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Wootla B, Denic A, Warrington AE, Rodriguez M. A monoclonal natural human IgM protects axons in the absence of remyelination. J Neuroinflammation 2016; 13:94. [PMID: 27126523 PMCID: PMC4850699 DOI: 10.1186/s12974-016-0561-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 04/24/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Whereas demyelination underlies early neurological symptoms in multiple sclerosis (MS), axonal damage is considered critical for permanent chronic deficits. Intracerebral infection of susceptible mouse strains with Theiler's murine encephalomyelitis virus (TMEV) results in chronic induced demyelinating disease (TMEV-IDD) with progressive axonal loss and neurologic dysfunction similar to progressive forms of MS. We previously reported that treatment of chronic TMEV-IDD mice with a neurite outgrowth-promoting natural human antibody, HIgM12, improved brainstem NAA concentrations and preserved functional motor activity. In order to translate this antibody toward clinical trial, we generated a fully human recombinant form of HIgM12, rHIgM12, determined the optimal in vivo dose for functional improvement in TMEV-IDD, and evaluated the functional preservation of descending spinal cord axons by retrograde labeling. FINDINGS SJL/J mice at 45 to 90 days post infection (dpi) were studied. A single intraperitoneal dose of 0.25 mg/kg of rHIgM12 per mouse is sufficient to preserve motor function in TMEV-IDD. The optimal dose was 10 mg/kg. rHIgM12 treatment protected the functional transport in spinal cord axons and led to 40 % more Fluoro-Gold-labeled brainstem neurons in retrograde transport studies. This suggests that axons are not only present but also functionally competent. rHIgM12-treated mice also contained more mid-thoracic (T6) spinal cord axons than controls. CONCLUSIONS This study confirms that a fully human recombinant neurite outgrowth-promoting monoclonal IgM is therapeutic in a model of progressive MS using multiple reparative readouts. The minimum effective dose is similar to that of a remyelination-promoting monoclonal human IgM discovered by our group that is presently in clinical trials for MS.
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Affiliation(s)
- Bharath Wootla
- Department of Neurology, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.,Mayo Clinic Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.,Center for Regenerative Medicine, Neuroregeneration, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Aleksandar Denic
- Department of Neurology, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.,Mayo Clinic Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Arthur E Warrington
- Department of Neurology, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.,Mayo Clinic Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Moses Rodriguez
- Department of Neurology, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. .,Mayo Clinic Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. .,Department of Immunology, Mayo Clinic College of Medicine, Mayo Clinic, 200 1st Street SW, Rochester, MN, 55905, USA.
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Kraus RM, Houmard JA, Kraus WE, Tanner CJ, Pierce JR, Choi MD, Hickner RC. Obesity, insulin resistance, and skeletal muscle nitric oxide synthase. J Appl Physiol (1985) 2012; 113:758-65. [PMID: 22797309 DOI: 10.1152/japplphysiol.01018.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The molecular mechanisms responsible for impaired insulin action have yet to be fully identified. Rodent models demonstrate a strong relationship between insulin resistance and an elevation in skeletal muscle inducible nitric oxide synthase (iNOS) expression; the purpose of this investigation was to explore this potential relationship in humans. Sedentary men and women were recruited to participate (means ± SE: nonobese, body mass index = 25.5 ± 0.3 kg/m(2), n = 13; obese, body mass index = 36.6 ± 0.4 kg/m(2), n = 14). Insulin sensitivity was measured using an intravenous glucose tolerance test with the subsequent modeling of an insulin sensitivity index (S(I)). Skeletal muscle was obtained from the vastus lateralis, and iNOS, endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) content were determined by Western blot. S(I) was significantly lower in the obese compared with the nonobese group (~43%; P < 0.05), yet skeletal muscle iNOS protein expression was not different between nonobese and obese groups. Skeletal muscle eNOS protein was significantly higher in the nonobese than the obese group, and skeletal muscle nNOS protein tended to be higher (P = 0.054) in the obese compared with the nonobese group. Alternative analysis based on S(I) (high and low tertile) indicated that the most insulin-resistant group did not have significantly more skeletal muscle iNOS protein than the most insulin-sensitive group. In conclusion, human insulin resistance does not appear to be associated with an elevation in skeletal muscle iNOS protein in middle-aged individuals under fasting conditions.
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Affiliation(s)
- Raymond M Kraus
- Department of Kinesiology, East Carolina University, Greenville, North Carolina 27858, USA
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3
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Schmidt J, Barthel K, Zschüntzsch J, Muth IE, Swindle EJ, Hombach A, Sehmisch S, Wrede A, Lühder F, Gold R, Dalakas MC. Nitric oxide stress in sporadic inclusion body myositis muscle fibres: inhibition of inducible nitric oxide synthase prevents interleukin-1β-induced accumulation of β-amyloid and cell death. ACTA ACUST UNITED AC 2012; 135:1102-14. [PMID: 22436237 DOI: 10.1093/brain/aws046] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Sporadic inclusion body myositis is a severely disabling myopathy. The design of effective treatment strategies is hampered by insufficient understanding of the complex disease pathology. Particularly, the nature of interrelationships between inflammatory and degenerative pathomechanisms in sporadic inclusion body myositis has remained elusive. In Alzheimer's dementia, accumulation of β-amyloid has been shown to be associated with upregulation of nitric oxide. Using quantitative polymerase chain reaction, an overexpression of inducible nitric oxide synthase was observed in five out of ten patients with sporadic inclusion body myositis, two of eleven with dermatomyositis, three of eight with polymyositis, two of nine with muscular dystrophy and two of ten non-myopathic controls. Immunohistochemistry confirmed protein expression of inducible nitric oxide synthase and demonstrated intracellular nitration of tyrosine, an indicator for intra-fibre production of nitric oxide, in sporadic inclusion body myositis muscle samples, but much less in dermatomyositis or polymyositis, hardly in dystrophic muscle and not in non-myopathic controls. Using fluorescent double-labelling immunohistochemistry, a significant co-localization was observed in sporadic inclusion body myositis muscle between β-amyloid, thioflavine-S and nitrotyrosine. In primary cultures of human myotubes and in myoblasts, exposure to interleukin-1β in combination with interferon-γ induced a robust upregulation of inducible nitric oxide synthase messenger RNA. Using fluorescent detectors of reactive oxygen species and nitric oxide, dichlorofluorescein and diaminofluorescein, respectively, flow cytometry revealed that interleukin-1β combined with interferon-γ induced intracellular production of nitric oxide, which was associated with necrotic cell death in muscle cells. Intracellular nitration of tyrosine was noted, which partly co-localized with amyloid precursor protein, but not with desmin. Pharmacological inhibition of inducible nitric oxide synthase by 1400W reduced intracellular production of nitric oxide and prevented accumulation of β-amyloid, nitration of tyrosine as well as cell death inflicted by interleukin-1β combined with interferon-γ. Collectively, these data suggest that, in skeletal muscle, inducible nitric oxide synthase is a central component of interactions between interleukin-1β and β-amyloid, two of the most relevant molecules in sporadic inclusion body myositis. The data further our understanding of the pathology of sporadic inclusion body myositis and may point to novel treatment strategies.
