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Sample records for choline kinase isoforms

  1. Crystal Structures of Human Choline Kinase Isoforms in Complex with Hemicholinium-3 Single Amino Acid near the Active Site Influences Inhibitor Sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Bum Soo; Allali-Hassani, Abdellah; Tempel, Wolfram; Finerty, Jr., Patrick J.; MacKenzie, Farrell; Dimov, Svetoslav; Vedadi, Masoud; Park, Hee-Won (Toronto)

    2010-07-06

    Human choline kinase (ChoK) catalyzes the first reaction in phosphatidylcholine biosynthesis and exists as ChoK{alpha} ({alpha}1 and {alpha}2) and ChoK{beta} isoforms. Recent studies suggest that ChoK is implicated in tumorigenesis and emerging as an attractive target for anticancer chemotherapy. To extend our understanding of the molecular mechanism of ChoK inhibition, we have determined the high resolution x-ray structures of the ChoK{alpha}1 and ChoK{beta} isoforms in complex with hemicholinium-3 (HC-3), a known inhibitor of ChoK. In both structures, HC-3 bound at the conserved hydrophobic groove on the C-terminal lobe. One of the HC-3 oxazinium rings complexed with ChoK{alpha}1 occupied the choline-binding pocket, providing a structural explanation for its inhibitory action. Interestingly, the HC-3 molecule co-crystallized with ChoK{beta} was phosphorylated in the choline binding site. This phosphorylation, albeit occurring at a very slow rate, was confirmed experimentally by mass spectroscopy and radioactive assays. Detailed kinetic studies revealed that HC-3 is a much more potent inhibitor for ChoK{alpha} isoforms ({alpha}1 and {alpha}2) compared with ChoK{beta}. Mutational studies based on the structures of both inhibitor-bound ChoK complexes demonstrated that Leu-401 of ChoK{alpha}2 (equivalent to Leu-419 of ChoK{alpha}1), or the corresponding residue Phe-352 of ChoK{beta}, which is one of the hydrophobic residues neighboring the active site, influences the plasticity of the HC-3-binding groove, thereby playing a key role in HC-3 sensitivity and phosphorylation.

  2. Differential role of human choline kinase alpha and beta enzymes in lipid metabolism: implications in cancer onset and treatment.

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    David Gallego-Ortega

    Full Text Available BACKGROUND: The Kennedy pathway generates phosphocoline and phosphoethanolamine through its two branches. Choline Kinase (ChoK is the first enzyme of the Kennedy branch of synthesis of phosphocholine, the major component of the plasma membrane. ChoK family of proteins is composed by ChoKalpha and ChoKbeta isoforms, the first one with two different variants of splicing. Recently ChoKalpha has been implicated in the carcinogenic process, since it is over-expressed in a variety of human cancers. However, no evidence for a role of ChoKbeta in carcinogenesis has been reported. METHODOLOGY/PRINCIPAL FINDINGS: Here we compare the in vitro and in vivo properties of ChoKalpha1 and ChoKbeta in lipid metabolism, and their potential role in carcinogenesis. Both ChoKalpha1 and ChoKbeta showed choline and ethanolamine kinase activities when assayed in cell extracts, though with different affinity for their substrates. However, they behave differentially when overexpressed in whole cells. Whereas ChoKbeta display an ethanolamine kinase role, ChoKalpha1 present a dual choline/ethanolamine kinase role, suggesting the involvement of each ChoK isoform in distinct biochemical pathways under in vivo conditions. In addition, while overexpression of ChoKalpha1 is oncogenic when overexpressed in HEK293T or MDCK cells, ChoKbeta overexpression is not sufficient to induce in vitro cell transformation nor in vivo tumor growth. Furthermore, a significant upregulation of ChoKalpha1 mRNA levels in a panel of breast and lung cancer cell lines was found, but no changes in ChoKbeta mRNA levels were observed. Finally, MN58b, a previously described potent inhibitor of ChoK with in vivo antitumoral activity, shows more than 20-fold higher efficiency towards ChoKalpha1 than ChoKbeta. CONCLUSION/SIGNIFICANCE: This study represents the first evidence of the distinct metabolic role of ChoKalpha and ChoKbeta isoforms, suggesting different physiological roles and implications in human

  3. Plasmodium falciparum Choline Kinase Inhibition Leads to a Major Decrease in Phosphatidylethanolamine Causing Parasite Death

    Science.gov (United States)

    Serrán-Aguilera, Lucía; Denton, Helen; Rubio-Ruiz, Belén; López-Gutiérrez, Borja; Entrena, Antonio; Izquierdo, Luis; Smith, Terry K.; Conejo-García, Ana; Hurtado-Guerrero, Ramon

    2016-01-01

    Malaria is a life-threatening disease caused by different species of the protozoan parasite Plasmodium, with P. falciparum being the deadliest. Increasing parasitic resistance to existing antimalarials makes the necessity of novel avenues to treat this disease an urgent priority. The enzymes responsible for the synthesis of phosphatidylcholine and phosphatidylethanolamine are attractive drug targets to treat malaria as their selective inhibition leads to an arrest of the parasite’s growth and cures malaria in a mouse model. We present here a detailed study that reveals a mode of action for two P. falciparum choline kinase inhibitors both in vitro and in vivo. The compounds present distinct binding modes to the choline/ethanolamine-binding site of P. falciparum choline kinase, reflecting different types of inhibition. Strikingly, these compounds primarily inhibit the ethanolamine kinase activity of the P. falciparum choline kinase, leading to a severe decrease in the phosphatidylethanolamine levels within P. falciparum, which explains the resulting growth phenotype and the parasites death. These studies provide an understanding of the mode of action, and act as a springboard for continued antimalarial development efforts selectively targeting P. falciparum choline kinase. PMID:27616047

  4. Understanding the muscular dystrophy caused by deletion of choline kinase beta in mice.

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    Wu, Gengshu; Sher, Roger B; Cox, Gregory A; Vance, Dennis E

    2009-05-01

    Choline kinase in mice is encoded by two genes, Chka and Chkb. Disruption of murine Chka leads to embryonic lethality, whereas a spontaneously occurring genomic deletion in murine Chkb results in neonatal bone deformity and hindlimb muscular dystrophy. We have investigated the mechanism by which a lack of choline kinase beta, encoded by Chkb, causes hindlimb muscular dystrophy. The biosynthesis of phosphatidylcholine (PC) is impaired in the hindlimbs of Chkb -/- mice, with an accumulation of choline and decreased amount of phosphocholine. The activity of CTP: phosphocholine cytidylyltransferase is also decreased in the hindlimb muscle of mutant mice. Concomitantly, the activities of PC phospholipase C and phospholipase A2 are increased. The mitochondria in Chkb -/- mice are abnormally large and exhibit decreased inner membrane potential. Despite the muscular dystrophy in Chkb -/- mice, we observed increased expression of insulin like growth factor 1 and proliferating cell nuclear antigen. However, regeneration of hindlimb muscles of Chkb -/- mice was impaired when challenged with cardiotoxin. Injection of CDP-choline increased PC content of hindlimb muscle and decreased creatine kinase activity in plasma of Chkb -/- mice. We conclude that the hindlimb muscular dystrophy in Chkb -/- mice is due to attenuated PC biosynthesis and enhanced catabolism of PC.

  5. Regulation of NADPH oxidase 5 by protein kinase C isoforms.

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    Feng Chen

    Full Text Available NADPH oxidase5 (Nox5 is a novel Nox isoform which has recently been recognized as having important roles in the pathogenesis of coronary artery disease, acute myocardial infarction, fetal ventricular septal defect and cancer. The activity of Nox5 and production of reactive oxygen species is regulated by intracellular calcium levels and phosphorylation. However, the kinases that phosphorylate Nox5 remain poorly understood. Previous studies have shown that the phosphorylation of Nox5 is PKC dependent, but this contention was based on the use of pharmacological inhibitors and the isoforms of PKC involved remain unknown. Thus, the major goals of this study were to determine whether PKC can directly regulate Nox5 phosphorylation and activity, to identify which isoforms are involved in the process, and to understand the functional significance of this pathway in disease. We found that a relatively specific PKCα inhibitor, Ro-32-0432, dose-dependently inhibited PMA-induced superoxide production from Nox5. PMA-stimulated Nox5 activity was significantly reduced in cells with genetic silencing of PKCα and PKCε, enhanced by loss of PKCδ and the silencing of PKCθ expression was without effect. A constitutively active form of PKCα robustly increased basal and PMA-stimulated Nox5 activity and promoted the phosphorylation of Nox5 on Ser490, Thr494, and Ser498. In contrast, constitutively active PKCε potently inhibited both basal and PMA-dependent Nox5 activity. Co-IP and in vitro kinase assay experiments demonstrated that PKCα directly binds to Nox5 and modifies Nox5 phosphorylation and activity. Exposure of endothelial cells to high glucose significantly increased PKCα activation, and enhanced Nox5 derived superoxide in a manner that was in prevented by a PKCα inhibitor, Go 6976. In summary, our study reveals that PKCα is the primary isoform mediating the activation of Nox5 and this maybe of significance in our understanding of the vascular

  6. Distribution of protein kinase Mzeta and the complete protein kinase C isoform family in rat brain

    DEFF Research Database (Denmark)

    Naik, M U; Benedikz, Eirikur; Hernandez, I

    2000-01-01

    Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region o...

  7. Noninvasive magnetic resonance spectroscopic pharmacodynamic markers of the choline kinase inhibitor MN58b in human carcinoma models.

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    Al-Saffar, Nada M S; Troy, Helen; Ramírez de Molina, Ana; Jackson, Laura E; Madhu, Basetti; Griffiths, John R; Leach, Martin O; Workman, Paul; Lacal, Juan C; Judson, Ian R; Chung, Yuen-Li

    2006-01-01

    MN58b is a novel anticancer drug that inhibits choline kinase, resulting in inhibition of phosphocholine synthesis. The aim of this work was to develop a noninvasive and robust pharmacodynamic biomarker for target inhibition and, potentially, tumor response following MN58b treatment. Human HT29 (colon) and MDA-MB-231 (breast) carcinoma cells were examined by proton (1H) and phosphorus (31P) magnetic resonance spectroscopy (MRS) before and after treatment with MN58b both in culture and in xenografts. An in vitro time course study of MN58b treatment was also carried out in MDA-MB-231 cells. In addition, enzymatic assays of choline kinase activity in cells were done. A decrease in phosphocholine and total choline levels (P < 0.05) was observed in vitro in both cell lines after MN58b treatment, whereas the inactive analogue ACG20b had no effect. In MDA-MB-231 cells, phosphocholine fell significantly as early as 4 hours following MN58b treatment, whereas a drop in cell number was observed at 48 hours. Significant correlation was also found between phosphocholine levels (measured by MRS) and choline kinase activities (r2 = 0.95, P = 0.0008) following MN58b treatment. Phosphomonoesters also decreased significantly (P < 0.05) in both HT29 and MDA-MB-231 xenografts with no significant changes in controls. 31P-MRS and 1H-MRS of tumor extracts showed a significant decrease in phosphocholine (P < or = 0.05). Inhibition of choline kinase by MN58b resulted in altered phospholipid metabolism both in cultured tumor cells and in vivo. Phosphocholine levels were found to correlate with choline kinase activities. The decrease in phosphocholine, total choline, and phosphomonoesters may have potential as noninvasive pharmacodynamic biomarkers for determining tumor response following treatment with choline kinase inhibitors.

  8. Different phosphoinositide 3-kinase isoforms mediate carrageenan nociception and inflammation.

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    Pritchard, Rory A; Falk, Lovissa; Larsson, Mathilda; Leinders, Mathias; Sorkin, Linda S

    2016-01-01

    Phosphoinositide 3-kinases (PI3Ks) participate in signal transduction cascades that can directly activate and sensitize nociceptors and enhance pain transmission. They also play essential roles in chemotaxis and immune cell infiltration leading to inflammation. We wished to determine which PI3K isoforms were involved in each of these processes. Lightly anesthetized rats (isoflurane) were injected subcutaneously with carrageenan in their hind paws. This was preceded by a local injection of 1% DMSO vehicle or an isoform-specific antagonist to PI3K-α (compound 15-e), -β (TGX221), -δ (Cal-101), or -γ (AS252424). We measured changes in the mechanical pain threshold and spinal c-Fos expression (4 hours after injection) as indices of nociception. Paw volume, plasma extravasation (Evans blue, 0.3 hours after injection), and neutrophil (myeloperoxidase; 1 hour after injection) and macrophage (CD11b+; 4 hour after injection) infiltration into paw tissue were the measured inflammation endpoints. Only PI3K-γ antagonist before treatment reduced the carrageenan-induced pain behavior and spinal expression of c-Fos (P ≤ 0.01). In contrast, pretreatment with PI3K-α, -δ, and-γ antagonists reduced early indices of inflammation. Plasma extravasation PI3K-α (P ≤ 0.05), -δ (P ≤ 0.05), and -γ (P ≤ 0.01), early (0-2 hour) edema -α (P ≤ 0.05), -δ (P ≤ 0.001), and -γ (P ≤ 0.05), and neutrophil infiltration (all P ≤ 0.001) were all reduced compared to vehicle pretreatment. Later (2-4 hour), edema and macrophage infiltration (P ≤ 0.05) were reduced by only the PI3K-δ and -γ isoform antagonists, with the PI3K-δ antagonist having a greater effect on edema. PI3K-β antagonism was ineffective in all paradigms. These data indicate that pain and clinical inflammation are pharmacologically separable and may help to explain clinical conditions in which inflammation naturally wanes or goes into remission, but pain continues unabated.

  9. Neuronal and intestinal protein kinase d isoforms mediate Na+ (salt taste)-induced learning.

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    Fu, Ya; Ren, Min; Feng, Hui; Chen, Lu; Altun, Zeynep F; Rubin, Charles S

    2009-08-11

    Ubiquitously expressed protein kinase D (PKD) isoforms are poised to disseminate signals carried by diacylglycerol (DAG). However, the in vivo regulation and functions of PKDs are poorly understood. We show that the Caenorhabditis elegans gene, dkf-2, encodes not just DKF-2A, but also a second previously unknown isoform, DKF-2B. Whereas DKF-2A is present mainly in intestine, we show that DKF-2B is found in neurons. Characterization of dkf-2 null mutants and transgenic animals expressing DKF-2B, DKF-2A, or both isoforms revealed that PKDs couple DAG signals to regulation of sodium ion (Na+)-induced learning. EGL-8 (a phospholipase Cbeta4 homolog) and TPA-1 (a protein kinase Cdelta homolog) are upstream regulators of DKF-2 isoforms in vivo. Thus, pathways containing EGL-8-TPA-1-DKF-2 enable learning and behavioral plasticity by receiving, transmitting, and cooperatively integrating environmental signals targeted to both neurons and intestine.

  10. Molecular and Functional Characterization of a Trypanosoma cruzi Nuclear Adenylate Kinase Isoform

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    María de los Milagros Cámara; Bouvier, León A.; Canepa, Gaspar E.; Mariana R Miranda; Pereira, Claudio A.

    2013-01-01

    Trypanosoma cruzi, the etiological agent of Chagas’ disease, is an early divergent eukaryote in which control of gene expression relies mainly in post-transcriptional mechanisms. Transcription levels are globally up and down regulated during the transition between proliferating and non-proliferating life-cycle stages. In this work we characterized a nuclear adenylate kinase isoform (TcADKn) that is involved in ribosome biogenesis. Nuclear adenylate kinases have been recently described in a fe...

  11. Isoform switch of pyruvate kinase M1 indeed occurs but not to pyruvate kinase M2 in human tumorigenesis.

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    Cheng Zhan

    Full Text Available Muscle type of pyruvate kinase (PKM is one of the key mediators of the Warburg effect and tumor metabolism. Due to alternative splicing, there are at least 12 known isoforms of the PKM gene, of which PKM1 and PKM2 are two major isoforms with only a 23 amino acid sequenced difference but quite different characteristics and functions. It was previously thought the isoform switch from PKM1 to PKM2 resulted in high PKM2 expression in tumors, providing a great advantage to tumor cells. However, this traditional view was challenged by two recent studies; one study claimed that this isoform switch does not occur during the Warburg effect; the other study asserted that the isoform switch is tissue-specific. Here, we re-analyzed the RNA sequencing data of 25 types of human tumors from The Cancer Genome Atlas Data Portal, and confirmed that PKM2 was the major isoform in the tumors and was highly elevated in addition to the entire PKM gene. We further demonstrated that the expression level of PKM1 significantly declined even though there was substantially increased expression of the entire PKM gene. The proportion of PKM1 in total transcript variants also significantly declined in tumors but the proportion of PKM2 did not change accordingly. Therefore, we conclude that the isoform switch of PKM1 does indeed occur, but it switches to other isoforms rather than PKM2. Considering the change in the expression levels of PKM1, PKM2 and the entire PKM gene, we propose that the upregulation of PKM2 is primarily due to elevated transcriptional levels of the entire PKM gene, instead of the isoform switch.

  12. Synthesis of Benzofuran Analogue of Go6976, an Isoform Selective Protein Kinase C Inhibitor

    Institute of Scientific and Technical Information of China (English)

    MA, Da-Wei; ZHANG, Xin-Rong; WU, Shi-Hui; TAO, Feng-Gang

    2001-01-01

    Based on the structure of Go6976, a known isoform-selective protein kinase C inhibitor, a benzofuran analogue (1) was designed. This analogue was synthesized by coupling of benzofuran 3-acetic acid and 8-oxo-tryptamine and subsequent intramolecular Dieckmann condensation, alkylation, oxidative photocyclization and cyanation reaction of mesylate.

  13. Choline kinase alpha and hexokinase-2 protein expression in hepatocellular carcinoma: association with survival.

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    Sandi A Kwee

    Full Text Available PURPOSE: Hexokinase-2 (HK2 and more recently choline kinase alpha (CKA expression has been correlated with clinical outcomes in several major cancers. This study examines the protein expression of HK2 and CKA in hepatocellular carcinoma (HCC in association with patient survival and other clinicopathologic parameters. METHODS: Immunohistochemical analysis for HK2 and CKA expression was performed on a tissue microarray of 157 HCC tumor samples. Results were analyzed in relation to clinicopathologic data from Surveillance, Epidemiology, and End-Results Program registries. Mortality rates were assessed by Kaplan-Meier estimates and compared using log-rank tests. Predictors of overall survival were assessed using proportional hazards regression. RESULTS: Immunohistochemical expression of HK2 and CKA was detected in 71 (45% and 55 (35% tumor samples, respectively. Differences in tumor HK2 expression were associated with tumor grade (p = 0.008 and cancer stage (p = 0.001, while CKA expression differed significantly only across cancer stage (p = 0.048. Increased mortality was associated with tumor HK2 expression (p = 0.003 as well as CKA expression (p = 0.03 with hazard ratios of 1.86 (95% confidence interval (CI 1.23-2.83 and 1.59 (95% CI 1.04-2.41, respectively. Similar effects on overall survival were noted in a subset analysis of early stage (I and II HCC. Tumor HK2 expression, but not CKA expression, remained a significant predictor of survival in multivariable analyses. CONCLUSION: HK2 and CKA expression may have biologic and prognostic significance in HCC, with tumor HK2 expression being a potential independent predictor of survival.

  14. Histone deacetylase inhibition increases levels of choline kinase α and phosphocholine facilitating noninvasive imaging in human cancers.

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    Beloueche-Babari, Mounia; Arunan, Vaitha; Troy, Helen; te Poele, Robert H; te Fong, Anne-Christine Wong; Jackson, L Elizabeth; Payne, Geoffrey S; Griffiths, John R; Judson, Ian R; Workman, Paul; Leach, Martin O; Chung, Yuen-Li

    2012-02-15

    Histone deacetylase (HDAC) inhibitors are currently approved for cutaneous T-cell lymphoma and are in mid-late stage trials for other cancers. The HDAC inhibitors LAQ824 and SAHA increase phosphocholine (PC) levels in human colon cancer cells and tumor xenografts as observed by magnetic resonance spectroscopy (MRS). In this study, we show that belinostat, an HDAC inhibitor with an alternative chemical scaffold, also caused a rise in cellular PC content that was detectable by (1)H and (31)P MRS in prostate and colon carcinoma cells. In addition, (1)H MRS showed an increase in branched chain amino acid and alanine concentrations. (13)C-choline labeling indicated that the rise in PC resulted from increased de novo synthesis and correlated with an induction of choline kinase α expression. Furthermore, metabolic labeling experiments with (13)C-glucose showed that differential glucose routing favored alanine formation at the expense of lactate production. Additional analysis revealed increases in the choline/water and phosphomonoester (including PC)/total phosphate ratios in vivo. Together, our findings provide mechanistic insights into the impact of HDAC inhibition on cancer cell metabolism and highlight PC as a candidate noninvasive imaging biomarker for monitoring the action of HDAC inhibitors.

  15. MAP kinase pathways and calcitonin influence CD44 alternate isoform expression in prostate cancer cells

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    Yang Kui

    2008-09-01

    Full Text Available Abstract Background Dysregulated expression and splicing of cell adhesion marker CD44 is found in many types of cancer. In prostate cancer (PC specifically, the standard isoform (CD44s has been found to be downregulated compared with benign tissue whereas predominant variant isoform CD44v7-10 is upregulated. Mitogen-activated protein kinase pathways and paracrine calcitonin are two common factors linked to dysregulated expression and splicing of CD44 in cancer. Calcitonin has been found to increase proliferation and invasion in PC acting through the protein kinase A pathway. Methods In androgen-independent PC with known high CD44v7-10 expression, CD44 total and CD44v7-10 RNA or protein were assessed in response to exogenous and endogenous calcitonin and to inhibitors of protein kinase A, MEK, JNK, or p38 kinase. Benign cells and calcitonin receptor-negative PC cells were also tested. Results MEK or p38 but not JNK reduced CD44 total RNA by 40%–65% in cancer and benign cells. Inhibition of protein kinase A reduced CD44 total and v7-10 protein expression. In calcitonin receptor-positive cells only, calcitonin increased CD44 variant RNA and protein by 3 h and persisting to 48 h, apparently dependent on an uninhibited p38 pathway. Cells with constitutive CT expression showed an increase in CD44v7-10 mRNA but a decrease in CD44 total RNA. Conclusion The MEK pathway increases CD44 RNA, while calcitonin, acting through the protein kinase A and p38 pathway, facilitates variant splicing. These findings could be used in the formulation of therapeutic methods for PC targeting CD44 alternate splicing.

  16. Structural basis for isoform selectivity in a class of benzothiazole inhibitors of phosphoinositide 3-kinase γ.

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    Collier, Philip N; Martinez-Botella, Gabriel; Cornebise, Mark; Cottrell, Kevin M; Doran, John D; Griffith, James P; Mahajan, Sudipta; Maltais, François; Moody, Cameron S; Huck, Emilie Porter; Wang, Tiansheng; Aronov, Alex M

    2015-01-08

    Phosphoinositide 3-kinase γ (PI3Kγ) is an attractive target to potentially treat a range of disease states. Herein, we describe the evolution of a reported phenylthiazole pan-PI3K inhibitor into a family of potent and selective benzothiazole inhibitors. Using X-ray crystallography, we discovered that compound 22 occupies a previously unreported hydrophobic binding cleft adjacent to the ATP binding site of PI3Kγ, and achieves its selectivity by exploiting natural sequence differences among PI3K isoforms in this region.

  17. Nonmetabolic functions of pyruvate kinase isoform M2 in controlling cell cycle progression and tumorigenesis

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    Zhimin Lu

    2012-01-01

    Pyruvate kinase catalyzes the rate-limiting final step of glycolysis,generating adenosine triphosphate (ATP) and pyruvate.The M2 tumor-specific isoform of pyruvate kinase (PKM2) promotes glucose uptake and lactate production in the presence of oxygen,known as aerobic glycolysis or the Warburg effect.As recently reported in Nature,PKM2,besides its metabolic function,has a nonmetabolic function in the direct control of cell cycle progression by activating β-catenin and inducing expression of the β-catenin downstream gene CCND1 (encoding for cyclin D1).This nonmetabolic function of PKM2 is essential for epidermal growth factor receptor (EGFR) activation-induced tumorigenesis.

  18. Cancer metabolism meets systems biology: Pyruvate kinase isoform PKM2 is a metabolic master regulator

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    Fabian V Filipp

    2013-01-01

    Full Text Available Pyruvate kinase activity is controlled by a tightly woven regulatory network. The oncofetal isoform of pyruvate kinase (PKM2 is a master regulator of cancer metabolism. PKM2 engages in parallel, feed-forward, positive and negative feedback control contributing to cancer progression. Besides its metabolic role, non-metabolic functions of PKM2 as protein kinase and transcriptional coactivator for c-MYC and hypoxia-inducible factor 1-alpha are essential for epidermal growth factor receptor activation-induced tumorigenesis. These biochemical activities are controlled by a shift in the oligomeric state of PKM2 that includes acetylation, oxidation, phosphorylation, prolyl hydroxylation and sumoylation. Metabolically active PKM2 tetramer is allosterically regulated and responds to nutritional and stress signals. Metabolically inactive PKM2 dimer is imported into the nucleus and can function as protein kinase stimulating transcription. A systems biology approach to PKM2 at the genome, transcriptome, proteome, metabolome and fluxome level reveals how differences in biomolecular structure translate into a global rewiring of cancer metabolism. Cancer systems biology takes us beyond the Warburg effect, opening unprecedented therapeutic opportunities.

  19. Differential regulation of T cell antigen responsiveness by isoforms of the src-related tyrosine protein kinase p59fyn

    OpenAIRE

    1992-01-01

    Recent observations suggest that the src-related tyrosine protein kinase p59fyn may be involved in antigen-induced T lymphocyte activation. As a result of alternative splicing, p59fyn exists as two isoforms that differ exclusively within a short sequence spanning the end of the Src Homology 2 (SH2) region and the beginning of the tyrosine protein kinase domain. While one p59fyn isoform (fynB) is highly expressed in brain, the alternative product (fynT) is principally found in T lymphocytes. T...

  20. Sequential activation of protein kinase C isoforms by organic dust is mediated by tumor necrosis factor.

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    Wyatt, Todd A; Slager, Rebecca E; Heires, Arthur J; Devasure, Jane M; Vonessen, Susanna G; Poole, Jill A; Romberger, Debra J

    2010-06-01

    Dust samples collected from Nebraska swine confinement facilities (hog dust extract [HDE]) are known to elicit proinflammatory cytokine release from human bronchial epithelial (HBE) cells in vitro. This response involves the activation of two protein kinase C (PKC) isoforms: PKCalpha and PKCepsilon. Experiments were designed to investigate the relationship between the two isoenzymes and the degree to which each is responsible for cytokine release in HBE. Experiments also examined the contribution of TNF-alpha to IL-6 and IL-8 release. PKCalpha and PKCepsilon activities were inhibited using isoform-specific pharmacologic inhibitors and genetically modified dominant-negative (DN) expressing cell lines. Release of the proinflammatory cytokines IL-6, IL-8, and TNF-alpha was measured and PKC isoform activities assessed. We found that HDE stimulates PKCalpha activity by 1 hour, and within 6 hours the activity returns to baseline. PKCalpha-specific inhibitor or PKCalphaDN cells abolish this HDE-mediated effect. Both IL-6 and IL-8 release are likewise diminished under these conditions compared with normal HBE, and treatment with TNF-alpha-neutralizing antibody does not further inhibit cytokine release. In contrast, PKCepsilon activity was enhanced by 6 hours after HDE treatment. TNF-alpha blockade abrogated this effect. HDE-stimulated IL-6, but not IL-8 release in PKCepsilonDN cells. The concentration of TNF-alpha released by HDE-stimulated HBE is sufficient to have a potent cytokine-eliciting effect. A time course of TNF-alpha release suggests that TNF-alpha is produced after PKCalpha activation, but before PKCepsilon. These results suggest a temporal ordering of events responsible for the release of cytokines, which initiate and exacerbate inflammatory events in the airways of people exposed to agricultural dust.

  1. Direct binding and activation of protein kinase C isoforms by steroid hormones.

    LENUS (Irish Health Repository)

    Alzamora, Rodrigo

    2008-10-01

    The non-genomic action of steroid hormones regulates a wide variety of cellular responses including regulation of ion transport, cell proliferation, migration, death and differentiation. In order to achieve such plethora of effects steroid hormones utilize nearly all known signal transduction pathways. One of the key signalling molecules regulating the non-genomic action of steroid hormones is protein kinase C (PKC). It is thought that rapid action of steroids hormones results from the activation of plasma membrane receptors; however, their molecular identity remains elusive. In recent years, an increasing number of studies have pointed at the selective binding and activation of specific PKC isoforms by steroid hormones. This has led to the hypothesis that PKC could act as a receptor as well as a transducer of the non-genomic effects of these hormones. In this review we summarize the current knowledge of the direct binding and activation of PKC by steroid hormones.

  2. Myophilin of Echinococcus granulosus: isoforms and phosphorylation by protein kinase C.

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    Martin, R M; Csar, X F; Gasser, R B; Felleisen, R; Lightowlers, M W

    1997-08-01

    Myophilin is a muscle-associated antigen of the taeniid cestode Echinococcus granulosus. This protein shows a high amino acid sequence homology with calponins and calponin-like proteins, which are proposed to be associated with the regulation of smooth muscle contraction. In order to provide supportive evidence for a relationship between these proteins, we characterized myophilin using electrophoretic, biochemical and molecular biological approaches. Two-dimensional protein electrophoretic separation of E. granulosus larval proteins defined 4 isoelectric isoforms of myophilin (alpha, beta, gamma and delta), which appeared to be a consequence of post-translational modification of a single gene product. It was also demonstrated biochemically that E. granulosus myophilin undergoes specific phosphorylation in vitro by protein kinase C (PKC). Finally, myophilin homologues were identified in extracts of Taenia hydatigena and T. ovis by immunoblot. A partial cDNA of the closely related species, E. multilocularis, was isolated by cloning procedures and showed 99% homology with the E. granulosus myophilin gene. The similarities of E. granulosus myophilin with calponins in their tissue localization, protein isoforms patterns, ability to be phosphorylated in vitro by PKC, and the relatively conserved nature of the protein among related parasites suggest that myophilin may be associated with smooth muscle contraction.

  3. Loss of glycogen synthase kinase 3 isoforms during murine oocyte growth induces offspring cardiac dysfunction.

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    Monteiro da Rocha, André; Ding, Jun; Slawny, Nicole; Wolf, Amber M; Smith, Gary D

    2015-05-01

    Glycogen synthase kinase-3 (GSK3) is a constitutively active serine threonine kinase with 1) two isoforms (GSK3A and GSK3B) that have unique and overlapping functions, 2) multiple molecular intracellular mechanisms that involve phosphorylation of diverse substrates, and 3) implications in pathogenesis of many diseases. Insulin causes phosphorylation and inactivation of GSK3 and mammalian oocytes have a functional insulin-signaling pathway whereby prolonged elevated insulin during follicle/oocyte development causes GSK3 hyperphosphorylation, reduced GSK3 activity, and altered oocyte chromatin remodeling. Periconceptional diabetes and chronic hyperinsulinemia are associated with congenital malformations and onset of adult diseases of cardiovascular origin. Objectives were to produce transgenic mice with individual or concomitant loss of GSK3A and/or GSK3B and investigate the in vivo role of oocyte GSK3 on fertility, fetal development, and offspring health. Wild-type males bred to females with individual or concomitant loss of oocyte GSK3 isoforms did not have reduced fertility. However, concomitant loss of GSK3A and GSK3B in the oocyte significantly increased neonatal death rate due to congestive heart failure secondary to ventricular hyperplasia. Individual loss of oocyte GSK3A or GSK3B did not induce this lethal phenotype. In conclusion, absence of oocyte GSK3 in the periconceptional period does not alter fertility yet causes offspring cardiac hyperplasia, cardiovascular defects, and significant neonatal death. These results support a developmental mechanism by which periconceptional hyperinsulinemia associated with maternal metabolic syndrome, obesity, and/or diabetes can act on the oocyte and affect offspring cardiovascular development, function, and congenital heart malformation.

  4. PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70-KILODALTON HEAT SHOCK PROTEIN HSPA2

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    THE PUTATIVE CREATINE KINASE M-ISOFORM IN HUMAN SPERM IS IDENTIFIED AS THE 70 kDa HEAT SHOCK PROTEIN HSPA2* Gabor Huszar1, Kathryn Stone2, David Dix3 and Lynne Vigue11The Sperm Physiology Laboratory, Department of Obstetrics and Gynecology, 2 W.M. Keck Foundatio...

  5. Design, synthesis, crystallization and biological evaluation of new symmetrical biscationic compounds as selective inhibitors of human Choline Kinase α1 (ChoKα1)

    Science.gov (United States)

    Schiaffino-Ortega, Santiago; Baglioni, Eleonora; Mariotto, Elena; Bortolozzi, Roberta; Serrán-Aguilera, Lucía; Ríos-Marco, Pablo; Carrasco-Jimenez, M. Paz; Gallo, Miguel A.; Hurtado-Guerrero, Ramon; Marco, Carmen; Basso, Giuseppe; Viola, Giampietro; Entrena, Antonio; López-Cara, Luisa Carlota

    2016-03-01

    A novel family of compounds derivative of 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bispyridinium or -bisquinolinium bromide (10a-l) containing a pair of oxygen atoms in the spacer of the linker between the biscationic moieties, were synthesized and evaluated as inhibitors of choline kinase against a panel of cancer-cell lines. The most promising compounds in this series were 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))bis(4-(dimethylamino)pyridinium) bromide (10a) and 1,1‧-(((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methylene))-bis(7-chloro-4-(pyrrolidin-1-yl)quinolinium) bromide (10l), which inhibit human choline kinase (ChoKα1) with IC50 of 1.0 and 0.92 μM, respectively, in a range similar to that of the previously reported biscationic compounds MN58b and RSM932A. Our compounds show greater antiproliferative activities than do the reference compounds, with unprecedented values of GI50 in the nanomolar range for several of the cancer-cell lines assayed, and more importantly they present low toxicity in non-tumoral cell lines, suggesting a cancer-cell-selective antiproliferative activity. Docking studies predict that the compounds interact with the choline-binding site in agreement with the binding mode of most previously reported biscationic compounds. Moreover, the crystal structure of ChoKα1 with compound 10a reveals that this compound binds to the choline-binding site and mimics HC-3 binding mode as never before.

  6. The phosphoarginine energy-buffering system of trypanosoma brucei involves multiple arginine kinase isoforms with different subcellular locations.

    Directory of Open Access Journals (Sweden)

    Frank Voncken

    Full Text Available Phosphagen energy-buffering systems play an essential role in regulating the cellular energy homeostasis in periods of high-energy demand or energy supply fluctuations. Here we describe the phosphoarginine/arginine kinase system of the kinetoplastid parasite Trypanosoma brucei, consisting of three highly similar arginine kinase isoforms (TbAK1-3. Immunofluorescence microscopy using myc-tagged protein versions revealed that each isoform is located in a specific subcellular compartment: TbAK1 is exclusively found in the flagellum, TbAK2 in the glycosome, and TbAK3 in the cytosol of T. brucei. The flagellar location of TbAK1 is dependent on a 22 amino acid long N-terminal sequence, which is sufficient for targeting a GFP-fusion protein to the trypanosome flagellum. The glycosomal location of TbAK2 is in agreement with the presence of a conserved peroxisomal targeting signal, the C-terminal tripeptide 'SNL'. TbAK3 lacks any apparent targeting sequences and is accordingly located in the cytosol of the parasite. Northern blot analysis indicated that each TbAK isoform is differentially expressed in bloodstream and procyclic forms of T. brucei, while the total cellular arginine kinase activity was 3-fold higher in bloodstream form trypanosomes. These results suggest a substantial change in the temporal and spatial energy requirements during parasite differentiation. Increased arginine kinase activity improved growth of procyclic form T. brucei during oxidative challenges with hydrogen peroxide. Elimination of the total cellular arginine kinase activity by RNA interference significantly decreased growth (>90% of procyclic form T. brucei under standard culture conditions and was lethal for this life cycle stage in the presence of hydrogen peroxide. The putative physiological roles of the different TbAK isoforms in T. brucei are further discussed.

  7. Two p90 ribosomal S6 kinase isoforms are involved in the regulation of mitotic and meiotic arrest in Artemia.

    Science.gov (United States)

    Duan, Ru-Bing; Zhang, Li; Chen, Dian-Fu; Yang, Fan; Yang, Jin-Shu; Yang, Wei-Jun

    2014-06-06

    There are multiple isoforms of p90 ribosomal S6 kinase (RSK), which regulate diverse cellular functions such as cell growth, proliferation, maturation, and motility. However, the relationship between the structures and functions of RSK isoforms remains undetermined. Artemia is a useful model in which to study cell cycle arrest because these animals undergo prolonged diapauses, a state of obligate dormancy. A novel RSK isoform was identified in Artemia, which was termed Ar-Rsk2. This isoform was compared with an RSK isoform that we previously identified in Artemia, termed Ar-Rsk1. Ar-Rsk2 has an ERK-docking motif, whereas Ar-Rsk1 does not. Western blot analysis revealed that Ar-Rsk1 was activated by phosphorylation, which blocked meiosis in oocytes. Knockdown of Ar-Rsk1 reduced the level of phosphorylated cdc2 and thereby suppressed cytostatic factor activity. This indicates that Ar-Rsk1 regulates the cytostatic factor in meiosis. Expression of Ar-Rsk2 was down-regulated in Artemia cysts in which mitosis was arrested. Knockdown of Ar-Rsk2 resulted in decreased levels of cyclin D3 and phosphorylated histone H3, and the production of pseudo-diapause cysts. This indicates that Ar-Rsk2 regulates mitotic arrest. PLK and ERK RNAi showed that Ar-Rsk2, but not Ar-Rsk1, could be activated by PLK-ERK in Artemia. This is the first study to report that RSK isoforms with and without an ERK-docking motif regulate mitosis and meiosis, respectively. This study provides insight into the relationship between the structures and functions of RSK isoforms.

  8. Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Wenjuan; Huang, Hui; Wang, Yanfei [Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wong, Tsz Yan [Food and Nutritional Sciences Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wang, C.C. [Department of Obstetrics and Gynecology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Leung, Lai K., E-mail: laikleung@cuhk.edu.hk [Biochemistry Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Food and Nutritional Sciences Programme, School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T. (Hong Kong)

    2013-06-01

    Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200 mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase. - Highlights: • The pollutant bisphenol A differentially activated PKC isoforms in the placenta. • CRE-binding activity in the nuclear protein of placenta was increased. • Bisphenol A induces CRH mRNA expression in mice.

  9. Early detection of skeletal muscle injury by assay of creatine kinase MM isoforms in serum after acute exercise

    DEFF Research Database (Denmark)

    Apple, F. S.; Hellsten, Ylva; Clarkson, P. M.

    1988-01-01

    concentric strength--a form of exercise previously shown to cause significant increases of CK in serum at 24 h and muscle soreness 48 h after exercise. Total CK and CK-MM isoform activities in serum were determined before and at 0.5, 0.75, 1, 1.5, 2, and 6 h after exercise. Using thin-film agarose gels......We could detect skeletal muscle injury early after an acute exercise bout by measuring creatine kinase (CK, EC 2.7.3.2) MM isoforms in serum. Eleven men performed 120 alternating-arm, eccentric (muscle lengthening) biceps contractions with the intensity of each contraction being 110% of maximal...... and a rapid isoelectric focusing technique, we separated the MM isoforms into MM3 (skeletal muscle form), MM2, and MM1 (in vivo conversion forms). The isoforms reflected the MM form released into the serum from tissue as well as the conversion of one form to another. There were no significant increases...

  10. Molecular cloning and biochemical characterization of three phosphoglycerate kinase isoforms from developing sunflower (Helianthus annuus L.) seeds.

    Science.gov (United States)

    Troncoso-Ponce, M A; Rivoal, J; Venegas-Calerón, M; Dorion, S; Sánchez, R; Cejudo, F J; Garcés, R; Martínez-Force, E

    2012-07-01

    Three cDNAs encoding different phosphoglycerate kinase (PGK, EC 2.7.2.3) isoforms, two cytosolic (HacPGK1 and HacPGK2) and one plastidic (HapPGK), were cloned and characterized from developing sunflower (Helianthus annuus L.) seeds. The expression profiles of these genes showed differences in heterotrophic tissues, such as developing seeds and roots, where HacPGK1 was predominant, while HapPGK was highly expressed in photosynthetic tissues. The cDNAs were expressed in Escherichia coli, and the corresponding proteins purified to electrophoretic homogeneity, using immobilized metal ion affinity chromatography, and biochemically characterized. Despite the high level of identity between sequences, the HacPGK1 isoform showed strong differences in terms of specific activity, temperature stability and pH sensitivity in comparison to HacPGK2 and HapPGK. A polyclonal immune serum was raised against the purified HacPGK1 isoform, which showed cross-immunoreactivity with the other PGK isoforms. This serum allowed the localization of high expression levels of PGK isozymes in embryo tissues.

  11. Progesterone receptor isoforms PRA and PRB differentially contribute to breast cancer cell migration through interaction with focal adhesion kinase complexes.

    Science.gov (United States)

    Bellance, Catherine; Khan, Junaid A; Meduri, Geri; Guiochon-Mantel, Anne; Lombès, Marc; Loosfelt, Hugues

    2013-05-01

    Progesterone receptor (PR) and progestins affect mammary tumorigenesis; however, the relative contributions of PR isoforms A and B (PRA and PRB, respectively) in cancer cell migration remains elusive. By using a bi-inducible MDA-MB-231 breast cancer cell line expressing PRA and/or PRB, we analyzed the effect of conditional PR isoform expression. Surprisingly, unliganded PRB but not PRA strongly enhanced cell migration as compared with PR(-) cells. 17,21-Dimethyl-19-norpregna-4,9-dien-3,20-dione (R5020) progestin limited this effect and was counteracted by the antagonist 11β-(4-dimethyl-amino)-phenyl-17β-hydroxy-17-(1-propynyl)-estra-4,9-dien-3-one (RU486). Of importance, PRA coexpression potentiated PRB-mediated migration, whereas PRA alone was ineffective. PR isoforms differentially regulated expressions of major players of cell migration, such as urokinase plasminogen activator (uPA), its inhibitor plasminogen activator inhibitor type 1, uPA receptor (uPAR), and β1-integrin, which affect focal adhesion kinase (FAK) signaling. Moreover, unliganded PRB but not PRA enhanced FAK Tyr397 phosphorylation and colocalized with activated FAK in cell protrusions. Because PRB, as well as PRA, coimmunoprecipitated with FAK, both isoforms can interact with FAK complexes, depending on their respective nucleocytoplasmic trafficking. In addition, FAK degradation was coupled to R5020-dependent turnovers of PRA and PRB. Such an effect of PRB/PRA expression on FAK signaling might thus affect adhesion/motility, underscoring the implication of PR isoforms in breast cancer invasiveness and metastatic evolution with underlying therapeutic outcomes.

  12. A tail-anchored myotonic dystrophy protein kinase isoform induces perinuclear clustering of mitochondria, autophagy, and apoptosis.

    Directory of Open Access Journals (Sweden)

    Ralph J A Oude Ophuis

    Full Text Available BACKGROUND: Studies on the myotonic dystrophy protein kinase (DMPK gene and gene products have thus far mainly concentrated on the fate of length mutation in the (CTGn repeat at the DNA level and consequences of repeat expansion at the RNA level in DM1 patients and disease models. Surprisingly little is known about the function of DMPK protein products. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate here that transient expression of one major protein product of the human gene, the hDMPK A isoform with a long tail anchor, results in mitochondrial fragmentation and clustering in the perinuclear region. Clustering occurred in a variety of cell types and was enhanced by an intact tubulin cytoskeleton. In addition to morphomechanical changes, hDMPK A expression induces physiological changes like loss of mitochondrial membrane potential, increased autophagy activity, and leakage of cytochrome c from the mitochondrial intermembrane space accompanied by apoptosis. Truncation analysis using YFP-hDMPK A fusion constructs revealed that the protein's tail domain was necessary and sufficient to evoke mitochondrial clustering behavior. CONCLUSION/SIGNIFICANCE: Our data suggest that the expression level of the DMPK A isoform needs to be tightly controlled in cells where the hDMPK gene is expressed. We speculate that aberrant splice isoform expression might be a codetermining factor in manifestation of specific DM1 features in patients.

  13. Activation of P2X7 receptors causes isoform-specific translocation of protein kinase C in osteoclasts.

    Science.gov (United States)

    Armstrong, Souzan; Pereverzev, Alexey; Dixon, S Jeffrey; Sims, Stephen M

    2009-01-01

    Nucleotides, released in response to mechanical or inflammatory stimuli, signal through P2 nucleotide receptors in many cell types. Osteoclasts express P2X7 receptors (encoded by P2rx7) - Ca(2+)-permeable channels that are activated by high concentrations of extracellular ATP. Genetic disruption of P2rx7 leads to increased resorption and reduced skeletal response to mechanical stimuli. To investigate whether P2X7 receptors couple to activation of protein kinase C (PKC), RAW 264.7 cells were differentiated into multinucleated osteoclast-like cells and live-cell confocal imaging was used to localize enhanced green fluorescent protein (EGFP)-tagged PKC. Benzoylbenzoyl-ATP (BzATP; a P2X7 agonist) induced transient translocation of PKCalpha to the basolateral membrane. UTP or ATP (10 microM), which activate P2 receptors other than P2X7, failed to induce translocation. Moreover, BzATP failed to induce PKC translocation in osteoclasts derived from the bone marrow of P2rx7(-/-) mice, demonstrating specificity for P2X7. BzATP induced a transient rise of cytosolic Ca(2+), and removal of extracellular Ca(2+) abolished the translocation of PKCalpha that was induced by BzATP (but not by phorbol ester). We examined the isoform specificity of this response, and observed translocation of the Ca(2+)-dependent isoforms PKCalpha and PKCbetaI, but not the Ca(2+)-independent isoform PKCdelta. Thus, activation of P2X7 receptors specifically induces Ca(2+)-dependent translocation of PKC to the basolateral membrane domain of osteoclasts, an aspect of spatiotemporal signaling not previously recognized.

  14. Distinct cellular and subcellular distributions of G protein-coupled receptor kinase and arrestin isoforms in the striatum.

    Directory of Open Access Journals (Sweden)

    Evgeny Bychkov

    Full Text Available G protein-coupled receptor kinases (GRKs and arrestins mediate desensitization of G protein-coupled receptors (GPCR. Arrestins also mediate G protein-independent signaling via GPCRs. Since GRK and arrestins demonstrate no strict receptor specificity, their functions in the brain may depend on their cellular complement, expression level, and subcellular targeting. However, cellular expression and subcellular distribution of GRKs and arrestins in the brain is largely unknown. We show that GRK isoforms GRK2 and GRK5 are similarly expressed in direct and indirect pathway neurons in the rat striatum. Arrestin-2 and arrestin-3 are also expressed in neurons of both pathways. Cholinergic interneurons are enriched in GRK2, arrestin-3, and GRK5. Parvalbumin-positive interneurons express more of GRK2 and less of arrestin-2 than medium spiny neurons. The GRK5 subcellular distribution in the human striatal neurons is altered by its phosphorylation: unphosphorylated enzyme preferentially localizes to synaptic membranes, whereas phosphorylated GRK5 is found in plasma membrane and cytosolic fractions. Both GRK isoforms are abundant in the nucleus of human striatal neurons, whereas the proportion of both arrestins in the nucleus was equally low. However, overall higher expression of arrestin-2 yields high enough concentration in the nucleus to mediate nuclear functions. These data suggest cell type- and subcellular compartment-dependent differences in GRK/arrestin-mediated desensitization and signaling.

  15. Diacylglycerol kinase theta and zeta isoforms : regulation of activity, protein binding partners and physiological functions

    NARCIS (Netherlands)

    Los, Alrik Pieter

    2007-01-01

    Diacylglycerol kinases (DGKs) phosphorylate the second messenger diacylglycerol (DAG) yielding phosphatidic acid (PA). In this thesis, we investigated which structural domains of DGKtheta are required for DGK activity. Furthermore, we showed that DGKzeta binds to and is activated by the Retinoblasto

  16. Na+/H+ exchanger isoform 1 induced cardiomyocyte hypertrophy involves activation of p90 ribosomal s6 kinase.

    Science.gov (United States)

    Jaballah, Maiy; Mohamed, Iman A; Alemrayat, Bayan; Al-Sulaiti, Fatima; Mlih, Mohamed; Mraiche, Fatima

    2015-01-01

    Studies using pharmacological and genetic approaches have shown that increased activity/expression of the Na+/H+ exchanger isoform 1 (NHE1) play a critical role in the pathogenesis of cardiac hypertrophy. Despite the importance of NHE1 in cardiac hypertrophy, severe cerebrovascular side effects were associated with the use of NHE1 inhibitors when administered to patients with myocardial infarctions. p90 ribosomal S6 Kinase (RSK), a downstream regulator of the mitogen-activated protein kinase pathway, has also been implicated in cardiac hypertrophy. We hypothesized that RSK plays a role in the NHE1 induced cardiomyocyte hypertrophic response. Infection of H9c2 cardiomyoblasts with the active form of the NHE1 adenovirus induced hypertrophy and was associated with an increase in the phosphorylation of RSK (Phypertrophy such as cell area, protein content and atrial natriuretic mRNA expression were significantly reduced in H9c2 cardiomyoblasts infected with active NHE1 in the presence of dominant negative RSK (DN-RSK) (Phypertrophy is accounted for by increased activation and phosphorylation of RSK, which subsequently increased the phosphorylation of GATA4; eventually activating fetal gene transcriptional machinery.

  17. Heterologous expression and biochemical characterization of two calcium-dependent protein kinase isoforms CaCPK1 and CaCPK2 from chickpea.

    Science.gov (United States)

    Syam Prakash, S R; Jayabaskaran, Chelliah

    2006-11-01

    In plants, calcium-dependent protein kinases (CPKs) constitute a unique family of enzymes consisting of a protein kinase catalytic domain fused to carboxy-terminal autoregulatory and calmodulin-like domains. We isolated two cDNAs encoding calcium-dependent protein kinase isoforms (CaCPK1 and CaCPK2) from chickpea. Both isoforms were expressed as fusion proteins in Escherichia coli. Biochemical analyses have identified CaCPK1 and CaCPK2 as Ca(2+)-dependent protein kinases since both enzymes phosphorylated themselves and histone III-S as substrate only in the presence of Ca(2+). The kinase activity of the recombinant enzymes was calmodulin independent and sensitive to CaM antagonists W7 [N-(6-aminohexyl)-5-chloro-1-naphthalene sulphonamide] and calmidazoilum. Phosphoamino acid analysis revealed that the isoforms transferred the gamma-phosphate of ATP only to serine residues of histone III-S and their autophosphorylation occurred on serine and threonine residues. These two isoforms showed considerable variations with respect to their biochemical and kinetic properties including Ca(2+) sensitivities. The recombinant CaCPK1 has a pH and temperature optimum of pH 6.8-8.6 and 35-42 degrees C, respectively, whereas CaCPK2 has a pH and temperature optimum of pH 7.2-9 and 35-42 degrees C, respectively. Taken together, our results suggest that CaCPK1 and CaCPK2 are functional serine/threonine kinases and may play different roles in Ca(2+)-mediated signaling in chickpea plants.

  18. Cloning and Characterization of Two NAD Kinases from Arabidopsis. Identification of a Calmodulin Binding Isoform1[w

    Science.gov (United States)

    Turner, William L.; Waller, Jeffrey C.; Vanderbeld, Barb; Snedden, Wayne A.

    2004-01-01

    NAD kinase (NADK; ATP:NAD 2′-phosphotransferase, EC 2.7.1.23), an enzyme found in both prokaryotes and eukaryotes, generates the important pyridine nucleotide NADP from substrates ATP and NAD. The role of NADKs in plants is poorly understood, and cDNAs encoding plant NADKs have not previously been described to our knowledge. We have cloned two cDNAs from Arabidopsis predicted to encode NADK isoforms, designated NADK1 and NADK2, respectively. Expressed as recombinant proteins in bacteria, both NADK1 and NADK2 were catalytically active, thereby confirming their identity as NADKs. Transcripts for both isoforms were detected in all tissues examined and throughout development. Although the predicted catalytic regions for NADK1 and NADK2 show sequence similarity to NADKs from other organisms, NADK2 possesses a large N-terminal extension that appears to be unique to plants. Using recombinant glutathione-S-transferase fusion proteins and calmodulin (CaM)-affinity chromatography, we delineated a Ca2+-dependent CaM-binding domain to a 45-residue region within the N-terminal extension of NADK2. Although recombinant NADK2 was not responsive to CaM in vitro, immunoblot analysis suggests that native NADK2 is a CaM-binding protein. In Arabidopsis crude extracts, CaM-dependent NADK activity was much greater than CaM-independent activity throughout development, particularly in young seedlings. A native CaM-dependent NADK was partially purified from Arabidopsis seedlings (KmNAD = 0.20 mM, KmMg2+−ATP = 0.17 mM). The enzyme was fully activated by conserved CaM (S0.5 = 2.2 nm) in the presence of calcium but displayed differential responsiveness to eight CaM-like Arabidopsis proteins. Possible roles for NADKs in plants are discussed in light of our observations. PMID:15247403

  19. Bisphenol A differentially activates protein kinase C isoforms in murine placental tissue.

    Science.gov (United States)

    Tan, Wenjuan; Huang, Hui; Wang, Yanfei; Wong, Tsz Yan; Wang, C C; Leung, Lai K

    2013-06-01

    Bisphenol A is utilized to make polycarbonate plastics and is an environmental pollutant. Recent research has indicated that it is an endocrine disruptor and may interfere with reproductive processes. Our lab has previously shown that bisphenol A could regulate corticotrophin releasing hormone and aromatase in cultured placental cells. In the present study, the effect of bisphenol A on these two genes in the placenta was investigated in mice. Pregnant ICR mice were gavaged with bisphenol A at 2, 20 and 200mg/kg body weight/day from E13 to E16 and were euthanized at E17. Compared to the control mice, increased plasma estrogen and corticotrophin releasing hormone were observed in bisphenol A-treated mice. Messenger RNA quantification indicated that placental crh but not cyp19 was induced in mice treated with bisphenol A. Tracking the related signaling pathway, we found that protein kinase C ζ/λ and δ were activated in the placentas of bisphenol A-treated mice. As the gene promoter of crh contains CRE and the half site of ERE, either phospho-PKC or estrogen could stimulate the gene transactivation. These results indicate that bisphenol A might increase plasma concentrations of estradiol, testosterone, corticotrophin releasing hormone and placental phospho-PKC ζ/λ and δ in mice. Ultimately, the incidence of premature birth in these mice could increase.

  20. Switching of pyruvate kinase isoform L to M2 promotes metabolic reprogramming in hepatocarcinogenesis.

    Directory of Open Access Journals (Sweden)

    Carmen Chak-Lui Wong

    Full Text Available Hepatocellular carcinoma (HCC is an aggressive tumor, with a high mortality rate due to late symptom presentation and frequent tumor recurrences and metastasis. It is also a rapidly growing tumor supported by different metabolic mechanisms; nevertheless, the biological and molecular mechanisms involved in the metabolic reprogramming in HCC are unclear. In this study, we found that pyruvate kinase M2 (PKM2 was frequently over-expressed in human HCCs and its over-expression was associated with aggressive clinicopathological features and poor prognosis of HCC patients. Furthermore, knockdown of PKM2 suppressed aerobic glycolysis and cell proliferation in HCC cell lines in vitro. Importantly, knockdown of PKM2 hampered HCC growth in both subcutaneous injection and orthotopic liver implantation models, and reduced lung metastasis in vivo. Of significance, PKM2 over-expression in human HCCs was associated with a down-regulation of a liver-specific microRNA, miR-122. We further showed that miR-122 interacted with the 3UTR of the PKM2 gene. Re-expression of miR-122 in HCC cell lines reduced PKM2 expression, decreased glucose uptake in vitro, and suppressed HCC tumor growth in vivo. Our clinical data and functional studies have revealed a novel biological mechanism involved in HCC metabolic reprogramming.

  1. Tolerance to the antinociceptive and hypothermic effects of morphine is mediated by multiple isoforms of c-Jun N-terminal kinase.

    Science.gov (United States)

    Yuill, Matthew B; Zee, Michael L; Marcus, David; Morgan, Daniel J

    2016-04-13

    The abuse and overdose of opioid drugs are growing public health problems worldwide. Although progress has been made toward understanding the mechanisms governing tolerance to opioids, the exact cellular machinery involved remains unclear. However, there is growing evidence to suggest that c-Jun N-terminal kinases (JNKs) play a major role in mu-opioid receptor regulation and morphine tolerance. In this study, we aimed to determine the potential roles of different JNK isoforms in the development of tolerance to the antinociceptive and hypothermic effects of morphine. We used the hot-plate and tail-flick tests for thermal pain to measure tolerance to the antinociceptive effects of once-daily subcutaneous injections with 10 mg/kg morphine. Body temperature was also measured to determine tolerance to the hypothermic effects of morphine. Tolerance to morphine was assessed in wild-type mice and compared with single knockout mice each lacking the JNK isoforms (JNK1, JNK2, or JNK3). We found that loss of each individual JNK isoform causes impairment in tolerance for the antinociceptive and hypothermic effects of daily morphine. However, disruption of JNK2 seems to have the most profound effect on morphine tolerance. These results indicate a clear role for JNK signaling pathways in morphine tolerance. This complements previous studies suggesting that the JNK2 isoform is required for morphine tolerance, but additionally presents novel data suggesting that additional JNK isoforms also contribute toward this process.

  2. Implications of automated creatine kinase (CK)-MM1,2,3/CK-MB1,2 isoform analysis as an early marker for the detection of myocardial tissue damage

    NARCIS (Netherlands)

    Swaanenburg, JCJM; Pentinga, M; Dejongste, MJL; Kema, IP

    1996-01-01

    Measurement of creatine kinase (CK) isoforms enables the clinician to detect myocardial tissue damage at an early stage after myocardial infarction. According to the manufacturer's specifications, it should be possible to perform CK isoform analysis automatically using the new Cardio Rep(TM) analyse

  3. A Direct Interaction between Leucine-rich Repeat Kinase 2 and Specific β-Tubulin Isoforms Regulates Tubulin Acetylation*

    Science.gov (United States)

    Law, Bernard M. H.; Spain, Victoria A.; Leinster, Veronica H. L.; Chia, Ruth; Beilina, Alexandra; Cho, Hyun J.; Taymans, Jean-Marc; Urban, Mary K.; Sancho, Rosa M.; Ramírez, Marian Blanca; Biskup, Saskia; Baekelandt, Veerle; Cai, Huaibin; Cookson, Mark R.; Berwick, Daniel C.; Harvey, Kirsten

    2014-01-01

    Mutations in LRRK2, encoding the multifunctional protein leucine-rich repeat kinase 2 (LRRK2), are a common cause of Parkinson disease. LRRK2 has been suggested to influence the cytoskeleton as LRRK2 mutants reduce neurite outgrowth and cause an accumulation of hyperphosphorylated Tau. This might cause alterations in the dynamic instability of microtubules suggested to contribute to the pathogenesis of Parkinson disease. Here, we describe a direct interaction between LRRK2 and β-tubulin. This interaction is conferred by the LRRK2 Roc domain and is disrupted by the familial R1441G mutation and artificial Roc domain mutations that mimic autophosphorylation. LRRK2 selectively interacts with three β-tubulin isoforms: TUBB, TUBB4, and TUBB6, one of which (TUBB4) is mutated in the movement disorder dystonia type 4 (DYT4). Binding specificity is determined by lysine 362 and alanine 364 of β-tubulin. Molecular modeling was used to map the interaction surface to the luminal face of microtubule protofibrils in close proximity to the lysine 40 acetylation site in α-tubulin. This location is predicted to be poorly accessible within mature stabilized microtubules, but exposed in dynamic microtubule populations. Consistent with this finding, endogenous LRRK2 displays a preferential localization to dynamic microtubules within growth cones, rather than adjacent axonal microtubule bundles. This interaction is functionally relevant to microtubule dynamics, as mouse embryonic fibroblasts derived from LRRK2 knock-out mice display increased microtubule acetylation. Taken together, our data shed light on the nature of the LRRK2-tubulin interaction, and indicate that alterations in microtubule stability caused by changes in LRRK2 might contribute to the pathogenesis of Parkinson disease. PMID:24275654

  4. Structural insights into FGFR kinase isoform selectivity: diverse binding modes of AZD4547 and ponatinib in complex with FGFR1 and FGFR4.

    Science.gov (United States)

    Tucker, Julie A; Klein, Tobias; Breed, Jason; Breeze, Alexander L; Overman, Ross; Phillips, Chris; Norman, Richard A

    2014-12-02

    The fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases has been implicated in a wide variety of cancers. Despite a high level of sequence homology in the ATP-binding site, the majority of reported inhibitors are selective for the FGFR1-3 isoforms and display much reduced potency toward FGFR4, an exception being the Bcr-Abl inhibitor ponatinib. Here we present the crystal structure of the FGFR4 kinase domain and show that both FGFR1 and FGFR4 kinase domains in complex with ponatinib adopt a DFG-out activation loop conformation. Comparison with the structure of FGFR1 in complex with the candidate drug AZD4547, combined with kinetic characterization of the binding of ponatinib and AZD4547 to FGFR1 and FGFR4, sheds light on the observed differences in selectivity profiles and provides a rationale for developing FGFR4-selective inhibitors.

  5. Urochordate ascidians possess a single isoform of Aurora kinase that localizes to the midbody via TPX2 in eggs and cleavage stage embryos.

    Directory of Open Access Journals (Sweden)

    Celine Hebras

    Full Text Available Aurora kinases are key proteins found throughout the eukaryotes that control mitotic progression. Vertebrate Aurora-A and B kinases are thought to have evolved from a single Aurora-kinase isoform closest to that found in present day urochordates. In urochordate ascidians Aurora binds both TPX2 (a vertebrate AURKA partner and INCENP (a vertebrate AURKB partner and localizes to centrosomes and spindle microtubules as well as chromosomes and midbody during both meiosis and mitosis. Ascidian Aurora also displays this localization pattern during mitosis in echinoderms, strengthening the idea that non-vertebrate deuterostomes such as the urochordates and echinoderms possess a single form of Aurora kinase that has properties of vertebrate Aurora-kinase A and B. In the ascidian, TPX2 localizes to the centrosome and the spindle poles also as in vertebrates. However, we were surprised to find that TPX2 also localized strongly to the midbody in ascidian eggs and embryos. We thus examined more closely Aurora localization to the midbody by creating two separate point mutations of ascidian Aurora predicted to perturb binding to TPX2. Both forms of mutated Aurora behaved as predicted: neither localized to spindle poles where TPX2 is enriched. Interestingly, neither form of mutated Aurora localized to the midbody where TPX2 is also enriched, suggesting that ascidian Aurora midbody localization required TPX2 binding in ascidians. Functional analysis revealed that inhibition of Aurora kinase with a pharmacological inhibitor or with a dominant negative kinase dead form of Aurora caused cytokinesis failure and perturbed midbody formation during polar body extrusion. Our data support the view that vertebrate Aurora-A and B kinases evolved from a single non-vertebrate deuterostome ancestor. Moreover, since TPX2 localizes to the midbody in ascidian eggs and cleavage stage embryos it may be worthwhile re-assessing whether Aurora A kinase or TPX2 localize to the midbody

  6. CK2(beta)tes gene encodes a testis-specific isoform of the regulatory subunit of casein kinase 2 in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Kalmykova, Alla I; Shevelyov, Yuri Y; Polesskaya, Oksana O

    2002-01-01

    An earlier described CK2(beta)tes gene of Drosophila melanogaster is shown to encode a male germline specific isoform of regulatory beta subunit of casein kinase 2. Western-analysis using anti-CK2(beta)tes Ig revealed CK2(beta)tes protein in Drosophila testes extract. Expression of a CK2(beta...... and coimmunoprecipitation analysis of protein extract from Drosophila testes, we demonstrated an association between CK2(beta)tes and CK2alpha. Northern-analysis has shown that another regulatory (beta') subunit found recently in D. melanogaster genome is also testis-specific. Thus, we describe the first example of two...

  7. Opposite effects of the p52shc/p46shc and p66shc splicing isoforms on the EGF receptor-MAP kinase-fos signalling pathway

    DEFF Research Database (Denmark)

    Migliaccio, E; Mele, S; Salcini, A E;

    1997-01-01

    66shc expression varies from cell type to cell type. p66shc differs from p52shc/p46shc in its inability to transform mouse fibroblasts in vitro. Like p52shc/p46shc, p66shc is tyrosine-phosphorylated upon epidermal growth factor (EGF) stimulation, binds to activated EGF receptors (EGFRs) and forms...... on the EGFR-MAP kinase and other signalling pathways that control fos promoter activity. Regulation of p66shc expression might, therefore, influence the cellular response to growth factors.......Shc proteins are targets of activated tyrosine kinases and are implicated in the transmission of activation signals to Ras. The p46shc and p52shc isoforms share a C-terminal SH2 domain, a proline- and glycine-rich region (collagen homologous region 1; CH1) and a N-terminal PTB domain. We have...

  8. Choline Magnesium Trisalicylate

    Science.gov (United States)

    Choline magnesium trisalicylate is used to relieve the pain, tenderness, inflammation (swelling), and stiffness caused by arthritis and painful ... used to relieve pain and lower fever. Choline magnesium trisalicylate is in a class of nonsteroidal anti- ...

  9. The ζ isoform of diacylglycerol kinase plays a predominant role in regulatory T cell development and TCR-mediated ras signaling.

    Science.gov (United States)

    Joshi, Rohan P; Schmidt, Amanda M; Das, Jayajit; Pytel, Dariusz; Riese, Matthew J; Lester, Melissa; Diehl, J Alan; Behrens, Edward M; Kambayashi, Taku; Koretzky, Gary A

    2013-11-26

    Diacylglycerol (DAG) is a critical second messenger that mediates T cell receptor (TCR)-stimulated signaling. The abundance of DAG is reduced by the diacylglycerol kinases (DGKs), which catalyze the conversion of DAG to phosphatidic acid (PA) and thus inhibit DAG-mediated signaling. In T cells, the predominant DGK isoforms are DGKα and DGKζ, and deletion of the genes encoding either isoform enhances DAG-mediated signaling. We found that DGKζ, but not DGKα, suppressed the development of natural regulatory T (T(reg)) cells and predominantly mediated Ras and Akt signaling downstream of the TCR. The differential functions of DGKα and DGKζ were not attributable to differences in protein abundance in T cells or in their localization to the contact sites between T cells and antigen-presenting cells. RasGRP1, a key DAG-mediated activator of Ras signaling, associated to a greater extent with DGKζ than with DGKα; however, in silico modeling of TCR-stimulated Ras activation suggested that a difference in RasGRP1 binding affinity was not sufficient to cause differences in the functions of each DGK isoform. Rather, the model suggested that a greater catalytic rate for DGKζ than for DGKα might lead to DGKζ exhibiting increased suppression of Ras-mediated signals compared to DGKα. Consistent with this notion, experimental studies demonstrated that DGKζ was more effective than DGKα at catalyzing the metabolism of DAG to PA after TCR stimulation. The enhanced effective enzymatic production of PA by DGKζ is therefore one possible mechanism underlying the dominant functions of DGKζ in modulating T(reg) cell development.

  10. Structure-Function Analysis of the Non-Muscle Myosin Light Chain Kinase (nmMLCK) Isoform by NMR Spectroscopy and Molecular Modeling: Influence of MYLK Variants.

    Science.gov (United States)

    Shen, Kui; Ramirez, Benjamin; Mapes, Brandon; Shen, Grace R; Gokhale, Vijay; Brown, Mary E; Santarsiero, Bernard; Ishii, Yoshitaka; Dudek, Steven M; Wang, Ting; Garcia, Joe G N

    2015-01-01

    The MYLK gene encodes the multifunctional enzyme, myosin light chain kinase (MLCK), involved in isoform-specific non-muscle and smooth muscle contraction and regulation of vascular permeability during inflammation. Three MYLK SNPs (P21H, S147P, V261A) alter the N-terminal amino acid sequence of the non-muscle isoform of MLCK (nmMLCK) and are highly associated with susceptibility to acute lung injury (ALI) and asthma, especially in individuals of African descent. To understand the functional effects of SNP associations, we examined the N-terminal segments of nmMLCK by 1H-15N heteronuclear single quantum correlation (HSQC) spectroscopy, a 2-D NMR technique, and by in silico molecular modeling. Both NMR analysis and molecular modeling indicated SNP localization to loops that connect the immunoglobulin-like domains of nmMLCK, consistent with minimal structural changes evoked by these SNPs. Molecular modeling analysis identified protein-protein interaction motifs adversely affected by these MYLK SNPs including binding by the scaffold protein 14-3-3, results confirmed by immunoprecipitation and western blot studies. These structure-function studies suggest novel mechanisms for nmMLCK regulation, which may confirm MYLK as a candidate gene in inflammatory lung disease and advance knowledge of the genetic underpinning of lung-related health disparities.

  11. Molecular characterisation of cAMP-dependent protein kinase (PK-A) catalytic subunit isoforms in the male tick, Amblyomma hebraeum.

    Science.gov (United States)

    Tabish, Mohammad; Clegg, Roger A; Turner, Philip C; Jonczy, Jan; Rees, Huw H; Fisher, Michael J

    2006-12-01

    The cAMP-dependent protein kinase (protein kinase A, PK-A) plays a central role in the regulation of diverse aspects of cellular activity. Specifically, PK-A appears to play a key controlling role in the maturation of spermatids. Using a PCR-based approach, with degenerate primers from the highly conserved regions of the PK-A catalytic (C) subunit in combination with 5' and 3' RACE, we have cloned three cDNAs for the PK-A C-subunit of the male tick, Amblyomma hebraeum. The three cDNAs have open reading frames of 1059, 1275 and 1404bp which encode proteins of 40.6, 48.2 and 52.5kDa, respectively. These transcripts appear to arise from 5' alternative splicing of RNA derived from a single gene for the PK-A C-subunit. One isoform (AH-PK-A C1), in common with PK-A C-subunits from a range of species, contains a consensus sequence for N-myristoylation. RT-PCR and Western blot experiments suggest that the three splice variants are expressed ubiquitously; however, expression of the myristoylatable AH-PK-A C1 isoform is predominant in all investigated tissues (accessory gland, midgut, Malpighian tubules, salivary gland, testis and immature spermatids). There is no evidence for a sperm-specific PK-A C-subunit (Cs) in tick sperm; however, tyrosine protein phosphorylation, previously shown to be modulated by PK-A activity during mammalian sperm maturation, was observed in tick sperm.

  12. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells.

    Science.gov (United States)

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-07-15

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca(2+)- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations ("spiking") at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K(+) depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca(2+) concentration ([Ca(2+)]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca(2+)]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca(2+)]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function.

  13. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells*

    Science.gov (United States)

    Wuttke, Anne; Yu, Qian; Tengholm, Anders

    2016-01-01

    PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca2+- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations (“spiking”) at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K+ depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca2+ concentration ([Ca2+]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca2+]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca2+]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function. PMID:27226533

  14. Generation and characterization of polyclonal antibodies specific to N-terminal extension of p85 isoform of ribosomal protein S6 kinase 1 (p85 S6K1

    Directory of Open Access Journals (Sweden)

    Savinska L. O.

    2015-08-01

    Full Text Available Aim. Generation of polyclonal antibodies specific to the ribosomal protein S6 kinase isoform – p85S6K1 and directed to the N-terminal (1–23 aa extension of p85S6K1. Methods. Animal immunization with synthetic (1–23 aa peptide, ELISA, Western blot, Immunoprecipitation, immunofluorescent analysis. Results. Polyclonal antibodies have been generated, which specifically recognize only p85 but not p70 isoform of S6K1 in western blot, immunoprecipitation and immunofluorescence analysis. Conclusions. The obtained antibodies can be recommended for studies on the p85S6K1 and other S6K1 isoforms possessing the N-terminal extension – the identification of binding protein partners, analysis of subcellular localization under different physiological conditions, elucidation of the signal transduction pathways involving different S6K1 isoforms.

  15. The selectivity and promiscuity of brain-neuroregenerative inhibitors between ROCK1 and ROCK2 isoforms: An integration of SB-QSSR modelling, QM/MM analysis and in vitro kinase assay.

    Science.gov (United States)

    Zhu, L; Yang, Y; Lu, X

    2016-01-01

    The Rho-associated kinases (ROCKs) have long been recognized as an attractive therapeutic target for various neurological diseases; selective inhibition of ROCK1 and ROCK2 isoforms would result in distinct biological effects on neurogenesis, neuroplasticity and neuroregeneration after brain surgery and traumatic brain injury. However, the discovery and design of isoform-selective inhibitors remain a great challenge due to the high conservation and similarity between the kinase domains of ROCK1 and ROCK2. Here, a structure-based quantitative structure-selectivity relationship (SB-QSSR) approach was used to correlate experimentally measured selectivity with the difference in inhibitor binding to the two kinase isoforms. The resulting regression models were examined rigorously through both internal cross-validation and external blind validation; a nonlinear predictor was found to have high fitting stability and strong generalization ability, which was then employed to perform virtual screening against a structurally diverse, drug-like compound library. Consequently, five and seven hits were identified as promising candidates of 1-o-2 and 2-o-1 selective inhibitors, respectively, from which seven purchasable compounds were tested in vitro using a standard kinase assay protocol to determine their inhibitory activity against and selectivity between ROCK1 and ROCK2. The structural basis, energetic property and biological implication underlying inhibitor selectivity and promiscuity were also investigated systematically using a hybrid quantum mechanics/molecular mechanics (QM/MM) scheme.

  16. Activation of medullary dorsal horn γ isoform of protein kinase C interneurons is essential to the development of both static and dynamic facial mechanical allodynia.

    Science.gov (United States)

    Pham-Dang, Nathalie; Descheemaeker, Amélie; Dallel, Radhouane; Artola, Alain

    2016-03-01

    The γ isoform of protein kinase C (PKCγ), which is concentrated in a specific class of interneurons within inner lamina II (IIi ) of the spinal dorsal horn and medullary dorsal horn (MDH), is known to be involved in the development of mechanical allodynia, a widespread and intractable symptom of inflammatory or neuropathic pain. However, although genetic and pharmacological impairment of PKCγ were shown to prevent mechanical allodynia in animal models of pain, after nerve injury or reduced inhibition, the functional consequences of PKCγ activation alone on mechanical sensitivity are still unknown. Using behavioural and anatomical approaches in the rat MDH, we tested whether PKCγ activation in naive animals is sufficient for the establishment of mechanical allodynia. Intracisternal injection of the phorbol ester, 12,13-dibutyrate concomitantly induced static as well as dynamic facial mechanical allodynia. Monitoring neuronal activity within the MDH with phospho-extracellular signal-regulated kinases 1 and 2 immunoreactivity revealed that activation of both lamina I-outer lamina II and IIi -outer lamina III neurons, including lamina IIi PKCγ-expressing interneurons, was associated with the manifestation of mechanical allodynia. Phorbol ester, 12,13-dibutyrate-induced mechanical allodynia and associated neuronal activations were all prevented by inhibiting selectively segmental PKCγ with KIG31-1. Our findings suggest that PKCγ activation, without any other experimental manipulation, is sufficient for the development of static and dynamic mechanical allodynia. Lamina IIi PKCγ interneurons have been shown to be directly activated by low-threshold mechanical inputs carried by myelinated afferents. Thus, the level of PKCγ activation within PKCγ interneurons might gate the transmission of innocuous mechanical inputs to lamina I, nociceptive output neurons, thus turning touch into pain.

  17. VER-246608, a novel pan-isoform ATP competitive inhibitor of pyruvate dehydrogenase kinase, disrupts Warburg metabolism and induces context-dependent cytostasis in cancer cells.

