder

    Full Text Available Advanced human thyroid cancers are densely infiltrated with tumor-associated macrophages (TAMs and this correlates with a poor prognosis. We used BRAF-induced papillary thyroid cancer (PTC mouse models to examine the role of TAMs in PTC progression. Following conditional activation of BRAF(V600E in murine thyroids there is an increased expression of the TAM chemoattractants Csf-1 and Ccl-2. This is followed by the development of PTCs that are densely infiltrated with TAMs that express Csf-1r and Ccr2. Targeting CCR2-expressing cells during BRAF-induction reduced TAM density and impaired PTC development. This strategy also induced smaller tumors, decreased proliferation and restored a thyroid follicular architecture in established PTCs. In PTCs from mice that lacked CSF-1 or that received a c-FMS/CSF-1R kinase inhibitor, TAM recruitment and PTC progression was impaired, recapitulating the effects of targeting CCR2-expressing cells. Our data demonstrate that TAMs are pro-tumorigenic in advanced PTCs and that they can be targeted pharmacologically, which may be potentially useful for patients with advanced thyroid cancers.

  18. 3-amido-4-anilinoquinolines as CSF-1R kinase inhibitors 2: Optimization of the PK profile.

    Science.gov (United States)

    Scott, David A; Bell, Kirsten J; Campbell, Cheryl T; Cook, Donald J; Dakin, Les A; Del Valle, David J; Drew, Lisa; Gero, Thomas W; Hattersley, Maureen M; Omer, Charles A; Tyurin, Boris; Zheng, Xiaolan

    2009-02-01

    The optimization of compounds from the 3-amido-4-anilinoquinolines series of CSF-1R kinase inhibitors is described. The series has excellent activity and kinase selectivity. Excellent physical properties and rodent PK profiles were achieved through the introduction of cyclic amines at the quinoline 6-position. Compounds with good activity in a mouse PD model measuring inhibition of pCSF-1R were identified.

  19. Sucrose nonfermenting AMPK-related kinase (SNARK) mediates contraction-stimulated glucose transport in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Koh, Ho-Jin; Toyoda, Taro; Fujii, Nobuharu

    2010-01-01

    -related protein kinases, significantly inhibited contraction-stimulated glucose transport. This finding, in conjunction with previous studies of ablated AMPKalpha2 activity showing no effect on contraction-stimulated glucose transport, suggests that one or more AMPK-related protein kinases are important...

  20. Knockout of the predominant conventional PKC isoform, PKCalpha, in mouse skeletal muscle does not affect contraction-stimulated glucose uptake

    DEFF Research Database (Denmark)

    Jensen, Thomas E; Maarbjerg, Stine J; Rose, Adam J

    2009-01-01

    -induced glucose uptake were similar in muscles lacking PKCalpha and in the wild type. It can be concluded that PKCalpha, representing approximately 97% of cPKC in skeletal muscle, is not required for contraction-stimulated glucose uptake. Thus the effect of the PKC blockers on glucose uptake is either nonspecific...

  1. LPS-Enhanced Glucose-Stimulated Insulin Secretion Is Normalized by Resveratrol.

    Directory of Open Access Journals (Sweden)

    Mark K Nøhr

    Full Text Available Low-grade inflammation is seen with obesity and is suggested to be a mediator of insulin resistance. The eliciting factor of low-grade inflammation is unknown but increased permeability of gut bacteria-derived lipopolysaccharides (LPS resulting in endotoxemia could be a candidate. Here we test the effect of LPS and the anti-inflammatory compound resveratrol on glucose homeostasis, insulin levels and inflammation. Mice were subcutaneously implanted with osmotic mini pumps infusing either low-dose LPS or saline for 28 days. Half of the mice were treated with resveratrol delivered through the diet. LPS caused increased inflammation of the liver and adipose tissue (epididymal and subcutaneous together with enlarged spleens and increased number of leukocytes in the blood. Resveratrol specifically reduced the inflammatory status in epididymal fat (reduced expression of TNFa and Il1b, whereas the increased macrophage infiltration was unaltered without affecting the other tissues investigated. By LC-MS, we were able to quantitate resveratrol metabolites in epididymal but not subcutaneous adipose tissue. LPS induced insulin resistance as the glucose-stimulated insulin secretion during an oral glucose tolerance test was increased despite similar plasma glucose level resulting in an increase in the insulinogenic index (IGI; delta0-15insulin/delta0-15glucose from 13.73 to 22.40 pmol/mmol (P < 0.001. This aberration in insulin and glucose homeostasis was normalized by resveratrol.Low-dose LPS enhanced the glucose-stimulated insulin secretion without affecting the blood glucose suggesting increased insulin resistance. Resveratrol restored LPS-induced alteration of the insulin secretion and demonstrated anti-inflammatory effects specifically in epididymal adipose tissue possibly due to preferential accumulation of resveratrol metabolites pointing towards a possible important involvement of this tissue for the effects on insulin resistance and insulin secretion.

  2. Insulin stimulation of glucose transport activity in rat skeletal muscle: increase in cell surface GLUT4 as assessed by photolabelling.

    OpenAIRE

    Wilson, C. M.; Cushman, S W

    1994-01-01

    We have used a photoaffinity label to quantify cell surface GLUT4 glucose transporters in isolated rat soleus muscles. In this system, insulin stimulated an 8.6-fold increase in 3-O-methylglucose glucose transport, while photolabelled GLUT4 increased 8-fold. These results demonstrate that the insulin-stimulated increase in glucose transport activity in skeletal muscle can be accounted for by an increase in surface-accessible GLUT4 content.

  3. SAA drives proinflammatory heterotypic macrophage differentiation in the lung via CSF-1R-dependent signaling.

    Science.gov (United States)

    Anthony, Desiree; McQualter, Jonathan L; Bishara, Maria; Lim, Ee X; Yatmaz, Selcuk; Seow, Huei Jiunn; Hansen, Michelle; Thompson, Michelle; Hamilton, John A; Irving, Louis B; Levy, Bruce D; Vlahos, Ross; Anderson, Gary P; Bozinovski, Steven

    2014-09-01

    Serum amyloid A (SAA) is expressed locally in chronic inflammatory conditions such as chronic obstructive pulmonary disease (COPD), where macrophages that do not accord with the classic M1/M2 paradigm also accumulate. In this study, the role of SAA in regulating macrophage differentiation was investigated in vitro using human blood monocytes from healthy subjects and patients with COPD and in vivo using an airway SAA challenge model in BALB/c mice. Differentiation of human monocytes with SAA stimulated the proinflammatory monokines IL-6 and IL-1β concurrently with the M2 markers CD163 and IL-10. Furthermore, SAA-differentiated macrophages stimulated with lipopolysaccharide (LPS) expressed markedly higher levels of IL-6 and IL-1β. The ALX/FPR2 antagonist WRW4 reduced IL-6 and IL-1β expression but did not significantly inhibit phagocytic and efferocytic activity. In vivo, SAA administration induced the development of a CD11c(high)CD11b(high) macrophage population that generated higher levels of IL-6, IL-1β, and G-CSF following ex vivo LPS challenge. Blocking CSF-1R signaling effectively reduced the number of CD11c(high)CD11b(high) macrophages by 71% and also markedly inhibited neutrophilic inflammation by 80%. In conclusion, our findings suggest that SAA can promote a distinct CD11c(high)CD11b(high) macrophage phenotype, and targeting this population may provide a novel approach to treating chronic inflammatory conditions associated with persistent SAA expression. © FASEB.

  4. Differential effects of CSF-1R D802V and KIT D816V homologous mutations on receptor tertiary structure and allosteric communication.

    Directory of Open Access Journals (Sweden)

    Priscila Da Silva Figueiredo Celestino Gomes

    Full Text Available The colony stimulating factor-1 receptor (CSF-1R and the stem cell factor receptor KIT, type III receptor tyrosine kinases (RTKs, are important mediators of signal transduction. The normal functions of these receptors can be compromised by gain-of-function mutations associated with different physiopatological impacts. Whereas KIT D816V/H mutation is a well-characterized oncogenic event and principal cause of systemic mastocytosis, the homologous CSF-1R D802V has not been identified in human cancers. The KIT D816V oncogenic mutation triggers resistance to the RTK inhibitor Imatinib used as first line treatment against chronic myeloid leukemia and gastrointestinal tumors. CSF-1R is also sensitive to Imatinib and this sensitivity is altered by mutation D802V. Previous in silico characterization of the D816V mutation in KIT evidenced that the mutation caused a structure reorganization of the juxtamembrane region (JMR and facilitated its departure from the kinase domain (KD. In this study, we showed that the equivalent CSF-1R D802V mutation does not promote such structural effects on the JMR despite of a reduction on some key H-bonds interactions controlling the JMR binding to the KD. In addition, this mutation disrupts the allosteric communication between two essential regulatory fragments of the receptors, the JMR and the A-loop. Nevertheless, the mutation-induced shift towards an active conformation observed in KIT D816V is not observed in CSF-1R D802V. The distinct impact of equivalent mutation in two homologous RTKs could be associated with the sequence difference between both receptors in the native form, particularly in the JMR region. A local mutation-induced perturbation on the A-loop structure observed in both receptors indicates the stabilization of an inactive non-inhibited form, which Imatinib cannot bind.

  5. Differential effects of CSF-1R D802V and KIT D816V homologous mutations on receptor tertiary structure and allosteric communication.

    Science.gov (United States)

    Da Silva Figueiredo Celestino Gomes, Priscila; Panel, Nicolas; Laine, Elodie; Pascutti, Pedro Geraldo; Solary, Eric; Tchertanov, Luba

    2014-01-01

    The colony stimulating factor-1 receptor (CSF-1R) and the stem cell factor receptor KIT, type III receptor tyrosine kinases (RTKs), are important mediators of signal transduction. The normal functions of these receptors can be compromised by gain-of-function mutations associated with different physiopatological impacts. Whereas KIT D816V/H mutation is a well-characterized oncogenic event and principal cause of systemic mastocytosis, the homologous CSF-1R D802V has not been identified in human cancers. The KIT D816V oncogenic mutation triggers resistance to the RTK inhibitor Imatinib used as first line treatment against chronic myeloid leukemia and gastrointestinal tumors. CSF-1R is also sensitive to Imatinib and this sensitivity is altered by mutation D802V. Previous in silico characterization of the D816V mutation in KIT evidenced that the mutation caused a structure reorganization of the juxtamembrane region (JMR) and facilitated its departure from the kinase domain (KD). In this study, we showed that the equivalent CSF-1R D802V mutation does not promote such structural effects on the JMR despite of a reduction on some key H-bonds interactions controlling the JMR binding to the KD. In addition, this mutation disrupts the allosteric communication between two essential regulatory fragments of the receptors, the JMR and the A-loop. Nevertheless, the mutation-induced shift towards an active conformation observed in KIT D816V is not observed in CSF-1R D802V. The distinct impact of equivalent mutation in two homologous RTKs could be associated with the sequence difference between both receptors in the native form, particularly in the JMR region. A local mutation-induced perturbation on the A-loop structure observed in both receptors indicates the stabilization of an inactive non-inhibited form, which Imatinib cannot bind.

  6. Differential regulation of sense and antisense promoter activity at the Csf1R locus in B cells by the transcription factor PAX5.

    Science.gov (United States)

    Ingram, Richard M; Valeaux, Stephanie; Wilson, Nicola; Bouhlel, M Amine; Clarke, Deborah; Krüger, Imme; Kulu, Divine; Suske, Guntram; Philipsen, Sjaak; Tagoh, Hiromi; Bonifer, Constanze

    2011-07-01

    The transcription factor PAX5 is essential for the activation of B-cell-specific genes and for the silencing of myeloid-specific genes. We previously determined the molecular mechanism by which PAX5 silences the myeloid-specific colony-stimulating-factor-receptor (Csf1R) gene and showed that PAX5 directly binds to the Csf1r promoter as well as to an intronic enhancer that generates an antisense transcript in B cells. Here we examine the role of PAX5 in the regulation of sense and antisense transcription in B cells. We performed PAX5-specific chromatin immunoprecipitation analyses across the Csfr1 locus. We investigated the role of PAX5 in regulating Csf1r sense and antisense promoter activity by transient transfections and by employing a Pax5(-/-) pro-B-cell line expressing an inducible PAX5 protein. PAX5 interacting factors were identified by pull-down experiments. The role of the transcription factor Sp3 in driving antisense promoter expression was examined in B cells from Sp3 knockout mice. PAX5 differentially regulates the Csf1r promoter and the promoter of the antisense transcript. PAX5 interferes with PU.1 transactivation at the sense promoter by binding to a PAX5 consensus sequence. At the antisense promoter, PAX5 does not specifically recognize DNA, but interacts with Sp3 to upregulate antisense promoter activity. Antisense promoter activation by PAX5 is dependent on the presence of its partial homeo-domain. We demonstrate that PAX5 regulates Csf1r in B cells by reducing the frequency of binding of the basal transcription machinery to the promoter and by activating antisense RNA expression. Copyright © 2011 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

  7. Stimulation of feeding by three different glucose-sensing mechanisms requires hindbrain catecholamine neurons.

    Science.gov (United States)

    Li, Ai-Jun; Wang, Qing; Dinh, Thu T; Powers, Bethany R; Ritter, Sue

    2014-02-15

    Previous work has shown that hindbrain catecholamine neurons are required components of the brain's glucoregulatory circuitry. However, the mechanisms and circuitry underlying their glucoregulatory functions are poorly understood. Here we examined three drugs, glucosamine (GcA), phloridzin (Phl) and 5-thio-d-glucose (5TG), that stimulate food intake but interfere in different ways with cellular glucose utilization or transport. We examined feeding and blood glucose responses to each drug in male rats previously injected into the hypothalamic paraventricular nucleus with anti-dopamine-β-hydroxylase conjugated to saporin (DSAP), a retrogradely transported immunotoxin that selectively lesions noradrenergic and adrenergic neurons, or with unconjugated saporin (SAP) control. Our major findings were 1) that GcA, Phl, and 5TG all stimulated feeding in SAP controls whether injected into the lateral or fourth ventricle (LV or 4V), 2) that each drug's potency was similar for both LV and 4V injections, 3) that neither LV or 4V injection of these drugs evoked feeding in DSAP-lesioned rats, and 4) that only 5TG, which blocks glycolysis, stimulated a blood glucose response. The antagonist of the MEK/ERK signaling cascade, U0126, attenuated GcA-induced feeding, but not Phl- or 5TG-induced feeding. Thus GcA, Phl, and 5TG, although differing in mechanism and possibly activating different neural populations, stimulate feeding in a catecholamine-dependent manner. Although results do not exclude the possibility that catecholamine neurons possess glucose-sensing mechanisms responsive to all of these agents, currently available evidence favors the possibility that the feeding effects result from convergent neural circuits in which catecholamine neurons are a required component.

  8. Mice with Deletion of Neuromedin B Receptor Exhibit Decreased Oral Glucose-Stimulated Insulin Release.

    Science.gov (United States)

    Paula, G S M; Souza, L L; Bressane, N O S; Maravalhas, R; Wilieman, M; Bento-Bernardes, T; Silva, K R; Mendonca, L S; Oliveira, K J; Pazos-Moura, C C

    2016-12-01

    Neuromedin B (NB) and gastrin-releasing peptide (GRP) are bombesin-like peptides, found in the gastrointestinal tube and pancreas, among other tissues. Consistent data proposed that GRP stimulates insulin secretion, acting directly in pancreatic cells or in the release of gastrointestinal hormones that are incretins. However, the role of NB remains unclear. We examined the glucose homeostasis in mice with deletion of NB receptor (NBR-KO). Female NBR-KO exhibited similar fasting basal glucose with lower insulinemia (48.4%) and lower homeostasis model assessment of insulin resistance index (50.5%) than wild type (WT). Additionally, they were more tolerant to oral glucose, demonstrated by a decrease in the area under the glucose curve (18%). In addition, 15 min after an oral glucose load, female and male NBR-KO showed lower insulin serum levels (45.6 and 26.8%, respectively) than WT, even though blood glucose rose to similar levels in both groups. Single injection of NB, one hour before the oral glucose administration, tended to induce higher serum insulin in WT (28.9%, p=0.3), however the same did not occur in NBR-KO. They showed no changes in fasting insulin content in pancreatic islets by immunohistochemistry, however, the fasting serum levels of glucagon-like peptide, a potent incretin, exhibited a strong trend to reduction (40%, p=0.07). Collectively, mice with deletion of NB receptor have lower insulinemia, especially in response to oral glucose, and females also exhibited a better glucose tolerance, suggesting the involvement of NB and its receptor in regulation of insulin secretion induced by incretins, and also, in insulin sensitivity. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Stimulation of splanchnic glucose production during exercise in humans contains a glucagon-independent component

    DEFF Research Database (Denmark)

    Coker, R H; Simonsen, L; Bülow, J

    2001-01-01

    To determine the importance of basal glucagon to the stimulation of net splanchnic glucose output (NSGO) during exercise, seven healthy males performed cycle exercise during a pancreatic islet cell clamp. In one group (BG), glucagon was replaced at basal levels and insulin was adjusted to achieve...... euglycemia. In another group (GD), only insulin was replaced at the identical rate used in BG, and basal glucagon was not replaced. Exogenous glucose infusion was necessary to maintain euglycemia during exercise in BG and during rest and exercise in GD. Arterial glucagon was at least twofold greater in BG...

  10. High Glucose Predisposes Gene Expression and ERK Phosphorylation to Apoptosis and Impaired Glucose-Stimulated Insulin Secretion via the Cytoskeleton

    Science.gov (United States)

    Yeo, Ronne Wee Yeh; Yang, Kaiyuan; Li, GuoDong; Lim, Sai Kiang

    2012-01-01

    Chronic high glucose (HG) inflicts glucotoxicity on vulnerable cell types such as pancreatic β cells and contributes to insulin resistance and impaired insulin secretion in diabetic patients. To identify HG-induced cellular aberrations that are candidate mediators of glucotoxicity in pancreatic β cells, we analyzed gene expression in ERoSHK6, a mouse insulin-secreting cell line after chronic HG exposure (six-day exposure to 33.3 mM glucose). Chronic HG exposure which reduced glucose-stimulated insulin secretion (GSIS) increased transcript levels of 185 genes that clustered primarily in 5 processes namely cellular growth and proliferation; cell death; cellular assembly and organization; cell morphology; and cell-to-cell signaling and interaction. The former two were validated by increased apoptosis of ERoSHK6 cells after chronic HG exposure and reaffirmed the vulnerability of β cells to glucotoxicity. The three remaining processes were partially substantiated by changes in cellular morphology and structure, and instigated an investigation of the cytoskeleton and cell-cell adhesion. These studies revealed a depolymerized actin cytoskeleton that lacked actin stress fibers anchored at vinculin-containing focal adhesion sites as well as loss of E-cadherin-mediated cell-cell adherence after exposure to chronic HG, and were concomitant with constitutive ERK1/2 phosphorylation that was refractory to serum and glucose deprivation. Although inhibition of ERK phosphorylation by PD98059 promoted actin polymerization, it increased apoptosis and GSIS impairment. These findings suggest that ERK phosphorylation is a proximate regulator of cellular processes targeted by chronic HG-induced gene expression and that dynamic actin polymerization and depolymerization is important in β cell survival and function. Therefore, chronic HG alters gene expression and signal transduction to predispose the cytoskeleton towards apoptosis and GSIS impairment. PMID:23024780

  11. Reduced malonyl-CoA content in recovery from exercise correlates with improved insulin-stimulated glucose uptake in human skeletal muscle

    DEFF Research Database (Denmark)

    Frøsig, Christian; Roepstorff, Carsten; Brandt, Nina

    2009-01-01

    uptake. Four days of Fat diet resulted in an increased content of intramyocellular triacylglycerol (Pbody insulin-stimulated glucose uptake. However, at the muscular level proximal insulin signaling and insulin-stimulated glucose uptake appeared...

  12. Relative contribution of glycogenolysis and gluconeogenesis to basal, glucagon- and nerve stimulation-dependent glucose output in the perfused liver from fed and fasted rats

    NARCIS (Netherlands)

    Beuers, U.; JUNGERMANN, K.

    1990-01-01

    The relative contribution to basal, glucagon- and nerve stimulation-enhanced glucose output of glycogenolysis (glucose output in the presence of the gluconeogenic inhibitor mercaptopicolinate) and gluconeogenesis (difference in glucose output in the absence and presence of the inhibitor) was

  13. Myostatin inhibits proliferation and insulin-stimulated glucose uptake in mouse liver cells.

    Science.gov (United States)

    Watts, Rani; Ghozlan, Mostafa; Hughey, Curtis C; Johnsen, Virginia L; Shearer, Jane; Hittel, Dustin S

    2014-06-01

    Although myostatin functions primarily as a negative regulator of skeletal muscle growth and development, accumulating biological and epidemiological evidence indicates an important contributing role in liver disease. In this study, we demonstrate that myostatin suppresses the proliferation of mouse Hepa-1c1c7 murine-derived liver cells (50%; p myostatin-responsive transcript in skeletal muscle, revealed a significant downregulation (25% and 50%, respectively; p myostatin-treated mice and liver cells. The importance of Malat1 in liver cell proliferation was confirmed via arrested liver cell proliferation (p Myostatin also significantly blunted insulin-stimulated glucose uptake and Akt phosphorylation in liver cells while increasing the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS), a protein that is essential for cancer cell proliferation and insulin-stimulated glucose transport. Together, these findings reveal a plausible mechanism by which circulating myostatin contributes to the diminished regenerative capacity of the liver and diseases characterized by liver insulin resistance.

  14. Oral L-Arginine Stimulates GLP-1 Secretion to Improve Glucose Tolerance in Male Mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Smajilovic, Sanela; Smith, Eric P

    2013-01-01

    in vivo, to augment postprandial insulin secretion and improve glucose tolerance. To test this, we administered l-arginine or vehicle by oral gavage, immediately prior to an oral glucose tolerance test in lean and diet-induced obese mice. In both lean and obese mice oral l-arginine increased plasma GLP-1......Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet......-induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid l-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral l-arginine acts as a GLP-1 secretagogue...

  15. Glucose transporters and in vivo glucose uptake in skeletal and cardiac muscle: fasting, insulin stimulation and immunoisolation studies of GLUT1 and GLUT4.

    OpenAIRE

    Kraegen, E. W.; Sowden, J A; Halstead, M B; Clark, P W; Rodnick, K J; Chisholm, D. J.; James, D E

    1993-01-01

    Our aim was to study glucose transporters GLUT1 and GLUT4 in relation to in vivo glucose uptake in rat cardiac and skeletal muscle. The levels of both transporters were of a similar order of magnitude in whole muscle tissue (GLUT1/GLUT4 ratio varied from 0.1 to 0.6), suggesting that both may have an important physiological role in regulating muscle glucose metabolism. GLUT4 correlated very strongly (r2 = 0.97) with maximal insulin-stimulated glucose uptake (Rg' max., estimated using the gluco...

  16. Superoxide generation is diminished during glucose-stimulated insulin secretion in INS-1E cells

    Czech Academy of Sciences Publication Activity Database

    Ježek, Petr; Hlavatá, Lydie; Špaček, Tomáš

    2008-01-01

    Roč. 275, Suppl.1 (2008), s. 310-310 ISSN 1742-464X. [FEBS Congress /33./ and IUBMB Conference /11./. 28.06.2008-03.07.2008, Athens] R&D Projects: GA MZd(CZ) NR7917; GA AV ČR(CZ) IAA500110701 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpo1 * superoxide production * glucose-stimulated insulin secretion * INS-1E cells Subject RIV: ED - Physiology

  17. A novel A792D mutation in the CSF1R gene causes hereditary diffuse leukoencephalopathy with axonal spheroids characterized by slow progression

    Directory of Open Access Journals (Sweden)

    Sakiho Ueda

    2015-03-01

    Full Text Available Hereditary diffuse leukoencephalopathy with spheroids (HDLS is an autosomal dominant white matter disease that causes adult-onset cognitive impairment. The clinical manifestations are a variable combination of personality and behavioral changes, cognitive decline, parkinsonism, spasticity, and epilepsy. In 2012, mutations in the gene encoding colony stimulating factor 1 receptor (CSF1R were identified as the cause of HDLS. As the numbers of reported mutations are limited, the understanding of whole pathogenesis needs accumulation of disease-causing mutations with detailed clinical descriptions. We describe a Japanese family with autosomal dominant adult-onset cognitive impairment and characteristic white matter lesions. Genetic testing revealed a novel p.A792D mutation in the tyrosine kinase domain of CSF1R in two affected family members. The symptom profile of the present cases mostly matched the previously reported cases, with the notable exceptions of late-onset and long disease duration.

  18. Mitochondrial pyruvate carrier 2 hypomorphism in mice leads to defects in glucose-stimulated insulin secretion.

    Science.gov (United States)

    Vigueira, Patrick A; McCommis, Kyle S; Schweitzer, George G; Remedi, Maria S; Chambers, Kari T; Fu, Xiaorong; McDonald, William G; Cole, Serena L; Colca, Jerry R; Kletzien, Rolf F; Burgess, Shawn C; Finck, Brian N

    2014-06-26

    Carrier-facilitated pyruvate transport across the inner mitochondrial membrane plays an essential role in anabolic and catabolic intermediary metabolism. Mitochondrial pyruvate carrier 2 (Mpc2) is believed to be a component of the complex that facilitates mitochondrial pyruvate import. Complete MPC2 deficiency resulted in embryonic lethality in mice. However, a second mouse line expressing an N-terminal truncated MPC2 protein (Mpc2(Δ16)) was viable but exhibited a reduced capacity for mitochondrial pyruvate oxidation. Metabolic studies demonstrated exaggerated blood lactate concentrations after pyruvate, glucose, or insulin challenge in Mpc2(Δ16) mice. Additionally, compared with wild-type controls, Mpc2(Δ16) mice exhibited normal insulin sensitivity but elevated blood glucose after bolus pyruvate or glucose injection. This was attributable to reduced glucose-stimulated insulin secretion and was corrected by sulfonylurea KATP channel inhibitor administration. Collectively, these data are consistent with a role for MPC2 in mitochondrial pyruvate import and suggest that Mpc2 deficiency results in defective pancreatic β cell glucose sensing. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Mitochondrial Pyruvate Carrier 2 Hypomorphism in Mice Leads to Defects in Glucose-Stimulated Insulin Secretion

    Directory of Open Access Journals (Sweden)

    Patrick A. Vigueira

    2014-06-01

    Full Text Available Carrier-facilitated pyruvate transport across the inner mitochondrial membrane plays an essential role in anabolic and catabolic intermediary metabolism. Mitochondrial pyruvate carrier 2 (Mpc2 is believed to be a component of the complex that facilitates mitochondrial pyruvate import. Complete MPC2 deficiency resulted in embryonic lethality in mice. However, a second mouse line expressing an N-terminal truncated MPC2 protein (Mpc2Δ16 was viable but exhibited a reduced capacity for mitochondrial pyruvate oxidation. Metabolic studies demonstrated exaggerated blood lactate concentrations after pyruvate, glucose, or insulin challenge in Mpc2Δ16 mice. Additionally, compared with wild-type controls, Mpc2Δ16 mice exhibited normal insulin sensitivity but elevated blood glucose after bolus pyruvate or glucose injection. This was attributable to reduced glucose-stimulated insulin secretion and was corrected by sulfonylurea KATP channel inhibitor administration. Collectively, these data are consistent with a role for MPC2 in mitochondrial pyruvate import and suggest that Mpc2 deficiency results in defective pancreatic β cell glucose sensing.

  20. The interrelation between aPKC and glucose uptake in the skeletal muscle during contraction and insulin stimulation.

    Science.gov (United States)

    Santos, J M; Benite-Ribeiro, S A; Queiroz, G; Duarte, J A

    2014-12-01

    Contraction and insulin increase glucose uptake in skeletal muscle. While the insulin pathway, better characterized, requires activation of phosphoinositide 3-kinase (PI3K) and atypical protein kinase (aPKC), muscle contraction seems to share insulin-activated components to increase glucose uptake. This study aimed to investigate the interrelation between the pathway involved in glucose uptake evoked by insulin and muscle contraction. Isolated muscle of rats was treated with solvent (control), insulin, wortmannin (PI3K inhibitor) and the combination of insulin plus wortmannin. After treatment, muscles were electrically stimulated (contracted) or remained at rest. Glucose transporter 4 (GLUT4) localization, glucose uptake and phospho-aPKC (aPKC activated form) were assessed. Muscle contraction and insulin increased glucose uptake in all conditions when compared with controls not stimulating an effect that was accompanied by an increase in GLUT4 and of phospho-aPKC at the muscle membrane. Contracted muscles treated with insulin did not show additive effects on glucose uptake or aPKC activity compared with the response when these stimuli were applied alone. Inhibition of PI3K blocked insulin effect on glucose uptake and aPKC but not in the contractile response. Thus, muscle contraction seems to stimulate aPKC and glucose uptake independently of PI3K. Therefore, aPKC may be a convergence point and a rate limit step in the pathway by which, insulin and contraction, increase glucose uptake in skeletal muscle. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Insulin-stimulated glucose transport in circulating mononuclear cells from nondiabetic and IDDM subjects.

    Science.gov (United States)

    Daneman, D; Zinman, B; Elliott, M E; Bilan, P J; Klip, A

    1992-02-01

    The objectives of this study were 1) to evaluate glucose transport and its regulation by insulin in easily accessible human cells, 2) to investigate the glucose transporter isoforms involved, and 3) to establish whether a defect in glucose transport is associated with peripheral insulin resistance, which is common in insulin-dependent diabetes mellitus (IDDM) patients. We measured 2-deoxyglucose (2-DG) uptake in circulating mononuclear cells from 23 nondiabetic adults, 16 adults with IDDM, and 10 children with IDDM. Circulating mononuclear cells were separated from whole blood by Ficoll gradients and incubated with +/- 1 nM insulin. 2-DG uptake was measured after incubation with [3H]2-DG and cell separation through corn oil-phthalate. Cytochalasin B-inhibitable 2-DG uptake (basal and insulin stimulated) was higher in control than in IDDM subjects (P less than 0.001). Insulin significantly increased 2-DG uptake or 3-O-methylglucose uptake in both groups. Basal and insulin-stimulated 2-DG uptake was similar for adults and children with IDDM and did not correlate with age or body mass index in any group or disease duration, insulin dosage, or HbA1c in IDDM. In separated monocytes and lymphocytes, 2-DG uptake increased in response to insulin only in the monocyte population. Insulin dose-response curves indicated maximal stimulation of hexose uptake at 1-2 nM insulin for both control and diabetic subjects and demonstrated a significant decrease in maximal insulin response in the latter. Immunoblotting with specific antibodies revealed that circulating mononuclear cells and separated monocytes express the GLUT1 but not the GLUT4 isoform of the glucose transporter.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. The mitochondrial 2-oxoglutarate carrier is part of a metabolic pathway that mediates glucose- and glutamine-stimulated insulin secretion

    National Research Council Canada - National Science Library

    Odegaard, Matthew L; Joseph, Jamie W; Jensen, Mette V; Lu, Danhong; Ilkayeva, Olga; Ronnebaum, Sarah M; Becker, Thomas C; Newgard, Christopher B

    2010-01-01

    Glucose-stimulated insulin secretion from pancreatic islet beta-cells is dependent in part on pyruvate cycling through the pyruvate/isocitrate pathway, which generates cytosolic alpha-ketoglutarate...

  3. The modulatory role of alpha-melanocyte stimulating hormone administered spinally in the regulation of blood glucose level in d-glucose-fed and restraint stress mouse models.

    Science.gov (United States)

    Sim, Yun-Beom; Park, Soo-Hyun; Kim, Sung-Su; Lim, Su-Min; Jung, Jun-Sub; Suh, Hong-Won

    2014-08-01

    Alpha-melanocyte stimulating hormone (α-MSH) is known as a regulator of the blood glucose homeostasis and food intake. In the present study, the possible roles of α-MSH located in the spinal cord in the regulation of the blood glucose level were investigated in d-glucose-fed and immobilization stress (IMO) mouse models. We found in the present study that intrathecal (i.t.) injection with α-MSH alone did not affect the blood glucose level. However, i.t. administration with α-MSH reduced the blood glucose level in d-glucose-fed model. The plasma insulin level was increased in d-glucose-fed model and was further increased by α-MSH, whereas α-MSH did not affect plasma corticosterone level in d-glucose-fed model. In addition, i.t. administration with glucagon alone enhanced blood glucose level and, i.t. injection with glucagon also increased the blood glucose level in d-glucose-fed model. In contrasted to results observed in d-glucose-fed model, i.t. treatment with α-MSH caused enhancement of the blood glucose level in IMO model. The plasma insulin level was increased in IMO model. The increased plasma insulin level by IMO was reduced by i.t. treatment with α-MSH, whereas i.t. pretreatment with α-MSH did not affect plasma corticosterone level in IMO model. Taken together, although spinally located α-MSH itself does not alter the blood glucose level, our results suggest that the activation of α-MSH system located in the spinal cord play important modulatory roles for the reduction of the blood glucose level in d-glucose fed model whereas α-MSH is responsible for the up-regulation of the blood glucose level in IMO model. The enhancement of insulin release may be responsible for modulatory action of α-MSH in down-regulation of the blood glucose in d-glucose fed model whereas reduction of insulin release may be responsible for modulatory action of α-MSH in up-regulation of the blood glucose in IMO model. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. CAP defines a second signalling pathway required for insulin-stimulated glucose transport

    Science.gov (United States)

    Baumann, Christian A.; Ribon, Vered; Kanzaki, Makoto; Thurmond, Debbie C.; Mora, Silvia; Shigematsu, Satoshi; Bickel, Perry E.; Pessin, Jeffrey E.; Saltiel, Alan R.

    2000-09-01

    Insulin stimulates the transport of glucose into fat and muscle cells. Although the precise molecular mechanisms involved in this process remain uncertain, insulin initiates its actions by binding to its tyrosine kinase receptor, leading to the phosphorylation of intracellular substrates. One such substrate is the Cbl protooncogene product. Cbl is recruited to the insulin receptor by interaction with the adapter protein CAP, through one of three adjacent SH3 domains in the carboxy terminus of CAP. Upon phosphorylation of Cbl, the CAP-Cbl complex dissociates from the insulin receptor and moves to a caveolin-enriched, triton-insoluble membrane fraction. Here, to identify a molecular mechanism underlying this subcellular redistribution, we screened a yeast two-hybrid library using the amino-terminal region of CAP and identified the caveolar protein flotillin. Flotillin forms a ternary complex with CAP and Cbl, directing the localization of the CAP-Cbl complex to a lipid raft subdomain of the plasma membrane. Expression of the N-terminal domain of CAP in 3T3-L1 adipocytes blocks the stimulation of glucose transport by insulin, without affecting signalling events that depend on phosphatidylinositol-3-OH kinase. Thus, localization of the Cbl-CAP complex to lipid rafts generates a pathway that is crucial in the regulation of glucose uptake.

  5. 3-amido-4-anilinocinnolines as a novel class of CSF-1R inhibitor.

    Science.gov (United States)

    Scott, David A; Dakin, Les A; Del Valle, David J; Diebold, R Bruce; Drew, Lisa; Gero, Thomas W; Ogoe, Claude A; Omer, Charles A; Repik, Galina; Thakur, Kumar; Ye, Qing; Zheng, Xiaolan

    2011-03-01

    3-Amido-4-anilinocinnolines have been identified as potent and highly selective inhibitors of CSF-1R. The synthesis and SAR of these compounds is reported, along with some physical property, pharmacokinetic and kinase selectivity data. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. CSF-1R, DAP12 and beta-catenin: a ménage à trois.

    Science.gov (United States)

    McVicar, Daniel W; Trinchieri, Giorgio

    2009-07-01

    DAP12-coupled receptors influence signals emanating from Toll-like receptors, integrins and receptors for cytokines and growth factors. New findings indicate that DAP12 also facilitates the ability of CSF-1R, the receptor for M-CSF, to induce the stabilization and nuclear translocation of beta-catenin.

  7. The influence of GLP-1 on glucose-stimulated insulin secretion

    DEFF Research Database (Denmark)

    Kjems, Lise L; Holst, Jens Juul; Vølund, Aage

    2003-01-01

    , 4, 6, 8, and 12 mg x kg(-1) x min(-1) over 150 min on four occasions with infusion of saline or GLP-1 at 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1). GLP-1 enhanced ISR in a dose-dependent manner during the graded glucose infusion from 332 +/- 51 to 975 +/- 198 pmol/kg in the patients with type 2....... However, the dose-response relationship between GLP-1 and basal and glucose-stimulated prehepatic insulin secretion rate (ISR) is currently not known. Seven patients with type 2 diabetes and seven matched nondiabetic control subjects were studied. ISR was determined during a graded glucose infusion of 2...... that of the control subjects without GLP-1. Our results show that GLP-1 increases insulin secretion in patients with type 2 diabetes and control subjects in a dose-dependent manner and that the beta-cell responsiveness to glucose may be increased to normal levels with a low dose of GLP-1 infusion. Nevertheless...

  8. The nitric oxide-donating derivative of acetylsalicylic acid, NCX 4016, stimulates glucose transport and glucose transporters translocation in 3T3-L1 adipocytes.

    Science.gov (United States)

    Kaddai, V; Gonzalez, T; Bolla, M; Le Marchand-Brustel, Y; Cormont, M

    2008-07-01

    NCX 4016 is a nitric oxide (NO)-donating derivative of acetylsalicylic acid. NO and salicylate, in vivo metabolites of NCX 4016, were shown to be potential actors in controlling glucose homeostasis. In this study, we evaluated the action of NCX 4016 on the capacity of 3T3-L1 adipocytes to transport glucose in basal and insulin-stimulated conditions. NCX 4016 induced a twofold increase in glucose uptake in parallel with the translocation of the glucose transporters GLUT1 and GLUT4 to the plasma membrane, leaving unaffected their total expression levels. Importantly, NCX 4016 further increased glucose transport induced by a physiological concentration of insulin. The stimulatory effect of NCX 4016 on glucose uptake appears to be mediated by its NO moiety. Indeed, it is inhibited by a NO scavenger and treatment with acetylsalicylic or salicylic acid had no effect. Although NO is involved in the action of NCX 4016, it did not mainly depend on the soluble cGMP cyclase/protein kinase G pathway. Furthermore, NCX 4016-stimulated glucose transport did not involve the insulin-signaling cascade required to stimulate glucose transport. NCX 4016 induces a small activation of the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase and no activation of other stress-activated signaling molecules, including extracellular signal-regulated kinase, inhibitory factor kappaB, or AMP-activated kinases. Interestingly, NCX 4016 modified the content of S-nitrosylated proteins in adipocytes. Taken together, our results indicate that NCX 4016 induced glucose transport in adipocytes through a novel mechanism possibly involving S-nitrosylation. NCX 4016 thus possesses interesting characteristics to be considered as a candidate molecule for the treatment of patients suffering from metabolic syndrome and type 2 diabetes.

  9. 5-(4-((4-[(18)F]Fluorobenzyl)oxy)-3-methoxybenzyl)pyrimidine-2,4-diamine: a selective dual inhibitor for potential PET imaging of Trk/CSF-1R.

    Science.gov (United States)

    Bernard-Gauthier, Vadim; Schirrmacher, Ralf

    2014-10-15

    The tropomyosin receptor kinases (TrkA/B/C) and colony-stimulating factor-1 receptor (CSF-1R) represent highly pursued oncological therapeutic targets. The 2,4-diaminopyrimidine inhibitor GW2580 (9) has been previously reported as a highly selective low nanomolar TrkB/TrkC/CSF-1R inhibitor. In this study, fluorinated derivatives of 9 were designed, synthesized and evaluated in enzymatic assays. The highly potent inhibitor 10 was identified, which retained the selectivity profile of the non fluorinated lead compound 9, and the radiosynthesis of [(18)F]10 was developed. The results obtained from the biological evaluation of 10 and the radiosynthesis of [(18)F]10 support further investigation of this tracer as a potential PET imaging probe for TrkB/TrkC and CSF-1R. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Ciliary Neurotrophic Factor Stimulates Muscle Glucose Uptake by a PI3-Kinase–Dependent Pathway That Is Impaired With Obesity

    Science.gov (United States)

    Steinberg, Gregory R.; Watt, Matthew J.; Ernst, Matthias; Birnbaum, Morris J.; Kemp, Bruce E.; Jørgensen, Sebastian Beck

    2009-01-01

    OBJECTIVE Ciliary neurotrophic factor (CNTF) reverses muscle insulin resistance by increasing fatty acid oxidation through gp130-LIF receptor signaling to the AMP-activated protein kinase (AMPK). CNTF also increases Akt signaling in neurons and adipocytes. Because both Akt and AMPK regulate glucose uptake, we investigated muscle glucose uptake in response to CNTF signaling in lean and obese mice. RESEARCH DESIGN AND METHODS Mice were injected intraperitoneally with saline or CNTF, and blood glucose was monitored. The effects of CNTF on skeletal muscle glucose uptake and AMPK/Akt signaling were investigated in incubated soleus and extensor digitorum longus (EDL) muscles from muscle-specific AMPKα2 kinase-dead, gp130ΔSTAT, and lean and obese ob/ob and high-fat–fed mice. The effect of C2-ceramide on glucose uptake and gp130 signaling was also examined. RESULTS CNTF reduced blood glucose and increased glucose uptake in isolated muscles in a time- and dose-dependent manner with maximal effects after 30 min with 100 ng/ml. CNTF increased Akt-S473 phosphorylation in soleus and EDL; however, AMPK-T172 phosphorylation was only increased in soleus. Incubation of muscles from AMPK kinase dead (KD) and wild-type littermates with the PI3-kinase inhibitor LY-294002 demonstrated that PI3-kinase, but not AMPK, was essential for CNTF-stimulated glucose uptake. CNTF-stimulated glucose uptake and Akt phosphorylation were substantially reduced in obesity (high-fat diet and ob/ob) despite normal induction of gp130/AMPK signaling—effects also observed when treating myotubes with C2-ceramide. CONCLUSIONS CNTF acutely increases muscle glucose uptake by a mechanism involving the PI3-kinase/Akt pathway that does not require AMPK. CNTF-stimulated glucose uptake is impaired in obesity-induced insulin resistance and by ceramide. PMID:19136654

  11. Nitrogenous compounds stimulate glucose-derived acid production by oral Streptococcus and Actinomyces.

    Science.gov (United States)

    Norimatsu, Yuka; Kawashima, Junko; Takano-Yamamoto, Teruko; Takahashi, Nobuhiro

    2015-09-01

    Both Streptococcus and Actinomyces can produce acids from dietary sugars and are frequently found in caries lesions. In the oral cavity, nitrogenous compounds, such as peptides and amino acids, are provided continuously by saliva and crevicular gingival fluid. Given that these bacteria can also utilize nitrogen compounds for their growth, it was hypothesized that nitrogenous compounds may influence their acid production; however, no previous studies have examined this topic. Therefore, the present study aimed to assess the effects of nitrogenous compounds (tryptone and glutamate) on glucose-derived acid production by Streptococcus and Actinomyces. Acid production was evaluated using a pH-stat method under anaerobic conditions, whereas the amounts of metabolic end-products were quantified using high performance liquid chromatography. Tryptone enhanced glucose-derived acid production by up to 2.68-fold, whereas glutamate enhanced Streptococcus species only. However, neither tryptone nor glutamate altered the end-product profiles, indicating that the nitrogenous compounds stimulate the whole metabolic pathways involving in acid production from glucose, but are not actively metabolized, nor do they alter metabolic pathways. These results suggest that nitrogenous compounds in the oral cavity promote acid production by Streptococcus and Actinomyces in vivo. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  12. Effect of Low Frequency Neuromuscular Electrical Stimulation on Glucose Profile of Persons with Type 2 Diabetes: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Georges Jabbour

    2015-06-01

    Full Text Available The purpose of this study was to examine the effect of low-frequency neuromuscular electrical stimulation (NMES on glucose profile in persons with type 2 diabetes mellitus (T2DM. Eight persons with T2DM (41 to 65 years completed a glucose tolerance test with and without NMES delivered to the knee extensors for a 1-hour period at 8 Hz. Three blood samples were collected: at rest, and then 60 and 120 minutes after consumption of a glucose load on the NMES and control days. In NMES groups glucose concentrations were significantly lower (P<0.01 than in the control conditions. Moreover, a significant positive correlation (r=0.9, P<0.01 was obtained between the intensity of stimulation and changes in blood glucose. Our results suggest that low-frequency stimulation seem suitable to induce enhance glucose uptake in persons with T2DM. Moreover, the intensity of stimulation reflecting the motor contraction should be considered during NMES procedure.

  13. Testosterone stimulates glucose uptake and GLUT4 translocation through LKB1/AMPK signaling in 3T3-L1 adipocytes.

    Science.gov (United States)

    Mitsuhashi, Kazuteru; Senmaru, Takafumi; Fukuda, Takuya; Yamazaki, Masahiro; Shinomiya, Katsuhiko; Ueno, Morio; Kinoshita, Shigeru; Kitawaki, Jo; Katsuyama, Masato; Tsujikawa, Muneo; Obayashi, Hiroshi; Nakamura, Naoto; Fukui, Michiaki

    2016-01-01

    Decreases in serum testosterone concentrations in aging men are associated with metabolic disorders. Testosterone has been reported to increase GLUT4-dependent glucose uptake in skeletal muscle cells and cardiomyocytes. However, studies on glucose uptake occurring in response to testosterone stimulation in adipocytes are currently not available. This study was designed to determine the effects of testosterone on glucose uptake in adipocytes. Glucose uptake was assessed with 2-[(3)H] deoxyglucose in 3T3-L1 adipocytes. GLUT4 translocation was evaluated in plasma membrane (PM) sheets and PM fractions by immunofluorescence and immunoblotting, respectively. Activation of GLUT4 translocation-related protein kinases, including Akt, AMPK, LKB1, CaMKI, CaMKII, and Cbl was followed by immunoblotting. Expression levels of androgen receptor (AR) mRNA and AR translocation to the PM were assessed by real-time RT-PCR and immunoblotting, respectively. The results showed that both high-dose (100 nM) testosterone and testosterone-BSA increased glucose uptake and GLUT4 translocation to the PM, independently of the intracellular AR. Testosterone and testosterone-BSA stimulated the phosphorylation of AMPK, LKB1, and CaMKII. The knockdown of LKB1 by siRNA attenuated testosterone- and testosterone-BSA-stimulated AMPK phosphorylation and glucose uptake. These results indicate that high-dose testosterone and testosterone-BSA increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes by inducing the LKB1/AMPK signaling pathway.

  14. Impaired insulin-stimulated nonoxidative glucose metabolism in pancreas-kidney transplant recipients. Dose-response effects of insulin on glucose turnover

    DEFF Research Database (Denmark)

    Christiansen, E; Vestergaard, H; Tibell, A

    1996-01-01

    Insulin resistance is a characteristic feature in recipients of a pancreas transplant, but the relative contribution of the liver and peripheral tissues to this abnormality within a spanning range of insulin concentrations is unknown. To assess the impact of insulin action on glucose metabolism....... The overall effects of insulin on whole-body glucose metabolism, determined as the glucose infusion rates versus the corresponding steady-state serum insulin concentrations, demonstrated a rightward shift in the dose-response curves of the transplanted groups compared with those of normal subjects. The dose......, this finding could only explain in part the degree of impairment in nonoxidative glucose metabolism. No differences were found in total hexokinase activity in muscle between normal subjects and the transplant groups at basal insulinemia or after insulin stimulation. During hyperinsulinemia, glucagon...

  15. Cyclosporin A stimulation of glucose-induced insulin secretion in MIN6 cells.

    Science.gov (United States)

    Ebihara, K; Fukunaga, K; Matsumoto, K; Shichiri, M; Miyamoto, E

    1996-12-01

    Effects of the immunosuppressant cyclosporin A (CsA), a specific inhibitor of Ca2+/calmodulin-dependent protein phosphatase (PP2B), were examined with regard to the induction of insulin secretion from MIN6 cells, a glucose-responsive cell line derived from mouse insulinoma. CsA had no effect on basal insulin secretion from MIN6 cells, but did increase glucose-, tolbutamide-, and KCl-induced insulin secretion. Treatment of the cells with CsA resulted in a dose-dependent increase in insulin secretion, which was maximal at 3 microM. CsA inhibited PP2B activity in a dose-dependent manner, and the increase in insulin secretion correlated with the decrease in PP2B activity. In 32P-labeled cells, treatment with CsA for 30 min increased phosphorylation of synapsin I-like protein by 50 +/- 5.7%. As revealed by one-dimensional phosphopeptide mapping of 32P-labeled synapsin I-like protein, treatment with CsA for 30 min increased phosphorylation of site II of synapsin I-like protein by 59 +/- 8%, which is phosphorylated by calmodulin kinase II. Messenger RNAs, which hybridize with complementary DNAs of calcineurin A and B subunits from rat brain, were detected in MIN6 cells. Western blot analysis showed a 61-kDa band, which interacts with rat brain calcineurin A antibody. Similar increases in secretagogue-induced insulin secretion with CsA were observed for HIT-T15 cells. These results suggest that CsA stimulates glucose-induced insulin secretion by inhibiting the activity of PP2B, an event that may be involved in mechanisms governing glucose-induced insulin secretion via dephosphorylation of synapsin I-like protein in MIN6 cells.

  16. Increased fetal myocardial sensitivity to insulin-stimulated glucose metabolism during ovine fetal growth restriction.

    Science.gov (United States)

    Barry, James S; Rozance, Paul J; Brown, Laura D; Anthony, Russell V; Thornburg, Kent L; Hay, William W

    2016-04-01

    Unlike other visceral organs, myocardial weight is maintained in relation to fetal body weight in intrauterine growth restriction (IUGR) fetal sheep despite hypoinsulinemia and global nutrient restriction. We designed experiments in fetal sheep with placental insufficiency and restricted growth to determine basal and insulin-stimulated myocardial glucose and oxygen metabolism and test the hypothesis that myocardial insulin sensitivity would be increased in the IUGR heart. IUGR was induced by maternal hyperthermia during gestation. Control (C) and IUGR fetal myocardial metabolism were measured at baseline and under acute hyperinsulinemic/euglycemic clamp conditions at 128-132 days gestation using fluorescent microspheres to determine myocardial blood flow. Fetal body and heart weights were reduced by 33% (P = 0.008) and 30% (P = 0.027), respectively. Heart weight to body weight ratios were not different. Basal left ventricular (LV) myocardial blood flow per gram of LV tissue was maintained in IUGR fetuses compared to controls. Insulin increased LV myocardial blood flow by ∼38% (P IUGR fetuses was 73% greater than controls. Similar to previous reports testing acute hypoxia, LV blood flow was inversely related to arterial oxygen concentration (r(2 )= 0.71) in both control and IUGR animals. Basal LV myocardial glucose delivery and uptake rates were not different between IUGR and control fetuses. Insulin increased LV myocardial glucose delivery (by 40%) and uptake (by 78%) (P IUGR fetuses compared to controls. During basal and hyperinsulinemic-euglycemic clamp conditions LV myocardial oxygen delivery, oxygen uptake, and oxygen extraction efficiency were not different between groups. These novel results demonstrate that the fetal heart exposed to nutrient and oxygen deprivation from placental insufficiency appears to maintain myocardial energy supply in the IUGR condition via increased glucose uptake and metabolic response to insulin, which support

  17. Nephrin is expressed on the surface of insulin vesicles and facilitates glucose-stimulated insulin release.

    Science.gov (United States)

    Fornoni, Alessia; Jeon, Jongmin; Varona Santos, Javier; Cobianchi, Lorenzo; Jauregui, Alexandra; Inverardi, Luca; Mandic, Slavena A; Bark, Christina; Johnson, Kevin; McNamara, George; Pileggi, Antonello; Molano, R Damaris; Reiser, Jochen; Tryggvason, Karl; Kerjaschki, Dontscho; Berggren, Per-Olof; Mundel, Peter; Ricordi, Camillo

    2010-01-01

    Nephrin, an immunoglobulin-like protein essential for the function of the glomerular podocyte and regulated in diabetic nephropathy, is also expressed in pancreatic beta-cells, where its function remains unknown. The aim of this study was to investigate whether diabetes modulates nephrin expression in human pancreatic islets and to explore the role of nephrin in beta-cell function. Nephrin expression in human pancreas and in MIN6 insulinoma cells was studied by Western blot, PCR, confocal microscopy, subcellular fractionation, and immunogold labeling. Islets from diabetic (n = 5) and nondiabetic (n = 7) patients were compared. Stable transfection and siRNA knockdown in MIN-6 cells/human islets were used to study nephrin function in vitro and in vivo after transplantation in diabetic immunodeficient mice. Live imaging of green fluorescent protein (GFP)-nephrin-transfected cells was used to study nephrin endocytosis. Nephrin was found at the plasma membrane and on insulin vesicles. Nephrin expression was decreased in islets from diabetic patients when compared with nondiabetic control subjects. Nephrin transfection in MIN-6 cells/pseudoislets resulted in higher glucose-stimulated insulin release in vitro and in vivo after transplantation into immunodeficient diabetic mice. Nephrin gene silencing abolished stimulated insulin release. Confocal imaging of GFP-nephrin-transfected cells revealed nephrin endocytosis upon glucose stimulation. Actin stabilization prevented nephrin trafficking as well as nephrin-positive effect on insulin release. Our data suggest that nephrin is an active component of insulin vesicle machinery that may affect vesicle-actin interaction and mobilization to the plasma membrane. Development of drugs targeting nephrin may represent a novel approach to treat diabetes.

