• Mass Spectrometry Letters
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• 제3권4호
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• pp.93-100
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• 2012

Cellular processes such as proliferation, differentiation, and adaptation to environmental changes are regulated by protein phosphorylation. In order to enhance the understanding of molecular dynamics for biological process in detail, it is necessary to develop sensitive and comprehensive analytical methods for the determination of protein phosphorylation. Neural stem cells hold great promise for neural repair following an injury or disease. In this study, we made differentiated oligodendrocytes from human neural stem cells using over-expression of olig2 gene. We confirmed using quantitative phosphoproteome analysis approach that combines stable isotope labeling by amino acids in cell culture (SILAC) and $TiO_2$ micro-column for phosphopeptide enrichment with $MS^2$ and $MS^3$ mass spectrometry. We detected 275 phosphopeptides which were modulated at least 2-fold between human neural stem cells and oligodendrocytes. Among them, 23 phosphoproteins were up-regulated in oligodendrocytes and 79 phosphoproteins were up-regulated in F3 cells.

• Genomics & Informatics
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• 제10권3호
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• pp.145-152
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• 2012

Chromatin structure and dynamics that are influenced by epigenetic marks, such as histone modification and DNA methylation, play a crucial role in modulating gene transcription. To understand the relationship between histone modifications and regulatory elements in breast cancer cells, we compared our chromatin immunoprecipitation sequencing (ChIP-Seq) histone modification patterns for histone H3K4me1, H3K4me3, H3K9/16ac, and H3K27me3 in MCF-7 cells with publicly available formaldehyde-assisted isolation of regulatory elements (FAIRE)-chip signals in human chromosomes 8, 11, and 12, identified by a method called FAIRE. Active regulatory elements defined by FAIRE were highly associated with active histone modifications, like H3K4me3 and H3K9/16ac, especially near transcription start sites. The H3K9/16ac-enriched genes that overlapped with FAIRE signals (FAIRE-H3K9/14ac) were moderately correlated with gene expression levels. We also identified functional sequence motifs at H3K4me1-enriched FAIRE sites upstream of putative promoters, suggesting that regulatory elements could be associated with H3K4me1 to be regarded as distal regulatory elements. Our results might provide an insight into epigenetic regulatory mechanisms explaining the association of histone modifications with open chromatin structure in breast cancer cells.

• Animal cells and systems
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• 제5권3호
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• pp.253-262
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• 2001

Ligand-receptor clustering event is the most important step in leukocyte adhesion and spreading on endothelial cells. Intercellular adhesion molecule-1 (ICAM-1) has been shown to enhance leukocyte adhesion, but the molecular event during the process of adhesion is unclear. To visualize the dynamics of ICAM-1 movement during adhesion, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 fused to a green fluorescent protein (IC1_GFP/CHO) and examined them under the fluorescence microscopy. The transfection of IC1_GFP alone in these cells was sufficient to support the adhesion of K562 cells that express $\alpha$L$\beta$2 (LFA-1) integrin stimulated by CBR LFA-1/2 mAb. This phenomenon was mediated by ICAM-1-LFA-1 interactions, as an mAb that specifically inhibits ICAM-1-LFA-1 interaction (RRl/l) completely abolished the adhesion of LFA-1＊ cells to IC1_ GFP/CHO cells. We found that the characteristic of adhesion was followed almost immediately (~10 min) by the rapid accumulation of ICAM-1 on CHO cells at a tight interface between the two cells. Interestingly, ICI_GFP/CHO cells projected plasma membrane and encircled approximately half surface of LFA-1+ cells, as defined by confocal microscopy. This unusual phenomenon was also confirmed on HUVEC after adhesion of LFA-1＊ cells. Neither cytochalasin D nor 2,3-butanedione 2-monoxime an inhibitor of myosin light chain kinase blocked LFA-1-mediated ICAM-1 clustering, indicating that actin cytoskeleton and myosin-dependent contractility are not necessary for ICAM-1 clustering. Taken together, we suggest that leukocyte adhesion to endothelial cells induces specialized form of ICAM-1 clustering that is distinct from immunological synapse mediated by T cell interaction with antigen presenting cells.

• 문화기술의 융합
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• 제6권1호
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• pp.23-29
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• 2020

기계가 움직일 때의 동작들은 일정한 원리에 의해 움직이기 때문에 아무리 복잡하고 다양한 기계라 할지라도 기계의 운동을 지배하는 근원적 원리가 있다. 자율적 움직임은 반복을 피할 수 있고, 더 인간적이며 더 자연적인 요소에 근접하는 길이다. 복제가 아닌 독창적인 움직임은 더더욱 그러하다. 따라서 현재, 기계의 역동성은 인간의 참여에 의해 더욱 다감각적으로 표현될 수 있는 가능성에 도전하고 있으며 사실과 복제의 경계에서 그 표현영역을 점점 확대시키고 있다. 테오얀센의 작품들은 각각의 시기별로 다른 환경에 적응토록 변화하여 그의 수십 년에 걸친 연구는 초기에서 현재까지 계속 진화되고 있음을 알 수 있다. 그 진화의 초점은 무엇보다 개체를 구성하는 부품들 간의 유기적 결합이 가진 원리로부터 반복되는 원형운동과 수평적 왕복운동이라는 동일한 근원지를 가지고 있음을 알 수 있다.

