Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1Citation - Scopus: 1Bioavailability Assessment of the Novel Gsh-Functionalized Feb Nanoparticles Via Oxidative Stress and Trace Element Metabolism in Vitro: Promising Tools for Biomedical Applications(Springer, 2024) Aydemir, Duygu; Aribuga, Dilara; Hashemkhani, Mahshid; Acar, Havva Yagci; Çağıran, Özge Balcı; Ulusu, Nuriye NurayIron-based magnetic nanoparticles (NPs) have attracted significant attention in biomedical research, particularly for applications such as cancer detection and therapy, targeted drug delivery, magnetic resonance imaging (MRI), and hyperthermia. This study focuses on the synthesis and glutathione (GSH) functionalization of iron boride (FeB) nanoparticles (NPs) for prospective biomedical use. The GSH-functionalized FeB NPs (FeB@GSH) demonstrated ferromagnetic behavior, with a saturation magnetization (Ms) of 45.8 emu/g and low coercivity (Hc = 1000 Oe), indicating desirable magnetic properties for biomedical applications. Transmission electron microscopy (TEM) analysis of the FeB@GSH revealed well-dispersed nanoparticles with diameters smaller than 30 nm. Comprehensive nanotoxicity and biocompatibility assessments were performed using various healthy and cancer cell lines, including 293 T, HeLa, 3T3, MCF7, HCT116, and CFPAC-1. Cytotoxicity assays were conducted on FeB@GSH-treated cells over a dose range of 0-300 mu g/mL during 24-h incubations. Results indicated no significant differences in cell viability between treated and untreated control groups, confirming the biocompatibility of FeB@GSH. Further nanotoxicity evaluations were carried out on 3T3, 293 T, and CFPAC-1 cell lines, focusing on oxidative stress markers and cellular metabolism by measuring antioxidant enzyme activity. Additionally, ion release and mineral metabolism were assessed using inductively coupled plasma mass spectrometry (ICP-MS), revealing no notable variations between the treated and control groups. These findings suggest that FeB@GSH NPs exhibit excellent biocompatibility, making them promising candidates for diverse biomedical applications, including medical imaging, drug delivery systems, and therapeutic interventions.Review Citation - WoS: 116Citation - Scopus: 125Salivary Biomarkers: Novel Noninvasive Tools To Diagnose Chronic Inflammation(Springer, 2023) Dongiovanni, Paola; Meroni, Marica; Casati, Sara; Goldoni, Riccardo; Thomaz, Douglas Vieira; Kehr, Nermin Seda; Galimberti, DanielaSeveral chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.Article Citation - WoS: 13Citation - Scopus: 15The Role of Cycloastragenol at the Intersection of Nrf2/Are, Telomerase, and Proteasome Activity(Elsevier, 2022) Yılmaz, Sinem; Bedir, Erdal; Ballar Kırmızıbayrak, PetekAging is well-characterized by the gradual decline of cellular functionality. As redox balance, proteostasis, and telomerase systems have been found to be associated with aging and age-related diseases, targeting these systems with small compounds has been considered a promising therapeutic approach. Cycloastragenol (CA), a small molecule telomerase activator obtained from Astragalus species, has been reported to positively affect several age-related pathophysiologies, but the mechanisms underlying CA activity have yet to be reported. Here, we presented that CA increased NRF2 nuclear localization and activity leading to upregulation of cytoprotective enzymes and attenuation of oxidative stress-induced ROS levels. Furthermore, CA-mediated induction of telomerase activity was found to be regulated by NRF2. CA not only increased the expression of hTERT but also its nuclear localization via upregulating the Hsp90-chaperon complex. In addition to modulating nuclear hTERT levels at unstressed conditions, CA alleviated oxidative stress-induced mitochondrial hTERT levels while increasing nuclear hTERT levels. Concomitantly, H2O2-induced mitochondrial ROS level was found to be significantly decreased by CA administration. Our data also revealed that CA strongly enhanced proteasome activity and assembly. More importantly, the proteasome activator effect of CA is dependent on the induction of telomerase