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Affiliation(s)
- Jens Schmidt
- Department of Neurology, University Medical Centre Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany.
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4
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Vassilakopoulos T, Hussain SNA. Ventilatory muscle activation and inflammation: cytokines, reactive oxygen species, and nitric oxide. J Appl Physiol (1985) 2007; 102:1687-95. [PMID: 17185492 DOI: 10.1152/japplphysiol.01273.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Strenuous diaphragmatic contractions that are induced by inspiratory resistive breathing initiate an inflammatory response that involves the elevation of pro- and anti-inflammatory cytokines within the diaphragm, which may then spill into the circulation. The production of reactive oxygen species within working respiratory muscles increases in response to these strenuous diaphragmatic contractions. At the same time, diaphragmatic nitric oxide (NO) production declines significantly, despite a time-dependent increase in NO synthase isoform protein expression. The increase in adhesion molecule expression and infiltration of granulocytes and macrophages that follows may contribute to the contraction-induced diaphragm injury. Enhanced generation of reactive oxygen species, oxidative stress augmentation, reduced NO production, and glycogen depletion are potential stimuli for the cytokine induction that is secondary to strenuous diaphragmatic contractions. This production of cytokines within the diaphragm may contribute to the diaphragmatic muscle fiber injury that occurs with strenuous contractions or to the expected repair process. TNF-α is a cytokine that compromises diaphragmatic contractility and may contribute to muscle wasting. IL-6 is a cytokine that may have beneficial systemic effects by mobilizing glucose from the liver and free fatty acids from the adipose tissue and providing them to the strenuously working respiratory muscles. Thus cytokine upregulation within the working diaphragm may be adaptive and maladaptive.
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Affiliation(s)
- Theodoros Vassilakopoulos
- Department of Critical Care and Pulmonary Services, University of Athens Medical School, Evangelismos Hospital, Athens, Greece
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5
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Smith JM, Sondgeroth KB, Wahler GM. Inhibition of nitric oxide synthase enhances contractile response of ventricular myocytes from streptozotocin-diabetic rats. Mol Cell Biochem 2007; 300:129-37. [PMID: 17225190 DOI: 10.1007/s11010-006-9376-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 11/06/2006] [Indexed: 11/26/2022]
Abstract
The contractile hyporesponsiveness of the streptozotocin diabetic rat heart in vitro to beta-adrenergic agonists is eliminated when the heart is perfused with N(G)-nitro-L-arginine methyl ester (L-NAME), a non-selective inhibitor of nitric oxide synthase (NOS). The following study evaluated the hypothesis that an increased production of NO/cGMP within the diabetic myocyte inhibits the beta-adrenergic-stimulated increase in calcium current and contractile response. Male Sprague-Dawley rats were given an intravenous injection of streptozotocin (60 mg/kg). After 8 weeks, L-type calcium currents were recorded in ventricular myocytes using the whole cell voltage-clamp method. Shortening of isolated myocytes was determined using a video edge detection system. cAMP and cGMP were measured using radioimmunoassay. Nitric oxide production was determined using the Griess assay kit. Basal cGMP levels and nitric oxide production were elevated in diabetic myocytes. Shortening of the diabetic myocytes in response to isoproterenol (1 microM) was markedly diminished. However, there was no detectable difference in the isoproterenol-stimulated L-type calcium current or cAMP levels between control and diabetic myocytes. Acute superfusion of the diabetic myocyte with L-NAME (1 mM) decreased basal cGMP and markedly enhanced the shortening response to isoproterenol but did not alter isoproterenol-stimulated calcium current. These data suggest that increased production of NO/cGMP within the diabetic myocyte suppressed beta-adrenergic stimulated shortening of the myocyte. However, NO/cGMP apparently does not suppress shortening of the myocyte by inhibition of the beta-stimulated calcium current.
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Affiliation(s)
- Jacquelyn M Smith
- Department of Physiology, Midwestern University, 555 31st Street, Downers Grove, IL 60515, USA.
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6
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Maslow AD, Stearns G, Butala P, Batula P, Schwartz CS, Gough J, Singh AK. The hemodynamic effects of methylene blue when administered at the onset of cardiopulmonary bypass. Anesth Analg 2006; 103:2-8, table of contents. [PMID: 16790616 DOI: 10.1213/01.ane.0000221261.25310.fe] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hypotension occurs during cardiopulmonary bypass (CPB), in part because of induction of the inflammatory response, for which nitric oxide and guanylate cyclase play a central role. In this study we examined the hemodynamic effects of methylene blue (MB), an inhibitor of guanylate cyclase, administered during cardiopulmonary bypass (CPB) to patients taking angiotensin-converting enzyme inhibitors. Thirty patients undergoing cardiac surgery were randomized to receive either MB (3 mg/kg) or saline (S) after institution of CPB and cardioplegic arrest. CPB was managed similarly for all study patients. Hemodynamic data were assessed before, during, and after CPB. The use of vasopressors was recorded. All study patients experienced a similar reduction in mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) with the onset of CPB and cardioplegic arrest. MB increased MAP and SVR and this effect lasted for 40 minutes. The saline group demonstrated a persistently reduced MAP and SVR throughout CPB. The saline group received phenylephrine more frequently during CPB, and more norepinephrine after CPB to maintain a desirable MAP. The MB group recorded significantly lower serum lactate levels despite equal or greater MAP and SVR. In conclusion, administration of MB after institution of CPB for patients taking angiotensin-converting enzyme inhibitors increased MAP and SVR and reduced the need for vasopressors. Furthermore, serum lactate levels were lower in MB patients, suggesting more favorable tissue perfusion.
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Affiliation(s)
- Andrew D Maslow
- Department of Anesthesiology, Rhode Island Hospital, Providence Rhode Island, USA.
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7
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Maeda N, Kanda F, Okuda S, Ishihara H, Chihara K. Transforming growth factor-beta enhances connective tissue growth factor expression in L6 rat skeletal myotubes. Neuromuscul Disord 2005; 15:790-3. [PMID: 16198104 DOI: 10.1016/j.nmd.2005.06.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 06/27/2005] [Accepted: 06/30/2005] [Indexed: 11/26/2022]
Abstract
Transforming growth factor (TGF)-beta plays an important role in fibrosis of various organs and tissues. TGF-beta1 stimulates fibroblastic cells to form extracellular matrix (ECM), and regulates all critical events in wound healing. Connective tissue growth factor (CTGF), a TGF-beta-inducible molecule, has recently been reported to promote fibroblast proliferation, migration, adhesion and extracellular matrix formation, both in vivo and in vitro. In this study, we demonstrated that TGF-beta1 enhances CTGF mRNA and protein levels in L6 rat skeletal muscle myotubes. TGF-beta might, therefore, play a role in fibrosis of skeletal muscle by stimulating CTGF expression in the muscle tissue itself.