  18. Design, synthesis and optimization of bis-amide derivatives as CSF1R inhibitors.

    Science.gov (United States)

    Ramachandran, Sreekanth A; Jadhavar, Pradeep S; Miglani, Sandeep K; Singh, Manvendra P; Kalane, Deepak P; Agarwal, Anil K; Sathe, Balaji D; Mukherjee, Kakoli; Gupta, Ashu; Haldar, Srijan; Raja, Mohd; Singh, Siddhartha; Pham, Son M; Chakravarty, Sarvajit; Quinn, Kevin; Belmar, Sebastian; Alfaro, Ivan E; Higgs, Christopher; Bernales, Sebastian; Herrera, Francisco J; Rai, Roopa

    2017-05-15

    Signaling via the receptor tyrosine kinase CSF1R is thought to play an important role in recruitment and differentiation of tumor-associated macrophages (TAMs). TAMs play pro-tumorigenic roles, including the suppression of anti-tumor immune response, promotion of angiogenesis and tumor cell metastasis. Because of the role of this signaling pathway in the tumor microenvironment, several small molecule CSF1R kinase inhibitors are undergoing clinical evaluation for cancer therapy, either as a single agent or in combination with other cancer therapies, including immune checkpoint inhibitors. Herein we describe our lead optimization effort that resulted in the identification of a potent, cellular active and orally bioavailable bis-amide CSF1R inhibitor. Docking and biochemical analysis allowed the removal of a metabolically labile and poorly permeable methyl piperazine group from an early lead compound. Optimization led to improved metabolic stability and Caco2 permeability, which in turn resulted in good oral bioavailability in mice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Vinegar Consumption Increases Insulin-Stimulated Glucose Uptake by the Forearm Muscle in Humans with Type 2 Diabetes.

    Science.gov (United States)

    Mitrou, Panayota; Petsiou, Eleni; Papakonstantinou, Emilia; Maratou, Eirini; Lambadiari, Vaia; Dimitriadis, Panayiotis; Spanoudi, Filio; Raptis, Sotirios A; Dimitriadis, George

    2015-01-01

    Vinegar has been shown to have a glucose-lowering effect in patients with glucose abnormalities. However, the mechanisms of this effect are still obscure. The aim of this randomised, crossover study was to investigate the effect of vinegar on glucose metabolism in muscle which is the most important tissue for insulin-stimulated glucose disposal. Eleven subjects with DM2 consumed vinegar or placebo (at random order on two separate days, a week apart), before a mixed meal. Plasma glucose, insulin, triglycerides, nonesterified fatty acids (NEFA), and glycerol were measured preprandially and at 30-60 min for 300 min postprandially from the radial artery and from a forearm vein. Muscle blood flow was measured with strain-gauge plethysmography. Glucose uptake was calculated as the arteriovenous difference of glucose multiplied by blood flow. Vinegar compared to placebo (1) increased forearm glucose uptake (p = 0.0357), (2) decreased plasma glucose (p = 0.0279), insulin (p = 0.0457), and triglycerides (p = 0.0439), and (3) did not change NEFA and glycerol. In DM2 vinegar reduces postprandial hyperglycaemia, hyperinsulinaemia, and hypertriglyceridaemia without affecting lipolysis. Vinegar's effect on carbohydrate metabolism may be partly accounted for by an increase in glucose uptake, demonstrating an improvement in insulin action in skeletal muscle. This trial is registered with Clinicaltrials.gov NCT02309424.

  20. Vinegar Consumption Increases Insulin-Stimulated Glucose Uptake by the Forearm Muscle in Humans with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Panayota Mitrou

    2015-01-01

    Full Text Available Background and Aims. Vinegar has been shown to have a glucose-lowering effect in patients with glucose abnormalities. However, the mechanisms of this effect are still obscure. The aim of this randomised, crossover study was to investigate the effect of vinegar on glucose metabolism in muscle which is the most important tissue for insulin-stimulated glucose disposal. Materials and Methods. Eleven subjects with DM2 consumed vinegar or placebo (at random order on two separate days, a week apart, before a mixed meal. Plasma glucose, insulin, triglycerides, nonesterified fatty acids (NEFA, and glycerol were measured preprandially and at 30–60 min for 300 min postprandially from the radial artery and from a forearm vein. Muscle blood flow was measured with strain-gauge plethysmography. Glucose uptake was calculated as the arteriovenous difference of glucose multiplied by blood flow. Results. Vinegar compared to placebo (1 increased forearm glucose uptake (p=0.0357, (2 decreased plasma glucose (p=0.0279, insulin (p=0.0457, and triglycerides (p=0.0439, and (3 did not change NEFA and glycerol. Conclusions. In DM2 vinegar reduces postprandial hyperglycaemia, hyperinsulinaemia, and hypertriglyceridaemia without affecting lipolysis. Vinegar’s effect on carbohydrate metabolism may be partly accounted for by an increase in glucose uptake, demonstrating an improvement in insulin action in skeletal muscle. This trial is registered with Clinicaltrials.gov NCT02309424.

  1. Effect of fiber type and nutritional state on AICAR- and contraction-stimulated glucose transport in rat muscle

    DEFF Research Database (Denmark)

    Ai, Hua; Ihlemann, Jacob; Hellsten, Ylva

    2002-01-01

    AMP-activated protein kinase (AMPK) may mediate the stimulatory effect of contraction and 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) on glucose transport in skeletal muscle. In muscles with different fiber type composition from fasted rats, AICAR increased 2-deoxyglucose transport......)- and alpha(2)-isoforms of AMPK. Expression of both isoforms varied with fiber types, and alpha(2) was highly expressed in nuclei. In conclusion, AICAR-stimulated glucose transport varies with muscle fiber type and nutritional state. AMPK is unlikely to be the sole mediator of contraction-stimulated glucose...... and total AMPK activity approximately twofold in epitrochlearis (EPI), less in flexor digitorum brevis, and not at all in soleus muscles. Contraction increased both transport and AMPK activity more than AICAR did. In EPI muscles, the effects of AICAR and contractions on glucose transport were partially...

  2. Fiber type effects on contraction-stimulated glucose uptake and GLUT4 abundance in single fibers from rat skeletal muscle.

    Science.gov (United States)

    Castorena, Carlos M; Arias, Edward B; Sharma, Naveen; Bogan, Jonathan S; Cartee, Gregory D

    2015-02-01

    To fully understand skeletal muscle at the cellular level, it is essential to evaluate single muscle fibers. Accordingly, the major goals of this study were to determine if there are fiber type-related differences in single fibers from rat skeletal muscle for: 1) contraction-stimulated glucose uptake and/or 2) the abundance of GLUT4 and other metabolically relevant proteins. Paired epitrochlearis muscles isolated from Wistar rats were either electrically stimulated to contract (E-Stim) or remained resting (No E-Stim). Single fibers isolated from muscles incubated with 2-deoxy-d-[(3)H]glucose (2-DG) were used to determine fiber type [myosin heavy chain (MHC) isoform protein expression], 2-DG uptake, and abundance of metabolically relevant proteins, including the GLUT4 glucose transporter. E-Stim, relative to No E-Stim, fibers had greater (P glucose uptake. Copyright © 2015 the American Physiological Society.

  3. Effect of Peripheral Electrical Stimulation (PES on Nocturnal Blood Glucose in Type 2 Diabetes: A Randomized Crossover Pilot Study.

    Directory of Open Access Journals (Sweden)

    Merav Catalogna

    Full Text Available Regulation of hepatic glucose production has been a target for antidiabetic drug development, due to its major contribution to glucose homeostasis. Previous pre-clinical study demonstrated that peripheral electrical stimulation (PES may stimulate glucose utilization and improve hepatic insulin sensitivity. The aim of the present study was to evaluate safety, tolerability, and the glucose-lowering effect of this approach in patients with type 2 diabetes (T2DM.Twelve patients with T2DM were recruited for an open label, interventional, randomized trial. Eleven patients underwent, in a crossover design, an active, and a no-intervention control periods, separated with a two-week washout phase. During the active period, the patients received a daily lower extremity PES treatment (1.33Hz/16Hz burst mode, for 14 days. Study endpoints included changes in glucose levels, number of hypoglycemic episodes, and other potential side effects. Endpoints were analyzed based on continuous glucose meter readings, and laboratory evaluation.We found that during the active period, the most significant effect was on nocturnal glucose control (P < 0.0004, as well as on pre-meal mean glucose levels (P < 0.02. The mean daily glucose levels were also decreased although it did not reach clinical significance (P = 0.07. A reduction in serum cortisol (P < 0.01 but not in insulin was also detected after 2 weeks of treatment. No adverse events were recorded.These results indicate that repeated PES treatment, even for a very short duration, can improve blood glucose control, possibly by suppressing hepatic glucose production. This effect may be mediated via hypothalamic-pituitary-adrenal axis modulation.ClinicalTrials.gov NCT02727790.

  4. Targeting distinct tumor-infiltrating myeloid cells by inhibiting CSF-1 receptor: combating tumor evasion of antiangiogenic therapy.

    Science.gov (United States)

    Priceman, Saul J; Sung, James L; Shaposhnik, Zory; Burton, Jeremy B; Torres-Collado, Antoni X; Moughon, Diana L; Johnson, Mai; Lusis, Aldons J; Cohen, Donald A; Iruela-Arispe, M Luisa; Wu, Lily

    2010-02-18

    Tumor-infiltrating myeloid cells (TIMs) support tumor growth by promoting angiogenesis and suppressing antitumor immune responses. CSF-1 receptor (CSF1R) signaling is important for the recruitment of CD11b(+)F4/80(+) tumor-associated macrophages (TAMs) and contributes to myeloid cell-mediated angiogenesis. However, the impact of the CSF1R signaling pathway on other TIM subsets, including CD11b(+)Gr-1(+) myeloid-derived suppressor cells (MDSCs), is unknown. Tumor-infiltrating MDSCs have also been shown to contribute to tumor angiogenesis and have recently been implicated in tumor resistance to antiangiogenic therapy, yet their precise involvement in these processes is not well understood. Here, we use the selective pharmacologic inhibitor of CSF1R signaling, GW2580, to demonstrate that CSF-1 regulates the tumor recruitment of CD11b(+)Gr-1(lo)Ly6C(hi) mononuclear MDSCs. Targeting these TIM subsets inhibits tumor angiogenesis associated with reduced expression of proangiogenic and immunosuppressive genes. Combination therapy using GW2580 with an anti-VEGFR-2 antibody synergistically suppresses tumor growth and severely impairs tumor angiogenesis along with reverting at least one TIM-mediated antiangiogenic compensatory mechanism involving MMP-9. These data highlight the importance of CSF1R signaling in the recruitment and function of distinct TIM subsets, including MDSCs, and validate the benefits of targeting CSF1R signaling in combination with antiangiogenic drugs for the treatment of solid cancers.

  5. Role of Akt substrate of 160 kDa in insulin-stimulated and contraction-stimulated glucose transport

    DEFF Research Database (Denmark)

    Cartee, Gregory D; Wojtaszewski, Jørgen F P

    2007-01-01

    Insulin and exercise, the most important physiological stimuli to increase glucose transport in skeletal muscle, trigger a redistribution of GLUT4 glucose transporter proteins from the cell interior to the cell surface, thereby increasing glucose transport capacity. The most distal insulin signal...

  6. Regulation of myosin light chain kinase during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.

    Science.gov (United States)

    Woody, Shelly; Stall, Richard; Ramos, Joseph; Patel, Yashomati M

    2013-01-01

    Myosin II (MyoII) is required for insulin-responsive glucose transporter 4 (GLUT4)-mediated glucose uptake in 3T3-L1 adipocytes. Our previous studies have shown that insulin signaling stimulates phosphorylation of the regulatory light chain (RLC) of MyoIIA via myosin light chain kinase (MLCK). The experiments described here delineate upstream regulators of MLCK during insulin-stimulated glucose uptake. Since 3T3-L1 adipocytes express two MyoII isoforms, we wanted to determine which isoform was required for insulin-stimulated glucose uptake. Using a siRNA approach, we demonstrate that a 60% decrease in MyoIIA protein expression resulted in a 40% inhibition of insulin-stimulated glucose uptake. We also show that insulin signaling stimulates the phosphorylation of MLCK. We further show that MLCK can be activated by calcium as well as signaling pathways. We demonstrate that adipocytes treated with the calcium chelating agent, 1,2-b (iso-aminophenoxy) ethane-N,N,N',N'-tetra acetic acid, (BAPTA) (in the presence of insulin) impaired the insulin-induced phosphorylation of MLCK by 52% and the RLC of MyoIIA by 45% as well as impairing the recruitment of MyoIIA to the plasma membrane when compared to cells treated with insulin alone. We further show that the calcium ionophore, A23187 alone stimulated the phosphorylation of MLCK and the RLC associated with MyoIIA to the same extent as insulin. To identify signaling pathways that might regulate MLCK, we examined ERK and CaMKII. Inhibition of ERK2 impaired phosphorylation of MLCK and insulin-stimulated glucose uptake. In contrast, while inhibition of CaMKII did inhibit phosphorylation of the RLC associated with MyoIIA, inhibition of CAMKIIδ did not impair MLCK phosphorylation or translocation to the plasma membrane or glucose uptake. Collectively, our results are the first to delineate a role for calcium and ERK in the activation of MLCK and thus MyoIIA during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.

  7. Regulation of myosin light chain kinase during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.

    Directory of Open Access Journals (Sweden)

    Shelly Woody

    Full Text Available Myosin II (MyoII is required for insulin-responsive glucose transporter 4 (GLUT4-mediated glucose uptake in 3T3-L1 adipocytes. Our previous studies have shown that insulin signaling stimulates phosphorylation of the regulatory light chain (RLC of MyoIIA via myosin light chain kinase (MLCK. The experiments described here delineate upstream regulators of MLCK during insulin-stimulated glucose uptake. Since 3T3-L1 adipocytes express two MyoII isoforms, we wanted to determine which isoform was required for insulin-stimulated glucose uptake. Using a siRNA approach, we demonstrate that a 60% decrease in MyoIIA protein expression resulted in a 40% inhibition of insulin-stimulated glucose uptake. We also show that insulin signaling stimulates the phosphorylation of MLCK. We further show that MLCK can be activated by calcium as well as signaling pathways. We demonstrate that adipocytes treated with the calcium chelating agent, 1,2-b (iso-aminophenoxy ethane-N,N,N',N'-tetra acetic acid, (BAPTA (in the presence of insulin impaired the insulin-induced phosphorylation of MLCK by 52% and the RLC of MyoIIA by 45% as well as impairing the recruitment of MyoIIA to the plasma membrane when compared to cells treated with insulin alone. We further show that the calcium ionophore, A23187 alone stimulated the phosphorylation of MLCK and the RLC associated with MyoIIA to the same extent as insulin. To identify signaling pathways that might regulate MLCK, we examined ERK and CaMKII. Inhibition of ERK2 impaired phosphorylation of MLCK and insulin-stimulated glucose uptake. In contrast, while inhibition of CaMKII did inhibit phosphorylation of the RLC associated with MyoIIA, inhibition of CAMKIIδ did not impair MLCK phosphorylation or translocation to the plasma membrane or glucose uptake. Collectively, our results are the first to delineate a role for calcium and ERK in the activation of MLCK and thus MyoIIA during insulin-stimulated glucose uptake in 3T3-L1 adipocytes.

  8. Effects of repeated tooth pulp stimulation on concentrations of plasma catecholamines, corticosterone, and glucose in rats.

    Science.gov (United States)

    Hasegawa, Makoto; Hada, Junichi; Fujiwara, Masanori; Honda, Kousuke

    2014-08-01

    In this study, we examined whether tooth pulp stimulation (TPS) affects the stress responses in anesthetized rats. As for stress response indices, we monitored changes in the concentrations of plasma catecholamines (CAs) (adrenaline, noradrenaline, and dopamine), corticosterone (CS), and glucose (Glu). We observed that repeated TPS attenuated plasma adrenaline, dopamine, CS, and Glu levels compared with those of sham-TPS. After administering naloxone, an opioid antagonist, repeated TPS reversed the decreases in plasma CAs, CS, and Glu. These findings showed that the effects of repeated TPS may be mediated by endogenous opioid administration. Our findings suggest that repeated TPS can induce stress-analgesia and that an endogenous descending pain modulation system exists.

  9. Recombinant canine single chain insulin analogues: insulin receptor binding capacity and ability to stimulate glucose uptake.

    Science.gov (United States)

    Adams, Jamie P; Holder, Angela L; Catchpole, Brian

    2014-12-01

    Virtually all diabetic dogs require exogenous insulin therapy to control their hyperglycaemia. In the UK, the only licensed insulin product currently available is a purified porcine insulin preparation. Recombinant insulin is somewhat problematic in terms of its manufacture, since the gene product (preproinsulin) undergoes substantial post-translational modification in pancreatic β cells before it becomes biologically active. The aim of the present study was to develop recombinant canine single chain insulin (SCI) analogues that could be produced in a prokaryotic expression system and which would require minimal processing. Three recombinant SCI constructs were developed in a prokaryotic expression vector, by replacing the insulin C-peptide sequence with one encoding a synthetic peptide (GGGPGKR), or with one of two insulin-like growth factor (IGF)-2 C-peptide coding sequences (human: SRVSRRSR; canine: SRVTRRSSR). Recombinant proteins were expressed in the periplasmic fraction of Escherichia coli and assessed for their ability to bind to the insulin and IGF-1 receptors, and to stimulate glucose uptake in 3T3-L1 adipocytes. All three recombinant SCI analogues demonstrated preferential binding to the insulin receptor compared to the IGF-1 receptor, with increased binding compared to recombinant canine proinsulin. The recombinant SCI analogues stimulated glucose uptake in 3T3-L1 adipocytes compared to negligible uptake using recombinant canine proinsulin, with the canine insulin/cIGF-2 chimaeric SCI analogue demonstrating the greatest effect. Thus, biologically-active recombinant canine SCI analogues can be produced relatively easily in bacteria, which could potentially be used for treatment of diabetic dogs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Sweet taste receptors in rat small intestine stimulate glucose absorption through apical GLUT2

    Science.gov (United States)

    Mace, Oliver J; Affleck, Julie; Patel, Nick; Kellett, George L

    2007-01-01

    Natural sugars and artificial sweeteners are sensed by receptors in taste buds. T2R bitter and T1R sweet taste receptors are coupled through G-proteins, α-gustducin and transducin, to activate phospholipase C β2 and increase intracellular calcium concentration. Intestinal brush cells or solitary chemosensory cells (SCCs) have a structure similar to lingual taste cells and strongly express α-gustducin. It has therefore been suggested over the last decade that brush cells may participate in sugar sensing by a mechanism analogous to that in taste buds. We provide here functional evidence for an intestinal sensing system based on lingual taste receptors. Western blotting and immunocytochemistry revealed that all T1R members are expressed in rat jejunum at strategic locations including Paneth cells, SCCs or the apical membrane of enterocytes; T1Rs are colocalized with each other and with α-gustducin, transducin or phospholipase C β2 to different extents. Intestinal glucose absorption consists of two components: one is classical active Na+–glucose cotransport, the other is the diffusive apical GLUT2 pathway. Artificial sweeteners increase glucose absorption in the order acesulfame potassium ∼ sucralose > saccharin, in parallel with their ability to increase intracellular calcium concentration. Stimulation occurs within minutes by an increase in apical GLUT2, which correlates with reciprocal regulation of T1R2, T1R3 and α-gustducin versus T1R1, transducin and phospholipase C β2. Our observation that artificial sweeteners are nutritionally active, because they can signal to a functional taste reception system to increase sugar absorption during a meal, has wide implications for nutrient sensing and nutrition in the treatment of obesity and diabetes. PMID:17495045

  11. Prognostic impact of CD57, CD68, M-CSF, CSF-1R, Ki67 and TGF-beta in soft tissue sarcomas

    Directory of Open Access Journals (Sweden)

    Sorbye Sveinung W

    2012-05-01

    Full Text Available Abstract Background Prognostic markers in curable STS may have the potential to guide therapy after surgical resection. The purpose of this study was to clarify the prognostic impact of the presence of cells and growth factors belonging to the innate immune system in soft tissue sarcomas (STS. The significance of macrophages (CD68, their growth factor macrophage colony-stimulating factor (M-CSF, its receptor colony-stimulating factor-1 receptor (CSF-1R, natural killer cells (CD57 and the general immunomodulating molecule (TGF-beta are all controversial in STS. Herein, these markers are evaluated and compared to the cell proliferation marker Ki67. Methods Tissue microarrays from 249 patients with non-gastrointestinal (non-GIST STS were constructed from duplicate cores of viable and representative neoplastic tumor areas and duplicate cores of peritumoral capsule. Immunohistochemistry was used to evaluate the expression of CD68, M-CSF, CSF-1R, CD57, TGF-beta and Ki67 in tumor and peritumoral capsule. Results In univariate analyses increased expression of M-CSF (P = 0.034, Ki67 (P  Conclusions Increased co-expression of M-CSF and TGF-beta in tumor in patients with STS, and increased expression of Ki67 in peritumoral capsule were independent negative prognostic factors for DSS.

  12. Rapid post-oral stimulation of intake and flavor conditioning by glucose and fat in the mouse

    Science.gov (United States)

    Zukerman, Steven; Ackroff, Karen

    2011-01-01

    Although widely assumed to have only satiating actions, nutrients in the gut can also condition increases in intake in some cases. Here we studied the time course of post-oral nutrient stimulation of ingestion in food-restricted C57BL/6J mice. In experiment 1, mice adapted to drink a 0.8% sucralose solution 1 h/day, rapidly increased their rate of licking (within 4–6 min) when first tested with an 8% glucose solution and even more so in tests 2 and 3. Other mice decreased their licking rate when switched from sucralose to 8% fructose, a sugar that is sweet like glucose but lacks positive post-oral effects in mice. The glucose-stimulated drinking is due to the sugar's post-oral rather than taste properties, because sucralose is highly preferred to glucose and fructose in brief choice tests. A second experiment showed that the glucose-stimulated ingestion is associated with a conditioned flavor preference in both intact and capsaicin-treated mice. This indicates that the post-oral stimulatory action of glucose is not mediated by capsaicin-sensitive visceral afferents. In experiment 3, mice consumed flavored saccharin solutions as they self-infused water or glucose via an intragastric (IG) catheter. The glucose self-infusion stimulated ingestion within 13–15 min in test 1 and produced a conditioned increase in licking that was apparent in the initial minute of tests 2 and 3. Experiment 4 revealed that IG self-infusions of a fat emulsion also resulted in post-oral stimulation of licking in test 1 and conditioned increases in tests 2 and 3. These findings indicate that glucose and fat can generate stimulatory post-oral signals early in a feeding session that increase ongoing ingestion and condition increases in flavor acceptance and preference revealed in subsequent feeding sessions. The test procedures developed here can be used to investigate the peripheral and central processes involved in stimulation of intake by post-oral nutrients. PMID:21975648

  13. Methylated trivalent arsenicals are potent inhibitors of glucose stimulated insulin secretion by murine pancreatic islets

    Energy Technology Data Exchange (ETDEWEB)

    Douillet, Christelle [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Currier, Jenna [Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Saunders, Jesse [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States); Bodnar, Wanda M. [Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7431 (United States); Matoušek, Tomáš [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); Stýblo, Miroslav, E-mail: styblo@med.unc.edu [Department of Nutrition, Gillings School of Global Public Health, 2302 MHRC, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461 (United States)

    2013-02-15

    Epidemiologic evidence has linked chronic exposure to inorganic arsenic (iAs) with an increased prevalence of diabetes mellitus. Laboratory studies have identified several mechanisms by which iAs can impair glucose homeostasis. We have previously shown that micromolar concentrations of arsenite (iAs{sup III}) or its methylated trivalent metabolites, methylarsonite (MAs{sup III}) and dimethylarsinite (DMAs{sup III}), inhibit the insulin-activated signal transduction pathway, resulting in insulin resistance in adipocytes. Our present study examined effects of the trivalent arsenicals on insulin secretion by intact pancreatic islets isolated from C57BL/6 mice. We found that 48-hour exposures to low subtoxic concentrations of iAs{sup III}, MAs{sup III} or DMAs{sup III} inhibited glucose-stimulated insulin secretion (GSIS), but not basal insulin secretion. MAs{sup III} and DMAs{sup III} were more potent than iAs{sup III} as GSIS inhibitors with estimated IC{sub 50} ≤ 0.1 μM. The exposures had little or no effects on insulin content of the islets or on insulin expression, suggesting that trivalent arsenicals interfere with mechanisms regulating packaging of the insulin transport vesicles or with translocation of these vesicles to the plasma membrane. Notably, the inhibition of GSIS by iAs{sup III}, MAs{sup III} or DMAs{sup III} could be reversed by a 24-hour incubation of the islets in arsenic-free medium. These results suggest that the insulin producing pancreatic β-cells are among the targets for iAs exposure and that the inhibition of GSIS by low concentrations of the methylated metabolites of iAs may be the key mechanism of iAs-induced diabetes. - Highlights: ► Trivalent arsenicals inhibit glucose stimulated insulin secretion by pancreatic islets. ► MAs{sup III} and DMAs{sup III} are more potent inhibitors than arsenite with IC{sub 50} ∼ 0.1 μM. ► The arsenicals have little or no effects on insulin expression in pancreatic islets. ► The inhibition of

  14. Studies on Colony Stimulating Factor Receptor-1 and Ligands Colony Stimulating Factor-1 and Interleukin-34 in Alzheimer's Disease Brains and Human Microglia.

    Science.gov (United States)

    Walker, Douglas G; Tang, Tiffany M; Lue, Lih-Fen

    2017-01-01

    Microglia are dependent on signaling through the colony stimulating factor-1 receptor (CSF-1R/CD115) for growth and survival. Activation of CSF-1R can lead to cell division, while blocking CSF-1R can lead to rapid microglia cell death. CSF-1R has two ligands, the growth factors colony stimulating factor-1 (CSF-1) and the more recently identified interleukin-34 (IL-34). Studies of IL-34 activation of rodent microglia and human macrophages have suggested it has different properties to CSF-1, resulting in an anti-inflammatory reparative phenotype. The goal of this study was to identify if the responses of human postmortem brain microglia to IL-34 differed from their responses to CSF-1 with the aim of identifying different phenotypes of microglia as a result of their responses. To approach this question, we also sought to identify differences between IL-34, CSF-1, and CSF-1R expression in human brain samples to establish whether there was an imbalance in Alzheimer's disease (AD). Using human brain samples [inferior temporal gyrus (ITG) and middle temporal gyrus (MTG)] from distinct cohorts of AD, control and high pathology, or mild cognitive impairment cases, we showed that there was increased expression of CSF-1R and CSF-1 mRNAs in both series of AD cases, and reduced expression of IL-34 mRNA in AD ITG samples. There was no change in expression of these genes in RNA from cerebellum of AD, Parkinson's disease (PD), or control cases. The results suggested an imbalance in CSF-1R signaling in AD. Using RNA sequencing to compare gene expression responses of CSF-1 and IL-34 stimulated human microglia, a profile of responses to CSF-1 and IL-34 was identified. Contrary to earlier work with rodent microglia, IL-34 induced primarily a classical activation response similar to that of CSF-1. It was not possible to identify any genes expressed significantly different by IL-34-stimulated microglia compared to CSF-1-stimulated microglia, but both cytokines did induce certain

  15. Studies on Colony Stimulating Factor Receptor-1 and Ligands Colony Stimulating Factor-1 and Interleukin-34 in Alzheimer's Disease Brains and Human Microglia

    Directory of Open Access Journals (Sweden)

    Douglas G. Walker

    2017-08-01

    Full Text Available Microglia are dependent on signaling through the colony stimulating factor-1 receptor (CSF-1R/CD115 for growth and survival. Activation of CSF-1R can lead to cell division, while blocking CSF-1R can lead to rapid microglia cell death. CSF-1R has two ligands, the growth factors colony stimulating factor-1 (CSF-1 and the more recently identified interleukin-34 (IL-34. Studies of IL-34 activation of rodent microglia and human macrophages have suggested it has different properties to CSF-1, resulting in an anti-inflammatory reparative phenotype. The goal of this study was to identify if the responses of human postmortem brain microglia to IL-34 differed from their responses to CSF-1 with the aim of identifying different phenotypes of microglia as a result of their responses. To approach this question, we also sought to identify differences between IL-34, CSF-1, and CSF-1R expression in human brain samples to establish whether there was an imbalance in Alzheimer's disease (AD. Using human brain samples [inferior temporal gyrus (ITG and middle temporal gyrus (MTG] from distinct cohorts of AD, control and high pathology, or mild cognitive impairment cases, we showed that there was increased expression of CSF-1R and CSF-1 mRNAs in both series of AD cases, and reduced expression of IL-34 mRNA in AD ITG samples. There was no change in expression of these genes in RNA from cerebellum of AD, Parkinson's disease (PD, or control cases. The results suggested an imbalance in CSF-1R signaling in AD. Using RNA sequencing to compare gene expression responses of CSF-1 and IL-34 stimulated human microglia, a profile of responses to CSF-1 and IL-34 was identified. Contrary to earlier work with rodent microglia, IL-34 induced primarily a classical activation response similar to that of CSF-1. It was not possible to identify any genes expressed significantly different by IL-34-stimulated microglia compared to CSF-1-stimulated microglia, but both cytokines did induce

  16. suPAR associates to glucose metabolic aberration during glucose stimulation in HIV-infected patients on HAART

    DEFF Research Database (Denmark)

    Andersen, Ove; Eugen-Olsen, Jesper; Kofoed, Kristian

    2008-01-01

    extend these findings by investigating the association of suPAR to glucose metabolic insufficiency during an oral glucose challenge (OGTT). METHODS: In 16 HIV-infected patients with lipodystrophy and 15 HIV-infected patients without lipodystrophy, glucose tolerance, insulin sensitivity (ISI......(composite)), prehepatic insulin secretion, proinsulin level and suppression of free fatty acids (FFA) were determined during an OGTT. Stability of suPAR was tested in 6 HIV-infected patients during a 3h OGTT. RESULTS: Lipodystrophy was associated with a 70% increase in plasma suPAR (P...PAR correlated inversely with ISI(composite) and positively with 2h plasma glucose, fasting insulin secretion, fasting intact proinsulin and FFA level during the OGTT (all P

  17. Effect of Bacterial Endotoxins on Superovulated Mouse Embryos In Vivo: Is CSF-1 Involved in Endotoxin-Induced Pregnancy Loss?

    Directory of Open Access Journals (Sweden)

    Yogesh Kumar Jaiswal

    2006-01-01

    Full Text Available Mammalian embryonic development is regulated by several cytokines and growth factors from embryonic or maternal origins. Since CSF-1 plays important role in embryonic development and implantation, we investigated its role in gram-negative bacterial LPS-induced implantation failure. The effect of LPS on normal (nonsuperovulated and superovulated in vivo-produced embryos was assessed by signs of morphological degeneration. A significantly similar number of morphologically degenerated embryos recovered from both nonsuperovulated and superovulated LPS treated animals on day 2.5 of pregnancy onwards were morphologically and developmentally abnormal as compared to their respective controls (P < .001. Normal CSF-1 expression level and pattern were also altered through the preimplantation period in the mouse embryos and uterine horns after LPS treatment. This deviation from the normal pattern and level of CSF-1 expression in the preimplantation embryos and uterine tissues suggest a role for CSF-1 in LPS-induced implantation failure.

  18. Chemokine polyreactivity of IL7Rα+CSF-1R+ lympho-myeloid progenitors in the developing fetal liver

    National Research Council Canada - National Science Library

    Kajikhina, Katja; Melchers, Fritz; Tsuneto, Motokazu

    2015-01-01

    .... Within early multipotent progenitors an IL7Rα(+)CSF-1R(+) subset expressed a mixture of lymphoid- and myeloid-specific genes and differentiated to lymphoid and myeloid lineages in vitro. By contrast, IL7Rα...

  19. Rac1 governs exercise-stimulated glucose uptake in skeletal muscle through regulation of GLUT4 translocation in mice.

    Science.gov (United States)

    Sylow, Lykke; Nielsen, Ida L; Kleinert, Maximilian; Møller, Lisbeth L V; Ploug, Thorkil; Schjerling, Peter; Bilan, Philip J; Klip, Amira; Jensen, Thomas E; Richter, Erik A

    2016-09-01

    Exercise increases skeletal muscle energy turnover and one of the important substrates for the working muscle is glucose taken up from the blood. The GTPase Rac1 can be activated by muscle contraction and has been found to be necessary for insulin-stimulated glucose uptake, although its role in exercise-stimulated glucose uptake is unknown. We show that Rac1 regulates the translocation of the glucose transporter GLUT4 to the plasma membrane in skeletal muscle during exercise. We find that Rac1 knockout mice display significantly reduced glucose uptake in skeletal muscle during exercise. Exercise increases skeletal muscle energy turnover and one of the important substrates for the working muscle is glucose taken up from the blood. Despite extensive efforts, the signalling mechanisms vital for glucose uptake during exercise are not yet fully understood, although the GTPase Rac1 is a candidate molecule. The present study investigated the role of Rac1 in muscle glucose uptake and substrate utilization during treadmill exercise in mice in vivo. Exercise-induced uptake of radiolabelled 2-deoxyglucose at 65% of maximum running capacity was blocked in soleus muscle and decreased by 80% and 60% in gastrocnemius and tibialis anterior muscles, respectively, in muscle-specific inducible Rac1 knockout (mKO) mice compared to wild-type littermates. By developing an assay to quantify endogenous GLUT4 translocation, we observed that GLUT4 content at the sarcolemma in response to exercise was reduced in Rac1 mKO muscle. Our findings implicate Rac1 as a regulatory element critical for controlling glucose uptake during exercise via regulation of GLUT4 translocation. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  20. An Open-Label, Multicenter, Phase I/II Study of JNJ-40346527, a CSF-1R Inhibitor, in Patients with Relapsed or Refractory Hodgkin Lymphoma.

    Science.gov (United States)

    von Tresckow, Bastian; Morschhauser, Franck; Ribrag, Vincent; Topp, Max S; Chien, Caly; Seetharam, Shobha; Aquino, Regina; Kotoulek, Sonja; de Boer, Carla J; Engert, Andreas

    2015-04-15

    This phase I/II study investigated JNJ-40346527, a selective inhibitor of the colony-stimulating factor-1 receptor (CSF-1R) tyrosine kinase as treatment for relapsed or refractory classical Hodgkin lymphoma (cHL). Patients ≥18 years with histopathologically confirmed initial diagnosis of cHL that had relapsed or was refractory after ≥1 appropriate therapies were assigned to sequential cohorts of oral daily doses of JNJ-40346527 (150, 300, 450, 600 mg every day, and 150 mg twice a day). For the dose-escalation phase, the primary endpoint was to establish the recommended phase II dose. Secondary endpoints included safety, pharmacokinetics, and pharmacodynamics. Twenty-one patients [(150 mg: 3; 300 mg: 5; 450 mg: 3, 600 mg: 3) every day, and 150 mg twice a day: 7] were enrolled, 10 men, median age 40 (range, 19-75) years, median number of prior systemic therapies 6 (range, 3-14). No dose-limiting toxicities were observed; maximum-tolerated dose was not established. Best overall response was complete remission in 1 patient (duration, +352 days) and stable disease in 11 patients: (duration, 1.5-8 months). Median number of cycles: 4 (range, 1-16). Most common (≥20% patients) possibly drug-related adverse events (per investigator assessment) were nausea (n = 6), headache, and pyrexia (n = 5 each). JNJ-40346527 exposure increased in near dose-proportional manner over a dose range of 150 to 450 mg every day, but plateaued at 600 mg every day. Target engagement was confirmed (>80% inhibition of CSF-1R phosphorylation, 4 hours after dosing). JNJ-40346527, a selective inhibitor of CSF-1R was well tolerated, and preliminary antitumor results suggested limited activity in monotherapy for the treatment of cHL. ©2015 American Association for Cancer Research.

  1. Glucose Stimulation of Transforming Growth Factor-β Bioactivity in Mesangial Cells Is Mediated by Thrombospondin-1

    Science.gov (United States)

    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

  2. Glucose stimulates neurotensin secretion from the rat small intestine by mechanisms involving SGLT1 and GLUT2 leading to cell depolarization and calcium influx

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Bechmann, Louise Ellegaard; Hartmann, Bolette

    2015-01-01

    , suggesting that glucose stimulates secretion by initial uptake by this transporter. However, secretion was also sensitive to GLUT2 inhibition (by phloretin) and blockage of oxidative phosphorylation (2-4-dinitrophenol). Direct KATP channel closure by sulfonylureas stimulated secretion. Therefore, glucose...

  3. Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas Møller; Treebak, Jonas Thue; Schjerling, Peter

    2014-01-01

    signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase α2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot......Background: Metformin-induced activation of AMPK has been associated with enhanced glucose uptake in skeletal muscle but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent upon AMPK...... analyzes. Results: Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (45%, P...

  4. Glucose-stimulated insulin release: Parallel perifusion studies of free and hydrogel encapsulated human pancreatic islets.

    Science.gov (United States)

    Buchwald, Peter; Tamayo-Garcia, Alejandro; Manzoli, Vita; Tomei, Alice A; Stabler, Cherie L

    2018-01-01

    To explore the effects immune-isolating encapsulation has on the insulin secretion of pancreatic islets and to improve our ability to quantitatively describe the glucose-stimulated insulin release (GSIR) of pancreatic islets, we conducted dynamic perifusion experiments with isolated human islets. Free (unencapsulated) and hydrogel encapsulated islets were perifused, in parallel, using an automated multi-channel system that allows sample collection with high temporal resolution. Results indicated that free human islets secrete less insulin per unit mass or islet equivalent (IEQ) than murine islets and with a less pronounced first-phase peak. While small microcapsules (d = 700 µm) caused only a slightly delayed and blunted first-phase insulin response compared to unencapsulated islets, larger capsules (d = 1,800 µm) completely blunted the first-phase peak and decreased the total amount of insulin released. Experimentally obtained insulin time-profiles were fitted with our complex insulin secretion computational model. This allowed further fine-tuning of the hormone-release parameters of this model, which was implemented in COMSOL Multiphysics to couple hormone secretion and nutrient consumption kinetics with diffusive and convective transport. The results of these GSIR experiments, which were also supported by computational modeling, indicate that larger capsules unavoidably lead to dampening of the first-phase insulin response and to a sustained-release type insulin secretion that can only slowly respond to changes in glucose concentration. Bioartificial pancreas type devices can provide long-term and physiologically desirable solutions only if immunoisolation and biocompatibility considerations are integrated with optimized nutrient diffusion and insulin release characteristics by design. © 2017 Wiley Periodicals, Inc.

  5. Disruption of microtubules in rat skeletal muscle does not inhibit insulin- or contraction-stimulated glucose transport

    DEFF Research Database (Denmark)

    Ai, Hua; Ralston, Evelyn; Lauritzen, Hans P M M

    2003-01-01

    found in all muscle fibers. Here, we test whether microtubules are required mediators of the effect of insulin and contractions. In three different incubated rat muscles with distinct fiber type composition, depolymerization of microtubules with colchicine for ...- or contraction-stimulated 2-deoxyglucose transport or force production. On the contrary, colchicine at least partially prevented the approximately 30% decrease in insulin-stimulated transport that specifically developed during 8 h of incubation in soleus muscle but not in flexor digitorum brevis...... or epitrochlearis muscles. In contrast, nocodazole, another microtubule-disrupting drug, rapidly and dose dependently blocked insulin- and contraction-stimulated glucose transport. A similar discrepancy between colchicine and nocodazole was also found in their ability to block glucose transport in muscle giant...

  6. Increasing palmitic acid intake enhances milk production and prevents glucose-stimulated fatty acid disappearance without modifying systemic glucose tolerance in mid-lactation dairy cows.

    Science.gov (United States)

    Mathews, A T; Rico, J E; Sprenkle, N T; Lock, A L; McFadden, J W

    2016-11-01

    first week of PALM treatment; however, glucose disposal following glucose tolerance tests was not modified. In contrast, C16:0 feeding reduced glucose-stimulated NEFA disappearance by wk 7. Results demonstrate that increasing dietary energy from C16:0 for 7wk improves milk yield and milk composition without modifying systemic glucose tolerance. Reduced glucose-stimulated NEFA disappearance with C16:0 feeding and elevated circulating NEFA may reflect changes in adipose tissue insulin sensitivity. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Imeglimin lowers glucose primarily by amplifying glucose-stimulated insulin secretion in high-fat-fed rodents

    DEFF Research Database (Denmark)

    Perry, Rachel J; Cardone, Rebecca L; Petersen, Max C

    2016-01-01

    Imeglimin is a promising new oral antihyperglycemic agent that has been studied in clinical trials as a possible monotherapy or add-on therapy to lower fasting plasma glucose and improve hemoglobin A1c (1-3, 9). Imeglimin was shown to improve both fasting and postprandial glycemia and to increase...... insulin secretion in response to glucose during a hyperglycemic clamp after 1-wk of treatment in type 2 diabetic patients. However, whether the β-cell stimulatory effect of imeglimin is solely or partially responsible for its effects on glycemia remains to be fully confirmed. Here, we show that imeglimin...

  8. Glucose-stimulated calcium dynamics in islets of Langerhans in acute mouse pancreas tissue slices.

    Directory of Open Access Journals (Sweden)

    Andraž Stožer

    Full Text Available In endocrine cells within islets of Langerhans calcium ions couple cell stimulation to hormone secretion. Since the advent of modern fluorimetry, numerous in vitro studies employing primarily isolated mouse islets have investigated the effects of various secretagogues on cytoplasmic calcium, predominantly in insulin-secreting beta cells. Due to technical limitations, insights of these studies are inherently limited to a rather small subpopulation of outermost cells. The results also seem to depend on various factors, like culture conditions and duration, and are not always easily reconcilable with findings in vivo. The main controversies regard the types of calcium oscillations, presence of calcium waves, and the level of synchronized activity. Here, we set out to combine the in situ acute mouse pancreas tissue slice preparation with noninvasive fluorescent calcium labeling and subsequent confocal laser scanning microscopy to shed new light on the existing controversies utilizing an innovative approach enabling the characterization of responses in many cells from all layers of islets. Our experiments reproducibly showed stable fast calcium oscillations on a sustained plateau rather than slow oscillations as the predominant type of response in acute tissue slices, and that calcium waves are the mechanistic substrate for synchronization of oscillations. We also found indirect evidence that even a large amplitude calcium signal was not sufficient and that metabolic activation was necessary to ensure cell synchronization upon stimulation with glucose. Our novel method helped resolve existing controversies and showed the potential to help answer important physiological questions, making it one of the methods of choice for the foreseeable future.

  9. Triiodothyronine acutely stimulates glucose transport into L6 muscle cells without increasing surface GLUT4, GLUT1, or GLUT3.

    Science.gov (United States)

    Teixeira, Silvania Silva; Tamrakar, Akhilesh K; Goulart-Silva, Francemilson; Serrano-Nascimento, Caroline; Klip, Amira; Nunes, Maria Tereza

    2012-07-01

    Thyroid hormones (THs) act genomically to stimulate glucose transport by elevating glucose transporter (Slc2a) expression and glucose utilization by cells. However, nongenomic effects of THs are now emerging. Here, we assess how triiodothyronine (T(3)) acutely affects glucose transport and the content of GLUT4, GLUT1, and GLUT3 at the surface of muscle cells, and possible interactions between T(3) and insulin action. Differentiated L6 myotubes transfected with myc-tagged Slc2a4 (L6-GLUT4myc) or Slc2a1 (L6-GLUT1myc) and wild-type L6 myotubes were studied in the following conditions: control, hypothyroid (Tx), Tx plus T(3), Tx plus insulin, and Tx plus insulin and T(3). Glucose uptake and GLUT4 content at the cell surface decreased in the Tx group relative to controls. T(3) treatment for 30 minutes increased glucose transport into L6-GLUT4myc cells without altering surface GLUT4 content, which increased only thereafter. The total amount of GLUT4 protein remained unchanged among the groups studied. The surface GLUT1 content of L6-GLUT1myc cells also remained unaltered after T(3) treatment; however, in these cells glucose transport was not stimulated by T(3). In wild-type L6 cells, although T(3) treatment increased the total amount of GLUT3, it did not change the surface GLUT3 content. Moreover, within 30 minutes, T(3) stimulation of glucose uptake was additive to that of insulin in L6-GLUT4myc cells. As expected, insulin elevated surface GLUT4 content and glucose uptake. However, interestingly, surface GLUT4 content remained unchanged or even dropped with T(3) plus insulin. These data reveal that T(3) rapidly increases glucose uptake in L6-GLUT4myc cells, which, at least for 30 minutes, did not depend on an increment in GLUT4 at the cell surface yet potentiates insulin action. We propose that this rapid T(3) effect involves activation of GLUT4 transporters at the cell surface, but cannot discount the involvement of an unknown GLUT.

  10. Platelet-derived growth factor stimulates glucose transport in skeletal muscles of transgenic mice specifically expressing platelet-derived growth factor receptor in the muscle, but it does not affect blood glucose levels.

    Science.gov (United States)

    Yuasa, Tomoyuki; Kakuhata, Rei; Kishi, Kazuhiro; Obata, Toshiyuki; Shinohara, Yasuo; Bando, Yoshimi; Izumi, Keisuke; Kajiura, Fumiko; Matsumoto, Mitsuru; Ebina, Yousuke

    2004-11-01

    Insulin stimulates the disposal of blood glucose into skeletal muscle and adipose tissues by the translocation of GLUT4 from intracellular pools to the plasma membrane, and consequently the concentration of blood glucose levels decreases rapidly in vivo. Phosphatidylinositol (PI) 3-kinase and Akt play a pivotal role in the stimulation of glucose transport by insulin, but detailed mechanisms are unknown. We and others reported that not only insulin but also platelet-derived growth factor (PDGF) and epidermal growth factor facilitate glucose uptake through GLUT4 translocation by activation of PI 3-kinase and Akt in cultured cells. However, opposite results were also reported. We generated transgenic mice that specifically express the PDGF receptor in skeletal muscle. In these mice, PDGF stimulated glucose transport into skeletal muscle in vitro and in vivo. Thus, PDGF apparently shares with insulin some of the signaling molecules needed for the stimulation of glucose transport. The degree of glucose uptake in vivo reached approximately 60% of that by insulin injection in skeletal muscle, but blood glucose levels were not decreased by PDGF in these mice. Therefore, PDGF-induced disposal of blood glucose into skeletal muscle is insufficient for rapid decrease of blood glucose levels.

  11. Endocytosis of AtRGS1 Is Regulated by the Autophagy Pathway after D-Glucose Stimulation

    Directory of Open Access Journals (Sweden)

    Quanquan Yan

    2017-07-01

    Full Text Available Sugar, as a signal molecule, has significant functions in signal transduction in which the seven-transmembrane regulator of G-protein signaling (RGS1 protein participates. D-Glucose causes endocytosis of the AtRGS1, leading to the physical uncoupling of AtRGS1 from AtGPA1 and thus a release of the GAP activity and concomitant sustained activation of G-protein signaling. Autophagy involves in massive degradation and recycling of cytoplasmic components to survive environmental stresses. The function of autophagy in AtRGS1 endocytosis during D-glucose stimulation has not been elucidated. In this study, we investigate the relationship between autophagy and AtRGS1 in response to D-glucose. Our findings demonstrated that AtRGS1 mediated the activation of autophagy by affecting the activities of the five functional groups of protein complexes and promoted the formation of autophagosomes under D-glucose application. When the autophagy pathway was interrupted, AtRGS1 recovery increased and endocytosis of ATRGS1 was inhibited, indicating that autophagy pathway plays an important role in regulating the endocytosis and recovery of AtRGS1 after D-glucose stimulation.

  12. α-Melanocyte stimulating hormone promotes muscle glucose uptake via melanocortin 5 receptors

    Directory of Open Access Journals (Sweden)

    Pablo J. Enriori

    2016-10-01

    Conclusion: These data describe a novel endocrine circuit that modulates glucose homeostasis by pituitary α-MSH, which increases muscle glucose uptake and thermogenesis through the activation of a MC5R-PKA-pathway, which is disrupted in obesity.

  13. Osteosarcoma cell-intrinsic colony stimulating factor-1 receptor functions to promote tumor cell metastasis through JAG1 signaling.

    Science.gov (United States)

    Wen, Zhi-Qiang; Li, Xi-Gong; Zhang, Yi-Jun; Ling, Zhi-Heng; Lin, Xiang-Jin

    2017-01-01

    Therapeutic antibodies or inhibitors targeting CSF-1R block colony stimulating factor-1/colony stimulating factor-1 receptor (CSF-1/CSF-R) signaling, and have shown remarkable efficacy in the treatment of cancer. However, little is known about tumor cell-intrinsic CSF-1R effects. Here, we show that human osteosarcomas contain CSF-1R-expressing cancer subpopulations, and demonstrate that osteosarcoma cell-intrinsic CSF-1R promotes growth in vitro and in vivo. CSF-1R inhibition in osteosarcoma cells by RNA interference suppresses cell proliferation and tumor growth in mice. Conversely, CSF-1R overexpression enhances cell proliferation and accelerates tumor growth. CSF-1R overexpression can significantly enhance osteosarcoma cell migration, invasion, and epithelial-mesenchymal transition (EMT), whereas silencing CSF-1R inhibits these processes. Microarray analysis suggests that jagged 1 (JAG1) can function as a downstream mediator of CSF-1R. Moreover, we report a signaling pathway involving CSF-1R and JAG1 that sustains osteosarcoma cell migration and invasion. Our results identify osteosarcoma cell intrinsic functions of the CSF-1R/JAG1 axis in dissemination of osteosarcoma cells.

  14. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    Science.gov (United States)

    Kristensen, Jonas Møller; Treebak, Jonas T.; Schjerling, Peter; Goodyear, Laurie

    2014-01-01

    Metformin-induced activation of the 5′-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P metformin treatment. Insulin signaling at the level of Akt and TBC1D4 protein expression as well as Akt Thr308/Ser473 and TBC1D4 Thr642/Ser711 phosphorylation were not changed by metformin treatment. Also, protein expressions of Rab4, GLUT4, and hexokinase II were unaltered after treatment. The acute metformin treatment did not affect glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. PMID:24644243

  15. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle.

    Science.gov (United States)

    Kristensen, Jonas Møller; Treebak, Jonas T; Schjerling, Peter; Goodyear, Laurie; Wojtaszewski, Jørgen F P

    2014-05-15

    Metformin-induced activation of the 5'-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. Copyright © 2014 the American Physiological Society.

  16. Role of the AMPKgamma3 isoform in hypoxia-stimulated glucose transport in glycolytic skeletal muscle

    DEFF Research Database (Denmark)

    Deshmukh, Atul S; Glund, Stephan; Tom, Robby Z

    2009-01-01

    Skeletal muscle glucose transport is regulated via the canonical insulin-signaling cascade as well as by energy-sensing signals. 5'-AMP-activated protein kinase (AMPK) has been implicated in the energy status regulation of glucose transport. We determined the role of the AMPKgamma3 isoform...... in hypoxia-mediated energy status signaling and glucose transport in fast-twitch glycolytic extensor digitorum longus (EDL) muscle from AMPKgamma3-knockout (KO) mice and wild-type mice. Although hypoxia increased glucose transport (P ... mice (45% reduction, P glucose transport in AMPKgamma3-KO and wild-type mice (P

  17. Rac1 Signaling Is Required for Insulin-Stimulated Glucose Uptake and Is Dysregulated in Insulin-Resistant Murine and Human Skeletal Muscle

    Science.gov (United States)

    Sylow, Lykke; Jensen, Thomas E.; Kleinert, Maximilian; Højlund, Kurt; Kiens, Bente; Wojtaszewski, Jørgen; Prats, Clara; Schjerling, Peter; Richter, Erik A.

    2013-01-01

    The actin cytoskeleton–regulating GTPase Rac1 is required for insulin-stimulated GLUT4 translocation in cultured muscle cells. However, involvement of Rac1 and its downstream signaling in glucose transport in insulin-sensitive and insulin-resistant mature skeletal muscle has not previously been investigated. We hypothesized that Rac1 and its downstream target, p21-activated kinase (PAK), are regulators of insulin-stimulated glucose uptake in mouse and human skeletal muscle and are dysregulated in insulin-resistant states. Muscle-specific inducible Rac1 knockout (KO) mice and pharmacological inhibition of Rac1 were used to determine whether Rac1 regulates insulin-stimulated glucose transport in mature skeletal muscle. Furthermore, Rac1 and PAK1 expression and signaling were investigated in muscle of insulin-resistant mice and humans. Inhibition and KO of Rac1 decreased insulin-stimulated glucose transport in mouse soleus and extensor digitorum longus muscles ex vivo. Rac1 KO mice showed decreased insulin and glucose tolerance and trended toward higher plasma insulin concentrations after intraperitoneal glucose injection. Rac1 protein expression and insulin-stimulated PAKThr423 phosphorylation were decreased in muscles of high fat–fed mice. In humans, insulin-stimulated PAK activation was decreased in both acute insulin-resistant (intralipid infusion) and chronic insulin-resistant states (obesity and diabetes). These findings show that Rac1 is a regulator of insulin-stimulated glucose uptake and a novel candidate involved in skeletal muscle insulin resistance. PMID:23423567

  18. Rac1 and AMPK Account for the Majority of Muscle Glucose Uptake Stimulated by Ex Vivo Contraction but Not In Vivo Exercise.

