8-hydroxy-2--deoxyguanosine and Diabetic-Retinopathy

We sought to assess a smartphone-based, gold nanoparticle-based colorimetric lateral flow immunoassay paper sensor for quantifying urine 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker for diabetic retinopathy (DR) screening.. Paper strips incorporate gold nanoparticle-8-OHdG antibody conjugates that produce color changes that are proportional to urine 8-OHdG and that are discernible on a smartphone camera photograph. Paper strip accuracy, precision, and stability studies were performed with 8-OHdG solutions of varying concentrations. Urine was collected from 97 patients with diabetes who were receiving DR screening examinations, including 7-field fundus photographs. DR was graded by standard methods as either low risk (no or mild DR) or high risk (moderate or severe DR). Paper sensor assays were performed on urine samples from patients and 8-OHdG values were correlated with DR grades. The differences in 8-OHdG values between the low- and high-risk groups were analyzed for outliers to identify the threshold 8-OHdG value that would minimize false-negative results.. Lateral flow immunoassay paper strips quantitatively measure 8-OHdG and were found to be accurate, precise, and stable. Average urine 8-OHdG concentrations in study patients were 22 ± 10 ng/mg of creatinine in the low-risk group and 55 ± 11 ng/mg of creatinine in the high-risk group. Screening cutoff values of 8-OHdG >50 ng/mg of creatinine or urine creatinine >1.5 mg minimized screen failures, with 91% sensitivity and 81% specificity.. Urinary 8-OHdG is a useful biomarker to screen DR. Quantitative 8-OHdG detection with the lateral flow immunoassay paper sensor and smartphone camera demonstrates its potential in DR screening. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biomarkers; Colorimetry; Creatinine; Diabetic Retinopathy; False Positive Reactions; Female; Gold; Humans; Immunoassay; Male; Middle Aged; Monitoring, Ambulatory; Nanoparticles; Predictive Value of Tests; Reproducibility of Results; Sensitivity and Specificity; Smartphone

Diabetic retinopathy (DRP) is the formation of edema and small vessels in the retina due to high blood glucose levels. Asprosin is a hormone that stimulates the release of glucose from the liver into the circulation. Considering the relationship between oxidative stress and DRP, our study aimed to determine the levels of the oxidative stress markers 4-hydroxynonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), as well as asprosin, in the blood and aqueous humor (Aq) of patients with and without DRP.. Thirty patients with single-eye DRP and cataract (DRP + C), 30 patients with diabetes mellitus and cataract without DRP (DM + C), and 30 healthy control (CON) participants were enrolled into this retrospective study. Except for healthy controls, Aq and blood samples were taken from these patients during their cataract operation. Asprosin, 4-HNE, and 8-OHdG concentrations were analyzed using enzyme-linked immunosorbent assays.. In patients with DRP, the levels of asprosin, 4-HNE, and 8-OHdG were significantly higher in both Aq and blood samples compared with the group of patients without DRP.. These findings suggest that the measurement of asprosin, 4-HNE, and 8-OHdG levels may support clinicians in determining the risk of DRP development.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Aldehydes; Aqueous Humor; Biomarkers; Cataract; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Female; Fibrillin-1; Humans; Male; Middle Aged; Oxidative Stress; Retrospective Studies

