Browsing by Author "Özbilgin, MK"

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    Antigen-presenting cells in the hypertrophic pharyngeal tonsils
    Özbilgin, MK; Polat, S; Mete, UÖ; Tap, Ö; Kaya, M
    The antigen presenting cells (APCs) with special interest to dendritic cells (DC), were investigated in 28 hypertrophic and 10 control pharyngeal tonsils of children by histochemistry, immunohistochemistry and electron microscopy. In this study, we are trying to clarify the function and classification of APC in pharyngeal tonsils using morphologic criteria, Human Leukocyte Antigen Monoclonal Antibody (HLA-DR MoAb), which is specific for APCs, and acid phosphatase (APh) reacting with both phagosomes and lysosomes. The surface epithelium of the patient group examined by light microscopy, heavy infiltration of lymphocytes, degenerated columnar cells and a few 14LA-DR MoAb (+) columnar cells was observed. Additionally, a significant number of APCs which were Langerhans cells (LCs), interdigitating dendritic cell (IDC), follicular dendritic cell (FDC) and macrophages were stained with both HLA-DR MoAb and APh in the epithelial, interfollicular-subepithelial and follicular areas. Ultrastructural examinations revealed that lymphocytes, macrophages, LC and M cells were found among the surface columnar epithelial cells of the patient group. The interactions between M cells and LC suggested that M cells probably passed antigens from surface to LC. In the interfollicular-subepithelial areas of the hypertrophic pharyngeal tonsil, IDCs were in close contact with lymphocytes, macrophages and plasma cells. Seven types of FDCs (FDC-1 - FDC-7) were recognised according to their ultrastructural appearances. Differentiated FDCs (FDC-4) were also in close contact with each active subtype of FDCs in follicular areas besides lymphocytes. These findings supported the idea that although the pharyngeal tonsils contained several types of active APCs, only DC were in close contact with immunocompetent cells and the other APC's. Therefore, these morphologic appearances of DC could be a sign of function to initiate the immune response of the pharyngeal tonsil.
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    Effect of high dose gonadotropin stimulation on follicular atresia through light chain 3B and voltage dependent anion channel 2
    Özbilgin, MK; Öztatlici, M; Üçöz, M
    Background: Follicle development takes place under the control of hormonal and environmental stimuli. It suggested that to improve in vitro fertilisation outcomes in poor responders increasing gonadotropin doses be used. Excessive gonadotropin leads to atresia and impairs follicular development, but the molecular mechanisms of follicular atresia remain largely unknown. Recently, it was suggested that autophagy may be an alternative mechanism involved in follicle depletion. Aims: In this study, we aimed to clarify the role of autophagic markers such as light chain (LC) 3B and voltage dependent anion channel 2 (VDAC2) in follicular atresia using the high dose gonadotropin stimulation. Settings and Design: The female 24 BALB/c mice were employed in the present study under the Committee for the Purpose of Control and Supervision of Experiments on Animals guidelines with ethical clearance from the institutional ethical committee. These mice were categorised into four groups, with six rats in each as control and test animals. Materials and Methods: Group 1 (control): no action will be taken. Group 2 (sham): only saline will be applied. Group 3: low-dose gonadotropin Pregnant mare's serum gonadotropin (PMSG) + human chorionic gonadotropin (HCG) will be applied. Group 4: high-dose gonadotropin + HCG will be applied. The animals were sacrificed 48 h after the last injection. For all group samples, both protein and mRNAs of the LC3B and VDAC2 were examined by immunohistochemical and reverse transcription-polymerase chain reaction techniques. Statistical Analysis Used: All variables were analysed using GraphPad Prism 8. Kruskal-Wallis t-test and Mann-Whitney U test were used to compare immunohistochemical results; in addition to this, parametric one-way ANOVA test and Shapiro-Wilk test were applied for quantitative polymerase chain reaction statistics. Results: An increased number of atretic follicles were observed in the high-dose gonadotropin + HCG group. LC3B immunoreactivity of the atretic secondary follicles in the high-dose group is higher than in other groups. The expression of VDAC2 protein in the secondary and Graafian follicles and also VDAC2 mRNA in the ovary were more highly expressed in the control and sham groups. The decrease in VDAC2 mRNA level and immunohistochemical expression was remarkable in the low-dose and high-dose follicle-stimulating hormone groups compared to the control and sham groups. Conclusion: In this study, the increased LC3B and decreased VDAC2 expression, which are autophagy markers, were observed in both the gonadotropins groups, so we suggested that high doses of gonadotropins may cause ovarian atresia.
