1
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Keshet R, Lee JS, Adler L, Iraqi M, Ariav Y, Lim LQJ, Lerner S, Rabinovich S, Oren R, Katzir R, Weiss Tishler H, Stettner N, Goldman O, Landesman H, Galai S, Kuperman Y, Kuznetsov Y, Brandis A, Mehlman T, Malitsky S, Itkin M, Koehler SE, Zhao Y, Talsania K, Shen TW, Peled N, Ulitsky I, Porgador A, Ruppin E, Erez A. Targeting purine synthesis in ASS1-expressing tumors enhances the response to immune checkpoint inhibitors. NATURE CANCER 2020; 1:894-908. [PMID: 35121952 DOI: 10.1038/s43018-020-0106-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 07/21/2020] [Indexed: 06/14/2023]
Abstract
Argininosuccinate synthase (ASS1) downregulation in different tumors has been shown to support cell proliferation and yet, in several common cancer subsets ASS1 expression associates with poor patient prognosis. Here we demonstrate that ASS1 expression under glucose deprivation is induced by c-MYC, providing survival benefit by increasing nitric oxide synthesis and activating the gluconeogenic enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase by S-nitrosylation. The resulting increased flux through gluconeogenesis enhances serine, glycine and subsequently purine synthesis. Notably, high ASS1-expressing breast cancer mice do not respond to immune checkpoint inhibitors and patients with breast cancer with high ASS1 have more metastases. We further find that inhibiting purine synthesis increases pyrimidine to purine ratio, elevates expression of the immunoproteasome and significantly enhances the response of autologous primary CD8+ T cells to anti-PD-1. These results suggest that treating patients with high-ASS1 cancers with purine synthesis inhibition is beneficial and may also sensitize them to immune checkpoint inhibition therapy.
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Affiliation(s)
- Rom Keshet
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel Hashomer, Israel
| | - Joo Sang Lee
- Cancer Data Science Lab, National Cancer Institutes of Health, Bethesda, MD, USA
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Samsung Medical Center, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Precision Medicine, School of Medicine, Sungkyunkwan University, Suwon, Republic of Korea
| | - Lital Adler
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Muhammed Iraqi
- Faculty of Health Sciences, The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Yarden Ariav
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Lisha Qiu Jin Lim
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Shaul Lerner
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Shiran Rabinovich
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Roni Oren
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Rotem Katzir
- Cancer Data Science Lab, National Cancer Institutes of Health, Bethesda, MD, USA
| | - Hila Weiss Tishler
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Noa Stettner
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Omer Goldman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Hadas Landesman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Sivan Galai
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Yael Kuperman
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Yuri Kuznetsov
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | - Alexander Brandis
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Tevi Mehlman
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Maxim Itkin
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - S Eleonore Koehler
- Department Anatomy & Embryology, Maastricht University, Maastricht, the Netherlands
| | - Yongmei Zhao
- Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Keyur Talsania
- Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Tsai-Wei Shen
- Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Nir Peled
- The Legacy Heritage Oncology Center and Dr. Larry Norton Institute, Soroka Medical Center and Ben-Gurion University, Beer-Sheva, Israel
| | - Igor Ulitsky
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Angel Porgador
- Faculty of Health Sciences, The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Eytan Ruppin
- Cancer Data Science Lab, National Cancer Institutes of Health, Bethesda, MD, USA.
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel.
