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Liudvytska O, Bandyszewska M, Skirecki T, Krzyżanowska-Kowalczyk J, Kowalczyk M, Kolodziejczyk-Czepas J. Anti-inflammatory and antioxidant actions of extracts from Rheum rhaponticum and Rheum rhabarbarum in human blood plasma and cells in vitro. Biomed Pharmacother 2023; 165:115111. [PMID: 37421780 DOI: 10.1016/j.biopha.2023.115111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 06/26/2023] [Accepted: 06/29/2023] [Indexed: 07/10/2023] Open
Abstract
Rheum rhaponticum L. (rhapontic rhubarb) and Rheum rhabarbarum L. (garden rhubarb) are edible and medicinal rhubarb species used for many centuries in traditional medicine. This work is focused on the biological activity of extracts from petioles and roots of R. rhaponticum and R. rhabarbarum as well as rhapontigenin and rhaponticin, typical stilbenes present in these rhubarbs, in a context of their effects on blood physiology and cardiovascular health. Anti-inflammatory properties of the examined substances were evaluated in human peripheral blood mononuclear cells (PBMCs) and THP1-ASC-GFP inflammasome reporter cells. Due to the coexistence of inflammation and oxidative stress in cardiovascular diseases, the study design included also antioxidant assays. This part of the work involved the assessment of the protective efficiency of the examined substances against the peroxynitrite-triggered damage to human blood plasma components, including fibrinogen, a protein of critical importance for blood clotting and maintaining the haemostatic balance. Pre-incubation of PBMCs with the examined substances (1-50 μg/mL) considerably decreased the synthesis of prostaglandin E2 as well as the release of pro-inflammatory cytokines (IL-2 and TNF-α) and metalloproteinase-9. A reduced level of secreted apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks in the THP-1-ASC-GFP cells was also observed. The examined substances significantly diminished the extent of ONOO‾induced oxidative modifications of blood plasma proteins and lipids and normalized, or even strengthened blood plasma antioxidant capacity. Furthermore, a reduction of oxidative damage to fibrinogen, including modifications of tyrosine and tryptophan residues along with the formation of protein aggregates was found.
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Affiliation(s)
- Oleksandra Liudvytska
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
| | - Magdalena Bandyszewska
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland.
| | - Tomasz Skirecki
- Department of Translational Immunology and Experimental Intensive Care, Centre of Postgraduate Medical Education, Marymoncka 99/103, 01-813 Warsaw, Poland.
| | - Justyna Krzyżanowska-Kowalczyk
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation, State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland.
| | - Mariusz Kowalczyk
- Department of Biochemistry and Crop Quality, Institute of Soil Science and Plant Cultivation, State Research Institute, Czartoryskich 8, 24-100 Puławy, Poland.
| | - Joanna Kolodziejczyk-Czepas
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
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Pluta R, Kiś J, Januszewski S, Jabłoński M, Czuczwar SJ. Cross-Talk between Amyloid, Tau Protein and Free Radicals in Post-Ischemic Brain Neurodegeneration in the Form of Alzheimer’s Disease Proteinopathy. Antioxidants (Basel) 2022; 11:antiox11010146. [PMID: 35052650 PMCID: PMC8772936 DOI: 10.3390/antiox11010146] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/05/2022] [Accepted: 01/09/2022] [Indexed: 02/04/2023] Open
Abstract
Recent years have seen remarkable progress in research into free radicals oxidative stress, particularly in the context of post-ischemic recirculation brain injury. Oxidative stress in post-ischemic tissues violates the integrity of the genome, causing DNA damage, death of neuronal, glial and vascular cells, and impaired neurological outcome after brain ischemia. Indeed, it is now known that DNA damage and repair play a key role in post-stroke white and gray matter remodeling, and restoring the integrity of the blood-brain barrier. This review will present one of the newly characterized mechanisms that emerged with genomic and proteomic development that led to brain ischemia to a new level of post-ischemic neuropathological mechanisms, such as the presence of amyloid plaques and the development of neurofibrillary tangles, which further exacerbate oxidative stress. Finally, we hypothesize that modified amyloid and the tau protein, along with the oxidative stress generated, are new key elements in the vicious circle important in the development of post-ischemic neurodegeneration in a type of Alzheimer’s disease proteinopathy.
