Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Article Blank Frame and Intensity Variation Distortion Detection and Restoration Pipeline for Phase-Contrast Microscopy Time-Lapse Images(Aves, 2024) Ucar, Mahmut; Iheme, Leonardo O.; Onal, Sevgi; Pesen-Okvur, Devrim; Yalcin-Ozuysal, Ozden; Toreyin, Behcet U.; Unay, DevrimIn this study, we propose a preprocessing pipeline for the detection and correction of distorted frames in time-lapse images obtained from phase-contrast microscopy. The proposed pipeline employs the average intensities of frames as a foundational element for the analysis. In order to evaluate the degree of correction required for intensity variance, a normalization technique is applied to the difference between the average intensity of a specific frame and the median average intensity of all frames within the study. Our restoration method increases the histogram similarity between the distorted and non-distorted frames, preserves trans-passing pixels in regions of interest, and mitigates the development of additional distortions. The efficacy of the proposed method was evaluated using 15 395 time-lapse image frames from 27 experiments using our own dataset and 830 time-lapse images from four different experiments obtained from the cell tracking challenge. The results of the validation demonstrate a high degree of numerical and visual accuracy of the proposed pipeline.Article Epithelial-Mesenchymal Transition as a Potential Route for Dapt Resistance in Breast Cancer Cells(Walter de Gruyter GmbH, 2023) Tellı, Kubra; Ozuysal, Ozden Yalcın; Telli, Kübra; Yalçın Özuysal, ÖzdenObjectives: Notch is a conserved pathway involved in cell- fate determination and homeostasis. Its dysregulation plays a role in poor prognosis and drug resistance in breast cancer. Targeting Notch signaling via inhibition of the gamma- secretase complex is in the spotlight of modern cancer treat- ments. Gamma-secretase inhibitors (GSI) have shown suc- cessful clinical activity in treating cancers, yet the possible resistance mechanism remains unstudied. Modeling the resistance and understanding culprit molecular mechanisms can improve GSI therapies. Accordingly, the aim of this study is to generate and analyze GSI-resistant breast cancer cells. Methods: Gradually increasing doses of DAPT, a well-known GSI, were applied to MCF-7 breast cancer cell lines to generate resistance. Cell viability, migration and gene expressions were assessed by MTT, wound healing and qRT-PCR analyses. Results: DAPT-resistant MCF-7 cells exhibited abnormal expression of Notch receptors, Notch targets (HES1, HES5, HEY1), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, ZO-1, SNAIL2, N-cadherin) to overcome the continuous increase in DAPT toxicity by increased migration through mesenchymal transition. Conclusions: This study prospects into the role of EMT in the potential resistance mechanism against DAPT treatment for breast cancer cells. Complementary targeting of EMT should be investigated further for a possible effect to potentiate DAPT’s anti-cancer effects.Article Determination of Resistance Levels To Clavibacter Michiganensis Subsp. Michiganensis in Some Solanum Species(Ege Tarımsal Araştırma Enstitüsü, 2022) Frary, Anne; Şanver, Utku; Akköse Baytar, Asena; Özaktan, Hatice; Doğanlar, SamiClavibacter michiganensis subsp. michiganensis (Cmm), is a devastating bacterial disease agent causing bacterial wilt and canker in tomatoes. There is no definitive solution to prevent yield losses by Cmm in tomatoes. Moreover, there is currently no commercially successful Cmm resistant tomato cultivar on the market. Therefore, we aimed to determine the tolerance level of some tomato accessions to Cmm in the present study. For this purpose, we screened seven tomato accessions representing four species (Solanum arcanum, S. habrochaites, S. pennellii, and S. peruvianum) from Peru, Ecuador, and Mexico against the highly virulent isolates Cmm-244 and Cmm-9. A root immersion method was used to identify new sources of resistance to this important disease. Two accessions, S. habrochaites LA1777, and S. arcanum LA2157 were found to be moderate and highly tolerant, respectively, and could serve as tolerance resources for tomato breeding in Türkiye. These materials can also be investigated more extensively to determine their intrinsic Cmm tolerance mechanism.Data Paper Knockdown of Death Receptor 5 Antisense Long Noncoding Rna and Cisplatin Treatment Modulate Similar Macromolecular and Metabolic Changes in Hela Cells(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Gürer, Dilek