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Salama RM, Ahmed RH, Farid AA, AbdElSattar BA, AbdelBaset RM, Youssef ME, El Wakeel SA. Gastroprotective effect of dapagliflozin in ethanol-induced gastric lesions in rats: Crosstalk between HMGB1/RAGE/PTX3 and TLR4/MyD88/VEGF/PDGF signaling pathways. Int Immunopharmacol 2023; 115:109686. [PMID: 36623411 DOI: 10.1016/j.intimp.2023.109686] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 12/29/2022] [Accepted: 12/31/2022] [Indexed: 01/09/2023]
Abstract
Alcohol abuse may lead to the development of gastric mucosal lesions. Dapagliflozin (DAPA), a sodium-glucose cotransporter-2 inhibitor, is clinically used to treat type 2 diabetes mellitus. However, studies showed protective effect of DAPA under various experimental conditions by alleviating oxidative stress and inflammation. The effect of DAPA on experimental gastric ulcer has not been studied yet. Therefore, we attempted to investigate DAPA's protective effect against ethanol (EtOH)-induced gastric lesions. Fifty-six (8-week-old) male Wistar rats were divided into seven groups. DAPA (1, 5, and 10 mg/kg/day; p.o.) was given for seven days, plus a single dose of absolute EtOH (5 ml/kg) on day 8. According to hematoxylin and eosin, and Alcian blue staining of gastric tissue sections, titratable acidity, and macroscopic assessments, DAPA high dose (10 mg/kg) was the most protective, with lesser ulcerations, and higher mucin, relative to the lower two doses and the standard treatment omeprazole (OME). In rats pre-treated with DAPA high dose, colorimetric and ELISA analyses revealed significantly decreased oxidative stress, pro-inflammatory, and apoptosis indices and increased levels of platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). Western blot analysis revealed reduced pentraxin-3 (PTX3), high-mobility group box 1 (HMGB1), receptor for advanced glycation end products (RAGE), toll-like receptor 4 (TLR4), and myeloid differentiation factor 88 (MyD88) expression. These results were comparable in DAPA (10 mg/kg) and OME pre-treated groups. Overall, DAPA exerted a dose-dependent protective effect against EtOH-induced gastric injury. Gastroprotective effects of DAPA (10 mg/kg) may be associated with influencing HMGB1/RAGE/PTX3 and TLR4/MyD88/VEGF/PDGF pathways.
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Affiliation(s)
- Rania M Salama
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
| | - Rodaina H Ahmed
- Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
| | - Alaa A Farid
- Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
| | | | | | - Merna E Youssef
- Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
| | - Sara A El Wakeel
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt.
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2
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Kotlyarov S. Immune and metabolic cross-links in the pathogenesis of comorbid non-alcoholic fatty liver disease. World J Gastroenterol 2023; 29:597-615. [PMID: 36742172 PMCID: PMC9896611 DOI: 10.3748/wjg.v29.i4.597] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/28/2022] [Accepted: 11/10/2022] [Indexed: 01/20/2023] Open
Abstract
In recent years, there has been a steady growth of interest in non-alcoholic fatty liver disease (NAFLD), which is associated with negative epidemiological data on the prevalence of the disease and its clinical significance. NAFLD is closely related to the metabolic syndrome and these relationships are the subject of active research. A growing body of evidence shows cross-linkages between metabolic abnormalities and the innate immune system in the development and progression of NAFLD. These links are bidirectional and largely still unclear, but a better understanding of them will improve the quality of diagnosis and management of patients. In addition, lipid metabolic disorders and the innate immune system link NAFLD with other diseases, such as atherosclerosis, which is of great clinical importance.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, Ryazan 390026, Russia
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3
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Kotlyarov S, Kotlyarova A. Involvement of Fatty Acids and Their Metabolites in the Development of Inflammation in Atherosclerosis. Int J Mol Sci 2022; 23:ijms23031308. [PMID: 35163232 PMCID: PMC8835729 DOI: 10.3390/ijms23031308] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/14/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
Despite all the advances of modern medicine, atherosclerosis continues to be one of the most important medical and social problems. Atherosclerosis is the cause of several cardiovascular diseases, which are associated with high rates of disability and mortality. The development of atherosclerosis is associated with the accumulation of lipids in the arterial intima and the disruption of mechanisms that maintain the balance between the development and resolution of inflammation. Fatty acids are involved in many mechanisms of inflammation development and maintenance. Endothelial cells demonstrate multiple cross-linkages between lipid metabolism and innate immunity. In addition, these processes are linked to hemodynamics and the function of other cells in the vascular wall, highlighting the central role of the endothelium in vascular biology.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
- Correspondence:
| | - Anna Kotlyarova
- Department of Pharmacology and Pharmacy, Ryazan State Medical University, 390026 Ryazan, Russia;
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4
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Lourenço CF, Laranjinha J. Nitric Oxide Pathways in Neurovascular Coupling Under Normal and Stress Conditions in the Brain: Strategies to Rescue Aberrant Coupling and Improve Cerebral Blood Flow. Front Physiol 2021; 12:729201. [PMID: 34744769 PMCID: PMC8569710 DOI: 10.3389/fphys.2021.729201] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/20/2021] [Indexed: 01/04/2023] Open
Abstract
The brain has impressive energy requirements and paradoxically, very limited energy reserves, implying its huge dependency on continuous blood supply. Aditionally, cerebral blood flow must be dynamically regulated to the areas of increased neuronal activity and thus, of increased metabolic demands. The coupling between neuronal activity and cerebral blood flow (CBF) is supported by a mechanism called neurovascular coupling (NVC). Among the several vasoactive molecules released by glutamatergic activation, nitric oxide (•NO) is recognized to be a key player in the process and essential for the development of the neurovascular response. Classically, •NO is produced in neurons upon the activation of the glutamatergic N-methyl-D-aspartate (NMDA) receptor by the neuronal isoform of nitric oxide synthase and promotes vasodilation by activating soluble guanylate cyclase in the smooth muscle cells of the adjacent arterioles. This pathway is part of a more complex network in which other molecular and cellular intervenients, as well as other sources of •NO, are involved. The elucidation of these interacting mechanisms is fundamental in understanding how the brain manages its energy requirements and how the failure of this process translates into neuronal dysfunction. Here, we aimed to provide an integrated and updated perspective of the role of •NO in the NVC, incorporating the most recent evidence that reinforces its central role in the process from both viewpoints, as a physiological mediator and a pathological stressor. First, we described the glutamate-NMDA receptor-nNOS axis as a central pathway in NVC, then we reviewed the link between the derailment of the NVC and neuronal dysfunction associated with neurodegeneration (with a focus on Alzheimer's disease). We further discussed the role of oxidative stress in the NVC dysfunction, specifically by decreasing the •NO bioavailability and diverting its bioactivity toward cytotoxicity. Finally, we highlighted some strategies targeting the rescue or maintenance of •NO bioavailability that could be explored to mitigate the NVC dysfunction associated with neurodegenerative conditions. In line with this, the potential modulatory effects of dietary nitrate and polyphenols on •NO-dependent NVC, in association with physical exercise, may be used as effective non-pharmacological strategies to promote the •NO bioavailability and to manage NVC dysfunction in neuropathological conditions.