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Affiliation(s)
- Ryszard Pluta
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 Str., 02-106 Warsaw, Poland;
- Correspondence: ; Tel.: +48-22-608-6540
| | - Jacek Kiś
- Department of Urology, 1st Military Clinical Hospital with the Outpatient Clinic, Al. Racławickie 23, 20-049 Lublin, Poland;
| | - Sławomir Januszewski
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 Str., 02-106 Warsaw, Poland;
| | - Mirosław Jabłoński
- Department of Rehabilitation and Orthopedics, Medical University of Lublin, Jaczewskiego 8 Str., 20-090 Lublin, Poland;
| | - Stanisław J. Czuczwar
- Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8b Str., 20-090 Lublin, Poland;
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Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3804979. [PMID: 29770166 PMCID: PMC5892600 DOI: 10.1155/2018/3804979] [Citation(s) in RCA: 278] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/07/2017] [Indexed: 12/16/2022]
Abstract
Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.
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Misztal T, Rusak T, Brańska-Januszewska J, Ostrowska H, Tomasiak M. Peroxynitrite may affect fibrinolysis via the reduction of platelet-related fibrinolysis resistance and alteration of clot structure. Free Radic Biol Med 2015; 89:533-47. [PMID: 26454084 DOI: 10.1016/j.freeradbiomed.2015.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 11/20/2022]
Abstract
We tested the hypothesis that in vitro peroxynitrite (ONOO(-), a product of activated inflammatory cells) may affect fibrinolysis in human blood through the reduction of platelet-related fibrinolysis resistance. It was found that ONOO(-) (25-300 µM) accelerated lysis of platelet-fibrin clots (in PRP) dose-dependently, whereas fibrinolysis of platelet-free clots was slightly inhibited by ≥ 1000 µM stressor. Concentrations of ONOO(-) affecting the lysis of platelet-rich clots, inhibited clot retraction (CR) in a dose-dependent manner. Thromboelastometry (ROTEM) measurements performed in PRP showed that treatment with ONOO(-) (threshold conc. 100 µM) prolongs clotting time, and reduces alpha angle, and clot formation velocity parameters indicating for reduced thrombin formation rate. In PRP, ONOO(-) (threshold conc. 100 µM) reduced the collagen-evoked exposure of phosphatidylserine (PS) on platelets' plasma membrane, the shedding of platelet-derived microparticles (PMP), and inhibited platelet-dependent thrombin generation (measured in artificial system), dose-dependently. As judged by confocal microscopy, similar ONOO(-) concentrations altered the architecture of clots formed in collagen-treated PRP. Clots formed in the presence of ONOO(-) were less dense and were composed of thicker fibers, which make them more susceptible to lysis. In platelet-depleted plasma, ONOO(-) (up to milimolar concentration) did not alter clot structure. Blockage of PS exposed on platelets resulted in an alteration of clot architecture toward more prone to lysis. ONOO(-), at lysis-affecting concentrations, inhibited the collagen-evoked secretion of fibrinolytic inhibitors from platelets. We conclude that physiologically relevant ONOO(-) concentrations may accelerate the lysis of platelet-fibrin clots predominantly via downregulation of platelet-related mechanisms including: platelet secretion, clot retraction, platelet procoagulant response, and the alteration in clot architecture associated with it.
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Affiliation(s)
- Tomasz Misztal
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland
| | - Tomasz Rusak
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland
| | | | - Halina Ostrowska
- Department of Biology, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland
| | - Marian Tomasiak
- Department of Physical Chemistry, Medical University of Bialystok, Kilinskiego 1, 15-089 Bialystok, Poland.
