Effect of pridoindole stobadine on liver tissue protein oxidation of STZ-Diabetic rats

Serbest radikalerle gercekle§en oksidatif protein hasan diyabet gibi gibi patolojik olaylann gelisjminde onemli bir rol oynar. Proteinler oksijen ve nitrojen radikaleri ie hasara ugrayabilir bu da proteinlerde enzimatik aktivite kaybi ve amino asiterin karbonil kahntanna donu§mesine neden olabilir. Aynca serbest radikalerin proteinlerin -SH (Tiyol) gruplannin oksidasyonuna neden oldugu bilinmektedir. Proteinlehn redoks potansiyelerinin varligi temel hucre onksiyaonlannm devami icin onemlidir. Dolayisiyla proteinlerdeki yapisal degisjmere bagh geli§en yeni molekuer mekanizmalar diyabetik komplikasyonlann gelismesine liderlik etmektedir. Bu cahsmada streptozotozin ie diyabet olusturulan ve kontrol ratarda pridoindol stobadin (STB; 24,7 mg/kg/gun) edavisinin karaciger dokusunda protein oksidasyonu belirtecleri zerine etkisini ara§trdk. Qah§mamzda ratar pehton igi streptozotosin (55/mg/kg) enjeksiyonu ie diyabet yapidi ve rastgele secien denekler, kontrol (n=7), kontrol+stobadin (n=7), diyabet (n=7), diyabet+stobadin (n=7) olmak zere dort gruba aynd. Karaciger homojenatannda, nitrotirozin seviyeleri ELiSA kiti ie, ieri oksidasyon protein runleri (AOPP) ve tiyol dzeyleri spektrofotometrik yontemerle, protein karbonil seviyeleri ise kolorimetrik deney kiti ie olcud. Tiyol seviyelerinin diyabetik ratarda dstugu,ancak AOPP ve karbonil dzeylerinin ise kontrole kiyasla arttgi (p<0,05) gozlemendi.Bununla birlikte diyabetik ratarda stobadin edavisi, tiyol dzeylerinde art§a, AOPP ve protein karbonil bakiyelerinde istatistiksel olarak anlamh derecede azah§a (p<0,05)neden olmustur. Ancak 3-nitrotirozin seviyelerinde turn gruplarda anlamh degisim belirlenmedi. Wistar-Abino ratann doku protein oksidasyon belirtegleri bakimmdan dort grup arasmda ki istatistiksel karsiastrma Mann-Whitney U esti kulaniarak yapidi ve p<0,05 istatistiksel olarak anlamh kabul edidi. Bu cahsmanm sonuclanna gore, diyabetin geli§imine neden olabiecek oksidatif protein hasannm onlenmesine, stobadin tedavisinin oksidatif stresi azalarak katkida bulunabiecegi vurgulanmaktadr.The oxidatve protein damage provoked by reactve ree radicals has been demonstrated o play a signicant role n several pathological events such as diabetes. Proteins can also be damaged by oxygen and nirogen radicals, eading o a oss of enzymatc actviy and the conversion of amno acids to carbonyl derivatves and t has already been shown hat ree radicals cause oxidaton of protein - H groups. Considerable evidence ndicates hat he maintenance of protein redox status s of fundamental mportance or cell functon, herefore structural changes n proteins are considered o be among he molecular mechanisms eading o diabetc complcatons, in he present study, we determned he efect of pridoindole stobadine supplementaton (STB; 24.7 mg/kg/day) on he markers of oxidatve protein damage n he ver ssue of TZ- diabetc rats and heir control and reated groups. Dabetes was nduced by ntraperitonal njecton of streptozotosin (55 mg/kg) and rats were randomy divided nto our groups as olows: control (K; n = 7), controlSTB (KTB; n=7), Dabet (DiA; n=7) and DabetSTB (DTB; n=7). 3- Nrotyrosine evels were measured by ELiSA. Thiols and AOPP evels of ver homogenates were studied by spectrophotometric methodand Protein carbonyl levels were determned by colorimetric assay kit. Total, protein and non-protein hiol levels were signicanty decreased n diabetc rats. On he other hand protein carbonyl content and advanced oxidaton protein product levels were signicanty ncreased n diabetc group compared w h hose of he controls (p<0,05). Stobadine reatment ed o signicanty ncrease hiol parameters and decreased protein carbonyl content and advanced oxidaton protein product (AOPP) evels n diabetSTB group (p<0.05).3-nirotyrosine evels weren't dierent in all groups.Tssue protein oxidaton parameters n he our groups of Wstar-Abino rats were compared using he Mann-Whiney U-test. When not specied p<0.05 was considered signicant. The resuls of his study suggest hat stobadine decreased oxidatve stres and may be efectve n preventng oxidatve protein damage, which may contribute to the development of diabetc complcatons

Effects of 4-hydroxynonenal on Endoplasmic reticulum stres, apoptosis, insulin release and detoxification enzymes in pancreatic beta cells (INS-1)