Cansu; Erdoğan Vatansever, İpek; Ceylan, Çağatay; 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 ametabolic changes in HeLa cervix cancer cells.Article Citation - WoS: 1Citation - Scopus: 1Cytoplasmically Localized Trna-Derived Fragments Inhibit Translation in Drosophila S2 Cells(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Hamid, Syed Muhammad; Akgül, BünyaminTransfer ribonucleic acids (tRNAs) serve not only as amino acid carriers during translation but also as a template for the biogenesis of short fragments that can regulate gene expression. Despite recent progress in the function of tRNA-derived fragments (tRFs), their intracellular localization, protein partners, and role in regulating translation are not well understood. We used synthetic tRFs to investigate their localization and function in Drosophila S2 cells. Under our experimental setting, all synthetic tRFs tested were localized at distinct sites within the cytoplasm in a similar manner in Drosophila S2 cells. Cytoplasmically-localized tRFs were positioned in close proximity to GW182 and XRN1 proteins. Functionally, tRFs, which slightly suppressed proliferation in S2 cells, inhibited translation without any major shift in the polysome profile. These results suggest that 5???-tRFs are cytoplasmically-localized and regulate gene expression through inhibition of translation in Drosophila.Article Citation - WoS: 3Citation - Scopus: 3Evaluation of Variation on Myostatin (mstn) Gene of Turkish Donkey Populations in Thrace Region of Turkey(Namık Kemal Üniversitesi, 2022) Işık, Raziye; Özdil, Fulya; Meral, SenaThe study aimed to determine the MSTN gene variation in 90 donkeys reared in the Thrace region of Turkey. Myostatin (MSTN), also named GDF-8 (growth differentiation factor 8) is a part of the transforming growth factor beta (TGF-beta) superfamily and it has a negative regulator role on muscle mass, growth and development in mammalian species. MSTN gene regulates the skeletal muscle growth in a negative way and has a significant role in homeostasis of skeletal muscles. Also, in muscle fibers balance of protein has been promoted by Myostatin factor. The total of 866 bp long partial intron 1 and 2, whole exon 2 regions of MSTN gene was amplified and PCR products analysed using DNA sequencing. In this study, a novel synonymous SNP was determined as g.4183919 G>A in the second exon region of the MSTN gene which does not cause an amino acid change in the protein. The G>A transition caused a silent mutation in leucine (leu) amino acid. Alterations in mRNA level and functionality of protein can occur due to synonymous mutations. Since leucine is an important amino acid that can avoid muscle mass loss and inhibits the expression of Myostatin, it can be said that silent mutation of Leu in donkeys may have altered the muscle mass and physical factor of donkeys in this study. Mutant leucine may have a lower efficient effect on preventing loss of muscles and causes more Myostatin protein expression. The identified SNP was firstly released and the DNA sequences of the MSTN gene in Turkish donkeys was revealed for the first time with recent study. Turkish donkeys lacked these mutations that were identified before in horses, which cause for the less might require for race ability of donkeys. The sequences of MSTN gene were submitted to the NCBI GenBank with the accession number: MW970078- MW970079. Further studies are needed to conduct, on protein and molecular levels, SNPs on the MSTN gene and their association with the morphological characters that may affect economic traits in donkey breeds.Article Molecular Genetic Characterization of the Turkish National Green Plum (prunus Cerasifera Ehrh.) Collection(Ege Tarımsal Araştırma Enstitüsü, 2021) Çakır, Gülsüm; Taşcıoğlu, Tülin; Çavdar, Andaç; Doğanlar, Sami; Frary, Amy; Frary, AnnePlum is an important fruit worldwide and has high nutritional value. Prunus cerasifera Ehrh., a type of European plum species, is very popular in Turkey and is usually eaten at the green, unripe stage. In this work for the first time, the genetic diversity and population structure of the 66 accessions housed in the Turkish National P. cerasifera collection were investigated using molecular markers. A total of 47 Sequence-Related Amplified Polymorphism (SRAP) primer pairs were used and found to be highly polymorphic with 98% of the 495 amplified alleles providing polymorphism. Average diversity of the accessions was 0.39 as determined using the dice coefficient and was similar to P. cerasifera