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    Jak-Stat signaling pathway may play a role in the pathogenesis of cholesteatoma
    Eskiizmir, G; Vatanseuer, HS; Özgür, E; Aslan, A; Tanyeri, G; Gözüaçik, D; Özbilgin, MK; Cingi, C
    Purpose: Jak-Stat signaling pathway is one of the major signal transduction cascades which regulates most of the cellular events such as cell proliferation, differentiation, cell migration and apoptosis. This study aims to determine the activity of Jak-Stat signaling pathway in the pathogenesis of cholesteatoma. Materials and Methods: Cholesteatoma and skin samples were obtained from 10 patients who underwent tympanomastoidectomy for chronic otitis media with cholesteatoma. Immunohistochemical analysis of cholesteatoma and skin was performed using anti-Jak1, anti-Jak2, anti-Jak3, anti-Stat1, anti-Stat2, anti-Stat3, anti-Stat4 and anti-Stat5 antibodies. The immunoreactivities in cholesteatoma and skin were quantified using H-score measurement and statistical comparison was performed. Results: Jak1, Jak2, Jak3, Stat1 and Stat3 immunoreactivities were not detected in cholesteatoma; in contrast to the skin (129.8; 226.7; 33.0; 66.4;115.9). In addition, when H-score measurements of Stat2, Stat4 and Stat5 immunoreactivities were compared between cholesteatoma (172.8; 166.7; 120.0) and skin (400.0; 284.9; 292.0), statistically significant differences were found (p < 0.0001, p < 0.0001, p < 0.0001). Conclusions: A remarkable deficiency in the family members of Jak-Stat signaling pathway was demonstrated in cholesteatoma. Therefore, perturbations in Jak-Stat signaling pathway may play a role in the pathogenesis of cholesteatoma. (C) 2014 Elsevier Inc. All rights reserved.
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    Cyclophosphamide suppresses spermatogenesis in the testis of mice through downregulation of miR-34b and miR-34c
    Özbilgin, MK; Demirören, S; Üçöz, M; Oztatlici, M
    Cyclophosphamide (CP) is commonly used as an anticancer agent but has been associated with high toxicity in several organs, including the testes. In this study, we aimed to evaluate the effects of CP-induced testicular toxicity, using glial cell line-derived neurotrophic factor (GDNF), occludin and transforming growth factor beta 3 (TGF-beta 3) primary antibodies, and miR-34b and miR-34c expressions. Eighteen young Balb/c male mice were divided into three groups. The control group received no treatment. The mice of CP group were injected 100 mg kg(-1) day(-1) CP for 5 days, and the same amount of saline was injected in the sham group. The animals were sacrificed 24 hr after the last injection. Immunohistochemical analysis of testicular tissues showed a decrease in both spermatogenic germ cell count and also GDNF, occludin expressions, but an increase in TGF-beta 3 expression in the CP group compared to the others group. The expressions of miR-34b and miR-34c were examined by qPCR technique, a significant decrease was observed in tissue samples in the CP-treated group. The expression of GDNF, occludin and TGF-beta 3 plays an important role in testicular injury caused by CP, and the decrease in the expression of miR-34b/c in tissue samples may be an important marker for the detection of testicular damage.
