Biyomühendislik Ana Bilim Dalı Tez Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/417

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Histon Deasetilaz İnhibitörlerinin PTEN/PI3K/AKT/mTOR Yolağı ve Kemorezistan Kolanjiokarsinoma Gelişimine Olan Etkilerinin Moleküler Düzeyde Belirlenmesi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2021) Helin, Sağır; Sağır, Helin; Akçok, Emel Başak Gencer
Kolanjiokarsinom (CCA) agresif bir adenokarsinomdur ve ikinci en sık görülen birincil karaciğer tümörüdür. CCA gelişiminin kesin etiyolojisi hala net olarak tanımlanmamıştır. Mevcut kemoterapötik tedaviler, çoklu ilaç direnci nedeniyle etkili olmadığından, kemorezistant CCA yaygındır. Histon deasetilaz inhibitörleri (HDACis); umut verici antikanser karakteri göstermektedir ve HDAC işlevindeki düzensizlikler otofaji için önemli olan ve kemo-dirençli CCA'da bulunan yolaklar ile ilişkilidir, örneğin PTEN/PI3K/AKT/mTOR. Bu nedenle, sisplatine dirençli CCA hücre hatları ürettik ve SAHA, MS-275 ve Romidepsin yoluyla HDAC inhibisyonunun ve Nocodazol ve Klorokin ile otofaji inhibisyonunun etkisini kontrol ettik. Romidepsin ve Nocodazol'ün kombinasyon tedavisi sisplatine dirençli hücrelerin proliferasyonunu azalttı. Apoptotik analiz yapıldı ve sonuçlar erken apoptotik ve apoptotik hücre ölümündeki artışı kanıtladı. Ayrıca, hücre döngüsü analizi sonuçları, hücre döngüsünde durdurulma göstermiştir. Western blotlama ile PTEN, Histon H3 ve Asetillenmiş H3 protein ekspresyonlarını kontrol ettik. Sonuçlar, PTEN ekspresyon seviyesi ile HDAC inhibisyonu arasındaki olası ilişkiyi gösteriyordu. Direnç durumunda PTEN lokalizasyonu çok önemli olduğundan, immünofloresan boyama gerçekleştirdik ve hem hassas hem de sisplatine dirençli hücrelerde PTEN'in yerini tespit ettik. Sonuçlar, sisplatine dirençli hücrelerinde sitoplazmaya PTEN translokasyonunu gösteriyordu. Sonuç olarak, HDAC ve otofaji inhibisyonunun kombinasyon tedavisi, kemorezistan kolanjiokarsinomaya karşı umut verici bir tedavidir.
Cisplatin Temelli Nefrotoksisite Karşıtı Böbrek Hedefli Bir Nanotaşıyıcı Formülasyonu Geliştirilmesi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2019) Çakır, Şerife; Aydın, Erkin
Kitosan doğal bir polimer olup diğer sentetik polimerlere oranla vücutta daha az toksik etki göstermektedir. İyonik jelasyon metodu ile üretilen kitosan sodyum tripolifosfat (TPP) nanopartiküllerin böbrek ve beyin dokusu gibi insan vücut dokuları için iyi bir ilaç salınım araçları olduğu bilinmektedir. Bu çalışmada bir anti-kanser ilacı olan cisplatinin böbreklere oluşturduğu nefrotoksisiteyi gidermek için, gen susturucu siRNA'larla yüklü kitozan-TPP nanoparçacıkları kullanılmıştır. In vitro çalışmalar human kidney cell line olan Hek293 hücrelerinde denenmiş olup nanoparçacıkların hücreye girişleri ise floresan mikroskobu ve flow sitometri ile doğrulanmıştır. MTT ve XTT sonuçlarına göre nanoparçacıkların toksik etkisi düşük bulunmuştur. In vivo çalışmalara bakıldığında ise, balb-c tip 6-8 haftalık farelere siRNA yüklü nanoparçacık enjeksiyonu yapılmıştır. Sisplatin ile muamele edilmiş fareler kontrol ve siRNA-yüklü kitosan nanopartiküller grubu olarak hayvan grupları kullanılmıştır. Sisplatin enjeksiyonlarından sonra, siRNA-nanopartükül verilmesinden sonra farelerdeki kreatinin ve BUN seviyeleri değişimi incelendi. GAPDH bir kontrol geni olup PKC, P53, OCT1, OCT2 ve GGT genleri böbrek proximal tübül hücrelerinde önemli rollere sahiptir. Bu çalışmada bu genlerin mRNA seviyelerine de kantitatif PCR ile bakılmıştır. Enjeksiyonun ilk günlerinde siRNA'lar azalmış iken devam eden günlerde bu etki kaybolmuştur. Böylelikle her siRNA'nın susturma potansiyeli değişkenlik göstermektedir. Fakat bu değişkenlik çalışmada anlamlı bir değişim göstermektedir.