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2
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Özyurt Bayraktar H, Yananlı H, Terzioğlu B, Oktay S, Kaleli M, Gören MZ. The role of NO in the posterior hypothalamus in amygdala-generated pressor responses in conscious rats. ACTA ACUST UNITED AC 2013; 33:7-16. [PMID: 23461535 DOI: 10.1111/aap.12004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 09/12/2012] [Accepted: 11/02/2012] [Indexed: 01/16/2023]
Abstract
The nitrergic system modulates cardiovascular functions of the central nucleus of amygdala (CeA) and the posterior hypothalamus (PH) which are involved in the central regulation of the cardiovascular system. The aim of this study was to investigate the contribution of nitric oxide (NO) in the PH in eliciting cardiovascular responses produced through electrical stimulation (ES) of the CeA. Rats were implanted with a stimulation electrode and a parenchymal cannula system into the CeA and a parenchymal cannula or a microdialysis probe into the PH. The next day, the femoral artery was cannulated for haemodynamic measurement. The CeA was electrically stimulated to produce cardiovascular response. The nitric oxide synthetase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME; 400 nmol/100 nl) or artificial cerebrospinal fluid were injected into the PH or the CeA before the ES of the CeA. The dialysates were collected from the PH to determine the L-citrulline and the L-glutamic acid levels. L-NAME injection into the CeA but not to the PH suppressed the increases in the mean arterial pressure produced by the ES of the CeA significantly; however, heart rate was not affected by L-NAME injection into either the PH or the CeA. L-citrulline and L-glutamic acid levels in the PH were shown to be increased by the ES of the CeA. NO is involved between the PH and the CeA which has a considerable role in the central regulation of the cardiovascular system.
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Affiliation(s)
- H Özyurt Bayraktar
- Department of Medical Pharmacology, School of Medicine, Marmara University, Istanbul, 34668, Turkey
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3
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Flam BR, Eichler DC, Solomonson LP. Endothelial nitric oxide production is tightly coupled to the citrulline-NO cycle. Nitric Oxide 2007; 17:115-21. [PMID: 17869551 DOI: 10.1016/j.niox.2007.07.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 07/02/2007] [Accepted: 07/20/2007] [Indexed: 11/30/2022]
Abstract
Nitric oxide (NO) is an important vasorelaxant produced along with L-citrulline from L-arginine in a reaction catalyzed by endothelial nitric oxide synthase (eNOS). Previous studies suggested that the recycling of L-citrulline to L-arginine is essential for NO production in endothelial cells. However, there is no direct evidence demonstrating the degree to which the recycling of L-citrulline to L-arginine is coupled to NO production. We hypothesized that the amount of NO formed would be significantly higher than the amount of L-citrulline formed due to the efficiency of L-citrulline recycling via the citrulline-NO cycle. To test this hypothesis, endothelial cells were incubated with [14C]-L-arginine and stimulated by various agents to produce NO. The extent of NO and [14C]-L-citrulline formation were simultaneously determined. NO production exceeded apparent L-citrulline formation of the order of 8 to 1, under both basal and stimulated conditions. As further support, alpha-methyl-DL-aspartate, an inhibitor of argininosuccinate synthase (AS), a component of the citrulline-NO cycle, inhibited NO production in a dose-dependent manner. The results of this study provide evidence for the essential and efficient coupling of L-citrulline recycling, via the citrulline-NO cycle, to endothelial NO production.
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Affiliation(s)
- Brenda R Flam
- Department of Internal Medicine, College of Medicine, University of South Florida, 12901 Bruce B. Downs Boulevard, Tampa, FL 33612-4799, USA
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4
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d'Anglemont de Tassigny X, Campagne C, Dehouck B, Leroy D, Holstein GR, Beauvillain JC, Buée-Scherrer V, Prevot V. Coupling of neuronal nitric oxide synthase to NMDA receptors via postsynaptic density-95 depends on estrogen and contributes to the central control of adult female reproduction. J Neurosci 2007; 27:6103-14. [PMID: 17553983 PMCID: PMC6672152 DOI: 10.1523/jneurosci.5595-06.2007] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Considerable research has been devoted to the understanding of how nitric oxide (NO) influences brain function. Few studies, however, have addressed how its production is physiologically regulated. Here, we report that protein-protein interactions between neuronal NO synthase (nNOS) and glutamate NMDA receptors via the scaffolding protein postsynaptic density-95 (PSD-95) in the hypothalamic preoptic region of adult female rats is sensitive to cyclic estrogen fluctuation. Coimmunoprecipitation experiments were used to assess the physical association between nNOS and NMDA receptor NR2B subunit in the preoptic region of the hypothalamus. We found that nNOS strongly interacts with NR2B at the onset of the preovulatory surge at proestrus (when estrogen levels are highest) compared with basal-stage diestrous rats. Consistently, estrogen treatment of gonadectomized female rats also increases nNOS/NR2B complex formation. Moreover, endogenous fluctuations in estrogen levels during the estrous cycle coincide with changes in the physical association of nNOS to PSD-95 and the magnitude of NO release in the preoptic region. Finally, temporary and local in vivo suppression of PSD-95 synthesis by using antisense oligodeoxynucleotides leads to inhibition of nNOS activity in the preoptic region and disrupted estrous cyclicity, a process requiring coordinated activation of neurons containing gonadotropin-releasing hormone (the neuropeptide controlling reproductive function). In conclusion, our findings identify a novel steroid-mediated molecular mechanism that enables the adult mammalian brain to control NO release under physiological conditions.
