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    The comparison of the impact of ghrelin and tacrolimus on vitreous cytokine levels in an experimental uveitis model
    (Springer, 2013) Gul, Fatih Cem; Turgut, Burak; Dagli, Ferda; Ilhan, Nevin; Ozgen, Metin
    We aimed to compare the effects of intraperitoneal ghrelin and tacrolimus on vitreous levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6) in an experimental autoimmune uveitis model. Twenty-four male rats, each weighing 300 g, were assigned into four groups, six rats in each. All the rats, except for those in group 1, were injected intravitreally with concanavalin a to induce experimental uveitis. The development of uveitis was confirmed by the histopathologic examination of two rat globes from each group. The rats in group 2 were not given any treatment after uveitis was induced. The rats in group 3 were administered 1 mg/kg/day of intraperitoneal tacrolimus on days 0, 1, 3, 5 and 7 following the induction of uveitis (on the 14th day of study). The rats in group 4 were given 10 ng/kg/day of intraperitoneal ghrelin for 7 days following the induction of uveitis. On the 21st day of the study, all rats were sacrificed, and the eyes enucleated were subjected to histopathologic examination. Vitreous levels of TNF-alpha, IL-1 and IL-6 were measured by the enzyme-linked immunosorbent assay method. The histopathologic evaluation carried out to confirm the development of uveitis revealed destruction in the retinae and ciliary bodies of the immunized rats. The mean vitreous levels of TNF-alpha, IL-1 and IL-6 were significantly higher in the sham group than in the control group (p < 0.05). The levels of these three cytokines showed a significant decrease in the tacrolimus treatment group (p < 0.05). Cytokine levels decreased in the ghrelin treatment group relative to the control group; however, the decrease was not found statistically significant (p > 0.05). Tacrolimus could be effective in uveitis treatment by neutralizing or decreasing the levels of cytokines such as TNF-alpha, IL-1 and IL-6 that have a critical part in the pathogenesis of uveitis. However, ghrelin failed to produce the desired effect. Further studies using different doses and different ways of administration are needed to determine the effective dose of ghrelin in uveitis.
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    EGFR blocker lapatinib inhibits the synthesis of matrix metalloproteinases from synovial fibroblasts
    (Tubitak Scientific & Technological Research Council Turkey, 2022) Kehribar, Demet Yalcin; Emmungil, Hakan; Turkmen, Nese Basak; Ciftci, Osman; Salva, Emine; Ozgen, Metin
    Background/aim: Epidermal growth factor receptor (EGFR) family members and their associated ligands may be related to bone and joint destruction in rheumatoid arthritis. Matrix metalloproteinases are responsible for joint and bone tissue degradation. This study is intended to investigate the effect of epidermal growth factor receptor inhibition by lapatinib on the synthesis of matrix metalloproteinases in in vitro. Materials and methods: Synovial fibroblast cell culture was obtained from a patient with rheumatoid arthritis who underwent knee arthroplasty. Interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) were added to the cell culture to stimulate synovial fibroblast cells and create an inflammatory character. Understimulated and nonstimulated conditions, lapatinib was applied to the culture in four different concentrations of 25, 50, 100, and 200 mu mol. Then, matrix metalloproteinase -1, -3, and, -13 levels were assessed. Results: When stimulated with IL-1 beta and TNF-alpha, the synthesis of matrix metalloproteinases from synovial fibroblast was increased significantly. When lapatinib is added to the stimulated synovial fibroblasts, matrix metalloproteinases synthesis is significantly suppressed. Conclusion: Inhibition of the EGFR pathway with lapatinib suppresses matrix metalloproteinases synthesis. Our results suggest EGFR pathway inhibition may be a promising option to prevent joint destruction in the treatment of rheumatoid arthritis.