Potansiyel Gen Dağıtımı Uygulamaları için Poegma ve Sistaminle Modifiye Plazmit DNA'lar İçeren Polimerik Konjugatlar
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Yıldız, Gizem; İşoğlu, İsmail Alper; İşoğlu, Sevil Dinçer
Polymer-based gene delivery systems have revealed significant advancements in the treatment of various diseases in recent years. Considering the potential of polymeric vectors, it is observed that the improvements in the field of gene therapy enable effective gene transfection and induced therapeutic protein production. In this thesis study, a strategy based on a new conjugation procedure is designed to increase the gene transfer and cellular uptake rate of plasmid DNAs. According to the findings, POEGMA-based carrier and cystamine-modified plasmid DNAs demonstrated successful conjugation through disulfide bond formation. MDA-MB-231 in vitro cellular uptake results of conjugates showed 94-98% cell internalization, indicating excellent results compared to the well-known polymers in the literature. As a result, the new delivery system we developed in this study determined the success of cystamine-modified plasmid DNAs binding to POEGMA polymer chains via a covalent linkage for the first time in the literature and provided a start for future studies.
RNA Etkileşimlerinin İn Silico Analizi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Orhan, Mehmet Emin; Demirci, Müşerref Duygu Saçar
Many supervised machine learning models have been developed for the classification and identification of non-coding RNA (ncRNA) sequences. These models play a significant role in the diagnosis and treatment of various diseases. During such analyses, positive learning datasets typically consist of known ncRNA examples, some of which may even be confirmed with strong experimental evidence. However, there is no database of validated negative sequences for ncRNA classes or standardized methodologies for generating high quality negative samples. To overcome this challenge, a new method for generating negative data called the NeRNA (Negative RNA) method has been developed in this study. NeRNA generates negative sequences using known ncRNA sequences and their octal representations, similar with frame shift mutations found in biology but without base deletions or insertions. In this thesis, the NeRNA method was tested separately with four different ncRNA datasets, including microRNA (miRNA), transfer RNA (tRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). Additionally, a species-specific case study was conducted to demonstrate and compare the performance of the study's miRNA predictions. The results of 1000-fold cross-validation on machine learning algorithms such as Decision Trees, Naive Bayes, Random Forest classifiers, and deep learning algorithms like Multilayer Perceptrons, Convolutional Neural Networks, and Simple Feedforward Neural Networks showed that models developed using datasets generated by NeRNA exhibited significantly high prediction performance. NeRNA has been published as an easy-to-use, updatable, and modifiable KNIME workflow, along with example datasets and required extensions that can be downloaded and utilized. NeRNA is designed specifically as a powerful tool for RNA sequence data analysis.
COVID-19 Virüs Pandemisinde Haftalık Döngünün Kökeni ve Sosyo-Ekonomik Faktörlerle İlişkisinin Araştırılması
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Yağmur, İsmail Emre; Ercan, Altan
The Covid-19 virus, which started in China in 2019 and affected the whole world, has caused a global pandemic. Looking at the worldwide data of this pandemic, the number of daily cases appears to have a weekly cycle that is underestimated as an artifact of the number of daily tests administered. In this thesis study, a new model is developed to calculate the daily infection numbers from daily case numbers by using the Weibull distribution and the natural characteristics of the COVID-19 virus. According to the results obtained, it is found that the number of daily cases has a real weekly cycle. It has been determined that the daily infection numbers calculated in this weekly cycle are minimum on weekdays. According to the analysis by the new methos, these weekly minimums are controlled by socio-economic factors such as human development index and annual national income per capita. During the ascending and descending phases of the pandemic, the weekly minimum shifts from Monday to Friday, exposing the presence of two separate environments for the transmission of the virus among people: working and social. Moreover, the data reveal a variable rather than a fixed reproduction number. As a result, the model we developed in this study successfully identifies the socio-economic factors as the effectors of the progression of the pandemic by taking into account the time of infection for the first time in the literature and is expected to guide the future pandemic studies and pandemic, itself.