activity, which is mediated by NRF2 system. In conclusion, our results not only revealed the cross-talk among NRF2, telomerase, and proteasome systems but also that CA functions at the intersection of these three major aging-related cellular pathways.Article Citation - WoS: 31Citation - Scopus: 34Curcumin: Novel Treatment in Neonatal Hypoxic-Ischemic Brain Injury(Frontiers Media S.A., 2019) Rocha-Ferreira, Eridan; Sisa, Claudia; Bright, Sarah; Fautz, Tessa; Harris, Michael; Riquelme, Ingrid Contreras; Kurulday, Tuğçe; Hristova, MariyaHypoxic-ischemic encephalopathy (HIE) is a major cause of mortality and morbidity in neonates, with an estimated global incidence of 3/1,000 live births. HIE brain damage is associated with an inflammatory response and oxidative stress, resulting in the activation of cell death pathways. At present, therapeutic hypothermia is the only clinically approved treatment available for HIE. This approach, however, is only partially effective. Therefore, there is an unmet clinical need for the development of novel therapeutic interventions for the treatment of HIE. Curcumin is an antioxidant reactive oxygen species scavenger, with reported anti-tumor and anti-inflammatory activity. Curcumin has been shown to attenuate mitochondrial dysfunction, stabilize the cell membrane, stimulate proliferation, and reduce injury severity in adult models of spinal cord injury, cancer, and cardiovascular disease. The role of curcumin in neonatal HIE has not been widely studied due to its low bioavailability and limited aqueous solubility. The aim of this study was to investigate the effect of curcumin treatment in neonatal HIE, including time of administration and dose-dependent effects. Our results indicate that curcumin administration prior to HIE in neonatal mice elevated cell and tissue loss, as well as glial activation compared to HI alone. However, immediate post-treatment with curcumin was significantly neuroprotective, reducing grey and white matter tissue loss, TUNEL+ cell death, microglia activation, reactive astrogliosis, and iNOS oxidative stress when compared to vehicle-treated littermates. This effect was dose-dependent, with 200 mu g/g body weight as the optimal dose-regimen, and was maintained when curcumin treatment was delayed by 60 or 120 min post-HI. Cell proliferation measurements showed no changes between curcumin and HI alone, suggesting that the protective effects of curcumin on the neonatal brain following HI are most likely due to curcumin's anti-inflammatory and antioxidant properties, as seen in the reduced glial and iNOS activity. In conclusion, this study suggests curcumin as a potent neuroprotective agent with potential for the treatment of HIE. The delayed application of curcumin further increases its clinical relevance.Article Citation - WoS: 32Citation - Scopus: 32Luminescent Device for the Detection of Oxidative Stress Biomarkers in Artificial Urine(American Chemical Society, 2018) Ammanath, Gopal; Yıldız, Ümit Hakan; Palaniappan, Alagappan; Liedberg, BoA luminescent paper-based device for the visual detection of oxidative stress biomarkers is reported. The device consists of a polyvinylidene fluoride membrane impregnated with poly(3-alkoxy-4-methylthiophene) (PT) for colorimetric detection. 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker associated with oxidative stress, is used as a model system for validating the proposed methodology. The detection strategy is based on monitoring the changes in optical properties of PT associated with its conformational changes upon interaction with an aptamer in the presence and in the absence of 8-OHdG. Fluorometric and colorimetric monitoring revealed linear responses for 8-OHdG concentrations between 50 pM and 500 nM (∼14 pg/mL to 140 ng/mL), with limits of detection of ∼300 pM and ∼350 pM, respectively for (n = 3). Colorimetric responses in artificial urine ascertained rapid, sensitive, and selective detection of 8-OHdG at clinically relevant (pM to nM) concentration levels. Furthermore, the proposed methodology enables point-of-care diagnostics for oxidative stress without requiring sophisticated instrumentation.Article