MO900ENHANCED EXPRESSION OF THIOREDOXIN-INTERACTING PROTEIN (TXNIP) RESULTS IN REDUCED TRX ACTIVITY AND INCREASED OXIDATIVE DNA-DAMAGE IN PERITONEAL DIALYSIS PATIENTS*

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Tina Oberacker ◽  
Severin Schricker ◽  
Moritz Schanz ◽  
Dominik M Alscher ◽  
Markus Ketteler
Keyword(s):  
Dna Damage ◽  
Peritoneal Dialysis ◽  
Protein Expression ◽  
High Glucose ◽  
Oxidative Dna Damage ◽  
Control Group ◽  
Healthy Controls ◽  
Plasma Samples ◽  
Peritoneal Membrane ◽  
Uremic Patients

Abstract Background and Aims Peritoneal dialysis (PD) is an effective method of renal replacement therapy (RRT). The long-term use of PD as a RRT is limited due to adverse effects of high glucose-based PD solutions to the structure and function of the peritoneal membrane. PD patients show excessive oxidative stress compared to healthy controls. However, there are only scare information on pathophysiological mechanisms leading to oxidative DNA-damage in PD patients. Therefore, the aim of this study was to elucidate the mechanism leading to excessive oxidative stress in human samples of the peritoneal membrane. Method Human peritoneal biopsies of healthy controls, PD patients and patients with EPS were collected. Protein expression of TXNIP was analysed by ELISA using plasma samples and by immunohistochemistry of peritoneal biopsies using a Histo-Score. Protein expression of TRX was examined by immunohistochemistry. To measure TRX activity a kit based on the reduction of insulin by reduced TRX was used. The resulting oxidative DNA-damage was investigated by immunohistochemistry using a Histo-Score or by ELISA using plasma samples of patients. Results Biopsies from the peritoneum of 8 healthy controls, 11 uremic patients, 22 patients on PD < 12 months or 29 patients on PD > 12 months and of 13 patients with EPS were collected. The age of the uremic patients was higher (median 65.0 years, IQR: 49.0-75.0) than in the other subgroups (PD < 12 months: median 62.0 years, IQR: 52.25-68.25, PD > 12 months: median 60.0 years, IQR: 39.5-70.5 and EPS: median 51.00 years, IQR: 40.0-57.5). In general, there were more female participants in the control-group (75 %) compared to all other groups (uremic group: 27%, PD < 12 months: 18 %, PD >12 months: 41% and EPS group 33 %). Time on PD was longer in EPS patients (median 72.0 months) than in PD patients (PD <12 months: median 10.0 months and PD > 12 months: 39.0 months). The ELISA study of plasma samples showed that TXNIP is upregulated in all groups compared to healthy controls. Immunohistochemically studies of peritoneal biopsies showed also an upregulation of TXNIP upon exposure to high glucose-based dialysis fluids (PD and EPS group). Interestingly, a glucose-related change in protein expression of its interacting partner and cellular anti-oxidant TRX was only observed in EPS samples. TRX activity in uremic patients was almost unchanged compared to healthy controls except for one patient. However, enhanced TXNIP expression correlated with a reduced activity of TRX in samples of PD as well as EPS patients. Reduced TRX activity resulted in an increase of produced ROS. Therefore, the effect on the generation of oxidative damage was analysed by ELISA of plasma samples and by immunohistochemistry on peritoneal sections. Both analysis showed an increase in the oxidative DNA-damage marker 8-Hydroxydesoxyguanosin (8-OHdG) in all PD samples and samples of EPS patients compared to the control group. Conclusion Here, we show that high glucose-based peritoneal dialysis solutions lead to an upregulation of TXNIP expression in human peritoneal samples. This increase in TXNIP expression reduces the activity of its interacting partner an antioxidant TRX leading to an increase in ROS production and enhanced levels of DNA-damage. In this study, we elucidate for the first time a novel mechanism showing that glucose-dependent upregulation of TXNIP induces a perturbation of the intracellular redox equilibrium leading to alterations of the peritoneal membrane. Therefore, manipulation of TXNIP expression may be a promising therapeutic target to improve peritoneal membrane function.