İmmunomagnetik ile Lösemi Hücrelerini Algılamak için Düşük Maliyetli Mikroakışkan Sistem Geliştirilmesi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2020) Akar, Ünal; İçöz, Kutay
Sensör teknolojileri fiziksel özellikleri ölçülebilir sinyallere dönüştürmek için kullanılır. Özellikle yarı iletken teknolojisindeki gelişmelerle birlikte, mikroakışkan olarak bilinen yeni bir teknoloji ortaya çıktı. Mikroakışkanlar zamandan ve maliyetten tasarruf sağlayan ileri bir teknolojidir. Kimya, biyoloji, bilgi teknolojisi, optik vb. gibi farklı kullanım alanlarına sahiptir. Akut lenfoblastik lösemi kötü huylu bir kan kanseridir, özellikle B öncüllü akut lenfoblastik lösemi çocukluk döneminde çok tehlikelidir. Eğer tedaviden sonra vücut içinde az bir miktar da olsa kanser hücresi kalırsa, doktorlar bu hücreleri fiziksel ya da diğer semptomları inceleyerek tespit edemeyebilirler, bu hücreler kanserin tekrar etmesine sebep olabilir bu duruma Minimal Kalıntı Hastalığı (MRD) denir. MRD, akım sitometrisi ve genetik çalışmalar ile teşhis edilebilir. Bu tür tedavilerin de kendi sınırlamaları vardır; örneğin pahalı olması ve eğitilmiş bir personele ihtiyaç duyulması gibi. Bu proje ile amacımız lösemi hücrelerinin yüzeyindeki belirteçleri antikor ile yakalamak (CD10, CD19 ve CD45) için düşük maliyetli bir mikroakışkan sistem geliştirmektir. Yakalama için antikor kaplı manyetik boncuklar kullanılmıştır. Son adımda; manyetik ayırma işleminden sonra lösemi hücreleri altın kareler üzerinde sabitlenmiştir. Böylece, hastaların tedavi süresince verdikleri dönütleri anlamak için hücreler sayılabilmiştir.
32-mer MaSP1 Geninin pBbB6c Plazmid Vektörüne Klonlanması ve Escherichia Coli NEB 10-beta'ya Transformasyonu
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2023) Benk, Ruveyda; Ortakcı, Fatih; Öz, Yahya
The main purpose of my thesis was to clone Masp1 spider silk protein encoding gene from dragline type spider into E.coli NEB 10-beta organism. The recombinant microbial production of spider silk protein and converting it into a fiber format would ultimately produce a biomaterial also called as biosteel with high toughness and elasticity whereas low density compared to Kevlar, steel and carbon fiber. For this purpose, the gene encoding the dragline spider protein (MaSP1) was cloned into E. coli NEB 10-beta using recombinant molecular methods. First, 8-mer MaSP1 was synthesized and cloned via pGSI high copy cloning vector by sticky end cutting with restriction enzymes of KpnI,Kpn2I followed by heat-shock transformation into E.coli. Second, we performed restriction of the 8-mer plasmid by NheI and Kpn2I to extract the 8-mer. Later, the restriction was performed by SpeI and Kpn2I to obtain linearized pGSI containing 8-mer Masp1. A ligation was applied to merge 8-mer and pGSI plasmid carrying 8-mer Masp1 to achieve 16-mer Masp1 containing pGSI. Again, this plasmid was heat-shock transformed into E.coli. Following the same restriction 32-mer Masp1 containing pGSI plasmid was achieved. Finally, 32-mer Masp1 fragment was cut from pGSI cloning vector and ligated to pBbB6c low copy expression plasmid followed by electroporation into E.coli. The band size of 32-mer Masp1 gene was aligned between 3 kb and 5 kb which is an agreement with the calculated size of 32-mer Masp1 gene. Future studies should focus on the expression of Masp1 and the efficient production of this valuable recombinant protein under bioreactor conditions with cutting edge bioprocessing techniques.
