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ABSTRACT: The study of the ovarian proteomic profile represents a new frontier in ovarian cancer research, since this approach is able to enlighten the wide variety of post-translational events (such as glycosylation and phosphorylation). Due to the possibility of analyzing thousands of proteins, which could be simultaneously altered, comparative proteomics represent a promising model of possible biomarker discovery for ovarian cancer detection and monitoring. Moreover, defining signaling pathways in ovarian cancer cells through proteomic analysis offers the opportunity to design novel drugs and to optimize the use of molecularly targeted agents against crucial and biologically active pathways. Proteomic techniques provide more information about different histological types of ovarian cancer, cell growth and progression, genes related to tumor microenvironment and specific molecular targets predictive of response to chemotherapy than sequencing or microarrays. Estimates of specificity with proteomics are less consistent, but suggest a new role for combinations of biomarkers in early ovarian cancer diagnosis, such as the OVA1 test. Finally, the definition of the proteomic profiles in ovarian cancer would be accurate and effective in identifying which pathways are differentially altered, defining the most effective therapeutic regimen and eventually improving health outcomes.
International Journal of Molecular Sciences 01/2013; 14(4):8271-8290. · 2.60 Impact Factor
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ABSTRACT: This is a comparative proteomic study on biopsies from patients with ovarian cancer to identify potential diagnostic/prognostic biomarkers in both healthy and tumor tissue, interstitial fluid (normal interstitial fluid and tumoral interstitial fluid and peritoneal effusion. Protein expression/identification was evaluated by 2-DE and MS analysis: six proteins showed differential expression in tumoral interstitial fluid and tumor tissue compared to normal interstitial fluid and healthy tissue: five were found to be downregulated and identified as galectin 3, glutathione S-transferase A-2, retinol binding protein 1, phosphatidylethanolamine-binding protein and annexin 5, while the calgranulin, was significantly upregulated in all pathological samples, including the ascitic fluid. Validation of S100A8 overexpression in carcinoma tissue was obtained by immunohistochemistry. To our knowledge, this is the first study to report an over-expression of calgranulin by 2-DE associated with MS/MS analysis on surgical biopsy. The reduced expression of galectin 3 and retinol binding protein 1 in cystic fluid and serum of patients with early stage disease is confirmed in this study. The results highlight alterations in proteins that control cell-cycle progression and apoptosis, as well as factors that modulate the activity of signal transduction pathways. Moreover, this study suggests that calgranulin expression may be used as a diagnostic and/or prognostic biomarker.
Electrophoresis 08/2011; 32(15):1992-2003. · 3.30 Impact Factor
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Laura Cortesi,
Andrea Barchetti,
Elisabetta De Matteis,
Elena Rossi,
Lara Della Casa,
Luigi Marcheselli,
Giovanni Tazzioli,
Maria Grazia Lazzaretti,
Guido Ficarra,
Massimo Federico, Anna Iannone
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ABSTRACT: An attempt for the identification of potential biomarkers predictive of response to chemotherapy (CHT) in breast cancer patients has been performed by the use of two-dimensional electrophoresis and mass spectrometry analysis. Since growth and progression of tumor cells depend also on stromal factors in the microenvironment, we choose to investigate the proteins secreted in Tumor Interstitial Fluid (TIF) and in Normal Interstitial Fluids (NIF). One-hundred and twenty-two proteins have been analyzed and a comparison was also made between the proteomic profile of responders versus nonresponders to CHT. At baseline, proteins isolated in TIF and NIF of all the 28 patients show significant differences in expression. Two clusters of proteins, differentially expressed in TIF with respect to NIF were found. Most significant is the decreased expression in TIF of CRYAB. In the protein metabolism group, also FIBB was found decreased. Some proteins involved in energy pathways were overexpressed (PGAM-1, ALDO A, PGK1, G3Pcn), while some other were down-regulated (CAH2, G3Pdx, PRDX6, TPIS). The same trend was observed for signal transduction proteins, with 14-3-3-Z overexpressed, and ANXA2 and PEBP 1 down-regulated. Moreover, an analysis has been conducted comparing protein expression in interstitial fluids of responders and nonresponders, irrespective of TIF or NIF source. This analysis lead us to identify two clusters of proteins with a modified expression, which might be predictive of response to CHT. In responders, an increase in expression of LDHA, G3Pdx, PGK1sx (energy pathways), VIME (cell growth and maintenance) and 14-3-3-Z (signal transduction), coupled with a decreased expression of TPIS, CAH 2, G3Psx, PGK 1dx (energy pathways), TBB5 (cell growth and maintenance), LDHB and FIBB (protein metabolism), was found. We observed that CHT modifies the expression of these cluster proteins since, after treatment, their expression in TIF of responder is generally decreased. Patients not responding to CHT show an unchanged expression pattern in TIF, with the exception of protein 14-3-3-Z, which is overexpressed, and a decreased expression in NIF of several cluster proteins. In conclusion, the identification of protein clusters associated with response to CHT might be important for predicting the efficacy of a specific antineoplastic drug and for the development of less empiric strategies in choosing the therapy to be prescribed to the single patient.
