Browsing by Author "Oltulu F."

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    Ovarian failure in diabetic rat model: Nuclear factor-kappaB, oxidative stress, and pentraxin-3
    (Elsevier Ltd, 2014) Erbas O.; Pala H.G.; Pala E.E.; Oltulu F.; Aktug H.; Yavasoglu A.; Taskiran D.
    Objective: The aim of the present study was to investigate the effects of diabetes mellitus (DM) on ovarian reserve and injury by considering laboratory and histopathological parameters in rat models. Materials and methods: An experimental DM model was created in 16 rats. Eight rats with normal blood glucose levels were included in the control group. Diabetic rats were divided randomly into two groups: nontreated and resveratrol-treated groups. Histopathological examination and nuclear factor (NF)-κB immunoexpression level determination were performed. Plasma malondialdehyde, glutathione, pentraxin-3, and anti-Müllerian hormone levels were measured. Relations between the variables were compared by Student t test, analysis of variance, and Mann-Whitney U and χ2 tests. Results: We found statistically significantly lower glutathione and anti-Müllerian hormone levels, and higher malondialdehyde and pentraxin-3 levels in nontreated diabetic group when compared with the control and resveratrol-treated diabetic groups. Stromal degeneration, follicle degeneration, stromal fibrosis scores, and NF-κB immunoexpression levels were significantly higher in nontreated diabetic rats. Primordial and primary follicle counts were significantly lower in the nontreated diabetic group when compared with the control and resveratrol-treated groups. There was no statistically significant difference in secondary and tertiary follicles between these groups. Conclusion: These findings provide strong evidence that the ovarian follicle pool in nontreated diabetic rats is affected in the early stages of the follicle development process. We precluded negative effects of DM on ovaries by inhibiting the NF-κB pathway with resveratrol. We thought that the NF-κB pathway plays a role in the pathophysiology of ovarian failure in diabetic rats. Further studies should evaluate this precise mechanism that leads to a decline in the anti-Müllerian hormone levels. In addition, the relationship between this abnormality and reproductive function in diabetic patients should be analyzed further. © 2014.
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    Therapeutic effect of sunitinib on diabetes mellitus related ovarian injury: An experimental rat model study
    (Informa Healthcare, 2015) Erbas O.; Pala H.G.; Pala E.E.; Artunc Ulkumen B.; Akman L.; Akman T.; Oltulu F.; Aktug H.; Yavasoglu A.
    The aim of our study is to investigate the effect of sunitinib on diabetes mellitus related-ovarian injury and fibrosis in rat models. An experimental diabetes mellitus model was created in 16 rats, and eight rats with normal blood glucose levels were included in control group (Group-1). The diabetic rats were divided into two groups:diabetic control group (water given)-Group-2 and sunitinib treatment group-Group-3. After four weeks, bilateral oophorectomy was performed and ovaries were examined histologically. The groups were compared by Student's t-test, analysis of variance (ANOVA) and Mann-Whitney's U-test. There was a significant increase in no-medication (water given) diabetic rat's ovary (Group-2) in terms of follicular degeneration, stromal degeneration, stromal fibrosis and NF-kappaB immune-expression compared with control group normal rats' ovary (Group-1) (p < 0.0001). Stromal degeneration (p = 0.04), stromal fibrosis (p = 0.01), follicular degeneration (p = 0.02), NF-kappaB immune-expression (p = 0.001) significantly decreased in sunitinib-treated diabetic rat's ovary (Group-3) when compared with no-medication (water given) diabetic rat's ovary (Group-2) (p < 0.05). When we used sunitinib in the treatment of diabetic rats, ovarian injury, fibrosis and NF-kappaB immunoexpression decreased significantly. The effects of sunitinib in rat models give hope to the improved treatment of premature ovarian failure due to diabetes mellitus in humans. © 2015 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted.
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    The effects of sunitinib on endometriosis
    (Informa Healthcare, 2015) Pala H.G.; Erbas O.; Pala E.E.; Ulkumen B.A.; Akman L.; Akman T.; Oltulu F.; Yavasoglu A.