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Kolodziejczyk-Czepas J, Ponczek MB, Nowak P. Peroxynitrite and fibrinolytic system-The effects of peroxynitrite on t-PA-induced plasmin activity. Int J Biol Macromol 2015; 81:212-9. [PMID: 26234576 DOI: 10.1016/j.ijbiomac.2015.07.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 07/29/2015] [Indexed: 11/25/2022]
Abstract
The aim of the present study was the investigation of peroxynitrite (ONOO(-)) effects on fibrinolysis in vitro and in silico. The exposure of human plasminogen to ONOO(-) (10-1000μM) resulted in a decrease of t-PA-induced amidolytic activity of plasmin; the inhibitory effect was associated with the increasing level of 3-nitrotyrosine in plasminogen/plasmin molecule. Furthermore, ONOO(-) displayed both the ability to impair the t-PA-induced activation of plasminogen to plasmin, and to reduce the rate of fibrin lysis by plasmin. The susceptibility of plasminogen in blood plasma to nitrative action of ONOO(-) was revealed by the immunoprecipitation technique. To confirm the hypothesis that 3-nitrotyrosine generation is crucial for the impairment of plasmin activity, (-)-epicatechin, a polyphenolic antioxidant that selectively prevents tyrosine nitration, was used both for in vitro experiments as well as for in silico studies on ONOO(-), ONOOH and (-)-epicatechin binding and plasminogen nitration. (-)-Epicatechin effectively protected plasminogen against ONOO(-)-induced inactivation and significantly reduced the level of 3-nitrotyrosine. The obtained results revealed tyrosine nitration as the most likely mechanism of the inhibitory effect of ONOO(-) on plasmin(ogen) functions. The possible role of tyrosine modifications was additionally confirmed by bioinformatics calculations with indication of nitration susceptible tyrosine residues.
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Affiliation(s)
- Joanna Kolodziejczyk-Czepas
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
| | - Michal Blazej Ponczek
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Pawel Nowak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
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Kolodziejczyk-Czepas J, Olas B, Malinowska J, Wachowicz B, Moniuszko-Szajwaj B, Kowalska I, Oleszek W, Stochmal A. Trifolium pallidum and Trifolium scabrum extracts in the protection of human plasma components. J Thromb Thrombolysis 2013; 35:193-9. [DOI: 10.1007/s11239-012-0792-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Hoda MN, Siddiqui S, Herberg S, Periyasamy-Thandavan S, Bhatia K, Hafez SS, Johnson MH, Hill WD, Ergul A, Fagan SC, Hess DC. Remote ischemic perconditioning is effective alone and in combination with intravenous tissue-type plasminogen activator in murine model of embolic stroke. Stroke 2012; 43:2794-9. [PMID: 22910893 DOI: 10.1161/strokeaha.112.660373] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Remote ischemic conditioning is cardioprotective in myocardial infarction and neuroprotective in mechanical occlusion models of stroke. However, there is no report on its therapeutic potential in a physiologically relevant embolic stroke model (embolic middle cerebral artery occlusion) in combination with intravenous tissue-type plasminogen activator (tPA). METHODS We tested remote ischemic perconditioning therapy (RIPerC) at 2 hours after embolic middle cerebral artery occlusion in the mouse with and without intravenous tPA at 4 hours. We assessed cerebral blood flow up to 6 hours, neurological deficits, injury size, and phosphorylation of Akt (Serine(473)) as a prosurvival signal in the ischemic hemisphere at 48 hours poststroke. RESULTS RIPerC therapy alone improved the cerebral blood flow and neurological outcomes. tPA alone at 4 hours did not significantly improve the neurological outcome even after successful thrombolysis. Individual treatments with RIPerC and intravenous tPA reduced the infarct size (25.7% and 23.8%, respectively). Combination therapy of RIPerC and tPA resulted in additive effects in further improving the neurological outcome and reducing the infarct size (50%). All the therapeutic treatments upregulated phosphorylation of Akt in the ischemic hemisphere. CONCLUSIONS RIPerC is effective alone after embolic middle cerebral artery occlusion and has additive effects in combination with intravenous tPA. RIPerC may be a simple, safe, and inexpensive combination therapy with intravenous tPA.