Journal of Proteome Research 10/2009; 8(11):4916-33. · 5.11 Impact Factor
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Anna Iannone,
Anna Petroni,
Elisabetta Murru,
Lina Cordeddu,
Gianfranca Carta,
Maria Paola Melis,
Stefania Bergamini,
Lara Della Casa,
Laura Cappiello,
Romina Carissimi,
Marianne O'Shea,
Doris Bell,
Enrico De Santis,
Sebastiano Banni
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ABSTRACT: 8-iso-PGF(2alpha) isoprostane (IP) is one of the most-used markers of lipid peroxidation in experimental models and humans. After its formation, it is promptly metabolized to 2,3 dinor (DIN) in peroxisomes. Conjugated linoleic acid (CLA) is preferentially beta-oxidized in peroxisomes which may compete with IP, and thereby may affect its metabolism. In order to verify whether CLA is able to influence IP formation and/or metabolism and to explain the mechanism, we challenged rats supplemented with CLA or with triolein (as a control fatty acid), with a single dose of carbon tetrachloride (CCl(4)) or of bacterial lipopolysaccharide (LPS). The results showed that IP and its precursor arachidonic acid hydroperoxide, as well as malondialdehyde (MDA), increase significantly in the liver of rats challenged with CCl(4), irrespective of the diet, while in LPS-treated rats only nitrites in liver and isoprostane in plasma increase. On the other hand, the peroxisomal beta-oxidation products of IP, the DIN, is significantly lower in the CLA group with respect to control and triolein groups. To further investigate whether this is due to competition between CLA and IP at the cellular level, we incubated human fibroblasts from healthy subjects or patients with adrenoleukodystrophy (ALD), with CLA and/or commercially available IP. The rationale of this approach is based on the deficient peroxisomal beta-oxidation of fibroblasts from ALD patients, leading to a reduced formation of DIN. In both normal and ALD cells, the presence of CLA significantly inhibits the formation of DIN from IP. We may conclude that both in vitro and in vivo studies strongly suggest that CLA may impair IP catabolism in peroxisomes. Consequently an increase of IP, as a sole result of CLA intake, cannot be considered as a marker of lipid peroxidation.
Prostaglandins Leukotrienes and Essential Fatty Acids 05/2009; 80(5-6):279-87. · 3.37 Impact Factor
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Valentino Martina,
Andi Masha,
Valentina Ramella Gigliardi,
Loredana Brocato,
Enzo Manzato,
Arrigo Berchio,
Paola Massarenti,
Fabio Settanni,
Lara Della Casa,
Stefania Bergamini, Anna Iannone
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ABSTRACT: Reactive oxygen and nitric oxide (NO) have recently been considered to be involved in the cardiovascular complications of patients with type 2 diabetes, as NO is thought to lose its beneficial physiological effects in the presence of oxygen radicals. For this reason, we tested the effects of l-arginine (ARG) and N-acetylcysteine (NAC) administration in increasing NO bioavailability by reducing free radical formation.
A double-blind study was performed on 24 male patients with type 2 diabetes and hypertension divided into two groups of 12 patients that randomly received either an oral supplementation of placebo or NAC + ARG for 6 months.