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Affiliation(s)
- Cátia F Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
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5
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Tanaka K, Adachi H, Akasaka H, Tamaoki J, Fuse Y, Kobayashi M, Kitazawa T, Teraoka H. Oxidative stress inducers potentiate 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated pre-cardiac edema in larval zebrafish. J Vet Med Sci 2021; 83:1050-1058. [PMID: 34024870 PMCID: PMC8349820 DOI: 10.1292/jvms.21-0081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We reported the involvement of oxidative stress and prostaglandins including thromboxane and prostacyclin in pre-cardiac edema (early edema) caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While the involvement of oxidative stress in TCDD-induced toxicity has been frequently reported, the mechanism of its action is still unclear. In the present study, oxidative stress inducers including paraquat, hydrogen peroxide (H2O2) and rotenone augmented early edema (edema) induced by a low concentration of TCDD (0.1 ppb) at 55 hr post fertilization (hpf), while each of them alone did not cause edema. Edema caused by TCDD plus oxidative stress inducers was almost abolished by antioxidants, an antagonist for thromboxane receptor (ICI-192,605) and an agonist for prostacyclin receptor (beraprost), suggesting that the site of action of these inducers was in the regular signaling pathway after activation of aryl hydrocarbon receptor type 2 (AHR2) by TCDD. Oxidative stress inducers also enhanced edema caused by an agonist for the thromboxane receptor (U46619), and the enhancement was also inhibited by antioxidants. Sulforaphane and auranofin, activators of Nrf2 that is a master regulator of anti-oxidative response, did not affect U46619-evoked edema but almost abolished TCDD-induced edema and potentiation by paraquat in both TCDD- and U46619-induced edema. Taken together, the results suggest that oxidative stress augments pre-cardiac edema caused by TCDD via activation of thromboxane receptor-mediated signaling in developing zebrafish. As paraquat and other oxidative stress inducers used also are environmental pollutants, interaction between dioxin-like compounds and exogenous source of oxidative stress should also be considered.
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Affiliation(s)
- Katsuki Tanaka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Hikaru Adachi
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Hironobu Akasaka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Junya Tamaoki
- Department of Molecular and Developmental Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuji Fuse
- Department of Molecular and Developmental Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Makoto Kobayashi
- Department of Molecular and Developmental Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Takio Kitazawa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| | - Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
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6
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Eligini S, Colli S, Habib A, Aldini G, Altomare A, Banfi C. Cyclooxygenase-2 Glycosylation Is Affected by Peroxynitrite in Endothelial Cells: Impact on Enzyme Activity and Degradation. Antioxidants (Basel) 2021; 10:496. [PMID: 33806920 PMCID: PMC8005028 DOI: 10.3390/antiox10030496] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 12/12/2022] Open
Abstract
The exposure of human endothelial cells to 3-morpholinosydnonimine (SIN-1) induced the expression of cyclooxygenase-2 (COX-2) in a dose- and time-dependent manner. Interestingly, after a prolonged incubation (>8 h) several proteoforms were visualized by Western blot, corresponding to different states of glycosylation of the protein. This effect was specific for SIN-1 that generates peroxynitrite and it was not detected with other nitric oxide-donors. Metabolic labeling experiments using 35S or cycloheximide suggested that the formation of hypoglycosylated COX-2 was dependent on de novo synthesis of the protein rather than the deglycosylation of the native protein. Moreover, SIN-1 reduced the activity of the hexokinase, the enzyme responsible for the first step of glycolysis. The hypoglycosylated COX-2 induced by SIN-1 showed a reduced capacity to generate prostaglandins and the activity was only partially recovered after immunoprecipitation. Finally, hypoglycosylated COX-2 showed a more rapid rate of degradation compared to COX-2 induced by IL-1α and an alteration in the localization with an accumulation mainly detected in the nuclear membrane. Our results have important implication to understand the effect of peroxynitrite on COX-2 expression and activity, and they may help to identify new pharmacological tools direct to increase COX-2 degradation or to inhibit its activity.
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Affiliation(s)
- Sonia Eligini
- Centro Cardiologico Monzino I.R.C.C.S., 20138 Milan, Italy;
| | - Susanna Colli
- Dipartimento di Scienze Farmacologiche, Università degli Studi di Milano, 20133 Milan, Italy;
| | - Aida Habib
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut 1107 2020, Lebanon;
- INSERM-UMR1149, Centre de Recherche sur l’Inflammation, and Sorbonne Paris Cité, Laboratoire d’Excellence Inflamex, Faculté de Médecine, Site Xavier Bichat, Université de Paris, 75018 Paris, France
| | - Giancarlo Aldini
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, 20133 Milano, Italy; (G.A.); (A.A.)
| | - Alessandra Altomare
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, 20133 Milano, Italy; (G.A.); (A.A.)
| | - Cristina Banfi
- Centro Cardiologico Monzino I.R.C.C.S., 20138 Milan, Italy;
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7
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Laranjinha J, Nunes C, Ledo A, Lourenço C, Rocha B, Barbosa RM. The Peculiar Facets of Nitric Oxide as a Cellular Messenger: From Disease-Associated Signaling to the Regulation of Brain Bioenergetics and Neurovascular Coupling. Neurochem Res 2020; 46:64-76. [PMID: 32193753 DOI: 10.1007/s11064-020-03015-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 03/07/2020] [Accepted: 03/12/2020] [Indexed: 12/13/2022]
Abstract
In this review, we address the regulatory and toxic role of ·NO along several pathways, from the gut to the brain. Initially, we address the role on ·NO in the regulation of mitochondrial respiration with emphasis on the possible contribution to Parkinson's disease via mechanisms that involve its interaction with a major dopamine metabolite, DOPAC. In parallel with initial discoveries of the inhibition of mitochondrial respiration by ·NO, it became clear the potential for toxic ·NO-mediated mechanisms involving the production of more reactive species and the post-translational modification of mitochondrial proteins. Accordingly, we have proposed a novel mechanism potentially leading to dopaminergic cell death, providing evidence that NO synergistically interact with DOPAC in promoting cell death via mechanisms that involve GSH depletion. The modulatory role of NO will be then briefly discussed as a master regulator on brain energy metabolism. The energy metabolism in the brain is central to the understanding of brain function and disease. The core role of ·NO in the regulation of brain metabolism and vascular responses is further substantiated by discussing its role as a mediator of neurovascular coupling, the increase in local microvessels blood flow in response to spatially restricted increase of neuronal activity. The many facets of NO as intracellular and intercellular messenger, conveying information associated with its spatial and temporal concentration dynamics, involve not only the discussion of its reactions and potential targets on a defined biological environment but also the regulation of its synthesis by the family of nitric oxide synthases. More recently, a novel pathway, out of control of NOS, has been the subject of a great deal of controversy, the nitrate:nitrite:NO pathway, adding new perspectives to ·NO biology. Thus, finally, this novel pathway will be addressed in connection with nitrate consumption in the diet and the beneficial effects of protein nitration by reactive nitrogen species.
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Affiliation(s)
- João Laranjinha
- Faculty of Pharmacy, University of Coimbra, Azinhaga Sta. Comba, 3000-548, Coimbra, Portugal. .,Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal.
