Kainik asitle indüklenen eksitotoksisite'de bazı spesifik beyin bölgelerinde mitokondriyal dna hasarı ve gama-glutamil sitein etil ester'in potansiyel koruyucu etkisinin araştırılması
Mitochondrial dna damage in spesific brain regions in kainic acid induced excitotoxicity and investigation of potential protective effect of gamma-glutamyl cysteine ethyl ester
Yazar: GİZEM ÇİZMECİ
Danışman: PROF. DR. AYFER YALÇIN
Ege Üniversitesi / Sağlık Bilimleri Enstitüsü / Sinir Bilimi Ana Bilim Dalı
Derece: Yüksek Lisans, 2014
Konu: Biyokimya = Biochemistry ; Fizyoloji = Physiology

Özet:
Kainik asit; epileptik aktiviteye neden olan eksitotoksik bir bileşiktir. Glutamat metabolizması sonucu oluşan; eksitotoksisitenin yaygın nöronal ölümle ilişkili merkezi sinir sistemi bozukluklarına katkıda bulunduğu kabul edilmektedir. Nörodejenerasyona katkıda bulunan en önemli süreç Reaktif Oksijen Türleri (ROS)'nin oluşumudur. KA uygulamasıyla oluşan ROS seviyesi artarsa, oksidatif stres gelişerek hücre hasarlarına neden olur, mitokondriyal ve selüler disfonksiyon meydana gelir. Oluşan ROS'lar ve mtDNA'nın lokalizasyonu oksidatif hasara karşı savunmasız hale getirir. mtDNA'daki oksidatif hasar miktarı nDNA'ya oranla 2-3 kat fazladır. Bu nedenle mtDNA hasarının nörodejenerasyon ve eksitotoksisiteye önemli katkısı bulunmaktadır. Bu nedenle GCEE gibi antioksidan bileşiklerin mtDNA üzerindeki koruyucu etkilerinin araştırılması oldukça önemlidir.
Çalışmamızda Sprague-Dawley sıçanlar kullanılmış ve deneyler serebellum ve korteks olmak üzere iki beyin bölgesinde Kontrol (n=4), KA (n=4) ve KA+GCEE (n=4) şeklinde gerçekleştirilmiştir. mtDNA'nın hasar düzeyinin tespiti hem Long PCR ve hem de difenilamin (DPA) fragmentasyonu yöntemleri ile saptanmıştır. 
Elde edilen sonuçlar kontrol grubu ile karşılaştırıldığında Long PCR yöntemiyle serebellumda KA grubunda mtDNA hasar düzeyi artmış, KA uygulaması sonrası yapılan GCEE uygulaması ise KA grubuna göre mtDNA hasar düzeyi azaltmıştır.
DPA yönteminde ise korteks dokularında mtDNA hasarı KA ve KA+ GCEE grubu kontrole göre anlamlı farklılık göstermiştir. Serebellum dokusunda ise mtDNA hasarı KA ve KA+ GCEE gruplarında kontrole göre farklılık göstermiş olup, bu farklılık istatistiksel olarak anlamlı bulunmamıştır.

Abstract:
KA ; is an excitotoxic compound that causes epileptic activity. Excitotoxicity that results from glutamate metabolism contributes to neuronal death associated with central nervous system disorders. The most important process that contributes to neurodegeneration is Reactive Oxygen Species (ROS) 's formation. If ROS levels increases by KA administration; oxidative stress could develop and causes cellular damage, mitochondrial and cellular dysfunction. ROS production and the localization of the mtDNA; makes the mitochondria vulnerable to oxidative stress. Oxidative damage levels in mtDNA is greater 2-3 times when compared with nuclear DNA. Therefore mtDNA damage contributes to neurodegeneration and excitotoxicity. For this reason investigation of protective effects of antioxidants such as GCEE on mtDNA is very important. 
In our study, Sprague- Dawley rats were used. Experiment are carried out in two different brain region as cerebellum and cortex and divided into three groups as control (n=4), KA (n=4) and KA + GCEE (n=4). Determination of mtDNA damage level carried out by Long PCR and DPA methods.
Our results indicate that KA treatment in cerebellum increased the mtDNA damage levels when compared to control group. In addition KA + GCEE treatment in cerebellum decreased the mtDNA damage levels when compared to KA group. These studies were performed with long PCR method.
According to results of DPA method; changes in cortex that results from KA and KA + GCEE treatment were significant when compared to control groups. On the other hand KA and KA + GCEE treatment in cerebellum showed differences when compared to control groups, but these differences were not statistically significant. 















KA ; is an excitotoxic compound that causes epileptic activity. Excitotoxicity that results from glutamate metabolism contributes to neuronal death associated with central nervous system disorders. The most important process that contributes to neurodegeneration is Reactive Oxygen Species (ROS) 's formation. If ROS levels increases by KA administration; oxidative stress could develop and causes cellular damage, mitochondrial and cellular dysfunction. ROS production and the localization of the mtDNA; makes the mitochondria vulnerable to oxidative stress. Oxidative damage levels in mtDNA is greater 2-3 times when compared with nuclear DNA. Therefore mtDNA damage contributes to neurodegeneration and excitotoxicity. For this reason investigation of protective effects of antioxidants such as GCEE on mtDNA is very important. 
In our study, Sprague- Dawley rats were used. Experiment are carried out in two different brain region as cerebellum and cortex and divided into three groups as control (n=4), KA (n=4) and KA + GCEE (n=4). Determination of mtDNA damage level carried out by Long PCR and DPA methods.
Our results indicate that KA treatment in cerebellum increased the mtDNA damage levels when compared to control group. In addition KA + GCEE treatment in cerebellum decreased the mtDNA damage levels when compared to KA group. These studies were performed with long PCR method.
According to results of DPA method; changes in cortex that results from KA and KA + GCEE treatment were significant when compared to control groups. On the other hand KA and KA + GCEE treatment in cerebellum showed differences when compared to control groups, but these differences were not statistically significant.