    Science.gov (United States)

    Moore, Jonathan D; Staniszewska, Anna; Shaw, Terence; D'Alessandro, Jalanie; Davis, Ben; Surgenor, Alan; Baker, Lisa; Matassova, Natalia; Murray, James; Macias, Alba; Brough, Paul; Wood, Mike; Mahon, Patrick C

    2014-12-30

    Pyruvate dehydrogenase kinase (PDK) is a pivotal enzyme in cellular energy metabolism that has previously been implicated in cancer through both RNAi based studies and clinical correlations with poor prognosis in several cancer types. Here, we report the discovery of a novel and selective ATP competitive pan-isoform inhibitor of PDK, VER-246608. Consistent with a PDK mediated MOA, VER-246608 increased pyruvate dehydrogenase complex (PDC) activity, oxygen consumption and attenuated glycolytic activity. However, these effects were only observed under D-glucose-depleted conditions and required almost complete ablation of PDC E1α subunit phosphorylation. VER-246608 was weakly anti-proliferative to cancer cells in standard culture media; however, depletion of either serum or combined D-glucose/L-glutamine resulted in enhanced cellular potency. Furthermore, this condition-selective cytostatic effect correlated with reduced intracellular pyruvate levels and an attenuated compensatory response involving deamination of L-alanine. In addition, VER-246608 was found to potentiate the activity of doxorubicin. In contrast, the lipoamide site inhibitor, Nov3r, demonstrated sub-maximal inhibition of PDK activity and no evidence of cellular activity. These studies suggest that PDK inhibition may be effective under the nutrient-depleted conditions found in the tumour microenvironment and that combination treatments should be explored to reveal the full potential of this therapeutic strategy.

  18. Protein kinase A type I activates a CRE-element more efficiently than protein kinase A type II regardless of C subunit isoform

    Directory of Open Access Journals (Sweden)

    Kvissel Anne-Katrine

    2011-02-01

    Full Text Available Abstract Background Protein kinase A type I (PKAI and PKAII are expressed in most of the eukaryotic cells examined. PKA is a major receptor for cAMP and specificity is achieved partly through tissue-dependent expression and subcellular localization of subunits with different biochemical properties. In addition posttranslational modifications help fine tune PKA activity, distribution and interaction in the cell. In spite of this the functional significance of two forms of PKA in one cell has not been fully determined. Here we have tested the ability of PKAI and PKAII formed by expression of the regulatory (R subunits RIα or RIIα in conjunction with Cα1 or Cβ2 to activate a co-transfected luciferace reporter gene, controlled by the cyclic AMP responsive element-binding protein (CREB in vivo. Results We show that PKAI when expressed at equal levels as PKAII was significantly (p Conclusion We suggest that differential effects of PKAI and PKAII in inducing Cre-luciferace activity depend on R and not C subunit identity.

  19. AMYGDALA KINDLING-INDUCED SEIZURES SELECTIVELY IMPAIR SPATIAL MEMORY .1. BEHAVIORAL-CHARACTERISTICS AND EFFECTS ON HIPPOCAMPAL NEURONAL PROTEIN-KINASE-C ISOFORMS

    NARCIS (Netherlands)

    BELDHUIS, HJA; EVERTS, HGJ; VANDERZEE, EA; LUITEN, PGM; BOHUS, B

    1992-01-01

    Protein kinase C (PKC) comprises a family of kinases consisting of nine subspecies that are differentially distributed in the central nervous system. This implies distinct functions. Its involvement is suggested in cellular and molecular mechanisms by which the hippocampus exerts influence on inform

  20. Human mesenchymal stem cell proliferation is regulated by PGE2 through differential activation of cAMP-dependent protein kinase isoforms

    DEFF Research Database (Denmark)

    Kleiveland, Charlotte Ramstad; Kassem, Moustapha; Lea, Tor

    2008-01-01

    with synthetic cAMP analogues, resulted in enhancement of proliferation. On the other side, we found that treatment of hMSC with high concentrations of PGE2 inhibited cell proliferation by arresting the cells in G0/G1 phase, an effect we found to be mediated by PKA I. Hence, the two different PKA isoforms seem....... Furthermore, PGE2 treatment leads to enhanced nuclear translocation of beta-catenin, thus influencing cell proliferation. The presence of two PKA isoforms, types I and II, prompted us to investigate their individual contribution in PGE2-mediated regulation of proliferation. Specific activation of PKA type II......The conditions used for in vitro differentiation of hMSCs contain substances that affect the activity and expression of cyclooxygenase enzymes (COX1/COX2) and thereby the synthesis of prostanoids. hMSC constitutively produce PGE2 when cultivated in vitro. In this study we have investigated effects...

  1. The Phosphoinositide 3-Kinase p110α Isoform Regulates Leukemia Inhibitory Factor Receptor Expression via c-Myc and miR-125b to Promote Cell Proliferation in Medulloblastoma.

    Directory of Open Access Journals (Sweden)

    Fabiana Salm

    Full Text Available Medulloblastoma (MB is the most common malignant brain tumor in childhood and represents the main cause of cancer-related death in this age group. The phosphoinositide 3-kinase (PI3K pathway has been shown to play an important role in the regulation of medulloblastoma cell survival and proliferation, but the molecular mechanisms and downstream effectors underlying PI3K signaling still remain elusive. The impact of RNA interference (RNAi-mediated silencing of PI3K isoforms p110α and p110δ on global gene expression was investigated by DNA microarray analysis in medulloblastoma cell lines. A subset of genes with selectively altered expression upon p110α silencing in comparison to silencing of the closely related p110δ isoform was revealed. Among these genes, the leukemia inhibitory factor receptor α (LIFR α was validated as a novel p110α target in medulloblastoma. A network involving c-Myc and miR-125b was shown to be involved in the control of LIFRα expression downstream of p110α. Targeting the LIFRα by RNAi, or by using neutralizing reagents impaired medulloblastoma cell proliferation in vitro and induced a tumor volume reduction in vivo. An analysis of primary tumors revealed that LIFRα and p110α expression were elevated in the sonic hedgehog (SHH subgroup of medulloblastoma, indicating its clinical relevance. Together, these data reveal a novel molecular signaling network, in which PI3K isoform p110α controls the expression of LIFRα via c-Myc and miR-125b to promote MB cell proliferation.

  2. BI-D1870 is a specific inhibitor of the p90 RSK (ribosomal S6 kinase) isoforms in vitro and in vivo

    DEFF Research Database (Denmark)

    Sapkota, Gopal P; Cummings, Lorna; Newell, Felicity S;

    2007-01-01

    ), which then mediate many of the physiological processes that are regulated by these extracellular agonists. It can be difficult to assess the individual functions of each AGC kinase because their substrate specificities are similar. Here we describe the small molecule BI-D1870, which inhibits RSK1, RSK2......, RSK3 and RSK4 in vitro with an IC(50) of 10-30 nM, but does not signi-ficantly inhibit ten other AGC kinase members and over 40 other protein kinases tested at 100-fold higher concentrations. BI-D1870 is cell permeant and prevents the RSK-mediated phorbol ester- and EGF (epidermal growth factor......)-induced phosphoryl-ation of glycogen synthase kinase-3beta and LKB1 in human embry-onic kidney 293 cells and Rat-2 cells. In contrast, BI-D1870 does not affect the agonist-triggered phosphorylation of substrates for six other AGC kinases. Moreover, BI-D1870 does not suppress the phorbol ester- or EGF...

  3. Genetic Variation in Choline-Metabolizing Enzymes Alters Choline Metabolism in Young Women Consuming Choline Intakes Meeting Current Recommendations

    Science.gov (United States)

    Ganz, Ariel B.; Cohen, Vanessa V.; Swersky, Camille C.; Stover, Julie; Vitiello, Gerardo A.; Lovesky, Jessica; Chuang, Jasmine C.; Shields, Kelsey; Fomin, Vladislav G.; Lopez, Yusnier S.; Mohan, Sanjay; Ganti, Anita; Carrier, Bradley; Malysheva, Olga V.; Caudill, Marie A.

    2017-01-01

    Single nucleotide polymorphisms (SNPs) in choline metabolizing genes are associated with disease risk and greater susceptibility to organ dysfunction under conditions of dietary choline restriction. However, the underlying metabolic signatures of these variants are not well characterized and it is unknown whether genotypic differences persist at recommended choline intakes. Thus, we sought to determine if common genetic risk factors alter choline dynamics in pregnant, lactating, and non-pregnant women consuming choline intakes meeting and exceeding current recommendations. Women (n = 75) consumed 480 or 930 mg choline/day (22% as a metabolic tracer, choline-d9) for 10–12 weeks in a controlled feeding study. Genotyping was performed for eight variant SNPs and genetic differences in metabolic flux and partitioning of plasma choline metabolites were evaluated using stable isotope methodology. CHKA rs10791957, CHDH rs9001, CHDH rs12676, PEMT rs4646343, PEMT rs7946, FMO3 rs2266782, SLC44A1 rs7873937, and SLC44A1 rs3199966 altered the use of choline as a methyl donor; CHDH rs9001 and BHMT rs3733890 altered the partitioning of dietary choline between betaine and phosphatidylcholine synthesis via the cytidine diphosphate (CDP)-choline pathway; and CHKA rs10791957, CHDH rs12676, PEMT rs4646343, PEMT rs7946 and SLC44A1 rs7873937 altered the distribution of dietary choline between the CDP-choline and phosphatidylethanolamine N-methyltransferase (PEMT) denovo pathway. Such metabolic differences may contribute to disease pathogenesis and prognosis over the long-term. PMID:28134761

  4. Endogenous type II cGMP-dependent protein kinase exists as a dimer in membranes and can Be functionally distinguished from the type I isoforms

    NARCIS (Netherlands)

    A.B. Vaandrager (Arie); M.J. Edixhoven (Marcel); A.G. Bot (Alice); M.A. Kroos (Marian); T. Jarchau; S. Lohmann; H.G. Genieser; H.R. de Jonge (Hugo)

    1997-01-01

    textabstractIn mammalian tissues two types of cGMP-dependent protein kinase (cGK) have been identified. In contrast to the dimeric cGK I, cGK II purified from pig intestine was shown previously to behave as a monomer. However, recombinant rat cGK II was found to have hy

  5. Chromosomal mapping and mutational analysis of the coding region of the glycogen synthase kinase-3alpha and beta isoforms in patients with NIDDM

    DEFF Research Database (Denmark)

    Hansen, L; Arden, K C; Rasmussen, S B

    1997-01-01

    Activation of glycogen synthesis in skeletal muscle in response to insulin results from the combined inactivation of glycogen synthase kinase-3 (GSK-3) and activation of the protein phosphatase-1, changing the ratio between the inactive phosphorylated state of the glycogen synthase to the active ...

  6. BCR-ABL isoforms associated with intrinsic or acquired resistance to imatinib : more heterogeneous than just ABL kinase domain point mutations?

    NARCIS (Netherlands)

    Gruber, Franz X.; Lundan, Tuija; Goll, Rasmus; Silye, Aleksandra; Mikkola, Ingvild; Rekvig, Ole Petter; Knuutila, Sakari; Remes, Kari; Gedde-Dahl, Tobias; Porkka, Kimmo; Hjorth-Hansen, Henrik

    2012-01-01

    Imatinib, a small molecule inhibitor of ABL, PDGFR and C-KIT, has revolutionized treatment of chronic myeloid leukaemia (CML). However, resistance to treatment is of increasing importance and often is due to point mutations in the Abl kinase domain (Abl KD). Here, we analysed clinical outcome and mu

  7. Exploring levels of hexosamine biosynthesis pathway intermediates and protein kinase C isoforms in muscle and fat tissue of Zucker Diabetic Fatty rats.

    NARCIS (Netherlands)

    Bosch, R.R.; Janssen, S.W.J.; Span, P.N.; Olthaar, A.J.; Emst-de Vries, S.E. van; Willems, P.H.G.M.; Martens, G.J.M.; Hermus, A.R.M.M.; Sweep, C.G.J.

    2003-01-01

    Many studies suggest that insulin resistance develops and/or is maintained by an increased flux of glucose through the hexosamine biosynthesis pathway. This pathway may attenuate insulin-stimulated glucose uptake by activating protein kinase C (PKC). Therefore, we investigated whether the concentrat

  8. Evaluation of the choline status in mink fed different levels and sources of choline

    DEFF Research Database (Denmark)

    Hedemann, Mette Skou; Damgaard, Birthe Marie; Clausen, T.N.;

    2012-01-01

    plasma samples were extracted to analyze the content of free choline and betaine by liquid chromatography-mass spectrometry. Plasma choline was only increased in mink kits fed the highest level of choline whereas plasma choline dit not change in full-grown mink irrespectively of choline level in the feed....... Plasma betaine increased when the level of choline in the diet increased. The changes in plasma betaine were most prominent in mink kits. The present study shows that plasma betaine may be a more reliable marker of choline status than plasma choline, especially in mink kits....

  9. DAF-16/FoxO directly regulates an atypical AMP-activated protein kinase gamma isoform to mediate the effects of insulin/IGF-1 signaling on aging in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Jennifer M A Tullet

    2014-02-01

    Full Text Available The DAF-16/FoxO transcription factor controls growth, metabolism and aging in Caenorhabditis elegans. The large number of genes that it regulates has been an obstacle to understanding its function. However, recent analysis of transcript and chromatin profiling implies that DAF-16 regulates relatively few genes directly, and that many of these encode other regulatory proteins. We have investigated the regulation by DAF-16 of genes encoding the AMP-activated protein kinase (AMPK, which has α, β and γ subunits. C. elegans has 5 genes encoding putative AMP-binding regulatory γ subunits, aakg-1-5. aakg-4 and aakg-5 are closely related, atypical isoforms, with orthologs throughout the Chromadorea class of nematodes. We report that ∼75% of total γ subunit mRNA encodes these 2 divergent isoforms, which lack consensus AMP-binding residues, suggesting AMP-independent kinase activity. DAF-16 directly activates expression of aakg-4, reduction of which suppresses longevity in daf-2 insulin/IGF-1 receptor mutants. This implies that an increase in the activity of AMPK containing the AAKG-4 γ subunit caused by direct activation by DAF-16 slows aging in daf-2 mutants. Knock down of aakg-4 expression caused a transient decrease in activation of expression in multiple DAF-16 target genes. This, taken together with previous evidence that AMPK promotes DAF-16 activity, implies the action of these two metabolic regulators in a positive feedback loop that accelerates the induction of DAF-16 target gene expression. The AMPK β subunit, aakb-1, also proved to be up-regulated by DAF-16, but had no effect on lifespan. These findings reveal key features of the architecture of the gene-regulatory network centered on DAF-16, and raise the possibility that activation of AMP-independent AMPK in nutritionally replete daf-2 mutant adults slows aging in C. elegans. Evidence of activation of AMPK subunits in mammals suggests that such FoxO-AMPK interactions may be

  10. Isoform-specific targeting of ROCK proteins in immune cells

    OpenAIRE

    Zanin-Zhorov, Alexandra; Flynn, Ryan; Waksal, Samuel D.; Blazar, Bruce R.

    2016-01-01

    ABSTRACT Rho-associated kinase 1 (ROCK1) and ROCK2 are activated by Rho GTPase and control cytoskeleton rearrangement through modulating the phosphorylation of their down-stream effector molecules. Although these 2 isoforms share more than 90% homology within their kinase domain the question of whether ROCK proteins function identically in different cell types is not clear. By using both pharmacological inhibition and genetic knockdown approaches recent studies suggest that the ROCK2 isoform ...

  11. Reduction of choline acetyltransferase activities in APP770 transgenic mice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Transgenic mice overexpressing the 770-amino acid isoform of human Alzheimer amyloid precursor protein exhibit extracellular b -amyloid deposits in brain regions including cerebral cortex and hippocampus, which are severely affected in Alzheimer's disease patients. Significant reduction in choline acetyltransferase (ChAT) activities has been observed in both cortical and hippocampal brain regions in the transgenic mice at the age of 10 months compared with the age-matched non-transgenic mice, but such changes have not been observed in any brain regions of the transgenic mice under the age of 5 months. These results suggest that deposition of b -amyloid can induce changes in the brain cholinergic system of the transgenic mice.

  12. Chemische contaminanten in diervoeder additief Choline Chloride

    NARCIS (Netherlands)

    Traag, W.A.; Hoogenboom, L.A.P.; Jong, de J.; Egmond, van H.J.; Dam, ten G.

    2010-01-01

    Dit briefrapport beschrijft de resultaten van een onderzoek naar chemische contaminanten in Choline Chloride. De doelstellingen waren: 1) Inzicht te verkrijgen in het voorkomen van (gebromeerde) vlamvertragers en broomdioxines in het diervoederadditief Choline Chloride en het, op basis van de result

  13. CDP-choline: acute toxicity study.

    Science.gov (United States)

    Grau, T; Romero, A; Sacristán, A; Ortiz, J A

    1983-01-01

    The acute toxicity of a single dose of cytidine diphosphate choline (CDP-choline, citicoline, Somazina) by different administration routes in mice and rats has been studied. LD50 values were determined according to the cumulative method by Reed-Muench for mortality rate, and Pizzi's method for calculation of standard error.

  14. 21 CFR 172.370 - Iron-choline citrate complex.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting approximately equimolecular quantities of ferric hydroxide, choline,...

  15. Choline incorporation by Schistosoma mansoni: distribution of choline metabolites during development and after sexual differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ancelin, M.L.; Torpier, G.; Vial, H.J.; Capron, A.

    1987-06-01

    Choline metabolism was investigated in Schistosoma mansoni during the main phases of its development, namely, schistosomula, 11- and 15-day-old worms, and adults. At the physiological choline concentration used in the assay (20 microM), betaine was, along with phosphatidylcholine, one of the most abundant choline metabolites, revealing considerable choline oxidation activity. Very little radioactivity was associated with CDP-choline, whereas a sustained incorporation into phosphocholine occurred. These results provide good evidence that CTP:phosphocholine cytidylyltransferase plays a regulatory role in the de novo pathway of phosphatidylcholine biosynthesis. During development, the incorporation of choline into its various metabolites was maximal in 11-day-old worms. At this stage, the oxidative pathway predominated over the Kennedy pathway, whereas at all other stages the de novo phosphatidylcholine biosynthesis was predominant. Furthermore, choline incorporation into betaine was much more important in the adult female worm than in the male, indicating a major difference in choline incorporation and distribution between the 2 sexes of the adult worms.

  16. Isoforms of receptors of fibroblast growth factors.

    Science.gov (United States)

    Gong, Siew-Ging

    2014-12-01

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

  17. 21 CFR 573.580 - Iron-choline citrate complex.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron-choline citrate complex. 573.580 Section 573.580 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made...

  18. Nuclear Choline Acetyltransferase Activates Transcription of a High-affinity Choline Transporter*

    OpenAIRE

    Matsuo, Akinori; Bellier, Jean-Pierre; Nishimura, Masaki; YASUHARA, Osamu; Saito, Naoaki; Kimura, Hiroshi

    2010-01-01

    Choline acetyltransferase (ChAT) synthesizes the neurotransmitter, acetylcholine, at cholinergic nerve terminals. ChAT contains nuclear localization signals and is also localized in the nuclei of neural and non-neuronal cells. Nuclear ChAT might have an as yet unidentified function, such as transcriptional regulation. In this study, we investigated the alteration of candidate gene transcription by ChAT. We chose high affinity choline transporter (CHT1) and vesicular acetylcholine transporter ...

  19. Choline and choline metabolite patterns and associations in blood and milk during lactation in dairy cows.

    Directory of Open Access Journals (Sweden)

    Virginia M Artegoitia

    Full Text Available Milk and dairy products are an important source of choline, a nutrient essential for human health. Infant formula derived from bovine milk contains a number of metabolic forms of choline, all contribute to the growth and development of the newborn. At present, little is known about the factors that influence the concentrations of choline metabolites in milk. The objectives of this study were to characterize and then evaluate associations for choline and its metabolites in blood and milk through the first 37 weeks of lactation in the dairy cow. Milk and blood samples from twelve Holstein cows were collected in early, mid and late lactation and analyzed for acetylcholine, free choline, betaine, glycerophosphocholine, lysophosphatidylcholine, phosphatidylcholine, phosphocholine and sphingomyelin using hydrophilic interaction liquid chromatography-tandem mass spectrometry, and quantified using stable isotope-labeled internal standards. Total choline concentration in plasma, which was almost entirely phosphatidylcholine, increased 10-times from early to late lactation (1305 to 13,535 µmol/L. In milk, phosphocholine was the main metabolite in early lactation (492 µmol/L, which is a similar concentration to that found in human milk, however, phosphocholine concentration decreased exponentially through lactation to 43 µmol/L in late lactation. In contrast, phosphatidylcholine was the main metabolite in mid and late lactation (188 µmol/L and 659 µmol/L, respectively, with the increase through lactation positively correlated with phosphatidylcholine in plasma (R2 = 0.78. Unlike previously reported with human milk we found no correlation between plasma free choline concentration and milk choline metabolites. The changes in pattern of phosphocholine and phosphatidylcholine in milk through lactation observed in the bovine suggests that it is possible to manufacture infant formula that more closely matches these metabolites profile in human milk.

  20. The Comparative effects of synthetic choline and herbal choline on hepatic lipid metabolism in broilers

    Directory of Open Access Journals (Sweden)

    G.R.Gangane1

    Full Text Available An experiment of 0-42 days in day old 150 Vencobb broiler chickens was conducted to determine comparative effects of synthetic choline and herbal sources of choline on hepatic lipid metabolism in broilers. Birds were randomly distributed into three groups (T0- T2, one untreated control and two treatments. Chicks in Group T0 were given feed without any additional source choline chloride. Chicks of Group T1 were fed with feed mixed with herbal product (Repchol supplied by Ayurvet Ltd., Baddi, India @ 500gm/tonne of feed and T2 was given combination of synthetic choline chloride@1kg/tonne (60% and biotin @ 150 mg/ton of feed. To study the effect of inclusion of herbal sources of choline and synthetic choline on hepatic lipid metabolism, serum triglycerides and cholesterol were estimated on day 21st and 42nd of experimental study. Gross pathological changes in liver were recorded on representative birds per group at the end of the study. It was recorded that inclusion of either synthetic choline or herbal source of choline exerted a hypocholesterolemic effect and also decreased the level of triglycerides as compared to untreated control thus minimizing the incidence of fatty liver, however the two treatment do not differ significantly. Gross pathological study also revealed no significant changes in the architecture of liver as compared to control. It can be concluded that the herbal supplements can successfully replace their synthetic analogues from broiler ration. [Veterinary World 2010; 3(7.000: 318-320

  1. Choline-PET/CT for imaging prostate cancer; Cholin-PET/CT zur Bildgebung des Prostatakarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Bernd Joachim [Klinik- und Poliklinik fuer Nuklearmedizin, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany); Treiber, U.; Schwarzenboeck, S.; Souvatzoglou, M. [Klinik fuer Urologie, Klinikum rechts der Isar, Technische Univ. Muenchen (Germany)

    2010-09-15

    PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives are increasingly being used for imaging of prostate cancer. The value of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in biochemical recurrence of prostate cancer has been examined in many studies and demonstrates an increasing importance. Primary prostate cancer can be detected with moderate sensitivity using PET and PET/CT using [{sup 11}C]- and [{sup 18}F]-labelled choline derivatives - the differentiation between benign prostatic hyperplasia, prostatitis or high-grade intraepithelial neoplasia (HGPIN) is not always possible. At the present time [{sup 11}C]choline PET/CT is not recommended in the primary setting but may be utilized in clinically suspected prostate cancer with repeatedly negative prostate biopsies, in preparation of a focused re-biopsy. Promising results have been obtained for the use of PET and PET/CT with [{sup 11}C]- and [{sup 18}F]-labelled choline derivates in patients with biochemical recurrence. The detection rate of choline PET and PET/CT for local, regional, and distant recurrence in patients with a biochemical recurrence shows a linear correlation with PSA values at the time of imaging and reaches about 75% in patients with PSA > 3 ng/mL. At PSA values below 1 ng/mL, the recurrence can be diagnosed with choline PET/CT in approximately 1/3 of the patients. PET and PET/CT with [{sup 11}C]- and [{sup 18}F]choline derivates can be helpful for choosing a therapeutic strategy in the sense of an individualized treatment: since an early diagnosis of recurrence is crucial to the choice of optimal treatment. The localization of the site of recurrence - local recurrence, lymph node metastasis or systemic dissemination - has important influence on the therapy regimen. (orig.)

  2. Gebromeerde vlamvertragers en broomdioxines in Choline Chloride

    NARCIS (Netherlands)

    Egmond, van H.J.; Traag, W.A.; Hoogenboom, L.A.P.

    2008-01-01

    Sinds begin 2008 worden in het Nationaal Plan Diervoeder Choline Chloride monsters (= diervoeder additief) gevonden waarbij de DR CALUX screenings-assay een sterk verdacht signaal geeft, maar bij de GC-HRMS geen dioxines en dl-PCB's worden gevonden. Dit rapport beschrijft de resultaten van nader ond

  3. Sustained release choline theophyllinate in nocturnal asthma.

    Science.gov (United States)

    Rhind, G B; Connaughton, J J; McFie, J; Douglas, N J; Flenley, D C

    1985-12-07

    Nocturnal wheeze is common in patients with asthma, and slow release theophyllines may reduce symptoms. As theophyllines are stimulants of the central nervous system the effect of 10 days' twice daily treatment with sustained release choline theophyllinate or placebo on symptoms, overnight bronchoconstriction, nocturnal oxygen saturation, and quality of sleep were studied in a double blind crossover study in nine stable patients with nocturnal asthma (five men, four women, age range 23-64 years; forced expiratory volume in one second (FEV1) 0.85-3.8 1; vital capacity 1.95-6.1 1). When treated with the active drug all patients had plasma theophylline concentrations of at least 28 mmol/l (5 micrograms/ml) (peak plasma theophylline concentrations 50-144 mmol/l (9-26 micrograms/ml]. Morning FEV1 was higher when treated with sustained release choline theophyllinate (2.7 (SEM 0.3) 1) than placebo (2.1 (0.3) 1) (p less than 0.01). Both daytime and nocturnal symptoms were reduced when the patients were treated with sustained release choline theophyllinate and subjective quality of sleep was improved (p less than 0.002). When treated with the active drug, however, quality of sleep determined by electroencephalography deteriorated with an increase in wakefulness and drowsiness (p less than 0.05) and a reduction in non-rapid eye movement sleep (p less than 0.005). Treatment with choline theophyllinate had no effect on either the occurrence or the severity of transient nocturnal hypoxaemic episodes or apnoeas or hypopnoeas. In conclusion, sustained release choline theophyllinate prevents overnight bronchoconstriction, but impairs quality of sleep defined by electroencephalography.

  4. Caffeine potentiates the enhancement by choline of striatal acetylcholine release

    Science.gov (United States)

    Johnson, D. A.; Ulus, I. H.; Wurtman, R. J.

    1992-01-01

    We investigated the effect of peripherally administered caffeine (50 mg/kg), choline (30, 60, or 120 mg/kg) or combinations of both drugs on the spontaneous release of acetylcholine (ACh) from the corpus striatum of anesthetized rats using in vivo microdialysis. Caffeine alone or choline in the 30 or 60 mg/kg dose failed to increase ACh in microdialysis samples; the 120 mg/kg choline dose significantly enhanced ACh during the 80 min following drug administration. Coadministration of caffeine with choline significantly increased ACh release after each of the choline doses tested. Peak microdialysate levels with the 120 mg/kg dose were increased 112% when caffeine was additionally administered, as compared with 54% without caffeine. These results indicate that choline administration can enhance spontaneous ACh release from neurons, and that caffeine, a drug known to block adenosine receptors on these neurons, can amplify the choline effect.

  5. Isoform-targeted regulation of cardiac adenylyl cyclase.

    Science.gov (United States)

    Ishikawa, Yoshihiro

    2003-01-01

    Numerous attempts have been made to develop strategies for regulating the intracellular cyclic AMP signal pharmacologically, with an intention to establish either new medical therapeutic methods or experimental tools. In the past decades, many pharmacological reagents have been identified that regulate this pathway at the level of the receptor. G protein, adenylyl cyclase, cyclic AMP, protein kinase A and phosphodiesterase. Since the cloning of adenylyl cyclase isoforms during the 1990s, investigators including ourselves have tried to find reagents that regulate the activity of this enzyme directly in an isoform-dependent manner. The ultimate goal of developing such reagents would be to regulate the cyclic AMP signal in an organ-dependent manner. Ourselves and other workers have reported that such reagents may vary from a simple cation to kinases. In a more recent study, using the results from crystallographic studies and computer-assisted drug design programs, we have identified subtype-selective regulators of adenylyl cyclase. Such regulators are mostly based upon forskolin, a diterpene compound obtained from Coleus forskolii, that acts directly on adenylyl cyclase to increase the intracellular levels of cyclic AMP. Similarly, novel reagents have been identified that inhibit a specific adenylyl cyclase isoform (e.g. type 5 adenylyl cyclase). Such reagents would potentially provide a new therapeutic strategy to treat hypertension, for example, as well as methods to selectively stimulate or inhibit this adenylyl cyclase isoform, which may be reminiscent of overexpression or knocking out of the cardiac adenylyl cyclase isoform by the use of a pharmacological method.

  6. Arrestin-3 binds c-Jun N-terminal kinase 1 (JNK1) and JNK2 and facilitates the activation of these ubiquitous JNK isoforms in cells via scaffolding.

    Science.gov (United States)

    Kook, Seunghyi; Zhan, Xuanzhi; Kaoud, Tamer S; Dalby, Kevin N; Gurevich, Vsevolod V; Gurevich, Eugenia V

    2013-12-27

    Non-visual arrestins scaffold mitogen-activated protein kinase (MAPK) cascades. The c-Jun N-terminal kinases (JNKs) are members of MAPK family. Arrestin-3 has been shown to enhance the activation of JNK3, which is expressed mainly in neurons, heart, and testes, in contrast to ubiquitous JNK1 and JNK2. Although all JNKs are activated by MKK4 and MKK7, both of which bind arrestin-3, the ability of arrestin-3 to facilitate the activation of JNK1 and JNK2 has never been reported. Using purified proteins we found that arrestin-3 directly binds JNK1α1 and JNK2α2, interacting with the latter comparably to JNK3α2. Phosphorylation of purified JNK1α1 and JNK2α2 by MKK4 or MKK7 is increased by arrestin-3. Endogenous arrestin-3 interacted with endogenous JNK1/2 in different cell types. Arrestin-3 also enhanced phosphorylation of endogenous JNK1/2 in intact cells upon expression of upstream kinases ASK1, MKK4, or MKK7. We observed a biphasic effect of arrestin-3 concentrations on phosphorylation of JNK1α1 and JNK2α2 both in vitro and in vivo. Thus, arrestin-3 acts as a scaffold, facilitating JNK1α1 and JNK2α2 phosphorylation by MKK4 and MKK7 via bringing JNKs and their activators together. The data suggest that arrestin-3 modulates the activity of ubiquitous JNK1 and JNK2 in non-neuronal cells, impacting the signaling pathway that regulates their proliferation and survival.

  7. Pharmacokinetics of 14C CDP-choline.

    Science.gov (United States)

    Dinsdale, J R; Griffiths, G K; Rowlands, C; Castelló, J; Ortiz, J A; Maddock, J; Aylward, M

    1983-01-01

    The absorption, metabolism and excretion of cytidine diphosphate choline (CDP-choline, citicoline, Somazina) were investigated in six adult healthy subjects after a single oral dose of 300 mg of the 14C-labelled compound. The compound was well tolerated by the subjects. Absorption was virtually complete with less than 1% of the dose being found in the faeces during the 5-day collection period. Two peaks were found in the plasma radioactivity time profile: the first at 1 h, and a second larger peak at 24 h post-dose. Elimination of the ingested dose occurred via respiratory CO2 and through urinary excretion; the former predominating, and both routes exhibited biphasic patterns characterized by an early phase followed by slower decline. It is postulated that in the healthy human subject CDP-choline is metabolized in the gut wall and in the liver; the products arising from the compound's extensive hepatic metabolism being subsequently available for diverse biosynthetic pathways, tissue metabolism, and excretion.

  8. Effect of choline carboxylate ionic liquids on biological membranes.

    Science.gov (United States)

    Rengstl, Doris; Kraus, Birgit; Van Vorst, Matthew; Elliott, Gloria D; Kunz, Werner

    2014-11-01

    Choline carboxylates, ChCm, with m=2-10 and choline oleate are known as biocompatible substances, yet their influence on biological membranes is not well-known, and the effect on human skin has not previously been investigated. The short chain choline carboxylates ChCm with m=2, 4, 6 act as hydrotropes, solubilizing hydrophobic compounds in aqueous solution, while the longer chain choline carboxylates ChCm with m=8, 10 and oleate are able to form micelles. In the present study, the cytotoxicity of choline carboxylates was tested using HeLa and SK-MEL-28 cells. The influence of these substances on liposomes prepared from dipalmitoylphosphatidylcholine (DPPC) was also evaluated to provide insights on membrane interactions. It was observed that the choline carboxylates with a chain length of m>8 distinctly influence the bilayer, while the shorter ones had minimal interaction with the liposomes.

  9. Exercise and neuromodulators: choline and acetylcholine in marathon runners

    Science.gov (United States)

    Conlay, L. A.; Sabounjian, L. A.; Wurtman, R. J.

    1992-01-01

    Certain neurotransmitters (i.e., acetylcholine, catecholamines, and serotonin) are formed from dietary constituents (i.e., choline, tyrosine and tryptophan). Changing the consumption of these precursors alters release of their respective neurotransmitter products. The neurotransmitter acetylcholine is released from the neuromuscular junction and from brain. It is formed from choline, a common constituent in fish, liver, and eggs. Choline is also incorporated into cell membranes; membranes may likewise serve as an alternative choline source for acetylcholine synthesis. In trained athletes, running a 26 km marathon reduced plasma choline by approximately 40%, from 14.1 to 8.4 uM. Changes of similar magnitude have been shown to reduce acetylcholine release from the neuromuscular junction in vivo. Thus, the reductions in plasma choline associated with strenuous exercise may reduce acetylcholine release, and could thereby affect endurance or performance.

  10. KEY PLAYERS IN CHOLINE METABOLIC REPROGRAMMING IN TRIPLE NEGATIVE BREAST CANCER

    Directory of Open Access Journals (Sweden)

    Egidio Iorio

    2016-09-01

    Full Text Available Triple negative breast cancer (TNBC, defined by lack of estrogen and progesterone receptors in the absence of protein overexpression/gene amplification of human epidermal growth factor receptor 2 (HER2, is still a clinical challenge despite progress in breast cancer (BC care. 1H magnetic resonance spectroscopy (MRS allows identification and non-invasive monitoring of TNBC metabolic aberrations and elucidation of some key mechanisms underlying tumor progression. Thus, it has the potential to improve in vivo diagnosis and follow-up, and identify new targets for treatment. Several studies have shown an altered phosphatidylcholine (PtdCho metabolism in TNBCs, both in patients and in experimental models. Up-regulation of choline kinase-alpha, an enzyme of the Kennedy pathway that phosphorylates free choline (Cho to phosphocholine (PCho, is a major contributor to the increased PCho content detected in TNBCs. Phospholipase-mediated PtdCho headgroup hydrolysis also contributes to the build-up of a PCho pool in TNBC cells. The oncogene-driven PtdCho cycle appears to be fine tuned in TNBC cells in at least three ways: by modulating the choline import, by regulating the activity or expression of specific metabolic enzymes, and by contributing to the rewiring of the entire metabolic network. Thus, only by thoroughly dissecting these mechanisms, it will be possible to effectively translate this basic knowledge into further development and implementation of Cho-based imaging techniques and novel classes of therapeutics.

  11. Choline Transporters in Human Lung Adenocarcinoma: Expression and Functional Implications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Choline is an essential nutrient for cell survival and proliferation, however, the expression and function of choline transporters have not been well identified in cancer. In this study, we detected the mRNA and protein expression of organic cation transporter OCT3, carnitine/cation transporters OCTN 1 and OCTN2,and choline transporter-like protein CTL1 in human lung adenocarcinoma cell lines A549, H1299 and SPC-A-1.Their expression pattern was further confirmed in 25 human primary adenocarcinoma tissues. The choline uptake in these cell lines was significantly blocked by CTL1 inhibitor, but only partially inhibited by OCT or OCTN inhibitors. The efficacy of these inhibitors on cell proliferation is closely correlated with their abilities to block choline transport. Under the native expression of these transporters, the total choline uptake was notably blocked by specific PI3K/AKT inhibitors. These results describe the expression of choline transporters and their relevant function in cell proliferation of human lung adenocarcinoma, thus providing a potential"choline-starvation" strategy of cancer interference through targeting choline transporters, especially CTL1.

  12. Choline transport via choline transporter-like protein 1 in conditionally immortalized rat syncytiotrophoblast cell lines TR-TBT.

    Science.gov (United States)

    Lee, N-Y; Choi, H-M; Kang, Y-S

    2009-04-01

    Choline is an essential nutrient for phospholipids and acetylcholine biosynthesis in normal development of fetus. In the present study, we investigated the functional characteristics of choline transport system and inhibitory effect of cationic drugs on choline transport in rat conditionally immortalized syncytiotrophoblast cell line (TR-TBT). Choline transport was weakly Na(+) dependent and significantly influenced by extracellular pH and by membrane depolarization. The transport process of choline is saturable with Michaelis-Menten constants (K(m)) of 68microM and 130microM in TR-TBT 18d-1 and TR-TBT 18d-2 respectively. Choline uptake in the cells was inhibited by unlabeled choline and hemicholinium-3 as well as various organic cations including guanidine, amiloride and acetylcholine. However, the prototypical organic cation tetraethylammonium and cimetidine showed very little inhibitory effect of choline uptake in TR-TBT cells. RT-PCR revealed that choline transporter-like protein 1 (CTL1) and organic cation transporter 2 (OCT2) are expressed in TR-TBT cells. The transport properties of choline in TR-TBT cells were similar or identical to that of CTL1 but not OCT2. CTL1 was also detected in human placenta. In addition, several cationic drugs such as diphenhydramine and verapamil competitively inhibited choline uptake in TR-TBT 18d-1 with K(i) of 115microM and 55microM, respectively. Our results suggest that choline transport system, which has intermediate affinity and weakly Na(+) dependent, in TR-TBT seems to occur through a CTL1 and this system may have relevance with the uptake of pharmacologically important organic cation drugs.

  13. Small-molecule inhibition of choline catabolism in Pseudomonas aeruginosa and other aerobic choline-catabolizing bacteria.

    Science.gov (United States)

    Fitzsimmons, Liam F; Flemer, Stevenson; Wurthmann, A Sandy; Deker, P Bruce; Sarkar, Indra Neil; Wargo, Matthew J

    2011-07-01

    Choline is abundant in association with eukaryotes and plays roles in osmoprotection, thermoprotection, and membrane biosynthesis in many bacteria. Aerobic catabolism of choline is widespread among soil proteobacteria, particularly those associated with eukaryotes. Catabolism of choline as a carbon, nitrogen, and/or energy source may play important roles in association with eukaryotes, including pathogenesis, symbioses, and nutrient cycling. We sought to generate choline analogues to study bacterial choline catabolism in vitro and in situ. Here we report the characterization of a choline analogue, propargylcholine, which inhibits choline catabolism at the level of Dgc enzyme-catalyzed dimethylglycine demethylation in Pseudomonas aeruginosa. We used genetic analyses and 13C nuclear magnetic resonance to demonstrate that propargylcholine is catabolized to its inhibitory form, propargylmethylglycine. Chemically synthesized propargylmethylglycine was also an inhibitor of growth on choline. Bioinformatic analysis suggests that there are genes encoding DgcA homologues in a variety of proteobacteria. We examined the broader utility of propargylcholine and propargylmethylglycine by assessing growth of other members of the proteobacteria that are known to grow on choline and possess putative DgcA homologues. Propargylcholine showed utility as a growth inhibitor in P. aeruginosa but did not inhibit growth in other proteobacteria tested. In contrast, propargylmethylglycine was able to inhibit choline-dependent growth in all tested proteobacteria, including Pseudomonas mendocina, Pseudomonas fluorescens, Pseudomonas putida, Burkholderia cepacia, Burkholderia ambifaria, and Sinorhizobium meliloti. We predict that chemical inhibitors of choline catabolism will be useful for studying this pathway in clinical and environmental isolates and could be a useful tool to study proteobacterial choline catabolism in situ.

  14. Choline alphoscerate (alpha-glyceryl-phosphoryl-choline) an old choline- containing phospholipid with a still interesting profile as cognition enhancing agent.

    Science.gov (United States)

    Traini, Enea; Bramanti, Vincenzo; Amenta, Francesco

    2013-12-01

    Cholinergic precursors have represented the first approach to counter cognitive impairment occurring in adultonset dementia disorders. These compounds were early leaved because their clinical efficacy was not clearly demonstrated. This is probably not true for some choline-containing phospholipids including choline alphoscerate. Choline alphoscerate increases the release of acetylcholine in rat hippocampus, facilitates learning and memory in experimental animals, improves brain transduction mechanisms and decreases age-dependent structural changes occurring in rat brain areas involved in learning and memory. The compound exerts neuroprotective effects in models of altered cholinergic neurotransmission and of brain vascular injury. In clinical studies choline alphoscerate improved memory and attention impairment, as well as affective and somatic symptoms in dementia disorders. An ongoing trial indicates that association between the acetylcholinesterase inhibitor donepezil and choline alphoscerate is accompanied by an improvement in several cognitive tests superior to that induced by donepezil alone. It is suggested that this association may represent a therapeutic option to prolong beneficial effects of cholinergic therapies in Alzheimer's disease patients with concomitant ischemic cerebrovascular disorders. In summary, choline alphoscerate has significant effects on cognitive function with a good safety profile and tolerability. Although limited both in terms of size of the samples investigated and of the length of treatment, preclinical and clinical results presented suggest that cognitive enhancing capabilities of choline alphoscerate merit of being further investigated in appropriate trials.

  15. A systematic evaluation of protein kinase A-A-kinase anchoring protein interaction motifs

    NARCIS (Netherlands)

    Burgers, Pepijn P; van der Heyden, MAG; Kok, Bart; Heck, Albert J R; Scholten, Arjen

    2015-01-01

    Protein kinase A (PKA) in vertebrates is localized to specific locations in the cell via A-kinase anchoring proteins (AKAPs). The regulatory subunits of the four PKA isoforms (RIα, RIβ, RIIα, and RIIβ) each form a homodimer, and their dimerization domain interacts with a small helical region present

  16. Choline associated hypersexuality in a 79-year-old man.

    Science.gov (United States)

    Calabrò, Rocco Salvatore; Cordici, Francesco; Genovese, Carmelo; Bramanti, Placido

    2014-01-01

    Hypersexuality, also referred to as sexually inappropriate behavior and sexual disinhibition, involves persistent, uninhibited sexual behaviors directed at oneself or at others, sometimes associated with neurodegenerative disorders. Choline is a water-soluble essential nutrient, used as a dietary supplement in different diseases. This report was aimed at considering choline intake as a possible cause of iatrogenic hypersexuality. After an evaluation, a 79-year-old man affected by memory loss was diagnosed with mild cognitive impairment and treated with oral choline. After 6 weeks of regular choline assumption, the patient showed a pathological increase in libido with sexual urges. As choline was withdrawn, the hypersexuality disappeared within 5 days. Since hypersexuality may be an underreported and overlooked adverse effect of drugs and dietary supplements acting on the cholinergic pathway, this should be considered when treating and counselling patients with inappropriate sexual behavior.

  17. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Science.gov (United States)

    Fearnley, Gareth W.; Smith, Gina A.; Abdul-Zani, Izma; Yuldasheva, Nadira; Mughal, Nadeem A.; Homer-Vanniasinkam, Shervanthi; Kearney, Mark T.; Zachary, Ian C.; Tomlinson, Darren C.; Harrison, Michael A.; Wheatcroft, Stephen B.; Ponnambalam, Sreenivasan

    2016-01-01

    ABSTRACT Vascular endothelial growth factor A (VEGF-A) binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145) promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes. PMID:27044325

  18. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Directory of Open Access Journals (Sweden)

    Gareth W. Fearnley

    2016-05-01

    Full Text Available Vascular endothelial growth factor A (VEGF-A binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145 promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes.

  19. Mast cells express novel functional IL-15 receptor alpha isoforms.

    Science.gov (United States)

    Bulanova, Elena; Budagian, Vadim; Orinska, Zane; Krause, Hans; Paus, Ralf; Bulfone-Paus, Silvia

    2003-05-15

    Mast cells previously have been reported to be regulated by IL-15 and to express a distinct IL-15R, termed IL-15RX. To further examine IL-15 binding and signaling in mast cells, we have studied the nature of the IL-15R and some of its biological activities in these cells. In this study, we report the existence of three novel isoforms of the IL-15R alpha chain in murine bone marrow-derived mast cells as a result of an alternative exon-splicing mechanism within the IL-15R alpha gene. These correspond to new mRNA transcripts lacking exon 4; exons 3 and 4; or exons 3, 4, and 5 (IL-15R alpha Delta 4, IL-15R alpha Delta 3,4, IL-15R alpha Delta 3,4,5). After transient transfection in COS-7 cells, all IL-15R alpha isoforms associate with the Golgi apparatus, the endoplasmic reticulum, the perinuclear space, and the cell membrane. Analysis of glycosylation pattern demonstrates the usage of a single N-glycosylation site, while no O-glycosylation is observed. Importantly, IL-15 binds with high affinity to, and promotes the survival of, murine BA/F3 cells stably transfected with the IL-15R alpha isoforms. Furthermore, we report that signaling mediated by IL-15 binding to the newly identified IL-15R alpha isoforms involves the phosphorylation of STAT3, STAT5, STAT6, Janus kinase 2, and Syk kinase. Taken together, our data indicate that murine mast cells express novel, fully functional IL-15R alpha isoforms, which can explain the selective regulatory effects of IL-15 on these cells.

  20. Bioelectrochemical response of a choline biosensor fabricated by using polyaniline

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On the basis of the isoelectric point of an enzyme and the doping principle of conducting polymers,choline oxidase was doped in a polyaniline film to form a biosensor. The amperometric detection of choline is based on the oxidation of the H2O2 enzymatically produced on the choline biosensor. The response current of the biosensor as a function of temperature was determined from 3 to 40℃. An apparent activation energy of 22.8 kJ·mol-1 was obtained. The biosensor had a wide linear response range from 5 × 10-7 to 1 × 10-4 M choline with a correlation coefficient of 0.9999 and a detection limit of 0.2 μM,and had a high sensitivity of 61.9 mA·M-1·cm-2 at 0.50 V and at pH 8.0. The apparent Michaelis constant and the optimum pH for the immobilized enzyme are 1.4 mM choline and 8.4,respectively,which are very close to those of choline oxidase in solution. The effect of selected organic compounds on the response of the choline biosensor was studied.

  1. Expression of pyruvate kinase isoform M2 and its relationship with BRAF mutation in papillary thyroid carcinoma%甲状腺乳头状癌中M2型丙酮酸激酶的表达及其与BRAF基因突变的关系

    Institute of Scientific and Technical Information of China (English)

    张薇; 王翠芳; 关海霞

    2013-01-01

    目的:检测甲状腺乳头状癌(papillary thyroid carcinoma,PTC)中M2型丙酮酸激酶(M2 isoform of pyruvate kinase,PKM2)的表达,并探讨其与临床病理特征及BRAF(B-type Raf kinase)基因突变之间的关系.方法:采用免疫组织化学法分别对82例PTC组织、40例正常甲状腺组织及20例结节性甲状腺肿组织中PKM2的表达情况进行检测;应用PCR法扩增获得BRAF基因,并用直接测序的方法对BRAF基因突变的情况进行检测.结果:免疫组织化学结果提示,82例PTC组织中有75例(91.5%)具有不同程度PKM2蛋白的表达,在正常甲状腺组织及结节性甲状腺肿组织中PKM2蛋白表达均为阴性.PKM2的表达与T临床分期及淋巴结转移相关(P<0.05).携带BRAF基因突变的PTC组织中PKM2表达强度更强,BRAF基因突变组为100.0% (46/46),而BRAF基因未突变组为86.1% (31/36) (P<0.05).结论:PKM2在PTC中表达增加,其表达与PTC的恶性程度及BRAF基因是否突变密切相关.

  2. Purification and kinase assay of PKN.

    Science.gov (United States)

    Mukai, Hideyuki; Ono, Yoshitaka

    2006-01-01

    PKN is a serine/threonine protein kinase, which has a catalytic domain highly homologous to that of protein kinase C (PKC) in the carboxyl-terminal region and three repeats of the antiparallel coiled coil (ACC) domain in the amino-terminal region. Mammalian PKN has three isoforms each derived from different genes, PKN1 (PKNalpha/PRK1/PAK1), PKN2 (PRK2/PAK2/PKNgamma), and PKN3 (PKNbeta). PKN isoforms show different enzymatic properties and tissue distributions and have been implicated in various distinct cellular processes (reviewed in Mukai [2003]). This chapter discusses methods to prepare purified enzymes and to assay substrate phosphorylation activities.

  3. Use of canonical variate analysis biplot in examination of choline content data of some foods.

    Science.gov (United States)

    Alkan, Baris; Atakan, Cemal

    2011-03-01

    Adequate intake (AI) of choline as part of the daily diet can help prevent major diseases. Low choline intake is a major risk factor for liver and several neurological disorders. Extreme choline consumption may cause diseases such as hypotension, sweating, diarrhea, and fishy body odor. The AI of choline is 425 mg/day for adult women; higher for pregnant and lactating women. The AI for adult men is 550 mg/day. The total choline content of foods is calculated as the sum of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin. These are called the choline variables. Observed values of choline variables may be different in amounts of nutrients. So different food groups in terms of choline variables are useful to compare. The present paper shows the advantages of using canonical variate analysis biplot to optimally separate groups and explore the differentiality of choline variables amounts in foods.

  4. Expression of phosphoinositide-specific phospholipase C isoforms in native endothelial cells.

    Directory of Open Access Journals (Sweden)

    Delphine M Béziau

    Full Text Available Phospholipase C (PLC comprises a superfamily of enzymes that play a key role in a wide array of intracellular signalling pathways, including protein kinase C and intracellular calcium. Thirteen different mammalian PLC isoforms have been identified and classified into 6 families (PLC-β, γ, δ, ε, ζ and η based on their biochemical properties. Although the expression of PLC isoforms is tissue-specific, concomitant expression of different PLC has been reported, suggesting that PLC family is involved in multiple cellular functions. Despite their critical role, the PLC isoforms expressed in native endothelial cells (ECs remains undetermined. A conventional PCR approach was initially used to elucidate the mRNA expression pattern of PLC isoforms in 3 distinct murine vascular beds: mesenteric (MA, pulmonary (PA and middle cerebral arteries (MCA. mRNA encoding for most PLC isoforms was detected in MA, MCA and PA with the exception of η2 and β2 (only expressed in PA, δ4 (only expressed in MCA, η1 (expressed in all but MA and ζ (not detected in any vascular beds tested. The endothelial-specific PLC expression was then sought in freshly isolated ECs. Interestingly, the PLC expression profile appears to differ across the investigated arterial beds. While mRNA for 8 of the 13 PLC isoforms was detected in ECs from MA, two additional PLC isoforms were detected in ECs from PA and MCA. Co-expression of multiple PLC isoforms in ECs suggests an elaborate network of signalling pathways: PLC isoforms may contribute to the complexity or diversity of signalling by their selective localization in cellular microdomains. However in situ immunofluorescence revealed a homogeneous distribution for all PLC isoforms probed (β3, γ2 and δ1 in intact endothelium. Although PLC isoforms play a crucial role in endothelial signal transduction, subcellular localization alone does not appear to be sufficient to determine the role of PLC in the signalling microdomains found

  5. Identification and characterization of a novel isoform of hepatopoietin

    Institute of Scientific and Technical Information of China (English)

    Jun Lu; Wang-Xiang Xu; Yi-Qun Zhan; Xiao-Lin Cui; Wei-Min Cai; Fu-Chu He; Xiao-Ming Yang

    2002-01-01

    AIM: To isolate a novel isoform of human HPO (HPO-205)human fetal liver Marathon-reedy cDNA andcharacterize its primary biological function.METHODS: 5'-RACE (rapid amplification of cDNA 5' ends)was used to isolate a novel isoform of hHPO in this paperThe constructed pcDNAHPO-205, pcDNAHPO and pcDNA eukaryotic expression vectors were respectively transfectedby lipofectamine method and the stimulation of DNAsynthesis was observed by 3H-TdR incorporation assay.Proteins extracted from different cells were analyzed byWestern blot.RESULTS: A novel isoform of hHPO (HPO-205) encoding a205 amino acid ORF corresponding to a translatedproduction of 23 kDa was isolated and distinguished fromthe previous HPO that lacked the N-terminal 80 amino acids.The dnse-dspendent stimulation of DNA synthesis of HepG2hepatoma cells by HPO-205 demonstrated its similarbiological activity with HPO in vitro. The level of MAPK(Mitogen-activated protein kinase) phnsphorylarion byWestern blot analysis revealed that HPO-205 might have thestronger activity of stimulating hepatic cell proliferation thanthat of HPO.CONCLUSION: A novel isoform of hHPO (HPO-205) wasisolated from hepatic-derived cells. The comparison of HPO-205 and HPO will lead to a new insight into the structure andfunction of hHPO, and provide the new way of thinking todeeply elucidate the biological roles of HPO/ALR.

  6. Trimethylaminuria: the use of choline as an aid to diagnosis.

    Science.gov (United States)

    Marks, R; Greaves, M W; Prottey, C; Hartop, P J

    1977-04-01

    Trimethylamine metabolism can be studied by means of choline loading. The value and some limitations of the method are illustrated by results obtained in normal subjects, a patient with the Fish Odour syndrome and his kindred.

  7. Histamine H3-receptor isoforms.

    Science.gov (United States)

    Bakker, R A

    2004-10-01

    Increasing evidence supports a role for HA as a neurotransmitter and neuromodulator in various brain functions, including emotion, cognition, and feeding. The recent cloning of the histamine H3 receptor allowed for the subsequent cloning of a variety of H3 receptor isoforms from different species as well as the H4 receptor. As a result a wide variety of H3-receptor isoforms are now known that display differential brain expression patterns and signalling properties. These recent discoveries are discussed in view of the growing interest of the H3 receptor as a target for the development of potential therapeutics.

  8. Measurement of choline and choline metabolite concentrations using high-pressure liquid chromatography and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Pomfret, E A; daCosta, K A; Schurman, L L; Zeisel, S H

    1989-07-01

    We have developed a reproducible and sensitive procedure for the isolation and measurement of choline, phosphocholine, glycerophosphocholine, phosphatidylcholine, lysophosphatidylcholine and acetylcholine in a single 100-mg sample of biological tissue. Tissues were spiked with 14C-methyl- and 2H-methyl- or 15N-choline labeled internal standards for each compound. They were extracted with chloroform/methanol/water and the aqueous and organic phases were dried. The organic phase was resuspended in chloroform/methanol (1/1, v/v) and an aliquot was applied to a silica-gel thin-layer chromatography plate. The plate was developed in chloroform/methanol/water (65/30/4, v/v). Segments which cochromatographed with external standards of phosphatidylcholine and lysophosphatidylcholine were stained, scraped, and hydrolyzed in 6 M methanolic-HCl at 80 degrees C for 60 min, liberating free choline. The aqueous phase was resuspended in methanol/water and injected onto a silica HPLC column. Choline and its metabolites were eluted using a binary nonlinear gradient of acetonitrile/ethanol/acetic acid/1 M ammonium acetate/water/0.1 M sodium phosphate (800/68/2/3/127/10, v/v changing to 400/68/44/88/400/10, v/v). Peaks were detected with an on-line radiometric detector, collected, and dried under vacuum. Each choline ester was digested in 6 M HCl at 80 degrees C to form choline. Choline was then converted to the propionyl ester and demethylated with sodium benzenethiolate. This volatile derivative was then isolated using gas chromatography and measured with a mass selective detector. Deuterated internal standards were used to correct for variations in recovery. Choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, lysophosphatidylcholine, and acetylcholine were measured in rat liver, heart, muscle, kidney, plasma, red blood cells, and brain and in human plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. [Folate metabolism--epigenetic role of choline and vitamin B12 during pregnancy].

    Science.gov (United States)

    Drews, Krzysztof

    2015-12-01

    Adequate choline intake during pregnancy is essential for proper fetal development. Nowadays studies suggest that even in high income countries regular pregnant women diet does not provide the satisfactory amount of choline. Choline demand during pregnancy is high and it seems to exceed present choline intake recommendations. Moreover lactation period also demands choline supplementation because of its high concentration in female milk. Numerous studies on animal model proved correlation between choline supplementation during pregnancy and proper fetal cognitive function development. Despite increased synthesis in maternal liver during pregnancy choline demand is much higher than common dietary uptake. Nowadays studies as to the nutritional recommendations during pregnancy concern also vitamin B12 supplementation. Vitamin B12 deficiency may be an important risk factor of neural tube defects development. Presented article contains a review of data on proper choline and vitamin B12 uptake during pregnancy and lactation and potential results of choline and vitamin B12 poor maternal status.

  10. 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...

  11. γIsoform-Selective Changes in PKC Immunoreactivity after Trace Eyeblink Conditioning in the Rabbit Hippocampus

    NARCIS (Netherlands)

    Zee, E.A. van der; Kronforst-Collins, M.A.; Maizels, E.T.; Hunzicker-Dunn, M.; Disterhoft, J.F.

    1997-01-01

    An immunocytochemical examination of the rabbit hippocampus was done to determine which of the Ca2+-dependent protein kinase C (PKC) isoforms (PKCα, -βI, -βII, or -γ) are involved in associative learning. The hippocampally dependent trace eyeblink conditioning task was used for behavioral training,

  12. Reciprocal regulation of protein kinase and pyruvate kinase activities of pyruvate kinase M2 by growth signals.

    Science.gov (United States)

    Gao, Xueliang; Wang, Haizhen; Yang, Jenny J; Chen, Jing; Jie, Jiang; Li, Liangwei; Zhang, Yinwei; Liu, Zhi-Ren

    2013-05-31

    Pyruvate kinase isoform M2 (PKM2) is an enzyme-catalyzing conversion of phosphoenolpyruvate to pyruvate in the glycolysis pathway. It was demonstrated that PKM2 interacts with tyrosine phosphopeptide, and the interaction with the tyrosine phosphopeptide affects the pyruvate kinase activity of PKM2. Our experiments suggest that PKM2 is also an active protein kinase (Gao, X., Wang, H., Yang, J. J., Liu, X., and Liu, Z. R. (2012) Mol. Cell 45, 598-609). We report here that growth signals reciprocally regulate the pyruvate kinase and protein kinase activities of PKM2 by different mechanisms. On the one hand, growth signals induce protein tyrosine phosphorylations. The tyrosine-phosphorylated protein(s) regulates the conversion of pyruvate kinase and protein kinase of PKM2 by directly interacting with PKM2. Binding of the tyrosyl-phosphorylated proteins at the fructose 1,6-bisphosphate-binding site converts the tetrameric PKM2 to a dimer. On the other hand, growth stimulations also lead to PKM2 phosphorylation, which consequently regulates the conversion of protein kinase and pyruvate kinase activities. Growth factor stimulations significantly increase the dimer/tetramer PKM2 ratio in cells and consequently activate the protein kinase activity of PKM2. Our study suggests that the conversion between the pyruvate kinase and protein kinase activities of PKM2 may be an important mechanism mediating the effects of growth signals in promoting cell proliferation.

  13. CHKA and PCYT1A gene polymorphisms, choline intake and spina bifida risk in a California population

    Directory of Open Access Journals (Sweden)

    Lammer Edward J

    2006-12-01

    Full Text Available Abstract Background Neural tube defects (NTDs are among the most common of all human congenital defects. Over the last two decades, accumulating evidence has made it clear that periconceptional intake of folic acid can significantly reduce the risk of NTD affected pregnancies. This beneficial effect may be related to the ability of folates to donate methyl groups for critical physiological reactions. Choline is an essential nutrient and it is also a methyl donor critical for the maintenance of cell membrane integrity and methyl metabolism. Perturbations in choline metabolism in vitro have been shown to induce NTDs in mouse embryos. Methods This study investigated whether single nucleotide polymorphisms (SNPs in human choline kinase A (CHKA gene and CTP:phosphocholine cytidylytransferase (PCYT1A gene were risk factors for spina bifida. Fluorescence-based allelic discrimination analysis was performed for the two CHKA intronic SNPs hCV1562388 (rs7928739 and hCV1562393, and PCYT1A SNP rs939883 and rs3772109. The study population consisted of 103 infants with spina bifida and 338 non-malformed control infants who were born in selected California counties in the period 1989–1991. Results The CHKA SNP hCV1562388 genotypes with at least one C allele were associated with a reduced risk of spina bifida (odds ratio = 0.60, 95%CI = 0.38–0.94. The PCYT1A SNP rs939883 genotype AA was associated with a twofold increased risk of spina bifida (odds ratio = 1.89, 95% CI = 0.97–3.67. These gene-only effects were not substantially modified by analytic consideration to maternal periconceptional choline intake. Conclusion Our analyses showed genotype effects of CHKA and PCYT1A genes on spina bifida risk, but did not show evidence of gene-nutrient interactions. The underlying mechanisms are yet to be resolved.

  14. Human choline dehydrogenase: medical promises and biochemical challenges.

    Science.gov (United States)

    Salvi, Francesca; Gadda, Giovanni

    2013-09-15

    Human choline dehydrogenase (CHD) is located in the inner membrane of mitochondria primarily in liver and kidney and catalyzes the oxidation of choline to glycine betaine. Its physiological role is to regulate the concentrations of choline and glycine betaine in the blood and cells. Choline is important for regulation of gene expression, the biosynthesis of lipoproteins and membrane phospholipids and for the biosynthesis of the neurotransmitter acetylcholine; glycine betaine plays important roles as a primary intracellular osmoprotectant and as methyl donor for the biosynthesis of methionine from homocysteine, a required step for the synthesis of the ubiquitous methyl donor S-adenosyl methionine. Recently, CHD has generated considerable medical attention due to its association with various human pathologies, including male infertility, homocysteinuria, breast cancer and metabolic syndrome. Despite the renewed interest, the biochemical characterization of the enzyme has lagged behind due to difficulties in the obtainment of purified, active and stable enzyme. This review article summarizes the medical relevance and the physiological roles of human CHD, highlights the biochemical knowledge on the enzyme, and provides an analysis based on the comparison of the protein sequence with that of bacterial choline oxidase, for which structural and biochemical information is available.

  15. The in vivo phosphorylation sites in multiple isoforms of amphiphysin I from rat brain nerve terminals

    DEFF Research Database (Denmark)

    Craft, George E; Graham, Mark E; Bache, Nicolai;

    2008-01-01

    -proline-directed kinases, Ser-626, -250, -252, and -539, contained low amounts of 32P and were not depolarization-responsive. At least one alternatively spliced amphI isoform was identified in synaptosomes as being constitutively phosphorylated because it did not incorporate 32P during the 1-h labeling period. Multiple......, incorporating 16 and 23% of the 32P. The multiple phosphopeptides containing Ser-268, Ser-276, Ser-272, and Ser-285 had 27% of the 32P. Evidence for a role for at least one proline-directed protein kinase and one non-proline-directed kinase was obtained. Four phosphosites predicted for non...

  16. Learning-dependent gene expression of CREB1 isoforms in the molluscan brain

    Directory of Open Access Journals (Sweden)

    Hisayo Sadamoto

    2010-05-01

    Full Text Available Cyclic AMP-responsive element binding protein1 (CREB1 has multiple functions in gene regulation. Various studies have reported that CREB1-dependent gene induction is necessary for memory formation and long-lasting behavioral changes in both vertebrates and invertebrates. In the present study, we characterized Lymnaea CREB1 (LymCREB1 mRNA isoforms of spliced variants in the central nervous system (CNS of the pond snail Lymnaea stagnalis. Among these spliced variants, the three isoforms that code a whole LymCREB1 protein are considered to be the activators for gene regulation. The other four isoforms, which code truncated LymCREB1 proteins with no kinase inducible domain, are the repressors. For a better understanding of the possible roles of different LymCREB1 isoforms, the expression level of these isoform mRNAs was investigated by a real-time quantitative RT-PCR method. Further, we examined the changes in gene expression for all the isoforms in the CNS after conditioned taste aversion (CTA learning or backward conditioning as a control. The results showed that CTA learning increased LymCREB1 gene expression, but it did not change the activator/repressor ratio. Our findings showed that the repressor isoforms, as well as the activator ones, are expressed in large amounts in the CNS, and the gene expression of CREB1 isoforms appeared to be specific for the given stimulus. This was the first quantitative analysis of the expression patterns of CREB1 isoforms at the mRNA level and their association with learning behavior.

  17. The mechanism of protein kinase C regulation

    Institute of Scientific and Technical Information of China (English)

    Julhash U. KAZI

    2011-01-01

    Protein kinase C (PKC) is a family ofserine/threonine protein kinases that plays a central role in transducing extracellular signals into a variety of intracellular responses ranging from cell proliferation to apoptosis.Nine PKC genes have been identified in the human genome,which encode 10 proteins.Each member of this protein kinase family displays distinct biochemical characteristics and is enriched in different cellular and subcellular locations.Activation of PKC has been implicated in the regulation of cell growth and differentiation.This review summarizes works of the past years in the field of PKC biochemistry that covers regulation and activation mechanism of different PKC isoforms.

  18. Protein Kinase D family kinases: roads start to segregate.

    Science.gov (United States)

    Wille, Christoph; Seufferlein, Thomas; Eiseler, Tim

    2014-01-01

    Highly invasive pancreatic tumors are often recognized in late stages due to a lack of clear symptoms and pose major challenges for treatment and disease management. Broad-band Protein Kinase D (PKD) inhibitors have recently been proposed as additional treatment option for this disease. PKDs are implicated in the control of cancer cell motility, angiogenesis, proliferation and metastasis. In particular, PKD2 expression is elevated in pancreatic cancer, whereas PKD1 expression is comparably lower. In our recent study we report that both kinases control PDAC cell invasive properties in an isoform-specific, but opposing manner. PKD1 selectively mediates anti-migratory/anti-invasive features by preferential regulation of the actin-regulatory Cofilin-phosphatase Slingshot1L (SSH1L). PKD2, on the other hand enhances invasion and angiogenesis of PDAC cells in 3D-ECM cultures and chorioallantois tumor models by stimulating expression and secretion of matrix-metalloproteinase 7 and 9 (MMP7/9). MMP9 also enhances PKD2-mediated tumor angiogenesis releasing extracellular matrix-bound VEGF-A. We thus suggest high PKD2 expression and loss of PKD1 may be beneficial for tumor cells to enhance their matrix-invading abilities. In our recent study we demonstrate for the first time PKD1 and 2 isoform-selective effects on pancreatic cancer cell invasion, in-vitro and in-vivo, defining isoform-specific regulation of PKDs as a major future issue.

  19. Characterisation of CDKL5 Transcript Isoforms in Human and Mouse.

    Directory of Open Access Journals (Sweden)

    Ralph D Hector

    Full Text Available Mutations in the X-linked Cyclin-Dependent Kinase-Like 5 gene (CDKL5 cause early onset infantile spasms and subsequent severe developmental delay in affected children. Deleterious mutations have been reported to occur throughout the CDKL5 coding region. Several studies point to a complex CDKL5 gene structure in terms of exon usage and transcript expression. Improvements in molecular diagnosis and more extensive research into the neurobiology of CDKL5 and pathophysiology of CDKL5 disorders necessitate an updated analysis of the gene. In this study, we have analysed human and mouse CDKL5 transcript patterns both bioinformatically and experimentally. We have characterised the predominant brain isoform of CDKL5, a 9.7 kb transcript comprised of 18 exons with a large 6.6 kb 3'-untranslated region (UTR, which we name hCDKL5_1. In addition we describe new exonic regions and a range of novel splice and UTR isoforms. This has enabled the description of an updated gene model in both species and a standardised nomenclature system for CDKL5 transcripts. Profiling revealed tissue- and brain development stage-specific differences in expression between transcript isoforms. These findings provide an essential backdrop for the diagnosis of CDKL5-related disorders, for investigations into the basic biology of this gene and its protein products, and for the rational design of gene-based and molecular therapies for these disorders.

  20. Characterisation of CDKL5 Transcript Isoforms in Human and Mouse.

    Science.gov (United States)

    Hector, Ralph D; Dando, Owen; Landsberger, Nicoletta; Kilstrup-Nielsen, Charlotte; Kind, Peter C; Bailey, Mark E S; Cobb, Stuart R

    2016-01-01

    Mutations in the X-linked Cyclin-Dependent Kinase-Like 5 gene (CDKL5) cause early onset infantile spasms and subsequent severe developmental delay in affected children. Deleterious mutations have been reported to occur throughout the CDKL5 coding region. Several studies point to a complex CDKL5 gene structure in terms of exon usage and transcript expression. Improvements in molecular diagnosis and more extensive research into the neurobiology of CDKL5 and pathophysiology of CDKL5 disorders necessitate an updated analysis of the gene. In this study, we have analysed human and mouse CDKL5 transcript patterns both bioinformatically and experimentally. We have characterised the predominant brain isoform of CDKL5, a 9.7 kb transcript comprised of 18 exons with a large 6.6 kb 3'-untranslated region (UTR), which we name hCDKL5_1. In addition we describe new exonic regions and a range of novel splice and UTR isoforms. This has enabled the description of an updated gene model in both species and a standardised nomenclature system for CDKL5 transcripts. Profiling revealed tissue- and brain development stage-specific differences in expression between transcript isoforms. These findings provide an essential backdrop for the diagnosis of CDKL5-related disorders, for investigations into the basic biology of this gene and its protein products, and for the rational design of gene-based and molecular therapies for these disorders.

  1. Antagonistic functions of two stardust isoforms in Drosophila photoreceptor cells.

    Science.gov (United States)

    Bulgakova, Natalia A; Rentsch, Michaela; Knust, Elisabeth

    2010-11-15

    Membrane-associated guanylate kinases (MAGUKs) are scaffolding proteins that organize supramolecular protein complexes, thereby partitioning the plasma membrane into spatially and functionally distinct subdomains. Their modular organization is ideally suited to organize protein complexes with cell type- or stage-specific composition, or both. Often more than one MAGUK isoform is expressed by one gene in the same cell, yet very little is known about their individual in vivo functions. Here, we show that two isoforms of Drosophila stardust, Sdt-H (formerly called Sdt-B2) and Sdt-D, which differ in their N terminus, are expressed in adult photoreceptors. Both isoforms associate with Crumbs and PATJ, constituents of the conserved Crumbs-Stardust complex. However, they form distinct complexes, localized at the stalk, a restricted region of the apical plasma membrane. Strikingly, Sdt-H and Sdt-D have antagonistic functions. While Sdt-H overexpression increases stalk membrane length and prevents light-dependent retinal degeneration, Sdt-D overexpression reduces stalk length and enhances light-dependent retinal degeneration. These results suggest that a fine-tuned balance of different Crumbs complexes regulates photoreceptor homeostasis.

  2. Structure and biological function of ENPP6, a choline-specific glycerophosphodiester-phosphodiesterase

    OpenAIRE

    Junko Morita; Kuniyuki Kano; Kazuki Kato; Hiroyuki Takita; Hideki Sakagami; Yasuo Yamamoto; Emiko Mihara; Hirofumi Ueda; Takanao Sato; Hidetoshi Tokuyama; Hiroyuki Arai; Hiroaki Asou; Junichi Takagi; Ryuichiro Ishitani; Hiroshi Nishimasu

    2016-01-01

    Choline is an essential nutrient for all living cells and is produced extracellularly by sequential degradation of phosphatidylcholine (PC). However, little is known about how choline is produced extracellularly. Here, we report that ENPP6, a choline-specific phosphodiesterase, hydrolyzes glycerophosphocholine (GPC), a degradation product of PC, as a physiological substrate and participates in choline metabolism. ENPP6 is highly expressed in liver sinusoidal endothelial cells and developing o...

  3. Inference of Isoforms from Short Sequence Reads

    Science.gov (United States)

    Feng, Jianxing; Li, Wei; Jiang, Tao

    Due to alternative splicing events in eukaryotic species, the identification of mRNA isoforms (or splicing variants) is a difficult problem. Traditional experimental methods for this purpose are time consuming and cost ineffective. The emerging RNA-Seq technology provides a possible effective method to address this problem. Although the advantages of RNA-Seq over traditional methods in transcriptome analysis have been confirmed by many studies, the inference of isoforms from millions of short sequence reads (e.g., Illumina/Solexa reads) has remained computationally challenging. In this work, we propose a method to calculate the expression levels of isoforms and infer isoforms from short RNA-Seq reads using exon-intron boundary, transcription start site (TSS) and poly-A site (PAS) information. We first formulate the relationship among exons, isoforms, and single-end reads as a convex quadratic program, and then use an efficient algorithm (called IsoInfer) to search for isoforms. IsoInfer can calculate the expression levels of isoforms accurately if all the isoforms are known and infer novel isoforms from scratch. Our experimental tests on known mouse isoforms with both simulated expression levels and reads demonstrate that IsoInfer is able to calculate the expression levels of isoforms with an accuracy comparable to the state-of-the-art statistical method and a 60 times faster speed. Moreover, our tests on both simulated and real reads show that it achieves a good precision and sensitivity in inferring isoforms when given accurate exon-intron boundary, TSS and PAS information, especially for isoforms whose expression levels are significantly high.

  4. Diacylglycerol Kinase Inhibition and Vascular Function.

    Science.gov (United States)

    Choi, Hyehun; Allahdadi, Kyan J; Tostes, Rita C A; Webb, R Clinton

    2009-01-01

    Diacylglycerol kinases (DGKs), a family of lipid kinases, convert diacylglycerol (DG) to phosphatidic acid (PA). Acting as a second messenger, DG activates protein kinase C (PKC). PA, a signaling lipid, regulates diverse functions involved in physiological responses. Since DGK modulates two lipid second messengers, DG and PA, regulation of DGK could induce related cellular responses. Currently, there are 10 mammalian isoforms of DGK that are categorized into five groups based on their structural features. These diverse isoforms of DGK are considered to activate distinct cellular functions according to extracellular stimuli. Each DGK isoform is thought to play various roles inside the cell, depending on its subcellular localization (nuclear, ER, Golgi complex or cytoplasm). In vascular smooth muscle, vasoconstrictors such as angiotensin II, endothelin-1 and norepinephrine stimulate contraction by increasing inositol trisphosphate (IP(3)), calcium, DG and PKC activity. Inhibition of DGK could increase DG availability and decrease PA levels, as well as alter intracellular responses, including calcium-mediated and PKC-mediated vascular contraction. The purpose of this review is to demonstrate a role of DGK in vascular function. Selective inhibition of DGK isoforms may represent a novel therapeutic approach in vascular dysfunction.

  5. Proteomic analysis of mice fed methionine and choline deficient diet reveals marker proteins associated with steatohepatitis.

    Directory of Open Access Journals (Sweden)

    Su Jin Lee

    Full Text Available The mechanisms underlying the progression of simple steatosis to steatohepatitis are yet to be elucidated. To identify the proteins involved in the development of liver tissue inflammation, we performed comparative proteomic analysis of non-alcoholic steatohepatitis (NASH. Mice fed a methionine and choline deficient diet (MCD developed hepatic steatosis characterized by increased free fatty acid (FFA and triglyceride levels as well as alpha-SMA. Two-dimensional proteomic analysis revealed that the change from the normal diet to the MCD diet affected the expressions of 50 proteins. The most-pronounced changes were observed in the expression of proteins involved in Met metabolism and oxidative stress, most of which were significantly downregulated in NASH model animals. Peroxiredoxin (Prx is the most interesting among the modulated proteins identified in this study. In particular, cross-regulated Prx1 and Prx6 are likely to participate in cellular defense against the development of hepatitis. Thus, these Prx isoforms may be a useful new marker for early stage steatohepatitis. Moreover, curcumin treatment results in alleviation of the severity of hepatic inflammation in steatohepatitis. Notably, curcumin administration in MCD-fed mice dramatically reduced CYP2E1 as well as Prx1 expression, while upregulating Prx6 expression. These findings suggest that curcumin may have a protective role against MCD fed-induced oxidative stress.

  6. Phosphoryl choline-grafted water-soluble carbon nanotube

    Institute of Scientific and Technical Information of China (English)

    Tao Zhang; Kai Xi; Min Gu; Zheng Sheng Jiang

    2008-01-01

    Water-soluble property is the precondition of biomedical evaluation and application of carbon nanotube (CNT). Novel watersoluble CNT was synthesized in this letter by grafting phosphoryi choline (PC) onto multi-wall CNTs. Utilizing FTIR, XPS, TGAand TEM, the title CNTs were characterized and it was found that the target products could facilely dissolve in water.