Peynirden İlk Defa İzole Edilen Loigolactobacillus Coryniformis FOL-19'un Yeni Nesil Dizilenmesi ve Diğer L. Coryniformis Suşlarıyla Karşılaştırmalı Genomik Analizleri
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2023) Gümüştop, İsmail; Ortakcı, Fatih
Loigolactobacillus coryniformis is a member of lactic acid bacteria isolated from various ecological niches. We isolated a novel L. coryniformis strain FOL-19 from artisanal Tulum cheese and performed the whole-genome sequencing for FOL-19 using Illumina NextSeq. Then, genomic characterization of FOL-19 against ten available whole genome sequences of the same species isolated from kimchi, silage, fermented meat, air of cowshed, and dairy was performed. The average genome size of 2.93 ±0.1 Mb, GC content of 42.96% ±0.002, number of CDS of 2905 ±165, number of tRNA of 56 ±10, and number of CRISPR elements of 6.55 ±1.83 was achieved. Both Type I and II Cas clusters were observed in L. coryniformis. Only one strain (CECT 5711) was predicted to encode a Carnocin CP52 bacteriocin gene cluster. The presence of CRISPR elements and Cas clusters suggests that L. coryniformis holds a promising potential for being a reservoir for new CRISPR-based tools. These findings put a step forward for the genomic characterization of L. coryniformis strains for biotechnological applications via genome-guided strain selection to identify industrially relevant traits.
THE ROLE OF CERAMIDE METABOLISM IN APOPTOSIS TRIGGERED BY RESVERATROL AND THE THERAPEUTIC POTENTIAL OF RESVERATROL IN PH+ ACUTE LYMPHOBLASTIC LEUKEMIA
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2019) Oğuz, Osman
The mechanisms underlying the growth inhibitory effect of resveratrol on Ph + ALL cells were investigated with regard to targeting of ceramide metabolism and changes in BCR-ABL expression. Growth inhibition and apoptotic effects of resveratrol, SK inhibitor (SKI II), GCS inhibitor (PDMP), SPT inhibitor (myriocin) and resveratrol-inhibitor combinations were investigated by MTT cell proliferation test, Annexin-V/PI staining, caspase-3, PARP expression and cytochrome c release by western blot, while cytostatic effect was investigated by flow cytometry. The effect of resveratrol, inhibitors and combinations on BCR-ABL protein expression was determined by western blot. The effect of resveratrol on SPT, SK-1/2, GCS protein expression was determined by western blot. In both cell lines resveratrol and resveratrol with SKI II and PDMP suppressed cell growth, triggered apoptosis and arrested the cell cycle at S phase. Resveratrol: myriocin combination showed cell-specific effects on cell growth and cell cycle, but triggered apoptosis in both cells. Resveratrol and combinations generally increased cytochrome-c release, caspase-3 cleavage and PARP cleavage, but cell-specific changes were also detected. Resveratrol decreased the expression of SK-1 / SK2 and GCS in both cells and increased SPT expression. While resveratrol, SKI II and PDMP decreased BCR-ABL expression and myriocin increased BCR-ABL expression. Resveratrol: SKI II and resveratrol: PDMP caused increases in BCR-ABL, while resveratrol: myriocin reduced BCR-ABL expression. As a result, resveratrol suppressed cell growth and triggered apoptosis on Ph + ALL by regulating ceramide metabolism and BCR-ABL expression.