| | - Carla Nunes
- Faculty of Pharmacy, University of Coimbra, Azinhaga Sta. Comba, 3000-548, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal
| | - Ana Ledo
- Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal
| | - Cátia Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal
| | - Bárbara Rocha
- Faculty of Pharmacy, University of Coimbra, Azinhaga Sta. Comba, 3000-548, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal
| | - Rui M Barbosa
- Faculty of Pharmacy, University of Coimbra, Azinhaga Sta. Comba, 3000-548, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Pólo 1, 3000-504, Coimbra, Portugal
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8
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Azlina MFN, Qodriyah HMS, Akmal MN, Ibrahim IAA, Kamisah Y. In vivo effect of Piper sarmentosum methanolic extract on stress-induced gastric ulcers in rats. Arch Med Sci 2019; 15:223-231. [PMID: 30697274 PMCID: PMC6348366 DOI: 10.5114/aoms.2016.63156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/12/2016] [Indexed: 01/22/2023] Open
Abstract
INTRODUCTION Piper sarmentosum (Piperaceae) is traditionally used by Asians to treat numerous common ailments including asthma, fever and gastritis. The aim of the research was to determine and compare the effects of Piper sarmentosum (PS) with omeprazole (OMZ) on gastric parameters in rats exposed to restraint stress. MATERIAL AND METHODS The methanolic extract of PS was prepared in the dose of 500 mg/kg. Twenty-eight male Wistar rats were assigned to 4 equal sized groups: two control groups and two treated groups which were supplemented with either PS or OMZ orally at a dose of 500 mg/kg and 20 mg/kg body weight respectively. After 28 days of treatment, one control group, the PS and OMZ group were subjected to a single exposure of water-immersion restraint stress for 3.5 h. After the last exposure to stress, the stomach was excised for evaluation of the parameters. RESULTS Oral supplementation of PS was as effective in preventing the formation of gastric lesion when compared with OMZ (p < 0.05). The increased gastric acidity and MDA due to stress was also reduced with supplementation of PS and OMZ. Only PS had the ability to reduce prostaglandin E2 loss (p = 0.0067) and have the ability to down regulate cyclooxygenase-2 (COX-2) mRNA expression (p = 0.01) with stress exposure. CONCLUSIONS Piper sarmentosum possesses a similar protective effect against stress-induced gastric lesions as omeprazole. The protective effect was associated with decreased lipid peroxidation, increased prostaglandin E2, reduction in gastric acidity and reduction in COX-2 mRNA expression which was altered by stress.
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Affiliation(s)
- Mohd Fahami Nur Azlina
- Department of Pharmacology, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia
| | - Hj Mohd Saad Qodriyah
- Department of Pharmacology, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia
| | - Muhamad Nurul Akmal
- Department of Pharmacology, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia
| | | | - Yusof Kamisah
- Department of Pharmacology, Faculty of Medicine, National University of Malaysia, Kuala Lumpur, Malaysia
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9
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Lourenço CF, Ledo A, Barbosa RM, Laranjinha J. Neurovascular-neuroenergetic coupling axis in the brain: master regulation by nitric oxide and consequences in aging and neurodegeneration. Free Radic Biol Med 2017; 108:668-682. [PMID: 28435052 DOI: 10.1016/j.freeradbiomed.2017.04.026] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 02/21/2017] [Accepted: 04/18/2017] [Indexed: 02/08/2023]
Abstract
The strict energetic demands of the brain require that nutrient supply and usage be fine-tuned in accordance with the specific temporal and spatial patterns of ever-changing levels of neuronal activity. This is achieved by adjusting local cerebral blood flow (CBF) as a function of activity level - neurovascular coupling - and by changing how energy substrates are metabolized and shuttled amongst astrocytes and neurons - neuroenergetic coupling. Both activity-dependent increase of CBF and O2 and glucose utilization by active neural cells are inextricably linked, establishing a functional metabolic axis in the brain, the neurovascular-neuroenergetic coupling axis. This axis incorporates and links previously independent processes that need to be coordinated in the normal brain. We here review evidence supporting the role of neuronal-derived nitric oxide (•NO) as the master regulator of this axis. Nitric oxide is produced in tight association with glutamatergic activation and, diffusing several cell diameters, may interact with different molecular targets within each cell type. Hemeproteins such as soluble guanylate cyclase, cytochrome c oxidase and hemoglobin, with which •NO reacts at relatively fast rates, are but a few of the key in determinants of the regulatory role of •NO in the neurovascular-neuroenergetic coupling axis. Accordingly, critical literature supporting this concept is discussed. Moreover, in view of the controversy regarding the regulation of catabolism of different neural cells, we further discuss key aspects of the pathways through which •NO specifically up-regulates glycolysis in astrocytes, supporting lactate shuttling to neurons for oxidative breakdown. From a biomedical viewpoint, derailment of neurovascular-neuroenergetic axis is precociously linked to aberrant brain aging, cognitive impairment and neurodegeneration. Thus, we summarize current knowledge of how both neurovascular and neuroenergetic coupling are compromised in aging, traumatic brain injury, epilepsy and age-associated neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease, suggesting that a shift in cellular redox balance may contribute to divert •NO bioactivity from regulation to dysfunction.
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Affiliation(s)
- Cátia F Lourenço
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
| | - Ana Ledo
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
| | - Rui M Barbosa
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - João Laranjinha
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.
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10
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Choi YJ, Kim N, Lee JY, Nam RH, Seo JH, Lee S, Kim HJ, Choi YJ, Lee HS, Lee DH. Gastroprotective Effects of PMK-S005 against Ethanol-Induced Acute Gastric Damage in Rats. Gut Liver 2017; 10:348-55. [PMID: 26347516 PMCID: PMC4849686 DOI: 10.5009/gnl14509] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background/Aims This study aimed to examine the gastroprotective effects of PMK-S005, which is a synthetic S-allyl-l-cysteine (SAC; a sulfur-containing amino acid), against acute ethanol-induced gastric damage in rats. Methods Sprague-Dawley rats were divided into six groups, including a nonethanol group, groups treated with absolute ethanol 1 hour after pretreatment with various doses of PMK-S005 (1, 5, and 10 mg/kg) or rebamipide (50 mg/kg), and an absolute ethanol-only group. Ethanol-induced gross ulcer and mucus levels were measured. Myeloperoxidase, tumor necrosis factor α, interleukin 1β, PGE2, LTB4, cPLA2, COX-1, and COX-2 levels were estimated by enzyme-linked immunosorbent assay or Western blot analysis. Furthermore, the protein expression levels of antioxidant enzymes, including heme oxygenase-1 (HO-1), NAD(P)H:quinine oxidoreductase 1 (NQO-1), GCLC, and GCLM, were assessed. Results PMK-S005 significantly attenuated the ethanol-induced gastric damage; it reduced mucosal inflammatory cytokine production and increased mucus levels. The expression levels of cPLA2, COX-1, and COX-2 were decreased by PMK-S005. PMK-S005 did not affect PGE2 synthesis, but LTB4 production was significantly suppressed. In addition, long-term administration of PMK-S005 significantly increased the expression of HO-1, NQO-1, GCLC, and GCLM. Conclusions These results strongly suggest that PMK-S005 prevents gastric mucosal damage and that these gastroprotective activities are due to anti-inflammatory effects and enhancement of the gastric defense system, including antioxidant enzymes.
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Affiliation(s)
- Yoon Jeong Choi
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Nayoung Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Ju Yup Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Ryoung Hee Nam
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Ji Hyung Seo
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Seonmin Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hee Jin Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Yoon Jin Choi
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Hye Seung Lee
- Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Dong Ho Lee
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.,Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea
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11
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Song JW, Seo CS, Kim TI, Moon OS, Won YS, Son HY, Son JK, Kwon HJ. Protective Effects of Manassantin A against Ethanol-Induced Gastric Injury in Rats. Biol Pharm Bull 2015; 39:221-9. [PMID: 26632199 DOI: 10.1248/bpb.b15-00642] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Manassantin A, a neolignan isolated from Saururus chinensis, is a major phytochemical compound that has various biological activities, including anti-inflammatory, neuroleptic, and human acyl-CoA : cholesterol acyltransferase (ACAT) inhibitory activities. In this study, we investigated the protective effects of manassantin A against ethanol-induced acute gastric injury in rats. Gastric injury was induced by intragastric administration of 5 mL/kg body weight of absolute ethanol to each rat. The positive control group and the manassantin A group were given oral doses of omeprazole (20 mg/kg) or manassantin A (15 mg/kg), respectively, 1 h prior to the administration of absolute ethanol. Our examinations revealed that manassantin A pretreatment reduced ethanol-induced hemorrhage, hyperemia, and epithelial cell loss in the gastric mucosa. Manassantin A pretreatment also attenuated the increased lipid peroxidation associated with ethanol-induced acute gastric lesions, increased the mucosal glutathione (GSH) content, and enhanced the activities of antioxidant enzymes. The levels of pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β were clearly decreased in the manassantin A-pretreated group. In addition, manassantin A pretreatment enhanced the levels of cyclooxygenase (COX)-1, COX-2, and prostaglandin E2 (PGE2) and reduced the inducible nitric oxide synthase (iNOS) overproduction and nuclear factor kappa B (NF-κB) phosphorylation. Collectively, these results indicate that manassantin A protects the gastric mucosa from ethanol-induced acute gastric injury, and suggest that these protective effects might be associated with COX/PGE2 stimulation, inhibition of iNOS production and NF-κB activation, and improvements in the antioxidant and anti-inflammatory status.
