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1.
Vitiligo is an acquired pigmentary disorder of the skin of unknown aetiology. The autocytotoxic hypothesis suggests that melanocyte impairment could be related to increased oxidative stress. Evidences have been reported that in vitiligo oxidative stress might also be present systemically. We used the comet assay (single cell alkaline gel electrophoresis) to evaluate DNA strand breaks and DNA base oxidation, measured as formamidopyrimidine DNA glycosylase (FPG)-sensitive sites, in peripheral blood cells from patients with active vitiligo and healthy controls. The basal level of oxidative DNA damage in mononuclear leukocytes was increased in vitiligo compared to normal subjects, whereas DNA strand breaks (SBs) were not changed. This alteration was not accompanied by a different capability to respond to in vitro oxidative challenge. No differences in the basal levels of DNA damage in polymorphonuclear leukocytes were found between patients and healthy subjects. Thus, this study supports the hypothesis that in vitiligo a systemic oxidative stress exists, and demonstrates for the first time the presence of oxidative alterations at the nuclear level. The increase in oxidative DNA damage shown in the mononuclear component of peripheral blood leukocytes from vitiligo patients was not particularly severe. However, these findings support an adjuvant role of antioxidant treatment in vitiligo.  相似文献   

2.
Summary. Gaucher disease is caused by an autosomal-recessive deficiency of glucocerebrosidase. Cells of monocytic/macrophagic origin accumulate glucosylceramide. This leads to hepatosplenomegaly, bone destruction, thrombocytopenia and anemia. Enzyme replacement therapy (ERT) with macrophage-targeted glucocerebrosidase leads to normalization of these parameters. The way of macrophage activation in Gaucher disease is not known. Recently, the osmolytes taurine, betaine and inositol were identified as important regulators of macrophage function in liver. Therefore, the role of plasma taurine in Gaucher disease as a primarily macrophage-derived disease was studied. Fasting plasma levels were measured from blood samples of healthy control subjects (n = 29, m : f = 11 : 18, mean age 37 ± 3 years), from un-treated Gaucher patients (n = 16, m : f = 7 : 9, mean age 44 ± 4 years) and those treated for 37 ± 2 months (n = 54, m : f = 19 : 35, mean age 47 ± 2 years). Amino acid analysis was carried out in a BioChrom amino acid analyzer. In the untreated patients, plasma taurine was 45 ± 3 μM, as compared to the controls with a plasma taurine of 63 ± 4 μM (p < 0.01). The aver-age increase of plasma taurine during the first year of ERT was 18 ± 8 μM (n = 10). Patients treated for an average of 37 months (range 1–9 years of ERT) had a plasma taurine of 65 ± 4 μM (n = 54), which was not different from the controls. It is concluded that Gaucher patients show decreased plasma taurine levels and that therapy of Gaucher disease might correct this. It has to be established, whether decreased taurine availability is a cofactor of the permanent activation of glucosylceramide-storing monocytes/macrophages in this disease. Received January 25, 2000/Accepted January 31, 2000  相似文献   

3.
We have previously derived 2 V79 clones resistant to menadione (Md1 cells) and cadmium (Cd1 cells), respectively. They both were shown to be cross-resistant to hydrogen peroxide. There was a modification in the antioxidant repertoire in these cells as compared to the parental cells. Md1 presented an increase in catalase and glutathione peroxidase activities whereas Cd1 cells exhibited an increase in metallothionein and glutathione contents. The susceptibility of the DNA of these cells to the damaging effect of H2O2 was tested using the DNA precipitation assay. Both Md1 and Cd1 DNAs were more resistant to the peroxide action. In the case of Md1 cells it seems clear that the extra resistance is provided by the increase in the two H2O2 scavenger enzymes, catalase and glutathione peroxidase. In the case of Cd1 cells the activities of these enzymes as well as of superoxide dismutases (Cu/Zn and Mn) are unaltered as compared to the parental cells. The facts that parental cells exposed to 100 μM Zn2+ in the medium exhibit an increase in metallothionein but not in glutathione and that these cells become more resistant to the DNA-damaging effect of H2O2 suggest that this protein might play a protective role in vivo against the OH radical attack on DNA.  相似文献   