germplasm from France, Iran and Belarus but higher than that from China. This difference was expected as Turkey, Iran and Belarus are within the geographical origin of this species which was distributed to Europe during ancient times. The genetic relationships among accessions of the germplasm collection were assessed using unweighted neighbor joining dendrogram and population structure analyses. The dendrogram and population structure results were strongly correlated as both methods clustered the material into two main groups with a much smaller third admixed group. The analysis also indicated that Can and Papaz types, despite their morphological differences are not genetically distinct and provides information about genetic relationships that can be used in future plum breeding.Article Citation - WoS: 14Citation - Scopus: 15Noncoding Rnas in Apoptosis: Identification and Function(TÜBİTAK, 2022) Tüncel, Özge; Kara, Merve; Yaylak, Bilge; Erdoğan, İpek; 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.Article Citation - WoS: 3Citation - Scopus: 6Improved Cell Segmentation Using Deep Learning in Label-Free Optical Microscopy Images(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2021) Ayanzadeh, Aydın; Yalçın Özuysal, Özden; Pesen Okvur, Devrim; Önal, Sevgi; Töreyin, Behçet Uğur; Ünay, DevrimThe recently popular deep neural networks (DNNs) have a significant effect on the improvement of segmentation accuracy from various perspectives, including robustness and completeness in comparison to conventional methods. We determined that the naive U-Net has some lacks in specific perspectives and there is high potential for further enhancements on the model. Therefore, we employed some modifications in different folds of the U-Net to overcome this problem. Based on the probable opportunity for improvement, we develop a novel architecture by using an alternative feature extractor in the encoder of U-Net and replacing the plain blocks with residual blocks in the decoder. This alteration makes the model superconvergent yielding improved performance results on two challenging optical microscopy image series: a phase-contrast dataset of our own (MDA-MB-231) and a brightfield dataset from a well-known challenge (DSB2018). We utilized the U-Net with pretrained ResNet-18 as the encoder for the segmentation task. Hence, following the modifications, we redesign a novel skip-connection to reduce the semantic gap between the encoder and the decoder. The proposed skip-connection increases the accuracy of the model on both datasets. The proposed segmentation approach results in Jaccard Index values of 85.0% and 89.2% on the DSB2018 and MDA-MB-231 datasets, respectively. The results reveal that our method achieves competitive results compared to the state-of-the-art approaches and surpasses the performance of baseline approaches.Article Citation - WoS: 2Citation - Scopus: 2Antiviral Microrna Expression Signatures Are Altered in Subacute Sclerosing Panencephalitis(Wolters Kluwer Medknow Publications, 2021) Tüfekçi, Kemal Uğur; Allmer, Jens; Çarman, Kürşat Bora; Bayram, Erhan; Topçu, Yasemin; Hız, Semra; Genç, Şermin; Yiş, UluçBackground: Subacute sclerosing panencephalitis (SSPE) is a chronic, progressive disease caused by a persistent infection of the measles virus. Despite extensive efforts, the exact neurodegeneration mechanism in SSPE remains unknown. MicroRNAs (miRNAs) have emerged as an essential part of cellular antiviral defense mechanisms and can be modulated by antiviral cytokines Such as interferon-beta (IFN-beta). Aims and Objectives: In this study, we aimed to elucidate the role of antiviral miRNAs in the pathogenesis of SSPE and analyze the interaction between host antiviral miRNAs and virus genes. Materials and Methods: Thirty-seven patients who were followed with SSPE and age-matched healthy children were included in the study. Peripheral blood mononuclear cell levels of miR-196b, miR-296, miR-431, and miR-448 were analyzed using quantitative polymerase chain reaction. Target predictions and pathway constructions of deregulated miRNAs were assessed. Results: Here, we showed that IFN-beta-modulated miR-196b, miR-296, and miR-431 were significantly upregulated in patients with SSPE compared with healthy controls. Besides, sequence complementarity analysis showed that miR-296 and miR-196b predicted binding regions in measles virus genomic RNA. Conclusion: Our findings suggest that antiviral miRNAs are upregulated in patients with SSPE, which could be a part of the host antiviral defense mechanism. </p>