Yesim Oztas

Beneficial Effects of N-Acetylcysteine and Ebselen on Renal Ischemia/Reperfusion Injury

Abstract Introduction: It has been demonstrated that peroxynitrite accompanies acute renal ischemia and contributes to the pathophysiology of renal damage. Therefore, we aimed to investigate the roles of N-acetylcysteine (NAC), a well-known powerful antioxidant, and ebselen (E), a scavenger of peroxynitrite, on renal injury induced by renal ischemia/reperfusion injury (IRI) of rat kidney. Materials and methods: Forty male Sprague–Dawley rats were divided into five groups: sham, renal IRI, renal IRI+NAC, renal IRI+E, and renal IRI+NAC+E. IR injury was induced by 60 min of bilateral renal ischemia followed by 6 h of reperfusion. After reperfusion, kidneys and blood samples were obtained for histopathological and biochemical evaluations. Results: Renal IR resulted in increased malondialdehyde and nitrite/nitrate levels suggesting increased lipid peroxidation and peroxynitrite production and decreased superoxide dismutase and glutathione peroxidase activities. Both NAC and E alone significantly decreased malondialdehyde and nitrite/nitrate levels and increased superoxide dismutase and glutathione peroxidase activities. Additionally in the renal IRI+NAC+E group, all biochemical results were quite close to those of sham group. Histopathologically, the kidney injury in rats treated with combination of NAC and E was found significantly less than the other groups. Conclusions: Both NAC and E are able to ameliorate IRI of the kidney by decreasing oxidative and nitrosative stresses and increasing free radical scavenger properties. Additionally, combination of NAC and E prevents kidney damage more than when each drug is used alone, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing renal IRI.

Plasma protein oxidation is correlated positively with plasma iron levels and negatively with hemolysate zinc levels in sickle-cell anemia patients

Introduction:  Sickle‐cell anemia (SCA) is a disease of high oxidative stress. The oxidative medium of SCA was evaluated by protein oxidation parameters and their correlation with lipids and ions were investigated both in the plasma and in the erythrocyte.

Integration of maternal genome into the neonate genome through breast milk mRNA transcripts and reverse transcriptase

Human milk samples contain microvesicles similar to the retroviruses. These microvesicles contain mRNA transcripts and possess reverse transcriptase activity. They contain about 14,000 transcripts representing the milk transcriptome. Microvesicles are also enriched with proteins related to “caveolar-mediated endocytosis signaling” pathway. It has recently been reported that microvesicles could be transferred to other cells by endocytosis and their RNA content can be translated and be functional in their new location. A significant percentage of the mammalian genome appears to be the product of reverse transcription, containing sequences whose characteristics point to RNA as a template precursor. These are mobile elements that move by way of transposition and are called retrotransposons. We thought that retrotransposons may stem from about 14,000 transcriptome of breast milk microvesicles, and reviewed the literature.The enhanced acceptance of maternal allografts in children who were breast-fed and tolerance to the maternal MHC antigens after breastfeeding may stem from RNAs of the breast milk microvesicles that can be taken up by the breastfed infant and receiving maternal genomic information. We conclude that milk microvesicles may transfer genetic signals from mother to neonate during breastfeeding. Moreover, transfer of wild type RNA from a healthy wet-nurse to the suckling neonate through the milk microvesicles and its subsequent reverse transcription and integration into the neonate genome could result in permanent correction of the clinical manifestations in genetic diseases.

Poly(ADP-ribose) polymerase inhibition modulates experimental acute necrotizing pancreatitis-induced oxidative stress, bacterial translocation and neopterin concentrations in rats

Various studies have been performed to find out novel treatment strategies for acute necrotizing pancreatitis (ANP). Inhibition of poly(ADP-ribose) polymerase (PARP) is shown to reduce inflammation in several pathological conditions. We aimed to evaluate the efficacy of benzamide, a PARP inhibitor, in an experimental model of ANP. Thirty Sprague–Dawley rats were divided into three groups: sham-operated, ANP and ANP + benzamide groups. All groups except the sham-operated group were subjected to the ANP procedure, induced by infusing of 1 mL/kg of 3% sodium taurocholate into the common biliopancreatic duct. The ANP + benzamide group received 100 mg/kg/day benzamide intraperitoneally for a total of three days after induction of pancreatitis. The surviving animals were killed at the fourth day and the pancreas was harvested for biochemical, microbiological and histological analysis. Blood samples were also obtained from the animals. In the ANP group, a significant increase was observed in concentrations of serum amylase and neopterin and tissue oxidative stress indices (malondialdehyde, superoxide dismutase and glutathione peroxidase). Almost all of these changes were found to be reversed to near their normal values in the ANP + benzamide group. Histological injury scores were significantly higher in the ANP group than in the sham group (P < 0.05, ANP versus sham), and were significantly lower in the ANP + benzamide group than in the ANP group (P < 0.05, ANP + benzamide versus ANP). Evaluation of bacterial translocation identified significantly fewer infected sites in the ANP + benzamide group than in the ANP animals (P < 0.01). We observed that inhibition of PARP with benzamide reduced the severity, the mortality, the bacterial translocation rates and the neopterin concentrations in an experimental ANP model in rats. These findings suggest that it may be possible to improve the outcome of ANP by using PARP inhibitors.