The NAC + ARG treatment caused a reduction of both systolic (P < 0.05) and diastolic (P < 0.05) mean arterial blood pressure, total cholesterol (P < 0.01), LDL cholesterol (P < 0.005), oxidized LDL (P < 0.05), high-sensitive C-reactive protein (P < 0.05), intracellular adhesion molecule (P < 0.05), vascular cell adhesion molecule (P < 0.01), nitrotyrosine (P < 0.01), fibrinogen (P < 0.01), and plasminogen activator inhibitor-1 (P < 0.05), and an improvement of the intima-media thickness during endothelial postischemic vasodilation (P < 0.02). HDL cholesterol increased (P < 0.05). No changes in other parameters studied were observed.
NAC + ARG administration seems to be a potential well-tolerated antiatherogenic therapy because it improves endothelial function in hypertensive patients with type 2 diabetes by improving NO bioavailability via reduction of oxidative stress and increase of NO production. Our study's results give prominence to its potential use in primary and secondary cardiovascular prevention in these patients.
Diabetes care 05/2008; 31(5):940-4. · 8.09 Impact Factor
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ABSTRACT: Diabetic nephropathy (DN) is a complication associated with diabetes, leading to end-stage renal disease (ESRD). Despite significant progress in understanding DN, the cellular mechanisms leading to the renal damage are incompletely defined. In this study, with the aim to identify urine biomarkers for the early renal alterations in type 2 diabetes mellitus (T2D), we performed urinary proteomic analysis of 10 normoalbuminuric patients with T2D, 12 patients with type 2 DN (T2DN), and 12 healthy subjects. Proteins were separated by 2-DE and identified with ESI-Q-TOF MS/MS. Comparing the patients proteomic profiles with those of normal subjects, we identified 11 gradually differently changed proteins. The decreased proteins were the prostatic acid phosphatase precursor, the ribonuclease and the kallikrein-3. Eight proteins were progressively increased in both patients groups: transthyretin precursor, Ig κ chain C region, Ig κ chain V-II region Cum, Ig κ-chain V-III region SIE, carbonic anhydrase 1, plasma retinol-binding protein, β-2-microglobulin precursor, β-2-glycoprotein 1. The proteomic analysis allowed us to identify several increased urinary proteins, not only in T2DN but also in T2D patients in which the microalbuminuria was in the normal range. These patterns of urinary proteins might represent a potential tool for a better understanding of diabetic renal damage.
Proteomics. Clinical applications 04/2008; 2(4):478-91. · 1.97 Impact Factor
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ABSTRACT: Oxidative stress plays a pivotal role in the pathogenesis of several chronic diseases and antioxidants may represent potential tools for the prevention of these diseases. Here, we investigated the antioxidant efficiency of different tocotrienol isoforms (alpha-, delta-, gamma-tocotrienols), and that of FeAox-6, a novel synthetic compound which combines, by a stable covalent bond, the chroman head of vitamin E and a polyisoprenyl sequence of four conjugated double bonds into a single molecule. The antioxidant efficiency was evaluated as the ability of the compounds to inhibit lipid peroxidation, reactive oxygen species (ROS) production, heat shock protein (hsp) expression in rat liver microsomal membranes as well as in RAT-1 immortalized fibroblasts challenged with different free radical sources, including 2,2'-azobis(2-amidinopropane) (AAPH), tert-butyl hydroperoxide (tert-BOOH) and H2O2. Our results show that individual tocotrienols display different antioxidant potencies. Irrespective of the prooxidant used, the order of effectiveness was:delta-tocotrienol > gamma-tocotrienol = alpha-tocotrienol in both isolated membranes and intact cells. This is presumably due to the decreased methylation of delta-tocotrienol chromane ring, which allows the molecule to be more easily incorporated into cell membranes. Moreover, we found that FeAox-6 showed an antioxidant potency greater than that of delta-tocotrienol. Such an efficiency seems to depend on the concomitant presence of a chromane ring and a phytyl chain in the molecule, which because of four conjugated double bonds, may induce a greater mobility and a more uniform distribution within cell membrane. In view of these results, FeAox-6 represents a new potential preventive agent in chronic diseases in which oxidative stress plays a pathogenic role.