  7. Conformational analysis of acetylcholine and related choline esters

    DEFF Research Database (Denmark)

    Frydenvang, Karla Andrea; Jensen, B

    1996-01-01

    ,2'-[(1,4-dioxo-1,4-butanediyl)bis(oxy)]bis(N,N,N-trimethylet hanaminium)¿ iodide have been redetermined at 105 K in order to obtain detailed and accurate information on the geometry of choline esters and to elucidate the conformationally dependent changes of geometry. The conformational flexibility...

  8. Spatial memory and hippocampal plasticity are differentially sensitive to the availability of choline in adulthood as a function of choline supply in utero.

    Science.gov (United States)

    Wong-Goodrich, Sarah J E; Glenn, Melissa J; Mellott, Tiffany J; Blusztajn, Jan K; Meck, Warren H; Williams, Christina L

    2008-10-27

    Altered dietary choline availability early in life leads to persistent changes in spatial memory and hippocampal plasticity in adulthood. Developmental programming by early choline nutrition may determine the range of adult choline intake that is optimal for the types of neural plasticity involved in cognitive function. To test this, male Sprague-Dawley rats were exposed to a choline chloride deficient (DEF), sufficient (CON), or supplemented (SUP) diet during embryonic days 12-17 and then returned to a control diet (1.1 g choline chloride/kg). At 70 days of age, we found that DEF and SUP rats required fewer choices to locate 8 baited arms of a 12-arm radial maze than CON rats. When switched to a choline-deficient diet (0 g/kg), SUP rats showed impaired performance while CON and DEF rats were unaffected. In contrast, when switched to a choline-supplemented diet (5.0 g/kg), DEF rats' performance was significantly impaired while CON and SUP rats were less affected. These changes in performance were reversible when the rats were switched back to a control diet. In a second experiment, DEF, CON, and SUP rats were either maintained on a control diet, or the choline-supplemented diet. After 12 weeks, DEF rats were significantly impaired by choline supplementation on a matching-to-place water-maze task, which was also accompanied by a decrease in dentate cell proliferation in DEF rats only. IGF-1 levels were elevated by both prenatal and adult choline supplementation. Taken together, these findings suggest that the in utero availability of an essential nutrient, choline, causes differential behavioral and neuroplastic sensitivity to the adult choline supply.

  9. Role of ROCK Isoforms in Regulation of Stiffness Induced Myofibroblast Differentiation in Lung Fibrosis.

    Science.gov (United States)

    Htwe, Su S; Cha, Byung H; Yue, Kan; Khademhosseini, Ali; Knox, Alan J; Ghaemmaghami, Amir M

    2017-02-22

    Fibrosis is a major cause of progressive organ dysfunction in several chronic pulmonary diseases. Rho associated coiled-coil forming kinase (ROCK) has shown to be involved in myofibroblast differentiation driven by altered matrix stiffness in fibrotic state. There are two known ROCK isoforms in human, ROCK1 (ROKβ) and ROCK2 (ROKα), but specific role of each isoform in myofibroblast differentiation in lung fibrosis remains unknown. To study this, we developed a Gelatin methacryloyl (GelMA) hydrogel based culture system with different stiffness levels relevant to healthy and fibrotic lungs. We have shown that stiff matrix and not soft matrix, can induce myofibroblast differentiation with high αSMA expression. Furthermore, our data confirm that the inhibition of ROCK signalling by a pharmacological inhibitor (i.e. Y27632) attenuates stiffness induced αSMA expression and fibre assembly in myofibroblasts. To assess the role of ROCK isoforms in this process we used siRNA to knock down the expression of each isoform. Our data showed that knocking down either ROCK1 or ROCK2 did not result in a reduction in αSMA expression in myofibroblasts on stiff matrix as opposed to soft matrix where αSMA expression was reduced significantly. Paradoxically, on stiff matrix, the absence of one isoform (particularly ROCK2) exaggerated αSMA expression and led to thick fibre assembly. Moreover complete loss of αSMA fibre assembly was seen only in the absence of both ROCK isoforms suggesting that both isoforms are implicated in this process. Overall our results indicate the differential role of ROCK isoforms in myofibroblast differentiation on soft and stiff matrices.

  10. Mechanism of choline deficiency and membrane alteration in postural orthostatic tachycardia syndrome primary skin fibroblasts.

    Science.gov (United States)

    Schenkel, Laila C; Singh, Ratnesh K; Michel, Vera; Zeisel, Steven H; da Costa, Kerry-Ann; Johnson, Amy R; Mudd, Harvey S; Bakovic, Marica

    2015-05-01

    Fibroblasts from a patient with postural orthostatic tachycardia syndrome (POTS), who presented with low plasma choline and betaine, were studied to determine the metabolic characteristics of the choline deficiency. Choline is required for the synthesis of the phospholipid phosphatidylcholine (PC) and for betaine, an important osmoregulator. Here, choline transport, lipid homeostasis, and mitochondria function were analyzed in skin fibroblasts from POTS and compared with control cells. The choline transporter-like protein 1/solute carrier 44A1 (CTL1/SLC44A1) and mRNA expression were 2-3 times lower in POTS fibroblasts, and choline uptake was reduced 60% (P < 0.05). Disturbances of membrane homeostasis were observed by reduced ratios between PC:phosphatidylethanolamine and sphingomyelin:cholesterol, as well as by modified phospholipid fatty acid composition. Choline deficiency also impaired mitochondria function, which was observed by a reduction in oxygen consumption, mitochondrial potential, and glycolytic activity. When POTS cells were treated with choline, transporter was up-regulated, and uptake of choline increased, offering an option for patient treatment. The characteristics of the POTS fibroblasts described here represent a first model of choline and CTL1/SLC44A1 deficiency, in which choline transport, membrane homeostasis, and mitochondrial function are impaired.

  11. Association of protein kinase Cmu with type II phosphatidylinositol 4-kinase and type I phosphatidylinositol-4-phosphate 5-kinase.

    Science.gov (United States)

    Nishikawa, K; Toker, A; Wong, K; Marignani, P A; Johannes, F J; Cantley, L C

    1998-09-04

    Protein kinase Cmu (PKCmu), also named protein kinase D, is an unusual member of the PKC family that has a putative transmembrane domain and pleckstrin homology domain. This enzyme has a substrate specificity distinct from other PKC isoforms (Nishikawa, K., Toker, A., Johannes, F. J., Songyang, Z., and Cantley, L. C. (1997) J. Biol. Chem. 272, 952-960), and its mechanism of regulation is not yet clear. Here we show that PKCmu forms a complex in vivo with a phosphatidylinositol 4-kinase and a phosphatidylinositol-4-phosphate 5-kinase. A region of PKCmu between the amino-terminal transmembrane domain and the pleckstrin homology domain is shown to be involved in the association with the lipid kinases. Interestingly, a kinase-dead point mutant of PKCmu failed to associate with either lipid kinase activity, indicating that autophosphorylation may be required to expose the lipid kinase interaction domain. Furthermore, the subcellular distribution of the PKCmu-associated lipid kinases to the particulate fraction depends on the presence of the amino-terminal region of PKCmu including the predicted transmembrane region. These results suggest a novel model in which the non-catalytic region of PKCmu acts as a scaffold for assembly of enzymes involved in phosphoinositide synthesis at specific membrane locations.

  12. Localisation of Protein Kinase C in Apoptosis and Neurite Outgrowth

    OpenAIRE

    Schultz, Anna

    2005-01-01

    Protein kinase C (PKC) is a family of serine/threonine kinases, which are subgrouped into classical (a, bI, bII, g), novel (d, e, h, q) and atypical (z, i/l) isoforms. One major aim of this thesis work was to investigate if altered levels of PKC isoforms influence the apoptotic responses of malignant cell-lines. We show that overexpression of PKCd or PKCq renders SK-N-BE(2) neuroblastoma cells sensitive to apoptosis induced by phorbol esters or C2-ceramide. Moreover, overexpression of PKCa, P...

  13. Isolation and characterization of patatin isoforms

    NARCIS (Netherlands)

    Pots, A.M.; Gruppen, H.; Hessing, M.; Boekel, M.A.J.S. van; Voragen, A.G.J.

    1999-01-01

    Patatin has, so far, been considered a homogeneous group of proteins. A comparison of the isoforms in terms of structural properties or stability has not been reported. A method to obtain various isoform fractions as well as a comparison of the physicochemical properties of these pools is presented.

  14. Influence of dietary protein and excess methionine on choline needs for young bobwhite quail

    Science.gov (United States)

    Serafin, J.A.

    1982-01-01

    Experiments were conducted with young Bobwhite quail (Colinus virginianus) to investigate the effect of differing dietary protein levels and nondetrimental amounts of excess methionine on choline needs. Growth and feed consumption of quail fed an adequate (27.3%) protein purified diet supplemented with 2000 mg/kg of choline were unaffected by increasing the level of excess methionine to 1.75%; however, greater amounts (2.0%, 2.25%) of excess methionine depressed growth (P less than .01), reduced feed consumption (P less than .01), and decreased feed utilization (P less than .05). Quail fed a purified diet containing 13.85% protein and 515 mg/kg of choline grew poorly. Growth was unaffected by additional choline in this diet. Growth was suboptimal among quail fed purified diets containing adequate or high (41.55%) levels of protein in which choline was limiting; however, a high level of protein did not in itself affect performance. Growth was improved by supplemental choline in these diets. Growth of quail fed purified diets with up to 1.35% excess methionine which were limiting (531 mg/kg) in choline was less than that of groups fed 2000 mg/kg of added dietary choline (P less than .01); however, excess methionine did not significantly influence growth of quail fed choline-deficient diets. These experiments indicate that neither high dietary protein nor excess methionine, fed at non-growth-depressing levels, increases dietary choline needs for young Bobwhite quail.

  15. Development of a new model system to dissect isoform specific Akt signalling in adipocytes

    Science.gov (United States)

    Kajno, Esi; McGraw, Timothy E.; Gonzalez, Eva

    2015-01-01

    Protein kinase B (Akt) kinases are critical signal transducers mediating insulin action. Genetic studies revealed that Akt1 and Akt2 signalling differentially contribute to sustain lipid and glucose homoeostasis; however Akt isoform-specific effectors remain elusive due to the lack of a suitable model system to mechanistically interrogate Akt isoform-specific signalling. To overcome those technical limitations we developed a novel model system that provides acute and specific control of signalling by Akt isoforms. We generated mutants of Akt1 and Akt2 resistant to the allosteric Akt inhibitor MK-2206. We then developed adipocyte cell lines, in which endogenous Akt1 or Akt2 has been replaced by their corresponding drug-resistant Akt mutant. Treatment of those cells with MK-2206 allowed for acute and specific control of either Akt1 or Akt2 function. Our data showed that Akt1W80A and Akt2W80A mutants are resistant to MK-2206, dynamically regulated by insulin and able to signal to Akt downstream effectors. Analyses of insulin action in this cellular system showed that Akt1 and Akt2 are both able to mediate insulin regulation of the transcription factor forkhead box O1 (FoxO1) and the glucose transporter 4 (GLUT4), revealing a redundant role for these Akt kinases in the control of glucose transport into fat cells. In contrast, Akt1 signalling is uniquely required for adipogenesis, by controlling the mitotic clonal expansion (MCE) of pre-adipocytes that precedes white adipose cell differentiation. Our data provide new insights into the role of Akt kinases in glucose transport and adipogenesis and support our model system as a valuable tool for the biochemical characterization of signalling by specific Akt isoforms. PMID:25856301

  16. The reaction of choline dehydrogenase with some electron acceptors.

    Science.gov (United States)

    Barrett, M C; Dawson, A P

    1975-12-01

    1. The choline dehydrogenase (EC 1.1.99.1) WAS SOLUBILIZED FROM ACETONE-DRIED POWDERS OF RAT LIVER MITOCHONDRIA BY TREATMENT WITH Naja naja venom. 2. The kinetics of the reaction of enzyme with phenazine methosulphate and ubiquinone-2 as electron acceptors were investigated. 3. With both electron acceptors the reaction mechanism appears to involve a free, modified-enzyme intermediate. 4. With some electron acceptors the maximum velocity of the reaction is independent of the nature of the acceptor. With phenazine methosulphate and ubiquinone-2 as acceptors the Km value for choline is also independent of the nature of the acceptor molecule. 5. The mechanism of the Triton X-100-solubilized enzyme is apparently the smae as that for the snake venom solubilized enzyme.

  17. Gold nanoparticle–choline complexes can block nicotinic acetylcholine receptors

    Directory of Open Access Journals (Sweden)

    Chur Chin

    2010-04-01

    Full Text Available Chur Chin1, In Kyeom Kim2, Dong Yoon Lim3, Ki Suk Kim4, Hyang Ae Lee4, Eun Joo Kim41Department of Pediatrics, Fatima Hospital, Daegu, Korea; 2Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Korea; 3Department of Pharmacology, School of Medicine, Chosun University, Gwangju, Korea; 4Korea Institute of Toxicology, Daejeon, KoreaAbstract: We identified a novel class of direct ion-channel blockers of ligand-gated ion channels called the gold nanoparticle–choline complex. Negatively charged gold nanoparticles (1.4 nm block ion pores by binding to the sulfur group of the cysteine loop of nicotinic acetylcholine receptors (nAChRs, and currents evoked by acetylcholine (Ach can break these bonds. The current evoked by ACh in nAChRs was blocked directly in ion pores by the gold nanoparticle–choline complex. In adrenal-gland perfusion studies, the complex also blocked nAChRs by diminishing catecholamine release by about 75%. An in vivo study showed muscle relaxation in rats after injection of the complex. These results will foster the application of gold nanoparticles as a direct ion-channel blocker. Keywords: negatively charged gold nanoparticle, choline, gold–sulfur bond, nicotinic acetylcholine receptor, direct ion-channel blocker

  18. Dietary choline and betaine intake, choline-metabolising genetic polymorphisms and breast cancer risk: a case-control study in China.

    Science.gov (United States)

    Du, Yu-Feng; Luo, Wei-Ping; Lin, Fang-Yu; Lian, Zhen-Qiang; Mo, Xiong-Fei; Yan, Bo; Xu, Ming; Huang, Wu-Qing; Huang, Jing; Zhang, Cai-Xia

    2016-09-01

    Choline and betaine are essential nutrients involved in one-carbon metabolism and have been hypothesised to affect breast cancer risk. Functional polymorphisms in genes encoding choline-related one-carbon metabolism enzymes, including phosphatidylethanolamine N-methyltransferase (PEMT), choline dehydrogenase (CHDH) and betaine-homocysteine methyltransferase (BHMT), have important roles in choline metabolism and may thus interact with dietary choline and betaine intake to modify breast cancer risk. This study aimed to investigate the interactive effect of polymorphisms in PEMT, BHMT and CHDH genes with choline/betaine intake on breast cancer risk among Chinese women. This hospital-based case-control study consecutively recruited 570 cases with histologically confirmed breast cancer and 576 age-matched (5-year interval) controls. Choline and betaine intakes were assessed by a validated FFQ, and genotyping was conducted for PEMT rs7946, CHDH rs9001 and BHMT rs3733890. OR and 95 % CI were estimated using unconditional logistic regression. Compared with the highest quartile of choline intake, the lowest intake quartile showed a significant increased risk of breast cancer. The SNP PEMT rs7946, CHDH rs9001 and BHMT rs3733890 had no overall association with breast cancer, but a significant risk reduction was observed among postmenopausal women with AA genotype of BHMT rs3733890 (OR 0·49; 95 % CI 0·25, 0·98). Significant interactions were observed between choline intake and SNP PEMT rs7946 (P interaction=0·029) and BHMT rs3733890 (P interaction=0·006) in relation to breast cancer risk. Our results suggest that SNP PEMT rs7946 and BHMT rs3733890 may interact with choline intake on breast cancer risk.

  19. The role of wild type RAS isoforms in cancer.

    Science.gov (United States)

    Zhou, Bingying; Der, Channing J; Cox, Adrienne D

    2016-10-01

    Mutationally activated RAS proteins are critical oncogenic drivers in nearly 30% of all human cancers. As with mutant RAS, the role of wild type RAS proteins in oncogenesis, tumour maintenance and metastasis is context-dependent. Complexity is introduced by the existence of multiple RAS genes (HRAS, KRAS, NRAS) and protein "isoforms" (KRAS4A, KRAS4B), by the ever more complicated network of RAS signaling, and by the increasing identification of numerous genetic aberrations in cancers that do and do not harbour mutant RAS. Numerous mouse model carcinogenesis studies and examination of patient tumours reveal that, in RAS-mutant cancers, wild type RAS proteins are likely to serve as tumour suppressors when the mutant RAS is of the same isoform. This evidence is particularly robust in KRAS mutant cancers, which often display suppression or loss of wild type KRAS, but is not as strong for NRAS. In contrast, although not yet fully elucidated, the preponderance of evidence indicates that wild type RAS proteins play a tumour promoting role when the mutant RAS is of a different isoform. In non-RAS mutant cancers, wild type RAS is recognized as a mediator of oncogenic signaling due to chronic activation of upstream receptor tyrosine kinases that feed through RAS. Additionally, in the absence of mutant RAS, activation of wild type RAS may drive cancer upon the loss of negative RAS regulators such as NF1 GAP or SPRY proteins. Here we explore the current state of knowledge with respect to the roles of wild type RAS proteins in human cancers.

  20. PKC isoforms interact with and phosphorylate DNMT1

    Directory of Open Access Journals (Sweden)

    Pradhan Sriharsa

    2011-05-01

    Full Text Available Abstract Background DNA methyltransferase 1 (DNMT1 has been shown to be phosphorylated on multiple serine and threonine residues, based on cell type and physiological conditions. Although recent studies have suggested that protein kinase C (PKC may be involved, the individual contribution of PKC isoforms in their ability to phosphorylate DNMT1 remains unknown. The PKC family consists of at least 12 isoforms that possess distinct differences in structure, substrate requirement, expression and localization. Results Here we show that PKCα, βI, βII, δ, γ, η, ζ and μ preferentially phosphorylate the N-terminal domain of human DNMT1. No such phosphorylation of DNMT1 was observed with PKCε. Using PKCζ as a prototype model, we also found that PKC physically interacts with and phosphorylates DNMT1. In vitro phosphorylation assays conducted with recombinant fragments of DNMT1 showed that PKCζ preferentially phosphorylated the N-terminal region of DNMT1. The interaction of PKCζ with DNMT1 was confirmed by GST pull-down and co-immunoprecipitation experiments. Co-localization experiments by fluorescent microscopy further showed that endogenous PKCζ and DNMT1 were present in the same molecular complex. Endogenous PKCζ activity was also detected when DNMT1 was immunoprecipitated from HEK-293 cells. Overexpression of both PKCζ and DNMT1 in HEK-293 cells, but not of either alone, reduced the methylation status of genes distributed across the genome. Moreover, in vitro phosphorylation of DNMT1 by PKCζ reduced its methytransferase activity. Conclusions Our results indicate that phosphorylation of human DNMT1 by PKC is isoform-specific and provides the first evidence of cooperation between PKCζ and DNMT1 in the control of the DNA methylation patterns of the genome.

  1. [Isoenzyme spectrum and kinetic properties of pyruvate kinase from the liver of thiamine-deficient rats].

    Science.gov (United States)

    Konovalenko, O V; Maglysh, S S; Gorbach, Z V

    1990-01-01

    Thiamine-deficiency in animals induced by everyday subcutaneous administration of oxythiamine in a dose of 4, 40 and 100 mg/kg of weight for 10 days results in a decrease of the total activity of pyruvate kinase in the liver tissue and does not affect the mentioned index in the kidney and heart tissues. It is shown that as a result of the enzyme fractionation in the column with DEAE-cellulose the total activity of pyruvate kinase in the liver tissue of rats with thiamine-deficiency decreases due to L-isoform while the content of M-isoform remains unchanged. Thiamine deficiency does not affect kinetic characteristics of the L-isoform, extracted from the liver and this shows the absence of changes in the degree of phosphorylation of pyruvate kinase L-isoform under these conditions.

  2. Rumen protected choline supplementation in beef cattle: effect on growth performance

    Directory of Open Access Journals (Sweden)

    Vittorio Dell’Orto

    2010-01-01

    Full Text Available The aim of this study was to investigate the effect of rumen-protected choline administration on growth performance in beef cattle. Thirty-two newly received Charolais steers (420 kg ± 8 kg initial BW, were assigned randomly to one of the two experimental groups: control (CTR, no choline supplementation; choline (RPC, supplemented with 5 g/day choline chloride in rumenprotected form. Experimental period was 122 d long. DMI at different times did not differ between treatments. Supplementation of 5 g of choline increased body weight, and average daily gain on day 89 of the experiment,but not later on. Feed conversion rate and killing out percentage were not affected by the treatment. Therefore ruminally protected choline can improve growth performance of newly received beef cattle, and its inclusion in receiving diet can be useful.

  3. Central injection of captopril inhibits the blood pressure response to intracerebroventricular choline

    Directory of Open Access Journals (Sweden)

    N. Isbil-Buyukcoskun

    2001-06-01

    Full Text Available In the present study, we investigated the involvement of the brain renin-angiotensin system in the effects of central cholinergic stimulation on blood pressure in conscious, freely moving normotensive rats. In the first step, we determined the effects of intracerebroventricular (icv choline (50, 100 and 150 µg on blood pressure. Choline increased blood pressure in a dose-dependent manner. In order to investigate the effects of brain renin-angiotensin system blockade on blood pressure increase induced by choline (150 µg, icv, an angiotensin-converting enzyme inhibitor, captopril (25 and 50 µg, icv, was administered 3 min before choline. Twenty-five µg captopril did not block the pressor effect of choline, while 50 µg captopril blocked it significantly. Our results suggest that the central renin-angiotensin system may participate in the increase in blood pressure induced by icv choline in normotensive rats.

  4. A flower-like nickel oxide nanostructure: synthesis and application for choline sensing.

    Science.gov (United States)

    Sattarahmady, N; Heli, H; Dehdari Vais, R

    2014-02-01

    Flower-like nickel oxide nanostructure was synthesized by a simple desolvation method. The nanostructure was then employed as the modifier of a carbon paste electrode to fabricate a choline sensor. The mechanism and kinetics of the electrocatalytic oxidation of choline on the modified electrode surface were studied by cyclic voltammetry, steady-state polarization curve, and chronoamperometry. The catalytic rate constant and the charge transfer coefficient of the choline electrooxidation process by an active nickel species, and the diffusion coefficient of choline were reported. An amperometric method was developed for determination of choline with a sensitivity of 60.5 mA mol(-1)Lcm(-2) and a limit of detection of 25.4 μmol L(-1). The sensor had the advantages of high electrocatalytic activity and sensitivity, and long-term stability toward choline, with a simple fabrication method without complications of immobilization steps and using any enzyme or reagent.

  5. Structures of alternatively spliced isoforms of human ketohexokinase.

    Science.gov (United States)

    Trinh, Chi H; Asipu, Aruna; Bonthron, David T; Phillips, Simon E V

    2009-03-01

    A molecular understanding of the unique aspects of dietary fructose metabolism may be the key to understanding and controlling the current epidemic of fructose-related obesity, diabetes and related adverse metabolic states in Western populations. Fructose catabolism is initiated by its phosphorylation to fructose 1-phosphate, which is performed by ketohexokinase (KHK). Here, the crystal structures of the two alternatively spliced isoforms of human ketohexokinase, hepatic KHK-C and the peripheral isoform KHK-A, and of the ternary complex of KHK-A with the substrate fructose and AMP-PNP are reported. The structure of the KHK-A ternary complex revealed an active site with both the substrate fructose and the ATP analogue in positions ready for phosphorylation following a reaction mechanism similar to that of the pfkB family of carbohydrate kinases. Hepatic KHK deficiency causes the benign disorder essential fructosuria. The effects of the disease-causing mutations (Gly40Arg and Ala43Thr) have been modelled in the context of the KHK structure.

  6. Moderate Perinatal Choline Deficiency Elicits Altered Physiology and Metabolomic Profiles in the Piglet.

    Science.gov (United States)

    Getty, Caitlyn M; Dilger, Ryan N

    2015-01-01

    Few studies have evaluated the impact of dietary choline on the health and well-being of swine, and those pivotal papers were aimed at determining dietary requirements for sows and growing pigs. This is of importance as the piglet is becoming a widely accepted model for human infant nutrition, but little is known about the impacts of perinatal choline status on overall health and metabolism of the growing piglet. In the present study, sows were provided either a choline deficient (CD, 625 mg choline/kg dry matter) or choline sufficient (CS, 1306 mg choline/kg dry matter) diet for the last 65 d of gestation (prenatal intervention). Piglets were weaned from the sow 48 h after farrowing and provided either a CD (477 mg choline/kg dry matter) or CS (1528 mg choline/kg dry matter) milk replacer (postnatal intervention) for 29 ± 2 d, resulting in a factorial arrangement of 4 treatment (prenatal/postnatal) groups: CS/CS, CS/CD, CD/CS, and CD/CD. Piglet growth was normal for artificially-reared piglets, and was not impacted by perinatal choline status. Piglets receiving the postnatal CD treatment had lower (P piglets receiving the postnatal CS treatment. Hepatic lipid content of piglets receiving the postnatal CD treatment was higher (P piglets receiving the postnatal CS treatment. Additionally, postnatally CD piglets had lower (P = 0.01) plasma cholesterol than postnatally CS piglets. Brain development was also impacted by perinatal choline status, with brains of piglets exposed to prenatal CD being smaller (P = 0.01) than those of prenatally CS piglets. These findings support the hypothesis that the piglet is a sensitive model for choline deficiency during the perinatal period. In the present study, piglets exhibited similarities in health markers and metabolomic profiles to rodents and humans when exposed to moderate choline deficiency.

  7. Influence of chain length and double bond on the aqueous behavior of choline carboxylate soaps.

    Science.gov (United States)

    Rengstl, Doris; Diat, Olivier; Klein, Regina; Kunz, Werner

    2013-02-26

    In preceding studies, we demonstrated that choline carboxylates ChC(m) with alkyl chain lengths of m = 12 - 18 are highly water-soluble (for m = 12, soluble up to 93 wt % soap and 0 °C). In addition, choline soaps are featured by an extraordinary lyotropic phase behavior. With decreasing water concentration, the following phases were found: micellar phase (L(1)), discontinuous cubic phase (I(1)' and I(1)"), hexagonal phase (H(1)), bicontinuous cubic phase (V(1)), and lamellar phase (L(α)). The present work is also focused on the lyotropic phase behavior of choline soaps but with shorter alkyl chains or different alkyl chain properties. We have investigated the aqueous phase behavior of choline soaps with C(8) and C(10) chain-lengths (choline octanoate and choline decanoate) and with a C(18) chain-length with a cis-double bond (choline oleate). We found that choline decanoate follows the lyotropic phase behavior of the longer-chain homologues mentioned above. Choline octanoate in water shows no discontinuous cubic phases, but an extended, isotropic micellar solution phase. In addition, choline octanoate is at the limit between a surfactant and a hydrotrope. The double bond in choline oleate leads also to a better solubility in water and a decrease of the solubilization temperature. It also influences the Gaussian curvature of the aggregates which results in a loss of discontinuous cubic phases in the binary phase diagram. The different lyotropic mesophases were identified by the penetration scan technique with polarizing light microscope and visual observations. To clarify the structural behavior small (SAXS) and wide (WAXS) angle X-ray scattering were performed. To further characterize the extended, isotropic micellar solution phase in the binary phase diagram of choline octanoate viscosity and conductivity measurements were also carried out.

  8. Feeding a diet devoid of choline to lactating rodents restricts growth and lymphocyte development in offspring.

    Science.gov (United States)

    Lewis, E D; Goruk, S; Richard, C; Dellschaft, N S; Curtis, J M; Jacobs, R L; Field, C J

    2016-09-01

    The nutrient choline is necessary for membrane synthesis and methyl donation, with increased requirements during lactation. The majority of immune development occurs postnatally, but the importance of choline supply for immune development during this critical period is unknown. The objective of this study was to determine the importance of maternal supply of choline during suckling on immune function in their offspring among rodents. At parturition, Sprague-Dawley dams were randomised to either a choline-devoid (ChD; n 7) or choline-sufficient (ChS, 1 g/kg choline; n 10) diet with their offspring euthanised at 3 weeks of age. In a second experiment, offspring were weaned to a ChS diet until 10 weeks of age (ChD-ChS, n 5 and ChS-ChS, n 9). Splenocytes were isolated, and parameters of immune function were measured. The ChD offspring received less choline in breast milk and had lower final body and organ weight compared with ChS offspring (Pstimulation (lower stimulation index and less IFN-γ production) ex vivo (Pstimulation compared with cells from ChS-ChS (P<0·05). Our study suggests that choline is required in the suckling diet to facilitate immune development, and choline deprivation during this critical period has lasting effects on T cell function later in life.

  9. Rumen-protected choline: A significance effect on dairy cattle nutrition

    Directory of Open Access Journals (Sweden)

    G. Jayaprakash

    2016-08-01

    Full Text Available Choline is a vitamin-like substance it has multi-function in animal production, reproduction, and health. The transition period is most crucial stage in lactation cycle of dairy cows due to its association with negative hormonal and energy balances. Unfortunately, unprotected choline easily degrades in the rumen; therefore, choline added to the diet in a rumenprotected form. The use of rumen-protected choline (RPC is a preventive measurement for the fatty liver syndrome and ketosis; may improve milk production as well as milk composition and reproduction parameters. This review summarizes the effectiveness of RPC on animal production, health, and reproduction.

  10. Bioelectrochemical Response and Kinetics of Choline Oxidase Entrapped in Polyaniline-Polyacrylonitrile Composite Film

    Institute of Scientific and Technical Information of China (English)

    XUE,Huai-Guo(薛怀国); SHEN,Zhi-Quan(沈之荃)

    2002-01-01

    A novel choline oxidase electrode was constructed by entrapping choline oxidase into polyaniline-polyacrylonitrile composite film. The enzyme film was prepared by in situ electropolymerization of aniline into porous polyacrylonitrile-coated platinum electrode in the presence of choline oxidase. The enzyme electrode exhibited sensitive and stable electrochemical response to choline. The kinetics analysis showed that the mass transport is partially rate-limiting. The influences of pH, applied potential and temperature on the response of the enzyme electrode were also described.

  11. 18F-Choline, 11C-choline and 11C-acetate PET/CT: comparative analysis for imaging prostate cancer patients.

    Science.gov (United States)

    Brogsitter, Claudia; Zöphel, Klaus; Kotzerke, Jörg

    2013-07-01

    Prostate cancer (PCA) is the second most common tumour in men worldwide. Whereas prostate specific antigen (PSA) is an established biochemical marker, the optimal imaging method for all clinical scenarios has not yet been found. With the rising number of PET centres there is an increasing availability and use of (18)F-/(11)C-choline or (11)C-acetate for staging of PCA. However, to date no final conclusion has been reached as to whether acetate or choline tracers should be preferred. In this review we provide an overview of the performance of choline and acetate PET for staging the primary and recurrent disease and lymph nodes in PCA, based on the literature of the last 10 years. Although predominantly choline has been used rather than acetate, both tracers performed in a similar manner in published studies. Choline as well as acetate have insufficient diagnostic accuracy for the staging of the primary tumour, due to a minimum detectable tumour size of 5 mm and inability to differentiate PCA from benign prostate hyperplasia, chronic prostatitis and high-grade intraepithelial neoplasia. Regarding lymph node staging, choline tracers have demonstrated a high specificity. Unfortunately, the sensitivity is only moderate. For staging recurrent disease, sensitivity depends on the level of serum PSA (PSA should be >2 ng/ml). This applies to both choline and acetate. However, despite these limitations, a significant number of patients with recurrent disease can benefit from PET imaging by a change in treatment planning.

  12. {sup 18}F-Choline, {sup 11}C-choline and {sup 11}C-acetate PET/CT: comparative analysis for imaging prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Brogsitter, Claudia; Zoephel, Klaus; Kotzerke, Joerg [Carl Gustav Carus Medical School, University of Dresden, Department of Nuclear Medicine, Dresden (Germany)

    2013-07-15

    Prostate cancer (PCA) is the second most common tumour in men worldwide. Whereas prostate specific antigen (PSA) is an established biochemical marker, the optimal imaging method for all clinical scenarios has not yet been found. With the rising number of PET centres there is an increasing availability and use of {sup 18}F-/{sup 11}C-choline or {sup 11}C-acetate for staging of PCA. However, to date no final conclusion has been reached as to whether acetate or choline tracers should be preferred. In this review we provide an overview of the performance of choline and acetate PET for staging the primary and recurrent disease and lymph nodes in PCA, based on the literature of the last 10 years. Although predominantly choline has been used rather than acetate, both tracers performed in a similar manner in published studies. Choline as well as acetate have insufficient diagnostic accuracy for the staging of the primary tumour, due to a minimum detectable tumour size of 5 mm and inability to differentiate PCA from benign prostate hyperplasia, chronic prostatitis and high-grade intraepithelial neoplasia. Regarding lymph node staging, choline tracers have demonstrated a high specificity. Unfortunately, the sensitivity is only moderate. For staging recurrent disease, sensitivity depends on the level of serum PSA (PSA should be >2 ng/ml). This applies to both choline and acetate. However, despite these limitations, a significant number of patients with recurrent disease can benefit from PET imaging by a change in treatment planning. (orig.)

  13. FSH isoform pattern in classic galactosemia

    OpenAIRE

    Gubbels, C.S.; Thomas, C. M.; Wodzig, K.W.H.; Olthaar, A. J.; Jaeken, J.; Sweep, F.C.; Rubio-Gozalbo, M.E.

    2010-01-01

    Female classic galactosemia patients suffer from primary ovarian insufficiency (POI). The cause for this long-term complication is not fully understood. One of the proposed mechanisms is that hypoglycosylation of complex molecules, a known secondary phenomenon of galactosemia, leads to FSH dysfunction. An earlier study showed less acidic isoforms of FSH in serum samples of two classic galactosemia patients compared to controls, indicating hypoglycosylation. In this study, FSH isoform patterns...

  14. Presenilin dependence of phospholipase C and protein kinase C signaling

    DEFF Research Database (Denmark)

    Dehvari, Nodi; Cedazo-Minguez, Angel; Isacsson, Ola

    2007-01-01

    -stimulated phospholipase C (PLC) activity which was gamma-secretase dependent. To further evaluate the dependence of PLC on PSs we measured PLC activity and the activation of variant protein kinase C (PKC) isoforms in mouse embryonic fibroblasts (MEFs) lacking either PS1, PS2, or both. PLC activity and PKCalpha...

  15. Enzyme kinetics and distinct modulation of the protein kinase N family of kinases by lipid activators and small molecule inhibitors

    Science.gov (United States)

    Falk, Matthew D.; Liu, Wei; Bolaños, Ben; Unsal-Kacmaz, Keziban; Klippel, Anke; Grant, Stephan; Brooun, Alexei; Timofeevski, Sergei

    2014-01-01

    The PKN (protein kinase N) family of Ser/Thr protein kinases regulates a diverse set of cellular functions, such as cell migration and cytoskeletal organization. Inhibition of tumour PKN activity has been explored as an oncology therapeutic approach, with a PKN3-targeted RNAi (RNA interference)-derived therapeutic agent in Phase I clinical trials. To better understand this important family of kinases, we performed detailed enzymatic characterization, determining the kinetic mechanism and lipid sensitivity of each PKN isoform using full-length enzymes and synthetic peptide substrate. Steady-state kinetic analysis revealed that PKN1–3 follows a sequential ordered Bi–Bi kinetic mechanism, where peptide substrate binding is preceded by ATP binding. This kinetic mechanism was confirmed by additional kinetic studies for product inhibition and affinity of small molecule inhibitors. The known lipid effector, arachidonic acid, increased the catalytic efficiency of each isoform, mainly through an increase in kcat for PKN1 and PKN2, and a decrease in peptide KM for PKN3. In addition, a number of PKN inhibitors with various degrees of isoform selectivity, including potent (Ki<10 nM) and selective PKN3 inhibitors, were identified by testing commercial libraries of small molecule kinase inhibitors. This study provides a kinetic framework and useful chemical probes for understanding PKN biology and the discovery of isoform-selective PKN-targeted inhibitors. PMID:27919031

  16. Citicoline (CDP-choline) increases Sirtuin1 expression concomitant to neuroprotection in experimental stroke.

    Science.gov (United States)

    Hurtado, Olivia; Hernández-Jiménez, Macarena; Zarruk, Juan G; Cuartero, María I; Ballesteros, Iván; Camarero, Guadalupe; Moraga, Ana; Pradillo, Jesús M; Moro, María A; Lizasoain, Ignacio

    2013-09-01

    CDP-choline has shown neuroprotective effects in cerebral ischemia. In humans, although a recent trial International Citicoline Trial on Acute Stroke (ICTUS) has shown that global recovery is similar in CDP-choline and placebo groups, CDP-choline was shown to be more beneficial in some patients, such as those with moderate stroke severity and not treated with t-PA. Several mechanisms have been proposed to explain the beneficial actions of CDP-choline. We have now studied the participation of Sirtuin1 (SIRT1) in the neuroprotective actions of CDP-choline. Fischer rats and Sirt1⁻/⁻ mice were subjected to permanent focal ischemia. CDP-choline (0.2 or 2 g/kg), sirtinol (a SIRT1 inhibitor; 10 mg/kg), and resveratrol (a SIRT1 activator; 2.5 mg/kg) were administered intraperitoneally. Brains were removed 24 and 48 h after ischemia for western blot analysis and infarct volume determination. Treatment with CDP-choline increased SIRT1 protein levels in brain concomitantly to neuroprotection. Treatment with sirtinol blocked the reduction in infarct volume caused by CDP-choline, whereas resveratrol elicited a strong synergistic neuroprotective effect with CDP-choline. CDP-choline failed to reduce infarct volume in Sirt1⁻/⁻ mice. Our present results demonstrate a robust effect of CDP-choline like SIRT1 activator by up-regulating its expression. Our findings suggest that therapeutic strategies to activate SIRT1 may be useful in the treatment of stroke. Sirtuin 1 (SIRT1) is implicated in a wide range of cellular functions. Regarding stroke, there is no direct evidence. We have demonstrated that citicoline increases SIRT1 protein levels in brain concomitantly to neuroprotection. Citicoline fails to reduce infarct volume in Sirt1⁻/⁻ mice. Our findings suggest that therapeutic strategies acting on SIRT1 may be useful in the treatment of stroke.

  17. The Bmx tyrosine kinase induces activation of the Stat signaling pathway, which is specifically inhibited by protein kinase Cdelta.

    Science.gov (United States)

    Saharinen, P; Ekman, N; Sarvas, K; Parker, P; Alitalo, K; Silvennoinen, O

    1997-12-01

    Members of the hematopoietically expressed Tec tyrosine kinase family have an important role in hematopoietic signal transduction, as exemplified by the crucial role of Btk for B-cell differentiation and activation. Although a variety of cell surface receptors have been found to activate Tec tyrosine kinases, the specific signaling pathways and substrate molecules used by Tec kinases are still largely unknown. In this study a Tec family kinase, Bmx, was found to induce activation of the Stat signaling pathway. Bmx induced the tyrosine phosphorylation and DNA binding activity of all the Stat factors tested, including Stat1, Stat3, and Stat5, both in mammalian and insect cells. Bmx also induced transcriptional activation of Stat1- and Stat5-dependent reporter genes. Other cytoplasmic tyrosine kinases, Syk, Fyn, and c-Src, showed no or only weak ability to activate Stat proteins. Expression of Bmx in mammalian cells was found to induce activation of endogenous Stat proteins without activation of endogenous Jak kinases. We further analyzed the Bmx-mediated activation of Stat1, which was found to be regulated by protein kinase C delta (PKCdelta) isoform, but not beta 1, epsilon, or zeta isoforms, leading to inhibition of Stat1 tyrosine phosphorylation. In conclusion, these studies show that Bmx, a Tec family kinase, can function as an activator of the Stat signaling pathway and identify a role for PKCdelta in the regulation of Bmx signaling.

  18. Choline Uptake by Glomerular Synapses Isolated from Bovine Cerebellar Vermis.

    Science.gov (United States)

    1986-01-01

    28 034 UNCLASSIFIED -7t. holing uptake by glomerular aynapaea isolated from bovine cerebellar venni - . 1) N1 IrRRIAN.E L NfISINndwr EtIIOMAS86 .t...w. -%FAt~Jr~a~etn 0,oAAM TX78215-5301 IL’SAJ) A-xpid ( kaolin 22nd. 19W5) hh.lhoac-anln uplake -ainalnnn 177 DIOMIDICAL DmIVIIN,~ F-5’. . Brain...Research. 366 (1986) 401-404 401 Elsevier BRE 21387 Choline uptake by glomerular synapses isolated from bovine cerebellar vermis D.M. TERRIAN, E.L

  19. The α and Δ isoforms of CREB1 are required to maintain normal pulmonary vascular resistance.

    Directory of Open Access Journals (Sweden)

    Lili Li

    Full Text Available Chronic hypoxia causes pulmonary hypertension associated with structural alterations in pulmonary vessels and sustained vasoconstriction. The transcriptional mechanisms responsible for these distinctive changes are unclear. We have previously reported that CREB1 is activated in the lung in response to alveolar hypoxia but not in other organs. To directly investigate the role of α and Δ isoforms of CREB1 in the regulation of pulmonary vascular resistance we examined the responses of mice in which these isoforms of CREB1 had been inactivated by gene mutation, leaving only the β isoform intact (CREB(αΔ mice. Here we report that expression of CREB regulated genes was altered in the lungs of CREB(αΔ mice. CREB(αΔ mice had greater pulmonary vascular resistance than wild types, both basally in normoxia and following exposure to hypoxic conditions for three weeks. There was no difference in rho kinase mediated vasoconstriction between CREB(αΔ and wild type mice. Stereological analysis of pulmonary vascular structure showed characteristic wall thickening and lumen reduction in hypoxic wild-type mice, with similar changes observed in CREB(αΔ. CREB(αΔ mice had larger lungs with reduced epithelial surface density suggesting increased pulmonary compliance. These findings show that α and Δ isoforms of CREB1 regulate homeostatic gene expression in the lung and that normal activity of these isoforms is essential to maintain low pulmonary vascular resistance in both normoxic and hypoxic conditions and to maintain the normal alveolar structure. Interventions that enhance the actions of α and Δ isoforms of CREB1 warrant further investigation in hypoxic lung diseases.

  20. 75 FR 760 - Choline chloride; Exemption from the Requirement of a Tolerance

    Science.gov (United States)

    2010-01-06

    ..., transmembrane signaling, methyl metabolism, and lipid and cholesterol transport and metabolism. Choline was... body functions including the maintenance of osmotic pressure, acid-base balance, muscular activity, and... metabolism. Choline chloride has demonstrated a low acute oral toxicity with LD 50 values for rats...

  1. Prenatal Choline Availability Alters the Context Sensitivity of Pavlovian Conditioning in Adult Rats

    Science.gov (United States)

    Lamoureux, Jeffrey A.; Meck, Warren H.; Williams, Christina L.

    2008-01-01

    The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline…

  2. Are dietary choline and betaine intakes determinants of total homocysteine concentration?

    Science.gov (United States)

    Elevated homocysteine concentrations are associated with an increased risk of cardiovascular disease and a decline in cognitive function. Intakes of choline and betaine, as methyl donors, may affect homocysteine concentrations. The objective was to examine whether choline and betaine intakes, assess...

  3. Plasma choline and betaine and their relation to plasma homocysteine in normal pregnancy

    NARCIS (Netherlands)

    Velzing-Aarts, Francien V; Holm, Pål I; Fokkema, M Rebecca; van der Dijs, Fey P; Ueland, Per M; Muskiet, Frits A

    2005-01-01

    Background: Plasma concentrations of total homocysteine (tHcy) decrease during pregnancy. This reduction has been investigated in relation to folate status, but no study has addressed the possible role of betaine and its precursor choline. Objective: We investigated the courses of plasma choline and

  4. Choline evokes fluid secretion by perfused rat mandibular gland without desensitization

    DEFF Research Database (Denmark)

    Murakami, M; Novak, I; Young, J A

    1986-01-01

    The secretomotor action of choline on salivary secretion has been studied in the isolated perfused mandibular gland of the rat. Choline made up in substituted Ringer solutions (Na concentrations of 40, 70, or 100 mM) was an effective secretomotor agonist in the concentration range of 1-100 mM and...

  5. Choline supplemented as phosphatidylcholine decreases fasting and postmethionine-loading plasma homocysteine concentrations in healthy men

    NARCIS (Netherlands)

    Olthof, M.R.; Brink, E.J.; Katan, M.B.; Verhoef, P.

    2005-01-01

    Background: A high homocysteine concentration is a potential risk factor for cardiovascular disease that can be reduced through betaine supplementation. Choline is the precursor for betaine, but the effects of choline supplementation on plasma total homocysteine (tHcy) concentrations in healthy huma

  6. What Choline Metabolism Can Tell Us About the Underlying Mechanisms of Fetal Alcohol Spectrum Disorders

    Science.gov (United States)

    2013-01-01

    The consequences of fetal exposure to alcohol are very diverse and the likely molecular mechanisms involved must be able to explain how so many developmental processes could go awry. If pregnant rat dams are fed alcohol, their pups develop abnormalities characteristic of fetal alcohol spectrum disorders (FASD), but if these rat dams were also treated with choline, the effects from ethanol were attenuated in their pups. Choline is an essential nutrient in humans, and is an important methyl group donor. Alcohol exposure disturbs the metabolism of choline and other methyl donors. Availability of choline during gestation directly influences epigenetic marks on DNA and histones, and alters gene expression needed for normal neural and endothelial progenitor cell proliferation. Maternal diets low in choline alter development of the mouse hippocampus, and decrement memory for life. Women eating low-choline diets have an increased risk of having an infant with a neural tube or or ofacial cleft birth defect. Thus, the varied effects of choline could affect the expression of FASD, and studies on choline might shed some light on the underlying molecular mechanisms responsible for FASD. PMID:21259123

  7. Moderate Perinatal Choline Deficiency Elicits Altered Physiology and Metabolomic Profiles in the Piglet.

    Directory of Open Access Journals (Sweden)

    Caitlyn M Getty

    Full Text Available Few studies have evaluated the impact of dietary choline on the health and well-being of swine, and those pivotal papers were aimed at determining dietary requirements for sows and growing pigs. This is of importance as the piglet is becoming a widely accepted model for human infant nutrition, but little is known about the impacts of perinatal choline status on overall health and metabolism of the growing piglet. In the present study, sows were provided either a choline deficient (CD, 625 mg choline/kg dry matter or choline sufficient (CS, 1306 mg choline/kg dry matter diet for the last 65 d of gestation (prenatal intervention. Piglets were weaned from the sow 48 h after farrowing and provided either a CD (477 mg choline/kg dry matter or CS (1528 mg choline/kg dry matter milk replacer (postnatal intervention for 29 ± 2 d, resulting in a factorial arrangement of 4 treatment (prenatal/postnatal groups: CS/CS, CS/CD, CD/CS, and CD/CD. Piglet growth was normal for artificially-reared piglets, and was not impacted by perinatal choline status. Piglets receiving the postnatal CD treatment had lower (P < 0.01 plasma choline and choline-containing phospholipid concentrations and higher (P < 0.05 liver enzyme (alkaline phosphatase and gamma-glutamyl transferase values compared with piglets receiving the postnatal CS treatment. Hepatic lipid content of piglets receiving the postnatal CD treatment was higher (P < 0.01 compared with piglets receiving the postnatal CS treatment. Additionally, postnatally CD piglets had lower (P = 0.01 plasma cholesterol than postnatally CS piglets. Brain development was also impacted by perinatal choline status, with brains of piglets exposed to prenatal CD being smaller (P = 0.01 than those of prenatally CS piglets. These findings support the hypothesis that the piglet is a sensitive model for choline deficiency during the perinatal period. In the present study, piglets exhibited similarities in health markers and

  8. Isoform specificity of the Na/K-ATPase association and regulation by phospholemman.

    Science.gov (United States)

    Bossuyt, Julie; Despa, Sanda; Han, Fei; Hou, Zhanjia; Robia, Seth L; Lingrel, Jerry B; Bers, Donald M

    2009-09-25

    Phospholemman (PLM) phosphorylation mediates enhanced Na/K-ATPase (NKA) function during adrenergic stimulation of the heart. Multiple NKA isoforms exist, and their function/regulation may differ. We combined fluorescence resonance energy transfer (FRET) and functional measurements to investigate isoform specificity of the NKA-PLM interaction. FRET was measured as the increase in the donor fluorescence (CFP-NKA-alpha1 or CFP-NKA-alpha2) during progressive acceptor (PLM-YFP) photobleach in HEK-293 cells. Both pairs exhibited robust FRET (maximum of 23.6 +/- 3.4% for NKA-alpha1 and 27.5 +/- 2.5% for NKA-alpha2). Donor fluorescence depended linearly on acceptor fluorescence, indicating a 1:1 PLM:NKA stoichiometry for both isoforms. PLM phosphorylation induced by cAMP-dependent protein kinase and protein kinase C activation drastically reduced the FRET with both NKA isoforms. However, submaximal cAMP-dependent protein kinase activation had less effect on PLM-NKA-alpha2 versus PLM-NKA-alpha1. Surprisingly, ouabain virtually abolished NKA-PLM FRET but only partially reduced co-immunoprecipitation. PLM-CFP also showed FRET to PLM-YFP, but the relationship during progressive photobleach was highly nonlinear, indicating oligomers involving >or=3 monomers. Using cardiac myocytes from wild-type mice and mice where NKA-alpha1 is ouabain-sensitive and NKA-alpha2 is ouabain-resistant, we assessed the effects of PLM phosphorylation on NKA-alpha1 and NKA-alpha2 function. Isoproterenol enhanced internal Na(+) affinity of both isoforms (K((1/2)) decreased from 18.1 +/- 2.0 to 11.5 +/- 1.9 mm for NKA-alpha1 and from 16.4 +/- 2.5 to 10.4 +/- 1.5 mm for NKA-alpha2) without altering maximum transport rate (V(max)). Protein kinase C activation also decreased K((1/2)) for both NKA-alpha1 and NKA-alpha2 (to 9.4 +/- 1.0 and 9.1 +/- 1.1 mm, respectively) but increased V(max) only for NKA-alpha2 (1.9 +/- 0.4 versus 1.2 +/- 0.5 mm/min). In conclusion, PLM associates with and modulates both NKA

  9. Circadian rhythmicity of active GSK3 isoforms modulates molecular clock gene rhythms in the suprachiasmatic nucleus.

    Science.gov (United States)

    Besing, Rachel C; Paul, Jodi R; Hablitz, Lauren M; Rogers, Courtney O; Johnson, Russell L; Young, Martin E; Gamble, Karen L

    2015-04-01

    The suprachiasmatic nucleus (SCN) drives and synchronizes daily rhythms at the cellular level via transcriptional-translational feedback loops comprising clock genes such as Bmal1 and Period (Per). Glycogen synthase kinase 3 (GSK3), a serine/threonine kinase, phosphorylates at least 5 core clock proteins and shows diurnal variation in phosphorylation state (inactivation) of the GSK3β isoform. Whether phosphorylation of the other primary isoform (GSK3α) varies across the subjective day-night cycle is unknown. The purpose of this study was to determine if the endogenous rhythm of GSK3 (α and β) phosphorylation is critical for rhythmic BMAL1 expression and normal amplitude and periodicity of the molecular clock in the SCN. Significant circadian rhythmicity of phosphorylated GSK3 (α and β) was observed in the SCN from wild-type mice housed in constant darkness for 2 weeks. Importantly, chronic activation of both GSK3 isoforms impaired rhythmicity of the GSK3 target BMAL1. Furthermore, chronic pharmacological inhibition of GSK3 with 20 µM CHIR-99021 enhanced the amplitude and shortened the period of PER2::luciferase rhythms in organotypic SCN slice cultures. These results support the model that GSK3 activity status is regulated by the circadian clock and that GSK3 feeds back to regulate the molecular clock amplitude in the SCN.

  10. Antiangiogenic VEGF Isoform in Inflammatory Myopathies

    Directory of Open Access Journals (Sweden)

    Nila Volpi

    2013-01-01

    Full Text Available Objective. To investigate expression of vascular endothelial growth factor (VEGF antiangiogenic isoform A-165b on human muscle in idiopathic inflammatory myopathies (IIM and to compare distribution of angiogenic/antiangiogenic VEGFs, as isoforms shifts are described in other autoimmune disorders. Subjects and Methods. We analyzed VEGF-A165b and VEGF-A by western blot and immunohistochemistry on skeletal muscle biopsies from 21 patients affected with IIM (polymyositis, dermatomyositis, and inclusion body myositis and 6 control muscle samples. TGF-β, a prominent VEGF inductor, was analogously evaluated. Intergroup differences of western blot bands density were statistically examined. Endomysial vascularization, inflammatory score, and muscle regeneration, as pathological parameters of IIM, were quantitatively determined and their levels were confronted with VEGF expression. Results. VEGF-A165b was significantly upregulated in IIM, as well as TGF-β. VEGF-A was diffusely expressed on unaffected myofibers, whereas regenerating/atrophic myofibres strongly reacted for both VEGF-A isoforms. Most inflammatory cells and endomysial vessels expressed both isoforms. VEGF-A165b levels were in positive correlation to inflammatory score, endomysial vascularization, and TGF-β. Conclusions. Our findings indicate skeletal muscle expression of antiangiogenic VEGF-A165b and preferential upregulation in IIM, suggesting that modulation of VEGF-A isoforms may occur in myositides.

  11. Choline-based ionic liquids-enhanced biodegradation of azo dyes.

    Science.gov (United States)

    Sekar, Sudharshan; Surianarayanan, Mahadevan; Ranganathan, Vijayaraghavan; MacFarlane, Douglas R; Mandal, Asit Baran

    2012-05-01

    Industrial wastewaters such as tannery and textile processing effluents are often characterized by a high content of dissolved organic dyes, resulting in large values of chemical and biological oxygen demand (COD and BOD) in the aquatic systems into which they are discharged. Such wastewater streams are of rapidly growing concern as a major environmental issue in developing countries. Hence there is a need to mitigate this challenge by effective approaches to degrade dye-contaminated wastewater. In this study, several choline-based salts originally developed for use as biocompatible hydrated ionic liquids (i.e., choline sacchrinate (CS), choline dihydrogen phosphate (CDP), choline lactate (CL), and choline tartarate (CT)) have been successfully employed as the cosubstrate with S. lentus in the biodegradation of an azo dye in aqueous solution. We also demonstrate that the azo dye has been degraded to less toxic components coupled with low biomass formation.

  12. Functionalization of Cellulose Nanocrystals in Choline Lactate Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Sarah Montes

    2016-06-01

    Full Text Available Cellulose nanocrystals (CNCs are valuable nanomaterials obtained from renewable resources. Their properties make them suitable for a wide range of applications, including polymer reinforcement. However, due to their highly hydrophilic character, it is necessary to modify their surface with non-polar functional groups before their incorporation into a hydrophobic polymer matrix. In this work, cellulose nanocrystals were modified using a silane coupling agent and choline lactate, an ionic liquid derived from renewable resources, as a reaction medium. Modified cellulose nanocrystals were characterized by infrared spectroscopy, showing new peaks associated to the modification performed. X-ray diffraction was used to analyze the crystalline structure of functionalized cellulose nanocrystals and to optimize the amount of silane for functionalization. Poly(lactic acid (PLA nanocomposites containing 1 wt % of functionalized cellulose nanocrystals were prepared. They were characterized by field-emission scanning electron microscopy (FE-SEM and mechanical tests. The use of choline lactate as reaction media has been shown to be an alternative method for the dispersion and silanization of the cellulose nanocrystals without the addition of an external catalyst.

  13. Absolute Quantification of Choline-Related Biomarkers in Breast Cancer Biopsies by Liquid Chromatography Electrospray Ionization Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Maria Chiara Mimmi

    2013-01-01

    Full Text Available It has been repeatedly demonstrated that choline metabolism is altered in a wide variety of cancers. In breast tumours, the choline metabolite profile is characterized by an elevation of phosphocholine and total choline-compounds. This pattern is increasingly being exploited as biomarker in cancer diagnosis.

  14. FGFR3 isoforms have distinct functions in the regulation of growth and cell morphology.

    Science.gov (United States)

    Shimizu, Akio; Takashima, Yuji; Kurokawa-Seo, Misuzu

    2002-01-11

    We have previously cloned the alternatively spliced isoform of fibroblast growth factor receptor 3 (FGFR3DeltaAB) that lacks the acid box in the extracellular region. To understand the biological functions and signal transduction of these FGFR3 isoforms, we analyzed the effect of FGF1 in ATDC5 cells, chondroprogenitor cell lines overexpressing these isoforms. In response to FGF1, FGFR3 induced a marked cell-morphology change to a round shape, while FGFR3DeltaAB did not. Furthermore, FGFR3 induced complete growth arrest, whereas FGFR3DeltaAB induced only moderate growth inhibition. Both receptors induced the expression of the CDK inhibitor p21(CIP1). However, only FGFR3 induced STAT1 phosphorylation that mediates the transcriptional induction of p21(CIP1), although both FGFR3 isoforms could induce a strong activation of mitogen-activated protein (MAP) kinases. Taken together, the different biological responses mediated by FGFR3 and FGFR3DeltaAB appear to be due to a difference in their ability to utilize STAT1 pathway and signals involved in cell rounding.

  15. Regulation of the viability of Nf1 deficient cells by PKC isoforms.

    Science.gov (United States)

    Zhou, Xiaodong; Shen, Ling; Parris, Toshima; Huang, Junchi; Yi, Bo; Helou, Khalil; Chen, Changyan

    2014-11-15

    Suppression of protein kinase C (PKC) is known to be synthetically lethal with ras mutations in various types of cancer cells. The studies also showed that blockade of PKC affected the viability of Nf1 deficient cells. Since PKC family consists of more than 10 isoforms, our study aimed at identifying which isoform(s) played the crucial role in sensitizing Nf1 deficient cells to apoptosis. Using genetic and chemical PKC inhibitors, we demonstrated that the concurrent inhibition of PKC α and β induced Nf1 deficient ST or 96.2 cells, but not SNF02.2 cells with a normal Nf1 or ST cells ectopically expressing Nf1 effective domain gene, to apoptosis. In this process, PKC δ in Nf1 deficient cells, but not in ST/Nf1 cells, was upregulated and translocated to the nucleus. Furthermore, caspase 3 was cleaved and cytochrome c was released to the cytosol. Thus, it appeared that PKC δ and α/β are the crucial components for sustaining the aberrant Ras signaling and further viability of Nf1 deficient cells. The abrogation of these two isoforms activated their opponent PKC δ for switching on the caspase 3-governed apoptotic machinery.

  16. Distinct Temporal Regulation of RET Isoform Internalization: Roles of Clathrin and AP2.

    Science.gov (United States)

    Crupi, Mathieu J F; Yoganathan, Piriya; Bone, Leslie N; Lian, Eric; Fetz, Andrew; Antonescu, Costin N; Mulligan, Lois M

    2015-11-01

    The RET receptor tyrosine kinase (RTK) contributes to kidney and nervous system development, and is implicated in a number of human cancers. RET is expressed as two protein isoforms, RET9 and RET51, with distinct interactions and signaling properties that contribute to these processes. RET isoforms are internalized from the cell surface into endosomal compartments in response to glial cell line-derived neurotropic factor (GDNF) ligand stimulation but the specific mechanisms of RET trafficking remain to be elucidated. Here, we used total internal reflection fluorescence (TIRF) microscopy to demonstrate that RET internalization occurs primarily through clathrin coated pits (CCPs). Activated RET receptors colocalize with clathrin, but not caveolin. The RET51 isoform is rapidly and robustly recruited to CCPs upon GDNF stimulation, while RET9 recruitment occurs more slowly and is less pronounced. We showed that the clathrin-associated adaptor protein complex 2 (AP2) interacts directly with each RET isoform through its AP2 μ subunit, and is important for RET internalization. Our data establish that interactions with the AP2 complex promote RET receptor internalization via clathrin-mediated endocytosis but that RET9 and RET51 have distinct internalization kinetics that may contribute to differences in their biological functions.

  17. Cadmium effects on p38/MAPK isoforms in MDA-MB231 breast cancer cells.

    Science.gov (United States)

    Casano, Caterina; Agnello, Maria; Sirchia, Rosalia; Luparello, Claudio

    2010-02-01

    Emerging evidence seems to indicate that the heavy metal cadmium (Cd) is able to regulate gene expression, drastically affecting the pattern of transcriptional activity in normal and pathological eukaryotic cells, also affecting intracellular signalization events. Human p38 is a family of mitogen-activated protein kinases consisting of four isoforms (alpha, beta, gamma and delta) which mediate signal transduction cascades controlling several aspects of cell physiology. In this study we examined whether exposure of MDA-MB231 tumor cells from the human breast to Cd may exert some effect on p38 isoform expression and accumulation, as well as on p38 activation. Employing a combination of proliferation tests, conventional and semiquantitative multiplex (SM)-polymerase chain reaction (PCR) and Western blot assays, we report that the treatment of breast cancer cells with 5 microM CdCl(2) induces a diversified modulation of the transcription patterns of p38 isoform genes and of the accumulation of the related protein products, which are, on the other hand, also affected by alpha and beta isoform functional inactivation induced by SB203580. Our findings suggest the existence of so far unexplored mechanisms of gene regulation in our model system and validate that MDA-MB231 cell line is a suitable in vitro model for further and more detailed studies on the intracellular mechanisms underlying the control of p38 expression, synthesis and activation in mammary tumor cells exposed to different stresses.

  18. Interactions between Casein kinase Iepsilon (CKIepsilon and two substrates from disparate signaling pathways reveal mechanisms for substrate-kinase specificity.

    Directory of Open Access Journals (Sweden)

    Caroline Lund Dahlberg

    Full Text Available BACKGROUND: Members of the Casein Kinase I (CKI family of serine/threonine kinases regulate diverse biological pathways. The seven mammalian CKI isoforms contain a highly conserved kinase domain and divergent amino- and carboxy-termini. Although they share a preferred target recognition sequence and have overlapping expression patterns, individual isoforms often have specific substrates. In an effort to determine how substrates recognize differences between CKI isoforms, we have examined the interaction between CKIepsilon and two substrates from different signaling pathways. METHODOLOGY/PRINCIPAL FINDINGS: CKIepsilon, but not CKIalpha, binds to and phosphorylates two proteins: Period, a transcriptional regulator of the circadian rhythms pathway, and Disheveled, an activator of the planar cell polarity pathway. We use GST-pull-down assays data to show that two key residues in CKIalpha's kinase domain prevent Disheveled and Period from binding. We also show that the unique C-terminus of CKIepsilon does not determine Dishevelled's and Period's preference for CKIepsilon nor is it essential for binding, but instead plays an auxillary role in stabilizing the interactions of CKIepsilon with its substrates. We demonstrate that autophosphorylation of CKIepsilon's C-terminal tail prevents substrate binding, and use mass spectrometry and chemical crosslinking to reveal how a phosphorylation-dependent interaction between the C-terminal tail and the kinase domain prevents substrate phosphorylation and binding. CONCLUSIONS/SIGNIFICANCE: The biochemical interactions between CKIepsilon and Disheveled, Period, and its own C-terminus lead to models that explain CKIepsilon's specificity and regulation.

  19. Ikaros isoforms:The saga continues

    Institute of Scientific and Technical Information of China (English)

    Laura; A; Perez-Casellas; Aleksandar; Savic; Sinisa; Dovat

    2011-01-01

    Through alternate splicing,the Ikaros gene produces multiple proteins.Ikaros is essential for normal hematopoiesis and possesses tumor suppressor activity.Ikaros isoforms interact to form dimers and potentially multimeric complexes.Diverse Ikaros complexes produced by the presence of different Ikaros isoforms are hypothesized to confer distinct functions.Small dominantnegative Ikaros isoforms have been shown to inhibit the tumor suppressor activity of full-length Ikaros.Here,we describe how Ikaros activity is regulated by the coordinated expression of the largest Ikaros isoforms IK-1 and IK-H.Although IK-1 is described as full-length Ikaros,IK-H is the longest Ikaros isoform.IK-H,which includes residues coded by exon 3B (60 bp that lie between exons 3 and 4),is abundant in human but not murine hematopoietic cells.Specific residues that lie within the 20 amino acids encoded by exon 3B give IK-H DNA-binding characteristics that are distinct from those of IK-1.Moreover,IK-H can potentiate or inhibit the ability of IK-1 to bind DNA.IK-H binds to the regulatory regions of genes that are upregulated by Ikaros,but not genes that are repressed by Ikaros.Although IK-1 localizes to pericentromeric heterochromatin,IK-H can be found in both pericentromeric and non-pericentromeric locations.Anti-silencing activity of gamma satellite DNA has been shown to depend on the binding of IK-H,but not other Ikaros isoforms.The unique features of IK-H,its influence on Ikaros activity,and the lack of IK-H expression in mice suggest that Ikaros function in humans may be more complex and possibly distinct from that in mice.

  20. Kinase/phosphatase overexpression reveals pathways regulating hippocampal neuron morphology.

    Science.gov (United States)

    Buchser, William J; Slepak, Tatiana I; Gutierrez-Arenas, Omar; Bixby, John L; Lemmon, Vance P

    2010-07-01

    Development and regeneration of the nervous system requires the precise formation of axons and dendrites. Kinases and phosphatases are pervasive regulators of cellular function and have been implicated in controlling axodendritic development and regeneration. We undertook a gain-of-function analysis to determine the functions of kinases and phosphatases in the regulation of neuron morphology. Over 300 kinases and 124 esterases and phosphatases were studied by high-content analysis of rat hippocampal neurons. Proteins previously implicated in neurite growth, such as ERK1, GSK3, EphA8, FGFR, PI3K, PKC, p38, and PP1a, were confirmed to have effects in our functional assays. We also identified novel positive and negative neurite growth regulators. These include neuronal-developmentally regulated kinases such as the activin receptor, interferon regulatory factor 6 (IRF6) and neural leucine-rich repeat 1 (LRRN1). The protein kinase N2 (PKN2) and choline kinase alpha (CHKA) kinases, and the phosphatases PPEF2 and SMPD1, have little or no established functions in neuronal function, but were sufficient to promote neurite growth. In addition, pathway analysis revealed that members of signaling pathways involved in cancer progression and axis formation enhanced neurite outgrowth, whereas cytokine-related pathways significantly inhibited neurite formation.

  1. Fluorescence of the Flavin group in choline oxidase. Insights and analytical applications for the determination of choline and betaine aldehyde.

    Science.gov (United States)

    Ortega, E; de Marcos, S; Sanz-Vicente, I; Ubide, C; Ostra, M; Vidal, M; Galbán, J

    2016-01-15

    Choline oxidase (ChOx) is a flavoenzyme catalysing the oxidation of choline (Ch) to betaine aldehyde (BA) and glycine betaine (GB). In this paper a fundamental study of the intrinsic fluorescence properties of ChOx due to Flavin Adenine Dinucleotide (FAD) is presented and some analytical applications are studied in detail. Firstly, an unusual alteration in the excitation spectra, in comparison with the absorption spectra, has been observed as a function of the pH. This is ascribed to a change of polarity in the excited state. Secondly, the evolution of the fluorescence spectra during the reaction seems to indicate that the reaction takes place in two consecutive, but partially overlapped, steps and each of them follows a different mechanism. Thirdly, the chemical system can be used to determine the Ch concentration in the range from 5×10(-6)M to 5×10(-5)M (univariate and multivariate calibration) in the presence of BA as interference, and the joint Ch+BA concentration in the range 5×10(-6)-5×10(-4)M (multivariate calibration) with mean errors under 10%; a semiquantitative determination of the BA concentration can be deduced by difference. Finally, Ch has been successfully determined in an infant milk sample.

  2. Casein kinases

    DEFF Research Database (Denmark)

    Issinger, O G

    1993-01-01

    subunits are highly conserved during evolution. The relationship between CK-2 alpha from humans and plants is still 73%. Similar relationships are reported for the beta-subunit. Chromosomal assignment of CK-2 alpha shows two gene loci, one of which is a pseudogene. They are located on different chromosomes......, no genetic changes are necessarily involved; the observed changes may be entirely due to a signal transduction pathway where CK-2 could be phosphorylated by another kinase(s). CK-2 cDNAs from various organisms have been isolated and characterized. From the deduced amino acid sequence it turns out that CK-2......-subunit affecting: (i) stability, (ii) enzyme specificity and (iii) enzyme activity. The question where CK-2 and its subunits are located throughout the cell cycle has also been addressed, mainly because of the large discrepancies that still exist between results obtained by different investigators. Tissue...

  3. Osmotic stress response in Acinetobacter baylyi: identification of a glycine-betaine biosynthesis pathway and regulation of osmoadaptive choline uptake and glycine-betaine synthesis through a choline-responsive BetI repressor.

    Science.gov (United States)

    Scholz, Anica; Stahl, Julia; de Berardinis, Veronique; Müller, Volker; Averhoff, Beate

    2016-04-01

    Acinetobacter baylyi, a ubiquitous soil bacterium, can cope with high salinity by uptake of choline as precursor of the compatible solute glycine betaine. Here, we report on the identification of a choline dehydrogenase (BetA) and a glycine betaine aldehyde dehydrogenase (BetB) mediating the oxidation of choline to glycine betaine. The betAB genes were found to form an operon together with the potential transcriptional regulator betI. The transcription of the betIBA operon and the two recently identified choline transporters was upregulated in response to choline and choline plus salt. The finding that the osmo-independent transporter BetT1 undergoes a higher upregulation in response to choline alone than betT2 suggests that BetT1 does not primarily function in osmoadaptation. Electrophoretic mobility shift assays led to the conclusion that BetI mediates transcriptional regulation of both, the betIBA gene operon and the choline transporters. BetI was released from the DNA in response to choline which together with the transcriptional upregulation of the bet genes in the presence of choline suggests that BetI is a choline sensing transcriptional repressor.

  4. Behavioural effects of chronic manipulations of dietary choline in senescent rats.

    Science.gov (United States)

    Fundaro, A; Paschero, A

    1990-01-01

    1. Senescent rats were maintained on choline-deficient and choline-enriched diets. The modifications in rat behaviour caused by the chronic manipulations of dietary choline were studied in two schedules of operant conditioning. 2. In the "periodic conditioning" test, the schedule of reinforcement, in a 100 min trial, was changed from a fixed ratio to a fixed interval schedule. In the "reversal" test the contingency for food delivery was switched four times from one lever to the other in a two lever Skinner box. 3. In the "periodic conditioning" test, the choline enriched group (430 mg/Kg/day) showed the same reduction of responses/reinforcement as controls, from the beginning to the end of trial; in the same group the time course reduction of responses/reinforcement became significant earlier than in the control group. The deficient-choline group in the last 40 min of "periodic conditioning" trial gave a reduction of responses/reinforcement greater than controls and one rat in the group did not learn the change of experimental schedule and extinguished its operant behaviour. 4. In the "reversal" test, the choline-enriched diet (320 mg/Kg/day) improved the reinforced responses in the IV reversal; one rat of the deficient-choline group could not learn the new operant schedule since the first reversal and continued to respond on the same lever during the whole of the test.

  5. No Acute Effects of Choline Bitartrate Food Supplements on Memory in Healthy, Young, Human Adults.

    Directory of Open Access Journals (Sweden)

    D P Lippelt

    Full Text Available Choline is a dietary component and precursor of acetylcholine, a crucial neurotransmitter for memory-related brain functions. In two double-blind, placebo-controlled cross-over experiments, we investigated whether the food supplement choline bitartrate improved declarative memory and working memory in healthy, young students one to two hours after supplementation. In experiment 1, 28 participants performed a visuospatial working memory task. In experiment 2, 26 participants performed a declarative picture memorization task. In experiment 3, 40 participants performed a verbal working memory task in addition to the visuospatial working memory and declarative picture task. All tasks were conducted approximately 60 minutes after the ingestion of 2.0-2.5g of either choline bitartrate or placebo. We found that choline did not significantly enhance memory performance during any of the tasks. The null hypothesis that choline does not improve memory performance as compared to placebo was strongly supported by Bayesian statistics. These results are in contrast with animal studies suggesting that choline supplementation boosts memory performance and learning. We conclude that choline likely has no acute effects on cholinergic memory functions in healthy human participants.

  6. Acute toxicity assessment of choline by inhalation, intraperitoneal and oral routes in Balb/c mice.

    Science.gov (United States)

    Mehta, Amit Kumar; Arora, Naveen; Gaur, Shailendra Nath; Singh, Bhanu Pratap

    2009-08-01

    Studies suggest that choline has potential to be used as a dietary supplement and a drug for immune inflammatory diseases like asthma and rhinitis. But there are apprehensions regarding adverse effects of choline when given orally in high doses. To address this knowledge gap, toxicity assessment of choline chloride was carried out by intranasal (i.n.), oral and intraperitoneal (i.p.) routes in Balb/c mice for 28days. Body weight, food and water consumption of mice were recorded daily. Hematology and clinical chemistry were assessed to check hepatocellular functions and morphological alterations of the cells. Splenocyte counts were analysed for evaluating cellular immunity. Liver function test was performed by assaying different enzyme systems in serum such as, urea, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Body weight, food and water consumption did not differ between mice treated with choline and the saline control group. Hematologic and biochemical variables were not affected with any increase in serum toxicity marker enzymes indicating normal liver functioning. Choline administration did not affect total cholesterol and high density lipoprotein levels as compared to their respective controls. Urea and blood urea nitrogen levels in choline treated mice were not different than controls. Creatinine level was, however, higher than control in i.p. treatment group, but other parameters were normal. In conclusion, the repeated consumption of choline chloride via i.n. and oral or i.p. routes did not cause toxicity in mice in the toxicological endpoints examined.

  7. Choline and betaine consumption lowers cancer risk: a meta-analysis of epidemiologic studies

    Science.gov (United States)

    Sun, Shanwen; Li, Xiao; Ren, Anjing; Du, Mulong; Du, Haina; Shu, Yongqian; Zhu, Lingjun; Wang, Wei

    2016-01-01

    A number of human and animal in vitro or in vivo studies have investigated the relationship between dietary choline and betaine and cancer risk, suggesting that choline and betaine consumption may be protective for cancer. There are also a few epidemiologic studies exploring this relationship, however, with inconsistent conclusions. The PubMed and Embase were searched, from their inception to March 2016, to identify relevant studies and we brought 11 articles into this meta-analysis eventually. The pooled relative risks (RRs) of cancer for the highest versus the lowest range were 0.82 (95% CI, 0.70 to 0.97) for choline consumption only, 0.86 (95%CI, 0.76 to 0.97) for betaine consumption only and 0.60 (95%CI, 0.40 to 0.90) for choline plus betaine consumption, respectively. Significant protective effect of dietary choline and betaine for cancer was observed when stratified by study design, location, cancer type, publication year, sex and quality score of study. An increment of 100 mg/day of choline plus betaine intake helped reduce cancer incidence by 11% (0.89, 95% CI, 0.87 to 0.92) through a dose-response analysis. To conclude, choline and betaine consumption lowers cancer incidence in this meta-analysis, but further studies are warranted to verify the results. PMID:27759060

  8. No Acute Effects of Choline Bitartrate Food Supplements on Memory in Healthy, Young, Human Adults.

    Science.gov (United States)

    Lippelt, D P; van der Kint, S; van Herk, K; Naber, M

    2016-01-01

    Choline is a dietary component and precursor of acetylcholine, a crucial neurotransmitter for memory-related brain functions. In two double-blind, placebo-controlled cross-over experiments, we investigated whether the food supplement choline bitartrate improved declarative memory and working memory in healthy, young students one to two hours after supplementation. In experiment 1, 28 participants performed a visuospatial working memory task. In experiment 2, 26 participants performed a declarative picture memorization task. In experiment 3, 40 participants performed a verbal working memory task in addition to the visuospatial working memory and declarative picture task. All tasks were conducted approximately 60 minutes after the ingestion of 2.0-2.5g of either choline bitartrate or placebo. We found that choline did not significantly enhance memory performance during any of the tasks. The null hypothesis that choline does not improve memory performance as compared to placebo was strongly supported by Bayesian statistics. These results are in contrast with animal studies suggesting that choline supplementation boosts memory performance and learning. We conclude that choline likely has no acute effects on cholinergic memory functions in healthy human participants.