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Affiliation(s)
- Xavier d'Anglemont de Tassigny
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Céline Campagne
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Bénédicte Dehouck
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Danièle Leroy
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Gay R. Holstein
- Department of Neurology, Mount Sinai School of Medicine, New York, New York 10029
| | - Jean-Claude Beauvillain
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Valérie Buée-Scherrer
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
| | - Vincent Prevot
- Inserm, Jean-Pierre Aubert Research Centre, U837, Development and Plasticity of the Postnatal Brain, 59045 Lille cedex, France
- University of Lille 2, School of Medicine, Institut de Médecine Prédictive et de Recherche Thérapeutique, 59046 Lille cedex, France, and
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5
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Sanderson NSR, Le BD, Crews D. Testosterone induction of male-typical sexual behavior is associated with increased preoptic NADPH diaphorase and citrulline production in female whiptail lizards. ACTA ACUST UNITED AC 2006; 66:1156-63. [PMID: 16838367 PMCID: PMC2394197 DOI: 10.1002/neu.20280] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In rodents, male-typical copulatory behavior is generally dependent on gonadal sex steroids such as testosterone, and it is thought that the mechanism by which the hormone gates the behavior involves the gaseous neurotransmitter nitric oxide. According to one model, testosterone induces an up-regulation of nitric oxide synthase (NOS) in the preoptic area, increasing nitric oxide synthesis following exposure to a sexual stimulus. Nitric oxide in turn, possibly through its effect on catecholamine turnover, influences the way the stimulus is processed and enables the appropriate copulatory behavioral response. In whiptail lizards (genus Cnemidophorus), administration of male-typical levels of testosterone to females induces the display of male-like copulatory responses to receptive females, and we hypothesized that this radical change in behavioral phenotype would be accompanied by a large change in the expression of NOS in the preoptic area. As well as comparing NOS expression using NADPH diaphorase histochemistry between testosterone-treated females and controls, we examined citrulline immunoreactivity (a marker of recent nitric oxide production) in the two groups, following a sexual stimulus and following a nonsexual stimulus. Substantially more NADPH diaphorase-stained cells were observed in the testosterone-treated animals. Citrulline immunoreactivity was greater in testosterone-implanted animals than in blank-implanted animals, but only following exposure to a sexual stimulus. This is the first demonstration that not only is NOS up-regulated by testosterone, but NOS thus up-regulated is activated during male-typical copulatory behavior.