Molecular and Cellular Biochemistry 08/2006; 287(1-2):21-32. · 2.06 Impact Factor
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ABSTRACT: Benzoyl peroxide is commonly used in the treatment of acne, even though some adverse effects have been reported, probably mediated by the formation of peroxide-derived free radicals and the depletion of antioxidants. In the present work we have studied, in a chemical system, the effect of alpha-tocopherol on benzoyl peroxide radical decomposition to analyse the presence of an interaction between these two compounds, leading to an enhanced peroxide-cytotoxicity, as we have previously reported. Under our experimental conditions alpha-tocopherol strongly amplified the peroxide free radical decomposition occurring either in the presence or in the absence of UV irradiation, and lead to the formation of an unknown radical species in addition to benzoyloxy, phenyl and tocopheroxyl free radicals. The results of this study show that the enhancement of benzoyl peroxide toxicity in cells exposed simultaneously to this peroxide and alpha-tocopherol, is likely due to the generation of the detected radical species.
Free Radical Research 07/2006; 40(6):637-45. · 2.88 Impact Factor
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ABSTRACT: There is a body of evidences demonstrating, in biological systems, a cooperative interaction between tocopherols and carotenoids. FeAOX-6 is a novel antioxidant that combines the chroman head of alpha-tocopherol and a fragment of the isoprenyl chain of lycopene. We have tested its antioxidant effect on different radical species generated in a chemical system, where peroxyl, alkoxyl and methyl radicals are generated by the ferrous ion-mediated decomposition of tert-butyl hydroperoxide. We found that FeAOX-6 has the same effectiveness of alpha-tocopherol in quenching peroxyl radical with no contribution by lycopene. The antioxidant activity of FeAOX-6 on alkoxyl and methyl radicals is comparable to that of the equimolar mixture of the parent compounds. Lycopene is able to quench alkoxyl radical, while it has no effect on peroxyl radical, showing a different antioxidant activity compared to other carotenoids, such as beta-carotene and lutein.
Free Radical Research 03/2006; 40(2):141-6. · 2.88 Impact Factor
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Chiara Mioni,
Carla Bazzani,
Daniela Giuliani,
Domenica Altavilla,
Sheila Leone,
Anna Ferrari,
Letteria Minutoli,
Alessandra Bitto,
Herbert Marini,
Davide Zaffe,
Annibale R Botticelli, Anna Iannone,
Aldo Tomasi,
Albertino Bigiani,
Alfio Bertolini,
Francesco Squadrito,
Salvatore Guarini
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ABSTRACT: A vagus nerve-mediated, brain cholinergic protective mechanism activated by melanocortin peptides is operative in conditions of circulatory shock; moreover, there is anatomical evidence of dual vagal-cardiac efferent pathways in rats, which could play different roles in controlling heart function. Therefore, we investigated the role and functional mechanism of such vagal efferent pathway(s) in an experimental model of ischemic heart disease.
Randomized experimental study.
Research laboratory.
Adult Wistar rats of either sex.
After bilateral cervical vagotomy (with or without pretreatment with atropine), efferent vagal fibers were electrically stimulated in rats subjected to coronary artery occlusion (5 mins) followed by reperfusion (5 mins). Other rats (intact, vagotomized, or pretreated with atropine) were treated with nanomolar doses of melanocortin peptides.
Electrical stimulation of efferent vagal fibers (5 V, 2 m secs, 1-9 Hz, for the whole period of ischemia/reperfusion) strongly reduced the high incidence of severe arrhythmias and lethality, reduced the increase in free radical blood levels and left-ventricle histologic alterations, and augmented the extracellular signal-regulated kinase activation. Treatment with the melanocortin peptides adrenocorticotropin and gamma2-melanocyte-stimulating hormone (162 nmol/kg intravenously or 16.2 nmol/kg intracerebroventricularly, during coronary occlusion) produced the same protective effects of electrical stimulation and with the same muscarinic acetylcholine receptor-dependent mechanism, seemingly through brain activation (mediated by melanocortin MC3 receptors, as previously described) of such efferent vagal pathway.
The present results give evidence for the identification of a protective, melanocortin-activated, efferent vagal cholinergic pathway, operative in conditions of myocardial ischemia/reperfusion. These data suggest that melanocortins and pertinent compounds able to activate such a pathway could provide the potential for development of a new class of drugs for a novel approach to management of ischemic heart disease.
