Akgül, Bünyamin
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Name Variants
Akgul, Bunyamin
Akgül, Bünyamin
Akgül,B.
Akgul,B.
Akgül, Bünyamin
Akgül,B.
Akgul,B.
Job Title
Prof. Dr.
Email Address
bunyaminakgul@iyte.edu.tr
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output
33
Articles
18
Citation Count
85
Supervised Theses
1
31 results
Scholarly Output Search Results
Now showing 1 - 10 of 31
Article Citation Count: 5Transcriptomics Profiling Identifies Cisplatin-Inducible Death Receptor 5 Antisense Long Non-coding RNA as a Modulator of Proliferation and Metastasis in HeLa Cells(Frontiers Media Sa, 2021) Gurer, Dilek Cansu; Erdogan, Ipek; Ahmadov, Ulvi; Basol, Merve; Sweef, Osama; Cakan-Akdogan, Gulcin; Akgul, Bunyamin; Akgül, BünyaminCisplatin is a well-known cancer chemotherapeutic agent but how extensively long non-coding RNA (lncRNA) expression is modulated by cisplatin is unknown. It is imperative to employ a comprehensive approach to obtain a better account of cisplatin-mediated changes in the expression of lncRNAs. In this study, we used a transcriptomics approach to profile lncRNAs in cisplatin-treated HeLa cells, which resulted in identification of 10,214 differentially expressed lncRNAs, of which 2,500 were antisense lncRNAs. For functional analyses, we knocked down one of the cisplatin inducible lncRNAs, death receptor 5 antisense (DR5-AS) lncRNA, which resulted in a morphological change in HeLa cell shape without inducing any cell death. A second round of transcriptomics-based profiling revealed differential expression of genes associated with immune system, motility and cell cycle in DR5-AS knockdown HeLa cells. Cellular analyses showed that DR5-AS reduced cell proliferation and caused a cell cycle arrest at S and G2/M phases. Moreover, DR5-AS knockdown reduced the invasive capacity of HeLa cells in zebrafish xenograft model. These results suggest that cisplatin-mediated pleiotropic effects, such as reduction in cell proliferation, metastasis and cell cycle arrest, may be mediated by lncRNAs.Article Citation Count: 0Knockdown of death receptor 5 antisense long noncoding RNA and cisplatin treatment modulate similar macromolecular and metabolic changes in HeLa cells(Tubitak Scientific & Technological Research Council Turkey, 2022) Gurer, Dilek Cansu; Erdogan Vatansever, Ipek; Ceylan, Cagatay; Akgul, Bunyamin; Akgül, BünyaminBackground/aim: Despite great progress in complex gene regulatory mechanisms in the dynamic tumor microenvironment, the potential contribution of long noncoding RNAs (lncRNAs) to cancer cell metabolism is poorly understood. Death receptor 5 antisense (DR5-AS) is a cisplatin inducible lncRNA whose knockdown modulates cell morphology. However, its effect on cell metabolism is unknown. The aim of this study is to examine metabolic changes modulated by cisplatin and DR5-AS lncRNA in HeLa cells.Materials and methods: We used cisplatin as a universal cancer therapeutic drug to modulate metabolic changes in HeLa cervix cancer cells. We then examined the extent of metabolic changes by Fourier transform infrared spectroscopy (FTIR). We also performed transcriptomics analyses by generating new RNA-seq data with total RNAs isolated from cisplatin-treated HeLa cells. Then, we compared cisplatin-mediated transcriptomics and macromolecular changes with those mediated by DR5-AS knockdown.Results: Cisplatin treatment caused changes in the unsaturated fatty acid and lipid-to-protein ratios and the glycogen content. These observations in altered cellular metabolism were supported by transcriptomics analyses. FTIR spectroscopy analyses have revealed that DR5-AS knockdown causes a 20.9% elevation in the lipid/protein ratio and a 76.6% decrease in lipid peroxidation. Furthermore, we detected a 3.42% increase in the chain length of the aliphatic lipids, a higher content of RNA, and a lower amount of glycogen indicating relatively lower metabolic activity in the DR5-AS knockdown HeLa cells. Interestingly, we observed a similar gene expression pattern under cisplatin treatment and DR5-AS knockdown HeLa cells. Conclusion: These results suggest that DR5-AS lncRNA appears to account for a fraction of cisplatin-mediated macromolecular and metabolic changes in HeLa cervix cancer cells.Master Thesis Isothermal corrosion testing of frit furnace refractories(Izmir Institute of Technology, 2008) Balıkoğlu, Fatih; Akgül, Bünyamin; Akkurt, SedatResults of a project aimed at understanding the corrosion behavior of aluminosilicate type of refractories in frit melts are presented. A refractory of largely andalusite and silimanite composition was compared to another brick of mullite and silimanite composition which was made by a different manufacturer for use in a different frit furnace. Density, porosity, microstructure and chemistry of both bricks are characterized before the corrosion