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Öğe Critical time point for apoptotic cell death in an experimental ischemia/reperfusion model and the effect of N-acetylcystein(Walter De Gruyter Gmbh, 2017) Ozsarlak-Sozer, Gonen; Emre, Mustafa; Demirkol, Serhat; Acikalin, Arbil; Cetiner, Salih; Topcu, Zeki; Demir-Dora, DevrimObjective: Kidney transplantation is an important treatment option in end stage renal failure. Tissue death may be an important problem when a kidney is removed from a cadaver and transported to a donor a long distance away. The purpose of this study is to determine the critical time point for apoptotic cell death in a renal ischemia/reperfusion model and determine the effects of N-acetylcystein on apoptosis induced by ischemia injury. Methods: Apoptotic cell death after induced renal ischemia followed by reperfusion, was estimated in a group of Wistar albino rats by immunoflourescence and ELISA techniques. N-acetylcystein, an antioxidant agent, was given to the rats to study the effect on apoptosis. Tissues were examined immunohistochemically at 0, 1 h, 24 h, 5 days and 10 days for detection of apoptotic cells. Results: Our results showed that an ischemia for 60 min followed by reperfusion for 60 min triggered apoptosis. Moreover, N-acetylcystein significantly diminished both the ischemia/reperfusion damage and apoptosis. Conclusion: We anticipate our results would be important for kidney transplantation in estimating the critical time point for apoptosis and administration of N-acetylcystein prior to removal of the organ may be important in delaying the onset of apoptosis.Öğe Decreased eNOS relaxations and relation with hsp90 in hypercholesterolemic rabbit aorta(Federation Amer Soc Exp Biol, 2013) Ozsarlak-Sozer, Gonen; Arun, Mehmet; Sevin, Gulnur; Ertuna, Elif; Yilmaz, Zeynep; Ulasan, Sema; Yetik-Anacak, GunayÖğe Development of liquid crystal biosensor for the detection of amyloid beta-42 levels associated with Alzheimer's disease(Soc Bioscience Bioengineering Japan, 2021) Kemiklioglu, Emine; Tuncgovde, Ebru Busra; Ozsarlak-Sozer, GonenThis study represents the development of a biosensor which is based on the liquid crystal (LC) orientation as a function of the peptide concentration to detect an amyloid-beta-42 (A beta 42) antibody-antigen binding events. The A beta 42 peptide binds to the A beta 42 antibody forming an immunocomplex which is immobilized on the Dimethyloctadecyl[3-(trimethoxysilyl)propyl] ammonium chloride (DMOAP) coated surface. The disturbed orientation of LCs as a result of the binding of the formed immunocomplex was observed using the polarized optical microscope (POM) as a function of decreasing A beta 42 peptide concentration from 1000 to 1 pg/ml. The concentration, as low as 1 pg/ml of A beta 42 peptide was able to be successfully detected in our system. Apolipoprotein E4 (ApoE4), that specifically bound to the A beta 42 peptide, was added into the system and a remarkable change in reflection spectra of samples was observed with increasing A beta 42 peptide concentration. The concentration of ApoE4 protein was detected in the range of 0.1-30 nM by this system due to the interaction between the two proteins. (C) 2021, The Society for Biotechnology, Japan. All rights reserved.Öğe Endothelin Receptor-Independent Correlation Between HSP47 and Collagen in Rabbit Model of Early Atherosclerosis(Ortadogu Ad Pres & Publ Co, 2011) Reel, Buket; Cavdar, Zahide; Ergur, Bekir Ugur; Ozkal, Sermin; Ozsarlak-Sozer, Gonen; Oktay, Gulgun; Kerry, ZelihaObjective: Collagen in the extracellular matrix (ECM) plays an important role in modulation of response to the vascular injury during the progression of atherosclerosis and restenosis. Collagen can regulate smooth muscle cell (SMC) proliferation, migration and matrix metalloproteinase (MMP) production. Therefore, collagen turnover in the arteries is an important determinant of intimal thickening. Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is thought to be essential for the processing and secretion of procollagen molecules. Endothelin (ET) is a strong chemoatractant and mitogen promoting SMC proliferation and migration. The aim of this study was to investigate the possible role of HSP47 and its relation to collagen synthesis, and the effects of a nonselective ETA/ETB receptor antagonist, TAK-044 in collar-induced early atherosclerosis model. Material and Methods: New Zealand white rabbits were divided into two groups. Both groups received vehicle (0.9% NaCl 0.8 ml/kg/day, s.c.) or TAK-044 (5 mg/kg/day, s.c.) for three weeks. On 8th day, a non-occlusive silicon collar was placed around the left carotid artery. The right carotid artery was sham-operated. HSP47 expression in carotid arteries were determined immunohistochemically. Furthermore, total collagen levels, collagen expression and type I procollagen expression were established. Results: HSP47 expression correlated with collagen expression did not change in collared arteries. TAK-044 treatment did not affect HSP47 and collagen levels. Conclusion: There was a correlation between HSP47 expression and collagen expression in carotid arteries. However, intimal thickening did not induce HSP47 expression and early collagen development. The ineffectivenes of TAK-044 suggests that ET-1 signaling may not be implicated in HSP47 and collagen in this model.Öğe Experimental Ischemia/Reperfusion Model in Relation to Apototic Cell Death(Federation Amer Soc Exp Biol, 2013) Emre, Mustafa; Demirkol, Serhat; Dora, Devrim D.; Unlukurt, Isa; Topcu, Zeki; Ozsarlak-Sozer, GonenÖğe Functional significance of hsp90-eNOS interaction in penile tissues(Federation Amer Soc Exp Biol, 2013) Yetik-Anacak, Gunay; Ertuna, Elif; Ozsarlak-Sozer, Gonen; di Pascoli, Saadet Turkseven; Koylu, Ersin; Gozen, Oguz; Sevin, Gulnur; Arun, Mehmet; Un, IsmailÖğe Glutathione Depletion by Buthionine Sulfoximine Induces Oxidative Damage to DNA in Organs of Rabbits in Vivo(Amer Chemical Soc, 2009) Gokce, Goksel; Ozsarlak-Sozer, Gonen; Oktay, Gulgun; Kirkali, Gueldal; Jaruga, Pawel; Dizdaroglu, Miral; Kerry, ZelihaGlutathione (GSH) exists in mammalian tissues in vivo at high concentrations and plays an important protective role against oxidatively induced damage to biological molecules, including DNA. We investigated oxidatively Induced damage to DNA by GSH depletion in different organs of rabbits in vivo. Rabbits were treated subcutaneously with buthionine sulfoximine (BSO), an effective GSH-depleting compound. GSH levels were measured in heart, brain, liver, and kidney of animals. BSO treatment significantly reduced GSH levels in heart, brain, and liver, but not in kidney. DNA was isolated from these tissues to test whether GSH depletion causes oxidatively induced DNA damage in vivo. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry with isotope dilution methods were applied to measure typical products of oxidatively induced damage in isolated DNA samples. Several such products were identified and quantified in all organs. BSO treatment caused significant formation of 8-hydroxyguanine, 2,6-diamino-4-hydroxy-5-formamidopyrimidine, 8-hydroxyadenine, and (5'S)-8,5'-cyclo-2'-deoxyadenosine in DNA of organs of rabbits. Animals were fed with the semiessential amino acid 2-aminoethanesulfonic acid (taurine) during BSO treatment. Taurine significantly inhibited GSH depletion and also formation of DNA products. Depletion of GSH correlated well with formation of DNA products, indicating the role of GSH in preventing oxidatively induced DNA damage. Our findings might contribute to the understanding of pathologies associated with DNA damage, oxidative stress, and/or defective antioxidant responses and improve our understanding of the effect of BSO in increasing the efficacy of anticancer therapeutics.Öğe Local Atherosclerotic Plaques Are a Source of Prognostic Biomarkers for Adverse Cardiovascular Events(Lippincott Williams & Wilkins, 2010) de Kleijn, Dominique P. V.; Moll, Frans L.; Hellings, Willem E.; Ozsarlak-Sozer, Gonen; de Bruin, Peter; Doevendans, Pieter A.; Vink, Aryan; Catanzariti, Louise M.; Schoneveld, Arjan H.; Algra, Ale; Daemen, Mat J.; Biessen, E. A.; de Jager, W.; Zhang, Huoming; de Vries, Jean-Paul; Falk, Erling; Lim, Sai K.; van der Spek, Peter J.; Sze, Siu Kwan; Pasterkamp, GerardObjective-Atherosclerotic cardiovascular disease is a major burden to health care. Because atherosclerosis is considered a systemic disease, we hypothesized that one single atherosclerotic plaque contains ample molecular information that predicts future cardiovascular events in all vascular territories. Methods and Results-AtheroExpress is a biobank collecting atherosclerotic lesions during surgery, with a 3-year follow-up. The composite primary outcome encompasses