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Affiliation(s)
- Ji-Won Song
- Department of Veterinary Pathology, College of Veterinary Medicine, Chungnam National University
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12
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Yu C, Mei XT, Zheng YP, Xu DH. Gastroprotective effect of taurine zinc solid dispersions against absolute ethanol-induced gastric lesions is mediated by enhancement of antioxidant activity and endogenous PGE2 production and attenuation of NO production. Eur J Pharmacol 2014; 740:329-36. [PMID: 25041839 DOI: 10.1016/j.ejphar.2014.07.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 07/04/2014] [Accepted: 07/09/2014] [Indexed: 12/18/2022]
Abstract
Zinc plays a key role in maintaining gastric mucosal integrity, while alcohol dependency can lead to low zinc status. Complexes containing zinc have been reported to have better ability to protect gastric mucosa than the compounds alone. In this study, taurine zinc [Zn(NH3CH2CH2SO3)2] solid dispersions (SDs) were synthesized and investigated in an ethanol-induced ulcer model in rats. Gastric ulcer index; gastric mucosa malondialdehyde (MDA) level, glutathione (GSH) content, superoxide dismutase (SOD) activity and prostaglandin E2 (PGE2) production; and serum nitric oxide (NO) were assessed and histological analysis of the gastric mucosa tissue was performed. Taurine zinc (100, 200 mg/kg) SDs protected rat gastric mucosa from ethanol-induced injury. Moreover, the gastroprotective effect of taurine zinc SDs was accompanied by a decrease in serum NO and significant increase in gastric prostaglandin E2 (PGE2). When indomethacin, a non-selective COX inhibitor was administered before the last dose of taurine zinc, the gastroprotective effect of taurine zinc was weakened. Furthermore, taurine zinc (200 mg/kg) SDs protected against ulceration more significantly than the same dose of taurine alone, suggesting a synergistic effect between taurine and zinc. These results indicate taurine zinc protects the gastric mucosa against ethanol-induced damage by elevating antioxidants, decreasing lipid peroxidation and inhibiting the production of nitric oxide. The gastroprotective effect of taurine zinc was also partially mediated by endogenous PGE2 production.
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Affiliation(s)
- Chuan Yu
- Lab of Traditional Chinese Medicine and Marine Drugs, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, China
| | - Xue-Ting Mei
- Lab of Traditional Chinese Medicine and Marine Drugs, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, China
| | - Yan-Ping Zheng
- Lab of Traditional Chinese Medicine and Marine Drugs, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, China
| | - Dong-Hui Xu
- Lab of Traditional Chinese Medicine and Marine Drugs, Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong Province, China.
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13
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Stobart JL, Anderson CM. Multifunctional role of astrocytes as gatekeepers of neuronal energy supply. Front Cell Neurosci 2013; 7:38. [PMID: 23596393 PMCID: PMC3622037 DOI: 10.3389/fncel.2013.00038] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 03/26/2013] [Indexed: 01/01/2023] Open
Abstract
Dynamic adjustments to neuronal energy supply in response to synaptic activity are critical for neuronal function. Glial cells known as astrocytes have processes that ensheath most central synapses and express G-protein-coupled neurotransmitter receptors and transporters that respond to neuronal activity. Astrocytes also release substrates for neuronal oxidative phosphorylation and have processes that terminate on the surface of brain arterioles and can influence vascular smooth muscle tone and local blood flow. Membrane receptor or transporter-mediated effects of glutamate represent a convergence point of astrocyte influence on neuronal bioenergetics. Astrocytic glutamate uptake drives glycolysis and subsequent shuttling of lactate from astrocytes to neurons for oxidative metabolism. Astrocytes also convert synaptically reclaimed glutamate to glutamine, which is returned to neurons for glutamate salvage or oxidation. Finally, astrocytes store brain energy currency in the form of glycogen, which can be mobilized to produce lactate for neuronal oxidative phosphorylation in response to glutamatergic neurotransmission. These mechanisms couple synaptically driven astrocytic responses to glutamate with release of energy substrates back to neurons to match demand with supply. In addition, astrocytes directly influence the tone of penetrating brain arterioles in response to glutamatergic neurotransmission, coordinating dynamic regulation of local blood flow. We will describe the role of astrocytes in neurometabolic and neurovascular coupling in detail and discuss, in turn, how astrocyte dysfunction may contribute to neuronal bioenergetic deficit and neurodegeneration. Understanding the role of astrocytes as a hub for neurometabolic and neurovascular coupling mechanisms is a critical underpinning for therapeutic development in a broad range of neurodegenerative disorders characterized by chronic generalized brain ischemia and brain microvascular dysfunction.
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Affiliation(s)
- Jillian L Stobart
- Division of Neurodegenerative Disorders, Department of Pharmacology and Therapeutics, St. Boniface Hospital Research, University of Manitoba Winnipeg, MB, Canada ; Department of Nuclear Medicine, Institute of Pharmacology and Toxicology, University of Zürich Zürich, Switzerland
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14
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Contestabile A, Monti B, Polazzi E. Neuronal-glial Interactions Define the Role of Nitric Oxide in Neural Functional Processes. Curr Neuropharmacol 2012; 10:303-10. [PMID: 23730254 PMCID: PMC3520040 DOI: 10.2174/157015912804143522] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/07/2012] [Accepted: 06/24/2012] [Indexed: 01/01/2023] Open
Abstract
Nitric oxide (NO) is a versatile cellular messenger performing a variety of physiologic and pathologic actions in most tissues. It is particularly important in the nervous system, where it is involved in multiple functions, as well as in neuropathology, when produced in excess. Several of these functions are based on interactions between NO produced by neurons and NO produced by glial cells, mainly astrocytes and microglia. The present paper briefly reviews some of these interactions, in particular those involved in metabolic regulation, control of cerebral blood flow, axonogenesis, synaptic function and neurogenesis. Aim of the paper is mainly to underline the physiologic aspects of these interactions rather than the pathologic ones.
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Duchemin S, Boily M, Sadekova N, Girouard H. The complex contribution of NOS interneurons in the physiology of cerebrovascular regulation. Front Neural Circuits 2012; 6:51. [PMID: 22907993 PMCID: PMC3414732 DOI: 10.3389/fncir.2012.00051] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 07/19/2012] [Indexed: 12/23/2022] Open
Abstract
Following the discovery of the vasorelaxant properties of nitric oxide (NO) by Furchgott and Ignarro, the finding by Bredt and coll. of a constitutively expressed NO synthase in neurons (nNOS) led to the presumption that neuronal NO may control cerebrovascular functions. Consequently, numerous studies have sought to determine whether neuraly-derived NO is involved in the regulation of cerebral blood flow (CBF). Anatomically, axons, dendrites, or somata of NO neurons have been found to contact the basement membrane of blood vessels or perivascular astrocytes in all segments of the cortical microcirculation. Functionally, various experimental approaches support a role of neuronal NO in the maintenance of resting CBF as well as in the vascular response to neuronal activity. Since decades, it has been assumed that neuronal NO simply diffuses to the local blood vessels and produce vasodilation through a cGMP-PKG dependent mechanism. However, NO is not the sole mediator of vasodilation in the cerebral microcirculation and is known to interact with a myriad of signaling pathways also involved in vascular control. In addition, cerebrovascular regulation is the result of a complex orchestration between all components of the neurovascular unit (i.e., neuronal, glial, and vascular cells) also known to produce NO. In this review article, the role of NO interneuron in the regulation of cortical microcirculation will be discussed in the context of the neurovascular unit.