P1146ENHANCED EXPRESSION OF THIOREDOXIN-INTERACTING-PROTEIN (TXNIP) MAY REGULATE OXIDATIVE DAMAGE IN PERITONEAL DIALYSIS PATIENTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Tina Oberacker ◽  
Severin Schricker ◽  
Moritz Schanz ◽  
Dominik M Alscher ◽  
Markus Ketteler
Keyword(s):  
Peritoneal Dialysis ◽  
Oxidative Damage ◽  
Protein Expression ◽  
Mrna Expression ◽  
High Glucose ◽  
Healthy Controls ◽  
Peritoneal Membrane ◽  
Membrane Function ◽  
Dialysis Solutions ◽  
Peritoneal Dialysis Solutions

Abstract Background and Aims Glucose-based solutions used as peritoneal dialysis fluids influence the peritoneal membrane. Exposure to high glucose-based peritoneal dialysis solutions induces reactive oxygen species (ROS) production due to upregulation of TXNIP as shown by several studies in rats as well as in human primary cells. Enhanced expression of TXINP also regulates oxidative damage. Therefore the aim of this study was to investigate the expression of TXNIP and the extent of oxidative damage in human peritoneal biopsies. Method Human peritoneal biopsies of healthy controls, PD patients and patients with EPS were collected. TXNIP and thioredoxin-1 (TRX) mRNA expression was determined by qPCR. Protein expression and the extent of oxidative damage were examined by immunohistochemistry. Results Biopsies from the peritoneum of 7 healthy controls, 36 patients on PD without signs of EPS as well as of 12 patients with EPS were collected. The age of the healthy controls was higher (median 64.00 years, IQR: 53.00-70.00) than in the other subgroups (PD: median 60.50 years, IQR: 46.00-69.00 and EPS: median 51.00 years, IQR: 38.00-58.75). Furthermore, compared to the PD- (39 %) and EPS-group (33 %), there were more female participants in the control-group (86 %). Time on PD was longer in EPS patients (median 70.00 months) than in PD patients (median 33.50 months). In a preliminary study, exposure to high glucose-based peritoneal dialysis solutions did not markedly influence the mRNA expression of TXNIP and TRX. However, on protein level a significant glucose-related upregulation of TXNIP could be observed especially in PD patients. Interestingly, there was no glucose-related change in protein expression of its interacting partner and cellular anti-oxidant TRX. To study the effect of TXNIP expression on the generation of oxidative damage, pH2AX positive nuclei were counted on peritoneal membrane sections. A slight increase of pH2AX positive nuclei upon exposure to dialysis solutions could be observed in the cohort analysed. Conclusion Here, we show for the first time a clear tendency for upregulation TXNIP in human peritoneal tissue after exposure to high glucose-based peritoneal dialysis solutions especially in PD patients. This increase in TXNIP expression may correlate with the accumulation of oxidative damage of macromolecules. Therefore, manipulation of TXNIP expression may be a promising therapeutic target to improve peritoneal membrane function.

MO710GALECTIN-3, IS IT A NEW PLAYER IN PERITONEAL INFLAMMATION AMONG PATIENTS UNDERGOING PERITONEAL DIALYSIS?

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Yael Einbinder ◽  
Keren Cohen-Hagai ◽  
Sydney Benchetrit ◽  
Tali Zitman-Gal
Keyword(s):  
Cell Culture ◽  
Peritoneal Dialysis ◽  
Endothelial Cell ◽  
Protein Expression ◽  
Inflammatory Process ◽  
Peritoneal Membrane ◽  
Peritoneal Equilibration Test ◽  
Endothelial Cell Culture ◽  
Dialysis Vintage ◽  
Mrna And Protein Expression