4.
Type 2 diabetes mellitus is associated with increased oxidative stress. Free radicals produced during this stress may damage various cellular components. Gliclazide, a second-generation sulfonylurea, is an oral hypoglycemic drug that possesses antioxidant properties. Therefore, gliclazide may diminish the harmful consequences of oxidative stress in diabetic patients. The aim of our study was to evaluate the action of gliclazide on DNA damage and repair in normal human peripheral blood lymphocytes and insulinoma mouse cells (beta-TC-6). DNA damage and repair were induced by hydrogen peroxide, gamma and ultraviolet radiation and MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) in the presence or absence of gliclazide and were analysed by the alkaline comet assay. DNA double-strand breaks were assayed by pulsed-field gel electrophoresis. Gliclazide protected DNA of both kinds of cells from DNA damage induced by chemicals and radiations. These results suggest that gliclazide may diminish the risk of free radical-related diseases associated with type 2 diabetes mellitus and possibly cancer.  相似文献   

5.
COVID-19 disease, which spreads worldwide, is a disease characterized by widespread inflammation and affects many organs, especially the lungs. The resulting inflammation can lead to reactive oxygen radicals, leading to oxidative DNA damage. The pneumonia severity of 95 hospitalized patients with positive RT-PCR test was determined and divided into three groups: mild, moderate, and severe/critical. Inflammation markers (neutrophil–lymphocyte ratio, serum reactive protein, procalcitonin, etc.) were determined, and IL-10 and IFN-γ measurements were analyzed using the enzyme-linked immunosorbent assay method. In evaluating oxidative damage, total thiol, native thiol, disulfide, and ischemia-modified albumin (IMA) levels were determined by measuring spectrophotometrically. The comet assay method’s percentage of tail DNA obtained was used to determine oxidative DNA damage. As a result, when the mild and severe/critical groups were compared, we found that total thiol, native thiol, and disulfide levels decreased significantly in the severe/critical group due to the increase in inflammation markers and cytokine levels (p < 0.05). We could not detect any significance in IMA levels between the groups (p > 0.05). At the same time, we determined an increase in the tail DNA percent level, that is, DNA damage, due to the increased oxidative effect. As a result, we determined that inflammation and oxidative stress increased in patients with severe pneumonia, and there was DNA damage in these patients.  相似文献   

6.
Phenylketonuria (PKU) is an inborn error of phenylalanine (Phe) metabolism, biochemically characterized by the accumulation of Phe and its metabolites in blood and tissues of affected patients. Treatment for PKU consists of a protein restricted diet supplemented with a mixture containing essential amino acids (other than Phe) and micronutrients. In recent years several authors have studied the pathomechanisms of the disease and demonstrated the existence of lipid and protein oxidative damage in PKU patients. In this work we investigated the in vivo and in vitro effects of Phe on DNA damage determined by the alkaline comet assay using silver staining and visual scoring. We found a dose-dependent effect of Phe on DNA damage in leukocytes from normal individuals incubated with different concentrations of Phe. Additionally, by analyzing blood leukocytes from two groups of treated PKU patients based on their blood Phe levels, we verified that the DNA damage index was significantly higher in PKU patients with high Phe blood levels (DI = 68.2 ± 12.3), compared to well-treated patients and the control group (healthy individuals). Furthermore, well-treated PKU patients had greater DNA damage (DI = 44.9 ± 7.6) relatively to controls (DI = 12.7 ± 4.1). Our present in vitro and in vivo findings indicate that DNA damage occurs in peripheral blood from PKU patients and is associated to Phe blood levels.  相似文献   