Rutin ameliorates methotrexate induced hepatic injury in rats.

PURPOSE To investigate the possible protective effect of rutin on methotrexate induced hepatotoxicity in rats. METHODS Twenty-two rats were divided into three experimental groups; Control-saline, Mtx, Mtx+Rutin. Hepatic tissue was taken for histological assessment and biochemical assays. Oxidative stress parameters malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were investigated. Liver markers aspartate aminotransferase (AST), alanine aminotransferase (ALT) were analyzed in serum. RESULTS Mtx+Rutin group showed lower histological injury compared to Mtx group, MDA and ALT levels were increased, while SOD and GSH-Px were decreased in Mtx group compared with Control-saline group. MDA and ALT levels were increased, while SOD and GSH-Px were decreased in Mtx group, compared with Mtx +Rutin group. Serum AST levels were similar among the groups. CONCLUSION Rutin may be a potential adjuvant drug to reduce the hepatic side effects observed during Mtx therapy for various clinical conditions.

Oxidative protein damage with carbonyl levels and nitrotyrosine expression after chemotherapy in bone marrow transplantation patients.

Protein oxidation is defined as the covalent modification of a protein, induced either directly by reactive oxygen species/reactive nitrogen species or indirectly by reaction with secondary by-products of oxidative stress. Protein carbonyls are the most commonly measured products of protein oxidation. Additionally, nitrotyrosine is a product of tyrosine nitration mediated by reactive nitrogen species such as peroxynitrite anion and nitrogen dioxide. Samples were collected before the preparative regimen (10 days before transplantation; day –10), on transplantation day (day 0), and after transplantation (days 7, 14, and 28) from 16 pediatric allogeneic hematopoietic stem cell transplantation (HSCT) patients. The erythrocyte 3-nitrotyrosine expression was shown to be significantly increased after chemotherapy. In accordance, the mean plasma carbonyl levels on days 14 and 28 were significantly higher than on the other days. High-dose chemotherapy applied in the preparative regimen of HSCT may be responsible for this long-term oxidation of plasma proteins. These results show that high-dose chemotherapy resulted in protein oxidation both in plasma and in erythrocytes in HSCT patients.

Efficacy of melatonin, mercaptoethylguanidine and 1400W in doxorubicin- and trastuzumab-induced cardiotoxicity.

Abstract:  Doxorubicin (DOX) and Trastuzumab (TRAST) are effective agents for the treatment of many neoplastic diseases. Cardiotoxicity is a major side effect of these drugs and limit their use. In this study, the possible protective effects of melatonin (MEL), mercaptoethylguanidine (MEG), or N‐(3‐(aminomethyl) benzyl) acetamidine (1400W) against the cardiotoxicity of DOX and TRAST were tested. Male Sprague‐Dawley rats received an injection of DOX (20 mg/kg) alone or in combination with TRAST (10 mg/kg) to induce cardiotoxicity; daily treatments with MEL (10 mg/kg × 2), MEG (10 mg/kg × 2), or 1400W (10 mg/kg × 2) were begun 36 hr before and continued for 72 hr after DOX and TRAST administration. Oxidant/antioxidant indices of the cardiac tissue, namely, malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px), as well as serum levels of creatine phosphokinase (CK‐MB) were measured. Additionally, the injury scores were evaluated histopathologically. Malondialdehyde levels were significantly higher, while SOD and GSH‐Px activities were significantly reduced in rats with DOX‐ or DOX+TRAST‐induced cardiotoxicity compared to normal values. All three treatment agents significantly reversed oxidative stress markers. Serum CK‐MB levels were significantly increased after treatment with DOX and DOX+TRAST; these changes were also reversed by each of the treatments and resulted in near normal levels. Both the DOX‐ and DOX+TRAST‐treated rats presented similar histopathologic injuries; in the animals treated with the protective agents, histologic protection of the cardiac tissue was apparent. These results suggested that MEL, MEG, as well as 1400W are effective in preventing DOX‐ or DOX+TRAST‐induced cardiotoxicity.

Cystatin C, Beta2 Microglobulin, N-Acetyl-beta-D-glucosaminidase, Retinol-Binding Protein, and Endothelin 1 Levels in the Evaluation of Sickle Cell Disease Nephropathy