Abstract Background and Aims Peritoneal dialysis (PD) is a common used method for renal replacement therapy. Prolonged PD treatment causes structural and functional changes in the peritoneal membrane which are attributed to local inflammatory process in the peritoneal cavity. Galectin-3 (Gal-3) is a galactoside-binding lectin with pro-inflammatory and pro-fibrotic effects. The aim of this study was to assess correlation between Gal-3 serum and dialysate effluent levels with peritoneal membrane transport characteristics. Method Gal-3 levels in serum and dialysate effluent were measured simultaneously in prevalent PD patients in morning visit or during peritoneal equilibration test (PET). Gal-3 levels were correlated with clinical and laboratory parameters. Interlukin (IL) -6 levels were measured in dialysate effluent. Gal-3 mRNA and protein expression were evaluated after exposure of primary endothelial cell culture to several dialysate solutions. Results 37 PD patients were included in the study; mean age was 65.7±13.1 years, mean dialysis vintage was 17.5±13 months. Gal-3 levels in dialysate effluent correlated with peritoneal equilibration test (PET) results (0.663, p=0.005) and effluent IL-6 levels (0.674, p=0.002) but not with serum Gal-3 levels or dialysis vintage. Patients with high PET results had higher effluent Gal-3 levels as compared average low PET results. In multivariate regression analysis effluent IL-6 level was the most dominant predictor of effluent Gal-3 levels. Gal-3 mRNA and protein expression in primary endothelial cell culture were not affected by stimulation with dialysate solutions. Conclusion Our study demonstrated presence of Gal-3 within the dialysate effluent in PD patients. Gal-3 levels correlated with peritoneal membrane transport characteristics and effluent IL-6 levels suggesting a role in the inflammatory process within the peritoneal cavity.

scholarly journals Oxidative lipid, protein, and DNA damage as oxidative stress markers in vascular complications of diabetes mellitus

2011 ◽  
Vol 34 (3) ◽  
pp. 163 ◽  
Author(s):  
Omur Tabak ◽  
Remise Gelisgen ◽  
Hayriye Erman ◽  
Fusun Erdenen ◽  
Cüneyt Muderrisoglu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Vascular Complications ◽  
Diabetic Group ◽  
Control Group ◽  
Diabetic Patients ◽  
Serum Samples ◽  
Type 2 Diabetic Patients

Purpose: The purpose of this study was to determine the effects of diabetic complications on oxidation of proteins, lipids, and DNA and to investigate the relationship between oxidative damage markers and clinical parameters. Methods: The study group consisted of 69 type 2 diabetic patients (20 patients without complication, 49 patients with complication) who attended internal medicine outpatient clinics of Istanbul Education and Research Hospital and 19 healthy control subjects. In serum samples of both diabetic patients and healthy subjects, 8-hydroxy-2’deoxyguanosine (8-OHdG), as a marker of oxidative DNA damage, Nε-(hexanoyl)lysine (HEL) and 15-F2t-iso-prostaglandin (15-F2t-IsoP). as products of lipooxidative damage, advanced oxidation protein products (AOPP), as markers of protein damage, and paraoxonase1 (PON1) as antioxidant were studied. Results: 15-F2t-IsoP (p < 0.005) and AOPP (p < 0.001) levels were significantly higher in diabetic group than control group while there were no significant differences in levels of 8-OHdG and HEL between the two groups. AOPP (p < 0.001) and 8-OHdG (p < 0.001) were significantly higher in diabetic group with complications compared to diabetic group without complications. Conclusions: Increased formation of free radicals and oxidative stress, under conditions of hyperglycaemia, is one of the probable causes for evolution of complications in diabetes mellitus. Our study supports the hypothesis that oxidant/antioxidant balance is disturbed in diabetic patients.