7.
8.
Mucopolysaccharidosis type II (MPS II) is an inborn error of the metabolism resulting from several possible mutations in the gene coding for iduronate-2-sulfatase (IDS), which leads to a great clinical heterogeneity presented by these patients. Many studies demonstrate the involvement of oxidative stress in the pathogenesis of inborn errors of metabolism, and mitochondrial dysfunction and oxidative stress can be related since most of reactive oxygen species come from mitochondria. Cellular models have been used to study different diseases and are useful in biochemical research to investigate them in a new promising way. The aim of this study is to develop a heterozygous cellular model for MPS II and analyze parameters of oxidative stress and mitochondrial dysfunction and investigate the in vitro effect of genistein and coenzyme Q10 on these parameters for a better understanding of the pathophysiology of this disease. The HP18 cells (heterozygous c.261_266del6/c.259_261del3) showed almost null results in the activity of the IDS enzyme and presented accumulation of glycosaminoglycans (GAGs), allowing the characterization of this knockout cellular model by MPS II gene editing. An increase in the production of reactive species was demonstrated (p < .05 compared with WT vehicle group) and genistein at concentrations of 25 and 50 µm decreased in vitro its production (p < .05 compared with HP18 vehicle group), but there was no effect of coenzyme Q10 in this parameter. There was a tendency for lysosomal pH change in HP18 cells in comparison to WT group and none of the antioxidants tested demonstrated any effect on this parameter. There was no increase in the activity of the antioxidant enzymes superoxide dismutase and catalase and oxidative damage to DNA in HP18 cells in comparison to WT group and neither genistein nor coenzyme q10 had any effect on these parameters. Regarding mitochondrial membrane potential, genistein induced mitochondrial depolarization in both concentrations tested (p < .05 compared with HP18 vehicle group and compared with WT vehicle group) and incubation with coenzyme Q10 demonstrated no effect on this parameter. In conclusion, it is hypothesized that our cellular model could be compared with a milder MPS II phenotype, given that the accumulation of GAGs in lysosomes is not as expressive as another cellular model for MPS II presented in the literature. Therefore, it is reasonable to expect that there is no mitochondrial depolarization and no DNA damage, since there is less lysosomal impairment, as well as less redox imbalance.  相似文献   

9.
Short-term storage and cryopreservation of sperm are two common procedures in aquaculture, used for routine practices in artificial insemination reproduction and gene banking, respectively. Nevertheless, both procedures cause injuries affecting sperm motility, viability, cell structure and DNA stability, which diminish reproductive success. DNA modification is considered extremely important, especially when sperm storage is carried out with gene banking purposes. DNA damage caused by sperm storage is not well characterized and previous studies have reported simple and double strand breaks that have been attributed to oxidative events promoted by the generation of free radicals during storage.The objective of this study was to reveal DNA fragmentation and to explore the presence of oxidized bases that could be produced by oxidative events during short-term storage and cryopreservation in sex-reversed rainbow trout (Oncorhynchus mykiss) spermatozoa. Sperm from six males was analyzed separately. Different aliquots of the samples were stored 2 h (fresh) or 5 days at 4 °C or were cryopreserved. Then spermatozoa were analyzed using the Comet assay, as well as combining this method with digestion with two endonucleases from Escherichia coli (Endonuclease III, that cut in oxidized cytosines, and FPG, cutting in oxidized guanosines). Both storage procedures yielded DNA fragmentation, but only short-term storage oxidative events were clearly detected, showing that oxidative processes affect guanosines rather than cytosines. Cryopreservation increases DNA fragmentation but the presence of oxidized bases was not noticed, suggesting that mechanisms other than oxidative stress could be involved in DNA fragmentation promoted by freezing.  相似文献   

10.
Abstract

Objectives

The presence of inflammatory cells indicates the development of epithelial cell injury in nasal polyposis (NP) and the potential for production of high levels of reactive oxygen and nitrogen species. The aim of our study was to clarify the role of oxidative stress and antioxidant status in the deterioration accompanying NP.

Methods

Twenty patients (11 men) aged 47.2 ± 17.0 years with nasal polyps were included in the study. Twenty healthy subjects (7 men) aged 48.2 ± 15.3 years formed the control group. The erythrocyte activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), and plasma nitric oxide (NO) concentrations were measured. An alkaline comet assay was used to determine the extent of blood lymphocyte DNA damage of oxidized purines as glicosylo-formamidoglicosylase (Fpg) sites, and oxidized pyrimidines as endonuclease III (Nth) sites.