    The aim of the present study was to evaluate the effect of sunitinib on endometriotic implants and adhesions in a rat endometriosis model. An experimental endometriosis model was created in 21 rats. These rats were randomly divided into three groups: Group 1 (control group, 7 rats) was given no medication; Group 2 (sunitinib group, 7 rats) was given 3 mg/ kg per day of oral sunitinib; and Group 3 (danazol group, 7 rats) was given 7.2 mg/kg per day of oral danazol. The volume of endometriotic implants was calculated. The extent and severity of adhesions were evaluated. The groups were compared by the Student's t-test, analysis of variance (ANOVA) and the Mann-Whitney U test. There was no statistically significant difference in the mean volume of endometriotic implants before medication between three groups. The volume of implants and extent, severity, total score of adhesions were significantly decreased after medication in Group 2 and Group 3. We noted that the volume of the endometriotic implants and adhesion formation were decreased both after sunitinib and danazol treatment. As a result, sunitinib seems to be effective for endometriotic peritoneal lesions. The effects of sunitinib in rat models give hope for improving the treatment of human endometriosis and prevention of pain symptoms. © 2014 Informa UK, Ltd.
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    The effectiveness of different neuroprotective agents in facial nerve injury: An experimental study
    (John Wiley and Sons Inc., 2015) Tanyeri G.; Celik O.; Erbas O.; Oltulu F.; Yilmaz Dilsiz O.
    Objectives/Hypothesis To examine and compare the neuroprotective effects of dexamethasone, oxytocin, and resveratrol administration on regeneration after facial nerve crush injury in a rat model. Study Design Prospective, randomized, controlled animal study. Methods A crush-type facial nerve injury was performed on the right side of all rats (injury group [IG]), whereas there was no injury on the left side (sham group [SG]). These main groups were divided into five subgroups: 1) no medicine (control); 2) physiological serum; 3) dexamethasone; 4) oxytocin; and 5) resveratrol (Res) administered (intraperitoneal injection) for 28 days. Functional recovery was evaluated by daily eye-blink reflex and facial electromyography. Nerve-muscle degeneration and regeneration, apoptosis, and intercellular connections were evaluated in histopathological and immunohistochemical examinations. Results Recovery time of the postinjury eye-blink reflex demonstrated faster recovery in IG + Res when compared with the other subgroups. In peak-to-peak amplitude values, a significant increase was observed in the dexamethasone (P = 0.007) and oxytocin subgroups (P = 0.004) and was even more apparent in the resveratrol subgroup (P < 0.001). Nerve regeneration is apparent in the resveratrol subgroup. Apoptotic changes were evaluated immunohistochemically with TUNEL and Caspase 3 and 6 antibodies staining. Caspase 3 and 6 immunoexpressions of resveratrol and oxytocin subgroups were moderate when compared with dexamethasone subgroup. Except for the resveratrol subgroup, which had an increase in expression, the majority of subgroups were similar to SG in terms of intercellular connections (Connexin 32 and 43). Conclusion Resveratrol leads to the best outcome after facial nerve crush injury in rats when compared with dexamethasone and oxytocin, even though these agents demonstrate a significant improvement in facial nerve regeneration. Level of Evidence N/A. Laryngoscope, 125:E356-E364, 2015 © 2015 The American Laryngological, Rhinological and Otological Society, Inc.
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    JAK/STAT pathway interacts with intercellular cell adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) while prostate cancer stem cells form tumor spheroids
    (Zerbinis Publications, 2015) Duzagac F.; Inan S.; Simsek F.E.; Acikgoz E.; Guven U.; Khan S.A.; Rouhrazi H.; Oltulu F.; Aktug H.; Erol A.; Oktem G.