• 조형예술학연구
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• 제4권
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• pp.91-122
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• 2002

`Bio morphism` are constituted in paintings where the artists try to embody the elementary properties of living creature as of growth and durability. They are the most appropriate concept of painting to harmonize human being with nature closely. The formative ways of them attach great importance to both unconsciousness and desire , as well as variations or dynamics, by noticing a flow of natural senses and feelings of human being. In other words, the formative ways are based on a recognition of nature as the intrinsic force of life, with the result that aesthetics of incompleteness is embodied in images. Therefore they are clearly distinguished from that of functional, geometric images. A tendency of painting at that time, in a word, 'return to figure and expression', means a conversion into organic images like the incomplete, atypical, and biomorphic forms, while denying the mechanical or geometric. Elizabeth Murray are analyzed, for these works are remarkable in the characteristics of 'Bio morphism'. Consequently the features of organic images, that is, 'the formative acceptance of natural figures, or an informality' and 'the force of free will, or an incompleteness', could obviously be revealed. It is a type that obtains a motif out of natural figures like an animal, a plant, or the concrete figures of human being. In conclusion, this thesis is focused on not only emphasizing that 'Bio morphism' were a major tendency among the various trends of postmodern painting in the 20th century, but also analysing both the painterly formation of organic images and the structure of them. In addition to these points, it is a central aim to evoke that Bio morphism should accurately be evaluated and positioned in postmodern painting. A new recognition of 'Bio morphism' is a peculiarity of the times that reflects a cultural aspect of the present, hence it should be recognized as another way to approach the postmodern painting.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.530-539
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• 2019

Brain aging is an inevitable process characterized by structural and functional changes and is a major risk factor for neurodegenerative diseases. Most brain aging studies are focused on neurons and less on astrocytes which are the most abundant cells in the brain known to be in charge of various functions including the maintenance of brain physical formation, ion homeostasis, and secretion of various extracellular matrix proteins. Altered mitochondrial dynamics, defective mitophagy or mitochondrial damages are causative factors of mitochondrial dysfunction, which is linked to age-related disorders. Etoposide is an anti-cancer reagent which can induce DNA stress and cellular senescence of cancer cell lines. In this study, we investigated whether etoposide induces senescence and functional alterations in cultured rat astrocytes. Senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity was used as a cellular senescence marker. The results indicated that etoposide-treated astrocytes showed cellular senescence phenotypes including increased SA-${\beta}$-gal-positive cells number, increased nuclear size and increased senescence-associated secretory phenotypes (SASP) such as IL-6. We also observed a decreased expression of cell cycle markers, including PhosphoHistone H3/Histone H3 and CDK2, and dysregulation of cellular functions based on wound-healing, neuronal protection, and phagocytosis assays. Finally, mitochondrial dysfunction was noted through the determination of mitochondrial membrane potential using tetramethylrhodamine methyl ester (TMRM) and the measurement of mitochondrial oxygen consumption rate (OCR). These data suggest that etoposide can induce cellular senescence and mitochondrial dysfunction in astrocytes which may have implications in brain aging and neurodegenerative conditions.

• Molecules and Cells
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• 제44권2호
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• pp.79-87
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• 2021

Chromatin dynamics is essential for maintaining genomic integrity and regulating gene expression. Conserved bromodomain-containing AAA+ ATPases play important roles in nucleosome organization as histone chaperones. Recently, the high-resolution cryo-electron microscopy structures of Schizosaccharomyces pombe Abo1 revealed that it forms a hexameric ring and undergoes a conformational change upon ATP hydrolysis. In addition, single-molecule imaging demonstrated that Abo1 loads H3-H4 histones onto DNA in an ATP hydrolysis-dependent manner. However, the molecular mechanism by which Abo1 loads histones remains unknown. Here, we investigated the details concerning Abo1-mediated histone loading onto DNA and the Abo1-DNA interaction using single-molecule imaging techniques and biochemical assays. We show that Abo1 does not load H2A-H2B histones. Interestingly, Abo1 deposits multiple copies of H3-H4 histones as the DNA length increases and requires at least 80 bp DNA. Unexpectedly, Abo1 weakly binds DNA regardless of ATP, and neither histone nor DNA stimulates the ATP hydrolysis activity of Abo1. Based on our results, we propose an allosteric communication model in which the ATP hydrolysis of Abo1 changes the configuration of histones to facilitate their deposition onto DNA.

• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.67-77
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• 2022

The elements that impact the dynamics and collaborations of waves and particles in the magnetosphere of planets have been considered here. Saturn's internal magnetosphere is determined by substantiated instabilities and discovered to be an exceptional zone of wave activity. Interchanged instability is found to be one of the responsible events in view of temperature anisotropy and energization processes of magnetospheric species. The generated active ions alongside electrons that constitute the populations of highly magnetized planets like Saturn's ring electron current are taken into consideration in the current framework. The previous and similar method of characteristics and the perturbed distribution function have been used to derive dispersion relation. In incorporating this investigation, the characteristics of electromagnetic ion cyclotron wave (EMIC) waves are determined by the composition of ions in plasmas through which the waves propagate. The effect of ring distribution illustrates non-monotonous description on growth rate (GR) depending upon plasma parameters picked out. Observations made by Cassini found appropriate for modern study, have been applied to the Kronian magnetosphere. Using Maxwellian ring distribution function of ions and detailed mathematical formulation, an expression for dispersion relation as well as GR and real frequency (RF) are evaluated. Analysis of plasma parameters shows that, proliferating EMIC waves are not developed much when propagation is parallelly aligned with magnetosphere as compared to waves propagating in oblique direction. GR for the oblique case, is influenced by temperature anisotropy as well as by alternating current (AC) frequency, whereas it is much affected only by AC frequency for parallel propagating waves.

• 한국발생생물학회지:발생과생식
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• 제26권2호
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• pp.71-77
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• 2022

In response to luteinizing hormone (LH), a higher concentration of progesterone (P4) is produced in luteal cells of corpus luteum (CL). Mitochondria are an essential cellular organelle in steroidogenesis. The specific engagement of the concept regarding mitochondrial shaping with early stages of steroidogenesis was suggested in reproductive endocrine cells. Although the specific involvement of GTPase dynamin-related protein 1 (Drp1) with steroidogenesis has been demonstrated in luteal cells of bovine CL in vitro, its actual relationship with ovarian steroidogenesis during the estrous cycle remains unknown. In this study, while Fis1 and Opa1 protein levels did not show significant changes during the estrous cycle, Drp1, Mfn1, and Mfn2 proteins exhibited relatively lower levels at proestrus than at estrus or diestrus. 3β-HSD showed higher levels at proestrus than at estrus or diestrus. In addition, Drp1 phosphorylation (s637) was higher in proestrus than in estrus or diestrus. Immune-positive cells for Drp1, pDrp1 (s637), and 3β-HSD were all localized in the cytoplasm of luteal cells in the CL. The immune-positive cells for 3β-HSD were more frequently seen in the CL at proestrus than at estrus or diestrus. Immunoreactivity for Drp1 in luteal cells at proestrus was weaker than that at estrus or diestrus. However, pDrp1 (s637) immune-positive cells were mostly detected in luteal cells at proestrus. These results imply that steroidogenesis (P4 production) in the CL is closely related to phosphorylation of Drp1 at serine 637. Taken together, this study presents evidence that Drp1 phosphorylation at serine 637 is an important step in steroidogenesis in the CL.

• 한국콘텐츠학회논문지
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• 제22권1호
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• pp.1-9
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• 2022

본 연구의 목적은 SNS를 기반으로 향유되는 챌린지 콘텐츠를 게이미피케이션 개념과 MDA 프레임워크를 통해 통합적으로 고찰하는 것이다. 챌린지 콘텐츠는 생성 주체에 따른 범주화를 넘어 참여자가 콘텐츠의 생성과 향유를 주도하는 능동적인 모습을 보인다. 챌린지 콘텐츠를 분석한 결과, 메카닉스의 측면에서는 '상대적인 레벨', '표현 목적을 지닌 도전 과제', '파이디아적인 규칙'이 중점적으로 나타났다. 이는 '더 나은 표현을 위한 선택 및 경쟁', '이타심, 우월감'과 같은 내적 성취감을 발현하는 참여자의 다이내믹스로 연결되는 한편, 지속적으로 챌린지 콘텐츠에 참여할 수 있도록 하는데 기여한다. 에스테틱스의 측면에서는 참여자가 챌린지 콘텐츠를 통해 콘텐츠의 생성과 향유를 주도하는 놀이 문화의 주체로 기능하고 있음을 알 수 있다. 이런 현상은 정보 전달이나 상업적 광고 분야의 소임이었던 콘텐츠의 생성과 분배의 헤게모니를 역전시키는 결과를 가지고 왔다는데 의의가 있다.