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Mauchauffée E, Leroy J, Chamcham J, Ejjoummany A, Maurel M, Nauton L, Ramassamy B, Mezghenna K, Boucher JL, Lajoix AD, Hernandez JF. S-Ethyl-Isothiocitrullin-Based Dipeptides and 1,2,4-Oxadiazole Pseudo-Dipeptides: Solid Phase Synthesis and Evaluation as NO Synthase Inhibitors. Molecules 2023; 28:5085. [PMID: 37446746 DOI: 10.3390/molecules28135085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
We previously reported dipeptidomimetic compounds as inhibitors of neuronal and/or inducible NO synthases (n/iNOS) with significant selectivity against endothelial NOS (eNOS). They were composed of an S-ethylisothiocitrullin-like moiety linked to an extension through a peptide bond or a 1,2,4-oxadiazole link. Here, we developed two further series where the extension size was increased to establish more favorable interactions in the NOS substrate access channel. The extension was introduced on the solid phase by the reductive alkylation of an amino-piperidine moiety or an aminoethyl segment in the case of dipeptide-like and 1,2,4-oxadiazole compounds, respectively, with various benzaldehydes. Compared to the previous series, more potent inhibitors were identified with IC50 in the micromolar to the submicromolar range, with significant selectivity toward nNOS. As expected, most compounds did not inhibit eNOS, and molecular modeling was carried out to characterize the reasons for the selectivity toward nNOS over eNOS. Spectral studies showed that compounds were interacting at the heme active site. Finally, selected inhibitors were found to inhibit intra-cellular iNOS and nNOS expressed in RAW264.7 and INS-1 cells, respectively.
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Affiliation(s)
- Elodie Mauchauffée
- Institut des Biomolécules Max Mousseron, CNRS, Univ. Montpellier, ENSCM, Pôle Chimie Balard, 34293 Montpellier, France
| | - Jérémy Leroy
- Centre Biocommunication en Cardio-Métabolique, Univ. Montpellier, UFR Pharmacie, 34093 Montpellier, France
| | - Jihanne Chamcham
- Institut des Biomolécules Max Mousseron, CNRS, Univ. Montpellier, ENSCM, Pôle Chimie Balard, 34293 Montpellier, France
| | - Abdelaziz Ejjoummany
- Institut des Biomolécules Max Mousseron, CNRS, Univ. Montpellier, ENSCM, Pôle Chimie Balard, 34293 Montpellier, France
| | - Manon Maurel
- Institut des Biomolécules Max Mousseron, CNRS, Univ. Montpellier, ENSCM, Pôle Chimie Balard, 34293 Montpellier, France
| | - Lionel Nauton
- Institut de Chimie de Clermont-Ferrand, Université Clermont-Auvergne, CNRS, 63178 Aubière, France
| | - Booma Ramassamy
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601, CNRS, Université Paris Descartes, CEDEX 06, 75270 Paris, France
| | - Karima Mezghenna
- Centre Biocommunication en Cardio-Métabolique, Univ. Montpellier, UFR Pharmacie, 34093 Montpellier, France
| | - Jean-Luc Boucher
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601, CNRS, Université Paris Descartes, CEDEX 06, 75270 Paris, France
| | - Anne-Dominique Lajoix
- Centre Biocommunication en Cardio-Métabolique, Univ. Montpellier, UFR Pharmacie, 34093 Montpellier, France
| | - Jean-François Hernandez
- Institut des Biomolécules Max Mousseron, CNRS, Univ. Montpellier, ENSCM, Pôle Chimie Balard, 34293 Montpellier, France
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Bahadoran Z, Mirmiran P, Ghasemi A. Role of Nitric Oxide in Insulin Secretion and Glucose Metabolism. Trends Endocrinol Metab 2020; 31:118-130. [PMID: 31690508 DOI: 10.1016/j.tem.2019.10.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 09/29/2019] [Accepted: 10/03/2019] [Indexed: 01/20/2023]
Abstract
Nitric oxide (NO) contributes to carbohydrate metabolism and decreased NO bioavailability is involved in the development of type 2 diabetes mellitus (T2DM). NO donors may improve insulin signaling and glucose homeostasis in T2DM and insulin resistance (IR), suggesting the potential clinical importance of NO-based interventions. In this review, site-specific roles of the NO synthase (NOS)-NO pathway in carbohydrate metabolism are discussed. In addition, the metabolic effects of physiological low levels of NO produced by constitutive NOS (cNOS) versus pathological high levels of NO produced by inducible NOS (iNOS) in pancreatic β-cells, adipocytes, hepatocytes, and skeletal muscle cells are summarized. A better understanding of the NOS-NO system in the regulation of glucose homeostasis can hopefully facilitate the development of new treatments for T2DM.