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Affiliation(s)
- N S R Sanderson
- Institute for Neuroscience, University of Texas at Austin, 1 University Station C0930, Austin, Texas 78712, USA
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6
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Curis E, Nicolis I, Moinard C, Osowska S, Zerrouk N, Bénazeth S, Cynober L. Almost all about citrulline in mammals. Amino Acids 2005; 29:177-205. [PMID: 16082501 DOI: 10.1007/s00726-005-0235-4] [Citation(s) in RCA: 368] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Accepted: 06/04/2005] [Indexed: 01/05/2023]
Abstract
Citrulline (Cit, C6H13N3O3), which is a ubiquitous amino acid in mammals, is strongly related to arginine. Citrulline metabolism in mammals is divided into two fields: free citrulline and citrullinated proteins. Free citrulline metabolism involves three key enzymes: NO synthase (NOS) and ornithine carbamoyltransferase (OCT) which produce citrulline, and argininosuccinate synthetase (ASS) that converts it into argininosuccinate. The tissue distribution of these enzymes distinguishes three "orthogonal" metabolic pathways for citrulline. Firstly, in the liver, citrulline is locally synthesized by OCT and metabolized by ASS for urea production. Secondly, in most of the tissues producing NO, citrulline is recycled into arginine via ASS to increase arginine availability for NO production. Thirdly, citrulline is synthesized in the gut from glutamine (with OCT), released into the blood and converted back into arginine in the kidneys (by ASS); in this pathway, circulating citrulline is in fact a masked form of arginine to avoid liver captation. Each of these pathways has related pathologies and, even more interestingly, citrulline could potentially be used to monitor or treat some of these pathologies. Citrulline has long been administered in the treatment of inherited urea cycle disorders, and recent studies suggest that citrulline may be used to control the production of NO. Recently, citrulline was demonstrated as a potentially useful marker of short bowel function in a wide range of pathologies. One of the most promising research directions deals with the administration of citrulline as a more efficient alternative to arginine, especially against underlying splanchnic sequestration of amino acids. Protein citrullination results from post-translational modification of arginine; that occurs mainly in keratinization-related proteins and myelins, and insufficiencies in this citrullination occur in some auto-immune diseases such as rheumatoid arthritis, psoriasis or multiple sclerosis.
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Affiliation(s)
- E Curis
- Laboratoire de Biomathématiques, E.A. 2498, Faculté de Pharmacie, Université René Descartes, Paris, France.
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7
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Pérez-Neri I, Montes S, Boll MC, Ramírez-Bermúdez J, Ríos C. Reply to comment on: “Assessment of nitric oxide biosynthesis and peroxynitrite formation within the central nervous system by measuring l-citrulline in the cerebrospinal fluid?”. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 819:345-6. [PMID: 15833300 DOI: 10.1016/j.jchromb.2004.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Indexed: 11/24/2022]
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8
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Smith GT, Allen AR, Oestreich J, Gammie SC. L-Citrulline Immunoreactivity Reveals Nitric Oxide Production in the Electromotor and Electrosensory Systems of the Weakly Electric Fish, Apteronotus leptorhynchus. BRAIN, BEHAVIOR AND EVOLUTION 2004; 65:1-13. [PMID: 15489561 DOI: 10.1159/000081106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2004] [Accepted: 05/24/2004] [Indexed: 11/19/2022]
Abstract
Weakly electric fish produce electric organ discharges (EODs) used for electrolocation and communication. In the brown ghost knifefish, Apteronotus leptorhynchus, several neuron types in brain regions that control the EOD or process electrosensory information express nitric oxide synthase (NOS). The present study used immunoreactivity for L-citrulline, a byproduct of the production of nitric oxide (NO) by NOS, to assess NO production in NOS-expressing neurons. A polyclonal antibody against L-citrulline produced specific labeling in most neuronal populations previously identified to express NOS. Specifically, several cell types that precisely encode temporal information and/or fire at high frequencies, including spherical cells in the electrosensory lateral line lobe, giant cells in layer VI of the dorsal torus semicircularis, and pacemaker and relay cells in the pacemaker nucleus, were strongly immunoreactive for L-citrulline. This suggests that these neurons produced high levels of NO. Notably, electromotor neurons, which also strongly express NOS, were not immunoreactive for L-citrulline, suggesting that NOS did not produce high levels of NO in these neurons. No apparent differences in L-citrulline distribution or intensity were observed between socially isolated fish and fish exposed to playback stimuli simulating the presence of a conspecific. This suggests that social stimulation by electrocommunication signals is not necessary for high levels of NO production in many NOS-positive neurons. Future studies focusing on regulation of NO production in these systems, and the effects of NO on electrosensory processing and electromotor pattern generation will help elucidate the function of NO signaling pathways in this system.