    Science.gov (United States)

    Sylow, Lykke; Møller, Lisbeth L V; Kleinert, Maximilian; D'Hulst, Gommaar; De Groote, Estelle; Schjerling, Peter; Steinberg, Gregory R; Jensen, Thomas E; Richter, Erik A

    2017-06-01

    Exercise bypasses insulin resistance to increase glucose uptake in skeletal muscle and therefore represents an important alternative to stimulate glucose uptake in insulin-resistant muscle. Both Rac1 and AMPK have been shown to partly regulate contraction-stimulated muscle glucose uptake, but whether those two signaling pathways jointly account for the entire signal to glucose transport is unknown. We therefore studied the ability of contraction and exercise to stimulate glucose transport in isolated muscles with AMPK loss of function combined with either pharmacological inhibition or genetic deletion of Rac1.Muscle-specific knockout (mKO) of Rac1, a kinase-dead α2 AMPK (α2KD), and double knockout (KO) of β1 and β2 AMPK subunits (β1β2 KO) each partially decreased contraction-stimulated glucose transport in mouse soleus and extensor digitorum longus (EDL) muscle. Interestingly, when pharmacological Rac1 inhibition was combined with either AMPK β1β2 KO or α2KD, contraction-stimulated glucose transport was almost completely inhibited. Importantly, α2KD+Rac1 mKO double-transgenic mice also displayed severely impaired contraction-stimulated glucose transport, whereas exercise-stimulated glucose uptake in vivo was only partially reduced by Rac1 mKO with no additive effect of α2KD. It is concluded that Rac1 and AMPK together account for almost the entire ex vivo contraction response in muscle glucose transport, whereas only Rac1, but not α2 AMPK, regulates muscle glucose uptake during submaximal exercise in vivo. © 2017 by the American Diabetes Association.

  19. Fed-state clamp stimulates cellular mechanisms of muscle protein anabolism and modulates glucose disposal in normal men.

    Science.gov (United States)

    Adegoke, Olasunkanmi A J; Chevalier, Stéphanie; Morais, José A; Gougeon, Réjeanne; Kimball, Scot R; Jefferson, Leonard S; Wing, Simon S; Marliss, Errol B

    2009-01-01

    Since maximum anabolism occurs postprandially, we developed a simulated fed state with clamped hyperinsulinemia, physiological hyperglycemia, and hyperaminoacidemia (Hyper-3) and explored muscle cellular mechanisms. Whole body [1-(13)C]leucine and [3-(3)H]glucose kinetics in healthy men were compared between hyperinsulinemic, euglycemic, isoaminoacidemic (Hyper-1, n = 10) and Hyper-3 (n = 9) clamps. In Hyper-3 vs. Hyper-1, nonoxidative leucine R(d) [rate of disappearance (synthesis)] was stimulated more (45 +/- 4 vs. 24 +/- 4 micromol/min, P anabolism, and muscle protein translation initiation pathways and decreases protein ubiquitination. The main contribution of hyperaminoacidemia is stimulation of synthesis rather than inhibition of proteolysis, and it attenuates the expected increment of glucose disposal.

  20. Overexpression of protein tyrosine phosphatase 1B impairs glucose-stimulated insulin secretion in INS-1 cells.

    Science.gov (United States)

    Lu, Bin; Gu, Ping; Xu, Yixin; Ye, Xiaozhen; Wang, Yingzhijie; DU, Hong; Shao, Jiaqing

    2016-03-01

    Protein tyrosine phosphatase 1B (PTP1B) has been implicated as a negative regulator of insulin signaling. We reported previously that impaired glucose-stimulated insulin secretion (GSIS) in rats fed high-fat diet was associated with higher PTP1B protein levels in islets. The aim of the present study was to investigate the effect of increasing PTP1B on insulin secretion in β-cells. INS-1 cells were transduced with recombinant adenoviruses containing human PTP1B cDNA (Ad-PTP1B), or no exogenous gene (Ad-ctrl). The expression levels of PTP1B, insulin receptor (IR), insulin receptor substrate-1(IRS-1), glucokinase and glucose transporter-2 were evaluated by Western blot. Then insulin-stimulated IR and IRS tyrosine phosphorylation, and Akt pathway activation were measured. GSIS was also performed to evaluate INS-1 cells function. PTP1B expression level was increased 5.9-fold at 48h post-transduction. The overexpression of PTP1B had no effect on proliferation and apoptosis of INS-1 cells. Compared with control cells, INS-1 cells overexpressing PTP1B showed decrease in insulin-stimulated tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate-1(IRS-1) by 56.4% and 53.1%, respectively. In addition, Akt phosphorylation was reduced 59.6%. Moreover, in Ad-PTP1B-transduced cells, 16.7mM glucose caused a 1.6±0.2 fold increase (vs. 3.9±0.7 fold in nontransduced cells) in insulin secretion relative to secretion at 2.8mM glucose. Further analysis determined that overexpression of PTP1B induced down-regulated expression of glucokinase (42%) and glucose transporter-2 (48%). Our findings suggested that overexpression of PTP1B can inhibit GSIS in INS-1 cells through negatively regulating insulin signaling.

  1. Glutathione Peroxidase Mimic Ebselen Improves Glucose-Stimulated Insulin Secretion in Murine Islets

    Science.gov (United States)

    Wang, Xinhui; Yun, Jun-Won

    2014-01-01

    Abstract Aims: Glutathione peroxidase (GPX) mimic ebselen and superoxide dismutase (SOD) mimic copper diisopropylsalicylate (CuDIPs) were used to rescue impaired glucose-stimulated insulin secretion (GSIS) in islets of GPX1 and(or) SOD1-knockout mice. Results: Ebselen improved GSIS in islets of all four tested genotypes. The rescue in the GPX1 knockout resulted from a coordinated transcriptional regulation of four key GSIS regulators and was mediated by the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α)-mediated signaling pathways. In contrast, CuDIPs improved GSIS only in the SOD1 knockout and suppressed gene expression of the PGC-1α pathway. Innovation: Islets from the GPX1 and(or) SOD1 knockout mice provided metabolically controlled intracellular hydrogen peroxide (H2O2) and superoxide conditions for the present study to avoid confounding effects. Bioinformatics analyses of gene promoters and expression profiles guided the search for upstream signaling pathways to link the ebselen-initiated H2O2 scavenging to downstream key events of GSIS. The RNA interference was applied to prove PGC-1α as the main mediator for that link. Conclusion: Our study revealed a novel metabolic use and clinical potential of ebselen in rescuing GSIS in the GPX1-deficient islets and mice, along with distinct differences between the GPX and SOD mimics in this regard. These findings highlight the necessities and opportunities of discretional applications of various antioxidant enzyme mimics in treating insulin secretion disorders. Rebound Track: This work was rejected during standard peer review and rescued by Rebound Peer Review (Antioxid Redox Signal 16: 293–296, 2012) with the following serving as open reviewers: Regina Brigelius-Flohe, Vadim Gladyshev, Dexing Hou, and Holger Steinbrenner. Antioxid. Redox Signal. 20, 191–203. PMID:23795780

  2. Regulation of myosin IIA and filamentous actin during insulin-stimulated glucose uptake in 3T3-L1 adipocytes

    Energy Technology Data Exchange (ETDEWEB)

    Stall, Richard; Ramos, Joseph; Kent Fulcher, F.; Patel, Yashomati M., E-mail: ympatel@uncg.edu

    2014-03-10

    Insulin stimulated glucose uptake requires the colocalization of myosin IIA (MyoIIA) and the insulin-responsive glucose transporter 4 (GLUT4) at the plasma membrane for proper GLUT4 fusion. MyoIIA facilitates filamentous actin (F-actin) reorganization in various cell types. In adipocytes F-actin reorganization is required for insulin-stimulated glucose uptake. What is not known is whether MyoIIA interacts with F-actin to regulate insulin-induced GLUT4 fusion at the plasma membrane. To elucidate the relationship between MyoIIA and F-actin, we examined the colocalization of MyoIIA and F-actin at the plasma membrane upon insulin stimulation as well as the regulation of this interaction. Our findings demonstrated that MyoIIA and F-actin colocalized at the site of GLUT4 fusion with the plasma membrane upon insulin stimulation. Furthermore, inhibition of MyoII with blebbistatin impaired F-actin localization at the plasma membrane. Next we examined the regulatory role of calcium in MyoIIA-F-actin colocalization. Reduced calcium or calmodulin levels decreased colocalization of MyoIIA and F-actin at the plasma membrane. While calcium alone can translocate MyoIIA it did not stimulate F-actin accumulation at the plasma membrane. Taken together, we established that while MyoIIA activity is required for F-actin localization at the plasma membrane, it alone is insufficient to localize F-actin to the plasma membrane. - Highlights: • Insulin induces colocalization of MyoIIA and F-actin at the cortex in adipocytes. • MyoIIA is necessary but not sufficient to localize F-actin at the cell cortex. • MyoIIA-F-actin colocalization is regulated by calcium and calmodulin.

  3. Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes

    DEFF Research Database (Denmark)

    Che, Brita Ngum; Oksbjerg, Niels; Hellgren, Lars

    2013-01-01

    ABSTRACT: BACKGROUND: Phytanic acid (PA) is a chlorophyll metabolite with potentials in regulating glucose metabolism, as it is a natural ligand of the peroxisome proliferator-activated receptor (PPAR) that is known to regulate hepatic glucose homeostasis. This study aimed to establish primary...... and tritiated 2-deoxyglucose (2-DOG) was used to measure glucose uptake, in relation to PA and 2-DOG exposure times and also in relation to PA and insulin concentrations. The MIXED procedure model of SAS was used for statistical analysis of data. RESULTS: PA increased glucose uptake by approximately 35...

  4. Prognostic impact of CD57, CD68, M-CSF, CSF-1R, Ki67 and TGF-beta in soft tissue sarcomas.

    Science.gov (United States)

    Sorbye, Sveinung W; Kilvaer, Thomas K; Valkov, Andrej; Donnem, Tom; Smeland, Eivind; Al-Shibli, Khalid; Bremnes, Roy M; Busund, Lill-Tove

    2012-05-03

    Prognostic markers in curable STS may have the potential to guide therapy after surgical resection. The purpose of this study was to clarify the prognostic impact of the presence of cells and growth factors belonging to the innate immune system in soft tissue sarcomas (STS). The significance of macrophages (CD68), their growth factor macrophage colony-stimulating factor (M-CSF), its receptor colony-stimulating factor-1 receptor (CSF-1R), natural killer cells (CD57) and the general immunomodulating molecule (TGF-beta) are all controversial in STS. Herein, these markers are evaluated and compared to the cell proliferation marker Ki67. Tissue microarrays from 249 patients with non-gastrointestinal (non-GIST) STS were constructed from duplicate cores of viable and representative neoplastic tumor areas and duplicate cores of peritumoral capsule. Immunohistochemistry was used to evaluate the expression of CD68, M-CSF, CSF-1R, CD57, TGF-beta and Ki67 in tumor and peritumoral capsule. In univariate analyses increased expression of M-CSF (P = 0.034), Ki67 (P < 0.001) and TGF-beta (P = 0.003) in tumor correlated with shorter disease-specific survival (DSS). Increased expression of CD68 in tumor correlated significantly with malignancy grade (P = 0.016), but not DSS (P = 0.270). Increased expression of Ki67 in peritumoral capsule tended to correlate with a shorter DSS (P = 0.057). In multivariate analyses, co-expression of M-CSF and TGF-beta (P = 0.022) in tumor and high expression of Ki67 (P = 0.019) in peritumoral capsule were independent negative prognostic factors for DSS. Increased co-expression of M-CSF and TGF-beta in tumor in patients with STS, and increased expression of Ki67 in peritumoral capsule were independent negative prognostic factors for DSS.

  5. PPARalpha activation and increased dietary lipid oppose thyroid hormone signaling and rescue impaired glucose-stimulated insulin secretion in hyperthyroidism.

    Science.gov (United States)

    Holness, Mark J; Greenwood, Gemma K; Smith, Nicholas D; Sugden, Mary C

    2008-12-01

    The aim of the study was to investigate the impact of hyperthyroidism on the characteristics of the islet insulin secretory response to glucose, particularly the consequences of competition between thyroid hormone and peroxisome proliferator-activated receptor (PPAR)alpha in the regulation of islet adaptations to starvation and dietary lipid-induced insulin resistance. Rats maintained on standard (low-fat/high-carbohydrate) diet or high-fat/low-carbohydrate diet were rendered hyperthyroid (HT) by triiodothyronine (T(3)) administration (1 mg.kg body wt(-1).day(-1) sc, 3 days). The PPARalpha agonist WY14643 (50 mg/kg body wt ip) was administered 24 h before sampling. Glucose-stimulated insulin secretion (GSIS) was assessed during hyperglycemic clamps or after acute glucose bolus injection in vivo and with step-up and step-down islet perifusions. Hyperthyroidism decreased the glucose responsiveness of GSIS, precluding sufficient enhancement of insulin secretion for the degree of insulin resistance, in rats fed either standard diet or high-fat diet. Hyperthyroidism partially opposed the starvation-induced increase in the glucose threshold for GSIS and decrease in glucose responsiveness. WY14643 administration restored glucose tolerance by enhancing GSIS in fed HT rats and relieved the impact of hyperthyroidism to partially oppose islet starvation adaptations. Competition between thyroid hormone receptor (TR) and PPARalpha influences the characteristics of GSIS, such that hyperthyroidism impairs GSIS while PPARalpha activation (and increased dietary lipid) opposes TR signaling and restores GSIS in the fed hyperthyroid state. Increased islet PPARalpha signaling and decreased TR signaling during starvation facilitates appropriate modification of islet function.

  6. Altered gene and protein expression of glucose transporter1 underlies dexamethasone inhibition of insulin-stimulated glucose uptake in chicken muscles.

    Science.gov (United States)

    Zhao, J P; Bao, J; Wang, X J; Jiao, H C; Song, Z G; Lin, H

    2012-12-01

    A study was performed to characterize the effects of dexamethasone (DEX) and insulin administration on gene expression of glucose transporters (GLUT) in chicken (Gallus gallus domesticus) skeletal muscles and in cultured embryonic myoblasts. Three groups of 1-wk-old male chickens were randomly subjected to one of the following treatments for 7 d: DEX (a subcutaneous injection of 1 mg/kg BW, twice daily at 0800 h and 2000 h), controls (injected with saline), and pair-fed controls (restricted to the same feed intake as for the DEX treatment). Expressions of GLUT-1, GLUT-3, GLUT-8, and 18S rRNA mRNA were determined by quantitative reverse transcription PCR in the pectoralis major (PM) and biceps femoris (BF) muscles. Using chicken embryonic myoblasts (CEM), the interaction between DEX (200 nM) and insulin (100 nM) administration was evaluated on GLUT gene and GLUT-1 protein expressions and 2-deoxy-D-[1, 2-(3)H]-glucose (2-DG) uptake. Myoblasts were incubated with serum-free medium for 3 h in the presence or absence of insulin (0, 0.02, 0.1, 0.5, and 2.5 μM). Although GLUT-1 is not considered an insulin-responsive GLUT in mammals, this study shows that insulin stimulated 2-DG uptake and GLUT-1 mRNA and protein expression in CEM (P muscle. Dexamethasone inhibited insulin-stimulated glucose uptake in CEM (P muscles. The results of the present study indicate that the altered GLUT-1 gene and protein expression may contribute to the insulin resistance induced by DEX treatment in chicken muscles.

  7. The impairment of glucose-stimulated insulin secretion in pancreatic β-cells caused by prolonged glucotoxicity and lipotoxicity is associated with elevated adaptive antioxidant response.

    Science.gov (United States)

    Fu, Jingqi; Cui, Qi; Yang, Bei; Hou, Yongyong; Wang, Huihui; Xu, Yuanyuan; Wang, Difei; Zhang, Qiang; Pi, Jingbo

    2017-02-01

    Type 2 diabetes (T2D) is a progressive disease characterized by sustained hyperglycemia and is frequently accompanied by hyperlipidemia. Deterioration of β-cell function in T2D patients may be caused, in part, by long-term exposure to high concentrations of glucose and/or lipids. We developed systems to study how chronic glucotoxicity and lipotoxicity might be linked to the impairment of glucose-stimulated insulin secretion (GSIS) machinery in pancreatic β-cells. INS-1 (832/13) were exposed to glucose and/or palmitate for up to 10 weeks. Chronic high glucose and/or palmitate exposure resulted in impaired GSIS accompanied by a dramatic increase in oxidative stress, as determined by basal intracellular peroxide levels. In addition, the GSIS-associated reactive oxygen species (ROS) signals, assessed as glucose-stimulated peroxide accumulation positively correlated with GSIS in glucose- and/or palmitate-exposed cells, as well as glucose-stimulated reductions in GSH/GSSG ratios. Furthermore, the impairment of GSIS caused by chronic high glucose and/or palmitate exposures were attributed to the induction of adaptive antioxidant response and mitochondrial uncoupling, which negatively regulates glucose-derived ROS generation. Taken together, persistent glucotoxicity- and/or lipotoxicity-mediated oxidative stress and subsequent adaptive antioxidant response impair glucose-derived ROS signaling and GSIS in pancreatic β-cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Rac1 signaling is required for insulin-stimulated glucose uptake and is dysregulated in insulin-resistant murine and human skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke; Jensen, Thomas Elbenhardt; Kleinert, Maximilian

    2013-01-01

    The actin-cytoskeleton-regulating GTPase Rac1 is required for insulin-stimulated GLUT4 translocation in cultured muscle cells. However, involvement of Rac1 and its downstream signaling in glucose transport in insulin sensitive and insulin resistant mature skeletal muscle has not previously been...... inhibition of Rac1 were used to determine whether Rac1 regulates insulin-stimulated glucose transport in mature skeletal muscle. Furthermore, Rac1 and PAK1 expression and signalling were investigated in muscle of insulin resistant mice and humans.Inhibition and KO of Rac1 decreased insulin-stimulated glucose...... transport in mouse soleus and EDL muscles ex vivo. Rac1 KO mice showed decreased insulin and glucose tolerance and trended towards higher plasma insulin concentrations following intraperitoneal glucose injection. Rac1 protein expression and PAK(Thr423) phosphorylation were decreased in muscles of high fat...

  9. Adrenal Demedullation and Oxygen Supplementation Independently Increase Glucose-Stimulated Insulin Concentrations in Fetal Sheep With Intrauterine Growth Restriction

    Science.gov (United States)

    Macko, Antoni R.; Yates, Dustin T.; Chen, Xiaochuan; Shelton, Leslie A.; Kelly, Amy C.; Davis, Melissa A.; Camacho, Leticia E.; Anderson, Miranda J.

    2016-01-01

    In pregnancies complicated by placental insufficiency and intrauterine growth restriction (IUGR), fetal glucose and oxygen concentrations are reduced, whereas plasma norepinephrine and epinephrine concentrations are elevated throughout the final third of gestation. Here we study the effects of chronic hypoxemia and hypercatecholaminemia on β-cell function in fetal sheep with placental insufficiency-induced IUGR that is produced by maternal hyperthermia. IUGR and control fetuses underwent a sham (intact) or bilateral adrenal demedullation (AD) surgical procedure at 0.65 gestation. As expected, AD-IUGR fetuses had lower norepinephrine concentrations than intact-IUGR fetuses despite being hypoxemic and hypoglycemic. Placental insufficiency reduced fetal weights, but the severity of IUGR was less with AD. Although basal plasma insulin concentrations were lower in intact-IUGR and AD-IUGR fetuses compared with intact-controls, glucose-stimulated insulin concentrations were greater in AD-IUGR fetuses compared with intact-IUGR fetuses. Interestingly, AD-controls had lower glucose- and arginine-stimulated insulin concentrations than intact-controls, but AD-IUGR and AD-control insulin responses were not different. To investigate chronic hypoxemia in the IUGR fetus, arterial oxygen tension was increased to normal levels by increasing the maternal inspired oxygen fraction. Oxygenation of IUGR fetuses enhanced glucose-stimulated insulin concentrations 3.3-fold in intact-IUGR and 1.7-fold in AD-IUGR fetuses but did not lower norepinephrine and epinephrine concentrations. Together these findings show that chronic hypoxemia and hypercatecholaminemia have distinct but complementary roles in the suppression of β-cell responsiveness in IUGR fetuses. PMID:26937714

  10. An inositol 1,4,5-triphosphate (IP3)-IP3 receptor pathway is required for insulin-stimulated glucose transporter 4 translocation and glucose uptake in cardiomyocytes.

    Science.gov (United States)

    Contreras-Ferrat, A E; Toro, B; Bravo, R; Parra, V; Vásquez, C; Ibarra, C; Mears, D; Chiong, M; Jaimovich, E; Klip, A; Lavandero, S

    2010-10-01

    Intracellular calcium levels ([Ca2+]i) and glucose uptake are central to cardiomyocyte physiology, yet connections between them have not been studied. We investigated whether insulin regulates [Ca2+]i in cultured cardiomyocytes, the participating mechanisms, and their influence on glucose uptake via SLC2 family of facilitative glucose transporter 4 (GLUT4). Primary neonatal rat cardiomyocytes were preloaded with the Ca2+ fluorescent dye fluo3-acetoxymethyl ester compound (AM) and visualized by confocal microscopy. Ca2+ transport pathways were selectively targeted by chemical and molecular inhibition. Glucose uptake was assessed using [3H]2-deoxyglucose, and surface GLUT4 levels were quantified in nonpermeabilized cardiomyocytes transfected with GLUT4-myc-enhanced green fluorescent protein. Insulin elicited a fast, two-component, transient increase in [Ca2+]i. Nifedipine and ryanodine prevented only the first component. The second one was reduced by inositol-1,4,5-trisphosphate (IP3)-receptor-selective inhibitors (xestospongin C, 2 amino-ethoxydiphenylborate), by type 2 IP3 receptor knockdown via small interfering RNA or by transfected Gβγ peptidic inhibitor βARKct. Insulin-stimulated glucose uptake was prevented by bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid-AM, 2-amino-ethoxydiphenylborate, and βARK-ct but not by nifedipine or ryanodine. Similarly, insulin-dependent exofacial exposure of GLUT4-myc-enhanced green fluorescent protein was inhibited by bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid-AM and xestospongin C but not by nifedipine. Phosphatidylinositol 3-kinase and Akt were also required for the second phase of Ca2+ release and GLUT4 translocation. Transfected dominant-negative phosphatidylinositol 3-kinase γ inhibited the latter. In conclusion, in primary neonatal cardiomyocytes, insulin induces an important component of Ca2+ release via IP3 receptor. This component signals to glucose uptake via GLUT4, revealing a so-far unrealized

  11. Studies of gene expression and activity of hexokinase, phosphofructokinase and glycogen synthase in human skeletal muscle in states of altered insulin-stimulated glucose metabolism

    DEFF Research Database (Denmark)

    Vestergaard, H

    1999-01-01

    of the review is to discuss our present knowledge of the activities and gene expression of hexokinase II (HKII), phosphofructokinase (PFK) and glycogen synthase (GS) in human skeletal muscle in states of altered insulin-stimulated glucose metabolism. My own experimental studies have comprised patients...... proximal to the GS protein. In insulin resistant diabetic patients the impact of these yet unknown abnormalities may be accentuated by the prevailing hyperglycaemia and hyperlipidaemia. Endurance training in young healthy subjects results in improved insulin-stimulated glucose disposal rates, predominantly......-stimulated glucose oxidation rate at the whole body level and PFK activity in muscle are normal. In parallel, no changes have been found in skeletal muscle levels of PFK mRNA and immunoreactive protein in NIDDM or IDDM patients. In endurance trained subjects insulin-stimulated whole body glucose oxidation rate...

  12. Involvement of Rac1 and the actin cytoskeleton in insulin- and contraction-stimulated intracellular signaling and glucose uptake in mature skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke

    to hyperinsulinemia and hyperglycemia. Blood glucose is taken up into skeletal muscle when glucose transporters move to the muscle cell surface. In muscle cells this process depends on the protein Rac1. Glucose uptake into skeletal muscle can also occur via insulin-independent mechanisms, such as during muscle...... contractions. Contraction-stimulated glucose uptake is not affected by insulin resistance, likely because the intracellular events that regulate GLUT4 translocation by insulin and muscle contraction are distinct. In addition, muscle contraction has insulin sensitizing effects. Activation of glucose uptake...... understood. The aim of the current PhD was therefore to investigate the involvement of Rac1 and the actin cytoskeleton in the regulation of insulin- and contraction-stimulated glucose uptake in mature skeletal muscle. The central findings of this PhD thesis was that Rac1 was activated by both insulin...

  13. Insulin stimulated-glucose transporter Glut 4 is expressed in the retina.

    Directory of Open Access Journals (Sweden)

    Gustavo Sánchez-Chávez

    Full Text Available The vertebrate retina is a very metabolically active tissue whose energy demands are normally met through the uptake of glucose and oxygen. Glucose metabolism in this tissue relies upon adequate glucose delivery from the systemic circulation. Therefore, glucose transport depends on the expression of glucose transporters. Here, we show retinal expression of the Glut 4 glucose transporter in frog and rat retinas. Immunohistochemistry and in situ hybridization studies showed Glut 4 expression in the three nuclear layers of the retina: the photoreceptor, inner nuclear and ganglionar cell layers. In the rat retina immunoprecipitation and Western blot analysis revealed a protein with an apparent molecular mass of 45 kDa. ¹⁴C-glucose accumulation by isolated rat retinas was significantly enhanced by physiological concentrations of insulin, an effect blocked by inhibitors of phosphatidyl-inositol 3-kinase (PI3K, a key enzyme in the insulin-signaling pathway in other tissues. Also, we observed an increase in ³H-cytochalasin binding sites in the presence of insulin, suggesting an increase in transporter recruitment at the cell surface. Besides, insulin induced phosphorylation of Akt, an effect also blocked by PI3K inhibition. Expression of Glut 4 was not modified in retinas of a type 1 diabetic rat model. To our knowledge, our results provide the first evidence of Glut4 expression in the retina, suggesting it as an insulin- responsive tissue.

  14. Involvement of Rac1 and the actin cytoskeleton in insulin- and contraction-stimulated intracellular signaling and glucose uptake in mature skeletal muscle

    DEFF Research Database (Denmark)

    Sylow, Lykke

    by exercise is therefore an important alternative way to maintain whole body glucose homeostasis in insulin resistant states such as Type 2 Diabetes. Although the insulin- and exercise-stimulated signaling pathways to glucose uptake have been studied extensively, the underlying mechanisms are not well...

  15. Akt and Rac1 signalling are jointly required for insulin-stimulated glucose uptake in skeletal muscle and downregulated in insulin resistance

    DEFF Research Database (Denmark)

    Sylow, Lykke; Kleinert, Maximilian; Pehmøller, Christian

    2014-01-01

    Skeletal muscle plays a major role in regulating whole body glucose metabolism. Akt and Rac1 are important regulators of insulin-stimulated glucose uptake in skeletal muscle. However the relative role of each pathway and how they interact is not understood. Here we delineate how Akt and Rac1 path...

  16. Combination of CD40 Agonism and CSF-1R Blockade Reconditions Tumor-Associated Macrophages and Drives Potent Antitumor Immunity.

    Science.gov (United States)

    Wiehagen, Karla R; Girgis, Natasha M; Yamada, Douglas H; Smith, Andressa A; Chan, Szeman Ruby; Grewal, Iqbal S; Quigley, Michael; Verona, Raluca I

    2017-12-01

    Efficacious antitumor immune responses must overcome multiple suppressive mechanisms in the tumor microenvironment to control cancer progression. In this study, we demonstrate that dual targeting of suppressive myeloid populations by inhibiting CSF-1/CSF-1R signaling and activation of antigen-presenting cells with agonist anti-CD40 treatment confers superior antitumor efficacy and increased survival compared with monotherapy treatment in preclinical tumor models. Concurrent CSF-1R blockade and CD40 agonism lead to profound changes in the composition of immune infiltrates, causing an overall decrease in immunosuppressive cells and a shift toward a more inflammatory milieu. Anti-CD40/anti-CSF-1R-treated tumors contain decreased tumor-associated macrophages and Foxp3+ regulatory T cells. This combination approach increases maturation and differentiation of proinflammatory macrophages and dendritic cells and also drives potent priming of effector T cells in draining lymph nodes. As a result, tumor-infiltrating effector T cells exhibit improved responses to tumor antigen rechallenge. These studies show that combining therapeutic approaches may simultaneously remove inhibitory immune populations and sustain endogenous antitumor immune responses to successfully impair cancer progression. Cancer Immunol Res; 5(12); 1109-21. ©2017 AACR. ©2017 American Association for Cancer Research.

  17. Chemokine polyreactivity of IL7Rα+CSF-1R+ lympho-myeloid progenitors in the developing fetal liver.

    Science.gov (United States)

    Kajikhina, Katja; Melchers, Fritz; Tsuneto, Motokazu

    2015-08-03

    In murine ontogeny, fetal liver is the major hemato- and B-lymphopoietic site until birth. Hematopoiesis develops in largely non-hematopoietic niches, which provide contacts, chemokines and cytokines that induce migration, residence, proliferation and differentiation of progenitors. Within early multipotent progenitors an IL7Rα(+)CSF-1R(+) subset expressed a mixture of lymphoid- and myeloid-specific genes and differentiated to lymphoid and myeloid lineages in vitro. By contrast, IL7Rα(+) cells were lymphoid-committed, and CSF-1R(+) cells were erythro-myeloid-restricted. To respond to a multitude of chemokines single biphenotypic cells expressed CXCR4 and as many as five other chemokine receptors. The monopotent IL7Rα(+) and CSF-1R(+)progenitors all expressed CXCR4, and mutually exclusive, more restricted sets of the analysed five chemokine receptors. This study proposes that chemokine polyreactive, cytokine-bipotent and monopotent progenitors transmigrate through LYVE-1(high) endothelium, attracted by selected chemokines, and reach the IL7- and CSF-1-producing ALCAM(high) mesenchymal niche, attracted by other sets of chemokines, to differentiate to B-lymphoid respectively myeloid cells.

  18. Dramatic Effect of Oral CSF-1R Kinase Inhibitor on Retinal Microglia Revealed by In Vivo Scanning Laser Ophthalmoscopy.

    Science.gov (United States)

    Ebneter, Andreas; Kokona, Despina; Jovanovic, Joël; Zinkernagel, Martin S

    2017-04-01

    This report provides sound evidence that the small molecule pharmaceutical PLX5622, a highly selective CSF-1R kinase inhibitor, crosses the blood-retina barrier and suppresses microglia activity. Members of this class of drug are in advanced clinical development stages and may represent a novel approach to modulate ocular inflammatory processes.

  19. Dramatic Effect of Oral CSF-1R Kinase Inhibitor on Retinal Microglia Revealed by In Vivo Scanning Laser Ophthalmoscopy

    Science.gov (United States)

    Ebneter, Andreas; Kokona, Despina; Jovanovic, Joël; Zinkernagel, Martin S.

    2017-01-01

    This report provides sound evidence that the small molecule pharmaceutical PLX5622, a highly selective CSF-1R kinase inhibitor, crosses the blood–retina barrier and suppresses microglia activity. Members of this class of drug are in advanced clinical development stages and may represent a novel approach to modulate ocular inflammatory processes. PMID:28458957

  20. Cannabinoid CB1 receptor inverse agonist MJ08 stimulates glucose production via hepatic sympathetic innervation in rats.

    Science.gov (United States)

    Chen, Wei; Liu, Hongying; Guan, Hua; Xue, Nina; Wang, Lili

    2017-11-05

    As a key insulin target tissue for maintaining systemic glucose homeostasis, the liver plays important roles in improving obesity-associated insulin intolerance via selective cannabinoid CB1 receptor antagonism/inverse agonism. However, it is unclear whether this receptor inverse agonism affects hepatic glucose metabolism. MJ08 is a novel cannabinoid CB1 receptor antagonist/inverse agonist that has superior inverse agonism over the well-known antagonist/inverse agonist, SR141716 (rimonabant). MJ08 remarkably elevates fasting blood glucose independent of inhibition of insulin release in mice. In the current study, MJ08 was used to investigate the mechanism by which liver cannabinoid CB1 receptor inverse activation regulates hepatic glucose metabolism. MJ08 stimulated hepatic glucose production (HGP) in a dose-dependent manner and promoted gluconeogenic gene expression in perfused rat liver. SR141716 exhibited similar but weaker effects. The cannabinoid CB1 receptor agonist (WIN 55,212-2), Gs protein-cyclic AMP (cAMP)-dependent pathway inhibitors (NF449 and H89), β-adrenoceptor antagonist (propranolol), and peripheral sympathetic inhibitor (reserpine) could antagonize MJ08-induced HGP. Furthermore, MJ08 and SR141716 induced monoamine neurotransmitter (noradrenaline) release and increased cAMP content significantly in perfused liver, although only a slight increase was observed in primary cultured hepatocytes. These results indicate that local liver cannabinoid CB1 receptor inverse agonism via hepatic sympathetic innervation is responsible for the HGP induced by MJ08. Thus, high inverse agonistic activity could increase fasting blood glucose levels and should be avoided in the development of peripheral cannabinoid CB1 receptor-targeted weight-loss drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Impact of PTBP1 rs11085226 on glucose-stimulated insulin release in adult Danes

    DEFF Research Database (Denmark)

    Hansen, Tue H; Vestergaard, Henrik; Jørgensen, Torben

    2015-01-01

    BACKGROUND: The variant rs11085226 (G) within the gene encoding polypyrimidine tract binding protein 1 (PTBP1) was reported to associate with reduced insulin release determined by an oral glucose tolerance test (OGTT) as well as an intravenous glucose tolerance test (IVGTT). The aim of the present......,641 glucose tolerant controls, respectively. Quantitative trait analyses were performed in up to 13,605 individuals subjected to an OGTT or blood samples obtained after an overnight fast, as well as in 596 individuals subjected to an IVGTT. RESULTS: Analyses of fasting and OGTT-derived quantitative traits did...... association with type 2 diabetes. METHODS: PTBP1 rs11085226 was genotyped in 20,911 individuals of Danish Caucasian ethnicity ascertained from 9 study samples. Case control analysis was performed on 5,634 type 2 diabetic patients and 11,319 individuals having a normal fasting glucose level as well as 4...

  2. An ancestral role for the mitochondrial pyruvate carrier in glucose-stimulated insulin secretion

    Directory of Open Access Journals (Sweden)

    Kyle S. McCommis

    2016-08-01

    Conclusions: Altogether, these studies suggest that the MPC plays an important and ancestral role in insulin-secreting cells in mediating glucose sensing, regulating insulin secretion, and controlling systemic glycemia.

  3. Potential contribution of tumor-associated slan(+) cells as anti-CSF-1R targets in human carcinoma.

    Science.gov (United States)

    Lonardi, Silvia; Licini, Sara; Micheletti, Alessandra; Finotti, Giulia; Vermi, William; Cassatella, Marco A

    2017-09-26

    The precise identification of the types and respective roles of the tumor-associated myeloid cells, which include tumor-associated Mϕs (TAMs), neutrophils, dendritic cells, and myeloid-derived suppressor cells, is under intensive investigation. Although tumor-associated myeloid cells may contribute to tumor cell eradication by virtue of their effector functions, they are retained to fulfill predominantly protumorigenic roles. It follows that depletion of tumor-associated myeloid cells represents one of the currently pursued therapeutic options in advanced malignancies. In that regard, RG7155/emactuzumab, a specific anti-CSF-1R humanized Ab, has been reported recently to deplete CSF-1R(+) TAMs, in association with objective clinical responses in patients with advanced cancer. Because RG7155/emactuzumab has also been shown to deplete blood non-classic CD14(dim/-)CD16(++) monocytes, which in large part include the CD16(++)slan(+) monocytes, we asked whether RG7155/emactuzumab could target tumor-associated slan(+) cells. In this study, we confirmed that slan(+) cells localize only to metastatic tumor-draining lymph nodes, not to primary tumors or distant metastases in patients with different types of carcinoma. Notably, by cell scoring on serial sections, we found that slan(+) cells represent a minor fraction of the total CSF-1R(+) cell pool, suggesting that slan(+) cells potentially represent minor targets of anti-CSF-1R therapy. Therefore, a protumorigenic role for slan(+) cells, such as that of CSF-1R(+)TAMs, based on our current data, remains questionable. © Society for Leukocyte Biology.

  4. Progressive glucose stimulation of islet beta cells reveals a transition from segregated to integrated modular functional connectivity patterns.

    Science.gov (United States)

    Markovič, Rene; Stožer, Andraž; Gosak, Marko; Dolenšek, Jurij; Marhl, Marko; Rupnik, Marjan Slak

    2015-01-19

    Collective beta cell activity in islets of Langerhans is critical for the supply of insulin within an organism. Even though individual beta cells are intrinsically heterogeneous, the presence of intercellular coupling mechanisms ensures coordinated activity and a well-regulated exocytosis of insulin. In order to get a detailed insight into the functional organization of the syncytium, we applied advanced analytical tools from the realm of complex network theory to uncover the functional connectivity pattern among cells composing the intact islet. The procedure is based on the determination of correlations between long temporal traces obtained from confocal functional multicellular calcium imaging of beta cells stimulated in a stepwise manner with a range of physiological glucose concentrations. Our results revealed that the extracted connectivity networks are sparse for low glucose concentrations, whereas for higher stimulatory levels they become more densely connected. Most importantly, for all ranges of glucose concentration beta cells within the islets form locally clustered functional sub-compartments, thereby indicating that their collective activity profiles exhibit a modular nature. Moreover, we show that the observed non-linear functional relationship between different network metrics and glucose concentration represents a well-balanced setup that parallels physiological insulin release.

  5. Increasing thyroid-stimulating hormone is associated with impaired glucose metabolism in euthyroid obese children and adolescents.

    Science.gov (United States)

    Radhakishun, Nalini N E; van Vliet, Mariska; von Rosenstiel, Ines A; Weijer, Olivier; Beijnen, Jos H; Brandjes, Dees P M; Diamant, Michaela

    2013-01-01

    Contrasting data exist regarding the relationship between thyroid-stimulating hormone (TSH) and obesity-related risk factors in children. In the present study, we investigated the association between TSH, free T4 (fT4) and cardiometabolic risk factors in euthyroid obese children and adolescents. A retrospective analysis of patient records was performed on data from 703 multi-ethnic obese children and adolescents who visited an obesity-outpatient clinic. We performed anthropometric measurements, an oral glucose tolerance test, and measured serum TSH, fT4 and lipid levels. A positive association between TSH and the standard deviation score of the body mass index (BMI-Z) was found. After adjustment for ethnicity, sex, pubertal stage and BMI-Z, logistic regression analysis showed significant associations between TSH levels and impaired fasting glucose, impaired glucose tolerance, high total cholesterol, high low-density lipoprotein cholesterol and high triglycerides. No significant associations between fT4 levels and cardiometabolic risk factors were found in linear/logistic regression analysis. In our multi-ethnic cohort of euthyroid obese children and adolescents increasing TSH was associated with impaired glucose metabolism and dyslipidemia.

  6. Epinephrine-stimulated glycogen breakdown activates glycogen synthase and increases insulin-stimulated glucose uptake in epitrochlearis muscles

    DEFF Research Database (Denmark)

    Kolnes, Anders J; Birk, Jesper Bratz; Eilertsen, Einar

    2015-01-01

    Adrenaline increases glycogen synthase (GS) phosphorylation and decreases GS activity but also stimulates glycogen breakdown and low glycogen content normally activates GS. To test the hypothesis that glycogen content directly regulates GS phosphorylation, glycogen breakdown was stimulated...... in condition with decreased GS activation. Saline or adrenaline (0.02mg/100g rat) was injected subcutaneously in Wistar rats (~130 g) with low (24 h fasted), normal (normal diet) and high glycogen content (fasted-refed) and epitrochlearis muscles were removed after 3 h and incubated ex vivo eliminating...... adrenaline action. Adrenaline injection reduced glycogen content in epitrochlearis muscles with high (120.7±17.8 vs 204.6±14.5 mmol•kg(-1); pglycogen (89.5±7.6 vs 152.6±8.1 mmol•kg(-1); pglycogen (90.0±5.0 vs 102.8±7.8 mmol•kg(-1); p=0...

  7. Stimulated Respiration and Net Photosynthesis in Cassiopeia sp. during Glucose Enrichment Suggests in hospite CO2 Limitation of Algal Endosymbionts

    KAUST Repository

    Radecker, Nils

    2017-08-15

    The endosymbiosis between cnidarians and dinoflagellates of the genus Symbiodinium is key to the high productivity of tropical coral reefs. In this endosymbiosis, Symbiodinium translocate most of their photosynthates to their animal host in exchange for inorganic nutrients. Among these, carbon dioxide (CO ) derived fromhost respiration helps to meet the carbon requirements to sustain photosynthesis of the dinoflagellates. Nonetheless, recent studies suggest that productivity in symbiotic cnidarians such as corals is CO -limited. Here we show that glucose enrichment stimulates respiration and gross photosynthesis rates by 80 and 140%, respectively, in the symbiotic upside-down jellyfish Cassiopeia sp. from the Central Red Sea. Our findings show that glucose was rapidly consumed and respired within the Cassiopeia sp. holobiont. The resulting increase of CO availability in hospite in turn likely stimulated photosynthesis in Symbiodinium. Hence, the increase of photosynthesis under these conditions suggests that CO limitation of Symbiodinium is a common feature of stable cnidarian holobionts and that the stimulation of holobiont metabolism may attenuate this CO limitation.

  8. Rebaudioside A potently stimulates insulin secretion from isolated mouse islets: studies on the dose-, glucose-, and calcium-dependency.

    Science.gov (United States)

    Abudula, Reziwanggu; Jeppesen, Per Bendix; Rolfsen, Stig Eric D; Xiao, Jianzhong; Hermansen, Kjeld

    2004-10-01

    Extracts of leaves of the plant Stevia rebaudiana Bertoni (SrB), have been used for many years in traditional treatment of diabetes in South America. Stevia leaves contain diterpene glycosides, stevioside and rebaudioside A being the most abundant. Recently, it was demonstrated that stevioside stimulates the insulin secretion both in vitro and in vivo. Subsequently, we wanted to elucidate the influence of rebaudioside A on the insulin release from mouse islets using static incubations, as well as perifusion experiments. Rebaudioside A (10(-16) to 10(-6) mol/L) dose-dependently stimulated the insulin secretion in the presence of 16.7 mmol/L glucose (P 6.6 mmol/L. The effect of rebaudioside A is critically dependent on the presence of extracellular Ca2+, ie, rebaudioside A-induced insulin stimulation at high glucose disappears in the absence of extracellular Ca2+. In conclusion, rebaudioside A possesses insulinotropic effects and may serve a potential role as treatment in type 2 diabetes mellitus.

  9. Stimulated Respiration and Net Photosynthesis in Cassiopeia sp. during Glucose Enrichment Suggests in hospite CO2 Limitation of Algal Endosymbionts

    Directory of Open Access Journals (Sweden)

    Nils Rädecker

    2017-08-01

    Full Text Available The endosymbiosis between cnidarians and dinoflagellates of the genus Symbiodinium is key to the high productivity of tropical coral reefs. In this endosymbiosis, Symbiodinium translocate most of their photosynthates to their animal host in exchange for inorganic nutrients. Among these, carbon dioxide (CO2 derived from host respiration helps to meet the carbon requirements to sustain photosynthesis of the dinoflagellates. Nonetheless, recent studies suggest that productivity in symbiotic cnidarians such as corals is CO2-limited. Here we show that glucose enrichment stimulates respiration and gross photosynthesis rates by 80 and 140%, respectively, in the symbiotic upside-down jellyfish Cassiopeia sp. from the Central Red Sea. Our findings show that glucose was rapidly consumed and respired within the Cassiopeia sp. holobiont. The resulting increase of CO2 availability in hospite in turn likely stimulated photosynthesis in Symbiodinium. Hence, the increase of photosynthesis under these conditions suggests that CO2 limitation of Symbiodinium is a common feature of stable cnidarian holobionts and that the stimulation of holobiont metabolism may attenuate this CO2 limitation.

  10. Altered local cerebral glucose utilization induced by electrical stimulations of the thalamic sensory and parafascicular nuclei in rats.

    Science.gov (United States)

    Aiko, Y; Shima, F; Hosokawa, S; Kato, M; Kitamura, K

    1987-04-07

    Alterations in local cerebral glucose utilization (LCGU) induced by electrical stimulation of the sensory relay nucleus (VPL) or parafascicular nucleus (Pf) of the thalamus in conscious rats were measured by the [14C]2-deoxyglucose method, the objective being to assess the mechanism of analgesia induced by electrical stimulations of these structures. Stimulation of the VPL induced an ipsilateral increase in LCGU in the sensory thalamic nucleus itself, the sensory cortex and substantia nigra. Stimulation of the Pf induced bilateral increases in LCGU in the Pf and central medial nucleus of the thalamus, sensory cortex, ventral areas of the striatum and substantia nigra, and ipsilateral increase in LCGU in the periaqueductal gray, parabrachial pontine nucleus and deep layers of the superior colliculus. No significant change in LCGU was detected in the raphe dorsalis, raphe magnus and spinal dorsal horn, in both groups. Our observations coincide with clinical findings that unilateral electrical stimulation of the Pf leads to amelioration of intractable pain bilaterally, while that of the VPL induces an analgesia restricted to the contralateral side.

  11. Studies of gene expression and activity of hexokinase, phosphofructokinase and glycogen synthase in human skeletal muscle in states of altered insulin-stimulated glucose metabolism

    DEFF Research Database (Denmark)

    Vestergaard, H

    1999-01-01

    with disorders characterized by insulin resistance like non-insulin-dependent diabetes mellitus (NIDDM) and insulin-dependent diabetes mellitus (IDDM) before and after therapeutic interventions, patients with microvascular angina and patients with severe insulin resistant diabetes mellitus and congenital muscle......When whole body insulin-stimulated glucose disposal rate is measured in man applying the euglycaemic, hyperinsulinaemic clamp technique it has been shown that approximately 75% of glucose is taken up by skeletal muscle. After the initial transport step, glucose is rapidly phosphorylated to glucose......-6-phosphate and routed into the major pathways of either glucose storage as glycogen or the glycolytic/tricarboxylic acid pathway. Glucose uptake in skeletal muscle involves-the activity of specific glucose transporters and hexokinases, whereas, phosphofructokinase and glycogen synthase hold...

  12. Video imaging of cytosolic Ca2+ in pancreatic beta-cells stimulated by glucose, carbachol, and ATP.

    Science.gov (United States)

    Theler, J M; Mollard, P; Guérineau, N; Vacher, P; Pralong, W F; Schlegel, W; Wollheim, C B

    1992-09-05

    In order to define the differences in the distribution of cytosolic free Ca2+ ([Ca2+]i) in pancreatic beta-cells stimulated with the fuel secretagogue glucose or the Ca(2+)-mobilizing agents carbachol and ATP, we applied digital video imaging to beta-cells loaded with fura-2.83% of the cells responded to glucose with an increase in [Ca2+]i after a latency of 117 +/- 24 s (mean +/- S.E., 85 cells). Of these cells, 16% showed slow wave oscillations (frequency 0.35/min). In order to assess the relationship between membrane potential and the distribution of the [Ca2+]i rise, digital image analysis and perforated patch-clamp methods were applied simultaneously. The system used allowed sufficient temporal resolution to visualize a subplasmalemmal Ca2+ transient due to a single glucose-induced action potential. Glucose could also elicit a slow depolarization which did not cause Ca2+ influx until the appearance of the first of a train of action potentials. [Ca2+]i rose progressively during spike firing. Inhibition of Ca2+ influx by EGTA abolished the glucose-induced rise in [Ca2+]i. In contrast, the peak amplitude of the [Ca2+]i response to carbachol was not significantly different in normal or in Ca(2+)-deprived medium. Occasionally, the increase of the [Ca2+]i rise was polarized to one area of the cell different from the subplasmalemmal rise caused by glucose. The amplitude of the response and the number of responding cells were significantly increased when carbachol was applied after the addition of high glucose (11.2 mM). ATP also raised [Ca2+]i and promoted both Ca2+ mobilization and Ca2+ influx. The intracellular distribution of [Ca2+]i was homogeneous during the onset of the response. A polarity in the [Ca2+]i distribution could be detected either in the descending phase of the peak or in subsequent peaks during [Ca2+]i oscillations caused by ATP. In the absence of extracellular Ca2+, the sequential application of ATP and carbachol revealed that carbachol was still

  13. Peroxisome proliferator-activated receptor alpha (PPARalpha) potentiates, whereas PPARgamma attenuates, glucose-stimulated insulin secretion in pancreatic beta-cells

    DEFF Research Database (Denmark)

    Ravnskjaer, Kim; Boergesen, Michael; Rubi, Blanca

    2005-01-01

    Fatty acids (FAs) are known to be important regulators of insulin secretion from pancreatic beta-cells. FA-coenzyme A esters have been shown to directly stimulate the secretion process, whereas long-term exposure of beta-cells to FAs compromises glucose-stimulated insulin secretion (GSIS) by mech...

  14. Thyroid hormone stimulated glucose uptake in human mononuclear blood cells from normal persons and from patients with non-insulin-dependent diabetes mellitus

    DEFF Research Database (Denmark)

    Kvetny, J; Matzen, L

    1989-01-01

    of stimulation of cells from control subjects and patients with NIDDM revealed an identical oxygen consumption, whereas the thyroid hormone-induced glucose uptake was significantly increased in cells from patients with NIDDM. T4 (5 mumol/l) stimulation in controls: 1.34 +/- 0.23 mmol.l-1 (mg DNA)-1.h-1, in NIDDM...

  15. Monosodium glutamate stimulates secretion of glucagon-like peptide-1 and reduces postprandial glucose after a lipid-containing meal.

    Science.gov (United States)

    Hosaka, H; Kusano, M; Zai, H; Kawada, A; Kuribayashi, S; Shimoyama, Y; Nagoshi, A; Maeda, M; Kawamura, O; Mori, M

    2012-11-01

    Monosodium l-glutamate (MSG) is known to influence the endocrine system and gastrointestinal (GI) motility. The mechanism of postprandial glycemic control by food in the GI tract is mostly unknown and of great interest. To investigate the effect of MSG on glucose homeostasis, incretin secretion and gastric emptying in humans after a lipid-containing meal. Thirteen healthy male volunteers (mean age, 25.5 years) and with no Helicobcter pylori infection were enrolled. A 400 mL (520 kcal) liquid meal with MSG (2 g, 0.5% wt:vol) or NaCl (control) was ingested in a single-blind placebo-controlled cross-over study. Blood glucose, serum insulin, plasma glucagon, plasma glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide were measured. Gastric emptying was monitored by a 13C acetate breath test. Postprandial symptoms were assessed on a visual analogue scale. The 30-min postprandial glucose concentration was significantly reduced by adding MSG to the test meal. The area under the glucose concentration vs. time curve (0-60 min) was also significantly reduced by adding MSG (40.6 ± 3.51 mg·1 hr/dL with MSG vs. 49.2 ± 3.86 mg·1 hr/dL with NaCl, P = 0.047), whereas, the 30-min postprandial plasma GLP-1 level was significantly increased (58.1 ± 15.8 pmol/L with MSG vs. 13.4 ± 15.8 pmol/L with NaCl, P = 0.035). MSG did not affect the half gastric emptying time or postprandial symptoms. Monosodium l-glutamate improved early postprandial glycaemia after a lipid-containing liquid meal. This effect was not associated with a change in gastric emptying, but was possibly related to stimulation of glucagon-like peptide-1 secretion.

  16. Rac1 and AMPK account for the majority of muscle glucose uptake stimulated by ex vivo contraction but not in vivo exercise

    DEFF Research Database (Denmark)

    Sylow, Lykke; Møller, Lisbeth Liliendal Valbjørn; Kleinert, Maximilian

    2017-01-01

    by Rac1 mKO with no additive effect of α2KD. It is concluded that Rac1 and α2AMPK together account for almost the entire ex vivo contraction-response in muscle glucose transport, while only Rac1, but not α2AMPK, regulates muscle glucose uptake during submaximal exercise in vivo....... but whether those two signaling pathways jointly account for the entire signal to glucose transport is unknown. We therefore studied the ability of contraction and exercise to stimulate glucose transport in isolated muscles with AMPK loss-of-function combined with either pharmacological inhibition or genetic...

  17. Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca2+ release

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Sylow, Lykke; Rose, Adam John

    2014-01-01

    signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca(2+) release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress......-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport...

  18. Glucose, other secretagogues, and nerve growth factor stimulate mitogen-activated protein kinase in the insulin-secreting beta-cell line, INS-1

    DEFF Research Database (Denmark)

    Frödin, M; Sekine, N; Roche, E

    1995-01-01

    -1. Phorbol ester, an activator of protein kinase C, stimulated 44-kDa MAP kinase by both Ca(2+)-dependent and -independent pathways. Nerve growth factor, independently of changes in cytosolic Ca2+, efficiently stimulated 44-kDa MAP kinase without causing insulin release, indicating that activation...... of this kinase is not sufficient for secretion. In the presence of glucose, however, nerve growth factor potentiated insulin secretion. In INS-1 cells, activation of 44-kDa MAP kinase was partially correlated with the induction of early response genes junB, nur77, and zif268 but not with stimulation of DNA......The signaling pathways whereby glucose and hormonal secretagogues regulate insulin-secretory function, gene transcription, and proliferation of pancreatic beta-cells are not well defined. We show that in the glucose-responsive beta-cell line INS-1, major secretagogue-stimulated signaling pathways...

  19. Ca2+ controls slow NAD(P)H oscillations in glucose-stimulated mouse pancreatic islets

    DEFF Research Database (Denmark)

    Luciani, Dan Seriano; Misler, S.; Polonsky, K.S.