    Purpose: JAK/STAT is an evolutionarily conserved pathway and very important for second messenger system. This pathway is important in malignant transformation and accumulated evidence indicates that this pathway is involved in tumorigenesis and progression of several cancers. It was possible to assume that activation of JAK/STAT pathway is associated with increase in the expressions of ICAM-1 and VCAM-1. In this study we hypothesized that when cells were maintained as spheroids or monolayers, the structure of cancer stem cells (CSCs) could show differentiation when compared with non-CSCs. Methods: DU-145 human prostate cancer cells were cultured using the Ege University molecular embryology laboratory medium supplemented with 10% fetal bovine serum. Clusters of differentiation 133 (CD133)(+high)/CD44(+high) prostate CSCs were isolated from the DU145 cell line by using BD FACSAria. CD133+/CD44+ CSCs were cultured until confluent with 3% noble agar. The expression of these proteins in CSCs and non-CSCs was analyzed by immunohistochemistry. Results: Different expression profiles were observed in the conventional two-dimensional (2D) and three-dimensional (3D) experimental model system when CSCs and non-CSCs were compared. Human prostate CSCs exhibited intense ICAM-1 and VCAM-1 immunoreaction when compared with non-CSCs. These findings were supported by the fact that VCAM-1 on the surface of cancer cells binds to its counterreceptor, the a4fil integrin (also known as very-late antigen, VLA-4), on metastasis-associated macrophages, triggering VCAM-1-mediated activation of the phosphoinositide 3-kinase growth and survival pathway in cancer cells. Conclusions: The results of this study showed that changes in JAK/STAT pathway are related with adhesion molecules and could affect cancer progression.
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    Histopathological and apoptotic changes on marine mussels Mytilus galloprovincialis (Lamark, 1819) following exposure to environmental pollutants
    (Elsevier Inc., 2016) Yavaşoğlu A.; Özkan D.; Güner A.; Katalay S.; Oltulu F.; Yavaşoğlu N.
    Marine bivalve mussels, especially Mytilus species are an earlywarning system used for determining of damage caused by the various aquatic pollutions. In the present study, Mytilus galloprovincialis L. (black mussel) have been utilised as a biomonitoring organism to reveal environmental pollution in the Aliaga, Foca and Urla where located along the Izmir Coast of Turkey. Mussels were collected at these areas and gill and hepatopancreas (digestive gland) tissues were excised. mRNA expressions of initiator (caspase-2 and − 8) and executioner (caspase − 3/7–1, − 3/7–2, − 3/7–3 and − 3/7–4) caspases of mussels tissues in areas exposed to pollution agent have been observed. TUNEL immunoreactivity in paralel to histopathological changes in both Aliaga and Foca areas were compared with Urla. This study is the first report to reveal the pollution with apoptotic expression on mussels in the coast of Turkey. © 2016 Elsevier Ltd
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    A comparison of cancer stem cell markers and nonclassical major histocompatibility complex antigens in colorectal tumor and noncancerous tissues
    (W.B. Saunders, 2016) Özgül Özdemir R.B.; Özdemir A.T.; Oltulu F.; Kurt K.; Yiğittürk G.; Kırmaz C.
    Colorectal carcinoma (CRC) is one of the most fatal types of cancer in both women and men, and, unfortunately, patients are often diagnosed at an advanced stage. Cancer stem cells (CSCs) are associated with poor prognosis, metastasis, and recurrence, as well as chemotherapy and radiotherapy resistance. Therefore, different treatment alternatives are needed to facilitate the elimination of CSCs. One such approach is immunotherapy; however, tumor cells can evade immune cells by alteration of the expression patterns of human leukocyte antigens (HLA). In this study, we immunohistochemically investigated the expression patterns of CSC-specific markers CD44, CD133, Nanog, and Oct3/4, and immunosuppressive molecules HLA-G and -E in advanced CRC tumor tissues and noncancerous colon biopsies. We found significantly increased CD44, Nanog, Oct3/4, HLA-G, and HLA-E expression in the CRC tumor tissues compared with the noncancerous colon biopsies. These findings suggest that some tumor cells may be CSC-like and that the increased expression of HLA-G and HLA-E may be considered as an immune-evasive adaptation. Therefore, the nonclassical major histocompatibility complex class Ib antigens HLA-G and HLA-E may be potential targets in the elimination of CRC-CSCs. However, more detailed studies are required to support our findings. © 2016 Elsevier Inc.