Increased Serum Level of 8-Hydroxy-2’-Deoxyguanosine may be an Indication of Pesticides Induced DNA Damage among Indian Farmers

2021 ◽  
Vol 11 (7) ◽  
pp. 89-98
Author(s):  
Arun Pandiyan ◽  
Summaiya Lari ◽  
Sudip Ghosh
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Serum Levels ◽  
Study Data ◽  
Exposed Group ◽  
Healthy Controls ◽  
Data Assessment ◽  
Pesticides Exposure ◽  
Immuno Assay ◽  
Enzyme Immuno Assay

The aim of the present hospital based study is to assess the serum levels of 8-hydroxy-2’-deoxyguanosine (8-OHdG) among 152 subjects. A total of 152 subjects, categorized into 3 groups: (i) pesticides exposed group (N=60), (ii) pesticide un-exposed group (N=42) and (iii) healthy controls group (N=50) were recruited for the study following the inclusion and exclusion criteria. The blood was drawn from the eligible subjects and Enzyme Immuno Assay (EIA) was performed to assess the 8-OHdG levels in serum. Appropriate statistical methods were used to analyse the study data. Assessment showed that pesticides exposed group has higher levels of serum 8-OHdG as compared to un-exposed group and healthy controls. Age and duration of exposure had an impact on the levels of serum 8-OHdG.The higher serum levels of 8-OHdG may be a marker for pesticides-induced oxidative DNA damage. Key words: pesticides; exposure; oxidative stress; 8-hydroxy-2’-deoxyguanosine (8-OHdG).

Histologic Change of Peritoneal Membrane in Relation to Adequacy of Dialysis in Continuous Ambulatory Peritoneal Dialysis Patients

2003 ◽  
Vol 23 (2_suppl) ◽  
pp. 26-30 ◽  
Author(s):  
Irini Savidaki ◽  
Dionisios Karavias ◽  
Florentia Sotsiou ◽  
Sotiria Alexandri ◽  
Pantelitsa Kalliakmani ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Structural Changes ◽  
Mesothelial Cells ◽  
Peritoneal Membrane ◽  
Histologic Change ◽  
Significant Difference ◽  
Uremic Patients ◽  
Group B ◽  
Histologic Changes

Background Long-term exposure of peritoneal membrane to bioincompatible dialysis solutions leads to structural changes and loss of ultrafiltration capability. Objective We studied the possible relationship between histologic change and the transport characteristics of peritoneal membrane and adequacy of dialysis in continuous ambulatory peritoneal dialysis (CAPD) patients. Patients and Methods The study included 18 CAPD patients (11 men, 7 women) who underwent a peritoneal biopsy either at initiation of treatment (group A, n = 9) or after a mean of 4 years on CAPD (group B, n = 9). The morphologic changes in the mesothelial cells and the vascular compartment and the thickness of the submesothelial collagenous zone were estimated and compared with observations from 6 patients with normal renal function who underwent biopsy of the parietal peritoneum during abdominal surgery. The relationship of the observed changes in CAPD patients to results from a peritoneal equilibration test (PET) and to adequacy of dialysis [total weekly creatinine clearance (CCr) and Kt/V urea] were also investigated. Results The main histologic changes in both groups of patients were loss of mesothelial cells and decrease in the normal mesothelial surface, thickening of the submesothelial collagenous zone, and presence of vascular hyalinosis. The thickness of the submesothelial collagenous zone in both groups of patients was significantly greater than that found in controls (410 μm and 580 μm vs 50 μm, p < 0.05). Although no significant difference was found between morphologic change in the peritoneal membrane of uremic patients starting on CAPD and those who had been on peritoneal dialysis (PD) for a mean period of 4 years, a trend was observed toward more severe lesions in the latter patients. The PET, CCr, and Kt/V urea were not significantly different in the two groups of patients. Those parameters also showed no significant changes when examined at initiation of CAPD and after a mean of 4 years of PD in the same patients (group B). No significant correlations were observed between the histologic changes and the PET, CCr, or Kt/V in both groups of patients. Conclusions Significant structural changes are observed in the peritoneal membrane of uremic patients, and those changes become worse with CAPD treatment. Structural changes are not followed by functional changes during the first 4 years on CAPD.