tests. Isothermal tests were conducted by partially immersing a 15x15x115mm square specimen into a frit melt between 1404 and 1504oC in a vertical tube furnace. The frit used had an industrially used transparent frit composition. The effects of temperature, duration of exposure and refractory type were investigated using a statistically designed set of experiments. The ANOVA (Analysis of variance) table indicated that temperature and duration were more important factor effects. Increasing exposure duration and temperature both led to increased amount of corrosion as measured by the cross sectional area loss of the corroded specimen.Postmortem microstructural analysis was also done on the specimens and extensive amount of ZnO.Al2O3 precipitation was observed along the frit-refractory interface where also other crystals of mullite and alumina were found to precipitate. Increasing amount of duration and temperature produced more ZnO.Al2O3 precipitation. As identified by SEM-EDS analysis, mullite cyrstals were in the needle like morphology while alumina crystals were generally cubic. Because of their small concentration, XRD analysis could not reveal the phases of these crystals. More experiments were done by rotating the specimens in the melt at 50 rpm of rotational speed. Due to the reduction of boundary layer thickness, more dissolution was observed from the rotated specimens. In all specimens corrosion was more pronounced in the bond phase than through the large filler grains of mullite and andalusite.Keywords: Refractories, frit, corrosion, test.Review Citation Count: 10Intracytoplasmic Re-localization of miRISC Complexes(Frontiers Media Sa, 2018) Akgul, Bunyamin; Erdogan, Ipek; Akgül, BünyaminMicroRNAs (miRNAs) are a conserved class of non-coding RNAs of 22 nucleotides that post-transcriptionally regulate gene expression through translational repression and/or mRNA degradation. A great progress has been made regarding miRNA biogenesis and miRNA-mediated gene regulation. Additionally, an ample amount of information exists with respect to the regulation of miRNAs. However, the cytoplasmic localization of miRNAs and its effect on gene regulatory output is still in progress. We provide a current review of the cytoplasmic miRNA localization in metazoans. We then discuss the dynamic changes in the intracytoplasmic localization of miRNAs as a means to regulate their silencing activity. We then conclude our discussion with the potential molecules that could modulate miRNA localization.Article Citation Count: 6Transcriptomics Analysis of Circular RNAs Differentially Expressed in Apoptotic HeLa Cells(Frontiers Media Sa, 2019) Yaylak, Bilge; Erdogan, Ipek; Akgul, Bunyamin; Akgül, BünyaminApoptosis is a form of regulated cell death that plays a critical role in survival and developmental homeostasis. There are numerous reports on regulation of apoptosis by protein-coding genes as well as small non-coding RNAs, such as microRNAs. However, there is no comprehensive investigation of circular RNAs (circRNA) that are differentially expressed under apoptotic conditions. We have performed a transcriptomics study in which we first triggered apoptosis in HeLa cells through treatment with four different agents, namely cisplatin, doxorubicin, TNF-alpha and anti-Fas mAb. Total RNAs isolated from control as well as treated cells were treated with RNAse R to eliminate the linear RNAs. The remaining RNAs were then subjected to deep-sequencing to identify differentially expressed circRNAs. Interestingly, some of the dys-regulated circRNAs were found to originate from protein-coding genes well-documented to regulate apoptosis. A number of candidate circRNAs were validated with qPCR with or without RNAse R treatment as well. We then took advantage of bioinformatics tools to investigate the coding potential of differentially expressed RNAs. Additionally, we examined the candidate circRNAs for the putative miRNA-binding sites and their putative target mRNAs. Our analyses point to a potential for circRNA-mediated sponging of miRNAs known to regulate apoptosis. In conclusion, this is the first transcriptomics study that provides a complete circRNA profile of apoptotic cells that might shed light onto the potential role of circRNAs in apoptosis.Book Part Citation Count: 38Endogenous miRNA Sponges(Humana Press Inc., 2022) Akgül, Bünyamin; Akgül,B.MicroRNAs (miRNAs) are a class of noncoding RNAs of 17–22 nucleotides in length with a critical function in posttranscriptional gene regulation. These master regulators are themselves subject to regulation both transcriptionally and posttranscriptionally. Recently, miRNA function has been shown to be modulated by exogenous RNA molecules that function as miRNA sponges. Interestingly, endogenous transcripts such as transcribed pseudogenes, long noncoding RNAs (lncRNAs), circular