Vanusa Manfredini

Globotriaosylceramide is correlated with oxidative stress and inflammation in Fabry patients treated with enzyme replacement therapy

Fabry disease is an X-linked inborn error of glycosphingolipid catabolism due to deficient activity of α-galactosidase A that leads to accumulation of the enzyme substrates, mainly globotriaosylceramide (Gb3), in body fluids and lysosomes of many cell types. Some pathophysiology hypotheses are intimately linked to reactive species production and inflammation, but until this moment there is no in vivo study about it. Hence, the aim of this study was to investigate oxidative stress parameters, pro-inflammatory cytokines and Gb3 levels in Fabry patients under treatment with enzyme replacement therapy (ERT) and finally to establish a possible relation between them. We analyzed urine and blood samples of patients under ERT (n=14) and healthy age-matched controls (n=14). Patients presented decreased levels of antioxidant defenses, assessed by reduced glutathione (GSH), glutathione peroxidase (GPx) activity and increased superoxide dismutase/catalase (SOD/CAT) ratio in erythrocytes. Concerning to the damage to biomolecules (lipids and proteins), we found that plasma levels of malondialdehyde (MDA) and protein carbonyl groups and di-tyrosine (di-Tyr) in urine were increased in patients. The pro-inflammatory cytokines IL-6 and TNF-α were also increased in patients. Urinary Gb3 levels were positively correlated with the plasma levels of IL-6, carbonyl groups and MDA. IL-6 levels were directly correlated with di-Tyr and inversely correlated with GPx activity. This data suggest that pro-inflammatory and pro-oxidant states occur, are correlated and seem to be induced by Gb3 in Fabry patients.

γ-Oryzanol protects against acute cadmium-induced oxidative damage in mice testes.

Cadmium is a non-essential heavy metal that is present at low levels mainly in food and water and also in cigar smoke. The present study evaluated the testicular damage caused by acute cadmium exposure and verified the protective role of γ-oryzanol (ORY). Mice were administrated with a single dose of 2.5mg/kg of CdCl2, and then treated with ORY (50mM in canola oil, 5mL/kg). Testes were removed after 24h and tested for lipid peroxidation (TBARS), protein carbonylation, DNA breakage, ascorbic acid, cadmium and non-proteic thiols contents, and for the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST) and δ-aminolevulic acid dehydratase (δ-ALA-D). Cadmium presented a significant alteration in all parameters, except GPx and CAT activities. Therapy reduced in a slight degree cadmium concentration in testes (around 23%). ORY restored SOD and GST activities as well as TBARS production to the control levels. Furthermore, ORY partially recovered δ-ALA-D activity inhibited by cadmium. This study provides the first evidence on the therapeutic properties of ORY in protecting against cadmium-induced testicular toxicity.

Protein and lipid damage in maple syrup urine disease patients: l-carnitine effect

Maple syrup urine disease (MSUD) is an inborn error of metabolism biochemically characterized by elevated levels of the branched chain amino acids (BCAA) leucine, isoleucine, valine and the corresponding branched‐chain α‐keto acids. This disorder is clinically characterized by ketoacidosis, seizures, coma, psychomotor delay and mental retardation whose pathophysiology is not completely understood. Recent studies have shown that oxidative stress may be involved in neuropathology of MSUD. l‐Carnitine (l‐Car) plays a central role in the cellular energy metabolism because it transports long‐chain fatty acids for oxidation and ATP generation. In recent years many studies have demonstrated the antioxidant role of this compound. In this work, we investigated the effect of BCAA‐restricted diet supplemented or not with l‐Car on lipid peroxidation and in protein oxidation in MSUD patients. We found a significant increase of malondialdehyde and of carbonyl content in plasma of MSUD patients under BCAA‐restricted diet compared to controls. Furthermore, patients under BCAA‐restricted diet plus l‐Car supplementation presented a marked reduction of malondialdehyde content in relation to controls, reducing the lipid peroxidation. In addition, free l‐Car concentrations were negatively correlated with malondialdehyde levels. Our data show that l‐Car may have an antioxidant effect, protecting against the lipid peroxidation and this could represent an additional therapeutic approach to the patients affected by MSUD.

DNA damage in leukocytes from pretreatment mucopolysaccharidosis type II patients; protective effect of enzyme replacement therapy.