Critical Care Medicine 12/2005; 33(11):2621-8. · 6.33 Impact Factor
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ABSTRACT: An increased free-radical production has been documented during hemodialysis (HD) particularly when bio-incompatible membranes are utilized. These highly reactive free radicals can cause damage through several pathways, one of the best known being lipid peroxidation. Malondialdehyde (MDA) is a product of lipid peroxidation, which can partly be removed by HD due to its low molecular weight and water solubility. Hydroperoxides are predominantly found in lipid substances, and therefore their removal by HD could be difficult. We evaluated the behavior of these two by-products of lipid peroxidation during HD, comparing their behavior in three different membranes, in order to study their reliability as markers of acute oxidative injury. Fifteen stable HD patients were dialyzed with each of the following membranes: cuprophan, polyamide, and polysulfone, three sessions for every membrane. MDA and hydroperoxides were measured pre-HD and then both from the arterial and venous line at 8, 15, 30, and 240 min. During HD with cuprophan membrane MDA decreased significantly in the venous line compared with the arterial line at 8, 15, and 30 min (P < 0.05). At the end of HD, MDA was significantly reduced compared with MDA pre-HD (P < 0.05). Plasma hydroperoxides increased significantly in the venous line compared with the arterial line at 8, 15, 30, and 240 min (P < 0.05). At the end of HD, hydroperoxides had increased significantly as compared with pre-HD (P < 0.05). When the polyamide and polysulfone membranes were used, the behavior of MDA was similar to that found with cuprophan. Hydroperoxides were unchanged during HD using both membranes. MDA is not a reliable marker of acute oxidative injury during HD as it is removed during HD. Hydroperoxide measurement is a better marker of acute oxidative injury during HD.
Artificial Organs 10/2005; 29(10):832-7. · 2.00 Impact Factor
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ABSTRACT: Low-molecular weight heparins (LMWHs), as compared with unfractionated heparin (UFH), present superior bioavailability, much longer plasma half-life, and lower incidence of side effects. For these reasons, over the past two decades LMWHs have become the drugs of choice for the treatment of deep venous thrombosis, pulmonary embolism, arterial thrombosis, and unstable angina. Furthermore, their use in acute ischemic stroke is currently under study. LMWHs are obtained by UFH depolymerization, which can be performed using various methods, including nitrous acid depolymerization, cleavage by beta-elimination of benzyl ester, enzymatic depolymerization, and peroxyl radical-dependent depolymerization. This article addresses the chemical depolymerization, obtained by free radical attack (mainly hydroxyl radical), of heparin. The electron spin resonance (ESR) spectroscopy, coupled to the spin trapping technique, was employed to study this reaction. Free radical-mediated heparin depolymerization was performed under different chemical conditions. The final products of the reactions were purified and classified on the basis of their molecular weight and other characteristics. The level of heparin fragmentation was different depending on the type of depolymerization reaction used. Moreover, the level of reproducibility and the resulting radical species were different for every type of reaction performed.
Analytical Biochemistry 10/2005; 344(2):193-203. · 3.00 Impact Factor
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Leonardo Lucchi,
Sebastiano Banni, Anna Iannone,
Maria Paola Melis,
Gianfranca Carta,
Elisabetta Murru,
Lina Cordeddu,
Lucia Stipo,
Simona Uggeri,
Valentina Gatti,
Vittoria Malaguti,
Alberto Albertazzi
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ABSTRACT: An increase in conjugated linoleic acid (CLA), a natural fatty acid present in our diet, which possesses anticarcinogenic and antiatherogenic activities in experimental models, has been found in both the plasma and adipose tissue of end-stage chronic renal failure (ESCRF) patients. Increased levels of retinol have also been found in those patients, due to a reduced excretion of the retinol-binding protein. Since retinol is known to influence lipid metabolism, we evaluated whether changes in retinol, CLA, and other fatty acids are correlated in the plasma of CRF patients. We measured CLA, retinol, and unsaturated fatty acids in the plasma of the following groups: (A) 35 ESCRF patients; (B) 20 hemodialysis (HD) patients; (C) 20 healthy controls. Subjects with total cholesterol and/or triglycerides higher than 250 mg/dL were excluded. We found a significant increase in CLA, retinol, palmitoleic (16:1), and oleic (18:1) acids in ESCRF patients. In HD patients we found a similar pattern, however, CLA increase was not significant. No changes were observed in the other fatty acids measured. In the groups of ESCRF and HD patients, a positive correlation between the levels of plasma retinol and CLA, and between retinol and 16:1 was found. These correlations were not detected in controls. The abnormal levels of plasma retinol in CRF patients might partly explain the changes in CLA and 16:1. The influence of retinol levels on these fatty acids might be due to an induction of delta 9 desaturase. In fact, 16:1 is known to be produced, partly, by delta 9 desaturation of palmitic acid. Moreover, the formation of CLA from delta 9 desaturation of vaccenic acid-a trans-monounsaturated fatty acid present in our diet-has recently been demonstrated in humans. Nevertheless, our data do not represent direct evidence supporting an increased delta 9 desaturase activity in CRF patients. Another possible explanation might be a variation in the exogenous intake.