    2006-01-01

    Exposure of pancreatic islets of Langerhans to physiological concentrations of glucose leads to secretion of insulin in an oscillatory pattern. The oscillations in insulin secretion are associated with oscillations in cytosolic Ca2+ concentration ([Ca2+](c)). Evidence suggests that the oscillatio...

  20. Cancer-Associated Fibroblasts Neutralize the Anti-tumor Effect of CSF1 Receptor Blockade by Inducing PMN-MDSC Infiltration of Tumors.

    Science.gov (United States)

    Kumar, Vinit; Donthireddy, Laxminarasimha; Marvel, Douglas; Condamine, Thomas; Wang, Fang; Lavilla-Alonso, Sergio; Hashimoto, Ayumi; Vonteddu, Prashanthi; Behera, Reeti; Goins, Marlee A; Mulligan, Charles; Nam, Brian; Hockstein, Neil; Denstman, Fred; Shakamuri, Shanti; Speicher, David W; Weeraratna, Ashani T; Chao, Timothy; Vonderheide, Robert H; Languino, Lucia R; Ordentlich, Peter; Liu, Qin; Xu, Xiaowei; Lo, Albert; Puré, Ellen; Zhang, Chunsheng; Loboda, Andrey; Sepulveda, Manuel A; Snyder, Linda A; Gabrilovich, Dmitry I

    2017-11-13

    Tumor-associated macrophages (TAM) contribute to all aspects of tumor progression. Use of CSF1R inhibitors to target TAM is therapeutically appealing, but has had very limited anti-tumor effects. Here, we have identified the mechanism that limited the effect of CSF1R targeted therapy. We demonstrated that carcinoma-associated fibroblasts (CAF) are major sources of chemokines that recruit granulocytes to tumors. CSF1 produced by tumor cells caused HDAC2-mediated downregulation of granulocyte-specific chemokine expression in CAF, which limited migration of these cells to tumors. Treatment with CSF1R inhibitors disrupted this crosstalk and triggered a profound increase in granulocyte recruitment to tumors. Combining CSF1R inhibitor with a CXCR2 antagonist blocked granulocyte infiltration of tumors and showed strong anti-tumor effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Annexin A1 N-terminal derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions.

    Directory of Open Access Journals (Sweden)

    Valentina Bizzarro

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we have evaluated whether Annexin A1 derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions. Using normal human skin fibroblasts WS1 in low glucose (LG or high glucose (HG we observed the enrichment of Annexin A1 protein at cell movement structures like lamellipodial extrusions and interestingly, a significant decrease in levels of the protein in HG conditions. The analysis of the translocation of Annexin A1 to cell membrane showed lower levels of Annexin A1 in both membrane pool and supernatants of WS1 cells treated with HG. Wound-healing assays using cell line transfected with Annexin A1 siRNAs indicated a slowing down in migration speed of cells suggesting that Annexin A1 has a role in the migration of WS1 cells. In order to analyze the role of extracellular Annexin A1 in cell migration, we have performed wound-healing assays using Ac2-26 showing that peptide was able to increase fibroblast cell migration in HG conditions. Experiments on the mobilization of intracellular calcium and analysis of p-ERK expression confirmed the activity of the FPR1 following stimulation with the peptide Ac2-26. A wound-healing assay on WS1 cells in the presence of the FPR agonist fMLP, of the FPR antagonist CsH and in the presence of Ac2-26 indicated that Annexin A1 influences fibroblast cell migration under HG conditions acting through FPR receptors whose expression was slightly increased in HG. In conclusion, these data demonstrate that (i Annexin A1 is involved in migration of WS1 cells, through interaction with FPRs; (ii N- terminal peptide of Annexin A1 Ac2-26 is able to stimulate direct migration of WS1 cells in high glucose treatment possibly due to the increased receptor expression observed in hyperglycemia conditions.

  2. Enzyme-free monitoring of glucose utilization in stimulated macrophages using carbon nanotube-decorated electrochemical sensor

    Science.gov (United States)

    Madhurantakam, Sasya; Karnam, Jayanth Babu; Rayappan, John Bosco Balaguru; Krishnan, Uma Maheswari

    2017-11-01

    Carbon nanotubes (CNTs) have been extensively explored for a diverse range of applications due to their unique electrical and mechanical properties. CNT-incorporated electrochemical sensors have exhibited enhanced sensitivity towards the analyte molecule due to the excellent electron transfer properties of CNTs. In addition, CNTs possess a large surface area-to-volume ratio that favours the adhesion of analyte molecules as well as enhances the electroactive area. Most of the electrochemical sensors have employed CNTs as a nano-interface to promote electron transfer and as an immobilization matrix for enzymes. The present work explores the potential of CNTs to serve as a catalytic interface for the enzymeless quantification of glucose. The figure of merits for the enzymeless sensor was comparable to the performance of several enzyme-based sensors reported in literature. The developed sensor was successfully employed to determine the glucose utilization of unstimulated and stimulated macrophages. The significant difference in the glucose utilization levels in activated macrophages and quiescent cells observed in the present investigation opens up the possibilities of new avenues for effective medical diagnosis of inflammatory disorders.

  3. Chronic Electrical Stimulation at Acupoints Reduces Body Weight and Improves Blood Glucose in Obese Rats via Autonomic Pathway.

    Science.gov (United States)

    Liu, Jiemin; Jin, Haifeng; Foreman, Robert D; Lei, Yong; Xu, Xiaohong; Li, Shiying; Yin, Jieyun; Chen, Jiande D Z

    2015-07-01

    The aim of this study was to investigate effects and mechanisms of chronic electrical stimulation at acupoints (CEA) using surgically implanted electrodes on food intake, body weight, and metabolisms in diet-induced obese (DIO) rats. Thirty-six DIO rats were chronically implanted with electrodes at acupoints ST-36 (Zusanli). Three sets of parameters were tested: electrical acupuncture (EA) 1 (2-s on, 3-s off, 0.5 ms, 15 Hz, 6 mA), EA2 (same as EA1 but continuous pulses), and EA3 (same as EA2 but 10 mA). A chronic study was then performed to investigate the effects of CEA on body weight and mechanisms involving gastrointestinal hormones and autonomic functions. EA2 significantly reduced food intake without uncomfortable behaviors. CEA at EA2 reduced body weight and epididymal fat pad weight (P postprandial blood glucose and HbA1c (P postprandial blood glucose (R (2) = 0.89, P blood glucose possibly attributed to multiple mechanisms involving gastrointestinal motility and hormones via the autonomic pathway.

  4. Enzyme-free monitoring of glucose utilization in stimulated macrophages using carbon nanotube-decorated electrochemical sensor

    Science.gov (United States)

    Madhurantakam, Sasya; Karnam, Jayanth Babu; Rayappan, John Bosco Balaguru; Krishnan, Uma Maheswari

    2017-10-01

    Carbon nanotubes (CNTs) have been extensively explored for a diverse range of applications due to their unique electrical and mechanical properties. CNT-incorporated electrochemical sensors have exhibited enhanced sensitivity towards the analyte molecule due to the excellent electron transfer properties of CNTs. In addition, CNTs possess a large surface area-to-volume ratio that favours the adhesion of analyte molecules as well as enhances the electroactive area. Most of the electrochemical sensors have employed CNTs as a nano-interface to promote electron transfer and as an immobilization matrix for enzymes. The present work explores the potential of CNTs to serve as a catalytic interface for the enzymeless quantification of glucose. The figure of merits for the enzymeless sensor was comparable to the performance of several enzyme-based sensors reported in literature. The developed sensor was successfully employed to determine the glucose utilization of unstimulated and stimulated macrophages. The significant difference in the glucose utilization levels in activated macrophages and quiescent cells observed in the present investigation opens up the possibilities of new avenues for effective medical diagnosis of inflammatory disorders.

  5. Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca2+ release

    Directory of Open Access Journals (Sweden)

    Thomas E. Jensen

    2014-10-01

    Full Text Available Understanding how muscle contraction orchestrates insulin-independent muscle glucose transport may enable development of hyperglycemia-treating drugs. The prevailing concept implicates Ca2+ as a key feed forward regulator of glucose transport with secondary fine-tuning by metabolic feedback signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca2+ release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport during muscle contraction, and call for a major reconsideration of the established Ca2+ centric paradigm.

  6. Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Florian; Schultz, Julia; Waterstradt, Rica; Baltrusch, Simone, E-mail: simone.baltrusch@med.uni-rostock.de

    2016-06-10

    Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 was down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion. -- Highlights: •Down-regulation of Drp1 in INS1 cells reduces mitochondrial fusion protein expression. •Mitochondrial membrane potential in INS1 cells is diminished after Drp1 down-regulation. •Mitochondria become elongated after down-regulation of Drp1 in beta cells. •Down-regulation of

  7. Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal.

    Science.gov (United States)

    Chen, Mimi Z; Hudson, Claire A; Vincent, Emma E; de Berker, David A R; May, Margaret T; Hers, Ingeborg; Dayan, Colin M; Andrews, Robert C; Tavaré, Jeremy M

    2015-01-01

    Weight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB), and compared this to lean volunteers. The hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR) in eight morbidly obese (body mass index, BMI=47.3 ± 2.2 kg/m(2)) patients, before and after RYGB, and in eight lean volunteers (BMI=20.7 ± 0.7 kg/m2). Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50) and maximal (GDR100) GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity. Pre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (PMANCOVA), and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA), and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively). Our data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.

  8. SU11248 inhibits tumor growth and CSF-1R-dependent osteolysis in an experimental breast cancer bone metastasis model.

    Science.gov (United States)

    Murray, Lesley J; Abrams, Tinya J; Long, Kelly R; Ngai, Theresa J; Olson, Lisa M; Hong, Weiru; Keast, Paul K; Brassard, Jacqueline A; O'Farrell, Anne Marie; Cherrington, Julie M; Pryer, Nancy K

    2003-01-01

    The aim of the study was to investigate inhibitory effects of the receptor tyrosine kinase (RTK) inhibitor SU11248 against CSF-1R and osteoclast (OC) formation. We developed an in vivo model of breast cancer metastasis to evaluate efficacy of SU11248 against tumor growth and tumor-induced osteolysis in bone. The in vitro effects of SU11248 on CSF-1R phosphorylation, OC formation and function were evaluated. Effects on 435/HAL-Luc tumor growth in bone were monitored by in vivo bioluminescence imaging (BLI), and inhibition of osteolysis was evaluated by measurement of serum pyridinoline (PYD) concentration and histology. Phosphorylation of the receptor for M-CSF (CSF-1R) expressed by NIH3T3 cells was inhibited by SU11248 with an IC50 of 50-100 nM, consistent with CSF-1R belonging to the class III split kinase domain RTK family. The early M-CSF-dependent phase of in vitro murine OC development and function were inhibited by SU11248 at 10-100 nM. In vivo inhibition of osteolysis was confirmed by significant lowering of serum PYD levels following SU11248 treatment of tumor-bearing mice (P = 0.047). Using BLI, SU11248 treatment at 40 mg/kg/day for 21 days showed 64% inhibition of tumor growth in bone (P = 0.006), and at 80 mg/kg/day showed 89% inhibition (P = 0.001). Collectively, these data suggest that SU11248 may be an effective and tolerated therapy to inhibit growth of breast cancer bone metastases, with the additional advantage of inhibiting tumor-associated osteolysis.

  9. Development of a rapid streptavidin capture-based assay for the tyrosine phosphorylated CSF-1R in peripheral blood mononuclear cells.

    Science.gov (United States)

    Chaturvedi, Shalini; Dell, Elayne; Siegel, Derick; Brittingham, Gregory; Seetharam, Shobha

    2013-01-01

    A novel assay was developed to measure ratio of p-FMS (phospho FMS) to FMS using the Meso Scale Discovery(®) (MSD) technology and compared to the routinely used, IP-Western based approach. The existing IP-Western assay used lysed PBMCs (Peripheral Blood Mononuclear Cells) that were immunoprecipitated (IP) overnight, and assayed qualitatively by Western analysis. This procedure takes three days for completion. The novel IP-MSD method described in this paper employed immunoprecipitation of the samples for one hour, followed by assessment of the samples by a ruthenium labeled secondary antibody on a 96-well Streptavidin-coated MSD plate. This IP-MSD method was semi-quantitative, could be run in less than a day, required one-eighth the volume of sample, and compared well to the IP-Western method. In order to measure p-FMS/FMS, samples from healthy volunteers (HV) were first stimulated with CSF-1(Macrophage colony-stimulating factor) to initiate the changes in the phosphotyrosyl signaling complexes in FMS. The objective of the present work was to develop a high throughput assay that measured p-FMS/FMS semi-quantitatively, with minimal sample requirement, and most importantly compared well to the current IP-Western assay.

  10. Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats.

    Science.gov (United States)

    Diepenbroek, Charlene; van der Plasse, Geoffrey; Eggels, Leslie; Rijnsburger, Merel; Feenstra, Matthijs G P; Kalsbeek, Andries; Denys, Damiaan; Fliers, Eric; Serlie, Mireille J; la Fleur, Susanne E

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is an effective therapy for obsessive compulsive disorder (OCD) and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc) influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of 1 h. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA) using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 μA increased Fos immunoreactivity in the LHA compared to sham or 100 μA stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity- dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients.

  11. Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats

    Directory of Open Access Journals (Sweden)

    Charlene eDiepenbroek

    2013-12-01

    Full Text Available Deep brain stimulation (DBS of the nucleus accumbens (NAc is an effective therapy for obsessive compulsive disorder (OCD and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of one hour. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 μA increased Fos immunoreactivity in the LHA compared to sham or 100 μA stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients.

  12. Roles of TBC1D1 and TBC1D4 in insulin- and exercise-stimulated glucose transport of skeletal muscle

    Science.gov (United States)

    Cartee, Gregory D.

    2014-01-01

    This review focuses on two paralogue Rab GTPase activating proteins known as TBC1D1 Tre-2/BUB2/cdc 1 domain family (TBC1D) 1 and TBC1D4 (also called Akt Substrate of 160 kDa, AS160) and their roles in controlling skeletal muscle glucose transport in response to the independent and combined effects of insulin and exercise. Convincing evidence implicates Akt2-dependent TBC1D4 phosphorylation on T642 as a key part of the mechanism for insulin-stimulated glucose uptake by skeletal muscle. TBC1D1 phosphorylation on several insulin-responsive sites (including T596, a site corresponding to T642 in TBC1D4) does not appear to be essential for in vivo insulin-stimulated glucose uptake by skeletal muscle. In vivo exercise or ex vivo contraction of muscle result in greater TBC1D1 phosphorylation on S237 that is likely to be secondary to increased AMP-activated protein kinase activity and potentially important for contraction-stimulated glucose uptake. Several studies that evaluated both normal and insulin-resistant skeletal muscle stimulated with a physiological insulin concentration after a single exercise session found that greater post-exercise insulin-stimulated glucose uptake was accompanied by greater TBC1D4 phosphorylation on several sites. In contrast, enhanced post-exercise insulin sensitivity was not accompanied by greater insulin-stimulated TBC1D1 phosphorylation. The mechanism for greater TBC1D4 phosphorylation in insulin-stimulated muscles after acute exercise is uncertain, and a causal link between enhanced TBC1D4 phosphorylation and increased post-exercise insulin sensitivity has yet to be established. In summary, TBC1D1 and TBC1D4 have important, but distinct roles in regulating muscle glucose transport in response to insulin and exercise. PMID:25280670

  13. Sweet Taste Receptor Activation in the Gut Is of Limited Importance for Glucose-Stimulated GLP-1 and GIP Secretion

    DEFF Research Database (Denmark)

    Saltiel, Monika Yosifova; Kuhre, Rune Ehrenreich; Christiansen, Charlotte Bayer

    2017-01-01

    secretion from an isolated perfused rat small intestine and whether selective STR activation by artificial sweeteners stimulates secretion. Intra-luminal administration of the STR agonists, acesulfame K (3.85% w/v), but not sucralose (1.25% w/v) and stevioside (2.5% w/v), stimulated GLP-1 secretion...... (acesulfame K: 31 ± 3 pmol/L vs. 21 ± 2 pmol/L, p sucralose (10 mM) and stevioside (10 mM), but not acesulfame K, stimulated GLP-1 secretion (sucralose: 51 ± 6 pmol/L vs. 34 ± 4 pmol/L, p ....05, n = 6), while 0.1 mM and 1 mM sucralose did not affect the secretion. Luminal glucose (20% w/v) doubled GLP-1 and GIP secretion, but basolateral STR inhibition by gurmarin (2.5 µg/mL) or the inhibition of the transient receptor potential cation channel 5 (TRPM5) by triphenylphosphine oxide (TPPO...

  14. Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal.

    Directory of Open Access Journals (Sweden)

    Mimi Z Chen

    Full Text Available Weight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB, and compared this to lean volunteers.The hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR in eight morbidly obese (body mass index, BMI=47.3 ± 2.2 kg/m(2 patients, before and after RYGB, and in eight lean volunteers (BMI=20.7 ± 0.7 kg/m2. Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50 and maximal (GDR100 GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity.Pre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (P<0.001. Weight-loss of 29.9 ± 4 kg after surgery significantly improved GDR50 (P=0.004 but not GDR100 (P=0.3. These subjects still remained significantly more insulin resistant than the lean individuals (p<0.001. Weight loss increased insulin-stimulated skeletal muscle Akt-Thr308 and Akt-Ser473 phosphorylation, P=0.02 and P=0.03 respectively (MANCOVA, and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA, and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively.Our data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.

  15. Alcohol decreases baseline brain glucose metabolism more in heavy drinkers than controls but has no effect on stimulation-induced metabolic increases.

    Science.gov (United States)

    Volkow, Nora D; Wang, Gene-Jack; Shokri Kojori, Ehsan; Fowler, Joanna S; Benveniste, Helene; Tomasi, Dardo

    2015-02-18

    During alcohol intoxication, the human brain increases metabolism of acetate and decreases metabolism of glucose as energy substrate. Here we hypothesized that chronic heavy drinking facilitates this energy substrate shift both for baseline and stimulation conditions. To test this hypothesis, we compared the effects of alcohol intoxication (0.75 g/kg alcohol vs placebo) on brain glucose metabolism during video stimulation (VS) versus when given with no stimulation (NS), in 25 heavy drinkers (HDs) and 23 healthy controls, each of whom underwent four PET-(18)FDG scans. We showed that resting whole-brain glucose metabolism (placebo-NS) was lower in HD than controls (13%, p = 0.04); that alcohol (compared with placebo) decreased metabolism more in HD (20 ± 13%) than controls (9 ± 11%, p = 0.005) and in proportion to daily alcohol consumption (r = 0.36, p = 0.01) but found that alcohol did not reduce the metabolic increases in visual cortex from VS in either group. Instead, VS reduced alcohol-induced decreases in whole-brain glucose metabolism (10 ± 12%) compared with NS in both groups (15 ± 13%, p = 0.04), consistent with stimulation-related glucose metabolism enhancement. These findings corroborate our hypothesis that heavy alcohol consumption facilitates use of alternative energy substrates (i.e., acetate) for resting activity during intoxication, which might persist through early sobriety, but indicate that glucose is still favored as energy substrate during brain stimulation. Our findings are consistent with reduced reliance on glucose as the main energy substrate for resting brain metabolism during intoxication (presumably shifting to acetate or other ketones) and a priming of this shift in HDs, which might make them vulnerable to energy deficits during withdrawal. Copyright © 2015 the authors 0270-6474/15/353248-08$15.00/0.

  16. Limited effects of exogenous glucose during severe hypoxia and a lack of hypoxia-stimulated glucose uptake in isolated rainbow trout cardiac muscle

    DEFF Research Database (Denmark)

    Becker, Tracy A.; DellaValle, Brian; Gesser, Hans

    2013-01-01

    any of the aerobic conditions applied. The extracellular concentration of glucose and cold temperature appear to determine and limit cardiomyocyte glucose uptake, respectively, and together may help define a metabolic strategy that relies predominantly on intracellular energy stores.......We examined whether exogenous glucose affects contractile performance of electrically paced ventricle strips from rainbow trout under conditions known to alter cardiomyocyte performance, ion regulation and energy demands. Physiological levels of d-glucose did not influence twitch force development...... by exogenous glucose. However, glucose did attenuate the fall in twitch force during severe hypoxia. Glucose uptake was assayed in non-contracting ventricle strips using 2-[(3)H] deoxy-d-glucose (2-DG) under aerobic and hypoxic conditions, at different incubation temperatures and with different inhibitors...

  17. The effects of TNF-α on GLP-1-stimulated plasma glucose kinetics

    DEFF Research Database (Denmark)

    Lehrskov-Schmidt, Louise; Lehrskov-Schmidt, Lars; Nielsen, Signe T

    2015-01-01

    Context: GLP-1 analogues have recently been promoted as anti-hyperglycemic agents in critically ill patients with systemic inflammation, but the effects of TNF-α on glucose metabolism during GLP-1 administration are unknown. Objective: To determine whether infusion of TNF-α at high physiological...... human TNF-α (1000 ng/m(2)/h) was infused from t = 0-6 hours. At t = 2 hours, GLP-1 infusion (0.5 pmol/kg/min) began. From t = 4-6 hours, the GLP-1 infusion rate was increased to 1.2 pmol/kg/min. Plasma glucose was clamped at 5 mmol/L throughout via a variable-rate 20% dextrose infusion. Trials were 7....... In contrast, infusion of TNF-α increased plasma TNF-α and IL-6, elevated body temperature, and blunted the GLP-1-induced suppression of EGP during high dose GLP-1 infusion (all PTNF-α vs. saline). However, TNF-α infusion lowered plasma GLP-1 during high dose GLP-1 infusion (PTNF...

  18. Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise

    Science.gov (United States)

    2015-01-01

    Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24–48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise. PMID:26487009

  19. Effects of acupuncture stimulation on blood glucose concentration in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, an animal model for type-2 diabetes mellitus.

    Science.gov (United States)

    Nakamura, Hironori; Ishigami, Tatsuyo; Kawase, Yoshiyuki; Yamada, Atsushi; Minagawa, Munenori; Fukuta, Hiroyasu; Kurono, Yasuzo; Suzuki, Hikaru

    2014-05-19

    Effects of acupuncture stimulation on blood glucose concentration and body weight were investigated in the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model for type-2 diabetes. Three groups of rats were used: OLETF, acupuncture-treated OLETF (AcOLETF), and Long-Evans Tokushima Otsuka (LETO) rats (as control for the OLETF rats). In AcOLETF rats, acupuncture stimulation was applied twice a week to 6 points (zhongwan, tianshu, qihai, ganshu, pishu, shenshu) and changes in blood glucose concentration and body weight were measured. Initially, at 6 weeks old, there was no significant difference in blood glucose levels between groups. Blood glucose levels increased with age in each group, reaching a maximum of about 430 mg/dl at 37 weeks in OLETF rats. In AcOLETF rats, blood glucose levels increased at a slower rate than in OLETF rats, reaching a maximum concentration of about 280 mg/dl at 37 weeks of age, significantly lower than that in OLETF rats. The concentration of blood glucose in LETO rats had stabilized at a maximum value of 120~140 mg/dl by 16 weeks, remaining at this level for up to 39 weeks. In each group, body weight increased with age and was not affected by acupuncture treatment. In OLETF rats, acupuncture treatment significantly reduced blood glucose levels, but not their body weight, suggesting that acupuncture therapy was effective in preventing the development of type-2 diabetes mellitus.

  20. Acute Hypoglycemia in Healthy Humans Impairs Insulin-Stimulated Glucose Uptake and Glycogen Synthase in Skeletal Muscle: A Randomized Clinical Study.

    Science.gov (United States)

    Voss, Thomas S; Vendelbo, Mikkel H; Kampmann, Ulla; Hingst, Janne R; Wojtaszewski, Jørgen F P; Svart, Mads V; Møller, Niels; Jessen, Niels

    2017-09-01

    Hypoglycemia is the leading limiting factor in glycemic management of insulin-treated diabetes. Skeletal muscle is the predominant site of insulin-mediated glucose disposal. Our study used a crossover design to test to what extent insulin-induced hypoglycemia affects glucose uptake in skeletal muscle and whether hypoglycemia counterregulation modulates insulin and catecholamine signaling and glycogen synthase activity in skeletal muscle. Nine healthy volunteers were examined on three randomized study days: 1) hyperinsulinemic hypoglycemia (bolus insulin), 2) hyperinsulinemic euglycemia (bolus insulin and glucose infusion), and 3) saline control with skeletal muscle biopsies taken just before, 30 min after, and 75 min after insulin/saline injection. During hypoglycemia, glucose levels reached a nadir of ∼2.0 mmol/L, and epinephrine rose to ∼900 pg/mL. Hypoglycemia impaired insulin-stimulated glucose disposal and glucose clearance in skeletal muscle, whereas insulin signaling in glucose transport was unaffected by hypoglycemia. Insulin-stimulated glycogen synthase activity was completely ablated during hyperinsulinemic hypoglycemia, and catecholamine signaling via cAMP-dependent protein kinase and phosphorylation of inhibiting sites on glycogen synthase all increased. © 2017 by the American Diabetes Association.

  1. Polymorphism rs11085226 in the gene encoding polypyrimidine tract-binding protein 1 negatively affects glucose-stimulated insulin secretion.

    Directory of Open Access Journals (Sweden)

    Martin Heni

    Full Text Available OBJECTIVE: Polypyrimidine tract-binding protein 1 (PTBP1 promotes stability and translation of mRNAs coding for insulin secretion granule proteins and thereby plays a role in β-cells function. We studied whether common genetic variations within the PTBP1 locus influence insulin secretion, and/or proinsulin conversion. METHODS: We genotyped 1,502 healthy German subjects for four tagging single nucleotide polymorphisms (SNPs within the PTBP1 locus (rs351974, rs11085226, rs736926, and rs123698 covering 100% of genetic variation with an r(2≥0.8. The subjects were metabolically characterized by an oral glucose tolerance test with insulin, proinsulin, and C-peptide measurements. A subgroup of 320 subjects also underwent an IVGTT. RESULTS: PTBP1 SNP rs11085226 was nominally associated with lower insulinogenic index and lower cleared insulin response in the OGTT (p≤0.04. The other tested SNPs did not show any association with the analyzed OGTT-derived secretion parameters. In the IVGTT subgroup, SNP rs11085226 was accordingly associated with lower insulin levels within the first ten minutes following glucose injection (p = 0.0103. Furthermore, SNP rs351974 was associated with insulin levels in the IVGTT (p = 0.0108. Upon interrogation of MAGIC HOMA-B data, our rs11085226 result was replicated (MAGIC p = 0.018, but the rs351974 was not. CONCLUSIONS: We conclude that common genetic variation in PTBP1 influences glucose-stimulated insulin secretion. This underlines the importance of PTBP1 for beta cell function in vivo.

  2. Rp-cAMPS Prodrugs Reveal the cAMP Dependence of First-Phase Glucose-Stimulated Insulin Secretion.

    Science.gov (United States)

    Schwede, Frank; Chepurny, Oleg G; Kaufholz, Melanie; Bertinetti, Daniela; Leech, Colin A; Cabrera, Over; Zhu, Yingmin; Mei, Fang; Cheng, Xiaodong; Manning Fox, Jocelyn E; MacDonald, Patrick E; Genieser, Hans-G; Herberg, Friedrich W; Holz, George G

    2015-07-01

    cAMP-elevating agents such as the incretin hormone glucagon-like peptide-1 potentiate glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. However, a debate has existed since the 1970s concerning whether or not cAMP signaling is essential for glucose alone to stimulate insulin secretion. Here, we report that the first-phase kinetic component of GSIS is cAMP-dependent, as revealed through the use of a novel highly membrane permeable para-acetoxybenzyl (pAB) ester prodrug that is a bioactivatable derivative of the cAMP antagonist adenosine-3',5'-cyclic monophosphorothioate, Rp-isomer (Rp-cAMPS). In dynamic perifusion assays of human or rat islets, a step-wise increase of glucose concentration leads to biphasic insulin secretion, and under these conditions, 8-bromoadenosine-3',5'-cyclic monophosphorothioate, Rp-isomer, 4-acetoxybenzyl ester (Rp-8-Br-cAMPS-pAB) inhibits first-phase GSIS by up to 80%. Surprisingly, second-phase GSIS is inhibited to a much smaller extent (≤20%). Using luciferase, fluorescence resonance energy transfer, and bioluminescence resonance energy transfer assays performed in living cells, we validate that Rp-8-Br-cAMPS-pAB does in fact block cAMP-dependent protein kinase activation. Novel effects of Rp-8-Br-cAMPS-pAB to block the activation of cAMP-regulated guanine nucleotide exchange factors (Epac1, Epac2) are also validated using genetically encoded Epac biosensors, and are independently confirmed in an in vitro Rap1 activation assay using Rp-cAMPS and Rp-8-Br-cAMPS. Thus, in addition to revealing the cAMP dependence of first-phase GSIS from human and rat islets, these findings establish a pAB-based chemistry for the synthesis of highly membrane permeable prodrug derivatives of Rp-cAMPS that act with micromolar or even nanomolar potency to inhibit cAMP signaling in living cells.

  3. Systemic and Cardiac Depletion of M2 Macrophage through CSF-1R Signaling Inhibition Alters Cardiac Function Post Myocardial Infarction.

    Science.gov (United States)

    Leblond, Anne-Laure; Klinkert, Kerstin; Martin, Kenneth; Turner, Elizebeth C; Kumar, Arun H; Browne, Tara; Caplice, Noel M

    2015-01-01

    The heart hosts tissue resident macrophages which are capable of modulating cardiac inflammation and function by multiple mechanisms. At present, the consequences of phenotypic diversity in macrophages in the heart are incompletely understood. The contribution of cardiac M2-polarized macrophages to the resolution of inflammation and repair response following myocardial infarction remains to be fully defined. In this study, the role of M2 macrophages was investigated utilising a specific CSF-1 receptor signalling inhibition strategy to achieve their depletion. In mice, oral administration of GW2580, a CSF-1R kinase inhibitor, induced significant decreases in Gr1lo and F4/80hi monocyte populations in the circulation and the spleen. GW2580 administration also induced a significant depletion of M2 macrophages in the heart after 1 week treatment as well as a reduction of cardiac arginase1 and CD206 gene expression indicative of M2 macrophage activity. In a murine myocardial infarction model, reduced M2 macrophage content was associated with increased M1-related gene expression (IL-6 and IL-1β), and decreased M2-related gene expression (Arginase1 and CD206) in the heart of GW2580-treated animals versus vehicle-treated controls. M2 depletion was also associated with a loss in left ventricular contractile function, infarct enlargement, decreased collagen staining and increased inflammatory cell infiltration into the infarct zone, specifically neutrophils and M1 macrophages. Taken together, these data indicate that CSF-1R signalling is critical for maintaining cardiac tissue resident M2-polarized macrophage population, which is required for the resolution of inflammation post myocardial infarction and, in turn, for preservation of ventricular function.

  4. Systemic and Cardiac Depletion of M2 Macrophage through CSF-1R Signaling Inhibition Alters Cardiac Function Post Myocardial Infarction.

    Directory of Open Access Journals (Sweden)

    Anne-Laure Leblond

    Full Text Available The heart hosts tissue resident macrophages which are capable of modulating cardiac inflammation and function by multiple mechanisms. At present, the consequences of phenotypic diversity in macrophages in the heart are incompletely understood. The contribution of cardiac M2-polarized macrophages to the resolution of inflammation and repair response following myocardial infarction remains to be fully defined. In this study, the role of M2 macrophages was investigated utilising a specific CSF-1 receptor signalling inhibition strategy to achieve their depletion. In mice, oral administration of GW2580, a CSF-1R kinase inhibitor, induced significant decreases in Gr1lo and F4/80hi monocyte populations in the circulation and the spleen. GW2580 administration also induced a significant depletion of M2 macrophages in the heart after 1 week treatment as well as a reduction of cardiac arginase1 and CD206 gene expression indicative of M2 macrophage activity. In a murine myocardial infarction model, reduced M2 macrophage content was associated with increased M1-related gene expression (IL-6 and IL-1β, and decreased M2-related gene expression (Arginase1 and CD206 in the heart of GW2580-treated animals versus vehicle-treated controls. M2 depletion was also associated with a loss in left ventricular contractile function, infarct enlargement, decreased collagen staining and increased inflammatory cell infiltration into the infarct zone, specifically neutrophils and M1 macrophages. Taken together, these data indicate that CSF-1R signalling is critical for maintaining cardiac tissue resident M2-polarized macrophage population, which is required for the resolution of inflammation post myocardial infarction and, in turn, for preservation of ventricular function.

  5. Preclinical characterization of 55P0251, a novel compound that amplifies glucose-stimulated insulin secretion and counteracts hyperglycaemia in rodents.

    Science.gov (United States)

    Stadlbauer, Karin; Brunmair, Barbara; Lehner, Zsuzsanna; Adorjan, Immanuel; Scherer, Thomas; Luger, Anton; Bauer, Leonhardt; Fürnsinn, Clemens

    2017-08-01

    55P0251 is a novel compound with blood glucose lowering activity in mice, which has been developed from a molecular backbone structure found in herbal remedies. We here report its basic pharmacological attributes and initial progress in unmasking the mode of action. Pharmacokinetic properties of 55P0251 were portrayed in several species. First efforts to elucidate the glucose lowering mechanism in rodents included numerous experimental protocols dealing with glucose tolerance, insulin secretion from isolated pancreatic islets and comparison to established drugs. A single oral dose of 55P0251 improved glucose tolerance in mice with an ED 50 between 1.5 and 2 mg/kg (reductions in areas under the curve, 1 mg/kg, -18%; 5 mg/kg, -30%; 27 mg/kg, -47%). Pharmacokinetic studies revealed attractive attributes, including a plasma half-life of approximately 3 hours and a bioavailability of approximately 58% in rats. 55P0251 amplified glucose stimulated insulin release from isolated mouse islets and improved glucose tolerance via increased insulin secretion in rats (increase in area under the insulin curve, +184%). Unlike sulfonylureas and glinides, 55P0251 hardly stimulated insulin release under basal conditions and did not induce hypoglycaemia in vivo, but it amplified the secretory response to glucose and other insulinotropic stimuli (KCl, glucagon-like peptide-1). Comparison to established anti-diabetic agents and examination of interaction with molecular targets (K ATP channel, dipeptidyl peptidase-4, glucagon-like peptide-1 receptor) excluded molecular mechanisms addressed by presently marketed drugs. 55P0251 is a novel compound that potently counteracts hyperglycaemia in rodents via amplification of glucose-stimulated insulin release. © 2017 John Wiley & Sons Ltd.

  6. Mitigation of cardiovascular toxicity in a series of CSF-1R inhibitors, and the identification of AZD7507.

    Science.gov (United States)

    Scott, David A; Dakin, Les A; Daly, Kevin; Del Valle, David J; Diebold, R Bruce; Drew, Lisa; Ezhuthachan, Jayachandran; Gero, Thomas W; Ogoe, Claude A; Omer, Charles A; Redmond, Sean P; Repik, Galina; Thakur, Kumar; Ye, Qing; Zheng, Xiaolan

    2013-08-15

    The potent and selective 3-amido-4-anilinoquinoline CSF-1R inhibitor AZ683 suffered from cardiovascular liabilities, which were linked to the off-target activities of the compound and ion channel activity in particular. Less basic and less lipophilic examples from both the quinoline and cinnoline series demonstrated cleaner secondary pharmacology profiles. Cinnoline 31 retained the required potency and oral PK profile, and was progressed through the safety screening cascade to be nominated into development as AZD7507. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Diastereomeric mixture of calophyllic acid and isocalophyllic acid stimulates glucose uptake in skeletal muscle cells: involvement of PI-3-kinase- and ERK1/2-dependent pathways.

    Science.gov (United States)

    Prasad, Janki; Maurya, Chandan Kumar; Pandey, Jyotsana; Jaiswal, Natasha; Madhur, Gaurav; Srivastava, Arvind Kumar; Narender, Tadigoppula; Tamrakar, Akhilesh Kumar

    2013-05-06

    The diastereomeric mixture of calophyllic acid and isocalophyllic acid (F015) isolated from the leaves of Calophyllum inophyllum was investigated for the metabolic effect on glucose transport in skeletal muscle cells. In L6 myotubes, F015 dose-dependently stimulated glucose uptake by increasing translocation of glucose transporter4 (GLUT4) to plasma membrane without affecting their gene expression. The effects on glucose uptake were additive to insulin. Inhibitors analyses revealed that F015-induced glucose uptake was dependent on the activation of phosphatidylinositol-3-kinase (PI-3-K) and extracellular signal-regulated kinases 1 and 2 (ERK1/2), while independent to the activation of 5'AMP-activated kinase (AMPK). F015 significantly increased the phosphorylation of AKT, AS160 and ERK1/2, account for the augmented glucose transport capacity in L6 myotubes. Furthermore, F015 improved glucose tolerance and enhanced insulin sensitivity in skeletal muscle of dexamethasone-induced insulin resistant mice. Our findings demonstrate that F015 activates glucose uptake in skeletal muscle cells through PI-3-K- and EKR1/2-dependent mechanisms and can be a potential lead for the management of diabetes and obesity. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Early long-term administration of the CSF1R inhibitor PLX3397 ablates microglia and reduces accumulation of intraneuronal amyloid, neuritic plaque deposition and pre-fibrillar oligomers in 5XFAD mouse model of Alzheimer's disease.

    Science.gov (United States)

    Sosna, Justyna; Philipp, Stephan; Albay, Ricardo; Reyes-Ruiz, Jorge Mauricio; Baglietto-Vargas, David; LaFerla, Frank M; Glabe, Charles G

    2018-03-01

    Besides the two main classical features of amyloid beta aggregation and tau-containing neurofibrillary tangle deposition, neuroinflammation plays an important yet unclear role in the pathophysiology of Alzheimer's disease (AD). Microglia are believed to be key mediators of neuroinflammation during AD and responsible for the regulation of brain homeostasis by balancing neurotoxicity and neuroprotective events. We have previously reported evidence that neuritic plaques are derived from dead neurons that have accumulated intraneuronal amyloid and further recruit Iba1-positive cells, which play a role in either neuronal demise or neuritic plaque maturation or both. To study the impact of microglia on neuritic plaque development, we treated two-month-old 5XFAD mice with a selective colony stimulation factor 1 receptor (CSF1R) inhibitor, PLX3397, for a period of 3 months, resulting in a significant ablation of microglia. Directly after this treatment, we analyzed the amount of intraneuronal amyloid and neuritic plaques and performed behavioral studies including Y-maze, fear conditioning and elevated plus maze. We found that early long-term PLX3397 administration results in a dramatic reduction of both intraneuronal amyloid as well as neuritic plaque deposition. PLX3397 treated young 5XFAD mice also displayed a significant decrease of soluble fibrillar amyloid oligomers in brain lysates, a depletion of soluble pre-fibrillar oligomers in plasma and an improvement in cognitive function measured by fear conditioning tests. Our findings demonstrate that CSF1R signaling, either directly on neurons or mediated by microglia, is crucial for the accumulation of intraneuronal amyloid and formation of neuritic plaques, suggesting that these two events are serially linked in a causal pathway leading to neurodegeneration and neuritic plaque formation. CSF1R inhibitors represent potential preventative or therapeutic approach that target the very earliest stages of the formation of

  9. Boehmeria nivea Stimulates Glucose Uptake by Activating Peroxisome Proliferator-Activated Receptor Gamma in C2C12 Cells and Improves Glucose Intolerance in Mice Fed a High-Fat Diet

    Directory of Open Access Journals (Sweden)

    Sung Hee Kim

    2013-01-01

    Full Text Available We examined the antidiabetic property of Boehmeria nivea (L. Gaud. Ethanolic extract of Boehmeria nivea (L. Gaud. (EBN increased the uptake of 2-[N-(nitrobenz-2-oxa-1,3-diazol-4-ylamino]-2-deoxy-d-glucose in C2C12 myotubes. To examine the mechanisms underlying EBN-mediated increase in glucose uptake, we examined the transcriptional activity and expression of peroxisome proliferator-activated receptor gamma (PPAR-γ, a pivotal target for glucose metabolism in C2C12 myotubes. We found that the EBN increased both the transcriptional activity and mRNA expression levels of PPAR-γ. In addition, we measured phosphorylation and expression levels of other targets of glucose metabolism, such as AMP-activated protein kinase (AMPK and protein kinase B (Akt/PKB. We found that EBN did not alter the phosphorylation or expression levels of these proteins in a time- or dose-dependent manner, which suggested that EBN stimulates glucose uptake through a PPAR-γ-dependent mechanism. Further, we investigated the antidiabetic property of EBN using mice fed a high-fat diet (HFD. Administration of 0.5% EBN reduced the HFD-induced increase in body weight, total cholesterol level, and fatty liver and improved the impaired fasting glucose level, blood insulin content, and glucose intolerance. These results suggest that EBN had an antidiabetic effect in cell culture and animal systems and may be useful for preventing diabetes.

  10. Gastrin treatment stimulates β-cell regeneration and improves glucose tolerance in 95% pancreatectomized rats.

    Science.gov (United States)

    Téllez, Noèlia; Joanny, Géraldine; Escoriza, Jéssica; Vilaseca, Marina; Montanya, Eduard

    2011-07-01

    β-Cell mass reduction is a central aspect in the development of type 1 and type 2 diabetes, and substitution or regeneration of the lost β-cells is a potentially curative treatment of diabetes. To study the effects of gastrin on β-cell mass in rats with 95% pancreatectomy (95%-Px), a model of pancreatic regeneration, rats underwent 95% Px or sham Px and were treated with [15 leu] gastrin-17 (Px+G and S+G) or vehicle (Px+V and S+V) for 15 d. In 95% Px rats, gastrin treatment reduced hyperglycemia (280 ± 52 mg vs. 436 ± 51 mg/dl, P Gastrin treatment induced β-cell regeneration by enhancing β-cell neogenesis (increased number of extraislet β-cells in Px+G: 0.42 ± 0.05 cells/mm(2) vs. Px+V: 0.27 ± 0.07 cells/mm(2), P gastrin-treated rats (Px+G: 0.07 ± 0.02%, Px+V: 0.23 ± 0.05%; P Gastrin action on β-cell regeneration and survival increased β-cell mass and improved glucose tolerance in 95% Px rats, supporting a potential role of gastrin in the treatment of diabetes.

  11. Pharmacological vasodilation improves insulin-stimulated muscle protein anabolism but not glucose utilization in older adults.

    Science.gov (United States)

    Timmerman, Kyle L; Lee, Jessica L; Fujita, Satoshi; Dhanani, Shaheen; Dreyer, Hans C; Fry, Christopher S; Drummond, Micah J; Sheffield-Moore, Melinda; Rasmussen, Blake B; Volpi, Elena

    2010-11-01

    Skeletal muscle protein metabolism is resistant to the anabolic action of insulin in healthy, nondiabetic older adults. This defect is associated with impaired insulin-induced vasodilation and mTORC1 signaling. We hypothesized that, in older subjects, pharmacological restoration of insulin-induced capillary recruitment would improve the response of muscle protein synthesis and anabolism to insulin. Twelve healthy, nondiabetic older subjects (71 ± 2 years) were randomized to two groups. Subjects were studied at baseline and during local infusion in one leg of insulin alone (Control) or insulin plus sodium nitroprusside (SNP) at variable rate to double leg blood flow. We measured leg blood flow by dye dilution; muscle microvascular perfusion with contrast enhanced ultrasound; Akt/mTORC1 signaling by Western blotting; and muscle protein synthesis, amino acid, and glucose kinetics using stable isotope methodologies. There were no baseline differences between groups. Blood flow, muscle perfusion, phenylalanine delivery to the leg, and intracellular availability of phenylalanine increased significantly (P anabolic effect of insulin in older adults.

  12. Increased nuclear tri-iodothyronine binding and thyroid hormone-stimulated glucose consumption in mononuclear blood cells from patients with liver cirrhosis

    DEFF Research Database (Denmark)

    Kvetny, J; Matzen, L

    1991-01-01

    control subjects. Serum T3 was decreased in patients with LC. The MBC of T3 was increased significantly (P less than 0.05) in cells from patients with LC compared with patients with AH and controls, whereas the equilibrium association constants did not differ. Unstimulated glucose consumption was slightly......Nuclear tri-iodothyronine (T3) maximal binding capacity (MBC) and thyroxine- and T3-stimulated cellular oxygen consumption and glucose consumption were examined in mononuclear blood cells from six patients with liver cirrhosis (LC), in six patients with alcoholic hepatitis (AH), and in six healthy...... increased (P less than 0.05) in cells from patients with AH and LC compared with controls. Thyroid hormone-stimulated glucose consumption was significantly (P less than 0.05) increased in cells from patients with LC compared with controls and patients with AH. Unstimulated oxygen consumption did not differ...

  13. Glucose allostasis

    DEFF Research Database (Denmark)

    Stumvoll, Michael; Tataranni, P Antonio; Stefan, Norbert

    2003-01-01

    In many organisms, normoglycemia is achieved by a tight coupling of nutrient-stimulated insulin secretion in the pancreatic beta-cell (acute insulin response [AIR]) and the metabolic action of insulin to stimulate glucose disposal (insulin action [M]). It is widely accepted that in healthy...... individuals with normal glucose tolerance, normoglycemia can always be maintained by compensatorily increasing AIR in response to decreasing M (and vice versa). This has been mathematically described by the hyperbolic relationship between AIR and M and referred to as glucose homeostasis, with glucose...... concentration assumed to remain constant along the hyperbola. Conceivably, glucose is one of the signals stimulating AIR in response to decreasing M. Hypothetically, as with any normally functioning feed-forward system, AIR should not fully compensate for worsening M, since this would remove the stimulus...

  14. Prolonged exposure of human beta-cells to high glucose increases their release of proinsulin during acute stimulation with glucose or arginine.

    Science.gov (United States)

    Hostens, K; Ling, Z; Van Schravendijk, C; Pipeleers, D

    1999-04-01

    The disproportionate hyperproinsulinemia in type 2 diabetes has been attributed to either a primary beta-cell defect or a secondary dysregulation of beta cells under sustained hyperglycemia. This study examines the effect of a 10- to 13-day exposure to 20 mmol/L glucose on subsequent proinsulin and insulin release by human islets isolated from nondiabetic donors. Compared to control preparations kept at 6 mmol/L glucose, the high glucose cultured beta-cells released more proinsulin and less insulin during perifusion at 5, 10, or 20 mmol/L glucose. The lower amounts of secreted insulin resulted from a marked reduction in cellular insulin content (5-fold lower than in controls). The higher amount of secreted proinsulin is attributed to the sustained state of cellular activation that is known to occur after prolonged exposure to high glucose levels. This activated state of the beta-cell population is also held responsible for its higher secretory responsiveness to 5 mmol/L arginine at a submaximal (5 mmol/L) glucose concentration (8-fold higher proinsulin levels than in the control population). It results, together with the reduction in cellular insulin content, in 7- to 10-fold higher proinsulin over insulin ratios in the medium; at 5 mmol/L glucose, this extracellular ratio is similar to that in the cells. These data add direct support to the view that a disproportionate hyperproinsulinemia can result from a sustained activation of human beta-cells after prolonged exposure to elevated glucose levels.

  15. The change in cerebral glucose metabolism after electroacupuncture: a possible marker to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa.

    Science.gov (United States)

    Liu, Tao-Tao; Hong, Qing-Xiong; Xiang, Hong-Bing

    2015-01-01

    Some reports have demonstrated that deep brain stimulation (DBS) is a promising treatment for patients who suffer from intractable anorexia nervosa. However, the nature of DBS may not be viewed as a standard clinical treatment option for anorexia nervosa because of the unpredictable outcome before DBS. Just like DBS in the brain, electroacupuncture at acupoints is also efficient in treating refractory anorexia nervosa. Some neuroimaging studies using functional magnetic resonance imaging, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) had revealed that both DBS and electroacupuncture at acupoints with electrical stimulation are related to the changes in cerebral glucose metabolism. Therefore, we hypothesize that the changes in cerebral glucose metabolism after electroacupuncture might be useful to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa.

  16. CSF1R inhibition with emactuzumab in locally advanced diffuse-type tenosynovial giant cell tumours of the soft tissue: a dose-escalation and dose-expansion phase 1 study.

    Science.gov (United States)

    Cassier, Philippe A; Italiano, Antoine; Gomez-Roca, Carlos A; Le Tourneau, Christophe; Toulmonde, Maud; Cannarile, Michael A; Ries, Carola; Brillouet, Anne; Müller, Claudia; Jegg, Anna-Maria; Bröske, Ann-Marie; Dembowski, Markus; Bray-French, Katharine; Freilinger, Christine; Meneses-Lorente, Georgina; Baehner, Monika; Harding, Ross; Ratnayake, Jayantha; Abiraj, Keelara; Gass, Nathalie; Noh, Karen; Christen, Randolph D; Ukarma, Lidia; Bompas, Emmanuelle; Delord, Jean-Pierre; Blay, Jean-Yves; Rüttinger, Dominik

    2015-08-01

    Diffuse-type tenosynovial giant cell tumour (dt-GCT) of the soft tissue (alternatively known as pigmented villonodular synovitis), an orphan disease with unmet medical need, is characterised by an overexpression of colony-stimulating factor 1 (CSF1), and is usually caused by a chromosomal translocation involving CSF1. CSF1 receptor (CSF1R) activation leads to the recruitment of CSF1R-expressing cells of the mononuclear phagocyte lineage that constitute the tumor mass in dt-GCT. Emactuzumab (RG7155) is a novel monoclonal antibody that inhibits CSF1R activation. We have assessed the safety, tolerability and activity of emactuzumab in patients with Dt-GCT of the soft tissue. In this phase 1, first-in-human dose-escalation and dose-expansion study, eligible patients were aged 18 years or older with dt-GCT of the soft tissue with locally advanced disease or resectable tumours requiring extensive surgery, an Eastern Cooperative Oncology Group performance status of 1 or less, measurable disease according to Response Evaluation Criteria In Solid Tumors version 1.1, and adequate end-organ function. Patients with GCT of the bone were not eligible. Patients received intravenous emactuzumab at 900 mg, 1350 mg, or 2000 mg every 2 weeks in the dose-escalation phase and at the optimal biological dose in a dose-expansion phase. The primary objective was to evaluate the safety and tolerability of emactuzumab, and to determine the maximum tolerated dose or optimal biological dose. All treated patients were included in the analyses. Expansion cohorts are currently ongoing. This study is registered with ClinicalTrials.gov, number NCT01494688. Between July 26, 2012, and Oct 21, 2013, 12 patients were enrolled in the dose-escalation phase. No dose-limiting toxicities were noted in the dose-escalation cohort; on the basis of pharmacokinetic, pharmacodynamic, and safety information, we chose a dose of 1000 mg every 2 week for the dose-expansion cohort, into which 17 patients were enrolled

  17. An aqueous extract of Curcuma longa (turmeric) rhizomes stimulates insulin release and mimics insulin action on tissues involved in glucose homeostasis in vitro.

    Science.gov (United States)

    Mohankumar, Sureshkumar; McFarlane, James R

    2011-03-01

    Curcuma longa (turmeric) has been used widely as a spice, particularly in Asian countries. It is also used in the Ayurvedic system of medicine as an antiinflammatory and antimicrobial agent and for numerous other curative properties. The aim of this study was to investigate the effects of an aqueous extract of Curcuma longa (AEC) on tissues involved in glucose homeostasis. The extract was prepared by soaking 100 g of ground turmeric in 1 L of water, which was filtered and stored at -20°C prior to use. Pancreas and muscle tissues of adult mice were cultured in DMEM with 5 or 12 mmol/L glucose and varying doses of extract. The AEC stimulated insulin secretion from mouse pancreatic tissues under both basal and hyperglycaemic conditions, although the maximum effect was only 68% of that of tolbutamide. The AEC induced stepwise stimulation of glucose uptake from abdominal muscle tissues in the presence and absence of insulin, and the combination of AEC and insulin significantly potentiated the glucose uptake into abdominal muscle tissue. However, this effect was attenuated by wortmannin, suggesting that AEC possibly acts via the insulin-mediated glucose uptake pathway. In summary, water soluble compounds of turmeric exhibit insulin releasing and mimicking actions within in vitro tissue culture conditions. Copyright © 2010 John Wiley & Sons, Ltd.

  18. Ketoisocaproic acid, a metabolite of leucine, suppresses insulin-stimulated glucose transport in skeletal muscle cells in a BCAT2-dependent manner.

    Science.gov (United States)

    Moghei, Mahshid; Tavajohi-Fini, Pegah; Beatty, Brendan; Adegoke, Olasunkanmi A J

    2016-09-01

    Although leucine has many positive effects on metabolism in multiple tissues, elevated levels of this amino acid and the other branched-chain amino acids (BCAAs) and their metabolites are implicated in obesity and insulin resistance. While some controversies exist about the direct effect of leucine on insulin action in skeletal muscle, little is known about the direct effect of BCAA metabolites. Here, we first showed that the inhibitory effect of leucine on insulin-stimulated glucose transport in L6 myotubes was dampened when other amino acids were present, due in part to a 140% stimulation of basal glucose transport (P glucose transport (-34%, P glucose transport was abrogated in cells depleted of branched-chain aminotransferase 2 (BCAT2), the enzyme that catalyzes the reversible transamination of KIC to leucine. We conclude that although KIC can modulate muscle glucose metabolism, this effect is likely a result of its transamination back to leucine. Therefore, limiting the availability of leucine, rather than those of its metabolites, to skeletal muscle may be more critical in the management of insulin resistance and its sequelae. Copyright © 2016 the American Physiological Society.

  19. C-peptide exhibits a late induction effect on matrix metallopeptidase-9 in high glucose-stimulated rat mesangial cells.