Escherichia Coli Konak Organizmada GLP-1 Analoğunun Rekombinant Üretimi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Çalış, Burak; Fidan, Özkan
Diabetes is the most serious metabolic disorder correlated with obesity, hypertension and cardiovascular conditions. High prevalence of Type II Diabetes Mellitus (T2DM) indicates the need for new medication development. In developing therapeutics, higher efficiency and fewer adverse effect features are targeted primarily. Recombinant protein-based biotechnological drug molecules have been developed and used for the treatment of T2DM. Especially, GLP-1 analogues are known by their self-limiting mechanism and insulinotropic effect. In this study, a novel GLP-1 analogue with increased stability and efficiency is produced using recombinant E. coli. The expression plasmid was constructed and confirmed by restriction digestion and whole plasmid sequencing. Then, itwas transformed into various E. coli strains followed by optimized lysis, growth and expression conditions to maximize the yield of the GLP-1 analogue. Various parameters such as pre-induction time, induction point, induction IPTG concentration and post-induction temperature were tested for the succesfull expression with maximum yield. Consequently, it was achieved that E. coli BL21(DE3) as strain, 0.2 mM IPTG induction at OD600nm of 0.6 and 18 °C overnight post-induction growth was the most promising conditions. Under these conditions, the GLP-1 analogue was obtained in the insoluble fraction. Following protein analysis and purification, quantification was performed and the highest titer of GLP-1 analogue was measured as 626 µg/ml. As future prospect, using another host organism and changing growth conditions can provide obtaining target protein in the soluble form. Keywords: T2DM, GLP-1 analogue, recombinant DNA technology, protein expression, E. coli
Yeni Bir Silya Geni Olan TMEM145'in Karakterizasyonu
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2020) Pir, Mustafa Samet; Kaplan, Oktay İsmail
Silya ve flagella çoğu organizmada bulunan, mikrotübül yapılı, yüksek korunumlu hücresel bir yapıdır. Bunlar, protozoalarda hareket sağlamadan, çok hücreli canlılarda sinyal iletimine kadar bir çok fonksiyona sahiptir. Silyanın yapısında veya fonksiyonunda meydana gelen bozulmalar insanlarda silyopati denilen çeşitli hastalıklara sebep olur. Silyada meydana gelen bu bozukluklar silya genlerinde veya silya fonksiyonunu etkileyen silya geni olmayan genlerde meydana gelen mutasyonlardan kaynaklanır. Bu yüzden silyopatilerin moleküler temelini ortaya çıkarmaya yardımcı olacak yeni silya genleri keşfetmeye ihtiyaç vardır. GPCR proteini olan, insan TMEM145 geninin ortoloğu olan ve Caenorhabditis elegans'ta bulunan C15A7.2 genini silya geni olarak tanımladık. C15A7.2 geni tarafından kodlanan TMEM-145 proteinin fonksiyonunu araştırdık ve C15A7.2 mutantlarda intraflagellar transport sisteminin hızının yavaşladığını bulduk. Ne tekli, ne de çeşitli çiftli mutantlarda herhangi bir yapısal bozukluk gözlemlemedik. Bu da TMEM-145'in silya yapımında görev almadığını gösteriyor. Silyada bulunan bu genin tam fonksiyonunu öğrenmek için ilave analizler yapılmalıdır.
B Hücreli Akut Lenfoblastik Lösemi Hücre Hattında Yüzey Proteomunun Belirlenmesi
(Abdullah Gül Üniversitesi / Fen Bilimleri Enstitüsü / Biyomühendislik Ana Bilim Dalı, 2022) Boyvat, Dudu; Güner, Şerife Ayaz
B hücreli akut lenfoblastik lösemi, B lenfositlerinin aşırı ve kontrolsüz ifadesi ile karakterizedir. B-ALL, anormal sitozolik sinyal iletimi ve gen mutasyonları, anormal protein etkileşimleri ve durdurulmamış hücre döngüsü gibi moleküler anormalliklerin bir sonucu olarak ortaya çıkabilir. Bu anormallikler nedeniyle, proteomun üçte birini oluşturan yüzey proteinleri, sağlıklı hücrelere kıyasla farklı ifadeler gösterir. Bu farklılıklar günümüzde tanı ve tedavi yaklaşımlarında kullanılmaktadır. Bu çalışmada, iki farklı yüzey protein izolasyon stratejisinin karşılaştırılması ile kütle spektrometrisi tabanlı proteomik yaklaşımı ile yeni, ek olası hedef antijenleri belirlemek için CCRF-SB hücre hattının yüzey proteinlerini izole etmeyi ve tanımlamayı amaçladık. CCRF-SB hücrelerinin yüzey proteinleri, biyotinilasyon yöntemi ve N-bağlı glikoprotein zenginleştirme yöntemleri ile izole edildi. Biyotinilasyon yöntemi ile % 1 FDR oranı ile 782 protein izole ettik. Gene Ontology Cellular Component analizi, bu izole edilmiş proteinlerin 467'sinin 'Membran' ile ilişkili, 263'ünün 'Hücre Dışı Boşluk' ile ilişkili olarak tanımlamıştır. Bu izole edilmiş hücre yüzeyi proteinlerinin, HLA protein komplekslerini ve iyi bilinen CD19 yüzey işaretleyicilerini içerdiği gösterilmiştir. N-bağlı glikozillenmiş protein zenginleştirme yöntemi ile %1 FDR oranı ile tanımlanan 229 protein Gene Ontology Cellular Component 155'inin 'Membran' olarak, bu proteinlerin 132'sinin 'Hücre Dışı Boşluk' ile ilişkili olarak açıklandığını gösterdi. Her iki yöntem de birbirinden farklı proteinleri tanımlamıştır. Bu sonuç, hücre yüzeyini proteomunu haritalamak için bu iki zenginleştirme yöntemini birleştirmenin gerekli olduğunu gösterdi.