Artificial Organs 06/2005; 29(5):413-8. · 2.00 Impact Factor
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ABSTRACT: An increased oxidative stress is now considered one of the major risk factors in chronic renal failure (CRF) patients that may be exacerbated by dialysis. It has been postulated that this increased oxidative stress might cause an augmented red blood cell (RBC) membrane lipid peroxidation with the consequent alteration in membrane deformability. The aim of this study was to evaluate RBC susceptibility to an in vitro induced oxidative stress and RBC antioxidant potential in different groups of CRF patients undergoing different substitutive treatment modalities. Fifteen end-stage CRF patients were evaluated in conservative treatment, 23 hemodialysis (HD) patients, 15 continuous ambulatory peritoneal dialysis (CAPD) patients, 15 kidney transplanted patients, and 16 controls. Their RBCs were incubated with the oxidative stress-inducing agent tert-butylhydroperoxide both in the presence and in the absence of the catalase inhibitor sodium azide, and the level of malondialdehyde (MDA) (a product of lipid peroxidation), was measured at 0, 5, 10, 15, and 30 min of incubation. In addition, the RBC content of reduced glutathione (GSH) was measured by HPLC. As opposed to the controls, RBCs from end-stage CRF patients exhibited an increased sensitivity to oxidative stress induced in vitro, both in the absence and presence of a catalase inhibitor, as demonstrated by a significantly higher level of MDA production at all the incubation times (P < 0.05). Different substitutive treatments had different impacts on this phenomenon; CAPD and kidney transplantation were able to normalize this alteration while HD was not. GSH appeared to be related to the increase in RBC susceptibility to oxidative stress; its content being significantly elevated in end-stage CRF and HD patients as compared with CAPD and transplanted patients and controls (P < 0.05). No significant changes were observed in the RBC glutathione content during the HD session. The increase of GSH in RBCs of end-stage CRF and HD patients seems to indicate the existence of an adaptive mechanism under increased oxidative stress occurring in vivo. Unlike HD, the beneficial effect of CAPD on the anemia of dialysis patients might partly be due to a condition of lower oxidative stress that might in addition counterbalance the cardiovascular negative effects of dislipidemia of CAPD patients.
Artificial Organs 01/2005; 29(1):67-72. · 2.00 Impact Factor
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ABSTRACT: Hypotension is one of the major complications in patients undergoing haemodialysis (HD), that is well evident in patients defined as "hypotension-prone." The mechanisms underlying the hypotensive episodes are not known. We carried out a clinical study on hypotension-prone HD patients to test the existence of a dysregulation in the nitric oxide (NO) generating pathway. Since asymmetric dimethylarginine (ADMA) is an endogenous compound which regulates NO synthesis, we measured its variation in plasma of stable-HD and hypotension-prone patients before, during, and at the end of HD. Before HD, the hypotension-prone patients have higher ADMA levels than stable-HD patients. The HD procedure significantly removes ADMA from plasma of stable-HD patients, while in the hypotension-prone ADMA levels are unchanged at the end of the HD. Moreover, in the hypotension-prone patients, during the hypotensive episode, a dramatic drop of ADMA levels is observed, followed by a rapid increase at the end of the HD. The symmetric dimethylarginine (SDMA), which has no effect on NO synthesis, is also high in plasma of both groups of HD patients compared to normal subjects, and in both groups its levels at the end of HD are significantly reduced. The hypotension-prone patients have basal TNF-alpha levels lower than the stable-HD groups, that significantly increase during the hypotensive episode. On the basis of these findings, we suggest that the hypotensive syndrome could be related to a dysregulation between ADMA metabolism and clearance due both to cytokines release and to an extremely fast ADMA clearance during HD, leading to an increase in NO blood levels.