Mucopolysaccharidosis type II (MPS II) is an X-linked recessive disease caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase, leading to progressive accumulation of glycosaminoglycans in nearly all cell types, tissues and organs. Enzyme replacement therapy reduces the storage of these substances in the lysosomes. Oxidative stress is related to the pathophysiology of many disorders, including inborn errors of metabolism. Oxidative damage to protein and lipid has been described in MPS types I and III. The aim of this study was to analyze DNA damage, as determined by the alkaline comet assay using silver staining, in peripheral leukocytes from MPS II patients before treatment and during the first six months of enzyme replacement therapy. We also correlated DNA damage with lipid and protein oxidative damages, analyzed by plasma malondialdehyde levels and carbonyl group content, respectively. We found a significant increase in lipid and protein damage in MPS II patients before treatment when compared to controls. Also, our results showed greater DNA damage in terms of damage index (DI) in pretreatment MPS II patients (DI=18.0 ± 2.4) when compared to controls (DI=66.0 ± 2.0). Enzyme replacement therapy led to a significant decrease in levels of malondialdehyde and DNA damage when compared to pretreatment, but did not reach control values. Significant positive correlations between DNA damage and malondialdehyde levels, as well as carbonyl group content, were observed. Our findings indicate that MPS II patients are subject to DNA damage and that enzyme replacement therapy is able to protect against this process.

Interaction between endothelial nitric oxide synthase gene polymorphisms (-786T>C, 894G>T and intron 4 a/b) and cardiovascular risk factors in acute coronary syndromes.

BACKGROUND AND AIMSnEndothelial rupture of coronary plaque can represent the pathomorphological substratum of acute coronary syndrome (ACS). Polymorphisms in the NOS3 gene (eNOS) -786T>C, 894G>T and intron 4 a/b VNTR can be associated with a higher susceptibility for ACS. The present study is focused on the investigation of the interaction of these polymorphisms and cardiovascular risk factors in 135 patients with ACS and 115 control subjects.nnnMETHODSnCase-control study where the allele and genotype frequencies of the polymorphisms -786T> C, 894G> T and intron 4 VNTR of the gene encoding eNOS were determined by PCR-RFLP associated with cardiovascular risk factors.nnnRESULTSnAn association of the 894TT genotype and 894GT+GG (OR 1.4; 95% CI 1.0-1.8) in ACS has been observed. Subjects without dyslipidemia and intron 4 a/b genotype present a lower chance for ACS development, whereas subjects without diabetes and 894TT genotype show a higher risk for ACS (OR 1.7; 95% CI 1.2-2.3). In patients without dyslipidemia, the 894GG genotype presented a tendency to behave as a protector factor against ACS. Also, the 894GG genotype has been a protective factor for ACS in females (OR 0.5; CI 95% 0.2-0.9).nnnCONCLUSIONSnOur results suggest that eNOS polymorphisms may be an additional risk factor in development of ACS.

Prevention of DNA damage by l-carnitine induced by metabolites accumulated in maple syrup urine disease in human peripheral leukocytes in vitro

Maple syrup urine disease (MSUD) is an inherited aminoacidopathy caused by a deficiency in branched-chain α-keto acid dehydrogenase complex activity that leads to the accumulation of the branched-chain amino acids (BCAAs) leucine (Leu), isoleucine, and valine and their respective α-keto-acids, α-ketoisocaproic acid (KIC), α keto-β-methylvaleric acid, and α-ketoisovaleric acid. The major clinical features presented by MSUD patients include ketoacidosis, failure to thrive, poor feeding, apnea, ataxia, seizures, coma, psychomotor delay, and mental retardation; however, the pathophysiology of this disease is poorly understood. MSUD treatment consists of a low protein diet supplemented with a mixture containing micronutrients and essential amino acids but excluding BCAAs. Studies have shown that oxidative stress may be involved in the neuropathology of MSUD, with the existence of lipid and protein oxidative damage in affected patients. In recent years, studies have demonstrated the antioxidant role of L-carnitine (L-Car), which plays a central function in cellular energy metabolism and for which MSUD patients have a deficiency. In this work, we investigated the in vitro effect of Leu and KIC in the presence or absence of L-Car on DNA damage in peripheral whole blood leukocytes using the alkaline comet assay with silver staining and visual scoring. Leu and KIC resulted in a DNA damage index that was significantly higher than that of the control group, and L-Car was able to significantly prevent this damage, mainly that due to KIC.

Homocysteine contribution to DNA damage in cystathionine β-synthase-deficient patients.