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Affiliation(s)
- Nobuya Maeda
- Division of Endocrinology/Metabolism, Neurology and Hematology/Oncology, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
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Pinard A, Lévesque S, Vallée J, Robitaille R. Glutamatergic modulation of synaptic plasticity at a PNS vertebrate cholinergic synapse. Eur J Neurosci 2004; 18:3241-50. [PMID: 14686898 DOI: 10.1111/j.1460-9568.2003.03028.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The presence and the functionality of a glutamatergic regulation was studied at the frog neuromuscular junction (NMJ), a singly innervated cholinergic synapse. Bath application of glutamate reduced transmitter release without affecting nerve-evoked presynaptic Ca2+ entry and handling. (1S,3R)-aminocyclopentanedicarboxylic acid (ACPD), a metabotropic glutamate receptor (mGluR) agonist, mimicked the effects of glutamate while (S)-alpha-methyl-4-carboxyphenylglycine (MCPG), a mGluR antagonist, blocked glutamate effects. MCPG had no effect on transmitter release evoked at low frequency (0.2 Hz) but significantly reduced synaptic depression (10 Hz, 80 s). This suggests that a frequency-dependent endogenous glutamatergic modulation is present at the frog NMJ and is mediated through mGluRs. Immunohistochemical labelling revealed the presence of mGluRs at the end plate area, primarily on muscle fibers. Functional glutamate uptake machinery was also found at the NMJ as blockade of glutamate transport by the inhibitor dl-threo-beta-benzyloxyaspartate (DL-TBOA) increased high frequency-induced depression, suggesting that the transporters system is used to eliminate glutamate from the extracellular space. Moreover, immunohistochemical labelling revealed that glutamate-aspartate transporters (GLASTs) are predominantly present on perisynaptic Schwann cells (PSCs). However, local application of glutamate on PSCs unreliability evoked small Ca2+ responses. Hence, these data suggest that functional glutamatergic interactions at a purely cholinergic synapse, shape synaptic efficacy and short-term plasticity in a frequency-dependent fashion.
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Affiliation(s)
- Audrée Pinard
- Centre de Recherche en Sciences Neurologiques and Département de physiologie, Université de Montréal, Montréal, Canada,H3C 3J7
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Miyabara EH, Tostes RC, Selistre-de-Araújo HS, Aoki MS, Moriscot AS. Role of nitric oxide in myotoxic activity induced by crotoxin in vivo. Toxicon 2004; 43:425-32. [PMID: 15051406 DOI: 10.1016/j.toxicon.2004.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Revised: 01/30/2004] [Accepted: 02/11/2004] [Indexed: 11/23/2022]
Abstract
This study was aimed to determine the role of nitric oxide on the skeletal myotoxic activity induced by crotoxin, the major component of the venom of Crotalus durissus terrificus. Rats were treated with N(G)-nitro-L-arginine methyl ester (L-NAME), a non-selective inhibitor of nitric oxide synthase or vehicle for 4 days, and on the 5th day received an intramuscular injection of crotoxin into the tibialis anterior muscle. Rats were also treated with aminoguanidine bicarbonate salt or 7-nitroindazole, inhibitors of the inducible and neuronal isoforms of nitric oxide synthase, respectively, for 4 days and on the 5th day injected with crotoxin. All treated groups were sacrificed 24 h after injection of crotoxin. Tibialis anterior and soleus muscles were removed, frozen and stored in liquid nitrogen. Histological sections were stained with toluidine blue and assayed for acid phosphatase. The results show that L-NAME significantly minimizes myonecrosis induced by crotoxin and both aminoguanidine and 7-nitroindazole partially prevented myonecrosis induced by crotoxin. Based on the present results we conclude that nitric oxide is a very important intracellular signaling molecule that mediates crotoxin myotoxic activity.
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Affiliation(s)
- E H Miyabara
- Department of Histology/Embriology, Institute of Biomedical Sciences, University of São Paulo, Av Lineu Prestes 1524, ICB I, 05508-900 São Paulo, Brazil
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Differential frequency-dependent regulation of transmitter release by endogenous nitric oxide at the amphibian neuromuscular synapse. J Neurosci 2001. [PMID: 11160378 DOI: 10.1523/jneurosci.21-04-01087.2001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nitric oxide (NO) is a potent neuromodulator in the CNS and PNS. At the frog neuromuscular junction (nmj), exogenous application of NO reduces neurotransmitter release, and NO synthases (NOSs), the enzymes producing NO, are present at this synapse. This work aimed at studying the molecular mechanisms by which NO modulates synaptic efficacy at the nmj using electrophysiological recordings and Ca(2+)-imaging techniques. Bath application of the NO donors S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside decreased end plate potential (EPP) amplitude as well as the frequency of miniature EPPs but not their amplitude. Ca(2+) responses elicited in presynaptic terminals by single action potentials were unaffected by NO, but responses evoked by a short train of stimuli were increased. Tonic endogenous production of NO was observed as suggested by the increase in EPP amplitude by bath application of the NO scavenger hemoglobin and the neuronal NOS inhibitor 3-bromo-7-nitroindazole sodium salt. A soluble guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY-83583), increased EPP amplitude and occluded the effects of the NO donor, suggesting that NO acts via a cGMP-dependent mechanism. High-frequency-induced depression was reduced in the presence of the NO scavenger but not by LY-83583. However, adenosine-induced depression was significantly reduced after bath perfusion of SNAP and in the presence of LY-83583. Our results indicate that NO regulates transmitter release and adenosine-induced depression via a cGMP-dependent mechanism that occurs after Ca(2+) entry and that high-frequency-induced synaptic depression is regulated by NO in a cGMP-independent manner.
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Kimura K, Kanda F, Okuda S, Chihara K. Insulin-like growth factor 1 inhibits glucocorticoid-induced glutamine synthetase activity in cultured L6 rat skeletal muscle cells. Neurosci Lett 2001; 302:154-6. [PMID: 11290410 DOI: 10.1016/s0304-3940(01)01667-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously demonstrated the preventive effect of insulin-like growth factor 1 (IGF-1) on steroid myopathy in rats. However, the mechanism by which IGF-1 inhibits steroid myopathy remains unclear. Recent studies have revealed that glutamine synthetase (GS) is induced by glucocorticoid and may be related to the development of steroid myopathy. In this study, we examined whether IGF-1 affected steroid-induced enhancement of GS activity in L6 rat skeletal muscle cells. Dexamethasone (10(-6) M) significantly increased GS activity in L6 cells (P < 0.01). IGF-1 dose-dependently inhibited dexamethasone-induced GS activity. Addition of IGF-1 (750 ng/ml) decreased GS activity to approximately 50% of that with dexamethasone alone (P < 0.01). These results suggest that a decrease in GS activity may be involved in the preventive effect of IGF-1 on steroid myopathy.
