TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Citation - WoS: 3Citation - Scopus: 3Endogenous Heat Shock Protein Groel of A. Actinomycetemcomitans Preferentially Targets Primary Human Cd8+t Cells(TÜBİTAK, 2015) Kant, Melis; Akgül, Bünyamin; Nalbant Aldanmaz, AytenApoptosis can be used to manipulate host cells by bacterial products such as bacterial heat shock proteins (Hsp). One of the virulence factors of periodontal pathogen Aggregatibacter actinomycetemcomitans is heat shock protein GroEL (AaGroEL), which has been shown to interact with host cells. AaGroEL (Hsp64) also has the potential to modulate immune system cells. In this study we used endogenous AaGroEL protein as an antigen to study bacterial Hsp-induced apoptosis in different immune system cells. Human peripheral blood mononuclear cells and cell lines were cultured with different doses (50-1000 ng/mL) of endogenous AaGroEL at various time points. Apoptosis of the cells was measured by Annexin V and 7AAD labeling. Apoptotic cells were analyzed by flow cytometry. Our data suggested that AaGroEL-responding primary CD8+ T cells were more susceptible to apoptosis than CD4+ T cells. Furthermore, the magnitude of apoptosis in the Jurkat T cell line was higher than that in primary CD8+ T cells. There was no statistically significant level of apoptosis in the chronic myeloid leukemia (K562) cell line, which belongs to myeloid lineages. Thus, A. actinomycetemcomitans GroEL protein has more potent apoptotic effect on cells that are derived from a lymphoid progenitor.Article Citation - WoS: 8Citation - Scopus: 11Application of Low Intensity Mechanical Vibrations for Bone Tissue Maintenance and Regeneration(TÜBİTAK, 2016) Ölçüm, Melis; Baskan, Öznur; Karadaş, Özge; Özçivici, EnginPhysical exercise is beneficial for bone tissue health, yet its usage is limited for preventing osteoporosis. Even though natural for the bone tissue from development to homeostasis, mechanical loads present with a multitude of physical parameters, including amplitude, duration, frequency, and distribution. Utilizing the most beneficial parameters of mechanical loads may potentiate a nonpharmaceutical tool for biotechnology to prevent and treat bone loss related to aging, bedrest, sedentary lifestyles, weightlessness, and other diseases. Low intensity vibrations (LIVs) consist of mechanical loads with amplitudes smaller than loads prescribed by habitual activity, with a higher frequency. In this review, literature covering LIV signal application on bone tissue and cellular and molecular level is presented. Studies indicate that LIV signals are safe, anabolic, and anticatabolic for skeletal tissue and are of great significance in regenerative medicine applications.Article Citation - WoS: 3Citation - Scopus: 3A Minimally Invasive Transfer Method of Mesenchymal Stem Cells To the Intact Periodontal Ligament of Rat Teeth: a Preliminary Study(TÜBİTAK, 2018) Gül Amuk, Nisa; Kurt, Gökmen; Kartal Yandım, Melis; Adan, Aysun; Baran, YusufThe aim of this study was to introduce a minimally invasive procedure for mesenchymal stem cell (MSC) transfer into the intact periodontal ligament (PDL) of the molar teeth in rats. Ten 12-week-old Wistar albino rats were used for this preliminary study. MSCs were obtained from bones of two animals and were labeled with green fluorescent protein (GFP). Four animals were randomly selected for MSC injection, while 4 animals served as a control group. Samples were prepared for histological analysis, Cox-2 mRNA expression polymerase chain reaction analysis, and fluorescent microscopy evaluation. The number of total cells, number of osteoclastic cells, and Cox-2 mRNA expression levels of the periodontal tissue of teeth were calculated. The number of total cells was increased with MSC injections in PDL significantly (P < 0.001). The number of osteoclastic cells and Cox-2 mRNA expression were found to be similar for the two groups. GFP-labeled MSCs were observed with an expected luminescence on the smear samples of the PDL with transferred MSCs. The results of this preliminary study demonstrate successful evidence of transferring MSCs to intact FIX in a nonsurgical way and offer a minimally invasive procedure for transfer of MSCs to periodontal tissues.Article Citation - WoS: 9Citation - Scopus: 10Effects of Notch Signalling on the Expression of Sema3c, Hmga2, Cxcl14, Cxcr7, and Ccl20 in Breast Cancer(TÜBİTAK, 2019) Küçükköse, Cansu; Yalçın Özuysal, ÖzdenMetastasis is the main reason for death in breast cancer. Understanding the molecular players in metastasis is crucial for diagnostic and therapeutic purposes. Notch signalling plays an oncogenic role in breast tumorigenesis and is involved in metastasis. Downstream mediators of Notch signalling in prometastatic processes are not yet fully discovered. Here we aimed to investigate whether Notch signalling regulates the expression of SEMA3C, HMGA2, CXCL14, CXCR7, and CCL20, which are involved in prometastatic processes, in breast cell lines. To this end, expression of the selected genes was analysed following Notch