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Affiliation(s)
- Sonia Duchemin
- Department of Pharmacology, Université de Montréal Montreal, QC, Canada
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16
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Abstract
Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts in our understanding of cerebral blood flow control have important implications for the development of new therapeutic approaches.
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Abstract
Cellular damage occurring under oxidative conditions has been ascribed mainly to the formation of peroxynitrite (ONOOH/ONOO(-)) that originates from the reaction of NO(*) with O(2) (*-). The detrimental effects of peroxynitrite are exacerbated by the reaction with CO(2) that leads to ONOOC(O)O(-), which further decays to the strong oxidant radicals NO(2) (*) and CO(3) (*-). The reaction with CO(2), however, may redirect peroxynitrite specificity. An excessive formation of peroxynitrite represents an important mechanism contributing to the DNA damage, the inactivation of metabolic enzymes, ionic pumps, and structural proteins, and the disruption of cell membranes. Because of its ability to oxidize biomolecules, peroxynitrite is implicated in an increasing list of diseases, including neurodegenerative and cardiovascular disorders, inflammation, pain, autoimmunity, cancer, and aging. However, peroxynitrite displays also protective activities: (i) at high concentrations, it shows anti-viral, anti-microbial, and anti-parasitic actions; and (ii) at low concentrations, it stimulates protective mechanisms in the cardiovascular, nervous, and respiratory systems. The detrimental effects of peroxynitrite and related reactive species are impaired by (pseudo-) enzymatic systems, mainly represented by heme-proteins (e.g., hemoglobin and myoglobin). Here, we report biochemical aspects of peroxynitrite actions being at the root of its biomedical effects.
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Miller JD, Peotta VA, Chu Y, Weiss RM, Zimmerman K, Brooks RM, Heistad DD. MnSOD protects against COX1-mediated endothelial dysfunction in chronic heart failure. Am J Physiol Heart Circ Physiol 2010; 298:H1600-7. [PMID: 20304815 DOI: 10.1152/ajpheart.01108.2009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endothelial function is impaired by oxidative stress in chronic heart failure (HF). Mechanisms that protect against increases in oxidative stress in HF are not clear. The goal of this study was to determine whether manganese superoxide dismutase (MnSOD) plays a key role in protecting against endothelial dysfunction in HF. Endothelial function and gene expression were examined in aorta from wild-type mice (MnSOD(+/+)) and mice deficient in MnSOD (MnSOD(+/-)) 12 wk after ligation of the left coronary artery (LCA). LCA ligation produced similar size myocardial infarctions in MnSOD(+/+) and MnSOD(+/-) mice and reduced ejection fraction to approximately 20% in both groups. Maximal relaxation in response to acetylcholine was 78 +/- 3% (mean +/- SE) and 66 +/- 8% in sham-operated MnSOD(+/+) and MnSOD(+/-) mice, respectively. Expression of antioxidant enzymes increased in MnSOD(+/+) mice with HF, and maximal relaxation to acetylcholine was slightly impaired (68 +/- 4%). Greater endothelial dysfunction was observed in MnSOD(+/-) mice with HF (46 +/- 5%, P < 0.05), which was significantly improved by polyethylene glycol-catalase but not Tempol. Incubation with the nonspecific cyclooxygenase (COX) inhibitor indomethacin or the COX1 inhibitor valeryl salicylate, but not the COX-2 inhibitor NS-398, significantly improved relaxation to acetylcholine in HF mice (maximum relaxation = 74 +/- 5, 91 +/- 1, and 58 +/- 5%). These data suggest that MnSOD plays a key role in protecting against endothelial dysfunction in HF. A novel mechanism was identified whereby chronic increases in oxidative stress, produced by mitochondrial SOD deficiency, impair vascular function via a hydrogen peroxide-dependent, COX1-dependent, endothelium-derived contracting factor.
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Affiliation(s)
- Jordan D Miller
- Division of Cardiovascular Surgery and Department of Physiology, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA.
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Fornai M, Antonioli L, Colucci R, Bernardini N, Ghisu N, Tuccori M, De Giorgio R, Del Tacca M, Blandizzi C. Emerging role of cyclooxygenase isoforms in the control of gastrointestinal neuromuscular functions. Pharmacol Ther 2010; 125:62-78. [DOI: 10.1016/j.pharmthera.2009.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 09/16/2009] [Indexed: 02/06/2023]
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20
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Zhao W, Zhu F, Shen W, Fu A, Zheng L, Yan Z, Zhao L, Fu G. Protective effects of DIDS against ethanol-induced gastric mucosal injury in rats. Acta Biochim Biophys Sin (Shanghai) 2009; 41:301-8. [PMID: 19352545 DOI: 10.1093/abbs/gmp014] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The compound 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) is an efficient anion exchanger inhibitor that can block the activities of anion exchanger 2 (AE2), which plays an indispensable role in gastric acid secretion. DIDS also has potent anti-oxidative and antiapoptosis activities. This study aimed to investigate the effect of DIDS on ethanol-induced mucosal damage in rats and to evaluate the underlying mechanisms that mediate the action of the compound. The rats received 1 ml of absolute ethanol or saline orally. DIDS [50 mg/kg intravenous (i.v.)] was given 5 min before ethanol administration. Gastric lesions were evaluated macroscopically, microscopically, and electron microscopically at 60 min after ethanol challenge. Gastric myeloperoxidase (MPO) activity, malonyldialdehyde (MDA) level, prostaglandin E2 (PGE2) synthesis, and cyclooxygenase-2 (COX-2) expression were assessed. For the evaluation of the effect of DIDS on gastric acid secretion, histamine-stimulatory gastric acid secretion was examined with or without pretreatment of DIDS (50 mg/kg; i.v.). Ethanol-induced gastric lesions were characterized by increasing gastric MDA level, MPO activity, and COX-2 expression, and decreasing PGE2 synthesis. It was found that DIDS significantly reduced the extent of gastric mucosal damage and reversed tissue MDA level and MPO activity. DIDS further enhanced the expression of COX-2 and reversed the decrease of PGE2. Our results suggested that DIDS is beneficial in rat model of gastric injury through mechanisms that involve inhibiting inflammatory cell infiltration and lipid peroxidation and up-regulating the COX-2/PGE2 pathway.
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Affiliation(s)
- Wei Zhao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Institutes of Medical Sciences, Department of Pathology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
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21
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Arora M, Kumar A, Kaundal RK, Sharma SS. Amelioration of neurological and biochemical deficits by peroxynitrite decomposition catalysts in experimental diabetic neuropathy. Eur J Pharmacol 2008; 596:77-83. [PMID: 18768138 DOI: 10.1016/j.ejphar.2008.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/31/2008] [Accepted: 08/07/2008] [Indexed: 12/11/2022]
Abstract
Diabetic neuropathy, a major complication of diabetes, affects more than 60% of diabetic patients. Recently, involvement of peroxynitrite has been postulated in diabetic neuropathy. In the present study, we have studied the effects of peroxynitrite decomposition catalysts (PDC's)-5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrinato iron(III) [FeTPPS] and 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrinato iron(III) [FeTMPyP]-in experimental diabetic neuropathy. Male Sprague-Dawley rats, with six weeks of untreated diabetes were treated for two weeks with peroxynitrite decomposition catalysts. Diabetic animals showed a significant decrease in motor nerve conduction velocity and nerve blood flow, nociception as evident from decreased tail flick latency (hyperalgesia) and increased paw withdrawal pressure (mechanical allodynia) along with elevation in peroxynitrite and reduction in nerve glutathione levels. Two weeks treatment with PDC's significantly improved all the above stated functional and biochemical deficits. Aftermath of this study advocates the beneficial effects of peroxynitrite decomposition catalysts in experimental diabetic neuropathy.