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Affiliation(s)
- K Kimura
- Third Division, Department of Medicine, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, 650-0017, Kobe, Japan
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12
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Xu X, Cubeddu LX, Malave A. Expression of inducible nitric oxide synthase in primary culture of rat bladder smooth muscle cells by plasma from cyclophosphamide-treated rats. Eur J Pharmacol 2001; 416:1-9. [PMID: 11282106 DOI: 10.1016/s0014-2999(01)00846-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Intraperitoneal administration of cyclophosphamide (50-150 mg/kg) for 6 or 12 h induced edema and hemorrhagic changes in rat bladder, which were both dose and time-dependent. Pretreatment with nitric oxide synthase (NOS) inhibitors N(G)-nitro-L-arginine methyl ester (L-NAME, 40 mg/kg) or with s-methylisothiourea (40 mg/kg) ameliorated the cyclophosphamide-induced cystitis. Cyclophosphamide administration also produced increases in NO-metabolite levels (nitrate+nitrite) in the urine and plasma of rats. Greater increases in NO metabolites were observed with 150 than with 50 mg/kg of cyclophosphamide, and at 12 than at 6 h after cyclophosphamide injection. Pretreatment with L-NAME and s-methylisothiourea significantly reduced cyclophosphamide-induced increases in urine and plasma NO-metabolite levels. To explore the mechanism by which cyclophosphamide increases the expression of inducible NOS (iNOS), primary cultures of rat bladder smooth muscle were developed. Exposure to tumor necrosis factor alpha (TNF-alpha) plus interferon gamma, produced a marked increase in the expression of iNOS and in NO production in the culture medium. However, exposure to cyclophosphamide or to its metabolite acrolein (10(-6)-10(-4) M for 24 h) did not increase iNOS or NO-metabolite levels. On the other hand, incubation of primary cell cultures with plasma from rats treated with cyclophosphamide (150 mg/kg, 12 h) produced a marked increase in iNOS expression and NO production. Taken together, our results indicate that NO plays an important role in the pathogenesis of cyclophosphamide-induced cystitis in rats, and some factors may be released in cyclophosphamide-treated rat plasma which stimulate iNOS expression in primary culture of rat bladder smooth muscle cells.
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Affiliation(s)
- X Xu
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328, USA
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Adams V, Lenk K, Schubert A, Gielen S, Schuler G, Hambrecht R. Differentially expressed genes in L6 rat skeletal muscle myoblasts after incubation with inflammatory cytokines. Cytokine 2001; 13:342-8. [PMID: 11292317 DOI: 10.1006/cyto.2000.0839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The mechanism underlying exercise intolerance in chronic heart failure is still unclear. An increased concentration of inflammatory cytokines could be detected in the serum of patients with chronic heart failure (CHF) exhibiting a correlation with the severity of the disease. The variety of molecular alterations triggered by these cytokines in the skeletal muscle is almost unknown. The study was designed to analyze the differential gene expression in skeletal muscle myoblasts after stimulation with inflammatory cytokines. METHODS L6 rat skeletal muscle myoblasts were incubated for 24 h with a combination of IL-1beta/IFN-gamma and the differential gene expression profile was determined by a PCR-based subtractive hybridization method. RESULTS Out of 173 picked clones 141 different sequences could be identified. By comparison with Genebank, the identity of 73 genes (51.7%) could be confirmed, whereas the rest did not show a homology to any known gene. Some of the identified genes are known to be altered in patients with CHF. CONCLUSION In summary, the results of this study provide information about changes in gene expression after exposure of skeletal muscle cells to inflammatory cytokines. This information may yield a new gene pool, worthwhile to be analyzed in skeletal muscle of patients with chronic heart failure.
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Affiliation(s)
- V Adams
- Department of Cardiology, Heart Center, University of Leipzig, Leipzig, Germany.
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Abstract
In the past five years, skeletal muscle has emerged as a paradigm of "nitric oxide" (NO) function and redox-related signaling in biology. All major nitric oxide synthase (NOS) isoforms, including a muscle-specific splice variant of neuronal-type (n) NOS, are expressed in skeletal muscles of all mammals. Expression and localization of NOS isoforms are dependent on age and developmental stage, innervation and activity, history of exposure to cytokines and growth factors, and muscle fiber type and species. nNOS in particular may show a fast-twitch muscle predominance. Muscle NOS localization and activity are regulated by a number of protein-protein interactions and co- and/or posttranslational modifications. Subcellular compartmentalization of the NOSs enables distinct functions that are mediated by increases in cGMP and by S-nitrosylation of proteins such as the ryanodine receptor-calcium release channel. Skeletal muscle functions regulated by NO or related molecules include force production (excitation-contraction coupling), autoregulation of blood flow, myocyte differentiation, respiration, and glucose homeostasis. These studies provide new insights into fundamental aspects of muscle physiology, cell biology, ion channel physiology, calcium homeostasis, signal transduction, and the biochemistry of redox-related systems.
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Affiliation(s)
- J S Stamler
- Howard Hughes Medical Institute, Department of Medicine, Divisions of Pulmonary and Cardiology and Department of Biochemistry, Duke University Medical Center, Durham, North Carolina, USA.
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15
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Zhang Y, Pilon G, Marette A, Baracos VE. Cytokines and endotoxin induce cytokine receptors in skeletal muscle. Am J Physiol Endocrinol Metab 2000; 279:E196-205. [PMID: 10893340 DOI: 10.1152/ajpendo.2000.279.1.e196] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proinflammatory cytokines are important factors in the regulation of diverse aspects of skeletal muscle function; however, the muscle cytokine receptors mediating these functions are uncharacterized. Binding kinetics (dissociation constant = 39+/-4.7 x 10(-9) M, maximal binding = 3.5+/-0.23 x 10(-12) mol/mg membrane protein) of muscle tumor necrosis factor (TNF) receptors were obtained. Skeletal muscle was found to express mRNAs encoding interleukin-1 type I and II receptors, interleukin-6 receptor (IL-6R), and interferon-gamma receptor by RT-PCR, but these receptors were below limits of detection of ligand-binding assay (> or =1 fmol binding sites/mg protein). Twenty-four hours after intraperitoneal administration of endotoxin to rats, TNF receptor type II (TNFRII) and IL-6R mRNA were increased in skeletal muscle (P<0.05). In cultured L6 cells, the expression of mRNA encoding TNFRII and IL-6R receptors was induced by TNF-alpha, and all six cytokine receptor mRNA were induced by a mixture of TNF-alpha, IFN-gamma, and endotoxin (P<0.05). This suggests that the low level of cytokine receptor expression is complemented by a capacity for receptor induction, providing a clear mechanism for amplification of cytokine responses at the muscle level.