Results

A significant increase of NO (P < 0.05) and non-significant decreases of SOD (P > 0.05), CAT (P > 0.05), and GPx (P > 0.05) were seen in NP patients compared to healthy controls. The level of blood lymphocyte oxidative DNA damage in NP patients was significantly higher compared to the control group (P = 0.01).

Discussion

The blood lymphocyte DNA damage level increased in patients with NP. Elevated DNA damage may be related to overproduction of reactive oxygen and nitrogen species and/or decreased antioxidant protection.  相似文献   

11.
The interaction of a quercetin copper(II) complex with DNA was investigated using UV–vis spectra, fluorescence measurement, viscosity measurement, agarose gel electrophoresis, and thiobarbituric acid reactive substances assay. The results indicate that the quercetin copper(II) complex can promote the cleavage of plasmid DNA, producing single and double DNA strand breaks, and intercalate into the stacked base pairs of DNA. Moreover, the complex can induce oxidative DNA damage involving generation of reactive oxygen species such as H2O2 and Cu(I)OOH. In addition, the cytotoxicity experiments carried out with A549 cells confirmed its apoptosis-inducing activity. And we also demonstrate that the levels of survivin protein expression in A549 cells decreased, and that relative activity of caspase-3 increased significantly after treatment with the complex. So our results suggest that the antitumor mechanism of the quercetin copper(II) complex involves not only its oxidative DNA damage with generation of reactive oxygen species but also its specific interaction with DNA. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

12.
Type 2 diabetes mellitus (T2DM) is associated with a high production of reactive oxygen species, which may cause oxidative DNA damage. High levels of genomic damage have been associated with renal failure and hemodialysis. However, no information is available in the literature concerning the levels of DNA damage in T2DM individuals who are dependent on hemodialysis. This study used the comet assay to assess the levels of DNA damage before, immediately after and 48 h after the hemodialysis session in 25 patients with T2DM and in a group of 20 healthy individuals, selected according to mean age, sex and smoking habit. Our results showed increased levels of DNA damage in hemodialysis-dependent T2DM individuals (12.36 ± 8.04) when compared with healthy individuals (7.35 ± 7.41) (p = 0.014). Damage levels increased immediately after the hemodialysis session (19.76 ± 12.40) (p = 0.04), which suggests a possible action of pro-oxidative factors related to the therapy, with a genotoxic effect on cells. Results obtained 48 h after hemodialysis (6.44 ± 5.99) evidenced damage removal (p = 0.001), which may be suggestive of DNA repair.  相似文献   

13.
Cultured human skin fibroblasts from control persons and from patients with the generalized and late-onset forms of Pompe's disease were labelled with radioactive leucine and the incorporation of radioactivity into acid alpha-glucosidase and cathepsin D was analysed by immunoprecipitation, gel electrophoresis and fluorography. When the labelling was carried out for 6-12 h in the presence of NH4Cl, the labelling of secreted alpha-glucosidase relative to that of secreted cathepsin D in fibroblasts from patients with the late-onset form of Pompe's disease was less than 15% of that in fibroblasts from control persons. However, when the fibroblasts were labelled for less than 1 h, the relative rate of incorporation of radioactivity into acid alpha-glucosidase was rather similar in the two types of fibroblasts. In fibroblasts from patients with the generalized form of Pompe's disease no incorporation of radioactivity into acid alpha-glucosidase could be detected.  相似文献   