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Affiliation(s)
- G Troy Smith
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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9
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Bernstein HG, Keilhoff G, Bukowska A, Ziegeler A, Funke S, Dobrowolny H, Kanakis D, Bogerts B, Lendeckel U. ADAM (a disintegrin and metalloprotease) 12 is expressed in rat and human brain and localized to oligodendrocytes. J Neurosci Res 2004; 75:353-60. [PMID: 14743448 DOI: 10.1002/jnr.10858] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
ADAM12 is a member of the large family of multidomain metalloprotease-disintegrins which possess cell-binding and metalloprotease properties. Typically, ADAM12 is expressed in mesenchymal cells, developing and regenerating heart and skeletal muscle, bone as well as in certain tumours. This report shows by means of reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry that the protease ADAM12 is detectable in human and rat brain tissue as well as in cultured cells derived from rat brain. With the exception of a very few immunopositive pyramidal neurons in the developing rat brain, the cellular localization of ADAM12 was exclusively confined to oligodendroglial cells. Thus, ADAM12 may be regarded a new suitable marker for this cell type.
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10
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Engelmann M, Wolf G, Putzke J, Bloom FE, Raber J, Landgraf R, Spina MG, Horn TFW. Nitric oxide is not involved in the control of vasopressin release during acute forced swimming in rats. Amino Acids 2003; 26:37-43. [PMID: 14752614 DOI: 10.1007/s00726-003-0040-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2003] [Accepted: 06/25/2003] [Indexed: 10/26/2022]
Abstract
Neurons of the hypothalamo-neurohypophyseal system (HNS) are known to contain high amounts of neuronal nitric oxide (NO) synthase (nNOS). NO produced by those neurons is commonly supposed to be involved as modulator in the release of the two nonapeptides vasopressin (AVP) and oxytocin into the blood stream. Previous studies showed that forced swimming fails to increase the release of AVP into the blood stream while its secretion into the hypothalamus is triggered. We investigated here whether hypothalamically acting NO contributes to the control of the AVP release into blood under forced swimming conditions. Intracerebral microdialysis and in situ hybridization were employed to analyze the activity of the nitrergic system within the supraoptic nucleus (SON), the hypothalamic origin of the HNS. A 10-min forced swimming session failed to significantly alter the local NO release as indicated both by nitrite and, the main by-product of NO synthesis, citrulline levels in microdialysis samples collected from the SON. Microdialysis administration of NO directly into the SON increased the concentration of AVP in plasma samples collected during simultaneous forced swimming. In an additional experiment the effect of the defined stressor exposure on the concentration of mRNA coding for nNOS within the SON was investigated by in situ hybridization. Forced swimming increased the expression of nNOS mRNA at two and four hours after onset of the stressor compared to untreated controls. Taken together, our results imply that NO within the SON does not contribute to the regulation of the secretory activity of HNS neurons during acute forced swimming. Increased nNOS mRNA in the SON after forced swimming and the increase in AVP release in the presence of exogenous NO under forced swimming points to a possible role of NO in the regulation of the HNS under repeated stressor exposure.
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Affiliation(s)
- M Engelmann
- Institut für Medizinische Neurobiologie, Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany.
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11
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Hara S, Mukai T, Kurosaki K, Kuriiwa F, Endo T. Characterization of suppression of nitric oxide production by carbon monoxide poisoning in the striatum of free-moving rats, as determined by in vivo brain microdialysis. Brain Res 2003; 979:27-36. [PMID: 12850567 DOI: 10.1016/s0006-8993(03)02842-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We examined the effect of carbon monoxide (CO) poisoning on the nitric oxide (NO) system in the striatum of free-moving rats by means of in vivo brain microdialysis. The extracellular levels of the oxidative NO products, nitrite (NO(2)(-)) and nitrate (NO(3)(-)), decreased during exposure to CO at 3000 ppm for 40 min, a condition which causes CO poisoning. The extracellular levels of citrulline (Cit; a by-product of NO production) and arginine (Arg; an NO precursor) also decreased during CO exposure. Following reoxygenation by withdrawal of CO, the NO(2)(-) and NO(3)(-) levels gradually recovered to the control values, though Arg and Cit remained at lower levels, except for a rapid, but transient, recovery shortly before and after reoxygenation, respectively. Simultaneous application of exogenous L-Arg (50 and 100 mM) with CO exposure attenuated the decreases in NO(2)(-) and NO(3)(-) during the CO exposure and accelerated their recovery following reoxygenation. However, D-Arg (100 mM) had no effect on the decrease in NO(2)(-) and NO(3)(-), except for slight and transient attenuation shortly after reoxygenation. Exogenous L-Cit (10 and 100 mM) failed to attenuate the CO-induced decrease in NO(2)(-) and NO(3)(-) levels. The decrease in the NO(2)(-) and NO(3)(-) levels during 8% O(2) exposure for 40 min, which was comparable with that in response to 3000 ppm CO, was resistant to exogenous 100 mM L-Arg, but the recovery of the NO(2)(-) and NO(3)(-) levels following reoxygenation was strongly accelerated. These findings suggest that CO poisoning suppresses NO production in rat striatum in vivo though a mechanism which may not be common with that in hypoxic hypoxia.