    Science.gov (United States)

    Wang, Junxia; Li, Yanning; Xu, Mingzhi; Li, Dandan; Wang, Yu; Qi, Jinsheng; He, Kunyu

    2016-12-01

    Insufficient matrix metalloproteinase (MMP)-9 and MMP-2 is considered to be a contributor of extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can reverse fibrosis, thus exerting a beneficial effect on DN. Whether C-peptide induces MMP-9 and MMP-2 to reverse ECM accumulation is not clear. In the present study, in order to determine ECM metabolism, rat mesangial cells were treated with high glucose (HG) and C-peptide intervention, then the early and late effects of C-peptide on HG-affected MMP-9 and MMP-2 were evaluated. Firstly, it was confirmed that HG mainly suppressed MMP-9 expression levels. Furthermore, C-peptide treatment induced MMP-9 expression at 6 h and suppressed it at 24 h, revealing the early dual effects of C-peptide on MMP-9 expression. Subsequently, significant increase in MMP-9 expression at 72, 96 and 120 h C-peptide treatment was observed. These changes in MMP-9 protein content confirmed its expression changes following late C-peptide treatment. Furthermore, at 96 and 120 h C-peptide treatment reversed the HG-inhibited MMP-9 secretion, further indicating the late induction effect of C-peptide on MMP-9. The present results demonstrated that C-peptide exerted a late induction effect on MMP-9 in HG-stimulated rat mesangial cells, which may be associated with the underlying mechanism of C-peptide's reversal effects on DN.

  20. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes.

    Science.gov (United States)

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2015-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have "anti-obesity properties" by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic acid and butyric acid inhibit isoproterenol- and adenosine deaminase-stimulated lipolysis as well as isoproterenol-stimulated lipolysis in the presence of a phosphodiesterase (PDE3) inhibitor. In addition, we show that propionic acid and butyric acid inhibit basal and insulin-stimulated de novo lipogenesis, which is associated with increased phosphorylation and thus inhibition of acetyl CoA carboxylase, a rate-limiting enzyme in fatty acid synthesis. Furthermore, we show that propionic acid and butyric acid increase insulin-stimulated glucose uptake. To conclude, our study shows that SCFAs have effects on fat storage and mobilization as well as glucose uptake in rat primary adipocytes. Thus, the SCFAs might contribute to healthier adipocytes and subsequently also to improved energy metabolism with for example less circulating free fatty acids, which is beneficial in the context of obesity and type 2 diabetes.

  1. Roles of TBC1D1 and TBC1D4 in insulin- and exercise-stimulated glucose transport of skeletal muscle

    OpenAIRE

    Cartee, Gregory D.

    2014-01-01

    This review focuses on two paralogue Rab GTPase activating proteins known as TBC1D1 Tre-2/BUB2/cdc 1 domain family (TBC1D) 1 and TBC1D4 (also called Akt Substrate of 160 kDa, AS160) and their roles in controlling skeletal muscle glucose transport in response to the independent and combined effects of insulin and exercise. Convincing evidence implicates Akt2-dependent TBC1D4 phosphorylation on T642 as a key part of the mechanism for insulin-stimulated glucose uptake by skeletal muscle. TBC1D1 ...

  2. AMPK alpha1 activation is required for stimulation of glucose uptake by twitch contraction, but not by H2O2, in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Schjerling, Peter; Viollet, Benoit

    2008-01-01

    , in wildtype and alpha-AMPK transgenic mouse muscles, this study aimed to define conditions where alpha(1) AMPK is required to increase muscle glucose uptake. METHODOLOGY/PRINCIPAL FINDINGS: Following stimulation with H(2)O(2) (3 mM, 20 min) or twitch-contraction (0.1 ms pulse, 2 Hz, 2 min), signaling and 2...... uptake was not reduced in any of the AMPK transgenic mouse models compared with wild type. In contrast, twitch-contraction increased the activity of alpha(1) AMPK, but not alpha(2) AMPK activity nor Akt or AS160 phosphorylation. Glucose uptake was markedly lower in alpha(1) AMPK knockout and KD AMPK...

  3. Chlorogenic acid stimulates glucose transport in skeletal muscle via AMPK activation: a contributor to the beneficial effects of coffee on diabetes.

    Directory of Open Access Journals (Sweden)

    Khang Wei Ong

    Full Text Available Chlorogenic acid (CGA has been shown to delay intestinal glucose absorption and inhibit gluconeogenesis. Our aim was to investigate the role of CGA in the regulation of glucose transport in skeletal muscle isolated from db/db mice and L6 skeletal muscle cells. Oral glucose tolerance test was performed on db/db mice treated with CGA and soleus muscle was isolated for 2-deoxyglucose transport study. 2DG transport was also examined in L6 myotubes with or without inhibitors such as wortmannin or compound c. AMPK was knocked down with AMPKα1/2 siRNA to study its effect on CGA-stimulated glucose transport. GLUT 4 translocation, phosphorylation of AMPK and Akt, AMPK activity, and association of IRS-1 and PI3K were investigated in the presence of CGA. In db/db mice, a significant decrease in fasting blood sugar was observed 10 minutes after the intraperitoneal administration of 250 mg/kg CGA and the effect persisted for another 30 minutes after the glucose challenge. Besides, CGA stimulated and enhanced both basal and insulin-mediated 2DG transports in soleus muscle. In L6 myotubes, CGA caused a dose- and time-dependent increase in glucose transport. Compound c and AMPKα1/2 siRNA abrogated the CGA-stimulated glucose transport. Consistent with these results, CGA was found to phosphorylate AMPK and ACC, consistent with the result of increased AMPK activities. CGA did not appear to enhance association of IRS-1 with p85. However, we observed activation of Akt by CGA. These parallel activations in turn increased translocation of GLUT 4 to plasma membrane. At 2 mmol/l, CGA did not cause any significant changes in viability or proliferation of L6 myotubes. Our data demonstrated for the first time that CGA stimulates glucose transport in skeletal muscle via the activation of AMPK. It appears that CGA may contribute to the beneficial effects of coffee on Type 2 diabetes mellitus.

  4. Chlorogenic acid stimulates glucose transport in skeletal muscle via AMPK activation: a contributor to the beneficial effects of coffee on diabetes.

    Science.gov (United States)

    Ong, Khang Wei; Hsu, Annie; Tan, Benny Kwong Huat

    2012-01-01

    Chlorogenic acid (CGA) has been shown to delay intestinal glucose absorption and inhibit gluconeogenesis. Our aim was to investigate the role of CGA in the regulation of glucose transport in skeletal muscle isolated from db/db mice and L6 skeletal muscle cells. Oral glucose tolerance test was performed on db/db mice treated with CGA and soleus muscle was isolated for 2-deoxyglucose transport study. 2DG transport was also examined in L6 myotubes with or without inhibitors such as wortmannin or compound c. AMPK was knocked down with AMPKα1/2 siRNA to study its effect on CGA-stimulated glucose transport. GLUT 4 translocation, phosphorylation of AMPK and Akt, AMPK activity, and association of IRS-1 and PI3K were investigated in the presence of CGA. In db/db mice, a significant decrease in fasting blood sugar was observed 10 minutes after the intraperitoneal administration of 250 mg/kg CGA and the effect persisted for another 30 minutes after the glucose challenge. Besides, CGA stimulated and enhanced both basal and insulin-mediated 2DG transports in soleus muscle. In L6 myotubes, CGA caused a dose- and time-dependent increase in glucose transport. Compound c and AMPKα1/2 siRNA abrogated the CGA-stimulated glucose transport. Consistent with these results, CGA was found to phosphorylate AMPK and ACC, consistent with the result of increased AMPK activities. CGA did not appear to enhance association of IRS-1 with p85. However, we observed activation of Akt by CGA. These parallel activations in turn increased translocation of GLUT 4 to plasma membrane. At 2 mmol/l, CGA did not cause any significant changes in viability or proliferation of L6 myotubes. Our data demonstrated for the first time that CGA stimulates glucose transport in skeletal muscle via the activation of AMPK. It appears that CGA may contribute to the beneficial effects of coffee on Type 2 diabetes mellitus.

  5. A diacylglycerol kinase inhibitor, R59022, stimulates glucose transport through a MKK3/6-p38 signaling pathway in skeletal muscle cells.

    Science.gov (United States)

    Takahashi, Nobuhiko; Nagamine, Miho; Tanno, Satoshi; Motomura, Wataru; Kohgo, Yutaka; Okumura, Toshikatsu

    2007-08-17

    Diacylglycerol kinase (DGK) is one of lipid-regulating enzymes, catalyzes phosphorylation of diacylglycerol to phosphatidic acid. Because skeletal muscle, a major insulin-target organ for glucose disposal, expresses DGK, we investigated in the present study a role of DGK on glucose transport in skeletal muscle cells. PCR study showed that C2C12 myotubes expressed DGKalpha, delta, epsilon, zeta, or theta isoform mRNA. R59022, a specific inhibitor of DGK, significantly increased glucose transport, p38 and MKK3/6 activation in C2C12 myotubes. The R59022-induced glucose transport was blocked by SB203580, a specific p38 inhibitor. In contrast, R59022 failed to stimulate both possible known mechanisms to enhance glucose transport, an IRS1-PI3K-Akt pathway, muscle contraction signaling or GLUT1 and 4 expression. All these results suggest that DGK may play a role in glucose transport in the skeletal muscle cells through modulating a MKK3/6-p38 signaling pathway.

  6. Identification of plant extracts with potential antidiabetic properties: effect on human peroxisome proliferator-activated receptor (PPAR), adipocyte differentiation and insulin-stimulated glucose uptake

    DEFF Research Database (Denmark)

    Christensen, Kathrine B; Minet, Ariane; Svenstrup, Henrik

    2009-01-01

    , and their use is associated with several side effects. Partial PPARgamma agonists appear to be associated with fewer side effects but may still confer the desired insulin sensitizing action. Extracts from common medicinal/food plants were tested in a screening platform comprising a series of bioassays......, including tests for PPARgamma, alpha and delta transactivation, adipocyte differentiation and insulin-stimulated glucose uptake, allowing identification of plants containing potentially interesting PPAR agonists. Twenty-two plant extracts out of 133 were found to increase insulin-stimulated glucose uptake...... and 18 extracts were found to activate PPARgamma, 3 to activate PPARalpha and gamma, 6 to activate PPARdelta and gamma, and 9 to activate PPARgamma, alpha and delta. Among the 24 different plant species tested in the platform, 50% were shown to contain compounds capable of activating PPARgamma...

  7. Enhanced Ovarian Cancer Tumorigenesis and Metastasis by the Macrophage Colony-Stimulating Factor

    Directory of Open Access Journals (Sweden)

    Eugene P. Toy

    2009-02-01

    Full Text Available Coexpression of the macrophage colony-stimulating factor (CSF-1 and its receptor (CSF-1R in metastatic ovarian cancer specimens is a predictor of poor outcome in epithelial ovarian cancer. This suggests that an autocrine loop is produced by which ovarian tumors can secrete CSF-1 stimulating the CSF-1R resulting in a more aggressive phenotype. Our current work sought to validate this autocrine stimulation model using stable transfection of a 4-kb CSF-1 construct into otherwise nonvirulent Bix3 ovarian cancer cells. A representative clone, Bix3T8.2, produced a 72-fold increase in CSF-1 gene transcription rate (by nuclear run-off assays and a 57-fold increase in secreted CSF-1 protein (by sandwich ELISA, compared to parent cells. Comparison of Bix3T8.2 invasion, adhesion, and motility in vitro and metastasis in vivo were made to parental and transfectant controls. Up to 12-fold higher invasiveness was seen with Bix3T8.2 and 2- and 6-fold higher adhesion and motility, respectively, over controls in vitro. In nude mice, i.p. injection of Bix3T8.2 produced a wide array of visceral, nodal, and distant metastasis with a degree of enhanced tumor burden not seen in any of the 10 mice inoculated with transfectant control cells. Complete absence of tumor take distinguished 40% of mice implanted with transfectant control cells. Disruption of this autocrine loop using antisense oligomer therapy against CSF-1R and 3′ untranslated region knockdown of CSF-1 protein resulted in reversal of in vitro and in vivo tumor phenotypes. This CSF-1 feedback loop offers a model by which novel biologic therapies can potentially target multiple levels of this pathway.

  8. Increased glucose-stimulated FGF21 response to oral glucose in obese non-diabetic subjects after Roux-en-Y Gastric Bypass

    DEFF Research Database (Denmark)

    Vienberg, Sara Gry; Jacobsen, Siv Hesse; Worm, Dorte

    2017-01-01

    fasting plasma FGF21 increased significantly after surgery. Furthermore, FGF21 levels increased significantly at t=90 and t=150 min in response to 50 g glucose, but not after a mixed meal. CONCLUSIONS: In conclusion, the observed increase in postprandial plasma FGF21 in response to glucose and the lack...... of FGF21 response to a mixed meal may have important implications for the physiologic role of FGF21. The increase in postprandial FGF21 in response to glucose in the early post-operative period may contribute to the metabolic improvements observed after gastric bypass. This article is protected......OBJECTIVE: The positive metabolic outcome of Roux-en-Y Gastric Bypass (RYGB) surgery may involve Fibroblast Growth Factor 21 (FGF21), both in the fasting state and postprandially. We measured the fasting levels of FGF21 before and after bariatric surgery as well as the postprandial FGF21 responses...

  9. The adipocytokine Nampt and its product NMN have no effect on beta-cell survival but potentiate glucose stimulated insulin secretion.

    Directory of Open Access Journals (Sweden)

    Robert Spinnler

    Full Text Available AIMS/HYPOTHESIS: Obesity is associated with a dysregulation of beta-cell and adipocyte function. The molecular interactions between adipose tissue and beta-cells are not yet fully elucidated. We investigated, whether or not the adipocytokine Nicotinamide phosphoribosyltransferase (Nampt and its enzymatic product Nicotinamide mononucleotide (NMN, which has been associated with obesity and type 2 diabetes mellitus (T2DM directly influence beta-cell survival and function. METHODS: The effect of Nampt and NMN on viability of INS-1E cells was assessed by WST-1 assay. Apoptosis was measured by Annexin V/PI and TUNEL assay. Activation of apoptosis signaling pathways was evaluated. Adenylate kinase release was determined to assess cytotoxicity. Chronic and acute effects of the adipocytokine Nampt and its enzymatic product NMN on insulin secretion were assessed by glucose stimulated insulin secretion in human islets. RESULTS: While stimulation of beta-cells with the cytokines IL-1β, TNFα and IFN-γ or palmitate significantly decreased viability, Nampt and NMN showed no direct effect on viability in INS-1E cells or in human islets, neither alone nor in the presence of pro-diabetic conditions (elevated glucose concentrations and palmitate or cytokines. At chronic conditions over 3 days of culture, Nampt and its product NMN had no effects on insulin secretion. In contrast, both Nampt and NMN potentiated glucose stimulated insulin secretion acutely during 1 h incubation of human islets. CONCLUSION/INTERPRETATION: Nampt and NMN neither influenced beta-cell viability nor apoptosis but acutely potentiated glucose stimulated insulin secretion.

  10. Rapid Changes of mRNA-binding Protein Levels following Glucose and 3-Isobutyl-1-methylxanthine Stimulation of Insulinoma INS-1 Cells *S⃞

    Science.gov (United States)

    Süss, Christin; Czupalla, Cornelia; Winter, Christof; Pursche, Theresia; Knoch, Klaus-Peter; Schroeder, Michael; Hoflack, Bernard; Solimena, Michele

    2009-01-01

    Glucose and cAMP-inducing agents such as 3-isobutyl-1-methylxanthine (IBMX) rapidly change the expression profile of insulin-producing pancreatic β-cells mostly through post-transcriptional mechanisms. A thorough analysis of these changes, however, has not yet been performed. By combining two-dimensional differential gel electrophoresis and mass spectrometry, we identified 165 spots, corresponding to 78 proteins, whose levels significantly change after stimulation of the β-cell model INS-1 cells with 25 mm glucose + 1 mm IBMX for 2 h. Changes in the expression of selected proteins were verified by one- and two-dimensional immunoblotting. Most of the identified proteins are novel targets of rapid regulation in β-cells. The transcription inhibitor actinomycin D failed to block changes in two-thirds of the spots, supporting their post-transcriptional regulation. More spots changed in response to IBMX than to glucose alone conceivably because of phosphorylation. Fourteen mRNA- binding proteins responded to stimulation, thus representing the most prominent class of rapidly regulated proteins. Bioinformatics analysis indicated that the mRNA 5′- and 3′-untranslated regions of 22 regulated proteins contain potential binding sites for polypyrimidine tract-binding protein 1, which promotes mRNA stability and translation in stimulated β-cells. Overall our findings support the idea that mRNA-binding proteins play a major role in rapid adaptive changes in insulin-producing cells following their stimulation with glucose and cAMP-elevating agents. PMID:18854578

  11. Receptor-Type Protein-Tyrosine Phosphatase ζ and Colony Stimulating Factor-1 Receptor in the Intestine: Cellular Expression and Cytokine- and Chemokine Responses by Interleukin-34 and Colony Stimulating Factor-1.

    Science.gov (United States)

    Zwicker, Stephanie; Bureik, Daniela; Bosma, Madeleen; Martinez, Gisele Lago; Almer, Sven; Boström, Elisabeth A

    2016-01-01

    Differential intestinal expression of the macrophage growth factors colony stimulating factor-1 (CSF-1), interleukin (IL)-34, and their shared CSF-1 receptor (CSF-1R) in inflammatory bowel disease (IBD) has been shown. Diverse expression between CSF-1 and IL-34, suggest that IL-34 may signal via an alternate receptor. Receptor-type protein-tyrosine phosphatase ζ (PTPRZ1, RPTP-ζ), an additional IL-34 receptor, was recently identified. Here, we aimed to assess PTPRZ1 expression in IBD and non-IBD intestinal biopsies. Further, we aimed to investigate cellular PTPRZ1 and CSF-1R expression, and cytokine- and chemokine responses by IL-34 and CSF-1. The expression of PTPRZ1 was higher in non-IBD colon compared to ileum. PTPRZ1 expression was not altered with inflammation in IBD, however, correlated to IL34, CSF1, and CSF1R. The expression patterns of PTPRZ1 and CSF-1R differed in peripheral blood mononuclear cells (PBMCs), monocytes, macrophages, and intestinal epithelial cell line. PBMCs and monocytes of the same donors responded differently to IL-34 and CSF-1 with altered expression of tumor-necrosis factor α (TNF-α), IL-1β, interferon γ (IFN-γ), IL-13, IL-8, and monocyte chemotactic protein-1 (MCP-1) levels. This study shows that PTPRZ1 was expressed in bowel tissue. Furthermore, CSF-1R protein was detected in an intestinal epithelial cell line and donor dependently in primary PBMCs, monocytes, and macrophages, and first hints also suggest an expression in these cells for PTPRZ1, which may mediate IL-34 and CSF-1 actions.

  12. Restoring Mitochondrial Function: A Small Molecule-mediated Approach to Enhance Glucose Stimulated Insulin Secretion in Cholesterol Accumulated Pancreatic beta cells

    Science.gov (United States)

    Asalla, Suman; Girada, Shravan Babu; Kuna, Ramya S.; Chowdhury, Debabrata; Kandagatla, Bhaskar; Oruganti, Srinivas; Bhadra, Utpal; Bhadra, Manika Pal; Kalivendi, Shasi Vardhan; Rao, Swetha Pavani; Row, Anupama; Ibrahim, A.; Ghosh, Partha Pratim; Mitra, Prasenjit

    2016-06-01

    Dyslipidemia, particularly the elevated serum cholesterol levels, aggravate the pathophysiology of type 2 diabetes. In the present study we explored the relationship between fasting blood sugar and serum lipid parameters in human volunteers which revealed a significant linear effect of serum cholesterol on fasting blood glucose. Short term feeding of cholesterol enriched diet to rodent model resulted in elevated serum cholesterol levels, cholesterol accumulation in pancreatic islets and hyperinsulinemia with modest increase in plasma glucose level. To explore the mechanism, we treated cultured BRIN-BD11 pancreatic beta cells with soluble cholesterol. Our data shows that cholesterol treatment of cultured pancreatic beta cells enhances total cellular cholesterol. While one hour cholesterol exposure enhances insulin exocytosis, overnight cholesterol accumulation in cultured pancreatic beta cells affects cellular respiration, and inhibits Glucose stimulated insulin secretion. We further report that (E)-4-Chloro-2-(1-(2-(2,4,6-trichlorophenyl) hydrazono) ethyl) phenol (small molecule M1) prevents the cholesterol mediated blunting of cellular respiration and potentiates Glucose stimulated insulin secretion which was abolished in pancreatic beta cells on cholesterol accumulation.

  13. Compared to glibenclamide, repaglinide treatment results in a more rapid fall in glucose level and beta-cell secretion after glucose stimulation.

    NARCIS (Netherlands)

    Abbink-Zandbergen, E.J.; Wal, P.S. van der; Sweep, C.G.J.; Smits, P.; Tack, C.J.J.

    2004-01-01

    BACKGROUND: The more rapid onset of action and the shorter half-life of repaglinide may reduce the post-load glucose excursion and limit sustained insulin secretion compared to sulphonylurea (SU) derivatives. METHODS: We studied 12 patients with type 2 diabetes (age 62 +/- 2 years, BMI 28.3 +/- 1.3

  14. Exercise training favors increased insulin-stimulated glucose uptake in skeletal muscle in contrast to adipose tissue: a randomized study using FDG PET imaging.

    Science.gov (United States)

    Reichkendler, M H; Auerbach, P; Rosenkilde, M; Christensen, A N; Holm, S; Petersen, M B; Lagerberg, A; Larsson, H B W; Rostrup, E; Mosbech, T H; Sjödin, A; Kjaer, A; Ploug, T; Hoejgaard, L; Stallknecht, B

    2013-08-15

    Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions, using dynamic (femoral region) and static (abdominal region) 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) PET/CT methodology during steady-state insulin infusion (40 mU·m⁻²·min⁻¹). Body composition was measured by dual X-ray absorptiometry and MRI. Sixty-one healthy, sedentary [V(O2max) 36(5) ml·kg⁻¹·min⁻¹; mean(SD)], moderately overweight [BMI 28.1(1.8) kg/m²], young [age: 30(6) yr] men were randomized to sedentary living (CON; n = 17 completers) or moderate (MOD; 300 kcal/day, n = 18) or high (HIGH; 600 kcal/day, n = 18) dose physical exercise for 11 wk. At baseline, insulin-stimulated glucose uptake was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior + posterior) subcutaneous adipose tissue (SAT), and femoral SAT (P exercise groups in femoral skeletal muscle (MOD 24[9, 39] μmol·kg⁻¹·min⁻¹, P = 0.004; HIGH 22[9, 35] μmol·kg⁻¹·min⁻¹, P = 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ~24% in anterior abdominal SAT and ~20% in posterior abdominal SAT compared with CON but not in either intra- or retroperitoneal VAT. Total adipose tissue mass decreased in both exercise groups, and the decrease was distributed equally among subcutaneous and intra-abdominal depots. In conclusion, aerobic exercise training increases insulin-stimulated glucose uptake in skeletal muscle but not in adipose tissue, which demonstrates some interregional differences.

  15. Increased enzymatic hydrolysis of sugarcane bagasse by a novel glucose- and xylose-stimulated β-glucosidase from Anoxybacillus flavithermus subsp. yunnanensis E13T.

    Science.gov (United States)

    Liu, Yang; Li, Rui; Wang, Jing; Zhang, Xiaohan; Jia, Rong; Gao, Yi; Peng, Hui

    2017-03-16

    β-Glucosidase is claimed as a key enzyme in cellulose hydrolysis. The cellulosic fibers are usually entrapped with hemicelluloses containing xylose. So there is ongoing interest in searching for glucose- and xylose-stimulated β-glucosidases to increase the efficiency of hydrolysis of cellulosic biomass. A thermostable β-glucosidase gene (Bglp) was cloned from Anoxybacillus flavithermus subsp. yunnanensis E13T and characterized. Optimal enzyme activity was observed at 60 °C and pH 7.0. Bglp was relatively stable at 60 °C with a 10-h half-life. The kinetic parameters V max and K m for p-nitrophenyl-β-D-glucopyranoside (pNPG) were 771 ± 39 μmol/min/mg and 0.29 ± 0.01 mM, respectively. The activity of Bglp is dramatically stimulated by glucose or xylose at concentrations up to 1.4 M. After Bglp was added to Celluclast® 1.5 L, the conversion of sugarcane bagasse was 48.4 ± 0.8%, which was much higher than of Celluclast® 1.5 L alone. Furthermore, Bglp showed obvious advantages in the hydrolysis when initial concentrations of glucose and xylose are high. The supplementation of BglP significantly enhanced the glucose yield from sugarcane bagasse, especially in the presence of high concentrations of glucose or xylose. Bglp should be a promising candidate for industrial applications.

  16. CSF-1R-Dependent Lethal Hepatotoxicity When Agonistic CD40 Antibody Is Given before but Not after Chemotherapy.

    Science.gov (United States)

    Byrne, Katelyn T; Leisenring, Nathan H; Bajor, David L; Vonderheide, Robert H

    2016-07-01

    Cancer immunotherapies are increasingly effective in the clinic, especially immune checkpoint blockade delivered to patients who have T cell-infiltrated tumors. Agonistic CD40 mAb promotes stromal degradation and, in combination with chemotherapy, drives T cell infiltration and de novo responses against tumors, rendering resistant tumors susceptible to current immunotherapies. Partnering anti-CD40 with different treatments is an attractive approach for the next phase of cancer immunotherapies, with a number of clinical trials using anti-CD40 combinations ongoing, but the optimal therapeutic regimens with anti-CD40 are not well understood. Pancreatic ductal adenocarcinoma (PDA) is classically resistant to immunotherapy and lacks baseline T cell infiltration. In this study, we used a tumor cell line derived from a genetically engineered mouse model of PDA to investigate alterations in the sequence of anti-CD40 and chemotherapy as an approach to enhance pharmacological delivery of chemotherapy. Unexpectedly, despite our previous studies showing anti-CD40 treatment after chemotherapy is safe in both mice and patients with PDA, we report in this article that anti-CD40 administration CSF-1R mAb. These studies highlight the dual nature of CD40 in activating both macrophages and T cell responses, and the need for preclinical investigation of optimal anti-CD40 treatment regimens for safe design of clinical trials. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. Nur77 deficiency in mice accelerates tumor invasion and metastasis by facilitating TNFα secretion and lowering CSF-1R expression.

    Science.gov (United States)

    Li, Xiu-Ming; Wang, Jing-Ru; Shen, Tong; Gao, Shang-Shang; He, Xiao-Shun; Li, Jiang-Nan; Yang, Tian-Yu; Zhang, Shen; Gan, Wen-Juan; Li, Jian-Ming; Wu, Hua

    2017-01-01

    Nur77, an orphan member of the nuclear receptor superfamily, plays critical roles in inflammation and immunity. However, the role of Nur77 in tumor microenvironment remains elusive. Results showed that deletion of Nur77 strikingly enhanced tumor metastasis compared to WT mice. Additionally, compared to the conditioned media derived from Nur77+/+ peritoneal macrophages (CM1), the conditioned media derived from Nur77-/- peritoneal macrophages (CM2) significantly promoted the EMT of cancer cells, and greatly enhanced the migratory and invasive abilities of cancer cells. Moreover, studies using TNF-α blocking antibody demonstrated that pro-inflammatory cytokine TNF-α was indispensable in supporting CM2-induced EMT to drive cancer cells migration and invasion. Furthermore, we found that Nur77 promoted the expression of CSF-1R, a novel downstream target gene of Nur77, and subsequently enhanced the migration of inflammatory cells. Notably, infiltration of inflammatory cells in the tumors of Nur77-/- mice was markedly abrogated compared to Nur77+/+ mice. Collectively, these results revealed that host Nur77 expression was pivotal in antitumor immune response, and in inhibiting tumor metastasis.

  18. Phenotypic and metabolic investigation of a CSF-1R kinase receptor inhibitor (BLZ945) and its pharmacologically active metabolite.

    Science.gov (United States)

    Krauser, Joel A; Jin, Yi; Walles, Markus; Pfaar, Ulrike; Sutton, James; Wiesmann, Marion; Graf, Daniel; Pflimlin-Fritschy, Veronique; Wolf, Thierry; Camenisch, Gian; Swart, Piet

    2015-02-01

    1. 4-[2((1R,2R)-2-Hydroxycyclohexylamino)-benzothiazol-6-yloxyl]-pyridine-2-carboxylic acid methylamide (BLZ945) is a small molecule inhibitor of CSF-1R kinase activity within osteoclasts designed to prevent skeletal related events in metastatic disease. Key metabolites were enzymatically and structurally characterized to understand the metabolic fate of BLZ945 and pharmacological implications. The relative intrinsic clearances for metabolites were derived from in vitro studies using human hepatocytes, microsomes and phenotyped with recombinant P450 enzymes. 2. Formation of a pharmacologically active metabolite (M9) was observed in human hepatocytes. The M9 metabolite is a structural isomer (diastereomer) of BLZ945 and is about 4-fold less potent. This isomer was enzymatically formed via P450 oxidation of the BLZ945 hydroxyl group, followed by aldo-keto reduction to the alcohol (M9). 3. Two reaction phenotyping approaches based on fractional clearances were applied to BLZ945 using hepatocytes and liver microsomes. The fraction metabolized (fm) or contribution ratio was determined for each metabolic reaction type (oxidation, glucuronidation or isomerization) as well as for each metabolite. The results quantitatively illustrate contribution ratios of the involved enzymes and pathways, e.g. the isomerization to metabolite M9 accounted for 24% intrinsic clearance in human hepatocytes. In summary, contribution ratios for the Phase I and Phase II pathways can be determined in hepatocytes.

  19. Structure-based drug design enables conversion of a DFG-in binding CSF-1R kinase inhibitor to a DFG-out binding mode

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Marvin J.; Pelc, Matthew; Kamtekar, Satwik; Day, Jacqueline; Poda, Gennadiy I.; Hall, Molly K.; Michener, Marshall L.; Reitz, Beverly A.; Mathis, Karl J.; Pierce, Betsy S.; Parikh, Mihir D.; Mischke, Deborah A.; Long, Scott A.; Parlow, John J.; Anderson, David R.; Thorarensen, Atli (Pfizer)

    2010-08-11

    The work described herein demonstrates the utility of structure-based drug design (SBDD) in shifting the binding mode of an HTS hit from a DFG-in to a DFG-out binding mode resulting in a class of novel potent CSF-1R kinase inhibitors suitable for lead development.

  20. Structure-based drug design enables conversion of a DFG-in binding CSF-1R kinase inhibitor to a DFG-out binding mode.

    Science.gov (United States)

    Meyers, Marvin J; Pelc, Matthew; Kamtekar, Satwik; Day, Jacqueline; Poda, Gennadiy I; Hall, Molly K; Michener, Marshall L; Reitz, Beverly A; Mathis, Karl J; Pierce, Betsy S; Parikh, Mihir D; Mischke, Deborah A; Long, Scott A; Parlow, John J; Anderson, David R; Thorarensen, Atli

    2010-03-01

    The work described herein demonstrates the utility of structure-based drug design (SBDD) in shifting the binding mode of an HTS hit from a DFG-in to a DFG-out binding mode resulting in a class of novel potent CSF-1R kinase inhibitors suitable for lead development. Copyright 2010 Elsevier Ltd. All rights reserved.

  1. Stimulation of glucose uptake by Musa sp. (cv. elakki bale) flower and pseudostem extracts in Ehrlich ascites tumor cells.

    Science.gov (United States)

    Bhaskar, Jamuna J; Salimath, Paramahans V; Nandini, Chilkunda D

    2011-06-01

    Glucose uptake study plays a major role in diabetes research. Impaired glucose uptake has been implicated in the development of hyperglycemia during diabetes. Banana plant is known for its anti-diabetic properties and our earlier report revealed that banana flower and pseudostem of Musa sp. cv. elakki bale is beneficial during diabetes in rat models. The present study was designed to evaluate the potential effect of banana flower and pseudostem extracts on glucose uptake in Ehrlich ascites tumor (EAT) cells using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG), a fluorescent analogue of 2-deoxyglucose. Methanol and aqueous extracts of banana flower and pseudostem were more potent in promoting glucose uptake in EAT cells, in comparison to acetone and ethanol extracts. At 20 µg dosage, highest net glucose uptake was observed in aqueous extracts of banana flower (18.17 ± 0.43 nmol L⁻¹) and pseudostem (19.69 ± 0.41 nmol L⁻¹). Total polyphenol content was higher in methanol (9.031 ± 0.036 g kg⁻¹) and aqueous (6.862 ± 0.024 g kg⁻¹) extracts of banana flower compared to pseudostem, which were 0.442 ± 0.006 and 0.811 ± 0.011 g kg⁻¹, respectively. Banana flower and pseudostem extracts are able to promote glucose uptake into the cells, presumably through glucose transporters 1 and 3, which could be beneficial in diabetes. Glucose uptake is likely promoted by phenolic acids besides other bioactives. It can be hypothesized that consumption of nutraceutical-rich extract of banana flower and pseudostem could replace some amount of insulin being taken for diabetes. Copyright © 2011 Society of Chemical Industry.

  2. Opuntia ficus-indica ingestion stimulates peripheral disposal of oral glucose before and after exercise in healthy men.

    Science.gov (United States)

    Van Proeyen, Karen; Ramaekers, Monique; Pischel, Ivo; Hespel, Peter

    2012-08-01

    The purpose of this study was to investigate the effect of Opuntia ficus-indica (OFI) cladode and fruit-skin extract on blood glucose and plasma insulin increments due to high-dose carbohydrate ingestion, before and after exercise. Healthy, physically active men (n = 6; 21.0 ± 1.6 years, 78.1 ± 6.0 kg) participated in a double-blind placebo-controlled crossover study involving 2 experimental sessions. In each session, the subjects successively underwent an oral glucose tolerance test at rest (OGTT(R)), a 30-min cycling bout at ~75% VO(2max), and another OGTT after exercise (OGTT(EX)). They received capsules containing either 1,000 mg OFI or placebo (PL) 30 min before and immediately after the OGTT(R). Blood samples were collected before (t₀) and at 30-min intervals after ingestion of 75 g glucose for determination of blood glucose and serum insulin. In OGTT(EX) an additional 75-g oral glucose bolus was administered at t₆₀. In OGTT(R), OFI administration reduced the area under the glucose curve (AUC(GLUC)) by 26%, mainly due to lower blood glucose levels at t₃₀ and t₆₀ (p < .05). Furthermore, a higher serum insulin concentration was noted after OFI intake at baseline and at t₃₀ (p < .05). In OGTT(EX), blood glucose at t₆₀ was ~10% lower in OFI than in PL, which resulted in a decreased AUC(GLUC) (-37%, p < .05). However, insulin values and AUC(INS) were not different between OFI and PL. In conclusion, the current study shows that OFI extract can increase plasma insulin and thereby facilitate the clearance of an oral glucose load from the circulation at rest and after endurance exercise in healthy men.

  3. Impaired proinsulin secretion before and during oral glucose stimulation in HIV-infected patients who display fat redistribution

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Halsall, Ian

    2007-01-01

    , the secretion patterns of SP and IP of 16 HIV-infected men with lipodystrophy (LIPO) and 15 HIV-infected men without lipodystrophy (NONLIPO) were studied during an oral glucose tolerance test (OGTT). All patients received highly active antiretroviral therapy. Insulin secretion rates were determined...... by deconvolution of plasma C-peptide concentrations. More LIPO than NONLIPO patients displayed diabetes mellitus and impaired glucose tolerance than normal glucose tolerance (LIPO 2/8/6 vs NONLIPO 1/2/12, P = .05). LIPO patients had increased fasting levels of SP and IP, ratio of SP/IP, and area under the curve...

  4. Impaired Glucose Metabolism in Response to High Fat Diet in Female Mice Conceived by In Vitro Fertilization (IVF) or Ovarian Stimulation Alone

    Science.gov (United States)

    Chen, Miaoxin; Wu, Linda; Wu, Fang; Wittert, Gary A.; Norman, Robert J.; Robker, Rebecca L.; Heilbronn, Leonie K.

    2014-01-01

    Individuals conceived by in vitro fertilization (IVF) may be at increased risk of cardio-metabolic disorders. We recently reported that IVF conceived male mice displayed impaired glucose metabolism at normal and high body weights. In this study, we examined glucose metabolism in mature female C57BL/6J mice that were conceived by natural conception (NC), by ovarian stimulation (OS) or by IVF following chow or high-fat diet (HFD) for 8 weeks. By design, litter size was comparable between groups, but interestingly the birth weight of IVF and OS females was lower than NC females (p≤0.001). Mature IVF female mice displayed increased fasting glucose as compared to NC and OS mice, irrespective of diet. Mature IVF and OS mice were also more susceptible to the metabolic consequences of high fat diet as compared with NC females, with impaired glucose tolerance (p≤0.01), whereas peripheral insulin resistance and increased hepatic expression of gluconeogenic genes Ppargc1α, Pck1 and G6pc was observed in IVF mice only (pIVF program distinct metabolic effects in females, but that high fat diet may be required to unmask these effects. This study adds to the growing body of literature that assisted reproduction procedures may increase the risk of developing type 2 diabetes in an obesity prone environment. PMID:25405530

  5. The influence of GLP-1 on glucose-stimulated insulin secretion: effects on beta-cell sensitivity in type 2 and nondiabetic subjects

    DEFF Research Database (Denmark)

    Kjems, Lise L; Holst, Jens J; Vølund, Aage

    2003-01-01

    , 4, 6, 8, and 12 mg x kg(-1) x min(-1) over 150 min on four occasions with infusion of saline or GLP-1 at 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1). GLP-1 enhanced ISR in a dose-dependent manner during the graded glucose infusion from 332 +/- 51 to 975 +/- 198 pmol/kg in the patients with type 2....... However, the dose-response relationship between GLP-1 and basal and glucose-stimulated prehepatic insulin secretion rate (ISR) is currently not known. Seven patients with type 2 diabetes and seven matched nondiabetic control subjects were studied. ISR was determined during a graded glucose infusion of 2...... that of the control subjects without GLP-1. Our results show that GLP-1 increases insulin secretion in patients with type 2 diabetes and control subjects in a dose-dependent manner and that the beta-cell responsiveness to glucose may be increased to normal levels with a low dose of GLP-1 infusion. Nevertheless...

  6. The influence of GLP-1 on glucose-stimulated insulin secretion: effects on beta-cell sensitivity in type 2 and nondiabetic subjects

    DEFF Research Database (Denmark)

    Kjems, Lise L; Holst, Jens J; Vølund, Aage

    2003-01-01

    The intestinally derived hormone glucagon-like peptide 1 (GLP-1) (7-36 amide) has potent effects on glucose-mediated insulin secretion, insulin gene expression, and beta-cell growth and differentiation. It is, therefore, considered a potential therapeutic agent for the treatment of type 2 diabetes....... However, the dose-response relationship between GLP-1 and basal and glucose-stimulated prehepatic insulin secretion rate (ISR) is currently not known. Seven patients with type 2 diabetes and seven matched nondiabetic control subjects were studied. ISR was determined during a graded glucose infusion of 2......, 4, 6, 8, and 12 mg x kg(-1) x min(-1) over 150 min on four occasions with infusion of saline or GLP-1 at 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1). GLP-1 enhanced ISR in a dose-dependent manner during the graded glucose infusion from 332 +/- 51 to 975 +/- 198 pmol/kg in the patients with type 2...

  7. Glucose-stimulated insulin response in pregnant sheep following acute suppression of plasma non-esterified fatty acid concentrations

    Directory of Open Access Journals (Sweden)

    Sriskandarajah Nadarajah

    2004-09-01

    Full Text Available Abstract Background Elevated non-esterified fatty acids (NEFA concentrations in non-pregnant animals have been reported to decrease pancreatic responsiveness. As ovine gestation advances, maternal insulin concentrations fall and NEFA concentrations increase. Experiments were designed to examine if the pregnancy-associated rise in NEFA concentration is associated with a reduced pancreatic sensitivity to glucose in vivo. We investigated the possible relationship of NEFA concentrations in regulating maternal insulin concentrations during ovine pregnancy at three physiological states, non-pregnant, non-lactating (NPNL, 105 and 135 days gestational age (dGA, term 147+/- 3 days. Methods The plasma concentrations of insulin, growth hormone (GH and ovine placental lactogen (oPL were determined by double antibody radioimmunoassay. Insulin responsiveness to glucose was measured using bolus injection and hyperglycaemic clamp techniques in 15 non-pregnant, non-lactating ewes and in nine pregnant ewes at 105 dGA and near term at 135 dGA. Plasma samples were also collected for hormone determination. In addition to bolus injection glucose and insulin Area Under Curve calculations, the Mean Plasma Glucose Increment, Glucose Infusion Rate and Mean Plasma Insulin Increment and Area Under Curve were determined for the hyperglycaemic clamp procedures. Statistical analysis of data was conducted with Students t-tests, repeated measures ANOVA and 2-way ANOVA. Results Maternal growth hormone, placental lactogen and NEFA concentrations increased, while basal glucose and insulin concentrations declined with advancing gestation. At 135 dGA following bolus glucose injections, peak insulin concentrations and insulin area under curve (AUC profiles were significantly reduced in pregnant ewes compared with NPNL control ewes (p Conclusions Results suggest that despite an acute suppression of circulating NEFA concentrations during pregnancy, the associated steroids and hormones

  8. Stimulation of Na{sup +}/K{sup +} ATPase activity and Na{sup +} coupled glucose transport by {beta}-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Sopjani, Mentor [Department of Physiology, University of Tuebingen (Germany); Department of Chemistry, University of Prishtina, Kosovo (Country Unknown); Alesutan, Ioana; Wilmes, Jan [Department of Physiology, University of Tuebingen (Germany); Dermaku-Sopjani, Miribane [Department of Physiology, University of Tuebingen (Germany); Faculty of Medicine, University of Prishtina, Kosovo (Country Unknown); Lam, Rebecca S. [Department of Physiology, University of Tuebingen (Germany); Department of Molecular Neurogenetics, Max Planck Institute of Biophysics, Frankfurt/Main (Germany); Koutsouki, Evgenia [Department of Physiology, University of Tuebingen (Germany); Jakupi, Muharrem [Faculty of Medicine, University of Prishtina, Kosovo (Country Unknown); Foeller, Michael [Department of Physiology, University of Tuebingen (Germany); Lang, Florian, E-mail: florian.lang@uni-tuebingen.de [Department of Physiology, University of Tuebingen (Germany)

    2010-11-19

    Research highlights: {yields} The oncogenic transcription factor {beta}-catenin stimulates the Na{sup +}/K{sup +}-ATPase. {yields} {beta}-Catenin stimulates SGLT1 dependent Na{sup +}, glucose cotransport. {yields} The effects are independent of transcription. {yields} {beta}-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: {beta}-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. {beta}-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that {beta}-catenin influences membrane transport. To this end, {beta}-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of {beta}-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na{sup +}/K{sup +}-ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of {beta}-catenin on the endogenous Na{sup +}/K{sup +}-ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of {beta}-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of {beta}-catenin expression. The stimulating effect of {beta}-catenin on both Na{sup +}/K{sup +} ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of {beta}-catenin, i.e. the regulation of transport.

  9. Effect of exercise training on in vivo insulin-stimulated glucose uptake in intra-abdominal adipose tissue in rats

    DEFF Research Database (Denmark)

    Enevoldsen, L H; Stallknecht, B; Fluckey, J D

    2000-01-01

    Intra-abdominal obesity may be crucial in the pathogenesis of the insulin-resistance syndrome, and training may alleviate this condition. We compared insulin-mediated glucose uptake in vivo in three intra-abdominal adipose tissues (ATs; retroperitoneal, parametrial, and mesenteric) and in subcuta......Intra-abdominal obesity may be crucial in the pathogenesis of the insulin-resistance syndrome, and training may alleviate this condition. We compared insulin-mediated glucose uptake in vivo in three intra-abdominal adipose tissues (ATs; retroperitoneal, parametrial, and mesenteric......) and in subcutaneous AT and also studied the effect of training. Rats were either swim trained (15 wk, n = 9) or sedentary (n = 16). While the rats were under anesthesia, a hyperinsulinemic ( approximately 900 pM), euglycemic clamp was carried out and local glucose uptake was measured by both the 2-deoxy-D-[(3)H...... hyperinsulinemia, in part, reflecting an effect in muscle. During hyperinsulinemia, interstitial glucose concentrations were lower, glucose uptake per 100 g of tissue was higher in AT in trained compared with sedentary rats, and training influenced glucose uptake identically in all ATs. In conclusion, differences...

  10. The MDM2-p53-pyruvate carboxylase signalling axis couples mitochondrial metabolism to glucose-stimulated insulin secretion in pancreatic β-cells

    DEFF Research Database (Denmark)

    Li, Xiaomu; Cheng, Kenneth K. Y.; Liu, Zhuohao

    2016-01-01

    Mitochondrial metabolism is pivotal for glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells. However, little is known about the molecular machinery that controls the homeostasis of intermediary metabolites in mitochondria. Here we show that the activation of p53 in β-cells, by genetic...... alleviates defective GSIS in diabetic islets by restoring PC expression. Thus, the MDM2-p53-PC signalling axis links mitochondrial metabolism to insulin secretion and glucose homeostasis, and could represent a therapeutic target in diabetes....... oxaloacetate and NADPH, and impaired oxygen consumption. The defective GSIS and mitochondrial metabolism in MDM2-null islets can be rescued by restoring PC expression. Under diabetogenic conditions, MDM2 and p53 are upregulated, whereas PC is reduced in mouse β-cells. Pharmacological inhibition of p53...

  11. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Peng [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); School of Public Health, China Medical University, Shenyang 110001 (China); Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Sun, Guifan [School of Public Health, China Medical University, Shenyang 110001 (China); Andersen, Melvin E. [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States); Pi, Jingbo, E-mail: jpi@thehamner.org [The Hamner Institutes for Health Sciences, Research Triangle Park, NC 27709 (United States)

    2011-04-08

    Highlights: {yields} In 3T3-L1 adipocytes iAs{sup 3+} decreases insulin-stimulated glucose uptake. {yields} iAs{sup 3+} attenuates insulin-induced phosphorylation of AKT S473. {yields} iAs{sup 3+} activates the cellular adaptive oxidative stress response. {yields} iAs{sup 3+} impairs insulin-stimulated ROS signaling. {yields} iAs{sup 3+} decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 {mu}M) inorganic arsenite (iAs{sup 3+}) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs{sup 3+} exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs{sup 3+} exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4

  12. Absence of colony stimulation factor-1 receptor results in loss of microglia, disrupted brain development and olfactory deficits.

    Directory of Open Access Journals (Sweden)

    Bryna Erblich

    Full Text Available The brain contains numerous mononuclear phagocytes called microglia. These cells express the transmembrane tyrosine kinase receptor for the macrophage growth factor colony stimulating factor-1 (CSF-1R. Using a CSF-1R-GFP reporter mouse strain combined with lineage defining antibody staining we show in the postnatal mouse brain that CSF-1R is expressed only in microglia and not neurons, astrocytes or glial cells. To study CSF-1R function we used mice homozygous for a null mutation in the Csflr gene. In these mice microglia are >99% depleted at embryonic day 16 and day 1 post-partum brain. At three weeks of age this microglial depletion continues in most regions of the brain although some contain clusters of rounded microglia. Despite the loss of microglia, embryonic brain development appears normal but during the post-natal period the brain architecture becomes perturbed with enlarged ventricles and regionally compressed parenchyma, phenotypes most prominent in the olfactory bulb and cortex. In the cortex there is increased neuronal density, elevated numbers of astrocytes but reduced numbers of oligodendrocytes. Csf1r nulls rarely survive to adulthood and therefore to study the role of CSF-1R in olfaction we used the viable null mutants in the Csf1 (Csf1(op gene that encodes one of the two known CSF-1R ligands. Food-finding experiments indicate that olfactory capacity is significantly impaired in the absence of CSF-1. CSF-1R is therefore required for the development of microglia, for a fully functional olfactory system and the maintenance of normal brain structure.

  13. Absence of Colony Stimulation Factor-1 Receptor Results in Loss of Microglia, Disrupted Brain Development and Olfactory Deficits

    Science.gov (United States)

    Etgen, Anne M.; Dobrenis, Kostantin; Pollard, Jeffrey W.

    2011-01-01

    The brain contains numerous mononuclear phagocytes called microglia. These cells express the transmembrane tyrosine kinase receptor for the macrophage growth factor colony stimulating factor-1 (CSF-1R). Using a CSF-1R-GFP reporter mouse strain combined with lineage defining antibody staining we show in the postnatal mouse brain that CSF-1R is expressed only in microglia and not neurons, astrocytes or glial cells. To study CSF-1R function we used mice homozygous for a null mutation in the Csflr gene. In these mice microglia are >99% depleted at embryonic day 16 and day 1 post-partum brain. At three weeks of age this microglial depletion continues in most regions of the brain although some contain clusters of rounded microglia. Despite the loss of microglia, embryonic brain development appears normal but during the post-natal period the brain architecture becomes perturbed with enlarged ventricles and regionally compressed parenchyma, phenotypes most prominent in the olfactory bulb and cortex. In the cortex there is increased neuronal density, elevated numbers of astrocytes but reduced numbers of oligodendrocytes. Csf1r nulls rarely survive to adulthood and therefore to study the role of CSF-1R in olfaction we used the viable null mutants in the Csf1 (Csf1op) gene that encodes one of the two known CSF-1R ligands. Food-finding experiments indicate that olfactory capacity is significantly impaired in the absence of CSF-1. CSF-1R is therefore required for the development of microglia, for a fully functional olfactory system and the maintenance of normal brain structure. PMID:22046273

  14. Two weeks of moderate-intensity continuous training, but not high-intensity interval training, increases insulin-stimulated intestinal glucose uptake.

    Science.gov (United States)

    Motiani, Kumail K; Savolainen, Anna M; Eskelinen, Jari-Joonas; Toivanen, Jussi; Ishizu, Tamiko; Yli-Karjanmaa, Minna; Virtanen, Kirsi A; Parkkola, Riitta; Kapanen, Jukka; Grönroos, Tove J; Haaparanta-Solin, Merja; Solin, Olof; Savisto, Nina; Ahotupa, Markku; Löyttyniemi, Eliisa; Knuuti, Juhani; Nuutila, Pirjo; Kalliokoski, Kari K; Hannukainen, Jarna C

    2017-05-01

    Similar to muscles, the intestine is also insulin resistant in obese subjects and subjects with impaired glucose tolerance. Exercise training improves muscle insulin sensitivity, but its effects on intestinal metabolism are not known. We studied the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on intestinal glucose and free fatty acid uptake from circulation in humans. Twenty-eight healthy, middle-aged, sedentary men were randomized for 2 wk of HIIT or MICT. Intestinal insulin-stimulated glucose uptake and fasting free fatty acid uptake from circulation were measured using positron emission tomography and [ 18 F]FDG and [ 18 F]FTHA. In addition, effects of HIIT and MICT on intestinal GLUT2 and CD36 protein expression were studied in rats. Training improved aerobic capacity ( P = 0.001) and whole body insulin sensitivity ( P = 0.04), but not differently between HIIT and MICT. Insulin-stimulated glucose uptake increased only after the MICT in the colon (HIIT = 0%; MICT = 37%) ( P = 0.02 for time × training) and tended to increase in the jejunum (HIIT = -4%; MICT = 13%) ( P = 0.08 for time × training). Fasting free fatty acid uptake decreased in the duodenum in both groups (HIIT = -6%; MICT = -48%) ( P = 0.001 time) and tended to decrease in the colon in the MICT group (HIIT = 0%; MICT = -38%) ( P = 0.08 for time × training). In rats, both training groups had higher GLUT2 and CD36 expression compared with control animals. This study shows that already 2 wk of MICT enhances insulin-stimulated glucose uptake, while both training modes reduce fasting free fatty acid uptake in the intestine in healthy, middle-aged men, providing an additional mechanism by which exercise training can improve whole body metabolism. NEW & NOTEWORTHY This is the first study where the effects of exercise training on the intestinal substrate uptake have been investigated using the most advanced techniques

  15. α-MSH stimulates glucose uptake in mouse muscle and phosphorylates Rab-GTPase-activating protein TBC1D1 independently of AMPK

    DEFF Research Database (Denmark)

    Møller, Cathrine Laustrup; Kjøbsted, Rasmus; Enriori, Pablo J

    2016-01-01

    The melanocortin system includes five G-protein coupled receptors (family A) defined as MC1R-MC5R, which are stimulated by endogenous agonists derived from proopiomelanocortin (POMC). The melanocortin system has been intensely studied for its central actions in body weight and energy expenditure...... regulation, which are mainly mediated by MC4R. The pituitary gland is the source of various POMC-derived hormones released to the circulation, which raises the possibility that there may be actions of the melanocortins on peripheral energy homeostasis. In this study, we examined the molecular signaling......D) family member 1 (S237 and T596), which is independent of upstream PKA and AMPK. We find no evidence to support that -MSH-stimulated glucose uptake involves TBC1D4 phosphorylation (T642 and S704) or GLUT4 translocation....

  16. Phenylboronic Acid Appended Pyrene-Based Low-Molecular-Weight Injectable Hydrogel: Glucose-Stimulated Insulin Release.