4-hidroksinonenal lipid peroksidasyonunun bir ürünü olup, yüksek konsantrasyanlarda hücrelerde proteinlerle stabil ürünler oluşturur. Artmış stabil ürünler endoplazmik retikulumda (ER) katlanmamış protein cevabını başlatır. Artmış katlanamamış protein cevabı veya kronik endoplazmik retikulum stres apoptozis ve otofajiyi indükler. Böylece bizde çalışmamızda, pankreatik beta hücrelerinde 4-hidroksinonenal in ER stres sensör proteinleri, detoksifikasyon enzimleri, apoptozis ve insulin salıverilmesi üzerine etkilerini araştırdık. INS-1 hücrelerinde 4-hidroksinonenal artan zamana ve doza bağlı olarak hücre canlılığını azaltmıştır. 4-hidroksinonenal toksik dozda bazal ve glukozla tetiklenen insulin salıverilmesini anlamlı derecede azaltmıştır. 4-hidroksinonenal uygulaması detoksifikasyonda görevli glutatyon-s-transferaz ve aldoz redüktaz 1B1 protein ifadelenmelerini toksik dozlarda uyarmıştır. Endoplazmik retikulum stres belirteci PERK fosforilasyonu ve IRE1-a düzeylerini toksik doz 4-hidroksinonenal uygulaması ile anlamlı derecede artırmıştır. 4-hidroksinonenal yüksek dozda endoplazmik retikulum aracılı hücre ölümünde etkili CHOP ve kaspaz 12 proteinlerin ifadelenmelerinde artışa neden olmuştur. Ayrıca toksik doz 4-hidroksinonenal uygulaması JNK, kaspaz 9 ve kaspaz 3 ün aktivasyonuna neden olmuştur. Sonuç olarak, 4-hidroksinonenal pankreatik beta hücre kaybında oldukça etkilidir. 4-hidroksinonenal insulin eksikliğine bağlı hipergliseminin gelişimine etken olabilir. Belki de pre-diyabetik evrede antioksidan veya lipid peroksitleri temizleyici tedavi yaklaşımları ile beta hücre kaybı engellenerek diyabetin seyri olumlu yönde değiştirilebilir.4-hydroxynonenal is a products of lipid peroxidation and, at the high concentration in the cell can be form to stabil products with cellular proteins. Increased stabil products leads to unfolded protein response in endoplasmic reticulum (ER). Increased unfolded protein response or chronic ER stress can induce apoptosis and autophagy. So aim of the our study is to investigate the effects of 4-hydroxy-trans-2-nonenal in ER stress sensor proteins, detoxification enzyme profiles, apoptosis and insulin release in pancreatic beta cells (INS-1). Cell viability was decreased in time and dose dependent manner after 4-hydroxynonenal incubation in INS-1 cells. 4-hydroxynonenal alleviated basal and stimulated insulin release at high toxic dose. On the other hand 4-hydroxynonenal induced expression of detoxification enzymes such as glutathione-S-transferase (GST) and Aldose reductase (AKR1B1). 4-hydroxynonenal increased phosphorilation of PERK and levels of IRE1-a which are the markers of endoplasmic reticulum stress. At a high toxic dose, 4-hydroxynonenal leaded to CHOP and caspase 12 expression whic are effective in ER-mediated cell death. Also toxic dose 4-hydoxynonenal exposure caused to an activation on JNK, caspase 9 and caspase 3 protein expressions. As a result, 4-hydroxynonenal is effective in loss of pancreatic beta cell mass. 4-hydroxynonenal can be a factor for progression of hyperglycemia depents on insulin defficiency. Perhaps in the pre diabetic stage, antioxidant and lipid peroxid

The Effects of Aldose Reductase Inhibitor Quercetin and Monochloropivaloylquercetin in Amyloid beta Peptide (1-42) Induced Neuroinflammation in Microglial Cells

Microglial over-activation plays a crucial roles during neuroinflammation. Aldose reductase (AR) is one of the enzymes that has been linked to inflammatory processes in several diseases. Therefore, inhibition of AR is considered as an important strategy to reduce inflammation. In the present study, Quercetin (Q) and monochloropivaloylquercetin (MCPQ) showed potent inhibition on AR expression and anti-neuroinflammatory effects in Amyloid beta (A beta) peptide (1-42) induced inflammatory process by inhibiting expression of inflammatory mediators from microglial cells. Furthermore, ablation of AR caused a significant reduction on COX2 expression in A beta-induced neuroinflammation. Q and MCPQ suppressed COX2 mRNA and protein expression, which further resulted in downstream inhibition of prostaglandin E-2 (PGE(2)) release in A beta-induced neuroinflammatory process. Additionally, All treatment resulted in activation of Mitogen Activated Protein Kinase (MAPK) and increased translocation of Nuclear Factor Kappa B (NF kappa B). Q and Sorbinil significantly reduced the activation of MAPK, at the same time Q, MCPQ and sorbinil decreased nuclear translocation of NF kappa B and diminished tumor necrosis factor (TNF)-alpha release in A beta-induced neuroinflammation. The results suggested that AR is a probable target for treatment of neuroinflammation as well as Q and MCPQ could be effective agents for treating or preventing inflammation-related neurodegenerative diseases by AR inhibition

Redox status related activation of endoplasmic reticulum stress and apoptosis caused by 4-hydroxynonenal exposure in INS-1 cells

4-Hydroxynonenal (HNE), a diffusible aldehyde product of membrane lipid peroxidation, can be produced by oxidative stress and has been detected in several diseases such as diabetes. In this study, we investigated the effects of HNE exposure on cytotoxicity, intracellular redox status, endoplasmic reticulum (ER) stress and apoptosis in insulinoma cell line (INS-1). Short-term (1 h) incubation of INS-1 cells with 0-50 mu M HNE decreased cell viability and caused depletion in reduced glutathione (GSH) levels and increased intracellular HNE-histidine adducts in a concentration-dependent manner. HNE activated the ER stress, leading to an increase in inositol-requiring enzyme-1a IRE1-alpha, phosphorylation of protein kinase-like ER kinase, phosphorylation of c-Jun N-terminal kinase (JNK) and increased the expression of CCAAT/enhancer binding protein (CHOP). Western blot analysis showed that HNE exposure induced dose-dependent activation of caspase 9 and caspase 3. These data indicate a potential role for HNE promoting deleterious effects toward pancreatic beta cell redox status and beta cell mass which may be important for the pathogenesis in diabetes