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Affiliation(s)
- Manish Arora
- Molecular Neuropharmacology Laboratory, Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, Punjab, India
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22
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Schildknecht S, van der Loo B, Weber K, Tiefenthaler K, Daiber A, Bachschmid MM. Endogenous peroxynitrite modulates PGHS-1-dependent thromboxane A2 formation and aggregation in human platelets. Free Radic Biol Med 2008; 45:512-20. [PMID: 18514074 DOI: 10.1016/j.freeradbiomed.2008.04.042] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 04/22/2008] [Accepted: 04/29/2008] [Indexed: 01/22/2023]
Abstract
Aggregation of activated platelets is considerably mediated by the autocrine action of thromboxane A2 (TxA2) which is formed in a prostaglandin endoperoxide H2 synthase-1 (PGHS-1 or COX-1)-dependent manner. The activity of PGHS-1 can be stimulated by peroxides, an effect termed "peroxide tone", that renders PGHS-1 the key regulatory enzyme in the formation of TxA2. Activated platelets release nitric oxide (*NO) and superoxide (O*2) but their interactions with the prostanoid pathway have been controversially discussed in platelet physiology and pathophysiology. The current study demonstrates that endogenously formed peroxynitrite at nanomolar concentrations, originating from the interaction of *NO and *O2, potently activated PGHS-1, which parallels TxA2 formation and aggregation in human platelets. Inhibition of the endogenous formation of either *NO or O*2 resulted in a concentration-dependent decline of PGHS-1 activity, TxA2 release, and aggregation. The concept of peroxynitrite as modulator of TxA2 formation and aggregation explains the interaction of *NO and O*2 with the PGHS pathway and suggests a mechanism by which antioxidants can regulate PGHS-1-dependent platelet aggregation. This may provide a molecular explanation for the clinically observed hyperreactivity of platelets in high-risk patients and serve as a basis for novel therapeutic interventions.
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Affiliation(s)
- Stefan Schildknecht
- Vascular Biology Unit, Boston University School of Medicine, Boston, MA, 02118, USA
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Martínez-Canabal A, Angoa-Pérez M, Rugerio-Vargas C, Borgonio-Perez G, Rivas-Arancibia S. Effect of growth hormone on Cyclooxygenase-2 expression in the hippocampus of rats chronically exposed to ozone. Int J Neurosci 2008; 118:455-69. [PMID: 18300015 DOI: 10.1080/00207450701593160] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The aim of this study was to determine GH-effects on Cyclooxygenase-2 (COX-2) expression on hippocampus alterations caused by ozone exposure. Seventy male rats were divided into: (1) control; (2) exposed to ozone for 7, 15, and 30 days; (3) exposed to ozone and treated with GH, for 7, 15, and 30 days. Results showed that lipoperoxidation levels and number of COX-2-positive cells increased in all groups exposed to ozone compared to control. In the groups treated with GH, COX-2 immunoreactive cell number decreased with respect to the ozone group. Therefore, GH could provide protection against damage induced by oxidative stress.
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Affiliation(s)
- Alonso Martínez-Canabal
- Physiology Department, School of Medicine, National Autonomous University of Mexico, Mexico-City, Mexico DF
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López D, Pavelkova M, Gallova L, Simonetti P, Gardana C, Lojek A, Loaiza R, Mitjavila MT. Dealcoholized red and white wines decrease oxidative stress associated with inflammation in rats. Br J Nutr 2007; 98:611-9. [PMID: 17521475 DOI: 10.1017/s0007114507721475] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In vitroexperiments have demonstrated that polyphenols exhibit antioxidant and anti-inflammatory activities. The present study was designed to test whether dealcoholized red (DRW) and white (DWW) wines can decrease the oxidative stress associated with inflammationin vivo. Rats were fed for 15 d either a control diet or one supplemented with DRW or DWW. Finally, a granuloma was induced by subcutaneous administration of carrageenan. Although DRW showed higher antioxidant activityin vitrothan DWW, both wines decreased the number of cells recruited into the granuloma pouch. Malondialdehyde decreased in plasma and inflammatory exudate from rats fed with DRW- and DWW-rich diets. Moreover, the concentration of NO increased in exudate, which correlates with the increase in the citrulline:arginine ratio. Polymorphonuclear leucocytes from the inflammatory exudate of rats fed dealcoholized wines showed decreased superoxide anion (O2∙−) production and increased NO productionex vivo. This change in NO production resulted from increased expression and activity of inducible NO synthase (EC 1.14.13.39). Moreover, the up regulation of cyclo-oxygenase-2 (EC 1.14.99.1) protein expression observed in rats fed the DRW-rich diet was not related to a direct effect of NO. The present results indicate that the non-alcoholic compounds of wines not only improve antioxidant status in an inflammatory situation, but also limit cell infiltration, possibly through a decrease in O2∙−and an increase in NO production.
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Affiliation(s)
- D López
- Department of Physiology, Faculty of Biology, University of Barcelona, Av. Diagonal 645, E-08028 Barcelona, Spain
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Ghosh S, Novak EM, Innis SM. Cardiac proinflammatory pathways are altered with different dietary n-6 linoleic to n-3 alpha-linolenic acid ratios in normal, fat-fed pigs. Am J Physiol Heart Circ Physiol 2007; 293:H2919-27. [PMID: 17720770 DOI: 10.1152/ajpheart.00324.2007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Although dietary fat has been associated with inflammation and cardiovascular diseases (CVD), most studies have focused on individuals with preexisting diseases. However, the role of dietary fatty acids on inflammatory pathways before the onset of any abnormality may be more relevant for identifying initiating factors and interventions for CVD prevention. We fed young male pigs one of three diets differing in n-6 and n-3 polyunsaturated fatty acids (PUFA) linoleic acid (LA, 18:2n-6) and alpha-linolenic acid (ALA, 18:3n-3) for 30 days. Cardiac membrane phospholipid fatty acids, phospholipase A(2) (PLA(2)) isoform activities, and cyclooxygenase (COX)-1 and -2 and 5-lipoxygenase (5-LO) expression were measured. The low PUFA diet (% energy, 1.2% LA+0.06% ALA) increased arachidonic acid (AA) and decreased eicosapentaenoic acid (EPA) in heart membranes and increased Ca(2+)-independent iPLA(2) activity, COX-2 expression, and activation of 5-LO. Increasing dietary ALA while keeping LA constant (1.4% LA+1.2% ALA) decreased the heart membrane AA, increased EPA, and prevented proinflammatory enzyme activation. However, regardless of high ALA, high dietary LA (11.6% LA and 1.2% ALA) decreased EPA and led to a high heart membrane AA, and Ca(2+)-dependent cPLA(2) with a marked increase in nitrosative stress. Our results suggest that the potential cardiovascular benefit of ALA is achieved only when dietary LA is reduced concomitantly rather than fed with high LA diet. The increased nitrosative stress in the unstressed heart with high dietary LA suggests that biomarkers of nitrosative stress may offer a useful early marker of the effects of dietary fat on oxidative tissue stress.