Objectives: Renal involvement is common in sickle cell disease (SCD). Early demonstration of renal injury and commencement of appropriate treatment will increase survival and quality of life in these patients. We investigated renal manifestations in our pediatric and adult SCD patients and evaluated the role of cystatin C, Beta2 microglobulin (B2M), retinol-binding protein (RBP), N-acetyl-beta-D-glucosaminidase (NAG), and endothelin-1 (ET-1) to indicate renal damage. Methods: The study involved 45 pediatric and 10 adult patients with SCD and 20 healthy children and 10 healthy adults as a control. All the patients were questioned for possible renal manifestations. 24-hour urine samples were collected and glomerular filtration rates (GFRs) were calculated by using creatinine (GFRcreatinine), Schwartz formula (GFRSchwartz), and cystatin C (GFRcystatin C). Blood and urine samples were collected and serum cystatin C, urine B2M, RBP, NAG, and ET-1 levels were measured. Results: Nocturnal enuresis and proteinuria were the most common renal manifestations in SCD patients. When the groups were compared in terms of GFR, GFRcreatinine and GFRSchwartz levels were higher in group 1 and 2 patients than in control 1 and 2 patients (P < .05). Cystatin C, B2M, RBP, NAG, and ET-1 values were normal in both the patient and the control groups. However, B2M/creatinine levels were higher than 160 μg/mg creatinine levels in 10 patients. Conclusions: Serum cystatin C, urine NAG, RBP, and ET-1 levels were found to be insufficient for the evaluation of SCD nephropathy. Increased B2M/creatinie levels can be valuable in estimating possible glomerular and tubular damage in SCD.

Inhibition of iNOS reduces the therapeutic effects of ozone in acute necrotizing pancreatitis: An in vivo animal study

Abstract Objective. Previously, it was shown that ozone and S-methylthiourea (SMT) treatments had ameliorative effects on experimental models of acute necrotizing pancreatitis (ANP). It is possible that the combination of ozone and SMT may be more effective than either therapy. Therefore, we investigated the efficacy of combination therapy with ozone and SMT in an experimental rat model of ANP. Material and methods. Sprague-Dawley rats were divided into five experimental groups. Groups were designed as Sham-operated, ANP, ANP + Ozone, ANP + SMT and ANP + Ozone + SMT. A model of ANP was induced by injection of sodium taurocholate into the common biliopancreatic duct. Four days after induction, blood and tissue samples were obtained for biochemical, microbiological and histopathological analysis. Results. Survival rates, serum amylase, lipase and neopterin levels, tissue oxidative stress parameters, bacterial translocation and tissue injury scores were better in the ozone and SMT groups than in the ANP group. There was no bacterial translocation in the ozone-treated groups. Tissue injury scores in the ozone group were better compared to all ANP induced groups. Ozone and SMT treatment in combination did not have better biochemical, microbiological and histological data compared to ozone or SMT treatments separately in experimental ANP. Conclusions. The combination of ozone and SMT did not provide any therapeutic advantage in ANP possibly because SMT inhibited nitric oxide synthesis which was needed for ozone action.

Structural Modification of Plasma Albumin in Sickle Cell Anemia

in SCA patients and controls. A comparison between urea-treated and untreated samples was carried out. There are various sophisticated methods that can be used; however, we preferred the routinely used plasma protein electrophoresis as a method in hand. This method provided us with sufficient data for interpretation. For the first time, we propose that albumin in the plasma of SCA patients undergoes structural modification as a result of the oxidation of the molecule itself. The local ethics review committee approved the study and informed consent was obtained. The steady-state SCA patients (n = 6) were follow-up patients with no hospitalization or transfusion for at least 3 months. SCA patients who were hospitalized for vaso-occlusive crisis but did not receive any blood transfusion were chosen for the crisis group (n = 6). The third group consisted of healthy children (n = 5), i.e. with no known disease. After overnight fasting, venous blood samples were collected into tubes containing EDTA. Plasma samples were separated from the centrifuged blood as soon as possible. They were then frozen at –20 ° C, until being analyzed 3 months later. In this study, we used denaturing conditions similar to studies investigating plasma proteins in other diseases [11, 12] . Urea is frequently used in protein analysis studies. We aimed at partial denaturation of the albumin with urea. It has been reported that at a concentration of 2.4 M, urea albumin starts to unfold [13] , and that it undergoes Sickle cell anemia (SCA) is a hemoglobinopathy caused by a point mutation in the beta globin gene. Besides the manifestations of chronic hemolysis, vaso-occlusion, endothelial injury and inflammation [1] , SCA is also a disease of increased oxidative stress [2] . Previous studies have reported increased levels of malondialdehyde [2] and protein carbonyl [3] in the plasma of SCA patients. Only a few studies have examined the plasma protein patterns by means of routine protein electrophoresis in SCA. Isichei [4] reported higher levels of total serum protein and globulin in pediatric SCA patients. Daga et al. [5] observed higher levels of serum total protein and albumin in adult SCA patients. Allamanis [6] reported a decrease of albumin during SCA crisis, and hypoalbuminemia and a reversal of albumin/globulin ratio were observed in crisis patients by Fenichel et al. [7] . In a historical paper by Swaby and Branson [8] , the albumin in the sickle cell plasma was found to have a higher electrophoretic mobility than that in normal plasma. They concluded that the greater mobility of albumin from SCA patients’ plasma could be attributed to a larger number of negative charges on the albumin molecule. It was previously documented that the free 34 cysteine residue of albumin reacted with reactive oxygen species and was oxidized [9, 10] . We chose urea, as a simple but well-known denaturant, for the investigation of the plasma protein structure Received: February 27, 2013 Accepted after revision: April 10, 2014 Published online: August 15, 2014