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Affiliation(s)
- Y Zhang
- Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta T6G 2P5
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16
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Chen CC, Lin YC, Chen SA, Luk HN, Ding PY, Chang MS, Chiang CE. Shortening of cardiac action potentials in endotoxic shock in guinea pigs is caused by an increase in nitric oxide activity and activation of the adenosine triphosphate-sensitive potassium channel. Crit Care Med 2000; 28:1713-20. [PMID: 10890608 DOI: 10.1097/00003246-200006000-00003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the roles of nitric oxide and adenosine triphosphate (ATP)-sensitive potassium channels (KATP) in the shortening of cardiac action potential in endotoxic shock. DESIGN Prospective animal study with concurrent controls. SETTING University animal research laboratory. SUBJECTS Adult Hartley guinea pigs, weighing 300-400 g. INTERVENTIONS Guinea pigs were anesthetized and mechanically ventilated for 6 hrs. Lipopolysaccharide (LPS) or saline (sham group) were given intravenously. Drug effects were examined at the end of 6 hrs. MEASUREMENTS AND MAIN RESULTS Plasma nitrate concentration was measured hourly, while guanosine 3',5'-cyclic monophosphate (cGMP) content and action potential duration at 90% of repolarization (APD90) of papillary muscle were examined every 2 hrs in the 6-hr endotoxemia in both the sham and the LPS-treated groups. The basal levels of these three variables showed no difference in the two groups. In the sham group, these variables did not change significantly (n = 14 for plasma nitrate determination; n = 5 for cGMP content measurement; n = 5-14 for APD90 measurement; all p > .05). But in the LPS-treated group, both plasma nitrate concentration and cGMP content of papillary muscle showed time-dependent increases and they were significantly higher than those in the sham group (at the 6th hr, plasma nitrate: 42.6 +/- 7.7 vs. 21.8 +/- 3.1 micromol/L, both n = 14, p < .01; cGMP: 1.52 +/- 0.15 vs. 0.73 +/- 0.08 pmol/mg protein, both n = 5, p < .01). In contrast, APD90 revealed a time-dependent decrease compared with that in the sham group (at the 6th hr, 137.1 +/- 52 vs. 188.2 +/- 4.8 msecs, both n = 14, p < .001). In the following 60-min in vitro recording of action potentials after the end of 6-hr endotoxemia, the shortened APD90 in the LPS-treated group did not recover and remained shorter compared with that in the sham group, in which the APD90 showed no significant changes (at the 60th min, 165.1 +/- 5.7 vs. 200.2 +/- 3.8 msecs, each n = 14, p < .01). However, in the presence of glibenclamide, a specific KATP blocker (100 micromol/L; n = 10), the APD90 could be reversed almost completely to the same value as that in the sham group (n = 14) (196.6 +/- 3.5 vs. 200.2 +/- 3.8 msecs; p > .05), despite glibenclamide having no effect on the APD90 in the sham group. In the LPS-treated group, NG-nitro-L-arginine methyl ester (1 mmol/L; n = 4), methylene blue (10 micromol/L; n = 5), and aminoguanidine (100 micromol/L; n = 4) significantly prolonged the shortened APD90 (192.5 +/- 3.1, 195.0 +/- 3.3, and 176.5 +/- 3.3 msecs, respectively; p < .01, p < .01, and p < .05, respectively, compared with that without these agents, 165.1 +/- 5.7 msecs, n = 14). These agents had negligible effects on the APD90 in the sham group (all p > .05). Furthermore, 8-bromoguanosine-3',5'-cyclic monophosphate (500 micromol/L; n = 5) decreased APD in intact papillary muscle (mean reduction of APD90, 13.5 +/- 3.5%, n = 5; p < .05), an effect abolished by pretreatment with glibenclamide (100 micromol/L; n = 5) that did not have an effect by itself. CONCLUSIONS In this experimental model, we provide reasonably convincing evidence to suggest that in endotoxic shock, an increase in nitric oxide activity may activate KATP, which plays a major role in the shortening of APD, presumably through a cGMP-dependent pathway.
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Affiliation(s)
- C C Chen
- Department of Medicine, Show Chwan Memorial Hospital, Chang-Hwa, Taiwan
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17
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Przyklenk K, Hata K, Whittaker P, Elliott GT. Monophosphoryl lipid A: a novel nitric oxide-mediated therapy to attenuate platelet thrombosis? J Cardiovasc Pharmacol 2000; 35:366-75. [PMID: 10710120 DOI: 10.1097/00005344-200003000-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nitric oxide (NO) is a potent inhibitor of platelet aggregation. However, the benefits of NO-based therapies can be confounded by concomitant hypotension. Monophosphoryl lipid A (MLA) is a nontoxic derivative of endotoxin that purportedly increases nitric oxide synthase (NOS) activity and, presumably, NO production, yet has a hemodynamically benign profile. Thus our aims were to determine whether (a) MLA attenuates in vivo platelet aggregation in damaged and stenotic canine coronary arteries by a NO-mediated mechanism but without reductions in arterial pressure; and (b) the platelet inhibitory effects are manifest in vitro. To address the first aim, anesthetized dogs underwent coronary injury + stenosis, resulting in cyclic variations in coronary blood flow (CFVs) caused by the formation/dislodgement of platelet-rich thrombi. In protocol I, dogs received MLA (100 microg/kg + 40 microg/kg/h) or vehicle beginning 15 min before stenosis. Protocol II was identical, except the NOS inhibitor aminoguanidine was coadministered with MLA/vehicle. Coronary patency was assessed throughout the initial 3 h after injury + stenosis. Infusion of MLA did not result in hypotension. However, in protocol I, the median nadir of the CFVs was higher (2.1 vs. 0.8 ml/min; p < 0.05), median duration of total thrombotic occlusion tended to be reduced (0 vs. 10.4 min; p = 0.1), and mean flow-time area, expressed as a percentage of baseline flow, was increased (53 +/- 9% vs. 33 +/- 3%; p < 0.05) in MLA-treated versus vehicle-treated dogs. In contrast, in protocol II, vessel patency was comparable in both groups. Finally, whole blood impedance aggregometry (protocol HI) revealed a significant reduction in the in vitro platelet aggregation in blood samples receiving exogenous MLA, which was blocked by coadministration of exogenous aminoguanidine. Thus MLA attenuates platelet-mediated thrombosis in both damaged and stenotic canine coronary arteries and in vitro, possibly by an NO-mediated mechanism, but without concomitant hypotension.