Citation - WoS: 44Citation - Scopus: 49Epo Mediates Neurotrophic, Neuroprotective, Anti-Oxidant, and Anti-Apoptotic Effects Via Downregulation of Mir-451 and Mir-885 in Sh-Sy5y Neuron-Like Cells(Frontiers Media S.A., 2014) Alural, Begüm; Duran, Gizem Ayna; Tüfekçi, Kemal Uğur; Allmer, Jens; Onkal, Zeynep; Tunalı, Doğa; Genç, Kürşad; Genç, ŞerminErythropoietin (EPO) is a neuroprotective cytokine, which has been applied in several animal models presenting neurological disorders. One of the proposed modes of action resulting in neuroprotection is post-transcriptional gene expression regulation. This directly brings to mind microRNAs (miRNAs), which are small non-coding RNAs that regulate gene expression at the post-transcriptional level. It has not yet been evaluated whether miRNAs participate in the biological effects of EPO or whether it, inversely, modulates specific miRNAs in neuronal cells. In this study, we employed miRNA and mRNA arrays to identify how EPO exerts its biological function. Notably, miR-451 and miR-885-5p are downregulated in EPO-treated SH-SY5Y neuronal-like cells. Accordingly, target prediction and transcriptome analysis of cells treated with EPO revealed an alteration of the expression of genes involved in apoptosis, cell survival, proliferation, and migration. Low expression of miRNAs in SH-SY5Y was correlated with high expression of their target genes, vascular endothelial growth factor A, matrix metallo peptidase 9 (MMP9), cyclin-dependent kinase 2 (CDK2), erythropoietin receptor, Mini chromosome maintenance complex 5 (MCM5), B-cell lymphoma 2 (BCL2), and Galanin (GAL). Cell viability, apoptosis, proliferation, and migration assays were carried out for functional analysis after transfection with miRNA mimics, which inhibited some biological actions of EPO such as neuroprotection, anti-oxidation, anti-apoptosis, and migratory effects. In this study, we report for the first time that EPO downregulates the expression of miRNAs (miR-451 and miR-885-5p) in SH-SY5Y neuronal-like cells. The correlation between the over-expression of miRNAs and the decrease in EPO-mediated biological effects suggests that miR-451 and miR-885-5p may play a key role in the mediation of biological function.Article Citation - WoS: 19Citation - Scopus: 22Absence of Superoxide Dismutase Activity Causes Nuclear Dna Fragmentation During the Aging Process(Academic Press Inc., 2014) Muid, Khandaker Ashfaqul; Karakaya, Hüseyin Çaglar; Koç, AhmetSuperoxide dismutases (SOD) serve as an important antioxidant defense mechanism in aerobic organisms, and deletion of these genes shortens the replicative life span in the budding yeast Saccharomyces cerevisiae. Even though involvement of superoxide dismutase enzymes in ROS scavenging and the aging process has been studied extensively in different organisms, analyses of DNA damages has not been performed for replicatively old superoxide dismutase deficient cells. In this study, we investigated the roles of SOD1, SOD2 and CCS1 genes in preserving genomic integrity in replicatively old yeast cells using the single cell comet assay. We observed that extend of DNA damage was not significantly different among the young cells of wild type, sod1Δ and sod2Δ strains. However, ccs1Δ mutants showed a 60% higher amount of DNA damage in the young stage compared to that of the wild type cells. The aging process increased the DNA damage rates 3-fold in the wild type and more than 5-fold in sod1Δ, sod2Δ, and ccs1Δ mutant cells. Furthermore, ROS levels of these strains showed a similar pattern to their DNA damage contents. Thus, our results confirm that cells accumulate DNA damages during the aging process and reveal that superoxide dismutase enzymes play a substantial role in preserving the genomic integrity in this process.Article Citation - WoS: 18Citation - Scopus: 16Determination of Some Heavy Metals and Mineral Nutrients of Bay Tree (laurus Nobilis L.) in Bartin City, Turkey(Pakistan Botanical Society, 2012) Yaşar, Ülkühan; Özyiğit, İbrahim İlker; Yalçın, İbrahim Ertuğrul; Doğan, İlhan; Demir, GökselConcentrations of Al, Cd, Cu, Ni, and Pb in Laurus nobilis L. were examined for assessment