activation by overexpression of the Notch1 intracellular domain in the normal breast epithelial cell line MCF10A, and inhibition by silencing of the Notch transcriptional mediator RBPj kappa in the breast cancer cell line MDA MB 231. SEMA3C and HMGA2 mRNA were decreased, while CXCL14 and CXCR7 mRNA were increased significantly in response to Notch activation in MCF10A cells. Notch inhibition in MDA MB 231 cells significantly decreased HMGA2 and CCL20 mRNA. Protein levels were not significantly altered by Notch modulation. In conclusion, we showed that Notch signalling regulates expression of SEMA3C, CXCL14, CCL20, CXCR7, and HMGA2, which are prominent candidate genes that might function downstream of Notch to induce prometastatic processes.Article The Frequency Function and Its Connections To the Lebesgue Points and the Hardy-Littlewood Maximal Function(TÜBİTAK, 2019) Temur, FarukThe aim of this work is to extend the recent work of the author on the discrete frequency function to the more delicate continuous frequency function tau, and further to investigate its relations to the Hardy-Littlewood maximal function M, and to the Lebesgue points. We surmount the intricate issue of measurability of tau f by approaching it with a sequence of carefully constructed auxiliary functions for which measurability is easier to prove. After this, we give analogues of the recent results on the discrete frequency function. We then connect the points of discontinuity of Mf for f simple to the zeros of tau f, and to the non-Lebesgue points of f.Article The Aggregatibacter Actinomycetemcomitans Heat Shock Protein Groel Interacts Directly With Human Peripheral Blood T Cells(TÜBİTAK, 2016) Nalbant, Ayten; Saygılı, TahsinHeat shock family protein GroEL of Aggregatibacter actinomycetemcomitans (Aa) has antigenic properties. We previously demonstrated that A. actinomycetemcomitans GroEL-like protein affects human CD4 T cells by converting them into IL-10 and IFNg double cytokine producing Tbet+ Th1 cells. The objective of this study was to investigate whether or not AaGroEL communicates with T cells directly. To do this, sorted cells from peripheral blood mononuclear cells were stimulated with AaGroEL for 48 h. Flow cytometry was used to measure soluble and intracellular cytokine expression in the cell cultures and detect TLR2 expression on the surface of T cells. Expression of six different soluble cytokines was evaluated by CBA assay. To determine whether AaGroEL affects CD3+ T cells directly or not, purified CD3+ T cells or CD14+ cells were cultured with AaGroEL separately, and the quantity of soluble cytokine was measured. Results showed that sorted CD3+ cells produced soluble IL-6, TNFα-and IFNγ cytokines. Additionally, the intracellular cytokine staining data showed that AaGroEL-stimulated CD3+ cells were also TNFα-and IFNγ-positive. Moreover, AaGroEL-responsive T cells slightly increased their TLR2 expression. These findings suggest that CD3+ T cells produce cytokines in response to AaGroEL protein without requirements for other cells, such as CD14+ monocytes.Article Citation - WoS: 8Citation - Scopus: 8Multidrug Resistance in Chronic Myeloid Leukemia(TÜBİTAK, 2014) Ünlü, Miray; Kiraz, Yağmur; Kacı, Fatma Necmiye; Özcan, Mehmet Ali; Baran, YusufChronic myeloid leukemia (CML) is characterized by the accumulation of Philadelphia chromosome-positive (Ph+) myeloid cells. Ph+ cells occur via a reciprocal translocation between the long arms of chromosomes 9 and 22 resulting in constitutively active Bcr-abl fusion protein. Tyrosine kinase inhibitors (TKIs) are used against the kinase activity of Bcr-abl fusion protein for the effective treatment of CML. However, the development of drug resistance, directed by different genetic mechanisms, is the major problem of clinical applications of TKIs. These mechanisms include mutations in the TKI binding site of Bcr-abl, overexpression of Bcr-abl, overexpression of ATP binding cassette transporters, aberrant ceramide metabolism, inhibition of apoptosis, and changes in expression levels of microRNAs. Recently, many studies have focused on understanding the molecular mechanisms of drug resistance in cancer while targeting therapies providing reversal of resistance. Cancer stem cells also have roles in tumor initiation, maintenance, progression, metastasis, and drug resistance. Uncovering the mechanisms of drug resistance can provide more efficient treatment of cancer since these findings may provide novel targets for a complete cure. In this review, we discuss recent findings on the mechanisms of multidrug resistance and its reversal in CML. © TÜBİTAK.Article Citation - WoS: 2Citation - Scopus: 3The Amido and Bisalkoxo-Complexes of [tri(3,5-Dimethylpyrazolyl)borato]molydenum Nitrosyl(TÜBİTAK, 1998) Topaloğlu, IşılIn this study, the amido nitrosyl molybdenum complex, [Mo{HM(3,5-Me2C3HN2)3}(NO)Cl(NH 2)], was prepared. This compound reacts with alocohols, yielding the bisalkoxo complexes, [Mo{HM(3,5-Me2C3HN2)3}(NO)(OR) 2] (R = Me, Et, Prn, Bun). The new complexes were analyzed by IR and 1H-NMR spectroscopy.