Resveratrol'ün FLT3+ Akut Miyeloid Lösemide Terapötik Potansiyeli ve Resveratrol Tarafından Tetiklenen Apoptozda Seramid Metabolizmasının Rolü
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2021) Nur Şebnem, ERSÖZ; Ersöz, Nur Şebnem; Adan, Aysun
Resveratrol'ün FLT3-ITD+ AML hücreleri üzerindeki büyüme engelleyici etkilerinin altında yatan mekanizmalar, seramid metabolizması hedeflenerek araştırıldı. Resveratrol, SK (sfingosin kinaz) inhibitörü (SKI II), GCS (glukosilseramid sentaz) inhibitörü (PDMP)'nin tek başına ve kombinasyon halinde MOLM-13 ve MV4-11 hücreleri üzerindeki antiproliferatif, apoptotik ve sitostatik etkileri sırasıyla MTT, akış sitometrik Annexin-V/PI boyama ve PI boyama ile araştırıldı. Resveratrol muamelesi sonucu kaspaz-3 ve PARP kesimleri, GCS ve SK-1 protein ifadeleri ve kombinasyon muameleleri sonucu PARP kesimi western blot ile kontrol edildi. Kombinasyon indeksleri CompuSyn yazılımı ile hesaplanmıştır. Resveratrol'ün tek başına ve SKI II ve PDMP ile kombinasyonları, aditif veya sinerjik etkilerle hücre proliferasyonunu baskılamış, apoptozu indüklemesi ve hücre döngüsü ilerlemesini durdurmuştur. Resveratrol, GCS ve SK-1 ifadesini baskılamış ve kaspaz-3 ve PARP kesimi yoluyla apoptozu indüklemiştir. Kombinasyon muameleleri PARP aktivasyonu yoluyla apoptozu indüklemiştir. Sonuç olarak, resveratrolün FLT3-ITD + AML hücrelerinde büyümeyi baskılayıcı etkisi, SK-1 ve GCS'ın inhibe edilmesi aracılığı ile olmuştur ve bu iki enzimin inhibisyonu resveratrolün aktivitesini arttırmıştır.
SARS-CoV-2 Omikron Varyantına Özgü Tek Domainli Antikorların Protein-Protein Kenetlenmesi Yaklaşımlarıyla Tanımlanması
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2022) İlmek, Özkan; Güner, Şerife Ayaz
Omicron, became the dominant variant in 2022 in terms of spreading rate, has managed to evade from an immune system of patients due to its unique mutations. Single domain antibodies (sdAb) which are functionally important parts of conventional antibodies are commonly used for diagnosis and treatment. Although there are many sdAbs developed to combat coronavirus in recent years, their effectiveness against Omicron variant has not been sufficiently tested and the effect of mutations regarding neutralization level is not clear. In this study, structure modelling of 850 sdAb sequences obtained from previous studies were generated using AlphaFold 2 and effectiveness of these sdAbs against Omicron variant was tested via protein-protein docking approach. In the docking process, within a realistic approach, missing residues were completed into Spike protein PDB structures, and Spike protein homotrimer structure in closed state conformation was used. Finally, top 1000 and top 100 scores are determined as a threshold value for different protein-protein docking scoring functions such as HDOCK, PRODIGY and Bluues. sdAbs that have successful results for Omicron variant were listed. There were 4 sdAbs which exceed the threshold values after 2 different docking experiments against the Omicron variant. The scripting codes and methodological approach developed within this thesis can be used against new SARS-CoV-2 variants that may emerge in the future or other diseases.