scholarly journals Valsartan ameliorates high glucose-induced peritoneal fibrosis by blocking mTORC1 signaling

2020 ◽  
Vol 245 (11) ◽  
pp. 983-993 ◽  
Author(s):  
Jing Liu ◽  
Yuan Feng ◽  
Cheng Sun ◽  
Wei Zhu ◽  
Qing-Yan Zhang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Peritoneal Dialysis ◽  
Protein Expression ◽  
High Glucose ◽  
Collagen I ◽  
Peritoneal Fibrosis ◽  
Dialysis Solution ◽  
Mtorc1 Pathway ◽  
Peritoneal Dialysis Solution

Our previous study demonstrated that the mammalian target of rapamycin complex 1 (mTORC1) pathway is activated in peritoneal fibrosis under high glucose condition. This study aimed to investigate whether valsartan inhibits high glucose-induced peritoneal fibrosis via decreasing the activity of the mTORC1 pathway. We used high glucose peritoneal dialysis solution in a mouse peritoneal dialysis model to induce peritoneal fibrosis in vivo and high glucose in human peritoneal mesothelial cells (HPMCs) to stimulate extracellular matrix accumulation in vitro. After injections of peritoneal dialysis solution containing 4.25% glucose for four weeks, mice showed typical features of peritoneal fibrosis, including markedly increased peritoneal thickness, excessive matrix deposition, increased peritoneal permeability, and higher expression of extracellular matrix proteins, such as α-smooth muscle actin (α-SMA) and collagen I. Oral gavage of valsartan significantly ameliorated these pathological changes at both week 6 and week 8. These effects of valsartan were closely correlated with a decrease in the activation of the mTORC1 signal, which was mediated by the downregulation of the protein expression of phosphorylated (p)-mTOR, p-eukaryotic initiation factor 4E-binding protein 1, and p-p70 S6 kinase 1. Further research showed that the protein expression of mTORC1 signal was positively correlated with the expression of both α-SMA and collagen I in the peritoneum. In vitro, high glucose increased the protein expression of α-SMA and collagen I in a dose-dependent manner, while valsartan significantly inhibited high glucose-induced extracellular matrix accumulation in HPMCs. The effect was also accompanied by a decrease in the activation of the mTORC1 signal. Furthermore, the mTOR agonist MHY1485 reversed the downregulation of extracellular matrix components in HPMCs, even in the presence of valsartan. We conclude that valsartan exerts a protective effect against high glucose-induced peritoneal fibrosis via suppressing the activity of the mTORC1 pathway. Impact statement Our study provided new insight into the mechanism underlying the preservation of the peritoneum by valsartan. The results demonstrated that the mice receiving chronic high glucose (HG) peritoneal dialysis solution infusion showed a typical feature of peritoneal fibrosis (PF), as well as higher expression of α-smooth muscle actin (α-SMA) and collagen I. In vitro, HG increased the protein expression of α-SMA and collagen I in a dose-dependent manner, while valsartan significantly ameliorated these pathological changes. Interestingly, there was a parallel decrease in the activity of mammalian target of rapamycin complex 1 (mTORC1) and the protein expression levels of α-SMA and collagen I upon treatment with valsartan in vivo and in vitro. Moreover, the mTOR agonist MHY1485 reversed the downregulation of α-SMA and collagen I in vitro, even in the presence of valsartan. Altogether, our findings reported for the first time that valsartan exerts a protective effect against HG-induced PF by inhibiting the activity of the mTORC1 pathway.