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Affiliation(s)
- Shuichi Hara
- Department of Forensic Medicine, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, 160-8402, Tokyo, Japan.
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12
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Keilhoff G, Wolf G. Citrulline immunohistochemistry may not necessarily identify nitric oxide synthase activity: the pitfall of peptidylarginine deiminase. Nitric Oxide 2003; 8:31-8. [PMID: 12586539 DOI: 10.1016/s1089-8603(02)00130-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nitric oxide synthase (NOS) converts L-arginine as a substrate to form nitric oxide and the "by-product" citrulline. To characterize NOS activity in the nervous tissue at the single-cell level, citrulline immunostaining is considered to be a suitable means of working on the principle that in brain tissue, due to the incomplete urea cycle, citrulline is produced exclusively by NOS. This assumption is correct for free citrulline but it does not consider the conversion of arginine to citrulline residues of proteins by the calcium-dependent peptidylarginine deiminase (PAD). Using a polyclonal antiserum against citrulline we observed in cerebellar cell cultures immunopositivity in a few, mostly NOS-positive, neurons, in activated microglia, and in oligodendroglia (which under control conditions are in doubt to be able to express NOS), but not in astroglia. Treatment with the excitotoxin kainate substantially enhanced the staining intensity for citrulline in neurons and glial cells. To distinguish between free (NOS-related) and protein-bound (PAD-related) citrulline we blocked NOS activity by 7-nitroindazole or L-N5-(1-iminoethyl)lysine. The results provide evidence that citrulline immunolabeling results partly from PAD-mediated protein citrullination, enhanced pathophysiologically under stimulated conditions by exposure to kainate. Our immunocytochemical observations were corroborated by Western blot analysis showing several bands of citrulline-positive proteins, whose number and staining intensity depended on kainate treatment and calcium ions.
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Affiliation(s)
- Gerburg Keilhoff
- Institute of Medical Neurobiology, Otto-von-Guericke University of Magdeburg, Leipziger Strasse 44, D-39120 Magdeburg, Germany.
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13
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Van Geldre LA, Timmermans JP, Lefebvre RA. L-citrulline recycling by argininosuccinate synthetase and lyase in rat gastric fundus. Eur J Pharmacol 2002; 455:149-60. [PMID: 12445581 DOI: 10.1016/s0014-2999(02)02584-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this study was to investigate in rat gastric fundus whether L-citrulline, the co-product in the nitric oxide (NO) biosynthesis catalyzed by neuronal nitric oxide synthase (nNOS), can be converted back to the nNOS substrate L-arginine. Immunohistochemistry showed that argininosuccinate synthetase and argininosuccinate lyase, that mediate transformation of L-citrulline to L-arginine in the ureum cycle in hepatocytes, co-localize with nNOS. In longitudinal smooth muscle strips, L-arginine as well as L-citrulline (10(-3) M) was capable of completely respectively partially preventing the N(G)-nitro-L-arginine methyl ester (L-NAME) (3 x 10(-5) M)-induced inhibition of electrically induced nitrergic relaxations, whereas D-citrulline (10(-3) M) was not. The L-citrulline-mediated prevention of the L-NAME-induced inhibition was reduced by L-glutamine (3 x 10(-3) M), the putative L-citrulline uptake inhibitor, and by succinate, an argininosuccinate lyase inhibitor. The results demonstrate that the L-citrulline recycling mechanism is active in rat gastric fundus. Recycling of L-citrulline might play a role in providing sufficient amounts of nNOS substrate during long-lasting relaxations in gastric fundus after food intake.