BBSome, Caenorhabditis Elegans'ta ARL13B'ye Bağımlı İki Farklı Silyanın Birlikte Uzamasını Düzenler
(Abdullah Gül Üniversitesi / Fen Bilimleri Enstitüsü, 2023) Turan, Merve Gül; Kaplan, Sebiha Çevik
Cilia or flagella are interchangeably used to refer to the hair-like organelles extending from the cell surface to communicate with environmental signals or triggers. Cilium, the singular form of cilia, and its components are well-conserved structures throughout evolution and are divided into motile and primary cilium. The primary cilia of different cells are seen to form joint cilia by extending in parallel. For instance, PHA and PHB primary cilia in C. elegans protrude from the ends of the dendrite but extend parallel to one another and intersect in the middle portion of the cilia, reaching the same length. Nevertheless, the molecular mechanisms underlying how parallel cilia get similar lengths remain mysterious. In this thesis, we used C. elagans as a model organism to examine the molecular mechanism associated with the cilia direction. We generated various single, double, and triple mutants to examine PHA and PHB cilia for phenotype and length. We found that a Joubert syndrome protein, ARL13B, is required for determining cilia direction in PHA & PHB cilia and ASE & ASI cilia.
Tasarlanmış Mikroorganizmalar ile Katma Değeri Yüksek Karotenoidlerin Biyosentezi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2024) Arslansoy, Nuriye; Fidan, Özkan
Carotenoids are pigment molecules that play an important role in coloring plants, algae, and other organisms. These molecules exhibit various biological activities such as anticancer, antiviral and antioxidant activities. They have a huge market size and are mainly used in the food, feed, and cosmetic industries. The current supply chain for carotenoids is mostly relied on the extraction from plants and/or chemical synthesis for certain carotenoids. However, these strategies have various bottlenecks and disadvantages such as being affected by climate change, more difficult and costly extraction processes, and environmental issues. These can be overcome with microbial biosynthesis, which not only addresses the previous problems but also provides advantages of producing in a short time and scale-up for industrial production. In this research, we aimed to biosynthesize the high value-added carotenoids by engineered microorganisms. The genome of a native producer of zeaxanthin diglucoside, identified as endophytic Pseudomonas sp. 102515, was first edited by CRISPR-Cas9 to knock out zeaxanthin glucosyltransferase (CrtX), lycopene β-cyclase (CrtY) and beta-carotene hydroxylase (CrtZ). This led to ΔcrtX, ΔcrtY and ΔcrtZ mutant strains of Pseudomonas sp. 102515. On the other hand, overexpression plasmids carrying crtW, CaZEP and CaZEP-CaCCSm40 genes were constructed and transformed to ΔcrtX mutant to synthesize astaxanthin, violaxanthin and capsanthin/capsorubin. HPLC analysis of extracts from mutant strains and overexpression strains revealed that all the engineered strains produced the corresponding carotenoids such as zeaxanthin, β-carotene, and lycopene. Thus, this study paved the way for the biosynthesis of valuable carotenoids in the engineered endophytic bacteria.
İn Siliko Analizlerle Yeni Patojenik Varyantlar Bulmak
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2022) Zorluer, Ziya Furkan; Kaplan, Oktay İsmail
Inherited diseases are health problems caused by one or more abnormalities in the genome. It can be caused by changes in a single gene (monogenic) or multiple genes (polygenic), or by a damage on chromosomes. Genetic variation is the differences in the DNA sequences that can be observed within a species or in alleles. Evaluation of genetic variants, together with reported phenotypic or pathogenic annotations from non-human organisms, facilitates the comparison of these variants with their human counterparts. In this work, we combined pathogenic and phenotypic annotations with variants, and these phenotypic orthologous variants from seven organisms can provide clues to the functional consequences of human genetic variants.
Meme Kanseri Hedefli, Çok Fonksiyonlu, Çapraz Bağlı Misel Nanotaşıyıcıların Geliştirilmesi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2023) Bayram, Nazende Nur; İşoğlu, Sevil Dinçer
In this thesis, we developed two different micelle-based nanocarriers, which are pH-responsive and core cross-linked micelle (CCMs), and specifically target HER2 receptor on breast cancer cells. Intracellularly degradable and stabilized micelles were prepared by core cross-linking and RAFT polymerization in the presence of an acid-sensitive cross-linker. Poly(OEGMA) and poly(SBMA) were used as shell parts of these micelles in order to compare the effect of hydrophilic coatings on nanocarrier characteristics. In the first design, we applied drug conjugation (Doxorubicin) with a cleavable linker while in the second design, we used the encapsulation method for drug loading. Targeted micelles were obtained by coupling of HER2-specific peptides (VSSTQDFP and LTVSPWY) and antibody (Herceptin) to POEGMA and poly (SBMA) based CCMs, respectively. These nanocarriers are designed to be stable in blood circulation but cleavable intracellulary to achieve controlled drug release. Nanocarriers were characterized structurally by FTIR and 1H-NMR spectroscopies for all synthesis and conjugation steps. Moreover, nanocarriers and drug-loaded formulations were investigated by Zetasizer, Nanosight, and TEM/SEM analysis. The results showed that designed nanocarriers have a very high potential for HER2-specific targeted drug release for the treatment of breast cancer. This thesis holds significant importance due to its successful demonstration of two distinct systems exhibiting high stability, pH sensitivity, and high selectivity for HER2-targeted therapy of breast cancer.