  9. Effects of temperature, moisture and choline chloride on vitamin A stability in broiler premix

    Institute of Scientific and Technical Information of China (English)

    SUN Haixia; SHAN Anshan; SHI Baoming

    2007-01-01

    A 2×2×2 factorial design was adopted to study the effects of temperature, moisture and choline chloride on vitamin A stability in premix. The results indicated that temperature, moisture and choline chloride damaged vitamin A significantly. The regression equations of vitamin A disappearance rate and storage time were as follows: in room temperature (18±3) ℃, y=14.368Ln(x)+ 4.1425,R2=978; in high temperature (4℃), y=22.24Ln(x)+13.27, R2=O.9918; in low moisture (2%-3%), y=10.408Ln(x)+9.5418, R2=O.9322; in high moisture (8%-9%), y=26.199Ln(x)+7.8741, R2=0.9949; in the condition of choline chloride free, y=9.5125Ln(x)+ 8.9869, R2=O.9826; supplemented with choline chloride, y=27.094Ln(x)+8.4276, R2=0.9984. Temperature had highly significant interaction with moisure and choline chloride on destruction of vitamin A, respectively from the periods of two months storage. However, from the period of the first month storage, the interaction of moisture and choline chloride, as well as the interaction of temperature, moisture and choline destroyed vitamin A remarkably.

  10. Application of bubble separation for quantitative analysis of choline in Dioscorea (yam) tubers.

    Science.gov (United States)

    Fu, Yi-Chung; Chen, Shiau-Huei; Huang, Pau-Yau; Li, Yun-Ju

    2005-04-06

    A modified assay based on the AACC official method 86-45 (AACC, 2000) for the determination of choline in three cereals and three varieties of Dioscorea (yam) tubers was developed. When tested in wheat, rice, and oat flour, choline estimated by the modified method was 34.0-45.3% higher than that of the original AACC method. In a system with higher contents of starch and mucilage, such as Dioscorea (yam) tubers, extra procedures in sample preparation needed to be carried out to separate starch and mucilage. The choline contents of the following Dioscorea (yam) tubers using the original AACC method and the present modified AACC method through coupling an additional bubble separation procedure, respectively, were (mean +/- SD, mg/g solid) Keelung yam (D. pseudojaponicaY.) 0.92 +/- 0.09 and 2.21 +/- 0.12, Yangmingshan yam (D. alata L.) 0.77 +/- 0.09 and 1.78 +/- 0.28, and Ming-Chien yam (D. purpurea) 0.44 +/- 0.09 and 1.35 +/- 0.19. Choline was 231-306% higher than when the original AACC method was used. Dioscorea (yam) tubers were much higher in choline content than they were in cereals. Bubble separation is an appropriate procedure in the practice for the maximum assay of choline in yams. It is accurate, rapid, easy to handle, and especially good for recovering choline from a starch and polysaccharide-protein-containing system.

  11. Dietary Intake and Plasma Levels of Choline and Betaine in Children with Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Joanna C. Hamlin

    2013-01-01

    Full Text Available Abnormalities in folate-dependent one-carbon metabolism have been reported in many children with autism. Because inadequate choline and betaine can negatively affect folate metabolism and in turn downstream methylation and antioxidant capacity, we sought to determine whether dietary intake of choline and betaine in children with autism was adequate to meet nutritional needs based on national recommendations. Three-day food records were analyzed for 288 children with autism (ASDs who participated in the national Autism Intervention Research Network for Physical Health (AIR-P Study on Diet and Nutrition in children with autism. Plasma concentrations of choline and betaine were measured in a subgroup of 35 children with ASDs and 32 age-matched control children. The results indicated that 60–93% of children with ASDs were consuming less than the recommended Adequate Intake (AI for choline. Strong positive correlations were found between dietary intake and plasma concentrations of choline and betaine in autistic children as well as lower plasma concentrations compared to the control group. We conclude that choline and betaine intake is inadequate in a significant subgroup of children with ASDs and is reflected in lower plasma levels. Inadequate intake of choline and betaine may contribute to the metabolic abnormalities observed in many children with autism and warrants attention in nutritional counseling.

  12. Egg Production and Quality of Quails Fed Diets with Varying Levels of Methionine and Choline Chloride

    Directory of Open Access Journals (Sweden)

    Khairani

    2016-04-01

    Full Text Available The aim of the present study was to determine the effect of choline chloride supplementation at 1500 ppm in diets containing various levels of methionine on egg production and egg quality in quails. A total of 180 birds, at 6 week-old quail were divided into 18 experimental units, and assigned to a 2 x 3 factorial design experiment with 3 replications (10 birds each in each treatment. The birds were offered diets containing choline chloride at either 0 (A1 or 1500 ppm (A2, with three levels of methionine namely, low (0.19%, B1, standard (0.79%, B2 and, high (1.05%, B3. The feeding trial lasted for 8 weeks. Supplementation of choline chloride in low methionine diet significantly (P<0.05 increased egg production, egg mass, and egg weight as compared to those without choline chloride supplementation. Supplementation of choline chloride significantly (P<0.05 increased egg yolk weight but decreased albumen and egg shell weight as compared to those fed diets without choline chloride supplementation. It can be concluded that supplementation of choline chloride to a diet containing low methionine increased egg production, without affecting egg quality.

  13. Crystal structure of pyridoxal kinase from the Escherichia coli pdxK gene: implications for the classification of pyridoxal kinases.

    Science.gov (United States)

    Safo, Martin K; Musayev, Faik N; di Salvo, Martino L; Hunt, Sharyn; Claude, Jean-Baptiste; Schirch, Verne

    2006-06-01

    The pdxK and pdxY genes have been found to code for pyridoxal kinases, enzymes involved in the pyridoxal phosphate salvage pathway. Two pyridoxal kinase structures have recently been published, including Escherichia coli pyridoxal kinase 2 (ePL kinase 2) and sheep pyridoxal kinase, products of the pdxY and pdxK genes, respectively. We now report the crystal structure of E. coli pyridoxal kinase 1 (ePL kinase 1), encoded by a pdxK gene, and an isoform of ePL kinase 2. The structures were determined in the unliganded and binary complexes with either MgATP or pyridoxal to 2.1-, 2.6-, and 3.2-A resolutions, respectively. The active site of ePL kinase 1 does not show significant conformational change upon binding of either pyridoxal or MgATP. Like sheep PL kinase, ePL kinase 1 exhibits a sequential random mechanism. Unlike sheep pyridoxal kinase, ePL kinase 1 may not tolerate wide variation in the size and chemical nature of the 4' substituent on the substrate. This is the result of differences in a key residue at position 59 on a loop (loop II) that partially forms the active site. Residue 59, which is His in ePL kinase 1, interacts with the formyl group at C-4' of pyridoxal and may also determine if residues from another loop (loop I) can fill the active site in the absence of the substrate. Both loop I and loop II are suggested to play significant roles in the functions of PL kinases.

  14. Structure of the kinase domain of Gilgamesh from Drosophila melanogaster.

    Science.gov (United States)

    Han, Ni; Chen, CuiCui; Shi, Zhubing; Cheng, Dianlin

    2014-04-01

    The CK1 family kinases regulate multiple cellular aspects and play important roles in Wnt/Wingless and Hedgehog signalling. The kinase domain of Drosophila Gilgamesh isoform I (Gilgamesh-I), a homologue of human CK1-γ, was purified and crystallized. Crystals of methylated Gilgamesh-I kinase domain with a D210A mutation diffracted to 2.85 Å resolution and belonged to space group P43212, with unit-cell parameters a = b = 52.025, c = 291.727 Å. The structure of Gilgamesh-I kinase domain, which was determined by molecular replacement, has conserved catalytic elements and an active conformation. Structural comparison indicates that an extended loop between the α1 helix and the β4 strand exists in the Gilgamesh-I kinase domain. This extended loop may regulate the activity and function of Gilgamesh-I.

  15. p53 isoforms change p53 paradigm

    OpenAIRE

    2014-01-01

    Although p53 defines cellular responses to cancer treatment it is not clear how p53 can be used to control cell fate outcome. Data demonstrate that so-called p53 does not exist as a single protein, but is in fact a group of p53 protein isoforms whose expression can be manipulated to control the cellular response to treatment.

  16. New isoforms of rat Aquaporin-4

    DEFF Research Database (Denmark)

    Moe, Svein Erik; Sorbo, Jan Gunnar; Søgaard, Rikke;

    2008-01-01

    an intracellular localization when expressed in cell lines and do not transport water when expressed in Xenopus oocytes. In contrast, the largest of the new isoforms, AQP4e, which contains a novel N-terminal domain, is localized at the plasma membrane in cell lines and functions as a water transporter in Xenopus...

  17. Dietary Supplementation of Alternative Methionine and Choline Sources in the Organic Broiler Production in Brazil

    Directory of Open Access Journals (Sweden)

    LC Demattê Filho

    2015-12-01

    Full Text Available ABSTRACT The objective of this study was to evaluate the use of natural and alternative sources of methionine and choline which can be allowed to use in organic livestock systems to feed broilers produced in Brazil. Seven hundred and twenty one-d-old male Cobb broilers were randomly allocated to four treatments with six replicates of 24 birds each. The treatments consisted in substituting the commonly used DL-methionine 99% by a vegetable source of methionine and cholinechloride 60% by alternative source of choline in the form of phosphatidylcholine. The following treatments were evaluated: I feed with DL-methionine 99% and choline chloride 60%, II feed with an vegetable methionine source and choline chloride 60%, III feed with DL-methionine 99% and choline as phosphatidylcholine, and IV feed with vegetable methionine source and choline as phosphatidylcholine. Daily weight gain, body weight, feed intake, feed conversion ratio, and mortality were evaluated for the periods of 1 to 21 and 1 to 42 days of age. During both periods, broilers fed the vegetable methionine source presented lower daily gain and lower body weight. When only choline chloride was substituted by the alternative choline source, broiler performance was not different compared with that of the control group. The group fed the diet with substitution of both DL-methionine 99% and choline chloride 60% by natural sources presented lower daily weight gain, final body weight, and feed intake. Further research on alternative nutrient sources are required for the development of the organic production chain.

  18. The antihyperalgesic effect of cytidine-5'-diphosphate-choline in neuropathic and inflammatory pain models.

    Science.gov (United States)

    Bagdas, Deniz; Sonat, Fusun Ak; Hamurtekin, Emre; Sonal, Songul; Gurun, Mine Sibel

    2011-09-01

    This study was designed to test the effects of intracerebroventricularly (i.c.v.) administered CDP-choline (cytidine-5'-diphosphate-choline; citicoline) and its metabolites in rat models of inflammatory and neuropathic pain. The i.c.v. administration of CDP-choline (0.5, 1.0 and 2.0 µmol) produced a dose and time-dependent reversal of mechanical hyperalgesia in both carrageenan-induced inflammatory and chronic constriction injury-induced neuropathic pain models in rats. The antihyperalgesic effect of CDP-choline was similar to that observed with an equimolar dose of choline (1 µmol). The CDP-choline-induced antihyperalgesic effect was prevented by central administration of the neuronal high-affinity choline uptake inhibitor hemicholinium-3 (1 µg), the nonselective nicotinic receptor antagonist mecamylamine (50 µg), the α7-selective nicotinic ACh receptor antagonist, α-bungarotoxin (2 µg) and the γ-aminobutyric acid B receptor antagonist CGP-35348 (20 µg). In contrast, i.c.v. pretreatment with the nonselective opioid receptor antagonist naloxone (10 µg) only prevented the CDP-choline-induced antihyperalgesic effect in the neuropathic pain model while the nonselective muscarinic receptor antagonist atropine (10 µg) did not alter the antihyperalgesic effect in the two models. These results indicate that CDP-choline-elicited antihyperalgesic effect in different models of pain occurs through mechanisms that seem to involve an interaction with supraspinal α7-selective nicotinic ACh receptors, and γ-aminobutyric acid B receptors, whereas central opioid receptors have a role only in the neuropathic pain model.

  19. Choline acetyltransferase-containing neurons in the human parietal neocortex

    Directory of Open Access Journals (Sweden)

    V Benagiano

    2009-06-01

    Full Text Available A number of immunocytochemical studies have indicated the presence of cholinergic neurons in the cerebral cortex of various species of mammals. Whether such cholinergic neurons in the human cerebral cortex are exclusively of subcortical origin is still debated. In this immunocytochemical study, the existence of cortical cholinergic neurons was investigated on surgical samples of human parietal association neocortex using a highly specific monoclonal antibody against choline acetyltransferase (ChAT, the acetylcholine biosynthesising enzyme. ChAT immunoreactivity was detected in a subpopulation of neurons located in layers II and III. These were small or medium-sized pyramidal neurons which showed cytoplasmic immunoreactivity in the perikarya and processes, often in close association to blood microvessels. This study, providing demonstration of ChAT neurons in the human parietal neocortex, strongly supports the existence of intrinsic cholinergic innervation of the human neocortex. It is likely that these neurons contribute to the cholinergic innervation of the intracortical microvessels.

  20. Absolute quantitation of protein posttranslational modification isoform.

    Science.gov (United States)

    Yang, Zhu; Li, Ning

    2015-01-01

    Mass spectrometry has been widely applied in characterization and quantification of proteins from complex biological samples. Because the numbers of absolute amounts of proteins are needed in construction of mathematical models for molecular systems of various biological phenotypes and phenomena, a number of quantitative proteomic methods have been adopted to measure absolute quantities of proteins using mass spectrometry. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with internal peptide standards, i.e., the stable isotope-coded peptide dilution series, which was originated from the field of analytical chemistry, becomes a widely applied method in absolute quantitative proteomics research. This approach provides more and more absolute protein quantitation results of high confidence. As quantitative study of posttranslational modification (PTM) that modulates the biological activity of proteins is crucial for biological science and each isoform may contribute a unique biological function, degradation, and/or subcellular location, the absolute quantitation of protein PTM isoforms has become more relevant to its biological significance. In order to obtain the absolute cellular amount of a PTM isoform of a protein accurately, impacts of protein fractionation, protein enrichment, and proteolytic digestion yield should be taken into consideration and those effects before differentially stable isotope-coded PTM peptide standards are spiked into sample peptides have to be corrected. Assisted with stable isotope-labeled peptide standards, the absolute quantitation of isoforms of posttranslationally modified protein (AQUIP) method takes all these factors into account and determines the absolute amount of a protein PTM isoform from the absolute amount of the protein of interest and the PTM occupancy at the site of the protein. The absolute amount of the protein of interest is inferred by quantifying both the absolute amounts of a few PTM

  1. Functional expression of choline transporter like-protein 1 (CTL1) and CTL2 in human brain microvascular endothelial cells.

    Science.gov (United States)

    Iwao, Beniko; Yara, Miki; Hara, Naomi; Kawai, Yuiko; Yamanaka, Tsuyoshi; Nishihara, Hiroshi; Inoue, Takeshi; Inazu, Masato

    2016-02-01

    In this study, we examined the molecular and functional characterization of choline transporter in human brain microvascular endothelial cells (hBMECs). Choline uptake into hBMECs was a saturable process that was mediated by a Na(+)-independent, membrane potential and pH-dependent transport system. The cells have two different [(3)H]choline transport systems with Km values of 35.0 ± 4.9 μM and 54.1 ± 8.1 μM, respectively. Choline uptake was inhibited by choline, acetylcholine (ACh) and the choline analog hemicholinium-3 (HC-3). Various organic cations also interacted with the choline transport system. Choline transporter-like protein 1 (CTL1) and CTL2 mRNA were highly expressed, while mRNA for high-affinity choline transporter 1 (CHT1) and organic cation transporters (OCTs) were not expressed in hBMECs. CTL1 and CTL2 proteins were localized to brain microvascular endothelial cells in human brain cortical sections. Both CTL1 and CTL2 proteins were expressed on the plasma membrane and mitochondria. CTL1 and CTL2 proteins are mainly expressed in plasma membrane and mitochondria, respectively. We conclude that choline is mainly transported via an intermediate-affinity choline transport system, CTL1 and CTL2, in hBMECs. These transporters are responsible for the uptake of extracellular choline and organic cations. CTL2 participate in choline transport mainly in mitochondria, and may be the major site for the control of choline oxidation.

  2. ACTIVATION OF PHOSPHATIDYLCHOLINE-SPECIFIC PHOSPHOLIPASE C IN BREAST AND OVARIAN CANCER:IMPACT ON MRS-DETECTED CHOLINE METABOLIC PROFILE AND PERSPECTIVES FOR TARGETED THERAPY

    Directory of Open Access Journals (Sweden)

    Franca Podo

    2016-08-01

    Full Text Available Elucidation of molecular mechanisms underlying the aberrant phosphatidylcholine-cycle in cancer cells plays in favor of the use of metabolic imaging in oncology and opens the way for designing new targeted therapies. The anomalous choline metabolic profile detected in cancer by magnetic resonance spectroscopy (MRS and spectroscopic imaging (MRSI provides molecular signatures of tumor progression and response to therapy.The increased level of intracellular phosphocholine (PCho typically detected in cancer cells is mainly attributed to upregulation of choline kinase, responsible for choline phosphorylation in the biosynthetic Kennedy pathway, but can also be partly produced by activation of phosphatidylcholine-specific phospholipase C (PC-PLC. This hydrolytic enzyme, known for implications in bacterial infection and in plant survival to hostile environmental conditions, is reported to be activated in mitogen- and oncogene-induced phosphatidylcholine cycles in mammalian cells, with effects on cell signaling, cell cycle regulation and cell proliferation.Recent investigations showed that PC-PLC activation could account for 20-to-50% of the intracellular PCho production in ovarian and breast cancer cells of different subtypes. Enzyme activation was associated with PC-PLC protein overexpression and subcellular redistribution in these cancer cells compared with non-tumoral counterparts. Moreover, PC-PLC co-immunoprecipitated with the human epidermal growth factor receptor-2 (HER2 and EGFR in HER2-overexpressing breast and ovarian cancer cells, while pharmacological PC-PLC inhibition resulted into long-lasting HER2 downregulation, retarded receptor re-expression on plasma membrane and anti-proliferative effects.This body of evidence points to PC-PLC as a potential target for newly designed therapies, whose effects can be pre-clinically and clinically monitored by metabolic imaging methods.

  3. Microbial conversion of choline to trimethylamine requires a glycyl radical enzyme.

    Science.gov (United States)

    Craciun, Smaranda; Balskus, Emily P

    2012-12-26

    Choline and trimethylamine (TMA) are small molecules that play central roles in biological processes throughout all kingdoms of life. These ubiquitous metabolites are linked through a single biochemical transformation, the conversion of choline to TMA by anaerobic microorganisms. This metabolic activity, which contributes to methanogenesis and human disease, has been known for over a century but has eluded genetic and biochemical characterization. We have identified a gene cluster responsible for anaerobic choline degradation within the genome of a sulfate-reducing bacterium and verified its function using both a genetic knockout strategy and heterologous expression in Escherichia coli. Bioinformatics and electron paramagnetic resonance (EPR) spectroscopy revealed the involvement of a C-N bond cleaving glycyl radical enzyme in TMA production, which is unprecedented chemistry for this enzyme family. Our discovery provides the predictive capabilities needed to identify choline utilization clusters in numerous bacterial genomes, underscoring the importance and prevalence of this metabolic activity within the human microbiota and the environment.

  4. Lecithin: a by-product of biodiesel production and a source of choline for dairy cows

    Directory of Open Access Journals (Sweden)

    Igino Andrighetto

    2012-04-01

    Full Text Available The aim of the present study was to compare the effects of soy lecithins (L, a by-product of the biodiesel production process, and choline chloride microencapsulated with hydrogenated vegetable oils (C on dry matter intake, milk yield,  milk quality traits, milk choline and haematological profile of dairy cows. A total of 12 mid-lactating Holstein Friesian cows were assigned to one of two experimental groups and fed according to cross-over design (2 diets x 2 periods. Diets were isoenergetic, isofibrous and isonitrogenous and had the same content of choline. Dry matter intake was not affected by the diet, but L led to lower milk choline (P

  5. Choline ameliorates cardiovascular damage by improving vagal activity and inhibiting the inflammatory response in spontaneously hypertensive rats

    Science.gov (United States)

    Liu, Longzhu; Lu, Yi; Bi, Xueyuan; Xu, Man; Yu, Xiaojiang; Xue, Runqing; He, Xi; Zang, Weijin

    2017-01-01

    Autonomic dysfunction and abnormal immunity lead to systemic inflammatory responses, which result in cardiovascular damage in hypertension. The aim of this report was to investigate the effects of choline on cardiovascular damage in hypertension. Eight-week-old male spontaneously hypertensive rats (SHRs) and Wistar-Kyoto rats were intraperitoneally injected with choline or vehicle (8 mg/kg/day). After 8 weeks, choline restored the cardiac function of the SHRs, as evidenced by decreased heart rate, systolic blood pressure, left ventricle systolic pressure, and ±dp/dtmax and increased ejection fraction and fractional shortening. Choline also ameliorated the cardiac hypertrophy of the SHRs, as indicated by reduced left ventricle internal dimensions and decreased cardiomyocyte cross-sectional area. Moreover, choline improved mesenteric arterial function and preserved endothelial ultrastructure in the SHRs. Notably, the protective effect of choline may be due to its anti-inflammatory effect. Choline downregulated expression of interleukin (IL)-6 and tumour necrosis factor-α and upregulated IL-10 in the mesenteric arteries of SHRs, possibly because of the inhibition of Toll-like receptor 4. Furthermore, choline restored baroreflex sensitivity and serum acetylcholine level in SHRs, thus indicating that choline improved vagal activity. This study suggests that choline elicits cardiovascular protective effects and may be useful as a potential adjunct therapeutic approach for hypertension. PMID:28225018

  6. THE FETAL ORIGINS OF MEMORY: THE ROLE OF DIETARY CHOLINE IN OPTIMAL BRAIN DEVELOPMENT

    OpenAIRE

    Steven H Zeisel

    2006-01-01

    Fetal nutrition sets the stage for organ function in later life. In this review we discuss the fetal and neonatal origins of brain function. Numerous research observations point to the importance of choline for the developing fetus and neonate. This essential nutrient is involved in 1-carbon metabolism and is the precursor for many important compounds, including phospholipids, acetylcholine, and the methyl donor betaine. Dietary intake of choline by the pregnant mother and later by the infant...

  7. Dietary Intake and Plasma Levels of Choline and Betaine in Children with Autism Spectrum Disorders

    OpenAIRE

    Hamlin, Joanna C.; Margaret Pauly; Stepan Melnyk; Oleksandra Pavliv; William Starrett; Crook, Tina A.; S Jill James

    2013-01-01

    Abnormalities in folate-dependent one-carbon metabolism have been reported in many children with autism. Because inadequate choline and betaine can negatively affect folate metabolism and in turn downstream methylation and antioxidant capacity, we sought to determine whether dietary intake of choline and betaine in children with autism was adequate to meet nutritional needs based on national recommendations. Three-day food records were analyzed for 288 children with autism (ASDs) who particip...

  8. Choline dehydrogenase interacts with SQSTM1/p62 to recruit LC3 and stimulate mitophagy

    OpenAIRE

    Park, Sungwoo; Choi, Seon-Guk; Yoo, Seung-Min; Son, Jin H.; Jung, Yong-Keun

    2014-01-01

    CHDH (choline dehydrogenase) is an enzyme catalyzing the dehydrogenation of choline to betaine aldehyde in mitochondria. Apart from this well-known activity, we report here a pivotal role of CHDH in mitophagy. Knockdown of CHDH expression impairs CCCP-induced mitophagy and PARK2/parkin-mediated clearance of mitochondria in mammalian cells, including HeLa cells and SN4741 dopaminergic neuronal cells. Conversely, overexpression of CHDH accelerates PARK2-mediated mitophagy. CHDH is found on both...

  9. Serial plasma choline measurements after cardiac arrest in patients undergoing mild therapeutic hypothermia: a prospective observational pilot trial.

    Directory of Open Access Journals (Sweden)

    Christian Storm

    Full Text Available OBJECTIVE: Choline is related to phospholipid metabolism and is a marker for global ischaemia with a small reference range in healthy volunteers. The aim of our study was to characterize the early kinetics of plasma free choline in patients after cardiac arrest. Additionally, we investigated the potential of plasma free choline to predict neurological outcome. METHODS: Twenty patients admitted to our medical intensive care unit were included in this prospective, observational trial. All patients were enrolled between May 2010 and May 2011. They received post cardiac arrest treatment including mild therapeutic hypothermia which was initiated with a combination of cold fluid and a feedback surface cooling device according to current guidelines. Sixteen blood samples per patient were analysed for plasma free choline levels within the first week after resuscitation. Choline was detected by liquid chromatography-tandem mass spectrometry. RESULTS: Most patients showed elevated choline levels on admission (median 14.8 µmol/L; interquartile range; IQR 9.9-20.1 which subsequently decreased. 48 hours after cardiac arrest choline levels in all patients reached subnormal levels at a median of 4.0 µmol/L (IQR 3-4.9; p = 0.001. Subsequently, choline levels normalized within seven days. There was no significant difference in choline levels when groups were analyzed in relation to neurological outcome. CONCLUSIONS: Our data indicate a choline deficiency in the early postresucitation phase. This could potentially result in impaired cell membrane recovery. The detailed characterization of the early choline time course may aid in planning of choline supplementation trials. In a limited number of patients, choline was not promising as a biomarker for outcome prediction.

  10. Functional studies of sodium pump isoforms

    DEFF Research Database (Denmark)

    Clausen, Michael Jakob

    The Na+,K+-ATPase is an essential ion pump found in all animal cells. It uses the energy from ATP hydrolysis to export three Na+ and import two K+, both against their chemical gradients and for Na+ also against the electrical potential. Mammals require four Na+,K+-ATPase isoforms that each have u...... synthesized cohorts of pumps from the Golgi apparatus to the plasma membrane....

  11. ROCK in CNS: Different Roles of Isoforms and Therapeutic Target for Neurodegenerative Disorders.

    Science.gov (United States)

    Chong, Cheong-Meng; Ai, Nana; Lee, Simon Ming-Yuen

    2017-01-01

    Rho-associated protein kinase (ROCK) is a serine-threonine kinase originally identified as a crucial regulator of actin cytoskeleton. Recent studies have defined new functions of ROCK as a critical component of diverse signaling pathways in neurons. In addition, inhibition of ROCK causes several biological events such as increase of neurite outgrowth, axonal regeneration, and activation of prosurvival Akt. Thus, it has attracted scientist's strong attentions and considered ROCK as a promising therapeutic target for the treatment of neurodegenerative disorders including Alzheimer disease, Parkinson's disease, Huntington';s disease, multiple sclerosis, and amyotrophic lateral sclerosis. However, ROCK has two highly homologous isoforms, ROCK1 and ROCK2. Accumulated evidences indicate that ROCK1 and ROCK2 might involve in distinct cellular functions in central nervous system (CNS) and neurodegenerative processes. This review summarizes recent updates regarding ROCK isoformspecific functions in CNS and the progress of ROCK inhibitors in preclinical studies for neurodegenerative diseases.

  12. FSH isoform pattern in classic galactosemia.

    Science.gov (United States)

    Gubbels, Cynthia S; Thomas, Chris M G; Wodzig, Will K W H; Olthaar, André J; Jaeken, Jaak; Sweep, Fred C G J; Rubio-Gozalbo, M Estela

    2011-04-01

    Female classic galactosemia patients suffer from primary ovarian insufficiency (POI). The cause for this long-term complication is not fully understood. One of the proposed mechanisms is that hypoglycosylation of complex molecules, a known secondary phenomenon of galactosemia, leads to FSH dysfunction. An earlier study showed less acidic isoforms of FSH in serum samples of two classic galactosemia patients compared to controls, indicating hypoglycosylation. In this study, FSH isoform patterns of five classic galactosemia patients with POI were compared to the pattern obtained in two patients with a primary glycosylation disorder (phosphomannomutase-2-deficient congenital disorders of glycosylation, PMM2-CDG) and POI, and in five postmenopausal women as controls. We used FPLC chromatofocussing with measurement of FSH concentration per fraction, and discovered that there were no significant differences between galactosemia patients, PMM2-CDG patients and postmenopausal controls. Our results do not support that FSH dysfunction due to a less acidic isoform pattern because of hypoglycosylation is a key mechanism of POI in this disease.

  13. Protein Kinase C and Toll-Like Receptor Signaling

    Directory of Open Access Journals (Sweden)

    Daniel J. Loegering

    2011-01-01

    Full Text Available Protein kinase C (PKC is a family of kinases that are implicated in a plethora of diseases, including cancer and cardiovascular disease. PKC isoforms can have different, and sometimes opposing, effects in these disease states. Toll-like receptors (TLRs are a family of pattern recognition receptors that bind pathogens and stimulate the secretion of cytokines. It has long been known that PKC inhibitors reduce LPS-stimulated cytokine secretion by macrophages, linking PKC activation to TLR signaling. Recent studies have shown that PKC-α, -δ, -ε, and -ζ are directly involved in multiple steps in TLR pathways. They associate with the TLR or proximal components of the receptor complex. These isoforms are also involved in the downstream activation of MAPK, RhoA, TAK1, and NF-κB. Thus, PKC activation is intimately involved in TLR signaling and the innate immune response.

  14. Uptake of (N-Me-3H)-choline by synaptosomes from the central nervous system of Locusta migratoria

    Energy Technology Data Exchange (ETDEWEB)

    Breer, H.

    1982-03-01

    The accumulation of 3H-choline by isolated synaptosomes from the central nervous system of locust was studied at concentrations varying from 0.05 to 40 microM. Kinetic analysis of the saturable process revealed a high-affinity and a low-affinity system. The high-affinity uptake was competitively inhibited by hemicholinium-3 and was absolutely dependent on external sodium. Elevated potassium concentrations inhibited choline uptake. The choline uptake by insect synaptosomes was found to be remarkably resistant to a variety of metabolic inhibitors. The reduced choline uptake under depolarizing conditions (high potassium concentration or veratridine) in the absence of calcium implies that electrochemical gradients are important for high-affinity choline uptake. Depolarization of preloaded synaptosomes under appropriate conditions resulted in a significant release of newly accumulated choline radioactivity.

  15. Kinetics of [{sup 11}C]choline uptake in prostate cancer: a PET stydy

    Energy Technology Data Exchange (ETDEWEB)

    Sutinen, Eija; Minn, Heikki [Turku PET Centre, Turku University Central Hospital, Turku (Finland); Department of Oncology and Radiotherapy, Turku University Central Hospital, PO Box 52, 20521, Turku (Finland); Nurmi, Martti [Department of Surgery, Turku University Central Hospital, Turku (Finland); Roivainen, Anne; Tolvanen, Tuula; Lehikoinen, Pertti [Turku PET Centre, Turku University Central Hospital, Turku (Finland); Varpula, Matti [Department of Radiology, Turku University Central Hospital, Turku (Finland)

    2004-03-01

    Carbon-11 choline has recently been introduced as a potential tracer for tumour imaging with positron emission tomography (PET). We evaluated the kinetics of the uptake of [{sup 11}C]choline in prostate cancer and benign prostatic hyperplasia. We also evaluated the association between the uptake of [{sup 11}C]choline and the histological grade of malignancy, Gleason score, volume of the prostate and prostate-specific antigen (PSA). Fourteen patients with histologically confirmed prostate cancer and five patients with benign prostatic hyperplasia were studied with [{sup 11}C]choline PET. A mean dose of 430{+-}31 MBq of [{sup 11}C]choline was injected intravenously and a dynamic emission acquisition of prostate was performed for 30 min. The uptake of [{sup 11}C]choline was measured as a standardised uptake value (SUV) and as a kinetic influx constant (K{sub i}) obtained from graphical analysis. Both cancerous and hyperplastic prostate were well visualised with [{sup 11}C]choline against low or moderate tracer accumulation in the bladder and rectal wall. The measured radioactivity in urine was invariably low. In the graphical analysis, linear plots were achieved. The mean K{sub i} of the untreated tumour was 0.205{+-}0.089 min{sup -1} (range 0.128-0.351; n=7) and the mean SUV was 5.6{+-}3.2 (range 1.9-15.5; n=15). K{sub i} values and SUVs correlated closely (r=0.964, P=0.0005), whereas no correlation could be demonstrated between the tumour uptake of [{sup 11}C]choline and the histological grade, Gleason score, volume of the prostate or PSA. The mean SUV and the mean K{sub i} of benign hyperplastic prostate were 3.5{+-}1.0 (range 2.0-4.5; n=4) and 0.119{+-}0.076 min{sup -1} (range 0.065-0.173; n=2). In conclusion, a high uptake of [{sup 11}C]choline characterises not only carcinomatous but also hyperplastic prostatic tissue. Dynamic imaging of the uptake of [{sup 11}C]choline in the prostate shows a good applicability of the graphical analysis model with an

  16. PET/CT in prostate cancer: non-choline radiopharmaceuticals.

    Science.gov (United States)

    Castellucci, P; Jadvar, H

    2012-08-01

    In this brief review, the major potential clinical applications of 18F-FDG, 11C-acetate, 18F-FDHT, 18F-FLT, 18F-FMAU, and anti-18F-FACBC in the imaging evaluation of men with prostate cancer are discussed. 18F-FDG has a limited role in primary diagnosis and staging but it may be able to reflect tumour aggressiveness, detect sites of recurrence in some men with high serum PSA after biochemical failure and assess response to chemo- and hormonal treatment in metastatic disease. 11C-acetate has been investigated for intra-prostatic primary tumour detection and staging as well as for re-staging in case of biochemical relapse with results that are overall similar to those with 18F- and 11C-labeled choline. 18F-FDHT targets the androgen receptor and may be particularly useful in the assessment of the pharmacodynamics of the androgen signalling pathway. PET in conjunction with 18F-FLT or 18F-FMAU that track the thymidine salvage pathway of DNA synthesis has also been investigated for imaging cellular proliferation in prostate cancer. Initial experience with the radiolabeled synthetic amino acid, anti-18F-FACBC, which displays slow urinary excretion has been encouraging but further studies will be needed to decipher its exact role in the imaging management of men with prostate cancer.

  17. Protein Kinase D Regulates Cell Death Pathways in Experimental Pancreatitis

    OpenAIRE

    Yuan, Jingzhen; Liu, Yannan; Tan, Tanya; Guha, Sushovan; Gukovsky, Ilya; Gukovskaya, Anna; Pandol, Stephen J.

    2012-01-01

    Inflammation and acinar cell necrosis are two major pathological responses of acute pancreatitis, a serious disorder with no current therapies directed to its molecular pathogenesis. Serine/threonine protein kinase D family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple physiological and pathophysiological effects. We recently reported that PKD/PKD1, the predominant PKD isoform expressed in rat pancreatic acinar cells, mediates early e...

  18. Microtubule affinity-regulating kinase 4: structure, function, and regulation.

    Science.gov (United States)

    Naz, Farha; Anjum, Farah; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2013-11-01

    MAP/Microtubule affinity-regulating kinase 4 (MARK4) belongs to the family of serine/threonine kinases that phosphorylate the microtubule-associated proteins (MAP) causing their detachment from the microtubules thereby increasing microtubule dynamics and facilitating cell division, cell cycle control, cell polarity determination, cell shape alterations, etc. The MARK4 gene encodes two alternatively spliced isoforms, L and S that differ in their C-terminal region. These isoforms are differentially regulated in human tissues including central nervous system. MARK4L is a 752-residue-long polypeptide that is divided into three distinct domains: (1) protein kinase domain (59-314), (2) ubiquitin-associated domain (322-369), and (3) kinase-associated domain (703-752) plus 54 residues (649-703) involved in the proper folding and function of the enzyme. In addition, residues 65-73 are considered to be the ATP-binding domain and Lys88 is considered as ATP-binding site. Asp181 has been proposed to be the active site of MARK4 that is activated by phosphorylation of Thr214 side chain. The isoform MARK4S is highly expressed in the normal brain and is presumably involved in neuronal differentiation. On the other hand, the isoform MARK4L is upregulated in hepatocarcinoma cells and gliomas suggesting its involvement in cell cycle. Several biological functions are also associated with MARK4 including microtubule bundle formation, nervous system development, and positive regulation of programmed cell death. Therefore, MARK4 is considered as the most suitable target for structure-based rational drug design. Our sequence, structure- and function-based analysis should be helpful for better understanding of mechanisms of regulation of microtubule dynamics and MARK4 associated diseases.

  19. Higher Dietary Choline and Betaine Intakes Are Associated with Better Body Composition in the Adult Population of Newfoundland, Canada.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available Choline is an essential nutrient and betaine is an osmolyte and methyl donor. Both are important to maintain health including adequate lipid metabolism. Supplementation of dietary choline and betaine increase muscle mass and reduce body fat in animals. However, little data is available regarding the role of dietary choline and betaine on body composition in humans.To investigate the association between dietary choline and betaine intakes with body composition in a large population based cross-sectional study.A total of 3214 subjects from the CODING (Complex Disease in Newfoundland population: Environment and Genetics study were assessed. Dietary choline and betaine intakes were computed from the Willett Food Frequency questionnaire. Body composition was measured using dual-energy X-ray absorptiometry following a 12-hour fast. Major confounding factors including age, sex, total calorie intake and physical activity level were controlled in all analyses.Significantly inverse correlations were found between dietary choline and betaine intakes, with all obesity measurements: total percent body fat (%BF, percent trunk fat (%TF, percent android fat (%AF, percent gynoid fat (%GF and anthropometrics: weight, body mass index, waist circumference, waist-to-hip ratio in both women and men (r range from -0.13 to -0.47 for choline and -0.09 to -0.26 for betaine, p<0.001 for all. Dietary choline intake had stronger association than betaine. Moreover, obese subjects had the lowest dietary choline and betaine intakes, with overweight subjects in the middle, and normal weight subjects consumed the highest dietary choline and betaine (p<0.001. Vice versa, when subjects were ranked according to dietary choline and betaine intakes, subjects with the highest intake of both had the lowest %TF, %AF, %GF, %BF and highest %LM among the groups in both sexes.Our findings indicate that high dietary choline and betaine intakes are significantly associated with favorable body

  20. Insights into molecular plasticity of choline binding proteins (pneumococcal surface proteins) by SAXS.

    Science.gov (United States)

    Buey, Rubén M; Monterroso, Begoña; Menéndez, Margarita; Diakun, Greg; Chacón, Pablo; Hermoso, Juan Antonio; Díaz, J Fernando

    2007-01-12

    Phosphocholine moieties decorating the pneumococcal surface are used as a docking station for a family of modular proteins, the so-called choline binding proteins or CBPs. Choline recognition is essential for CBPs function and may also be a determinant for their quaternary structure. There is little knowledge about modular arrangement or oligomeric structures in this family. Therefore, we have used the small angle X-ray scattering (SAXS) technique combined with analytical ultracentrifugation in order to model the three-dimensional envelope of two highly different CBPs: the phage encoded Cpl-1 lysozyme and the pneumococcal phosphorylcholine esterase Pce. Both enzymes have an N-terminal catalytic module and a C-terminal choline-binding module (CBM) that attaches them to the bacterial surface and comprises six and ten sequence repeats in Cpl-1 and Pce, respectively. SAXS experiments have shown an inherent conformational plasticity in Cpl-1 that accounts for the different relative position of these regions in the solution and crystal structures. Dimerization of Cpl-1 upon choline binding has been also visualised for the first time, and monomer-monomer interactions take place through the first CBR where a non-canonical choline binding site has now been identified. This mode of association seems to be independent of the absence or presence of the Cpl-1 catalytic module and reveals that the arrangement of the monomers differs from that previously found in the isolated CBM dimer of pneumococcal LytA amidase. In contrast, Pce displays the same modular disposition in the solution and crystal structures, and remains almost invariant upon choline binding. The present results suggest that protein dimerization and duplication of CBRs may be alternative but not equivalent ways of improving cell wall recognition by CBPs, since they provide different interaction geometries for choline residues present in (lipo)teichoic acids.

  1. Decreased expression of fibroblast and keratinocyte growth factor isoforms and receptors during scarless repair.

    Science.gov (United States)

    Dang, Catherine M; Beanes, Steven R; Soo, Chia; Ting, Kang; Benhaim, Prosper; Hedrick, Marc H; Lorenz, H Peter

    2003-05-01

    Fibroblast growth factors (FGFs) are a family of 21 cytokines with a broad spectrum of activities, including regulation of cell proliferation, differentiation, and migration. The various FGFs bind to one or more of four different tyrosine kinase receptor types. FGFs 1, 2, 5, 7, and 10 are up-regulated during adult cutaneous wound healing. However, the expression of FGFs during fetal skin development and scarless wound healing has not been characterized. It was hypothesized that differential expression of FGF isoforms and receptors occurs during fetal skin development and that this differential expression pattern may regulate the transition from scarless repair to healing with scar formation. Excisional wounds (2 mm) were created on fetal rats at gestational days 16.5 (scarless) (one wound per fetus, n = 36 fetuses) and 19.5 (scarring) (one wound per fetus, n = 36 fetuses). Wounds were harvested at 24, 48, and 72 hours. Survival until wound harvest ranged from 66 to 75 percent for the gestational day 16 fetuses, and from 83 to 92 percent for the gestational day 19 fetuses. Nonwounded fetal skin from littermates (n = 12 fetuses per wound harvest time point) was used as the control. Wounds/skins were pooled by harvest time point, and RNA was isolated from pooled wounds/skins. Reduced-cycle, specific-primer reverse transcriptase-polymerase chain reaction was performed to determine the expression of FGF isoforms 2, 5, 7, 9, and 10 and FGF receptors 1, 2, and 4 in wounds relative to unwounded skin.In unwounded fetal skin, FGF isoform 5 expression more than doubled at birth. FGF 10 expression doubled during the transition period. FGF 7 expression increased more than sevenfold at birth. Expression of FGF isoforms 2 and 9 did not change during late fetal skin development. The expression of FGF receptors 1, 2, and 4 increased at birth. After wounding, expression of FGF isoforms 7 and 10 was down-regulated in scarless wounds, whereas FGF receptor 2 expression decreased in

  2. Experience-dependent regulation of TrkB isoforms in rodent visual cortex.

    Science.gov (United States)

    Bracken, Bethany K; Turrigiano, Gina G

    2009-04-01

    Within primary visual cortex (V1), brain-derived neurotrophic factor (BDNF) signaling through its high-affinity receptor TrkB is important for normal development and experience-dependent plasticity. TrkB is expressed in several alternatively spliced isoforms, including full-length TrkB (TrkB.FL), and several truncated isoforms (TrkB.T1, TrkB.T2, and TrkB.T4) that lack the intracellular tyrosine kinase domain. These isoforms are important components of BDNF signaling, yet little is known about the developmental or experience-dependent regulation of their expression. Using immunohistochemistry, we found TrkB.FL and TrkB.T1 expressed in interneurons and pyramidal neurons within V1, but not in cortical astrocytes. We used real-time PCR to quantify the changes in mRNA expression of BDNF, the four TrkB isoforms, and the low-affinity receptor P75NTR during normal development, and in response to visual deprivation at two different ages. BDNF expression increased between postnatal days 10 (P10) and P30, and was rapidly down-regulated by 3 days of visual deprivation during both the pre-critical period (P14-P17) and the critical period (P18-P21). Over the same developmental period, expression of each TrkB isoform was regulated independently; TrkB.T1 increased, TrkB.FL and TrkB.T2 decreased, and TrkB.T4 showed transient changes. Neither brief visual deprivation nor prolonged dark-rearing induced changes in either TrkB.FL or TrkB.T1 expression. However, TrkB.T4 expression was reduced by brief visual deprivation, whereas TrkB.T4, TrkB.T2 and P75(NTR) were up-regulated by prolonged dark-rearing into the critical period. Our data indicate that TrkB isoform expression can be selectively regulated by visual experience, and may contribute to experience-dependent cortical plasticity.

  3. Role of JNK isoforms in the development of neuropathic pain following sciatic nerve transection in the mouse

    Directory of Open Access Journals (Sweden)

    Manassero Giusi

    2012-05-01

    Full Text Available Abstract Background Current tools for analgesia are often only partially successful, thus investigations of new targets for pain therapy stimulate great interest. Consequent to peripheral nerve injury, c-Jun N-terminal kinase (JNK activity in cells of the dorsal root ganglia (DRGs and spinal cord is involved in triggering neuropathic pain. However, the relative contribution of distinct JNK isoforms is unclear. Using knockout mice for single isoforms, and blockade of JNK activity by a peptide inhibitor, we have used behavioral tests to analyze the contribution of JNK in the development of neuropathic pain after unilateral sciatic nerve transection. In addition, immunohistochemical labelling for the growth associated protein (GAP-43 and Calcitonin Gene Related Peptide (CGRP in DRGs was used to relate injury related compensatory growth to altered sensory function. Results Peripheral nerve injury produced pain–related behavior on the ipsilateral hindpaw, accompanied by an increase in the percentage of GAP43-immunoreactive (IR neurons and a decrease in the percentage of CGRP-IR neurons in the lumbar DRGs. The JNK inhibitor, D-JNKI-1, successfully modulated the effects of the sciatic nerve transection. The onset of neuropathic pain was not prevented by the deletion of a single JNK isoform, leading us to conclude that all JNK isoforms collectively contribute to maintain neuropathy. Autotomy behavior, typically induced by sciatic nerve axotomy, was absent in both the JNK1 and JNK3 knockout mice. Conclusions JNK signaling plays an important role in regulating pain threshold: the inhibition of all of the JNK isoforms prevents the onset of neuropathic pain, while the deletion of a single splice JNK isoform mitigates established sensory abnormalities. JNK inactivation also has an effect on axonal sprouting following peripheral nerve injury.

  4. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    Science.gov (United States)

    Eilers, Wouter; Gevers, Wouter; van Overbeek, Daniëlle; de Haan, Arnold; Jaspers, Richard T.; Hilbers, Peter A.; van Riel, Natal; Flück, Martin

    2014-01-01

    We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII) contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE) coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis) and slow-type muscle (soleus) for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02). In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII. PMID:25054156

  5. Muscle-Type Specific Autophosphorylation of CaMKII Isoforms after Paced Contractions

    Directory of Open Access Journals (Sweden)

    Wouter Eilers

    2014-01-01

    Full Text Available We explored to what extent isoforms of the regulator of excitation-contraction and excitation-transcription coupling, calcium/calmodulin protein kinase II (CaMKII contribute to the specificity of myocellular calcium sensing between muscle types and whether concentration transients in its autophosphorylation can be simulated. CaMKII autophosphorylation at Thr287 was assessed in three muscle compartments of the rat after slow or fast motor unit-type stimulation and was compared against a computational model (CaMuZclE coupling myocellular calcium dynamics with CaMKII Thr287 phosphorylation. Qualitative differences existed between fast- (gastrocnemius medialis and slow-type muscle (soleus for the expression pattern of CaMKII isoforms. Phospho-Thr287 content of δA CaMKII, associated with nuclear functions, demonstrated a transient and compartment-specific increase after excitation, which contrasted to the delayed autophosphorylation of the sarcoplasmic reticulum-associated βM CaMKII. In soleus muscle, excitation-induced δA CaMKII autophosphorylation demonstrated frequency dependence (P = 0.02. In the glycolytic compartment of gastrocnemius medialis, CaMKII autophosphorylation after excitation was blunted. In silico assessment emphasized the importance of mitochondrial calcium buffer capacity for excitation-induced CaMKII autophosphorylation but did not predict its isoform specificity. The findings expose that CaMKII autophosphorylation with paced contractions is regulated in an isoform and muscle type-specific fashion and highlight properties emerging for phenotype-specific regulation of CaMKII.

  6. Androgen receptor isoforms in human and rat prostate

    Institute of Scientific and Technical Information of China (English)

    Shu-JieXIA; Gang-YaoHAO; Xiao-DaTANG

    2000-01-01

    Aim: To investigate the androgen receptor (AR) isoforms and its variability of expression in human and rat prostatic tissues. Methods: Human benign prostatic hyperplasia (BPH) and prostatic cancer tissues were obtained from patients undergoing prostatectomy, and rat ventral prostate was incised 3 days after castration. Forty-one AR-positive BPH specimens, 3 prostatic cancer specimens, and 6 rat prostates were used. After processing at 4℃, the tissues were examined by means of high resolution isoelectric focusing (IEF) technique to determine their AR isoforms. Results:From the prostatic specimens, 3 types of AR isoforms were detected with pI values at 6.5, 6.0, and 5.3. In human BPH tissues, 15/41 (36.6%) specimens showed all the three types of isoforms, while 19/41 (46.3%) showed 2 isoforms at various combinations and 7/41(17.1%), 1 isoform. For the 3 prostatic cancer specimens, one showed 3 isoforms, one, 2 isoforms, and the other failed to show any isoform. All rat prostatic tissues showed 2 isoforms at different combinations. Binding of 3H-dihydrotestosterone (DHT) to the isoforms was inhibited by the addition of 100-fold excess of DHT or testosterone, but not progesterone, oestradiol or diethylstilboestrol. Conclusion: AR isoforms are different in different patients. Although their genesis is not clear, the therapeutic implication of the present observation appears to be interesting, that may help clarifying the individual differences in the response to hormonal therapy.(Asian J Androl 2000 Dec;2:307-310)

  7. Choline and betaine ameliorate liver lipid accumulation induced by vitamin B6 deficiency in rats.

    Science.gov (United States)

    Kitagawa, Erina; Yamamoto, Tatsuya; Fujishita, Mayuko; Ota, Yuki; Yamamoto, Kohei; Nakagawa, Tomoyuki; Hayakawa, Takashi

    2017-02-01

    We investigated the efficacy of supplementing the diet with choline or betaine in ameliorating lipid accumulation induced by vitamin B6 (B6) deficiency in rat liver. Male Wistar rats were fed a control, B6-deficient, choline-supplemented (2, 4, or 6 g choline bitartrate/kg diet) B6-deficient diet or betaine-supplemented (1, 2, or 4 g betaine anhydrous/kg diet) B6-deficient diet for 35 d; all diets contained 9 g L-methionine (Met)/kg diet. Choline or betaine supplementation attenuated liver lipid deposition and restored plasma lipid profiles to control levels. These treatments restored the disruptions in Met metabolism and the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio induced by B6 deficiency in liver microsomes. These results suggest that choline and betaine ameliorated liver lipid accumulation induced by B6 deficiency via recovery of Met metabolism and very low-density lipoprotein secretion by restoring the supply of PC derived from PE.

  8. Choline Ameliorates Disease Phenotypes in Human iPSC Models of Rett Syndrome.

    Science.gov (United States)

    Chin, Eunice W M; Marcy, Guillaume; Yoon, Su-In; Ma, Dongliang; Rosales, Francisco J; Augustine, George J; Goh, Eyleen L K

    2016-09-01

    Rett syndrome (RTT) is a postnatal neurodevelopmental disorder that primarily affects girls. Mutations in the methyl-CpG-binding protein 2 (MECP2) gene account for approximately 95 % of all RTT cases. To model RTT in vitro, we generated induced pluripotent stem cells (iPSCs) from fibroblasts of two RTT patients with different mutations (MECP2 (R306C) and MECP2 (1155Δ32)) in their MECP2 gene. We found that these iPSCs were capable of differentiating into functional neurons. Compared to control neurons, the RTT iPSC-derived cells had reduced soma size and a decreased amount of synaptic input, evident both as fewer Synapsin 1-positive puncta and a lower frequency of spontaneous excitatory postsynaptic currents. Supplementation of the culture media with choline rescued all of these defects. Choline supplementation may act through changes in the expression of choline acetyltransferase, an important enzyme in cholinergic signaling, and also through alterations in the lipid metabolite profiles of the RTT neurons. Our study elucidates the possible mechanistic pathways for the effect of choline on human RTT cell models, thereby illustrating the potential for using choline as a nutraceutical to treat RTT.

  9. Suppressed expression of choline monooxygenase in sugar beet on the accumulation of glycine betaine.

    Science.gov (United States)

    Yamada, Nana; Takahashi, Hiroyuki; Kitou, Kunihide; Sahashi, Kosuke; Tamagake, Hideto; Tanaka, Yoshito; Takabe, Teruhiro

    2015-11-01

    Glycine betaine (GB) is an important osmoprotectant and synthesized by two-step oxidation of choline. Choline monooxygenase (CMO) catalyzes the first step of the pathway and is believed to be a rate limiting step for GB synthesis. Recent studies have shown the importance of choline-precursor supply for GB synthesis. In order to investigate the role of CMO for GB accumulation in sugar beet (Beta vulgaris), transgenic plants carrying the antisense BvCMO gene were developed. The antisense BvCMO plants showed the decreased activity of GB synthesis from choline compared to wild-type (WT) plants which is well related to the suppressed level of BvCMO protein. However, GB contents were similar between transgenic and WT plants with the exception of young leaves and storage roots. Transgenic plants showed enhanced susceptibility to salt stress than WT plants. These results suggest the importance of choline-precursor-supply for GB accumulation, and young leaves and storage root are sensitive sites for GB accumulation.

  10. Amperometric Choline Biosensor Fabricated through Electrostatic Assembly of Bienzyme/Polyelectrolyte Hybrid Layers on Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun; Liu, Guodong; Lin, Yuehe

    2006-03-01

    We report a flow injection amperometric choline biosensors based on the electrostatic assembly of an enzyme of choline oxidase (ChO) and a bi-enzyme of ChO and horseradish peroxidase (HRP) onto multi-wall carbon nanotubes (MWCNT) modified glassy carbon (GC) electrodes. These choline biosensors were fabricated by immobilization of enzymes on the negatively charged MWCNT surface through alternatively assembling a cationic polydiallydiimethylammonium chloride (PDDA) layer and an enzyme layer. Using this layer-by-layer assembling approach, bioactive nanocomposite film of a PDDA/ChO/PDDA/HRP/PDDA/CNT (ChO/HRP/CNT) and a PDDA/ChO/PDDA/ CNT (ChO/ CNT) were fabricated on GC surface, respectively. Owning to the electrocatalytic effect of carbon nanotubes, the measurement of faradic responses resulting from enzymatic reactions has been realized at low potential with acceptable sensitivity. It is found the ChO/HRP/CNT biosensor is more sensitive than the ChO/CNT one. Experimental parameters affecting the sensitivity of biosensors, e.g. applied potential, flow rate, etc. were optimized and potential interference was examined. The response time for this choline biosensor is fast (less than a few seconds). The linear range of detection for the choline biosensor is from 5 x 10-5 to 5 x 10-3 M and the detection limit is determined to be about 1.0 x 10-5 M.

  11. C-11 Choline and FDG PET/CT Imaging of Primary Cholangiocarcinoma – a Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Chanisa Chotipanich

    2015-01-01

    Full Text Available Objective(s: This study aimed to compare the diagnostic values of 11C-choline and 18F-fluorodeoxyglucose (18F-FDG positron emission tomography/computed tomography (PET/CT in patients with cholangiocarcinoma (CCA. Methods: This prospective study was conducted on 10 patients (6 males and 4 females, aged 42-69 years, suspected of having CCA based on CT or magnetic resonance imaging (MRI results. 11C-choline and 18F-FDG PET/CT studies were performed in all patients over 1 week. PET/CT results were visually analyzed by 2 independent nuclear medicine physicians and quantitatively by calculating the tumor-to-background ratio (T/B. Results: No 11C-choline PET/CT uptake was observed in primary extrahepatic or intrahepatic CCA cases. Intense 18F-FDG avidity was detected in the tumors of 8 patients (%80. Two patients, who were 18F-FDG negative, had primary extrahepatic CCA. Ki-67 measurements were positive in all patients (range; 14.2%-39.9%. The average T/B values of 11C-choline and 18F-FDG were 0.4±0.2 and 2.0±1.0 in all cases of primary CCA, respectively; these values were significantly lower for 11C-choline (P

  12. Nociceptor beta II, delta, and epsilon isoforms of PKC differentially mediate paclitaxel-induced spontaneous and evoked pain.

    Science.gov (United States)

    He, Ying; Wang, Zaijie Jim

    2015-03-18

    As one of the most effective and frequently used chemotherapeutic agents, paclitaxel produces peripheral neuropathy (paclitaxel-induced peripheral neuropathy or PIPN) that negatively affects chemotherapy and persists after cancer therapy. The mechanisms underlying this dose-limiting side effect remain to be fully elucidated. This study aimed to investigate the role of nociceptor protein kinase C (PKC) isoforms in PIPN. Employing multiple complementary approaches, we have identified a subset of PKC isoforms, namely βII, δ, and ϵ, were activated by paclitaxel in the isolated primary afferent sensory neurons. Persistent activation of PKCβII, PKCδ, and PKCϵ was also observed in the dorsal root ganglion neurons after chronic treatment with paclitaxel in a mouse model of PIPN. Isoform-selective inhibitors of PKCβII, PKCδ, and PKCϵ given intrathecally dose-dependently attenuated paclitaxel-induced mechanical allodynia and heat hyperalgesia. Surprisingly, spinal inhibition of PKCβII and PKCδ, but not PKCϵ, blocked the spontaneous pain induced by paclitaxel. These data suggest that a subset of nociceptor PKC isoforms differentially contribute to spontaneous and evoked pain in PIPN, although it is not clear whether PKCϵ in other regions regulates spontaneous pain in PIPN. The findings can potentially offer new selective targets for pharmacological intervention of PIPN.

  13. Involvement of yeast HSP90 isoforms in response to stress and cell death induced by acetic acid.

    Science.gov (United States)

    Silva, Alexandra; Sampaio-Marques, Belém; Fernandes, Angela; Carreto, Laura; Rodrigues, Fernando; Holcik, Martin; Santos, Manuel A S; Ludovico, Paula

    2013-01-01

    Acetic acid-induced apoptosis in yeast is accompanied by an impairment of the general protein synthesis machinery, yet paradoxically also by the up-regulation of the two isoforms of the heat shock protein 90 (HSP90) chaperone family, Hsc82p and Hsp82p. Herein, we show that impairment of cap-dependent translation initiation induced by acetic acid is caused by the phosphorylation and inactivation of eIF2α by Gcn2p kinase. A microarray analysis of polysome-associated mRNAs engaged in translation in acetic acid challenged cells further revealed that HSP90 mRNAs are over-represented in this polysome fraction suggesting preferential translation of HSP90 upon acetic acid treatment. The relevance of HSP90 isoform translation during programmed cell death (PCD) was unveiled using genetic and pharmacological abrogation of HSP90, which suggests opposing roles for HSP90 isoforms in cell survival and death. Hsc82p appears to promote survival and its deletion leads to necrotic cell death, while Hsp82p is a pro-death molecule involved in acetic acid-induced apoptosis. Therefore, HSP90 isoforms have distinct roles in the control of cell fate during PCD and their selective translation regulates cellular response to acetic acid stress.

  14. 14-3-3 proteins interact with specific MEK kinases.

    Science.gov (United States)

    Fanger, G R; Widmann, C; Porter, A C; Sather, S; Johnson, G L; Vaillancourt, R R

    1998-02-06

    MEK (mitogen-activated protein kinase/extracellular signal-regulated kinase kinase) kinases (MEKKs) regulate c-Jun N-terminal kinase and extracellular response kinase pathways. The 14-3-3zeta and 14-3-3epsilon isoforms were isolated in a two-hybrid screen for proteins interacting with the N-terminal regulatory domain of MEKK3. 14-3-3 proteins bound both the N-terminal regulatory and C-terminal kinase domains of MEKK3. The binding affinity of 14-3-3 for the MEKK3 N terminus was 90 nM, demonstrating a high affinity interaction. 14-3-3 proteins also interacted with MEKK1 and MEKK2, but not MEKK4. Endogenous 14-3-3 protein and MEKK1 and MEKK2 were similarly distributed in the cell, consistent with their in vitro interactions. MEKK1 and 14-3-3 proteins colocalized using two-color digital confocal immunofluorescence. Binding of 14-3-3 proteins mapped to the N-terminal 393 residues of 196-kDa MEKK1. Unlike MEKK2 and MEKK3, the C-terminal kinase domain of MEKK1 demonstrated little or no ability to interact with 14-3-3 proteins. MEKK1, but not MEKK2, -3 or -4, is a caspase-3 substrate that when cleaved releases the kinase domain from the N-terminal regulatory domain. Functionally, caspase-3 cleavage of MEKK1 releases the kinase domain from the N-terminal 14-3-3-binding region, demonstrating that caspases can selectively alter protein kinase interactions with regulatory proteins. With regard to MEKK1, -2 and -3, 14-3-3 proteins do not appear to directly influence activity, but rather function as "scaffolds" for protein-protein interactions.

  15. Fibronectin matrix assembly requires distinct contributions from Rho kinases I and -II

    DEFF Research Database (Denmark)

    Yoneda, Atsuko; Ushakov, Dmitriy; Multhaupt, Hinke A B;

    2006-01-01

    Extracellular matrix is integral to tissue architecture and regulates many aspects of cell behavior. Fibronectin matrix assembly involves the actin cytoskeleton and the small GTPase RhoA, but downstream signaling is not understood. Here, down-regulation of either rho kinase isoform (ROCK I or -II...

  16. Glycogen synthase kinase 3α regulates urine concentrating mechanism in mice

    DEFF Research Database (Denmark)

    Nørregaard, Rikke; Tao, Shixin; Nilsson, Line;

    2015-01-01

    In mammals, glycogen synthase kinase (GSK)3 comprises GSK3α and GSK3β isoforms. GSK3β has been shown to play a role in the ability of kidneys to concentrate urine by regulating vasopressin-mediated water permeability of collecting ducts, whereas the role of GSK3α has yet to be discerned. To inves...

  17. Unexpected Discovery of Dichloroacetate Derived Adenosine Triphosphate Competitors Targeting Pyruvate Dehydrogenase Kinase To Inhibit Cancer Proliferation.

    Science.gov (United States)

    Zhang, Shao-Lin; Hu, Xiaohui; Zhang, Wen; Tam, Kin Yip

    2016-04-14

    Pyruvate dehydrogenase kinases (PDKs) have recently emerged as an attractive target for cancer therapy. Herein, we prepared a series of compounds derived from dichloroacetate (DCA) which inhibited cancer cells proliferation. For the first time, we have successfully developed DCA derived inhibitors that preferentially bind to the adenosine triphosphate (ATP) pocket of PDK isoform 1 (PDK1).

  18. Serine is a natural ligand and allosteric activator of pyruvate kinase M2

    NARCIS (Netherlands)

    Chaneton, Barbara; Hillmann, Petra; Zheng, Liang; Martin, Agnes C. L.; Maddocks, Oliver D. K.; Chokkathukalam, Achuthanunni; Coyle, Joseph E.; Jankevics, Andris; Holding, Finn P.; Vousden, Karen H.; Frezza, Christian; O'Reilly, Marc; Gottlieb, Eyal

    2012-01-01

    Cancer cells exhibit several unique metabolic phenotypes that are critical for cell growth and proliferation(1). Specifically, they overexpress the M2 isoform of the tightly regulated enzyme pyruvate kinase (PKM2), which controls glycolytic flux, and are highly dependent on de novo biosynthesis of s

  19. A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

    Directory of Open Access Journals (Sweden)

    Hosanagara N. Harishkumar

    2011-01-01

    Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

  20. Bacterial use of choline to tolerate salinity shifts in sea-ice brines

    DEFF Research Database (Denmark)

    Firth, E.; Carpenter, S. D.; Sørensen, H. L.

    2016-01-01

    Bacteria within the brine network of sea ice experience temperature-driven fluctuations in salinity on both short and long temporal scales, yet their means of osmoprotection against such fluctuations is poorly understood. One mechanism used to withstand the ion fluxes caused by salinity shifts...... brines drained from sea ice in Kanajorsuit Bay (2013) and Kobbefjord (2014), Greenland, we measured the utilization of 14C-choline (precursor to glycine betaine, a common compatible solute) at -1°C upon salinity shifts to double and to half the starting salinity. In all cases and across a range...... of starting salinities, when salinity was increased, 14C-solute (choline or derivatives) was preferentially retained as an intracellular osmolyte; when salinity was decreased, 14C-choline was preferentially respired to 14CO2. Additional experiments with cold-adapted bacteria in culture indicated...

  1. In vivo uptake of [C-11]choline does not correlate with cell proliferation in human prostate cancer

    NARCIS (Netherlands)

    Pruim, J; Jongen, MM; Suurmeijer, AJ; Vaalburg, W; Nijman, RJ; de Jong, IJ; Breeuwsma, J.

    2005-01-01

    Purpose: Prostate cancer is the second leading cause of death from cancer among US men. Positron emission tomography (PET) with [C-11] choline has been shown to be useful in the staging and detection of prostate cancer. The background of the increased uptake of choline in human prostate cancer is no

  2. Pachastrissamine (jaspine B) and its stereoisomers inhibit sphingosine kinases and atypical protein kinase C.

    Science.gov (United States)

    Yoshimitsu, Yuji; Oishi, Shinya; Miyagaki, Jun; Inuki, Shinsuke; Ohno, Hiroaki; Fujii, Nobutaka

    2011-09-15

    Sphingosine kinases (SphKs) are oncogenic enzymes that regulate the critical balance between ceramide and sphingosine-1-phosphate. Much effort has been dedicated to develop inhibitors against these enzymes. Naturally occurring pachastrissamine (jaspine B) and all its stereoisomers were prepared and evaluated for their inhibitory effects against SphKs. All eight stereoisomers exhibited moderate to potent inhibitory activity against SphK1 and SphK2. Inhibitory effects were profiled against protein kinase C (PKC) isoforms by in vitro experiments. Atypical PKCs (PKCζ and PKCι) were inhibited by several pachastrissamine stereoisomers. The improved activity over N,N-dimethylsphingosine suggests that the cyclic scaffold in pachastrissamines facilitates potential favorable interactions with SphKs and PKCs.

  3. Osmoprotectants in Halomonas elongata: High-affinity betaine transport system and choline-betaine pathway

    OpenAIRE

    Nieto Gutiérrez, Joaquín José; Cánovas, David; Vargas, C; Ventosa Ucero, Antonio; Csonka, Laszlo N.

    1996-01-01

    The osmoregulatory pathways of the moderately halophilic bacterium Halomonas elongata DSM 3043 have been investigated. This strain grew optimally at 1.5 to 2 M NaCl in M63 glucose-defined medium. It required at least 0.5 M NaCl for growth, which is a higher concentration than that exhibited by the H. elongata type strain ATCC 33173. Externally provided betaine, choline, or choline-O-sulfate (but not proline, ectoine, or proline betaine) enhanced the growth of H. elongata on 3 M NaCl-glucose-M...

  4. How polar are choline chloride-based deep eutectic solvents?

    Science.gov (United States)

    Pandey, Ashish; Rai, Rewa; Pal, Mahi; Pandey, Siddharth

    2014-01-28

    Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1 : 2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in

  5. The identification of acetylcholine and choline in oat seedlings by gas chromatography and nuclear magnetic resonance (NMR

    Directory of Open Access Journals (Sweden)

    Andrzej Tretyn

    2014-02-01

    Full Text Available Four methods of isolation and purification of choline esters from green 7-day-old oat ( Avena sativa L. cv. Diadem seedlings were tested The results showed that the best recovery of acetylcholine and choline from plant tissues was obtained using an extraction solution composed of 15% 1N formic acid and 85%, acetone followed by precipitation of both these substances with ammonium reineckate. The presence of acetylcholine and choline in the plant extracts was confirmed by nuclear magnetic resonance (NMR and gas chromatography. In the case of gas chromatography, after isolation and purification of the studied compounds from the plant material, estrification of choline followed by N-demethylation of acetylcholine and estrified choline were performed The demethylation reaction was conducted in a reaction mixture of 50 mM sodium thiophenolate and 25 mM thiophenol in anhydrous acetone. After its completion, the mixture was removed with pentanone and the demethylated esters were extracted into chloroform.

  6. Isoforms of murine and human serum amyloid P component

    DEFF Research Database (Denmark)

    Nybo, Mads; Hackler, R; Kold, B;

    1998-01-01

    Isoelectric focusing (IEF) and immunofixation of murine serum amyloid P component (SAP), purified and in serum, showed a distinct and strain-dependent isoform pattern with up to seven bands (pI 5.1-5.7). Neuraminidase treatment caused a shift of the isoforms to more basic pI values, but did not a...... treatment caused a shift of the isoforms, but no reduction in isoform number. Two-dimensional gel electrophoresis confirmed the existence of multiple isoforms of human SAP monomers.......Isoelectric focusing (IEF) and immunofixation of murine serum amyloid P component (SAP), purified and in serum, showed a distinct and strain-dependent isoform pattern with up to seven bands (pI 5.1-5.7). Neuraminidase treatment caused a shift of the isoforms to more basic pI values, but did...... not affect their number. When the acute-phase response was analysed in three mouse strains, CBA/J and C3H/HeN initially showed seven SAP isoforms in serum and C57BL/6 J three or four. The responses in all three strains peaked at day 2 and were normalized within 14 days. On days 2 and 4, CBA/J and C3H...

  7. Isoforms of Melanopsin Mediate Different Behavioral Responses to Light

    Science.gov (United States)

    Jagannath, Aarti; Hughes, Steven; Abdelgany, Amr; Pothecary, Carina A.; Di Pretoro, Simona; Pires, Susana S.; Vachtsevanos, Athanasios; Pilorz, Violetta; Brown, Laurence A.; Hossbach, Markus; MacLaren, Robert E.; Halford, Stephanie; Gatti, Silvia; Hankins, Mark W.; Wood, Matthew J.A.; Foster, Russell G.; Peirson, Stuart N.

    2015-01-01

    Summary Melanopsin (OPN4) is a retinal photopigment that mediates a wide range of non-image-forming (NIF) responses to light [1, 2] including circadian entrainment [3], sleep induction [4], the pupillary light response (PLR) [5], and negative masking of locomotor behavior (the acute suppression of activity in response to light) [6]. How these diverse NIF responses can all be mediated by a single photopigment has remained a mystery. We reasoned that the alternative splicing of melanopsin could provide the basis for functionally distinct photopigments arising from a single gene. The murine melanopsin gene is indeed alternatively spliced, producing two distinct isoforms, a short (OPN4S) and a long (OPN4L) isoform, which differ only in their C terminus tails [7]. Significantly, both isoforms form fully functional photopigments [7]. Here, we show that different isoforms of OPN4 mediate different behavioral responses to light. By using RNAi-mediated silencing of each isoform in vivo, we demonstrated that the short isoform (OPN4S) mediates light-induced pupillary constriction, the long isoform (OPN4L) regulates negative masking, and both isoforms contribute to phase-shifting circadian rhythms of locomotor behavior and light-mediated sleep induction. These findings demonstrate that splice variants of a single receptor gene can regulate strikingly different behaviors. PMID:26320947

  8. Nuclear fibroblast growth factor 2 (FGF2) isoforms inhibit bone marrow stromal cell mineralization through FGF23/FGFR/MAPK in vitro.

    Science.gov (United States)

    Xiao, Liping; Esliger, Alycia; Hurley, Marja M

    2013-01-01

    Fibroblast growth factor 23 (FGF23) is responsible for phosphate wasting and the phenotypic changes observed in human diseases such as X-linked hypophosphatemia (XLH). Targeted overexpression of nuclear high-molecular weight fibroblast growth factor 2 isoforms (HMW isoforms) in osteoblasts resulted in a transgenic mouse with phenotypic changes similar to XLH, including increased FGF23, hypophosphatemia, and rickets/osteomalacia. The goal of this study was to assess whether HMW isoforms also reduced mineralized bone formation via phosphate-independent effects in bone marrow stromal cells (BMSCs) by modulating FGF23/FGF receptor (FGFR)/extracellular signal-regulated kinase (ERK) signaling. To determine if decreased bone formation in BMSC cultures from HMW transgenic mice could be rescued by blocking this pathway, an FGF23 neutralizing antibody, the FGFR tyrosine kinase inhibitor SU5402 and the mitogen-activated protein kinase (MAPK) inhibitor PD98059 were used. FGF23 levels in the conditioned medium of HMW BMSC cultures were dramatically increased compared to BMSC from control (Vector) mice. Mineralized nodule formation was significantly decreased in HMW BMSC cultures compared with control cultures. The decreased nodule formation in HMW cultures was partially rescued by the FGF23 neutralizing antibody, SU5402 and PD98059. mRNA levels for the osteoblast-related genes, osteocalcin, Runt-related transcription factor 2 (Runx2), and osterix, and the osteocyte-related gene dentin matrix acidic phosphoprotein 1 (Dmp1) were significantly decreased in HMW cultures compared with control cultures, and the decreases were partially rescued by SU5402 or PD98059 treatment. Matrix-gla-protein (Mgp) mRNA was significantly higher in HMW cultures compared with control cultures, reduced by SU5402, but further increased by PD98059. Our results suggest that phosphate-independent effects of HMW isoforms in vitro may be directly mediated in part via FGF23 and that HMW isoforms signal via

  9. The germinal center kinase GCK-1 is a negative regulator of MAP kinase activation and apoptosis in the C. elegans germline.

    Directory of Open Access Journals (Sweden)

    Katherine R Schouest

    Full Text Available The germinal center kinases (GCK constitute a large, highly conserved family of proteins that has been implicated in a wide variety of cellular processes including cell growth and proliferation, polarity, migration, and stress responses. Although diverse, these functions have been attributed to an evolutionarily conserved role for GCKs in the activation of ERK, JNK, and p38 MAP kinase pathways. In addition, multiple GCKs from different species promote apoptotic cell death. In contrast to these paradigms, we found that a C. elegans GCK, GCK-1, functions to inhibit MAP kinase activation and apoptosis in the C. elegans germline. In the absence of GCK-1, a specific MAP kinase isoform is ectopically activated and oocytes undergo abnormal development. Moreover, GCK-1- deficient animals display a significant increase in germ cell death. Our results suggest that individual germinal center kinases act in mechanistically distinct ways and that these functions are likely to depend on organ- and developmental-specific contexts.

  10. Multiple host kinases contribute to Akt activation during Salmonella infection.

    Science.gov (United States)

    Roppenser, Bernhard; Kwon, Hyunwoo; Canadien, Veronica; Xu, Risheng; Devreotes, Peter N; Grinstein, Sergio; Brumell, John H

    2013-01-01

    SopB is a type 3 secreted effector with phosphatase activity that Salmonella employs to manipulate host cellular processes, allowing the bacteria to establish their intracellular niche. One important function of SopB is activation of the pro-survival kinase Akt/protein kinase B in the infected host cell. Here, we examine the mechanism of Akt activation by SopB during Salmonella infection. We show that SopB-mediated Akt activation is only partially sensitive to PI3-kinase inhibitors LY294002 and wortmannin in HeLa cells, suggesting that Class I PI3-kinases play only a minor role in this process. However, depletion of PI(3,4) P2/PI(3-5) P3 by expression of the phosphoinositide 3-phosphatase PTEN inhibits Akt activation during Salmonella invasion. Therefore, production of PI(3,4) P2/PI(3-5) P3 appears to be a necessary event for Akt activation by SopB and suggests that non-canonical kinases mediate production of these phosphoinositides during Salmonella infection. We report that Class II PI3-kinase beta isoform, IPMK and other kinases identified from a kinase screen all contribute to Akt activation during Salmonella infection. In addition, the kinases required for SopB-mediated activation of Akt vary depending on the type of infected host cell. Together, our data suggest that Salmonella has evolved to use a single effector, SopB, to manipulate a remarkably large repertoire of host kinases to activate Akt for the purpose of optimizing bacterial replication in its host.

  11. Multiple host kinases contribute to Akt activation during Salmonella infection.

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    Bernhard Roppenser

    Full Text Available SopB is a type 3 secreted effector with phosphatase activity that Salmonella employs to manipulate host cellular processes, allowing the bacteria to establish their intracellular niche. One important function of SopB is activation of the pro-survival kinase Akt/protein kinase B in the infected host cell. Here, we examine the mechanism of Akt activation by SopB during Salmonella infection. We show that SopB-mediated Akt activation is only partially sensitive to PI3-kinase inhibitors LY294002 and wortmannin in HeLa cells, suggesting that Class I PI3-kinases play only a minor role in this process. However, depletion of PI(3,4 P2/PI(3-5 P3 by expression of the phosphoinositide 3-phosphatase PTEN inhibits Akt activation during Salmonella invasion. Therefore, production of PI(3,4 P2/PI(3-5 P3 appears to be a necessary event for Akt activation by SopB and suggests that non-canonical kinases mediate production of these phosphoinositides during Salmonella infection. We report that Class II PI3-kinase beta isoform, IPMK and other kinases identified from a kinase screen all contribute to Akt activation during Salmonella infection. In addition, the kinases required for SopB-mediated activation of Akt vary depending on the type of infected host cell. Together, our data suggest that Salmonella has evolved to use a single effector, SopB, to manipulate a remarkably large repertoire of host kinases to activate Akt for the purpose of optimizing bacterial replication in its host.