of the impact of heavy metal exposure during winter periods, since these metals have the highest toxic potential. In this study, leaf (washed and unwashed), bark and branch samples of L. nobilis and soil samples were collected from 13 different localities, belonged to three stations. In conjunction with analyzing impact of the heavy metal exposure on the city using L. nobilis as a biomonitoring tool, the uptake and composition of mineral nutrients of L. nobilis were also investigated for determining the effects of heavy metals on mineral nutrition metabolism of the plant. The heavy metal and mineral nutrient concentrations of the collected samples were measured by using ICP-OES. The obtained data was analyzed with SPSS statistics program. As a result of measurements, the lowest and highest heavy metal accumulations and the amount of mineral nutrients measured in plants were as follows; Al (14.69-122.44 mg/kg d. wt), Cd (0.23-0.89 mg/kg d. wt), Cu (1.64-14.25 mg/kg d. wt.), Ni (0.001-0.45 mg/kg d. wt.), Pb (2.06-5.28 mg/kg d. wt.) and B (1.04- 6.67 mg/kg d. wt.), Ca (1195.34-4919.03 mg/kg d. wt.), Fe (17.13-203.25 mg/kg d. wt.), K (538.99-3778.37 mg/kg d. wt.), Mg(48.1-268.5 mg/kg d. wt.), Na (24.91-77.43 mg/kg d. wt.) and Zn (4.75-15.74 mg/kg d. wt.). According to the experimental data, the volume of the air pollution was analyzed and found significant in the city. Also, it was noticed that the metabolism of mineral nutrients of L. nobilis was altered by heavy metals. Finally, it was proved that L. nobilis is a suitable organism to be used as a biomonitoring tool for conducting research on heavy metal pollution.Article Citation - WoS: 18Citation - Scopus: 19Assessment of Chronological Lifespan Dependent Molecular Damages in Yeast Lacking Mitochondrial Antioxidant Genes(Elsevier Ltd., 2010) Demir, Ayşe Banu; Koç, AhmetThe free radical theory of aging states that oxidative damage to biomolecules causes aging and that antioxidants neutralize free radicals and thus decelerate aging. Mitochondria produce most of the reactive oxygen species, but at the same time have many antioxidant enzymes providing protection from these oxidants. Expecting that cells without mitochondrial antioxidant genes would accumulate higher levels of oxidative damage and, therefore, will have a shorter lifespan, we analyzed oxidative damages to biomolecules in young and chronologically aged mutants lacking the mitochondrial antioxidant genes: G. RX2, CCP1, SOD1, GLO4, TRR2, TRX3, CCS1, SOD2, GRX5, and PRX1. Among these mutants, ccp1Δ, trx3Δ, grx5Δ, prx1Δ, mutants were sensitive to diamide, and ccs1Δ and sod2Δ were sensitive to both diamide and menadione. Most of the mutants were less viable in stationary phase. Chronologically aged cells produced higher amount of superoxide radical and accumulated higher levels of oxidative damages. Even though our results support the findings that old cells harbor higher amount of molecular damages, no significant difference was observed between wild type and mutant cells in terms of their damage content. © 2010 Elsevier Inc.Article Citation - WoS: 18Citation - Scopus: 22Fucoxanthin Content of Cylindrotheca Closterium and Its Oxidative Stress Mediated Enhancement(Central Fisheries Research Inst, 2016) Erdoğan, Ayşegül; Demirel, Zeliha; Conk Dalay, Meltem; Eroğlu, Ahmet EminProduction of fucoxanthin by diatoms has become an alternative research area due to their low cost, convenience and diversity. The fucoxanthin content of Cylindrotheca closterium and its enhancement by altering the cultivation conditions via oxidative stress were investigated in this study. For this purpose, the extraction parameters were optimized and the highest fucoxanthin concentration (6.58 mg g-1) was achieved within 15.0 minutes at 40 °C. Then, this yield reached to 10.15 mg g-1 in the presence of NaOCl and Fe2+. It is worth noting that, this is the first time that the effect of oxidative stress on fucoxanthin production in diatom has been studied according to our knowledge. Therefore, the results of this study and the discussion about the mechanisms can be a reference for the enrichment of fucoxanthin from other diatoms.