We investigated the link among the proinflammatory cytokine high-mobility group box 1 (HMGB1) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a marker of oxidative DNA damage, the endothelial adhesion molecule and oxidase enzyme vascular adhesion protein-1 (VAP-1), and the inducible cytoprotective molecule heme oxygenase-1 (HO-1) in proliferative diabetic retinopathy (PDR). We correlated the levels of these molecules with clinical disease activity and studied the proinflammatory activities of HMGB1 on rat retinas and human retinal microvascular endothelial cells (HRMECs).. Vitreous samples from 47 PDR and 19 non-diabetic patients, epiretinal membranes from 11 patients with PDR, human retinas (16 from diabetic patients and 16 from non-diabetic subjects), rat retinas, and HRMECs were studied by enzyme-linked immunosorbent assay, immunohistochemistry, western blot immunofluorescence, and RT-PCR analyses. In addition, we assessed the adherence of leukocytes to HMGB1-stimulated HRMECs.. HMGB1, 8-OHdG, and soluble VAP-1 (sVAP-1) levels were significantly higher in vitreous samples from PDR patients than in those from non-diabetics (p = 0.001, <0.0001, <0.0001, respectively). The HMGB1, 8-OHdG, sVAP-1, and HO-1 levels in PDR with active neovascularization were significantly higher than those in inactive PDR (p = 0.025, <0.0001, <0.0001, 0.012, respectively). Significant positive correlations were observed between the levels of HMGB1 and the levels of 8-OHdG (r = 0.422; p = 0.001) and sVAP-1 (r = 0.354; p = 0.004) and between the levels of 8-OHdG and the levels of sVAP-1 (r = 0.598; p<0.0001). In epiretinal membranes, VAP-1 and 8-OHdG were expressed in vascular endothelial cells and stromal cells. Significant increases in the VAP-1 mRNA and protein levels were detected in the RPE, but not in the neuroretina of diabetic patients. Treatment of HRMEC with HMGB1, diabetes induction, and an intravitreal injection of HMGB1 in normal rats induced a significant upregulation of the adhesion molecule intercellular adhesion molecule-1 (ICAM-1) in HRMECs and retinas. On the other hand, the expressions of vascular cell adhesion molecule-1 and VAP-1 were not affected. Oral administration of the HMGB1 inhibitor glycyrrhizin in rats attenuated the diabetes-induced upregulation of the retinal ICAM-1 expression. Treatment of HRMECs with HMGB1 increased leukocyte adhesion and induced the upregulation of 8-OHdG and HO-1 and the membranous translocation of VAP-1.. Our results suggest a potential link among the proinflammatory cytokine HMGB1, VAP-1, oxidative stress, and HO-1 in the pathogenesis of PDR.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Amine Oxidase (Copper-Containing); Animals; Biomarkers; Blotting, Western; Cell Adhesion Molecules; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; DNA Damage; Endothelium, Vascular; Enzyme-Linked Immunosorbent Assay; Female; Heme Oxygenase-1; HMGB1 Protein; Humans; Male; Middle Aged; Oxidative Stress; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; RNA, Messenger; Vitreous Body

Lithospermic acid B (LAB), an active component isolated from Salvia miltiorrhiza radix, has been reported to have antioxidant effects. We examined the effects of LAB on the prevention of diabetic retinopathy in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of type 2 diabetes.. LAB (10 or 20 mg/kg) or normal saline were given orally once daily to 24-week-old male OLETF rats for 52 weeks. At the end of treatment, fundoscopic findings, vascular endothelial growth factor (VEGF) expression in the eyeball, VEGF levels in the ocular fluid, and any structural abnormalities in the retina were assessed. Glucose metabolism, serum levels of high-sensitivity C-reactive protein (hsCRP), monocyte chemotactic protein-1 (MCP1), and tumor necrosis factor-alpha (TNFα) and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were also measured. Treatment with LAB prevented vascular leakage and basement membrane thickening in retinal capillaries in a dose-dependent manner. Insulin resistance and glucose intolerance were significantly improved by LAB treatment. The levels of serum hsCRP, MCP1, TNFα, and urinary 8-OHdG were lower in the LAB-treated OLETF rats than in the controls.. Treatment with LAB had a preventive effect on the development of diabetic retinopathy in this animal model, probably because of its antioxidative effects and anti-inflammatory effects.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Benzofurans; C-Reactive Protein; Chemokine CCL2; Deoxyguanosine; Depsides; Diabetic Retinopathy; Glucose; Glucose Intolerance; Insulin Resistance; Male; Obesity; Rats; Rats, Long-Evans; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Oxidative stress is increased in the retina in diabetes, and it is considered to play an important role in the development of retinopathy. Findings indicate that obtusifolin has antioxidant properties. The purpose of this study was to examine the effect of obtusifolin on retinal capillary cell apoptosis and the development of pathology in diabetes. Retina was used from streptozotocin-induced diabetic rats receiving diets supplemented with or without obtusifolin (100, 200, and 400 mg/kg) for 11 months of diabetes. Capillary cell apoptosis (by terminal transferase-mediated dUTP nick-end labeling) and formation of acellular capillaries were investigated in the trypsin-digested retinal microvessels. The effect of obtusifolin administration on retinal 8-hydroxy-2'deoxyguanosine (8-OHdG) and nitrotyrosine levels was determined by enzyme-linked immunosorbent assay. Obtusifolin administration for the entire duration of diabetes inhibited capillary cell apoptosis and the number of acellular capillaries in the retina, despite similar severity of hyperglycemia in the four diabetic groups (with and without obtusifolin). Retinal 8-OHdG and nitrotyrosine levels were significantly increased, respectively, in diabetes, and obtusifolin administration inhibited these increases. Our results demonstrate that the long-term administration of obtusifolin has beneficial effects on the development of diabetic retinopathy via inhibition of accumulation of oxidatively modified DNA and nitrotyrosine in the retina. Obtusifolin represents an achievable adjunct therapy to help prevent vision loss in diabetic patients.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Oral; Animals; Anthraquinones; Antioxidants; Apoptosis; Capillaries; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Hyperglycemia; Male; NF-kappa B; Oxidative Stress; Rats; Rats, Wistar; Retina; Tyrosine