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    Impact of ghrelin on vitreous cytokine levels in an experimental uveitis model
    (Dove Medical Press Ltd, 2013) Turgut, Burak; Gul, Fatih Cem; Dagli, Ferda; Ilhan, Nevin; Ozgen, Metin
    Background: The purpose of this study was to investigate the effect of intraperitoneal ghrelin on vitreous levels of interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha) and to compare its effects with those of intraperitoneal infliximab in an experimental uveitis model. Methods: Twenty-four male rats were assigned to four groups of six rats in each. All the rats, except for those in group 1 (controls), were injected intravitreally with concanavalin A to induce experimental uveitis. Rats in group 2 (sham) were not given any treatment after uveitis was induced. Rats in group 3 were given intraperitoneal infliximab 0.5 mg/100 mL on days 0, 1, 3, 5, and 7 following induction of uveitis on day 14 of the study. Rats in group 4 were given intraperitoneal ghrelin 10 ng/kg/day for 7 days following induction of uveitis. On day 21 of the study, enucleated globes were subjected to histopathologic examination. Vitreous levels of IL-1, IL-6, and TNF-alpha were measured by enzyme-linked immunosorbent assay. Results: Vitreous levels of IL-1, IL-6, and TNF-alpha were significantly increased in the sham group relative to the control group (P < 0.05), but showed a significant decrease in the group treated with infliximab (P < 0.05). Cytokine levels also decreased in the ghrelin-treated group, but the decrease was not statistically significant (P > 0.05). Conclusion: Ghrelin failed to decrease the IL-1, IL-6, and TNF-alpha levels that play a critical role in the pathogenesis of uveitis.
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    The role of A268V exon-7 polymorphism of PPARA in development of axial spondyloarthritis
    (Walter De Gruyter Gmbh, 2022) Akbulut, Ekrem; Yolbas, Servet; Ozgen, Metin
    Objectives: Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that mainly affects the axial skeleton. Peroxisome proliferator activated receptor alpha (PPARA) is an intracellular transcription factor, which play a role in inflammation and osteoblasting activity. This study is designed to investigate the relationship of NG_012204.2:p.A1a268Val polymorphism of PPARA with axSpA risk and its role in disease development. Methods: This study was conducted with 168 patients and 181 controls. Genotyping was done with MALDITOF. Gene expression level was analyzed by quantitative real time PCR (RT-qPCR). The protein homology models of PPARA were created with ProMod3. Ligand binding dynamics were tested using the AutoDock4 docking program. Statistical evaluations were made with SPSS (ver24) and GeneGlobe. Results: Our results showed that C>T polymorphism causing NG_012204.2:p.A1a268Val change was associated with disease risk (p=0.024) and T allele increased disease risk 1.7 times (95% CI=1.070-2.594). PPARA expression decreased (p<0.05) in individuals carrying the T allele. We determined that the ligand entry pocket was opened 1.1 A in the polymorphic PPARA. Polymorphic change caused a decrease in the ligand binding affinity. Conclusions: Our results provide an important contribution to elucidating the development of axSpA and demonstrate the potential of PPARA as a marker for the diagnosis of axSpA.
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    The rs3768777-G allele of ITGAV gene is associated with rheumatoid arthritis
    (Springer Heidelberg, 2014) Koca, Suleyman Serdar; Kara, Murat; Ozgen, Metin; Dagli, Mustafa Necati; Gozel, Nevzat; Yolbas, Servet; Gundogdu, Baris
    Integrin alpha v beta 3 (vitronectin receptor) plays a prominent role in angiogenesis, a key pathogenic feature of rheumatoid arthritis (RA). Moreover, integrin alpha(V) (ITGAV) subunit gene has been associated with a susceptibility to RA. The aim of the present study was to detect the potential association between ITGAV gene polymorphisms and a susceptibility to RA in a Turkish cohort. DNA samples were harvested from 160 patients with RA and 144 healthy controls (HC). Three single-nucleotide polymorphisms of ITGAV gene (rs3738919, rs3768777, and rs10174098) were genotyped using real-time PCR. Serum vitronectin levels were analyzed in 30 RA patients, 28 Beh double dagger et's disease (BD) patients, and 30 HC subjects. There was no significant difference between the RA and HC groups in terms of the genotypic and allelic distributions of rs3738919 and rs10174098 polymorphisms. However, the prevalence of rs3768777-G allele was higher in the RA group than in the HC group (OR 2.3, 95 % CI 1.6-3.2, p < 0.0001). Moreover, there was a significant association between RA and the genotypic distribution of rs3768777 (GG + AG vs. AA: OR 2.1, 95 % CI 1.3-3.4; GG vs. AG + AA: OR 4.1, 95 % CI 2.1-7.8). Serum vitronectin levels were lower in the RA and BD groups than in the HC group (p (ANOVA) = 0.002). The rs3738919 and rs10174098 polymorphisms of the ITGAV gene seem not to be associated with susceptibility to RA in Turkish patients. However, rs3768777 increases the risk of RA in this group. These results suggest that the ITGAV gene may be a candidate gene for the etiopathogenesis of RA.
