Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Article Citation - WoS: 20Citation - Scopus: 21Progression of Irradiated Mesenchymal Stromal Cells From Early To Late Senescence: Changes in Sasp Composition and Anti-Tumour Properties(Wiley, 2023) Alessio, Nicola; Acar, Mustafa Burak; Squillaro, Tiziana; Aprile, Domenico; Ayaz Güner, Şerife; Di Bernardo, Giovanni; Özcan, ServetGenotoxic injuries converge on senescence-executive program that promotes production of a senescence-specific secretome (SASP). The study of SASP is particularly intriguing, since through it a senescence process, triggered in a few cells, can spread to many other cells and produce either beneficial or negative consequences for health. We analysed the SASP of quiescent mesenchymal stromal cells (MSCs) following stress induced premature senescence (SIPS) by ionizing radiation exposure. We performed a proteome analysis of SASP content obtained from early and late senescent cells. The bioinformatics studies evidenced that early and late SASPs, besides some common ontologies and signalling pathways, contain specific factors. In spite of these differences, we evidenced that SASPs can block in vitro proliferation of cancer cells and promote senescence/apoptosis. It is possible to imagine that SASP always contains core components that have an anti-tumour activity, the progression from early to late senescence enriches the SASP of factors that may promote SASP tumorigenic activity only by interacting and instructing cells of the immune system. Our results on Caco-2 cancer cells incubated with late SASP in presence of peripheral white blood cells strongly support this hypothesis. We evidenced that quiescent MSCs following SIPS produced SASP that, while progressively changed its composition, preserved the capacity to block cancer growth by inducing senescence and/or apoptosis only in an autonomous manner.Article Citation - WoS: 3Citation - Scopus: 3A Subtractive Proteomics Approach for the Identification of Immunodominant Acinetobacter Baumannii Vaccine Candidate Proteins(Frontiers Media S.A., 2022) Acar, Mustafa Burak; Ayaz Güner, Şerife; Güner, Hüseyin; Dinç, Gökçen; Ulu Kılıç, Ayşegül; Doğanay, Mehmet; Özcan, ServetBackground: Acinetobacter baumannii is one of the most life-threatening multidrug-resistant pathogens worldwide. Currently, 50%–70% of clinical isolates of A. baumannii are extensively drug-resistant, and available antibiotic options against A. baumannii infections are limited. There is still a need to discover specific de facto bacterial antigenic proteins that could be effective vaccine candidates in human infection. With the growth of research in recent years, several candidate molecules have been identified for vaccine development. So far, no public health authorities have approved vaccines against A. baumannii. Methods: This study aimed to identify immunodominant vaccine candidate proteins that can be immunoprecipitated specifically with patients’ IgGs, relying on the hypothesis that the infected person’s IgGs can capture immunodominant bacterial proteins. Herein, the outer-membrane and secreted proteins of sensitive and drug-resistant A. baumannii were captured using IgGs obtained from patient and healthy control sera and identified by Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) analysis. Results: Using the subtractive proteomic approach, we determined 34 unique proteins captured only in drug-resistant A. baumannii strain via patient sera. After extensively evaluating the predicted epitope regions, solubility, transverse membrane characteristics, and structural properties, we selected several notable vaccine candidates. Conclusion: We identified vaccine candidate proteins that triggered a de facto response of the human immune system against the antibiotic-resistant A. baumannii. Precipitation of bacterial proteins via patient immunoglobulins was a novel approach to identifying the proteins that could trigger a response in the patient immune system.Article Citation - WoS: 4Citation - Scopus: 4Protocol for Cell Surface Biotinylation of Magnetic Labeled and Captured Human Peripheral Blood Mononuclear Cells(Elsevier, 2022) Ayaz Güner, Şerife; Acar, Mustafa Burak; Boyvat, Dudu; Güner, Hüseyin; Bozalan, Habibe; Güzel, Melis; Yıldır, Selin Kübra; Altınsoy, Nilay; Fındık, Fatma; Karakükçü, Musa; Özcan, ServetAnalysis of the surfaceome of a blood cell subset requires cell sorting, followed by surface protein enrichment. Here, we present a protocol combining magnetically activated cell sorting (MACS) and surface biotinylation of the target cell subset from human peripheral blood mononuclear cells (PBMCs). We describe the steps for isolating target cells and their in-column surface biotinylation, followed by isolation and mass spectrometry analysis of biotinylated proteins. The protocol enables in-column surface biotinylation of specific cell subsets with minimal membrane disruption.Article Citation - WoS: 6Citation - Scopus: 6An Integrative-Omics Analysis of an Industrial Clavulanic Acid-Overproducing Streptomyces Clavuligerus(Springer, 2022) Kurt Kızıldoğan, Aslıhan; Çelik, Gözde; Ünsaldı, Eser; Özcan, Servet; Ayaz Güner, Şerife; Özcengiz, GülayClavulanic acid (CA) is a clinically important secondary metabolite used to treat infectious diseases. We aimed to decipher complex regulatory mechanisms acting in CA biosynthesis by analyzing transcriptome- and proteome-wide alterations in an industrial CA overproducer Streptomyces clavuligerus strain, namely DEPA and its wild-type counterpart NRRL3585. A total of 924 differentially expressed genes (DEGs) and 271 differentially produced proteins (DPPs) were obtained by RNA-seq and nanoLC-MS/MS analyses, respectively. In particular, CA biosynthetic genes, namely, car (cad), cas2, oat2, pah, bls, ceas2, orf12, and claR, a cluster situated regulatory (CSR) gene, were significantly upregulated as shown by RNA-seq. Enzymes of clavam biosynthesis were downregulated considerably in the DEPA strain, while the genes involved in the arginine biosynthesis, one of the precursors of CA pathway, were overexpressed. However, the biosynthesis of the other CA precursor, glyceraldehyde-3-phosphate (G3P), was not affected. CA overproduction in the DEPA strain was correlated with BldD, BldG, BldM, and BldN (AdsA) overrepresentation. In addition, TetR, WhiB, and Xre family transcriptional regulators were shown to be significantly overrepresented. Several uncharacterized/unknown proteins differentially expressed in the DEPA strain await further studies for functional characterization. Correlation analysis indicated an acceptable degree of consistency between the transcriptome and proteome data. The study represents the first integrative-omics analysis in a CA overproducer S. clavuligerus strain, providing insights into the critical control points and potential rational engineering targets for a purposeful increase of CA yields in strain improvement.