    Science.gov (United States)

    Mandal, Deep; Mandal, Subhra Kanti; Ghosh, Moumita; Das, Prasanta Kumar

    2015-08-17

    A pyrene-containing phenylboronic acid (PBA) functionalized low-molecular-weight hydrogelator was synthesized with the aim to develop glucose-sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8-12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL(-1) . The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π-π stacking, and van der Waals interactions are the key factors for the self-assembled gelation. The diol-sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose-responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose-induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin-loaded hydrogel showed thixotropic self-recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Impact of suprapharmacological androgenic steroid administration on basal and insulin-stimulated glucose and amino acid metabolism.

    Science.gov (United States)

    Wasserman, D H; Ruzumna, P A; Bracy, D P; Lacy, D B; Boothe, H W; Williams, P E; Abumrad, N N

    1994-10-01

    Effects of androgenic steroids at doses used by athletes were studied in a canine model system in which dosage, diet, and activity were controlled. Dogs were treated with 19-nortestosterone (200 mg/wk intramuscularly) or vehicle and were studied at 18 (n = 4 in steroid and vehicle) or 32 (n = 6 in steroid and n = 4 in vehicle) days. A laparotomy was performed under general anesthesia 17 days before experimentation, and catheters were placed in an artery, portal vein, and hepatic vein. Studies consisted of an equilibration (120 minutes) and a control (40 minutes) period and a three-step immunoreactive insulin euglycemic clamp (1, 2, and 15 mU/kg.min). Step 1 was 150 minutes, and steps 2 and 3 were 90 minutes. Data were collected during the last 30 minutes of each step. Glucose and leucine kinetics were assessed with 3H-glucose and 14C-leucine. Plasma glucose in steroid and vehicle groups was 104 +/- 5 (mean +/- SE) versus 108 +/- 3 mg/dL and 100 +/- 5 versus 107 +/- 4 mg/dL at 18 and 32 days. Glucose turnover was similar at 18 days in steroid and vehicle groups (3.9 +/- 0.3 v 3.6 +/- 0.3 mg/kg.min, respectively), but was elevated in the steroid group at 32 days (5.4 +/- 0.5 v 3.2 +/- 0.4 mg/kg.min). Glucose infusion rates were lower in the steroid group with 15 mU/kg.min immunoreactive insulin at 32 days (15.0 +/- 1.1 v 21.2 +/- 1.4 mU/kg.min). Immunoreactive insulin-independent glucose utilization (Rd) was unaffected at 18 days of steroid treatment, but was increased by almost fourfold at 32 days.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Reduced plasma glucose and leptin after 12 weeks of functional electrical stimulation-rowing exercise training in spinal cord injury patients.

    Science.gov (United States)

    Jeon, Justin Y; Hettinga, Dries; Steadward, Robert D; Wheeler, Garry D; Bell, Gordon; Harber, Vicki

    2010-12-01

    To investigate the effects of exercise training with a functional electrical stimulation (FES) rowing machine on insulin resistance, plasma leptin levels, and body composition in people with spinal cord injury (SCI). Experimental study. A fitness and research center for people with disabilities. Healthy male participants with paraplegia (N=6) participated in the study (mean age, 48.6±6y; mean weight, 70.06±3.28kg; injury levels between T4-5 and T10). Twelve weeks of FES-rowing exercise training 3 to 4 times a week (600-800kcal). Peak oxygen consumption, plasma leptin, insulin, and glucose levels, insulin sensitivity, body composition. Twelve weeks of FES-rowing training improved aerobic fitness significantly (P=.048). In addition, plasma glucose and leptin levels were significantly decreased after exercise training by 10% and 28% (P<.028), respectively. A trend toward fat mass reduction was seen in 4 of the 6 subjects; this change did not reach statistical significance (P=.08). A 12-week training program that included FES rowing improved aerobic fitness and fasting glucose and leptin levels in the absence of significant change to body composition, fasting insulin levels, or calculated insulin sensitivity in people with SCI. Copyright © 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. Adrenal Demedullation and Oxygen Supplementation Independently Increase Glucose-Stimulated Insulin Concentrations in Fetal Sheep With Intrauterine Growth Restriction

    OpenAIRE

    Macko, Antoni R.; Yates, Dustin T.; Chen, Xiaochuan; Shelton, Leslie A.; Kelly, Amy C.; Davis, Melissa A.; Camacho, Leticia E.; Anderson, Miranda J.; Limesand, Sean W.

    2016-01-01

    In pregnancies complicated by placental insufficiency and intrauterine growth restriction (IUGR), fetal glucose and oxygen concentrations are reduced, whereas plasma norepinephrine and epinephrine concentrations are elevated throughout the final third of gestation. Here we study the effects of chronic hypoxemia and hypercatecholaminemia on β-cell function in fetal sheep with placental insufficiency-induced IUGR that is produced by maternal hyperthermia. IUGR and control fetuses underwent a sh...

  20. Probiotic Lactobacillus gasseri SBT2055 improves glucose tolerance and reduces body weight gain in rats by stimulating energy expenditure.

    Science.gov (United States)

    Shirouchi, Bungo; Nagao, Koji; Umegatani, Minami; Shiraishi, Aya; Morita, Yukiko; Kai, Shunichi; Yanagita, Teruyoshi; Ogawa, Akihiro; Kadooka, Yukio; Sato, Masao

    2016-08-01

    Probiotic Lactobacillus gasseri SBT2055 (LG2055) reduces postprandial TAG absorption and exerts anti-obesity effects in rats and humans; however, the underlying mechanisms are not fully understood. In the present study, we addressed the mechanistic insights of the anti-obesity activity of LG2055 by feeding Sprague-Dawley rats diets containing skimmed milk fermented or not by LG2055 for 4 weeks and by analysing energy expenditure, glucose tolerance, the levels of SCFA in the caecum and serum inflammatory markers. Rats fed the LG2055-containing diet demonstrated significantly higher carbohydrate oxidation in the dark cycle (active phase for rats) compared with the control group, which resulted in a significant increase in energy expenditure. LG2055 significantly reduced cumulative blood glucose levels (AUC) compared with the control diet after 3 weeks and increased the molar ratio of butyrate:total SCFA in the caecum after 4 weeks. Furthermore, the LG2055-supplemented diet significantly reduced the levels of serum amyloid P component - an indicator of the inflammatory process. In conclusion, our results demonstrate that, in addition to the inhibition of dietary TAG absorption reported previously, the intake of probiotic LG2055 enhanced energy expenditure via carbohydrate oxidation, improved glucose tolerance and attenuated inflammation, suggesting multiple additive and/or synergistic actions underlying the anti-obesity effects exerted by LG2055.

  1. Role of the water extract from Coccinia indica stem on the stimulation of glucose transport in L8 myotubes

    Directory of Open Access Journals (Sweden)

    Chaweewan Jansakul

    2006-11-01

    Full Text Available Hypoglycemic effect of Coccinia indica used for treatment of diabetes in traditional remedies has known to relate with increased transport of glucose into peripheral tissues. However, the cellular mechanisms for this effect remain unclear. This present study reports that the water extract (WE of C. indica stem exhibited a dose-dependent induction of 2-deoxyglucose (2-DG uptake in rat L8 myotubes. Maximal uptake was observed with approximately 3-fold increase in 2-DG transport in 16 h treatment compared with the control. Effect of WE was stronger than that of 1 mM metformin. The effects of insulin and WE were additive. WE-induced glucose uptake was significantly inhibited by cycloheximide and partially reversed by SB203580. GLUT1 protein was markedly increased in response to WE. Conversely, WE had no effect on GLUT4 protein level. Redistribution of GLUT4 to the plasma membrane was demonstrated. Triterpenoids and carbohydrates were detected in WE. In conclusion, new GLUT1 protein synthesis is necessary for WEstimulated glucose transport while p38-MAPK-dependent activation of transporter intrinsic activity partly contributes to WE action. These results may explain and support the use of C. indica for the prevention and treatment of diabetes.

  2. High Expression of Macrophage Colony-Stimulating Factor-1 Receptor in Peritumoral Liver Tissue Is Associated with Poor Outcome in Hepatocellular Carcinoma After Curative Resection

    Science.gov (United States)

    Jia, Jin-Bin; Wang, Wen-Quan; Sun, Hui-Chuan; Zhu, Xiao-Dong; Liu, Liang; Zhuang, Peng-Yuan; Zhang, Ju-Bo; Zhang, Wei; Xu, Hua-Xiang; Kong, Ling-Qun; Lu, Lu; Wu, Wei-Zhong; Wang, Lu

    2010-01-01

    Background. Macrophage colony-stimulating factor 1 receptor (CSF-1R) expression in hepatocellular carcinoma (HCC) and its prognostic values are unclear. This study evaluated the prognostic values of the intratumoral and peritumoral expression of CSF-1R in HCC patients after curative resection. Methods. Tissue microarrays containing material from cohort 1 (105 patients) and cohort 2 (32 patients) were constructed. Immunohistochemistry was performed and prognostic values of these and other clinicopathological data were evaluated. The CSF-1R mRNA level was assessed by quantitative real-time polymerase chain reaction in cohort 3 (52 patients). Results. Both the CSF-1R density and its mRNA level were significantly higher in peritumoral liver tissue than in the corresponding tumor tissue. CSF-1R was distributed in a gradient in the long-distance peritumoral tissue microarray, with its density decreasing as the distance from the tumor margin increased. High peritumoral CSF-1R was significantly associated with more intrahepatic metastases and poorer survival. Peritumoral CSF-1R was an independent prognostic factor for both overall survival and time to recurrence and affected the incidence of early recurrence. However, intratumoral CSF-1R did not correlate with any clinicopathological feature. Peritumoral CSF-1R was also associated with both overall survival and time to recurrence in a subgroup with small HCCs (≤5 cm). Conclusions. Peritumoral CSF-1R is associated with intrahepatic metastasis, tumor recurrence, and patient survival after hepatectomy, highlighting the critical role of the peritumoral liver milieu in HCC progression. CSF-1R may become a potential therapeutic target for postoperative adjuvant treatment. PMID:20551429

  3. Meal-stimulated glucagon release is associated with postprandial blood glucose level and does not interfere with glycemic control in children and adolescents with new-onset type 1 diabetes

    DEFF Research Database (Denmark)

    Pörksen, Sven; Nielsen, Lotte B; Kaas, Anne

    2007-01-01

    CONTEXT: The role of glucagon in hyperglycemia in type 1 diabetes is unresolved, and in vitro studies suggest that increasing blood glucose might stimulate glucagon secretion. OBJECTIVE: Our objective was to investigate the relationship between postprandial glucose and glucagon level during...... stimulation (Boost) at 1, 6, and 12 months after diagnosis. RESULTS: Compound symmetric repeated-measurements models including all three visits showed that postprandial glucagon increased by 17% during follow-up (P = 0.001). Glucagon levels were highly associated with postprandial blood glucose levels because...... completed the 12-month follow-up. SETTING: The study was conducted at pediatric outpatient clinics. MAIN OUTCOME MEASURES: We assessed residual beta-cell function (C-peptide), glycosylated hemoglobin (HbA(1c)), blood glucose, glucagon, and glucagon-like peptide-1 (GLP-1) release in response to a 90-min meal...

  4. Stimulation of glucose incorporation and amino acid transport by insulin and an insulin-like growth factor in fibroblasts with defective insulin receptors cultured from a patient with leprechaunism.

    OpenAIRE

    Knight, A B; Rechler, M M; Romanus, J A; Van Obberghen-Schilling, E E; Nissley, S P

    1981-01-01

    Fibroblasts cultured from an infant with leprechaunism and insulin resistance have been reported to exhibit profound, selective defect in insulin binding. We now examine the effect of this defect on two acute metabolic actions of insulin thought to be mediated by the insulin receptor, glucose incorporation and N-methyl-alpha-aminoisobutyric acid (Me-AiBu) uptake. In the patient's fibroblasts, maximal insulin-stimulated glucose incorporation was less than 25% of that in control fibroblasts, wh...

  5. Rac1 governs exercise-stimulated glucose uptake in skeletal muscle through regulation of GLUT4 translocation in mice

    DEFF Research Database (Denmark)

    Sylow, Lykke; Laurent, Ida; Kleinert, Maximilian

    2016-01-01

    % in gastrocnemius and tibialis anterior muscles, respectively, in muscle-specific inducible Rac1 knockout (mKO) mice compared to wildtype littermates. By developing an assay to quantify endogenous GLUT4 translocation, we observed that GLUT4 content at the sarcolemma in response to exercise was reduced in Rac1 m......KO muscle. Our findings implicate Rac1 as a regulatory element critical for controlling glucose uptake during exercise via regulation of GLUT4 translocation. This article is protected by copyright. All rights reserved....

  6. Colony-Stimulating Factor-1 Receptor Is Required for Nurse-like Cell Survival in Chronic Lymphocytic Leukemia.

    Science.gov (United States)

    Polk, Avery; Lu, Ye; Wang, Tianjiao; Seymour, Erlene; Bailey, Nathanael G; Singer, Jack W; Boonstra, Philip S; Lim, Megan S; Malek, Sami; Wilcox, Ryan A

    2016-12-15

    Monocytes and their progeny are abundant constituents of the tumor microenvironment in lymphoproliferative disorders, including chronic lymphocytic leukemia (CLL). Monocyte-derived cells, including nurse-like cells (NLC) in CLL, promote lymphocyte proliferation and survival, confer resistance to chemotherapy, and are associated with more rapid disease progression. Colony-stimulating factor-1 receptor (CSF-1R) regulates the homeostatic survival of tissue-resident macrophages. Therefore, we sought to determine whether CSF-1R is similarly required for NLC survival. CSF-1R expression by NLC was examined by flow cytometry and IHC. CSF-1R blocking studies were performed using an antagonistic mAb to examine its role in NLC generation and in CLL survival. A rational search strategy was performed to identify a novel tyrosine kinase inhibitor (TKI) targeting CSF-1R. The influence of TKI-mediated CSF-1R inhibition on NLC and CLL viability was examined. We demonstrated that the generation and survival of NLC in CLL is dependent upon CSF-1R signaling. CSF-1R blockade is associated with significant depletion of NLC and consequently inhibits CLL B-cell survival. We found that the JAK2/FLT3 inhibitor pacritinib suppresses CSF-1R signaling, thereby preventing the generation and survival of NLC and impairs CLL B-cell viability. CSF-1R is a novel therapeutic target that may be exploited in lymphoproliferative disorders, like CLL, that are dependent upon lymphoma-associated macrophages. Clin Cancer Res; 22(24); 6118-28. ©2016 AACR. ©2016 American Association for Cancer Research.

  7. Exercise training favors increased insulin-stimulated glucose uptake in skeletal muscle in contrast to adipose tissue: a randomized study using FDG PET imaging

    DEFF Research Database (Denmark)

    Reichkendler, M. H.; Auerbach, P.; Rosenkilde, M.

    2013-01-01

    Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions...... was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior + posterior) subcutaneous adipose tissue (SAT), and femoral SAT (P ... groups in femoral skeletal muscle (MOD 24[9, 39] μmol·kg−1·min−1, P = 0.004; HIGH 22[9, 35] μmol·kg−1·min−1, P = 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ∼24% in anterior abdominal SAT and ∼20% in posterior...

  8. Prolonged Activation of the Htr2b Serotonin Receptor Impairs Glucose Stimulated Insulin Secretion and Mitochondrial Function in MIN6 Cells.

    Science.gov (United States)

    Cataldo, Luis Rodrigo; Mizgier, María L; Bravo Sagua, Roberto; Jaña, Fabián; Cárdenas, César; Llanos, Paola; Busso, Dolores; Olmos, Pablo; Galgani, José E; Santos, José L; Cortés, Víctor A

    2017-01-01

    Pancreatic β-cells synthesize and release serotonin (5 hydroxytryptamine, 5HT); however, the role of 5HT receptors on glucose stimulated insulin secretion (GSIS) and the mechanisms mediating this function is not fully understood. The aims of this study were to determine the expression profile of 5HT receptors in murine MIN6 β-cells and to examine the effects of pharmacological activation of 5HT receptor Htr2b on GSIS and mitochondrial function. mRNA levels of 5HT receptors in MIN6 cells were quantified by RT qPCR. GSIS was assessed in MIN6 cells in response to global serotonergic activation with 5HT and pharmacological Htr2b activation or inhibition with BW723C86 or SB204741, respectively. In response to Htr2b activation also was evaluated the mRNA and protein levels of PGC1α and PPARy by RT-qPCR and western blotting and mitochondrial function by oxygen consumption rate (OCR) and ATP cellular content. We found that mRNA levels of most 5HT receptors were either very low or undetectable in MIN6 cells. By contrast, Htr2b mRNA was present at moderate levels in these cells. Preincubation (6 h) of MIN6 cells with 5HT or BW723C86 reduced GSIS and the effect of 5HT was prevented by SB204741. Preincubation with BW723C86 increased PGC1α and PPARy mRNA and protein levels and decreased mitochondrial respiration and ATP content in MIN6 cells. Our results indicate that prolonged Htr2b activation in murine β-cells decreases glucose-stimulated insulin secretion and mitochondrial activity by mechanisms likely dependent on enhanced PGC1α/PPARy expression.

  9. Experimental evaluation and computational modeling of the effects of encapsulation on the time-profile of glucose-stimulated insulin release of pancreatic islets.

    Science.gov (United States)

    Buchwald, Peter; Cechin, Sirlene R; Weaver, Jessica D; Stabler, Cherie L

    2015-03-28

    In type 1 diabetic patients, who have lost their ability to produce insulin, transplantation of pancreatic islet cells can normalize metabolic control in a manner that is not achievable with exogenous insulin. To be successful, this procedure has to address the problems caused by the immune and autoimmune responses to the graft. Islet encapsulation using various techniques and materials has been and is being extensively explored as a possible approach. Within this framework, it is of considerable interest to characterize the effect encapsulation has on the insulin response of pancreatic islets. To improve our ability to quantitatively describe the glucose-stimulated insulin release (GSIR) of pancreatic islets in general and of micro-encapsulated islets in particular, we performed dynamic perifusion experiments with frequent sampling. We used unencapsulated and microencapsulated murine islets in parallel and fitted the results with a complex local concentration-based finite element method (FEM) computational model. The high-resolution dynamic perifusion experiments allowed good characterization of the first-phase and second-phase insulin secretion, and we observed a slightly delayed and blunted first-phase insulin response for microencapsulated islets when compared to free islets. Insulin secretion profiles of both free and encapsulated islets could be fitted well by a COMSOL Multiphysics model that couples hormone secretion and nutrient consumption kinetics with diffusive and convective transport. This model, which was further validated and calibrated here, can be used for arbitrary geometries and glucose stimulation sequences and is well suited for the quantitative characterization of the insulin response of cultured, perifused, transplanted, or encapsulated islets. The present high-resolution GSIR experiments allowed for direct characterization of the effect microencapsulation has on the time-profile of insulin secretion. The multiphysics model, further validated

  10. EXERCISE-INDUCED LOWERING OF CHEMERIN IS ASSOCIATED WITH REDUCED CARDIOMETABOLIC RISK AND GLUCOSE-STIMULATED INSULIN SECRETION IN OLDER ADULTS

    Science.gov (United States)

    MALIN, S.K.; NAVANEETHAN, S.D.; MULYA, A.; HUANG, H.; KIRWAN, J.P.

    2015-01-01

    Objective To determine the effect of exercise on chemerin in relation to changes in fat loss, insulin action, and dyslipidemia in older adults. Participants Thirty older (65.9±0.9yr) obese adults (BMI:34.5±0.7kg/m2). Setting Single-center, Cleveland Clinic. Design Prospective clinical trial. Intervention Twelve-weeks of exercise training (60minutes/day, 5day/week at ~85% HRmax). Subjects were instructed to maintain habitual nutrient intake. Measurements Plasma chemerin was analyzed using an enzyme-linked immunosorbent assay. Peripheral and hepatic insulin sensitivity was assessed using a euglycemic-hyperinsulinic clamp with glucose kinetics. First-phase and total glucose-stimulated insulin secretion (GSIS) was calculated from an oral glucose tolerance test. Fasting blood lipids (cholesterol, triglycerides), total/visceral fat (dual-x-ray absorptiometry and computerized tomography) and cardiorespiratory fitness (treadmill test) were also tested pre and post intervention. Results Exercise increased fitness and reduced total/visceral fat, blood lipids, and first-phase GSIS (Pchemerin (87.1±6.0 vs. 78.1±5.8ng/ml; P=0.02), and the reduction correlated with decreased visceral fat (r=0.50, P=0.009), total body fat (r=0.42, P=0.02), cholesterol (r=0.38, P=0.04), triglycerides (r=0.36, P=0.05), and first-phase and total GSIS (r=0.39, P=0.03 and r=0.43, P=0.02, respectively). Conclusions Lower chemerin appears to be an important hormone involved in cardiometabolic risk and GSIS reduction following exercise in older adults. PMID:24950152

  11. Chromanol 293B, an inhibitor of KCNQ1 channels, enhances glucose-stimulated insulin secretion and increases glucagon-like peptide-1 level in mice.

    Science.gov (United States)

    Liu, Lijie; Wang, Fanfan; Lu, Haiying; Ren, Xiaomei; Zou, Jihong

    2014-01-01

    Glucose-stimulated insulin secretion (GSIS) is a highly regulated process involving complex interaction of multiple factors. Potassium voltage-gated channel subfamily KQT member 1 (KCNQ1) is a susceptibility gene for type 2 diabetes (T2D) and the risk alleles of the KCNQ1 gene appear to be associated with impaired insulin secretion. The role of KCNQ1 channel in insulin secretion has been explored by previous work in clonal pancreatic β-cells but has yet to be investigated in the context of primary islets as well as intact animals. Genetic studies suggest that altered incretin glucagon-like peptide-1 (GLP-1) secretion might be a potential link between KCNQ1 variants and impaired insulin secretion, but this hypothesis has not been verified so far. In the current study, we examined KCNQ1 expression in pancreas and intestine from normal mice and then investigated the effects of chromanol 293B, a KCNQ1 channel inhibitor, on insulin secretion in vitro and in vivo. By double-immunofluorescence staining, KCNQ1 was detected in insulin-positive β-cells and GLP-1-positive L-cells. Administration of chromanol 293B enhanced GSIS in cultured islets and intact animals. Along with the potentiated insulin secretion during oral glucose tolerance tests (OGTT), plasma GLP-1 level after gastric glucose load was increased in 293B treated mice. These data not only provided new evidence for the participation of KCNQ1 in GSIS at the level of pancreatic islet and intact animal but also indicated the potential linking role of GLP-1 between KCNQ1 and insulin secretion.

  12. Polyunsaturated Fatty Acids Stimulate De novo Lipogenesis and Improve Glucose Homeostasis during Refeeding with High Fat Diet.

    Science.gov (United States)

    Crescenzo, Raffaella; Mazzoli, Arianna; Cancelliere, Rosa; Bianco, Francesca; Giacco, Antonia; Liverini, Giovanna; Dulloo, Abdul G; Iossa, Susanna

    2017-01-01

    Aims: The recovery of body weight after a period of caloric restriction is accompanied by an enhanced efficiency of fat deposition and hyperinsulinemia-which are exacerbated by isocaloric refeeding on a high fat diet rich in saturated and monounsaturated fatty acids (SFA-MUFA), and poor in polyunsaturated fatty acids (PUFA), and associated with a blunting of de novo lipogenesis in adipose tissue and liver. As high fat diets rich in PUFA have been shown to limit the excess fat deposition and improve glucose homeostasis, we investigated here the extent to which de novo lipogenesis in liver and adipose tissues (white and brown), as well as hepatic oxidative stress, are influenced by refeeding on diets rich in PUFA. Design: In rats calorically restricted for 14 days and refed for 14 days on isocaloric amounts of a high fat diet rich in lard (i.e., high SFA-MUFA) or in safflower and linseed oils (rich in PUFA), we investigated energy balance, body composition, glycemic profile, and the regulation of fatty acid synthase (rate-limiting enzyme of de novo lipogenesis) in liver, white and brown adipose tissue. We also evaluated oxidative stress in liver and skeletal muscle and markers of hepatic inflammation. Results: Rats refed the PUFA diet gained less lipids and more proteins compared to rats refed SFA-MUFA diet and showed lower amount of visceral and epididymal white adipose tissue, but increased depots of interscapular brown adipose tissue, with higher expression of the uncoupling protein 1. A significant increase in non-protein respiratory quotient and carbohydrate utilization was found in rats refed PUFA diet. Rats refed PUFA diet showed improved glucose homeostasis, as well as lower triglycerides and cholesterol levels. Fatty acid synthase activity was significantly higher in liver, white and brown adipose tissue, while lipid peroxidation and the degree of inflammation in the liver were significantly lower, in rats refed PUFA diet. Conclusions: When considering the

  13. Impaired proinsulin secretion before and during oral glucose stimulation in HIV-infected patients who display fat redistribution

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Halsall, Ian

    2007-01-01

    The beta-cell function of HIV-infected patients on highly active antiretroviral therapy who display lipodystrophy may be impaired. An early defect in beta-cell function may be characterized by an increase in secretion of 32-33 split proinsulin (SP) and intact proinsulin (IP). To address this issue......, the secretion patterns of SP and IP of 16 HIV-infected men with lipodystrophy (LIPO) and 15 HIV-infected men without lipodystrophy (NONLIPO) were studied during an oral glucose tolerance test (OGTT). All patients received highly active antiretroviral therapy. Insulin secretion rates were determined...... with lipodystrophy display major perturbations of proinsulin secretion in the fasting state and during an OGTT, which is compatible with the notion of a beta-cell dysfunction of such patients. Udgivelsesdato: 2007-Jul...

  14. Results from a Phase IIA Parallel Group Study of JNJ-40346527, an Oral CSF-1R Inhibitor, in Patients with Active Rheumatoid Arthritis despite Disease-modifying Antirheumatic Drug Therapy.

    Science.gov (United States)

    Genovese, Mark C; Hsia, Elizabeth; Belkowski, Stanley M; Chien, Caly; Masterson, Tara; Thurmond, Robin L; Manthey, Carl L; Yan, Xiaoyu David; Ge, Tingting; Franks, Carol; Greenspan, Andrew

    2015-10-01

    To assess the efficacy and safety of JNJ-40346527, a selective inhibitor of colony-stimulating factor-1 (CSF-1) receptor kinase that acts to inhibit macrophage survival, proliferation, and differentiation in patients with active rheumatoid arthritis (RA) despite disease-modifying antirheumatic drug (DMARD) therapy. In this randomized, double-blind, placebo-controlled, parallel group study, adults were randomized (2:1) to receive oral JNJ-40346527 100 mg or placebo twice daily through Week 12. Patients with RA had disease activity [≥ 6 swollen/≥ 6 tender joints, C-reactive protein (CRP) ≥ 0.8 mg/dl] despite DMARD therapy for ≥ 6 months. The primary endpoint was change from baseline at Week 12 in the 28-joint Disease Activity Score with CRP (DAS28-CRP). Pharmacokinetic/pharmacodynamic analyses were also performed, and safety was assessed through Week 16. Ninety-five patients were treated (63 JNJ-40346527, 32 placebo); 8 patients discontinued treatment (6 JNJ-40346527, 2 placebo) through Week 12. Mean improvements in DAS28-CRP from baseline to Week 12 were 1.15 for the JNJ-40346527 group and 1.42 for the placebo group (p = 0.30); thus, a statistically significant difference was not observed for the primary endpoint. Pharmacokinetic exposure to JNJ-40346527 and its active metabolites was above the projected concentration needed for pharmacologic activity, and effective target engagement and proof of activity were demonstrated by increased levels of CSF-1 and decreased CD16+ monocytes in JNJ-40346527-treated, but not placebo-treated, patients. Thirty-seven (58.7%) JNJ-40346527-treated and 16 (50.0%) placebo-treated patients reported ≥ 1 adverse event (AE); 1 (1.6%) JNJ-40346527-treated and 3 (9.4%) placebo-treated patients reported ≥ 1 serious AE. Although adequate exposure and effective peripheral target engagement were evident, JNJ-40346527 efficacy was not observed in patients with DMARD-refractory active RA. ClinicalTrials.gov identifier: NCT01597739

  15. Protocatechuic Acid, a Phenolic from Sansevieria roxburghiana Leaves, Suppresses Diabetic Cardiomyopathy via Stimulating Glucose Metabolism, Ameliorating Oxidative Stress, and Inhibiting Inflammation

    Directory of Open Access Journals (Sweden)

    Niloy Bhattacharjee

    2017-05-01

    Full Text Available Persistent hyperglycemia, impairment of redox status and establishment of inflammatory pathophysiology integrally play important role in the pathogenesis of diabetic cardiomyopathy (DC. Present study examined the therapeutic potential of protocatechuic acid isolated from the Sansevieria roxburghiana rhizomes against DC employing rodent model of type 2 diabetes (T2D. T2D was induced by high fat diet + a low-single dose of streptozotocin (35 mg/kg, i.p.. T2D rats exhibited significantly (p < 0.01 high fasting blood glucose level. Alteration in serum lipid profile (p < 0.01 and increased levels of lactate dehydrogenase (p < 0.01 and creatine kinase (p < 0.01 in the sera of T2D rats revealed the occurrence of hyperlipidemia and diabetic pathophysiology. A significantly (p < 0.01 high levels of serum C-reactive protein and pro-inflammatory mediators revealed the establishment of inflammatory occurrence in T2D rats. Besides, significantly high levels of troponins in the sera revealed the establishment of cardiac dysfunctions in T2D rats. However, protocatechuic acid (50 and 100 mg/kg, p.o. treatment could significantly reverse the changes in serum biochemical parameters related to cardiac dysfunctions. Molecular mechanism studies demonstrated impairment of signaling cascade, IRS1/PI3K/Akt/AMPK/p 38/GLUT4, in glucose metabolism in the skeletal muscle of T2D rats. Significant (p < 0.01 activation of polyol pathway, enhanced production of AGEs, oxidative stress and up-regulation of inflammatory signaling cascades (PKC/NF-κB/PARP were observed in the myocardial tissue of T2D rats. However, protocatechuic acid (50 and 100 mg/kg, p.o. treatment could significantly (p < 0.05–0.01 stimulate glucose metabolism in skeletal muscle, regulated glycemic and lipid status, reduced the secretion of pro-inflammatory cytokines, and restored the myocardial physiology in T2D rats near to normalcy. Histological assessments were also in agreement with the above findings

  16. Two chalcones, 4-hydroxyderricin and xanthoangelol, stimulate GLUT4-dependent glucose uptake through the LKB1/AMP-activated protein kinase signaling pathway in 3T3-L1 adipocytes.

    Science.gov (United States)

    Ohta, Mitsuhiro; Fujinami, Aya; Kobayashi, Norihiro; Amano, Akiko; Ishigami, Akihito; Tokuda, Harukuni; Suzuki, Nobutaka; Ito, Fumitake; Mori, Taisuke; Sawada, Morio; Iwasa, Koichi; Kitawaki, Jo; Ohnishi, Katsunori; Tsujikawa, Muneo; Obayashi, Hiroshi

    2015-07-01

    4-Hydroxyderricin (4HD) and xanthoangelol (XAG) are major components of n-hexane/ethyl acetate (5:1) extract of the yellow-colored stem juice of Angelica keiskei. 4-Hydroxyderricin and XAG have been reported to increase glucose transporter 4 (GLUT4)-dependent glucose uptake in 3T3-L1 adipocytes, but the detailed mechanism of this phenomenon remains unknown. This present study was aimed at clarifying the detailed mechanism by which 4HD and XAG increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes. Both 4HD and XAG increased glucose uptake and GLUT4 translocation to the plasma membrane. 4-Hydroxyderricin and XAG also stimulated the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK) and its downstream target acetyl-CoA carboxylase. In addition, phosphorylation of liver kinase B1 (LKB1), which acts upstream of AMPK, was also increased by 4HD and XAG treatment. Small interfering RNA knockdown of LKB1 attenuated 4HD- and XAG-stimulated AMPK phosphorylation and suppressed glucose uptake. These findings demonstrate that 4HD and XAG can increase GLUT4-dependent glucose uptake through the LKB1/AMPK signaling pathway in 3T3-L1 adipocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. The NADPH oxidase Nox2 regulates VEGFR1/CSF-1R-mediated microglial chemotaxis and promotes early postnatal infiltration of phagocytes in the subventricular zone of the mouse cerebral cortex.

    Science.gov (United States)

    Lelli, Aurélia; Gervais, Annie; Colin, Catherine; Chéret, Cyril; Ruiz de Almodovar, Carmen; Carmeliet, Peter; Krause, Karl-Heinz; Boillée, Séverine; Mallat, Michel

    2013-09-01

    The phagocyte NADPH oxidase Nox2 generates superoxide ions implicated in the elimination of microorganisms and the redox control of inflammatory signaling. However, the role of Nox2 in phagocyte functions unrelated to immunity or pathologies is unknown. During development, oriented cell migrations insure the timely recruitment and function of phagocytes in developing tissues. Here, we have addressed the role of Nox2 in the directional migration of microglial cells during development. We show that microglial Nox2 regulates the chemotaxis of purified microglia mediated by the colony stimulating factor-1 receptor (CSF-1R) and the vascular endothelial growth factor receptor-1 (VEGFR1). Stimulation of these receptors triggers activation of Nox2 at the leading edge of polarized cells. In the early postnatal stages of mouse brain development, Nox2 is activated in macrophages / microglial cells in the lateral ventricle or the adjacent subventricular zone (SVZ). Fluorescent microglia injected into the lateral ventricle infiltrate the dorso-caudal SVZ through a mechanism that is blocked by pretreatment of the injected cells with an irreversible Nox inhibitor. Infiltration of endogenous microglia into the caudal SVZ of the cerebral cortex is prevented by (1) Nox2 gene deficiency, (2) treatment with a Nox2 inhibitor (apocynin), and (3) invalidation of the VEGFR1 kinase. We conclude that phagocytes move out of the lateral ventricle soon after birth and infiltrate the cortical SVZ through a mechanism requiring microglial Nox2 and VEGFR1 activation. Nox2 therefore modulates the migration of microglia and their development. Copyright © 2013 Wiley Periodicals, Inc.

  18. The p38 mitogen-activated protein kinase inhibitor SB203580 reduces glucose turnover by the glucose transporter-4 of 3T3-L1 adipocytes in the insulin-stimulated state

    NARCIS (Netherlands)

    Bazuine, Merlijn; Carlotti, Françoise; Rabelink, Martijn J. W. E.; Vellinga, Jort; Hoeben, Rob C.; Maassen, J. Antonie

    2005-01-01

    Insulin induces a profound increase in glucose uptake in 3T3-L1 adipocytes through the activity of the glucose transporter-4 (GLUT4). Apart from GLUT4 translocation toward the plasma membrane, there is also an insulin-induced p38 MAPK-dependent step involved in the regulation of glucose uptake.

  19. Colony stimulating factor-1 receptor signaling networks inhibit mouse macrophage inflammatory responses by induction of microRNA-21

    Science.gov (United States)

    Caescu, Cristina I.; Guo, Xingyi; Tesfa, Lydia; Bhagat, Tushar D.; Verma, Amit; Zheng, Deyou

    2015-01-01

    Macrophage polarization between the M2 (repair, protumorigenic) and M1 (inflammatory) phenotypes is seen as a continuum of states. The detailed transcriptional events and signals downstream of colony-stimulating factor 1 receptor (CSF-1R) that contributes to amplification of the M2 phenotype and suppression of the M1 phenotype are largely unknown. Macrophage CSF-1R pTyr-721 signaling promotes cell motility and enhancement of tumor cell invasion in vitro. Combining analysis of cellular systems for CSF-1R gain of function and loss of function with bioinformatic analysis of the macrophage CSF-1R pTyr-721–regulated transcriptome, we uncovered microRNA-21 (miR-21) as a downstream molecular switch controlling macrophage activation and identified extracellular signal-regulated kinase1/2 and nuclear factor-κB as CSF-1R pTyr-721–regulated signaling nodes. We show that CSF-1R pTyr-721 signaling suppresses the inflammatory phenotype, predominantly by induction of miR-21. Profiling of the miR-21–regulated messenger RNAs revealed that 80% of the CSF-1–regulated canonical miR-21 targets are proinflammatory molecules. Additionally, miR-21 positively regulates M2 marker expression. Moreover, miR-21 feeds back to positively regulate its own expression and to limit CSF-1R–mediated activation of extracellular signal-regulated kinase1/2 and nuclear factor-κB. Consistent with an anti-inflammatory role of miRNA-21, intraperitoneal injection of mice with a miRNA-21 inhibitor increases the recruitment of inflammatory monocytes and enhances the peritoneal monocyte/macrophage response to lipopolysaccharide. These results identify the CSF-1R–regulated miR-21 network that modulates macrophage polarization. PMID:25573988

  20. Implementing a Reminder System in the Northern Part of Belgium to Stimulate Postpartum Screening for Glucose Intolerance in Women with Gestational Diabetes: The “Sweet Pregnancy” Project

    Directory of Open Access Journals (Sweden)

    Katrien Benhalima

    2017-01-01

    Full Text Available Aims. To evaluate the feasibility and efficacy of a gestational diabetes (GDM recall register on the long-term screening uptake postpartum and to evaluate the prevalence of prediabetes postpartum. Methods. Evaluation of a GDM recall register implemented in 66 obstetrical centers in the northern part of Belgium from 2009 to 2016. Registrants receive yearly reminders to have a fasting plasma glucose test in primary care to timely detect prediabetes. Results. After 6 years, 7269 women were registered. The yearly response rates varied from 74.4% after the first year to 61.8% after the fifth year. The number of women who reported a screening test varied from 67.4% after the first year to 71.9% after the fifth year. Compared to women who responded at least once to a reminder, women who never responded were more often <30 years (41.4% versus 33.9%, p<0.001 and were more often obese (29.3% versus 20.8%, p≤0.001. Over a period of 6 years, 7.3% (CI 6.0%–8.8% developed diabetes and 27.4% (CI 23.9%–31.0% developed impaired fasting glycaemia. Conclusion. We show now the long-term feasibility and efficacy of a GDM recall register to stimulate screening postpartum. One-third of women developed prediabetes within 6 years.

  1. Colony-Stimulating Factor 1 Receptor Blockade Inhibits Tumor Growth by Altering the Polarization of Tumor-Associated Macrophages in Hepatocellular Carcinoma.

    Science.gov (United States)

    Ao, Jian-Yang; Zhu, Xiao-Dong; Chai, Zong-Tao; Cai, Hao; Zhang, Yuan-Yuan; Zhang, Ke-Zhi; Kong, Ling-Qun; Zhang, Ning; Ye, Bo-Gen; Ma, De-Ning; Sun, Hui-Chuan

    2017-08-01

    Colony-stimulating factor-1 (CSF-1) and its receptor, CSF-1R, regulate the differentiation and function of macrophages and play an important role in macrophage infiltration in the context of hepatocellular carcinoma. The therapeutic effects of CSF-1R blockade in hepatocellular carcinoma remain unclear. In this study, we found that CSF-1R blockade by PLX3397, a competitive inhibitor with high specificity for CSF-1R tyrosine kinase, significantly delayed tumor growth in mouse models. PLX3397 inhibited the proliferation of macrophages in vitro, but intratumoral macrophage infiltration was not decreased by PLX3397 in vivo Gene expression profiling of tumor-associated macrophages (TAM) showed that TAMs from the PLX3397-treated tumors were polarized toward an M1-like phenotype compared with those from vehicle-treated tumors. In addition, PLX3397 treatment increased CD8(+) T-cell infiltration, whereas CD4(+) T-cell infiltration was decreased. Further study revealed that tumor cell-derived CSF-2 protected TAMs from being depleted by PLX3397. In conclusion, CSF-1R blockade delayed tumor growth by shifting the polarization rather than the depletion of TAMs. CSF-1R blockade warrants further investigation in the treatment of hepatocellular carcinoma. Mol Cancer Ther; 16(8); 1544-54. ©2017 AACR. ©2017 American Association for Cancer Research.

  2. Modulation of nuclear T3 binding by T3 in a human hepatocyte cell-line (Chang-liver) - T3 stimulation of cell growth but not of malic enzyme, glucose-6-phosphatdehydrogenase or 6-phosphogluconate-dehydrogenase

    DEFF Research Database (Denmark)

    Matzen, L E; Kristensen, S R; Kvetny, J

    1991-01-01

    The T3 modulation of nuclear T3 binding (NBT3), the T3 effect on cell growth, and the T3 and insulin effects on malic enzyme (ME), glucose-6-phosphat-dehydrogenase (G6PD) and 6-phosphogluconat-dehydrogenase (G6PD) were studied in a human hepatocyte cell-line (Chang-liver). T3 was bound to a high...... modulation of NBT3 associated to receptor saturation; 2) stimulation of cell growth; 3) contrary to the findings in rat hepatocytes no stimulation of ME, G6PD or 6PGD. Insulin enhanced ME and 6PGD....

  3. High Expression of Colony-Stimulating Factor 1 Receptor Associates with Unfavorable Cancer-Specific Survival of Patients with Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Yang, Liu; Liu, Yidong; An, Huimin; Chang, Yuan; Zhang, Weijuan; Zhu, Yu; Xu, Le; Xu, Jiejie

    2016-03-01

    Colony-stimulating factor 1 receptor (CSF-1R), a single-pass type III transmembrane tyrosine-protein kinase, is mainly involved in inflammation and immune regulation to facilitate the progression of solid tumors. This study aimed to evaluate the impact of CSF-1R expression on clinical outcome of patients with clear cell renal cell carcinoma (ccRCC) after surgery. We retrospectively enrolled 268 patients with ccRCC undergoing nephrectomy between 2001 and 2004. Clinicopathologic features and cancer-specific survival (CSS) were collected. Western blot analysis was performed in the pairwise comparisons of CSF-1R expression in peritumor and tumor tissues of patients with ccRCC. Immunohistochemistry was conducted to determine CSF-1R expression level in tumor specimens. Survival analysis was performed by the Kaplan-Meier method. Cox regression models were used to evaluate the impact of prognostic factors on CSS. A concordance index was calculated to measure prognostic accuracy. A prognostic nomogram was constructed on the basis of the identified independent prognostic factors. CSF-1R expression in tumor tissues was higher than in peritumor tissues in 71.4% (5 of 7) patients. CSF-1R expression of tumor tissues was positively associated with metastasis, tumor, node, metastasis classification system (TNM) stage, Eastern Cooperative Oncology Group performance status score and poor CSS. CSF-1R expression was determined as an independent prognostic factor for CSS in patients with ccRCC. Furthermore, extension of the well-established prognostic models with CSF-1R expression presented significantly improved prognostic accuracy. An efficient prognostic nomogram was constructed on the basis of the independent prognostic factors. High CSF-1R expression is a potential independent adverse prognostic factor for CSS in patients with ccRCC.

  4. Plasma vascular endothelial growth factor B levels are increased in patients with newly diagnosed type 2 diabetes mellitus and associated with the first phase of glucose-stimulated insulin secretion function of β-cell.

    Science.gov (United States)

    Wu, J; Wei, H; Qu, H; Feng, Z; Long, J; Ge, Q; Deng, H

    2017-11-01

    To detect plasma vascular endothelial growth factor B (VEGF-B) in individuals with different glucose tolerance and investigate the relationship between plasma VEGF-B levels and the first phase of glucose-stimulated insulin secretion. A cross-sectional study was conducted involving 45 patients with newly diagnosed type 2 diabetes mellitus (T2DM), 37 patients with impaired glucose regulation (IGR), and 39 Normal glucose tolerance (NGT) subjects, all of whom underwent intravenous glucose tolerance test. Plasma VEGF-B levels were assayed by ELISA. The first phase of insulin secretion was evaluated by acute insulin response (AIR), the area under the curve of the first-phase (0-10 min) insulin secretion (AUC) and glucose disposition index (GDI). The T2DM and IGR groups had higher plasma VEGF-B levels than the NGT group (P B levels were negatively correlated with AIR, AUC, GDI, HOMA-β (P B levels [145.59-180.07 pg/ml, OR 3.55 (95% CI 1.05-12.02) and >180.07 pg/ml, OR 3.64 (95% CI 1.16-11.42)] were related to a greater probability of β-cell hypofunction, compared with low VEGF-B levels (B levels and β-cell hypofunction disappeared (P > 0.05). Our study provides evidence that plasma VEGF-B levels were higher in patients with newly diagnosed T2DM, and were strongly associated with glucose and lipid metabolism and the first-phase insulin secretion function of β-cells. VEGF-B may be involved in the mechanism of β-cell dysfunction in T2DM.

  5. High Glucose Concentration Stimulates NHE-1 Activity in Distal Nephron Cells: the Role of the Mek/Erk1/2/p90RSK and p38MAPK Signaling Pathways

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    Juliana Martins da Costa-Pessoa

    2014-02-01

    Full Text Available Aims: In models of diabetes, distal nephron cells contribute to glucose uptake and oxidation. How these cells contribute to the use of glucose for the regulation of H+ extrusion remains unknown. We used Madin-Darby Canine Kidney (MDCK cells to investigate the effect of acute or chronic high glucose concentration on the abundance and activity of the Na+/H+ exchanger (NHE-1. Methods: Using RT-PCR, we also evaluated the mRNA expression for sodium glucose co-transporters SGLT1 and SGLT2. Protein abundance was analyzed using immunoblotting, and intracellular pH (pHi recovery was evaluated using microscopy in conjunction with the fluorescent probe BCECF/AM. The Na+-dependent pHi recovery rate was monitored with HOE-694 (50 µM and/or S3226 (10 µM, specific NHE-1 and NHE-3 inhibitors. Results: MDCK cells did not express the mRNA for SGLT1 or SGLT2 but did express the GLUT2, NHE-1 and NHE-3 proteins. Under control conditions, we observed a greater contribution of NHE-1 to pHi recovery relative to the other H+ transporters. Acute high glucose treatment increased the HOE-694-sensitive pHi recovery rate and p-Erk1/2 and p90RSK abundance. These parameters were reduced by PD-98059, a Mek inhibitor (1 µM. Chronic high glucose treatment also increased the HOE-694-sensitive pHi recovery rate and p-p38MAPK abundance. Both parameters were reduced by SB-203580, a p38MAPK inhibitor (10 µM. Conclusion: These results suggested that extracellular high glucose stimulated NHE-1 acutely and chronically through Mek/Erk1/2/p90RSK and p38MAPK pathways, respectively.

  6. Modulation of nuclear T3 binding by T3 in a human hepatocyte cell-line (Chang-liver) - T3 stimulation of cell growth but not of malic enzyme, glucose-6-phosphatdehydrogenase or 6-phosphogluconate-dehydrogenase

    DEFF Research Database (Denmark)

    Matzen, L E; Kristensen, S R; Kvetny, J

    1991-01-01

    The T3 modulation of nuclear T3 binding (NBT3), the T3 effect on cell growth, and the T3 and insulin effects on malic enzyme (ME), glucose-6-phosphat-dehydrogenase (G6PD) and 6-phosphogluconat-dehydrogenase (G6PD) were studied in a human hepatocyte cell-line (Chang-liver). T3 was bound to a high...... was unchanged. T3 stimulated cell growth (p G6PD, and 6PGD. Insulin (1 mumol/l) enhanced the activities of ME (p ... modulation of NBT3 associated to receptor saturation; 2) stimulation of cell growth; 3) contrary to the findings in rat hepatocytes no stimulation of ME, G6PD or 6PGD. Insulin enhanced ME and 6PGD....

  7. mCSF1, a nucleus-encoded CRM protein required for the processing of many mitochondrial introns, is involved in the biogenesis of respiratory complexes I and IV in Arabidopsis.

    Science.gov (United States)

    Zmudjak, Michal; Colas des Francs-Small, Catherine; Keren, Ido; Shaya, Felix; Belausov, Eduard; Small, Ian; Ostersetzer-Biran, Oren

    2013-07-01

    The coding regions of many mitochondrial genes in plants are interrupted by intervening sequences that are classified as group II introns. Their splicing is essential for the expression of the genes they interrupt and hence for respiratory function, and is facilitated by various protein cofactors. Despite the importance of these cofactors, only a few of them have been characterized. CRS1-YhbY domain (CRM) is a recently recognized RNA-binding domain that is present in several characterized splicing factors in plant chloroplasts. The Arabidopsis genome encodes 16 CRM proteins, but these are largely uncharacterized. Here, we analyzed the intracellular location of one of these hypothetical proteins in Arabidopsis, mitochondrial CAF-like splicing factor 1 (mCSF1; At4 g31010), and analyzed the growth phenotypes and organellar activities associated with mcsf1 mutants in plants. Our data indicated that mCSF1 resides within mitochondria and its functions are essential during embryogenesis. Mutant plants with reduced mCSF1 displayed inhibited germination and retarded growth phenotypes that were tightly associated with reduced complex I and IV activities. Analogously to the functions of plastid-localized CRM proteins, analysis of the RNA profiles in wildtype and mcsf1 plants showed that mCSF1 acts in the splicing of many of the group II intron RNAs in Arabidopsis mitochondria. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  8. Syntaxin-4 mediates exocytosis of pre-docked and newcomer insulin granules underlying biphasic glucose-stimulated insulin secretion in human pancreatic beta cells.

    Science.gov (United States)

    Xie, Li; Zhu, Dan; Dolai, Subhankar; Liang, Tao; Qin, Tairan; Kang, Youhou; Xie, Huanli; Huang, Ya-Chi; Gaisano, Herbert Y

    2015-06-01

    Of the four exocytotic syntaxins (Syns), much is now known about the role of Syn-1A (pre-docked secretory granules [SGs]) and Syn-3 (newcomer SGs) in insulin exocytosis. Some work was reported on Syn-4's role in biphasic glucose-stimulated insulin secretion (GSIS), but its precise role in insulin SG exocytosis remains unclear. In this paper we examine this role in human beta cells. Endogenous function of Syn-4 in human islets was assessed by knocking down its expression with lentiviral single hairpin RNA (lenti-shRNA)-RFP. Biphasic GSIS was determined by islet perifusion assay. Single-cell analysis of exocytosis of red fluorescent protein (RFP)-positive beta cells (exhibiting near-total depletion of Syn-4) was by patch clamp capacitance measurements (Cm) and total internal reflection fluorescence microscopy (TIRFM), the latter to further assess single SG behaviour. Co-immunoprecipitations were conducted on INS-1 cells to assess exocytotic complexes. Syn-4 knockdown (KD) of 77% in human islets caused a concomitant reduction in cognate Munc18c expression (46%) without affecting expression of other exocytotic proteins; this resulted in reduction of GSIS in the first phase (by 42%) and the second phase (by 40%). Cm of RFP-tagged Syn-4-KD beta cells showed severe inhibition in the readily releasable pool (by 71%) and mobilisation from reserve pools (by 63%). TIRFM showed that Syn-4-KD-induced inhibition of first-phase GSIS was attributed to reduction in exocytosis of both pre-docked and newcomer SGs (which undergo minimal residence or docking time at the plasma membrane before fusion). Second-phase inhibition was attributed to reduction in newcomer SGs. Stx-4 co-immunoprecipitated Munc18c, VAMP2 and VAMP8, suggesting that these exocytotic complexes may be involved in exocytosis of pre-docked and newcomer SGs. Syn-4 is involved in distinct molecular machineries that influence exocytosis of both pre-docked and newcomer SGs in a manner functionally redundant to Syn-1A and

  9. Structural Elucidation of a Novel Polysaccharide from Pseudostellaria heterophylla and Stimulating Glucose Uptake in Cells and Distributing in Rats by Oral.

    Science.gov (United States)

    Chen, Jinlong; Pang, Wensheng; Shi, Wentao; Yang, Bin; Kan, Yongjun; He, Zhaodong; Hu, Juan

    2016-09-14

    The semi-refined polysaccharide of Pseudostellaria heterophylla is a complex polysaccharide that exhibits significantly hypoglycemic activities. A novel homogeneous polysaccharide, named as H-1-2, was isolated from the semi-refined polysaccharide. The mean molecular weight of H-1-2 was 1.4 × 10⁴ Da and it was only composed of d-glucose monosaccharide. Structure elucidation indicated that H-1-2 contains pyranride, and has the characteristics of the α-iso-head configuration, a non-reducing end (T-), 4-, 1,6-, and 1,4,6-connection, in all four ways to connect glucose. H-1-2 was a type of glucan, where chemical combination exists in the main chain between 1→4 linked glucose, and contains a small amount of 1,6-linked glucose, which was in the branched chain. In vitro HepG2, 3T3-L1, and L6 cells were used to assess cellular glucose consumption and cellular glucose uptake by glucose oxidase, and the transport of 2-NBDG fluorescence probe results showed that H-1-2 could clearly increase glucose uptake and utilization in muscle and adipose cells, which is beneficial to screen for in the discovery of anti-diabetes lead compounds. H-1-2 was labeled with radioisotopes ((99m)Tc-pertechnetate). (99m)Tc-labeled-H-1-2 was performed by SPECT/CT analysis images after oral administration in rats. At 4 h post ingestion, about 50% of the radioactivity was observed in the intestine. No significant radioactivity was found in the heart, liver, and kidney, conjecturing that absorption of (99m)Tc-labeled H-1-2 might, via intestinal mucosa, be absorbed into systemic circulation. This problem, as to whether the polysaccharide is absorbed orally, will need further examination.