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Affiliation(s)
- Zahra Bahadoran
- Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvin Mirmiran
- Department of Clinical Nutrition and Human Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Abstract
The family of nitric oxide synthases (NOS) has significant importance in various physiological mechanisms and is also involved in many pathological processes. Three NOS isoforms have been identified: neuronal NOS (nNOS or NOS 1), endothelial NOS (eNOS or NOS 3), and an inducible NOS (iNOS or NOS 2). Both nNOS and eNOS are constitutively expressed. Classically, eNOS is considered the main isoform involved in the control of the vascular function. However, more recent studies have shown that nNOS is present in the vascular endothelium and importantly contributes to the maintenance of the homeostasis of the cardiovascular system. In physiological conditions, besides nitric oxide (NO), nNOS also produces hydrogen peroxide (H2O2) and superoxide ([Formula: see text]) considered as key mediators in non-neuronal cells signaling. This mini-review highlights recent scientific releases on the role of nNOS in vascular homeostasis and cardiovascular disorders such as hypertension and atherosclerosis.
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Affiliation(s)
- Eduardo D Costa
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Bruno A Rezende
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas GeraisBelo Horizonte, Brazil; Department of Health Sciences, Post-graduate Institute, Medical Sciences CollegeBelo Horizonte, Brazil
| | - Steyner F Cortes
- Department of Pharmacology, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
| | - Virginia S Lemos
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
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Chaudhury A. Similarity in Transcytosis of nNOSα in Enteric Nerve Terminals and Beta Cells of Pancreatic Islet. Front Med (Lausanne) 2014; 1:20. [PMID: 25705631 PMCID: PMC4335384 DOI: 10.3389/fmed.2014.00020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/15/2014] [Indexed: 02/06/2023] Open
Affiliation(s)
- Arun Chaudhury
- Division of Surgery, Brigham and Women's Hospital, Harvard Medical School and VA Boston HealthCare System , Boston, MA , USA
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da Costa AV, Calábria LK, de Souza Santos P, Goulart LR, Espindola FS. Glibenclamide treatment modulates the expression and localization of myosin-IIB in diabetic rat brain. J Neurol Sci 2014; 340:159-64. [PMID: 24725740 DOI: 10.1016/j.jns.2014.03.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 02/10/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Myosin-IIB is a non-muscle isoform in the brain with increased expression in the brains of diabetic rats. Chronic hyperglycemia caused by diabetes can impair learning and memory. Oral hypoglycemic agents such as glibenclamide have been used to control hyperglycemia. We report changes in the expression and distribution of myosin-IIB in the frontal cortex and hippocampus of diabetic rats treated with glibenclamide. METHODS The brains were removed after 43 days of treatment with glibenclamide (6 mg/kg bw orally), homogenized and analyzed by Western blotting, qRT-PCR and immunohistochemistry. RESULTS Myosin-IIB expression increased in the brains of diabetic rats. However, protein expression returned to control levels when treated with glibenclamide. In addition, the expression of MYH10 gene encoding non-muscle myosin heavy chain-B decreased in diabetic rats treated with glibenclamide. Moreover, we found weak myosin-IIB labeling in the hippocampus and frontal cortex of rats treated with glibenclamide. Therefore, the expression of myosin-IIB is affected by diabetes mellitus and may be modulated by glibenclamide treatment in rats. Structural changes in the hippocampus and prefrontal cortex are reversible, and glibenclamide treatment may reduce the patho-physiological changes in the brain. CONCLUSIONS Our findings can contribute to the understanding of the regulation of myosins in the brains of diabetic rats.