Diabetic retinopathy (DR) is characterized by increased oxidative and nitrosative stress, both of which lead to neurotoxicity and vascular permeability. Previous studies on a variety of organs indicate that hydrogen-rich saline not only has considerable antioxidant and anti-inflammatory properties, but also suppresses oxidative stress-induced injury. In the present study, we assessed the effects of hydrogen-rich saline on neurovascular dysfunction and oxidative stress in an animal model (rat) of DR.. Male Sprague-Dawley rats with streptozotocin (STZ)-induced diabetes mellitus (DM) were injected intraperitoneally with 5 ml/kg hydrogen-saturated (experimental) or plain (control) saline daily for one month. Visual function and blood-retinal barrier (BRB) integrity were evaluated by electroretinography (ERG) and bovine serum albumin (BSA)-fluorescence, respectively. Histological changes in the inner retina were assessed by light microscopy. Biomarkers of oxidative stress, including 4-hydroxynonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OH-dG), and antioxidant enzymes, including superoxide dismutase, glutathione peroxidase, glutathione reductase and glutathione transferase, were evaluated by ELISA. Synaptophysin and brain-derived neurotrophic factor (BDNF) levels were measured by immunoblotting.. STZ-diabetic rats were marked by clearly reduced b-wave amplitudes and oscillatory potentials, DM-related BRB breakdown and histological changes in the inner retina, all of which were suppressed following treatment with hydrogen-rich saline. Furthermore, hydrogen-rich saline reduced oxidative stress, increased antioxidant enzyme activities and preserved synaptophysin and BDNF levels in the diabetic rat retina.. Based on its inhibition of oxidative stress and up-regulation of anti-oxidative enzymes, we conclude that hydrogen-rich saline is a potentially valuable therapeutic modality for the treatment of DR.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aldehydes; Animals; Blood Glucose; Blood-Retinal Barrier; Blotting, Western; Body Weight; Brain-Derived Neurotrophic Factor; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Electroretinography; Enzyme-Linked Immunosorbent Assay; Male; Oxidative Stress; Oxidoreductases; Rats; Rats, Sprague-Dawley; Retinal Neovascularization; Sodium Chloride; Synaptophysin

To correlate changes between VEGF expression with systemic and retinal oxidative stress and inflammation in rodent models of obesity induced insulin resistance and diabetes.. Retinal VEGF mRNA and protein levels were assessed by RT-PCR and VEGF ELISA, respectively. Urinary 8-hydroxydeoxyguanosine (8-OHdG), blood levels of C-reactive protein (CRP), malondialdehyde (MDA), and CD11b/c positive cell ratio were used as systemic inflammatory markers. Retinal expression of Nox2, Nox4, and p47phox mRNA levels were measured as oxidative stress markers. TNF-α, inter-cellular adhesion molecule-1 (ICAM-1), IL1β, and activation of nuclear factor κB (NF-κB) were used as retinal inflammatory markers.. Retinal VEGF mRNA and protein expression increased in Zucker diabetic fatty (ZDF(fa/fa)) rats and streptozotosin (STZ) induced diabetic Sprague-Dawley rats, after two months of disease, but not in Zucker fatty (ZF) rats. Systemic markers of oxidative stress and inflammation were elevated in insulin resistant and diabetic rats. Some oxidative stress and inflammatory markers (TNF-α, IL-6, ICAM-1, and IL1-β) were upregulated in the retina of ZDF(fa/fa) and STZ diabetic rats after 4 months of disease. In contrast, activation of NF-κB in the retina was observed in high fat fed nondiabetic and diabetic cis-NF-κB(EGFP) mice, ZF, ZDF(fa/fa), and STZ-induced diabetic rats.. Only persistent hyperglycemia and diabetes increased retinal VEGF expression. Some markers of inflammation and oxidative stress were elevated in the retina and systemic circulation of obese and insulin resistant rodents with and without diabetes. Induction of VEGF and its associated retinal pathologies by diabetes requires chronic hyperglycemia and factors in addition to inflammation and oxidative stress.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Biomarkers; C-Reactive Protein; CD11b Antigen; CD11c Antigen; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Inflammation; Insulin Resistance; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; NF-kappa B; Obesity; Oxidative Stress; Rats; Rats, Sprague-Dawley; Rats, Zucker; Retina; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stress, Physiological; Vascular Endothelial Growth Factor A