  10. Structural Elucidation of a Novel Polysaccharide from Pseudostellaria heterophylla and Stimulating Glucose Uptake in Cells and Distributing in Rats by Oral

    Directory of Open Access Journals (Sweden)

    Jinlong Chen

    2016-09-01

    Full Text Available The semi-refined polysaccharide of Pseudostellaria heterophylla is a complex polysaccharide that exhibits significantly hypoglycemic activities. A novel homogeneous polysaccharide, named as H-1-2, was isolated from the semi-refined polysaccharide. The mean molecular weight of H-1-2 was 1.4 × 104 Da and it was only composed of d-glucose monosaccharide. Structure elucidation indicated that H-1-2 contains pyranride, and has the characteristics of the α-iso-head configuration, a non-reducing end (T-, 4-, 1,6-, and 1,4,6-connection, in all four ways to connect glucose. H-1-2 was a type of glucan, where chemical combination exists in the main chain between 1→4 linked glucose, and contains a small amount of 1,6-linked glucose, which was in the branched chain. In vitro HepG2, 3T3-L1, and L6 cells were used to assess cellular glucose consumption and cellular glucose uptake by glucose oxidase, and the transport of 2-NBDG fluorescence probe results showed that H-1-2 could clearly increase glucose uptake and utilization in muscle and adipose cells, which is beneficial to screen for in the discovery of anti-diabetes lead compounds. H-1-2 was labeled with radioisotopes (99mTc-pertechnetate. 99mTc-labeled-H-1-2 was performed by SPECT/CT analysis images after oral administration in rats. At 4 h post ingestion, about 50% of the radioactivity was observed in the intestine. No significant radioactivity was found in the heart, liver, and kidney, conjecturing that absorption of 99mTc-labeled H-1-2 might, via intestinal mucosa, be absorbed into systemic circulation. This problem, as to whether the polysaccharide is absorbed orally, will need further examination.

  11. Glucose metabolism in chronic lung disease

    NARCIS (Netherlands)

    Sauerwein, H. P.; Schols, A. M. W. J.

    2002-01-01

    Chronic disease in general induces insulin resistance on glucose metabolism on hepatic and peripheral levels. Hypoxia in healthy subjects, induced by chronic altitude exposure, stimulates glucose production with decreased hepatic insulin sesitivity, but increases peripheral insulin sensitivity.

  12. Depletion of Tumor-Associated Macrophages with a CSF-1R Kinase Inhibitor Enhances Antitumor Immunity and Survival Induced by DC Immunotherapy.

    Science.gov (United States)

    Dammeijer, Floris; Lievense, Lysanne A; Kaijen-Lambers, Margaretha E; van Nimwegen, Menno; Bezemer, Koen; Hegmans, Joost P; van Hall, Thorbald; Hendriks, Rudi W; Aerts, Joachim G

    2017-07-01

    New immunotherapeutic strategies are needed to induce effective antitumor immunity in all cancer patients. Malignant mesothelioma is characterized by a poor prognosis and resistance to conventional therapies. Infiltration of tumor-associated macrophages (TAM) is prominent in mesothelioma and is linked to immune suppression, angiogenesis, and tumor aggressiveness. Therefore, TAM depletion could potentially reactivate antitumor immunity. We show that M-CSFR inhibition using the CSF-1R kinase inhibitor PLX3397 (pexidartinib) effectively reduced numbers of TAMs, circulating nonclassical monocytes, as well as amount of neoangiogenesis and ascites in mesothelioma mouse models, but did not improve survival. When combined with dendritic cell vaccination, survival was synergistically enhanced with a concomitant decrease in TAMs and an increase in CD8(+) T-cell numbers and functionality. Total as well as tumor antigen-specific CD8(+) T cells in tumor tissue of mice treated with combination therapy showed reduced surface expression of the programmed cell death protein-1 (PD-1), a phenomenon associated with T-cell exhaustion. Finally, mice treated with combination therapy were protected from tumor rechallenge and displayed superior T-cell memory responses. We report that decreasing local TAM-mediated immune suppression without immune activation does not improve survival. However, combination of TAM-mediated immune suppression with dendritic cell immunotherapy generates robust and durable antitumor immunity. These findings provide insights into the interaction between immunotherapy-induced antitumor T cells and TAMs and offer a therapeutic strategy for mesothelioma treatment. Cancer Immunol Res; 5(7); 535-46. ©2017 AACR. ©2017 American Association for Cancer Research.

  13. Zinc stimulates glucose oxidation and glycemic control by modulating the insulin signaling pathway in human and mouse skeletal muscle cell lines.

    Directory of Open Access Journals (Sweden)

    Shaghayegh Norouzi

    Full Text Available Zinc is a metal ion that is an essential cell signaling molecule. Highlighting this, zinc is an insulin mimetic, activating cellular pathways that regulate cellular homeostasis and physiological responses. Previous studies have linked dysfunctional zinc signaling with several disease states including cancer, obesity, cardiovascular disease and type 2 diabetes. The present study evaluated the insulin-like effects of zinc on cell signaling molecules including tyrosine, PRSA40, Akt, ERK1/2, SHP-2, GSK-3β and p38, and glucose oxidation in human and mouse skeletal muscle cells. Insulin and zinc independently led to the phosphorylation of these proteins over a 60-minute time course in both mouse and human skeletal muscle cells. Similarly, utilizing a protein array we identified that zinc could active the phosphorylation of p38, ERK1/2 and GSK-3B in human and ERK1/2 and GSK-3B in mouse skeletal muscle cells. Glucose oxidation assays were performed on skeletal muscle cells treated with insulin, zinc, or a combination of both and resulted in a significant induction of glucose consumption in mouse (p<0.01 and human (p<0.05 skeletal muscle cells when treated with zinc alone. Insulin, as expected, increased glucose oxidation in mouse (p<0.001 and human (0.001 skeletal muscle cells, however the combination of zinc and insulin did not augment glucose consumption in these cells. Zinc acts as an insulin mimetic, activating key molecules implicated in cell signaling to maintain glucose homeostasis in mouse and human skeletal muscle cells. Zinc is an important metal ion implicated in several biological processes. The role of zinc as an insulin memetic in activating key signaling molecules involved in glucose homeostasis could provide opportunities to utilize this ion therapeutically in treating disorders associated with dysfunctional zinc signaling.

  14. Glucose-stimulated prehepatic insulin secretion is associated with circulating alanine, triglyceride, glucagons, lactate and TNF-alfa in patients with HIV-lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Pedersen, SB

    2006-01-01

    OBJECTIVES: We examined whether insulin-resistant lipodystrophic HIV-infected patients with known high fasting prehepatic insulin secretion rates (FISRs) displayed alterations in first-phase prehepatic insulin response to intravenous glucose (ISREG0-10 min). METHODS: Eighteen normoglycaemic lipod...

  15. Both fasting and glucose-stimulated proinsulin levels predict hyperglycemia and incident type 2 diabetes: a population-based study of 9,396 Finnish men.

    Science.gov (United States)

    Vangipurapu, Jagadish; Stančáková, Alena; Kuulasmaa, Teemu; Kuusisto, Johanna; Laakso, Markku

    2015-01-01

    Hyperproinsulinemia is an indicator of β-cell dysfunction, and fasting proinsulin levels are elevated in patients with hyperglycemia. It is not known whether proinsulin levels after a glucose load are better predictors of hyperglycemia and type 2 diabetes than fasting proinsulin. Participants were 9,396 Finnish men (mean±SD, age 57.3±7.1 years, BMI 27.0±4.0 kg/m2) of the population-based METabolic Syndrome In Men Study who were non-diabetic at the recruitment, and who participated in a 6-year follow-up study. Proinsulin and insulin levels were measured in the fasting state and 30 and 120 min after an oral glucose load. Area under the curve (AUC) and proinsulin to insulin ratios were calculated. Fasting proinsulin, proinsulin at 30 min and proinsulin AUC during the first 30 min of an oral glucose tolerance test significantly predicted both the worsening of hyperglycemia and type 2 diabetes after adjustment for confounding factors. Further adjustment for insulin sensitivity (Matsuda index) or insulin secretion (Disposition index) weakened these associations. Insulin sensitivity had a major impact on these associations. Our results suggest that proinsulin in the fasting state and after an oral glucose load similarly predict the worsening of hyperglycemia and conversion to type 2 diabetes.

  16. Anti-diabetic effects of Caulerpa lentillifera: stimulation of insulin secretion in pancreatic β-cells and enhancement of glucose uptake in adipocytes.

    Science.gov (United States)

    Sharma, Bhesh Raj; Rhyu, Dong Young

    2014-07-01

    To evaluate anti-diabetic effect of Caulerpa lentillifera (C. lentillifera). The inhibitory effect of C. lentillifera extract on dipeptidyl peptidase-IV and α-glucosidase enzyme was measured in a cell free system. Then, interleukin-1β and interferon-γ induced cell death and insulin secretion were measured in rat insulinoma (RIN) cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and ELISA kit, respectively. Glucose uptake and glucose transporter expression were measured by fluorometry and western blotting, using 3T3-L1 adipocytes. C. lentillifera extract significantly decreased dipeptidyl peptidase-IV and α-glucosidase enzyme activities, and effectively inhibited cell death and iNOS expression in interleukin-1β and interferon-γ induced RIN cells. Furthermore, C. lentillifera extract significantly enhanced insulin secretion in RIN cells and glucose transporter expression and glucose uptake in 3T3-L1 adipocytes. Thus, our results suggest that C. lentillifera could be used as a potential anti-diabetic agent.

  17. Glucagon-like peptide-2, but not glucose-dependent insulinotropic polypeptide, stimulates glucagon release in patients with type 1 diabetes

    DEFF Research Database (Denmark)

    Christensen, Mikkel; Knop, Filip K; Vilsbøll, Tina

    2010-01-01

    This study investigated the glucagon-releasing properties of the hormones glucagon-like peptide-2 (GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) in 8 patients with type 1 diabetes mellitus (T1DM) without paracrine intraislet influence of insulin (C-peptide negative following a 5 g...

  18. Long-term fenofibrate treatment impaired glucose-stimulated insulin secretion and up-regulated pancreatic NF-kappa B and iNOS expression in monosodium glutamate-induced obese rats: Is that a latent disadvantage?

    Directory of Open Access Journals (Sweden)

    Liu Shuai-nan

    2011-10-01

    Full Text Available Abstract Background Fenofibrate, a PPAR alpha agonist, has been widely used in clinics as lipid-regulating agent. PPAR alpha is known to be expressed in many organs including pancreatic beta cells and regulate genes involved in fatty acid metabolism. Some reports based on cell lines or animals have provided evidences that PPAR alpha agonists may affect (increased or suppressed beta cell insulin secretion, and several studies are producing interesting but still debated results. Methods In this research, we investigated the long term effects of fenofibrate on beta cell function in a metabolic syndrome animal model, monosodium glutamate (MSG induced obese rats. Obese MSG rats were administered by gavage with fenofibrate at a dose of 100 mg/kg for 12 weeks. Oral glucose tolerance and insulin tolerance tests were performed to evaluate glucose metabolism and insulin sensitivity. We have used the hyperglycemic clamp technique to evaluate the capacity of beta cell insulin secretion. This technique provides an unbiased approach to understand the beta cell function in vivo. The changes of gene and protein expression in the pancreas and islets were also analyzed by Real-Time-PCR, Western blot and immunostaining. Results Fenofibrate reduced the plasma lipid levels within a few days, and showed no beneficial effects on glucose homeostasis or insulin sensitivity in obese MSG rats. But the animals treated with fenofibrate exhibited significantly decreased fasting plasma insulin and impaired insulin secretory response to glucose stimulation. Further studies confirmed that fenofibrate increased MDA level and decreased total ATPase activity in pancreatic mitochondrion, accompanied by the upregulation of iNOS and NF-kappa B and TNF alpha expression in pancreatic islets of obese MSG rats. Conclusions Long-term fenofibrate treatment disrupted beta cell function, and impaired glucose-stimulated insulin secretion in obese MSG rats, perhaps to some extent associated

  19. Aqueous fraction of Beta vulgaris ameliorates hyperglycemia in diabetic mice due to enhanced glucose stimulated insulin secretion, mediated by acetylcholine and GLP-1, and elevated glucose uptake via increased membrane bound GLUT4 transporters.

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    Ashraf Ul Kabir

    Full Text Available The study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris.Aqueous fraction of B. Vulgaris extract was the only active fraction (50mg/kg. Plasma insulin level was found to be the highest at 30 mins after B. Vulgaris administration at a dose of 200mg/kg. B. Vulgaris treated mice were also assayed for plasma Acetylcholine, Glucagon Like Peptide-1 (GLP-1, Gastric Inhibitory Peptide (GIP, Vasoactive Intestinal Peptide, Pituitary Adenylate Cyclase-Activating Peptide (PACAP, Insulin Like Growth Factor-1 (IGF-1, Pancreatic Polypeptides (PP, and Somatostatin, along with the corresponding insulin levels. Plasma Acetylcholine and GLP-1 significantly increased in B. Vulgaris treated animals and were further studied. Pharmacological enhancers, inhibitors, and antagonists of Acetylcholine and GLP-1 were also administered to the test animals, and corresponding insulin levels were measured. These studies confirmed the role of acetylcholine and GLP-1 in enhanced insulin secretion (p<0.05. Principal signaling molecules were quantified in isolated mice islets for the respective pathways to elucidate their activities. Elevated concentrations of Acetylcholine and GLP-1 in B. Vulgaris treated mice were found to be sufficient to activate the respective pathways for insulin secretion (p<0.05. The amount of membrane bound GLUT1 and GLUT4 transporters were quantified and the subsequent glucose uptake and glycogen synthesis were assayed. We showed that levels of membrane bound GLUT4 transporters, glucose-6-phosphate in skeletal myocytes, activity of glycogen synthase, and level of glycogen deposited in the skeletal muscles all increased (p<0.05.Findings of the present study clearly prove the role of Acetylcholine and GLP-1 in the Insulin secreting activity of B. Vulgaris. Increased glucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in the anti-hyperglycemic activity of B. Vulgaris.

  20. Colony stimulating factor 1 receptor inhibition delays recurrence of glioblastoma after radiation by altering myeloid cell recruitment and polarization.

    Science.gov (United States)

    Stafford, Jason H; Hirai, Takahisa; Deng, Lei; Chernikova, Sophia B; Urata, Kimiko; West, Brian L; Brown, J Martin

    2016-06-01

    Glioblastoma (GBM) may initially respond to treatment with ionizing radiation (IR), but the prognosis remains extremely poor because the tumors invariably recur. Using animal models, we previously showed that inhibiting stromal cell-derived factor 1 signaling can prevent or delay GBM recurrence by blocking IR-induced recruitment of myeloid cells, specifically monocytes that give rise to tumor-associated macrophages. The present study was aimed at determining if inhibiting colony stimulating factor 1 (CSF-1) signaling could be used as an alternative strategy to target pro-tumorigenic myeloid cells recruited to irradiated GBM. To inhibit CSF-1 signaling in myeloid cells, we used PLX3397, a small molecule that potently inhibits the tyrosine kinase activity of the CSF-1 receptor (CSF-1R). Combined IR and PLX3397 therapy was compared with IR alone using 2 different human GBM intracranial xenograft models. GBM xenografts treated with IR upregulated CSF-1R ligand expression and increased the number of CD11b+ myeloid-derived cells in the tumors. Treatment with PLX3397 both depleted CD11b+ cells and potentiated the response of the intracranial tumors to IR. Median survival was significantly longer for mice receiving combined therapy versus IR alone. Analysis of myeloid cell differentiation markers indicated that CSF-1R inhibition prevented IR-recruited monocyte cells from differentiating into immunosuppressive, pro-angiogenic tumor-associated macrophages. CSF-1R inhibition may be a promising strategy to improve GBM response to radiotherapy. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Glucose-stimulated prehepatic insulin secretion is associated with circulating alanine, triglyceride, glucagon, lactate and TNF-alpha in patients with HIV-lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, S B; Andersen, O; Pedersen, S B

    2006-01-01

    OBJECTIVES: We examined whether insulin-resistant lipodystrophic HIV-infected patients with known high fasting prehepatic insulin secretion rates (FISRs) displayed alterations in first-phase prehepatic insulin response to intravenous glucose (ISREG0-10 min). METHODS: Eighteen normoglycaemic...... lipodystrophic HIV-infected (LIPO) patients and 25 normoglycaemic nonlipodystrophic HIV-infected patients (controls) were included in the study. The prehepatic insulin secretion rate was estimated by deconvolution of C-peptide concentrations, and insulin sensitivity (SIRd) was estimated by the glucose clamp...... patients compared with controls. Three LIPO groups were identified arbitrarily according to their FISR and ISREG0-10 min values relative to those of controls. Four LIPO patients displayed high FISR [+3 standard deviations (SD), P

  2. Glucose Sensing

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    Topics in Fluorescence Spectroscopy, Glucose Sensing is the eleventh volume in the popular series Topics in Fluorescence Spectroscopy, edited by Drs. Chris D. Geddes and Joseph R. Lakowicz. This volume incorporates authoritative analytical fluorescence-based glucose sensing reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. Glucose Sensing is an essential reference for any lab working in the analytical fluorescence glucose sensing field. All academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in the continuously emerging field of glucose sensing, and diabetes care & management, will find this volume an invaluable resource. Topics in Fluorescence Spectroscopy Volume 11, Glucose Sensing Chapters include: Implantable Sensors for Interstitial Fluid Smart Tattoo Glucose Sensors Optical Enzyme-based Glucose Biosensors Plasmonic Glucose Sens...

  3. Aqueous fraction of Beta vulgaris ameliorates hyperglycemia in diabetic mice due to enhanced glucose stimulated insulin secretion, mediated by acetylcholine and GLP-1, and elevated glucose uptake via increased membrane bound GLUT4 transporters.

    Science.gov (United States)

    Ul Kabir, Ashraf; Samad, Mehdi Bin; Ahmed, Arif; Jahan, Mohammad Rajib; Akhter, Farjana; Tasnim, Jinat; Hasan, S M Nageeb; Sayfe, Sania Sarker; Hannan, J M A

    2015-01-01

    The study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris. Aqueous fraction of B. Vulgaris extract was the only active fraction (50mg/kg). Plasma insulin level was found to be the highest at 30 mins after B. Vulgaris administration at a dose of 200mg/kg. B. Vulgaris treated mice were also assayed for plasma Acetylcholine, Glucagon Like Peptide-1 (GLP-1), Gastric Inhibitory Peptide (GIP), Vasoactive Intestinal Peptide, Pituitary Adenylate Cyclase-Activating Peptide (PACAP), Insulin Like Growth Factor-1 (IGF-1), Pancreatic Polypeptides (PP), and Somatostatin, along with the corresponding insulin levels. Plasma Acetylcholine and GLP-1 significantly increased in B. Vulgaris treated animals and were further studied. Pharmacological enhancers, inhibitors, and antagonists of Acetylcholine and GLP-1 were also administered to the test animals, and corresponding insulin levels were measured. These studies confirmed the role of acetylcholine and GLP-1 in enhanced insulin secretion (ptransporters were quantified and the subsequent glucose uptake and glycogen synthesis were assayed. We showed that levels of membrane bound GLUT4 transporters, glucose-6-phosphate in skeletal myocytes, activity of glycogen synthase, and level of glycogen deposited in the skeletal muscles all increased (pglucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in the anti-hyperglycemic activity of B. Vulgaris.

  4. Glucose oxidation positively regulates glucose uptake and improves cardiac function recovery after myocardial reperfusion.

    Science.gov (United States)

    Li, Tingting; Xu, Jie; Qin, Xinghua; Hou, Zuoxu; Guo, Yongzheng; Liu, Zhenhua; Wu, Jianjiang; Zheng, Hong; Zhang, Xing; Gao, Feng

    2017-11-01

    Myocardial reperfusion decreases glucose oxidation and uncouples glucose oxidation from glycolysis. Therapies that increase glucose oxidation lessen myocardial ischemia-reperfusion (I/R) injury. However, the regulation of glucose uptake during reperfusion remains poorly understood. We found that glucose uptake was remarkably diminished in the myocardium following reperfusion in Sprague-Dawley rats as detected by 18 F-labeled and fluorescent-labeled glucose analogs, even though GLUT1 was upregulated by threefold and GLUT4 translocation remained unchanged compared with those of sham-treated rats. The decreased glucose uptake was accompanied by suppressed glucose oxidation. Interestingly, stimulating glucose oxidation by inhibition of pyruvate dehydrogenase kinase 4 (PDK4), a rate-limiting enzyme for glucose oxidation, increased glucose uptake and alleviated I/R injury. In vitro data in neonatal myocytes showed that PDK4 overexpression decreased glucose uptake, whereas its knockdown increased glucose uptake, suggesting that PDK4 has a role in regulating glucose uptake. Moreover, inhibition of PDK4 increased myocardial glucose uptake with concomitant enhancement of cardiac insulin sensitivity following myocardial I/R. These results showed that the suppressed glucose oxidation mediated by PDK4 contributes to the reduced glucose uptake in the myocardium following reperfusion, and enhancement of glucose uptake exerts cardioprotection. The findings suggest that stimulating glucose oxidation via PDK4 could be an efficient approach to improve recovery from myocardial I/R injury. Copyright © 2017 the American Physiological Society.

  5. Propionic acid and butyric acid inhibit lipolysis and de novo lipogenesis and increase insulin-stimulated glucose uptake in primary rat adipocytes.

    OpenAIRE

    Heimann, Emilia; Nyman, Margareta; Degerman, Eva

    2015-01-01

    Fermentation of dietary fibers by colonic microbiota generates short-chain fatty acids (SCFAs), e.g., propionic acid and butyric acid, which have been described to have "anti-obesity properties" by ameliorating fasting glycaemia, body weight and insulin tolerance in animal models. In the present study, we therefore investigate if propionic acid and butyric acid have effects on lipolysis, de novo lipogenesis and glucose uptake in primary rat adipocytes. We show that both propionic ac...

  6. Noninvasive imaging oral absorption of insulin delivered by nanoparticles and its stimulated glucose utilization in controlling postprandial hyperglycemia during OGTT in diabetic rats.

    Science.gov (United States)

    Chuang, Er-Yuan; Lin, Kun-Ju; Su, Fang-Yi; Mi, Fwu-Long; Maiti, Barnali; Chen, Chiung-Tong; Wey, Shiaw-Pyng; Yen, Tzu-Chen; Juang, Jyuhn-Huarng; Sung, Hsing-Wen

    2013-12-10

    This work examined the feasibility of preparing a pH-responsive nanoparticle (NP) system composed of chitosan and poly(γ-glutamic acid) conjugated with ethylene glycol tetraacetic acid (γPGA-EGTA) for oral insulin delivery in diabetic rats during an oral glucose tolerance test (OGTT). OGTT has been used largely as a model to mimic the period that comprises and follows a meal, which is often associated with postprandial hyperglycemia. Based on Förster resonance energy transfer (FRET), this work also demonstrated the ability of γPGA-EGTA to protect insulin from an intestinal proteolytic attack in living rats, owing to its ability to deprive the environmental calcium. Additionally, EGTA-conjugated NPs were effective in disrupting the epithelial tight junctions, consequently facilitating the paracellular permeation of insulin throughout the entire small intestine. Moreover, results of positron emission tomography and computer tomography demonstrated the effective absorption of the permeated insulin into the systemic circulation as well as promotion of the glucose utilization in the myocardium, and skeletal muscles of the chest wall, forelimbs and hindlimbs, resulting in a significant glucose-lowering effect. Above results indicate that as-prepared EGTA-conjugated NPs are a promising oral insulin delivery system to control postprandial hyperglycemia and thus may potentially prevent the related diabetic complications. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Contraction-mediated glucose uptake is increased in men with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Skov-Jensen, Camilla; Skovbro, Mette; Flint, Anne

    2007-01-01

    stimulation alone and with superimposed exercise. Patients with type 2 diabetes, subjects with impaired glucose tolerance (IGT), healthy controls, and endurance-trained subjects were studied. The groups were matched for age and lean body mass (LBM), and differed in peak oxygen uptake (VO2 peak), body fat......Exercise superimposed on insulin stimulation is shown to increase muscle glucose metabolism and these two stimuli have synergistic effects. The objective of this study was to investigate glucose infusion rates (GIR) in groups with a wide variation in terms of insulin sensitivity during insulin...... on insulin stimulation. Humans with IGT are resistant to insulin-stimulated but not to exercise-induced glucose uptake....

  8. Proximal tubule-derived colony stimulating factor-1 mediates polarization of renal macrophages and dendritic cells, and recovery in acute kidney injury.

    Science.gov (United States)

    Wang, Yinqiu; Chang, Jian; Yao, Bing; Niu, Aolei; Kelly, Emily; Breeggemann, Matthew C; Abboud Werner, Sherry L; Harris, Raymond C; Zhang, Ming-Zhi

    2015-12-01

    Infiltrating cells play an important role in both the development of and recovery from acute kidney injury (AKI). Macrophages and renal dendritic cells are of particular interest because they can exhibit distinctly different functional phenotypes, broadly characterized as proinflammatory (M1) or tissue reparative (M2). Resident renal macrophages and dendritic cells participate in recovery from AKI in response to either ischemia/reperfusion or a model of selective proximal tubule injury induced by diphtheria-toxin-induced apoptosis in transgenic mice expressing the human diphtheria toxin receptor on proximal tubule cells. Colony-stimulating factor-1 (CSF-1) is an important factor mediating the recovery from AKI, and CSF-1 can stimulate macrophage and dendritic cell proliferation and polarization during the recovery phase of AKI. The kidney, and specifically the proximal tubule, is a major source of intrarenal CSF-1 production in response to AKI. We induced selective deletion of proximal tubule CSF-1 to determine its role in expansion and proliferation of renal macrophages and dendritic cells and in recovery from AKI. In both models of AKI, there was decreased M2 polarization, delayed functional and structural recovery, and increased tubulointerstitial fibrosis. Thus, intrarenal CSF-1 is an important mediator of macrophage/dendritic cell polarization and recovery from AKI.

  9. Deletion of CDKAL1 affects high-fat diet-induced fat accumulation and glucose-stimulated insulin secretion in mice, indicating relevance to diabetes.

    Directory of Open Access Journals (Sweden)

    Tadashi Okamura

    Full Text Available BACKGROUND/OBJECTIVE: The CDKAL1 gene is among the best-replicated susceptibility loci for type 2 diabetes, originally identified by genome-wide association studies in humans. To clarify a physiological importance of CDKAL1, we examined effects of a global Cdkal1-null mutation in mice and also evaluated the influence of a CDKAL1 risk allele on body mass index (BMI in Japanese subjects. METHODS: In Cdkal1-deficient (Cdkal1⁻/⁻ mice, we performed oral glucose tolerance test, insulin tolerance test, and perfusion experiments with and without high-fat feeding. Based on the findings in mice, we tested genetic association of CDKAL1 variants with BMI, as a measure of adiposity, and type 2 diabetes in Japanese. PRINCIPAL FINDINGS: On a standard diet, Cdkal1⁻/⁻ mice were modestly lighter in weight than wild-type littermates without major alterations in glucose metabolism. On a high fat diet, Cdkal1⁻/⁻ mice showed significant reduction in fat accumulation (17% reduction in %intraabdominal fat, P = 0.023 vs. wild-type littermates with less impaired insulin sensitivity at an early stage. High fat feeding did not potentiate insulin secretion in Cdkal1⁻/⁻ mice (1.0-fold, contrary to the results in wild-type littermates (1.6-fold, P<0.01. Inversely, at a later stage, Cdkal1⁻/⁻ mice showed more prominent impairment of insulin sensitivity and glucose tolerance. mRNA expression analysis indicated that Scd1 might function as a critical mediator of the altered metabolism in Cdkal1⁻/⁻ mice. In accordance with the findings in mice, a nominally significant (P<0.05 association between CDKAL1 rs4712523 and BMI was replicated in 2 Japanese general populations comprising 5,695 and 12,569 samples; the risk allele for type 2 diabetes was also associated with decreased BMI. CONCLUSIONS: Cdkal1 gene deletion is accompanied by modestly impaired insulin secretion and longitudinal fluctuations in insulin sensitivity during high-fat feeding in mice

  10. Both Fasting and Glucose-Stimulated Proinsulin Levels Predict Hyperglycemia and Incident Type 2 Diabetes: A Population-Based Study of 9,396 Finnish Men

    OpenAIRE

    Jagadish Vangipurapu; Alena Stančáková; Teemu Kuulasmaa; Johanna Kuusisto; Markku Laakso

    2015-01-01

    Background Hyperproinsulinemia is an indicator of ?-cell dysfunction, and fasting proinsulin levels are elevated in patients with hyperglycemia. It is not known whether proinsulin levels after a glucose load are better predictors of hyperglycemia and type 2 diabetes than fasting proinsulin. Methods Participants were 9,396 Finnish men (mean?SD, age 57.3?7.1 years, BMI 27.0?4.0 kg/m2) of the population-based METabolic Syndrome In Men Study who were non-diabetic at the recruitment, and who parti...

  11. The change in cerebral glucose metabolism after electroacupuncture: a possible marker to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa

    OpenAIRE

    Liu, Tao-Tao; Hong, Qing-Xiong; Xiang, Hong-Bing

    2015-01-01

    Some reports have demonstrated that deep brain stimulation (DBS) is a promising treatment for patients who suffer from intractable anorexia nervosa. However, the nature of DBS may not be viewed as a standard clinical treatment option for anorexia nervosa because of the unpredictable outcome before DBS. Just like DBS in the brain, electroacupuncture at acupoints is also efficient in treating refractory anorexia nervosa. Some neuroimaging studies using functional magnetic resonance imaging, sin...

  12. Insulin-stimulated glucose uptake and pathways regulating energy metabolism in skeletal muscle cells: the effects of subcutaneous and visceral fat, and long-chain saturated, n-3 and n-6 polyunsaturated fatty acids.

    Science.gov (United States)

    Lam, Y Y; Hatzinikolas, G; Weir, J M; Janovská, A; McAinch, A J; Game, P; Meikle, P J; Wittert, G A

    2011-01-01

    The study aims to determine the effect of long-chain saturated and polyunsaturated (PUFA) fatty acids, specifically palmitic acid (PA; 16:0), docosahexaenoic acid (DHA; 22:6n-3) and linoleic acid (LA; 18:2n-6), and their interactions with factors from adipose tissue, on insulin sensitivity and lipid metabolism in skeletal muscle. L6 myotubes were cultured with PA, DHA or LA (0.4mmol/l), with or without conditioned media from human subcutaneous (SC) and visceral (IAB) fat. Insulin-stimulated glucose uptake, lipid content, mRNA expression of key genes involved in nutrient utilization and protein expression of inhibitor protein inhibitor kappa B (IκB)-α and mammalian target of rapamycin (mTOR) were measured. PA and IAB fat reduced insulin-stimulated glucose uptake and their combined effect was similar to that of PA alone. PA-induced insulin resistance was ameliorated by inhibiting the de novo synthesis of ceramide, IκBα degradation or mTOR activation. The PA effect was also partially reversed by DHA and completely by LA in the presence of SC fat. PA increased diacylglycerol content, which was reduced by LA and to a greater extent when either IAB or SC fat was also present. PA increased SCD1 whereas DHA and LA increased AMPKα2 mRNA. In the presence of SC or IAB fat, the combination of PA with either DHA or LA decreased SCD1 and increased AMPKα2 mRNA. PA-induced insulin resistance in skeletal muscle involves inflammatory (nuclear factor kappa B/mTOR) and nutrient (ceramide) pathways. PUFAs promote pathways, at a transcriptional level, that increase fat oxidation and synergize with factors from SC fat to abrogate PA-induced insulin resistance. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Glucose-induced insulin resistance of skeletal-muscle glucose transport and uptake

    DEFF Research Database (Denmark)

    Richter, Erik; Hansen, B F; Hansen, S A

    1988-01-01

    , impairment of insulin action on muscle glucose transport and uptake. Thus maximal insulin-stimulated glucose uptake at 12 mM-glucose decreased from 34.8 +/- 1.9 to 11.5 +/- 1.1 mumol/h per g (mean +/- S.E.M., n = 10) during 5 h perfusion. This decrease in glucose uptake was accompanied by a similar change...... in the presence of glucose and insulin. The data indicate that exposure to a moderately increased glucose concentration (12 mM) leads to rapidly developing resistance of skeletal-muscle glucose transport and uptake to maximal insulin stimulation. The effect of glucose is enhanced by simultaneous insulin exposure......, whereas exposure for 5 h to insulin itself does not cause measurable resistance to maximal insulin stimulation....

  14. Glucose Stimulates GLP-1 Secretion from Isolated Perfused Rat Small Intestine by SGLT1 and GLUT2 Mediated Uptake, Causing V-gated Calcium Channel Activation

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Frost, Charlotte Rasmussen; Svendsen, Berit

    2014-01-01

    inhibition (1 mM phloretin) (Glu. 13.94 ± 2.5 vs. 30.90 ± 10.9 pM, Glu.+PT: 12.44 ± 1.3 vs. 17.18 ± 3.4 pM, P > 0.0001, n = 6), and KATP-channel closure by two sulfonylurea drugs stimulated GLP-1 release (tolbutamide: 14.7 ± 0.2 vs. 28.6 ± 5.2 pM; gliclazide: 15.2 ± 0.3 vs. 24.6 ± 2.4 pM, P

  15. Alterations of serum concentrations of thyroid hormones and sex hormone-binding globulin, nuclear binding of tri-iodothyronine and thyroid hormone-stimulated cellular uptake of oxygen and glucose in mononuclear blood cells from patients with non-thyroidal illness

    DEFF Research Database (Denmark)

    Kvetny, J; Matzen, L

    1990-01-01

    Nuclear tri-iodothyronine (T3) binding and thyroid hormone-stimulated oxygen consumption and glucose uptake were examined in mononuclear blood cells from patients with non-thyroidal illness (NTI) in which serum T3 was significantly (P less than 0.05) depressed (0.62 +/- 0.12 (S.D.) nmol/l) compared...... which tend to maintain intracellular homeostasis....

  16. Loss of 50% of excess weight using a very low energy diet improves insulin-stimulated glucose disposal and skeletal muscle insulin signalling in obese insulin-treated type 2 diabetic patients

    NARCIS (Netherlands)

    Jazet, I. M.; Schaart, G.; Gastaldelli, A.; Ferrannini, E.; Hesselink, M. K.; Schrauwen, P.; Romijn, J. A.; Maassen, J. A.; Pijl, H.; Ouwens, D. M.; Meinders, A. E.

    2008-01-01

    Both energy restriction (ER) per se and weight loss improve glucose metabolism in obese insulin-treated type 2 diabetic patients. Short-term ER decreases basal endogenous glucose production (EGP) but not glucose disposal. In contrast the blood glucose-lowering mechanism of long-term ER with

  17. Baccharis dracunculifolia methanol extract enhances glucose-stimulated insulin secretion in pancreatic islets of monosodium glutamate induced-obesity model rats.

    Science.gov (United States)

    Hocayen, Palloma de A S; Grassiolli, Sabrina; Leite, Nayara C; Pochapski, Márcia T; Pereira, Ricardo A; da Silva, Luiz A; Snack, Andre L; Michel, R Garcia; Kagimura, Francini Y; da Cunha, Mário A A; Malfatti, Carlos R M

    2016-07-01

    Obesity is the main risk factor for type 2 diabetes mellitus. Secondary metabolites with biological activities and pharmacological potential have been identified in species of the Baccharis genus that are specifically distributed in the Americas. This study evaluated the effects of methanol extracts from Baccharis dracunculifolia DC. Asteraceae on metabolic parameters, satiety, and growth in monosodium glutamate (MSG) induced-obesity model rats. MSG was administered to 32 newborn rats (4 mg/g of body weight) once daily for 5 consecutive days. Four experimental groups (control, control + extract, MSG, and MSG + extract) were treated for 30 consecutive days with 400 mg/kg of B. dracunculifolia extract by gavage. Biochemical parameters, antioxidant activity, total extract phenolic content (methanolic, ethanolic, and acetone extractions), and pancreatic islets were evaluated. High levels of phenolic compounds were identified in B. dracunculifolia extracts (methanol: 46.2 ± 0.4 mg GAE/L; acetate: 70.5 ± 0.5 mg GAE/L; and ethanol: 30.3 ± 0.21 mg GAE/L); high antioxidant activity was detected in B. dracunculifolia ethanol and methanol extracts. The concentration of serum insulin increased 30% in obese animals treated with extract solutions (1.4-2.0 µU/mL, p < 0.05). Insulin secretion in pancreatic islets was 8.3 mM glucose (58%, p < 0.05) and 16.7 mM (99.5%, p < 0.05) in rats in the MSG + extract and MSG groups, respectively. Treatment with B. dracunculifolia extracts protected pancreatic islets and prevented the irreversible cellular damage observed in animals in obesity and diabetes models.

  18. Inhibition of the colony-stimulating-factor-1 receptor affects the resistance of lung cancer cells to cisplatin.

    Science.gov (United States)

    Pass, Harvey I; Lavilla, Carmencita; Canino, Claudia; Goparaju, Chandra; Preiss, Jordan; Noreen, Samrah; Blandino, Giovanni; Cioce, Mario

    2016-08-30

    In the present work we show that multiple lung cancer cell lines contain cisplatin resistant cell subpopulations expressing the Colony-Stimulating-Factor-Receptor-1 (CSF-1R) and surviving chemotherapy-induced stress. By exploiting siRNA-mediated knock down in vitro and the use of an investigational CSF-1R TKI (JNJ-40346527) in vitro and in vivo, we show that expression and function of the receptor are required for the clonogenicity and chemoresistance of the cell lines. Thus, inhibition of the kinase activity of the receptor reduced the levels of EMT-associated genes, stem cell markers and chemoresistance genes. Additionally, the number of high aldehyde dehydrogenase (ALDH) expressing cells was reduced, consequent to the lack of cisplatin-induced increase of ALDH isoforms. This affected the collective chemoresistance of the treated cultures. Treatment of tumor bearing mice with JNJ-40346527, at pharmacologically relevant doses, produced strong chemo-sensitizing effects in vivo. These anticancer effects correlated with a reduced number of CSF-1Rpos cells, in tumors excised from the treated mice. Depletion of the CD45pos cells within the treated tumors did not, apparently, play a major role in mediating the therapeutic response to the TKI. Thus, lung cancer cells express a functional CSF-1 and CSF-1R duo which mediates pro-tumorigenic effects in vivo and in vitro and can be targeted in a therapeutically relevant way. These observations complement the already known role for the CSF-1R at mediating the pro-tumorigenic properties of tumor-infiltrating immune components.

  19. Functional involvement of protein kinase C-betaII and its substrate, myristoylated alanine-rich C-kinase substrate (MARCKS), in insulin-stimulated glucose transport in L6 rat skeletal muscle cells.

    Science.gov (United States)

    Chappell, D S; Patel, N A; Jiang, K; Li, P; Watson, J E; Byers, D M; Cooper, D R

    2009-05-01

    Insulin stimulates phosphorylation cascades, including phosphatidylinositol-3-kinase (PI3K), phosphatidylinositol-dependent kinase (PDK1), Akt, and protein kinase C (PKC). Myristoylated alanine-rich C-kinase substrate (MARCKS), a PKCbetaII substrate, could link the effects of insulin to insulin-stimulated glucose transport (ISGT) via phosphorylation of its effector domain since MARCKS has a role in cytoskeletal rearrangements. We examined phosphoPKCbetaII after insulin treatment of L6 myocytes, and cytosolic and membrane phosphoMARCKS, MARCKS and phospholipase D1 in cells pretreated with LY294002 (PI3K inhibitor), CG53353 (PKCbetaII inhibitor) or W13 (calmodulin inhibitor), PI3K, PKCbetaII and calmodulin inhibitors, respectively, before insulin treatment, using western blots. ISGT was examined after cells had been treated with inhibitors, small inhibitory RNA (siRNA) for MARCKS, or transfection with MARCKS mutated at a PKC site. MARCKS, PKCbetaII, GLUT4 and insulin receptor were immunoblotted in subcellular fractions with F-actin antibody immunoprecipitates to demonstrate changes following insulin treatment. GLUT4 membrane insertion was followed after insulin with or without CG53353. Insulin increased phosphoPKCbetaII(Ser660 and Thr641); LY294002 blocked this, indicating its activation by PI3K. Insulin treatment increased cytosolic phosphoMARCKS, decreased membrane MARCKS and increased membrane phospholipase D1 (PLD1), a protein regulating glucose transporter vesicle fusion resulted. PhosphoMARCKS was attenuated by CG53353 or MARCKS siRNA. MARCKS siRNA blocked ISGT. Association of PKCbetaII and GLUT4 with membrane F-actin was enhanced by insulin, as was that of cytosolic and membrane MARCKS. ISGT was attenuated in myocytes transfected with mutated MARCKS (Ser152Ala), whereas overproduction of wild-type MARCKS enhanced ISGT. CG53353 blocked insertion of GLUT4 into membranes of insulin treated cells. The results suggest that PKCbetaII is involved in mediating

  20. Salivary Glucose Concentration and Excretion in Normal and Diabetic Subjects

    OpenAIRE

    Jurysta, Cedric; Bulur, Nurdan; Oguzhan, Berrin; Satman, Ilhan; Yilmaz, Temel M.; Malaisse, Willy J.; Sener, Abdullah

    2009-01-01

    The present report aims mainly at a reevaluation of salivary glucose concentration and excretion in unstimulated and mechanically stimulated saliva in both normal and diabetic subjects. In normal subjects, a decrease in saliva glucose concentration, an increase in salivary flow, but an unchanged glucose excretion rate were recorded when comparing stimulated saliva to unstimulated saliva. In diabetic patients, an increase in salivary flow with unchanged salivary glucose concentration and gluco...

  1. Blood Test: Glucose

    Science.gov (United States)

    ... Videos for Educators Search English Español Blood Test: Glucose KidsHealth / For Parents / Blood Test: Glucose What's in ... liver or kidneys) is working. What Is a Glucose Test? A glucose test measures how much glucose ...

  2. Blood Glucose Monitoring Devices

    Science.gov (United States)

    ... In Vitro Diagnostics Blood Glucose Monitoring Devices Blood Glucose Monitoring Devices Share Tweet Linkedin Pin it More ... care settings to measure the amount of sugar (glucose) in your blood. What is glucose? Glucose is ...

  3. Macrophage colony-stimulating factor and its receptor signaling augment glycated albumin-induced retinal microglial inflammation in vitro

    Directory of Open Access Journals (Sweden)

    Jiang Chun H

    2011-01-01

    Full Text Available Abstract Background Microglial activation and the proinflammatory response are controlled by a complex regulatory network. Among the various candidates, macrophage colony-stimulating factor (M-CSF is considered an important cytokine. The up-regulation of M-CSF and its receptor CSF-1R has been reported in brain disease, as well as in diabetic complications; however, the mechanism is unclear. An elevated level of glycated albumin (GA is a characteristic of diabetes; thus, it may be involved in monocyte/macrophage-associated diabetic complications. Results The basal level of expression of M-CSF/CSF-1R was examined in retinal microglial cells in vitro. Immunofluorescence, real-time PCR, immunoprecipitation, and Western blot analyses revealed the up-regulation of CSF-1R in GA-treated microglial cells. We also detected increased expression and release of M-CSF, suggesting that the cytokine is produced by activated microglia via autocrine signaling. Using an enzyme-linked immunosorbent assay, we found that GA affects microglial activation by stimulating the release of tumor necrosis factor-α and interleukin-1β. Furthermore, the neutralization of M-CSF or CSF-1R with antibodies suppressed the proinflammatory response. Conversely, this proinflammatory response was augmented by the administration of M-CSF. Conclusions We conclude that GA induces microglial activation via the release of proinflammatory cytokines, which may contribute to the inflammatory pathogenesis of diabetic retinopathy. The increased microglial expression of M-CSF/CSF-1R not only is a response to microglial activation in diabetic retinopathy but also augments the microglial inflammation responsible for the diabetic microenvironment.

  4. Glucose-dependent insulinotropic polypeptide directly induces glucose transport in rat skeletal muscle.

    Science.gov (United States)

    Snook, Laelie A; Nelson, Emery M; Dyck, David J; Wright, David C; Holloway, Graham P

    2015-08-01

    Several gastrointestinal proteins have been identified to have insulinotropic effects, including glucose-dependent insulinotropic polypeptide (GIP); however, the direct effects of incretins on skeletal muscle glucose transport remain largely unknown. Therefore, the purpose of the current study was to examine the role of GIP on skeletal muscle glucose transport and insulin signaling in rats. Relative to a glucose challenge, a mixed glucose+lipid oral challenge increased circulating GIP concentrations, skeletal muscle Akt phosphorylation, and improved glucose clearance by ∼35% (P muscle preparation, GIP directly stimulated glucose transport and increased GLUT4 accumulation on the plasma membrane in the absence of insulin. Moreover, the ability of GIP to stimulate glucose transport was mitigated by the addition of the PI 3-kinase (PI3K) inhibitor wortmannin, suggesting that signaling through PI3K is required for these responses. We also provide evidence that the combined stimulatory effects of GIP and insulin on soleus muscle glucose transport are additive. However, the specific GIP receptor antagonist (Pro(3))GIP did not attenuate GIP-stimulated glucose transport, suggesting that GIP is not signaling through its classical receptor. Together, the current data provide evidence that GIP regulates skeletal muscle glucose transport; however, the exact signaling mechanism(s) remain unknown. Copyright © 2015 the American Physiological Society.

  5. A point mutation at tyrosine-809 in the human colony-stimulating factor 1 receptor impairs mitogenesis without abrogating tyrosine kinase activity, association with phosphatidylinositol 3-kinase, or induction of c-fos and junB genes

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, M.F. (Univ. of Tennessee, Memphis (USA)); Shurtleff, S.A.; Downing, J.R. (Saint Jude Children' s Research Hospital, Memphis, TN (USA)); Sherr, C.J. (Univ. of Tennessee College of Medicine, Memphis (USA) Saint Jude Children' s Research Hospital, Memphis, TN (USA))

    1990-09-01

    Substitution of phenylalanine for tyrosine-809 in the human colony-stimulating factor 1 receptor (CSF-1R) inhibited its ability to transduce ligand-dependent mitogenic signals in mouse NIH 3T3 cells. When combined with an activating mutation at codon 301 that induces constitutive CSF-1R tyrosine kinase activity, the codon 809 mutation suppressed ligand-independent cell transformation. Comparative mapping tryptic phosphopeptides from mutant and wild-type CSF-1R indicated that tyrosine-809 is a site of ligand-dependent receptor phosphorylation in vivo. The mutant receptor was active as a tyrosine kinase in vitro and in vivo, underwent CSF-1-dependent association with a phosphatidylinositol 3-kinase, and induced expression of the protooncogenes c-fos and junB, underscoring its ability to trigger some of the known cellular responses to CSF-1. The mutant receptor is likely to be impaired in its ability to interact with critical cellular effectors whose activity is required for mitogenesis.

  6. Green Tea Polyphenols Precondition against Cell Death Induced by Oxygen-Glucose Deprivation via Stimulation of Laminin Receptor, Generation of Reactive Oxygen Species, and Activation of Protein Kinase Cϵ

    Science.gov (United States)

    Gundimeda, Usha; McNeill, Thomas H.; Elhiani, Albert A.; Schiffman, Jason E.; Hinton, David R.; Gopalakrishna, Rayudu

    2012-01-01

    As the development of synthetic drugs for the prevention of stroke has proven challenging, utilization of natural products capable of preconditioning neuronal cells against ischemia-induced cell death would be a highly useful complementary approach. In this study using an oxygen-glucose deprivation and reoxygenation (OGD/R) model in PC12 cells, we show that 2-day pretreatment with green tea polyphenols (GTPP) and their active ingredient, epigallocatechin-3-gallate (EGCG), protects cells from subsequent OGD/R-induced cell death. A synergistic interaction was observed between GTPP constituents, with unfractionated GTPP more potently preconditioning cells than EGCG. GTPP-induced preconditioning required the 67-kDa laminin receptor (67LR), to which EGCG binds with high affinity. 67LR also mediated the generation of reactive oxygen species (ROS) via activation of NADPH oxidase. An exogenous ROS-generating system bypassed 67LR to induce preconditioning, suggesting that sublethal levels of ROS are indeed an important mediator in GTPP-induced preconditioning. This role for ROS was further supported by the fact that antioxidants blocked GTPP-induced preconditioning. Additionally, ROS induced an activation and translocation of protein kinase C (PKC), particularly PKCϵ from the cytosol to the membrane/mitochondria, which was also blocked by antioxidants. The crucial role of PKC in GTPP-induced preconditioning was supported by use of its specific inhibitors. Preconditioning was increased by conditional overexpression of PKCϵ and decreased by its knock-out with siRNA. Collectively, these results suggest that GTPP stimulates 67LR and thereby induces NADPH oxidase-dependent generation of ROS, which in turn induces activation of PKC, particularly prosurvival isoenzyme PKCϵ, resulting in preconditioning against cell death induced by OGD/R. PMID:22879598

  7. Increased muscle glucose uptake after exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Ploug, Thorkil; Galbo, Henrik

    1985-01-01

    It has recently been shown that insulin sensitivity of skeletal muscle glucose uptake and glycogen synthesis is increased after a single exercise session. The present study was designed to determine whether insulin is necessary during exercise for development of these changes found after exercise....... Diabetic rats and controls ran on a treadmill and their isolated hindquarters were subsequently perfused at insulin concentrations of 0, 100, and 20,000 microU/ml. Exercise increased insulin sensitivity of glucose uptake and glycogen synthesis equally in diabetic and control rats, but insulin...... responsiveness of glucose uptake was noted only in controls. Analysis of intracellular glucose-6-phosphate, glucose, glycogen synthesis, and glucose transport suggested that the exercise effect on responsiveness might be due to enhancement of glucose disposal. After electrical stimulation of diabetic...

  8. Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

    DEFF Research Database (Denmark)

    Ploug, T; Stallknecht, B M; Pedersen, O

    1990-01-01

    exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training...... session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold...... number of glucose transporters....

  9. Role of the glucose-sensing receptor in insulin secretion.

    Science.gov (United States)

    Kojima, Itaru; Medina, Johan; Nakagawa, Yuko

    2017-09-01

    Glucose is a primary stimulator of insulin secretion. It has been thought that glucose exerts its effect by a mechanism solely dependent on glucose metabolism. We show here that glucose induces rapid Ca2+ and cyclic AMP signals in β-cells. These rapid signals are independent of glucose-metabolism and are reproduced by non-metabolizable glucose analogues. These results led us to postulate that glucose activates a cell-surface receptor, namely the glucose-sensing receptor. Rapid signals induced by glucose are blocked by inhibition of a sweet taste receptor subunit T1R3 and a calcium-sensing receptor subunit CaSR. In accordance with these observations, T1R3 and CaSR form a heterodimer. In addition, a heterodimer of T1R3 and CaSR is activated by glucose. These results suggest that a heterodimer of T1R3 and CaSR is a major component of the glucose-sensing receptor. When the glucose-sensing receptor is blocked, glucose-induced insulin secretion is inhibited. Also, ATP production is significantly attenuated by the inhibition of the receptor. Conversely, stimulation of the glucose-sensing receptor by either artificial sweeteners or non-metabolizable glucose analogue increases ATP. Hence, the glucose-sensing receptor signals promote glucose metabolism. Collectively, glucose activates the cell-surface glucose-sensing receptor and promotes its own metabolism. Glucose then enters the cells and is metabolized through already activated metabolic pathways. The glucose-sensing receptor is a key molecule regulating the action of glucose in β-cells. © 2017 John Wiley & Sons Ltd.

  10. Stimulatory effect of insulin on glucose uptake by muscle involves the central nervous system in insulin-sensitive mice

    NARCIS (Netherlands)

    Coomans, C.P.; Biermasz, N.R.; Geerling, J.J.; Guigas, B.; Rensen, P.C.N.; Havekes, L.M.; Romijn, J.A.

    2011-01-01

    OBJECTIVE - Insulin inhibits endogenous glucose production (EGP) and stimulates glucose uptake in peripheral tissues. Hypothalamic insulin signaling is required for the inhibitory effects of insulin on EGP. We examined the contribution of central insulin signaling on circulating insulin-stimulated

  11. Modulation of glucose uptake in adipose tissue by nitric oxide ...

    Indian Academy of Sciences (India)

    Madhu

    We hypothesized that increased NO generated from its donors may alter basal and/or insulin-stimulated glucose uptake in adipose tissues of both normoglycaemic and diabetic rats. To test this hypothesis, we investigated the effect of GSNO and SNAP on basal and insulin-stimulated glucose uptake in isolated adipocytes.

  12. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming

    Science.gov (United States)

    Choi, Kevin

    2015-01-01

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg−1·min−1 and boost glucose disposal to 40.1 ± 13 μmol·kg−1·min−1. These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. PMID:26719305

  13. General aspects of muscle glucose uptake

    Directory of Open Access Journals (Sweden)

    RAFAEL O. ALVIM

    2015-03-01

    Full Text Available Glucose uptake in peripheral tissues is dependent on the translocation of GLUT4 glucose transporters to the plasma membrane. Studies have shown the existence of two major signaling pathways that lead to the translocation of GLUT4. The first, and widely investigated, is the insulin activated signaling pathway through insulin receptor substrate-1 and phosphatidylinositol 3-kinase. The second is the insulin-independent signaling pathway, which is activated by contractions. Individuals with type 2 diabetes mellitus have reduced insulin-stimulated glucose uptake in skeletal muscle due to the phenomenon of insulin resistance. However, those individuals have normal glucose uptake during exercise. In this context, physical exercise is one of the most important interventions that stimulates glucose uptake by insulin-independent pathways, and the main molecules involved are adenosine monophosphate-activated protein kinase, nitric oxide, bradykinin, AKT, reactive oxygen species and calcium. In this review, our main aims were to highlight the different glucose uptake pathways and to report the effects of physical exercise, diet and drugs on their functioning. Lastly, with the better understanding of these pathways, it would be possible to assess, exactly and molecularly, the importance of physical exercise and diet on glucose homeostasis. Furthermore, it would be possible to assess the action of drugs that might optimize glucose uptake and consequently be an important step in controlling the blood glucose levels in diabetic patients, in addition to being important to clarify some pathways that justify the development of drugs capable of mimicking the contraction pathway.