High blood levels of homocysteine (Hcy) are found in patients affected by homocystinuria, a genetic disorder caused by deficiency of cystathionine β-synthase (CBS) activity, as well as in nutritional deficiencies (vitamin B12 or folate) and in abnormal renal function. We previously demonstrated that lipid and protein oxidative damage is increased and the antioxidant defenses diminished in plasma of CBS-deficient patients, indicating that oxidative stress is involved in the pathophysiology of this disease. In the present work, we extended these investigations by evaluating DNA damage through the comet assay in peripheral leukocytes from CBS-deficient patients, as well as by analyzing of the in vitro effect of Hcy on DNA damage in white blood cells. We verified that DNA damage was significantly higher in the CBS-deficient patients under treatment based on a protein-restricted diet and pyridoxine, folic acid, betaine and vitamin B12 supplementation, when compared to controls. Furthermore, the in vitro study showed a concentration-dependent effect of Hcy inducing DNA damage. Taken together, the present data indicate that DNA damage occurs in treated CBS-deficient patients, possibly due to high Hcy levels.

Green tea infusion improves cyclophosphamide-induced damage on male mice reproductive system

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Hypoxanthine Intrastriatal Administration Alters Neuroinflammatory Profile and Redox Status in Striatum of Infant and Young Adult Rats

Hypoxanthine, the major oxypurine metabolite involved in purine’s salvage pathway in the brain, is accumulated in Lesch-Nyhan disease, an inborn error of metabolism of purine. The purpose of this study was to investigate the effects of hypoxanthine intrastriatal administration on infant and young adult rats submitted to stereotactic surgery. We analyzed the effect of hypoxanthine on neuroinflammatory parameters, such as cytokine levels, immunocontent of NF-κB/p65 subunit, iNOS immunocontent, nitrite levels, as well as IBA1 and GFAP immunocontent in striatum of infant and young adult rats. We also evaluate some oxidative parameters, including reactive species production, superoxide dismutase, catalase, glutathione peroxidase activities, as well as DNA damage. Wistar rats of 21 and 60xa0days of life underwent stereotactic surgery and were divided into two groups: control (infusion of saline 0.9xa0%) and hypoxanthine (10xa0μM). Intrastriatal administration of hypoxanthine increased IL-6 levels in striatum of both ages of rats tested, while TNF-α increased only in 21-day-old rats. Hypoxanthine also increased nuclear immunocontent of NF-κB/p65 subunit in striatum of both ages of rats. Nitrite levels were decreased in striatum of 21-day-old rats; however, the immunocontent of iNOS was increased in striatum of hypoxanthine groups. Microglial and astrocyte activation was seen by the increase in IBA1 and GFAP immunocontent, respectively, in striatum of infant rats. All oxidative parameters were altered, suggesting a strong neurotoxic hypoxanthine role on oxidative stress. According to our results, hypoxanthine intrastriatal administration increases neuroinflammatory parameters perhaps through oxidative misbalance, suggesting that this process may be involved, at least in part, to neurological disorders found in patients with Lesch-Nyhan disease.

Hyperprolinemia induces DNA, protein and lipid damage in blood of rats: antioxidant protection.

The present study investigated the effects of hyperprolinemia on oxidative damage to biomolecules (protein, lipids and DNA) and the antioxidant status in blood of rats. The influence of the antioxidants on the effects elicited by proline was also examined. Wistar rats received two daily injections of proline and/or vitamin E plus C (6th-28th day of life) and were killed 12h after the last injection. Results showed that hyperprolinemia induced a significant oxidative damage to proteins, lipids and DNA demonstrated by increased carbonyl content, malondialdehyde levels and a greater damage index in comet assay, respectively. The concomitant antioxidants administration to proline treatment completely prevented oxidative damage to proteins, but partially prevented lipids and DNA damage. We also observed that the non-enzymatic antioxidant potential was decreased by proline treatment and partially prevented by antioxidant supplementation. The plasma levels of vitamins E and C significantly increased in rats treated exogenously with these vitamins but, interestingly, when proline was administered concomitantly with vitamin E plus C, the levels of these vitamins were similar to those found in plasma of control and proline rats. Our findings suggest that hyperprolinemia promotes oxidative damage to the three major classes of macromolecules in blood of rats. These effects were accomplished by decrease in non-enzymatic antioxidant potential and decrease in vitamins administered exogenously, which significantly decreased oxidative damage to biomolecules studied. These data suggest that antioxidants may be an effective adjuvant therapeutic to limit oxidative damage caused by proline.