  12. Isoform-Specific Biased Agonism of Histamine H3 Receptor Agonists.

    Science.gov (United States)

    Riddy, Darren M; Cook, Anna E; Diepenhorst, Natalie A; Bosnyak, Sanja; Brady, Ryan; Mannoury la Cour, Clotilde; Mocaer, Elisabeth; Summers, Roger J; Charman, William N; Sexton, Patrick M; Christopoulos, Arthur; Langmead, Christopher J

    2017-02-01

    The human histamine H3 receptor (hH3R) is subject to extensive gene splicing that gives rise to a large number of functional and nonfunctional isoforms. Despite the general acceptance that G protein-coupled receptors can adopt different ligand-induced conformations that give rise to biased signaling, this has not been studied for the H3R; further, it is unknown whether splice variants of the same receptor engender the same or differential biased signaling. Herein, we profiled the pharmacology of histamine receptor agonists at the two most abundant hH3R splice variants (hH3R445 and hH3R365) across seven signaling endpoints. Both isoforms engender biased signaling, notably for 4-[3-(benzyloxy)propyl]-1H-imidazole (proxyfan) [e.g., strong bias toward phosphorylation of glycogen synthase kinase 3β (GSK3β) via the full-length receptor] and its congener 3-(1H-imidazol-4-yl)propyl-(4-iodophenyl)-methyl ether (iodoproxyfan), which are strongly consistent with the former's designation as a "protean" agonist. The 80 amino acid IL3 deleted isoform hH3R365 is more permissive in its signaling than hH3R445: 2-(1H-imidazol-5-yl)ethyl imidothiocarbamate (imetit), proxyfan, and iodoproxyfan were all markedly biased away from calcium signaling, and principal component analysis of the full data set revealed divergent profiles for all five agonists. However, most interesting was the identification of differential biased signaling between the two isoforms. Strikingly, hH3R365 was completely unable to stimulate GSK3β phosphorylation, an endpoint robustly activated by the full-length receptor. To the best of our knowledge, this is the first quantitative example of differential biased signaling via isoforms of the same G protein-coupled receptor that are simultaneously expressed in vivo and gives rise to the possibility of selective pharmacological targeting of individual receptor splice variants.

  13. Localization and functional characterization of the human NKCC2 isoforms

    DEFF Research Database (Denmark)

    Carota, I; Theilig, F; Oppermann, M;

    2010-01-01

    AIM: Salt reabsorption across the apical membrane of cells in the thick ascending limb (TAL) of Henle is primarily mediated by the bumetanide-sensitive Na(+)/K(+)/2Cl(-) cotransporter NKCC2. Three full-length splice variants of NKCC2 (NKCC2B, NKCC2A and NKCC2F) have been described. The NKCC2...... isoforms have specific localizations and transport characteristics, as assessed for rabbit, rat and mouse. In the present study, we aimed to address the localization and transport characteristics of the human NKCC2 isoforms. METHODS: RT-PCR, in situ hybridization and uptake studies in Xenopus oocytes were...... performed to characterize human NKCC2 isoforms. RESULTS: All three classical NKCC2 isoforms were detected in the human kidney; in addition, we found splice variants with tandem duplicates of the variable exon 4. Contrary to rodents, in which NKCC2F is the most abundant NKCC2 isoform, NKCC2A was the dominant...

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

    Science.gov (United States)

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

    2010-06-01

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

  15. A kinase-anchoring proteins and adenylyl cyclase in cardiovascular physiology and pathology.

    Science.gov (United States)

    Efendiev, Riad; Dessauer, Carmen W

    2011-10-01

    3'-5'-Cyclic adenosine monophosphate (cAMP), generated by adenylyl cyclase (AC), serves as a second messenger in signaling pathways regulating many aspects of cardiac physiology, including contraction rate and action potential duration, and in the pathophysiology of hypertrophy and heart failure. A kinase-anchoring proteins localize the effect of cAMP in space and time by organizing receptors, AC, protein kinase A, and other components of the cAMP cascade into multiprotein complexes. In this review, we discuss how the interaction of A kinase-anchoring proteins with distinct AC isoforms affects cardiovascular physiology.

  16. Method of empirical dependences in estimation and prediction of activity of creatine kinase isoenzymes in cerebral ischemia

    Science.gov (United States)

    Sergeeva, Tatiana F.; Moshkova, Albina N.; Erlykina, Elena I.; Khvatova, Elena M.

    2016-04-01

    Creatine kinase is a key enzyme of energy metabolism in the brain. There are known cytoplasmic and mitochondrial creatine kinase isoenzymes. Mitochondrial creatine kinase exists as a mixture of two oligomeric forms - dimer and octamer. The aim of investigation was to study catalytic properties of cytoplasmic and mitochondrial creatine kinase and using of the method of empirical dependences for the possible prediction of the activity of these enzymes in cerebral ischemia. Ischemia was revealed to be accompanied with the changes of the activity of creatine kinase isoenzymes and oligomeric state of mitochondrial isoform. There were made the models of multiple regression that permit to study the activity of creatine kinase system in cerebral ischemia using a calculating method. Therefore, the mathematical method of empirical dependences can be applied for estimation and prediction of the functional state of the brain by the activity of creatine kinase isoenzymes in cerebral ischemia.

  17. Engineering of insulin receptor isoform-selective insulin analogues.

    Directory of Open Access Journals (Sweden)

    Tine Glendorf

    Full Text Available BACKGROUND: The insulin receptor (IR exists in two isoforms, A and B, and the isoform expression pattern is tissue-specific. The C-terminus of the insulin B chain is important for receptor binding and has been shown to contact the IR just adjacent to the region where the A and B isoforms differ. The aim of this study was to investigate the importance of the C-terminus of the B chain in IR isoform binding in order to explore the possibility of engineering tissue-specific/liver-specific insulin analogues. METHODOLOGY/PRINCIPAL FINDINGS: Insulin analogue libraries were constructed by total amino acid scanning mutagenesis. The relative binding affinities for the A and B isoform of the IR were determined by competition assays using scintillation proximity assay technology. Structural information was obtained by X-ray crystallography. Introduction of B25A or B25N mutations resulted in analogues with a 2-fold preference for the B compared to the A isoform, whereas the opposite was observed with a B25Y substitution. An acidic amino acid residue at position B27 caused an additional 2-fold selective increase in affinity for the receptor B isoform for analogues bearing a B25N mutation. Furthermore, the combination of B25H with either B27D or B27E also resulted in B isoform-preferential analogues (2-fold preference even though the corresponding single mutation analogues displayed no differences in relative isoform binding affinity. CONCLUSIONS/SIGNIFICANCE: We have discovered a new class of IR isoform-selective insulin analogues with 2-4-fold differences in relative binding affinities for either the A or the B isoform of the IR compared to human insulin. Our results demonstrate that a mutation at position B25 alone or in combination with a mutation at position B27 in the insulin molecule confers IR isoform selectivity. Isoform-preferential analogues may provide new opportunities for developing insulin analogues with improved clinical benefits.

  18. The 44 kDa Pim-1 kinase directly interacts with tyrosine kinase Etk/BMX and protects human prostate cancer cells from apoptosis induced by chemotherapeutic drugs.

    Science.gov (United States)

    Xie, Y; Xu, K; Dai, B; Guo, Z; Jiang, T; Chen, H; Qiu, Y

    2006-01-05

    Protein kinase Pim-1 has been implicated in the development of hematopoietic and prostatic malignancies. Here, we present the evidence that two isoforms, the 44 and 33 kDa Pim-1, are expressed in all human prostate cancer cell lines examined. The subcellular localization of human 44 kDa Pim-1 is primarily on the plasma membrane, while the 33 kDa isoform is present in both the cytosol and nucleus in PCA cells. The 44 kDa Pim-1 contains the proline-rich motif at the N-terminus and directly binds to the SH3 domain of tyrosine kinase Etk. Such interaction leads to the activation of Etk kinase activity possibly by competing with the tumor suppressor p53. This is corroborated by the fact that overexpression of the 44 kDa Pim-1 in prostate cancer cells confers the resistance to chemotherapeutic drugs. Our results suggest that these two isoforms of Pim-1 kinase may regulate distinct substrates and the 44 kDa Pim-1 may play a more prominent role in drug resistance in prostate cancer cells.

  19. Inhibitors of p21-activated kinases (PAKs).

    Science.gov (United States)

    Rudolph, Joachim; Crawford, James J; Hoeflich, Klaus P; Wang, Weiru

    2015-01-08

    The p21-activated kinase (PAK) family of serine/threonine protein kinases plays important roles in cytoskeletal organization, cellular morphogenesis, and survival, and members of this family have been implicated in many diseases including cancer, infectious diseases, and neurological disorders. Owing to their large and flexible ATP binding cleft, PAKs, particularly group I PAKs (PAK1, -2, and -3), are difficult to drug; hence, few PAK inhibitors with satisfactory kinase selectivity and druglike properties have been reported to date. Examples are a recently discovered group II PAK (PAK4, -5, -6) selective inhibitor series based on a benzimidazole core, a group I PAK selective series based on a pyrido[2,3-d]pyrimidine-7-one core, and an allosteric dibenzodiazepine PAK1 inhibitor series. Only one compound, an aminopyrazole based pan-PAK inhibitor, entered clinical trials but did not progress beyond phase I trials. Clinical proof of concept for pan-group I, pan-group II, or PAK isoform selective inhibition has yet to be demonstrated.

  20. The unmediated choline sensor based on layered double hydroxides in hydrogen peroxide detection mode

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this work,we have developed a novel choline biosensor on the basis of immobilization of choline oxidase (ChOx) by the attractive materials layered double hydroxides (LDHs). Amperometric detection of choline was evaluated by holding the modified electrode at 0.5 V (vs. SCE). Due to the special properties of LDHs ([Zn3-Al-Cl]),such as chemical inertness,high porosity,and swelling property,the [Zn3-Al-Cl]/ChOx modified electrode exhibited an enhanced analytical performance. The biosensor provided a linear response to choline over a concentration range from 3.7 × 10-6 to 6.3 × 10-4 M with a low detection limit of 3 × 10-7 M based on S/N=3. The apparent Michaelis-Menten constant was calculated to be 1.38 mM. In addition,the interaction between ChOx and LDHs has also been investigated using FT-IR spectroscopy.

  1. Comparable stability of Hoogsteen and Watson-Crick base pairs in ionic liquid choline dihydrogen phosphate.

    Science.gov (United States)

    Tateishi-Karimata, Hisae; Nakano, Miki; Sugimoto, Naoki

    2014-01-08

    The instability of Hoogsteen base pairs relative to Watson-Crick base pairs has limited biological applications of triplex-forming oligonucleotides. Hydrated ionic liquids (ILs) provide favourable environments for a wide range of chemical reactions and are known to impact the stabilities of Watson-Crick base pairs. We found that DNA triplex formation was significantly stabilized in hydrated choline dihydrogen phosphate as compared with an aqueous buffer at neutral pH. Interestingly, the stability of Hoogsteen base pairs was found to be comparable with that of Watson-Crick base pairs in the hydrated IL. Molecular dynamics simulations of a DNA triplex in the presence of choline ions revealed that the DNA triplex was stabilized because of the binding of choline ion around the third strand in the grooves. Our finding will facilitate the development of new DNA materials. Our data also indicate that triplex formation may be stabilized inside cells where choline ions and their derivatives are abundant in vivo.

  2. Prospective study on dietary intakes of folate, betaine, and choline and cardiovascular disease risk in women

    NARCIS (Netherlands)

    Dalmeijer, G.W.; Olthof, M.R.; Verhoef, P.; Bots, M.L.; Schouw, van der Y.T.

    2008-01-01

    Objective: To investigate the association between dietary intakes of folate, betaine and choline and the risk of cardiovascular disease (CVD). Design: Prospective cohort study. Subjects: A total of 16 165 women aged 49¿70 years without prior CVD. Subjects were breast cancer screening participants in

  3. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  4. S-Propargyl-cysteine Exerts a Novel Protective Effect on Methionine and Choline Deficient Diet-Induced Fatty Liver via Akt/Nrf2/HO-1 Pathway

    Directory of Open Access Journals (Sweden)

    Wenwen Li

    2016-01-01

    Full Text Available This study investigated the antioxidative effect of S-propargyl-cysteine (SPRC on nonalcoholic fatty liver (NAFLD by treating mice fed a methionine and choline deficient (MCD diet with SPRC for four weeks. We found that SPRC significantly reduced hepatic reactive oxygen species (ROS and methane dicarboxylic aldehyde (MDA levels. Moreover, SPRC also increased the superoxide dismutase (SOD activity. By Western blot, we found that this protective effect of SPRC was importantly attributed to the regulated hepatic antioxidant-related proteins, including protein kinase B (Akt, heme oxygenase-1 (HO-1, nuclear factor erythroid 2-related factor 2 (Nrf2, and cystathionine γ-lyase (CSE, an enzyme that synthesizes hydrogen sulfide. Next, we examined the detailed molecular mechanism of the SPRC protective effect using oleic acid- (OA- induced HepG2 cells. The results showed that SPRC significantly decreased intracellular ROS and MDA levels in OA-induced HepG2 cells by upregulating the phosphorylation of Akt, the expression of HO-1 and CSE, and the translocation of Nrf2. SPRC-induced HO-1 expression and Nrf2 translocation were abolished by the phosphoinositide 3-kinase (PI3K inhibitor LY294002. Moreover, the antioxidative effect of SPRC was abolished by CSE inhibitor DL-propargylglycine (PAG and HO-1 siRNA. Therefore, these results proved that SPRC produced an antioxidative effect on NAFLD through the PI3K/Akt/Nrf2/HO-1 signaling pathway.

  5. Mechanisms for redox-regulation of protein kinase C

    Directory of Open Access Journals (Sweden)

    Susan F. Steinberg

    2015-06-01

    Full Text Available Protein kinase C (PKC is comprised of a family of signal-regulated enzymes that play pleiotropic roles in the control of many physiological and pathological responses. PKC isoforms are traditionally viewed as allosterically-activated enzymes that are recruited to membranes by growth factor receptor-generated lipid cofactors. An inherent assumption of this conventional model of PKC isoform activation is that PKCs act exclusively at membrane-delimited substrates and that PKC catalytic activity is an inherent property of each enzyme that is not altered by the activation process. This traditional model of PKC activation does not adequately explain the many well-documented actions of PKC enzymes in mitochondrial, nuclear, and cardiac sarcomeric (non-sarcolemmal subcellular compartments. Recent studies address this dilemma by identifying stimulus-specific differences in the mechanisms for PKC isoform activation during growth factor activation versus oxidative stress. This review discusses a number of noncanonical redox-triggered mechanisms that can alter the catalytic properties and subcellular compartmentation patterns of PKC enzymes. While some redox-activated mechanisms act at structural determinants that are common to all PKCs, the redox-dependent mechanism for PKCδ activation requires Src-dependent tyrosine phosphorylation of a unique phosphorylation motif on this enzyme and is isoform specific. Since oxidative stress contributes to pathogenesis of a wide range of clinical disorders, these stimulus specific differences in the controls and consequences of PKC activation have important implications for the design and evaluation of PKC-targeted therapeutics.

  6. Unlocking Doors without Keys: Activation of Src by Truncated C-terminal Intracellular Receptor Tyrosine Kinases Lacking Tyrosine Kinase Activity

    Directory of Open Access Journals (Sweden)

    Belén Mezquita

    2014-02-01

    Full Text Available One of the best examples of the renaissance of Src as an open door to cancer has been the demonstration that just five min of Src activation is sufficient for transformation and also for induction and maintenance of cancer stem cells [1]. Many tyrosine kinase receptors, through the binding of their ligands, become the keys that unlock the structure of Src and activate its oncogenic transduction pathways. Furthermore, intracellular isoforms of these receptors, devoid of any tyrosine kinase activity, still retain the ability to unlock Src. This has been shown with a truncated isoform of KIT (tr-KIT and a truncated isoform of VEGFR-1 (i21-VEGFR-1, which are intracellular and require no ligand binding, but are nonetheless able to activate Src and induce cell migration and invasion of cancer cells. Expression of the i21-VEGFR-1 is upregulated by the Notch signaling pathway and repressed by miR-200c and retinoic acid in breast cancer cells. Both Notch inhibitors and retinoic acid have been proposed as potential therapies for invasive breast cancer.

  7. Measurement of concentrations of whole blood levels of choline, betaine, and dimethylglycine and their relations to plasma levels.

    Science.gov (United States)

    Awwad, Hussain Mohamad; Kirsch, Susanne H; Geisel, Juergen; Obeid, Rima

    2014-04-15

    We aimed at developing a method for the measurement of choline and its metabolites in whole blood (WB). After an extraction step, quantification of choline, betaine, and dimethylglycine (DMG) was performed using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Plasma and WB metabolites were evaluated in a group of 61 elderly people. The calibration curves were linear (r(2)>0.997) for all compounds. The inter- and intra-assay coefficients of variation for all analytes were 90% and the relative matrix effect were ≤4.0%. The median concentrations of choline, betaine, and DMG were 11.3, 27.8, and 5.9μmol/L in plasma and 66.6, 165, and 13.7μmol/L in WB, respectively. There were positive correlations between WB and plasma markers; for choline (r=0.42), betaine (r=0.61), and DMG (r=0.56) (all p≤0.001). The concentrations of betaine in WB and plasma were significantly higher in men than in women. The concentrations of WB choline and DMG did not differ significantly according to sex. In conclusion, we have established a reliable method for measuring choline metabolites in WB. The concentrations of WB choline, betaine, and DMG seem to reflect intracellular concentrations of these metabolites.

  8. Role of central arginine vasopressin receptors in the analgesic effect of CDP-choline on acute and neuropathic pain.

    Science.gov (United States)

    Bagdas, Deniz; Yucel-Ozboluk, Hasret; Orhan, Fulya; Kanat, Ozkan; Isbil-Buyukcoskun, Naciye; Gurun, Mine S

    2013-12-04

    Recent studies have demonstrated that arginine vasopressin (AVP) plays a crucial role in pain modulation. In addition, our previous studies have proven that centrally administered cytidine-5'-diphosphate-choline (CDP-choline; citicoline) elicits an analgesic effect in different pain models in rats. Given that CDP-choline enhances central and peripheral vasopressin levels, the present study was designed to investigate the role of central AVP receptors in the analgesic effect of CDP-choline in acute and chronic constriction injury-induced neuropathic pain models. For this purpose, rats were pretreated intracerebroventricularly with the AVP V1 or AVP V2 receptor antagonist 15 min before intracerebroventricular injection of CDP-choline or saline, and pain threshold was determined using the Randall-Selitto test. AVP V1 and AVP V2 receptor antagonist blocked the CDP-choline-induced analgesic effect either in acute or neuropathic models of pain in rats. These results suggest, for the first time, that central AVP receptors are involved in the CDP-choline-elicited analgesic effect.

  9. Nonmuscle myosin II isoforms coassemble in living cells.

    Science.gov (United States)

    Beach, Jordan R; Shao, Lin; Remmert, Kirsten; Li, Dong; Betzig, Eric; Hammer, John A

    2014-05-19

    Nonmuscle myosin II (NM II) powers myriad developmental and cellular processes, including embryogenesis, cell migration, and cytokinesis [1]. To exert its functions, monomers of NM II assemble into bipolar filaments that produce a contractile force on the actin cytoskeleton. Mammalian cells express up to three isoforms of NM II (NM IIA, IIB, and IIC), each of which possesses distinct biophysical properties and supports unique as well as redundant cellular functions [2-8]. Despite previous efforts [9-13], it remains unclear whether NM II isoforms assemble in living cells to produce mixed (heterotypic) bipolar filaments or whether filaments consist entirely of a single isoform (homotypic). We addressed this question using fluorescently tagged versions of NM IIA, IIB, and IIC, isoform-specific immunostaining of the endogenous proteins, and two-color total internal reflection fluorescence structured-illumination microscopy, or TIRF-SIM, to visualize individual myosin II bipolar filaments inside cells. We show that NM II isoforms coassemble into heterotypic filaments in a variety of settings, including various types of stress fibers, individual filaments throughout the cell, and the contractile ring. We also show that the differential distribution of NM IIA and NM IIB typically seen in confocal micrographs of well-polarized cells is reflected in the composition of individual bipolar filaments. Interestingly, this differential distribution is less pronounced in freshly spread cells, arguing for the existence of a sorting mechanism acting over time. Together, our work argues that individual NM II isoforms are potentially performing both isoform-specific and isoform-redundant functions while coassembled with other NM II isoforms.

  10. Methionine- and choline-deficient diet induces hepatic changes characteristic of non-alcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    Éder Marcolin

    2011-03-01

    Full Text Available CONTEXT: Non-alcoholic steatohepatitis is a disease with a high incidence, difficult diagnosis, and as yet no effective treatment. So, the use of experimental models for non-alcoholic steatohepatitis induction and the study of its routes of development have been studied. OBJECTIVES: This study was designed to develop an experimental model of non-alcoholic steatohepatitis based on a methionine- and choline-deficient diet that is manufactured in Brazil so as to evaluate the liver alterations resulting from the disorder. METHODS: Thirty male C57BL6 mice divided in two groups (n = 15 were used: the experimental group fed a methionine- and choline-deficient diet manufactured by Brazilian company PragSoluções®, and the control group fed a normal diet, for a period of 2 weeks. The animals were then killed by exsanguination to sample blood for systemic biochemical analyses, and subsequently submitted to laparotomy with total hepatectomy and preparation of the material for histological analysis. The statistical analysis was done using the Student's t-test for independent samples, with significance level of 5%. RESULTS: The mice that received the methionine- and choline-deficient diet showed weight loss and significant increase in hepatic damage enzymes, as well as decreased systemic levels of glycemia, triglycerides, total cholesterol, HDL and VLDL. The diagnosis of non-alcoholic steatohepatitis was performed in 100% of the mice that were fed the methionine- and choline-deficient diet. All non-alcoholic steatohepatitis animals showed some degree of macrovesicular steatosis, ballooning, and inflammatory process. None of the animals which were fed the control diet presented histological alterations. All non-alcoholic steatohepatitis animals showed significantly increased lipoperoxidation and antioxidant enzyme GSH activity. CONCLUSION: The low cost and easily accessible methionine- and choline-deficient diet explored in this study is highly effective in

  11. In vivo uptake of [{sup 11}C]choline does not correlate with cell proliferation in human prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Breeuwsma, Anthonius J. [Groningen University Hospital, Department of Urology, Groningen (Netherlands); Groningen University Hospital, PET Centre, Groningen (Netherlands); Pruim, Jan; Vaalburg, Wim [Groningen University Hospital, PET Centre, Groningen (Netherlands); Jongen, Maud M.; Nijman, Rien J.; Jong, Igle J. de [Groningen University Hospital, Department of Urology, Groningen (Netherlands); Suurmeijer, Albert J. [Groningen University Hospital, Department of Pathology, Groningen (Netherlands)

    2005-06-01

    Prostate cancer is the second leading cause of death from cancer among US men. Positron emission tomography (PET) with [{sup 11}C]choline has been shown to be useful in the staging and detection of prostate cancer. The background of the increased uptake of choline in human prostate cancer is not completely understood. The aim of this study was to prospectively investigate the relationship between the [{sup 11}C]choline uptake and the cell proliferation in human prostate cancer. Prostate cancer tissue from 18 patients who had undergone a radical prostatectomy for histologically proven disease was studied. An [{sup 11}C]choline PET scan was performed prior to surgery. Post-prostatectomy specimens were prepared and stained with the antibody MIB-1 for Ki-67, which depicts proliferation. Two independent observers counted the amount of stained nuclei per specimen. Prostate cancer showed Ki-67 staining and high uptake of [{sup 11}C]choline. Statistical analysis showed no significant correlation between [{sup 11}C]choline uptake and Ki-67 staining (R=0.23; P=0.34). No significant relationships were found between the uptake of [{sup 11}C]choline (SUV) and either preoperative PSA (R=0.14; P=0.55) or Gleason sum score (R=0.28; P=0.25). In vivo uptake of [{sup 11}C]choline does not correlate with cell proliferation in human prostate cancer as depicted by Ki-67. Our results suggest that a process other than proliferation is responsible for the uptake of [{sup 11}C]choline in prostate cancer. (orig.)

  12. p53 Family: Role of Protein Isoforms in Human Cancer

    Directory of Open Access Journals (Sweden)

    Jinxiong Wei

    2012-01-01

    Full Text Available TP53, TP63, and TP73 genes comprise the p53 family. Each gene produces protein isoforms through multiple mechanisms including extensive alternative mRNA splicing. Accumulating evidence shows that these isoforms play a critical role in the regulation of many biological processes in normal cells. Their abnormal expression contributes to tumorigenesis and has a profound effect on tumor response to curative therapy. This paper is an overview of isoform diversity in the p53 family and its role in cancer.

  13. Diacylglycerol Kinase-ε: Properties and Biological Roles

    Directory of Open Access Journals (Sweden)

    Richard M Epand

    2016-10-01

    Full Text Available In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK. All catalyze the phosphorylation of diacylglycerol (DAG to phosphatidic acid (PA. Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e.1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε,is also the only DGK devoid of a regulatory domain.DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal.DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane.DGKε is likely present in both of these membranes.DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS. This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease.Thus,DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms.DGKε homologs also contain a number of conserved sequence features that are distinctive

  14. Diacylglycerol Kinase-ε: Properties and Biological Roles

    Science.gov (United States)

    Epand, Richard M.; So, Vincent; Jennings, William; Khadka, Bijendra; Gupta, Radhey S.; Lemaire, Mathieu

    2016-01-01

    In mammals there are at least 10 isoforms of diacylglycerol kinases (DGK). All catalyze the phosphorylation of diacylglycerol (DAG) to phosphatidic acid (PA). Among DGK isoforms, DGKε has several unique features. It is the only DGK isoform with specificity for a particular species of DAG, i.e., 1-stearoyl-2-arachidonoyl glycerol. The smallest of all known DGK isoforms, DGKε, is also the only DGK devoid of a regulatory domain. DGKε is the only DGK isoform that has a hydrophobic segment that is predicted to form a transmembrane helix. As the only membrane-bound, constitutively active DGK isoform with exquisite specificity for particular molecular species of DAG, the functional overlap between DGKε and other DGKs is predicted to be minimal. DGKε exhibits specificity for DAG containing the same acyl chains as those found in the lipid intermediates of the phosphatidylinositol-cycle. It has also been shown that DGKε affects the acyl chain composition of phosphatidylinositol in whole cells. It is thus likely that DGKε is responsible for catalyzing one step in the phosphatidylinositol-cycle. Steps of this cycle take place in both the plasma membrane and the endoplasmic reticulum membrane. DGKε is likely present in both of these membranes. DGKε is the only DGK isoform that is associated with a human disease. Indeed, recessive loss-of-function mutations in DGKε cause atypical hemolytic-uremic syndrome (aHUS). This condition is characterized by thrombosis in the small vessels of the kidney. It causes acute renal insufficiency in infancy and most patients develop end-stage renal failure before adulthood. Disease pathophysiology is poorly understood and there is no therapy. There are also data suggesting that DGKε may play a role in epilepsy and Huntington disease. Thus, DGKε has many unique molecular and biochemical properties when compared to all other DGK isoforms. DGKε homologs also contain a number of conserved sequence features that are distinctive

  15. Targeted Proteomics Enables Simultaneous Quantification of Folate Receptor Isoforms and Potential Isoform-based Diagnosis in Breast Cancer.

    Science.gov (United States)

    Yang, Ting; Xu, Feifei; Fang, Danjun; Chen, Yun

    2015-11-17

    The distinct roles of protein isoforms in cancer are becoming increasingly evident. FRα and FRβ, two major isoforms of the folate receptor family, generally have different cellular distribution and tissue specificity. However, the presence of FRβ in breast tumors, where FRα is normally expressed, complicates this situation. Prior to applying any FR isoform-based diagnosis and therapeutics, it is essential to monitor the expression profile of FR isoforms in a more accurate manner. An LC-MS/MS-based targeted proteomics assay was developed and validated in this study because of the lack of suitable methodology for the simultaneous and specific measurement of highly homologous isoforms occurring at low concentrations. FRα and FRβ monitoring was achieved by measuring their surrogate isoform-specific peptides. Five human breast cell lines, isolated macrophages and 60 matched pairs of breast tissue samples were subjected to the analysis. The results indicated that FRβ was overexpressed in tumor-associated macrophages (TAMs) but not epithelial cells, in addition to an enhanced level of FRα in breast cancer cells and tissue samples. Moreover, the levels of the FR isoforms were evaluated according to the histology, histopathological features and molecular subtypes of breast cancer. Several positive associations with PR/ER and HER2 status and metastasis were revealed.

  16. DEVELOPMENTAL REGULATION OF PROTEIN KINASE B ACTIVATION IS ISOFORM SPECIFIC IN SKELETAL MUSCLE OF NEONATAL PIGS

    Science.gov (United States)

    The postprandial activation of the insulin signaling pathway that leads to translation initiation is enhanced in skeletal muscle of the neonate and decreases with development in parallel with the developmental decline in muscle protein synthesis. Our previous study showed that the activity of protei...

  17. Aliskiren attenuates steatohepatitis and increases turnover of hepatic fat in mice fed with a methionine and choline deficient diet.

    Directory of Open Access Journals (Sweden)

    Kuei-Chuan Lee

    Full Text Available BACKGROUND & AIMS: Activation of the renin-angiotensin-system is known to play a role in nonalcoholic steatohepatitis. Renin knockout mice manifest decreased hepatic steatosis. Aliskiren is the first direct renin inhibitor to be approved for clinical use. Our study aims to evaluate the possible therapeutic effects and mechanism of the chronic administration of aliskiren in a dietary steatohepatitis murine model. METHODS: Male C57BL/6 mice were fed with a methionine and choline-deficient (MCD diet to induce steatohepatitis. After 8 weeks of feeding, the injured mice were randomly assigned to receive aliskiren (50 mg·kg(-1 per day or vehicle administration for 4 weeks. Normal controls were also administered aliskiren (50 mg·kg(-1 per day or a vehicle for 4 weeks. RESULTS: In the MCD mice, aliskiren attenuated hepatic steatosis, inflammation and fibrosis. Aliskiren did not change expression of lipogenic genes but increase turnover of hepatic fat by up-regulating peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a, cytochrome P450-4A14 and phosphorylated AMP-activated protein kinase. Furthermore, aliskiren decreased the hepatic expression of angiotensin II and nuclear factor κB. The levels of oxidative stress, hepatocyte apoptosis, activation of Kupffer cells and hepatic stellate cells, and pro-fibrotic markers were also reduced in the livers of the MCD mice receiving aliskiren. CONCLUSIONS: Aliskiren attenuates steatohepatitis and fibrosis in mice fed with a MCD diet. Thus, the noted therapeutic effects might come from not only the reduction of angiotensin II but also the up-regulation of fatty acid oxidation-related genes.

  18. Inhibition of PaCaMKII-E isoform in the dorsal unpaired median neurosecretory cells of cockroach reduces nicotine- and clothianidin-induced currents.

    Science.gov (United States)

    List, Olivier; Calas-List, Delphine; Taillebois, Emiliane; Juchaux, Marjorie; Heuland, Emilie; Thany, Steeve H

    2014-08-01

    Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII), which transduces the signal into downstream effects. We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms, and only PaCaMKII-E isoform is specifically expressed in the dorsal unpaired median neurosecretory cells. In the present study, using antisense oligonucleotides, we demonstrated that PaCaMKII-E isoform inhibition reduced nicotine-induced currents through α-bungarotoxin-sensitive and -insensitive nicotinic acetylcholine receptor subtypes. Specifically, PaCaMKII-E isoform is sufficient to repress nicotinic current amplitudes as a result of its depression by antisense oligonucleotides. Similar results were found using the neonicotinoid insecticide clothianidin, which acted as a full agonist of dorsal unpaired median neuron nicotinic acetylcholine receptors. Clothianidin current amplitudes are strongly reduced under bath application of PaCaMKII-E antisense oligonucleotides but no significant results are found with α-bungarotoxin co-applied, demonstrating that CaMKII-E isoform affects nicotine currents through α-bungarotoxin-sensitive and -insensitive receptor subtypes whereas clothianidin currents are reduced via α-bungarotoxin-insensitive receptors. In addition, we found that intracellular calcium increase induced by nicotine and clothianidin were reduced by PaCaMKII-E antisense oligonucleotides, demonstrating that intracellular calcium increase induced by nicotine and clothianidin are affected by PaCaMKII-E inhibition. Cellular responses to Ca(2+) require intermediary proteins such as calcium/calmodulin-dependent protein kinase II (CaMKII). We recently demonstrated that the cockroach genome encodes five different CaMKII isoforms and only PaCaMKII-E isoform was specifically expressed in the dorsal unpaired median neurosecretory cells. Here we show that specific inhibition of PaCaMKII-E isoform is

  19. Targeting PI3 kinase in cancer.

    Science.gov (United States)

    Bauer, Todd M; Patel, Manish R; Infante, Jeffrey R

    2015-02-01

    The PI3K/Akt/mTOR pathway is the most frequently known activated aberrant pathway in human cancers. Pathologic activation can occur at multiple levels along the signaling pathway by a variety of mechanisms, including point mutations, amplifications, and inactivation of tumor suppressor genes. This pathway is also a known resistance pathway, as it can be activated by both receptor tyrosine kinases and other oncogenes. mTOR inhibitors were the first targeted molecules in this pathway, and have already been FDA-approved in multiple indications. Because of the broad potential applications of inhibiting this pathway upstream of mTOR, multiple compounds targeting PI3K are in development. In this review, we discuss the clinical development of these inhibitors, including dual PI3K/mTOR inhibitors, pan-PI3K inhibitors, and isoform-selective PI3K inhibitors. Common adverse events, including rash, nausea, vomiting, diarrhea, and hyperglycemia, have created a narrow therapeutic window for all classes of PI3K inhibitors. Furthermore, single agent clinical activity has also been limited, with the exception of isoform-selective inhibitors, particularly the PI3Kδ and PI3Kγ inhibitors in hematologic malignancies. The future role of inhibitors of the PI3K/Akt/mTOR pathway in the clinical practice of oncology likely depends on the development of patient selection strategies and the results of combination trials that are currently ongoing.

  20. Histone deacetylase inhibition increases levels of choline kinase alpha and phosphocholine facilitating non-invasive imaging in human cancers

    OpenAIRE

    2011-01-01

    Histone deacetylase (HDAC) inhibitors are currently approved for cutaneous T-cell lymphoma and are in mid-late stage trials for other cancers. The HDAC inhibitors LAQ824 and SAHA increase phosphocholine (PC) levels in human colon cancer cells and tumor xenografts as observed by magnetic resonance spectroscopy (MRS). In this study, we show that belinostat, an HDAC inhibitor with an alternative chemical scaffold, also caused a rise in cellular PC content that was detectable by 1H and 31P MRS in...

  1. Autophosphorylation of serine 608 in the p85 regulatory subunit of wild type or cancer-associated mutants of phosphoinositide 3-kinase does not affect its lipid kinase activity

    Directory of Open Access Journals (Sweden)

    Layton Meredith J

    2012-12-01

    Full Text Available Abstract Background The α-isoform of the Type 1A Phosphoinositide 3-kinases (PI3Kα has protein kinase activity as well as phosphoinositide lipid kinase activity. The best described substrate for its protein kinase activity is its regulatory subunit, p85α, which becomes phosphorylated on Serine 608. Phosphorylation of Serine 608 has been reported to down-regulate its lipid kinase activity. Results We have assessed whether oncogenic mutants of PI3Kα, which have up-regulated lipid kinase activity, have altered levels of Serine 608 phosphorylation compared to wild type PI3Kα, and whether differential phosphorylation of Serine 608 contributes to increased activity of oncogenic forms of PI3Kα with point mutations in the helical or the kinase domains. Despite markedly increased lipid kinase activity, protein kinase activity was not altered in oncogenic compared to wild type forms of PI3Kα. By manipulating levels of phosphorylation of Serine 608 in vitro, we found no evidence that the protein kinase activity of PI3Kα affects its phosphoinositide lipid kinase activity in either wild-type or oncogenic mutants of PI3Kα. Conclusions Phosphorylation of p85α S608 is not a significant regulator of wild-type or oncogenic PI3Kα lipid kinase activity.

  2. Neuronal profilin isoforms are addressed by different signalling pathways.

    Directory of Open Access Journals (Sweden)

    Kai Murk

    Full Text Available Profilins are prominent regulators of actin dynamics. While most mammalian cells express only one profilin, two isoforms, PFN1 and PFN2a are present in the CNS. To challenge the hypothesis that the expression of two profilin isoforms is linked to the complex shape of neurons and to the activity-dependent structural plasticity, we analysed how PFN1 and PFN2a respond to changes of neuronal activity. Simultaneous labelling of rodent embryonic neurons with isoform-specific monoclonal antibodies revealed both isoforms in the same synapse. Immunoelectron microscopy on brain sections demonstrated both profilins in synapses of the mature rodent cortex, hippocampus and cerebellum. Both isoforms were significantly more abundant in postsynaptic than in presynaptic structures. Immunofluorescence showed PFN2a associated with gephyrin clusters of the postsynaptic active zone in inhibitory synapses of embryonic neurons. When cultures were stimulated in order to change their activity level, active synapses that were identified by the uptake of synaptotagmin antibodies, displayed significantly higher amounts of both isoforms than non-stimulated controls. Specific inhibition of NMDA receptors by the antagonist APV in cultured rat hippocampal neurons resulted in a decrease of PFN2a but left PFN1 unaffected. Stimulation by the brain derived neurotrophic factor (BDNF, on the other hand, led to a significant increase in both synaptic PFN1 and PFN2a. Analogous results were obtained for neuronal nuclei: both isoforms were localized in the same nucleus, and their levels rose significantly in response to KCl stimulation, whereas BDNF caused here a higher increase in PFN1 than in PFN2a. Our results strongly support the notion of an isoform specific role for profilins as regulators of actin dynamics in different signalling pathways, in excitatory as well as in inhibitory synapses. Furthermore, they suggest a functional role for both profilins in neuronal nuclei.

  3. Membrane targeting of cGMP-dependent protein kinase is required for cystic fibrosis transmembrane conductance regulator Cl- channel activation

    NARCIS (Netherlands)

    A.B. Vaandrager (Arie); A. Smolenski; B.C. Tilly (Bernard); A.B. Houtsmuller (Adriaan); E.M.E. Ehlert (Ehrich); A.G. Bot (Alice); M.J. Edixhoven (Marcel); W.E. Boomaars (Wendy); S.M. Lohmann (Suzanne); H.R. de Jonge (Hugo)

    1998-01-01

    textabstractA recently cloned isoform of cGMP-dependent protein kinase (cGK), designated type II, was implicated as the mediator of cGMP-provoked intestinal Cl- secretion based on its localization in the apical membrane of enterocytes and on its capacity to activate cys

  4. Thymidine kinases in archaea

    DEFF Research Database (Denmark)

    Clausen, A.R.; Matakos, A.; Sandrini, Michael;

    2006-01-01

    Twenty-six fully sequenced archaeal genomes were searched for genes coding for putative deoxyribonucleoside kinases (dNKs). We identified only 5 human-like thymidine kinase 1 genes (TK1s) and none for non-TK1 kinases. Four TK1s were identified in the Euryarchaea and one was found in the Crenarchaea...... that a functional deoxyribonucleoside salvage pathway is not crucial for the archaeal cell....

  5. Choline PET and PET/CT in Primary Diagnosis and Staging of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    S. Schwarzenböck, M. Souvatzoglou, B. J. Krause

    2012-01-01

    Full Text Available PET and PET/CT using [11C]- and [18F]-labelled choline derivates is increasingly being used for imaging of primary and recurrent prostate cancer. While PET and PET/CT with [11C]- and [18F]-labelled choline derivates in patients suffering from biochemical recurrence of prostate cancer has been examined in many studies that demonstrate an increasing importance, its role in the primary staging of prostate cancer is still a matter of debate.Morphological and functional imaging techniques such as CT, MRI and TRUS have demonstrated only limited accuracy for the diagnosis of primary prostate cancer. Molecular imaging with PET and PET/CT could potentially increase accuracy to localize primary prostate cancer. A considerable number of studies have examined the value of PET/CT with [11C]- and [18F]- labelled choline derivates for the diagnosis of primary prostate cancer with mixed results. Primary prostate cancer can only be detected with moderate sensitivity using [11C]- and [18F]choline PET and PET/CT. The detection rate depends on the tumour configuration. Detection is also limited by a considerable number of microcarcinomas that cannot be detected due to partial volume effects. Therefore small and in part rind-like tumours can often not be visualized. Furthermore, the differentiation between benign changes like prostatitis, high-grade intraepithelial neoplasia (HGPIN or prostatic hyperplasia is not always possible. Therefore, at the present time, the routine use of PET/CT with [11C]- and [18F]-labelled choline derivates cannot be recommended as a first-line screening procedure for primary prostate cancer in men at risk. A potential application of choline PET and PET/CT may be to increase the detection rate of clinically suspected prostate cancer with multiple negative prostate biopsies, for example in preparation of a focused re-biopsy and may play a role in patient stratification with respect to primary surgery and radiation therapy in the future.

  6. Cell-specific expression of TLR9 isoforms in inflammation.

    Science.gov (United States)

    McKelvey, Kelly J; Highton, John; Hessian, Paul A

    2011-02-01

    Toll-like receptors (TLRs) are key pattern recognition receptors during an immune response. With five isoforms of human TLR9 described, we hypothesised that differential expression of TLR9 isoforms in different cell types would result in variable contributions to the overall input from TLR9 during inflammation. We assessed the molecular expression of the TLR9 isoforms, TLR9-A, -C and -D. In normal peripheral blood mononuclear cells, B-lymphocytes express ∼100-fold more TLR9-A transcript than monocytes or T-lymphocytes, which predominantly express the TLR9-C transcript. Switches in isoform predominance accompany B-lymphocyte development. TLR9 protein expression in rheumatoid inflammatory lesions reflected the TLR9 isoform expression by immune cells. Herein we suggest that B-lymphocytes and plasmacytoid dendritic cells contribute the ∼3-fold higher TLR9-A transcript levels observed in inflamed synovium when compared to subcutaneous rheumatoid nodules. In contrast, macrophages and T-lymphocytes contribute the ∼4-fold higher TLR9-C transcript levels seen in nodules, compared to synovia. From protein sequence, predictions of subcellular localisation suggest TLR9-B may locate to the mitochondria, whereas TLR9-D adopts an opposing orientation in the endoplasmic reticulum. Consistent with this, structure models raise the possibility of alternative ligands for the TLR9-B and TLR9-D variants. Our results highlight differences in the expression of human TLR9 isoforms in normal and inflamed tissues, with differing contributions to inflammation.

  7. Recombinant erythropoietin in humans has a prolonged effect on circulating erythropoietin isoform distribution

    DEFF Research Database (Denmark)

    Aachmann-Andersen, Niels Jacob; Just Christensen, Søren; Lisbjerg, Kristian

    2014-01-01

    The membrane-assisted isoform immunoassay (MAIIA) quantitates erythropoietin (EPO) isoforms as percentages of migrated isoforms (PMI). We evaluated the effect of recombinant human EPO (rhEPO) on the distribution of EPO isoforms in plasma in a randomized, placebo-controlled, double-blinded, cross...

  8. Choline molecular imaging with small-animal PET for monitoring tumor cellular response to photodynamic therapy of cancer

    Science.gov (United States)

    Fei, Baowei; Wang, Hesheng; Wu, Chunying; Meyers, Joseph; Xue, Liang-Yan; MacLennan, Gregory; Schluchter, Mark

    2009-02-01

    We are developing and evaluating choline molecular imaging with positron emission tomography (PET) for monitoring tumor response to photodynamic therapy (PDT) in animal models. Human prostate cancer (PC-3) was studied in athymic nude mice. A second-generation photosensitizer Pc 4 was used for PDT in tumor-bearing mice. MicroPET images with 11C-choline were acquired before PDT and 48 h after PDT. Time-activity curves of 11C-choline uptake were analyzed before and after PDT. For treated tumors, normalized choline uptake decreased significantly 48 h after PDT, compared to the same tumors pre-PDT (p detect early tumor response to PDT in the animal model of human prostate cancer.

  9. Molecular Basis of C–N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase

    Energy Technology Data Exchange (ETDEWEB)

    Bodea, Smaranda; Funk, Michael A.; Balskus, Emily P.; Drennan, Catherine L.

    2016-10-01

    We report that deamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. Lastly, this work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production.

  10. Radiosynthesis and pre-clinical evaluation of [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Graham [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Zhao Yongjun [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Leyton, Julius [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Shan Bo [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Nguyen, Quang-de; Perumal, Meg [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Turton, David [GE-Imanet, Hammersmith Hospital, Du Cane Road, London, W12 0NN (United Kingdom); Arstad, Erik; Luthra, Sajinder K.; Robins, Edward G. [MDx Discovery (part of GE Healthcare) at Hammersmith Imanet, Ltd., Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom); Aboagye, Eric O., E-mail: eric.aboagye@imperial.ac.u [Comprehensive Cancer Imaging Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, Du Cane Road, London W12 0NN (United Kingdom)

    2011-01-15

    Introduction: Choline radiotracers are widely used for clinical PET diagnosis in oncology. [{sup 11}C]Choline finds particular utility in the imaging of brain and prostate tumor metabolic status, where 2-[{sup 18}F]fluoro-2-deoxy-D-glucose ('FDG') shows high background uptake. More recently we have extended the clinical utility of [{sup 11}C]choline to breast cancer where radiotracer uptake correlates with tumor aggressiveness (grade). In the present study, a new choline analog, [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline, was synthesized and evaluated as a potential PET imaging probe. Methods: [{sup 18}F]Fluorocholine, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline were synthesized by alkylation of the relevant precursor with [{sup 18}F]fluorobromomethane or [{sup 18}F]fluoromethyl tosylate. Radiosynthesis of [{sup 18}F]fluoromethyl tosylate required extensive modification of the existing method. [{sup 18}F]Fluorocholine and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline were then subjected to in vitro oxidative stability analysis in a chemical oxidation model using potassium permanganate and an enzymatic model using choline oxidase. The two radiotracers, together with the corresponding di-deuterated compound, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline, were then evaluated in vivo in a time-course biodistribution study in HCT-116 tumor-bearing mice. Results: Alkylation with [{sup 18}F]fluoromethyl tosylate proved to be the most reliable radiosynthetic route. Stability models indicate that [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline possesses increased chemical and enzymatic (choline oxidase) oxidative stability relative to [{sup 18}F]fluorocholine. The distribution of the three radiotracers, [{sup 18}F]fluorocholine, [{sup 18}F]fluoro-[1-{sup 2}H{sub 2}]choline and [{sup 18}F]fluoro-[1,2-{sup 2}H{sub 4}]choline, showed a similar uptake profile in most organs. Crucially, tumor uptake of [{sup 18}F

  11. High-throughput, cell-free, liposome-based approach for assessing in vitro activity of lipid kinases.

    Science.gov (United States)

    Demian, Douglas J; Clugston, Susan L; Foster, Meta M; Rameh, Lucia; Sarkes, Deborah; Townson, Sharon A; Yang, Lily; Zhang, Melvin; Charlton, Maura E

    2009-08-01

    Lipid kinases are central players in lipid signaling pathways involved in inflammation, tumorigenesis, and metabolic syndrome. A number of these kinase targets have proven difficult to investigate in higher throughput cell-free assay systems. This challenge is partially due to specific substrate interaction requirements for several of the lipid kinase family members and the resulting incompatibility of these substrates with most established, homogeneous assay formats. Traditional, cell-free in vitro investigational methods for members of the lipid kinase family typically involve substrate incorporation of [gamma-32P] and resolution of signal by thin-layer chromatography (TLC) and autoradiograph densitometry. This approach, although highly sensitive, does not lend itself to high-throughput testing of large numbers of small molecules (100 s to 1 MM+). The authors present the development and implementation of a fully synthetic, liposome-based assay for assessing in vitro activity of phosphatidylinositol-5-phosphate-4-kinase isoforms (PIP4KIIbeta and alpha) in 2 commonly used homogeneous technologies. They have validated these assays through compound testing in both traditional TLC and radioactive filterplate approaches as well as binding validation using isothermic calorimetry. A directed library representing known kinase pharmacophores was screened against type IIbeta phosphatidylinositol-phosphate kinase (PIPK) to identify small-molecule inhibitors. This assay system can be applied to other types and isoforms of PIPKs as well as a variety of other lipid kinase targets.

  12. Early second trimester maternal plasma choline and betaine are related to measures of early cognitive development in term infants.

    Directory of Open Access Journals (Sweden)

    Brian T F Wu

    Full Text Available BACKGROUND: The importance of maternal dietary choline for fetal neural development and later cognitive function has been well-documented in experimental studies. Although choline is an essential dietary nutrient for humans, evidence that low maternal choline in pregnancy impacts neurodevelopment in human infants is lacking. We determined potential associations between maternal plasma free choline and its metabolites betaine and dimethylglycine in pregnancy and infant neurodevelopment at 18 months of age. METHODOLOGY: This was a prospective study of healthy pregnant women and their full-term, single birth infants. Maternal blood was collected at 16 and 36 weeks of gestation and infant neurodevelopment was assessed at 18 months of age for 154 mother-infant pairs. Maternal plasma choline, betaine, dimethylglycine, methionine, homocysteine, cysteine, total B12, holotranscobalamin and folate were quantified. Infant neurodevelopment was evaluated using the Bayley Scales of Infant Development-III. Multivariate regression, adjusting for covariates that impact development, was used to determine the associations between maternal plasma choline, betaine and dimethylglycine and infant neurodevelopment. RESULTS: The maternal plasma free choline at 16 and 36 weeks gestation was median (interquartile range 6.70 (5.78-8.03 and 9.40 (8.10-11.3 µmol/L, respectively. Estimated choline intakes were (mean ± SD 383 ± 98.6 mg/day, and lower than the recommended 450 mg/day. Betaine intakes were 142 ± 70.2 mg/day. Significant positive associations were found between infant cognitive test scores and maternal plasma free choline (B=6.054, SE=2.283, p=0.009 and betaine (B=7.350, SE=1.933, p=0.0002 at 16 weeks of gestation. Maternal folate, total B12, or holotranscobalamin were not related to infant development. CONCLUSION: We show that choline status in the first half of pregnancy is associated with cognitive development among healthy term gestation infants. More work

  13. Multiple isoform recovery (MIR)-PCR: a simple method for the isolation of related mRNA isoforms.

    OpenAIRE

    Fagotti, A; Gabbiani, G.; Pascolini, R; Neuville, P

    1998-01-01

    We present a rapid and efficient method for the detection of related transcripts with different expression levels. This approach combines the rapid amplification of cDNA ends (RACE) method with a cDNA subtractive technique. The strategy is based on successive subtractions of prevalent isoforms resulting in enrichment of less expressed transcripts. For each subtraction, a biotinylated primer specific for the prevalent isoform is hybridized on the total cDNA and the hybrid is retained on a stre...

  14. Rapid Amplification of 5′ cDNA End of S. Liaotungensis Choline Monooxygenase Using Inverse PCR RACE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on part of a known cDNA sequence of Suaeda Liaotungensis choline monooxygenase, the authors successfully cloned the 5′ cDNA end of Suaeda Lianotungensis choline monooxygenase using Inverse PCR RACE with a specially designed 5′-phosphated RT primer and two pairs of specific inverse PCR primers. Compared with the anchored PCR RACE, inverse PCR RACE has better specificity and higher amplification.

  15. Regulation of the high-affinity choline transporter activity and trafficking by its association with cholesterol-rich lipid rafts.

    Science.gov (United States)

    Cuddy, Leah K; Winick-Ng, Warren; Rylett, Rebecca Jane

    2014-03-01

    The sodium-coupled, hemicholinium-3-sensitive, high-affinity choline transporter (CHT) is responsible for transport of choline into cholinergic nerve terminals from the synaptic cleft following acetylcholine release and hydrolysis. In this study, we address regulation of CHT function by plasma membrane cholesterol. We show for the first time that CHT is concentrated in cholesterol-rich lipid rafts in both SH-SY5Y cells and nerve terminals from mouse forebrain. Treatment of SH-SY5Y cells expressing rat CHT with filipin, methyl-β-cyclodextrin (MβC) or cholesterol oxidase significantly decreased choline uptake. In contrast, CHT activity was increased by addition of cholesterol to membranes using cholesterol-saturated MβC. Kinetic analysis of binding of [(3)H]hemicholinium-3 to CHT revealed that reducing membrane cholesterol with MβC decreased both the apparent binding affinity (KD) and maximum number of binding sites (Bmax ); this was confirmed by decreased plasma membrane CHT protein in lipid rafts in cell surface protein biotinylation assays. Finally, the loss of cell surface CHT associated with lipid raft disruption was not because of changes in CHT internalization. In summary, we provide evidence that CHT association with cholesterol-rich rafts is critical for transporter function and localization. Alterations in plasma membrane cholesterol cholinergic nerve terminals could diminish cholinergic transmission by reducing choline availability for acetylcholine synthesis. The sodium-coupled choline transporter CHT moves choline into cholinergic nerve terminals to serve as substrate for acetylcholine synthesis. We show for the first time that CHT is concentrated in cholesterol-rich lipid rafts, and decreasing membrane cholesterol significantly reduces both choline uptake activity and cell surface CHT protein levels. CHT association with cholesterol-rich rafts is critical for its function, and alterations in plasma membrane cholesterol could diminish cholinergic

  16. Isoform-specific regulation of the Na+-K+ pump by adenosine in guinea pig ventricular myocytes

    Institute of Scientific and Technical Information of China (English)

    Zhe ZHANG; Hui-cai GUO; Li-nan ZHANG; Yong-li WANG

    2009-01-01

    Aim: The present study investigated the effect of adenosine on Na+-K+ pumps in acutely isolated guinea pig (C, avia sp.) ven-tricular myocytes.Methods: The whole-cell, patch-damp technique was used to record the Na+-K+ pump current (Ip) in acutely isolated guinea pig ventricular myocytes.Results: Adenosine inhibited the high DHO-affinity pump current (Ih) in a concentration-dependent manner, which was blocked by the selective adenosine A1 receptor antagonist DPCPX and the general protein kinase C (PKC) antagonists stau-rosporine, GF 109203X or the specific δ isoform antagonist rottlerin. In addition, the inhibitory action of adenosine was mimicked by a selective A1 receptor agonist CCPA and a specific activator peptide of PKC-δ, PP114. In contrast, the selec-tive A2A receptor agonist CGS21680 and A3 receptor agonist Cl-IB-MECA did not affect lb. Application of the selective A2A receptor antagonist SCH58261 and A3 receptor antagonist MRS1191 also failed to block the effect of adenosine. Further-more, H89, a selective protein kinase A (PKA) antagonist, did not exert any effect on adenosine-induced Ih inhibition.Conclusion: The present study provides the electrophysiological evidence that adenosine can induce significant inhibition of Ih via adenosine A1 receptors and the PKC-δ isoform.

  17. Daunorubicin and doxorubicin inhibit the [{sup 11}C]choline accumulation in cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Mikecz, Pal [Department of Nuclear Medicine, University of Debrecen, Medical and Health Science Centre, 4012 Debrecen, Nagyerdei krt. 98 (Hungary)], E-mail: pal@pet.dote.hu; Marian, Terez; Miklovicz, Tuende; Galuska, Laszlo [Department of Nuclear Medicine, University of Debrecen, Medical and Health Science Centre, 4012 Debrecen, Nagyerdei krt. 98 (Hungary); Krasznai, Zoltan; Toth, Agnes; Goda, Katalin [Department of Biophysics and Cell Biology, University of Debrecen, Medical and Health Science Centre, 4012 Debrecen, Nagyerdei krt. 98 (Hungary); Tron, Lajos [Department of Nuclear Medicine, University of Debrecen, Medical and Health Science Centre, 4012 Debrecen, Nagyerdei krt. 98 (Hungary); Hernadi, Zoltan; Krasznai, Zoard T. [Department of Obstetrics and Gynecology, University of Debrecen, Medical and Health Science Centre, 4012 Debrecen, Nagyerdei krt. 98 (Hungary)

    2009-10-15

    We studied how very short (10-40 min) incubation with anthracycline derivatives modifies the accumulation of PET tumor-diagnostic radiotracers in cancer cells. The human ovarian A2780 and A2780AD, human B lymphoid JY, human epidermoid KB-3-1 and KB-V-1, and smooth muscle DDT1 MF-2 cells were pre-incubated with daunorubicin and doxorubicin, and the uptake of [{sup 18}F]FDG and [{sup 11}C]choline was measured. Anthracycline treatment decreased remarkably the [{sup 11}C]choline accumulation in a concentration dependent manner, while it did not modify significantly the [{sup 18}F]FDG uptake of the cells.

  18. Choline supplementation alters some amino acid concentrations with no change in homocysteine in children with cystic fibrosis and pancreatic insufficiency.

    Science.gov (United States)

    Alshaikh, Belal; Schall, Joan I; Maqbool, Asim; Mascarenhas, Maria; Bennett, Michael J; Stallings, Virginia A

    2016-05-01

    The present study determined the plasma amino acid status in children with cystic fibrosis (CF) and pancreatic insufficiency (PI) in the modern medical and nutritional care setting and investigated the effect of choline supplementation on amino acid status. A total of 110 children aged 5 to 18 years with CF and PI were randomized to receive choline-enriched structured lipid (LYM-X-SORB) or placebo with similar energy and fat content. Plasma amino acids were measured at baseline and 3 and 12 months. We hypothesized that choline supplementation would result in lower plasma homocysteine concentrations in children with CF. At baseline, dietary protein intake was high and the amino acid profile was within laboratory reference ranges in most participants. Alanine and cysteine were elevated in 24% and 36% of participants, respectively. Children with baseline alanine above reference range had improved weight, body mass index, and fat-free mass. Low homocysteine was found in 62% of children 11 years and older. After 3 and 12 months, there was no effect of choline supplementation on methionine or homocysteine status. Compared with placebo, choline supplementation resulted in increased glycine and decreased threonine, histidine, valine, and total branch chained amino acids at 12 months. In conclusion, daily choline supplementation with LYM-X-SORB did not alter methionine-homocysteine metabolism but did result in alterations in other amino acids in children with CF and PI.

  19. Effect of choline supplementation on rapid weight loss and biochemical variables among female taekwondo and judo athletes.

    Science.gov (United States)

    Elsawy, Gehan; Abdelrahman, Osama; Hamza, Amr

    2014-03-27

    Taekwondo and judo competitions are divided into weight categories. Many athletes reduce their body mass a few days before competition in order to obtain a competitive advantage over lighter opponents. To achieve fast body mass reduction, athletes use a number of nutritional strategies, including choline supplementation. The goal of this study was to identify the effects of choline supplementation on body mass reduction and leptin levels among female taekwondo and judo athletes. Twenty-two female athletes (15 taekwondo and 7 judo athletes) were selected from different weight categories and divided into two groups, according to weight. The players in the experimental group took choline tablets for one week before a competition. The results revealed significant differences between pre- and post-competition measurements of leptin, free plasma choline, urine choline and urine malondialdehyde levels; body mass was also reduced in the post-competition measurements. In conclusion, choline supplementation could rapidly reduce body mass without any side effects on biochemical levels or static strength.

  20. Usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base: comparison with FDG-PET

    Directory of Open Access Journals (Sweden)

    Ito Shin

    2012-02-01

    Full Text Available Abstract Background Choline is a new PET tracer that is useful for the detection of malignant tumor. Choline is a precursor of the biosynthesis of phosphatidylcholine, a major phospholipid in the cell membrane of eukaryotic cells. Malignant tumors have an elevated level of phosphatidylcholine in cell membrane. Thus, choline is a marker of tumor malignancy. Method The patient was a 51-year-old man with repeated recurrent hemangiopericytoma in the skull base. We performed Choline-PET in this patient after various treatments and compared findings with those of FDG-PET. Results Choline accumulated in this tumor, but FDG did not accumulate. We diagnosed this tumor as residual hemangiopericytoma and performed the resection of the residual tumor. FDG-PET is not appropriate for skull base tumor detection because uptake in the brain is very strong. Conclusion We emphasize the usefulness of Choline-PET for the detection of residual hemangiopericytoma in the skull base after various treatments, compared with FDG-PET.

  1. With no lysine L-WNK1 isoforms are negative regulators of the K+-Cl- cotransporters.

    Science.gov (United States)

    Mercado, Adriana; de Los Heros, Paola; Melo, Zesergio; Chávez-Canales, María; Murillo-de-Ozores, Adrián R; Moreno, Erika; Bazúa-Valenti, Silvana; Vázquez, Norma; Hadchouel, Juliette; Gamba, Gerardo

    2016-07-01

    The K(+)-Cl(-) cotransporters (KCC1-KCC4) encompass a branch of the SLC12 family of electroneutral cation-coupled chloride cotransporters that translocate ions out of the cell to regulate various factors, including cell volume and intracellular chloride concentration, among others. L-WNK1 is an ubiquitously expressed kinase that is activated in response to osmotic stress and intracellular chloride depletion, and it is implicated in two distinct hereditary syndromes: the renal disease pseudohypoaldosteronism type II (PHAII) and the neurological disease hereditary sensory neuropathy 2 (HSN2). The effect of L-WNK1 on KCC activity is unknown. Using Xenopus laevis oocytes and HEK-293 cells, we show that the activation of KCCs by cell swelling was prevented by L-WNK1 coexpression. In contrast, the activity of the Na(+)-K(+)-2Cl(-) cotransporter NKCC1 was remarkably increased with L-WNK1 coexpression. The negative effect of L-WNK1 on the KCCs is kinase dependent. Elimination of the STE20 proline-alanine rich kinase (SPAK)/oxidative stress-responsive kinase (OSR1) binding site or the HQ motif required for the WNK-WNK interaction prevented the effect of L-WNK1 on KCCs, suggesting a required interaction between L-WNK1 molecules and SPAK. Together, our data support that NKCC1 and KCCs are coordinately regulated by L-WNK1 isoforms.

  2. A cytoplasmic negative regulator isoform of ATF7 impairs ATF7 and ATF2 phosphorylation and transcriptional activity.

    Science.gov (United States)

    Diring, Jessica; Camuzeaux, Barbara; Donzeau, Mariel; Vigneron, Marc; Rosa-Calatrava, Manuel; Kedinger, Claude; Chatton, Bruno

    2011-01-01

    Alternative splicing and post-translational modifications are processes that give rise to the complexity of the proteome. The nuclear ATF7 and ATF2 (activating transcription factor) are structurally homologous leucine zipper transcription factors encoded by distinct genes. Stress and growth factors activate ATF2 and ATF7 mainly via sequential phosphorylation of two conserved threonine residues in their activation domain. Distinct protein kinases, among which mitogen-activated protein kinases (MAPK), phosphorylate ATF2 and ATF7 first on Thr71/Thr53 and next on Thr69/Thr51 residues respectively, resulting in transcriptional activation. Here, we identify and characterize a cytoplasmic alternatively spliced isoform of ATF7. This variant, named ATF7-4, inhibits both ATF2 and ATF7 transcriptional activities by impairing the first phosphorylation event on Thr71/Thr53 residues. ATF7-4 indeed sequesters the Thr53-phosphorylating kinase in the cytoplasm. Upon stimulus-induced phosphorylation, ATF7-4 is poly-ubiquitinated and degraded, enabling the release of the kinase and ATF7/ATF2 activation. Our data therefore conclusively establish that ATF7-4 is an important cytoplasmic negative regulator of ATF7 and ATF2 transcription factors.

  3. A cytoplasmic negative regulator isoform of ATF7 impairs ATF7 and ATF2 phosphorylation and transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Jessica Diring

    Full Text Available Alternative splicing and post-translational modifications are processes that give rise to the complexity of the proteome. The nuclear ATF7 and ATF2 (activating transcription factor are structurally homologous leucine zipper transcription factors encoded by distinct genes. Stress and growth factors activate ATF2 and ATF7 mainly via sequential phosphorylation of two conserved threonine residues in their activation domain. Distinct protein kinases, among which mitogen-activated protein kinases (MAPK, phosphorylate ATF2 and ATF7 first on Thr71/Thr53 and next on Thr69/Thr51 residues respectively, resulting in transcriptional activation. Here, we identify and characterize a cytoplasmic alternatively spliced isoform of ATF7. This variant, named ATF7-4, inhibits both ATF2 and ATF7 transcriptional activities by impairing the first phosphorylation event on Thr71/Thr53 residues. ATF7-4 indeed sequesters the Thr53-phosphorylating kinase in the cytoplasm. Upon stimulus-induced phosphorylation, ATF7-4 is poly-ubiquitinated and degraded, enabling the release of the kinase and ATF7/ATF2 activation. Our data therefore conclusively establish that ATF7-4 is an important cytoplasmic negative regulator of ATF7 and ATF2 transcription factors.

  4. An alternative splicing isoform of MITA antagonizes MITA-mediated induction of type I IFNs.

    Science.gov (United States)

    Chen, Honghe; Pei, Rongjuan; Zhu, Wandi; Zeng, Rui; Wang, Yun; Wang, Yanyi; Lu, Mengji; Chen, Xinwen

    2014-02-01

    Mediator of IFN regulatory transcription factor 3 activation (MITA) is an important adaptor protein to mediate the induction of type I IFNs. In this study, we identified an alternatively spliced isoform of MITA lacking exon 7, termed MITA-related protein (MRP). MRP shares the N-terminal portion aa 1-253 with MITA but possesses a unique 30-aa sequence at the carboxyl terminal part, therefore lacking the conserved domains including TANK-binding kinase 1 (TBK1) and cyclic diguanylate binding domain. MRP is expressed in multiple tissues and distinct cell lines. Overexpression of MRP inhibited MITA-mediated activation of IFN-β promoter by sendai virus infection and cyclic diguanylate treatment but enhanced that in HSV-1 infection. Interestingly, MRP expression was reduced after Sendai virus infection but was upregulated after HSV-1 infection. Overexpression of MRP inhibited MITA-mediated induction of IFN-β via TBK1-IFN regulatory transcription factor 3 by disrupting the MITA-TBK1 interaction. However, NF-κB pathway was still activated by MRP, as MRP retained the ability to interact with inducible inhibitor of NF-κB (iκB) kinase. Thus, MRP acts as a dominant negative regulator of MITA-mediated induction of IFN production.

  5. Comparable Stability of Hoogsteen and Watson–Crick Base Pairs in Ionic Liquid Choline Dihydrogen Phosphate

    OpenAIRE

    Hisae Tateishi-Karimata; Miki Nakano; Naoki Sugimoto

    2014-01-01

    The instability of Hoogsteen base pairs relative to Watson–Crick base pairs has limited biological applications of triplex-forming oligonucleotides. Hydrated ionic liquids (ILs) provide favourable environments for a wide range of chemical reactions and are known to impact the stabilities of Watson–Crick base pairs. We found that DNA triplex formation was significantly stabilized in hydrated choline dihydrogen phosphate as compared with an aqueous buffer at neutral pH. Interestingly, the stabi...

  6. Muscle phosphorylase kinase deficiency

    DEFF Research Database (Denmark)

    Preisler, N; Orngreen, M C; Echaniz-Laguna, A;

    2012-01-01

    To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD).......To examine metabolism during exercise in 2 patients with muscle phosphorylase kinase (PHK) deficiency and to further define the phenotype of this rare glycogen storage disease (GSD)....

  7. Differential activities of glucocorticoid-induced leucine zipper protein isoforms.

    Science.gov (United States)

    Soundararajan, Rama; Wang, Jian; Melters, Daniël; Pearce, David

    2007-12-14

    Glucocorticoid-induced leucine zipper protein (GILZ) is expressed in both epithelial and immune tissues and modulates a variety of cellular functions, including proliferation and epithelial sodium channel (ENaC) activity. A number of reports have described various GILZ activities, focusing on a single isoform with molecular mass of approximately 17 kDa, now termed GILZ1. In GILZ immunoblots using a newly developed antiserum, we detected multiple species in extracts from cultured kidney cells. Mass spectrometric analysis revealed that one of these represented a previously uncharacterized distinct isoform of GILZ, GILZ2. Rapid amplification of cDNA ends was used to clone cDNAs corresponding to four isoforms, which, in addition to GILZ1 and GILZ2, included new isoforms GILZ3 and GILZ4. Heterologous expression of these four GILZ isoforms in cultured cells revealed striking functional differences. Notably, GILZ1 was the only isoform that significantly stimulated ENaC-mediated Na+ current in a kidney collecting duct cell line, although GILZ2 and GILZ3 also stimulated ENaC surface expression in HEK 293 cells. GILZ1 and GILZ3, and to a lesser extent GILZ2, inhibited ERK phosphorylation. Interestingly, GILZ4, which had no effect on either ENaC or ERK, potently suppressed cellular proliferation, as did GILZ1, but not GILZ2 or GILZ3. Finally, rat and mouse tissues all expressed multiple GILZ species but varied in the relative abundance of each. These data suggest that multiple GILZ isoforms are expressed in most cells and tissues and that these play distinct roles in regulating key cellular functions, including proliferation and ion transport. Furthermore, GILZ inhibition of ERK appears to play an essential role in stimulation of cell surface ENaC but not in inhibition of proliferation.

  8. Distinct functional interactions between actin isoforms and nonsarcomeric myosins.

    Directory of Open Access Journals (Sweden)

    Mirco Müller

    Full Text Available Despite their near sequence identity, actin isoforms cannot completely replace each other in vivo and show marked differences in their tissue-specific and subcellular localization. Little is known about isoform-specific differences in their interactions with myosin motors and other actin-binding proteins. Mammalian cytoplasmic β- and γ-actin interact with nonsarcomeric conventional myosins such as the members of the nonmuscle myosin-2 family and myosin-7A. These interactions support a wide range of cellular processes including cytokinesis, maintenance of cell polarity, cell adhesion, migration, and mechano-electrical transduction. To elucidate differences in the ability of isoactins to bind and stimulate the enzymatic activity of individual myosin isoforms, we characterized the interactions of human skeletal muscle α-actin, cytoplasmic β-actin, and cytoplasmic γ-actin with human myosin-7A and nonmuscle myosins-2A, -2B and -2C1. In the case of nonmuscle myosins-2A and -2B, the interaction with either cytoplasmic actin isoform results in 4-fold greater stimulation of myosin ATPase activity than was observed in the presence of α-skeletal muscle actin. Nonmuscle myosin-2C1 is most potently activated by β-actin and myosin-7A by γ-actin. Our results indicate that β- and γ-actin isoforms contribute to the modulation of nonmuscle myosin-2 and myosin-7A activity and thereby to the spatial and temporal regulation of cytoskeletal dynamics. FRET-based analyses show efficient copolymerization abilities for the actin isoforms in vitro. Experiments with hybrid actin filaments show that the extent of actomyosin coupling efficiency can be regulated by the isoform composition of actin filaments.

  9. Choline Modulation of the Aβ P1-40 Channel Reconstituted into a Model Lipid Membrane

    Directory of Open Access Journals (Sweden)

    Daniela Meleleo

    2010-01-01

    Full Text Available Nicotinic acetylcholine receptors (AChRs, implicated in memory and learning, in subjects affected by Alzheimer's disease result altered. Stimulation of α7-nAChRs inhibits amyloid plaques and increases ACh release. β-amyloid peptide (AβP forms ion channels in the cell and model phospholipid membranes that are retained responsible in Alzheimer disease. We tested if choline, precursor of ACh, could affect the AβP1-40 channels in oxidized cholesterol (OxCh and in palmitoyl-oleoyl-phosphatidylcholine (POPC:Ch lipid bilayers. Choline concentrations of 5 × 10−11 M–1.5 × 10−8 M added to the cis- or trans-side of membrane quickly increased AβP1-40 ion channel frequency (events/min and ion conductance in OxCh membranes, but not in POPC:Ch membranes. Circular Dichroism (CD spectroscopy shows that after 24 and 48 hours of incubation with AβP1-40, choline stabilizes the random coil conformation of the peptide, making it less prone to fibrillate. These actions seem to be specific in that ACh is ineffective either in solution or on AβP1-40 channel incorporated into PLMs.

  10. {sup 11}C-Choline PET/pathology image coregistration in primary localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Grosu, Anca-Ligia; Prokic, Vesna [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); Technical University of Munich, Department of Radiation Oncology, Munich (Germany); Weirich, Gregor [Technical University of Munich, Institute of Pathology, Munich (Germany); Wendl, Christina; Geinitz, Hans; Molls, Michael [Technical University of Munich, Department of Radiation Oncology, Munich (Germany); Kirste, Simon [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany); Souvatzoglou, Michael; Schwaiger, Markus [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany); Gschwend, Juergen E.; Treiber, Uwe [Technical University of Munich, Department of Urology, Munich (Germany); Weber, Wolfgang A. [Memorial Sloan-Kettering Cancer Center, Molecular Imaging and Therapy Service, New York (United States); Krause, Bernd Joachim [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany); University of Rostock, Department of Nuclear Medicine, Rostock (Germany)

    2014-12-15

    The aim of this study was to develop a methodology for the comparison of pathology specimens after prostatectomy (post-S) with PET images obtained before surgery (pre-S). This method was used to evaluate the merit of {sup 11}C-choline PET/CT for delineation of gross tumour volume (GTV) in prostate cancer (PC). In 28 PC patients, {sup 11}C-choline PET/CT was performed before surgery. PET/CT data were coregistered with the pathology specimens. GTV on PET images (GTV-PET) was outlined automatically and corrected manually. Tumour volume in the prostate (TVP) was delineated manually on the pathology specimens. Based on the coregistered PET/pathology images, the following parameters were assessed: SUVmax and SUVmean in the tumoral and nontumoral prostate (NP), GTV-PET (millilitres) and TVP (millilitres). PET/pathology image coregistration was satisfactory. Mean SUVmax in the TVP was lower than in the NP: 5.0 and 5.5, respectively (p = 0.093). Considering the entire prostate, SUVmax was located in the TVP in two patients, in the TVP and NP in 12 patients and exclusively in NP in 14 patients. Partial overlap the TVP and GTV-PET was seen in 71 % of patients, and complete overlap in 4 %. PET/pathology image coregistration can be used for evaluation of different imaging modalities. {sup 11}C-Choline PET failed to distinguish tumour from nontumour tissue. (orig.)

  11. Experience with carbon-11 choline positron emission tomography in prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kotzerke, J.; Neumaier, B.; Guhlmann, A.; Reske, S.N. [Ulm Univ. (Germany). Dept. of Nuclear Medicine; Prang, J.; Volkmer, B.; Kleinschmidt, K.; Hautmann, R. [Dept. of Urology, Univ. of Ulm (Germany)

    2000-09-01

    We investigated the potential of carbon-11 choline positron emission tomography (PET) for the detection of lymph node and bone metastases in prostate cancer. A total of 23 patients were studied (known metastases: 8; suspicion of metastases: 3; primary staging: 12). Whole-body PET imaging was performed 5 min after injection of the tracer and completed within 1 h. Focally increased tracer uptake in bone or abdominal lymph node regions was interpreted as representing tumour involvement. All known bone and lymph node metastases could be recognized by [{sup 11}C]choline PET. One out of ten negative scans for primary staging was false-negative (lymph node <1 cm) and one out of two positive scans was false-positive with regard to lymph node involvement (focal bowel activity). It is concluded that [{sup 11}C]choline PET is a promising new tool for the primary staging of prostate cancer, with lymph node and bone metastases demonstrating high tracer uptake. Therapeutic management could be influenced by these results in that the technique may permit avoidance of surgical lymph node exploration. (orig.)

  12. Discovery of novel inhibitors of Aurora kinases with indazole scaffold: In silico fragment-based and knowledge-based drug design.

    Science.gov (United States)

    Chang, Chun-Feng; Lin, Wen-Hsing; Ke, Yi-Yu; Lin, Yih-Shyan; Wang, Wen-Chieh; Chen, Chun-Hwa; Kuo, Po-Chu; Hsu, John T A; Uang, Biing-Jiun; Hsieh, Hsing-Pang

    2016-11-29

    Aurora kinases have emerged as important anticancer targets so that there are several inhibitors have advanced into clinical study. Herein, we identified novel indazole derivatives as potent Aurora kinases inhibitors by utilizing in silico fragment-based approach and knowledge-based drug design. After intensive hit-to-lead optimization, compounds 17 (dual Aurora A and B), 21 (Aurora B selective) and 30 (Aurora A selective) possessed indazole privileged scaffold with different substituents, which provide sub-type kinase selectivity. Computational modeling helps in understanding that the isoform selectivity could be targeted specific residue in the Aurora kinase binding pocket in particular targeting residues Arg220, Thr217 or Glu177.

