Yazar "Demir, Necdet" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    Effect of c-Abl gene silencing by siRNA on proliferation of mouse granulosa cells
    (Wiley-Blackwell, 2015) Yaba, Aylin; Agus, Sam; Eyüboğlu, Siğnem; Demir, Necdet; Yılmaz, Bayram
    [Abstract Not Available]
  • Küçük Resim
    Öğe
    Expression of CCM2 and CCM3 during mouse gonadogenesis
    (Springer New York, 2015) Yaba, Aylin; Ordueri, Ece; Tanrıöver, Gamze; Şahin, Pınar; Demir, Necdet; Çelik-Özenci, Çiler
    Three cerebral cavernous malformation (CCM) proteins, CCM1, CCM2, and CCM3, regulate cell-cell adhesion, cell shape and polarity, and most likely cell adhesion to extracellular matrix. Recently, CCM2 and CCM3 are known to be expressed in control and varicocele-induced rat testes, but little is known about these proteins during gonadogenesis. This led us to study the CCM proteins during the mouse gonadogenesis. Neonatal (PND 0), postnatal, and adult mice testes and ovaries were obtained from mice. CCM2 and CCM3 expression were analyzed during mouse testicular and ovarian development by immunohistochemistry and quantitative real-time PCR. The results showed that in both sexes, Ccm2 and Ccm3 mRNA and protein were first detectable after gonadogenesis when the gonads were well differentiated and remained present until the adult stage. In the testis, CCM2 and CCM3 expression were restricted to the nuclei of Sertoli cells, suggesting a conserved role in testicular differentiation. In the ovary, the CCM2 and CCM3 proteins were localized in the cytoplasm of oocytes, suggesting an unexpected role during oogenesis. Quantitative real-time PCR (qRT-PCR) results showed that expression of Ccm2 and Ccm3 genes could play a role in the regulation of mouse gonadogenesis translational activation upon testicular and ovarian development. The localization of CCM2 and CCM3 proteins show their different functions for CCM2 and CCM3 which may have important roles in testicular and ovarian differentiation. In conclusion, CCM2 and CCM3 may be involved in establishing the differential expression pattern in developing mouse testis and ovary.
  • Küçük Resim
    Öğe
    Farede prematüre over yetmezliğinde mTERT telomeraz katalitik alt ünitesinin rolünün belirlenmesi
    (2019) Yaba Uçar, Aylin; Yiğitbaşı, Türkan; Demir, Necdet
    Memelilerde prenatal hayatta oluşan oosit rezervi, postnatal hayatta azalarak tükenmektedir. Foliküler atrezi olarak adlandırılan bu mekanizma ile ovariyal yaşlanma meydana gelmektedir. Primordiyal folikül havuzu tekrardan yenilenemediği için bu tükeniş sonucunda infertilite ya da Prematüre Over Yetmezliği (POY) ile karşı karşıya kalınmaktadır. Polisiklik aromatik hidrokarbon 7, 12-dimetilbenz (7,12-dimethylbenz-[a]anthracene (DMBA)), ovaryum da dahil olmak üzere pekçok tümörü tetikleyen ve günlük hayatta da sıklıkla maaruz kaldığımız bir çevresel karsinojendir. Telomeraz, hücrenin bölünmesi esnasında kromozomların kararlı yapılarının korunmasını sağlar ve fare telomeraz ters transkriptaz (mTERT), telomeraz kompleksinin gerekli bir bileşenidir. c-Abl protein tirozin kinaz, DNA çift sarmalında kırıkların oluşması ile aktive olan ve telomer kontrolü esnasında bu kırıkların tamir edilmesine katılan bir proteindir. Telomer kısalması, hücre bölünmesini zamanla durduran bir işlemdir. Bu nedenle çalışmamızda DMBA indüklü ovotoksisite sonucu oluşan POY’de c-Abl ve mTERT’in önemli bir role sahip olabileceğini düşünmekteyiz. Buradan yola çıkarak günlük yaşamda sürekli olarak maaruz kalınan DMBA’nın ovaryumdaki oosit rezervi, oosit kalitesi ve granuloza hücreleri üzerindeki etkisini c-Abl (Abelson Tirozin Kinaz) ve mTERT (telomeraz katalitik altünitesi) belirteçleri ile açıklamayı hedefledik. Çalışmamızda postnatal (PND) 28 günlük BalbC türü farelere 7 gün boyunca susam yağı içerisinde çözülen 1mg/kg DMBA uygulaması yapıldı. İzole edilen ovaryum dokularında Hematoksilen-Eozin boyama ile morfolojik değerlendirme ve folikül sayımı yapıldı. İmmünofloresan yöntemi ile c-Abl ve mTERT lokalizasyonları gösterildi. Ayrıca ELISA, western blot ve qRT-PCR yöntemleri kullanılarak fare ovaryumunda DMBA tedavisinin telomeraz aktivitesi üzerine olan etkisi gösterildi. Ayrıca, Transmisyon Elektron Mikroskobi yöntemi ile oosit-granuloza hücresi arasındaki ilişki ultrastrüktürel düzeyde incelendi. Çalışmamızda DMBA indüklü ovotoksisite sonucu oluşan POY’de c-Abl ve mTERT, ilk defa gösterilmiştir. Bu proje ile DMBA uygulanmış fare ovaryumunda c-Abl ve mTERT ekspresyonlarındaki değişimin gösterilmesiyle, projemizin sonuçlarının POY’de erken over yaşlanması ve kadın infertilitesine ilişkin sinyal mekanizmalarına ışık tutacağını düşünmekteyiz.(TÜBİTAK-215S867).