Nitric Oxide 12/2004; 11(3):273-8. · 3.55 Impact Factor
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ABSTRACT: Benzoyl peroxide is a free-radical generating compound widely used in the polymer industry and also in pharmaceuticals as antimicrobial agent to treat acne. However, benzoyl peroxide causes irritation and contact dermatitis in about 1% of patients. Concern over the use of this compound is motivated by the demonstration that it can also act as skin tumor promoter in mice. In addition, benzoyl peroxide induces DNA strand breaks in many cells, including keratinocytes. Benzoyl peroxide toxicity is presumably mediated by the formation of reactive free radicals and by the consumption of intracellular antioxidants. In this work we investigated the effect of both the lipophilic antioxidant alpha-tocopherol and the hydrophilic thiol donor N-acetylcysteine (NAC) in human keratinocyte line HaCaT exposed to benzoyl peroxide. A protective effect against benzoyl peroxide cytotoxicity was achieved when cells were grown on a alpha-tocopherol layer. On the contrary, the addition of alpha-tocopherol dissolved in ethanol had a pro-oxidant effect, leading to an enhancement of benzoyl peroxide toxicity. Cytotoxicity was also reduced adding NAC to the culture medium; the presence of both NAC and alpha-tocopherol exerts a synergistic cytoprotection.
Journal of Biochemical and Molecular Toxicology 02/2004; 18(2):107-14. · 1.38 Impact Factor
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Chiara Mioni,
Daniela Giuliani,
Maria Michela Cainazzo,
Sheila Leone, Anna Iannone,
Carla Bazzani,
Paolo Grieco,
Ettore Novellino,
Aldo Tomasi,
Alfio Bertolini,
Salvatore Guarini
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ABSTRACT: In rats subjected to myocardial ischemia/reperfusion, melanocortin peptides, including gamma(1)-melanocyte-stimulating hormone (gamma(1)-MSH), are able to exert a protective effect by stimulating brain melanocortin MC(3) receptors. A non-melanocortin receptor belonging to a group of receptors for Phe-Met-Arg-Phe-NH(2) (FMRFamide)-like peptides may be involved in some of the cardiovascular effects of the gamma-MSHs. FMRFamide-like peptides and gamma(1)-/gamma(2)-MSH share, among other things, the C-terminal Arg-Phe sequence, which seems to be essential for cardiovascular effects in normal animals. So we aimed to further investigate which receptor and which structure are involved in the protective effects of melanocortins in anesthetized rats subjected to myocardial ischemia by ligature of the left anterior descending coronary artery (5 min), followed by reperfusion. In saline-treated rats, reperfusion induced, within a few seconds, a high incidence of ventricular tachycardia and ventricular fibrillation, and a high percentage of death within the 5 min of observation period. Reperfusion was associated with a massive increase in free radical blood levels and with an abrupt and marked fall in systemic arterial pressure. The i.v. treatment (162 nmol/kg) during the ischemic period with the adrenocorticotropin fragment 1-24 [ACTH-(1-24): the reference protective melanocortin which binds all melanocortin receptors], as well as with both the melanocortin MC(3) receptor agonists gamma(2)-MSH and [D-Trp(8)]gamma(2)-MSH, reduced the incidence of ventricular tachycardia, ventricular fibrillation and death, the increase in free radical blood levels and the fall in arterial pressure. On the contrary, gamma(2)-MSH-(6-12) (a fragment unable to bind melanocortin receptors) was ineffective. Such protective effect was prevented by the melanocortin MC(3)/MC(4) receptor antagonist SHU 9119. In normal (i.e., not subjected to myocardial ischemia/reperfusion) rats, the same i.v. dose (162 nmol/kg) of gamma(2)-MSH, [D-Trp(8)]gamma(2)-MSH and gamma(2)-MSH-(6-12) provoked a prompt and transient increase in arterial pressure; on the other hand, ACTH-(1-24), which lacks the C-terminal Arg-Phe sequence, decreased arterial pressure, but only at higher doses. Heart rate of normal rats was not affected by any of the assayed peptides. The present data confirm and extend our previous findings that melanocortins prevent myocardial reperfusion injury by activating melanocortin MC(3) receptors. Moreover, they further support the notion that, in normal rats, cardiovascular effects of gamma-MSHs are mediated by receptors for FMRFamide-like peptides, for whose activation, but not for that of melanocortin MC(3) receptors, the C-terminal Arg-Phe structure being relevant.