  13. Pharmacological Targeting of AMP-Activated Protein Kinase and Opportunities for Computer-Aided Drug Design.

    Science.gov (United States)

    Miglianico, Marie; Nicolaes, Gerry A F; Neumann, Dietbert

    2016-04-14

    As a central regulator of metabolism, the AMP-activated protein kinase (AMPK) is an established therapeutic target for metabolic diseases. Beyond the metabolic area, the number of medical fields that involve AMPK grows continuously, expanding the potential applications for AMPK modulators. Even though indirect AMPK activators are used in the clinics for their beneficial metabolic outcome, the few described direct agonists all failed to reach the market to date, which leaves options open for novel targeting methods. As AMPK is not actually a single molecule and has different roles depending on its isoform composition, the opportunity for isoform-specific targeting has notably come forward, but the currently available modulators fall short of expectations. In this review, we argue that with the amount of available structural and ligand data, computer-based drug design offers a number of opportunities to undertake novel and isoform-specific targeting of AMPK.

  14. Blockades of mitogen-activated protein kinase and calcineurin both change fibre-type markers in skeletal muscle culture

    DEFF Research Database (Denmark)

    Higginson, James; Wackerhage, Henning; Woods, Niall

    2002-01-01

    A and mitogen-activated protein kinase kinase (MEK1/2) blockade with U0126 upon myosin heavy chain (MHC) isoform mRNA levels and activities of metabolic enzymes after 1 day, 3 days and 7 days of treatment in primary cultures of spontaneously twitching rat skeletal muscle. U0126 treatment significantly decreased......Activation of either the calcineurin or the extracellular signal-regulated kinase (ERK1/2) pathway increases the percentage of slow fibres in vivo suggesting that both pathways can regulate fibre phenotypes in skeletal muscle. We investigated the effect of calcineurin blockade with cyclosporin...

  15. Phosphoinositide-3-kinases p110alpha and p110beta mediate S phase entry in astroglial cells in the marginal zone of rat neocortex

    Directory of Open Access Journals (Sweden)

    Rabea eMüller

    2013-03-01

    Full Text Available In cells cultured from neocortex of newborn rats, phosphoinositide-3-kinases of class I regulate the DNA synthesis in a subgroup of astroglial cells. We have studied the location of these cells as well as the kinase isoforms which facilitate the S phase entry. Using dominant negative isoforms as well as selective pharmacological inhibitors we quantified S phase entry by nuclear labeling with bromodeoxyuridine. Only in astroglial cells harvested from the marginal zone of the neocortex inhibition of phosphoinositide-3-kinases reduced the nuclear labeling with bromodeoxyuridine, indicating that neocortical astroglial cells differ in the regulation of proliferation. The two kinase isoforms p110 and p110were essential for S phase entry. p110 diminished the level of the p27Kip1 which inactivates the complex of cyclin E and CDK2 necessary for entry into the S phase. p110phosphorylated and inhibited glycogen synthase kinase-3which can prevent S-phase entry. Taken together, both isoforms mediated S phase in a subgroup of neocortical astroglial cells and acted via distinct pathways.

  16. Fully automated SPE-based synthesis and purification of 2-[{sup 18}F]fluoroethyl-choline for human use

    Energy Technology Data Exchange (ETDEWEB)

    Schmaljohann, Joern [Department of Nuclear Medicine, University of Bonn, Bonn (Germany); Department of Nuclear Medicine, University of Aachen, Aachen (Germany); Schirrmacher, Esther [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Waengler, Bjoern; Waengler, Carmen [Department of Nuclear Medicine, Ludwig-Maximilians University, Munich (Germany); Schirrmacher, Ralf, E-mail: ralf.schirrmacher@mcgill.c [McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec (Canada); Guhlke, Stefan, E-mail: stefan.guhlke@ukb.uni-bonn.d [Department of Nuclear Medicine, University of Bonn, Bonn (Germany)

    2011-02-15

    Introduction: 2-[{sup 18}F]Fluoroethyl-choline ([{sup 18}F]FECH) is a promising tracer for the detection of prostate cancer as well as brain tumors with positron emission tomography (PET). [{sup 18}F]FECH is actively transported into mammalian cells, becomes phosphorylated by choline kinase and gets incorporated into the cell membrane after being metabolized to phosphatidylcholine. So far, its synthesis is a two-step procedure involving at least one HPLC purification step. To allow a wider dissemination of this tracer, finding a purification method avoiding HPLC is highly desirable and would result in easier accessibility and more reliable production of [{sup 18}F]FECH. Methods: [{sup 18}F]FECH was synthesized by reaction of 2-bromo-1-[{sup 18}F]fluoroethane ([{sup 18}F]BFE) with dimethylaminoethanol (DMAE) in DMSO. We applied a novel and very reliable work-up procedure for the synthesis of [{sup 18}F]BFE. Based on a combination of three different solid-phase cartridges, the purification of [{sup 18}F]BFE from its precursor 2-bromoethyl-4-nitrobenzenesulfonate (BENos) could be achieved without using HPLC. Following the subsequent reaction of the purified [{sup 18}F]BFE with DMAE, the final product [{sup 18}F]FECH was obtained as a sterile solution by passing the crude reaction mixture through a combination of two CM plus cartridges and a sterile filter. The fully automated synthesis was performed using as well a Raytest SynChrom module (Raytest, Germany) or a Scintomics HotboxIII module (Scintomics, Germany). Results: The radiotracer [{sup 18}F]FECH can be synthesized in reliable radiochemical yields (RCY) of 37{+-}5% (Synchrom module) and 33{+-}5% (Hotbox III unit) in less than 1 h using these two fully automated commercially available synthesis units without HPLC involvement for purification. Detailed quality control of the final injectable [{sup 18}F]FECH solution proved the high radiochemical purity and the absence of Kryptofix2.2.2, DMAE and DMSO used in the

  17. p53 isoform profiling in glioblastoma and injured brain.

    Science.gov (United States)

    Takahashi, R; Giannini, C; Sarkaria, J N; Schroeder, M; Rogers, J; Mastroeni, D; Scrable, H

    2013-06-27

    The tumor suppressor p53 has been found to be the most commonly mutated gene in human cancers; however, the frequency of p53 mutations varies from 10 to 70% across different cancer types. This variability can partly be explained by inactivating mechanisms aside from direct genomic polymorphisms. The p53 gene encodes 12 isoforms, some of which can modulate full-length p53 activity in cancer. In this study, we characterized p53 isoform expression patterns in glioblastoma, gliosis, non-tumor brain and neural progenitor cells by SDS-PAGE, immunoblot, mass spectrometry and reverse transcription-PCR. We found that the most consistently expressed isoform in glioblastoma, Δ40p53, was uniquely expressed in regenerative processes, such as those involving neural progenitor cells and gliosis compared with tumor samples. Isoform profiling of glioblastoma tissues revealed the presence of both Δ40p53 and full-length p53, neither of which were detected in non-tumor cerebral cortex. Upon xenograft propagation of tumors, p53 levels increased. The variability of overall p53 expression and relative levels of isoforms suggest fluctuations in subpopulations of cells with greater or lesser capacity for proliferation, which can change as the tumor evolves under different growth conditions.

  18. Pre-Conditioning with CDP-Choline Attenuates Oxidative Stress-Induced Cardiac Myocyte Death in a Hypoxia/Reperfusion Model

    OpenAIRE

    Héctor González-Pacheco; Aurelio Méndez-Domínguez; Salomón Hernández; Rebeca López-Marure; Vazquez-Mellado, Maria J.; Cecilia Aguilar; Leticia Rocha-Zavaleta

    2014-01-01

    Background. CDP-choline is a key intermediate in the biosynthesis of phosphatidylcholine, which is an essential component of cellular membranes, and a cell signalling mediator. CDP-choline has been used for the treatment of cerebral ischaemia, showing beneficial effects. However, its potential benefit for the treatment of myocardial ischaemia has not been explored yet. Aim. In the present work, we aimed to evaluate the potential use of CDP-choline as a cardioprotector in an in vitro model of ...

  19. Protein Kinase D Enzymes as Regulators of EMT and Cancer Cell Invasion

    Directory of Open Access Journals (Sweden)

    Nisha Durand

    2016-02-01

    Full Text Available The Protein Kinase D (PKD isoforms PKD1, PKD2, and PKD3 are effectors of the novel Protein Kinase Cs (nPKCs and diacylglycerol (DAG. PKDs impact diverse biological processes like protein transport, cell migration, proliferation, epithelial to mesenchymal transition (EMT and apoptosis. PKDs however, have distinct effects on these functions. While PKD1 blocks EMT and cell migration, PKD2 and PKD3 tend to drive both processes. Given the importance of EMT and cell migration to the initiation and progression of various malignancies, abnormal expression of PKDs has been reported in multiple types of cancers, including breast, pancreatic and prostate cancer. In this review, we discuss how EMT and cell migration are regulated by PKD isoforms and the significance of this regulation in the context of cancer development.

  20. Adenosine-5'-phosphosulfate kinase is essential for Arabidopsis viability.

    Science.gov (United States)

    Mugford, Sarah G; Matthewman, Colette A; Hill, Lionel; Kopriva, Stanislav

    2010-01-04

    In Arabidopsis thaliana, adenosine-5'-phosphosulfate kinase (APK) provides activated sulfate for sulfation of secondary metabolites, including the glucosinolates. We have successfully isolated three of the four possible triple homozygous mutant combinations of this family. The APK1 isoform alone was sufficient to maintain WT levels of growth and development. Analysis of apk1 apk2 apk3 and apk1 apk3 apk4 mutants suggests that APK3 and APK4 are functionally redundant, despite being located in cytosol and plastids, respectively. We were, however, unable to isolate apk1 apk3 apk4 mutants, most probably because the apk1 apk3 apk4 triple mutant combination is pollen lethal. Therefore, we conclude that APS kinase is essential for plant reproduction and viability.

  1. Ocular lesions and experimental choline deficiency Lesiones oculares y deficiencia experimental de colina

    Directory of Open Access Journals (Sweden)

    Georgina P. Ossani

    2006-10-01

    Full Text Available Previous studies have shown ocular haemorrhages in choline-deficient rats. The aim of this paper is to study further the relationship between ocular and renal lesions and biochemical alterations in rats fed a choline-deficient diet. Fifty one weanling male Wistar rats, were divided into two groups. Thirty one of them were fed a choline-deficient diet and the rest was fed a choline-supplemented diet ad libitum. Animals from both groups were killed between the fifth and the eighth day. Urea, creatinine and homocysteine concentrations in blood were determined. Eyes were used for light microscopy study; high resolution light microscopy and the study of the retina as "rétine a plat". Kidneys were studied by light microscopy. Choline-supplemented rats did not show ocular or renal lesion. Choline-deficient rats that showed renal lesions, tubular or cortical necrosis, did not always have ocular changes. There were no ocular changes in the only choline-deficient rat without renal lesion. The ocular changes consisted mainly in haemorrhage in both cameras and ciliary and vitreous bodies. Correlations between ocular and renal lesion (r=0.72, pEstudios previos han demostrado hemorragia ocular en ratas deficientes en colina. El objetivo de este trabajo es profundizar en la relación entre las alteraciones oculares, renales y bioquímicas en ratas deficientes en colina. Cincuenta y una ratas Wistar macho recién destetadas fueron divididas en dos grupos: treinta y una fueron alimentadas con una dieta colino deficiente y el resto con colina suplementada ad-libitum. Los animales de ambos grupos fueron sacrificados entre el quinto y el octavo día. Se midió la concentración de urea, creatinina y homocisteína en sangre. Los ojos fueron estudiados por microscopía de luz, microscopía óptica de alta resolución y para el estudio de la retina como retina plana. Los riñones fueron estudiados por microscopía de luz. Las ratas suplementadas con colina no

  2. Laminin isoforms in endothelial and perivascular basement membranes.

    Science.gov (United States)

    Yousif, Lema F; Di Russo, Jacopo; Sorokin, Lydia

    2013-01-01

    Laminins, one of the major functional components of basement membranes, are found underlying endothelium, and encasing pericytes and smooth muscle cells in the vessel wall. Depending on the type of blood vessel (capillary, venule, postcapillary venule, vein or artery) and their maturation state, both the endothelial and mural cell phenotype vary, with associated changes in laminin isoform expression. Laminins containing the α4 and α5 chains are the major isoforms found in the vessel wall, with the added contribution of laminin α2 in larger vessels. We here summarize current data on the precise localization of these laminin isoforms and their receptors in the different layers of the vessel wall, and their potential contribution to vascular homeostasis.

  3. Oxygenation properties and isoform diversity of snake hemoglobins

    DEFF Research Database (Denmark)

    Storz, Jay F.; Natarajan, Chandrasekhar; Moriyama, Hideaki

    2015-01-01

    Available data suggest that snake hemoglobins (Hbs) are characterized by a combination of unusual structural and functional properties relative to the Hbs of other amniote vertebrates, including oxygenation-linked tetramer- dimer dissociation. However, standardized comparative data are lacking...... for snake Hbs, and the Hb isoform composition of snake red blood cells has not been systematically characterized. Here we present the results of an integrated analysis of snake Hbs and the underlying - and -type globin genes to characterize 1) Hb isoform composition of definitive erythrocytes, and 2......) the oxygenation properties of isolated isoforms as well as composite hemolysates. We used species from three families as subjects for experimental studies of Hb function: South American rattlesnake, Crotalus durissus (Viperidae); Indian python, Python molurus (Pythonidae); and yellow-bellied sea snake, Pelamis...

  4. Proteogenomic Analysis Identifies a Novel Human SHANK3 Isoform

    Directory of Open Access Journals (Sweden)

    Fahad Benthani

    2015-05-01

    Full Text Available Mutations of the SHANK3 gene have been associated with autism spectrum disorder. Individuals harboring different SHANK3 mutations display considerable heterogeneity in their cognitive impairment, likely due to the high SHANK3 transcriptional diversity. In this study, we report a novel interaction between the Mutated in colorectal cancer (MCC protein and a newly identified SHANK3 protein isoform in human colon cancer cells and mouse brain tissue. Hence, our proteogenomic analysis identifies a new human long isoform of the key synaptic protein SHANK3 that was not predicted by the human reference genome. Taken together, our findings describe a potential new role for MCC in neurons, a new human SHANK3 long isoform and, importantly, highlight the use of proteomic data towards the re-annotation of GC-rich genomic regions.

  5. Choline status and neurodevelopmental outcomes at 5 years of age in the Seychelles Child Development Nutrition Study.

    Science.gov (United States)

    Strain, J J; McSorley, Emeir M; van Wijngaarden, Edwin; Kobrosly, Roni W; Bonham, Maxine P; Mulhern, Maria S; McAfee, Alison J; Davidson, Philip W; Shamlaye, Conrad F; Henderson, Juliette; Watson, Gene E; Thurston, Sally W; Wallace, Julie M W; Ueland, Per M; Myers, Gary J

    2013-07-28

    Choline is an essential nutrient that is found in many food sources and plays a critical role in the development of the central nervous system. Animal studies have shown that choline status pre- and postnatally can have long-lasting effects on attention and memory; however, effects in human subjects have not been well studied. The aim of the present study was to examine the association between plasma concentrations of free choline and its related metabolites in children and their neurodevelopment in the Seychelles Child Development Nutrition Study, an ongoing longitudinal study assessing the development of children born to mothers with high fish consumption during pregnancy. Plasma concentrations of free choline, betaine, dimethylglycine (DMG), methionine and homocysteine and specific measures of neurodevelopment were measured in 210 children aged 5 years. The children's plasma free choline concentration (9·17 (sd 2·09) μmol/l) was moderately, but significantly, correlated with betaine (r 0·24; P= 0·0006), DMG (r 0·15; P= 0·03), methionine (r 0·24; P= 0·0005) and homocysteine (r 0·19; P= 0·006) concentrations. Adjusted multiple linear regression revealed that betaine concentrations were positively associated with Preschool Language Scale – total language scores (β = 0·066; P= 0·04), but no other associations were evident. We found no indication that free choline concentration or its metabolites, within the normal physiological range, are associated with neurodevelopmental outcomes in children at 5 years of age. As there is considerable animal evidence suggesting that choline status during development is associated with cognitive outcome, the issue deserves further study in other cohorts.

  6. Value of {sup 11}C-choline PET and PET/CT in patients with suspected prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Scher, Bernhard; Albinger, Wolfram; Tiling, Reinhold; Gildehaus, Franz-Josef; Dresel, Stefan [University of Munich, Department of Nuclear Medicine, Munich (Germany); Seitz, Michael [University of Munich, Department of Urology, Munich (Germany); Scherr, Michael; Becker, Hans-Christoph [University of Munich, Department of Radiology, Munich (Germany); Souvatzogluou, Michael; Wester, Hans-Juergen [Technical University of Munich, Department of Nuclear Medicine, Munich (Germany)

    2007-01-15

    The value and limitations of {sup 11}C-choline PET and PET/CT for the detection of prostate cancer remain controversial. The aim of this study was to investigate the diagnostic efficacy of {sup 11}C-choline PET and PET/CT in a large group of patients with suspected prostate cancer. Fifty-eight patients with clinical suspicion of prostate cancer underwent {sup 11}C-choline PET (25/58, Siemens ECAT Exact HR+) or PET/CT (33/58, Philips Gemini) scanning. On average, 500 MBq of {sup 11}C-choline was administered intravenously. Studies were interpreted by raters blinded to clinical information and other diagnostic procedures. Qualitative image analysis as well as semiquantitative SUV measurement was carried out. The reference standard was histopathological examination of resection specimens or biopsy. Prevalence of prostate cancer in this selected patient population was 63.8% (37/58). {sup 11}C-choline PET and PET/CT showed a sensitivity of 86.5% (32/37) and a specificity of 61.9% (13/21) in the detection of the primary malignancy. With regard to metastatic spread, PET showed a per-patient sensitivity of 81.8% (9/11) and produced no false positive findings. Based on our findings, differentiation between benign prostatic changes, such as benign prostatic hyperplasia or prostatitis, and prostate cancer is feasible in the majority of cases when image interpretation is primarily based on qualitative characteristics. SUV{sub max} may serve as guidance. False positive findings may occur due to an overlap of {sup 11}C-choline uptake between benign and malignant processes. By providing functional information regarding both the primary malignancy and its metastases, {sup 11}C-choline PET may prove to be a useful method for staging prostate cancer. (orig.)

  7. Application of a coupled enzyme assay to characterize nicotinamide riboside kinases.

    Science.gov (United States)

    Dölle, Christian; Ziegler, Mathias

    2009-02-15

    The recently identified nicotinamide riboside kinases (Nrks) constitute a distinct pathway of nicotinamide adenine dinucleotide (NAD) biosynthesis. Here we present the combination of an established optical adenosine triphosphatase (ATPase) test, the pyruvate kinase/lactate dehydrogenase system, with the Nrk-catalyzed reaction to determine kinetic properties of these enzymes, in particular affinities for ATP. The assay allows variation of both nucleoside and phosphate donor substrates, thereby providing major advantages for the characterization of these enzymes. We confirm previously established kinetic parameters and identify differences in substrate selectivity between the two human Nrk isoforms. The proposed assay is inexpensive and may be applied for high-throughput screening.

  8. Identification and characterization of novel NuMA isoforms

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jin, E-mail: petersdu2112@hotmail.com [Key Laboratory for Cell Proliferation and Regulation of the Ministry of Education, Beijing Normal University, Beijing (China); Xu, Zhe [Department of Clinical Laboratory Diagnosis, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); Core Laboratory for Clinical Medical Research, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); He, Dacheng [Key Laboratory for Cell Proliferation and Regulation of the Ministry of Education, Beijing Normal University, Beijing (China); Lu, Guanting, E-mail: guantlv@126.com [Beijing DnaLead Science and Technology Co., LTD, Beijing (China)

    2014-11-21

    Highlights: • Seven NuMA isoforms generated by alternative splicing were categorized into 3 groups: long, middle and short. • Both exons 15 and 16 in long NuMA were “hotspot” for alternative splicing. • Lower expression of short NuMA was observed in cancer cells compared with nonneoplastic controls. • Distinct localization pattern of short isoforms indicated different function from that of long and middle NuMA. - Abstract: The large nuclear mitotic apparatus (NuMA) has been investigated for over 30 years with functions related to the formation and maintenance of mitotic spindle poles during mitosis. However, the existence and functions of NuMA isoforms generated by alternative splicing remains unclear. In the present work, we show that at least seven NuMA isoforms (categorized into long, middle and short groups) generated by alternative splicing from a common NuMA mRNA precursor were discovered in HeLa cells and these isoforms differ mainly at the carboxyl terminus and the coiled-coil domains. Two “hotspot” exons with molecular mass of 3366-nt and 42-nt tend to be spliced during alternative splicing in long and middle groups. Furthermore, full-length coding sequences of long and middle NuMA obtained by using fusion PCR were constructed into GFP-tagged vector to illustrate their cellular localization. Long NuMA mainly localized in the nucleus with absence from nucleoli during interphase and translocated to the spindle poles in mitosis. Middle NuMA displayed the similar cell cycle-dependent distribution pattern as long NuMA. However, expression of NuMA short isoforms revealed a distinct subcellular localization. Short NuMA were present in the cytosol during the whole cycle, without colocalization with mitotic apparatus. These results have allowed us tentatively to explore a new research direction for NuMA’s various functions.

  9. Studying Kinetochore Kinases

    NARCIS (Netherlands)

    Saurin, Adrian T; Kops, Geert J P L

    2016-01-01

    Mitotic kinetochores are signaling network hubs that regulate chromosome movements, attachment error-correction, and the spindle assembly checkpoint. Key switches in these networks are kinases and phosphatases that enable rapid responses to changing conditions. Describing the mechanisms and dynamics

  10. Knockout of the PKN family of Rho effector kinases reveals a non-redundant role for PKN2 in developmental mesoderm expansion

    OpenAIRE

    Ivan Quétier; Jacqueline J.T. Marshall; Bradley Spencer-Dene; Sylvie Lachmann; Adele Casamassima; Claudio Franco; Sarah Escuin; Joseph T. Worrall; Priththivika Baskaran; Vinothini Rajeeve; Michael Howell; Andrew J. Copp; Gordon Stamp; Ian Rosewell; Pedro Cutillas

    2016-01-01

    Summary In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible s...

  11. Knockout of the PKN Family of Rho Effector Kinases Reveals a Non-redundant Role for PKN2 in Developmental Mesoderm Expansion

    OpenAIRE

    Quétier, I.; Marshall, J. J.; Spencer-Dene, B.; Lachmann, S.; Casamassima, A.; Franco, C.; Escuin, S.; Worrall, J. T.; Baskaran, P.; Rajeeve, V.; Howell, M.; Copp, A. J.; Stamp, G.; Rosewell, I.; Cutillas, P.

    2016-01-01

    In animals, the protein kinase C (PKC) family has expanded into diversely regulated subgroups, including the Rho family-responsive PKN kinases. Here, we describe knockouts of all three mouse PKN isoforms and reveal that PKN2 loss results in lethality at embryonic day 10 (E10), with associated cardiovascular and morphogenetic defects. The cardiovascular phenotype was not recapitulated by conditional deletion of PKN2 in endothelial cells or the developing heart. In contrast, inducible systemic ...

  12. Inhibition of RAF Isoforms and Active Dimers by LY3009120 Leads to Anti-tumor Activities in RAS or BRAF Mutant Cancers.

    Science.gov (United States)

    Peng, Sheng-Bin; Henry, James R; Kaufman, Michael D; Lu, Wei-Ping; Smith, Bryan D; Vogeti, Subha; Rutkoski, Thomas J; Wise, Scott; Chun, Lawrence; Zhang, Youyan; Van Horn, Robert D; Yin, Tinggui; Zhang, Xiaoyi; Yadav, Vipin; Chen, Shih-Hsun; Gong, Xueqian; Ma, Xiwen; Webster, Yue; Buchanan, Sean; Mochalkin, Igor; Huber, Lysiane; Kays, Lisa; Donoho, Gregory P; Walgren, Jennie; McCann, Denis; Patel, Phenil; Conti, Ilaria; Plowman, Gregory D; Starling, James J; Flynn, Daniel L

    2015-09-14

    LY3009120 is a pan-RAF and RAF dimer inhibitor that inhibits all RAF isoforms and occupies both protomers in RAF dimers. Biochemical and cellular analyses revealed that LY3009120 inhibits ARAF, BRAF, and CRAF isoforms with similar affinity, while vemurafenib or dabrafenib have little or modest CRAF activity compared to their BRAF activities. LY3009120 induces BRAF-CRAF dimerization but inhibits the phosphorylation of downstream MEK and ERK, suggesting that it effectively inhibits the kinase activity of BRAF-CRAF heterodimers. Further analyses demonstrated that LY3009120 also inhibits various forms of RAF dimers including BRAF or CRAF homodimers. Due to these unique properties, LY3009120 demonstrates minimal paradoxical activation, inhibits MEK1/2 phosphorylation, and exhibits anti-tumor activities across multiple models carrying KRAS, NRAS, or BRAF mutation.

  13. Role of choline and glycine betaine in the formation of N,N-dimethylpiperidinium (mepiquat) under Maillard reaction conditions.

    Science.gov (United States)

    Bessaire, Thomas; Tarres, Adrienne; Stadler, Richard H; Delatour, Thierry

    2014-01-01

    This study is the first to examine the role of choline and glycine betaine, naturally present in some foods, in particular in cereal grains, to generate N,N-dimethylpiperidinium (mepiquat) under Maillard conditions via transmethylation reactions involving the nucleophile piperidine. The formation of mepiquat and its intermediates piperidine - formed by cyclisation of free lysine in the presence of reducing sugars - and N-methylpiperidine were monitored over time (240°C, up to 180 min) using high-resolution mass spectrometry in a model system comprised of a ternary mixture of lysine/fructose/alkylating agent (choline or betaine). The reaction yield was compared with data recently determined for trigonelline, a known methylation agent present naturally in coffee beans. The role of choline and glycine betaine in nucleophilic displacement reactions was further supported by experiments carried out with stable isotope-labelled precursors (¹³C- and deuterium-labelled). The results unequivocally demonstrated that the piperidine ring of mepiquat originates from the carbon chain of lysine, and that either choline or glycine betaine furnishes the N-methyl groups. The kinetics of formation of the corresponding demethylated products of both choline and glycine betaine, N,N-demethyl-2-aminoethanol and N,N-dimethylglycine, respectively, were also determined using high-resolution mass spectrometry.

  14. ApoE isoform-dependent changes in hippocampal synaptic function

    Directory of Open Access Journals (Sweden)

    Sullivan Patrick M

    2009-05-01

    Full Text Available Abstract The lipoprotein receptor system in the hippocampus is intimately involved in the modulation of synaptic transmission and plasticity. The association of specific apoE isoform expression with human neurodegenerative disorders has focused attention on the role of these apoE isoforms in lipoprotein receptor-dependent synaptic modulation. In the present study, we used the apoE2, apoE3 and apoE4 targeted replacement (TR mice along with recombinant human apoE isoforms to determine the role of apoE isoforms in hippocampus area CA1 synaptic function. While synaptic transmission is unaffected by apoE isoform, long-term potentiation (LTP is significantly enhanced in apoE4 TR mice versus apoE2 TR mice. ApoE isoform-dependent differences in LTP induction require NMDA-receptor function, and apoE isoform expression alters activation of both ERK and JNK signal transduction. Acute application of specific apoE isoforms also alters LTP induction while decreasing NMDA-receptor mediated field potentials. Furthermore, acute apoE isoform application does not have the same effects on ERK and JNK activation. These findings demonstrate specific, isoform-dependent effects of human apoE isoforms on adult hippocampus synaptic plasticity and highlight mechanistic differences between chronic apoE isoform expression and acute apoE isoform exposure.

  15. Systematically differentiating functions for alternatively spliced isoforms through integrating RNA-seq data.

    Science.gov (United States)

    Eksi, Ridvan; Li, Hong-Dong; Menon, Rajasree; Wen, Yuchen; Omenn, Gilbert S; Kretzler, Matthias; Guan, Yuanfang

    2013-01-01

    Integrating large-scale functional genomic data has significantly accelerated our understanding of gene functions. However, no algorithm has been developed to differentiate functions for isoforms of the same gene using high-throughput genomic data. This is because standard supervised learning requires 'ground-truth' functional annotations, which are lacking at the isoform level. To address this challenge, we developed a generic framework that interrogates public RNA-seq data at the transcript level to differentiate functions for alternatively spliced isoforms. For a specific function, our algorithm identifies the 'responsible' isoform(s) of a gene and generates classifying models at the isoform level instead of at the gene level. Through cross-validation, we demonstrated that our algorithm is effective in assigning functions to genes, especially the ones with multiple isoforms, and robust to gene expression levels and removal of homologous gene pairs. We identified genes in the mouse whose isoforms are predicted to have disparate functionalities and experimentally validated the 'responsible' isoforms using data from mammary tissue. With protein structure modeling and experimental evidence, we further validated the predicted isoform functional differences for the genes Cdkn2a and Anxa6. Our generic framework is the first to predict and differentiate functions for alternatively spliced isoforms, instead of genes, using genomic data. It is extendable to any base machine learner and other species with alternatively spliced isoforms, and shifts the current gene-centered function prediction to isoform-level predictions.

  16. Systematically differentiating functions for alternatively spliced isoforms through integrating RNA-seq data.

    Directory of Open Access Journals (Sweden)

    Ridvan Eksi

    Full Text Available Integrating large-scale functional genomic data has significantly accelerated our understanding of gene functions. However, no algorithm has been developed to differentiate functions for isoforms of the same gene using high-throughput genomic data. This is because standard supervised learning requires 'ground-truth' functional annotations, which are lacking at the isoform level. To address this challenge, we developed a generic framework that interrogates public RNA-seq data at the transcript level to differentiate functions for alternatively spliced isoforms. For a specific function, our algorithm identifies the 'responsible' isoform(s of a gene and generates classifying models at the isoform level instead of at the gene level. Through cross-validation, we demonstrated that our algorithm is effective in assigning functions to genes, especially the ones with multiple isoforms, and robust to gene expression levels and removal of homologous gene pairs. We identified genes in the mouse whose isoforms are predicted to have disparate functionalities and experimentally validated the 'responsible' isoforms using data from mammary tissue. With protein structure modeling and experimental evidence, we further validated the predicted isoform functional differences for the genes Cdkn2a and Anxa6. Our generic framework is the first to predict and differentiate functions for alternatively spliced isoforms, instead of genes, using genomic data. It is extendable to any base machine learner and other species with alternatively spliced isoforms, and shifts the current gene-centered function prediction to isoform-level predictions.

  17. Value of Fused 18F-Choline-PET/MRI to Evaluate Prostate Cancer Relapse in Patients Showing Biochemical Recurrence after EBRT: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Arnoldo Piccardo

    2014-01-01

    Full Text Available Purpose. We compared the accuracy of 18F-Choline-PET/MRI with that of multiparametric MRI (mMRI, 18F-Choline-PET/CT, 18F-Fluoride-PET/CT, and contrast-enhanced CT (CeCT in detecting relapse in patients with suspected relapse of prostate cancer (PC after external beam radiotherapy (EBRT. We assessed the association between standard uptake value (SUV and apparent diffusion coefficient (ADC. Methods. We evaluated 21 patients with biochemical relapse after EBRT. Patients underwent 18F-Choline-PET/contrast-enhanced (CeCT, 18F-Fluoride-PET/CT, and mMRI. Imaging coregistration of PET and mMRI was performed. Results. 18F-Choline-PET/MRI was positive in 18/21 patients, with a detection rate (DR of 86%. DRs of 18F-Choline-PET/CT, CeCT, and mMRI were 76%, 43%, and 81%, respectively. In terms of DR the only significant difference was between 18F-Choline-PET/MRI and CeCT. On lesion-based analysis, the accuracy of 18F-Choline-PET/MRI, 18F-Choline-PET/CT, CeCT, and mMRI was 99%, 95%, 70%, and 85%, respectively. Accuracy, sensitivity, and NPV of 18F-Choline-PET/MRI were significantly higher than those of both mMRI and CeCT. On whole-body assessment of bone metastases, the sensitivity of 18F-Choline-PET/CT and 18F-Fluoride-PET/CT was significantly higher than that of CeCT. Regarding local and lymph node relapse, we found a significant inverse correlation between ADC and SUV-max. Conclusion. 18F-Choline-PET/MRI is a promising technique in detecting PC relapse.

  18. Rapamycin induces mitogen-activated protein (MAP) kinase phosphatase-1 (MKP-1) expression through activation of protein kinase B and mitogen-activated protein kinase kinase pathways.

    Science.gov (United States)

    Rastogi, Ruchi; Jiang, Zhongliang; Ahmad, Nisar; Rosati, Rita; Liu, Yusen; Beuret, Laurent; Monks, Robert; Charron, Jean; Birnbaum, Morris J; Samavati, Lobelia

    2013-11-22

    Mitogen-activated protein kinase phosphatase-1 (MKP-1), also known as dual specificity phosphatase-1 (DUSP-1), plays a crucial role in the deactivation of MAPKs. Several drugs with immune-suppressive properties modulate MKP-1 expression as part of their mechanism of action. We investigated the effect of mTOR inhibition through rapamycin and a dual mTOR inhibitor (AZD2014) on MKP-1 expression. Low dose rapamycin led to a rapid activation of both AKT and ERK pathways with a subsequent increase in MKP-1 expression. Rapamycin treatment led to phosphorylation of CREB, transcription factor 1 (ATF1), and ATF2, three transcription factors that bind to the cyclic AMP-responsive elements on the Mkp-1 promoter. Inhibition of either the MEK/ERK or the AKT pathway attenuated rapamycin-mediated MKP-1 induction. AZD2014 did not activate AKT but activated the ERK pathway, leading to a moderate MKP-1 induction. Using bone marrow-derived macrophages (BMDMs) derived from wild-type (WT) mice or mice deficient in AKT1 and AKT2 isoforms or BMDM from targeted deficiency in MEK1 and MEK2, we show that rapamycin treatment led to an increased MKP1 expression in BMDM from WT but failed to do so in BMDMs lacking the AKT1 isoform or MEK1 and MEK2. Importantly, rapamycin pretreatment inhibited LPS-mediated p38 activation and decreased nitric oxide and IL-6 production. Our work provides a conceptual framework for the observed immune modulatory effect of mTOR inhibition.

  19. Studies of antimony telluride and copper telluride films electrodeposition from choline chloride containing ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Catrangiu, Adriana-Simona; Sin, Ion [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Prioteasa, Paula [INCDIE ICPE-Advanced Research, Splaiul Unirii 313, Bucharest (Romania); Cotarta, Adina [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Cojocaru, Anca, E-mail: a_cojocaru@chim.upb.ro [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania); Anicai, Liana [Center of Surface Science and Nanotechnology, University POLITEHNICA of Bucharest, Splaiul Independentei 313, Bucharest (Romania); Visan, Teodor [Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, POLITEHNICA University of Bucharest, Calea Grivitei 132, Bucharest (Romania)

    2016-07-29

    Cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the deposition of antimony telluride or copper telluride from ionic liquid consisting in mixture of choline chloride with oxalic acid. In addition, the cathodic process during copper telluride formation was studied in the mixture of choline chloride with ethylene glycol. The results indicate that the Pt electrode is first covered with a Te layer, and then the more negative polarisation leads to the deposition of Sb{sub x}Te{sub y} or Cu{sub x}Te{sub y} semiconductor compounds. Thin films were deposited on copper and carbon steel at 60–70 °C and were characterised by scanning electron microscopy, energy X-ray dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Their stoichiometry depends on the bath composition and applied potential. EDS and XRD patterns indicate the possible synthesis of stoichiometric Sb{sub 2}Te{sub 3} phase and Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, and Cu{sub 2.8}Te{sub 2} phases, respectively, by controlling the ratio of ion concentrations in ionic liquid electrolytes and deposition potential. - Highlights: • Sb{sub x}Te{sub y} and Cu{sub x}Te{sub y} films electrodeposited from choline-chloride-based ionic liquids. • The stoichiometry of film depends on the bath composition and deposition potential. • Sb{sub 2}Te{sub 3}, Cu{sub 2}Te, Cu{sub 5}Te{sub 3}, Cu{sub 2.8}Te{sub 2} phases were identified in X-ray diffraction patterns.

  20. Differential water permeability and regulation of three aquaporin 4 isoforms

    DEFF Research Database (Denmark)

    Fenton, Robert A.; Moeller, Hanne B; Zelenina, Marina

    2010-01-01

    Aquaporin 4 (AQP4) is expressed in the perivascular glial endfeet and is an important pathway for water during formation and resolution of brain edema. In this study, we examined the functional properties and relative unit water permeability of three functional isoforms of AQP4 expressed in the b...

  1. Isoforms of transferrin in psoriasis patients abusing alcohol

    NARCIS (Netherlands)

    P. Hoefkens (Peter); E.M. Higgins; R.J. Ward (Roberta); H.G. van Eijk (Henk)

    1997-01-01

    textabstractThe different isoforms of transferrin have been quantified by isoelectric focusing in the sera of psoriasis patients with and without a history of abusing alcohol. In both male and female psoriasis subjects abusing alcohol, there were significant increases in the 2-sial

  2. Murine Sirt3 protein isoforms have variable half-lives

    Science.gov (United States)

    Sirt3 is a NAD+-dependent protein deacetylase mainly localized in mitochondria. Recent studies indicate that the murine Sirt3 gene expresses different transcript variants resulting in three possible Sirt3 protein isoforms with variable lengths at the N-terminus: M1 (aa 1-334), M2 (aa 15-334), and M3...

  3. Protein tyrosine phosphatase PTPRR isoforms in cellular signaling and trafficking

    NARCIS (Netherlands)

    Dilaver, Gönül

    2005-01-01

    Previous work has revealed the existence of two Protein Tyrosine Phosphatases in mouse, PTPBR7 and PTP-SL, that were in part identical, suggesting that they originated from the same gene, termed Ptprr (1,5,6). In this thesis, I report on the characterization of the various PTPRR isoforms in neuronal

  4. Distinct Functions of Endophilin Isoforms in Synaptic Vesicle Endocytosis

    Directory of Open Access Journals (Sweden)

    Jifeng Zhang

    2015-01-01

    Full Text Available Endophilin isoforms perform distinct characteristics in their interactions with N-type Ca2+ channels and dynamin. However, precise functional differences for the endophilin isoforms on synaptic vesicle (SV endocytosis remain unknown. By coupling RNA interference and electrophysiological recording techniques in cultured rat hippocampal neurons, we investigated the functional differences of three isoforms of endophilin in SV endocytosis. The results showed that the amplitude of normalized evoked excitatory postsynaptic currents in endophilin1 knockdown neurons decreased significantly for both single train and multiple train stimulations. Similar results were found using endophilin2 knockdown neurons, whereas endophilin3 siRNA exhibited no change compared with control neurons. Endophilin1 and endophilin2 affected SV endocytosis, but the effect of endophilin1 and endophilin2 double knockdown was not different from that of either knockdown alone. This result suggested that endophilin1 and endophilin2 functioned together but not independently during SV endocytosis. Taken together, our results indicate that SV endocytosis is sustained by endophilin1 and endophilin2 isoforms, but not by endophilin3, in primary cultured hippocampal neurons.

  5. Bacteria-Induced Dscam Isoforms of the Crustacean, Pacifastacus leniusculus.

    Directory of Open Access Journals (Sweden)

    Apiruck Watthanasurorot

    2011-06-01

    Full Text Available The Down syndrome cell adhesion molecule, also known as Dscam, is a member of the immunoglobulin super family. Dscam plays an essential function in neuronal wiring and appears to be involved in innate immune reactions in insects. The deduced amino acid sequence of Dscam in the crustacean Pacifastacus leniusculus (PlDscam, encodes 9(Ig-4(FNIII-(Ig-2(FNIII-TM and it has variable regions in the N-terminal half of Ig2 and Ig3 and the complete Ig7 and in the transmembrane domain. The cytoplasmic tail can generate multiple isoforms. PlDscam can generate more than 22,000 different unique isoforms. Bacteria and LPS injection enhanced the expression of PlDscam, but no response in expression occurred after a white spot syndrome virus (WSSV infection or injection with peptidoglycans. Furthermore, PlDscam silencing did not have any effect on the replication of the WSSV. Bacterial specific isoforms of PlDscam were shown to have a specific binding property to each tested bacteria, E. coli or S. aureus. The bacteria specific isoforms of PlDscam were shown to be associated with bacterial clearance and phagocytosis in crayfish.

  6. Choline Acetyltransferase Activity in Striatum of Neonatal Rats Increased by Nerve Growth Factor

    Science.gov (United States)

    Mobley, William C.; Rutkowski, J. Lynn; Tennekoon, Gihan I.; Buchanan, Karen; Johnston, Michael V.

    1985-07-01

    Some neurodegenerative disorders may be caused by abnormal synthesis or utilization of trophic molecules required to support neuronal survival. A test of this hypothesis requires that trophic agents specific for the affected neurons be identified. Cholinergic neurons in the corpus striatum of neonatal rats were found to respond to intracerebroventricular administration of nerve growth factor with prominent, dose-dependent, selective increases in choline acetyltransferase activity. Cholinergic neurons in the basal forebrain also respond to nerve growth factor in this way. These actions of nerve growth factor may indicate its involvement in the normal function of forebrain cholinergic neurons as well as in neurodegenerative disorders involving such cells.

  7. An Incidental Renal Oncocytoma: 18F-Choline PET/MRI

    Directory of Open Access Journals (Sweden)

    Andrew Mallia

    2016-04-01

    Full Text Available PET/MRI is a new hybrid imaging modality and has the potential to become a powerful imaging tool. It is currently one of the most active areas of research in diagnostic imaging. The characterisation of an incidental renal lesion can be difficult. In particular, the differentiation of an oncocytoma from other solid renal lesions such as renal cell carcinoma (RCC represents a diagnostic challenge. We describe the detection of an incidental renal oncocytoma in a 79-year gentleman who underwent a re-staging 18F-Choline PET/MRI following a rise in PSA values (4.07, nadir 1.3.

  8. Choline-based biodegradable ionic liquid catalyst for Mannich-type reaction

    Indian Academy of Sciences (India)

    PENG HUAN; HU YULIN; XING RONG; FANG DONG

    2016-12-01

    A three-component Mannich-type reaction of aromatic aldehydes, ketones, and amines was catalyzed by a novel choline-based acidic ionic liquid. The proposed catalyst was a Lewis-BrØnsted dual acid catalyst as well as water-tolerant. The β-amino carbonyl compounds were obtained at room temperature in reasonable to good yields ranging from 63 to 98%. After the reaction, the catalyst could be recycled and reused for 5 times without obvious decrease of the yield. Further, the catalyst was environment-friendly with a significant biodegradation rate.

  9. Cloning, expression and alternative splicing of the novel isoform of hTCP11 gene

    DEFF Research Database (Denmark)

    Ma, Yong-xin; Zhang, Si-zhong; Wu, Qia-qing;

    2003-01-01

    To identify a novel isoform of hTCP11 gene and investigate its expression and alternative splicing.......To identify a novel isoform of hTCP11 gene and investigate its expression and alternative splicing....

  10. Heparan sulfate proteoglycan isoforms of the CD44 hyaluronan receptor induced in human inflammatory macrophages can function as paracrine regulators of fibroblast growth factor action.

    Science.gov (United States)

    Jones, M; Tussey, L; Athanasou, N; Jackson, D G

    2000-03-17

    The CD44 glycoprotein is expressed in multiple isoforms on a variety of cell types where it functions as a receptor for hyaluronan-mediated motility. Recently, interest has centered on CD44 heparan sulfate proteoglycan (HSPG) isoforms because of their potential to sequester heparin-binding growth factors and chemokines. Expression of these isoforms on ectodermal cells has recently been shown to regulate limb morphogenesis via presentation of fibroblast growth factor (FGF) 4/FGF 8 while expression on tumor cells was shown to sequester hepatocyte growth factor and promote tumor dissemination. To date, however, CD44 HSPG expression in tissue macrophages and lymphocytes has not been adequately investigated, despite the fact these cells actively synthesize growth factors and chemokines and indirect evidence that monocyte CD44 sequesters macrophage inflammatory protein-1beta. Here we show primary human monocytes rather than lymphocytes express CD44 HSPGs, but only following in vitro differentiation to macrophages or activation with the proinflammatory cytokine interleukin-1alpha or bacterial lipopolysaccharide. Furthermore, we show these isoforms are preferentially modified with heparan rather than chondroitin sulfate, bind the macrophage-derived growth factors FGF-2, vascular endothelial growth factor, and heparin-binding epidermal growth factor with varying affinities (K(d) 25-330 nM) and in the case of FGF-2, can stimulate productive binding to the high affinity tyrosine kinase FGF receptor 1 (FGFR1). In contrast, we find no evidence for significant binding to C-C chemokines. Last, we confirm by immunofluorescent antibody staining that inflamed synovial membrane macrophages express CD44 HSPGs and that expression is greatest in cells containing high FGF-2 levels. These results suggest a paracrine role for macrophage CD44 HSPG isoforms in the regulation of growth factor action during inflammation.

  11. Exposure to chronic psychosocial stress and corticosterone in the rat : Effects on spatial discrimination learning and hippocampal protein kinase C gamma immunoreactivity

    NARCIS (Netherlands)

    Krugers, HJ; Douma, BRK; Bohus, B; Korf, J; Luiten, PGM; Krugers, Harm J.

    1997-01-01

    Previous reports have demonstrated a striking increase of the immunoreactivity of the gamma-isoform of protein kinase C (PKC gamma-ir) in Ammon's horn and dentate gyrus (DC) of rodent hippocampus after training in a spatial orientation task. In the present study, we investigated how 8 days of psycho

  12. Mitochondrial affinity for ADP is twofold lower in creatine kinase knock-out muscles - Possible role in rescuing cellular energy homeostasis

    NARCIS (Netherlands)

    ter Veld, F; Jeneson, JAL; Nicolay, K

    2005-01-01

    Adaptations of the kinetic properties of mitochondria in striated muscle lacking cytosolic (M) and/or mitochondrial (Mi) creatine kinase (CK) isoforms in comparison to wild-type (WT) were investigated in vitro. Intact mitochondria were isolated from heart and gastrocnemius muscle of WT and single- a

  13. Pre-Conditioning with CDP-Choline Attenuates Oxidative Stress-Induced Cardiac Myocyte Death in a Hypoxia/Reperfusion Model

    Science.gov (United States)

    González-Pacheco, Héctor; Méndez-Domínguez, Aurelio; Hernández, Salomón; López-Marure, Rebeca; Vazquez-Mellado, Maria J.; Aguilar, Cecilia; Rocha-Zavaleta, Leticia

    2014-01-01

    Background. CDP-choline is a key intermediate in the biosynthesis of phosphatidylcholine, which is an essential component of cellular membranes, and a cell signalling mediator. CDP-choline has been used for the treatment of cerebral ischaemia, showing beneficial effects. However, its potential benefit for the treatment of myocardial ischaemia has not been explored yet. Aim. In the present work, we aimed to evaluate the potential use of CDP-choline as a cardioprotector in an in vitro model of ischaemia/reperfusion injury. Methods. Neonatal rat cardiac myocytes were isolated and subjected to hypoxia/reperfusion using the coverslip hypoxia model. To evaluate the effect of CDP-choline on oxidative stress-induced reperfusion injury, the cells were incubated with H2O2 during reperfusion. The effect of CDP-choline pre- and postconditioning was evaluated using the cell viability MTT assay, and the proportion of apoptotic and necrotic cells was analyzed using the Annexin V determination by flow cytometry. Results. Pre- and postconditioning with 50 mg/mL of CDP-choline induced a significant reduction of cells undergoing apoptosis after hypoxia/reperfusion. Preconditioning with CDP-choline attenuated postreperfusion cell death induced by oxidative stress. Conclusion. CDP-choline administration reduces cell apoptosis induced by oxidative stress after hypoxia/reperfusion of cardiac myocytes. Thus, it has a potential as cardioprotector in ischaemia/reperfusion-injured cardiomyocytes. PMID:24578622

  14. Choline metabolism in glycinebetaine accumulating and non-accumulating near-isogenic lines of Zea mays and Sorghum bicolor.

    Science.gov (United States)

    Peel, Gregory J; Mickelbart, Michael V; Rhodes, David

    2010-03-01

    Glycinebetaine (GB) is a compatible solute that is accumulated by some plant species, especially under conditions leading to tissue osmotic stress. Genetic modification for accumulation of GB in an attempt to produce more stress tolerant plants has been a focus for several groups in recent years. However, attempts to increase tissue GB concentrations have been unsuccessful, with many transgenic lines accumulating far lower concentrations than naturally-occurring GB accumulators. A better understanding of the metabolic regulation of GB synthesis is necessary for successful molecular breeding and biotechnology. We utilized previously developed near-isogenic lines for GB accumulation to characterize the biochemical basis for GB deficiency in maize and sorghum. Salinity resulted in increased accumulation of choline in both accumulating and non-accumulating lines. When grown in the presence of NaCl, GB-non-accumulating lines had increased concentrations of choline and phosphocholine, but not GB. Decreased GB synthesis can be explained from the increased concentrations of phosphocholine in planta and the strong inhibition of N-phosphoethanolamine methyltransferase by phosphocholine observed in vitro. The lack of GB accumulation in GB-/- homozygous NILs was not due to the lack of the putative choline monooxygenase (the enzyme responsible for choline oxidation to betaine aldehyde) gene or protein that we describe. The previously identified bet1 locus does not appear to be choline monooxygenase. However, the lack of GB synthesis does affect the synthesis and turnover of choline moieties in GB non-accumulating lines, which may lead to alterations in overall 1-carbon metabolism in plants.

  15. Choline supplementation mitigates trace, but not delay, eyeblink conditioning deficits in rats exposed to alcohol during development.

    Science.gov (United States)

    Thomas, Jennifer D; Tran, Tuan D

    2012-03-01

    Children exposed to alcohol prenatally suffer from a range of physical, neuropathological, and behavioral alterations, referred to as fetal alcohol spectrum disorders (FASD). Both the cerebellum and hippocampus are affected by alcohol exposure during development, which may contribute to behavioral and cognitive deficits observed in children with FASD. Despite the known neuropathology associated with prenatal alcohol exposure, many pregnant women continue to drink (heavy drinkers, in particular), creating a need to identify effective treatments for their children who are adversely affected by alcohol. We previously reported that choline supplementation can mitigate alcohol's effects on cognitive development, specifically on tasks which depend on the functional integrity of the hippocampus. The present study examined whether choline supplementation could differentially mitigate alcohol's effects on trace eyeblink classical conditioning (ECC, a hippocampal-dependent task) and delay ECC (a cerebellar-dependent task). Long-Evans rats were exposed to 5.25 g/kg/day alcohol via gastric intubation from postnatal days (PD) 4-9, a period of brain development equivalent to late gestation in humans. A sham-intubated control group was included. From PD 10-30, subjects received subcutaneous injections of 100 mg/kg choline chloride or vehicle. Beginning on PD 32-34, subjects were trained on either delay or trace eyeblink conditioning. Performance of subjects exposed to alcohol was significantly impaired on both tasks, as indicated by significant reductions in percentage and amplitude of conditioned eyeblink responses, an effect that was attenuated by choline supplementation on the trace, but not delay conditioning task. Indeed, alcohol-exposed subjects treated with choline performed at control levels on the trace eyeblink conditioning task. There were no significant main or interactive effects of sex. These data indicate that choline supplementation can significantly reduce the

  16. N-methyl-D-aspartate increases acetylcholine release from rat striatum and cortex: its effect is augmented by choline

    Science.gov (United States)

    Ulus, I. H.; Buyukuysal, R. L.; Wurtman, R. J.

    1992-01-01

    We examined the effects of N-methyl-D-aspartate (NMDA), a glutamate agonist, and of glutamate itself, on acetylcholine (ACh) release from superfused rat striatal slices. In a Mg(++)-free medium, NMDA (32-1000 microM) as well as glutamate (1 mM) increased basal ACh release by 35 to 100% (all indicated differences, P less than .05), without altering tissue ACh or choline contents. This augmentation was blocked by Mg++ (1.2 mM) or by MK-801 (10 microM). Electrical stimulation (15 Hz, 75 mA) increased ACh release 9-fold (from 400 to 3660 pmol/mg of protein): this was enhanced (to 4850 pmol/mg of protein) by NMDA (100 microM). ACh levels in stimulated slices fell by 50 or 65% depending on the absence or presence of NMDA. The addition of choline (40 microM) increased ACh release both basally (570 pmol/mg of protein) and with electrical stimulation (6900 pmol/mg of protein). In stimulated slices choline acted synergistically with NMDA, raising ACh release to 10,520 pmol/mg of protein. The presence of choline also blocked the fall in tissue ACh. No treatment affected tissue phospholipid or protein levels. NMDA (32-320 microM) also augmented basal ACh release from cortical but not hippocampal slices. Choline efflux from striatal and cortical (but not hippocampal) slices decreased by 34 to 50% in Mg(++)-free medium. These data indicate that NMDA-like drugs may be useful, particularly in combination with choline, to enhance striatal and cortical cholinergic activity. ACh release from rat hippocampus apparently is not affected by NMDA receptors.

  17. Immunohistochemical determination of the extracellular matrix modulation in a rat model of choline-deprived myocardium: the effects of carnitine.

    Science.gov (United States)

    Strilakou, Athina; Perelas, Apostolos; Lazaris, Andreas; Papavdi, Asteria; Karkalousos, Petros; Giannopoulou, Ioanna; Kriebardis, Anastasios; Panayiotides, Ioannis; Liapi, Charis

    2016-02-01

    Choline has been identified as an essential nutrient with crucial role in many vital biological functions. Recent studies have demonstrated that heart dysfunction can develop in the setting of choline deprivation even in the absence of underlying heart disease. Matrix metalloproteinases (MMPs) are responsible for extracellular matrix degradation, and the dysregulation of MMP-2 and MMP-9 has been involved in the pathogenesis of various cardiovascular disorders. The aim of the study was to investigate the role of MMPs and their inhibitors (TIMPs), in the pathogenesis of choline deficiency-induced cardiomyopathy, and the way they are affected by carnitine supplementation. Male Wistar Albino adult rats were divided into four groups and received standard or choline-deficient diet with or without L-carnitine in drinking water (0.15% w/v) for 1 month. Heart tissue immunohistochemistry for MMP-2, MMP-9, TIMP-1, and TIMP-2 was performed. Choline deficiency was associated with suppressed immunohistochemical expression of MMP-2 and an increased expression of TIMP-2 compared to control, while it had no impact on TIMP-1. MMP-9 expression was decreased without, however, reaching statistical significance. Carnitine did not affect MMP-2, MMP-9, TIMP-1 or TIMP-2 expression. The pattern of TIMP and MMP modulation observed in a choline deficiency setting appears to promote fibrosis. Carnitine, although shown to suppress fibrosis, does not seem to affect MMP-2, MMP-9, TIMP-1 or TIMP-2 expression. Further studies will be required to identify the mechanism underlying the beneficial effects of carnitine.

  18. The expression of COX-2 in VEGF-treated endothelial cells is mediated through protein tyrosine kinase

    Directory of Open Access Journals (Sweden)

    Pravit Akarasereenont

    2002-01-01

    Full Text Available Cyclooxygenase (COX, existing as the COX-1 and COX-2 isoforms, converts arachidonic acid to prostaglandin H2, which is then further metabolized to various prostaglandins. Vascular endothelial growth factor (VEGF has been shown to play important roles in inflammation and is upregulated by the prostaglandin E series through COX-2 in several cell types. Here, we have investigated the effects of VEGF on the COX isoform expressed in human umbilical vein endothelial cells (HUVEC. The signalling mechanism of the COX isoform expressed in endothelial cells activated with VEGF will be also investigated using the tyrosine kinase inhibitor, genistein, and protein kinase C inhibitor, staurosporine. The activity of COX2 was assessed by measuring the production of 6-keto-prostaglandin F1α in the presence of exogenous arachidonic acids (10 μM, 10 min by enzyme immunoassay. The expression of COX isoform protein was detected by immunoblot using specific antibodies. Untreated HUVEC contained no COX-2 protein. In HUVEC treated with VEGF (0.01-50 ng/ml, COX-2 protein, but not COX-1, and COX activity were increased in a dose-dependent manner. Interestingly, the increased COX-2 protein and activity in response to VEGF (10 ng/ml was inhibited by the tyrosine kinase inhibitor, genistein (0.05-5 μg/ml, but not by the protein kinase C inhibitor, staurosporine (0.1-10 ng/ml. Thus, the induction of COX-2 by VEGF in endothelial cells was mediated through protein tyrosine kinase, and the uses of specific COX-2 inhibitors in these conditions, in which VEGF was involved, might have a role.

  19. PINCH proteins regulate cardiac contractility by modulating integrin-linked kinase-protein kinase B signaling.

    Science.gov (United States)

    Meder, Benjamin; Huttner, Inken G; Sedaghat-Hamedani, Farbod; Just, Steffen; Dahme, Tillman; Frese, Karen S; Vogel, Britta; Köhler, Doreen; Kloos, Wanda; Rudloff, Jessica; Marquart, Sabine; Katus, Hugo A; Rottbauer, Wolfgang

    2011-08-01

    Integrin-linked kinase (ILK) is an essential component of the cardiac mechanical stretch sensor and is bound in a protein complex with parvin and PINCH proteins, the so-called ILK-PINCH-parvin (IPP) complex. We have recently shown that inactivation of ILK or β-parvin activity leads to heart failure in zebrafish via reduced protein kinase B (PKB/Akt) activation. Here, we show that PINCH proteins localize at sarcomeric Z disks and costameres in the zebrafish heart and skeletal muscle. To investigate the in vivo role of PINCH proteins for IPP complex stability and PKB signaling within the vertebrate heart, we inactivated PINCH1 and PINCH2 in zebrafish. Inactivation of either PINCH isoform independently leads to instability of ILK, loss of stretch-responsive anf and vegf expression, and progressive heart failure. The predominant cause of heart failure in PINCH morphants seems to be loss of PKB activity, since PKB phosphorylation at serine 473 is significantly reduced in PINCH-deficient hearts and overexpression of constitutively active PKB reconstitutes cardiac function in PINCH morphants. These findings highlight the essential function of PINCH proteins in controlling cardiac contractility by granting IPP/PKB-mediated signaling.

  20. Glucose regulates diacylglycerol intracellular levels and protein kinase C activity by modulating diacylglycerol kinase subcellular localization.

    Science.gov (United States)

    Miele, Claudia; Paturzo, Flora; Teperino, Raffaele; Sakane, Fumio; Fiory, Francesca; Oriente, Francesco; Ungaro, Paola; Valentino, Rossella; Beguinot, Francesco; Formisano, Pietro

    2007-11-02

    Although chronic hyperglycemia reduces insulin sensitivity and leads to impaired glucose utilization, short term exposure to high glucose causes cellular responses positively regulating its own metabolism. We show that exposure of L6 myotubes overexpressing human insulin receptors to 25 mm glucose for 5 min decreased the intracellular levels of diacylglycerol (DAG). This was paralleled by transient activation of diacylglycerol kinase (DGK) and of insulin receptor signaling. Following 30-min exposure, however, both DAG levels and DGK activity returned close to basal levels. Moreover, the acute effect of glucose on DAG removal was inhibited by >85% by the DGK inhibitor R59949. DGK inhibition was also accompanied by increased protein kinase C-alpha (PKCalpha) activity, reduced glucose-induced insulin receptor activation, and GLUT4 translocation. Glucose exposure transiently redistributed DGK isoforms alpha and delta, from the prevalent cytosolic localization to the plasma membrane fraction. However, antisense silencing of DGKdelta, but not of DGKalpha expression, was sufficient to prevent the effect of high glucose on PKCalpha activity, insulin receptor signaling, and glucose uptake. Thus, the short term exposure of skeletal muscle cells to glucose causes a rapid induction of DGK, followed by a reduction of PKCalpha activity and transactivation of the insulin receptor signaling. The latter may mediate, at least in part, glucose induction of its own metabolism.

  1. Expression, purification and enzymatic characterization of the catalytic domains of human tryptophan hydroxylase isoforms

    DEFF Research Database (Denmark)

    Windahl, Michael Skovbo; Boesen, Jane; Karlsen, Pernille Efferbach;

    2009-01-01

    Tryptophan hydroxylase exists in two isoforms: Isoform 1 catalyses the first and rate-limiting step in the synthesis of serotonin in the peripheral parts of the body while isoform 2 catalyses this step in the brain. The catalytic domains of human tryptophan hydroxylase 1 and 2 have been expressed...

  2. Identification of cardiac myofilament protein isoforms using multiple mass spectrometry based approaches

    NARCIS (Netherlands)

    Kooij, V.; Venkatraman, V.; Kirk, J.A.; Ubaida-Mohien, C.; Graham, D.R.; Faber, M.J.; Eyk, J.E. Van

    2014-01-01

    PURPOSE: The identification of protein isoforms in complex biological samples is challenging. We, therefore, used an MS approach to unambiguously identify cardiac myofilament protein isoforms based on the observation of a tryptic peptide consisting of a sequence unique to a particular isoform. EXPER

  3. Determination of the class and isoform selectivity of small-molecule histone deacetylase inhibitors

    DEFF Research Database (Denmark)

    Khan, N.; Jeffers, M.; Kumar, S.;

    2008-01-01

    ) against a panel of rhHDAC (recombinant human HDAC) isoforms. Eight rhHDACs were expressed using a baculoviral system, and a Fluor de Lystrade mark (Biomol International) HDAC assay was optimized for each purified isoform. The potency and selectivity of ten HDACs on class I isoforms (rhHDAC1, rhHDAC2, rh...

  4. Electrochemical Deposition of Niobium onto the Surface of Copper Using a Novel Choline Chloride-Based Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Wixtroma, Alex I. [Christopher Newport U.; Buhlera, Jessica E. [Christopher Newport U.; Reece, Charles E. [JLAB; Abdel-Fattah, Tarek M. [Christopher Newport U.

    2013-06-01

    Recent research has shown that choline chloride-based solutions can be used to replace acid-based electrochemical polishing solutions. In this study niobium metal was successfully deposited on the surface of copper substrate via electrochemical deposition using a novel choline chloride-based ionic liquid. The niobium metal used for deposition on the Cu had been dissolved in the solution from electrochemical polishing of a solid niobium piece prior to the deposition. The visible coating on the surface of the Cu was analyzed using scanning electron microscopy (SEM) and electron dispersive x-ray spectroscopy (EDX). This deposition method effectively recycles previously dissolved niobium from electrochemical polishing.

  5. Discovery of Compounds that Positively Modulate the High Affinity Choline Transporter

    Science.gov (United States)

    Choudhary, Parul; Armstrong, Emma J.; Jorgensen, Csilla C.; Piotrowski, Mary; Barthmes, Maria; Torella, Rubben; Johnston, Sarah E.; Maruyama, Yuya; Janiszewski, John S.; Storer, R. Ian; Skerratt, Sarah E.; Benn, Caroline L.

    2017-01-01

    Cholinergic hypofunction is associated with decreased attention and cognitive deficits in the central nervous system in addition to compromised motor function. Consequently, stimulation of cholinergic neurotransmission is a rational therapeutic approach for the potential treatment of a variety of neurological conditions. High affinity choline uptake (HACU) into acetylcholine (ACh)-synthesizing neurons is critically mediated by the sodium- and pH-dependent high-affinity choline transporter (CHT, encoded by the SLC5A7 gene). This transporter is comparatively well-characterized but otherwise unexplored as a potential drug target. We therefore sought to identify small molecules that would enable testing of the hypothesis that positive modulation of CHT mediated transport would enhance activity-dependent cholinergic signaling. We utilized existing and novel screening techniques for their ability to reveal both positive and negative modulation of CHT using literature tools. A screening campaign was initiated with a bespoke compound library comprising both the Pfizer Chemogenomic Library (CGL) of 2,753 molecules designed specifically to help enable the elucidation of new mechanisms in phenotypic screens and 887 compounds from a virtual screening campaign to select molecules with field-based similarities to reported negative and positive allosteric modulators. We identified a number of previously unknown active and structurally distinct molecules that could be used as tools to further explore CHT biology or as a starting point for further medicinal chemistry. PMID:28289374

  6. Immunolocalization of choline acetyltransferase of common type in the central brain mass of Octopus vulgaris

    Directory of Open Access Journals (Sweden)

    A. Casini

    2012-07-01

    Full Text Available Acetylcholine, the first neurotransmitter to be identified in the vertebrate frog, is widely distributed among the animal kingdom. The presence of a large amount of acetylcholine in the nervous system of cephalopods is well known from several biochemical and physiological studies. However, little is known about the precise distribution of cholinergic structures due to a lack of a suitable histochemical technique for detecting acetylcholine. The most reliable method to visualize the cholinergic neurons is the immunohistochemical localization of the enzyme choline acetyltransferase, the synthetic enzyme of acetylcholine. Following our previous study on the distribution patterns of cholinergic neurons in the Octopus vulgaris visual system, using a novel antibody that recognizes choline acetyltransferase of the common type (cChAT, now we extend our investigation on the octopus central brain mass. When applied on sections of octopus central ganglia, immunoreactivity for cChAT was detected in cell bodies of all central brain mass lobes with the notable exception of the subfrontal and subvertical lobes. Positive varicosed nerves fibers where observed in the neuropil of all central brain mass lobes.

  7. Electrochemical synthesis of nanosized TiO{sub 2} nanopowder involving choline chloride based ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Anicai, Liana, E-mail: lanicai@itcnet.ro [POLITEHNICA University of Bucharest, Center of Surface Science and Nanotechnology, Splaiul Independentei 313, Bucharest, 060042 (Romania); Petica, Aurora [Leather and Footwear Research Institute (ICPI), Ion Minulescu 93, Bucharest, 031215 (Romania); Patroi, Delia; Marinescu, Virgil; Prioteasa, Paula [INCDIE ICPE-Advanced Research, Splaiul Unirii 313, Bucharest (Romania); Costovici, Stefania [POLITEHNICA University of Bucharest, Center of Surface Science and Nanotechnology, Splaiul Independentei 313, Bucharest, 060042 (Romania)

    2015-09-15

    Highlights: • TiO{sub 2} nanopowder electrochemically prepared using choline chloride based ionic liquids. • The new proposed method allowed high anodic synthesis efficiencies of minimum 92%. • High surface area of the electrochemically synthesized titania nanopowders. • Enhanced photocatalytic activity. - Abstract: The paper presents some experimental results regarding the electrochemical synthesis of TiO{sub 2} nanopowders through anodic dissolution of Ti metal in choline chloride based eutectic mixtures (DES). A detailed characterization of the obtained titania has been performed, using various techniques, including XRD, Raman spectroscopy, XPS, SEM associated with EDX analysis, BET and UV–vis diffuse reflectance spectra. The anodic behavior of Ti electrode in DES has been also investigated. The photoreactivity of the synthesized materials was evaluated for the degradation of Orange II dye under UV (λ = 365 nm) and visible light irradiation. An anodic synthesis efficiency of minimum 92% has been determined. The as-synthesized TiO{sub 2} showed amorphous structure and a calcination post-treatment at temperatures between 400 and 600 °C yielded anatase. The anodically obtained nanocrystalline oxides have crystallite sizes of 8–18 nm, a high surface area and enhanced photocatalytic effect.

  8. Choline acetyltransferase in the hippocampus is associated with learning strategy preference in adult male rats.

    Science.gov (United States)

    Hawley, Wayne R; Witty, Christine F; Daniel, Jill M; Dohanich, Gary P

    2015-08-01

    One principle of the multiple memory systems hypothesis posits that the hippocampus-based and striatum-based memory systems compete for control over learning. Consistent with this notion, previous research indicates that the cholinergic system of the hippocampus plays a role in modulating the preference for a hippocampus-based place learning strategy over a striatum-based stimulus--response learning strategy. Interestingly, in the hippocampus, greater activity and higher protein levels of choline acetyltransferase (ChAT), the enzyme that synthesizes acetylcholine, are associated with better performance on hippocampus-based learning and memory tasks. With this in mind, the primary aim of the current study was to determine if higher levels of ChAT and the high-affinity choline uptake transporter (CHT) in the hippocampus were associated with a preference for a hippocampus-based place learning strategy on a task that also could be solved by relying on a striatum-based stimulus--response learning strategy. Results confirmed that levels of ChAT in the dorsal region of the hippocampus were associated with a preference for a place learning strategy on a water maze task that could also be solved by adopting a stimulus-response learning strategy. Consistent with previous studies, the current results support the hypothesis that the cholinergic system of the hippocampus plays a role in balancing competition between memory systems that modulate learning strategy preference.

  9. Overexpression, purification and crystallization of a choline-binding protein CbpI from Streptococcus pneumoniae

    Energy Technology Data Exchange (ETDEWEB)

    Paterson, Neil G., E-mail: neison@chem.gla.ac.uk; Riboldi-Tunicliffe, Alan [Department of Chemistry and WestCHEM, Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom); Mitchell, Timothy J. [Division of Infection and Immunity (IBLS), Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom); Isaacs, Neil W. [Department of Chemistry and WestCHEM, Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom)

    2006-07-01

    The choline-binding protein CbpI from S. pneumoniae has been purified and crystallized and diffraction data have been collected to 3.5 Å resolution. The choline-binding protein CbpI from Streptococcus pneumoniae is a 23.4 kDa protein with no known function. The protein has been successfully purified initially using Ni–NTA chromatography and to homogeneity using Q-Sepharose ion-exchange resin as an affinity column. CbpI was crystallized using PEG 3350 as a precipitant and X-ray crystallographic analysis showed that the crystals belonged to the tetragonal space group P4, with unit-cell parameters a = b = 83.31, c = 80.29 Å, α = β = γ = 90°. The crystal contains two molecules in the asymmetric unit with a solvent content of 55.7% (V{sub M} = 2.77 Å{sup 3} Da{sup −1}) and shows a diffraction limit of 3.5 Å.

  10. Immunolocalization of choline acetyltransferase of common type in the central brain mass of Octopus vulgaris.

    Science.gov (United States)

    Casini, A; Vaccaro, R; D'Este, L; Sakaue, Y; Bellier, J P; Kimura, H; Renda, T G

    2012-07-19

    Acetylcholine, the first neurotransmitter to be identified in the vertebrate frog, is widely distributed among the animal kingdom. The presence of a large amount of acetylcholine in the nervous system of cephalopods is well known from several biochemical and physiological studies. However, little is known about the precise distribution of cholinergic structures due to a lack of a suitable histochemical technique for detecting acetylcholine. The most reliable method to visualize the cholinergic neurons is the immunohistochemical localization of the enzyme choline acetyltransferase, the synthetic enzyme of acetylcholine. Following our previous study on the distribution patterns of cholinergic neurons in the Octopus vulgaris visual system, using a novel antibody that recognizes choline acetyltransferase of the common type (cChAT), now we extend our investigation on the octopus central brain mass. When applied on sections of octopus central ganglia, immunoreactivity for cChAT was detected in cell bodies of all central brain mass lobes with the notable exception of the subfrontal and subvertical lobes. Positive varicosed nerves fibers where observed in the neuropil of all central brain mass lobes.

  11. Hydride transfer made easy in the oxidation of alcohols catalyzed by choline oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Gadda, G.; Orville, A.; Pennati, A.; Francis, K.; Quaye, O.; Yuan, H.; Rungsrisuriyachai, K.; Finnegan, S.; Mijatovic, S.; Nguyen, T.

    2008-06-08

    Choline oxidase (E.C. 1.1.3.17) catalyzes the two-step, four-electron oxidation of choline to glycine betaine with betaine aldehyde as enzyme-associated intermediate and molecular oxygen as final electron acceptor (Scheme 1). The gem-diol, hydrated species of the aldehyde intermediate of the reaction acts as substrate for aldehyde oxidation, suggesting that the enzyme may use similar strategies for the oxidation of the alcohol substrate and aldehyde intermediate. The determination of the chemical mechanism for alcohol oxidation has emerged from biochemical, mechanistic, mutagenetic, and structural studies. As illustrated in the mechanism of Scheme 2, the alcohol substrate is initially activated in the active site of the enzyme by removal of the hydroxyl proton. The resulting alkoxide intermediate is then stabilized in the enzyme-substrate complex via electrostatic interactions with active site amino acid residues. Alcohol oxidation then occurs quantum mechanically via the transfer of the hydride ion from the activated substrate to the N(5) flavin locus. An essential requisite for this mechanism of alcohol oxidation is the high degree of preorganization of the activated enzyme-substrate complex, which is achieved through an internal equilibrium of the Michaelis complex occurring prior to, and independently from, the subsequent hydride transfer reaction. The experimental evidence that support the mechanism for alcohol oxidation shown in Scheme 2 is briefly summarized in the Results and Discussion section.

  12. Dietary choline deprivation impairs rat brain mitochondrial function and behavioral phenotype.

    Science.gov (United States)

    Pacelli, Consiglia; Coluccia, Addolorata; Grattagliano, Ignazio; Cocco, Tiziana; Petrosillo, Giuseppe; Paradies, Giuseppe; De Nitto, Emanuele; Massaro, Antonio; Persichella, Michele; Borracci, Pietro; Portincasa, Piero; Carratù, Maria Rosaria

    2010-06-01

    Dietary choline deprivation (CD) is associated with behavioral changes, but mechanisms underlying these detrimental effects are not well characterized. For instance, no literature data are available concerning the CD effects on brain mitochondrial function related to impairment in cognition. Therefore, we investigated brain mitochondrial function and redox status in male Wistar rats fed a CD diet for 28 d. Moreover, the CD behavioral phenotype was characterized. Compared with rats fed a control diet (CTRL), CD rats showed lower NAD-dependent mitochondrial state III and state IV respiration, 40% lower complex I activity, and significantly higher reactive oxygen species production. Total glutathione was oxidatively consumed more in CD than in CTRL rats and the rate of protein oxidation was 40% higher in CD than in CTRL rats, reflecting an oxidative stress condition. The mitochondrial concentrations of cardiolipin, a phospholipid required for optimal activity of complex I, was 20% lower in CD rats than in CTRL rats. Compared with CTRL rats, the behavioral phenotype of CD rats was characterized by impairment in motor coordination and motor learning assessed with the rotarod/accelerod test. Furthermore, compared with CTRL rats, CD rats were less capable of learning the active avoidance task and the number of attempts they made to avoid foot shock was fewer. The results suggest that CD-induced dysfunction in brain mitochondria may be responsible for impairment in cognition and underline that, similar to the liver, the brain also needs an adequate choline supply for its normal functioning.

  13. Enterococcus faecalis phosphomevalonate kinase.

    Science.gov (United States)

    Doun, Stephanie S; Burgner, John W; Briggs, Scott D; Rodwell, Victor W

    2005-05-01

    The six enzymes of the mevalonate pathway of isopentenyl diphosphate biosynthesis represent potential for addressing a pressing human health concern, the development of antibiotics against resistant strains of the Gram-positive streptococci. We previously characterized the first four of the mevalonate pathway enzymes of Enterococcus faecalis, and here characterize the fifth, phosphomevalonate kinase (E.C. 2.7.4.2). E. faecalis genomic DNA and the polymerase chain reaction were used to clone DNA thought to encode phosphomevalonate kinase into pET28b(+). Double-stranded DNA sequencing verified the sequence of the recombinant gene. The encoded N-terminal hexahistidine-tagged protein was expressed in Escherichia coli with induction by isopropylthiogalactoside and purified by Ni(++) affinity chromatography, yield 20 mg protein per liter. Analysis of the purified protein by MALDI-TOF mass spectrometry established it as E. faecalis phosphomevalonate kinase. Analytical ultracentrifugation revealed that the kinase exists in solution primarily as a dimer. Assay for phosphomevalonate kinase activity used pyruvate kinase and lactate dehydrogenase to couple the formation of ADP to the oxidation of NADH. Optimal activity occurred at pH 8.0 and at 37 degrees C. The activation energy was approximately 5.6 kcal/mol. Activity with Mn(++), the preferred cation, was optimal at about 4 mM. Relative rates using different phosphoryl donors were 100 (ATP), 3.6 (GTP), 1.6 (TTP), and 0.4 (CTP). K(m) values were 0.17 mM for ATP and 0.19 mM for (R,S)-5-phosphomevalonate. The specific activity of the purified enzyme was 3.9 micromol substrate converted per minute per milligram protein. Applications to an immobilized enzyme bioreactor and to drug screening and design are discussed.