To investigate if nitric oxide (NO) system contributes to the beneficial effect of angiotensin II type 1 receptor (AT(1)) blocker losartan in the retina of diabetic spontaneously hypertensive rats (SHR).. Diabetic SHR were randomized to receive oral treatment with losartan (DM-SHRLos). After 20 days, the rats were euthanized and the retinas collected.. Diabetic SHR rats exhibited a significant increase in glial fibrillary acidic protein (GFAP) and decrease in occludin, markers of early diabetic retinopathy (DR). The oxidative status, evaluated by NO end-products (NO(x)(-)) levels along with the antioxidative system superoxide dismutase, revealed an accentuated imbalance in favor to oxidants in DM-SHR leading to a higher tyrosine nitration and DNA damage. The inducible NO synthase (iNOS) was also elevated in DM-SHR rats. The treatment with losartan ameliorated all of the above alterations.. Oral treatment with losartan reduces iNOS expression and reestablishes the redox status, thus ameliorating the early markers of DR in a model of diabetes and hypertension.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Oral; Angiotensin II Type 1 Receptor Blockers; Animals; Biomarkers; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Down-Regulation; Losartan; Male; Nitrates; Nitric Oxide Synthase Type II; Nitrites; Osmolar Concentration; Oxidation-Reduction; Rats; Rats, Inbred SHR; Retina; Superoxide Dismutase; Tyrosine; Up-Regulation

We determined the intravitreous level of 8-hydroxydeoxyguanosine (8-OHdG) in diabetic retinopathy (DR) and analyzed the relation between oxidative stress and DR. Vitreous 8-OHdG concentration increased significantly in 18 patients (20 eyes) with DR compared with controls with macular disease. This result suggests that increased oxidative stress is involved in DR.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Deoxyguanosine; Diabetic Retinopathy; Female; Humans; In Vitro Techniques; Male; Middle Aged; Vitreous Body

Pigment epithelium-derived factor (PEDF) is the most potent inhibitor of angiogenesis in the mammalian eye, thus suggesting that PEDF may protect against proliferative diabetic retinopathy. However, a role for PEDF in early diabetic retinopathy remains to be elucidated. We investigated here whether and how PEDF could prevent the development of diabetic retinopathy.. Streptozotocin-induced diabetic rats were treated with or without intravenous injection of PEDF for 4 weeks. Early neuronal derangements were evaluated by electroretinogram (ERG) and immunofluorescent staining of glial fibrillary acidic protein (GFAP). Expression of PEDF and 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative stress, was localized by immunofluorescence. Vascular endothelial growth factor (VEGF) and p22phox expression were evaluated with western blots. Breakdown of blood retinal barrier (BRB) was quantified with fluorescein isothiocynate (FITC)-conjugated dextran. NADPH oxidase activity was measured with lucigenin luminescence.. Retinal PEDF levels were reduced, and amplitudes of a- and b-wave in the ERG were decreased in diabetic rats, which were in parallel with GFAP overexpression in the Müller cells. Further, retinal 8-OHdG, p22phox and VEGF levels and NADPH oxidase activity were increased, and BRB was broken in diabetic rats. Administration of PEDF ameliorated all of the characteristic changes in early diabetic retinopathy.. Results suggest that PEDF could prevent neuronal derangements and vascular hyperpermeability in early diabetic retinopathy via inhibition of NADPH oxidase-driven oxidative stress generation. Substitution of PEDF may offer a promising strategy for halting the development of diabetic retinopathy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Glucose; Blood-Retinal Barrier; Body Weight; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Electroretinography; Eye Proteins; Glial Fibrillary Acidic Protein; Image Processing, Computer-Assisted; Male; NADPH Oxidases; Nerve Growth Factors; Neurons; Organ Specificity; Oxidative Stress; Rats; Rats, Wistar; Retina; Serpins; Vascular Endothelial Growth Factors