all cardiovascular events and interventions, eg, cardiovascular death, myocardial infarction, stroke, and endovascular interventions. A proteomics search identified osteopontin as a potential plaque biomarker. Patients undergoing carotid surgery (n=574) served as the cohort in which plaque osteopontin levels were examined in relation to their outcome during follow-up and was validated in a cohort of patients undergoing femoral endarterectomy (n=151). Comparing the highest quartile of carotid plaque osteopontin levels with quartile 1 showed a hazard ratio for the primary outcome of 3.8 (95% confidence interval, 2.6-5.9). The outcome did not change after adjustment for plaque characteristics and traditional risk factors (hazard ratio, 3.5; 95% confidence interval, 2.0-5.9). The femoral validation cohort showed a hazard ratio of 3.8 (95% confidence interval 2.0 to 7.4) comparing osteopontin levels in quartile 4 with quartile 1. Conclusion-Plaque osteopontin levels in single lesions are predictive for cardiovascular events in other vascular territories. Local atherosclerotic plaques are a source of prognostic biomarkers with a high predictive value for secondary manifestations of atherosclerotic disease. (Arterioscler Thromb Vasc Biol. 2010;30:612-619.)Öğe Low-Dose Fluvastatin Prevents the Functional Alterations of Endothelium Induced by Short-Term Cholesterol Feeding in Rabbit Carotid Artery(Hindawi Publishing Corporation, 2012) Sevin, Gulnur; Akcay, Yasemin Delen; Ozsarlak-Sozer, Gonen; Yasa, Mukadder3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, commonly known as statins, are the medical treatment of choice for hypercholesterolemia. In addition to lowering serum-cholesterol levels, statins appear to promote pleiotropic effects that are independent of changes in serum cholesterol. In this study, we investigated the effects of low-dose fluvastatin on antioxidant enzyme activities (superoxide dismutase, SOD; catalase), total nitrite/nitrate levels, and vascular reactivity in 2% cholesterol-fed rabbits. This diet did not generate any fatty streak lesions on carotid artery wall. However, SOD activity significantly increased with cholesterol feeding whereas the catalase activities decreased. The levels of nitrite/nitrate, stable products of NO degradation, diminished. Moreover, dietary cholesterol reduced vascular responses to acetylcholine, but contractions to serotonin were augmented. Fluvastatin treatment abrogated the cholesterol-induced increase in SOD, increased the levels of nitric oxide metabolites in tissue, and restored both the impaired vascular responses to acetylcholine and the augmented contractile responses to serotonin without affecting plasma-cholesterol levels. Phenylephrine contractions and nitroglycerine vasodilatations did not change in all groups. This study indicated that fluvastatin treatment performed early enough to improve impaired vascular responses may delay cardiovascular complications associated with several cardiovascular diseases.Öğe MMP-2 and MMP-9 Alteration in Response to Collaring in Rabbits: The Effects of Endothelin Receptor Antagonism(Sage Publications Inc, 2009) Reel, Buket; Oktay, Gulgun; Ozkal, Sermin; Islekel, Huray; Ozer, Erdener; Ozsarlak-Sozer, Gonen; Cavdar, Zahide; Akhisaroglu, Serpil Tanriverdi; Kerry, ZelihaMatrix metalloproteinases (MMPs), and, in particular, gelatinases (MMP-2 and MMP-9), have been implicated in vascular cell proliferation and/or migration, contributing to intimal thickening, an essential stage in the development of atherosclerosis and restenosis following balloon angioplasty. Endothelin, a strong chemoatractant and mitogen, has been shown to promote smooth muscle cell proliferation and migration by activating MMPs via endothelin-A (ETA) receptors. The positioning of a soft silicon collar around the left carotid artery in rabbits results in intimal thickening. In this study, we investigate the possible role of gelatinases and the effect of a nonselective ETA/ETB receptor antagonist, TAK-044 (5 mg/kg body weight/day, subcutaneously [sc]), on these enzymes. Our results demonstrated that both MMP-2 and MMP-9 activities increased in response to collaring in placebo group, while treatment with TAK-044 significantly suppressed both gelatinase activities and proMMP-2 levels, and inhibited intimal thickening in collared arteries. These results suggest that either enhanced MMP expression or endothelin receptor antagonism may be involved in the formation of intimal thickening in this model.