14.
Fabry disease is an X-linked lysosomal storage disease (LSD) caused by deficient activity of α-Galactosidase A (α-Gal A). As a result, glycosphingolipids, mainly globotriaosylceramide (Gb3), progressively accumulate in body fluids and tissues. Studies aiming at the identification of secondary lipid alterations in Fabry disease may be potentially useful for the monitorization of the response to enzyme replacement therapy (ERT) and development of future therapies. The focus of this study was to evaluate if α-Gal A deficiency has an effect on two key groups of molecules of sphingolipids metabolism: glucosylceramides (GlucCers) and ceramides (Cers). Studies performed in a mouse model of Fabry disease showed reduced level of GlucCer and normal level of Cer in plasma, liver, spleen, kidney and heart. Moreover, analysis of GlucCer isoforms in Fabry knockout mice showed that GlucCer isoforms are unequally reduced in different tissues of these animals. ERT had a specific effect on the liver's GlucCer levels of Fabry knockout mice, increasing hepatic GlucCer to the levels observed in wild type mice. In contrast to Fabry knockout mice, plasma of Fabry patients had normal GlucCer and Cer but an increased GlucCer/Cer ratio. This alteration showed a positive correlation with plasma globotriaosylsphingosine (lyso-Gb3) concentration. In conclusion, this work reveals novel secondary lipid imbalances caused by α-Gal A deficiency.  相似文献   

15.
16.
This study was aimed to determine the effects of boric acid on oxidative stress, testicular tissue and spermatozoon DNA. Experiments were performed with Swiss Albino mice divided equally into two groups based on the tratment period: one for 4 and the other for 6-week duration. These groups were further divided into subgroups as Control and those administered daily at oral doses of 115 mg/kg, 250 mg/kg and 450 mg/kg of boric acid. Then, testicular tissue were examined postmortem and analyzed using ex-vivo biochemical tools for oxidative stress, spermatozoon membrane integrity, sperm motility and live cell rate (%). In both 4 and 6-week groups, v. seminalis weight, membrane integrity, motility, live cells and GSH levels exhibited a decreasing trent compared to the controls. In addition, 6-week group had a decrease in SOD level. MDA level was higher in controls in both 4 and 6-week groups. Spermatozoon DNA was intact in the 4-week group, but damaged in the 6-week group, and the degree of the damage dependent on the administered dose. Boric acid induces oxidative stress in testicular tissue, and its long-term application (only 6 weeks) caused damage in spermatozoon DNA.  相似文献   

17.
Background: Chronic kidney failure (CKF) patients on renal replacement therapies exhibit elevated levels of DNA lesions and this is directly related to high mortality.

Objective: This study aimed to evaluate the effect of neuromuscular electrical stimulation (NMES) on genomic damage in CKF patients on conventional haemodialysis (HD).

Methods: Twenty-one patients with CKF on HD were randomized into control (CG =10) or neuromuscular electrical stimulation (NMESG?=?11) groups. NMES was applied on the quadriceps muscle during the HD session, three times a week, for 8 weeks in NMESG. DNA damage in blood was evaluated by the alkaline comet assay prior to follow-up, after 4 and 8 weeks of intervention.

Results: Intradialytic NMES in CKF patients induced a significant decrease in DNA damage after four [49.9 (3.68) vs 101.5 (6.53); p?=?0.000] than eight [19.9 (2.07) vs 101.5 (6.53); p?=?0.000] weeks compared to baseline. Genomic damage was also significantly less after four [NMESG: 49.9 (3.68) vs CG: 92.9 (12.61); p?=?0.001] than after eight [NMESG: 19.9 (2.07) vs CG: 76.4 (11.15); p?=?0.000] weeks compared to CG.

Conclusions: This study demonstrates for the first time that intradialytic NMES is able to reduce DNA damage in blood of CKF patients.  相似文献   