Oxidative damage and growth factors are implicated in the pathogenesis of retinopathy in diabetes. Recent studies have shown that two dietary carotenoids, lutein and zeaxanthin (Zx), that are specifically concentrated within ocular tissues, may play important roles in maintaining their integrity. This study is to evaluate the potential protective effects of Zx against retinal oxidative damage and growth factors in diabetes.. A group of rats received normal powdered diet or powdered diet supplemented with 0.02% or 0.1% Zx soon after induction of diabetes. Age-matched normal rats served as control subjects. At 2 months of diabetes, oxidative stress, vascular endothelial cell growth factor (VEGF), and intercellular adhesion molecule (ICAM)-1 were quantified in the retina.. Zx supplementation prevented diabetes-induced increase in retinal damage, and increases in VEGF and ICAM-1. The levels of lipid peroxide, oxidatively modified DNA, electron transport complex III, nitrotyrosine, and mitochondrial superoxide dismutase were similar in the retinas of Zx-treated diabetic rats and normal control rats, and these values were significantly different from those obtained from diabetic rats without any supplementation. In the same rats, Zx also prevented diabetes-induced increases in retinal VEGF and ICAM-1. Both 0.02% and 0.1% Zx had similar effects on diabetes-induced retinal abnormalities, and these effects were achieved without ameliorating the severity of hyperglycemia. However, Zx administration failed to prevent a diabetes-induced decrease in retinal GSH levels.. Zx significantly inhibits diabetes-induced retinal oxidative damage and elevation in VEGF and adhesion molecule, all abnormalities that are associated with the pathogenesis of diabetic retinopathy. The results suggest that Zx supplementation has the potential to inhibit the development of retinopathy in diabetic patients.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blood Glucose; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Diet; Electron Transport Complex III; Intercellular Adhesion Molecule-1; Male; Nitric Oxide Synthase Type II; Oxidative Stress; Rats; Rats, Inbred Lew; RNA, Messenger; Superoxide Dismutase; Tyrosine; Vascular Endothelial Growth Factor A; Xanthophylls; Zeaxanthins

The present study was undertaken to investigate the redox status in the retina of an experimental model that combines hypertension and diabetes. Spontaneously hypertensive rats (SHR) and their control Wystar Kyoto (WKY) rats were rendered diabetic and, after 20 days, the rats were sacrificed and the retinas collected. The superoxide production was higher in diabetic than in control WKY (p < 0.03) and SHR rats showed elevated superoxide production compared with WKY groups (p < 0.009). The glutathione antioxidant system was diminished only in diabetic SHR (p < 0.04). Tirosyne nitration was higher in diabetic WKY and control SHR compared with control WKY (p < 0.03), and further increment was observed in diabetic SHR (p < 0.02). The DNA damage estimated by immunohystochemistry for 8-OHdG was higher in control SHR than in WKY, mainly in diabetic SHR (p < 0.0001). Hypertension aggravates oxidative-induced cytotoxicity in diabetic retina due to increasing of superoxide production and impairment of antioxidative system.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Deoxyguanosine; Diabetic Retinopathy; DNA Damage; Glutathione; Hypertension; Male; Nitrogen; Oxidative Stress; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Superoxide Dismutase; Tyrosine

Diabetic retinopathy is shown to share many similarities with chronic inflammatory disease, and in diabetes, accelerated apoptosis of retinal capillary cells is evident before histopathology can be seen. The purpose of this study was to examine the effect of interleukin (IL)-1beta on capillary cell apoptosis in rat retina and to determine the effect of antioxidants on diabetes-induced changes in retinal IL-1beta.. The effect of injection of IL-1beta into the vitreous (5 ng/5 microL) of normal rats on capillary cell apoptosis (detected by terminal transferase dUTP nick-end labeling [TUNEL]) and formation of acellular capillaries was investigated in the trypsin digested retinal microvessels. The levels of IL-1beta were quantified (by ELISA and Western blot) in the retina of rats diabetic for 2 months, and the effect of administration of antioxidants on diabetes-induced changes in retinal IL-1beta was determined.. The number of TUNEL-positive capillary cells in the retinal microvessels obtained from normal rats that received intravitreal injection of IL-1beta was increased by more than threefold and that of acellular capillaries by more than twofold, compared with the microvessels obtained from rats that received an intravitreal injection of PBS (5 microL) or BSA (5 ng/5 microL). IL-1beta also increased the levels of 8-hydroxy-2'-deoxyguanosine (an indicator of oxidative stress) and nitric oxide by more than 40% and activated NF-kappaB by 35% to 55%. Two months of diabetes in rats increased retinal IL-1beta levels by more than twofold, and antioxidants inhibited such increases.. IL-1beta, by activation of NF-kappaB and an increase in oxidative stress, plays an important role in the retinal microvascular disease that is characteristic of diabetic retinopathy. Antioxidants inhibit diabetes-induced increases in retinal IL-1beta. These studies offer a possible rationale to test IL-1beta-targeted therapies to inhibit the development of retinopathy in diabetes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Apoptosis; Blotting, Western; Capillaries; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; In Situ Nick-End Labeling; Interleukin-1; Male; NF-kappa B; Nitric Oxide; Oxidative Stress; Rats; Rats, Wistar; Retinal Vessels