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    Mitophagy in the A549 lung cancer cell line, radiation-induced damage, and the effect of ATM and PARKIN on the mitochondria
    Kurtman, C; Öztatlici, M; Üçöz, M; Çelik, ÖK; Sokur, I; Özbilgin, MK
    Background: Non-small cell lung cancer (NSCLC) is the most commonly diagnosed cancer, and radiotherapy (RT) is used for the cancer therapy. RT affects DNA and causes DNA double-strand breaks which are repaired by DNA repair protein ataxia telangiectasia mutated (ATM). RT also affects the mitochondria which is a key player in mediating the radiation response in tumors and removing damaged mitochondria through mitophagy. During mitophagy, PARKIN accumulates on defective mitochondria to mediate the clearance of damaged mitochondria. This study examines the effect of radiation on mitophagy using PARKIN and ATM antibodies on the human NSCLC A549 line. Materials and Methods: A549 cells were treated with 2, 4, 6 and 8 Gy of radiation were analyzed on days 1 and 3 after a single dose of radiotherapy. PARKIN and ATM expressions of A549 cells were examined by using immunohistochemical technique. Results: In the control groups, weak immunoreactivity of ATM and PARKIN was observed on both days 1 and 3. The most intense ATM expression was seen in the 6 and 8 Gy groups after day 1. The most intense PARKIN expression was seen after the days 1 and 3 in the 2 Gy groups. PARKIN immunoreactivity decreased due to increasing radiation dose. Conclusion: It must be considered that mitophagy mechanisms are activated in RT applications. It must be considered that the activation of mitophagy mechanisms in RT and A549 lung cancer cell lines may provide hemostasis in cancer cells. Molecules targeting mitophagy must be developed for use with radiotherapy.
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    Paratracheal extramedullary hematopoiesis
    Kurtman, C; Özbilgin, MK; Andrieu, MN; Çelebioglu, B
    Extramedullary hematopoiesis (EMH) is a rare finding in hematology. A 73-year-old female patient with a 1-week history of severe progressive dyspnea was examined, and computed tomography (CT) showed a paratracheal mass 3 cm in size located 1 cm below the vocals cords and causing obliteration of the tracheal airway. Cytology of a needle biopsy revealed EMH. External radiotherapy of 200-cGy fractions to a total dose of 2000 cGy was administered with 3-dimensional conformal planning to treat the progressive symptoms. The patient's clinical symptoms started to improve 2 days after radiotherapy and had completely disappeared after 7 days. CT scans showed complete response on follow-up at 1 week to 5 months after radiotherapy. Mature and immature hematopoietic cells and many adipose cells were seen in the pretreatment samples. Histologic findings in the posttreatment samples showed that these cells had completely disappeared due to the conformal radiotherapy. On the basis of clinical, radiologic, and histologic results, we suggest that conformal radiotherapy may be useful for the treatment of paratracheal localization of EMH because good tumoral irradiation was obtained in this case, with the protection of normal tissues. Int J Hematol. 2001:73:492-495. (C) 2001 The Japanese Society of Hematology.
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    An Experimental Study of Radiation Effect on Normal Tissue: Analysis of HIF-1α, VEGF, eIF2, TIA-1, and TSP-1 Expression
    Aktas, C; Kurtman, C; Özbilgin, MK; Tek, I; Toprak, SK
    Objective: This study investigated whether or not the stress and hypoxia, which are the effects of radiation on normal vascular endothelium, leading to the release of HIF-1 alpha, VEGF, eIF2, TIA-1, and TSP-1 were related and the possibility of them stimulating angiogenesis. Materials and Methods: Twenty-four male Swiss Albino mice were separated into 4 groups. The first group was the control group (Group 1), and the second, third, and fourth groups were euthanized after 24 h (Group 2), 48 h (Group 3), and 7 days (Group 4), respectively. A single-fractioned 10 Gy of ionizing radiation was applied to all mice's pelvic zone with Co-60. Bladders were removed completely from the pelvic region. Immunohistochemistry and light microscopy were used to investigate whether there would be an increase or not in the angiogenesis pathway by using the HIF-1 alpha, VEGF, eIF2, TIA-1, and TSP-1 antibodies. Results: The HIP-1 alpha antibody showed strong staining in Group 3, while the staining intensity was less in other groups. VEGF showed weak staining in Groups 1 and 4, while moderate staining in Group 2 and strong staining in Group 3 was observed. eIF2 showed strong staining in Groups 1 and 4. Groups 2 and 3 were stained weakly. In the present study, staining with TSP-1 was very strong in the samples belonging to Group 1, while other groups showed very weak staining. Conclusion: When normal tissue was exposed to radiation, the positively effective factors (HIF-1, VEGF, eIF2, and TIA-1) on the angiogenesis pathway were increased while the negative factor (TSP-1) was decreased. Radiation may initiate physiological angiogenesis in the normal tissue and accelerate healing in the damaged normal tissue.