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Affiliation(s)
- Lieve A Van Geldre
- Heymans Institute of Pharmacology, Ghent University, De Pintelaan 185, B-9000 Gent, Belgium
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14
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Martinelli GPT, Friedrich VL, Holstein GR. L-citrulline immunostaining identifies nitric oxide production sites within neurons. Neuroscience 2002; 114:111-22. [PMID: 12207959 DOI: 10.1016/s0306-4522(02)00238-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker.
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Affiliation(s)
- G P T Martinelli
- Department of Neurology, Mount Sinai School of Medicine, Box 1140, One Gustave Levy Place, New York, NY 10029, USA
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15
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Roychowdhury S, Luthe A, Keilhoff G, Wolf G, Horn TFW. Oxidative stress in glial cultures: detection by DAF-2 fluorescence used as a tool to measure peroxynitrite rather than nitric oxide. Glia 2002; 38:103-14. [PMID: 11948804 DOI: 10.1002/glia.10024] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
4,5-diaminofluorescein diacetate (DAF-2DA) is widely used as a fluorescent probe to detect endogenously produced nitric oxide (NO). Recent reports that refer to the high sensitivity of DAF-2 toward NO prompted us to test its efficiency and specificity in a mixed murine primary glial culture model, in which the NO-synthesizing enzyme inducible nitric oxide synthase (iNOS) is expressed by stimulation with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Cultures were loaded with DAF-2DA and the fluorescence was measured using confocal microscopy. NO production in the cultures was determined using the ozone/chemiluminescence technique. Due to the extremely high photosensitivity of DAF-2, low laser intensities were used to avoid artifacts. No difference in DAF-2 fluorescence was observed in NO-producing cultures compared to control cultures, whereas the NO/peroxynitrite-sensitive dye 2,7-dihydrodichlorofluorescein (DCF) showed a significant fluorescence increase specifically in microglia cells. A detectable gain in fluorescence was seen when NO-containing buffer was added to the DAF-2DA-loaded cells with a minimum NO concentration at 7.7 microM. An additional gain of DAF-2 fluorescence was obtained when the cells were depleted of glutathione (GSH) with L-buthionine S,R-sulfoximine (BSO). Hence, we monitored the change in DAF-2 fluorescence intensity in the presence of NO and O(-*)(2) in a cell-free solution. The fluorescence due to NO was indeed larger when O(-*)(2) was added, implying a higher sensitivity of DAF-2 for peroxynitrite. Nevertheless, our results also indicate that measurement of DCF fluorescence is a better tool for monitoring intracellular changes in the levels of NO and/or peroxynitrite than DAF-2.
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Affiliation(s)
- Sanjoy Roychowdhury
- Otto-von-Guericke University, Institute for Medical Neurobiology, Magdeburg, Germany
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16
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Giordano A, Tonello C, Bulbarelli A, Cozzi V, Cinti S, Carruba MO, Nisoli E. Evidence for a functional nitric oxide synthase system in brown adipocyte nucleus. FEBS Lett 2002; 514:135-40. [PMID: 11943139 DOI: 10.1016/s0014-5793(02)02245-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The intracellular localization and activity of the nitric oxide synthase (NOS) isoforms were investigated in rat brown adipocytes. Immunohistochemistry showed cytoplasmic and nuclear staining for the endothelial NOS (eNOS) and inducible NOS (iNOS) isoforms; accordingly, anti-L-citrulline antibody, a marker of NOS activity, immunostained both the cytoplasm and the nucleus. The presence of metabolically active NOS in the nucleus was further confirmed by immunoblotting analyses of subcellular fractions of homogenates from cultured brown adipocytes and by measurements of NOS activity in the cytosol and nucleus. Sympathetic stimulation in vivo (i.e. cold exposure or beta(3)-adrenergic agonist treatment) and in vitro (i.e. noradrenaline treatment of cultured cells) significantly increased both cytosolic and nuclear eNOS and iNOS expression and activities. By contrast, the number of iNOS-positive, but not eNOS-positive, nuclei was significantly lower in the functionally impaired brown fat of genetically obese Zucker fa/fa rats. These data suggest the existence of a noradrenaline-modulated functional NOS system in the nucleus of brown adipocytes.