Histon Deasetilaz İnhibisyonu ve Otofaji Modülasyonunun Kolanjiokarsinoma Hücrelerine Etkisi
(Abdullah Gül Üniversitesi, Fen Bilimleri Enstitüsü, 2022) Yenigül, Münevver; Yenigül, Münevver; Akçok, Emel Başak Gencer; Akçok, İsmail
Cholangiocarcinoma (CCA), also known as biliary tract cancer, is a heterogeneous group of malignancies formed by the differentiation of epithelial cells in the biliary tract. CCA is the second most common primary liver tumor and it has both an increasing rate and high mortality worldwide with its late diagnosis, refractory type, and aggressiveness. The effects of autophagy modulators and HDAC inhibitors in CCA are not fully known. This study is proposed a novel treatment approach with the combinational therapy of autophagy and HDAC inhibitors for CCA patients. In results obtained with alone HDACis, alone autophagy modulators, and combinations of HDACis and autophagy modulators, Nocodazole from autophagy modulators and MS-275 and Romidepsin from HDAC inhibitors showed a better synergistic effect on the TFK-1 and EGI-1 cell lines of the cholangiocarcinoma. In cell cycle analysis of the combination, was achieved arrest at the S phase and G2/M phase. In conclusion, this study highlights the important combination of HDAC inhibitors and autophagy modulators, which is a promising therapy in CCA. Keywords: Cholangiocarcinoma, HDAC inhibitors, Autophagy modulators, Combination therapy
Kolanjiyokarsinoma Proliferasyonunun Otofaji ve Hedgehog Sinyal Yolaklarının İnhibisyonu ile Azaltılması
(Abdullah Gül Üniversitesi, 2019) AKTAŞ, NİHAN; Aktaş, Nihan; Khatıb, Mona El
Cholangiocarcinoma (CCA) is the second most common liver cancer type. The median survival rate of CCA patients is really low. Aberrant signaling pathways such as PI3K/AKT/mTOR pathway could be main drivers in CCA pathogenesis. Hedgehog (Hh) pathway is also dysregulated in several carcinomas including CCA. It regulates and crosstalks with autophagy, which is a lysosomal degradation process. There is no study showing the crosstalk between Hh pathway and autophagy in the context of CCA. Since both autophagy and Hh pathways are dysregulated in CCA, better understanding of how they crosstalk with each other and contribute to CCA pathogenesis is important. Considering this crosstalk between Hh pathway and autophagy, we conducted a combination treatment comprising Hh and autophagy pathway inhibitors in EGI-1 and TFK-1 CCA cell lines. In our study, we firstly checked anti-proliferative effects of Hh pathway inhibitor, GANT61, and different autophagy blockers using MTT and Annexin V assay and cell cycle analysis. After determination of IC30 of GANT61 (15 uM), chloroquine (25 uM for TFK-1 and 50 uM for EGI-1), and nocodazole (0.2 uM for EGI-1 and 0.4 uM for TFK-1), we conducted combination experiments. When we inhibit Hh pathway with targeting different steps of autophagy, we observed that proliferation of both EGI-1 and TFK-1 cells decreased compared to single treatments. After that, we checked the expression of autophagy-related LC3B protein and Akt, a negative regulator of autophagy, using western blotting after single treatments and combinational treatments. Based on the change in LC3B and Akt expression, we also concluded that, inhibition of autophagy with Hh pathway either induce or inhibit autophagy depends on the administered treatments. This study highlights the importance of deciphering the exact mechanisms that control autophagy in CCA, thus leading to better treatment.

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