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Affiliation(s)
- Alice Vieira da Costa
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Campus Umuarama, Uberlândia, MG 38400-902, Brazil
| | - Luciana Karen Calábria
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Campus Umuarama, Uberlândia, MG 38400-902, Brazil; Faculty of Integrated Sciences, Federal University of Uberlândia, Campus Pontal, Ituiutaba, MG 38304-402, Brazil
| | - Paula de Souza Santos
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Campus Umuarama, Uberlândia, MG 38400-902, Brazil
| | - Luiz Ricardo Goulart
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Campus Umuarama, Uberlândia, MG 38400-902, Brazil
| | - Foued Salmen Espindola
- Institute of Genetics and Biochemistry, Federal University of Uberlândia, Campus Umuarama, Uberlândia, MG 38400-902, Brazil.
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Chaudhury A, Cristofaro V, Carew JA, Goyal RK, Sullivan MP. Myosin Va plays a role in nitrergic smooth muscle relaxation in gastric fundus and corpora cavernosa of penis. PLoS One. 2014;9:e86778. [PMID: 24516539 DOI: 10.1371/journal.pone.0086778] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/17/2013] [Indexed: 12/12/2022] Open
Abstract
The intracellular motor protein myosin Va is involved in nitrergic neurotransmission possibly by trafficking of neuronal nitric oxide synthase (nNOS) within the nerve terminals. In this study, we examined the role of myosin Va in the stomach and penis, proto-typical smooth muscle organs in which nitric oxide (NO) mediated relaxation is critical for function. We used confocal microscopy and co-immunoprecipitation of tissue from the gastric fundus (GF) and penile corpus cavernosum (CCP) to localize myosin Va with nNOS and demonstrate their molecular interaction. We utilized in vitro mechanical studies to test whether smooth muscle relaxations during nitrergic neuromuscular neurotransmission is altered in DBA (dilute, brown, non-agouti) mice which lack functional myosin Va. Myosin Va was localized in nNOS-positive nerve terminals and was co-immunoprecipitated with nNOS in both GF and CCP. In comparison to C57BL/6J wild type (WT) mice, electrical field stimulation (EFS) of precontracted smooth muscles of GF and CCP from DBA animals showed significant impairment of nitrergic relaxation. An NO donor, Sodium nitroprusside (SNP), caused comparable levels of relaxation in smooth muscles of WT and DBA mice. These normal postjunctional responses to SNP in DBA tissues suggest that impairment of smooth muscle relaxation resulted from inhibition of NO synthesis in prejunctional nerve terminals. Our results suggest that normal physiological processes of relaxation of gastric and cavernosal smooth muscles that facilitate food accommodation and penile erection, respectively, may be disrupted under conditions of myosin Va deficiency, resulting in complications like gastroparesis and erectile dysfunction.
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Mezghenna K, Leroy J, Azay-Milhau J, Tousch D, Castex F, Gervais S, Delgado-Betancourt V, Gross R, Lajoix AD. Counteracting neuronal nitric oxide synthase proteasomal degradation improves glucose transport in insulin-resistant skeletal muscle from Zucker fa/fa rats. Diabetologia 2014; 57:177-86. [PMID: 24186360 DOI: 10.1007/s00125-013-3084-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 09/30/2013] [Indexed: 12/18/2022]
Abstract
AIMS/HYPOTHESIS Insulin-mediated glucose transport and utilisation are decreased in skeletal muscle from type 2 diabetic and glucose-intolerant individuals because of alterations in insulin receptor signalling, GLUT4 translocation to the plasma membrane and microvascular blood flow. Catalytic activity of the muscle-specific isoform of neuronal nitric oxide synthase (nNOS) also participates in the regulation of glucose transport and appears to be decreased in a relevant animal model of drastic insulin resistance, the obese Zucker fa/fa rat. Our objective was to determine the molecular mechanisms involved in this defect. METHODS Isolated rat muscles and primary cultures of myocytes were used for western blot analysis of protein expression, immunohistochemistry, glucose uptake measurements and GLUT4 translocation assays. RESULTS nNOS expression was reduced in skeletal muscle from fa/fa rats. This was caused by increased ubiquitination of the enzyme and subsequent degradation by the ubiquitin proteasome pathway. The degradation occurred through a greater interaction of nNOS with the chaperone heat-shock protein 70 and the co-chaperone, carboxyl terminus of Hsc70-interacting protein (CHIP). In addition, an alteration in nNOS sarcolemmal localisation was observed. We confirmed the implication of nNOS breakdown in defective insulin-induced glucose transport by demonstrating that blockade of proteasomal degradation or overexpression of nNOS improved basal and/or insulin-stimulated glucose uptake and GLUT4 translocation in primary cultures of insulin-resistant myocytes. CONCLUSIONS/INTERPRETATION Recovery of nNOS in insulin-resistant muscles should be considered a potential new approach to address insulin resistance.