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Affiliation(s)
- Md Nasrul Hoda
- Department of Neurology, Georgia Health Sciences University, 1120 15 Street, CA 1014, Augusta, GA 30912, USA.
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Kolodziejczyk-Czepas J, Talar B, Nowak P, Olas B, Wachowicz B. Homocysteine and its thiolactone impair plasmin activity induced by urokinase or streptokinase in vitro. Int J Biol Macromol 2012; 50:754-8. [DOI: 10.1016/j.ijbiomac.2011.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/06/2011] [Accepted: 12/07/2011] [Indexed: 01/10/2023]
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Kvietys PR, Granger DN. Role of reactive oxygen and nitrogen species in the vascular responses to inflammation. Free Radic Biol Med 2012; 52:556-592. [PMID: 22154653 PMCID: PMC3348846 DOI: 10.1016/j.freeradbiomed.2011.11.002] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/04/2011] [Accepted: 11/04/2011] [Indexed: 12/23/2022]
Abstract
Inflammation is a complex and potentially life-threatening condition that involves the participation of a variety of chemical mediators, signaling pathways, and cell types. The microcirculation, which is critical for the initiation and perpetuation of an inflammatory response, exhibits several characteristic functional and structural changes in response to inflammation. These include vasomotor dysfunction (impaired vessel dilation and constriction), the adhesion and transendothelial migration of leukocytes, endothelial barrier dysfunction (increased vascular permeability), blood vessel proliferation (angiogenesis), and enhanced thrombus formation. These diverse responses of the microvasculature largely reflect the endothelial cell dysfunction that accompanies inflammation and the central role of these cells in modulating processes as varied as blood flow regulation, angiogenesis, and thrombogenesis. The importance of endothelial cells in inflammation-induced vascular dysfunction is also predicated on the ability of these cells to produce and respond to reactive oxygen and nitrogen species. Inflammation seems to upset the balance between nitric oxide and superoxide within (and surrounding) endothelial cells, which is necessary for normal vessel function. This review is focused on defining the molecular targets in the vessel wall that interact with reactive oxygen species and nitric oxide to produce the characteristic functional and structural changes that occur in response to inflammation. This analysis of the literature is consistent with the view that reactive oxygen and nitrogen species contribute significantly to the diverse vascular responses in inflammation and supports efforts that are directed at targeting these highly reactive species to maintain normal vascular health in pathological conditions that are associated with acute or chronic inflammation.
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Affiliation(s)
- Peter R Kvietys
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - D Neil Granger
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA.
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Hypochlorous acid is a potent inactivator of human plasminogen at concentrations secreted by activated granulocytes. Clin Chem Lab Med 2008; 46:1403-9. [DOI: 10.1515/cclm.2008.272] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Nowak P, Zbikowska HM, Ponczek M, Kolodziejczyk J, Wachowicz B. Different vulnerability of fibrinogen subunits to oxidative/nitrative modifications induced by peroxynitrite: functional consequences. Thromb Res 2007; 121:163-74. [PMID: 17467041 DOI: 10.1016/j.thromres.2007.03.017] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 01/24/2007] [Accepted: 03/20/2007] [Indexed: 10/23/2022]
Abstract
Based on previous studies suggesting that fibrinogen (Fg) might be a potential target for peroxynitrite (PN) action in plasma, we investigated the effects of PN on structure and hemostatic function of Fg in vitro. Using fluorescence and spectrophotometric methods, we estimated that about 0.5, 2 and 8 tyrosine residues per molecule were nitrated following the reaction of Fg at concentration 5.88 muM with 10, 100 and 1000 muM PN, respectively. At the same molar ratios of Fg to PN, about 0.01, 0.19 and 0.34 of tyrosine residues per molecule were oxidized to dityrosine and the amount of carbonyl groups in Fg increased 1.3-, 2,3- and 3.6-fold when compared to control Fg. SDS-PAGE analysis of PN-modified Fg suggests that inter- and intramolecular dityrosine cross-links occur between A alpha chains of Fg. Vulnerability of Fg subunits to oxidative/nitrative modifications induced by PN was different. Within the Fg molecule, mainly alpha C domains as well as D domains (contrary to E domain) undergo the majority of the modifications. Low extent of nitration and oxidation of Fg molecule (induced by 10 microM PN) did not affect its clotting activity and susceptibility to degradation by plasmin. Modification of Fg induced by higher PN concentrations decreased these properties.