Impact of the Ser326Cys polymorphism of the OGG1 gene on the level of oxidative DNA damage in patients with colorectal cancer

2018 ◽  
Vol 90 (2) ◽  
pp. 13-15 ◽  
Author(s):  
Jacek Kabzinski ◽  
Anna Walczak ◽  
Adam Dziki ◽  
Michał Mik ◽  
Ireneusz Majsterek
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Oxidative Damage ◽  
Oxidative Dna Damage ◽  
Excision Repair ◽  
Genetic Material ◽  
Control Group ◽  
Ogg1 Gene ◽  
Increased Risk ◽  
Ser326cys Polymorphism

As a result of reactive oxygen species operation, cell damage occurs in both cellular organelles and molecules, including DNA. Oxidative damage within the genetic material can lead to accumulation of mutations and consequently to cancer transformation. OGG1 glycosylase, a component of the Base Excision Repair (BER) system, is one of the enzymes that prevents excessive accumulation of 8-oxoguanine (8-oxG), the most common compound formed by oxidative DNA damage. In case of structural changes of OGG1 resulting from polymorphic variants, we can observe a significant increase in the concentration of 8-oxG. Linking individual polymorphisms to DNA repair systems with increased risk of colorectal cancer will allow patients to be classified as high risk and included in a prophylactic program. The aim of the study was to determine the level of oxidative DNA damage and to analyze the distribution of Ser326Cys polymorphism of the OGG1 gene in a group of patients with colorectal cancer and in a control group in the Polish population. Material and methodology. DNA was isolated from the blood of 174 patients with colorectal cancer. The control group consisted of 176 healthy individuals. The level of oxidative damage was determined by analyzing the amount of 8-oxguanine using the HT 8-oxo-dG ELISA II Kit. Genotyping was performed via the TaqMan method. Results. The obtained results indicate that Ser326Cys polymorphism of the OGG1 gene increases the risk of RJG and is associated with significantly increased levels of 8-oxoguanine. Conclusions. Based on the results obtained, we conclude that Ser326Cys polymorphism of the OGG1 gene may modulate the risk of colorectal cancer by increasing the level of oxidative DNA damage.

Association between Peritoneal Glucose Exposure and Peritonitis in Peritoneal Dialysis Patients: TheBalANZ Trial

2017 ◽  
Vol 37 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Melissa Nataatmadja ◽  
Yeoungjee Cho ◽  
Elaine M. Pascoe ◽  
Darsy Darssan ◽  
Carmel M. Hawley ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Peritoneal Dialysis ◽  
High Glucose ◽  
Controlled Trial ◽  
Exposure Group ◽  
Peritoneal Membrane ◽  
Randomized Controlled ◽  
Increased Risk ◽  
Low Glucose ◽  
Glucose Exposure

BackgroundGlucose is the primary osmotic medium used in most peritoneal dialysis (PD) solutions, and exposure to glucose has been shown to exert detrimental effects both locally, at the peritoneal membrane, and systemically. Moreover, high dialysate glucose exposure may predispose patients to an increased risk of peritonitis, perhaps as a result of impaired host defences, vascular disease, and damage to the peritoneal membrane.MethodsIn this post-hoc analysis of a multicenter, multinational, open-label randomized controlled trial of neutral pH, low-glucose degradation product (GDP) versus conventional PD solutions ( balANZ trial), the relationship between peritonitis rates of low (< 123.1 g/day) versus high (≥ 123.1 g/day) dialysate glucose exposure was evaluated in 177 incident PD patients over a 2-year study period.ResultsPeritonitis rates were 0.44 episodes per patient-year in the low-glucose exposure group and 0.31 episodes per patient-year in the high-glucose exposure group, (incidence rate ratio [IRR] 0.69, p = 0.09). There was no significant association between dialysate glucose exposure and peritonitis-free survival on univariable analysis (high glucose exposure hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.40 –1.08) or on multivariable analysis (adjusted HR 0.64, 95% CI 0.39 – 1.05). Moreover, there was no relationship between peritoneal glucose exposure and type of organism causing peritonitis. Physician-rated severity of first peritonitis episodes was similar between groups, as was rate and duration of hospital admission.ConclusionsOverall, this study did not identify an association between peritoneal dialysate glucose exposure and peritonitis occurrence, severity, hospitalization, or outcomes. A further large-scale, prospective, randomized controlled trial evaluating patient-level outcomes is merited.