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Affiliation(s)
- Sanjoy Ghosh
- Nutrition Research Program, Child and Family Research Institute, Department of Pedicatrics, University of British Columbia, Vancouver, British Columbia, Canada
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Reyes-Martin P, Alique M, Parra T, Hornedo JPD, Lucio-Cazana J. Cyclooxygenase-independent inhibition of H2O2-induced cell death by S-ketoprofen in renal cells. Pharmacol Res 2007; 55:295-302. [PMID: 17291778 DOI: 10.1016/j.phrs.2006.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 12/20/2006] [Accepted: 12/22/2006] [Indexed: 01/15/2023]
Abstract
The stress response of the distal tubule to oxidative attack may be relevant to recovery from acute renal failure. In distal tubular Madin-Darby cells (MDCK), H(2)O(2) induced up-regulation of cyclooxygenases (COX-1 and COX-2), prostaglandin-E(2) production and caspase-independent cell death. Cell death was inhibited by S-ketoprofen, but not by the much weaker COX inhibitor R-ketoprofen. Interestingly, we identified 15-deoxy-Delta(12,14)-prostaglandin-J(2) (15d-PGJ(2)), a peroxisome-proliferator activated receptor-gamma agonist, as a lethal prostaglandin whose effect was reproduced by the PPAR-gamma agonist ciglitazone. Nevertheless, H(2)O(2)-induced cell death was unaffected by other non-steroidal anti-inflammatory drugs (NSAIDs) or all-trans-retinoic acid. Moreover, c-Jun-N-terminal kinase inhibitor SP600125 prevented 15-deoxy-Delta(12,14)-PGJ(2)-induced cell death, but not H(2)O(2)-induced cell death. PPAR-gamma antagonist GW9662 showed no affect on the cell death. These results indicated that protection by S-ketoprofen was COX-independent and PPARgamma independent. Moreover, the IC(50) value of the action of S-ketoprofen for the inhibition of H(2)O(2)-induced MDCK cell death ( approximately equal 140microM) was much higher than the IC(50) value for the inhibition of COX-1 and COX-2 activities ( approximately equal 1microM). Further design of S-ketoprofen derivatives devoid of COX inhibitory activity will give opportunity to protect the kidney against oxidative attack while avoiding unwanted effects of NSAID.
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Zhang X, Hung TM, Phuong PT, Ngoc TM, Min BS, Song KS, Seong YH, Bae K. Anti-inflammatory activity of flavonoids from Populus davidiana. Arch Pharm Res 2007; 29:1102-8. [PMID: 17225458 DOI: 10.1007/bf02969299] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An in vitro bioassay-guide revealed that the methanol (MeOH) extract of the stem bark of Populus davidiana showed considerable inhibitory activity against cyclooxygenase (COX-1, COX-2). Continuous phytochemical study of the MeOH extract of this plant led to the isolation of ten flavonoids; sakuranetin (1), rhamnocitrin (2), 7-O-methylaromadendrin (3), naringenin (4), eriodictyol (5), aromadendrin (6), kaempferol (7), neosakuranin (8), sakuranin (9) and sakurenetin-5,4'-di-beta-D-glucopyranoside (10). Their structures were identified on the basis of their physicochemical and spectroscopic analyses. The isolated compounds, 1-10, were tested for their inhibitory activities against COX-1 and COX-2. Compound 7 was found to have potent inhibitory effect on COX-1 and a moderate effect on COX-2, meanwhile, compounds 1-6 showed moderate inhibition against COX-1 only. Moreover, compounds 5-8 exhibited suppressive effects on xanthine oxidase (XO). These results may explain, in part, the traditional uses of P. davidiana in ethnomedicine.
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Affiliation(s)
- XinFeng Zhang
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea
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Chin LC, Achike FI, Mustafa MR. Hydrogen peroxide modulates angiotensin II-induced contraction of mesenteric arteries from streptozotocin-induced diabetic rats. Vascul Pharmacol 2007; 46:223-8. [PMID: 17126611 DOI: 10.1016/j.vph.2006.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 09/18/2006] [Accepted: 10/03/2006] [Indexed: 12/18/2022]
Abstract
Hydrogen peroxide (H(2)O(2)) contributes in the regulation of vascular tone, especially in pathological states. The role of H(2)O(2) and superoxide anion free radicals in angiotensin II (Ang II)-induced contraction of diabetic tissues was examined with the aim of elucidating the underlying mechanisms. Isometric tension in response to various drug treatments was measured in isolated superior mesenteric arteries of streptozotocin (STZ)-induced diabetic WKY rats using the Mulvany wire myograph. Compared to the normal (euglycaemic) arteries, the Ang II-induced contraction was significantly reduced in diabetic arteries. Superoxide dismutase (SOD; converts superoxide to H(2)O(2)) significantly reduced the contraction in both types of arteries -- an effect abolished by catalase (H(2)O(2) scavenger), suggesting that the SOD effect was mediated by H(2)O(2). Treatment with catalase had no effect on the Ang II contraction in euglycaemic arteries, but it raised the contraction in diabetic arteries to euglycaemic levels. This increase was similar to that observed with diabetic arteries incubated with L-NAME. Combined catalase and L-NAME treatment further enhanced the contraction in diabetic arteries, suggesting that the catalase effect was not mediated by nitric oxide (NO). The catalase effect was abolished by indomethacin treatment. These results suggest that attenuation of Ang II-induced contraction in diabetic tissues is modulated by endogenous H(2)O(2), the scavenging of which unmasks an indomethacin-sensitive (and therefore cyclooxygenase product-mediated) Ang II-induced contraction.
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Affiliation(s)
- L C Chin
- Department of Pharmacology, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia
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Börekçi B, Aksoy H, Toker A, Ozkan A. Placental tissue cyclo-oxygenase 1 and 2 in pre-eclamptic and normal pregnancy. Int J Gynaecol Obstet 2006; 95:127-31. [PMID: 16930602 DOI: 10.1016/j.ijgo.2006.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 06/19/2006] [Accepted: 06/20/2006] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To investigate the activities of the 2 isoforms of prostaglandin synthetic enzyme cyclo-oxygenase (COX), COX-1 and COX-2, in the placental tissue of women with pre-eclampsia and healthy pregnant women. The relationship between placental lipid peroxidation and the activities of COX-1 and COX-2 was also investigated. METHODS Tissue specimens were obtained from pre-eclamptic women (20 had severe pre-eclampsia and 38 had mild pre-eclampsia) and 27 healthy pregnant women who underwent cesarean section before the onset of labor. Malondialdehyde (MDA) levels and COX-1 and COX-2 activities were measured in placental tissue homogenates. RESULTS Mean activities for COX-1 and COX-2 were significantly lower in women with severe pre-eclampsia than in healthy controls (P<0.05 and P<0.01, respectively). COX-1 and COX-2 activities were also lower in women with mild pre-eclampsia than in healthy controls, but the difference was of borderline significance (P=0.049 and P=0.059, respectively). The mean placental MDA level was significantly higher in pregnant women with severe and mild pre-eclampsia than in healthy pregnant women (P<0.01 for both). The correlation analysis showed significant negative correlations between MDA and COX-1 (r=-0.44, P<0.001) and MDA and COX-2 (r=-0.45, P<0.001) in the placental tissue of women with pre-eclampsia. CONCLUSION These results suggest that COX-1 and COX-2 activities are decreased in the placental tissue of women with pre-eclampsia, probably by oxidative stress.