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Affiliation(s)
- K Przyklenk
- Heart Institute, Good Samaritan Hospital, and Department of Medicine, University of Southern California, Los Angeles 90017-2395, USA.
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18
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Sugishita Y, Shimizu T, Yao A, Kinugawa KI, Nojiri T, Harada K, Matsui H, Nagai R, Takahashi T. Lipopolysaccharide augments expression and secretion of vascular endothelial growth factor in rat ventricular myocytes. Biochem Biophys Res Commun 2000; 268:657-62. [PMID: 10679260 DOI: 10.1006/bbrc.2000.2165] [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: 11/22/2022]
Abstract
Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is highly expressed in the myocardium under various stimuli including hypoxia and ischemia. On the other hand, lipopolysaccharide (LPS) causes systemic inflammatory response syndrome (SIRS), which consists of systemic pathophysiological changes related to vascular hyperpermeability. To test the hypothesis that VEGF is one of the important mediators of SIRS, we examined effects of LPS on the VEGF expression and secretion in cultured neonatal rat ventricular myocytes. LPS (10 microg/ml) rapidly (within 1 h) augmented the levels of VEGF mRNA in these cells. Pharmacological inhibition of nucleic factor-kappaB or tyrosine kinases did not affect the LPS-induced augmentation of VEGF mRNA expression, while these treatments markedly suppressed the up-regulation of inducible nitric oxide synthase (iNOS) expression by LPS. The VEGF concentrations in the conditioned media were also significantly increased by the LPS treatment of 6 h. In conclusion, LPS augments VEGF expression and secretion in rat ventricular myocytes, suggesting that VEGF may be involved in pathogenesis of SIRS. LPS may induce VEGF mRNA through the signaling pathways that are distinct from those responsible for the iNOS induction.
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Affiliation(s)
- Y Sugishita
- Department of Cardiovascular Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
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19
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Niess AM, Sommer M, Schneider M, Angres C, Tschositsch K, Golly IC, Battenfeld N, Northoff H, Biesalski HK, Dickhuth HH, Fehrenbach E. Physical exercise-induced expression of inducible nitric oxide synthase and heme oxygenase-1 in human leukocytes: effects of RRR-alpha-tocopherol supplementation. Antioxid Redox Signal 2000; 2:113-26. [PMID: 11232592 DOI: 10.1089/ars.2000.2.1-113] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This study evaluated the effects of RRR-alpha-tocopherol (500 IU/day, 8 days) on in vivo cytokine response and cytoplasmic expression of inducible nitric oxide synthase (iNOS) and the antioxidant stress protein heme oxygenase-1 (HO-1) in human leukocytes after exhaustive exercise. Thirteen men were investigated in a double-blind, placebo-controlled, cross-over study with a wash-out period of 28 days. The exercise procedure consisted of an incremental treadmill test followed by a continuous run until exhaustion at 110% of the individual anaerobic threshold (total duration 28.5 +/- 0.8 min). HO-1 and iNOS protein were assessed in mono- (M), lympho-, and granulocytes (G) using flow cytometry. Plasma interleukin-6 (IL-6) and IL-8 were measured by ELISA. IL-6 rose significantly whereas IL-8 did not exhibit significant changes after exercise. Changes of IL-6 were not affected by RRR-alpha-tocopherol. Exercise induced an increase of iNOS protein primarily in M and G. A small, but significant, increase of HO-1 protein was measured in M and G. RRR-alpha-Tocopherol did not show any significant effects on cytoplasmic expression of iNOS and HO-1 at rest and after exercise. In conclusion, exhaustive exercise induces expression of iNOS and HO-1 in human leukocytes by a mechanism that is not sensitive to RRR-alpha-tocopherol supplementation.
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Affiliation(s)
- A M Niess
- Medical Clinic & Polyclinic, Department of Sports Medicine, University of Tuebingen, Germany.
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20
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Cruz MT, Duarte CB, Gonçalo M, Carvalho AP, Lopes MC. Involvement of JAK2 and MAPK on type II nitric oxide synthase expression in skin-derived dendritic cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:C1050-7. [PMID: 10600756 DOI: 10.1152/ajpcell.1999.277.6.c1050] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In this report, we demonstrate that a fetal mouse skin-derived dendritic cell line produces nitric oxide (NO) in response to the endotoxin [lipopolysaccharide (LPS)] and to cytokines [tumor necrosis factor-alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF)]. Expression of the inducible isoform of NO synthase (iNOS) was confirmed by immunofluorescence with an antibody against iNOS. The tyrosine kinase inhibitor genistein decreased LPS- and GM-CSF-induced nitrite (NO(-2)) production. The effect of LPS and cytokines on NO(-2) production was inhibited by the Janus kinase 2 (JAK2) inhibitor tyrphostin B42. The p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB-203580 also reduced the NO(-2) production evoked by LPS, TNF-alpha, or GM-CSF, but it was not as effective as tyrphostin B42. Inhibition of MAPK kinase with PD-098059 also slightly reduced the effect of TNF-alpha or GM-CSF on NO(-2) production. Immunocytochemistry studies revealed that the transcription factor nuclear factor-kappaB was translocated from the cytoplasm into the nuclei of fetal skin-derived dendritic cells (FSDC) stimulated with LPS, and this translocation was inhibited by tyrphostin B42. Our results show that JAK2 plays a major role in the induction of iNOS in FSDC.
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Affiliation(s)
- M T Cruz
- Faculdade de Farmácia e, Universidade de Coimbra, 3000 Coimbra, Portugal
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21
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Galea E, Feinstein DL. Regulation of the expression of the inflammatory nitric oxide synthase (NOS2) by cyclic AMP. FASEB J 1999; 13:2125-37. [PMID: 10593859 DOI: 10.1096/fasebj.13.15.2125] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The enzyme nitric oxide synthase 2 (NOS2), often called inducible NOS, plays a central role in the inflammatory reactions that follow infection or tissue damage. NOS2 has been detected in virtually every cell type, and the NO it produces can perform both beneficial and detrimental actions. It is thus conceivable that regulatory mechanisms exist which control the timing and intensity of NO production by NOS2 in order to outweigh protective effects against detrimental ones. Since cyclic AMP inhibits numerous immunological reactions, studies have been carried out to determine whether cAMP-dependent pathways could inhibit NOS2 expression as well. Pharmacological studies in cultured cells show that, depending on the cell type examined, increased cAMP can exert opposite effects on the endotoxin- or cytokine-induced expression of NOS2, being either stimulatory or inhibitory in macrophages, stimulatory in adipocytes, smooth muscle, skeletal muscle, and brain endothelial cells, and inhibitory in pancreatic, liver, and brain glial cells. Regulation of NOS2 gene transcription appears to be the primary mechanism of action of cAMP, and whether it is stimulatory or inhibitory hinges on the cell-specific regulation of transcription factors including CREB, NF-kappaB, and C/EBP. Cyclic AMP must therefore be considered a modulator rather than a suppressor of NOS2 expression. This review summarizes evidence derived from in vitro studies, considers regulation of NOS2 by cAMP in vivo, and discusses possible therapeutic applications of cAMP treatment.-Galea, E., Feinstein, D. L. Regulation of the expression of the inflammatory nitric oxide synthase (NOS2) by cyclic AMP.