  14. EGFR soluble isoforms and their transcripts are expressed in meningiomas.

    Directory of Open Access Journals (Sweden)

    Angélique Guillaudeau

    Full Text Available The EGFR (epidermal growth factor receptor is involved in the oncogenesis of many tumors. In addition to the full-length EGFR (isoform a, normal and tumor cells produce soluble EGFR isoforms (sEGFR that lack the intracellular domain. sEGFR isoforms b, c and d are encoded by EGFR variants 2 (v2, 3 (v3 and 4 (v4 mRNA resulting from gene alternative splicing. Accordingly, the results of EGFR protein expression analysis depend on the domain targeted by the antibodies. In meningiomas, EGFR expression investigations mainly focused on EGFR isoform a. sEGFR and EGFRvIII mutant, that encodes a constitutively active truncated receptor, have not been studied. In a 69 meningiomas series, protein expression was analyzed by immunohistochemistry using extracellular domain targeted antibody (ECD-Ab and intracellular domain targeted antibody (ICD-Ab. EGFRv1 to v4 and EGFRvIII mRNAs were quantified by RT-PCR and EGFR amplification revealed by MLPA. Results were analyzed with respect to clinical data, tumor resection (Simpson grade, histological type, tumor grade, and patient outcome.Immunochemical staining was stronger with ECD-Ab than with ICD-Ab. Meningiomas expressed EGFRv1 to -v4 mRNAs but not EGFRvIII mutant. Intermediate or high ECD-Ab staining and high EGFRv1 to v4 mRNA levels were associated to a better progression free survival (PFS. PFS was also improved in women, when tumor resection was evaluated as Simpson 1 or 2, in grade I vs. grade II and III meningiomas and when Ki67 labeling index was lower than 10%. Our results suggest that, EGFR protein isoforms without ICD and their corresponding mRNA variants are expressed in meningiomas in addition to the whole isoform a. EGFRvIII was not expressed. High expression levels seem to be related to a better prognosis. These results indicate that the oncogenetic mechanisms involving the EGFR pathway in meningiomas could be different from other tumor types.

  15. Differential regulation of macropinocytosis by Abi1/Hssh3bp1 isoforms.

    Directory of Open Access Journals (Sweden)

    Patrycja M Dubielecka

    Full Text Available BACKGROUND: Macropinocytosis, which is a constitutive cellular process of fluid and macromolecule uptake, is regulated by actin cytoskeleton rearrangements near the plasma membrane. Activation of Rac1, which is proposed to act upstream of the actin polymerization regulatory Wave 2 complex, has been found to correlate with enhanced macropinocytosis. One of the components of the Wave 2 complex is Abi1. Multiple, alternatively spliced isoforms of Abi1 are expressed in mammalian cells, but the functional significance of the various isoforms is unknown. PRINCIPAL FINDINGS: Here, using flow cytometric assay analysis for Alexa Fluor 647, we demonstrate that Abi1 isoforms 2 and 3 differentially regulate macropinocytosis. LNCaP cells expressing isoform 3 had increased macropinocytic uptake that correlated with enhanced cell spreading and higher Rac1 activation in comparison to cells expressing isoform 2. Isoform 2 expressing cells had decreased macropinocytic uptake, but demonstrated greater sensitivity to Rac1 activation. Moreover, more isoform 2 was localized within the cytoplasm in comparison to isoform 3, which was more associated with the plasma membrane. Activated Rac1 was found to specifically bind to a site in exon 10 of isoform 2 in vitro. Because of alternative mRNA splicing, exon 10 is absent from isoform 3, precluding similar binding of activated Rac1. Both isoforms, however, bound to inactive Rac1 through the same non-exon 10 site. Thus, Abi1 isoform 3-containing Wave 2 complex exhibited a differential binding to activated vs. inactive Rac1, whereas isoform 2-containing Wave 2 complex bound activated or inactive Rac1 comparably. CONCLUSION: Based on these observations, we postulate that Abi1 isoforms differentially regulate macropinocytosis as a consequence of their different relative affinities for activated Rac1 in Wave 2 complex. These findings also raise the possibility that isoform-specific roles occur in other Abi1 functions.

  16. Inositol hexakisphosphate kinase 1 maintains hemostasis in mice by regulating platelet polyphosphate levels.

    Science.gov (United States)

    Ghosh, Somadri; Shukla, Dhananjay; Suman, Komjeti; Lakshmi, B Jyothi; Manorama, R; Kumar, Satish; Bhandari, Rashna

    2013-08-22

    Polyphosphate (polyP), a polymer of orthophosphate moieties released from the dense granules of activated platelets, is a procoagulant agent. Inositol pyrophosphates, another group of phosphate-rich molecules, consist of mono- and diphosphates substituted on an inositol ring. Diphosphoinositol pentakisphosphate (IP7), the most abundant inositol pyrophosphate, is synthesized on phosphorylation of inositol hexakisphosphate (IP6) by IP6 kinases, of which there are 3 mammalian isoforms (IP6K1/2/3) and a single yeast isoform. Yeast lacking IP6 kinase are devoid of polyP, suggesting a role for IP6 kinase in maintaining polyP levels. We theorized that the molecular link between IP6 kinase and polyP is conserved in mammals and investigated whether polyP-dependent platelet function is altered in IP6K1 knockout (Ip6k1(-/-)) mice. We observe a significant reduction in platelet polyP levels in Ip6k1(-/-) mice, along with slower platelet aggregation and lengthened plasma clotting time. Incorporation of polyP into fibrin clots was reduced in Ip6k1(-/-) mice, thereby altering clot ultrastructure, which was rescued on the addition of exogenous polyP. In vivo assays revealed longer tail bleeding time and resistance to thromboembolism in Ip6k1(-/-) mice. Taken together, our data suggest a novel role for IP6K1 in regulation of mammalian hemostasis via its control of platelet polyP levels.

  17. Proteomic Validation of Transcript Isoforms, Including Those Assembled from RNA-Seq Data

    DEFF Research Database (Denmark)

    Tay, Aidan P; Pang, Chi Nam Ignatius; Twine, Natalie a;

    2015-01-01

    data, and proteomic analysis of the same sample, can identify protein isoforms. RNA-seq data from human mesenchymal (hMSC) stem cells were analyzed with our new TranscriptCoder tool to generate a database of protein isoform sequences. MS/MS data from matching hMSC samples were then matched against...... the TranscriptCoder-derived database, along with Ensembl and the neXtProt database. Querying the TranscriptCoder-derived or Ensembl database could unambiguously identify ∼450 protein isoforms, with isoform-specific proteotypic peptides, including candidate hMSC-specific isoforms for the genes DPYSL2 and FXR1...

  18. Discoidin domain receptor 1: isoform expression and potential functions in cirrhotic human liver.

    Science.gov (United States)

    Song, Sunmi; Shackel, Nicholas A; Wang, Xin M; Ajami, Katerina; McCaughan, Geoffrey W; Gorrell, Mark D

    2011-03-01

    Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that binds and is activated by collagens. Transcriptional profiling of cirrhosis in human liver using a DNA array and quantitative PCR detected elevated mRNA expression of DDR1 compared with that in nondiseased liver. The present study characterized DDR1 expression in cirrhotic and nondiseased human liver and examined the cellular effects of DDR1 expression. mRNA expression of all five isoforms of DDR1 was detected in human liver, whereas DDR1a demonstrated differential expression in liver with hepatitis C virus and primary biliary cirrhosis compared with nondiseased liver. In addition, immunoblot analysis detected shed fragments of DDR1 more readily in cirrhotic liver than in nondiseased liver. Inasmuch as DDR1 is subject to protease-mediated cleavage after prolonged interaction with collagen, this differential expression may indicate more intense activation of DDR1 protein in cirrhotic compared with nondiseased liver. In situ hybridization and immunofluorescence localized intense DDR1 mRNA and protein expression to epithelial cells including hepatocytes at the portal-parenchymal interface and the luminal aspect of the biliary epithelium. Overexpression of DDR1a altered hepatocyte behavior including increased adhesion and less migration on extracelular matrix substrates. DDR1a regulated extracellular expression of matrix metalloproteinases 1 and 2. These data elucidate DDR1 function pertinent to cirrhosis and indicate the importance of epithelial cell-collagen interactions in chronic liver injury.

  19. ROCK-Isoform-Specific Polarization of Macrophages Associated with Age-Related Macular Degeneration

    Directory of Open Access Journals (Sweden)

    Souska Zandi

    2015-02-01

    Full Text Available Age is a major risk factor in age-related macular degeneration (AMD, but the underlying cause is unknown. We find increased Rho-associated kinase (ROCK signaling and M2 characteristics in eyes of aged mice, revealing immune changes in aging. ROCK isoforms determine macrophage polarization into M1 and M2 subtypes. M2-like macrophages accumulated in AMD, but not in normal eyes, suggesting that these macrophages may be linked to macular degeneration. M2 macrophages injected into the mouse eye exacerbated choroidal neovascular lesions, while M1 macrophages ameliorated them, supporting a causal role for macrophage subtypes in AMD. Selective ROCK2 inhibition with a small molecule decreased M2-like macrophages and choroidal neovascularization. ROCK2 inhibition upregulated M1 markers without affecting macrophage recruitment, underlining the plasticity of these macrophages. These results reveal age-induced innate immune imbalance as underlying AMD pathogenesis. Targeting macrophage plasticity opens up new possibilities for more effective AMD treatment.

  20. Characterization of four hemocyanin isoforms in Litopenaeus vannamei

    Institute of Scientific and Technical Information of China (English)

    XU Jingxiang; RUAN Lingwei; LI Zhen; YU Xiaoman; LI Sedong; SHI Hong; XU Xun

    2015-01-01

    In this study, the gene encoding hemocyanin subunit L, LvHcL, was cloned from Litopenaeus vannamei and the genomic organization was characterized. This gene was diverse with many SNPs and also had at least four isoforms, while one of them (LvHcL4) only had two exons and the exon2 was missed. Transcription analysis showed that these isoforms of LvHcL were up-regulated after WSSV challenge in WSSV-resistant shrimp, while the transcriptions were decreased constantly in WSSV-susceptible shrimp. It is suggested that the hemocyanin had rich polymorphism and was involved in the antiviral response. These results could extend our previous findings and provide insights into the immune feature of hemocyanin, which would be helpful for further studies aimed at antiviral mechanism in inver-tebrate.

  1. Disulfide isoforms of recombinant glia maturation factor beta.

    Science.gov (United States)

    Zaheer, A; Lim, R

    1990-09-14

    Recombinant human glia maturation factor beta (r-hGMF-beta) is a single-chain polypeptide (141 amino acid residues) containing three cysteines, at positions 7, 86 and 95. Nascent r-hGMF-beta exists in the reduced state and has no biological activity. The protein can be activated through oxidative refolding by incubation with a mixture of reduced and oxidized glutathione. Reverse-phase HPLC analysis of the refolded r-hGMF-beta shows the presence of four peaks, corresponding to the reduced form plus three newly generated intrachain disulfide-containing isoforms predicted from the number of cysteine residues. Only one isoform shows biological activity when tested for growth suppression on C6 glioma cells. We infer from the HPLC elution pattern that the active form contains the disulfide bridge Cys86-Cys95.

  2. Plant phosphatidylinositol 3-kinase

    NARCIS (Netherlands)

    Lee, Y.; Munnik, T.; Munnik, T.

    2010-01-01

    Phosphatidylinositol 3-kinase (PI3K) phosphorylates the D-3 position of phosphoinositides. In Arabidopsis, only one PI3K exists, which belongs to the class-III PI3K subfamily which makes phosphatidylinositol 3-phosphate (PtdIns3P). The single AtPI3K gene is essential for survival, since loss of its

  3. Method for analysing glycoprotein isoforms by capillary electrophoresis

    OpenAIRE

    Frutos, Mercedes de; Díez-Masa, José Carlos; Morales-Cid, Gabriel

    2011-01-01

    [EN] The present invention relates to a new method for the purification, concentration, separation and determination of the isoforms of alpha-1-acid glycoprotein (AGP) in human blood serum samples using capillary electrophoresis. The new method is based on the immunocapture and preconcentration of the sample within the separation capillary by using an immunoadsorbent phase magnetically immobilized within the electrophoresis capillary and the subsequent desorption and separation of the glycopr...

  4. Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

    Directory of Open Access Journals (Sweden)

    M. R. Aquino-Silva

    Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

  5. Differential expression of syndecan isoforms during mouse incisor amelogenesis.

    Science.gov (United States)

    Muto, Taro; Miyoshi, Keiko; Munesue, Seiichi; Nakada, Hiroshi; Okayama, Minoru; Matsuo, Takashi; Noma, Takafumi

    2007-08-01

    Syndecans are transmembranous heparan sulfate proteoglycans (HSPGs) with covalently attached glycosaminoglycan side-chains located on the cell surface. The mammalian syndecan family is composed of four types of syndecans (syndecan-1 to -4). Syndecans interact with the intracellular cytoskeleton through the cytoplasmic domains of their core proteins and membrane proteins, extracellular enzymes, growth factors, and matrix components, through their heparan-sulfate chains, to regulate developmental processes.Here, as a first step to assess the possible roles of syndecan proteins in amelogenesis, we examined the expression patterns of all syndecan isoforms in continuously growing mouse incisors, in which we can overview major differentiation stages of amelogenesis at a glance. Understanding the expression domain of each syndecan isoform during specific developmental stages seems useful for investigating their physiological roles in amelogenesis. Immunohistochemical analysis of syndecan core proteins in the lower incisors from postnatal day 1 mice revealed spatially and temporally specific expression patterns, with syndecan-1 expressed in undifferentiated epithelial and mesenchymal cells, and syndecan-2, -3, and -4 in more differentiated cells. These findings suggest that each syndecan isoform functions distinctly during the amelogenesis of the incisors of mice.

  6. Efficacy of oral nicotinic acid and choline in the treatment and prevention of fatty liver in dairy cow

    Institute of Scientific and Technical Information of China (English)

    TianWenru; YangDianjun; 等

    1994-01-01

    Nicotinic acid (N.C.)and choline were given orally to the periparturient cows to treat and prevent fatty liver.Blood parameters of glucose,β-hydroxybutyrate,albumin,total protein,magnesium,aspartate aminotransferase(AST) and non-esterified fatty acid(NEFA) were measured.There were no significant differences between the reated and untreated groups in the plasma concentrations of albumin,total,protein and magnsium.Significant decrease in plasma concentrations of β-hydroxybutyrate,NEFA and AST were observed in the treated cows following administration of N.C.and choline.All the fatty liver cows(100%) treated with N.C.and choline recovered within 5 weeks after calving compared with 71.4%(5/7) of untreated cows recovered.The incident ate of fatty liver postpartum in the cows with N.C.and choline given 2 weeks before calving was 30%(3/10),and the affected cows had a range of mild to moderate fatty liver whilst the incident rate was 50%(5/10)in the untreated cows.which had a range of mild to of severe fatty liver,Meanwhile,the treated cows had a significant higher prodection of milk and shorter intervals from calving to uterine involution,to the first postpartum ovulation and to conception.

  7. Effect of rumen-protected choline on performance, blood metabolites, and hepatic triacylglycerols of periparturient dairy cattle

    NARCIS (Netherlands)

    Zom, R.L.G.; Baal, van J.; Goselink, R.M.A.; Bakker, J.A.; Veth, M.J.; Vuuren, van A.M.

    2011-01-01

    The effects of a dietary supplement of rumen-protected choline on feed intake, milk yield, milk composition, blood metabolites, and hepatic triacylglycerol were evaluated in periparturient dairy cows. Thirty-eight multiparous cows were blocked into 19 pairs and then randomly allocated to either one

  8. Suppression Effects of Betaine-Enriched Spinach on Hyperhomocysteinemia Induced by Guanidinoacetic Acid and Choline Deficiency in Rats

    Directory of Open Access Journals (Sweden)

    Yi-Qun Liu

    2014-01-01

    Full Text Available Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25C was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT and cystathionine β-synthase (CBS in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

  9. Distributions of choline acetyltransferase and acetylcholinesterase activities in the retinal layers of the red-tailed hawk and road runner.

    Science.gov (United States)

    White, L E; Ross, C D; Godfrey, D A

    1991-01-01

    The activities of choline acetyltransferase and acetylcholinesterase were assayed in submicrogram samples from layers of red-tailed hawk and road runner retina. Both enzyme activities were concentrated in and near the inner plexiform layer. Within the inner plexiform layers of both species, activities of each enzyme were concentrated in two bands, one in each half of this layer. Little choline acetyltransferase activity was found superficial to the middle third of the inner nuclear layer. The distributions of acetylcholinesterase activities corresponded well to those of choline acetyltransferase, except in the outer plexiform layer and the outer margin of the inner nuclear layer of the hawk. These distributions of enzyme activities indicate that populations of amacrine cells in the retinae of these species are cholinergic. In addition to these same cells and presumably cholinoceptive amacrine and ganglion cells, acetylcholinesterase activity in the hawk was associated with a population of horizontal cells that may be unrelated to synaptic cholinergic neurotransmission. Choline acetyltransferase activities associated with amacrine somata and processes were about four times greater in the hawk than in the road runner, suggesting important differences in the density and function of cholinergic elements between species. Possible synaptic relationships in the inner plexiform layer consistent with the interspecies differences in enzyme activities are considered.

  10. SALT ACCLIMATION OF TRITICUM-AESTIVUM BY CHOLINE CHLORIDE - PLANT-GROWTH, MINERAL-CONTENT, AND CELL-PERMEABILITY

    NARCIS (Netherlands)

    MANSOUR, MM; STADELMANN, EJ; LEESTADELMANN, OY

    1993-01-01

    Seedlings of a salt sensitive line of Triticum aestivum were grown in Hoagland solution supplemented with 100 mM NaCl following a pretreatment with choline chloride (ChCl). Changes in growth, mineral content of roots and shoots, and passive permeability of the cell membrane were measured. Relative g

  11. Effect of rumen-protected choline supplementation on liver and adipose gene expression during the transition period in dairy cattle

    NARCIS (Netherlands)

    Goselink, R.M.A.; Baal, van J.; Widjaja, H.C.A.; Dekker, R.A.; Zom, R.L.G.; Veth, M.J.; Vuuren, van A.M.

    2013-01-01

    We previously reported that supplementation of rumen-protected choline (RPC) reduces the hepatic triacylglycerol concentration in periparturient dairy cows during early lactation. Here, we investigated the effect of RPC on the transcript levels of lipid metabolism-related genes in liver and adipose

  12. Crotoxin, the major toxin from the rattlesnake Crotalus durissus terrificus, inhibits ³H-choline uptake in guinea pig ileum

    Directory of Open Access Journals (Sweden)

    L.S. Kattah

    2000-09-01

    Full Text Available We examined the effect of crotoxin, the neurotoxic complex from the venom of the South American rattlesnake Crotalus durissus terrificus, on the uptake of ³H-choline in minces of smooth muscle myenteric plexus from guinea pig ileum. In the concentration range used (0.03-1 µM and up to 10 min of treatment, crotoxin decreased ³H-choline uptake by 50-75% compared to control. This inhibition was time dependent and did not seem to be associated with the disruption of the neuronal membrane, because at least for the first 20 min of tissue exposure to the toxin (up to 1 µM the levels of lactate dehydrogenase (LDH released into the supernatant were similar to those of controls. Higher concentrations of crotoxin or more extensive incubation times with this toxin resulted in elevation of LDH activity detected in the assay supernatant. The inhibitory effect of crotoxin on ³H-choline uptake seems to be associated with its phospholipase activity since the equimolar substitution of Sr2+ for Ca2+ in the incubation medium or the modification of the toxin with p-bromophenacyl bromide substantially decreased this effect. Our results show that crotoxin inhibits ³H-choline uptake with high affinity (EC25 = 10 ± 5 nM. We suggest that this inhibition could explain, at least in part, the blocking effect of crotoxin on neurotransmission.

  13. Choline and methionine differentially alter methyl carbon metabolism in bovine neonatal hepatocytes

    Science.gov (United States)

    Chandler, Tawny L.

    2017-01-01

    Intersections in hepatic methyl group metabolism pathways highlights potential competition or compensation of methyl donors. The objective of this experiment was to examine the expression of genes related to methyl group transfer and lipid metabolism in response to increasing concentrations of choline chloride (CC) and DL-methionine (DLM) in primary neonatal hepatocytes that were or were not exposed to fatty acids (FA). Primary hepatocytes isolated from 4 neonatal Holstein calves were maintained as monolayer cultures for 24 h before treatment with CC (61, 128, 2028, and 4528 μmol/L) and DLM (16, 30, 100, 300 μmol/L), with or without a 1 mmol/L FA cocktail in a factorial arrangement. After 24 h of treatment, media was collected for quantification of reactive oxygen species (ROS) and very low-density lipoprotein (VLDL), and cell lysates were collected for quantification of gene expression. No interactions were detected between CC, DLM, or FA. Both CC and DLM decreased the expression of methionine adenosyltransferase 1A (MAT1A). Increasing CC did not alter betaine-homocysteine S-methyltranferase (BHMT) but did increase 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) and methylenetetrahydrofolate reductase (MTHFR) expression. Increasing DLM decreased expression of BHMT and MTR, but did not affect MTHFR. Expression of both phosphatidylethanolamine N-methyltransferase (PEMT) and microsomal triglyceride transfer protein (MTTP) were decreased by increasing CC and DLM, while carnitine palmitoyltransferase 1A (CPT1A) was unaffected by either. Treatment with FA decreased the expression of MAT1A, MTR, MTHFR and tended to decrease PEMT but did not affect BHMT and MTTP. Treatment with FA increased CPT1A expression. Increasing CC increased secretion of VLDL and decreased the accumulation of ROS in media. Within neonatal bovine hepatocytes, choline and methionine differentially regulate methyl carbon pathways and suggest that choline may play a critical role in

  14. Phosphatidylethanolamine N-methyltransferase and choline dehydrogenase gene polymorphisms are associated with human sperm concentration

    Institute of Scientific and Technical Information of China (English)

    Leandros Lazaros; Ioannis Georgiou; Nectaria Xita; Elissavet Hatzi; Apostolos Kaponis; Georgios Makrydimas; Atsushi Takenaka; Nikolaos Sofikitis; Theodoros Stefos; Konstantinos Zikopoulos

    2012-01-01

    Choline is a crucial factor in the regulation of sperm membrane structure and fluidity,and this nutrient plays an important role in the maturation and fertilizing capacity of spermatozoa.Transcripts of phosphatidylethanolamine N-methyltransferase (PEMT) and choline dehydrogenase (CHDH),two basic enzymes of choline metabolism,have been observed in the human testis,demonstrating their gene expression in this tissue.In the present study,we explored the contribution of the PEMTand CHDHgene variants to sperm parameters.Two hundred oligospermic and 250 normozoospermic men were recruited.DNA was extracted from the spermatozoa,and the PEMT -774G>C and CHDH +432G>T polymorphisms were genotyped.The genotype distribution of the PEMT -774G>C polymorphism did not differ between oligospermic and normozoospermic men.In contrast,in the case of the CHDH +432G>T polymorphism,oligospermic men presented the CHDH432G/G genotype more frequently than normozoospermic men (62% vs.42%,P<0.001).The PEMT774G/G genotype was associated with a higher sperm concentration compared to the PEMT774G/C and 774C/C genotypes in oligospermic men (12.5±5.6×106 spermatozoa ml-1 vs.8.3±5.2×106 spermatozoa ml-1,P<0.002) and normozoospermic men (81.5±55.6×106 vs.68.1±44.5× 106 spermatozoa ml-1,P<0.006).In addition,the CHDH432G/G genotype was associated with higher sperm concentration compared to CHDH432G/T and 432T/T genotypes in oligospermic (11.8± 5.1 × 106 VS.7.8±5.3 × 106spermatozoa ml-1,P<0.003)and normozoospermic men(98.6±62.2×106vs.58.8±33.6×106 spermatozoa ml-1,p<0.001).In our series,the PEMT-774G>C and CHDH +432G>T polymorphisms were associated with sperm concentration.This finding suggests a possible influence of these genes on sperm quality.

  15. [{sup 11}C]Choline as pharmacodynamic marker for therapy response assessment in a prostate cancer xenograft model

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Bernd J.; Souvatzoglou, Michael; Herrmann, Ken; Weber, Axel W.; Buck, Andreas K.; Wester, Hans-Juergen; Ziegler, Sibylle I.; Senekowitsch-Schmidtke, Reingard; Schwaiger, Markus [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar (Germany); Schuster, Tibor [Technische Universitaet Muenchen, Department of Statistics (Germany); Nawroth, Roman; Treiber, Uwe [Technische Universitaet Muenchen, Department of Urology (Germany); Weirich, Gregor [Technische Universitaet Muenchen, Institute of Pathology (Germany)

    2010-10-15

    [{sup 11}C]Choline has been established as a PET tracer for imaging prostate cancer. The aim of this study was to determine whether [{sup 11}C]choline can be used for monitoring the effects of therapy in a prostate cancer mouse xenograft model. The androgen-independent human prostate cancer cell line PC-3 was implanted subcutaneously into the flanks of 13 NMRI (nu/nu) mice. All mice were injected 4-6 weeks after xenograft implantation with 37 MBq [{sup 11}C]choline via a tail vein. Dynamic imaging was performed for 60 min with a small-animal PET/CT scanner (Siemens Medical Solutions). Six mice were subsequently injected intravenously with docetaxel twice (days 1 and 5) at a dose of 3 mg/kg body weight. Seven mice were treated with PBS as a control. [{sup 11}C]Choline imaging was performed prior to and 1, 2 and 3 weeks after treatment. To determine choline uptake the images were analysed in terms of tumour-to-muscle (T/M) ratios. Every week the size of the implanted tumour was determined with a sliding calliper. The PC-3 tumours could be visualized by [{sup 11}C]choline PET. Before treatment the T/M{sub mean} ratio was 1.6{+-}0.5 in the control group and 1.8{+-}0.4 in the docetaxel-treated group (p=0.65). There was a reduction in the mean [{sup 11}C]choline uptake after docetaxel treatment as early as 1 week after initiation of therapy (T/M ratio 1.8{+-}0.4 before treatment, 0.9{+-}0.3 after 1 week, 1.1{+-}0.3 after 2 weeks and 0.8{+-}0.2 after 3 weeks). There were no decrease in [{sup 11}C]choline uptake in the control group following treatment (T/M ratio 1.6{+-}0.5 before treatment, 1.7{+-}0.4 after 1 week, 1.8{+-}0.7 after 2 weeks and 1.7{+-}0.4 after 3 weeks). For analysis of the dynamic data, a generalized estimation equation model revealed a significant decrease in the T/M{sub dyn} ratios 1 week after docetaxel treatment, and the ratio remained at that level through week 3 (mean change -0.93{+-}0.24, p<0.001, after 1 week; -0.78{+-}0.21, p<0.001, after 2 weeks

  16. Human p38{delta} MAP kinase mediates UV irradiation induced up-regulation of the gene expression of chemokine BRAK/CXCL14

    Energy Technology Data Exchange (ETDEWEB)

    Ozawa, Shigeyuki [Oral Health Science Research Center (Japan); Department of Biochemistry and Molecular Biology (Japan); Department of Oral and Maxillofacial Surgery, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka 238-8580 (Japan); Ito, Shin; Kato, Yasumasa [Oral Health Science Research Center (Japan); Department of Biochemistry and Molecular Biology (Japan); Kubota, Eiro [Department of Biochemistry and Molecular Biology (Japan); Department of Oral and Maxillofacial Surgery, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka 238-8580 (Japan); Hata, Ryu-Ichiro, E-mail: ryuhata@gmail.com [Oral Health Science Research Center (Japan); Department of Biochemistry and Molecular Biology (Japan)

    2010-06-11

    The mitogen-activated protein kinase (MAPK) family comprises ERK, JNK, p38 and ERK5 (big-MAPK, BMK1). UV irradiation of squamous cell carcinoma cells induced up-regulation of gene expression of chemokine BRAK/CXCL14, stimulated p38 phosphorylation, and down-regulated the phosphorylation of ERK. Human p38 MAPKs exist in 4 isoforms: p38{alpha}, {beta}, {gamma} and {delta}. The UV stimulation of p38 phosphorylation was not inhibited by the presence of SB203580 or PD169316, inhibitors of p38{alpha} and {beta}, suggesting p38 phosphorylation was not dependent on these 2 isoforms and that p38{gamma} and/or {delta} was responsible for the phosphorylation. In fact, inhibition of each of these 4 p38 isoforms by the introduction of short hairpin (sh) RNAs for respective isoforms revealed that only shRNA for p38{delta} attenuated the UV-induced up-regulation of BRAK/CXCL14 gene expression. In addition, over-expression of p38 isoforms in the cells showed the association of p38{delta} with ERK1 and 2, concomitant with down-regulation of ERK phosphorylation. The usage of p38{delta} isoform by UV irradiation is not merely due to the abundance of this p38 isoform in the cells. Because serum deprivation of the cells also induced an increase in BRAK/CXCL14 gene expression, and in this case p38{alpha} and/or {beta} isoform is responsible for up-regulation of BRAK/CXCL14 gene expression. Taken together, the data indicate that the respective stress-dependent action of p38 isoforms is responsible for the up-regulation of the gene expression of the chemokine BRAK/CXCL14.

  17. The role of Protein Kinase Cη in T cell biology

    Directory of Open Access Journals (Sweden)

    Nicholas R.J. Gascoigne

    2012-06-01

    Full Text Available Protein kinase Cη (PKCη is a member of the novel PKC subfamily, which also includes δ, ε, and θ isoforms. Compared to the other novel PKCs, the function of PKCη in the immune system is largely unknown. Several studies have started to reveal the role of PKCη, particularly in T cells. PKCη is highly expressed in T cells, and is upregulated during thymocyte positive selection. Interestingly, like the θ isoform, PKCη is also recruited to the immunological synapse that is formed between a T cell and an antigen-presenting cell. However, unlike PKCθ, which becomes concentrated to the central region of the synapse, PKCη remains in a diffuse pattern over the whole area of the synapse, suggesting distinctive roles of these two isoforms in signal transduction. Although PKCη is dispensable for thymocyte development, further analysis of PKCη− or PKCθ−deficient and double knockout mice revealed the redundancy of these two isoforms in thymocyte development. In contrast, PKCη rather than PKCθ, plays an important role for T cell homeostatic proliferation, which requires recognition of self-antigen. Another piece of evidence demonstrating that PKCη and PKCθ have isoform specific as well as redundant roles come from the analysis of CD4 to CD8 T cell ratios in the periphery of these knockout mice. Deficiency in PKCη or PKCθ had opposing effects as PKCη knockout mice had a higher ratio of CD4 to CD8 T cells compared to that of wild-type mice, whereas PKCθ-deficient mice had a lower ratio. Biochemical studies showed that calcium flux and NFκB translocation is impaired in PKCη-deficient T cells upon TCR crosslinking stimulation, a character shared with PKCθ-deficient T cells. However, unlike the case with PKCθ, the mechanistic study of PKCη is at early stage and the signaling pathways involving PKCη, at least in T cells, are essentially unknown. In this review, we will cover the topics mentioned above as well as provide some

  18. Alternative splicing of fibroblast growth factor receptor 3 produces a secreted isoform that inhibits fibroblast growth factor-induced proliferation and is repressed in urothelial carcinoma cell lines.

    Science.gov (United States)

    Tomlinson, Darren C; L'Hôte, Corine G; Kennedy, Wendy; Pitt, Eva; Knowles, Margaret A

    2005-11-15

    Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases that play key roles in proliferation, differentiation, and tumorigenesis. FGFR3 was identified as the major family member expressed in both normal human urothelium and cultured normal human urothelial (NHU) cells and was expressed as the IIIb isoform. We also identified a splice variant, FGFR3 Delta8-10, lacking exons encoding the COOH-terminal half of immunoglobulin-like domain III and the transmembrane domain. Previous reports have assumed that this is a cancer-specific splice variant. We showed that FGFR3 Delta8-10 is a normal transcript in NHU cells and is translated, N-glycosylated, and secreted. Primary urothelium expressed high levels of FGFR3 transcripts. In culture, levels were reduced in actively proliferating cells but increased at confluence and as cells approached senescence. Cells overexpressing FGFR3 IIIb showed FGF1-induced proliferation, which was inhibited by the addition of FGFR3 Delta8-10. In bladder tumor cell lines derived from aggressive carcinomas, there were significant alterations in the relative expression of isoforms including an overall decrease in the proportion of FGFR3 Delta8-10 and predominant expression of FGFR3 IIIc in some cases. In summary, alternative splicing of FGFR3 IIIb in NHU cells represents a normal mechanism to generate a transcript that regulates proliferation and in bladder cancer, the ratio of FGFR3 isoforms is significantly altered.

  19. Choline Phospholipid Metabolites of Human Vascular Endothelial Cells Altered by Cyclooxygenase Inhibition, Growth Factor Depletion, and Paracrine Factors Secreted by Cancer Cells

    Directory of Open Access Journals (Sweden)

    Noriko Mori

    2003-04-01

    Full Text Available Magnetic resonance studies have previously shown that solid tumors and cancer cells in culture typically exhibit high phosphocholine and total choline. Treatment of cancer cells with the anti-inflammatory agent, indomethacin (INDO, reverted the phenotype of choline phospholipid metabolites in cancer cells towards a less malignant phenotype. Since endothelial cells form a key component of tumor vasculature, in this study, we used MR spectroscopy to characterize the phenotype of choline phospholipid metabolites in human umbilical vein endothelial cells (HUVECs. We determined the effect of growth factors, the anti-inflammatory agent INDO, and conditioned media obtained from a malignant cell line, on choline phospholipid metabolites. Growth factor depletion or treatment with INDO induced similar changes in the choline phospholipid metabolites of HUVECs. Treatment with conditioned medium obtained from MDA-MB-231 cancer cells induced changes similar to the presence of growth factor supplements. These results suggest that cancer cells secrete growth factors and/or other molecules that influence the choline phospholipid metabolism of HUVECs. The ability of INDO to alter choline phospholipid metabolism in the presence of growth factor supplements suggests that the inflammatory response pathways of HUVECs may play a role in cancer cell-HUVEC interaction and in the response of HUVECs to growth factors.

  20. CDP-choline: effects of the procholine supplement on sensory gating and executive function in healthy volunteers stratified for low, medium and high P50 suppression.

    Science.gov (United States)

    Knott, Verner; Smith, Dylan; de la Salle, Sara; Impey, Danielle; Choueiry, Joelle; Beaudry, Elise; Smith, Meaghan; Saghir, Salman; Ilivitsky, Vadim; Labelle, Alain

    2014-12-01

    Diminished auditory sensory gating and associated neurocognitive deficits in schizophrenia have been linked to altered expression and function of the alpha-7 nicotinic acetycholinergic receptor (α7 nAChR), the targeting of which may have treatment potential. Choline is a selective α7 nAChR agonist and the aim of this study was to determine whether cytidine 5'-diphosphocholine (CDP-choline), or citicoline, a dietary source of choline, increases sensory gating and cognition in healthy volunteers stratified for gating level. In a randomized, placebo-controlled, double-blind design involving acute administration of low, moderate doses (500 mg, 1000 mg) of CDP-choline, 24 healthy volunteers were assessed for auditory gating as indexed by suppression of the P50 event-related potential (ERP) in a paired-stimulus (S1, S2) paradigm, and for executive function as measured by the Groton Maze Learning Task (GMLT) of the CogState Schizophrenia Battery. CDP-choline improved gating (1000 mg) and suppression of the S2 P50 response (500 mg, 1000 mg), with the effects being selective for individuals with low gating (suppression) levels. Tentative support was also shown for increased GMLT performance (500 mg) in low suppressors. These preliminary findings with CDP-choline in a healthy, schizophrenia-like surrogate sample are consistent with a α7 nAChR mechanism and support further trials with choline as a pro-cognitive strategy.

  1. The relationship between choline plus creatine- to-citrate ratio in magnetic resonance spectroscopy with the invasion of prostate cancer

    Directory of Open Access Journals (Sweden)

    M Ghafoori

    2012-12-01

    Full Text Available Background: Prostate cancer is the most common cancer and the second cause of cancer mortality in men. Although histopathological examination is the gold-standard for its diagnosis, tendency toward less invasive methods is growing. The purpose of this study was to evaluate the relationship between choline plus creatine- to-citrate ratio in magnetic resonance spectroscopy (MRS with the invasion of prostate cancer in a series of patients with prostate cancer.Methods: Totally, 200 patients with pathologically proven prostate cancer were enrolled in this cross-sectional study by a non-probability sampling method in Hazrat Rasul Akram Hospital in Tehran, Iran during 2009-2010. Pathological staging was the gold standard for the diagnosis of prostate cancer while the patients underwent MRS for choline plus creatine- to-citrate ratio determination. MRS and pathological results were compared and analyzed.Results: The mean (±SD values of choline plus creatine- to-citrate ratio in patients with Gleason scores less than 3, 3 to 4 and greater than 4 were 245.8±146.8, 427.1±173.6 and 427.1±173.6, respectively (P<0.001. The mean (±SD values of choline plus creatine- to-citrate ratio in patients with PSA levels less than 4, 4 to 10 and greater than 10 were 180.7±58.3, 247±93.5 and 385.1±106.6, respectively (P<0.001.Conclusion: Choline plus creatine- to-citrate ratio determined by magnetic resonance spectroscopy has a significant relationship with the degree of invasion of prostate cancer and can be used for the staging of the disease.

  2. PET imaging of hepatocellular carcinoma with {sup 18}F-fluoroethylcholine and {sup 11}C-choline

    Energy Technology Data Exchange (ETDEWEB)

    Kolthammer, Jeffrey A.; Tenley, Nathan [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Corn, David J.; Wu, Chunying; Tian, Haibin; Wang, Yanming [University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States); Lee, Zhenghong [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); University Hospitals Case Medical Center, Nuclear Medicine Division, Department of Radiology, Cleveland, OH (United States)

    2011-07-15

    Choline-based radiotracers have been studied for PET imaging of hepatocellular carcinoma (HCC). Using an {sup 18}F-labeled choline analog, instead of the {sup 11}C-labeled native choline, would facilitate its widespread use in the clinic. In this study, PET with {sup 18}F-fluoroethylcholine (FEC) and {sup 11}C-choline (CHOL) were compared using an animal model of HCC. The effects of fasting on the performance of choline-based tracers were also investigated. A woodchuck model of HCC was used to compare the two tracers, which were administered and imaged in sequence during the same imaging session. Dynamic PET images were generated spanning 50 min starting from tracer injection. Time-activity curves and tracer contrast were calculated in liver regions with tracer accumulation, and the contrast at a late time-point with the two tracers, and between fasted and nonfasted states, were compared. Foci of HCC with increased uptake ranged in size from 1.0 to 1.6 cm, with mean tumor-to-background contrast of 1.3 with FEC and 1.5 with CHOL at 50 min after injection. The tracers show similar patterns of uptake immediately following administration, and both activities plateaued at 10 min after injection. No significant differences in uptake dynamics or final contrast were observed between the fasted and nonfasted states. PET imaging of HCC is possible with both CHOL and FEC. Fasting was not found to affect accumulation of either tracer. These results encourage further investigation into the clinical utility of FEC for HCC imaging. (orig.)

  3. Fatigue resistance of rat extraocular muscles does not depend on creatine kinase activity

    Directory of Open Access Journals (Sweden)

    Hayeß Katrin

    2005-08-01

    Full Text Available Abstract Background Creatine kinase (CK links phosphocreatine, an energy storage system, to cellular ATPases. CK activity serves as a temporal and spatial buffer for ATP content, particularly in fast-twitch skeletal muscles. The extraocular muscles are notoriously fast and active, suggesting the need for efficient ATP buffering. This study tested the hypotheses that (1 CK isoform expression and activity in rat extraocular muscles would be higher, and (2 the resistance of these muscles to fatigue would depend on CK activity. Results We found that mRNA and protein levels for cytosolic and mitochondrial CK isoforms were lower in the extraocular muscles than in extensor digitorum longus (EDL. Total CK activity was correspondingly decreased in the extraocular muscles. Moreover, cytoskeletal components of the sarcomeric M line, where a fraction of CK activity is found, were downregulated in the extraocular muscles as was shown by immunocytochemistry and western blotting. CK inhibition significantly accelerated the development of fatigue in EDL muscle bundles, but had no major effect on the extraocular muscles. Searching for alternative ATP buffers that could compensate for the relative lack of CK in extraocular muscles, we determined that mRNAs for two adenylate kinase (AK isoforms were expressed at higher levels in these muscles. Total AK activity was similar in EDL and extraocular muscles. Conclusion These data indicate that the characteristic fatigue resistance of the extraocular muscles does not depend on CK activity.

  4. Expression patterns of protein kinase D 3 during mouse development

    Directory of Open Access Journals (Sweden)

    Lutz Sylke

    2008-04-01

    Full Text Available Abstract Background The PKD family of serine/threonine kinases comprises a single member in Drosophila (dPKD, two isoforms in C. elegans (DKF-1 and 2 and three members, PKD1, PKD2 and PKD3 in mammals. PKD1 and PKD2 have been the focus of most studies up to date, which implicate these enzymes in very diverse cellular functions, including Golgi organization and plasma membrane directed transport, immune responses, apoptosis and cell proliferation. Concerning PKD3, a role in the formation of vesicular transport carriers at the trans-Golgi network (TGN and in basal glucose transport has been inferred from in vitro studies. So far, however, the physiological functions of the kinase during development remain unknown. Results We have examined the expression pattern of PKD3 during the development of mouse embryos by immunohistochemistry. Using a PKD3 specific antibody we demonstrate that the kinase is differentially expressed during organogenesis. In the developing heart a strong PKD3 expression is constantly detected from E10 to E16.5. From E12.5 on PKD3 is increasingly expressed in neuronal as well as in the supporting connective tissue and in skeletal muscles. Conclusion The data presented support an important role for PKD3 during development of these tissues.

  5. Role of choline deficiency in the Fatty liver phenotype of mice fed a low protein, very low carbohydrate ketogenic diet.

    Directory of Open Access Journals (Sweden)

    Rebecca C Schugar

    Full Text Available Though widely employed for clinical intervention in obesity, metabolic syndrome, seizure disorders and other neurodegenerative diseases, the mechanisms through which low carbohydrate ketogenic diets exert their ameliorative effects still remain to be elucidated. Rodent models have been used to identify the metabolic and physiologic alterations provoked by ketogenic diets. A commonly used rodent ketogenic diet (Bio-Serv F3666 that is very high in fat (~94% kcal, very low in carbohydrate (~1% kcal, low in protein (~5% kcal, and choline restricted (~300 mg/kg provokes robust ketosis and weight loss in mice, but through unknown mechanisms, also causes significant hepatic steatosis, inflammation, and cellular injury. To understand the independent and synergistic roles of protein restriction and choline deficiency on the pleiotropic effects of rodent ketogenic diets, we studied four custom diets that differ only in protein (5% kcal vs. 10% kcal and choline contents (300 mg/kg vs. 5 g/kg. C57BL/6J mice maintained on the two 5% kcal protein diets induced the most significant ketoses, which was only partially diminished by choline replacement. Choline restriction in the setting of 10% kcal protein also caused moderate ketosis and hepatic fat accumulation, which were again attenuated when choline was replete. Key effects of the 5% kcal protein diet - weight loss, hepatic fat accumulation, and mitochondrial ultrastructural disarray and bioenergetic dysfunction - were mitigated by choline repletion. These studies indicate that synergistic effects of protein restriction and choline deficiency influence integrated metabolism and hepatic pathology in mice when nutritional fat content is very high, and support the consideration of dietary choline content in ketogenic diet studies in rodents to limit hepatic mitochondrial dysfunction and fat accumulation.

  6. The octopamine receptor OAMB mediates ovulation via Ca2+/calmodulin-dependent protein kinase II in the Drosophila oviduct epithelium.

    Directory of Open Access Journals (Sweden)

    Hyun-Gwan Lee

    Full Text Available Ovulation is an essential physiological process in sexual reproduction; however, the underlying cellular mechanisms are poorly understood. We have previously shown that OAMB, a Drosophila G-protein-coupled receptor for octopamine (the insect counterpart of mammalian norepinephrine, is required for ovulation induced upon mating. OAMB is expressed in the nervous and reproductive systems and has two isoforms (OAMB-AS and OAMB-K3 with distinct capacities to increase intracellular Ca2+ or intracellular Ca2+ and cAMP in vitro. Here, we investigated tissue specificity and intracellular signals required for OAMB's function in ovulation. Restricted OAMB expression in the adult oviduct epithelium, but not the nervous system, reinstated ovulation in oamb mutant females, in which either OAMB isoform was sufficient for the rescue. Consistently, strong immunoreactivities for both isoforms were observed in the wild-type oviduct epithelium. To delineate the cellular mechanism by which OAMB regulates ovulation, we explored protein kinases functionally interacting with OAMB by employing a new GAL4 driver with restricted expression in the oviduct epithelium. Conditional inhibition of Ca2+/Calmodulin-dependent protein kinase II (CaMKII, but not protein kinase A or C, in the oviduct epithelium inhibited ovulation. Moreover, constitutively active CaMKII, but not protein kinase A, expressed only in the adult oviduct epithelium fully rescued the oamb female's phenotype, demonstrating CaMKII as a major downstream molecule conveying the OAMB's ovulation signal. This is consistent with the ability of both OAMB isoforms, whose common intracellular signal in vitro is Ca2+, to reinstate ovulation in oamb females. These observations reveal the critical roles of the oviduct epithelium and its cellular components OAMB and CaMKII in ovulation. It is conceivable that the OAMB-mediated cellular activities stimulated upon mating are crucial for secretory activities suitable for egg

  7. The Semi-automatic Synthesis of 18F-fluoroethyl-choline by Domestic FDG Synthesizer

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    ZHOU Ming

    2016-02-01

    Full Text Available As an important complementary imaging agent for 18F-FDG, 18F-fluoroethyl-choline (18F-FECH has been demonstrated to be promising in brain and prostate cancer imaging. By using domestic PET-FDG-TI-I CPCU synthesizer, 18F-FECH was synthesized by different reagents and consumable supplies. The C18 column was added before the product collection bottle to remove K2.2.2. The 18F-FECH was synthesized by PET-FDG-IT-I synthesizer efficiently about 30 minutes by radiochemical yield of 42.0% (no decay corrected, n=5, and the radiochemical purity was still more than 99.0% after 6 hours. The results showed the domestic PET-FDG-IT-I synthesizer could semi-automatically synthesize injectable 18F-FECH in high efficiency and radiochemical purity

  8. Effect Of Choline Chloride (CC On 'Monroe' Peach Fruit Quality And Leaf Characteristics

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    Melike ÇETİNBAŞ

    2014-07-01

    Full Text Available The effect of choline chloride (CC were evaluated on fruit quality of ‘Monroe’ peach over 2-year period in a commercial orchard. Spray treatments of CC (0, 1000, 2000 and 3000 ppm were applied to 7, 21 and 30 days before commercial harvest (DBH. Some fruit quality parameters fruit weight (g, fruit flesh firmness (N, soluble solids content (SSC, %, titratable acidity (TA, %, fruit colour (CIELab, sugars, ethylene production, respiration rate were assessed for per treatments. All treatments were increased fruit size and fruit weight. In the applications of CC the most determined results have occurred on colourness which is the one of significant quality parameter in peaches and they had positive effect on the development red colour.Treatments of CC have been increased of total sugar contents

  9. Synthesis of cadmium and zinc semiconductor compounds from an ionic liquid containing choline chloride and urea

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Phillip J. [Department of Chemistry, University of Bath, BA2 7AY (United Kingdom)]. E-mail: p.j.dale@bath.ac.uk; Samantilleke, Anura P. [Department of Chemistry, University of Bath, BA2 7AY (United Kingdom); Shivagan, Dilip D. [Department of Chemistry, University of Bath, BA2 7AY (United Kingdom); Peter, Laurence M. [Department of Chemistry, University of Bath, BA2 7AY (United Kingdom)

    2007-05-31

    A eutectic mixture of choline chloride and urea (commercially known as Reline) has been used as a medium from which CdS, CdSe, and ZnS thin films have been electrodeposited for the first time. Reline is a conductive room temperature ionic liquid (RTIL) with a wide electrochemical window, which is suitable for use as a medium for electrodeposition. The voltammetric behaviour of the Reline-Cd(II)-sulfur system has been investigated. Thin films of CdS deposited at constant potential were characterized by photocurrent and electrolyte electroabsorbance spectroscopies. Thin films of CdSe and ZnS have also been prepared, and their photocurrent excitation spectra have been measured.

  10. Electrochemical Polishing Applications and EIS of a Novel Choline Chloride-Based Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Wixtrom, Alex I. [Christopher Newport University, Newport News, VA (United States); Buhler, Jessica E. [Christopher Newport University, Newport News, VA (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Abdel-Fattah, Tarek M. [Christopher Newport University, Newport News, VA (United States)

    2013-06-01

    Minimal surface roughness is a critical feature for high-field superconducting radio frequency (SRF) cavities used to engineer particle accelerators. Current methods for polishing Niobium cavities typically utilize solutions containing a mixture of concentrated sulfuric and hydrofluoric acid. Polishing processes such as these are effective, yet there are many hazards and costs associated with the use (and safe disposal) of the concentrated acid solutions. An alternative method for electrochemical polishing of the cavities was explored using a novel ionic liquid solution containing choline chloride. Potentiostatic electrochemical impedance spectroscopy (EIS) was used to analyze the ionic polishing solution. Final surface roughness of the Nb was found to be comparable to that of the acid-polishing method, as assessed by atomic force microscopy (AFM). This indicates that ionic liquid-based electrochemical polishing of Nb is a viable replacement for acid-based methods for preparation of SRF cavities.

  11. Tyrosine kinases in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Kobayashi Akiko

    2011-08-01

    Full Text Available Abstract Rheumatoid arthritis (RA is an inflammatory, polyarticular joint disease. A number of cellular responses are involved in the pathogenesis of rheumatoid arthritis, including activation of inflammatory cells and cytokine expression. The cellular responses involved in each of these processes depends on the specific signaling pathways that are activated; many of which include protein tyrosine kinases. These pathways include the mitogen-activated protein kinase pathway, Janus kinases/signal transducers and activators transcription pathway, spleen tyrosine kinase signaling, and the nuclear factor κ-light-chain-enhancer of activated B cells pathway. Many drugs are in development to target tyrosine kinases for the treatment of RA. Based on the number of recently published studies, this manuscript reviews the role of tyrosine kinases in the pathogenesis of RA and the potential role of kinase inhibitors as new therapeutic strategies of RA.

  12. Acute and chronic pharmacokinetics of asymmetrical doses of slow release choline theophyllinate in asthma.

    Science.gov (United States)

    Hibberd, S G; Alveyn, C; Coombes, E J; Holgate, S T

    1986-09-01

    The day and night pharmacokinetics of assymetrical doses of slow release choline theophyllinate (Sabidal SR 270) were compared at day 1 and at day 4 of treatment when steady state had been achieved. Ten patients with chronic asthma were given oral choline theophyllinate 424 mg at 09.00 h and 848 mg at 21.00 h for 4 days. At regular intervals during day 1 and day 4 of treatment theophylline concentrations were measured in plasma and dried blood spots by fluorimmunoassay. Theophylline concentrations measured from dried blood spots were slightly lower than those in plasma, the difference remaining constant at all time points during day 1 and day 4 of treatment. On day 1 the mean peak plasma theophylline concentration was 5.4 +/- 1.0 (+/- s.e. mean) micrograms ml-1 4 h after the morning dose and 11.2 +/- 1.6 micrograms ml-1 4 h after the evening dose which were significantly (P less than 0.01) different. Similarly the areas under the plasma theophylline concentration-time curves at night were significantly (P less than 0.001) greater than those observed during the day. During day 4 mean peak plasma concentrations of theophylline after the morning and larger evening dose were 13.2 +/- 1.3 and 12.1 +/- 1.4 micrograms ml-1 respectively, which were not significantly different. No significant difference was observed between the areas under the plasma theophylline concentration-time curves during the day and at night. However the post-dose time to peak was significantly delayed at night (6 h) compared to the morning (2 h, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Increased susceptibility to experimental steatohepatitis induced by methionine-choline deficiency in HBs-Tg mice

    Institute of Scientific and Technical Information of China (English)

    Miao-MiaoFu; RuiSun; Zhi-GangTian; Hai-MingWei

    2010-01-01

    BACKGROUND: Worldwide, about 25% of individuals with chronic hepatitis B have fatty liver disease. Lipogenic diets that are completely devoid of methionine and choline induce nonalcoholic fatty liver disease. However, no animal model of nonalcoholic steatohepatitis associated with HBV infection is available, and the influence of viral infection on nutritional hepatic steatosis is unclear. METHODS: We used HBV surface antigen transgenic mice (HBs-Tg mice), which mimic healthy human carriers with hepatitis B surface antigen. The mice were fed with a high-fat methionine-choline-deficient diet (MCD) to build a reliable rodent nutritional model of nonalcoholic steatohepatitis associated with HBV infection, and the changes in body weight and serum triglycerides were measured. Hepatocyte ballooning changes were determined by hematoxylin and eosin staining. The extent of hepatic fat accumulation was evaluated by oil red O staining. Immunohistochemical assays were performed to detect proliferating cell nuclear antigen as an index of cell proliferation. RESULTS: MCD feeding provoked systemic weight loss and liver injury. MCD feeding caused more macrovesicular fat droplets and fat accumulation in the livers of HBs-Tg mice than in wild-type C57BL/6 mice. In addition, within 30 days of MCD exposure, more PCNA-positive nuclei were found in the livers of HBs-Tg mice. CONCLUSIONS: HBs-Tg mice fed with a lipogenic MCD form more macrovesicular fat droplets earlier, coincident with more hepatocyte proliferation, resulting in the appearance of increased susceptibility to experimental steatohepatitis in these mice.

  14. Green synthesis of choline chloride%氯化胆碱的绿色合成

    Institute of Scientific and Technical Information of China (English)

    陈瑞瑞; 袁存光

    2012-01-01

    以环氧乙烷和三甲胺盐酸盐为原料,用经过酸碱活化的绿色环保阴离子交换树脂为催化剂合成氯化胆碱.用质量分数为0.5%的活化的阴离子交换树脂作催化剂,在n(环氧乙烷)∶n(三甲胺盐酸盐)=1.1∶1,反应温度为60℃,反应时间为1h的条件下,合成的氯化胆碱产品的产率≥96%.催化剂经酸碱活化1次可重复使用若干次而不影响催化效果.%In this paper, a kind of environment friendly anion exchange resin catalyst which was activated by acid and base was applied in synthesizing choline chloride. The ethylene oxide and trimethylamine hydrochlorate were used as the raw material in this study. When the weight of catalyst is 0. 5% of total reactant mass, molar ratio of C2H4O and ( CH3 )3N-HC1 is 1. 1 ,the reaction temperature is 601 and the reaction time is 1 hour,the yield of choline chloride is above 96%. The activity of catalyst is almost the same as the one activated once,when it is used several times.

  15. Choline dehydrogenase interacts with SQSTM1/p62 to recruit LC3 and stimulate mitophagy.

    Science.gov (United States)

    Park, Sungwoo; Choi, Seon-Guk; Yoo, Seung-Min; Son, Jin H; Jung, Yong-Keun

    2014-01-01

    CHDH (choline dehydrogenase) is an enzyme catalyzing the dehydrogenation of choline to betaine aldehyde in mitochondria. Apart from this well-known activity, we report here a pivotal role of CHDH in mitophagy. Knockdown of CHDH expression impairs CCCP-induced mitophagy and PARK2/parkin-mediated clearance of mitochondria in mammalian cells, including HeLa cells and SN4741 dopaminergic neuronal cells. Conversely, overexpression of CHDH accelerates PARK2-mediated mitophagy. CHDH is found on both the outer and inner membranes of mitochondria in resting cells. Interestingly, upon induction of mitophagy, CHDH accumulates on the outer membrane in a mitochondrial potential-dependent manner. We found that CHDH is not a substrate of PARK2 but interacts with SQSTM1 independently of PARK2 to recruit SQSTM1 into depolarized mitochondria. The FB1 domain of CHDH is exposed to the cytosol and is required for the interaction with SQSTM1, and overexpression of the FB1 domain only in cytosol reduces CCCP-induced mitochondrial degradation via competitive interaction with SQSTM1. In addition, CHDH, but not the CHDH FB1 deletion mutant, forms a ternary protein complex with SQSTM1 and MAP1LC3 (LC3), leading to loading of LC3 onto the damaged mitochondria via SQSTM1. Further, CHDH is crucial to the mitophagy induced by MPP+ in SN4741 cells. Overall, our results suggest that CHDH is required for PARK2-mediated mitophagy for the recruitment of SQSTM1 and LC3 onto the mitochondria for cargo recognition.

  16. Cytidine 5'-diphosphocholine (CDP-choline) adversely effects on pilocarpine seizure-induced hippocampal neuronal death.

    Science.gov (United States)

    Kim, Jin Hee; Lee, Dong Won; Choi, Bo Young; Sohn, Min; Lee, Song Hee; Choi, Hui Chul; Song, Hong Ki; Suh, Sang Won

    2015-01-21

    Citicoline (CDP-choline; cytidine 5'-diphosphocholine) is an important intermediate in the biosynthesis of cell membrane phospholipids. Citicoline serves as a choline donor in the biosynthetic pathways of acetylcholine and neuronal membrane phospholipids, mainly phosphatidylcholine. The ability of citicoline to reverse neuronal injury has been tested in animal models of cerebral ischemia and clinical trials have been performed in stroke patients. However, no studies have examined the effect of citicoline on seizure-induced neuronal death. To clarify the potential therapeutic effects of citicoline on seizure-induced neuronal death, we used an animal model of pilocarpine-induced epilepsy. Temporal lobe epilepsy (TLE) was induced by intraperitoneal injection of pilocarpine (25mg/kg) in adult male rats. Citicoline (100 or 300 mg/kg) was injected into the intraperitoneal space two hours after seizure onset and a second injection was performed 24h after the seizure. Citicoline was injected once per day for one week after pilocarpine- or kainate-induced seizure. Neuronal injury and microglial activation were evaluated at 1 week post-seizure. Surprisingly, rather than offering protection, citicoline treatment actually enhanced seizure-induced neuronal death and microglial activation in the hippocampus compared to vehicle treated controls. Citicoline administration after seizure-induction increased immunoglobulin leakage via BBB disruption in the hippocampus compared with the vehicle-only group. To clarify if this adverse effect of citicoline is generalizable across alternative seizure models, we induced seizure by kainate injection (10mg/kg, i.p.) and then injected citicoline as in pilocarpine-induced seizure. We found that citicoline did not modulate kainate seizure-induced neuronal death, BBB disruption or microglial activation. These results suggest that citicoline may not have neuroprotective effects after seizure and that clinical application of citicoline after

  17. [{sup 11}C]Choline PET/CT predicts survival in hormone-naive prostate cancer patients with biochemical failure after radical prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Giovacchini, Giampiero [Stadtspital Triemli, Department of Radiology and Nuclear Medicine, Zurich (Switzerland); Incerti, Elena; Mapelli, Paola; Gianolli, Luigi; Picchio, Maria [IRCCS San Raffaele Scientific Institute, Department of Nuclear Medicine, Milano (Italy); Kirienko, Margarita [University of Milano-Bicocca, Milano (Italy); Briganti, Alberto; Gandaglia, Giorgio; Montorsi, Francesco [IRCCS San Raffaele Scientific Institute, Department of Urology, Milano (Italy)

    2015-05-01

    Over the last decade, PET/CT with radiolabelled choline has been shown to be useful for restaging patients with prostate cancer (PCa) who develop biochemical failure. The limitations of most clinical studies have been poor validation of [{sup 11}C]choline PET/CT-positive findings and lack of survival analysis. The aim of this study was to assess whether [{sup 11}C]choline PET/CT can predict survival in hormone-naive PCa patients with biochemical failure. This retrospective study included 302 hormone-naive PCa patients treated with radical prostatectomy who underwent [{sup 11}C]choline PET/CT from 1 December 2004 to 31 July 2007 because of biochemical failure (prostate-specific antigen, PSA, >0.2 ng/mL). Median PSA was 1.02 ng/mL. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathological variables and PCa-specific survival. The coefficients of the covariates included in the Cox regression analysis were used to develop a novel nomogram. Median follow-up was 7.2 years (1.4 - 18.9 years). [{sup 11}C]Choline PET/CT was positive in 101 of 302 patients (33 %). Median PCa-specific survival after prostatectomy was 14.9 years (95 % CI 9.7 - 20.1 years) in patients with positive [{sup 11}C]choline PET/CT. Median survival was not achieved in patients with negative [{sup 11}C]choline PET/CT. The 15-year PCa-specific survival probability was 42.4 % (95 % CI 31.7 - 53.1 %) in patients with positive [{sup 11}C]choline PET/CT and 95.5 % (95 % CI 93.5 - 97.5 %) in patients with negative [{sup 11}C]choline PET/CT. In multivariate analysis, [{sup 11}C]choline PET/CT (hazard ratio 6.36, 95 % CI 2.14 - 18.94, P < 0.001) and Gleason score >7 (hazard ratio 3.11, 95 % CI 1.11 - 8.66, P = 0.030) predicted PCa-specific survival. An internally validated nomogram predicted 15-year PCa-specific survival probability with an accuracy of 80 %. Positive [{sup 11}C]choline PET/CT after biochemical failure

  18. Low-Q peak in X-ray patterns of choline-phenylalanine and -homophenylalanine: A combined effect of chain and stacking

    Science.gov (United States)

    Campetella, Marco; Martino, Delia Chillura; Scarpellini, Eleonora; Gontrani, Lorenzo

    2016-09-01

    In this contribution we report for the first time the X-ray patterns of choline-phenylalanine and choline-homophenylalanine ionic liquids. The presence of a low Q peak in both systems is another evidence that a long alkyl chain is not always needed to establish a nanodomain segregation in the liquid sufficient to be revealed by the diffraction experiment. These new data are compared with the diffraction patterns and the theoretical calculations of other choline-aminoacid ionic liquids recently reported. A significant role might be played by the stacking interactions between aromatic rings.

  19. Enterococcus faecalis phosphomevalonate kinase

    OpenAIRE

    Doun, Stephanie S.; Burgner, John W.; Briggs, Scott D.; Rodwell, Victor W.

    2005-01-01

    The six enzymes of the mevalonate pathway of isopentenyl diphosphate biosynthesis represent potential for addressing a pressing human health concern, the development of antibiotics against resistant strains of the Gram-positive streptococci. We previously characterized the first four of the mevalonate pathway enzymes of Enterococcus faecalis, and here characterize the fifth, phosphomevalonate kinase (E.C. 2.7.4.2). E. faecalis genomic DNA and the polymerase chain reaction were used to clone D...

  20. Oncoprotein protein kinase

    Energy Technology Data Exchange (ETDEWEB)

    Karin, Michael (San Diego, CA); Hibi, Masahiko (San Diego, CA); Lin, Anning (La Jolla, CA); Davis, Roger (Princeton, MA); Derijard, Benoit (Shrewsbury, MA)

    2003-02-04

    An isolated polypeptide (JNK) characterized by having a molecular weight of 46kD as determined by reducing SDS-PAGE, having serine and threonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

  1. Cytoplasmic Phospholipase A2 Modulation of Adolescent Rat Ethanol-Induced Protein Kinase C Translocation and Behavior

    Science.gov (United States)

    Santerre, J. L.; Kolitz, E. B.; Pal, R.; Rogow, J. A.; Werner, D. F.

    2015-01-01

    Ethanol consumption typically begins during adolescence, a developmental period which exhibits many age-dependent differences in ethanol behavioral sensitivity. Protein kinase C (PKC) activity is largely implicated in ethanol-behaviors, and our previous work indicates that regulation of novel PKC isoforms likely contributes to decreased high-dose ethanol sensitivity during adolescence. The cytoplasmic Phospholipase A2 (cPLA2) signaling cascade selectivity modulates novel and atypical PKC isoform activity, as well as adolescent ethanol hypnotic sensitivity. Therefore, the current study was designed to ascertain adolescent cPLA2 activity both basally and in response to ethanol, as well as it's involvement in ethanol-induced PKC isoform translocation patterns. cPLA2 expression was elevated during adolescence, and activity was increased only in adolescents following high-dose ethanol administration. Novel, but not atypical PKC isoforms translocate to cytosolic regions following high-dose ethanol administration. Inhibiting cPLA2 with AACOCF3 blocked ethanol-induced PKC cytosolic translocation. Finally, inhibition of novel, but not atypical, PKC isoforms when cPLA2 activity was elevated, modulated adolescent high-dose ethanol-sensitivity. These data suggest that the cPLA2/PKC pathway contributes to the acute behavioral effects of ethanol during adolescence. PMID:25791059

  2. hMena+11a Isoform Serves as a Marker of Epithelial Phenotype and Sensitivity to EGFR Inhibition in Human Pancreatic Cancer Cell Lines

    Science.gov (United States)

    Pino, Maria S.; Balsamo, Michele; Di Modugno, Francesca; Mottolese, Marcella; Alessio, Massimo; Melucci, Elisa; Milella, Michele; McConkey, David J.; Philippar, Ulrike; Gertler, Frank B.; Natali, Pier Giorgio; Nistico, Paola

    2008-01-01

    Purpose hMena, member of the Ena/VASP protein family, is a cytoskeletal protein that is involved in the regulation of cell motility and adhesion. The aim of this study was to determine whether or not the expression of hMena isoforms correlated with sensitivity to EGFR tyrosine kinase inhibitors and could serve as markers with potential clinical use. Experimental design Human pancreatic ductal adenocarcinoma (PDAC) cell lines were characterized for in vitro sensitivity to erlotinib, expression of HER family receptors, markers of epithelial to mesenchymal transition (EMT), and expression of hMena and its isoform hMena+11a. The effects of EGF and erlotinib on hMena expression as well as the effect of hMena knock-down on cell proliferation were also evaluated. Results hMena was detected in all of the pancreatic tumor cell lines tested as well as in the majority of the human tumor samples [primary (92%) and metastatic (86%)]. Intriguingly, in vitro hMena+11a isoform was specifically associated with an epithelial phenotype, EGFR dependency and sensitivity to erlotinib. In epithelial BxPC3 cells EGF upregulated hMena/hMena+11a and erlotinib downregulated expression. hMena knock-down reduced cell proliferation and MAPK and AKT activation in BxPC3 cells and promoted the growth inhibitory effects of erlotinib. Conclusions Collectively, our data indicate that the hMena+11a isoform is associated with an epithelial phenotype and identifies EGFR dependent cell lines that are sensitive to the EGFR inhibitor erlotinib. The availability of anti-hMena+11a specific probes may offer a new tool in pancreatic cancer management if these results can be verified prospectively in cancer patients. PMID:18676769

  3. Distinct regulation of p53-mediated apoptosis by protein kinase calpha, delta, epsilon and zeta : evidence in yeast for transcription-dependent and -independent p53 apoptotic mechanisms

    OpenAIRE

    Coutinho, Isabel; Pereira, Clara; Pereira, Gil; Gonçalves, Jorge; Côrte-Real, Manuela; Saraiva, Lucília

    2011-01-01

    The role of individual protein kinase C (PKC) isoforms in the regulation of p53- mediated apoptosis is still uncertain. Using yeast cells co-expressing the human wild-type p53 and a single mammalian PKCa, d, e or z, we showed a differential regulation of p53- mediated apoptosis by these PKC isoforms. Whereas PKCa and z had no effect on p53 activity, PKCd and e stimulated a p53-mediated mitochondria-dependent apoptosis. Moreover, using pifithrin-a and -m, selective inhibitors of...

  4. Differential expression of five protein kinase C isoenzymes in FAO and HepG2 hepatoma cell lines compared with normal rat hepatocytes.

    Science.gov (United States)

    Ducher, L; Croquet, F; Gil, S; Davy, J; Féger, J; Bréhier, A

    1995-12-14

    We analyzed the expression of five protein kinase C (PKC) isoforms in cytosolic and membrane fractions from normal rat hepatocytes compared with those of two tumorigenic cell lines FAO and HepG2. Western blots with PKC-specific isoenzymes polyclonal antibodies provide evidences for the presence of the five isoforms alpha, beta II, delta, epsilon and zeta in normal rat hepatocytes. In hepatoma cells, we show differences in the level of expression, the molecular sizes and the responses to Phorbol 12-myristate 13-acetate (PMA).

  5. PSA Isoforms' Velocities for Early Diagnosis of Prostate Cancer.

    Science.gov (United States)

    Heidegger, Isabel; Klocker, Helmut; Pichler, Renate; Horninger, Wolfgang; Bektic, Jasmin

    2015-06-01

    Free prostate-specific antigen (fPSA) and its molecular isoforms are suggested for enhancement of PSA testing in prostate cancer (PCa). In the present study we evaluated whether PSA isoforms' velocities might serve as a tool to improve early PCa diagnosis. Our study population included 381 men who had undergone at least one ultrasound-guided prostate biopsy whose pathologic examination yielded PCa or showed no evidence of prostatic malignancy. Serial PSA, fPSA, and proPSA measurements were performed on serum samples covering 7 years prior to biopsy using Beckmann Coulter Access immunoassays. Afterwards, velocities of PSA (PSAV), fPSA% (fPSA%V), proPSA% (proPSA%V) and the ratio proPSA/PSA/V were calculated and their ability to discriminate cancer from benign disease was evaluated. Among 381 men included in the study, 202 (53%) were diagnosed with PCa and underwent radical prostatectomy at our Department. PSAV, fPSA%V, proPSA%V as well as proPSA/PSA/V were able to differentiate significantly between PCa and non-cancerous prostate. The highest discriminatory power between cancer and benign disease has been observed two and one year prior to diagnosis with all measured parameters. Among all measured parameters, fPSA%V showed the best cancer specificity of 45.3% with 90% of sensitivity. In summary, our results highlight the value of PSA isoforms' velocity for early detection of PCa. Especially fPSA%V should be used in the clinical setting to increase cancer detection specificity.

  6. Regulation of Autophagy by Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda, E-mail: alakananda.basu@unthsc.edu [Department of Molecular Biology and Immunology, Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2011-06-09

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  7. Design and synthesis of protein kinase C epsilon selective diacylglycerol lactones (DAG-lactones).

    Science.gov (United States)

    Ann, Jihyae; Yoon, Suyoung; Baek, Jisoo; Kim, Da Hye; Lewin, Nancy E; Hill, Colin S; Blumberg, Peter M; Lee, Jeewoo

    2015-01-27

    DAG-lactones afford a synthetically accessible, high affinity platform for probing structure activity relationships at the C1 regulatory domain of protein kinase C (PKC). Given the central role of PKC isoforms in cellular signaling, along with their differential biological activities, a critical objective is the design of isoform selective ligands. Here, we report the synthesis of a series of DAG-lactones varying in their side chains, with a particular focus on linoleic acid derivatives. We evaluated their selectivity for PKC epsilon versus PKC alpha both under standard lipid conditions (100% phosphatidylserine, PS) as well as in the presence of a nuclear membrane mimetic lipid mixture (NML). We find that selectivity for PKC epsilon versus PKC alpha tended to be enhanced in the presence of the nuclear membrane mimetic lipid mixture and, for our lead compound, report a selectivity of 32-fold.

  8. The FU gene and its possible protein isoforms

    Directory of Open Access Journals (Sweden)

    Nöthen Markus M

    2004-07-01

    Full Text Available Abstract Background FU is the human homologue of the Drosophila gene fused whose product fused is a positive regulator of the transcription factor Cubitus interruptus (Ci. Thus, FU may act as a regulator of the human counterparts of Ci, the GLI transcription factors. Since Ci and GLI are targets of Hedgehog signaling in development and morphogenesis, it is expected that FU plays an important role in Sonic, Desert and/or Indian Hedgehog induced cellular signaling. Results The FU gene was identified on chromosome 2q35 at 217.56 Mb and its exon-intron organization determined. The human developmental disorder Syndactyly type 1 (SD1 maps to this region on chromosome 2 and the FU coding region was sequenced using genomic DNA from an affected individual in a linked family. While no FU mutations were found, three single nucleotide polymorphisms were identified. The expression pattern of FU was thoroughly investigated and all examined tissues express FU. It is also clear that different tissues express transcripts of different sizes and some tissues express more than one transcript. By means of nested PCR of specific regions in RT/PCR generated cDNA, it was possible to verify two alternative splicing events. This also suggests the existence of at least two additional protein isoforms besides the FU protein that has previously been described. This long FU and a much shorter isoform were compared for the ability to regulate GLI1 and GLI2. None of the FU isoforms showed any effects on GLI1 induced transcription but the long form can enhance GLI2 activity. Apparently FU did not have any effect on SUFU induced inhibition of GLI. Conclusions The FU gene and its genomic structure was identified. FU is a candidate gene for SD1, but we have not identified a pathogenic mutation in the FU coding region in a family with SD1. The sequence information and expression analyses show that transcripts of different sizes are expressed and subjected to alternative splicing

  9. Isoform-specific regulation of adenylyl cyclase: a potential target in future pharmacotherapy.

    Science.gov (United States)

    Iwatsubo, Kousaku; Tsunematsu, Takashi; Ishikawa, Yoshihiro

    2003-06-01

    Adenylyl cyclase (AC) is a target enzyme of multiple G-protein-coupled receptors (GPCRs). In the past decade, the cloning, structure and biochemical properties of nine AC isoforms were reported, and each isoform of AC shows distinct patterns of tissue distribution and biochemical/pharmacological properties. In addition to the conventional regulators of this enzyme, such as calmodulin (CaM) or PKC, novel regulators, for example, caveolin, have been identified. Most importantly, these regulators work on AC in an isoform dependent manner. Recent studies have demonstrated that certain classic AC inhibitors, i.e., P-site inhibitors, show an isoform-dependent inhibition of AC. The side chain modifications of forskolin, a diterpene extract from Coleus forskolii, markedly enhance its isoform selectivity. When taken together, these findings suggest that it is feasible to develop new pharmacotherapeutic agents that target AC isoforms to regulate various neurohormonal signals in a highly tissue-/organ-specific manner.

  10. Soluble malate dehydrogenase of Geophagus brasiliensis (Cichlidae, Perciformes: isolated isoforms and kinetics properties

    Directory of Open Access Journals (Sweden)

    Maria Regina de Aquino-Silva

    2008-01-01

    Full Text Available Kinetic properties and thermal stabilities of Geophagus brasiliensis skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to examine a possible sMDH-B* locus duplication in a fixation process influenced by genetic drift. Two optimal pHs were detected: 7.5 for AB1 unfractionated muscle phenotype and its B1 isoform, and 8.0 for AB1B2 unfractionated muscle phenotype, A and B2 isoforms. While G. brasiliensis A isoform could be characterized as thermostable, the duplicated B isoform cannot be assumed as thermolabile. Km values for isolated B2 isoforms were 1.6 times lower than for B1. A duplication event in progress best explains the electrophoretic six-band pattern detected in G. brasiliensis, which would be caused by genetic drift.

  11. Separation of arginase isoforms by capillary zone electrophoresis and isoelectric focusing in density gradient column.

    Science.gov (United States)

    Pedrosa, M M; Legaz, M E

    1995-04-01

    Four major arginase isoforms, I, II, III and IV, have been detected in Evernia prunastri thallus. They differ in terms of both physical and biochemical properties. The isoelectric point (pI) of these proteins has been determined by both isoelectric focusing in density gradient column and high-performance capillary electrophoresis (HPCE). Isoelectric focusing revealed charge microheterogeneity for isoforms II and IV whereas arginases I and II had the same pI value of 5.8. HPCE separation confirmed this charge microheterogeneity for isoform IV but not for isoform III, and provided evidence of microheterogeneity for isoforms I and II. The effect of various electrolyte buffers and running conditions on the HPCE separation of arginase isoform were investigated. Addition of 0.5 mM spermidine (SPD) to the running buffer reduced the electroosmotic flow (EOF) and permitted discriminating between the native proteins and protein fragments.