To evaluate urinary 8-hydroxydeoxyguanosine (8-OHdG) as a marker for the progression of diabetic macroangiopathic complications.. The content of urinary 8-OHdG, common carotid intima-media thickness (IMT), the coronary heart disease (CHD) risk score, the severity of diabetic retinopathy, and urinary albumin excretion were examined in 96 patients with type 2 diabetes, including 32 patients who had been nominated for the Kumamoto Study [Shichiri M, et al. Diabetes Care 23 (Suppl 2):B21-B29, 2000]. In addition, the patients from the Kumamoto Study were further evaluated regarding the effect of intensive insulin therapy on urinary 8-OHdG excretion.. The urinary 8-OHdG:creatinine ratio (U8-OHdG) was 2.5-fold higher in patients with increased HbA(1c) than in those with normal HbA(1c) (P < 0.05). In addition, U8-OHdG was 2.3-fold higher in patients with increased IMT (P < 0.005). A similar result was observed between U8-OHdG and CHD risk score (P < 0.01). U8-OHdG was significantly higher in patients with simple retinopathy (P < 0.05) and those with advanced retinopathy (P < 0.01) than in patients without retinopathy. Similarly, U8-OHdG was significantly higher in patients with albuminuria (P < 0.01). Furthermore, in the Kumamoto Study, U8-OHdG was significantly lower in the multiple insulin injection therapy group compared with the conventional insulin injection therapy group (P < 0.01).. Hyperglycemia independently increases 8-OHdG in patients with type 2 diabetes. 8-OHdG is a useful biomarker of not only microvascular but also macrovascular complications in patients with type 2 diabetes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Albuminuria; Biomarkers; Carotid Artery, Common; Creatinine; Deoxyguanosine; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Retinopathy; Drug Administration Schedule; Female; Humans; Insulin; Male; Middle Aged; Risk Factors; Tunica Intima; Tunica Media

Augmented oxidative stress induced by hyperglycaemia possibly contributes to the pathogenesis of diabetic complications. Oxidative stress is known to increase the conversion of deoxyguanosine to 8-oxo, 2'-deoxyguanosine in DNA. To investigate the possible contribution of oxidative DNA damage to the pathogenesis of diabetic complications, we measured the content of 8-oxo, 2'-deoxyguanosine in the urine and the blood mononuclear cells of Type II (non-insulin-dependent) diabetic patients.. We studied 53 Type II diabetic patients and 39 age-matched healthy control subjects. We assayed 8-oxo, 2'-deoxyguanosine by HPLC-electrochemical detection method.. The content of 8-oxo, 2'-deoxyguanosine in the urine and the mononuclear cells of the Type II diabetic patients was much higher than that of the control subjects. Urinary 8-oxo, 2'-deoxyguanosine excretion and the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells from the diabetic patients with complications were higher than those from the diabetic patients without complications. Urinary excretion of 8-oxo, 2'-deoxyguanosine was significantly correlated with the 8-oxo, 2'-deoxyguanosine content in the mononuclear cells. The 8-oxo, 2'-deoxyguanosine content in the urine and mononuclear cells was correlated with the haemoglobin A1c value.. This is the first report of a direct association between oxidative DNA damage and the complications of diabetes. The augmented oxidative DNA damage in diabetes is speculated to contribute to the pathogenesis of diabetic complications.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Analysis of Variance; Biomarkers; Deoxyguanosine; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diabetic Retinopathy; DNA Damage; Female; Glycated Hemoglobin; Humans; Male; Middle Aged; Oxidative Stress; Reference Values; Smoking