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Affiliation(s)
- Pawel Nowak
- Department of General Biochemistry, University of Lodz, Banacha 12/16 Street, 90-237 Lodz, Poland.
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Abstract
The discovery that mammalian cells have the ability to synthesize the free radical nitric oxide (NO) has stimulated an extraordinary impetus for scientific research in all the fields of biology and medicine. Since its early description as an endothelial-derived relaxing factor, NO has emerged as a fundamental signaling device regulating virtually every critical cellular function, as well as a potent mediator of cellular damage in a wide range of conditions. Recent evidence indicates that most of the cytotoxicity attributed to NO is rather due to peroxynitrite, produced from the diffusion-controlled reaction between NO and another free radical, the superoxide anion. Peroxynitrite interacts with lipids, DNA, and proteins via direct oxidative reactions or via indirect, radical-mediated mechanisms. These reactions trigger cellular responses ranging from subtle modulations of cell signaling to overwhelming oxidative injury, committing cells to necrosis or apoptosis. In vivo, peroxynitrite generation represents a crucial pathogenic mechanism in conditions such as stroke, myocardial infarction, chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders. Hence, novel pharmacological strategies aimed at removing peroxynitrite might represent powerful therapeutic tools in the future. Evidence supporting these novel roles of NO and peroxynitrite is presented in detail in this review.
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Affiliation(s)
- Pál Pacher
- Section on Oxidative Stress Tissue Injury, Laboratory of Physiologic Studies, National Institutes of Health, National Institute of Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
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Hermo R, Mier C, Mazzotta M, Tsuji M, Kimura S, Gugliucci A. Circulating levels of nitrated apolipoprotein A-I are increased in type 2 diabetic patients. Clin Chem Lab Med 2005; 43:601-6. [PMID: 16006255 DOI: 10.1515/cclm.2005.104] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractRecent work has shown that high-density lipoprotein (HDL) isolated from human atherosclerotic lesions and the blood of patients with established coronary artery disease contains elevated levels of 3-nitrotyrosine and 3-chlorotyrosine. A higher nitrotyrosine content in lipoprotein is significantly associated with diminished cholesterol efflux capacity of the lipoprotein. Since accelerated atherogenesis is a key complication of diabetes mellitus, and nitrosative stress has recently been implicated in diabetic pathology, we set out to demonstrate an increase in the circulating levels of nitrated apolipoprotein A (apoA)-I in type 2 diabetic patients and its putative correlation with metabolic biomarkers. In this work we addressed this hypothesis in a case-control study with 30 type 2 diabetic patients and 30 age-matched control subjects. Nitrated apoA-I was 3280±1910 absorbance peak area/apoA-I (g/L) for diabetic patients and 2320±890 for control subjects (p<0.037). This represents a 50% increase in circulating nitrated apoA-I in diabetic patients to age-matched controls. Diabetic patients also showed increases of a similar magnitude in circulating advanced glycation endproducts measured as pentosidine fluorescence (44.16±16.26 vs. 30.84±12.86 AU; p<0.01) and in circulating lipoperoxides (46.0±18.0 vs. 37.2±18.0nmol/L; p<0.03). No significant correlation was found between nitration of apoA-I and glycosylated hemoglobin or any of the other parameters measured. If proven in subsequent functional and in vivo studies, increased nitrated apoA-I would represent another mechanism by which nitrosative stress participates in diabetic macro-angiopathy.
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Affiliation(s)
- Ricardo Hermo
- Department of Clinical Laboratory, Facultad de Medicina, Universidad de la Republica, Montevideo, Uruguay
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