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Affiliation(s)
- E Galea
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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22
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Arstall MA, Sawyer DB, Fukazawa R, Kelly RA. Cytokine-mediated apoptosis in cardiac myocytes: the role of inducible nitric oxide synthase induction and peroxynitrite generation. Circ Res 1999; 85:829-40. [PMID: 10532951 DOI: 10.1161/01.res.85.9.829] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Increased production of nitric oxide (NO) after induction of the cytokine-inducible isoform of nitric oxide synthase (iNOS or NOS2) in cardiac myocytes and other parenchymal cells within the heart may in addition to contributing to myocyte contractile dysfunction also contribute to the induction of programmed cell death (apoptosis). To investigate the mechanism(s) by which increased NO production leads to apoptosis, we examined the role of NO in primary cultures of neonatal rat ventricular myocytes (NRVMs) after induction by the cytokines interleukin-1beta (IL-1beta) and interferon gamma (IFNgamma) or exposure to the exogenous NO donor S-nitroso-N-acetylcysteine (SNAC) or peroxynitrite (ONOO(-)). Both SNAC (1 mmol/L) and ONOO(-) (100 micromol/L), but not their respective controls (ie, N-acetylcysteine and pH-inactivated ONOO(-)), induced apoptosis in confluent, serum-starved NRVMs at 48 hours. Similarly, incubation of NRVMs with IL-1beta and IFNgamma for 48 hours resulted in an increase in iNOS expression, nitrite production, and programmed cell death. Both the cytokine-induced nitrite accumulation and myocyte apoptosis could be completely prevented by the nonselective NOS inhibitor L-nitroarginine (3 mmol/L) or the specific iNOS inhibitor 2-amino-5, 6-dihydro-6-methyl-4H-1,3-thiazine (AMT, 100 micromol/L). NO-mediated myocyte apoptosis was not attenuated by the inhibition of soluble guanylyl cyclase with ODQ, nor could apoptosis be induced by the incubation of NRVMs with 1 mmol/L 8-bromo-cGMP, a cell-permeant cGMP analogue. However, NO-mediated apoptosis was significantly attenuated by the superoxide dismutase mimetic and ONOO(-) scavenger Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP, 100 micromol/L). NO/ONOO(-)-mediated apoptosis was associated with increased expression of Bax with no change in Bcl-2 mRNA abundance. Furthermore, apoptotic cell death was also confirmed in adult rat ventricular myocytes (ARVMs) when grown in heteroculture with IL-1beta- and IFNgamma-treated rat cardiac microvascular endothelial cells. Therefore, cytokine-induced apoptosis in NRVMs and ARVMs is mediated by iNOS induction, ONOO(-), and associated with an increase in Bax levels.
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Affiliation(s)
- M A Arstall
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
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23
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Abstract
Cytokines constitute a major class of mediators responsible for "activation" of hepatic stellate cells (HSCs) in vitro and in vivo. They are largely divided into mitogenic (transforming growth factor-alpha, platelet-derived growth factor, interleukin-1, tumor necrosis factor-alpha, and insulin-like growth factor) and fibrogenic (transforming growth factor-beta and interleukin-6) cytokines. In addition to their mitogenic (stimulation of cell proliferation) and fibrogenic (induction of matrix proteins) properties, they are also shown to confer in vitro unique cellular changes known to be the key features of HSC "activation," including loss of vitamin A, stimulation of migration, enhanced cellular contractility, and matrix metalloproteinase and tissue inhibitor of metalloproteinase induction. Potential cellular sources of the cytokines consist of hepatic macrophages, endothelial cells, biliary epithelial cells, lymphocytes, platelets, hepatocytes, and activated HSCs. To better understand the mode of actions and the pathogenetic significance of cytokines/chemokines involved in "activation" of HSCs, the following four questions need to be addressed: (1) What other cytokines are expressed by HSCs to establish critical autocrine stimulation? (2) What are endogenous or exogenous priming factors for HSC stimulation? (3) What is the mechanism of activation for transforming growth factor-beta, the pivotal fibrogenic cytokine? (4) How important are HSC-derived proinflammatory mediators in liver fibrosis? This review will discuss these questions, along with the current understanding of the role of cytokines in HSC activation.
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Affiliation(s)
- H Tsukamoto
- Department of Medicine, University of Southern California School of Medicine, Los Angeles 90033, USA.
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24
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Pernet P, Coudray-Lucas C, Le Boucher J, Schlegel L, Giboudeau J, Cynober L, Aussel C. Is the L-arginine-nitric oxide pathway involved in endotoxemia-induced muscular hypercatabolism in rats? Metabolism 1999; 48:190-3. [PMID: 10024080 DOI: 10.1016/s0026-0495(99)90032-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigated the role of the nitric oxide (NO) synthase (NOS) pathway in muscular metabolism during endotoxemia in four groups of male Wistar rats. Two groups were injected with the lipopolysaccharide (LPS) of Escherichia coli (3 mg/kg), with one group treated using N(G)-nitro-L-arginine methylester ([L-NAME] 85 mg/kg/d) and the other not. The two control groups included one treated with L-NAME and the other not. After 24 hours of fasting, the rats were fed by controlled enteral nutrition and killed on day 3. The results showed that (1) NOS inhibition was detrimental during endotoxemia, increasing lethality from 20% to 80.5%, and (2) NOS inhibition did not modify the hypercatabolic state consecutive to endotoxemia, particularly at the muscular level (nitrogen balance, total-body and muscular weight loss, and muscular protein and glutamine concentrations). However, myofibrillar catabolism was delayed in the LPS-NAME group. In conclusion, NO production is of major importance for survival after an endotoxemic challenge, but contributes weakly to the metabolic response of muscle to injury.
