Phd Degree / Doktora
Permanent URI for this collectionhttps://hdl.handle.net/11147/2869
Browse
3 results
Search Results
Doctoral Thesis Therapeutic Efficacy Of Intrathecal Administration Of AAVrh10-mHEXA Vector In A Mouse Model Of Tay-Sachs Disease(01. Izmir Institute of Technology, 2025) Can Özgür, Melike; Seyrantepe, VolkanTay-Sachs hastalığı, bir lizozomal depolama hastalığıdır ve HEXA genindeki mutasyonlar sonucu oluşmaktadrr. HEXA geni, GM2 gangliosidini parçalamaktan sorumlu β-hekzosaminidaz A enziminin α-alt birimini kodlar. Son zamanlarda, Hexa ve Neu3 genlerinin birleşik eksikliklerine sahip Tay-Sachs hastalığı fare modeli (DKO fareleri), şiddetli nöropatolojik semptomlar ve nöroinflamasyon sergileyerek 20 haftaya kadar hayatta kalmıştır. Birçok lizozomal depolama hastalığı için tedavi stratejileri değerlendirilmiş olsa da, Tay-Sachs hastalığı için etkin tedaviler henüz geliştirilememiştir. Bu çalışmada, AAVrh10-mHexa (AAV) vektörünün intratekal uygulanmasının DKO farelerinde terapötik etkinliğini araştırmayı amaçladık. Ayrıca, AAV ilişkili gen tedavisi ile bir anti-inflamatuar ajanı olan istradefylline tedavisinin, DKO farelerinde nöroinflamasyonu hafifletme potansiyelini değerlendirdik. Moleküler biyolojik, immünohistokimyasal ve davranışsal analizler yapıldı. AAV tek başına ve istradefylline ile kombinasyon halinde uygulandıktan sonra DKO farelerinin yaşam süresinin 30 haftaya kadar uzadığını gösterdik. Moleküler biyolojik analizler, AAV tedavisi uygulanan ve istradefylline ile kombinasyon halinde tedavi edilen DKO farelerinin korteks, beyincik ve böbrek, karaciğer ve dalak gibi organlarında Hexa aktivitesinin arttığını ve lizozomal markerlar ile pro-inflamatuar sitokinler olan Ccl2 ve Ccl3 seviyelerinin azaldığını ortaya koydu. İmmünohistokimyasal veriler, AAV ve AAV-istradefylline kombinasyonu ile tedavi edilen farelerin beyinlerinde GM2 birikintisinin temizlendiğini, lizozom sayılarının azaldığını, aktif astrosit düzeylerinin düştüğünü ve nöronlar ile oligodendrositlerde iyileşmeler olduğunu gösterdi. Ayrıca, bu farelerde motor aktivitesi de iyileşti. Bu sonuçlar, AAVrh10 ilişkili intratekal uygulamanın, tek başına veya istradefylline ile kombinasyon halinde, Tay-Sachs hastalığını tedavi etmek için umut verici bir terapötik yaklaşım olduğunu göstermektedir.Doctoral Thesis Investigation of the Effects of Ketogenic Diet Therapy in a Mouse Model of Gm2 Gangliosidosis(01. Izmir Institute of Technology, 2024) İnci, Orhan Kerim; Seyrantepe, VolkanGM2 gangliosidosis is an autosomal recessive lysosomal storage disorder in which GM2 ganglioside is accumulated, especially in the brain. GM2 gangliosidosis is divided into three different variants: Tay Sachs (B-variant or type I), Sandhoff (O-variant or type 2), and GM2AP deficiency (AB-variant). Accumulation of the GM2 ganglioside in brain causes disease pathology as neurodegeneration and neuroinflammation. Our lab first displayed the novel GM2 gangliosidosis type-I mouse model (Hexa-/-Neu3-/-). Compared to control, this model could survive a maximum of five-months due to severe pathologies, neurodegeneration, and neuroinflammation. The ketogenic diet is high-fat and low-carbohydrate/protein diet that triggers burning fat instead of carbohydrates. The ketogenic diet is used comprehensively in neurodegenerative disorders such as Sandhoff, Alzheimer’s, and Parkinson’s to regulate inflammation, neurodegeneration, and autophagy. In addition, elevation of CCL2 expression in Hexa-/-Neu3-/- mice resulted in increased amounts of active microglia and astrocytes. Therefore, the CCL2/CCR2 signaling inhibitor of propagermanium was used in addition to ketogenic diet. Thus, reducing neuroinflammation is aimed to be more effective as a combined therapy. In my Ph.D. thesis, expression and protein levels of autophagy and inflammation-associated genes were analyzed in the mouse brain to exhibit whether beneficial effects on autophagic flux and neuroinflammation are found after the ketogenic diet and propagermanium treatment. The pathology of the GM2 gangliosidosis mouse type-I brain was illustrated by thin-layer chromatography and immunofluorescence staining to display whether the ketogenic diet affects the ganglioside metabolism. Briefly, ketogenic diet therapy and its anti-inflammatory and neuroprotective effects were explored in the GM2 gangliosidosis mouse model.Doctoral Thesis Investigation of the Effects of Antiinflammatory in the Tissues of Gm2 Gangliosidosis Mouse Model(01. Izmir Institute of Technology, 2023) Ateş, Nurselin; Seyrantepe, VolkanTay- Sachs disease is an autosomal recessively inherited lysosomal storage disorder caused by mutations on the HEXA gene encoding α-subunit of β- Hexosaminidase A enzyme. The enzyme catalyzes GM2 to GM3 conversion but when it is deficient the GM2 degradation is interrupted and GM2 ganglioside is progressively accumulated especially in neurons. Progressive accumulation of GM2 causes increasing death of neurons, disruption in mental and motor functions and eventually death at 2-4 years of age. The Hexa-/- Tay-Sachs model was normal thanks to a bypass mechanism mediated by Neurominidase3. It was determined that Hexa-/-Neu3-/- mice mimicked the neuropathologic and clinical phenotype of the Tay-Sachs disease. Previously we showed GM2 accumulation in Hexa-/-Neu3-/- Tay Sachs disease mouse model triggers release of proinflammatory cytokines, microgliosis, astrogliosis consequently activation of inflammatory cascades as well as oxidative stress. These inflammatory events contribute to neurodegeneration observed in the disease pathology. In Sandhoff Disease mouse model it was shown that astrocytes express adenosine A2A receptors which induces ccl2 chemokine overexpression. A2A receptor antagonist istradefylline treatment reduces microglial activation and ccl2 expression in Sandhoff mice. In this study; A2A receptor antagonist istradefylline treatment was applied to Tay Sachs disease mouse model and whether this treatment would alleviate the neuroinflammation and redox imbalance; and prolong the lifespan was investigated by molecular biological and behavioural analyses. Modulation of ccl2 expression by istradefylline was used as potential therapeutic target to slow down Tay Sachs disease mouse model.