RNAs (circRNAs) and mRNAs may serve as natural miRNA sponges. These transcripts, which bind to miRNAs and competitively sequester them away from their targets, are naturally existing endogenous miRNA sponges, called competing endogenous RNAs (ceRNAs). Here we present a historical background of miRNAs, exogenous and endogenous miRNA sponges as well as some examples of endogenous miRNA sponges involved in regulatory mechanisms associated with various diseases, developmental stages, and other cellular processes. © 2022, Springer Science+Business Media, LLC, part of Springer Nature.Article Citation Count: 6Re-arrangements in the cytoplasmic distribution of small RNAs following the maternal-to-zygotic transition in Drosophila embryos(MDPI AG, 2018) Akgül, Bünyamin; Yiğit,H.; Kizil,C.; Akgül,B.Small ribonucleic acids (RNAs) are known to regulate gene expression during early development. However, the dynamics of interaction between small RNAs and polysomes during this process is largely unknown. To investigate this phenomenon, 0-1 h and 7-8 h Drosophila melanogaster embryos were fractionated on sucrose density gradients into four fractions based on A254 reading (1) translationally inactive messenger ribonucleoprotein (mRNP), (2) 60S, (3) monosome, and (4) polysome. Comparative analysis of deep-sequencing reads from fractionated and un-fractionated 0-1 h and 7-8 h embryos revealed development-specific co-sedimentation pattern of small RNAs with the cellular translation machinery. Although most micro RNAs (miRNAs) did not have a specific preference for any state of the translational machinery, we detected fraction-specific enrichment of a few miRNAs such as dme-miR-1-3p, -184-3p, 5-5p and 263-5p. More interestingly, we observed changes in the subcellular location of a subset of miRNAs in fractionated embryos despite no measurable difference in their amount in unfractionated embryos. Transposon-derived endo small interfering RNAs (siRNAs) were over-expressed in 7-8 h embryos and associated mainly with the mRNP fraction. In contrast, transposon-derived PIWI-interacting RNAs (piRNA), which were more abundant in 0-1 h embryos, co-sedimented primarily with the polysome fractions. These results suggest that there appears to be a complex interplay among the small RNAs with respect to their polysome-cosedimentation pattern during early development in Drosophila melanogaster. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.Article Citation Count: 3Small RNA data set that includes tRNA-derived fragments from Jurkat cells treated with camptothecin(Elsevier Science Bv, 2018) Cosacak, Mehmet Ilyas; Erdogan, Ipek; Nalbant, Ayten; Akgul, Bunyamin; Akgül, BünyaminIn this article, we report a small RNA data set obtained from human T cell acute leukemia Jurkat cells, which were treated with the universal apoptotic agent camptothecin. Based on the Annexin-V labeling pattern, we sorted two Jurkat subpopulations in treated cells: one that is sensitive to the drug and the other being relatively more resistant. We report new original data that include the frequency of tRNA-derived fragments (tRF) in drug-sensitive and resistant cells. We also present partially analyzed data to show the origin of reads on tRNAs as well as the borders of the fragments. We believe that this data can benefit the science community working in the field of tRF and/or apoptosis. (C) 2018 The Authors. Published by Elsevier Inc.Review Citation Count: 3Noncoding RNAs in apoptosis: identification and function(Tubitak Scientific & Technological Research Council Turkey, 2022) Tuncel, Ozge; Kara, Merve; Yaylak, Bilge; Erdogan, Ipek; Akgul, Bunyamin; Akgül, BünyaminApoptosis is a vital cellular process that is critical for the maintenance of homeostasis in health and disease. The derailment of apoptotic mechanisms has severe consequences such as abnormal development, cancer, and neurodegenerative diseases. Thus, there exist complex regulatory mechanisms in eukaryotes to preserve the balance between cell growth and cell death. Initially, protein coding genes were prioritized in the search for such regulatory macromolecules involved in the regulation of apoptosis. However, recent genome annotations and transcriptomics studies have uncovered a plethora of regulatory noncoding RNAs that have the ability to modulate not only apoptosis but also many other biochemical processes in eukaryotes. In this review article, we will cover a brief summary of apoptosis and detection methods followed by an extensive discussion on microRNAs, circular RNAs, and long noncoding RNAs in apoptosis.Conference Object Citation Count: 0Dietary Garlic Prevents Development of Diabesity in Mice(Federation Amer Soc Exp Biol, 2009) Tu, Chen-Pei David; Akgul, Bunyamin; Lin, Kai-Wei; Pan, Huei-Ju; Chen, Yen-Hui; Lu, Tzu-Huan; Chen, Yuan-Tsong; Akgül, Bünyamin[No Abstract Available]