  12. Predictive factors of [{sup 11}C]choline PET/CT in patients with biochemical failure after radical prostatectomy

    Energy Technology Data Exchange (ETDEWEB)

    Giovacchini, Giampiero; Coradeschi, Elisa [University of Milano-Bicocca, Center for Molecular Bioimaging, Milano (Italy); Picchio, Maria; Bettinardi, Valentino; Gianolli, Luigi [Scientific Institute San Raffaele, Department of Nuclear Medicine, Milano (Italy); Scattoni, Vincenzo; Rigatti, Patrizio [Scientific Institute San Raffaele, Department of Urology, Milano (Italy); Cozzarini, Cesare; Di Muzio, Nadia [Scientific Institute San Raffaele, Department of Radiation Oncology, Milano (Italy); Fazio, Ferruccio [University of Milano-Bicocca, Center for Molecular Bioimaging, Milano (Italy); Scientific Institute San Raffaele, Department of Nuclear Medicine, Milano (Italy); Scientific Institute San Raffaele, Department of Radiation Oncology, Milano (Italy); Messa, Cristina [University of Milano-Bicocca, Center for Molecular Bioimaging, Milano (Italy); National Research Council, Institute for Bioimaging and Molecular Physiology, Milano (Italy); Hospital San Gerardo, Department of Nuclear Medicine, Monza (Italy)

    2010-02-15

    Detection of recurrence in prostate cancer patients with biochemical failure after radical prostatectomy by [{sup 11}C]choline PET/CT depends on the prostate-specific antigen (PSA) level. The role of other clinical and pathological variables has not been explored. A total of 2,124 prostate cancer patients referred to our Institution for [{sup 11}C]choline PET/CT from December 2004 to January 2007 for restaging of disease were retrospectively considered for this study. Inclusion criteria were: previous treatment by radical prostatectomy, and biochemical failure, defined as at least two consecutive PSA measurements of >0.2 ng/ml. These criteria were met for 358 patients. Binary logistic analysis was used to investigate the predictive factors of [{sup 11}C]choline PET/CT. PET/CT findings were validated using criteria based on histological analysis, and follow-up clinical and imaging data. Receiver operating characteristic (ROC) analysis was used to assess the performance of [{sup 11}C]choline PET/CT in relation to PSA levels. The mean PSA level was 3.77 {+-} 6.94 ng/ml (range 0.23-45 ng/ml; median 1.27 ng/ml). PET/CT was positive for recurrence in 161 of 358 patients (45%). On an anatomical region basis, [{sup 11}C]choline pathological uptake was observed in lymph nodes (107/161 patients, 66%), prostatectomy bed (55/161 patients, 34%), and in the skeleton (46/161 patients, 29%). PET/CT findings were validated using histological criteria (46/358, 13%), and follow-up clinical and imaging criteria (312/358, 87%). Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were, respectively, 85%, 93%, 91%, 87%, and 89%. In multivariate analysis, high PSA levels, advanced pathological stage, previous biochemical failure and older age were significantly (P < 0.05) associated with an increased risk of positive PET/CT findings. The percentage of positive scans was 19% in those with a PSA level between 0.2 and 1 ng/ml, 46% in those

  13. Amyloid-beta Isoform Metabolism Quantitation by Stable Isotope Labeled Kinetics

    OpenAIRE

    Mawuenyega, Kwasi G.; Kasten, Tom; Sigurdson, Wendy; Bateman, Randall J.

    2013-01-01

    Abundant evidence suggests a central role for the amyloid-β (Aβ) peptide in Alzheimer’s disease (AD) pathogenesis. Production and clearance of different Aβ isoforms have been established as targets of proposed disease-modifying therapeutic treatments of AD. However, previous studies used multiple sequential purification steps to isolate the isoforms individually and quantitate them based on a common mid-domain peptide. We created a method to simultaneously purify Aβ isoforms and quantitate th...

  14. Identification of signals that facilitate isoform specific nucleolar localization of myosin IC

    Energy Technology Data Exchange (ETDEWEB)

    Schwab, Ryan S.; Ihnatovych, Ivanna; Yunus, Sharifah Z.S.A.; Domaradzki, Tera [Department of Physiology and Biophysics, University at Buffalo—State University of New York, Buffalo, NY (United States); Hofmann, Wilma A., E-mail: whofmann@buffalo.edu [Department of Physiology and Biophysics, University at Buffalo—State University of New York, Buffalo, NY (United States)

    2013-05-01

    Myosin IC is a single headed member of the myosin superfamily that localizes to the cytoplasm and the nucleus, where it is involved in transcription by RNA polymerases I and II, intranuclear transport, and nuclear export. In mammalian cells, three isoforms of myosin IC are expressed that differ only in the addition of short isoform-specific N-terminal peptides. Despite the high sequence homology, the isoforms show differences in cellular distribution, in localization to nuclear substructures, and in their interaction with nuclear proteins through yet unknown mechanisms. In this study, we used EGFP-fusion constructs that express truncated or mutated versions of myosin IC isoforms to detect regions that are involved in isoform-specific localization. We identified two nucleolar localization signals (NoLS). One NoLS is located in the myosin IC isoform B specific N-terminal peptide, the second NoLS is located upstream of the neck region within the head domain. We demonstrate that both NoLS are functional and necessary for nucleolar localization of specifically myosin IC isoform B. Our data provide a first mechanistic explanation for the observed functional differences between the myosin IC isoforms and are an important step toward our understanding of the underlying mechanisms that regulate the various and distinct functions of myosin IC isoforms. - Highlights: ► Two NoLS have been identified in the myosin IC isoform B sequence. ► Both NoLS are necessary for myosin IC isoform B specific nucleolar localization. ► First mechanistic explanation of functional differences between the isoforms.

  15. Multiforms of mammalian adenylate kinase and its monoclonal antibody against AK1.

    Science.gov (United States)

    Kurokawa, Y; Takenaka, H; Sumida, M; Oka, K; Hamada, M; Kuby, S A

    1990-01-01

    An attempt has been made to determine the intracellular distribution of the multiforms of the adenylate kinase (AK) isoenzymes in mammalian tissues, to shed some light on their physiological roles, especially in energy metabolism. The adenylate kinase zymograms obtained from isoelectric focusing yielded two typical isoform patterns: (1) with a pI greater than or equal to 9 and 8.6, specific for bovine skeletal muscle, heart, aorta and brain, and (2) with a pI = 7.9 and 7.1, specific for liver and kidney. Pattern (1) was attributed to the cytosolic isoenzyme (AK1) as demonstrated by immunostaining with anti-AK1. Pattern (2) was attributed to the mitochondrial isoenzyme (AK2). These results were largely confirmed by chromatofocusing experiments. The AK1 isoenzyme was partially purified from the cytosol fraction of bovine aortic smooth muscle and had an apparent Mr of 23.5 kilodaltons. Its kinetic features are discussed from a comparative standpoint. Finally, the human serum AK1 isoform was also detected by Western blotting with a monoclonal antibody directed against crystalline porcine muscle AK1. These results are to form the basis of further studies on the 'aberrant' adenylate kinase isoenzyme from the serum of Duchenne muscular dystrophics.

  16. The role of the Drosophila LAMMER protein kinase DOA in somatic sex determination

    Indian Academy of Sciences (India)

    Leonard Rabinow; Marie-Laure Samson

    2010-09-01

    DOA kinase, the Drosophila member of the LAMMER/Clk protein kinase family, phosphorylates SR and SR-like proteins, including TRA, TRA2 and RBP1, which are responsible for the alternative splicing of transcripts encoding the key regulator of sex-specific expression in somatic cells of the fly, DOUBLESEX. Specific Doa alleles induce somatic female-to-male sex transformations, which can be enhanced when combined with mutations in loci encoding SR and SR-like proteins. The Doa locus encodes six different kinases, of which a 69-kDa isoform is expressed solely in females. Expression of this isoform is itself under the regulation of the somatic sex determination regulatory network, thus forming a putative positive autoregulatory loop which would reinforce the choice of the female cell-fate. We speculate that this loop is part of the evolutionary ancestral sex-determination machinery, based upon evidence demonstrating the existence of an autoregulatory loop involving TRA and TRA2 in several other insect species.

  17. Identification of signals that facilitate isoform specific nucleolar localization of myosin IC.

    Science.gov (United States)

    Schwab, Ryan S; Ihnatovych, Ivanna; Yunus, Sharifah Z S A; Domaradzki, Tera; Hofmann, Wilma A

    2013-05-01

    Myosin IC is a single headed member of the myosin superfamily that localizes to the cytoplasm and the nucleus, where it is involved in transcription by RNA polymerases I and II, intranuclear transport, and nuclear export. In mammalian cells, three isoforms of myosin IC are expressed that differ only in the addition of short isoform-specific N-terminal peptides. Despite the high sequence homology, the isoforms show differences in cellular distribution, in localization to nuclear substructures, and in their interaction with nuclear proteins through yet unknown mechanisms. In this study, we used EGFP-fusion constructs that express truncated or mutated versions of myosin IC isoforms to detect regions that are involved in isoform-specific localization. We identified two nucleolar localization signals (NoLS). One NoLS is located in the myosin IC isoform B specific N-terminal peptide, the second NoLS is located upstream of the neck region within the head domain. We demonstrate that both NoLS are functional and necessary for nucleolar localization of specifically myosin IC isoform B. Our data provide a first mechanistic explanation for the observed functional differences between the myosin IC isoforms and are an important step toward our understanding of the underlying mechanisms that regulate the various and distinct functions of myosin IC isoforms.

  18. Molecular cloning and pharmacology of functionally distinct isoforms of the human histamine H(3) receptor

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Goodman, M W; Burstein, E S

    2002-01-01

    The pharmacology of histamine H(3) receptors suggests the presence of distinct receptor isoforms or subtypes. We herein describe multiple, functionally distinct, alternatively spliced isoforms of the human H(3) receptor. Combinatorial splicing at three different sites creates at least six distinct...... H(3) agonists, while all agonists tested displayed increased potency at isoform 2 relative to isoform 1. Histamine, N(alpha)-methylhistamine, and R(-) and S(+)-alpha-methylhistamine are 16-23-fold more potent, while immepip and imetit are three to fivefold more potent. Antagonist experiments...

  19. Nuclear progesterone receptor isoforms and their functions in the female reproductive tract.

    Science.gov (United States)

    Rekawiecki, R; Kowalik, M K; Kotwica, J

    2011-01-01

    Progesterone (P4), which is produced by the corpus luteum (CL), creates proper conditions for the embryo implantation, its development, and ensures proper conditions for the duration of pregnancy. Besides the non-genomic activity of P4 on target cells, its main physiological effect is caused through genomic action by the progesterone nuclear receptor (PGR). This nuclear progesterone receptor occurs in two specific isoforms, PGRA and PGRB. PGRA isoform acts as an inhibitor of transcriptional action of PGRB. The inactive receptor is connected with chaperone proteins and attachment of P4 causes disconnection of chaperones and unveiling of DNA binding domain (DBD). After receptor dimerization in the cells' nucleus and interaction with hormone response element (HRE), the receptor coactivators are connected and transcription is initiated. The ratio of these isoforms changes during the estrous cycle and reflects the different levels of P4 effect on the reproductive system. Both isoforms, PGRA and PGRB, also show a different response to the P4 receptor antagonist activity. Connection of the antagonist to PGRA can block PGRB, but acting through the PGRB isoform, P4 receptor antagonist may undergo conversion to a strongly receptor agonist. A third isoform, PGRC, has also been revealed. This isoform is the shortest and does not have transcriptional activity. Alternative splicing and insertion of additional exons may lead to the formation of different PGR isoforms. This paper summarizes the available data on the progesterone receptor isoforms and its regulatory action within the female reproductive system.

  20. 3D-segmentation of the 18F-choline PET signal for target volume definition in radiation therapy of the prostate.

    Science.gov (United States)

    Ciernik, I Frank; Brown, Derek W; Schmid, Daniel; Hany, Thomas; Egli, Peter; Davis, J Bernard

    2007-02-01

    Volumetric assessment of PET signals becomes increasingly relevant for radiotherapy (RT) planning. Here, we investigate the utility of 18F-choline PET signals to serve as a structure for semi-automatic segmentation for forward treatment planning of prostate cancer. 18F-choline PET and CT scans of ten patients with histologically proven prostate cancer without extracapsular growth were acquired using a combined PET/CT scanner. Target volumes were manually delineated on CT images using standard software. Volumes were also obtained from 18F-choline PET images using an asymmetrical segmentation algorithm. PTVs were derived from CT 18F-choline PET based clinical target volumes (CTVs) by automatic expansion and comparative planning was performed. As a read-out for dose given to non-target structures, dose to the rectal wall was assessed. Planning target volumes (PTVs) derived from CT and 18F-choline PET yielded comparable results. Optimal matching of CT and 18F-choline PET derived volumes in the lateral and cranial-caudal directions was obtained using a background-subtracted signal thresholds of 23.0+/-2.6%. In antero-posterior direction, where adaptation compensating for rectal signal overflow was required, optimal matching was achieved with a threshold of 49.5+/-4.6%. 3D-conformal planning with CT or 18F-choline PET resulted in comparable doses to the rectal wall. Choline PET signals of the prostate provide adequate spatial information amendable to standardized asymmetrical region growing algorithms for PET-based target volume definition for external beam RT.

  1. Effects of irradiation on the [methyl-{sup 3}H]choline uptake in the human prostate cancer cell lines LNCaP and PC3

    Energy Technology Data Exchange (ETDEWEB)

    Holzapfel, K.; Mueller, S.A.; Seidl, C.; Schwaiger, M.; Senekowitsch-Schmidtke, R. [Dept. of Nuclear Medicine, Technical Univ. of Munich (Germany); Grosu, A.L. [Dept. of Radiation Oncology, Technical Univ. of Munich (Germany)

    2008-06-15

    Background and purpose: choline positron emission tomography (PET) can help to optimize radiation treatment strategy of prostate cancer. Therefore, the aim of this study was to elucidate the effects of ionizing radiation on the choline uptake in an androgen-dependent (LNCaP) and an androgen-independent (PC3) prostate cancer cell line. Material and methods: uptake of [methyl-{sup 3}H]choline chloride was investigated between 4 and 96 h after irradiation with 6 Gy. Dose dependence of choline uptake was examined following irradiation with 2-12 Gy, and cell survival was analyzed via the clonogenic assay. Michaelis-Menten kinetics was determined 24 h (PC3) and 48 h (LNCaP) after irradiation with 6 Gy. Results: PC3 cells showed a significant transitory increase of [methyl-{sup 3}H]choline uptake with a maximum at 24 h after irradiation. In LNCaP cells irradiation induced a significant decrease with a minimum at 48 h. Changes in choline uptake in both cell lines were almost dose-independent up to 12 Gy. Following irradiation with 6 Gy, transport capacity (v{sub max}) increased and Michaelis-Menten constant (K{sub M}) decreased in PC3 cells, while in LNCaP cells the two parameters behaved vice versa. Conclusion: changes in choline uptake following irradiation might be due to metabolic changes associated with initiation of processes that finally cause cell death. Thus, changes in tumor choline uptake monitored by PET after radiotherapy might not exclusively reflect therapeutic success but also altered tracer uptake as a consequence of irradiation. (orig.)

  2. A Review of Metallothionein Isoforms and their Role in Pathophysiology

    Directory of Open Access Journals (Sweden)

    Senthil kumar M

    2011-05-01

    Full Text Available Abstract The Metallothionein (MT is a protein which has several interesting biological effects and has been demonstrated increase focus on the role of MT in various biological systems in the past three decades. The studies on the role of MT were limited with few areas like apoptosis and antioxidants in selected organs even fifty years after its discovery. Now acknowledge the exploration of various isoforms of MT such as MT-I, MT-II, MT-III and MT-IV and other isoforms in various biological systems. Strong evidence exists that MT modulates complex diseases and the immune system in the body but the primary function of MT still remains unknown. This review's main objective is to explore the capability to specifically manipulate MT levels in cells and in animals to provide answers regarding how MT could impact those complex disease scenarios. The experimental result mentioned in this review related among MT, zinc, cadmium, diabetic, heart disease, bone retardation, neuro toxicity, kidney dysfunction, cancer, and brain suggest novel method for exploration and contribute significantly to the growing scientist to research further in this field.

  3. Entropy-based model for miRNA isoform analysis.

    Directory of Open Access Journals (Sweden)

    Shengqin Wang

    Full Text Available MiRNAs have been widely studied due to their important post-transcriptional regulatory roles in gene expression. Many reports have demonstrated the evidence of miRNA isoform products (isomiRs in high-throughput small RNA sequencing data. However, the biological function involved in these molecules is still not well investigated. Here, we developed a Shannon entropy-based model to estimate isomiR expression profiles of high-throughput small RNA sequencing data extracted from miRBase webserver. By using the Kolmogorov-Smirnov statistical test (KS test, we demonstrated that the 5p and 3p miRNAs present more variants than the single arm miRNAs. We also found that the isomiR variant, except the 3' isomiR variant, is strongly correlated with Minimum Free Energy (MFE of pre-miRNA, suggesting the intrinsic feature of pre-miRNA should be one of the important factors for the miRNA regulation. The functional enrichment analysis showed that the miRNAs with high variation, particularly the 5' end variation, are enriched in a set of critical functions, supporting these molecules should not be randomly produced. Our results provide a probabilistic framework for miRNA isoforms analysis, and give functional insights into pre-miRNA processing.

  4. Inhibition of formyl peptide-stimulated superoxide anion generation by Fal-002-2 occurs mainly through the blockade of the p21-activated kinase and protein kinase C signaling pathways in ratneutrophils.

    Science.gov (United States)

    Tsai, Ya-Ru; Huang, Li-Jiau; Lin, Hui-Yi; Hung, Yun-Jie; Lee, Miau-Rong; Kuo, Sheng-Chu; Hsu, Mei-Feng; Wang, Jih-Pyang

    2013-02-15

    In formyl-Met-Leu-Phe (fMLP)-stimulated rat neutrophils, a synthetic compound, 6-chloro-2-(2-chlorophenyl)-4-oxo-1,4-dihydroquinoline-3-carboxylate (Fal-002-2), inhibited superoxide anion (O2(•-)) generation with an IC50 value of about 11μM, which was not mediated by scavenging the generated O2(•-) or by a cytotoxic effect on neutrophils. Fal-002-2 effectively attenuated the phosphorylation of Ser residues in p47(phox) and the association between p47(phox) and p22(phox) in fMLP-stimulated neutrophils. The interaction of p47(phox) with protein kinase C (PKC) isoforms (α, βI, βII, δ and ζ) was attenuated by Fal-002-2 with a similar IC50 value to that required for inhibition of O2(•-) generation, whereas Fal-002-2 had no prominent effect on PKC isoform membrane translocation and did not affect the kinase activity. Moreover, Fal-002-2 had no effect on the phosphorylation of Akt and downstream glycogen synthase kinase-3β, only slightly affected the intracellular free Ca(2+) concentration, phosphorylation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase (MAPK), but effectively attenuated the downstream MAPK-activated protein kinase-2 phosphorylation. The interaction of p21-activated kinase (PAK) 1with p47(phox), phosphorylation of PAK1 (Thr423/Ser144) and the membrane recruitment of PAK1 were effectively inhibited by Fal-002-2. Fal-002-2 also blocked the activation of Rac1 and Cdc42 in a concentration range that effectively inhibited PAK activation. Taken together, these results suggest that Fal-002-2 inhibits fMLP-stimulated O2(•-) generation in neutrophils mainly through the blockade of PKC and PAK signaling pathways and partly through p38 MAPK signaling.

  5. Phosphatidylinositol 3-kinase in myogenesis.

    Science.gov (United States)

    Kaliman, P; Zorzano, A

    1997-08-01

    Phosphatidylinositol 3-kinase (PI 3-kinase) has been cloned and characterized in a wide range of organisms. PI 3-kinases are activated by a diversity of extracellular stimuli and are involved in multiple cell processes such as cell proliferation, protein trafficking, cell motility, differentiation, regulation of cytoskeletal structure, and apoptosis. It has recently been shown that PI 3-kinase is a crucial second messenger in the signaling of myogenesis. Two structurally unrelated highly specific inhibitors of PI 3-kinase-wortmannin and LY294002-block the morphological and biochemical differentiation program of different skeletal-muscle cell models. Moreover, L6E9 myoblasts overexpressing a dominant-negative mutant of PI 3-kinase p85 regulatory subunit (Δp85) are unable to differentiate. Furthermore, PI 3-kinase is specifically involved in the insulinlike growth factor (IGF)-dependent myogenic pathway. Indeed, the ability of IGF-I, des-1,3-IGF-I, and IGF-II to promote cell fusion and muscle-specific protein expression is impaired after treatment with PI 3-kinase inhibitors or in cells overexpressing Δp85. The identification of additional key downstream elements of the IGF/PI 3-kinase myogenic cascade is crucial to a detailed understanding of the process of muscle differentiation and may generate new tools for skeletal and cardiac muscle regeneration therapies. (Trends Cardiovasc Med 1997;7:198-202). © 1997, Elsevier Science Inc.

  6. INFLUENCE OF NEOMYCIN AND INGESTED ENDOTOXIN IN THE PATHOGENESIS OF CHOLINE DEFICIENCY CIRRHOSIS IN THE ADULT RAT

    Science.gov (United States)

    Broitman, Selwyn A.; Gottlieb, Leonard S.; Zamcheck, Norman

    1964-01-01

    Two groups of adult rats fed a choline-deficient diet supplemented with neomycin in their drinking water for 250 or 350 days were protected against the development of liver fibrosis and cirrhosis. At the termination of the study these animals weighed more than others not receiving neomycin. This difference in weight did not appear to be caused by a growth-promoting effect of neomycin but rather reflected the increased severity of liver disease and a resultant weight loss in animals not receiving neomycin. Protection by neomycin was cancelled when Salmonella typhosa endotoxin was added to the drinking water. It was concluded that the protective effect of neomycin was mediated by an alteration in the intestinal microflora resulting in a reduction in the numbers of organisms contributing to intraluminal endotoxin. In the presence of choline deficiency, absorption of intraluminal endotoxin may contribute to the development of fibrosis and cirrhosis. PMID:14151103

  7. Simultaneous targeted analysis of trimethylamine-N-oxide, choline, betaine, and carnitine by high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Liu, Jia; Zhao, Mingming; Zhou, Juntuo; Liu, Changjie; Zheng, Lemin; Yin, Yuxin

    2016-11-01

    Trimethylamine-N-oxide (TMAO) is a metabolite generated from choline, betaine and carnitine in a gut microbiota-dependent way. This molecule is associated with development of atherosclerosis and cardiovascular events. A sensitive liquid chromatographic electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) has been developed and validated for the simultaneous determination of TMAO related molecules including TMAO, betaine, choline, and carnitine in mouse plasma. Analytes are extracted after protein precipitation by methanol and subjected to LC-ESI-MS/MS without preliminary derivatization. Separation of analytes was achieved on an amide column with acetonitrile-water as the mobile phase. This method has been fully validated in this study in terms of selectivity, linearity, sensitivity, precision, accuracy, and carryover effect, and the stability of the analyte under various conditions has been confirmed. This developed method has successfully been applied to plasma samples of our mouse model.

  8. Associations of gut-flora-dependent metabolite trimethylamine-N-oxide, betaine and choline with non-alcoholic fatty liver disease in adults.

    Science.gov (United States)

    Chen, Yu-ming; Liu, Yan; Zhou, Rui-fen; Chen, Xiao-ling; Wang, Cheng; Tan, Xu-ying; Wang, Li-jun; Zheng, Rui-dan; Zhang, Hong-wei; Ling, Wen-hua; Zhu, Hui-lian

    2016-01-08

    Many studies suggest that trimethylamine-N-oxide (TMAO), a gut-flora-dependent metabolite of choline, contributes to the risk of cardiovascular diseases, but little is known for non-alcoholic fatty liver disease (NAFLD). We examined the association of circulating TMAO, choline and betaine with the presence and severity of NAFLD in Chinese adults. We performed a hospital-based case-control study (CCS) and a cross-sectional study (CSS). In the CCS, we recruited 60 biopsy-proven NAFLD cases and 35 controls (18-60 years) and determined serum concentrations of TMAO, choline and betaine by HPLC-MS/MS. For the CSS, 1,628 community-based adults (40-75 years) completed the blood tests and ultrasonographic NAFLD evaluation. In the CCS, analyses of covariance showed adverse associations of ln-transformed serum levels of TMAO, choline and betaine/choline ratio with the scores of steatosis and total NAFLD activity (NAS) (all P-trend betaine and betaine/choline ratio (all P-trend betaine-NAFLD relationship in the community-based participants.

  9. Protein kinase C expression in salivary gland acinar epithelial cells in non-obese diabetic mice, an experimental model for Sjögren's syndrome.

    Science.gov (United States)

    Tensing, E-K; Ma, J; Hukkanen, M; Fox, H S; Li, T-F; Törnwall, J; Konttinen, Y T

    2005-01-01

    We planned to investigate the expression of protein kinase C (PKC) isoforms in acinar epithelial cells of salivary glands in the non-obese diabetic (NOD) mouse to find out if they develop changes of the PKC system like those seen in the human counterpart, i.e. in Sjögren's syndrome. Parotid, submandibular, and sublingual glands from NOD and control BALB/c mice were stained with a panel of monoclonal antibodies directed against conventional (alpha, beta, and gamma), novel (delta, epsilon, and theta), and atypical (lambda and iota) PKC isoforms using the streptavidin/HRP method. Similarly to human labial salivary glands, acinar epithelial cells of the healthy control BALB/c mice contained two of the conventional PKC isoforms, alpha and beta. Acinar and ductal epithelial cells also contained the atypical PKC isoforms lambda and iota. PKC isoforms gamma, delta, epsilon, and theta were not found. NOD mice which displayed focal sialadenitis contained the same conventional and atypical PKC isoforms. The acinar cells in NOD mice, in contrast to the Sjögren's syndrome patients, did not lack PKC alpha or beta. On the contrary, PKC alpha and beta staining was stronger than in the control BALB/c mice. The present results demonstrate that both conventional and atypical PKC isoforms participate in the salivary epithelial cell biology and that there are mouse strain-associated and/or disease state-associated changes in their expression. The lack of PKC alpha and beta isoforms found in Sjögren's syndrome was not reproduced in NOD mice, which discloses one more difference between the human disease and its NOD mouse model.

  10. Non-corrosive green lubricants:strengthened lignin–[choline][amino acid] ionic liquids interaction via reciprocal hydrogen bonding

    OpenAIRE

    Mu, Liwen; Shi, Yijun; Guo, Xiaojing; Ji, Tuo; Chen, Long; Yuan, Ruixia; Brisbin, Logan; Wang, Huaiyuan; Zhu, Jiahua

    2015-01-01

    A series of novel green lubricants with dissolved lignin in [choline][amino acid] ([CH][AA]) ionic liquids (ILs) have been synthesized in this work. The effect of lignin on the thermal and tribological properties of the lignin/[CH][AA] lubricants was systematically investigated by means of thermogravimetric analysis, differential scanning calorimetry, and a friction and wear tester. The lignin in [CH][AA] has been demonstrated to be an effective additive to improve thermal stability, reduce t...

  11. The protective effect of diammonium glycyrrhizinate and polyene phosphatidyl choline on livery damage caused by anti-tuberculosis drugs

    Institute of Scientific and Technical Information of China (English)

    Li Wang

    2016-01-01

    Objective:To study the protective effect of diammonium glycyrrhizinate and polyene phosphatidyl choline on livery damage caused by anti-tuberculosis drugs.Methods:Patients who received initial 2HRS(E)Z/4HR short-range anti-tuberculosis treatment in our hospital from October 2013 to October 2015 were selected and randomly divided into diammonium glycyrrhizinate group (group A) and polyene phosphatidyl choline group (group B), and after 4 weeks of liver protection treatment, serum levels of liver damage marker molecules, stress marker molecules and NF-κB-mediated inflammatory molecules as well as protein expression levels of bile acid metabolism genes were determined.Results: Serum ALT, AST, GGT, ALP, GDH, TBIL, NF-κB, IL-1β, TNF-α and MCP-1 levels of group B were significantly lower than those of group A while HO-1, GSH-Px, SOD, ERK, MEK and SIRT1 levels were significantly higher than those of group A; serum CYP7A1, FXR and SHP protein expression levels of group B were significantly lower than those of group A while BESP protein expression level was significantly higher than that of group A.Conclusion:Polyene phosphatidyl choline has better protective effect on liver damage caused by anti-tuberculosis drugs than diammonium glycyrrhizinate, and the molecular mechanisms of polyene phosphatidyl choline to protect the liver are enhancing the antioxidant effect mediated by HO-1 and SIRT1, inhibiting the inflammatory response mediated by NF-κB and regulating the expression of bile acid metabolism genes.

  12. Nuclear Magnetic Resonance Detects Phosphoinositide 3-Kinase/Akt-Independent Traits Common to Pluripotent Murine Embryonic Stem Cells and Their Malignant Counterparts

    Directory of Open Access Journals (Sweden)

    Hanna M. Romanska

    2009-12-01

    Full Text Available Pluripotent embryonic stem (ES cells, a potential source of somatic precursors for cell therapies, cause tumors after transplantation. Studies of mammalian carcinogenesis using nuclear magnetic resonance (NMR spectroscopy have revealed changes in the choline region, particularly increased phosphocholine (PCho content. High PCho levels in murine ES (mES cells have recently been attributed to cell pluripotency. The phosphoinositide 3-kinase (PI3K/Akt pathway has been implicated in tumor-like properties of mES cells. This study aimed to examine a potential link between the metabolic profile associated with choline metabolism of pluripotent mES cells and PI3K/Akt signaling. We used mES (ES-D3 and murine embryonal carcinoma cells (EC-F9 and compared the metabolic profiles of 1 pluripotent mES (ESD0, 2 differentiated mES (ESD14, and 3 pluripotent F9 cells. Involvement of the PI3K/Akt pathway was assessed using LY294002, a selective PI3K inhibitor. Metabolic profiles were characterized in the extracted polar fraction by 1H NMR spectroscopy. Similarities were found between the levels of choline phospholipid metabolites (PCho/total choline and PCho/glycerophosphocholine [GPCho] in ESD0 and F9 cell spectra and a greater-than five-fold decrease of the PCho/GPCho ratio associated with mES cell differentiation. LY294002 caused no significant change in relative PCho levels but led to a greater-than two-fold increase in PCho/GPCho ratios. These results suggest that the PCho/GPCho ratio is a metabolic trait shared by pluripotent and malignant cells and that PI3K does not underlie its development. It is likely that the signature identified here in a mouse model may be relevant for safe therapeutic applications of human ES cells.

  13. Megakaryocytes Regulate Expression of Pyk2 Isoforms and Caspase-mediated Cleavage of Actin in Osteoblasts*

    Science.gov (United States)

    Kacena, Melissa A.; Eleniste, Pierre P.; Cheng, Ying-Hua; Huang, Su; Shivanna, Mahesh; Meijome, Tomas E.; Mayo, Lindsey D.; Bruzzaniti, Angela

    2012-01-01

    The proliferation and differentiation of osteoblast (OB) precursors are essential for elaborating the bone-forming activity of mature OBs. However, the mechanisms regulating OB proliferation and function are largely unknown. We reported that OB proliferation is enhanced by megakaryocytes (MKs) via a process that is regulated in part by integrin signaling. The tyrosine kinase Pyk2 has been shown to regulate cell proliferation and survival in a variety of cells. Pyk2 is also activated by integrin signaling and regulates actin remodeling in bone-resorbing osteoclasts. In this study, we examined the role of Pyk2 and actin in the MK-mediated increase in OB proliferation. Calvarial OBs were cultured in the presence of MKs for various times, and Pyk2 signaling cascades in OBs were examined by Western blotting, subcellular fractionation, and microscopy. We found that MKs regulate the temporal expression of Pyk2 and its subcellular localization. We also found that MKs regulate the expression of two alternatively spliced isoforms of Pyk2 in OBs, which may regulate OB differentiation and proliferation. MKs also induced cytoskeletal reorganization in OBs, which was associated with the caspase-mediated cleavage of actin, an increase in focal adhesions, and the formation of apical membrane ruffles. Moreover, BrdU incorporation in MK-stimulated OBs was blocked by the actin-polymerizing agent, jasplakinolide. Collectively, our studies reveal that Pyk2 and actin play an important role in MK-regulated signaling cascades that control OB proliferation and may be important for therapeutic interventions aimed at increasing bone formation in metabolic diseases of the skeleton. PMID:22447931

  14. Megakaryocytes regulate expression of Pyk2 isoforms and caspase-mediated cleavage of actin in osteoblasts.

    Science.gov (United States)

    Kacena, Melissa A; Eleniste, Pierre P; Cheng, Ying-Hua; Huang, Su; Shivanna, Mahesh; Meijome, Tomas E; Mayo, Lindsey D; Bruzzaniti, Angela

    2012-05-18

    The proliferation and differentiation of osteoblast (OB) precursors are essential for elaborating the bone-forming activity of mature OBs. However, the mechanisms regulating OB proliferation and function are largely unknown. We reported that OB proliferation is enhanced by megakaryocytes (MKs) via a process that is regulated in part by integrin signaling. The tyrosine kinase Pyk2 has been shown to regulate cell proliferation and survival in a variety of cells. Pyk2 is also activated by integrin signaling and regulates actin remodeling in bone-resorbing osteoclasts. In this study, we examined the role of Pyk2 and actin in the MK-mediated increase in OB proliferation. Calvarial OBs were cultured in the presence of MKs for various times, and Pyk2 signaling cascades in OBs were examined by Western blotting, subcellular fractionation, and microscopy. We found that MKs regulate the temporal expression of Pyk2 and its subcellular localization. We also found that MKs regulate the expression of two alternatively spliced isoforms of Pyk2 in OBs, which may regulate OB differentiation and proliferation. MKs also induced cytoskeletal reorganization in OBs, which was associated with the caspase-mediated cleavage of actin, an increase in focal adhesions, and the formation of apical membrane ruffles. Moreover, BrdU incorporation in MK-stimulated OBs was blocked by the actin-polymerizing agent, jasplakinolide. Collectively, our studies reveal that Pyk2 and actin play an important role in MK-regulated signaling cascades that control OB proliferation and may be important for therapeutic interventions aimed at increasing bone formation in metabolic diseases of the skeleton.

  15. Effects of rumen-protected choline supplementation on metabolic and performance responses of transition dairy cows.

    Science.gov (United States)

    Leiva, T; Cooke, R F; Brandão, A P; Marques, R S; Vasconcelos, J L M

    2015-04-01

    The objective of this experiment was to compare metabolic and milk production parameters in dairy cows supplemented and nonsupplemented with rumen-protected choline (RPC) during the transition period. Twenty-three nonlactating, multiparous, pregnant Holstein cows were ranked by BW and BCS 21 d before expected date of calving and immediately were assigned to receive (n = 12) or not receive (control; n = 11) RPC until 45 d in milk (DIM). Cows supplemented with RPC received (as-fed basis) 50 and 100 g/d of RPC (18.8% choline) before and after calving, respectively. Before calving, cows were maintained in 2 drylot pens according to treatment with ad libitum access to corn silage, and individually they received (as-fed basis) 3 kg/cow daily of a concentrate. Upon calving, cows were moved to 2 adjacent drylot pens according to treatment, milked twice daily, offered (as-fed basis) 35 kg/cow daily of corn silage, and individually received a concentrate formulated to meet their nutritional requirements after milking. The RPC was individually offered to cows as a topdressing into the morning concentrate feeding. Before calving, cow BW and BCS were recorded weekly, and blood samples were collected every 5 d beginning on d -21 relative to expected calving date. Upon calving and until 45 DIM, BW and BCS were recorded weekly, individual milk production was recorded daily, and milk samples were collected once a week and analyzed for fat, protein, and total solids. Blood samples were collected every other day from 0 to 20 DIM and every 5 d from 20 to 45 DIM. Based on actual calving dates, cows receiving RPC or control began receiving treatments 16.8 ± 1.7 and 17.3 ± 2.0 d before calving, respectively. No treatment effects were detected (P ≥ 0.18) on postpartum concentrate intake, BW and BCS, or serum concentrations of cortisol, β-hydroxybutyrate, NEFA, glucose, and IGF-I. Cows supplemented with RPC had greater (P ≤ 0.01) mean serum haptoglobin and insulin concentrations

  16. Differential impact of genetically modulated choline transporter expression on the release of endogenous versus newly synthesized acetylcholine.

    Science.gov (United States)

    Iwamoto, Hideki; Calcutt, M Wade; Blakely, Randy D

    2016-09-01

    The efficient import of choline into cholinergic nerve terminals by the presynaptic, high-affinity choline transporter (CHT, SLC5A7) dictates the capacity for acetylcholine (ACh) synthesis and release. Tissue levels of ACh are significantly reduced in mice heterozygous for a loss of function mutation in Slc5a7 (HET, CHT(+/-)), but significantly elevated in overexpressing, Slc5a7 BAC-transgenic mice (BAC). Since the readily-releasable pool of ACh is thought to constitute a small fraction of the total ACh pool, these genotype-dependent changes raised the question as to whether CHT expression or activity might preferentially influence the size of reserve pool ACh vesicles. In the current study, we approached this question by evaluating CHT genotype effects on the release of ACh from suprafused mouse forebrain slices. We treated slices from HET, BAC or wildtype (WT) controls with elevated K(+) and monitored release of both newly synthesized and storage pools of ACh. Newly synthesized ACh produced following uptake of [(3)H]choline was quantified by scintillation spectrometry whereas release of endogenous ACh storage pools was quantified by an HPLC-MS approach, from the same samples. Whereas endogenous ACh release scaled with CHT gene dosage, preloaded [(3)H]ACh release displayed no significant genotype dependence. Our findings suggest that CHT protein levels preferentially impact the capacity for ACh release afforded by mobilization of reserve pool vesicles.

  17. INS, DFT and temperature dependent IR investigations of dynamical properties of low temperature phase of choline chloride

    Energy Technology Data Exchange (ETDEWEB)

    Pawlukojć, A., E-mail: andrzej@jinr.ru [Institute of Nuclear Chemistry and Technology, Dorodna 16 str., 03-195 Warsaw (Poland); Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Hetmańczyk, Ł. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Faculty of Chemistry, Jagiellonian University, Ingardena 3 str., 30-060 Cracow (Poland)

    2014-12-05

    Highlights: • Choline chloride was investigated by INS and IR. • DFT calculations for solids state model were performed. • Full vibrational analysis was performed. • Activation energy for the CH{sub 3} group reorientation was obtained. - Abstract: Within the framework of the research the inelastic neutron scattering and temperature dependent infra-red spectroscopy investigations of the low temperature phase of choline chloride were performed. The infra-red spectra in wavenumber region 4000–80 cm{sup −1} and in a temperature range 9–300 K were collected. The density functional theory calculations with the periodic boundary conditions for determination and description of the normal modes in the vibration spectra of choline chloride were applied. Bands assigned to the CH{sub 3} torsional vibration were observed at 288 and 249 cm{sup −1}. From the analysis of the temperature dependence of the full-width-at-half-maximum the activation energy for CH{sub 3} group reorientation is found to be equal to 1.6 ± 0.2 kcal/mol.

  18. Serum levels of choline-containing compounds are associated with aerobic fitness level: the HUNT-study.

    Directory of Open Access Journals (Sweden)

    Anja Bye

    Full Text Available BACKGROUND: Cardiovascular disease (CVD is a leading cause of death worldwide, and the number of people at risk is continuously growing. New methods for early risk prediction are therefore needed to actuate prevention strategies before the individuals are diagnosed with CVD. Several studies report that aerobic fitness level, measured as maximal oxygen uptake (VO(2max, is the single best predictor of future CVD mortality in healthy people. Based on this, we wanted to study differences between healthy individuals with a large difference in VO(2max-level to identify new biomarkers of low aerobic fitness that may also have potential as early biomarkers of CVD risk. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples from 218 healthy individuals with a low VO(2max (n = 108, 63 women or high VO(2max (n = 110, 64 women were analysed with MR metabolomics. In addition, standard clinical-chemical analyses for glucose, lipids, liver enzymes, micro-CRP, and colorimetric analysis on circulating choline were performed. Individuals in the low VO(2max-group had increased serum levels of free choline, decreased phosphatidylcholine, increased glucosę and decreased unsaturated fatty acids compared to the individuals in the high VO(2max-group. CONCLUSIONS/SIGNIFICANCE: Aerobic fitness dependent differences in serum levels of free choline and phosphatidylcholine are observed. They should be further studied as potential early markers of CVD risk.

  19. Crystallization and preliminary X-ray diffraction studies of choline-binding protein F from Streptococcus pneumoniae

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Rafael [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); González, Ana; Moscoso, Miriam; García, Pedro [Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid (Spain); Stelter, Meike; Kahn, Richard [Institut de Biologie Structurale J.-P. Ebel CEA CNRS UJF, Laboratoire de Cristallographie Macromoléculaire, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 1 (France); Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es [Grupo de Cristalografía Macromolecular y Biología Estructural, Instituto Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2007-09-01

    The modular choline-binding protein F (CbpF) from S. pneumoniae has been crystallized by the hanging-drop vapour-diffusion method. A SAD data set from a gadolinium-complex derivative has been collected to 2.1 Å resolution. Choline-binding protein F (CbpF) is a modular protein that is bound to the pneumococcal cell wall through noncovalent interactions with choline moieties of the bacterial teichoic and lipoteichoic acids. Despite being one of the more abundant proteins on the surface, along with the murein hydrolases LytA, LytB, LytC and Pce, its function is still unknown. CbpF has been crystallized using the hanging-drop vapour-diffusion method at 291 K. Diffraction-quality orthorhombic crystals belong to space group P2{sub 1}2{sub 1}2, with unit-cell parameters a = 49.13, b = 114.94, c = 75.69 Å. A SAD data set from a Gd-HPDO3A-derivatized CbpF crystal was collected to 2.1 Å resolution at the gadolinium L{sub III} absorption edge using synchrotron radiation.

  20. Amperometric choline biosensor based on multiwalled carbon nanotubes/zirconium oxide nanoparticles electrodeposited on glassy carbon electrode.

    Science.gov (United States)

    Pundir, S; Chauhan, N; Narang, J; Pundir, C S

    2012-08-01

    A bienzymatic choline biosensor was constructed by coimmobilizing acetylcholinesterase (AChE) and choline oxidase (ChO) onto nanocomposite of carboxylated multiwalled carbon nanotubes (c-MWCNTs) and zirconium oxide nanoparticles (ZrO(2)NPs) electrodeposited on the surface of a glassy carbon electrode (GCE) and using it (AChE-ChO/c-MWCNT/ZrO(2)NPs/GCE) as working electrode, Ag/AgCl as reference electrode, and Pt wire as auxiliary electrode connected through a potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and cyclic voltammetry (CV) studies, optimized, and evaluated. The biosensor exhibited optimum response within 4 s at +0.2V, pH 7.4, and 25 °C. The detection limit and working range of the biosensor were 0.01 μM and 0.05 to 200 μM, respectively. The half-life of the enzyme electrode was 60 days at 4 °C. The serum choline level, as measured by the biosensor, was 9.0 to 12.8 μmol/L (with a mean of 10.81 μmol/L) in apparently healthy persons and 5.0 to 8.4 μmol/L (with a mean of 6.53 μmol/L) in persons suffering from Alzheimer's disease. The enzyme electrode was unaffected by a number of serum substances.

  1. Differential sensitivity of rat voltage-sensitive sodium channel isoforms to pyrazoline-type insecticides.

    Science.gov (United States)

    Silver, Kristopher S; Soderlund, David M

    2006-07-15

    Pyrazoline-type insecticides are potent inhibitors of insect and mammalian voltage-sensitive sodium channels. In mammals, there are nine sodium channel alpha subunit isoforms that have unique distributions and pharmacological properties, but no published data exist that compare the relative sensitivity of these different mammalian sodium channel isoforms to inhibition by pyrazoline-type insecticides. This study employed the Xenopus oocyte expression system to examine the relative sensitivity of rat Na(v)1.2a, Na(v)1.4, Na(v)1.5, and Na(v)1.8 sodium channel alpha subunit isoforms to the pyrazoline-type insecticides indoxacarb, DCJW, and RH 3421. Additionally, we assessed the effect of coexpression with the rat beta1 auxiliary subunit on the sensitivity of the Na(v)1.2a and Na(v)1.4 isoforms to these compounds. The relative sensitivity of the four sodium channel alpha subunits differed for each of the three compounds we examined. With DCJW, the order of sensitivity was Na(v)1.4 > Na(v)1.2a > Na(v)1.5 > Na(v)1.8. In contrast, the relative sensitivity of these isoforms to indoxacarb differed from that to DCJW: the Na(v)1.8 isoform was most sensitive, the Na(v)1.4 isoform was completely insensitive, and the sensitivities of the Na(v)1.5 and Na(v)1.2a isoforms were intermediate between these two extremes. Moreover, the pattern of sensitivity to RH 3421 among these four isoforms was different from that for either indoxacarb or DCJW: the Na(v)1.4 isoform was most sensitive to RH 3421, whereas the sensitivities of the remaining three isoforms were substantially less than that of the Na(v)1.4 isoform and were approximately equivalent. The only statistically significant effect of coexpression of either the Na(v)1.2a or Na(v)1.4 isoforms with the beta1 subunit was the modest reduction in the sensitivity of the Na(v)1.2a isoform to RH 3421. These results demonstrate that mammalian sodium channel isoforms differ in their sensitivities to pyrazoline-type insecticides.

  2. Nesprins: tissue-specific expression of epsilon and other short isoforms.

    Directory of Open Access Journals (Sweden)

    Nguyen Thuy Duong

    Full Text Available Nesprin-1-giant and nesprin-2-giant regulate nuclear positioning by the interaction of their C-terminal KASH domains with nuclear membrane SUN proteins and their N-terminal calponin-homology domains with cytoskeletal actin. A number of short isoforms lacking the actin-binding domains are produced by internal promotion. We have evaluated the significance of these shorter isoforms using quantitative RT-PCR and western blotting with site-specific monoclonal antibodies. Within a complete map of nesprin isoforms, we describe two novel nesprin-2 epsilon isoforms for the first time. Epsilon isoforms are similar in size and structure to nesprin-1-alpha. Expression of nesprin isoforms was highly tissue-dependent. Nesprin-2-epsilon-1 was found in early embryonic cells, while nesprin-2-epsilon-2 was present in heart and other adult tissues, but not skeletal muscle. Some cell lines lack shorter isoforms and express only one of the two nesprin genes, suggesting that either of the giant nesprins is sufficient for basic cell functions. For the first time, localisation of endogenous nesprin away from the nuclear membrane was shown in cells where removal of the KASH domain by alternative splicing occurs. By distinguishing between degradation products and true isoforms on western blots, it was found that previously-described beta and gamma isoforms are expressed either at only low levels or with a limited tissue distribution. Two of the shortest alpha isoforms, nesprin-1-alpha-2 and nesprin-2-alpha-1, were found almost exclusively in cardiac and skeletal muscle and a highly conserved and alternatively-spliced exon, available in both nesprin genes, was always included in these tissues. These "muscle-specific" isoforms are thought to form a complex with emerin and lamin A/C at the inner nuclear membrane and mutations in all three proteins cause Emery-Dreifuss muscular dystrophy and/or inherited dilated cardiomyopathy, disorders in which only skeletal muscle and

  3. Role of Protein Kinase C (PKC in Podocytes and Development of Glomerular Damage in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Beina eTeng

    2014-11-01

    Full Text Available The early glomerular changes in diabetes include a podocyte phenotype with loss of slit diaphragm proteins, changes in the actin cytoskeleton and foot process architecture. This review focusses on the role of the Protein Kinase C family in podocytes and points out the differential roles of classical, novel and atypical PKCs in podocytes. Some PKC-isoforms are indispensable for proper glomerular development and slit diaphragm maintenance whereas others might be harmful when activated in the diabetic milieu. Therefore some might be interesting treatment targets in the early phase of diabetes.

  4. Metformin attenuates ovarian cancer cell growth in an AMP-kinase dispensable manner

    OpenAIRE

    Rattan, R; Giri, S.; Hartmann, LC; Shridhar, V

    2009-01-01

    Abstract Metformin, the most widely used drug for type 2 diabetes activates 59 adenosine monophosphate (AMP)-activated protein kinase (AMPK), which regulates cellular energy metabolism. Here, we report that ovarian cell lines VOSE, A2780, CP70, C200, OV202, OVCAR3, SKOV3ip, PE01 and PE04 predominantly express -α1, -β1, -γ1 and -γ2 isoforms of AMPK subunits. Our studies show that metformin treatment (1) significantly inhibited proliferation of diverse chemo-responsive and -resistant ovarian ca...

  5. The role of Na,K-ATPase/Src-kinase signaling pathway in the vascular wall contaction

    DEFF Research Database (Denmark)

    Bouzinova, Elena

    ,K-ATPase by ouabain elevates blood pressure. Consequently, ouabain was shown to potentiate arterial contraction in vitro. In contrast, we have demonstrated that siRNA-induced down-regulation of the α-2 isoform Na,K-ATPase expression reduced arterial sensitivity to agonist stimulation and prevented the effect...... of ouabain. Here we demonstrate results of our research on the mechanisms involved in the modulation of vascular wall contractility by ouabain-sensitive Na,K-ATPase. Methods: The experiments were performed using rat mesenteric arteries in isometric myograph conditions. To inhibit kinase activity a Src-family...

  6. [{sup 11}C]Choline PET/CT detection of bone metastases in patients with PSA progression after primary treatment for prostate cancer: comparison with bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Picchio, Maria [San Raffaele Scientific Institute, Nuclear Medicine Department, Milan (Italy); National Research Council (IBFM-CNR), Institute for Bioimaging and Molecular Physiology, Milan (Italy); Spinapolice, Elena Giulia; Crivellaro, Cinzia [University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); Fallanca, Federico; Gianolli, Luigi [San Raffaele Scientific Institute, Nuclear Medicine Department, Milan (Italy); Giovacchini, Giampiero [University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Messa, Cristina [National Research Council (IBFM-CNR), Institute for Bioimaging and Molecular Physiology, Milan (Italy); University of Milano-Bicocca, Center for Molecular Bioimaging, Milan (Italy); San Gerardo Hospital, Department of Nuclear Medicine, Monza (Italy)

    2012-01-15

    The aim of this study was to evaluate the clinical usefulness of [{sup 11}C]choline positron emission tomography (PET)/CT in comparison with bone scintigraphy (BS) in detecting bone metastases (BM) of patients with biochemical progression after radical treatment for prostate cancer (PCa). Seventy-eight consecutive patients with biochemical progression of PCa (mean prostate-specific antigen 21.1 ng/ml, range 0.2-500.0 ng/ml) referred for both [{sup 11}C]choline PET/CT and BS for restaging purposes were retrospectively analysed. The diagnostic accuracy of [{sup 11}C]choline PET/CT and BS was assessed by using morphological imaging and/or follow-up as standards of reference. As equivocal findings were found, the accuracy analysis was performed twice, once including them as positive and once as negative. A separate analysis was also performed in hormone-resistant patients and data compared with those of patients who did not receive anti-androgenic treatment. Equivocal findings occurred in 1 of 78 (1%) cases in [{sup 11}C]choline PET/CT and in 21 of 78 (27%) cases in BS. Depending on their attribution as either positive or negative, the ranges of sensitivity, specificity, positive predictive value, negative predictive value and accuracy for [{sup 11}C]choline PET/CT were 89-89%, 98-100%, 96-100%, 94-96% and 95-96%, respectively. For BS they were 100-70%, 75-100%, 68-100%, 100-86% and 83-90%, respectively. Concordant findings between [{sup 11}C]choline PET/CT and BS occurred in 55 of 78 (71%) cases. The accuracy of [{sup 11}C]choline PET/CT did not significantly (p = 0.30) differ between hormone-resistant patients (97%) and those who did not receive anti-androgenic treatment (95%). In clinical practice, [{sup 11}C]choline PET/CT may not replace BS because of its lower sensitivity. However, for its high specificity, [{sup 11}C]choline PET/CT positive findings may accurately predict the presence of BM. Equivocal findings are more frequent in BS than [{sup 11}C]choline PET

  7. Interaction Mechanism Insights on the Solvation of Fullerene B(80)with Choline-based Ionic Liquids.

    Science.gov (United States)

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2015-09-24

    Beyond carbon allotropes, other nanostructures such as fullerene B80 are attracting a growing interest due to their potential applications. The use of new materials based on fullerene B80 is still in a premature stage; however many of these applications would require the use of B80 in solution. This paper reports an unprecedented density functional theory (DFT) analysis on the interaction mechanism between B80 and two choline-based ionic liquids as a first insight for the fullerene B80 solvation by ionic liquids. The analysis of properties such as binding energies, charge distributions or intermolecular interactions shed light on the main features, which should govern interaction between ionic liquids and fullerene B80. In addition, the optimization of systems composed by six ionic pairs around a fullerene B80 has supplied some information about the first solvation shell at the molecular level. As a summary, this paper provides the first insights in the rational design of ionic liquids with suitable properties for the solvation of B80.

  8. Retinol status and expression of retinol-related proteins in methionine-choline deficient rats.

    Science.gov (United States)

    Miyazaki, Hiroshi; Takitani, Kimitaka; Koh, Maki; Inoue, Akiko; Kishi, Kanta; Tamai, Hiroshi

    2014-01-01

    Retinol and its derivative, retinoic acid, have pleiotropic functions including vision, immunity, hematopoiesis, reproduction, cell differentiation/growth, and development. Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases in developed countries and encompasses a broad spectrum of forms, ranging from steatosis to steatohepatitis, which develops further to cirrhosis. Retinol status has an important role in liver homeostasis. The purpose of this study was to evaluate the retinol status and expression of retinol-related proteins, including enzymes and binding proteins, in methionine-choline deficient (MCD) rats as a model of NAFLD. We examined retinol levels in the plasma and liver and gene expression for β-carotene 15,15'-monooxygenase (BCMO), lecithIn: retinol acyltransferase (LRAT), aldehyde dehydrogenase 1A1 (ALDH1A1), ALDH1A2, and cellular retinol binding protein (CRBP)-I in MCD rats. The plasma retinol levels in MCD rats were lower than those in the controls, whereas hepatic retinol levels in MCD rats were higher. BCMO expression in the intestine and liver in MCD rats was lower, whereas that in the testes and the kidneys was higher than in control rats. Expression of LRAT, CRBP-I, ALDH1A1, and ALDH1A2 in the liver of MCD rats was also higher. Altered expression of retinol-related proteins may affect retinol status in NAFLD.

  9. Synaptic proteins and choline acetyltransferase loss in visual cortex in dementia with Lewy bodies.

    Science.gov (United States)

    Mukaetova-Ladinska, Elizabeta B; Andras, Alina; Milne, Joan; Abdel-All, Zeinab; Borr, Iwo; Jaros, Evelyn; Perry, Robert H; Honer, William G; Cleghorn, Andrea; Doherty, Jeanette; McIntosh, Gary; Perry, Elaine K; Kalaria, Raj N; McKeith, Ian G

    2013-01-01

    Functional neuroimaging studies have consistently reported abnormalities in the visual cortex in patients with dementia with Lewy bodies (DLB), but their neuropathologic substrates are poorly understood. We analyzed synaptic proteins and choline acetyltransferase (ChAT) in the primary (BA17) and association (BAs18/19) visual cortex in DLB and similar aged control and Alzheimer disease (AD) subjects. We found lower levels of synaptophysin, syntaxin, SNAP-25, and γ-synuclein in DLB subjects versus both aged control (68%-78% and 27%-72% for BA17 and BAs18/19, respectively) and AD cases (54%-67% and 10%-56% for BA17 and BAs18/19, respectively). The loss in ChAT activity in DLB cases was also greater in BA17 (72% and 87% vs AD and control values, respectively) than in BAs18/19 (52% and 65% vs AD and control groups, respectively). The observed synaptic and ChAT changes in the visual cortices were not associated with tau or β-amyloid pathology in the occipital or the frontal, temporal, and parietal neocortex. However, the neocortical densities of LBs, particular those in BA17 and BAs18/19, correlated with lower synaptic and ChAT levels in these brain areas. These findings draw attention to molecular changes within the primary visual cortex in DLB and correlate with the neuroimaging findings within the occipital lobe in patients with this disorder.

  10. Novel ligands of Choline Acetyltransferase designed by in silico molecular docking, hologram QSAR and lead optimization.

    Science.gov (United States)

    Kumar, Rajnish; Långström, Bengt; Darreh-Shori, Taher

    2016-01-01

    Recent reports have brought back the acetylcholine synthesizing enzyme, choline acetyltransferase in the mainstream research in dementia and the cholinergic anti-inflammatory pathway. Here we report, a specific strategy for the design of novel ChAT ligands based on molecular docking, Hologram Quantitative Structure Activity Relationship (HQSAR) and lead optimization. Molecular docking was performed on a series of ChAT inhibitors to decipher the molecular fingerprint of their interaction with the active site of ChAT. Then robust statistical fragment HQSAR models were developed. A library of novel ligands was generated based on the pharmacophoric and shape similarity scoring function, and evaluated in silico for their molecular interactions with ChAT. Ten of the top scoring invented compounds are reported here. We confirmed the activity of α-NETA, the only commercially available ChAT inhibitor, and one of the seed compounds in our model, using a new simple colorimetric ChAT assay (IC50 ~ 88 nM). In contrast, α-NETA exhibited an IC50 of ~30 μM for the ACh-degrading cholinesterases. In conclusion, the overall results may provide useful insight for discovering novel ChAT ligands and potential positron emission tomography tracers as in vivo functional biomarkers of the health of central cholinergic system in neurodegenerative disorders, such as Alzheimer's disease.

  11. Positive correlations between cerebral choline and renal dysfunction in chronic renal failure

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Osamu; Nakahama, Hajime; Nakamura, Satoko; Inenaga, Takashi; Kawano, Yuhei [National Cardiovascular Center, Division of Hypertension and Nephrology, Department of Internal Medicine, Osaka (Japan); Hattori, Noriaki; Inoue, Noriko; Sawada, Tohru [BF Research Institute, Osaka (Japan); Kohno, Shigeru [Nagasaki University School of Medicine, Second Department of Internal Medicine, Nagasaki (Japan)

    2006-05-15

    Cerebral metabolism in chronic renal failure (CRF) patients has not been fully evaluated. This study examined cerebral metabolites in CRF, using proton magnetic resonance spectroscopy (MRS). Subjects comprised 19 CRF patients and 21 healthy volunteers. Spectra were acquired from voxels of interest positioned in the parietal gray and white matter, and concentrations of the following cerebral metabolites were measured: N-acetyl group (NA), creatine + phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol and glutamate + glutamine. Among the 19 CRF patients, 9 who were started on hemodialysis (HD) underwent careful follow-up. Proton MRS was performed before and about 2 weeks after starting HD. In six patients in whom follow-up was possible, a third MRS was performed after about 18 months. The NA/Cr ratio was not significantly changed in CRF. However, elevations in the Cho/Cr ratio were found in both gray and white matter compared with controls. To the best of our knowledge, this is the first report of positive correlations between the Cho/Cr ratio in both regions and serum osmotic pressure. (orig.)

  12. Early milk availability modulates the activity of choline acetyltransferase in the cerebral cortex of rats.

    Science.gov (United States)

    Aizawa, Shu; Nakamura, Ryosuke; Yamaguchi, Yuki; Sensui, Naoto; Yamamuro, Yutaka

    2011-10-01

    The purpose of the present study was to investigate the effect of milk in the early stage of lactation on the maturation of cholinergic neurons in the cerebral cortex of rats. Pups were removed from their mothers immediately following parturition and placed with foster dams at days 5-7 of lactation. At days 18 and 56 after birth, the activity of choline acetyltransferase (ChAT), an enzyme responsible for acetylcholine synthesis, in different areas of the cerebral cortex was examined by high-performance liquid chromatography electrochemical detection. In the frontal and hindlimb/parietal regions of the cerebral cortex, the lack of early milk significantly decreased ChAT activity at days 18 and 56. There was no effect on gains in the body or brain weight of infants. ChAT activity in the occipital area tended to be lower in the early milk-deprived rats. The intake of early milk potentially contributes not only to nutrients for the growth of newborn infants, but also to the functional maturation of the cholinergic neurotransmission system in a region-specific manner.

  13. Choline-induced selective fluorescence quenching of acetylcholinesterase conjugated Au@BSA clusters.

    Science.gov (United States)

    Mathew, Meegle S; Baksi, Ananya; Pradeep, T; Joseph, Kuruvilla

    2016-07-15

    We have developed a highly selective sensitive fluorescent detection of acetylcholine (ACh) using bovine serum albumin (BSA) protected atomically precise clusters of gold. The gold quantum clusters (AuQC@BSA) synthesized using bovine serum albumin and conjugated with acetylcholinesterase (AChE), an enzyme specific for acetylcholine, resulting in AuQC@BSA-AChE. The enzyme, AChE hydrolyzes acetylcholine (ACh) to choline (Ch) which in turn interacts with AuQC@BSA-AChE and quenches its fluorescence, enabling sensing. We have carried out the real time monitoring of the hydrolysis of ACh using electrospray ionization mass spectrometry (ESI MS) to find out the mechanism of fluorescent quenching. The validity of present method for determination of concentration of acetylcholine in real system such as blood was demonstrated. Further, the sensor, AuQC@BSA-AChE can be easily coated on paper and an efficient and cheap sensor can be developed and detection limit for ACh is found to be 10nM. The fluorescent intensity of AuQC@BSA-AChE is sensitive towards acetylcholine in range of 10nM to 6.4µM. This suggests that AuQC@BSA-AChE has an excellent potential to be used for diagnosis of various neuropsychological and neuropsychiatric disorders.

  14. Quantification of Muscle Choline Concentration by Proton MR Spectroscopy at 3 Tesla: Technical Feasibility

    Science.gov (United States)

    Fayad, Laura M.; Salibi, Nouha; Wang, Xin; Machado, Antonio J.; Jacobs, Michael A.; Ouwerkerk, Ronald; Okollie, Baasile; Bluemke, David A.; Eng, John; Barker, Peter B.

    2011-01-01

    Purpose To establish the feasibility of measuring the concentration of Choline (Cho) by proton MR spectroscopy (MRS) in skeletal muscle at 3T. Materials and Methods At 3T, Cho measurements were performed in phantoms and healthy volunteers by MRS (PRESS, TR/TE: 2000/144 ms). In vitro Cho concentrations were measured in 3 phantom solutions (10, 5, 1.25mmol). Cho T1 and T2 relaxation times were measured in muscles of 5 subjects. In vivo Cho concentrations were measured using water as an internal reference and average T1 and T2 times, in 20 muscle locations (quadriceps, hamstring) of 7 subjects (3 males, 4 females). Descriptive statistics were reported. Results In vitro, the average measured Cho concentrations of the 10, 5 and 1.25 mmol solutions were 9.91, 5.03 and 1.22 mmol respectively. In vivo, the average T1 and T2 relaxation times of Cho were 1372 +/−57 and 134 +/−11 ms respectively. Inter-individual variation existed (quadriceps range, 6.7–13 mmol/kg), but there was little gender or intra-individual variation. Conclusion In the musculoskeletal system, the measurement of Cho concentration by MRS at 3T is feasible using water as an internal reference. These data provide a quantitative basis for future investigations of metabolite concentration in normal and diseased musculoskeletal tissues. PMID:20028894

  15. Initial prostate cancer diagnosis and disease staging--the role of choline-PET-CT.

    Science.gov (United States)

    Mapelli, Paola; Picchio, Maria

    2015-09-01

    An early and correct diagnosis together with accurate staging of prostate cancer is necessary in order to plan the most appropriate treatment strategy. Morphological imaging modalities such as transrectal ultrasonography (TRUS), CT, and MRI can have some limitations regarding their accuracy for primary diagnosis and staging of prostate cancer; for instance, they have limited specificity in differentiating cancer from benign prostatic conditions and, by using size as the only criterion to characterize lymph node metastases, they might not be accurate enough for tumour characterization. In this scenario, PET-CT with (11)C-labelled or (18)F-labelled choline derivatives provides morphological and functional characterization and could overcome the limitations of the conventional imaging techniques. PET-CT is one of the most investigated molecular imaging modalities for prostate cancer diagnosis and staging. Currently, the main investigations on the role of PET-CT in the diagnosis and staging of prostate cancer have been performed on a retrospective basis and this type of analysis might be one of the main reasons why different results regarding its diagnostic accuracy have been reported.

  16. Effects of choline chloride on electrodeposited Ni coating from a Watts-type bath

    Science.gov (United States)

    Wang, Yurong; Yang, Caihong; He, Jiawei; Wang, Wenchang; Mitsuzak, Naotoshi; Chen, Zhidong

    2016-05-01

    Electrodeposition of bright nickel (Ni) was carried out in a Watts-type bath. Choline chloride (ChCl) was applied as a multifunctional additive and substitute for nickel chloride (NiCl2) in a Watts-type bath. The function of ChCl was investigated through conductivity tests, anodic polarization, and cathodic polarization experiments. The studies revealed that ChCl performed well as a conducting salt, anodic activator, and cathodic inhibitor. The effects of ChCl on deposition rate, preferred orientation, grain size, surface morphology, and microhardness of Ni coatings were also studied. The deposition rate reached a maximum value of greater than 27 μm h-1 when 20 g L-1 ChCl was introduced to the bath. Using X-ray diffraction, it was confirmed that progressive addition of ChCl promoted the preferred crystal orientation modification from (2 0 0) and (2 2 0) to (1 1 1), refined grain size, and enhanced microhardness. The presence of ChCl lowered the roughness of the coating.

  17. HI-6 assisted catalytic scavenging of VX by acetylcholinesterase choline binding site mutants.

    Science.gov (United States)

    Maček Hrvat, Nikolina; Žunec, Suzana; Taylor, Palmer; Radić, Zoran; Kovarik, Zrinka

    2016-11-25

    The high toxicity of organophosphorus compounds originates from covalent inhibition of acetylcholinesterase (AChE), an essential enzyme in cholinergic neurotransmission. Poisonings that lead to life-threatening toxic manifestations require immediate treatment that combines administration of anticholinergic drugs and an aldoxime as a reactivator of AChE. An alternative approach to reduce the in vivo toxicity of OPs focuses on the use of bioscavengers against the parent organophosphate. Our previous research showed that AChE mutagenesis can enable aldoximes to substantially accelerate the reactivation of OP-enzyme conjugates, while dramatically slowing down rates of OP-conjugate dealkylation (aging). Herein, we demonstrate an efficient HI-6-assisted VX detoxification, both ex vivo in human blood and in vivo in mice by hAChE mutants modified at the choline binding site (Y337A and Y337A/F338A). The catalytic scavenging of VX in mice improved therapeutic outcomes preventing lethality and resulted in a delayed onset of toxicity symptoms.

  18. Roles of the troponin isoforms during indirect flight muscle development in Drosophila.

    Science.gov (United States)

    Singh, Salam Herojeet; Kumar, Prabodh; Ramachandra, Nallur B; Nongthomba, Upendra

    2014-08-01

    Troponin proteins in cooperative interaction with tropomyosin are responsible for controlling the contraction of the striated muscles in response to changes in the intracellular calcium concentration. Contractility of the muscle is determined by the constituent protein isoforms, and the isoforms can switch over from one form to another depending on physiological demands and pathological conditions. In Drosophila, amajority of themyofibrillar proteins in the indirect flight muscles (IFMs) undergo post-transcriptional and post-translational isoform changes during pupal to adult metamorphosis to meet the high energy and mechanical demands of flight. Using a newly generated Gal4 strain (UH3-Gal4) which is expressed exclusively in the IFMs, during later stages of development, we have looked at the developmental and functional importance of each of the troponin subunits (troponin-I, troponin-T and troponin-C) and their isoforms. We show that all the troponin subunits are required for normal myofibril assembly and flight, except for the troponin-C isoform 1 (TnC1). Moreover, rescue experiments conducted with troponin-I embryonic isoform in the IFMs, where flies were rendered flightless, show developmental and functional differences of TnI isoforms and importance of maintaining the right isoform.

  19. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity

    DEFF Research Database (Denmark)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T

    2014-01-01

    Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms...

  20. Translational control of C/EBPalpha and C/EBPbeta isoform expression

    NARCIS (Netherlands)

    Calkhoven, C F; Müller, C; Leutz, A

    2000-01-01

    Transcription factors derived from CCAAT/enhancer binding protein (C/EBP)alpha and C/EBPbeta genes control differentiation and proliferation in a number of cell types. Various C/EBP isoforms arise from unique C/EBPbeta and C/EBPalpha mRNAs by differential initiation of translation. These isoforms re

  1. Comprehensive analysis of tropomyosin isoforms in skeletal muscles by top-down proteomics.

    Science.gov (United States)

    Jin, Yutong; Peng, Ying; Lin, Ziqing; Chen, Yi-Chen; Wei, Liming; Hacker, Timothy A; Larsson, Lars; Ge, Ying

    2016-04-01

    Mammalian skeletal muscles are heterogeneous in nature and are capable of performing various functions. Tropomyosin (Tpm) is a major component of the thin filament in skeletal muscles and plays an important role in controlling muscle contraction and relaxation. Tpm is known to consist of multiple isoforms resulting from different encoding genes and alternative splicing, along with post-translational modifications. However, a systematic characterization of Tpm isoforms in skeletal muscles is still lacking. Therefore, we employed top-down mass spectrometry (MS) to identify and characterize Tpm isoforms present in different skeletal muscles from multiple species, including swine, rat, and human. Our study revealed that Tpm1.1 and Tpm2.2 are the two major Tpm isoforms in swine and rat skeletal muscles, whereas Tpm1.1, Tpm2.2, and Tpm3.12 are present in human skeletal muscles. Tandem MS was utilized to identify the sequences of the major Tpm isoforms. Furthermore, quantitative analysis revealed muscle-type specific differences in the abundance of un-modified and modified Tpm isoforms in rat and human skeletal muscles. This study represents the first systematic investigation of Tpm isoforms in skeletal muscles, which not only demonstrates the capabilities of top-down MS for the comprehensive characterization of skeletal myofilament proteins but also provides the basis for further studies on these Tpm isoforms in muscle-related diseases.

  2. Glial fibrillary acidic protein isoform expression in plaque related astrogliosis in Alzheimer's disease.

    Science.gov (United States)

    Kamphuis, Willem; Middeldorp, Jinte; Kooijman, Lieneke; Sluijs, Jacqueline A; Kooi, Evert-Jan; Moeton, Martina; Freriks, Michel; Mizee, Mark R; Hol, Elly M

    2014-03-01

    In Alzheimer's disease (AD), amyloid plaques are surrounded by reactive astrocytes with an increased expression of intermediate filaments including glial fibrillary acidic protein (GFAP). Different GFAP isoforms have been identified that are differentially expressed by specific subpopulations of astrocytes and that impose different properties to the intermediate filament network. We studied transcript levels and protein expression patterns of all known GFAP isoforms in human hippocampal AD tissue at different stages of the disease. Ten different transcripts for GFAP isoforms were detected at different abundancies. Transcript levels of most isoforms increased with AD progression. GFAPδ-immunopositive astrocytes were observed in subgranular zone, hilus, and stratum-lacunosum-moleculare. GFAPδ-positive cells also stained for GFAPα. In AD donors, astrocytes near plaques displayed increased staining of both GFAPα and GFAPδ. The reading-frame-shifted isoform, GFAP(+1), staining was confined to a subset of astrocytes with long processes, and their number increased in the course of AD. In conclusion, the various GFAP isoforms show differential transcript levels and are upregulated in a concerted manner in AD. The GFAP(+1) isoform defines a unique subset of astrocytes, with numbers increasing with AD progression. These data indicate the need for future exploration of underlying mechanisms concerning the functions of GFAPδ and GFAP(+1) isoforms in astrocytes and their possible role in AD pathology.

  3. Roles of the troponin isoforms during indirect flight muscle development in Drosophila

    Indian Academy of Sciences (India)

    Salam Herojeet Singh; Prabodh Kumar; Nallur B. Ramachandra; Upendra Nongthomba

    2014-08-01

    Troponin proteins in cooperative interaction with tropomyosin are responsible for controlling the contraction of the striated muscles in response to changes in the intracellular calcium concentration. Contractility of the muscle is determined by the constituent protein isoforms, and the isoforms can switch over from one form to another depending on physiological demands and pathological conditions. In Drosophila, amajority of themyofibrillar proteins in the indirect flight muscles (IFMs) undergo post-transcriptional and post-translational isoform changes during pupal to adult metamorphosis to meet the high energy and mechanical demands of flight. Using a newly generated Gal4 strain (UH3-Gal4) which is expressed exclusively in the IFMs, during later stages of development, we have looked at the developmental and functional importance of each of the troponin subunits (troponin-I, troponin-T and troponin-C) and their isoforms. We show that all the troponin subunits are required for normal myofibril assembly and flight, except for the troponin-C isoform 1 (TnC1). Moreover, rescue experiments conducted with troponin-I embryonic isoform in the IFMs, where flies were rendered flightless, show developmental and functional differences of TnI isoforms and importance of maintaining the right isoform.

  4. Insulin receptor isoforms : an integrated view focused on gestational diabetes mellitus

    NARCIS (Netherlands)

    Westermeier, F.; Sáez, T.; Arroyo, P.; Toledo, F.; Gutierrez, J.; Sanhueza, C.; Pardo, F.; Leiva, A.; Sobrevia, L.

    2016-01-01

    The human insulin receptor (IR) exists in two isoforms that differ by the absence (IR-A) or the presence (IR-B) of a 12-amino acid segment encoded by exon 11. Both isoforms are functionally distinct regarding their binding affinities and intracellular signalling. However, the underlying mechanisms r

  5. Differences in expression, actions and cocaine regulation of two isoforms for the brain transcriptional regulator NAC1.

    Science.gov (United States)

    Korutla, L; Wang, P J; Lewis, D M; Neustadter, J H; Stromberg, M F; Mackler, S A

    2002-01-01

    BTB/POZ proteins can influence the cell cycle and contribute to oncogenesis. Many family members are present in the mammalian CNS. Previous work demonstrated elevated NAC1 mRNA levels in the rat nucleus accumbens in response to cocaine. NAC1 acts like other BTB/POZ proteins that regulate transcription but is unusual because of the absence of identifiable DNA binding domains. cDNAs were isolated encoding two NAC1 isoforms differing by only 27 amino acids (the longer isoform contains 514 amino acids). The mRNAs for both isoforms were simultaneously expressed throughout the rat brain and peripheral tissues. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed that the mRNA of the longer isoform was more abundant than the mRNA of the shorter isoform. Western blot analysis demonstrated a similar unequal distribution between the isoforms in the CNS. The longer isoform was the more abundant of the two NAC1 proteins and the ratio between them differed throughout the rat brain. The shorter isoform was not detected in most of the examined peripheral tissues, suggesting differences from the CNS in post-transcriptional processing. Both isoforms repressed transcription in H293T cells using a Gal4-luciferase reporter system. However, the shorter isoform did not repress transcription as effectively as the longer isoform. Transfection of different ratios for both isoforms, in order to replicate the relative amounts observed throughout the CNS, supported an interaction between the isoforms. The net effect on transcriptional repression was determined by the ratio of the two NAC1 isoforms. Each isoform exhibited the subnuclear localization that is characteristic of many BTB/POZ proteins. A rapid and transient increase in the level of the shorter isoform occurred in the nucleus accumbens 2 h following a single i.p. cocaine injection. We conclude that the two isoforms of NAC1 may differentially affect neuronal functions, including the regulation of

  6. Identification and Characterization of the Nuclear Isoform of Drosophila melanogaster CTP:Phosphocholine Cytidylyltransferase

    Science.gov (United States)

    CTP:phosphocholine cytidylyltransferase (CCT) catalyzes the conversion of phosphocholine and cytidine 5'-triphosphate (CTP) to CDP-choline for the eventual synthesis of phosphatidylcholine (PC). The enzyme is regulated by reversible association with cellular membranes, with the rate of catalysis in...

  7. Influences of Short -term Aerobic Exercise and Supplementation of Carnitine With or Without Choline on Body Weight, Serum Leptin and Carnitine as Well as Lipid Status In Male Rats

    OpenAIRE

    Neamat E. Hishem*, Bushra H. El-Zawahry*, Seham M.S. El Nakeeb**

    2006-01-01

    Background: Carnitine is essential for fatty acids translocation, muscles function and exercise performance. Choline is a lipotropic agent that prevents deposition of fat in the liver. The studies concerning the effects of carnitine and choline supplementation with exercise on carnitine status and serum leptin are rare. The aim of the present study was to study the effect of carnitine and its combination with choline, with or without exercise on body and total fat pad (TFP) weights, serum car...

  8. Characterization of myotonic dystrophy kinase (DMK) in heterologous expression systems

    Energy Technology Data Exchange (ETDEWEB)

    Waring, J.D.; Haq, R.; Mahadevan, M.S. [Children`s Hospital of Eastern Ontario, Ottawa (Canada)] [and others

    1994-09-01

    Myotonic dystrophy is caused by expansion of a (CTG){sub n} repeat within the 3{prime} untranslated region of the DMK gene. This gene encodes a product with a predicted M.W. of {approximately}69 kDa which has homology to cAMP-regulated serine-threonine protein kinases. In addition, there is a domain with similarity to coiled-coil regions found in myofibrillar proteins and a predicted transmembrane domain found at the extreme C-terminus. As an approach to identifying the function of this gene, we have expressed various forms of DMK by both in