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Affiliation(s)
- Antonio Giordano
- Institute of Normal Human Morphology, Faculty of Medicine, University of Ancona, Ancona, Italy
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17
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Gören MZ, Aricioglu-Kartal F, Yurdun T, Uzbay IT. Investigation of extracellular L-citrulline concentration in the striatum during alcohol withdrawal in rats. Neurochem Res 2001; 26:1327-33. [PMID: 11885785 DOI: 10.1023/a:1014253618835] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this study, changes in striatal extracellular L-citrulline concentrations were investigated hourly for 5 h following alcohol withdrawal in chronic alcohol feeding Wistar rats. Alcohol (7.2% ethyl alcohol, v/v) was given to rats as modified liquid diet for 20 days. Signs of alcohol withdrawal appeared from the 1st h of alcohol withdrawal and the total alcohol withdrawal scores remained higher during the course of experiments. The mean of basal levels of L-citrulline in the microdialysis samples collected in conscious rat model from the striatum of control and alcoholized rats were found to be 1.28 +/- 0.48 microM and 0.35 +/- 0.08 microM, respectively. L-citrulline levels in the striatum of alcoholized rats increased by 4 folds significantly within 1 h following alcohol withdrawal. The increased striatal L-citrulline concentration was blocked by NG-nitro-L-arginine methyl ester (L-NAME; 60 mg/kg), a nitric oxide synthase inhibitor, pretreatment. Our results indicate an increased L-citrulline level in the rat striatum during early alcohol withdrawal and this situation may be related to an increased nitric oxide production.
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Affiliation(s)
- M Z Gören
- Department of Medical Pharmacology, Gülhane Military Medical Academy, Ankara, Turkey
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Gören MZ, Akici A, Karaalp A, Aker R, Oktay S. The role of nitric oxide in the reversal of hemorrhagic shock by oxotremorine. Eur J Pharmacol 2001; 428:261-7. [PMID: 11675044 DOI: 10.1016/s0014-2999(01)01294-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the present study, the effect of the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methylester (L-NAME), on the antishock actions of oxotremorine was investigated in rats subjected to hemorrhagic shock under urethane anesthesia. L-citrulline production in the AV3V region, as an indicator of nitric oxide (NO) synthesis, was assayed by high-performance liquid chromatography (HPLC) with fluorescent detection throughout the experiment. The rats were pretreated with either intravenous (i.v.) physiological saline or L-NAME (2.5 mg/kg) before bleeding. L-NAME potentiated the reversal of hypotension by oxotremorine (25 microg/kg, i.v.). However, oxotremorine either alone or in combination with L-NAME did not produce any significant change in 60-min survival rate at this low dose. Analysis of microdialysis samples collected from the AV3V region showed that L-citrulline concentration increased during bleeding and that this increase was abolished by L-NAME pretreatment. These results may suggest that nitric oxide production contributes to hypotension in rats bled to shock since nitric oxide levels in the AV3V region increased in response to bleeding and nitric oxide synthase (NOS) inhibition abolished this increase and potentiated the oxotremorine-induced reversal of hypotension.
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Affiliation(s)
- M Z Gören
- Department of Pharmacology and Clinical Pharmacology, School of Medicine, Marmara University, Haydarpaşa, TR 81326 Istanbul, Turkey
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Holstein GR, Friedrich VL, Martinelli GP. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons. Ann N Y Acad Sci 2001; 942:65-78. [PMID: 11710504 DOI: 10.1111/j.1749-6632.2001.tb03736.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.
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Affiliation(s)
- G R Holstein
- Department of Neurology, Mount Sinai School of Medicine, New York, New York 10029, USA.
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