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    Serum IL-33 level and IL-33 gene polymorphisms in Behcet's disease
    (Springer Heidelberg, 2015) Koca, Suleyman Serdar; Kara, Murat; Deniz, Firat; Ozgen, Metin; Demir, Caner Feyzi; Ilhan, Nevin; Isik, Ahmet
    Beh double dagger et's disease (BD) is a chronic inflammatory disease. Increased productions of cytokines including interleukin (IL)-1 beta and IL-18 are documented, and IL-1 alpha and beta gene polymorphisms are associated with susceptibility to the disease. IL-33 is a recently discovered member of IL-1 cytokine family. The aim of the study was to detect serum IL-33 level and IL-33 gene polymorphisms in a cohort of BD. Unrelated 117 patients with BD and 149 healthy controls (HC) were enrolled. Serum IL-33 levels were analyzed by enzyme-linked immunosorbent assay method. DNA samples were harvested using an appropriate commercial DNA isolation kit. Four single nucleotide polymorphisms of IL-33 gene (rs7044343, rs1157505, rs11792633 and rs1929992) were genotyped using the appropriate commercial primer/probe sets on real-time PCR. Serum IL-33 level was not significantly different in the BD and HC groups (p > 0.05). However, its level was lower in the active BD patients compared to the inactive ones and HC group (p = 0.044 and p = 0.037, respectively). There was no significant difference in terms of the genotypic and allelic distributions of rs1157505 and rs1929992 polymorphisms (p > 0.05 for all). However, the TT variants of rs7044343 and rs11792633 polymorphisms were very rare, and the T allele frequencies of these polymorphisms were lower, in the BD group compared to the HC group (p < 0.0001 for all). The rs7044343 and rs11792633 variants of IL-33 gene are associated with the decreased risk of BD in our cohort. Therefore, it may be concluded that IL-33 acts a protective role on the pathogenesis of BD.
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    Serum salusin-? levels in systemic lupus erythematosus and systemic sclerosis
    (Aves, 2014) Koca, Suleyman Serdar; Ozgen, Metin; Isik, Bahar; Dagli, Mustafa Necati; Ustundag, Bilal; Isik, Ahmet
    Objective: Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), chronic inflammatory diseases, demonstrate an increased incidence of cardiovascular manifestations and subclinical atherosclerotic disease. Salusin-alpha is a novel bioactive peptide that suppresses the formation of macrophage foam cells, and its serum level is significantly lower in patients with angiographically proven coronary artery disease. The aims of the study were to assess serum salusin-alpha level and its potential association with the predictors of atherosclerosis in SLE and SSc. Material and Methods: The study included 20 SLE and 22 SSc patients and 23 healthy controls (HC). All of the participants were female. Tumour necrosis factor-alpha (TNF-alpha), IL-6 and salusin-alpha levels, homeostasis model assessment for insulin resistance (HOMA-IR) index and common carotid intima-media thickness (IMT) were determined. Results: Salusin-alpha levels were lower and the IMTs were higher in the SLE and SSc groups than in the HC group. The salusin-alpha level was correlated with neither the disease activity scores nor cytokine levels and IMT in the SLE and SSc groups, although it was correlated with triglyceride level in the SLE group (r=-0.564, p=0.012), and with HOMA-IR index in the HC group (r=0.485, p=0.019). Conclusion: The present preliminary study may support the idea that SSc leads to subclinical atherosclerosis, as in SLE. Moreover, it can be concluded that the decreased salusin-a levels in SLE and SSc may contribute to subclinical atherosclerosis. However, further studies with larger sample size are needed to demonstrate this contribution in SLE and SSc.