  14. Neuroscience of glucose homeostasis

    NARCIS (Netherlands)

    La Fleur, S E; Fliers, E; Kalsbeek, A

    2014-01-01

    Plasma glucose concentrations are homeostatically regulated and maintained within strict boundaries. Several mechanisms are in place to increase glucose output when glucose levels in the circulation drop as a result of glucose utilization, or to decrease glucose output and increase tissue glucose

  15. Salivary glucose concentration and excretion in normal and diabetic subjects.

    Science.gov (United States)

    Jurysta, Cedric; Bulur, Nurdan; Oguzhan, Berrin; Satman, Ilhan; Yilmaz, Temel M; Malaisse, Willy J; Sener, Abdullah

    2009-01-01

    The present report aims mainly at a reevaluation of salivary glucose concentration and excretion in unstimulated and mechanically stimulated saliva in both normal and diabetic subjects. In normal subjects, a decrease in saliva glucose concentration, an increase in salivary flow, but an unchanged glucose excretion rate were recorded when comparing stimulated saliva to unstimulated saliva. In diabetic patients, an increase in salivary flow with unchanged salivary glucose concentration and glucose excretion rate were observed under the same experimental conditions. Salivary glucose concentration and excretion were much higher in diabetic patients than in control subjects, whether in unstimulated or stimulated saliva. No significant correlation between glycemia and either glucose concentration or glucose excretion rate was found in the diabetic patients, whether in unstimulated or stimulated saliva. In the latter patients, as compared to control subjects, the relative magnitude of the increase in saliva glucose concentration was comparable, however, to that of blood glucose concentration. The relationship between these two variables was also documented in normal subjects and diabetic patients undergoing an oral glucose tolerance test.

  16. Increased muscle glucose uptake during contractions

    DEFF Research Database (Denmark)

    Ploug, Thorkil; Galbo, Henrik; Richter, Erik

    1984-01-01

    We reinvestigated the prevailing concept that muscle contractions only elicit increased muscle glucose uptake in the presence of a so-called "permissive" concentration of insulin (Berger et al., Biochem. J. 146: 231-238, 1975; Vranic and Berger, Diabetes 28: 147-163, 1979). Hindquarters from rats...... in severe ketoacidosis were perfused with a perfusate containing insulin antiserum. After 60 min perfusion, electrical stimulation increased glucose uptake of the contracting muscles fivefold. Also, subsequent contractions increased glucose uptake in hindquarters from nondiabetic rats perfused for 1.5 h......-methylglucose uptake increased during contractions and glucose uptake was negative at rest and zero during contractions. An increase in muscle transport and uptake of glucose during contractions does not require the presence of insulin. Furthermore, glucose transport in contracting muscle may only increase if glycogen...

  17. An Epstein-Barr virus encoded inhibitor of Colony Stimulating Factor-1 signaling is an important determinant for acute and persistent EBV infection.

    Directory of Open Access Journals (Sweden)

    Makoto Ohashi

    2012-12-01

    Full Text Available Acute Epstein-Barr virus (EBV infection is the most common cause of Infectious Mononucleosis. Nearly all adult humans harbor life-long, persistent EBV infection which can lead to development of cancers including Hodgkin Lymphoma, Burkitt Lymphoma, nasopharyngeal carcinoma, gastric carcinoma, and lymphomas in immunosuppressed patients. BARF1 is an EBV replication-associated, secreted protein that blocks Colony Stimulating Factor 1 (CSF-1 signaling, an innate immunity pathway not targeted by any other virus species. To evaluate effects of BARF1 in acute and persistent infection, we mutated the BARF1 homologue in the EBV-related herpesvirus, or lymphocryptovirus (LCV, naturally infecting rhesus macaques to create a recombinant rhLCV incapable of blocking CSF-1 (ΔrhBARF1. Rhesus macaques orally challenged with ΔrhBARF1 had decreased viral load indicating that CSF-1 is important for acute virus infection. Surprisingly, ΔrhBARF1 was also associated with dramatically lower virus setpoints during persistent infection. Normal acute viral load and normal viral setpoints during persistent rhLCV infection could be restored by Simian/Human Immunodeficiency Virus-induced immunosuppression prior to oral inoculation with ΔrhBARF1 or infection of immunocompetent animals with a recombinant rhLCV where the rhBARF1 was repaired. These results indicate that BARF1 blockade of CSF-1 signaling is an important immune evasion strategy for efficient acute EBV infection and a significant determinant for virus setpoint during persistent EBV infection.

  18. Inducible transgenes under the control of the hCD68 promoter identifies mouse macrophages with a distribution that differs from the F4/80 - and CSF-1R-expressing populations.

    Science.gov (United States)

    Pillai, Manoj M; Hayes, Brian; Torok-Storb, Beverly

    2009-12-01

    Macrophages are critical components of diverse microenvironments (ME) in adulthood, as well as during embryogenesis. Their role in development precludes the use of gene-targeting and knockout approaches for studying their function. Hence, we proposed to create a macrophage-specific inducible transgenic mouse where genes can be turned on or off at will. A transgenic mouse in which the reverse tetracycline activator (rtTA-M2) is expressed under the hCD68 promoter for macrophage-specific gene induction was developed and crossed with a second transgenic reporter mouse strain in which the gene for green fluorescent protein (GFP) is under the control of tetracycline responsive element promoter. After doxycycline induction of the double transgenic animals (designated CD68-rtTA-tet-GFP), inducible expression of GFP was characterized by multicolor flow cytometric analysis of blood, marrow, and spleen cells and by demonstration of GFP expression in fresh-frozen sections in diverse tissues. In bone marrow, inducible GFP expression was not confined to, or inclusive of, all cells expressing the classical macrophage markers, such as F4/80. However, GFP-expressing cells in thioglycollate-elicited peritoneal macrophages were also positive for F4/80 and monocyte-macrophage-specific 2 antigen. Interestingly, flow analysis also indicated little overlap between the F4/80 and CSF-1R-positive populations. Fresh-frozen samples of tissues known to contain macrophages revealed GFP-expressing cells with variable morphologies. Our results show that the hCD68 promoter directs gene expression in a macrophage population distinct from that defined by classical monocyte-macrophage markers or promoters. Whether this population is functionally distinct remains to be established.

  19. TXNIP Regulates Peripheral Glucose Metabolism in Humans

    Science.gov (United States)

    Parikh, Hemang; Carlsson, Emma; Chutkow, William A; Johansson, Lovisa E; Storgaard, Heidi; Poulsen, Pernille; Saxena, Richa; Ladd, Christine; Schulze, P. Christian; Mazzini, Michael J; Jensen, Christine Bjørn; Krook, Anna; Björnholm, Marie; Tornqvist, Hans; Zierath, Juleen R; Ridderstråle, Martin; Altshuler, David; Lee, Richard T; Vaag, Allan; Groop, Leif C; Mootha, Vamsi K

    2007-01-01

    Background Type 2 diabetes mellitus (T2DM) is characterized by defects in insulin secretion and action. Impaired glucose uptake in skeletal muscle is believed to be one of the earliest features in the natural history of T2DM, although underlying mechanisms remain obscure. Methods and Findings We combined human insulin/glucose clamp physiological studies with genome-wide expression profiling to identify thioredoxin interacting protein (TXNIP) as a gene whose expression is powerfully suppressed by insulin yet stimulated by glucose. In healthy individuals, its expression was inversely correlated to total body measures of glucose uptake. Forced expression of TXNIP in cultured adipocytes significantly reduced glucose uptake, while silencing with RNA interference in adipocytes and in skeletal muscle enhanced glucose uptake, confirming that the gene product is also a regulator of glucose uptake. TXNIP expression is consistently elevated in the muscle of prediabetics and diabetics, although in a panel of 4,450 Scandinavian individuals, we found no evidence for association between common genetic variation in the TXNIP gene and T2DM. Conclusions TXNIP regulates both insulin-dependent and insulin-independent pathways of glucose uptake in human skeletal muscle. Combined with recent studies that have implicated TXNIP in pancreatic β-cell glucose toxicity, our data suggest that TXNIP might play a key role in defective glucose homeostasis preceding overt T2DM. PMID:17472435

  20. TXNIP regulates peripheral glucose metabolism in humans.

    Directory of Open Access Journals (Sweden)

    Hemang Parikh

    2007-05-01

    Full Text Available Type 2 diabetes mellitus (T2DM is characterized by defects in insulin secretion and action. Impaired glucose uptake in skeletal muscle is believed to be one of the earliest features in the natural history of T2DM, although underlying mechanisms remain obscure.We combined human insulin/glucose clamp physiological studies with genome-wide expression profiling to identify thioredoxin interacting protein (TXNIP as a gene whose expression is powerfully suppressed by insulin yet stimulated by glucose. In healthy individuals, its expression was inversely correlated to total body measures of glucose uptake. Forced expression of TXNIP in cultured adipocytes significantly reduced glucose uptake, while silencing with RNA interference in adipocytes and in skeletal muscle enhanced glucose uptake, confirming that the gene product is also a regulator of glucose uptake. TXNIP expression is consistently elevated in the muscle of prediabetics and diabetics, although in a panel of 4,450 Scandinavian individuals, we found no evidence for association between common genetic variation in the TXNIP gene and T2DM.TXNIP regulates both insulin-dependent and insulin-independent pathways of glucose uptake in human skeletal muscle. Combined with recent studies that have implicated TXNIP in pancreatic beta-cell glucose toxicity, our data suggest that TXNIP might play a key role in defective glucose homeostasis preceding overt T2DM.

  1. [Intracellular signals involved in glucose control].

    Science.gov (United States)

    Cruz, M; Velasco, E; Kumate, J

    2001-01-01

    Many proteins are involved in glucose control. The first step for glucose uptake is insulin receptor-binding. Stimulation of the insulin receptor results in rapid autophosphorylation and conformational changes in the beta chain and the subsequent phosphorylation of the insulin receptor substrate. This results in the docking of several SH2 domain proteins, including PI 3-kinase and other adapters. The final event is glucose transporter (GLUT) translocation to the cell surface. GLUT is in the cytosol but after insulin stimulation, several proteins are activated either in the GLUT vesicles or in the inner membrane. The role of the cytoskeleton is not well known, but it apparently participates in membrane fusion and vesicle mobilization. After glucose uptake, several hexokines metabolize the glucose to generate energy, convert the glucose in glycogen and store it. Type 2 diabetes is characterized by high glucose levels and insulin resistance. The insulin receptor is diminished on the cell surface membrane, tyrosine phosphorylation is decreased, serine and threonine phosphorylation is augmented. Apparently, the main problem with GLUT protein is in its translocation to the cell surface. At present, we know the role of many proteins involved in glucose control. However, we do not understand the significance of insulin resistance at the molecular level with type 2 diabetes.

  2. Colony stimulating factor-1 receptor as a treatment for cognitive deficits postfractionated whole-brain irradiation

    Directory of Open Access Journals (Sweden)

    Susanna Rosi

    2017-01-01

    Full Text Available Whole-brain irradiation (WBI is commonly used to treat primary tumors of the central nervous systems tumors as well as brain metastases. While this technique has increased survival among brain tumor patients, the side effects of including a decline in cognitive abilities that are generally progressive. In an effort to combat WBI side effects, researchers explored the treatment of colony stimulating factor-1 receptor (CSF-1R inhibitor. Data show that when a CSF-1R inhibitor is administered with fractionated WBI treatment, there is a decline in the number of resident and peripheral mononuclear phagocytes, a decrease in dendritic spine loss and a reduction in functional and memory deficits. CSFR-1R inhibitors have displayed promising results as an effective counter-treatment for WBI-induced deficits. Further research is required to optimize treatment strategies, establish a treatment timeline and gain a better understanding of the long-term side effects of targeting CSF-1R as a treatment strategy for WBI symptoms. This paper is a review article. Referred literature in this paper has been listed in the references section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors' experiences.

  3. Low Blood Glucose (Hypoglycemia)

    Science.gov (United States)

    ... Dental Problems Diabetes & Sexual & Urologic Problems Low Blood Glucose (Hypoglycemia) What is hypoglycemia? Hypoglycemia, also called low ... actions can also help prevent hypoglycemia: Check blood glucose levels Knowing your blood glucose level can help ...

  4. Glucose and cardiovascular risk

    NARCIS (Netherlands)

    Fuchs, M.; Hoekstra, J. B. L.; Mudde, A. H.

    2002-01-01

    The American Diabetes Association and the World Health Organisation have recently redefined the spectrum of abnormal glucose tolerance. The criteria for diabetes mellitus were sharpened and impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were classified as intermediate stages

  5. Leukemia inhibitory factor increases glucose uptake in mouse skeletal muscle

    DEFF Research Database (Denmark)

    Brandt, Nina; O'Neill, Hayley M; Kleinert, Maximilian

    2015-01-01

    INTRODUCTION: Members of the interleukin-6 (IL-6) family, IL-6 and ciliary neurotrophic factor (CNTF) have been shown to increase glucose uptake and fatty acid oxidation in skeletal muscle. However, the metabolic effects of another family member, leukemia inhibitory factor (LIF), are not well...... indicated that Mammalian Target of Rapamycin complex (mTORC) 2, but not mTORC1, also is required for LIF-stimulated glucose uptake. In contrast to CNTF, LIF-stimulation did not alter palmitate oxidation. LIF-stimulated glucose uptake was maintained in EDL from obese insulin resistant mice, whereas soleus...

  6. First-in-Human Study of AMG 820, a Monoclonal Anti-Colony-Stimulating Factor 1 Receptor Antibody, in Patients with Advanced Solid Tumors.

    Science.gov (United States)

    Papadopoulos, Kyriakos P; Gluck, Larry; Martin, Lainie P; Olszanski, Anthony J; Tolcher, Anthony W; Ngarmchamnanrith, Gataree; Rasmussen, Erik; Amore, Benny M; Nagorsen, Dirk; Hill, John S; Stephenson, Joe

    2017-10-01

    Purpose: Binding of colony-stimulating factor 1 (CSF1) ligand to the CSF1 receptor (CSF1R) regulates survival of tumor-associated macrophages, which generally promote an immunosuppressive tumor microenvironment. AMG 820 is an investigational, fully human CSF1R antibody that inhibits binding of the ligands CSF1 and IL34 and subsequent ligand-mediated receptor activation. This first-in-human phase I study evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of AMG 820.Experimental Design: Adult patients with relapsed or refractory advanced solid tumors received intravenous AMG 820 0.5 mg/kg once weekly or 1.5 to 20 mg/kg every 2 weeks until disease progression, adverse event (AE), or consent withdrawal.Results: Twenty-five patients received ≥1 dose of AMG 820. AMG 820 was tolerated up to 20 mg/kg; the MTD was not reached. One dose-limiting toxicity was observed (20 mg/kg; nonreversible grade 3 deafness). Most patients (76%) had treatment-related AEs; the most common were periorbital edema (44%), increased aspartate aminotransferase (AST; 28%), fatigue (24%), nausea (16%), increased blood alkaline phosphatase (12%), and blurred vision (12%). No patients had serious or fatal treatment-related AEs; 28% had grade ≥3 treatment-related AEs. Grade 3 AST elevations resolved when treatment was withheld. AMG 820 showed linear pharmacokinetics, with minimal accumulation (AMG 820 was tolerated with manageable toxicities up to 20 mg/kg every 2 weeks. Pharmacodynamic response was demonstrated, and limited antitumor activity was observed. Clin Cancer Res; 23(19); 5703-10. ©2017 AACR. ©2017 American Association for Cancer Research.

  7. Hepatic carboxylesterase 1 is induced by glucose and regulates postprandial glucose levels.

    Directory of Open Access Journals (Sweden)

    Jiesi Xu

    Full Text Available Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1 is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, glucose stimulated CES1 promoter activity and increased acetylation of histone 3 and histone 4 in the CES1 chromatin. Knockdown of ATP-citrate lyase (ACL, an enzyme that regulates histone acetylation, abolished glucose-mediated histone acetylation in the CES1 chromatin and glucose-induced hepatic CES1 expression. Finally, knockdown of hepatic CES1 significantly increased postprandial blood glucose levels. In conclusion, the present study uncovers a novel glucose-CES1-glucose pathway which may play an important role in regulating postprandial blood glucose levels.

  8. Resistin modulates glucose uptake and glucose transporter-1 (GLUT-1) expression in trophoblast cells

    Science.gov (United States)

    Di Simone, Nicoletta; Di Nicuolo, Fiorella; Marzioni, Daniela; Castellucci, Mario; Sanguinetti, Maurizio; D’lppolito, Silvia; Caruso, Alessandro

    2009-01-01

    Abstract The adipocytokine resistin impairs glucose tolerance and insulin sensitivity. Here, we examine the effect of resistin on glucose uptake in human trophoblast cells and we demonstrate that transplacental glucose transport is mediated by glucose transporter (GLUT)-1. Furthermore, we evaluate the type of signal transduction induced by resistin in GLUT-1 regulation. BeWo choriocarcinoma cells and primary cytotrophoblast cells were cultured with increasing resistin concentrations for 24 hrs. The main outcome measures include glucose transport assay using [3H]-2-deoxy glucose, GLUT-1 protein expression by Western blot analysis and GLUT-1 mRNA detection by quantitative real-time RT-PCR. Quantitative determination of phospho(p)-ERK1/2 in cell lysates was performed by an Enzyme Immunometric Assay and Western blot analysis. Our data demonstrate a direct effect of resistin on normal cytotrophoblastic and on BeWo cells: resistin modulates glucose uptake, GLUT-1 messenger ribonucleic acid (mRNA) and protein expression in placental cells. We suggest that ERK1/2 phosphorylation is involved in the GLUT-1 regulation induced by resistin. In conclusion, resistin causes activation of both the ERK1 and 2 pathway in trophoblast cells. ERK1 and 2 activation stimulated GLUT-1 synthesis and resulted in increase of placental glucose uptake. High resistin levels (50–100 ng/ml) seem able to affect glucose-uptake, presumably by decreasing the cell surface glucose transporter. PMID:18410529

  9. Hepatic Carboxylesterase 1 Is Induced by Glucose and Regulates Postprandial Glucose Levels

    Science.gov (United States)

    Xu, Jiesi; Yin, Liya; Xu, Yang; Li, Yuanyuan; Zalzala, Munaf; Cheng, Gang; Zhang, Yanqiao

    2014-01-01

    Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1) is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, glucose stimulated CES1 promoter activity and increased acetylation of histone 3 and histone 4 in the CES1 chromatin. Knockdown of ATP-citrate lyase (ACL), an enzyme that regulates histone acetylation, abolished glucose-mediated histone acetylation in the CES1 chromatin and glucose-induced hepatic CES1 expression. Finally, knockdown of hepatic CES1 significantly increased postprandial blood glucose levels. In conclusion, the present study uncovers a novel glucose-CES1-glucose pathway which may play an important role in regulating postprandial blood glucose levels. PMID:25285996

  10. CSF glucose test

    Science.gov (United States)

    Glucose test - CSF; Cerebrospinal fluid glucose test ... The glucose level in the CSF should be 50 to 80 mg/100 mL (or greater than 2/3 ... Abnormal results include higher and lower glucose levels. Abnormal ... or fungus) Inflammation of the central nervous system Tumor

  11. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know ... Checking Your Blood Glucose A1C and eAG Hypoglycemia (Low blood glucose) Hyperglycemia (High blood glucose) Dawn Phenomenon Checking for Ketones Tight ...

  12. Helicobacter pylori infection and fasting plasma glucose concentration

    OpenAIRE

    Peach, H; Barnett, N.

    2001-01-01

    Background—Helicobacter pylori infection raises basal and meal stimulated serum gastrin concentrations and lowers iron stores, which may in turn reduce fasting plasma glucose concentrations in the population.

  13. Multilevel control of glucose homeostasis by adenylyl cyclase 8

    NARCIS (Netherlands)

    Raoux, Matthieu; Vacher, Pierre; Papin, Julien; Picard, Alexandre; Kostrzewa, Elzbieta; Devin, Anne; Gaitan, Julien; Limon, Isabelle; Kas, Martien J.|info:eu-repo/dai/nl/185967019; Magnan, Christophe; Lang, Jochen

    2015-01-01

    Aims/hypothesis: Nutrient homeostasis requires integration of signals generated by glucose metabolism and hormones. Expression of the calcium-stimulated adenylyl cyclase ADCY8 is regulated by glucose and the enzyme is capable of integrating signals from multiple pathways. It may thus have an

  14. Interrelationship of growth hormone, glucose and lipid metabolism ...

    African Journals Online (AJOL)

    On the contrary, negative correlations were shown between GH vs the fasting levels of glucose,GH vs lipid and GH vs HSL. Conclusion: GH caused the reduction of the blood levels of glucose and, lipid using HSL as mediator, by inhibiting gluconeogenesis and stimulating lipolysis, respectively. Keywords: Growth hormone ...

  15. Colony-stimulating factor 1 receptor blockade prevents fractionated whole-brain irradiation-induced memory deficits.

    Science.gov (United States)

    Feng, Xi; Jopson, Timothy D; Paladini, Maria Serena; Liu, Sharon; West, Brian L; Gupta, Nalin; Rosi, Susanna

    2016-08-30

    Primary central nervous system (CNS) neoplasms and brain metastases are routinely treated with whole-brain radiation. Long-term survival occurs in many patients, but their quality of life is severely affected by the development of cognitive deficits, and there is no treatment to prevent these adverse effects. Neuroinflammation, associated with activation of brain-resident microglia and infiltrating monocytes, plays a pivotal role in loss of neurological function and has been shown to be associated with acute and long-term effects of brain irradiation. Colony-stimulating factor 1 receptor (CSF-1R) signaling is essential for the survival and differentiation of microglia and monocytes. Here, we tested the effects of CSF-1R blockade by PLX5622 on cognitive function in mice treated with three fractions of 3.3 Gy whole-brain irradiation. Young adult C57BL/6J mice were given three fractions of 3.3 Gy whole-brain irradiation while they were on diet supplemented with PLX5622, and the effects on periphery monocyte accumulation, microglia numbers, and neuronal functions were assessed. The mice developed hippocampal-dependent cognitive deficits at 1 and 3 months after they received fractionated whole-brain irradiation. The impaired cognitive function correlated with increased number of periphery monocyte accumulation in the CNS and decreased dendritic spine density in hippocampal granule neurons. PLX5622 treatment caused temporary reduction of microglia numbers, inhibited monocyte accumulation in the brain, and prevented radiation-induced cognitive deficits. Blockade of CSF-1R by PLX5622 prevents fractionated whole-brain irradiation-induced memory deficits. Therapeutic targeting of CSF-1R may provide a new avenue for protection from radiation-induced memory deficits.

  16. Four grams of glucose

    OpenAIRE

    Wasserman, David H.

    2008-01-01

    Four grams of glucose circulates in the blood of a person weighing 70 kg. This glucose is critical for normal function in many cell types. In accordance with the importance of these 4 g of glucose, a sophisticated control system is in place to maintain blood glucose constant. Our focus has been on the mechanisms by which the flux of glucose from liver to blood and from blood to skeletal muscle is regulated. The body has a remarkable capacity to satisfy the nutritional need for glucose, while ...

  17. Anti-Diabetic Activities of Gastrodia elata Blume Water Extracts Are Mediated Mainly by Potentiating Glucose-Stimulated Insulin Secretion and Increasing β-Cell Mass in Non-Obese Type 2 Diabetic Animals

    Directory of Open Access Journals (Sweden)

    Hye Jeong Yang

    2016-03-01

    Full Text Available The brain is an important modulator of glucose metabolism, and is known to respond Gastrodia elata Blume water extract (GEB. Therefore, we examined whether long-term administration of GEB has hypoglycemic activity, and its action mechanism was explored in partially-pancreatectomized rats that exhibit similar characteristics as Asian type 2 diabetes, non-obese insulin-insufficient diabetes. The rats were provided high-fat diets supplemented with either of (1 0.5% GEB (GEB-L, (2 2% GEB (GEB-H, (3 2% dextrin (control, or (4 2% dextrin with rosiglitazone (20 mg/kg body weight; positive-control for eight weeks. GEB dose-dependently improved hypothalamic insulin signaling, enhanced whole-body insulin sensitivity during hyperinsulinemic euglycemic clamp, and reduced hepatic glucose output in a hyperinsulinemic state. GEB dose-dependently increased the area under the curve of the serum insulin levels at the first and second phases during hyperglycemic clamp compared to the control, whereas the positive control had no effect. Insulin sensitivity during the hyperglycemic state also improved, dose-dependently, in response to GEB compared with that of the control, but was less than the positive control. GEB-H increased the mass of β-cells by potentiating proliferation and decreasing apoptosis. In conclusion, GEB could be a therapeutic agent for treating Asian type 2 diabetes.

  18. Glucose, memory, and aging.

    Science.gov (United States)

    Korol, D L; Gold, P E

    1998-04-01

    Circulating glucose concentrations regulate many brain functions, including learning and memory. Much of the evidence for this view comes from experiments assessing stress-related release of epinephrine with subsequent increases in blood glucose concentrations. One application of this work has been to investigate whether age-related memory impairments result from dysfunctions in the neuroendocrine regulation of the brain processes responsible for memory. Like humans, aged rodents exhibit some memory impairments that can be reversed by administration of epinephrine or glucose. In elderly humans, ingestion of glucose enhances some cognitive functions, with effects best documented thus far on tests of verbal contextual and noncontextual information. Glucose also effectively enhances cognition in persons with Alzheimer disease or Down syndrome. Although earlier evidence suggested that glucose does not enhance cognitive function in healthy young adults, more recent findings suggest that glucose is effective in this population, provided the tests are sufficiently difficult. In college students, glucose consumption significantly enhanced memory of material in a paragraph. Glucose also appeared to enhance attentional processes in these students. Neither face and word recognition nor working memory was influenced by treatment with glucose. The neurobiological mechanisms by which glucose acts are under current investigation. Initial evidence suggests that glucose or a metabolite may activate release of the neurotransmitter acetylcholine in rats when they are engaged in learning. Consequently, the issue of nutrition and cognition becomes increasingly important in light of evidence that circulating glucose concentrations have substantial effects on brain and cognitive functions.

  19. THE MALATE ASPARTATE SHUTTLE AND PYRUVATE-KINASE AS TARGETS INVOLVED IN THE STIMULATION OF GLUCONEOGENESIS BY PHENYLEPHRINE

    NARCIS (Netherlands)

    Leverve, X. M.; Verhoeven, A. J.; Groen, A. K.; Meijer, A. J.; Tager, J. M.

    1986-01-01

    The mechanisms responsible for the stimulation by phenylephrine of gluconeogenesis from dihydroxyacetone and glycerol were studied in perifused rat hepatocytes. The stimulation by phenylephrine of glucose formation from dihydroxyacetone was biphasic. Transient stimulation of about 25% after 3 min

  20. Effects of fasting on plasma glucose and prolonged tracer measurement of hepatic glucose output in NIDDM

    Energy Technology Data Exchange (ETDEWEB)

    Glauber, H.; Wallace, P.; Brechtel, G.

    1987-10-01

    We studied the measurement of hepatic glucose output (HGO) with prolonged (3-/sup 3/H)glucose infusion in 14 patients with non-insulin-dependent diabetes mellitus (NIDDM). Over the course of 10.5 h, plasma glucose concentration fell with fasting by one-third, from 234 +/- 21 to 152 +/- 12 mg/dl, and HGO fell from 2.35 +/- 0.18 to 1.36 +/- 0.07 mg . kg-1 . min-1 (P less than .001). In the basal state, HGO and glucose were significantly correlated (r = 0.68, P = .03), and in individual patients, HGO and glucose were closely correlated as both fell with fasting (mean r = 0.79, P less than .01). Plasma (3-/sup 3/H)glucose radioactivity approached a steady state only 5-6 h after initiation of the primed continuous infusion, and a 20% overestimate of HGO was demonstrated by not allowing sufficient time for tracer labeling of the glucose pool. Assumption of steady-state instead of non-steady-state kinetics in using Steele's equations to calculate glucose turnover resulted in a 9-24% overestimate of HGO. Stimulation of glycogenolysis by glucagon injection demonstrated no incorporation of (3-/sup 3/H)glucose in hepatic glycogen during the prolonged tracer infusion. In a separate study, plasma glucose was maintained at fasting levels (207 +/- 17 mg/dl) for 8 h with the glucose-clamp technique. Total glucose turnover rates remained constant during this prolonged tracer infusion. However, HGO fell to 30% of the basal value simply by maintaining fasting hyperglycemia in the presence of basal insulin levels.

  1. Glucose test (image)

    Science.gov (United States)

    ... person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. Following your health ...

  2. Glucose-6-phosphate dehydrogenase

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that ...

  3. Your Glucose Meter

    Science.gov (United States)

    ... by Audience For Women Women's Health Topics Your Glucose Meter Share Tweet Linkedin Pin it More sharing ... Your Blood Sugar and Caring for Your Meter Glucose meters test and record how much sugar (called ...

  4. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... high blood glucose (blood sugar). High blood glucose happens when the body has too little insulin or ... give 5% back to the Association. » « Connect With Us Register for diabetes news, research and food & fitness ...

  5. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Health Step On Up Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women ... Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page Text Size: A A A ...

  6. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing ...

  7. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... your doctor about how to handle this condition. Medical IDs Many people with diabetes, particularly those who ... In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood Glucose A1C ...

  8. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical term for high blood glucose (blood sugar). High ... called ketones are produced. Your body cannot tolerate large amounts of ketones and will try to get ...

  9. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... you to lower your blood glucose level. Cutting down on the amount of food you eat might ... use glucose for fuel, so your body breaks down fats to use for energy. When your body ...

  10. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose ...

  11. 2-Methoxyoestradiol inhibits glucose transport in rodent skeletal muscle.

    Science.gov (United States)

    Zhang, Shi-Jin; Sandström, Marie; Ahlsén, Maria; Ivarsson, Niklas; Zhu, Hua; Ma, Jianjie; Ren, Jian-Ming; Westerblad, Håkan; Katz, Abram

    2010-08-01

    2-Methoxyoestradiol (2-ME) is an oestrogen derivative that inhibits superoxide dismutase (which converts superoxide anions to H(2)O(2)). Since reactive oxygen species have been implicated in glucose transport, we determined the effect of 2-ME on glucose transport in skeletal muscle. Experiments were performed on isolated mouse extensor digitorum longus (EDL, glycolytic, fast-twitch) muscle. Glucose uptake was measured using 2-deoxy-d-[1,2-(3)H]glucose. 2-Methoxyoestradiol (50 microm) reduced glucose uptake induced by insulin, contraction and hypoxia by approximately 60%. Exogenous H(2)O(2) activated glucose uptake, and this effect was also blocked by 2-ME, demonstrating that 2-ME was exerting its inhibitory effect on glucose uptake at a site other than superoxide dismutase. When glucose uptake was stimulated by insulin, followed by addition of 2-ME, there was also an attenuation of the effect of insulin (approximately 60%). Moreover, basal glucose uptake was decreased by 2-ME (approximately 50%). In contrast, insulin-mediated translocation of glucose transporter type 4 protein to the plasma membrane was not affected by 2-ME. Similar results were obtained in soleus (oxidative, slow-twitch) muscle. In conclusion, 2-ME appears to decrease glucose transport in skeletal muscle by directly interfering with the function of glucose transport proteins in surface membranes.

  12. [Blood glucose self monitoring].

    Science.gov (United States)

    Wascher, Thomas C; Stechemesser, Lars

    2016-04-01

    Self monitoring of blood glucose contributes to the integrated management of diabetes mellitus. It, thus, should be available for all patients with diabetes mellitus type-1 and type-2. Self monitoring of blood glucose improves patients safety, quality of life and glucose control. The current article represents the recommendations of the Austrian Diabetes Association for the use of blood glucose self monitoring according to current scientific evidence.

  13. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... by Mail Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page Text Size: ... and-how-tos, . In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood Glucose A1C ...

  14. G-allele of intronic rs10830963 in MTNR1B confers increased risk of impaired fasting glycemia and type 2 diabetes through an impaired glucose-stimulated insulin release: studies involving 19,605 Europeans

    DEFF Research Database (Denmark)

    Sparsø, Thomas; Bonnefond, Amélie; Andersson, Ehm

    2009-01-01

    ,656), in the North Finland Birth Cohort 86 (n = 5,258), and in the Haguenau study (n = 1,461). RESULTS: The MTNR1B intronic variant, rs10830963, carried most of the effect on FPG and showed the strongest association with FPG (combined P = 5.3 x 10(-31)) and type 2 diabetes. The rs10830963 G-allele increased the risk...... independent effect on FPG with isolated impaired fasting glycemia (i-IFG), isolated impaired glucose tolerance (i-IGT), type 2 diabetes, and measures of insulin release and peripheral and hepatic insulin sensitivity. RESEARCH DESIGN AND METHODS: We examined European-descent participants in the Inter99 study...

  15. Neuronal calcium sensor synaptotagmin-9 is not involved in the regulation of glucose homeostasis or insulin secretion

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wang, Xiaorui; Wang, Yue

    2010-01-01

    /PRINCIPAL FINDINGS: In this study we tested whether synaptotagmin-9 participates in the regulation of glucose-stimulated insulin release by using pancreas-specific synaptotagmin-9 knockout (p-S9X) mice. Deletion of synaptotagmin-9 in the pancreas resulted in no changes in glucose homeostasis or body weight. Glucose......, is not involved in the regulation of glucose-stimulated insulin release from pancreatic β-cells....

  16. Glucose screening tests during pregnancy

    Science.gov (United States)

    Oral glucose tolerance test - pregnancy; OGTT - pregnancy; Glucose challenge test - pregnancy; Gestational diabetes - glucose screening ... During the first step, you will have a glucose screening test: You DO NOT need to prepare ...

  17. Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Ploug, T.; Stallknecht, B.M.; Pedersen, O.; Kahn, B.B.; Ohkuwa, T.; Vinten, J.; Galbo, H. (Panum Institute, Copenhagen (Denmark))

    1990-12-01

    The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.

  18. Ca2+ effects on glucose transport and fatty acid oxidation in L6 skeletal muscle cell cultures

    Directory of Open Access Journals (Sweden)

    Darrick Balu

    2016-03-01

    We did find a Ca2+ stimulation (using either caffeine or ionomycin of fatty acid oxidation. This was observed in the absence (but not the presence of added glucose. We conclude that Ca2+ stimulates fatty acid oxidation at a mitochondrial site, secondary to malonyl CoA inhibition (represented by the presence of glucose in our experiments. In summary, the experiments resolve a controversy on Ca2+ stimulation of glucose transport by skeletal muscle, introduce an important experimental consideration for the measurement of glucose transport, and uncover a new site of action for Ca2+ stimulation of fatty acid oxidation.

  19. Oxytocin increases extrapancreatic glucagon secretion and glucose production in pancreatectomized dogs

    Energy Technology Data Exchange (ETDEWEB)

    Altszuler, N.; Puma, F.; Winkler, B.; Fontan, N.; Saudek, C.D.

    1986-05-01

    Infusion of oxytocin into normal dogs increases plasma levels of insulin and glucagon and glucose production and uptake. To determine whether infused oxytocin also increases glucagon secretion from extrapancreatic sites, pancreatectomized dogs, off insulin of 18 hr, were infused with oxytocin and plasma glucagon, and glucose production and uptake were measured using the (6-/sup 3/H)glucose primer-infusion technique. The diabetic dogs, in the control period, had elevated plasma glucose and glucagon levels, an increased rate of glucose production, and a relative decrease in glucose uptake (decreased clearance). Infusion of oxytocin (500 ..mu..U/kg/min) caused a rise in plasma glucagon and glucose levels, increased glucose production, and further decreased glucose clearance. it is concluded that oxytocin can stimulate secretion of extrapancreatic glucagon, which contributes to the increased glucose production.

  20. Triiodothyronine (T3)-associated upregulation and downregulation of nuclear T3 binding in the human fibroblast cell (MRC-5)--stimulation of malic enzyme, glucose-6-phosphate-dehydrogenase, and 6-phosphogluconate-dehydrogenase by insulin, but not by T3

    DEFF Research Database (Denmark)

    Matzen, L E; Kristensen, S R; Kvetny, J

    1991-01-01

    The specific nuclear binding of triiodothyronine (T3) (NBT3) and the activity of malic enzyme (ME), glucose-6-phosphate-dehydrogenase (G6PD), and 6-phosphogluconate-dehydrogenase (6PGD) were studied in the human fibroblast cell (MRC-5). The overall apparent binding affinity (Ka) was 2.7 x 10(9) L...... and a low-affinity binding site with Ka2 2.9 +/- 1.1 x 10(8) L.mol-1 and MBC2 124.7 +/- 22.1 fmol/mg DNA (n = 6). Incubation of cells with 6 nmol/L T3 for 20 hours reduced NBT3 to 62.2% +/- 15.7% (P less than .01, n = 11). The Ka estimated from kinetic studies was reduced to 6.7 x 10(7) L.mol-1......, and the scatchard plots were linear, with Ka 4.5 +/- 1.6 x 10(8) L.mol-1 and MBC 137.0 +/- 44.6 fmol/mg DNA (n = 3) of the same magnitude as the low-affinity binding site in cells incubated without T3 (NS). The reduction in NBT3 was reversible and maximal at T3 concentrations saturating the high-affinity binding...

  1. Activation of the AMPK/Sirt1 pathway by a leucine-metformin combination increases insulin sensitivity in skeletal muscle, and stimulates glucose and lipid metabolism and increases life span in Caenorhabditis elegans.

    Science.gov (United States)

    Banerjee, Jheelam; Bruckbauer, Antje; Zemel, Michael B

    2016-11-01

    We have previously shown leucine (Leu) to activate Sirt1 by lowering its KM for NAD+, thereby amplifying the effects of other sirtuin activators and improving insulin sensitivity. Metformin (Met) converges on this pathway both indirectly (via AMPK) and by direct activation of Sirt1, and we recently found Leu to synergize with Met to improve insulin sensitivity and glycemic control while achieving ~80% dose-reduction in diet-induced obese mice. Accordingly, we sought here to define the mechanism of this interaction. Muscle cells C2C12 and liver cells HepG2 were used to test the effect of Met-Leu on Sirt1 activation. Caenorhabditis elegans was used for glucose utilization and life span studies. Leu (0.5mmol/L)+Met (50-100μmol/L) synergistically activated Sirt1 (pmetformin exerted no independent effect at any concentration (0.1-0.5mmol/L). Thus, Leu and Met synergize to enable Sirt1 activation at low NAD+ concentrations (typical of energy replete states). Sirt1 and AMPK activations are required for Met-Leu's full action, which result in improvements in energy metabolism and insulin sensitivity. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Shikonin increases glucose uptake in skeletal muscle cells and improves plasma glucose levels in diabetic Goto-Kakizaki rats.

    Directory of Open Access Journals (Sweden)

    Anette I Öberg

    Full Text Available BACKGROUND: There is considerable interest in identifying compounds that can improve glucose homeostasis. Skeletal muscle, due to its large mass, is the principal organ for glucose disposal in the body and we have investigated here if shikonin, a naphthoquinone derived from the Chinese plant Lithospermum erythrorhizon, increases glucose uptake in skeletal muscle cells. METHODOLOGY/PRINCIPAL FINDINGS: Shikonin increases glucose uptake in L6 skeletal muscle myotubes, but does not phosphorylate Akt, indicating that in skeletal muscle cells its effect is medaited via a pathway distinct from that used for insulin-stimulated uptake. Furthermore we find no evidence for the involvement of AMP-activated protein kinase in shikonin induced glucose uptake. Shikonin increases the intracellular levels of calcium in these cells and this increase is necessary for shikonin-mediated glucose uptake. Furthermore, we found that shikonin stimulated the translocation of GLUT4 from intracellular vesicles to the cell surface in L6 myoblasts. The beneficial effect of shikonin on glucose uptake was investigated in vivo by measuring plasma glucose levels and insulin sensitivity in spontaneously diabetic Goto-Kakizaki rats. Treatment with shikonin (10 mg/kg intraperitoneally once daily for 4 days significantly decreased plasma glucose levels. In an insulin sensitivity test (s.c. injection of 0.5 U/kg insulin, plasma glucose levels were significantly lower in the shikonin-treated rats. In conclusion, shikonin increases glucose uptake in muscle cells via an insulin-independent pathway dependent on calcium. CONCLUSIONS/SIGNIFICANCE: Shikonin increases glucose uptake in skeletal muscle cells via an insulin-independent pathway dependent on calcium. The beneficial effects of shikonin on glucose metabolism, both in vitro and in vivo, show that the compound possesses properties that make it of considerable interest for developing novel treatment of type 2 diabetes.

  3. Bitter taste receptors influence glucose homeostasis.

    Directory of Open Access Journals (Sweden)

    Cedrick D Dotson

    Full Text Available TAS1R- and TAS2R-type taste receptors are expressed in the gustatory system, where they detect sweet- and bitter-tasting stimuli, respectively. These receptors are also expressed in subsets of cells within the mammalian gastrointestinal tract, where they mediate nutrient assimilation and endocrine responses. For example, sweeteners stimulate taste receptors on the surface of gut enteroendocrine L cells to elicit an increase in intracellular Ca(2+ and secretion of the incretin hormone glucagon-like peptide-1 (GLP-1, an important modulator of insulin biosynthesis and secretion. Because of the importance of taste receptors in the regulation of food intake and the alimentary responses to chemostimuli, we hypothesized that differences in taste receptor efficacy may impact glucose homeostasis. To address this issue, we initiated a candidate gene study within the Amish Family Diabetes Study and assessed the association of taste receptor variants with indicators of glucose dysregulation, including a diagnosis of type 2 diabetes mellitus and high levels of blood glucose and insulin during an oral glucose tolerance test. We report that a TAS2R haplotype is associated with altered glucose and insulin homeostasis. We also found that one SNP within this haplotype disrupts normal responses of a single receptor, TAS2R9, to its cognate ligands ofloxacin, procainamide and pirenzapine. Together, these findings suggest that a functionally compromised TAS2R receptor negatively impacts glucose homeostasis, providing an important link between alimentary chemosensation and metabolic disease.

  4. Age and Expression of CD163 and Colony-Stimulating Factor 1 Receptor (CD115) Are Associated With the Biological Behavior of Central Giant Cell Granuloma.

    Science.gov (United States)

    Kahn, Adrian; Chaushu, Gavriel; Ginene, Lana; Vered, Marilena

    2017-07-01

    Central giant cell granulomas (CGCGs) are clinically classified as nonaggressive (nA-CGCGs) and aggressive (A-CGCGs). However, histopathologically, all lesions feature spindle mononuclear cells (MCs) and multinuclear giant cells (GCs) in a hemorrhage-rich stroma. We aimed to investigate the presence of cells with a monocyte- or macrophage-related phenotype and, together with clinical variables, to examine their predictive potential for the biological behavior of CGCGs. For our investigation, we implemented a retrospective cohort study. Sections were immunohistochemically stained for colony-stimulating factor 1 receptor (CSF-1R) (CD115), CD163, CD68, and nuclear factor κB. The clinical variables included age, gender, and location of lesions. Associations between immunostains, clinical variables, and CGCG aggressiveness were analyzed by the Wilcoxon (Mann-Whitney) exact test and t test. Significant variables were further analyzed by a logistic regression model followed by receiver operating characteristic (ROC) curve analysis for diagnostic sensitivity. Significance was set at P CSF-1R (CD115)-MC combined were the best predictor in distinguishing nA-CGCGs from A-CGCGs (area under ROC curve, 0.814; P CSF-1R (CD115)-MC can serve as significant predictors of nA-CGCGs. A functional link between CD163-GC and the characteristic areas of extravasation of erythrocytes is discussed. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  5. growth stimulant

    African Journals Online (AJOL)

    Effects of timing and duration of supplementation of LIVFIT VET ® (growth stimulant) as substitute for fish meal on the growth performance, haematology and clinical enzymes concentration of growing pigs.

  6. Computational modeling of glucose transport in pancreatic β-cells identifies metabolic thresholds and therapeutic targets in diabetes.

    Directory of Open Access Journals (Sweden)

    Camilla Luni

    Full Text Available Pancreatic β-cell dysfunction is a diagnostic criterion of Type 2 diabetes and includes defects in glucose transport and insulin secretion. In healthy individuals, β-cells maintain plasma glucose concentrations within a narrow range in concert with insulin action among multiple tissues. Postprandial elevations in blood glucose facilitate glucose uptake into β-cells by diffusion through glucose transporters residing at the plasma membrane. Glucose transport is essential for glycolysis and glucose-stimulated insulin secretion. In human Type 2 diabetes and in the mouse model of obesity-associated diabetes, a marked deficiency of β-cell glucose transporters and glucose uptake occurs with the loss of glucose-stimulated insulin secretion. Recent studies have shown that the preservation of glucose transport in β-cells maintains normal insulin secretion and blocks the development of obesity-associated diabetes. To further elucidate the underlying mechanisms, we have constructed a computational model of human β-cell glucose transport in health and in Type 2 diabetes, and present a systems analysis based on experimental results from human and animal studies. Our findings identify a metabolic threshold or "tipping point" whereby diminished glucose transport across the plasma membrane of β-cells limits intracellular glucose-6-phosphate production by glucokinase. This metabolic threshold is crossed in Type 2 diabetes and results in β-cell dysfunction including the loss of glucose stimulated insulin secretion. Our model further discriminates among molecular control points in this pathway wherein maximal therapeutic intervention is achieved.

  7. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)

    2017-01-01

    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  8. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing ...

  9. Blood Glucose Levels

    Directory of Open Access Journals (Sweden)

    Carlos Estela

    2011-01-01

    Full Text Available The purpose of this study was to establish a mathematical model which can be used to estimate glucose levels in the blood over time. The equations governing this process were manipulated with the use of techniques such as separation of variables and integration of first order differential equations, which resulted in a function that described the glucose concentration in terms of time. This function was then plotted, which allowed us to find when glucose concentration was at its highest. The model was then used to analyze two cases where the maximum glucose level could not exceed a certain level while the amount of carbohydrates and glycemic index were varied, independently.

  10. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Nephropathy) Gastroparesis Mental Health Step On Up Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy ...

  11. Effects of hyperglycemia on glucose production and utilization in humans. Measurement with (3H)-2-, (3H)-3-, and (14C)-6-glucose

    Energy Technology Data Exchange (ETDEWEB)

    Bell, P.M.; Firth, R.G.; Rizza, R.A.

    1986-06-01

    Studies with tritiated isotopes of glucose have demonstrated that hyperglycemia per se stimulates glucose utilization and suppresses glucose production in humans. These conclusions rely on the assumption that tritiated glucose provides an accurate measure of glucose turnover. However, if in the presence of hyperglycemia the isotope either loses its label during futile cycling or retains its label during cycling through glycogen, then this assumption is not valid. To examine this question, glucose utilization and glucose production rates were measured in nine normal subjects with a simultaneous infusion of (/sup 3/H)-2-glucose, an isotope that may undergo futile cycling but does not cycle through glycogen; (/sup 14/C)-6-glucose, an isotope that may cycle through glycogen but does not futile cycle; and (/sup 3/H)-3-glucose, an isotope that can both undergo futile cycling and cycle through glycogen. In the postabsorptive state at plasma glucose concentration of 95 mg X dl-1, glucose turnover determined with (/sup 14/C)-6-glucose (2.3 +/- 0.1 mg X kg-1 X min-1) was greater than that determined with (3/sup 3/H)glucose (2.1 +/- 0.1 mg X kg-1 X min-1, P = 0.002) and slightly less than that determined with (/sup 3/H)-2-glucose (2.7 +/- 0.2 mg X kg-1 X min-1, P = 0.08). Plasma glucose was then raised from 95 to 135 to 175 mg X dl-1 while insulin secretion was inhibited, and circulating insulin, glucagon, and growth hormone concentrations were maintained constant by infusion of these hormones and somatostatin. Glucose production and utilization rates determined with (/sup 14/C)-6-glucose continued to be less than those determined with (/sup 3/H)-2-glucose and greater than those seen with (/sup 3/H)-3-glucose.

  12. Glinide, but Not Sulfonylurea, Can Evoke Insulin Exocytosis by Repetitive Stimulation: Imaging Analysis of Insulin Exocytosis by Secretagogue-Induced Repetitive Stimulations

    Directory of Open Access Journals (Sweden)

    Kyota Aoyagi

    2009-01-01

    Full Text Available To investigate the different effects between sulfonylurea (SU and glinide drugs in insulin secretion, pancreatic β-cells were repeatedly stimulated with SU (glimepiride or glinide (mitiglinide. Total internal reflection fluorescent (TIRF microscopy revealed that secondary stimulation with glimepiride, but not glucose and mitiglinide, failed to evoke fusions of insulin granules although primary stimulation with glucose, glimepiride, and mitiglinide induced equivalent numbers of exocytotic responses. Glimepiride, but not glucose and mitiglinide, induced abnormally sustained [Ca2+]i elevations and reductions of docked insulin granules on the plasma membrane. Our data suggest that the effect of glinide on insulin secretory mechanisms is similar to that of glucose.

  13. Enhanced muscle glucose metabolism after exercise

    DEFF Research Database (Denmark)

    Richter, Erik; Garetto, L P; Goodman, M N

    1984-01-01

    Studies in the rat suggest that after voluntary exercise there are two phases of glycogen repletion in skeletal muscle (preceding study). In phase I glucose utilization and glycogen synthesis are enhanced both in the presence and absence of insulin, whereas in phase II only the increase in the pr......Studies in the rat suggest that after voluntary exercise there are two phases of glycogen repletion in skeletal muscle (preceding study). In phase I glucose utilization and glycogen synthesis are enhanced both in the presence and absence of insulin, whereas in phase II only the increase...... in the presence of insulin is found. To determine whether these alterations and in particular those mediated by insulin are due to local or systemic factors, one hindlimb of an anesthetized rat was electrically stimulated, and both hindlimbs were perfused immediately thereafter. Glucose and glycogen metabolism...... in the stimulated leg closely mimicked that observed previously after voluntary exercise on a treadmill. With no insulin added to the perfusate, glucose incorporation into glycogen was markedly enhanced in muscles that were glycogen depleted as were the uptake of 2-deoxyglucose and 3-O-methylglucose. Likewise...

  14. [6]-Gingerol, from Zingiber officinale, potentiates GLP-1 mediated glucose-stimulated insulin secretion pathway in pancreatic β-cells and increases RAB8/RAB10-regulated membrane presentation of GLUT4 transporters in skeletal muscle to improve hyperglycemia in Leprdb/db type 2 diabetic mice.

    Science.gov (United States)

    Samad, Mehdi Bin; Mohsin, Md Nurul Absar Bin; Razu, Bodiul Alam; Hossain, Mohammad Tashnim; Mahzabeen, Sinayat; Unnoor, Naziat; Muna, Ishrat Aklima; Akhter, Farjana; Kabir, Ashraf Ul; Hannan, J M A

    2017-08-09

    [6]-Gingerol, a major component of Zingiber officinale, was previously reported to ameliorate hyperglycemia in type 2 diabetic mice. Endocrine signaling is involved in insulin secretion and is perturbed in db/db Type-2 diabetic mice. [6]-Gingerol was reported to restore the disrupted endocrine signaling in rodents. In this current study on Leprdb/db diabetic mice, we investigated the involvement of endocrine pathway in the insulin secretagogue activity of [6]-Gingerol and the mechanism(s) through which [6]-Gingerol ameliorates hyperglycemia. Leprdb/db type 2 diabetic mice were orally administered a daily dose of [6]-Gingerol (200 mg/kg) for 28 days. We measured the plasma levels of different endocrine hormones in fasting and fed conditions. GLP-1 levels were modulated using pharmacological approaches, and cAMP/PKA pathway for insulin secretion was assessed by qRT-PCR and ELISA in isolated pancreatic islets. Total skeletal muscle and its membrane fractions were used to measure glycogen synthase 1 level and Glut4 expression and protein levels. 4-weeks treatment of [6]-Gingerol dramatically increased glucose-stimulated insulin secretion and improved glucose tolerance. Plasma GLP-1 was found to be significantly elevated in the treated mice. Pharmacological intervention of GLP-1 levels regulated the effect of [6]-Gingerol on insulin secretion. Mechanistically, [6]-Gingerol treatment upregulated and activated cAMP, PKA, and CREB in the pancreatic islets, which are critical components of GLP-1-mediated insulin secretion pathway. [6]-Gingerol upregulated both Rab27a GTPase and its effector protein Slp4-a expression in isolated islets, which regulates the exocytosis of insulin-containing dense-core granules. [6]-Gingerol treatment improved skeletal glycogen storage by increased glycogen synthase 1 activity. Additionally, GLUT4 transporters were highly abundant in the membrane of the skeletal myocytes, which could be explained by the increased expression of Rab8 and Rab10

  15. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... when ketones are present may make your blood glucose level go even higher. You'll need to work with your doctor to find the safest way for you to lower your blood glucose level. Cutting down on the amount of food you eat might also help. Work with your dietitian to make changes in your ...

  16. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... by Mail Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page ... and-how-tos, In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood ...

  17. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Your Carbs Count Glycemic Index Low-Calorie Sweeteners Sugar and Desserts Fitness Exercise & Type 1 Diabetes Get Started Safely Get And Stay Fit Types ... the following: High blood glucose High levels of sugar in the ... Part of managing your diabetes is checking your blood glucose often. Ask your ...

  18. Blood Glucose Determination

    DEFF Research Database (Denmark)

    Lippi, Giuseppe; Nybo, Mads; Cadamuro, Janne

    2018-01-01

    The measurement of fasting plasma glucose may be biased by a time-dependent decrease of