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Affiliation(s)
- Karima Mezghenna
- Centre for Pharmacology and Innovation in Diabetes, University Montpellier 1, EA 7288, 15 Avenue Charles Flahault, BP 14491, 34093, Montpellier cedex 5, France
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Mezghenna K, Pomiès P, Chalançon A, Castex F, Leroy J, Niclauss N, Nadal B, Cambier L, Cazevieille C, Petit P, Gomis R, Berney T, Gross R, Lajoix AD. Increased neuronal nitric oxide synthase dimerisation is involved in rat and human pancreatic beta cell hyperactivity in obesity. Diabetologia 2011; 54:2856-66. [PMID: 21847584 DOI: 10.1007/s00125-011-2264-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 06/22/2011] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Pancreatic beta cell hyperactivity is known to occur in obesity, particularly in insulin-resistant states. Our aim was to investigate whether changes in neuronal nitric oxide synthase (nNOS) function affect beta cell compensation in two relevant models: the Zucker fa/fa rats and pancreatic islets from obese humans. METHODS Glucose-induced insulin response was evaluated in the isolated perfused rat pancreas and in human pancreatic islets from obese individuals. Expression of nNOS (also known as NOS1) and subcellular localisation of nNOS were studied by quantitative RT-PCR, immunoblotting, immunofluorescence and electron microscopy. RESULTS Pancreatic beta cells from Zucker fa/fa rats and obese individuals were found to be hyper-responsive to glucose. Pharmacological blockade of nNOS was unable to modify beta cell response to glucose in fa/fa rats and in islets from obese individuals, suggesting an abnormal control of insulin secretion by the enzyme. In both cases, nNOS activity in islet cell extracts remained unchanged, despite a drastic increase in nNOS protein and an enhancement in the dimer/monomer ratio, pointing to the presence of high amounts of catalytically inactive enzyme. This relative decrease in activity could be mainly related to increases in islet asymmetric dimethyl-arginine content, an endogenous inhibitor of nNOS activity. In addition, mitochondrial nNOS level was decreased, which contrasts with a strongly increased association with insulin granules. CONCLUSIONS/INTERPRETATION Increased nNOS production and dimerisation, together with a relative decrease in catalytic activity and relocalisation, are involved in beta cell hyperactivity in insulin-resistant rats but also in human islets isolated from obese individuals.