18.
Vascular smooth muscle cells (VSMCs) undergo death during atherosclerosis, a widespread cardiovascular disease. Recent studies suggest that oxidative damage occurs in VSMCs and induces atherosclerosis. Here, we analyzed oxidative damage repair in VSMCs and found that VSMCs are hypersensitive to oxidative damage. Further analysis showed that oxidative damage repair in VSMCs is suppressed by a low level of poly (ADP-ribosyl)ation (PARylation), a key post-translational modification in oxidative damage repair. The low level of PARylation is not caused by the lack of PARP-1, the major poly(ADP-ribose) polymerase activated by oxidative damage. Instead, the expression of poly(ADP-ribose) glycohydrolase, PARG, the enzyme hydrolyzing poly(ADP-ribose), is significantly higher in VSMCs than that in the control cells. Using PARG inhibitor to suppress PARG activity facilitates oxidative damage-induced PARylation as well as DNA damage repair. Thus, our study demonstrates a novel molecular mechanism for oxidative damage-induced VSMCs death. This study also identifies the use of PARG inhibitors as a potential treatment for atherosclerosis. [BMB Reports 2015; 48(6): 354-359]  相似文献   

19.
The objective of the present study was to establish the effect of deoxynivalenol (DON) and T-2 toxin on lipid peroxidation, lymphocyte DNA fragmentation and immunoglobulin production in weaned pigs, and furthermore, to evaluate the potential of vitamin E (α-tocopheryl acetate) in prevention of toxin mediated changes. Forty-eight weaned castrated male crossbred pigs (mean live weight at the beginning of the experimental period was 11.7 kg) were randomly assigned to five experimental groups: control (without toxin and vitamin E), T-2 (3 mg/kg T-2 toxin), T-2 + E (3 mg/kg T-2 toxin + 100 mg/kg vitamin E), DON (4 mg/kg DON) and DON + E (4 mg/kg DON + 100 mg/kg vitamin E). After 14 days of treatment blood was collected for analysis. Lipid peroxidation was studied by assays of malondialdehyde (MDA), total antioxidant status (TAS) of plasma and erythrocyte glutathione peroxidase (GPx). DNA damage in lymphocytes was measured by comet assay. Serum immunoglobulin levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and the hepatotoxicity was studied by measuring plasma liver enzyme levels (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl-transferase (GGT). Production parameters of both DON groups were significantly impaired in comparison to the control. DON significantly increased the amount of DNA damage in lymphocytes by 28%. Moreover, the levels of TAS were lowered by addition of DON. T-2 toxin significantly impaired daily live weight gain and feed conversion, increased the amount of DNA damage in lymphocytes by 27%, decreased total serum IgG and did not alter plasma TAS. Plasma and 24-h urinary malondialdehyde (MDA) excretion rate and erythrocyte Gpx levels did not differ among the groups. Supplementation with vitamin E did not improve production parameters impaired by DON and T-2 toxin and only partially protected lymphocyte DNA from toxin impact. To our knowledge, these are the first data on genotoxic effects of moderate doses of DON and T-2 toxin on pig lymphocytes. The effect of DON and T-2 toxin on the immune system was reflected as a change in immunoglobulin synthesis, which might be toxin and species specific. According to other results no major induction of oxidative stress could be proven. Enhancement of antioxidant status with vitamin E in the case of DON and T-2 toxin intoxication can be beneficial for remaining the lymphocyte DNA integrity.  相似文献   

20.
《Autophagy》2013,9(11):1697-1700
The autophagy-lysosome system is essential for muscle cell homeostasis and its dysfunction has been linked to muscle disorders that are typically distinguished by massive autophagic buildup. Among them, glycogen storage disease type II (GSDII) is characterized by the presence of large glycogen-filled lysosomes in the skeletal muscle, due to a defect in the lysosomal enzyme acid α-glucosidase (GAA). The accumulation of autophagosomes is believed to be detrimental for myofiber function. However, the role of autophagy in the pathogenesis of GSDII is still unclear. To address this issue we monitored autophagy in muscle biopsies and myotubes of early and late-onset GSDII patients at different time points of disease progression. Moreover we also analyzed muscles from patients treated with enzyme replacement therapy (ERT). Our data suggest that autophagy is a protective mechanism that is required for myofiber survival in late-onset forms of GSDII. Importantly, our findings suggest that a normal autophagy flux is important for a correct maturation of GAA and for the uptake of recombinant human GAA. In conclusion, autophagy failure plays an important role in GSDII disease progression, and the development of new drugs to restore the autophagic flux should be considered to improve ERT efficacy.  相似文献   

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