scholarly journals OGG1 Involvement in High Glucose-Mediated Enhancement of Bupivacaine-Induced Oxidative DNA Damage in SH-SY5Y Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Zhong-Jie Liu ◽  
Wei Zhao ◽  
Qing-Guo Zhang ◽  
Le Li ◽  
Lu-Ying Lai ◽  
...  
Keyword(s):  
Dna Damage ◽  
High Glucose ◽  
Oxidative Dna Damage ◽  
Functional Expression ◽  
Culture Conditions ◽  
Control Culture ◽  
Ros Production ◽  
Dna Oxidative Damage ◽  
Repair Enzymes ◽  
Polymerase Chain

Hyperglycemia can inhibit expression of the 8-oxoG-DNA glycosylase (OGG1) which is one of the key repair enzymes for DNA oxidative damage. The effect of hyperglycemia on OGG1 expression in response to local anesthetics-induced DNA damage is unknown. This study was designed to determine whether high glucose inhibits OGG1 expression and aggravates bupivacaine-induced DNA damage via reactive oxygen species (ROS). SH-SY5Y cells were cultured with or without 50 mM glucose for 8 days before they were treated with 1.5 mM bupivacaine for 24 h. OGG1 expression was measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. ROS was estimated using the redox-sensitive fluorescent dye DCFH-DA. DNA damage was investigated with immunostaining for 8-oxodG and comet assays. OGG1 expression was inhibited in cells exposed to high glucose with concomitant increase in ROS production and more severe DNA damage as compared to control culture conditions, and these changes were further exacerbated by bupivacaine. Treatment with the antioxidant N-acetyl-L-cysteine (NAC) prevented high glucose and bupivacaine mediated increase in ROS production and restored functional expression of OGG1, which lead to attenuated high glucose-mediated exacerbation of bupivacaine neurotoxicity. Our findings indicate that subjects with diabetes may experience more detrimental effects following bupivacaine use.

scholarly journals The oxidative effect of Hyperbaric Oxygen Therapy on Human retinal pigment epithelium cells

2019 ◽  
Author(s):  
Jialin Li ◽  
I-Chen Chao ◽  
Jie Luan
Keyword(s):  
Cell Proliferation ◽  
Dna Damage ◽  
Retinal Pigment Epithelium ◽  
Hyperbaric Oxygen ◽  
Oxidative Dna Damage ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Control Group ◽  
Rpe Cells ◽  
Human Retinal Pigment Epithelium

Abstract Background: Hyperbaric oxygen (HBO) therapy has been widely used in various diseases, which is considered safe and effective. Whereas recent studies discovered that HBO therapy could result in oxidative damage to tissues. The goal of our study was to investigate the oxidative effect of hyperbaric oxygen therapy on human retinal pigment epithelium (RPE) cells. Method: Human REP cells (ARPE-19) were cultured in vitro, and divided into normoxic group （incubated with DMEM/F12 broth）and hypoxic group (incubated with DMEM/F12 broth containing 200μmol/L CoCl2) randomly. The experimental groups were exposed to 100% pure oxygen under different pressures (0.15MPa, 0.2MPa, and 0.25MPa) for 60 and 90 minutes thrice, with 24 hours interval. Then the cell viability, 8-OHdG expression and hOGG1 expression of RPE cells were detected by MTT assay, immunocytochemistry (ICC) and western blot seperately. Result: After HBO exposure, cell proliferation decreased, 8-OHdG and hOGG1 expression increased in normoxic RPE cells compared with control group, whereas in hypoxic RPE cells, cell proliferation increased, 8-OHdG and hOGG1 expression decreased compared with hypoxic control group. Conclusion: HBO therapy could suppress the cell proliferation and cause oxidative DNA damage of RPE cells in normoxic status. Conversely, in hypoxic status, HBO therapy could promote the proliferation and ameliorate oxidative DNA damage of human retinal pigment epithelium cells. Meanwhile, HBO therapy could trigger the oxidative DNA damage repair of RPE cells in both normoxic and hypoxic statues.

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