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Affiliation(s)
- P Pernet
- Service de Biochimie A, Hôpital Saint-Antoine, Paris, France
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25
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Balon TW. Role of nitric oxide in contraction induced glucose transport. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 441:87-95. [PMID: 9781316 DOI: 10.1007/978-1-4899-1928-1_8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Nitric oxide (NO) is a vasoactive substance, which was first described as endothelium derived relaxing factor (EDRF). Subsequently, NO has been found to be a messenger molecule abundantly present in the nervous system. Functioning as a neurotransmitter in the peripheral nervous system, NO mediates an array of physiological functions such as gastrointestinal motility, regional blood flow, smooth muscle contraction, neuroendocrine activity and immune function. Recently NO biosynthesis has been found in skeletal muscle, where NO exerts an effect on both the metabolic and contractile processes. This review will focus on the actions of NO in skeletal muscle metabolism. NO donors have been shown to increase glucose transport in skeletal muscle. Inhibition of NOS activity blunts contraction-stimulated glucose transport but has no effect on insulin-stimulated glucose transport. NOS protein expression is enhanced by chronic exercise suggesting that NO may play a role in the improved glucose tolerance and increased insulin sensitivity characteristic of the trained state.
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Affiliation(s)
- T W Balon
- Department of Diabetes, Endocrinology, and Metabolism, City of Hope National Medical Center, Duarte, California 91010, USA
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26
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Choe N, Tanaka S, Kagan E. Asbestos fibers and interleukin-1 upregulate the formation of reactive nitrogen species in rat pleural mesothelial cells. Am J Respir Cell Mol Biol 1998; 19:226-36. [PMID: 9698594 DOI: 10.1165/ajrcmb.19.2.3111] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Nitric oxide radical (.NO) and peroxynitrite anion (ONOO-) have been implicated in lung inflammation and may be important in pleural injury. The present study was undertaken to determine the effects of asbestos exposure and cytokine stimulation on .NO and ONOO- production by rat pleural mesothelial cells. Accordingly, rat parietal pleural mesothelial cells were cultured for 2 to 72 h with or without 50 ng/ml of recombinant interleukin-1beta (IL-1beta) in the presence (1.05 to 8.4 microg/cm2) or absence of crocidolite or chrysotile asbestos fibers. The effects of asbestos were compared with those of carbonyl iron, a nonfibrogenic particulate. Mesothelial cell messenger RNA (mRNA) expression of the inducible form of .NO synthase (iNOS), assessed with the reverse transcription-polymerase chain reaction (RT-PCR), increased progressively from 2 to 12 h in IL-1beta-containing cultures. Nitrite (NO2-), the stable oxidation product of .NO in mesothelial cell conditioned medium, was assayed through the Griess reaction. Both types of asbestos fibers (chrysotile > crocidolite) upregulated the formation of NO2- in mesothelial cells costimulated with IL-1beta in a concentration-dependent and time-dependent fashion. In contrast, carbonyl iron did not upregulate NO2- formation in IL-1beta-stimulated cells. Both types of asbestos fibers also induced iNOS protein expression and the formation of nitrotyrosine in mesothelial cells and greatly induced the formation of nitrate (NO3-), a surrogate marker of ONOO- formation, in IL-1beta-stimulated cells. However, the effects of chrysotile were notably greater than those of crocidolite. These findings may have significance for the induction of pleural injury by asbestos fibers.
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Affiliation(s)
- N Choe
- Department of Pathology, Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, Maryland, USA
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27
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el-Dwairi Q, Comtois A, Guo Y, Hussain SN. Endotoxin-induced skeletal muscle contractile dysfunction: contribution of nitric oxide synthases. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 274:C770-9. [PMID: 9530109 DOI: 10.1152/ajpcell.1998.274.3.c770] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aims of this study were to assess the role of nitric oxide (NO) and the contribution of different NO synthase (NOS) isoforms in skeletal muscle contractile dysfunction in septic shock. Four groups of conscious rats were examined. Group 1 served as control; group 2, 3, and 4 were injected with Escherichia coli endotoxin [lipopolysaccharide (LPS), 20 mg/kg i.p.] and killed after 6, 12, and 24 h, respectively. Protein expression was assessed by immunoblotting and immunostaining. LPS injection elicited a transient expression of the inducible NOS isoform, which peaked 12 h after LPS injection and disappeared within 24 h. This expression coincided with a significant increase in nitrotyrosine formation (peroxynitrite foot-print). Muscle expression of the endothelial and neuronal NOS isoforms, by comparison, rose significantly and remained higher than control levels 24 h after LPS injection. In vitro measurement of muscle contractility 24 h after LPS injection showed that incubation with NOS inhibitor (S-methyliosothiourea) restored the decline in submaximal force generation, whereas maximal muscle force remained unaffected. We conclude that NO plays a significant role in muscle contractile dysfunction in septic animals and that increased NO production is due to induction of the inducible NOS isoform and upregulation of constitutive NOS isoforms.
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Affiliation(s)
- Q el-Dwairi
- Critical Care Division, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada
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28
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Kinugawa K, Shimizu T, Yao A, Kohmoto O, Serizawa T, Takahashi T. Transcriptional regulation of inducible nitric oxide synthase in cultured neonatal rat cardiac myocytes. Circ Res 1997; 81:911-21. [PMID: 9400371 DOI: 10.1161/01.res.81.6.911] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Previous work has demonstrated that inducible NO synthase (iNOS) can be expressed in cardiac myocytes. In this study, we investigated transcriptional regulation of the iNOS gene in these cells. Lipopolysaccharide (LPS) induced iNOS mRNA and protein in cultured neonatal rat cardiac myocytes. H-89, dexamethasone, herbimycin, genistein, staurosporine, or pyrrolidine dithiocarbamate (PDTC) attenuated the iNOS induction by LPS. Forskolin, interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, or interferon (IFN)-gamma enhanced the LPS-induced iNOS expression. Combined stimulation of IL-6 and TNF-alpha also induced iNOS. The 5'-upstream sequence of the rat iNOS gene contains the nuclear factor-kappa B (NF-kappa B) site, CAAT box, IFN-gamma activation site (GAS), and IFN regulatory factor (IRF) site. DNase I footprinting assay revealed that the nuclear factors binding to these elements were increased by LPS exposure. Transient transfection assay suggested that these elements were indispensable for transcriptional regulation of the iNOS induction. Electrophoretic mobility shift assay revealed that LPS or TNF-alpha increased binding activity for the NF-kappa B site. A slower-migrating complex binding to the CAAT box gave rise after exposure to LPS or forskolin. Competition assay suggested that this slower-migrating complex consisted of a heterodimer between a member of CAAT box/enhancer binding (C/EBP) protein family and cAMP responsive element binding protein (CREB). LPS or IL-6 increased binding complexes for the IRF site, which was compatible with induction of IRF-1. LPS, IL-6, or IFN-gamma induced a novel binding complex for GAS, which also existed in the 5'-flanking region of the IRF-1 gene. These data suggest that (1) iNOS induction simultaneously requires both NF-kappa B activation and IRF-1 induction, and (2) the heterodimer between C/EBP and CREB has synergistic effects on the iNOS induction via the CAAT box.
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Affiliation(s)
- K Kinugawa
- Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
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