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Affiliation(s)
- K Mezghenna
- University Montpellier 1, CNRS FRE 3400, Centre for Pharmacology and Innovation in Diabetes (CPID), Faculté de Pharmacie, 15 avenue Charles Flahault, BP 14491, 34093 Montpellier Cedex 5, France
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Chaudhury A, He XD, Goyal RK. Myosin Va plays a key role in nitrergic neurotransmission by transporting nNOSα to enteric varicosity membrane. Am J Physiol Gastrointest Liver Physiol 2011; 301:G498-507. [PMID: 21680773 PMCID: PMC3174543 DOI: 10.1152/ajpgi.00164.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nitrergic neurotransmission at the smooth muscle neuromuscular junctions requires nitric oxide (NO) release that is dependent on the transport and docking of neuronal NO synthase (nNOS) α to the membrane of nerve terminals. However, the mechanism of translocation of nNOSα in actin-rich varicosities is unknown. We report here that the processive motor protein myosin Va is necessary for nitrergic neurotransmission. In wild-type mice, nNOSα-stained enteric varicosities colocalized with myosin Va and its tail constituent light chain 8 (LC8). In situ proximity ligation assay showed close association among nNOSα, myosin Va, and LC8. nNOSα was associated with varicosity membrane. Varicosities showed nitric oxide production upon stimulation with KCl. Intracellular microelectrode studies showed nitrergic IJP and smooth muscle hyperpolarizing responses to NO donor diethylenetriamine-NO (DNO). In contrast, enteric varicosities from myosin Va-deficient DBA (for dilute, brown, non-agouti) mice showed near absence of myosin Va but normal nNOSα and LC8. Membrane-bound nNOSα was not detectable, and the varicosities showed reduced NO production. Intracellular recordings in DBA mice showed reduced nitrergic IJPs but normal hyperpolarizing response to DNO. The nitrergic slow IJP was 9.1 ± 0.7 mV in the wild-type controls and 3.4 ± 0.3 mV in the DBA mice (P < 0.0001). Deficiency of myosin Va resulted in loss of nitrergic neuromuscular neurotransmission despite normal presence of nNOSα in the varicosities. These studies reveal the critical importance of myosin Va in nitrergic neurotransmission by facilitating transport of nNOSα to the varicosity membrane.
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Affiliation(s)
- Arun Chaudhury
- Center for Swallowing & Motility Disorders, VA Boston HealthCare System and Harvard Medical School, Boston, Massachusetts
| | - Xue-Dao He
- Center for Swallowing & Motility Disorders, VA Boston HealthCare System and Harvard Medical School, Boston, Massachusetts
| | - Raj K. Goyal
- Center for Swallowing & Motility Disorders, VA Boston HealthCare System and Harvard Medical School, Boston, Massachusetts
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Balibrea JM, García-Martín MC, Cuesta-Sancho S, Olmedilla Y, Arias-Díaz J, Fernández-Sevilla E, Vara E, Balibrea JL. Tacrolimus modulates liver and pancreas nitric oxide synthetase and heme-oxygenase isoforms and cytokine production after endotoxemia. Nitric Oxide 2011; 24:113-22. [PMID: 21255669 DOI: 10.1016/j.niox.2011.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 12/08/2010] [Accepted: 01/10/2011] [Indexed: 12/16/2022]
Abstract
Cytoprotective effects of tacrolimus are due to its unspecific anti-inflammatory and anti-oxidant properties. Neither the exact mechanisms nor if there is any organ-specificity or dose-dependent response have not been yet elucidated. Our aim was to evaluate the effect of tacrolimus on oxidative stress and mediator production in liver and pancreatic tissue secondary to endotoxemia. Wistar rats were pretreated with intraperitoneal injection of tacrolimus (0.07, 0.15, and 0.3mg/kg) 24h before Escherichia coli LPS was administrated. Animals were sacrificed 24h after LPS administration and iNOS, eNOS, and nNOS and type 1 and 2 heme-oxygenase (HO) expression were measured. TNF-α and IL-1 tissue expression and plasmatic NO, CO, TNF-α, and IL-1 were also determined. LPS exposure increased iNOS expression in both organs, eNOS did not show variations and liver nNOS expression was significantly lower. Tacrolimus diminished both pancreas and liver iNOS and nNOS expression. Both liver and pancreatic eNOS expression augmented when tacrolimus was administrated. High doses of tacrolimus were correlated with ameliorated liver HO-1 plus HO-2 and pancreas HO-1 expression after LPS stimulation. Tacrolimus treatment diminished TNF-α but not IL-1 expression increase after LPS challenge in hepatic tissue. Pancreatic TNF-α and IL-1 values diminished partially when high doses were employed. Plasmatic NO, CO, TNF-α, and IL-1 concentrations increase after LPS challenge was diminished when highest doses of tacrolimus were given. In conclusion, tacrolimus exerts a protective effect on commonly observed harmful phenomena after LPS stimulation by modulating liver and pancreas oxidative enzyme expression and cytokine production.