European Journal of Pharmacology 10/2003; 477(3):227-34. · 2.52 Impact Factor
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ABSTRACT: N-Acetylcysteine (NAC) has a wide spectrum of biological activities, either related to the ability to increase intracellular thiols or directly acting as an antioxidant. We used an in vivo animal model to study NAC modulation of nitric oxide (NO) production in response to lipopolysaccharide treatment. A comparison was made between NAC and the N-[3-(aminomethyl)benzyl] acetamidine (1400W), an inhibitor of the inducible NO synthase (iNOS). Both inhibit NO production, although NAC lacks any effect if given when iNOS is already induced; this indicates that the decrease of NO generation is not due to an effect on iNOS activity. We found that the DNA binding activity of nuclear transcription factor-kappaB in peripheral blood cells was inhibited by NAC given before lipopolysaccharide, whereas tumor necrosis factor-alpha secretion was not affected.
Antioxidants and Redox Signaling 03/2002; 4(1):221-6. · 8.46 Impact Factor
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ABSTRACT: This in vivo study evaluates the effect of N-acetylcysteine (NAC) administration on nitric oxide (NO) production by the inducible form of nitric oxide synthase (iNOS). NO production was induced in the rat by the ip administration of 2 mg/100 g lipopolysaccharide (LPS). This treatment caused: (1) a decrease in body temperature within 90 min, followed by a slow return to normal levels; (2) an increase in plasma levels of urea, nitrite/nitrate, and citrulline; (3) the appearance in blood of nitrosyl–hemoglobin (NO–Hb) and in liver of dinitrosyl–iron–dithiolate complexes (DNIC); and (4) increased expression of iNOS mRNA in peripheral blood mononuclear cells (PBMC). Rat treatment with 15 mg/100 g NAC ip, 30 min before LPS, resulted in a significant decrease in blood NO–Hb levels, plasma nitrite/nitrate and citrulline concentrations, and liver DNIC complexes. PBMC also showed a decreased expression of iNOS mRNA. NAC pretreatment did not modify the increased levels of plasma urea or the hypothermic effect induced by the endotoxin. The administration of NAC following LPS intoxication (15 min prior to sacrifice) did not affect NO–Hb levels. These results demonstrate that NAC administration can modulate the massive NO production induced by LPS. This can be attributed mostly to the inhibitory effect of NAC on one of the events leading to iNOS protein expression. This hypothesis is also supported by the lack of effect of late NAC administration.
Nitric Oxide 09/2001; · 3.55 Impact Factor
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ABSTRACT: Isolated hepatocytes and liver microsomes incubated with monomethyl-1,1 dimethyl- and 1,2 dimethyl-hydrazines produced free radical intermediates which were detected by ESR spectroscopy by using 4-pyridyl-1-oxide-t-butyl nitrone (4-POBN) as spin trapping agent.The spectral features of the spin adducts derived from all three hydrazine derivatives corresponded to the values reported for the methyl free radical adduct of 4-POBN.In the microsomal preparations inhibitors of the mixed function oxidase system and the destruction of cytochrome P450 by pretreating the rats with CoCl2 all decreased the free radical formation. Methimazole, an inhibitor of FAD-containing monoxygenase system, similarly decreased the activation of 1,1 dimethyl-hydrazine, but not that of monomethyl- and 1,2 dimethyl-hydrazines.The addition to liver microsomes of physiological concentrations of glutathione (GSH) lowered by approx. 80% the intensities of the ESR signals. Consistently, incubation of isolated hepatocytes with methyl-hydrazines decreased the intracellular GSH content, suggesting that GSH can effectively scavenge the methyl free radicals.The results obtained suggest that methyl free radicals could be the alkylating species responsible for the toxic and/or carcinogenic effect of methyl-hydrazines.
Free Radical Biology and Medicine.