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    Histological investigation of experimentally induced diabetes effects on the distribution of transforming growth factor (TGFβ), nuclear factor kappa b (NF-κb), heat schock 90β (hsp90β) and e-cadherin proteins in testicular tissue; [Investigación histológica de los efectos de la diabetes inducida experimentalmente en la distribución del factor de crecimiento transformante (TGFβ), nuclear factor kappa b (NF-κb), y proteinas heat schock 90β (hsp90β) y e-cadherina en tejido testicular]
    (Universidad de la Frontera, 2021) Toros P.; Oltulu F.; Tuglu I.; Uysal A.; Özçinar E.; Turgan N.; Rouhrazi H.; Aktug H.
    Diabetes is a metabolic disorder characterized by high blood sugar levels and it causes complications in many systems, including the reproductive system. As a result of diabetic conditions, one of the mechanisms that can cause repression of reproductive activity is testicular oxidant stress. The identification of diabetes on the cell signaling molecules axis is still under discussion. The aim of this study was to determine the effect of Transforming Growth Factor (TGFβ), Nuclear Factor kappa B (NF-κB), Heat-schock 90β (HSP90β) signal pathways and E-cadherin cell adhesion molecule on infertility in diabetic rat testicular tissue. In our study, includes histological, molecular and biochemical analysis of testicular tissue removed at the end of the 2 weeks experiment period. A total of 14 adult male rats were divided as control and diabetes. No intervention was given to 7 male rats in the control group. For the diabetic group, 7 male rats were injected by intraperitoneal with a single dose of 55 mg/kg streptozotocin (STZ). TGFβ, NF-κB, HSP90β and E-cadherin proteins were immunohistochemically studied to investigate possible tissue damage, inflammatory process, cell stabilization and integrity due to diabetes. In order to determine oxidant stress, lipid peroxidation product malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GPx) analyzes were performed. Fibrosis, inflammatory changes and loss of spermatogenetic series are prominent findings in the diabetic group. On analysis of all the samples with immunostaining, in the diabetic group, TGFβ and NF-κB immunoexpression significantly increased, while Hsp90β and E-cadherin immunoexpression significantly decreased compared with control groups. Experimental diabetes was found to cause fibrosis, inflammation, disrupting cell adhesion and stabilization in testicular tissue. These results suggest that cellular therapy studies are needed for possible damage. © 2021, Universidad de la Frontera. All rights reserved.
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    Oxidative stress-induced apoptotic changes after acute exposure to antifouling agent zinc pyrithione (ZnPT) in Mytilus galloprovincialis Lamark (Mediterranean mussels) tissues
    (Taylor and Francis Ltd., 2022) Katalay S.; Guner A.; Dagdeviren M.; Yigitturk G.; Yavasoglu A.; Gunal A.C.; Karabay Yavasoglu N.U.; Oltulu F.
    Zinc pyrithione (ZnPT) is one of the components used in antifouling paints and can be an alternative to classical toxic chemicals such as organotin. However, there is still remarkable concern about the environmental safeness of ZnPT due to rapid transchelation and degradation into several metabolites that have their own toxicity. The effect after acute exposure of ZnPT is investigated on Mediterranean mussels exposed to 20 and 40 μg/L concentrations for 48 and 96 h and antioxidant responses [superoxide dismutase (SOD), and reduced glutathione (GSH)], genotoxicity [micronuclei (MN) frequency], apoptotic and histological changes were determined. Severe histological changes in hepatopancreas and gill tissues of mussels were observed in ZnPT exposed groups due to dose-dependent increase. ZnPT also caused a dose-dependent increase of TUNEL-positive cell count in the mussel tissues, especially in the hepatopancreas. Increasing in SOD activities and decreasing in GSH levels in both ZnPT concentrations compared to the control were observed. MN and binuclei numbers in all exposure groups were significantly increased. The results of the present study demonstrate that acute exposure to ZnPT could cause an adverse effect on mussel tissues at especially higher concentrations. © 2022 Informa UK Limited, trading as Taylor & Francis Group.