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Affiliation(s)
- José M Balibrea
- Department of Surgery, Germans Trias i Pujol Hospital, Universitat Autònoma, Ctra Del Canyet s/n, 08916 Badalona, Barcelona, Spain.
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Huang D, Zhou X, Lyon CJ, Hsueh WA, Wong STC. MicroRNA-integrated and network-embedded gene selection with diffusion distance. PLoS One 2010; 5:e13748. [PMID: 21060785 PMCID: PMC2966417 DOI: 10.1371/journal.pone.0013748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Accepted: 05/17/2010] [Indexed: 11/19/2022] Open
Abstract
Gene network information has been used to improve gene selection in microarray-based studies by selecting marker genes based both on their expression and the coordinate expression of genes within their gene network under a given condition. Here we propose a new network-embedded gene selection model. In this model, we first address the limitations of microarray data. Microarray data, although widely used for gene selection, measures only mRNA abundance, which does not always reflect the ultimate gene phenotype, since it does not account for post-transcriptional effects. To overcome this important (critical in certain cases) but ignored-in-almost-all-existing-studies limitation, we design a new strategy to integrate together microarray data with the information of microRNA, the major post-transcriptional regulatory factor. We also handle the challenges led by gene collaboration mechanism. To incorporate the biological facts that genes without direct interactions may work closely due to signal transduction and that two genes may be functionally connected through multi paths, we adopt the concept of diffusion distance. This concept permits us to simulate biological signal propagation and therefore to estimate the collaboration probability for all gene pairs, directly or indirectly-connected, according to multi paths connecting them. We demonstrate, using type 2 diabetes (DM2) as an example, that the proposed strategies can enhance the identification of functional gene partners, which is the key issue in a network-embedded gene selection model. More importantly, we show that our gene selection model outperforms related ones. Genes selected by our model 1) have improved classification capability; 2) agree with biological evidence of DM2-association; and 3) are involved in many well-known DM2-associated pathways.
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Affiliation(s)
- Di Huang
- Bioinformatics Core, The Methodist Hospital Research Institute, Weill Medical College, Cornell University, Houston, Texas, United States of America
| | - Xiaobo Zhou
- Bioinformatics Core, The Methodist Hospital Research Institute, Weill Medical College, Cornell University, Houston, Texas, United States of America
| | - Christopher J. Lyon
- Diabetes Research Center, The Methodist Hospital Research Institute, Weill Medical College, Cornell University, Houston, Texas, United States of America
| | - Willa A. Hsueh
- Diabetes Research Center, The Methodist Hospital Research Institute, Weill Medical College, Cornell University, Houston, Texas, United States of America
| | - Stephen T. C. Wong
- Bioinformatics Core, The Methodist Hospital Research Institute, Weill Medical College, Cornell University, Houston, Texas, United States of America
- * E-mail:
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Abstract
Nitric oxide (NO) and NO synthases (NOSs) are crucial factors in many pathophysiological processes such as inflammation, vascular/neurological function, and many types of cancer. Noninvasive imaging of NO or NOS can provide new insights in understanding these diseases and facilitate the development of novel therapeutic strategies. In this review, we will summarize the current state-of-the-art multimodality imaging in detecting NO and NOSs, including optical (fluorescence, chemiluminescence, and bioluminescence), electron paramagnetic resonance (EPR), magnetic resonance (MR), and positron emission tomography (PET). With continued effort over the last several years, these noninvasive imaging techniques can now reveal the biodistribution of NO or NOS in living subjects with high fidelity which will greatly facilitate scientists/clinicians in the development of new drugs and/or patient management. Lastly, we will also discuss future directions/applications of NO/NOS imaging. Successful development of novel NO/NOS imaging agents with optimal in vivo stability and desirable pharmacokinetics for clinical translation will enable the maximum benefit in patient management.
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Affiliation(s)
- Hao Hong
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705-2275, USA
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