Öğe MMP-2 and MMP-9 Alteration in Response to Collaring in Rabbits: The Effects of Endothelin Receptor Antagonism(Sage Publications Inc, 2009) Reel, Buket; Oktay, Gulgun; Ozkal, Sermin; Islekel, Huray; Ozer, Erdener; Ozsarlak-Sozer, Gonen; Cavdar, Zahide; Akhisaroglu, Serpil Tanriverdi; Kerry, ZelihaMatrix metalloproteinases (MMPs), and, in particular, gelatinases (MMP-2 and MMP-9), have been implicated in vascular cell proliferation and/or migration, contributing to intimal thickening, an essential stage in the development of atherosclerosis and restenosis following balloon angioplasty. Endothelin, a strong chemoatractant and mitogen, has been shown to promote smooth muscle cell proliferation and migration by activating MMPs via endothelin-A (ETA) receptors. The positioning of a soft silicon collar around the left carotid artery in rabbits results in intimal thickening. In this study, we investigate the possible role of gelatinases and the effect of a nonselective ETA/ETB receptor antagonist, TAK-044 (5 mg/kg body weight/day, subcutaneously [sc]), on these enzymes. Our results demonstrated that both MMP-2 and MMP-9 activities increased in response to collaring in placebo group, while treatment with TAK-044 significantly suppressed both gelatinase activities and proMMP-2 levels, and inhibited intimal thickening in collared arteries. These results suggest that either enhanced MMP expression or endothelin receptor antagonism may be involved in the formation of intimal thickening in this model.Öğe Oxidative stress in relation to telomere length maintenance in vascular smooth muscle cells following balloon angioplasty(Springer, 2011) Ozsarlak-Sozer, Gonen; Kerry, Zeliha; Gokce, Goksel; Oran, Ismail; Topcu, ZekiTelomeres are specialized DNA-protein complexes found at the tips of linear chromosomes. In this study, we investigated the effects of oxidative stress on telomeric length distribution of proliferating vascular smooth muscle cells following balloon injury in single or combined treatment of rabbits with either buthionine sulfoximine or taurine. Exposure to oxidative stress increased the balloon injury whereas taurine treatment significantly diminished l-buthionine-sulfoximine-related intimal hyperplasia. Our results also showed that both variables had a significant influence on mean telomeric length distribution.Öğe Taurine inhibits increased MMP-2 expression in a model of oxidative stress induced by glutathione depletion in rabbit heart(Elsevier Science Bv, 2013) Sevin, Gulnur; Ozsarlak-Sozer, Gonen; Keles, Didem; Gokce, Goksel; Reel, Buket; Ozgur, Halil Hakan; Oktay, Gulgun; Kerry, ZelihaMatrix metalloproteinase enzymes (MMPs) activated by oxidative stress are involved in the pathogenesis of cardiovascular diseases. Glutathione (GSH) plays an important protective role against oxidatively induced damage in mammalian tissues. We investigated the possible role of gelatinases and the effect of the semiessential amino acid 2-aminoethanesulfonic acid (taurine) in oxidatively induced damage by GSH depletion in rabbit cardiac tissues. Rabbits were treated with buthionine sulfoximine (BSO), an effective GSH-depleting compound. BSO treatment significantly reduced GSH and increased MDA (malondialdehyde) levels. BSO treatment caused significant increase in proMMP-2 levels. MMP-9 (pro and active) expressions were not found in either treated- or untreated heart tissues. TIMP-1(endogenous inhibitor of MMP-9) and MT-MMP1 (endogenous activator of MMP-2) were not affected by BSO. Immunoscoring showed that MMP-2 expression significantly increased in hearts from BSO treated group but MMP-9 antibody did not show any significant positive immunostaining from all groups. Type I procollagen and total collagen did not significantly alter in heart tissues from all treatment groups. Taurine restored the increased MDA and the diminished GSH levels by BSO treatment. Pro MMP-2 expression was prevented by taurine. These results suggest that MMP-2 is a major gelanitase in rabbit hearts under oxidative stress and pharmacological inhibition of MMP-2 activation by taurine could represent a useful strategy for the prevention and/or treatment of different cardiovascular disorders. (C) 2013 Elsevier B.V. All rights reserved.
