Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik

Permanent URI for this collectionhttps://hdl.handle.net/11147/9

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Department: search.filters.department.İzmir Institute of Technology. BioengineeringPublisher: search.filters.publisher.Springer

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Now showing 1 - 5 of 5
  • Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Connexin 32 Overexpression Increases Proliferation, Reduces Gap Junctional Intercellular Communication, Motility and Epithelial-To Transition in Hs578t Breast Cancer Cells
    (Springer, 2022) Uğur, Deniz; Güngül, Taha Buğra; Yücel, Simge; Özçivici, Engin; Yalçın Özuysal, Özden; Meşe Özçivici, Gülistan
    Connexins (Cx) are primary components of gap junctions that selectively allow molecules to be exchanged between adjacent cells, regulating multiple cellular functions. Along with their channel forming functions, connexins play a variety of roles in different stages of tumorigenesis and their roles in tumor initiation and progression is isoform- and tissue-specific. While Cx26 and Cx43 were downregulated during breast tumorigenesis, Cx32 was accumulated in the cytoplasm of the cells in lymph node metastasis of breast cancers and Cx32 was further upregulated in metastasis. Cx32's effect on cell proliferation, gap junctional communication, hemichannel activity, cellular motility and epithelial-to-mesenchymal transition (EMT) were investigated by overexpressing Cx32 in Hs578T and MCF7 breast cancer cells. Additionally, the expression and localization of Cx26 and Cx43 upon Cx32 overexpression were examined by Western blot and immunostaining experiments, respectively. We observed that MCF7 cells had endogenous Cx32 while Hs578T cells did not and when Cx32 was overexpressed in these cells, it caused a significant increase in the percentages of Hs578T cells at the S phase in addition to increasing their proliferation. Further, while Cx32 overexpression did not induce hemichannel activity in either cell, it decreased gap junctional communication between Hs578T cells. Additionally, Cx32 was mainly observed in the cytoplasm in both cells, where it did not form gap junction plaques but Cx32 overexpression reduced Cx43 levels without affecting Cx26. Moreover, migration and invasion potentials of Hs578T and migration in MCF7 were reduced upon Cx32 overexpression. Finally, the protein level of mesenchymal marker N-cadherin decreased while epithelial marker ZO-1 and E-cadherin increased in Hs578T cells. We observed that Cx32 overexpression altered cell proliferation, communication, migration and EMT in Hs578T, suggesting a tumor suppressor role in these cells while it had minor effects on MCF7 cells.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Frequency-Specific Sensitivity of 3t3-L1 Preadipocytes To Low-Intensity Vibratory Stimulus During Adipogenesis
    (Springer, 2022) Baskan, Öznur; Sarıgil, Öykü; Meşe Özçivici, Gülistan; Özçivici, Engin
    Adipocyte accumulation in the bone marrow is a severe complication leading to bone defects and reduced regenerative capacity. Application of external mechanical signals to bone marrow cellular niche is a non-invasive and non-pharmaceutical methodology to improve osteogenesis and suppress adipogenesis. However, in the literature, the specific parameters related to the nature of low-intensity vibratory (LIV) signals appear to be arbitrarily selected for amplitude, bouts, and applied frequency. In this study, we performed a LIV frequency sweep ranging from 30 to 120 Hz with increments of 15 Hz applied onto preadipocytes during adipogenesis for 10 d. We addressed the effect of LIV with different frequencies on single-cell density, adipogenic gene expression, lipid morphology, and triglycerides content. Results showed that LIV signals with 75-Hz frequency had the most significant suppressive effect during adipogenesis. Our results support the premise that mechanical-based interventions for suppressing adipogenesis may benefit from optimizing input parameters.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Low Magnitude High Frequency Vibrations Expedite the Osteogenesis of Bone Marrow Stem Cells on Paper Based 3d Scaffolds
    (Springer, 2020) Karadaş, Özge; Meşe, Gülistan; Özçivici, Engin
    Anabolic effects of low magnitude high frequency (LMHF) vibrations on bone tissue were consistently shown in the literature in vivo, however in vitro efforts to elucidate underlying mechanisms are generally limited to 2D cell culture studies. Three dimensional cell culture platforms better mimic the natural microenvironment and biological processes usually differ in 3D compared to 2D culture. In this study, we used laboratory grade filter paper as a scaffold material for studying the effects of LHMF vibrations on osteogenesis of bone marrow mesenchymal stem cells in a 3D system. LMHF vibrations were applied 15 min/day at 0.1 g acceleration and 90 Hz frequency for 21 days to residing cells under quiescent and osteogenic conditions. mRNA expression analysis was performed for alkaline phosphatase (ALP) and osteocalcin (OCN) genes, Alizarin red S staining was performed for mineral nodule formation and infrared spectroscopy was performed for determination of extracellular matrix composition. The highest osteocalcin expression, mineral nodule formation and the phosphate bands arising from the inorganic phase was observed for the cells incubated in osteogenic induction medium with vibration. Our results showed that filter paper can be used as a model scaffold system for studying the effects of mechanical loads on cells, and LMHF vibrations induced the osteogenic differentiation of stem cells.
  • Book Part
    Citation - Scopus: 15
    Stem Cell Culture Under Simulated Microgravity
    (Springer, 2020) Anıl İnevi, Müge; Sarıgil, Öykü; Kızılkaya, Melike; Meşe, Gülistan; Tekin, Hüseyin Cumhur; Özçivici, Engin
    Challenging environment of space causes several pivotal alterations in living systems, especially due to microgravity. The possibility of simulating microgravity by ground-based systems provides research opportunities that may lead to the understanding of in vitro biological effects of microgravity by eliminating the challenges inherent to spaceflight experiments. Stem cells are one of the most prominent cell types, due to their self-renewal and differentiation capabilities. Research on stem cells under simulated microgravity has generated many important findings, enlightening the impact of microgravity on molecular and cellular processes of stem cells with varying potencies. Simulation techniques including clinostat, random positioning machine, rotating wall vessel and magnetic levitation-based systems have improved our knowledge on the effects of microgravity on morphology, migration, proliferation and differentiation of stem cells. Clarification of the mechanisms underlying such changes offers exciting potential for various applications such as identification of putative therapeutic targets to modulate stem cell function and stem cell based regenerative medicine. © Springer Nature Switzerland AG 2020.
  • Book Part
    Citation - Scopus: 9
    Differential Expression of Toxoplasma Gondii Micrornas in Murine and Human Hosts
    (Springer, 2016) Allmer, Jens; Saçar Demirci, Müşerref Duygu; Bağcı, Caner
    MicroRNAs are short RNA sequences involved in post-transcriptional gene regulation. MicroRNAs are known for a wide variety of species ranging from bacteria to plants. It has become clear that some cross-kingdom regulation is possible especially between viruses and their hosts. We hypothesized that intracellular parasites, like Toxoplasma gondii, similar to viruses would be able to modulate their host’s gene expression. We were able to show that T. gondii produces many putative pre-miRNAs which are actually transcribed. Furthermore, some of these expressed pre-miRNAs have a striking resemblance to host mature miRNAs. Previous studies indicated that T. gondii infection coincides with increased abundance of some miRNAs. Here we were able to show that many of these miRNAs have close relatives in T. gondii which may not be distinguishable using PCR. Taken together, the similarity to host miRNAs, their confirmed expression, and their upregulation during infection, it suggests that T. gondii actively transfers miRNAs to regulate its host. We conclude, that this type of cross-kingdom regulation may be possible, but that targeted analysis is necessary to consolidate our computational findings. © Springer International Publishing Switzerland 2016. All rights are reserved.