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Affiliation(s)
- B Börekçi
- Department of Obstetrics and Gynecology, School of Medicine, Ataturk University, Erzurum, Turkey
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Choi SH, Langenbach R, Bosetti F. Cyclooxygenase-1 and -2 enzymes differentially regulate the brain upstream NF-kappa B pathway and downstream enzymes involved in prostaglandin biosynthesis. J Neurochem 2006; 98:801-11. [PMID: 16787416 PMCID: PMC1534077 DOI: 10.1111/j.1471-4159.2006.03926.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
We have recently reported that cyclooxygenase (COX)-2-deficiency affects brain upstream and downstream enzymes in the arachidonic acid (AA) metabolic pathway to prostaglandin E2 (PGE2), as well as enzyme activity, protein and mRNA levels of the reciprocal isozyme, COX-1. To gain a better insight into the specific roles of COX isoforms and characterize the interactions between upstream and downstream enzymes in brain AA cascade, we examined the expression and activity of COX-2 and phospholipase A2 enzymes (cPLA2 and sPLA2), as well as the expression of terminal prostaglandin E synthases (cPGES, mPGES-1, and - 2) in wild type and COX-1(-/-) mice. We found that brain PGE2 concentration was significantly increased, whereas thromboxane B2 (TXB2) concentration was decreased in COX-1(-/-) mice. There was a compensatory up-regulation of COX-2, accompanied by the activation of the NF-kappaB pathway, and also an increase in the upstream cPLA2 and sPLA2 enzymes. The mechanism of NF-kappaB activation in the COX-1(-/-) mice involved the up-regulation of protein expression of the p50 and p65 subunits of NF-kappaB, as well as the increased protein levels of phosphorylated IkappaBalpha and of phosphorylated IKKalpha/beta. Overall, our data suggest that COX-1 and COX-2 play a distinct role in brain PG biosynthesis, with basal PGE2 production being metabolically coupled with COX-2 and TXB2 production being preferentially linked to COX-1. Additionally, COX-1 deficiency can affect the expression of reciprocal and coupled enzymes, COX-2, Ca2+ -dependent PLA2, and terminal mPGES-2, to overcome defects in brain AA cascade.
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Affiliation(s)
- Sang-Ho Choi
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA
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Dhir A, Padi SSV, Naidu PS, Kulkarni SK. Protective effect of naproxen (non-selective COX-inhibitor) or rofecoxib (selective COX-2 inhibitor) on immobilization stress-induced behavioral and biochemical alterations in mice. Eur J Pharmacol 2006; 535:192-8. [PMID: 16522321 DOI: 10.1016/j.ejphar.2006.01.064] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 01/11/2006] [Accepted: 01/25/2006] [Indexed: 01/22/2023]
Abstract
Chronic stress precipitates many neuropsychiatric disorders and alters the various oxidative stress parameters in brain. Cyclooxygenase (COX) is reported to play an important role in pathogenesis of various neurodegenerative disorders including stroke and seizures. In the present study, we examined the effect of naproxen (non-selective COX-inhibitor having much potency towards COX-I isoform) or rofecoxib (a selective COX-2 inhibitor) in subchronic immobilization stress. Mice were subjected to immobilized stress for 6 h daily for a period of seven days. Naproxen (7 mg/kg, i.p.) or rofecoxib (2 mg/kg, i.p.) was administered daily for 7 days before challenging them to immobilization stress. Behavioral analysis revealed the hyperlocomotor activity and increased anxiety response. Subchronic stress decreased percent retention of memory and also caused hyperalgesia in mice. Biochemical analysis revealed that chronic immobilization stress significantly increased lipid peroxidation and nitrite levels and decreased the reduced glutathione and adrenal ascorbic acid levels. Chronic treatment with naproxen or rofecoxib significantly attenuated the immobilization stress-induced behavioral and biochemical alterations. These results suggested that the use of COX-inhibitors (naproxen or rofecoxib) could be a useful neuroprotective strategy in the treatment of stress.
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Affiliation(s)
- Ashish Dhir
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160014 India
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Fornai M, Blandizzi C, Antonioli L, Colucci R, Bernardini N, Segnani C, De Ponti F, Del Tacca M. Differential role of cyclooxygenase 1 and 2 isoforms in the modulation of colonic neuromuscular function in experimental inflammation. J Pharmacol Exp Ther 2006; 317:938-45. [PMID: 16474005 DOI: 10.1124/jpet.105.098350] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This study examines the role played by cyclooxygenase (COX) isoforms (COX-1 and -2) in the regulation of colonic neuromuscular function in normal rats and after induction of colitis by 2,4-dinitrobenzenesulfonic acid (DNBS). The expression of COX-1 and COX-2 in the colonic neuromuscular layer was assessed by reverse transcription-polymerase chain reaction and immunohistochemistry. The effects of COX inhibitors on in vitro motility were evaluated by studying electrically induced and carbachol-induced contractions of the longitudinal muscle. Both COX isoforms were constitutively expressed in normal colon; COX-2 was up-regulated in the presence of colitis. In normal and inflamed colon, both COX isoforms were mainly localized in neurons of myenteric ganglia. In the normal colon, indomethacin (COX-1/COX-2 inhibitor), SC-560 [5-(4-chloro-phenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole] (COX-1 inhibitor), or DFU [5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furanone] (COX-2 inhibitor) enhanced atropine-sensitive electrically evoked contractions. The most prominent effects were observed with indomethacin or SC-560 plus DFU. In the inflamed colon, SC-560 lost its effect, whereas indomethacin and DFU maintained their enhancing actions. These results were more evident after blockade of noncholinergic pathways. In rats with colitis, in vivo treatment with superoxide dismutase or S-methylisothiourea (inhibitor of inducible nitric-oxide synthase) restored the enhancing motor effect of SC-560. COX inhibitors had no effect on carbachol-induced contractions in normal or DNBS-treated rats. In conclusion, in the normal colon, both COX isoforms act at the neuronal level to modulate the contractile activity driven by excitatory cholinergic pathways. In the presence of inflammation, COX-1 activity is hampered by oxidative stress, and COX-2 seems to play a predominant role in maintaining an inhibitory control of colonic neuromuscular function.
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Affiliation(s)
- Matteo Fornai
- Division of Pharmacology and Chemotherapy, Department of Internal Medicine, University of Pisa, Pisa, Italy
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Chien PS, Mak OT, Huang HJ. Induction of COX-2 protein expression by vanadate in A549 human lung carcinoma cell line through EGF receptor and p38 MAPK-mediated pathway. Biochem Biophys Res Commun 2005; 339:562-8. [PMID: 16300728 DOI: 10.1016/j.bbrc.2005.11.045] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 11/03/2005] [Indexed: 01/22/2023]
Abstract
Vanadate is a transition metal widely distributed in the environment. It has been reported that vanadate associated with air pollution particles can modify DNA synthesis, causing cell growth arrest, and apoptosis. Moreover, vanadium exposure was also found to cause the synthesis of inflammatory cytokines, such as interleukin-1, tumor necrosis factor-alpha, and prostaglandin E(2). Here, we found that exposure of A549 human lung carcinoma cells to vanadate led to extracellular signal-regulated kinase, c-Jun NH(2)-terminal protein kinases (JNKs), p38 mitogen-activated protein kinase (p38) activation, and COX-2 protein expression in a dose-dependent manner. SB203580, a p38 MAPK inhibitor, but not PD098059 and SP600125, specific inhibitor of MKK1 and selective inhibitor of JNK, respectively, suppressed COX-2 expression. Furthermore, the epithelial growth factor (EGF) receptor specific inhibitor (PD153035) reduced vanadate-induced COX-2 expression. However, scavenging of vanadate-induced reactive oxygen species by catalase, a specific H(2)O(2) inhibitor, or DPI, an NADPH oxidase inhibitor, resulted in no inhibition on COX-2 expression. Together, we suggested that EGF receptor and p38 MAPK signaling pathway may be involved in vanadate-induced COX-2 protein expression in A549 human lung carcinoma cell line.
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Affiliation(s)
- Pei-Shan Chien
- Institute of Biotechnology, National Cheng Kung University, No. 1 University Rd. 701, Tainan, Taiwan
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