  • Küçük Resim
    Öğe
    The p38 MAPK signalling pathway is required for glucose metabolism, lineage specification and embryo survival during mouse preimplantation development
    (Elsevier, 2015) Sozen, Berna; Öztürk, Saffet; Yaba, Aylin; Demir, Necdet
    Preimplantation embryo development is an important and unique period and is strictly controlled. This period includes a series of critical events that are regulated by multiple signal-transduction pathways, all of which are crucial in the establishment of a viable pregnancy. The p38 mitogen-activated protein kinase ( MAPK) signalling pathway is one of these pathways, and inhibition of its activity during preimplantation development has a deleterious effect. The molecular mechanisms underlying the deleterious effects of p38 MAPK suppression in early embryo development remain unknown. To investigate of the effect of p38 MAPK inhibition on late preimplantation stages in detail, we cultured 2-cell stage embryos in the presence of SB203580 for 48 h and analysed the 8-cell, morula, and blastocyst stages. We determined that prolonged inhibition of the p38 MAPK altered the expression levels of Glut1 and Glut4, decreased glucose uptake during the 8-cell to blastocyst transition, changed the expression levels of transcripts which will be important to lineage commitment, including Oct4/Pou5f1, Nanog, Sox2, and Gata6, and increased cell death in 8-16 cell stage embryos onwards. Strikingly, while the expression levels of Nanog, Gata6 and Oct4/Pou5f1 mRNAs were significantly decreased, Sox2 mRNA was increased in SB203580-treated blastocysts. Taken together, our results provide important insight into the biological processes controlled by the p38 MAPK pathway and its critical role during preimplantation development.
  • Küçük Resim
    Öğe
    Topical application of cyclosporine reduces epineurial fibrosis: Gross post-surgical, histopathological and ultrastructural analysis in a rat sciatic nerve model
    (Turkish Neurosurgical Soc, 2017) Çetinalp, Nuri Eralp; Albayrak, Serdar Baki; İsmailoğlu, Özgür; Temiz, Nail Çağlar; Solmaz, İlker; Tanrıöver, Gamze; Demir, Necdet
    AIM: To investigate the anti-scarring potential of topical cyclosporine on rat sciatic nerves. MATERIAL and METHODS: Both sciatic nerves were exposed in 24 adult male albino Wistar rats, and an abrasion injury was made on the biceps femoris close to the sciatic nerve. Cotton pads soaked with cyclosporine (5 mg/mL) and saline (0.9% NaCl) were placed around the nerves for 10 minutes in the experimental group and control group, respectively. All rats were sacrificed 8 weeks later and the sciatic nerves were examined. Epineurial adhesions were assessed using light and electron microscopy. Quantitative histological parameters, epineurial thickness, and scar density were evaluated in the histological investigation. RESULTS: Significantly fewer epineurial adhesions were observed in the cyclosporine group in the post-surgical assessment, and the histopathological and ultrastructural examinations of the nerve segments than in the controls. The cyclosporine- treated animals had a statistically significant reduction in the density and quantity of epineurial scarring compared with the controls. CONCLUSION: Topical cyclosporine effectively reduces epineurial scar formation on rat sciatic nerves.